MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Journal of Microscopy' source. Wed, 17 Mar 2010 17:00:13 +0100 http://www.medworm.com/index.php?rid=3358693&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03375.x Three-dimensional quantitative compositional analysis of nanowires is a challenge for standard techniques such as secondary ion mass spectrometry because of specimen size and geometry considerations; however, it is precisely the size and geometry of nanowires that makes them attractive candidates for analysis via atom probe tomography. The resulting boron composition of various trimethylboron vapour[ndash]liquid[ndash]solid grown silicon nanowires were measured both with time-of-flight secondary ion mass spectrometry and pulsed-laser atom probe tomography. Both characterization techniques yielded similar results for relative composition. Specialized specimen preparation for pulsed-laser atom probe tomography was utilized and is described in detail whereby individual silicon nanowires are f... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358693 Fri, 12 Mar 2010 00:00:00 +0100 3358693 http://www.medworm.com/index.php?rid=3358699&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03364.x Convergent beam electron diffraction patterns of silicon from the gate channel region of a complementary metal-oxide-semiconductor transistor with recessed Si.82Ge.18 stressors were analysed using three zone axes: , and . Values measured using these axes were compared with each other with regards to strain along the [] and the [001] directions. It was demonstrated that strain measurements made using all three axes showed reasonable agreement with each other: an increase in the [] compressive strain and a switch from compressive to tensile strain in the [001] with decreasing distance below the gate. It was also observed that the strain calculations using the axis had the lowest uncertainty whereas the axis allowed for measurements closest to the gate due to the improved lateral resolution a... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358699 Thu, 11 Mar 2010 00:00:00 +0100 3358699 http://www.medworm.com/index.php?rid=3358698&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03365.x A classification method based on textural information for metallic surfaces displaying complex random patterns is proposed. Because these kinds of textures show fluctuations at a small scale and some uniformity at a larger scale, a probabilistic approach is followed, considering textural variations as realizations of random functions. Taking into account information of pixel neighbourhoods, the texture for each pixel is described at different scales. By means of statistical learning, the most relevant textural descriptors are selected for each application. The performance of this approach is established on a real data set of steel surfaces. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358698 Thu, 11 Mar 2010 00:00:00 +0100 3358698 http://www.medworm.com/index.php?rid=3358697&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03367.x Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology. ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358697 Thu, 11 Mar 2010 00:00:00 +0100 3358697 http://www.medworm.com/index.php?rid=3358696&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03368.x Using a single-mode dielectric-loaded surface plasmon polariton waveguide doped with quantum dots, we were able to slightly increase the propagation length of the mode by stimulated emission of plasmon. We analyse the amplification phenomenon in the visible range by combining leakage radiation microscopy and surface plasmon coupled emission techniques. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358696 Thu, 11 Mar 2010 00:00:00 +0100 3358696 http://www.medworm.com/index.php?rid=3358695&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03370.x We describe the microstructure of Nd:YAG continuous wave laser surface melted high-speed steel, namely AISI M2, treated with different laser scanning speeds and beam diameters on its surface. Microstructural characterization of the remelted surface layer was performed using light optical and scanning electron microscopy and X-ray diffraction. The combination of the three techniques provided new insights into the substantial changes induced by laser surface melting of the steel surface layer. The advantage of the method is that it avoids the difficult and tedious work of preparing samples of this hard material for transmission electron microscopy, which is the technique normally used to study these fine microstructures. A melted zone with a dendritic structure and a partially melted zone wi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358695 Thu, 11 Mar 2010 00:00:00 +0100 3358695 http://www.medworm.com/index.php?rid=3358694&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03374.x Direct measurements of cells from photo micrographs are becoming increasingly used when investigating the position and/or distribution of chromosomal loci in bacteria. In general, these measurements have been done manually, and without clear definition of how they are made. Here we present a procedure for standardizing the measurement of cell properties from phase contrast images. Furthermore, we present a program using these standardized methods that can measure the intracellular positions of fluorescent foci in bacterial cells faster and with more precision than manual measurement. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3358694 Thu, 11 Mar 2010 00:00:00 +0100 3358694 http://www.medworm.com/index.php?rid=3346323&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03361.x In Jonasson et al. (2008), we presented a new pixel-based maximum likelihood framework for the estimation of diffusion coefficients from data on fluorescence recovery after photobleaching (FRAP) with confocal laser scanning microscopy (CLSM). The main method there, called the Gaussian profile method below, is based on the assumption that the initial intensity profile after photobleaching is approximately Gaussian. In the present paper, we introduce a method, called the Monotone profile method, where the maximum likelihood framework is extended to a general initial bleaching profile only assuming that the profile is a non-decreasing function of the distance to the bleaching centre. The statistical distribution of the image noise is further assumed to be Poisson instead of normal, which shou... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3346323 Tue, 09 Mar 2010 00:00:00 +0100 3346323 http://www.medworm.com/index.php?rid=3334978&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03376.x Elemental mapping in the energy filtering transmission electron microscope (EFTEM) can be extended into three dimensions (3D) by acquiring a series of two-dimensional (2D) core-edge images from a specimen oriented over a range of tilt angles, and then reconstructing the volume using tomographic methods. EFTEM has been applied to imaging the distribution of biological molecules in 2D, e.g. nucleic acid and protein, in sections of plastic-embedded cells, but no systematic study has been undertaken to assess the extent to which beam damage limits the available information in 3D. To address this question, 2D elemental maps of phosphorus and nitrogen were acquired from unstained sections of plastic-embedded isolated mouse thymocytes. The variation in elemental composition, residual specimen mas... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3334978 Fri, 05 Mar 2010 00:00:00 +0100 3334978 http://www.medworm.com/index.php?rid=3334979&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2010.03371.x In this study, two strategies were attempted to enhance its angular intensity, and their experimental results are reported. The first scheme is to employ a higher extraction field for increasing the brightness. However, the tip shape transformation was found to induce undesirably elevated emission from the facet edges at high fields. The second scheme exploits the fact that the angular intensity is proportional to the square of the electron gun focal length [Fujita, S. & Shimoyama, H. (2005) Theory of cathode trajectory characterization by canonical mapping transformation. J. Electron Microsc. 54, 331[ndash]343], which can be increased by scaling-up the emitter tip radius. A high angular current intensity (J[Omega][sim] 1.5 mA sr[minus]1) was obtained from a scaled-up emitter. Preliminary ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3334979 Thu, 04 Mar 2010 00:00:00 +0100 3334979 http://www.medworm.com/index.php?rid=3193565&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03360.x In this study, the potential of the common dye Congo red as a fluorescence marker for chitin in the exoskeleton of small crustaceans and collagen in the polychaete cuticle was tested. The Congo red staining turned out to be rather efficient and yielded intensively fluorescing structures, which made a very detailed visualization by confocal laser scanning microscopy possible. The excellent results are comparable to those described for the utilization of other efficient fluorescence dyes and intense autofluorescence. The application of Congo red is easy, the fluorescence of this dye is very stable, and the excitation maximum of the structures stained with Congo red is in a range, which is covered by the lasers of most of the confocal laser scanning microscopes. These advantageous properties ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3193565 Thu, 21 Jan 2010 00:00:00 +0100 3193565 http://www.medworm.com/index.php?rid=3188968&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03362.x In this study, we present the first systematic study on friction, adhesion, durability and influence of humidity on adhesion and surface charging of skin and various skin creams using atomic force microscopy. Skin is subjected to various daily activities with time, and the durability is closely tied to product compositions. Durability of various skin creams was studied by repeated cycling tests. In order to better understand the frictional behaviour, the dynamic viscosities of various skin creams were measured. Skin cream thinly coats the skin surface and can cause drastic changes in the mechanical properties. In addition to mechanical properties, adhesive force is one of the important factors in determining the tactile perception of skin cream and is directly affected by the film thicknes... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3188968 Wed, 20 Jan 2010 00:00:00 +0100 3188968 http://www.medworm.com/index.php?rid=3188971&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03279.x Transmission and scanning electron microscopic investigations were carried out to characterize Cr-35Re alloy. A continuous film of precipitates at the grain boundaries and precipitates inside the grains were observed. Identification of the phases was based on the analysis of the chemical composition and the diffraction patterns. It has been found that the matrix is a solid solution of Re in Cr and sigma phase CrRe2 was one of the phases present at the grain boundaries. In the majority of the precipitates chromium, rhenium and nitrogen were detected, which indicates the existence of a ternary compound. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3188971 Tue, 19 Jan 2010 00:00:00 +0100 3188971 http://www.medworm.com/index.php?rid=3188970&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03303.x The zirconia nanopowder stabilized with 2.5 mol% Y2O3 and doped with 18 mol% TiO2 (Zr(Y,Ti)O2) was homogenized with 5.2 wt% multiwall carbon nanotubes (MWCNT) through colloidal processing. The resultant mixture was heat-treated for 2 h at 1200°C in vacuum under a pressure of 5 · 10[minus]4 mbar. The microstructure characterization was performed using the TECNAI FEG (200 kV) SuperTWIN transmission electron microscope, equipped with the integrated EDAX detector. The TEM observations of the as-received samples showed single strands of the carbon nanotubes uniformly dispersed among zirconia crystallites. Heat treatment of the Zr(Y,Ti)O2-MWCNT mixture caused the transformation of carbon nanotubes into polycrystalline TiC nanofibres and nanorods as confirmed by both the energy dispersive X-ray... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3188970 Tue, 19 Jan 2010 00:00:00 +0100 3188970 http://www.medworm.com/index.php?rid=3188969&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03319.x The present study examines a friction stir welded 2017A aluminium alloy. Transmission electron microscope investigations of the weld nugget revealed the average grain size of 5 [mu]m, moderate density of dislocations as well as the presence of nanometric precipitates located mostly in grains interiors. Scanning electron microscope observations of fractures showed the presence of ductile fracture in the region of the weld nugget with brittle precipitates in the lower part. The microhardness analysis performed on the cross-section of the joints showed fairly small changes; however, after the artificial ageing process an increase in hardness was observed. The change of the joint hardness subject to the ageing process indicates partial supersaturation in the material during friction stir weldi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3188969 Tue, 19 Jan 2010 00:00:00 +0100 3188969 http://www.medworm.com/index.php?rid=3178651&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03363.x Lipophilic fluorescent dyes have been used to trace neuronal connections because of their ability to diffuse laterally within nerve cell membranes. Given the hundreds to thousands of connections that a typical neuron makes with its neighbours, a diffusion-matched set of spectrally distinct dyes is desirable. To extend a set of these dyes to obtain six independent labels, we have characterized the properties of novel violet and near-infrared candidates. By combining two-photon and confocal microscopy all of these candidates can be imaged using a single Titanium Sapphire laser. Here we present measurements of the two-photon action cross-sections and diffusion properties of the dyes, using either the relative diffusion distance or fluorescence recovery after photobleaching techniques, and dem... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3178651 Sat, 16 Jan 2010 00:00:00 +0100 3178651 http://www.medworm.com/index.php?rid=3178653&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03288.x Transmission electron microscopy studies of the artefacts in the form of network of dislocations induced by focused ion beam technique in austenitic stainless steel have been performed. Images of the microstructure with different diffraction vector g were analyzed. Transmission electron microscopy investigations of the artefacts induced by focused ion beam machining in the austenite revealed set of parallel dislocations with edge character located near the free surface of the thin foils. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3178653 Fri, 15 Jan 2010 00:00:00 +0100 3178653 http://www.medworm.com/index.php?rid=3178652&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03293.x NiFe/Cu multilayer films have been electrodeposited potentiostatically on (001)-oriented Si and polycrystalline Cu substrates by a single bath technique. Standard error of mean and energy dispersive X-ray studies of single NiFe(Cu) layers allow us to establish the right deposition parameters for NiFe and Cu sublayer. Standard error of mean results reveal the layered structure of deposits for relatively thick bilayer thickness (ca. [sim]200 nm). The modulated structure of NiFe/Cu multilayers with extremely thin bilayer thickness (nominal period [Lambda]= 8 nm) was investigated by transmission electron microscope techniques. A columnar structure of the deposit with column diameter in the range from 10 to 30 nm was observed. These results are comparable with X-ray diffraction measurements of ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3178652 Fri, 15 Jan 2010 00:00:00 +0100 3178652 http://www.medworm.com/index.php?rid=3171661&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03290.x This study was done on the IN-738 type alloy with thermal barrier coatings. On the basic surface of the NiCoCrAlY superalloy, VPS-sprayed powder was applied as the bond-coat. In addition, ZrO2× 8%Y2O3 powder was used for a deposition outside the top surface of a ceramic layer by the APS method. Appropriate control of the spraying process parameters permitted to obtain a gradient of porosity on the thickness of the ceramic coating. Then a static oxidation test at 1100°C and for 1100 h was performed. The basic conclusions of that testing showed that main degradation modes of the gradient thermal barrier coating system were connected with formation of porous NiAl2O4 oxides in the thermally grown oxide area and, consequently, formation of micro-cracks, delamination of a ceramic layer and fin... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3171661 Thu, 14 Jan 2010 00:00:00 +0100 3171661 http://www.medworm.com/index.php?rid=3171660&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03296.x Metal alloys can be formed successfully in a partially liquid state if they display a particular globular microstructure. The article presents an analysis of a study carried out of the development, by means of the strain-induced melt-activated method, of such a microstructure for an X210CrW12 steel. Hot rolled samples, with subsequent cooling, were heated to the temperature range at which the liquid and solid phases coexist in the material. The spheroidal shapes for solid particles, required for semi-solid processing, were found. The investigations were carried out using scanning electron microscopy in combination with energy dispersive spectroscopy. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3171660 Thu, 14 Jan 2010 00:00:00 +0100 3171660 http://www.medworm.com/index.php?rid=3171659&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03310.x The effect of mechanical alloying on the microstructure of atomized 6061 aluminium alloy powder and 6061 powder with a zirconium addition was studied in the work. The atomized 6061 aluminium alloy powder and 6061 powder with addition of 2 wt.% Zr were milled in a planetary ball mill and investigated using X-ray diffraction measurements, conventional and high-resolution electron microscopy (TEM/HRTEM) and high-angle annular dark field scanning transmission electron microscopy combined with energy dispersive X-ray microanalysis. An increase of stresses was observed in milled powders after the refinement of crystallites beyond 100 nm. In the powder with zirconium addition, some part of the Zr atoms diffused in aluminium forming a solid solution containing up to 0.5 wt.% Zr. The remaining was ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3171659 Thu, 14 Jan 2010 00:00:00 +0100 3171659 http://www.medworm.com/index.php?rid=3163605&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03359.x The statistical 1NN method is an elegant way to derive the composition of small B-enriched clusters in a random AB solid solution from 3D atomic fields. An extension of this method is proposed that includes the contribution of interface region and provides an estimate of the core composition of clusters. This model is applied to boron-implanted silicon containing boron-enriched clusters. A comparison with the previous model is performed. This new approach gives relevant information, i.e. the core composition of clusters and the cluster[ndash]matrix interface width. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3163605 Tue, 12 Jan 2010 00:00:00 +0100 3163605 http://www.medworm.com/index.php?rid=3163606&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03358.x In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16[ndash]17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11[ndash]12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed num... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3163606 Mon, 11 Jan 2010 00:00:00 +0100 3163606 http://www.medworm.com/index.php?rid=3153140&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03294.x This article presents results of the processing and microstructure evolution of ductile cast iron, modified by an addition of vanadium. The ductile iron was austenitized closed to the solidus (1095°C) for 100 h, cooled down to 640°C and held on at this temperature for 16 h. The heat treatment led to the dissolution of primary vanadium-rich carbides and their subsequent re-precipitation in a more dispersed form. The result of mechanical tests indicated that addition of vanadium and an appropriate heat treatment makes age hardening of ductile iron feasible. The precipitation processes as well as the effect of Si content on the alloy microstructure were examined by scanning and transmission electron microscopy. It was shown that adjacent to uniformly spread out vanadium-rich carbides with a... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3153140 Fri, 08 Jan 2010 00:00:00 +0100 3153140 http://www.medworm.com/index.php?rid=3153141&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03286.x TiN and TiO2 coatings, which are known from their low chemical reactivity, high hardness and wear and corrosion resistance, are used for protecting the NiTi surface. In the present work, nearly equiatomic NiTi (50.6 at.%) shape memory alloy was covered with the layers obtained by nitriding under glow discharge at 1073 K. Additionally, at the end of the process some amount of oxygen was added. Characterization of the nitrided/oxided layers structure was carried out using transmission and scanning electron microscopy. The investigations were focused on the structure of the multilayer nitrided/oxided NiTi surface. The surface is formed from nanocrystalline and columnar grains of the TiN phase. Between the top layer and [beta]-NiTi substrate the interface Ti2Ni layer was formed. Addition of ox... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3153141 Thu, 07 Jan 2010 00:00:00 +0100 3153141 http://www.medworm.com/index.php?rid=3148906&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03309.x In this work, an Nb15Al10Ti alloy produced by mechanical alloying was investigated. The milling of elemental powders of Nb, Al as well as TiAl intermetallic phase resulted in the formation of homogenous niobium solid solution, Nbss, and refinement of powder particles. Powder after milling was consolidated by conventional hot pressing at 1300°C under pressure of 25 MPa as well as by hot isostatic pressing at 1200°C under pressure of 1 GPa. Microstructure of consolidated material was examined by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. Materials after consolidation were composed of three phases: niobium solid solution Nbss, Nb3Al intermetallic phase and titanium oxide dispersoid TiO. The analysis of the mechanical properties indicated that both ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148906 Thu, 07 Jan 2010 00:00:00 +0100 3148906 http://www.medworm.com/index.php?rid=3148916&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03254.x Nano-composite layers of Au nano-crystallites embedded in amorphous silica matrix were obtained by a radio-frequency co-sputtering technique. Glass or single crystal silicon wafers were chosen as substrates. After deposition, the layers were heat treated at 900°C for 60 min. Microstructure of the layers was investigated using a TECNAI G2 FEG SuperTwin (200 kV) transmission electron microscope. Thin foils were cut using a focused ion beam Quanta 3D. The investigations confirmed that the applied process allowed obtaining nano-composite layers containing spherical Au crystallites of average size of [sim]3 nm embedded in an amorphous silica matrix. Some of the nano-crystallites were twinned. The layers were heat treated in subsequent step and rise of the crystallite average size up to 5.5 nm ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148916 Wed, 06 Jan 2010 00:00:00 +0100 3148916 http://www.medworm.com/index.php?rid=3148915&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03264.x In this paper, we present results of transmission electron microscopy studies on erbium silicide structures fabricated under various thermal conditions. A titanium cap has been used as a protective layer against oxidation during rapid thermal annealing of an erbium layer in a temperature range of 300[ndash]700°C. Both layers (200 nm Ti and 25 nm Er) were deposited by electron-beam sputtering. The investigations have shown that the transformation of the 25-nm-thick erbium into erbium silicide is completed after annealing at 500°C. At higher temperatures, the formation of a titanium silicide layer above erbium silicide is observed. The lowest Schottky barrier has been measured in the sample annealed at 700°C. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148915 Wed, 06 Jan 2010 00:00:00 +0100 3148915 http://www.medworm.com/index.php?rid=3148914&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03278.x In this study, microstructures of dental composites were observed using high resolution scanning transmission electron microscopy (HR STEM). Samples for these observations were prepared by focused ion beam system. Two kinds of dental composites were investigated: (1) polymer-ceramic composite containing nano-sized ceramic fillers and (2) ceramic-polymer composite based on the nano-structured yttrium stabilized zirconia. The first composite is a popular material for dental fillings whereas the second is used for the fabrication of fixed partial dentures. The results are discussed in terms of the evaluation of fabrication process of the composites. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148914 Wed, 06 Jan 2010 00:00:00 +0100 3148914 http://www.medworm.com/index.php?rid=3148913&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03355.x Hepatic iron overload is a common clinical problem resulting from hyperabsorption syndromes and from chronic transfusion therapy. Not only does iron loading vary between reticuloendothelial stores and hepatocytes, but iron is heterogeneously distributed within hepatocytes as well. Since the accessibility of iron particles to chelation may depend, in part, on their distribution, we sought to characterize the shape and scale of iron deposition in humans with transfusional iron overload. Toward this end, we performed a histological analysis of iron stores in liver biopsy specimens of 20 patients (1.3[ndash]57.8 mg iron/g dry tissue weight) with aid of electron and light microscopy. We estimated distributions related to variability in siderosomal size, proximity of iron centres and inter-cellu... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148913 Wed, 06 Jan 2010 00:00:00 +0100 3148913 http://www.medworm.com/index.php?rid=3148912&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03263.x Elemental powders of Co, Ni and Al in the proper amounts to obtain Co35Ni40Al25 and Co40Ni35Al25 nominal compositions were ball milled in a high-energy mill for 80 h. After 40 h of milling, the formation of a Co (Ni, Al) solid solution with f.c.c. structure was verified by a change of the original lattice parameter and crystallite size. Analytical transmission electron microscopy observations and X-ray diffraction measurements of the final Co (Ni, Al) solid solution showed that the crystallite size scattered from 4 to 8 nm and lattice parameter a = 0.36086 nm. The chemical EDS point analysis of the milled powder particles allowed the calculation of the e/a ratio and revealed a high degree of chemical homogeneity of the powders. Hot pressing in vacuum of the milled powders resulted in obtai... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148912 Wed, 06 Jan 2010 00:00:00 +0100 3148912 http://www.medworm.com/index.php?rid=3148911&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03272.x Control over pore geometry opens the way to a number of new applications of track-etch membranes (TMs). A special method of etching was developed to produce TMs with non-cylindrical pore profile. The direct observation of channel shape on fractures of track membranes was performed with a scanning electron microscope (SEM). The SEM images of the surface and cross-section of TMs with different pore morphology are shown. The channel diameter as a function of the depth below surface was measured and quantitative analysis was realized. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148911 Wed, 06 Jan 2010 00:00:00 +0100 3148911 http://www.medworm.com/index.php?rid=3148910&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03295.x We analyse theoretically the influence of the asymmetry of the two-beam geometry on quantitative measurements of the energy-loss magnetic chiral dichroism. Our simulations indicate that this asymmetry is not very strong inside or close to the Thales circle, but in other regions of the diffraction plane it can hinder an accurate extraction of the orbital to spin moment ratio. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148910 Wed, 06 Jan 2010 00:00:00 +0100 3148910 http://www.medworm.com/index.php?rid=3148909&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03297.x The paper presents the results of investigations of the microstructures and properties of the aluminium coatings deposited by vacuum evaporation and magnetron sputtering. These coatings generally have a very refined microstructure with elongated nano-grains. However, the surface topography of the aluminium coating deposited by vacuum evaporation is more developed, its microstructure is less homogeneous and more porous. The residual tensile stresses in the aluminium coating deposited by magnetron sputtering are close to 130 MPa, and the texture is relatively pronounced. Vacuum evaporation does not induce residual stresses in the coatings and the texture is very weak. The results obtained indicate that the aluminium coatings produced by magnetron sputtering are more suitable for the diffusiv... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148909 Wed, 06 Jan 2010 00:00:00 +0100 3148909 http://www.medworm.com/index.php?rid=3148908&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03298.x An alloy with a chemical composition of Ti-45Al-5V (at.%) was synthesized by mechanical alloying in a Szegvari-type attritor from elemental powders of high purity. Before compaction, the powders were characterized by X-ray diffraction and scanning as well as transmission electron microscopy. The compaction of powders was carried out by hot isostatic pressing and hot isostatic extrusion. The resulting material was subjected to microstructural and mechanical characterization. The microstructure investigated by transmission and scanning electron microscopy supplemented by X-ray diffraction revealed that the bulk material was composed of a mixture of TiAl- and Ti3Al-based phases, however, the typical lamellar microstructure for such alloys was not observed. The materials exhibited exceptionall... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148908 Wed, 06 Jan 2010 00:00:00 +0100 3148908 http://www.medworm.com/index.php?rid=3148907&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03307.x Ar-filled bubbles in an oxide-dispersion-strengthened (ODS) alloy were characterized by analytical transmission electron microscopy. Energy dispersive X-ray analysis combined with nanoscale imaging was employed for quantitative analysis of Ar gas locked in a bubble 6 nm in size. As the Ar bubbles are formed at the ODS particles [ndash] matrix interface, the known Ti2Y2O7 composition and size of ODS particles served as a reference in quantification of the Ar signal and for the calculation of the bubble size and the Ar density inside. The Ar pressure was also calculated by modified Van der Waals equation. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3148907 Wed, 06 Jan 2010 00:00:00 +0100 3148907 http://www.medworm.com/index.php?rid=3145766&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03268.x This work presents results of HRTEM and XRD studies on microstructure of ceria-based mixed oxides subjected to high-temperature heat treatment in air. Nano-sized (4[ndash]5 nm) crystallites of Ce0.5Ln0.5O1.75 oxides (Ln = Yb, Lu) with narrow size distribution were prepared by a microemulsion method (W/O). Presence of an intermediate cubic phase, with oxygen vacancy ordering, was found for the Ce0.5Ln0.5O1.75 mixed oxides. A simple model of the intermediate phase has been proposed and tested. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3145766 Wed, 06 Jan 2010 00:00:00 +0100 3145766 http://www.medworm.com/index.php?rid=3142358&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03345.x Regularized phase tomography was used to image non-calcified fibrous matrix in in vitro cell-cultivated porous bone scaffold samples. 3D micro-architecture of bone and bone scaffold has previously been studied by micro-computed tomography, synchrotron radiation (SR) micro-computed tomography and microdiffraction. However, neither of these techniques can resolve the low-calcified immature pre-bone fibrous structures. Skelite porous scaffold discs were seeded with osteoblasts, a combination of osteoblast and pre-osteoclasts and, as controls, with pre-osteoclasts only, and then cultivated for 8 weeks. They were subsequently imaged using SR propagation-based phase contrast imaging. Reconstructions using a regularized holographic phase tomography approach were compared to standard (absorption) ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3142358 Mon, 04 Jan 2010 00:00:00 +0100 3142358 http://www.medworm.com/index.php?rid=3129150&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03282.x The phase imaging atomic force microscopy is a powerful tool in surface characterization of the biomaterials, and the resulting phase image is able to detect chemical variation and reveal more detailed surface properties than the morphological image. However, the chemical- and morphological-dependent phase images were still not distinguished well. In order to better understand actual occurring phase images, we examined non-carious human maxillary incisor, microphase separated polyurethane and self-assembling peptide nanofibres. We herein reported that phase image mainly plotted the morphological change: the phase peak corresponding to the morphological valley, and the morphological peak to the phase valley, and exhibited fine surface structures of materials. The chemical-dependent phase co... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3129150 Wed, 30 Dec 2009 00:00:00 +0100 3129150 http://www.medworm.com/index.php?rid=3120290&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03356.x The stereological estimation of second-order descriptors of spatial architecture appears to be inherently more time-consuming and labour-intensive than the estimation of first-order quantities (total quantities or ratios). Therefore, far fewer researchers tend to make use of second-order approaches in their stereological research projects. In this paper, we use a tutorial approach to illustrate how a desire for practical simplicity has provided us with a data collection method that can be used to simultaneously estimate both first-order and second-order properties of the microstructure of a defined anatomical feature of an organ. The approach does not rely on new results from theory, but nevertheless allows either isotropic uniform random or vertical uniform random sections to be used to m... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3120290 Fri, 25 Dec 2009 00:00:00 +0100 3120290 http://www.medworm.com/index.php?rid=3100509&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03247.x The research was aimed at microstructure characterization of the reaction products formed between molten aluminium and CoO single crystal during a sessile drop wettability test performed in vacuum at 700 and 1000°C for 120 min using contact heating procedure. The solidified Al/CoO couples were sectioned and used for cutting thin foils with focused ion beam. The transmission electron microscopy and energy dispersive X-ray spectroscopy were used for microstructure and local chemical analysis. The interaction of molten aluminium with CoO substrate at 700°C caused the formation of a corrugated 10[ndash]40 [mu]m thick reaction zone (RZ). It consisted of aluminium matrix and Al2O3 crystallites varying in size, i.e. of [sim]0.2 [mu]m near the Al drop/RZ interface, growing up to 1[ndash]2 [mu]m ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100509 Fri, 18 Dec 2009 00:00:00 +0100 3100509 http://www.medworm.com/index.php?rid=3100508&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03251.x The results of investigation of two different Ni-based glasses with compositions Ni58Nb10Zr13Ti12Al7 and Ni58Nb25Zr8Ti6Al3 are presented. The structure of the melt spun ribbons was amorphous. The supercooled liquid range decreased and primary crystallization temperature increased with increasing Nb content while the parameter Tg/Tm slightly increased. The crystallization process proceeded in a different way. The ribbon containing 10 at.% Nb showed typical primary crystallization of the 50 nm grains of the NiTi(Nb) cubic phase; the ribbon containing 25 at.% of Nb revealed high thermal stability of the amorphous phase, which crystallized only in a small amount in the range of primary crystallization, preserving large fraction of the amorphous phase even high above the end of the crystallizat... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100508 Fri, 18 Dec 2009 00:00:00 +0100 3100508 http://www.medworm.com/index.php?rid=3100507&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03262.x The set of unalloyed steels with various carbon concentrations were irradiated with intense plasma pulses with following process parameters: energy density 5 J cm[minus]2, pulse duration 2 [mu]s, argon or nitrogen atmosphere. The energy density of each pulse was high enough to melt the surface layer of material. The cooling rate was estimated for 108 K s[minus]1 using the modelling method which takes into account heat evolution in the iron sample. Samples were characterized using the scanning electron microscopy technique for remelted surface morphology investigations. The tests with profilometer allowed us to investigate the changes of roughness of the surface layers. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100507 Fri, 18 Dec 2009 00:00:00 +0100 3100507 http://www.medworm.com/index.php?rid=3100506&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03352.x Imaging is an important component of spectroscopy. A good imaging system is expected to work with a high-pixel resolution using signals of high count-rates with as little dead time as possible to deliver an image quickly and reliably. It is not uncommon for such a system to be highly specialized, expensive and to consist of many dedicated electronic components. In this work, we present a simple imaging algorithm that can be used with a pulse (TTL) data signal, such as that produced by some photomultipliers and electron detectors. This algorithm works with only a simple general purpose data acquisition computer card (NI PXI/PCI-6259) from National Instruments residing in a computer. The system has been tested with signal rates in excess of 100 kHz to produce images at a pixel resolution of ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100506 Fri, 18 Dec 2009 00:00:00 +0100 3100506 http://www.medworm.com/index.php?rid=3100505&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03267.x The main goal of the present contribution was to describe morphology and chemical composition of the intermetallic phases, which were formed during diffusion soldering process of the silver using tin. The Ag3Sn intermetallics is the main constituent of the joint after diffusion soldering at 235°C and 265°C. A closer inspection of the Ag/Ag3Sn interface revealed also the small crystallites of the second intermetallic phase, Ag5Sn, which was not previously observed using scanning electron microscope. Both phases are characterized by high melting temperatures: 480°C and 724°C, respectively. Therefore, their presence guarantees high thermal stability of the interconnection, which can be even three times higher than the temperature used for soldering. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100505 Fri, 18 Dec 2009 00:00:00 +0100 3100505 http://www.medworm.com/index.php?rid=3100504&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03269.x Iron-gold alloys with compositions Fe70Au30 and Fe50Au50 were prepared by arc melting. The alloys were investigated by means of the high-resolution scanning electron microscopy (SEM-FEG) in the as-cast state and upon annealing in two steps, i.e. at 250°C for 24 h and subsequently at 500°C for 48 h. The alloys were composed of two phases, i.e. a BCC phase rich in iron and a FCC phase rich in gold. The single-phase regions have equivalent diameter of about 50 nm. SEM images show self-similar structure for the spatial distribution of the above phases on scales ranging from about 1 mm till about 100 nm. The roughness of the images has been used to estimate a fractal dimension of the phase mixture. For larger scales of the as-cast samples one finds fractal dimension of about 1.7 for Fe70Au30 ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100504 Fri, 18 Dec 2009 00:00:00 +0100 3100504 http://www.medworm.com/index.php?rid=3100503&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03271.x Intensive deformations influence strongly microstructure. The very well-known phenomenon is the diminishing dimension of grain size by the severe plastic deformation (SPD) methods. The nanometric features of microstructure were discovered after the SPD deformation of various materials, such as aluminium alloys, iron and others. The observed changes depended on the kind of the deformed material, amount of deformation, strain rate, existence of different phases and stacking fault energy. The influence of the strain and strain rate on the microstructure is commonly investigated nowadays. It was found that the high strain rates activate deformation in shear bands, microbands and adiabatic shear bands. It was observed that bands were places of the nucleation of nanograins in the material deform... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100503 Fri, 18 Dec 2009 00:00:00 +0100 3100503 http://www.medworm.com/index.php?rid=3100502&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03273.x This paper presents a chemical extraction technique for determination of intermetallic phases formed in the casting AlSi5Cu1Mg aluminium alloy. Commercial aluminium alloys contain a wide range of intermetallic particles that are formed during casting, homogenization and thermomechanical processing. During solidification, particles of intermetallics are dispersed in interdendritic spaces as fine primary phases. Coarse intermetallic compounds that are formed in this aluminium alloy are characterized by unique atomic arrangement (crystallographic structure), morphology, stability, physical and mechanical properties. The volume fraction, chemistry and morphology of the intermetallics significantly affect properties and material behaviour during thermomechanical processing. Therefore, accurate ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100502 Fri, 18 Dec 2009 00:00:00 +0100 3100502 http://www.medworm.com/index.php?rid=3100501&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03275.x Nickel is known to increase the resistance to cleavage fracture of iron and decrease a ductile-to-brittle transition temperature. The medium-carbon, low-alloy martensitic steels attain the best combination of properties in low-tempered condition, with tempered martensite, retained austenite and transition carbides in the microstructure. This paper is focused on the influence of Ni addition (from 0.35 to 4.00%) on the microstructure and fracture toughness of structural steels after tempering. In this research, four model alloys of different concentration of Ni and constant concentration of carbon and other elements were used. All samples were in as-quenched and tempered conditions. Quenching was performed in oil at room temperature. After quenching, samples were tempered at 200°C for 2 h. ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100501 Fri, 18 Dec 2009 00:00:00 +0100 3100501 http://www.medworm.com/index.php?rid=3100500&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03276.x Hot deformation tests were performed on an AA7039-matrix composite reinforced with a 20% addition of SiC whiskers. The flow stress maximum was reduced with deformation temperature from 640 MPa to [sim]8 MPa at 293 K and 823 K, respectively. TEM observations, performed on as deformed samples, revealed a highly recovered substructure of the matrix and a striated structure of the whiskers. The fringes, which are perpendicular to the whiskers' longitudinal axis, were ascribed to nano-sized twins and stacking faults formed during the crystal growth rather than to some effects of the deformation process. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100500 Fri, 18 Dec 2009 00:00:00 +0100 3100500 http://www.medworm.com/index.php?rid=3100499&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03277.x Mechanical alloying and hot extrusion method were used for manufacturing AlMg-based composites reinforced with addition of niobium oxide (Nb2O5) and zirconium silicide (ZrSi2) particles. High mechanical properties of the materials were found to result from heavily refined structure of composites. It was found that the composite structure was transformed at high temperature as a result of irreversible chemical reaction between disperse reinforcements and surrounding matrix. Chemical reaction for AlMg[ndash]Nb2O5 composite results in a growth of intermetallic grains of Al3Nb type and very fine oxides particles of 5[ndash]20 nm in diameter. In the annealed AlMg[ndash]ZrSi2 composite, new grains of Al3Zr, Mg2Si and Al(Mg)O are formed as a result of zirconium silicide decomposition. Hot compres... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100499 Fri, 18 Dec 2009 00:00:00 +0100 3100499 http://www.medworm.com/index.php?rid=3100498&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03357.x We have analysed the formation of streak artefacts in the reconstruction based on the filtered back projection algorithm in electron tomography (ET) and accordingly applied an adaptive interpolation technique to artefact reduction. In the adaptive interpolation to recover the missing information, the edge positions in a projection curve were tracked to reduce the interpolation error. A simulation was used to demonstrate the effectiveness of the artefact reduction. Furthermore, image reconstruction of integrated circuit specimens in the ET experiments with the ultra-high voltage electron microscope show that the strong streak artefacts can be reduced effectively by our artefact reduction technique. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3100498 Fri, 18 Dec 2009 00:00:00 +0100 3100498 http://www.medworm.com/index.php?rid=3056414&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03353.x This paper presents a tutorial discussion of the principles underlying the depth-dependent Kikuchi pattern formation of backscattered electrons in the scanning electron microscope. To illustrate the connections between various electron diffraction methods, the formation of Kikuchi bands in electron backscatter diffraction in the scanning electron microscope and in transmission electron microscopy are compared with the help of simulations employing the dynamical theory of electron diffraction. The close relationship between backscattered electron diffraction and convergent beam electron diffraction is illuminated by showing how both effects can be calculated within the same theoretical framework. The influence of the depth-dependence of diffuse electron scattering on the formation of the ex... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3056414 Fri, 04 Dec 2009 00:00:00 +0100 3056414 http://www.medworm.com/index.php?rid=3056417&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03347.x Fluorescence recovery after photobleaching is a widely established method for the estimation of diffusion coefficients, strip bleaching with an associated recovery curve analysis being one of the simplest techniques. However, its implementation requires near 100% bleaching in the region of interest with negligible fluorescence loss outside, both constraints being hard to achieve concomitantly for fast diffusing molecules. We demonstrate that when these requirements are not met there is an error in the estimation of the diffusion coefficient D, either an under- or overestimation depending on which assumption is violated the most. We propose a simple modification to the recovery curve analysis incorporating the concept of the relative bleached mass m giving a revised recovery time parametriz... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3056417 Thu, 03 Dec 2009 00:00:00 +0100 3056417 http://www.medworm.com/index.php?rid=3056416&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03229.x The work presents the microstructure characterization of the new (Fe, Ni)[ndash]Cu[ndash](P, Si, B) melt-spun glass forming alloys investigated by means of transmission electron microscope. The results are compared with the data obtained by other complementary methods such as XRD and Mössbauer spectroscopy. The phases occurring during the crystallization of the glassy matrix are identified and characterized in terms of a long-range order and a short-range order. The thermal stability of the alloy is characterized by differential scanning calorimetry. The study describes the mechanical and magnetic properties of the new alloys at room temperature as well as characteristics resulting from heating the as-cast melt-spun alloy at elevated temperatures. The changes of the properties of the allo... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3056416 Thu, 03 Dec 2009 00:00:00 +0100 3056416 http://www.medworm.com/index.php?rid=3056415&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03260.x Implantation was performed on surface-polished and thermal-treated alumina discs with 75 keV monocharged carbon ions at doses of 1 × 1017 and 5 × 1017 ions cm[minus]2. The alumina targets were kept at room temperature. The structural modifications induced during ion irradiation were studied by the scanning and scanning transmission electron microscopes. Alumina is readily amorphized at room temperature with carbon ions. The width of the ion-beam induced disordered area increases with ion dose. As it was established by selected area electron diffraction and electron energy loss spectra, low implanted specimens still show subsurface crystalline areas whose diffraction patterns could be assigned to a deformed structure of alumina. This deformed belt is shown beneath the amorphous region on ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3056415 Thu, 03 Dec 2009 00:00:00 +0100 3056415 http://www.medworm.com/index.php?rid=3029600&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03238.x The aim of this work was to study the influence of thermo-mechanical controlled process parameters on the refinement of microstructure during processing as well as the final microstructure and mechanical properties of Nb microalloyed steel. The steel was investigated and thermo-mechanical controlled process simulations were carried out using the material testing system 810. The effect of deformation sequences with constant finish rolling temperature and accelerated controlled cooling rate were studied with regard to strength and microstructure of heavy plate. The optimized thermo-mechanical controlled process parameters will be discussed in relation to the microstructure and precipitate evolution, as well as the mechanical properties of high-strength steel, microalloyed with Nb and Ti. The... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029600 Thu, 26 Nov 2009 00:00:00 +0100 3029600 http://www.medworm.com/index.php?rid=3029607&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03258.x We report on transmission electron microscopy studies of Au/Pt/Ti/Pt(10[ndash]30 nm) contact structures for high power GaAs/InGaAs semiconductor lasers. The studies showed that annealing at 450°C of contact structures causes the reaction of whole Pt with substrate components (Ga and As) and the formation of Pt-GaAs interlayers with smooth interfaces as required for such structures. Annealing of the structures at 470 and 490°C unfavourably affects the contact structure. At this condition, the strong downward diffusion of Au and Pt from the top layers causes a formation of Au-Pt pits, which break the Ti barrier. Transmission electron microscopy observation revealed that Au/Pt/Ti/Pt(10[ndash]30 nm) system annealed at 450°C is appropriate for practical applications. The EDS technique used t... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029607 Wed, 25 Nov 2009 00:00:00 +0100 3029607 http://www.medworm.com/index.php?rid=3029606&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03230.x Ball milling of easy glass forming Ti25Zr17Ni29Cu29 alloys lead to the formation of an amorphous structure accompanied by a substantial increase of powder microhardness. The powders show clear glass transition effect and a few stage crystallization starting above 500°C. High-resolution transmission electron microscope technique allowed identifying nanocrystalline inclusions as Cu12NiTi7 within the amorphous powder. The amorphous powders mixed with nanocrystalline iron or silver powders were hot pressed to form composites. A narrow 200 nm broad intermediate single-phase layer at the amorphous-phase/iron interface containing all elements present in the composite was identified using transmission electron microscope and high-angle annular dark field detector techniques. scanning transmission... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029606 Wed, 25 Nov 2009 00:00:00 +0100 3029606 http://www.medworm.com/index.php?rid=3029605&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03237.x Complementary structural characterization of the reaction product region formed due to high-temperature interaction (1273 K) between molten aluminum and dense polycrystalline yttria substrate was performed. The reaction product region extending up to 1 mm into the oxide substrate was characterized by a wavy shape morphology and multilayer structure consisted of three-layered zones. The application of transmission electron microscopy coupled with focused ion beam preparation technique allowed the detailed structural examination of reactively formed compounds and interfaces between different zones and phases. Fine crystalline precipitates of Al5Y3O12 (YAG) phase surrounded by the Al3Y were detected within the first zone. The second layer consisted of much bigger AlYO3 (YAP) crystals and the ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029605 Wed, 25 Nov 2009 00:00:00 +0100 3029605 http://www.medworm.com/index.php?rid=3029604&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03239.x The electron back scattered diffraction method was applied for carrying out detailed surface studies of the ternary Ni[ndash]Ti[ndash]Co alloy produced using melt-spinning and twin roll casting techniques. The samples were studied in the as-cast state without grinding or polishing. It was found that in the melt-spun ribbon apart from fine narrow columnar grains, that extended along the ribbon thickness, wider columnar grains parallel to the ribbon surface were also observed. These grains were textured along the {100}〈011〉 orientation. The twin roll cast strip revealed more complex and inhomogeneous morphology of its surface. Mainly, the axes of the grains were oriented along two textural components: 〈100〉 for the fine grains and {100}〈011〉 for the ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029604 Wed, 25 Nov 2009 00:00:00 +0100 3029604 http://www.medworm.com/index.php?rid=3029603&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03242.x The mechanism of high emission of InGaN-based multiple quantum wells, which exhibit exceptionally high light emission efficiency despite their high defect density, is still not fully understood. Here, we deal with this problem, showing the details of structure and formation of V defects in the multiple quantum wells and reviewing interpretations proposed so far. Then, we show a structural investigation of three-dimensional high-density quantum dots, fabricated instead of quantum wells in the active layer. The shape and size of the InGaN quantum dots and the SiNx masks for the growth of the dots have been revealed using high-angle annular dark field scanning transmission electron microscopy, energy dispersive X-ray spectroscopy nanoanalysis and high-resolution transmission electron microsco... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029603 Wed, 25 Nov 2009 00:00:00 +0100 3029603 http://www.medworm.com/index.php?rid=3029602&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03244.x The microstructure of as received and surface treated carbon-bonded carbon fibre composites has been examined by light microscopy, scanning and transmission electron microscopy. The microstructure of the as received material consists of a bonded together layered carbon fiber network, identified as graphitic carbon (hexagonal close packed). To improve the erosion resistance of the carbon-bonded carbon fibre composites composite, the SiC and silicate glass[ndash]ceramic coatings from the system SiO2[ndash]Al2O3[ndash]Y2O3 were produced on carbon-bonded carbon fibre composites composites by a low-cost slurry technique. Transmission electron microscopy investigations of cross-section thin foils allowed for detailed analysis of the coatings microstructure. It was found that the SiC coating was ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029602 Wed, 25 Nov 2009 00:00:00 +0100 3029602 http://www.medworm.com/index.php?rid=3029601&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03348.x We identified tomographic reconstruction of a scanning electron microscopy tilt series recording the secondary electron signal as a well-suited method to generate high-contrast three-dimensional data of intermediate filament (IF) networks in pancreatic cancer cells. Although the tilt series does not strictly conform to the projection requirement of tomographic reconstruction, this approach is possible due to specific properties of the detergent-extracted samples. We introduce an algorithm to extract the graph structure of the IF networks from the tomograms based on image analysis tools. This allows a high-resolution analysis of network morphology, which is known to control the mechanical response of the cells to large-scale deformations. Statistical analysis of the extracted network graphs... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3029601 Wed, 25 Nov 2009 00:00:00 +0100 3029601 http://www.medworm.com/index.php?rid=3026479&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03354.x Bitumen is a complex mixture of hydrocarbons for which microstructural understanding is incomplete. In an effort to detail this microstructure, a asphalt cement sample (CAP 30/45) was analysed by thermal phase detection atomic force microscopy. Phase contrast and topography images showed that sample morphology is highly dependent on temperature. The 'bee structure' changed considerably at temperatures between 50°C and 56°C. A decrease of the oscillation amplitude was observed upon heating and the 'bees' completely disappeared at temperatures above 57°C. When the temperature was decreased after melting at 170°C, the 'bees' began to nucleate gradually at temperatures of 57°C and its evolution with time was followed. Changes in morphology were compared to thermal analysis results and a m... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026479 Wed, 25 Nov 2009 00:00:00 +0100 3026479 http://www.medworm.com/index.php?rid=3026484&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03249.x This study shows that the films contain a large number of defects. The most dominant defects in the m-plane GaN are intrinsic I1 basal plane stacking faults ([sim]104 cm[minus]1), threading dislocations ([sim]109 cm[minus]2) as well as a complex defect network consisting of planar defects located on prismatic GaN and differently inclined pyramidal planes. A large number of the stacking faults nucleate at the GaN/LiAlO2 interface. Furthermore, the inclined planar defects act as additional nucleation sites for the basal plane stacking faults. A decreasing crystal quality with an increasing layer thickness can be explained by this defect formation mechanism. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026484 Tue, 24 Nov 2009 00:00:00 +0100 3026484 http://www.medworm.com/index.php?rid=3026483&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03253.x The high temperature microstructure of Ca-doped NiO single crystals was analysed to clear the experimental data on electrical conductivity, Seebeck's effect, diffusion and kinetic demixing. Combined transmission light microscopy and transmission electron microscopy examinations coupled with EDS analyses revealed the presence of CaO precipitates in localized (eutectic-like) zones for a wide range of analysed oxygen partial pressure. Their presence in the structure was confirmed for equilibrium (air) conditions in NiO-CaO system at about 1700°C ([sim]42 mol% CaO), according to phase diagrams (Smith et al., 1969). For the wide range of oxygen partial pressure and high temperature (1000 ÷ 1200°C) the spinel phase was not observed, which is opposite to our previous results obtained for Ca-do... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026483 Tue, 24 Nov 2009 00:00:00 +0100 3026483 http://www.medworm.com/index.php?rid=3026482&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03257.x Aberration-corrected high-resolution transmission electron microscopy (HRTEM) has been applied to resolve the atomic structure of a complex layered crystal, (PbS)1.14NbS2, which comprises a high density of incommensurate interfaces. The strong suppression of image delocalization and the favourable contrast transfer under negative Cs imaging (NCSI) conditions have been exploited for obtaining HRTEM images which directly reveal the projected crystal structure and allow to study lattice imperfections, like stacking disorder and layer undulations, with atomic scale resolution. The advantages of aberration-corrected HRTEM over conventional HRTEM are demonstrated by direct comparison of experimental images and computer simulations. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026482 Tue, 24 Nov 2009 00:00:00 +0100 3026482 http://www.medworm.com/index.php?rid=3026481&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03259.x Microstructural changes occurring during fatigue tests of austenitic-ferritic duplex stainless steel (DSS) in air and in hydrogen-generating environment have been investigated. Hydrogen charging of steel samples during fatigue crack growth (FCG) tests was performed by cathodic polarization of specimens in 0.1M H2SO4 aqueous solution. Microstructural investigations of specimens after FCG tests were carried out using transmission electron microscopy to reveal the density and arrangement of dislocations formed near crack tip. To determine the way of crack propagation in the microstructure, electron backscatter diffraction investigations were performed on fatigue-tested samples in both kinds of environment. To reveal hydrogen-induced phase transformations the atomic force microscopy was used. ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026481 Tue, 24 Nov 2009 00:00:00 +0100 3026481 http://www.medworm.com/index.php?rid=3026480&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03349.x Segmentation of 3D images of granular materials obtained by microtomography is not an easy task. Because of the conditions of acquisition and the nature of the media, the available images are not exploitable without a reliable method of extraction of the grains. The high connectivity in the medium, the disparity of the object's shape and the presence of image imperfections make classical segmentation methods (using image gradient and watershed constrained by markers) extremely difficult to perform efficiently. In this paper, we propose a non-parametric method using the stochastic watershed, allowing to estimate a 3D probability map of contours. Procedures allowing to extract final segmentation from this function are then presented. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3026480 Tue, 24 Nov 2009 00:00:00 +0100 3026480 http://www.medworm.com/index.php?rid=3022965&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03243.x This work presents results of high-resolution transmission electron microscope investigations of microstructure evolution of Au/CoCr2O4 catalyst subjected to various chemical treatments (reduction in hydrogen, reaction of propane oxidation and reaction of CO oxidation). Crystallites of CoCr2O4 support have octahedral or truncated octahedral shape and exhibit well-developed faces, mostly (111). No change in the support morphology was noticed in catalyst samples after various chemical treatments. Small ([sim]8 nm) nanocrystals of gold supported on crystalline CoCr2O4 were observed for the fresh sample. The nanoparticles grow at the surface of CoCr2O4 as thin, disk-like crystallites, in the preferred (111)Au∥(111)CoCr2O4 epitaxial orientation. Further treatment in hydrogen and in react... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3022965 Tue, 24 Nov 2009 00:00:00 +0100 3022965 http://www.medworm.com/index.php?rid=3022967&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03236.x RuO2 thin films have been deposited on Si substrates by spin coating with precursor solutions having a pH varying between 1.4 and 4. X-ray diffraction and transmission electron microscopy analyses are used to determine correlations between the solution pH and the film microstructure. As the pH varies, the RuO2 crystal sizes reach a minimum value then increase; the porosity increases at the substrate/film interface with formation of large cavities. The catalytic activity of these RuO2 layers in the presence of flowing air[ndash]methane is analysed by Fourier transform infrared spectroscopy of the conversion of CH4 into CO2. The increasing porosity seems to improve the catalytic conversion rate of methane. Electrical impedance spectroscopy analyses show that the conductivity strongly depends... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3022967 Mon, 23 Nov 2009 00:00:00 +0100 3022967 http://www.medworm.com/index.php?rid=3022966&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03241.x The paper describes the investigations of nitride precipitates in a spearhead and a sword found in the territory of Poland, in cremation graveyards of the Przeworsk Culture, dated to the Roman Period. Three different techniques of the examination of nitride precipitates were employed: optical microscope, scanning electron microscope (scanning electron microscope with energy dispersive X-ray spectrometer) and transmission electron microscope. Two types of precipitates have been observed, and their plate-like shape was demonstrated. The large precipitate has been confirmed to be [gamma]'-Fe4N, whereas the small one has been identified as [alpha]"-Fe16N2. The origin of nitride precipitates in archaeological iron artefacts from Poland is probably a result of the manufacturing process or cremat... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3022966 Mon, 23 Nov 2009 00:00:00 +0100 3022966 http://www.medworm.com/index.php?rid=3012146&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03351.x Historically, electron microscopy of dynamic biological processes has been impossible to achieve in real time because conventional electron microscopy requires specimen fixation, dehydration and metallic coating. The advent of the environmental scanning electron microscope removes these restrictions, allowing fully hydrated samples to be imaged in their native state. We explore the possibility of secondary electron imaging of biological systems undergoing natural morphological changes in the microscope chamber and present a proof of principle study on the closure of stomatal pores in Tradescantia andersonia leaf tissue. An imaging protocol is developed and the advantages and limitations of this high-resolution imaging technique are considered, including a discussion of potential beam damag... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012146 Fri, 20 Nov 2009 00:00:00 +0100 3012146 http://www.medworm.com/index.php?rid=3012156&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03226.x A systematic study of crystal lattice reorientation in early stages of recrystallization has been carried out to correlate the orientations of recrystallization nuclei with the deformation microtexture and with slip systems. Microstructure and texture of Al[ndash]1 wt.% Mn single crystals of unstable initial orientations of {112}〈111〉, {100}〈001〉 and {001}〈110〉 have been examined by high-resolution field-emission gun scanning electron microscope local orientation measurements. All single crystals were channel-die deformed at room temperature and then annealed for a short time. It was shown that often observed presence of the 〈112〉 directions as rotation axes in the formation of new nuclei orientation directly suggested a close link wi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012156 Thu, 19 Nov 2009 00:00:00 +0100 3012156 http://www.medworm.com/index.php?rid=3012155&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03228.x Cross-sectional transmission electron microscopy and X-ray phase analysis were used to study the structure of a layer formed during nitriding the AISI 316L stainless steel at temperature 440°C. It was found that the applied treatment led to the formation of 6-[mu]m-thick layer of the S-phase. There is no evidence of CrN precipitation. The X-ray diffraction experiments proved that the occurred austenite lattice expansion [ndash] due to nitrogen atoms [ndash] depended on the crystallographic direction. The cross-sectional transmission electron microscopy studies showed that the layer consisted of a single cubic phase that contained a lot of defects such as dislocations, stacking faults, slip bands and twins. The high-resolution electron microscopy observations were applied to study the defe... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012155 Thu, 19 Nov 2009 00:00:00 +0100 3012155 http://www.medworm.com/index.php?rid=3012154&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03232.x The method, which allows shape reconstruction by reading the intensity from the scanning electron microscopy image, is presented and discussed in details. The method is applied to read the morphology of etch-pits, which were formed on the GaN surface by etching in molten KOH[ndash]NaOH eutectic mixture to delineate dislocations. The etch-pit depth distributions are obtained and used to determine densities of pits related to screw, mixed or edge-type dislocations. The results are compared with atomic force microscopy. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012154 Thu, 19 Nov 2009 00:00:00 +0100 3012154 http://www.medworm.com/index.php?rid=3012153&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03240.x The microstructures of the Fe[ndash]Cu-based alloys melt-spun from various temperatures are presented. Two compositions, with different Fe and Cu content, revealing liquid miscibility gap, were studied. Nonuniform, large-elongated areas were observed for lower melt-spinning temperatures, indicating liquid/liquid phase separation in the crucible before cooling. An increase of the melt ejection temperature, followed by rapid cooling, brought about precipitation process within homogeneous melt. Studies of the system with higher Fe content proved amorphous nature of the matrix and crystalline structure of the primary formed Cu-rich precipitates. Moreover, generations of the secondary spherical particles, precipitated within the previously formed Cu-rich melt, were observed. The microstructure ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012153 Thu, 19 Nov 2009 00:00:00 +0100 3012153 http://www.medworm.com/index.php?rid=3012152&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03245.x Two concepts of the secondary electron detection inside the intermediate chamber of the variable pressure scanning electron microscopy have been discussed. One of them, the two-stage secondary electron detector has been the subject of previous publications. The other one, the intermediate secondary electron detector is an improved solution in respect of its complexity, vacuum demands and dimensions. Both detector systems apply some kinds of scintillators, so they present advantages specific for scintillator detectors but extended to a wide range of gas pressures, from high vacuum to pressures exceeding 10 mbar. The detector functioning is illustrated with computer simulations of electron and ion flow in the input region of the detectors made with use of the MC[ndash]SIMION program. This so... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012152 Thu, 19 Nov 2009 00:00:00 +0100 3012152 http://www.medworm.com/index.php?rid=3012151&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03248.x The dependence of spatially and spectrally resolved cathodoluminescence in a scanning electron microscope on resistances in semiconductor structures, especially on the layer resistance, is reported. This previously unstudied dependence is utilized for thin-layer sheet-resistance measurement. The method is illustrated by an assessment of lateral confinements in semiconductor-laser heterostructures. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012151 Thu, 19 Nov 2009 00:00:00 +0100 3012151 http://www.medworm.com/index.php?rid=3012150&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03250.x The microstructure and texture of Cu[ndash]8 at.% Al alloy single crystal with (112)[11] orientation plane strain compressed at 77 K were characterized by scanning electron microscope and transmission electron microscope orientation mappings in order to investigate the influence of twins and shear bands on slip propagation across a structure of twin-matrix layers and the resulting texture evolution. It was shown that the strong, initial texture changes are due to deformation twinning at low deformations. At larger deformations, twin-matrix bending within some narrow areas led to the formation of kink-type bands, which became the precursors of shear bands. It is shown with scanning electron microscope and transmission electron microscope orientation mappings how the structure of twins and m... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012150 Thu, 19 Nov 2009 00:00:00 +0100 3012150 http://www.medworm.com/index.php?rid=3012149&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03252.x Different types of distortions in scanning electron microscopy require different methods of their elimination, and therefore influence of these types on particular elements of the SEM system should be known. The proposed method allows for separation of the direct influence of the magnetic field on the electron beam in the SEM chamber from its influence in the SEM column and from the distortions generated in the SEM scanning block. For this purpose, a series of distorted images is registered for several working distances (between the final aperture of the electron column and the specimen) and for several energies of the electrons. Magnitudes of the distortions are measured on these images. For each applied electron energy, the dependence of the results versus the working distance is approxi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012149 Thu, 19 Nov 2009 00:00:00 +0100 3012149 http://www.medworm.com/index.php?rid=3012148&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03256.x CdTe/ZnTe axial nanowires were successfully fabricated by molecular beam epitaxy with the use of Au nano-catalysts and vapour[ndash]liquid[ndash]solid growth mechanism. Nanowires had zinc-blende structure with numerous stacking faults in the bottom ZnTe part and near perfect crystalline structure in the top CdTe part. Energy dispersive X-ray spectroscopy (EDXS) and lattice fringe spacing analysis revealed nonabrupt nature of hetero[minus]interface, whose width was estimated to be 50[ndash]70 nm for the nanowires having a diameter in the range from 40 to 50 nm. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012148 Thu, 19 Nov 2009 00:00:00 +0100 3012148 http://www.medworm.com/index.php?rid=3012147&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03261.x TEM studies of creep tested CMSX-4 nickel-base single crystal superalloy were performed to analyse a microstructure evolution during creep at temperature 750°C, and uniaxial tensile stress of 675 MPa. Microstructural analyses were focused mainly on examination of dislocation configurations during primary and secondary creep stages of high temperature deformation. At such low temperature and high stress creep deformation proceed by cutting of [gamma]' particles by dislocations. It was found that primary creep is initiated by movement of dislocations with Burgers vector a/2 in the [gamma] phase. The second type of dislocations active at primary creep stage are extended dislocation ribbons with overall a Burgers vector, separated by superlattice stacking faults, cutting both the [gamma] and ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=3012147 Thu, 19 Nov 2009 00:00:00 +0100 3012147 http://www.medworm.com/index.php?rid=2980895&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03344.x The unique phase-sensitive acoustic microscope is used for the structural and mechanical characterization of thin films of polystyrene/polymethylmethacrylate blends. The effect of annealing on blends of polystyrene/polymethylmethacrylate spin coated from different solvents unto a substrate is studied. Varying the solvents according to vapour pressure and spin coating at different speeds (for thickness variation) led to changes in phase domain distributions and overall structural properties before annealing. Annealing in vacuum at 190°C for 48 h resulted in the elimination of solvent effects with all samples reverting to a similar morphology irrespective of common solvent and thickness. The Young's moduli at specific points on the film (Epolystyrene= 3.4 ± 0.3 GPa, Epolymethylmethacrylate... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2980895 Wed, 11 Nov 2009 00:00:00 +0100 2980895 http://www.medworm.com/index.php?rid=2977099&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03342.x A non-destructive technique for obtaining voltage contrast information with photoelectron emission microscopy is described. Samples consisting of electrically isolated metal lines were used to quantify voltage contrast in photoelectron emission microscopy. The voltage contrast behaviour is characterized by comparing measured voltage contrast with calculated voltage contrast from two electrostatic models. Measured voltage contrast was found to agree closely with the calculated voltage contrast, demonstrating that voltage contrast in photoelectron emission microscopy can be used to probe local voltage information in microelectronic devices in a non-intrusive fashion. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2977099 Tue, 10 Nov 2009 00:00:00 +0100 2977099 http://www.medworm.com/index.php?rid=2934520&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03350.x We present a toolbox for determining telomere positions within the nucleus with subresolution accuracy and tracking telomeres in 4D controlled light exposure microscopy (CLEM) recordings. The use of CLEM allowed for durable imaging and thereby improved segmentation performance considerably. With minor modifications, the underlying algorithms can be expanded to the analysis of other intranuclear features, such as nuclear bodies or DNA double stranded break foci. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2934520 Wed, 28 Oct 2009 00:00:00 +0100 2934520 http://www.medworm.com/index.php?rid=2934523&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03328.x An exponential contrast stretching (ECS) technique is developed to reduce the charging effects on scanning electron microscope images. Compared to some of the conventional histogram equalization methods, such as bi-histogram equalization and recursive mean-separate histogram equalization, the proposed ECS method yields better image compensation. Diode sample chips with insulating and conductive surfaces are used as test samples to evaluate the efficiency of the developed algorithm. The algorithm is implemented in software with a frame grabber card, forming the front-end video capture element. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2934523 Tue, 27 Oct 2009 00:00:00 +0100 2934523 http://www.medworm.com/index.php?rid=2934522&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03332.x We present an unbiased estimator of the total number of alveolar structures distal to the transition from a bronchiole to an alveolar duct system ('ventilatory units', VUs). In species without respiratory bronchioles, including mice, the number of VUs is equivalent to the number of acini. The acinus is a functional unit of gas exchange, defined as a parenchymal unit distal to a terminal bronchiole in which all airways contain alveoli and thus participate in gas exchange. The estimator combines two different estimators of the number of VUs: (1) an estimator derived from the Euler number of all the openings of the bronchial tree and (2) an estimator derived from direct counts of topological changes occurring at bronchiole-alveolar duct junctions. Combining the two estimators eliminates the r... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2934522 Tue, 27 Oct 2009 00:00:00 +0100 2934522 http://www.medworm.com/index.php?rid=2934521&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03336.x Preparation and sectioning of bacterial spores by focused ion beam and subsequent high resolution secondary ion mass spectrometry analytical imaging is demonstrated. Scanning transmission electron microscopy mode imaging in a scanning electron microscope is used to show that the internal structure of the bacterial spore can be preserved during focused ion beam sectioning and can be imaged without contrast staining. Ion images of the sections show that the internal elemental distributions of the sectioned spores are preserved. A rapid focused ion beam top-sectioning method is demonstrated to yield comparable ion images without the need for sample trenching and section lift-out. The lift-out and thinning method enable correlated transmission electron microscopy and high resolution secondary ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2934521 Tue, 27 Oct 2009 00:00:00 +0100 2934521 http://www.medworm.com/index.php?rid=2923156&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03337.x The recent development of complex chemical and small interfering RNA (siRNA) collections has enabled large-scale cell-based phenotypic screening. High-content and high-throughput imaging are widely used methods to record phenotypic data after chemical and small interfering RNA treatment, and numerous image processing and analysis methods have been used to quantify these phenotypes. Currently, there are no standardized methods for evaluating the effectiveness of new and existing image processing and analysis tools for an arbitrary screening problem. We generated a series of benchmarking images that represent commonly encountered variation in high-throughput screening data and used these image standards to evaluate the robustness of five different image analysis methods to changes in signal-... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2923156 Fri, 23 Oct 2009 23:00:00 +0100 2923156 http://www.medworm.com/index.php?rid=2923159&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03312.x The purpose of this study was to investigate the reaction of the pulp of dogs' teeth after insertion of soft carious dentin from freshly extracted human teeth into the buccal cavities for short and longer periods of time. Forty-seven mature lower and upper teeth were used in this study. On the middle of the buccal side of the teeth, 3 × 5 mm class [nu] cavities were prepared, soft carious dentin from freshly extracted human teeth was inserted into the floor of the cavity, and those were filled with glass ionomer. The dogs were killed after 7, 14, 28 and 47 days using vital perfusion techniques. Six-micrometre sections were prepared and blindly evaluated by pathologist. An inflammatory reaction occurred in all of the samples. Moderate to severe inflammation were shown in all periods except... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2923159 Thu, 22 Oct 2009 23:00:00 +0100 2923159 http://www.medworm.com/index.php?rid=2923158&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03341.x This paper reports a procedure to combine the focused ion beam micro-sampling method with conventional Ar-milling to prepare high-quality site-specific transmission electron microscopy cross-section samples. The advantage is to enable chemical and structural evaluations of oxygen dissolved in a molten iron sample to be made after quenching and recovery from high-pressure experiments in a laser-heated diamond anvil cell. The evaluations were performed by using electron energy-loss spectroscopy and high-resolution transmission electron microscopy. The high signal to noise ratios of electron energy-loss spectroscopy core-loss spectra from the transmission electron microscopy thin foil, re-thinned down to 40 nm in thickness by conventional Argon ion milling, provided us with oxygen quantitativ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2923158 Thu, 22 Oct 2009 23:00:00 +0100 2923158 http://www.medworm.com/index.php?rid=2923157&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03329.x Aclar, a copolymer film with properties very similar to those of tissue culture plastic, is a versatile substrate to grow cells for light (including fluorescence) and electron microscopic applications in combination with both chemical fixation and cryoimmobilization. In this paper, we describe complete procedures to perform correlative light and electron microscopy using Aclar as substrate for the culture of cell monolayers to be finally embedded in plastic. First, we developed straightforward, efficient and flexible ways to mark the surface of the Aclar to create substrates to locate cells first at the light microscopy and then the electron microscopy level. All the methods enable the user to self-design gridded Aclar pieces, according to the purpose of the experiments, and create a large... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2923157 Thu, 22 Oct 2009 23:00:00 +0100 2923157 http://www.medworm.com/index.php?rid=2915924&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03327.x Recent technical developments allowed the accurate correlation of fluorescently labelled organelles in living cells to cryo-electron micrographs. We aimed at expanding this approach to Plasmodium berghei sporozoites, the motile forms of a rodent malaria parasite, which can be imaged by cryo-electron tomography in toto without the need for sectioning. Sporozoites are crescent shaped eukaryotic cells that move on flat supports including EM grids in a circular, unidirectional manner. While sporozoites can be visualized with fluorescent light and cryo-light microscopy prior to tomography, few motile sporozoites remained on the grid after blotting excess liquid impairing a complete correlation from light microscopy to cryo-electron tomography. Comparison with cells showing different adhesion st... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915924 Wed, 21 Oct 2009 23:00:00 +0100 2915924 http://www.medworm.com/index.php?rid=2915923&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03330.x Multiphoton excitation laser scanning microscopy, relying on the simultaneous absorption of two or more photons by a molecule, is one of the most exciting recent developments in biomedical imaging. Thanks to its superior imaging capability of deeper tissue penetration and efficient light detection, this system becomes more and more an inspiring tool for intravital bulk tissue imaging. Two-photon excitation microscopy including 2-photon fluorescence and second harmonic generated signal microscopy is the most common multiphoton microscopic application. In the present review we take diverse ocular tissues as intravital samples to demonstrate the advantages of this approach. Experiments with registration of intracellular 2-photon fluorescence and extracellular collagen second harmonic generate... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915923 Wed, 21 Oct 2009 23:00:00 +0100 2915923 http://www.medworm.com/index.php?rid=2915922&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03331.x Quantitative measures for anisotropic characteristics of spatial structure are needed when relating the morphology of microstructured heterogeneous materials to tensorial physical properties such as elasticity, permeability and conductance. Tensor-valued Minkowski functionals, defined in the framework of integral geometry, provide a concise set of descriptors of anisotropic morphology. In this article, we describe the robust computation of these measures for microscopy images and polygonal shapes. We demonstrate their relevance for shape description, their versatility and their robustness by applying them to experimental data sets, specifically microscopy data sets of non-equilibrium stationary Turing patterns and the shapes of ice grains from Antarctic cores. (Source: Journal of Microscop... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915922 Wed, 21 Oct 2009 23:00:00 +0100 2915922 http://www.medworm.com/index.php?rid=2915921&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03333.x Preparation of vital bacteria for atomic force microscope study under aqueous fluid, such as physiological buffer or bacterial growth medium, presents challenges as cells will often desorb from the supporting surface or be dislodged by the atomic force microscope tip during imaging. An established method of immobilizing coccoid bacteria is to trap cells in polycarbonate track etched filter pores. We have significantly improved this method by modifying the pore diameter of commercially available filters to correspond to the diameter of the target strain, enabling high-resolution imaging of stationary organisms under buffer and dividing organisms under growth media. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915921 Wed, 21 Oct 2009 23:00:00 +0100 2915921 http://www.medworm.com/index.php?rid=2915920&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03335.x The detailed examination of the internal and functional anatomy of soft-bodied marine worms has, until now, only been possible using the time consuming and destructive techniques of dissection, histology and electron microscopy. This is the first description of soft body morphology in polychaetes (Nephtys hombergii) derived by means of a bench-top X-ray micro-CT scanner. The data are augmented, for comparison, by dissections, microscopy and scanning electron microscopy of the same species to show how this non-destructive technique can rapidly and reliably produce high-quality morphological data. It can also be applied to rare or unique invertebrate soft tissue material from museum collections and also to large-scale invertebrate comparative anatomical studies possibly leading to greater ev... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915920 Wed, 21 Oct 2009 23:00:00 +0100 2915920 http://www.medworm.com/index.php?rid=2915919&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03338.x The aim of this work was to present and discuss a quality control protocol for in vitro micro-computed tomography (microCT), based on the adaptation of the quality control protocols for medical computed tomography. The importance of establishing a quality control protocol is related to the opportunity to identify problems on time comparing the microCT images acquired in different time points, and in this way to verify the performance of the device. The proposed quality control protocol was applied for a long-time monitoring period to verify the stability of the micro-tomographic system over time. The protocol proposed in this study was applied to the histomorphometric characterization of bone tissue, but it can be used on a wide range of in vitro microCT applications. Noise and uniformity ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915919 Wed, 21 Oct 2009 23:00:00 +0100 2915919 http://www.medworm.com/index.php?rid=2915918&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03340.x The quantitative theory of image contrast in an electron microscope in the mirror operation mode is given in this paper. This theory permits us to calculate the potential distribution on the object surface from the current density distribution on the microscope screen. The potential distribution results in image formation on the screen. Local electric fields existing on the object surface lead to a perturbation of electron trajectories above the object and to a redistribution of the current density on the screen, causing image contrast. Using the quantitative correlation between these fields and the function of current density distribution on the screen, it is possible to calculate the magnitude of these microfields as well. As illustration, a measured potential distribution on an object s... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915918 Wed, 21 Oct 2009 23:00:00 +0100 2915918 http://www.medworm.com/index.php?rid=2915917&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03343.x A new computer code has been developed to automatically extract quantitative twin statistics from electron backscatter diffraction data. The new code is an improvement upon previous codes in that it handles materials of any crystal symmetry, type I, Type II and compound twins, and general stress states. Moreover, accuracy of the results has been greatly improved. In addition, twin statistics including number, area fraction, twin thickness and twinning dependencies on orientation, grain size and neighbourhood effects can be routinely analysed. The new code has been applied to scan data from deformed magnesium, zirconium and uranium, and can potentially be used for any twinning material for which reliable electron backscatter diffraction results can be obtained. (Source: Journal of Microscop... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2915917 Wed, 21 Oct 2009 23:00:00 +0100 2915917 http://www.medworm.com/index.php?rid=2908395&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03326.x We have coupled a spectrophotometer with a scanning near-field optical microscope to obtain, with a single scan, simultaneously scanning near-field optical microscope fluorescence images at different wavelengths as well as topography and transmission images. Extraction of the fluorescence spectra enabled us to decompose the different wavelengths of the fluorescence signals which normally overlap. We thus obtained images of the different fluorescence emissions of acridine orange bound to single or double stranded nucleic acids in human metaphase chromosomes before and after DNAse I or RNAse A treatment. The analysis of these images allowed us to visualize some specific chromatin areas where RNA is associated with DNA showing that such a technique could be used to identify multiple component... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2908395 Mon, 19 Oct 2009 23:00:00 +0100 2908395 http://www.medworm.com/index.php?rid=2901559&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03339.x Experiments on model organisms are used to extend the understanding of complex biological processes. In Caenorhabditis elegans studies, populations of specimens are sampled to measure certain morphological properties and a population is characterized based on statistics extracted from such samples. Automatic detection of C. elegans in such culture images is a difficult problem. The images are affected by clutter, overlap and image degradations. In this paper, we exploit shape and appearance differences between C. elegans and non-C. elegans segmentations. Shape information is captured by optimizing a parametric open contour model on training data. Features derived from the contour energies are proposed as shape descriptors and integrated in a probabilistic framework. These descriptors are e... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2901559 Fri, 16 Oct 2009 23:00:00 +0100 2901559 http://www.medworm.com/index.php?rid=2901563&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03300.x In this report, we establish the relationships between the spatial autocorrelation function feature size, temporal autocorrelation function characteristic time and the diffusion coefficient for uniform illumination image correlation microscopy using analytical, Monte Carlo and experimental validation with particle tracking algorithms. Additionally, we demonstrate uniform illumination image correlation microscopy analysis of adhesion molecule domain aggregation and diffusion on the surface of human neutrophils. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2901563 Thu, 15 Oct 2009 23:00:00 +0100 2901563 http://www.medworm.com/index.php?rid=2901562&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03324.x Two-photon fluorescence microscopy and confocal reflectance microscopy were compared to detect intracellular gold nanorods in rat basophilic leukaemia cells. The two-photon photoluminescence images of gold nanorods were acquired by an 800 nm fs laser with the power of milliwatts. The advantages of the obtained two-photon photoluminescence images are high spatial resolution and reduced background. However, a remarkable photothermal effect on cells was seen after 30 times continuous scanning of the femto-second laser, potentially affecting the subcellular localization pattern of the nanorods. In the case of confocal reflectance microscopy the images of gold nanorods can be obtained with the power of light source as low as microwatts, thus avoiding the photothermal effect, but the resolution ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2901562 Thu, 15 Oct 2009 23:00:00 +0100 2901562 http://www.medworm.com/index.php?rid=2901561&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03325.x Interpolation techniques that are used for image magnification to obtain more useful details of the surface such as morphology and mechanical contrast usually rely on the signal information distributed around edges and areas of sharp changes and these signal information can also be used to predict missing details from the sample image. However, many of these interpolation methods tend to smooth or blur out image details around the edges. In the present study, a Lagrange time delay estimation interpolator method is proposed and this method only requires a small filter order and has no noticeable estimation bias. Comparing results with the original scanning electron microscope magnification and results of various other interpolation methods, the Lagrange time delay estimation interpolator is... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2901561 Thu, 15 Oct 2009 23:00:00 +0100 2901561 http://www.medworm.com/index.php?rid=2901560&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03334.x Amplification of metal-complexed polymerized diaminobenzidine by two light-insensitive physical developers was systematically examined in a dot blot model system following either polymerizing diaminobenzidine in the presence of transition metal salts or applying the metal salts post-diaminobenzidine polymerization. The effect of sodium sulphide treatment on subsequent amplification was also investigated. Those metal[ndash]diaminobenzidine complexes that facilitated the most powerful amplification were subsequently tested in an immunohistochemical setting. The most dramatic amplification of polymerized diaminobenzidine was observed following its post-polymerization treatment with salts of platinum alone, or gold or vanadium with subsequent sulphide treatment, and allowed previously invisibl... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2901560 Thu, 15 Oct 2009 23:00:00 +0100 2901560 http://www.medworm.com/index.php?rid=2890303&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03313.x A variety of different methods exist for gathering three-dimensional information for micro- and nanoscale objects. Tilting of samples in a scanning electron microscope provides a non-destructive way of generating these data. Traditionally, the reconstruction of this image data is performed by stereo photogrammetric methods that compare features from two or three frames. We propose the application of techniques from the structure-from-motion community as being efficient, high-precision alternatives to stereo methods, which allows for automated utilization of a large number of sampled images. We propose the use of nanobelts to generate localized rotational motions. Using this method alleviates the demand of high-precision actuators, allows 360° rotations, and provides a useful tool for micr... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2890303 Tue, 13 Oct 2009 23:00:00 +0100 2890303 http://www.medworm.com/index.php?rid=2868744&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03322.x Heterodyne measurement of the amplitude and phase of a cross-polarized two-frequency laser beam reflected from a patterned surface enables simultaneous imaging in both the amplitude and phase-contrast modes. Such imaging duality provides additional information for inspection. Besides, spatial resolution in the phase-contrast mode of operation is not limited by the width of the focused beam and, therefore, may be better than that of traditional imaging techniques. This phenomenon, commonly referred to as super-resolution, was experimentally observed. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2868744 Tue, 06 Oct 2009 23:00:00 +0100 2868744 http://www.medworm.com/index.php?rid=2827993&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03323.x This paper addresses the problem of 3D deconvolution of through focus widefield microscope datasets (Z-stacks). One of the most difficult stages in brightfield deconvolution is finding the point spread function. A theoretically calculated point spread function (called a 'synthetic PSF' in this paper) requires foreknowledge of many system parameters and still gives only approximate results. A point spread function measured from a sub-resolution bead suffers from low signal-to-noise ratio, compounded in the brightfield setting (by contrast to fluorescence) by absorptive, refractive and dispersal effects. This paper describes a method of point spread function estimation based on measurements of a Z-stack through a thin sample. This Z-stack is deconvolved by an idealized point spread function ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2827993 Wed, 23 Sep 2009 23:00:00 +0100 2827993 http://www.medworm.com/index.php?rid=2803776&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03318.x We present an evaluation of electron tomography of buried InAs quantum dots using dark field 002 imaging conditions. The compositional sensitivity of this imaging condition gives strong contrast among III-V materials of differing compositions and, in principle, should allow an accurate 3D model of the buried structures to be produced. The large extinction distance allows specimens several hundred nanometres in thickness to be examined and reduces the effect of strain contrast in the images, with the advantage that it can be performed using conventional transmission electron microscopy techniques. A two-beam condition must be maintained for all images, and the presence of other strong diffraction effects at certain specimen orientation results reduces the number of orientations available fo... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2803776 Wed, 16 Sep 2009 23:00:00 +0100 2803776 http://www.medworm.com/index.php?rid=2803778&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03315.x Live imaging in cell biology requires three-dimensional data acquisition with the best resolution and signal-to-noise ratio possible. Depth aberrations are a major source of image degradation in three-dimensional microscopy, causing a significant loss of resolution and intensity deep into the sample. These aberrations occur because of the mismatch between the sample refractive index and the immersion medium index. We have built a wide-field fluorescence microscope that incorporates a large-throw deformable mirror to simultaneously focus and correct for depth aberration in three-dimensional imaging. Imaging fluorescent beads in water and glycerol with an oil immersion lens we demonstrate a corrected point spread function and a 2-fold improvement in signal intensity. We apply this new micros... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2803778 Tue, 15 Sep 2009 23:00:00 +0100 2803778 http://www.medworm.com/index.php?rid=2803777&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03299.x In conclusion although cryo electron microscopy of vitreous sections must be considered the 'gold standard' among sectioning methods for electron microscopy, because it avoids solvents and stains, the use of optimally prepared freeze substitution also offers some advantages for ultrastructural analysis of bacteria. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2803777 Tue, 15 Sep 2009 23:00:00 +0100 2803777 http://www.medworm.com/index.php?rid=2796293&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03317.x We report on a microscope that acquired fluorescence images using illumination across the spectral range 450[ndash]680 nm; the full emission spectrum was detected simultaneously across the same range. The microscope was also combined with structured illumination optical sectioning to give three-dimensionally resolved images with improved background rejection. Full spectrum fluorescence images of biological specimens are demonstrated. As this system is more versatile than the standard fluorescence microscope, it could be of benefit in many fluorescence imaging applications. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2796293 Mon, 14 Sep 2009 23:00:00 +0100 2796293 http://www.medworm.com/index.php?rid=2757498&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03304.x A model based method for the accurate quantification of the 3D structure of fluorescently labelled cellular objects similar in size to the optical resolution limit is presented. This method is applied to both simulated confocal images of chromatin structures and to real confocal data obtained on a Fluorescence in situ Hybridization (FISH) labelled gene domain. The model assumes that the object is composed of a small number of discrete points which are convolved with the microscope point spread function to give the image. Fitting this model to image data results in a method to assess object structure which is accurate, shows a low bias, and does not require user intervention or the potentially subjective setting of a threshold. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2757498 Tue, 01 Sep 2009 23:00:00 +0100 2757498 http://www.medworm.com/index.php?rid=2757500&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03280.x We present a new algorithm to analyse information content in images acquired using automated fluorescence microscopy. The algorithm belongs to the group of autofocusing methods, but differs from its predecessors in that it can handle thick specimens and operate also in confocal mode. It measures the information content in images using a 'content function', which is essentially the same concept as a focus function. Unlike previously presented algorithms, this algorithm tries to find all significant axial positions in cases where the content function applied to real data is not unimodal, which is often the case. This requirement precludes using algorithms that rely on unimodality. Moreover, choosing a content function requires careful consideration, because some functions suppress local maxi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2757500 Mon, 31 Aug 2009 23:00:00 +0100 2757500 http://www.medworm.com/index.php?rid=2757499&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03292.x An investigation by electron backscatter diffraction on gypsum shows that this technique can be used to study the microstructures and crystallographic preferred orientation of gypsum. Presented here are the methods, verification tests and data obtained from a naturally deformed sample of gypsum-rich rock. The electron backscatter diffraction data show the sample has a strong crystallographic preferred orientation. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2757499 Mon, 31 Aug 2009 23:00:00 +0100 2757499 http://www.medworm.com/index.php?rid=2741156&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03306.x A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 [mu]m. A three... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2741156 Thu, 27 Aug 2009 23:00:00 +0100 2741156 http://www.medworm.com/index.php?rid=2741155&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03320.x Pulsed-laser atom-probe tomography is used to compare the field-evaporation mass spectrum and spatial distribution of molecular fragments from various poly(3-alkylthiophene) films deposited on sharpened aluminium specimen carriers using two different deposition methods. Films deposited via a modified solution-cast methodology yield small fragments with a uniform structural morphology whereas films deposited via an electrospray ionization methodology yield a wide range of fragments with a very non-uniform structural morphology. The main field-evaporated chemical species identified for both deposition types were, in order of typical relative abundance, C2H5+, CH3+, C2H4+, followed by C3H7,8+/SC+ and SCH+. Thick electrospray depositions allowed investigation of the influence of laser-pulse en... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2741155 Thu, 27 Aug 2009 23:00:00 +0100 2741155 http://www.medworm.com/index.php?rid=2737513&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03321.x Competing concepts exist regarding surgery for instance of the cleft lip and palate to date. Morphology-based simulations at histological scale may one day be used to help the surgeon predict the possible outcome of a variety of approaches. It however can be a challenge to generate volume meshes that are applicable to the mathematical modelling of three-dimensional spatial modifications. Computation of surface meshes may be considered less delicate. The aim of this study is to design and evaluate a novel algorithm that supports finite element methods. Images of histological serial sections of a striated muscle were segmented. Results of the three-dimensional reconstruction of multiple layers of the polygonal segmentation data characterized the hull of the muscle. The corresponding surface ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2737513 Wed, 26 Aug 2009 23:00:00 +0100 2737513 http://www.medworm.com/index.php?rid=2737517&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03287.x We present and benchmark different algorithms for noise reduction and demonstrate the use of non-maximum suppression to quickly find likely fluorophore positions in high depth and very noisy images. The algorithm is evaluated and compared in terms of speed, accuracy and robustness by means of simulated data. On real biological samples, we find that real-time data processing is possible and that super-resolution imaging with organic fluorophores of cellular structures with [sim]20 nm optical resolution can be completed in less than 10 s. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2737517 Tue, 25 Aug 2009 23:00:00 +0100 2737517 http://www.medworm.com/index.php?rid=2737516&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03301.x We present recent data on dynamic imaging of Rac1 activity in live T-cells. Förster resonance energy transfer between enhanced green and monomeric red fluorescent protein pairs which form part of a biosensor molecule provides a metric of this activity. Microscopy is performed using a multi-functional high-content screening instrument using fluorescence anisotropy to provide a means of monitoring protein[ndash]protein activity with high temporal resolution. Specifically, the response of T-cells upon interaction of a cell surface receptor with an antibody coated multi-well chamber was measured. We observed dynamic changes in the activity of the biosensor molecules with a time resolution that is difficult to achieve with traditional methodologies for observing Förster resonance energy trans... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2737516 Tue, 25 Aug 2009 23:00:00 +0100 2737516 http://www.medworm.com/index.php?rid=2737515&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03281.x The unique phenomenon of cell proliferation and apoptosis is encountered in the ovarian follicles undergoing early stages of atresia. The aim of this study was to verify the morphological variations in these two physiologically distinct processes operating in antral follicles of caprine ovaries using histological and ultrastructural techniques. Histologically the degenerating granulosa cells were characterized by condensed cytoplasm, and nucleus fragmentation in hazy cytosol. The pyknotic nuclei of degenerating cells stained darkly with haematoxylin and giemsa while the cytoplasm was eosinophilic. Under electron microscopy, apoptosis was marked by asymmetrical shrinkage, vacuolization of cytoplasm, swollen and vacuolated mitochondria, increased irregularity and/or fragmentation of nucleus,... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2737515 Tue, 25 Aug 2009 23:00:00 +0100 2737515 http://www.medworm.com/index.php?rid=2737514&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03314.x Solid state nuclear track detectors are used to determine the concentration of [alpha] particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of [alpha] particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A 'LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. T... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2737514 Tue, 25 Aug 2009 23:00:00 +0100 2737514 http://www.medworm.com/index.php?rid=2733891&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03308.x We present a method for the automated identification of Mycobacterium tuberculosis in images of Ziehl-Neelsen-stained sputum smears obtained using a bright-field microscope. We use two stages of classification. The first comprises a one-class pixel classifier for object segmentation. Geometric transformation invariant features are extracted for implementation of the second stage, namely one-class object classification. Different classifiers are compared; the sensitivity of all tested classifiers is above 90% for the identification of a single bacillus object using all extracted features. The mixture of Gaussians classifier performed well in both stages of classification. This method may be used as a step in the automation of tuberculosis screening, in order to reduce technician involvement... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2733891 Tue, 25 Aug 2009 23:00:00 +0100 2733891 http://www.medworm.com/index.php?rid=2733892&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03205.x Deconvolution techniques have been widely used for restoring the 3-D quantitative information of an unknown specimen observed using a wide-field fluorescence microscope. Deconv, an open-source deconvolution software package, was developed for 3-D quantitative fluorescence microscopy imaging and was released under the GNU Public License. Deconv provides numerical routines for simulation of a 3-D point spread function and deconvolution routines implemented three constrained iterative deconvolution algorithms: one based on a Poisson noise model and two others based on a Gaussian noise model. These algorithms are presented and evaluated using synthetic images and experimentally obtained microscope images, and the use of the library is explained. Deconv allows users to assess the utility of the... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2733892 Mon, 24 Aug 2009 23:00:00 +0100 2733892 http://www.medworm.com/index.php?rid=2729934&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03302.x In this report, we followed the rearrangement of the surface membrane structure and the actin cytoskeletal organization in C2C12 myoblasts at different stages of myogenesis using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). AFM imaging of living myoblasts undergoing fusion unveiled that within minutes of making cell[ndash]cell contact, membrane tubules appear that unite the myoblasts and increase in girth as fusion proceeds. CLSM identified these membrane tubules as built on scaffolds of actin filaments that nucleate at points of contact between fusing myoblasts. In contrast, similarly behaving membrane tubules are absent during cytokinesis. The results from our study in combination with recent findings in literature further expand the understanding of the b... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2729934 Mon, 24 Aug 2009 23:00:00 +0100 2729934 http://www.medworm.com/index.php?rid=2729935&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03209.x A prototype for automatic control of mechanical forces acting on cell biomembranes is proposed in this paper. This prototype consists of vision-guided position control of the holder and micro-force sensor, automatic mechanical property characterization of cell biomembranes and automatic control of mechanical forces acting on cell biomembranes. A template-free calibration method and autofocusing of multiple objects are introduced in the vision-guided position control to minimize external biological contamination and position the cell, holder and micro-force sensor into the same focal plane, respectively. A third-order polynomial modified from biomembrane point-load model describing the relationship between the measured mechanical force and the deformations of biomembranes is proposed. This ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2729935 Sun, 23 Aug 2009 23:00:00 +0100 2729935 http://www.medworm.com/index.php?rid=2719538&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03305.x Accurate preservation of microtubule and actin microfilament arrays is crucial for investigating their roles in plant cell development. Aldehyde fixatives such as paraformaldehyde or glutaraldehyde preserve cortical microtubule arrays but, unless actin microfilaments are stabilized with drugs such as m-maleimidobenzoyl N-hydroxysuccinimide ester (MBS), ethylene glycol bis[sulfosuccinimidylsuccinate] (sulfo-EGS) or phalloidin, their arrays are often poorly preserved. Cryofixation, used primarily for electron microscopy, preserves actin microfilaments well but is used rarely to fix plant cells for optical microscopy. We developed a novel whole-mount cryofixation method to preserve microtubule and microfilament arrays within Tradescantia virginiana leaf epidermal cells for investigation using... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2719538 Thu, 20 Aug 2009 23:00:00 +0100 2719538 http://www.medworm.com/index.php?rid=2691317&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03206.x We present methods for variability estimation of the local stereological volume estimators. This variability arises during the stereological estimation procedure and in the particle population. Both of these components can be estimated separately from planar sections. Our aim is to give a preliminary analysis of the possibility to include the particle structure interaction into the estimation procedure. For this reason, not only the section profiles, but also their locations, have to be recorded. The methods are applied for the sectional data obtained from neurons in the hippocampal brain region subiculum of four 3-month-old male Wistar rats. The proposed procedure enables one to obtain information about particle volume distribution. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2691317 Tue, 11 Aug 2009 23:00:00 +0100 2691317 http://www.medworm.com/index.php?rid=2657397&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03215.x The evolution of hydrogen from many hydrated cryo-preserved soft materials under electron irradiation in the transmission electron microscope can be observed at doses of the order of 1000 e nm[minus]2 and above. Such hydrogen causes artefacts in conventional transmission electron microscope or scanning transmission electron microscopy (STEM) imaging as well as in analyses by electron energy-loss spectroscopy. Here we show that the evolution of hydrogen depends on specimen thickness. Using wedge-shaped specimens of frozen-hydrated Nafion, a perfluorinated ionomer, saturated with the organic solvent DMMP together with both thin and thick sections of frozen-hydrated porcine skin, we show that there is a thickness below which hydrogen evolution is not detected either by bubble observation in t... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2657397 Thu, 30 Jul 2009 23:00:00 +0100 2657397 http://www.medworm.com/index.php?rid=2637669&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03197.x This paper describes modifications to a hyperspectral imaging microscope that extend its capabilities into the near-infrared (950[ndash]1300 nm). The major changes include installing a grating, charge-coupled device camera, and lenses and filters appropriate for infrared wavelengths. Calibration of the system and validation with lead sulfide quantum dots of known emission wavelength is reported. Cells from the breast carcinoma cell line SkBr3 were scanned with lead sulfide quantum dots that emit at 1100 nm as the background and an image which contains the integrated spectral data is presented. We also demonstrate that this instrument is capable of detecting the photoluminescence spectra of single-walled carbon nanotubes dispersed in aqueous solution. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2637669 Fri, 24 Jul 2009 23:00:00 +0100 2637669 http://www.medworm.com/index.php?rid=2634207&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03216.x In this study a non-conductive biological sample is observed free of charging artefacts when placed on a cooled Peltier stage in the specimen chamber of an alternative form of the environmental scanning electron microscope, equipped with a specially designed hydration system. This system was used to create dynamically changing surrounding conditions leading to controlled dehydration of the sample enabling us to visualize the topographical structure of a rat tongue in the transition region between the liquid and the gas state of water in the microscope specimen chamber. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2634207 Thu, 23 Jul 2009 23:00:00 +0100 2634207 http://www.medworm.com/index.php?rid=2634208&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03194.x A new and robust parameter estimation technique, named Gaussian-Taylor interpolation, is proposed to predict the signal-to-noise ratio (SNR) of scanning electron microscope images. The results of SNR and variance estimation values are tested and compared with piecewise cubic Hermite interpolation, quadratic spline interpolation, autoregressive moving average and moving average. Overall, the proposed estimations for noise-free peak and SNR are most consistent and accurate to within a certain acceptable degree compared with the others. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2634208 Wed, 22 Jul 2009 23:00:00 +0100 2634208 http://www.medworm.com/index.php?rid=2610736&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03191.x We present a robust and versatile method to process SPM images and reproducibly estimate nanoobject position and dimensions. This method is using dedicated fits based on the least-square method and the matrix operations. The corresponding algorithms have been implemented in the FabViewer portable application. We illustrate how these algorithms permit not only to correct SPM images but also to precisely determine the position and dimensions of nanocrystals and adatoms on surface. A robustness test is successfully performed using distorted SPM images. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610736 Thu, 16 Jul 2009 23:00:00 +0100 2610736 http://www.medworm.com/index.php?rid=2610735&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03204.x Serial block face imaging is a microscopy technique in which the top of a specimen is cut or ground away and a mosaic of images is collected of the newly revealed cross-section. Images collected from each slice are then digitally stacked to achieve 3D images. The development of fully automated image acquisition devices has made serial block face imaging more attractive by greatly reducing labour requirements. The technique is particularly attractive for studies of biological activity within cancellous bone as it has the capability of achieving direct, automated measures of biological and morphological traits and their associations with one another. When used with fluorescence microscopy, serial block face imaging has the potential to achieve 3D images of tissue as well as fluorescent marke... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610735 Thu, 16 Jul 2009 23:00:00 +0100 2610735 http://www.medworm.com/index.php?rid=2610734&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03207.x (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610734 Thu, 16 Jul 2009 23:00:00 +0100 2610734 http://www.medworm.com/index.php?rid=2610733&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03210.x Lead[ndash]calcium alloys are commonly used for their high mechanical properties, compared with pure lead. These alloys evolve quickly at room temperature and could in a few months, or years, undergo a softening (overageing). During the last decade, much research has been carried out on the subject without any unanimous results, due mainly to the diversity of the alloy's transformations and the difficulties of observation (wide range of kinetics, heterogeneity of transformations, etc.). The use of several in situ techniques developed specifically for lead alloys in our laboratories has enabled us to identify five transformations in lead[ndash]calcium alloys. The structural hardening begins by two discontinuous transformations. The first one is complete and the second one of ordering type r... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610733 Thu, 16 Jul 2009 23:00:00 +0100 2610733 http://www.medworm.com/index.php?rid=2610732&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03214.x Transmission electron microscopy specimens in the form of elongated, conical needles were made using a dual-beam focused ion beam system, allowing the specimen thickness to be geometrically determined for a range of thickness values. From the same samples electron energy loss maps were acquired and the plasmon mean free path ([lambda]) for inelastic scattering was determined experimentally from the measured values of specimen thickness. To test the method [lambda] was determined for Ni (174 ± 17 nm), [alpha]-Al2O3 (143 ± 14 nm), Si (199 ± 20 nm) and amorphous SiO2 (238 ± 12 nm), and compared both to experimental values of [lambda] taken from the literature and to calculated values. The calculated values of [lambda] significantly underestimate the true sample thickness for high accelera... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610732 Thu, 16 Jul 2009 23:00:00 +0100 2610732 http://www.medworm.com/index.php?rid=2610739&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03188.x The advent of supercontinuum laser sources has enabled the implementation of compact and tunable stimulated emission depletion fluorescence microscopes for imaging far below the diffraction barrier. Here we report on an enhanced version of this approach displaying an all-physics based resolution down to (19 ± 3) nm in the focal plane. Alternatively, this single objective lens system can be configured for 3D imaging with resolution down to 45 × 45 × 108 nm in a cell. The obtained results can be further improved by mathematical restoration algorithms. The far-field optical nanoscale resolution is attained in a variety of biological samples featuring strong variations in the local density of features. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610739 Wed, 15 Jul 2009 23:00:00 +0100 2610739 http://www.medworm.com/index.php?rid=2610738&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03200.x A stochastic version of the watershed algorithm is obtained by choosing randomly in the image the seeds from which the watershed regions are grown. The output of the procedure is a probability density function corresponding to the probability that each pixel belongs to a boundary. In the present paper, two stochastic seed-generation processes are explored to avoid over-segmentation. The first is a non-uniform Poisson process, the density of which is optimized on the basis of opening granulometry. The second process positions the seeds randomly within disks centred on the maxima of a distance map. The two methods are applied to characterize the grain structure of nuclear fuel pellets. Estimators are proposed for the total edge length and grain number per unit area, LA and NA, which take adv... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610738 Wed, 15 Jul 2009 23:00:00 +0100 2610738 http://www.medworm.com/index.php?rid=2610737&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03208.x We describe the adaptation of a commercially available light-emitting diode flashlight for use as a source for fluorescence excitation. This light source is long-lived, inexpensive and is effective for excitation in the range of 440[ndash]600 nm. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2610737 Wed, 15 Jul 2009 23:00:00 +0100 2610737 http://www.medworm.com/index.php?rid=2601626&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03192.x An image quality based method was applied to quantitatively analyse the contribution of electrodeposited copper twinning. This method, based on the image quality as obtained from electron backscattering diffraction, involves three processes: hexagonal edge detection, thinning algorithm and twin determination. The twin density determined by the new algorithm was 65.61% which is higher than the twin density, 57.44% as determined by the Orientation Imaging Microscopy (OIM) analysis. The newly developed algorithm provides an alternative to twin boundary detection. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2601626 Tue, 14 Jul 2009 23:00:00 +0100 2601626 http://www.medworm.com/index.php?rid=2591313&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03189.x Collection of the secondary electrons in the scanning electron microscope was simulated and the results have been experimentally verified for two types of the objective lens and three detection systems. The aberration coefficients of both objective lenses as well as maximum axial magnetic fields in the specimen region are presented. Compared are a standard side-attached secondary electron detector, in which only weak electrostatic and nearly no magnetic field influence the signal trajectories in the specimen vicinity, and the side-attached (lower) and upper detectors in an immersion system with weak electrostatic but strong magnetic field penetrating towards the specimen. The collection efficiency was calculated for all three detection systems and several working distances. The ability of ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2591313 Fri, 10 Jul 2009 23:00:00 +0100 2591313 http://www.medworm.com/index.php?rid=2508265&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03184.x We report here the development of instruments and protocols for carrying out high numerical aperture immersion light microscopy on cryogenic specimens. Imaging by this modality greatly increases the lifetimes of fluorescence probes, including those commonly used for protein localization studies, while retaining the ability to image the specimen with high fidelity and spatial resolution. The novel use of a cryogenic immersion fluid also minimizes the refractive index mismatch between the sample and lens, leading to a more efficient coupling of the light from the sample to the image forming system. This enhancement is applicable to both fluorescence and transmitted light microscopy techniques. The design concepts used for the cryogenic microscope can be applied to virtually any existing ligh... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2508265 Thu, 25 Jun 2009 09:04:38 +0100 2508265 http://www.medworm.com/index.php?rid=2508275&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03187.x In this study, methods of spatial statistics were used to study the spatial distribution of proliferating cells within tumour tissue quantitatively and objectively. Mammary cancer tissue was studied as an example. It was attempted to clarify whether cell division occurs entirely at random (random labelling), i.e. the process of division occurs at random, independently from the state of the neighbouring nuclei, or whether the spatial distribution of proliferation is more complex, e.g. in the form of actively proliferating clusters alternating with relatively silent zones. In the case of random labelling, the reduced second moment functions K(r) of the labelled and the unlabelled nuclei would be identical. The same would hold for the pair correlation functions g(r). The alternative hypothesi... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2508275 Sun, 21 Jun 2009 23:00:00 +0100 2508275 http://www.medworm.com/index.php?rid=2508274&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03186.x The analysis of cell motion is an essential process in fundamental medical studies because most active cellular functions involve motion. In this paper, a computer-assisted motion analysis system is proposed for cell tracking. In the proposed tracking process, unlike in conventional tracking methods, cellular states referring to the cellular life cycle are defined and appropriate strategies are adopted for cells at different states. The use of cellular state recognition allows detection of possible cell division and hence can improve the robustness of cell tracking. Experimental results show that cells can be successfully segmented and tracked over a long period of time, and the proposed system is found to be as accurate as manual tracking. Various quantitative analyses and visualizations ... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2508274 Sun, 21 Jun 2009 23:00:00 +0100 2508274 http://www.medworm.com/index.php?rid=2508273&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03185.x A simplified procedure based on Mueller-matrix polarimetry has recently been reported as a method of retinal image improvement in a confocal ophthalmoscope [J. M. Bueno et al., J. Opt. Soc. Am. A 24, 1337 (2007)]. Here, we have applied the technique to imaging static samples providing well-defined reflection properties. The method uses a generator of polarization states in the illumination pathway of a confocal scanning laser system. From the calculated four elements of the Mueller matrix of any sample and instrument combination, the best images defined by different metrics were constructed. For samples with specular, diffuse and mixed reflections, the best-constructed images showed an enhancement in both objective and subjective image quality compared to the original images and those obta... Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2508273 Sun, 21 Jun 2009 23:00:00 +0100 2508273 http://www.medworm.com/index.php?rid=2508272&cid=s_37693_166_f&fid=37693&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1365-2818.2009.03183.x We report on a chromatic axial scanning method for two-photon excitation fluorescence imaging. Effective axial scanning is achieved by incorporating a Fresnel lens in the system, which has large chromatic aberration and can therefore focus the excitation beam to different axial positions depending on its wavelength. We experimentally demonstrated this technique and used it to image the cross-section of fluorescent microspheres. (Source: Journal of Microscopy) Journal of Microscopy journals http://www.medworm.com/rss/comments.php?id=2508272 Sun, 21 Jun 2009 23:00:00 +0100 2508272