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 'Research Letters in Nanotechnology' source. Tue, 07 Feb 2012 10:30:14 +0100 http://www.medworm.com/index.php?rid=5645359&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fijhep%2F2012%2F428373%2F This study highlights the potent antioxidant properties of TD which contribute to its therapeutic effect in AFB1-induced HCC in rats. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=5645359 Wed, 01 Feb 2012 11:48:01 +0100 5645359 http://www.medworm.com/index.php?rid=5645358&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fecam%2F2012%2F762918%2F This study was conducted to determine if oral administration of the novel herbal medicine, KIOM-MA, and its Lactobacillus acidophilus-fermented product, KIOM-MA128, has therapeutic properties for the treatment of atopic dermatitis (AD). Using AD-induced BALB/c mice by Ovalbumin and aluminum hydroxide, the effectiveness of KIOM-MA and KIOM-MA128 on AD was evaluated. Oral administration of KIOM-MA and KIOM-MA128 reduced major clinical signs of AD including erythema/darkening, edema/papulation, excoriations, lichenification/prurigo, and dryness. Interestingly, KIOM-MA128 more significantly improved AD-related symptoms including decrease of IgE level in the plasma as well as reduction of scratching behavior, skin severity in the AD BALB/c model. HPLC analysis showed the significant changes in ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=5645358 Wed, 01 Feb 2012 11:48:01 +0100 5645358 http://www.medworm.com/index.php?rid=5645357&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Flci%2F2012%2F659365%2F Tobacco smoke and radioactive radon gas impose a high risk for lung cancer. The radon-derived ionizing radiation and some components of cigarette smoke induce oxidative stress by generating reactive oxygen species (ROS). Respiratory lung cells are subject to the ROS that causes DNA breaks, which subsequently bring about DNA mutagenesis and are intimately linked with carcinogenesis. The damaged cells by oxidative stress are often destroyed through the active apoptotic pathway. However, the ROS also perform critical signaling functions in stress responses, cell survival, and cell proliferation. Some molecules enhance radiation-induced tumor cell killing via the reduction in DNA repair levels. Hence the DNA repair levels may be a novel therapeutic modality in overcoming drug resistance in lun... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=5645357 Wed, 01 Feb 2012 11:48:01 +0100 5645357 http://www.medworm.com/index.php?rid=5579447&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Farp%2F2012%2F708754%2F We hypothesized that combined peripheral nerve block (CPNB) technique might reduce mortality in hip fracture patients with the advantage of preserved cardiovascular stability. We retrospectively analyzed 257 hip fracture patients for mortality rates and affecting factors according to general anesthesia (GA), neuraxial block (NB), and CPNB techniques. Patients’ gender, age at admission, trauma date, ASA status, delay in surgery, followup period, and Barthel Activities of Daily Living Index were determined. There were no differences between three anesthesia groups regarding to sex, followup, delay in surgery, and Barthel score. NB patients was significantly younger and CPNB patients’ ASA status were significantly worse than other groups. Mortality was lower for regional group (NB + CPNB)... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=5579447 Thu, 12 Jan 2012 14:38:32 +0100 5579447 http://www.medworm.com/index.php?rid=5103289&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fcggr%2F2011%2F979270%2F Type 2 diabetes is associated with higher fracture risk. Diabetes-related conditions may account for this risk. Cardiovascular Health Study participants (N=5641; 42.0% men; 15.5% black; 72.8±5.6 years) were followed 10.9 ± 4.6 years. Diabetes was defined as hypoglycemic medication use or fasting glucose (FG) ≥126 mg/dL. Peripheral artery disease (PAD) was defined as ankle-arm index <0.9. Incident hip fractures were from medical records. Crude hip fracture rates (/1000 person-years) were higher for diabetic vs. non-diabetic participants with BMI <25 (13.6, 95% CI: 8.9–20.2 versus 11.4, 95% CI: 10.1–12.9) and BMI ≥25 to <30 (8.3, 95% CI: 5.7–11.9 versus 6.6, 95% CI: 5.6–7.7), but similar f... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=5103289 Sun, 07 Aug 2011 09:32:47 +0100 5103289 http://www.medworm.com/index.php?rid=4984289&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fisrn%2Fobgyn%2F2011%2F345431%2F Conclusion. HFUPR falls before and in relation to the time of onset of labor rather than in relation to gestational age. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=4984289 Thu, 30 Jun 2011 16:47:47 +0100 4984289 http://www.medworm.com/index.php?rid=4813113&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Faav%2F2011%2F276898%2F Exposure to whole-body vibration (WBV) is associated with a wide variety of health disorders and as a result WBV levels are frequently assessed. Literature outlining WBV accelerations rarely address the calibration techniques and procedures used for WBV sensors to any depth, nor are any detailed information provided regarding such procedures or sensor calibration ranges. The purpose of this paper is to describe a calibration method for a 6 DOF transducer using a hexapod robot. Also described is a separate motion capture technique used to verify the calibration for acceleration values obtained which were outside the robot calibration range in order to include an acceptable calibration range for WBV environments. The sensor calibrated in this study used linear (Y=mX) calibration equations re... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=4813113 Thu, 12 May 2011 11:25:12 +0100 4813113 http://www.medworm.com/index.php?rid=4309498&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F579708.html In the absence of another (photo)radical initiator Sb:SnO2 nanoparticles (0≤Sb≤13 at %) photocatalyze during irradiation with UV light the radical polymerization of (meth)acrylate monomers. When cured hard and transparent (>98%) films with a low haze (<1%) are required, when these particles are grafted in advance with 3-methacryloxypropyltrimethoxysilane (MPS) and doped with Sb. Public knowledge about the photocatalytic properties of Sb:SnO2 nanoparticles is hardly available. Therefore, the influence of particle concentration, surface groups, and Sb doping on the rate of C=C (meth)acrylate bond polymerization was determined with aid of real-time FT-IR spectroscopy. By using a wavelength of irradiation with a narrow bandgab (315±5 nm) th... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=4309498 Wed, 05 Jan 2011 01:59:24 +0100 4309498 http://www.medworm.com/index.php?rid=4294478&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F256906.html Recent research in plasma chemical vapor deposition (CVD) for single-walled carbon nanotube (SWNT) growth has achieved low-temperature synthesis, individually freestanding formation, and structure control of diameter, chirality, and length. Detailed growth kinetics of SWNTs are revealed using a combination of techniques for plasma control and nanomaterial analysis. Plasma CVD also allows tube metallicity to be controlled by tuning the mean diameter of SWNTs. This plasma CVD progress contributes to the next stage of nanotube fabrication, which is required for practical use of SWNTs in a variety of applications. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=4294478 Wed, 29 Dec 2010 06:20:35 +0100 4294478 http://www.medworm.com/index.php?rid=4031123&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F420432.html Curing kinetic of an epoxy resin reinforced with amino-functionalized MWCNTs has been studied by DSC and the obtained results were explained through morphological studies carried out by SEM, TEM, FEG-SEM, and molecular simulation tools. The presence of MWCNTs in the curing reaction induces a retardation effect of curing reaction and a decrease of the reaction heat. Both are associated with the adsorption of curing agent molecules inside carbon nanotubes, which was proved through the application of electron microscopic techniques and molecular simulation tools. It has been also demonstrated that there is a chemical reaction between amine groups anchored to the nanotubes and oxirane rings of epoxy monomer, which improves the nanoreinforcement/matrix interfacial adhesion, appearing a chemical... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=4031123 Tue, 05 Oct 2010 16:00:57 +0100 4031123 http://www.medworm.com/index.php?rid=3802313&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F279608.html New TEM grids coated with ultrathin amorphous Al2O3 films have been developed using atomic layer deposition technique. The amorphous Al2O3 films can withstand temperatures over 600∘C in air and 900∘C in vacuum when the thickness of the Al2O3 film is 2 nm, and up to 1000∘C in air when the thickness is 25 nm, which makes heating TEM grids with nanoparticles up to 1000∘C in air and immediate TEM observation without interrupting the nanoparticles possible. Such coated TEM grids are very much desired for applications in high-temperature high-resolution transmission electron microscopy. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3802313 Fri, 30 Jul 2010 08:22:57 +0100 3802313 http://www.medworm.com/index.php?rid=3772138&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F868492.html Using a combination of continuum modeling, atomistic simulations, and numerical optimization, we estimate the flexural rigidity of a graphene sheet. We consider a rectangular sheet that is initially parallel to a rigid substrate. The sheet interacts with the substrate by van der Waals forces and deflects in response to loading on a pair of opposite edges. To estimate the flexural rigidity, we model the graphene sheet as a continuum and numerically solve an appropriate differential equation for the transverse deflection. This solution depends on the flexural rigidity. We then use an optimization procedure to find the value of the flexural rigidity that minimizes the difference between the numerical solutions and the deflections predicted by atomistic simulations. This procedure predicts a f... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3772138 Wed, 21 Jul 2010 08:09:49 +0100 3772138 http://www.medworm.com/index.php?rid=3611871&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F487193.html The epitaxial growth of Pt and Ru deposits by spontaneous, as well as by dynamic, electrodeposition onto Ru(0001) and Pt(111), respectively, have been studied by reflection high energy electron diffraction (RHEED) and Auger electron spectroscopy (AES). For the Pt deposit on Ru(0001), at submonolayer range, it preferably grows compressed commensurate bilayer thick islands on Ru(0001). This is the first time that RHEED observation of the onset of Pt twinning occurs in ca. 2-3 layer thick islands on Ru at room temperature, at which the surface strain due to the 2.5% lattice mismatch of Pt and Ru remains intact. For multilayer thick islands (>6 ML) ordered reflection twins (diameter of ∼3 nm) develop and are embedded in a (111) matrix with an incoherent (11-2) twin... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3611871 Sun, 30 May 2010 15:20:28 +0100 3611871 http://www.medworm.com/index.php?rid=3529685&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F492074.html In order to apply Radio Frequency Micro-nano-Electro-Mechanical System (MEMS/NEMS) technologies to produce miniature, high isolation, low insertion loss, good linear characteristic, and low power consumption microwave switches, we present a novel NEMS switch with nanoscaling in this paper through the analysis of electrics and mechanics of the RF switch. The measured data show the pull-in voltage of 24.1 V and the good RF performance of the insertion loss of below −10 dB at 0 GHz on the “on” state, and the isolation of beyond –40 dB at 0–40 GHz on the “off” state, indicating that the witch is suitable for the 0–40 GHz applications. Our analysis shows that the NEMS switch not only c... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3529685 Tue, 04 May 2010 15:25:44 +0100 3529685 http://www.medworm.com/index.php?rid=3457809&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F531284.html Polyacrylates have become the preferred materials for optical applications replacing the conventionally used glass due to their superior optical clarity. The major disadvantage with polyacrylates is their low (1.40–1.50) refractive index besides their poor impact resistance. The improvements in refractive index as well as mechanical properties can be achieved by way of incorporation of metals or metal compounds in the matrix. A novel methodology for the incorporation of high refractive index metals into low refractive index polymeric materials to improve the refractive index and impact resistance of the latter has been developed. With the in-situ formation of nanoparticles of TiO2, the refractive index of polyacrylates improved from 1.45 to 1.53 and the Abbe number increased from 40 ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3457809 Sun, 11 Apr 2010 15:38:33 +0100 3457809 http://www.medworm.com/index.php?rid=3398812&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F605362.html The paper presents the results of X-ray diffraction analysis of nonequilibrium structural and elastic stress states in TiNi surface layers irradiated by low-energy electron beams. It is found that a surface layer with a mixed (2D columnar and 3D equiaxial) submicrocrystalline structure is formed on the irradiated side of the TiNi specimens, and the volume fractions of the two structure types depend on the beam energy parameters and number of pulses. The B2 phase synthesized in the layer is characterized by lattice microstrain due to stresses of the first and second kinds (εI≈±1%, εII=0.25%), and the layer as such is an internal stress concentrator for underlying layers of the material. In the intermediate layer beneath the stress concentrator, rela... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3398812 Wed, 24 Mar 2010 16:58:04 +0100 3398812 http://www.medworm.com/index.php?rid=3386849&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F479172.html Hierarchical MnO2 microfibers were prepared by using cotton as the template and KMnO4 as the precursor via an ultrasonic assistance route. The results of scanning electron microscope characterization showed that the concentration of KMnO4 had a significant effect on the morphology of MnO2 microfiber. At low concentration of KMnO4, the microfiber was composed of MnO2 nanorods with single crystal structure. With increasing the concentration of KMnO4, the secondary nanostructure of MnO2 microfibers had a transformation from nanorod to nanoparticle. The results of N2 adsorption-desorption analysis indicated that MnO2 microfibers had BET surface area of about 25 m2/g. This synthesis provides a new way to control the secondary nanostructure of MnO2 microfiber by adjusting the concentratio... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3386849 Sun, 21 Mar 2010 17:37:44 +0100 3386849 http://www.medworm.com/index.php?rid=3374038&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F176517.html Pure lithium iron phosphate (LiFePO4) and carbon-coated LiFePO4 (C-LiFePO4) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO4 and C-LiFePO4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO4 where as in case of C-LiFePO4 that ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3374038 Wed, 17 Mar 2010 17:09:15 +0100 3374038 http://www.medworm.com/index.php?rid=3366113&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F953212.html We present the design and the fabrication of a novel 1×2 nanophotonic switch. The switch is a photonic T-junction in which a gold nano particle is being positioned in the junction using the tip of an atomic force microscope (AFM). The novelty of this 1×2 switch is related to its ability to control the direction of wave that propagates along a photonic structure. The selectivity of the direction is determined by a gold nanoparticle having dimension of a few tens of nanometer. This particle can be shifted. The shift of the gold nano particle can be achieved by applying voltage or by illuminating it with a light source. The shifts of the particle, inside the air gap, direct the input beam ones to the left output of the junction and once to its right output. Three types of simula... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3366113 Mon, 15 Mar 2010 17:08:50 +0100 3366113 http://www.medworm.com/index.php?rid=3322260&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2010%2F860178.html Pitch-based carbon fibers are commonly used to produce polymeric carbon fiber structural composites. Several investigations have reported different methods for dispersing and subsequently aligning carbon nanotubes (CNTs) as a filler to reinforce polymer matrix. The significant difficulty in dispersing CNTs suggested the controlled-growth of CNTs on surfaces where they are needed. Here we compare between two techniques for depositing the catalyst iron used toward growing CNTs on pitch-based carbon fiber surfaces. Electrochemical deposition of iron using pulse voltametry is compared to DC magnetron iron sputtering. Carbon nanostructures growth was performed using a thermal CVD system. Characterization for comparison between both techniques was compared via SEM, TEM, and Raman spectroscopy an... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3322260 Tue, 02 Mar 2010 18:15:56 +0100 3322260 http://www.medworm.com/index.php?rid=3275716&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F593410.html In this study, a UV-cured methacrylate copolymer was developed for use in creating replicas of living cells and was tested on rat muscle cells. Bioimprints of muscle cells were formed by spin coating under UV irradiation. The polymer replicas were then separated from the muscle cells and were analyzed under an Atomic Force Microscope (AFM), in tapping mode, because it has low tip-sample forces and thus will not destroy the fine structures of the imprint. The new polymer is biocompatible with higher replication resolution and has a faster curing process than other types of silicon-based organic polymers such as PDMS. High resolution images of the muscle cell imprints showed the micro-and nanostructures of the muscle cells, including cellular fibers and structures within the cell membranes. ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3275716 Tue, 16 Feb 2010 16:51:56 +0100 3275716 http://www.medworm.com/index.php?rid=3251127&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F769142.html Silicon nanocrystals (Si-nc) embedded in a silicon-rich silicon oxide matrix codoped with Er3+ ions have been fabricated by electron-cyclotron plasma-enhanced chemical vapor deposition. Indirect excitation of erbium photoluminescence via silicon nanocrystals has been obtained within a broad pump wavelength range. The influence of different nanocrystal sizes on the excitation transfer from the Si-nc to Er3+ ions is discussed. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3251127 Mon, 08 Feb 2010 17:07:27 +0100 3251127 http://www.medworm.com/index.php?rid=3208248&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F794740.html We report improving ballistic performance of polyurethane foam by reinforcing it with nanoscale TiO2 particles. Particles were dispersed through a sonic cavitation process and the loading of particles was 3 wt% of the total polymer. Once foams were reinforced, sandwich panels were made and impacted with fragment simulating projectiles (FSPs) in a 1.5-inch gas gun. Projectile speed was set up to have complete penetration of the target in each experiment. Test results have indicated that sandwich with nanophased cores absorbed about 20% more kinetic energy than their neat counterpart. The corresponding increase in ballistic limit was around 12% over the neat control samples. The penetration phenomenon was also monitored using a high-speed camera. Analyses of digital image... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3208248 Tue, 26 Jan 2010 17:00:10 +0100 3208248 http://www.medworm.com/index.php?rid=3066950&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F827174.html We report a method of patterning the 1D and 2D arrays of gold nanoparticles on the DNA self-assembled scaffolds. The 5 nm gold nanoparticle was well positioned at the center of each 4×4 tile motif of the DNA scaffold. The precisely located gold particles can form 1D and 2D arrays. This controllable scaffolding technology may become a promising tool for nanoscaled fabrication of electronics and photonic devices. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066950 Tue, 08 Dec 2009 16:24:22 +0100 3066950 http://www.medworm.com/index.php?rid=3066949&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F527294.html This report describes the viability of a strategy for manipulating the assembly/disassembly processes of DNA-Au nanoparticles by molecular intervention. Using the temperature-induced assembly and disassembly processes of DNAs and gold nanoparticles as a model system, the introduction of a molecular recognition probe is demonstrated to lead to the intervention of the assembly/disassembly processes depending on its specific biorecognition. This process can be detected by monitoring the change in the optical properties of gold nanoparticles and their DNA assemblies. Implications of the preliminary results to exploration of the resulting nanostructures for fine-tuning of the interfacial reactivities in DNA-based bioassays and biomaterial engineering are also discussed. (Source: Research Letter... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066949 Tue, 08 Dec 2009 16:24:22 +0100 3066949 http://www.medworm.com/index.php?rid=3066948&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F853253.html Inelastic electron tunneling spectroscopy (IETS) is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nanoelectronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable system... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066948 Tue, 08 Dec 2009 16:24:22 +0100 3066948 http://www.medworm.com/index.php?rid=3066947&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F789153.html Devices based on nanomaterials are emerging as a powerful and general class of ultrasensitive sensors for the direct detection of biological and chemical species. In this work, we report the preparation and the full characterization of nanomaterials such as gold nanowires and TiO2 nanostructured films to be used for assembling of electrochemical biosensors. Gold nanowires were prepared by electroless deposition within the pores of polycarbonate particle track-etched membranes (PTMs). Glucose oxidase was deposited onto the nanowires using self-assembling monolayer as an anchor layer for the enzyme molecules. Finally, cyclic voltammetry was performed for different enzymes to test the applicability of gold nanowires as biosensors. Considering another interesting nanomaterial, the realization ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066947 Tue, 08 Dec 2009 16:24:22 +0100 3066947 http://www.medworm.com/index.php?rid=3066946&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F756843.html Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray-pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order-of-magnitude (from 200 to 20 nm) smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066946 Tue, 08 Dec 2009 16:24:22 +0100 3066946 http://www.medworm.com/index.php?rid=3066945&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F974072.html The fluorescence of emitters embedded in a photonic crystal is known to be inhibited by the presence of an incomplete photonic band gap or pseudogap acting in their emission range. Here, we present a study of the angular dependence of the fluorescence emission of emitters embedded in a photonic crystal. Our results clearly show an angular dependence of the fluorescence emission, which is caused by the presence of an incomplete 3D band gap. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066945 Tue, 08 Dec 2009 16:24:22 +0100 3066945 http://www.medworm.com/index.php?rid=3066944&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F296928.html An apparent enhanced solubility of single-wall carbon nanotubes (SWNTs) in the deuterated form of the standard 3 : 1 sulfuric (H2SO4) to nitric (HNO3) acid mixture treatment is reported and attributed to the stronger interaction of deuterium bonds with the single-wall carbon nanotube surface. UV-Visible spectroscopy was used to characterize the apparent enhanced solubility of the SWNTs treated in deuterated forms of the acid mixture in comparison to the standard acid mix, while FTIR was used to analyze the nature of the functional groups generated on the SWNTs as a result of the different acid treatments. The apparent enhanced solubility reported here is consistent with the limited number of computational and experimental results published in the literature regarding the interaction of car... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066944 Tue, 08 Dec 2009 16:24:22 +0100 3066944 http://www.medworm.com/index.php?rid=3066943&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F516478.html The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, and N2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumi... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066943 Tue, 08 Dec 2009 16:24:22 +0100 3066943 http://www.medworm.com/index.php?rid=3066942&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F765398.html Discrete track media (DTM) fabricated by nanoimprint lithography (NIL) is considered as a potential technology for future hard disk drives (HDD). In the fabrication of a master mold for NIL, patterning the resist tracks with a narrow distribution in the width is the first critical step. This paper reports the challenges involved in the fabrication of high aspect ratio discrete tracks on Polymethylmethacrylate (PMMA) resist by means of electron beam lithography. It was observed that fabrication parameters applied for successful patterning of discrete tracks in nanoscale length were not directly suitable for the patterning of discrete tracks in micron scale. Hence different approaches such as thick layer resist coating, introducing of post exposure baking process, and varying of exposure par... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066942 Tue, 08 Dec 2009 16:24:22 +0100 3066942 http://www.medworm.com/index.php?rid=3066941&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F156358.html The possibility of using single-walled carbon nanotubes (SWCNTs) aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV-11 on single-walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant (k) for S.aureus and E.coli determined from batch adsorption study was found to be 9×108 and 2×108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The res... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066941 Tue, 08 Dec 2009 16:24:22 +0100 3066941 http://www.medworm.com/index.php?rid=3066940&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F389512.html Polyethylene terephthalate-polylactic acid copolymer (PET-PLA) was synthesized from bis (2-hydroxyethyl terephthalate) and L-lactic acid oligomer in the presence of manganese antimony glycoxide as a catalyst. The synthesized PET-PLA copolymer was used for controlled drug release systems with gold nanoparticles. Fluorouracil containing PET-PLA nanocapsules was prepared in the presence of gold nanoparticles by solvent evaporation method. The morphologies of the nanocapsules were characterized using scanning electron microscopy and transmission electron microscopy. Controlled release of Fu and Fu@Au was carried out in 0.1 M phosphate buffer (pH 7.4) and 0.1 M HCl solution. The results indicated that the drug release for gold nanoparticles/fluorouracil (Au@Fu) incorporated PET-PL... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066940 Tue, 08 Dec 2009 16:24:22 +0100 3066940 http://www.medworm.com/index.php?rid=3066939&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F138468.html In this work, TiO2 nanocrystals were synthesized by the sol-gel method. These materials were annealed at 200 and 500∘C; and characterized by the XRD-Rietveld refinement; and by BET and TEM. As for the low-temperature-treated sample (200∘C), nanocrystals with small crystallite sizes (7 nm) and high abundance of anatase, coexisting with the brookite phase, were obtained. Meanwhile, the sample annealed at 500∘C showed an increased crystallite size (22 nm) and an important polymorphic increment. The sample annealed at 200∘C showed a high activity in the photocatalytic decomposition of acetaldehyde. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066939 Tue, 08 Dec 2009 16:24:22 +0100 3066939 http://www.medworm.com/index.php?rid=3066938&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F217510.html The molybdenum trioxide (MoO3) thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066938 Tue, 08 Dec 2009 16:24:22 +0100 3066938 http://www.medworm.com/index.php?rid=3066937&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F492478.html A convenient lithographic technique is proposed in this paper, which can be used to produce subdiffraction-limit arrays of nanopatterns over large areas (about several square centimeters). An array of polystyrene spheres (PS) is arranged on the surface of a layer of silver which has a thickness of about tens of nanometers. With the normal illumination light of wavelength 365 nm perpendicular to the substrate, PS can generate an array of optical patterns with high intensity at their contact points with silver. By designing the silver slab, the evanescent waves that carry subwavelength information about the optical patterns are substantially enhanced, while propagating components are restrained. In the photoresist which is on the other side of silver, the optical intensity is redistri... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066937 Tue, 08 Dec 2009 16:24:22 +0100 3066937 http://www.medworm.com/index.php?rid=3066936&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F734940.html FeTi clusters with a diameter of less than 10 nm and covered with a graphitic layer have been preferentially produced in an H2 gas atmosphere at pressures of 10 and 26.6 kPa by the simultaneous evaporation of Fe and Ti wires from a concave carbon boat. To compare this result with cluster formation in an inert gas atmosphere, the result for an Ar gas pressure of 10 kPa is also discussed. The formation of disordered FeNi clusters predominately took place in an H2 gas atmosphere. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066936 Tue, 08 Dec 2009 16:24:22 +0100 3066936 http://www.medworm.com/index.php?rid=3066935&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2008%2F701813.html Zinc oxide nanorods with 100 nm diameter and 900 nm length were grown on the surface of a silver wire (0.25 mm in diameter) with the aim to produce electrochemical nanosensors. It is shown that the ZnO nanorods exhibit a Ca2+-dependent electrochemical potentiometric behavior in an aqueous solution. The potential difference was found to be linear over a large logarithmic concentration range (1 μM to 0.1 M) using Ag/AgCl as a reference electrode and the response time was less than one minute. In order to adapt the sensors for calcium ion measurements in biological fluids with sufficient selectivity and stability, plastic membrane coatings containing ionophores were applied. These functionalized ZnO nanorods sensors showed a high sensitivity (26.55&#x... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066935 Tue, 08 Dec 2009 16:24:22 +0100 3066935 http://www.medworm.com/index.php?rid=3066934&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F971423.html A new single source approach was developed to synthesize Pd-Co nanoparticles using a bimetallic compound, [Et3NH]2[CoPd2(μ-4-I-3,5-Me2pz)4Cl4] (CoPd2), as a molecular precursor to obtain dispersed catalyst on highly ordered pyrolytic graphite (HOPG) surface, in view of preparing oxygen reduction catalysts for low temperature fuel cells. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques were employed to characterize the nanostructure formations and to determine the composition and morphology of the complex on the HOPG. Results of high resolution XPS analysis (HR-XPS) revealed the binding energies corresponding to the atomic constituents of the precursor. When the precursor solution was placed on the surface of the HOPG, the bimetall... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066934 Tue, 08 Dec 2009 16:24:22 +0100 3066934 http://www.medworm.com/index.php?rid=3066933&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F540257.html We have measured temperature-dependent (between 20 and 80∘C) electrical conductivity and molecular structure (Raman spectroscopy) of DNA-lipid cast film. Our findings show that the conductivity is strongly influenced by premelting effects in the molecular structure starting near physiological temperatures (∼40∘C), prior to the global DNA denaturation. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066933 Tue, 08 Dec 2009 16:24:22 +0100 3066933 http://www.medworm.com/index.php?rid=3066932&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F405153.html The significant factor that determines the improvement of properties in rubber by the incorporation of nanoclay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nanoclay will not contribute for the good dispersion of nanofiller in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nanoclay in the matrix polymer. Epoxidized natural rubber and organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay employed in this study is Cloisite 20A. The obtained nanocomposites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray dif... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066932 Tue, 08 Dec 2009 16:24:22 +0100 3066932 http://www.medworm.com/index.php?rid=3066931&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F313962.html Preparation and electrocatalytic reactions of nanoporous materials in biodegradable fluids were studied. Electrochemical etching was conducted to selectively extract metallic elements from alloys to form porous structures. Electrocatalytic properties of the porous electrodes were characterized. Comparative studies on the electrochemical activities of the nanoporous metallic electrodes with bulk metallic wire catalysts were performed. It is found that the current density at the nanoporous electrode is three times higher than that of the bulk electrode. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066931 Tue, 08 Dec 2009 16:24:22 +0100 3066931 http://www.medworm.com/index.php?rid=3066930&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F373986.html The influence of different activation conditions, including activating agent/CNFs ratio, activation temperature, and He flow rate, on the pore structure development of herringbone carbon nanofibers (CNFs) was studied. The best results of activated CNFs with larger specific surface area can be achieved using the following optimized factors: RbOH/CNFs ratio = 4/1, activation temperature = 900∘C ,and a He flow rate = 850 ml/min. The optimization of these three factors leads to high CNFs micropore volume, being the surface area increased by a factor of 3 compared to the raw CNFs. It is important to note that only the creation of micropores (ultramicropores principally) took place, and mesopores were not generated if compared with raw CNFs. (Source: Research Letters in Nanotechnol... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066930 Tue, 08 Dec 2009 16:24:22 +0100 3066930 http://www.medworm.com/index.php?rid=3066929&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F614301.html Protein self-assembly into highly ordered fibrillar aggregates has attracted increasing attention over recent years, due primarily to its association with disease states such as Alzheimer's. More recently, however, research has focused on understanding the generic behavior of protein self-assembly where fibrillation is typically induced under harsh conditions of low pH and/or high temperature. Moreover the inherent properties of these fibrils, including their nanoscale dimension, environmental responsiveness, and biological compatibility, are attracting substantial interest for exploiting these fibrils for the creation of new materials. Here we will show how protein fibrils can be formed under physiological conditions and their subsequent gelation driven using the ionic strength of cel... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066929 Tue, 08 Dec 2009 16:24:22 +0100 3066929 http://www.medworm.com/index.php?rid=3066928&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F280797.html Amorphous TiO2 thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at 250∘C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density. By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analytical extrapolation to the fully crystallized state. Electron diffractio... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066928 Tue, 08 Dec 2009 16:24:22 +0100 3066928 http://www.medworm.com/index.php?rid=3066927&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F709748.html The formation of polydimethylsiloxanes (PDMSs)-based layer-by-layer multilayer ultrathin films on charged surfaces prepared from water and phosphate buffer solutions has been investigated. The multilayer films prepared under these conditions showed different surface roughness. Nanoscale islands and network structures were observed homogeneously on the multilayer film prepared from pure water solutions, which is attributing to the ultrahydrobic property of the multilayer film. The formation of nanoscale islands and network structures was due to the aggregation of PDMS-based polyelectrolytes in water. This work provides a facile approach for generating ultrahydrophobic thin films on any charged surfaces by PDMS polyelectrolytes. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066927 Tue, 08 Dec 2009 16:24:22 +0100 3066927 http://www.medworm.com/index.php?rid=3066926&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F590763.html Femtosecond laser ablation hydrodynamics has been analyzed numerically. The nucleation process of two materials (silicon and graphite) in an expanding plume produced by a femtosecond laser ablation is analyzed within the framework of the Zeldovich-Raizer theory (RZ theory). RZ theory is the most appropriate theory applicable to an expanding plume created by a femtosecond laser ablation and has been used to estimate the critical times in the evolution of nanoparticle formation. However, there is no experimental result to directly substantiate the theoretical model on a fundamental level. This paper gives an experimental approach to prove theoretical predictions of critical times to nucleation in laser-ablated graphite and silicon plumes. The critical time to nucleation deduced using the RZ ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066926 Tue, 08 Dec 2009 16:24:22 +0100 3066926 http://www.medworm.com/index.php?rid=3066925&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F217469.html A new and effective method has been developed where self-assembled gold nanoparticles (Au-NPs) of ∼10 nm diameter are successfully attached onto the surface of sidewalls and ends of thiol-terminated multi-walled carbon nanotubes (MWNTs) functionalized with orthomercaptoaniline, acting as a bridging agent. It can bridge the carbon nanotubes (CNTs) and Au-NPs via the bi-functional moiety with benzene unit at one end and thiol group at the other end by self-assembly. The ortho-mercaptoaniline was first grafted onto the surface of the CNTs via π-π interaction between the benzene ring of the mercaptoaniline and π-conjugated body of MWNTs surface to produce thiol-terminated CNTs. The bare surface of Au-NPs facilitates to attach on the thiol group of the thiol-... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066925 Tue, 08 Dec 2009 16:24:22 +0100 3066925 http://www.medworm.com/index.php?rid=3066924&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F149691.html Different electrochemical regimes and porous alumina were applied for template synthesis of cobalt nanowire (nw) arrays, revealing several peculiar cases. In contrast to quite uniform filling of sulfuric acid alumina templates by alternating current deposition, nonuniform growth of the Co nw tufts and mushrooms was obtained for the case of oxalic acid templates. We showed herein for the first time that such configurations arise from the spontaneous growth of cobalt nw groups evolving from the cobalt balls at the Al/alumina interface. Nevertheless, the uniform growth of densely packed cobalt nw arrays, up to tens of micrometers in length, was obtained via long-term direct current galvanostatic deposition at low current density using oxalic acid templates one-side coated by conducting layer.... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066924 Tue, 08 Dec 2009 16:24:22 +0100 3066924 http://www.medworm.com/index.php?rid=3066923&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F184702.html Recent research on biosystems at the nanoscale has created one of the most dynamic science and technology domains at the confluence of physical sciences, molecular engineering, biology, biotechnology, and medicine. This domain includes better understanding of living and thinking systems, revolutionary biotechnology processes, synthesis of new drugs and their targeted delivery, regenerative medicine, neuromorphic engineering, and developing a sustainable environment. Nanobiosystems research is a priority in many countries and its relevance within nanotechnology is expected to increase in the future. The realisation that the nanoscale has certain properties needed to solve important medical challenges and cater to unmet medical needs is driving nanomedical research. The present review explor... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066923 Tue, 08 Dec 2009 16:24:22 +0100 3066923 http://www.medworm.com/index.php?rid=3066922&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F238536.html Drug-carrying magnetic nanocomposite spheres were synthesized using magnetite nanoparticles and poly (D,L-lactide-co-glycolide) (PLGA) for the purpose of magnetic targeted drug delivery. Magnetic nanoparticles (∼13 nm on average) of magnetite were prepared by a chemical coprecipitation of ferric and ferrous chloride salts in the presence of a strong basic solution (ammonium hydroxide). An oil-in-oil emulsion/solvent evaporation technique was conducted at 7000 rpm and 1.5–2 hours agitation for the synthesis of nanocomposite spheres. Specifically, PLGA and drug were first dissolved in acetonitrile (oily phase I) and combined with magnetic nanoparticles, then added dropwise into viscous paraffin oil combined with Span 80 (oily phase II). With different contents (0&#... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066922 Tue, 08 Dec 2009 16:24:22 +0100 3066922 http://www.medworm.com/index.php?rid=3066921&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fjnt%2F2009%2F759374.html Multiwall carbon nanotubes (MWNTs) were modified with polycarbosilane-derived silicon carbide (SiC) to improve its dispersion in the polymer matrix. PEEK/LCP/MWNTs nanocomposites were prepared by melt blending. TEM images show the improved dispersion of SiC-coated MWNTs against agglomerated structure of pure MWNTs in the blend. FESEM images shows better fibrillation of LCP in presence of SiC-coated MWNTs. TGA reveals that nanocomposites with SiC-coated MWNTs shows higher thermal stability than MWNTs filled blend system. Based on enhanced dispersion, storage modulus, tensile modulus and tensile strength were increased drastically with the incorporation of SiC-coated MWNTs. Glass transition temperature of the nanocomposites shows significant improvement with the incorporation of MWNTs. (Sour... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=3066921 Tue, 08 Dec 2009 16:24:22 +0100 3066921 http://www.medworm.com/index.php?rid=2882951&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F280797.html Amorphous TiO2 thin films were radio frequency sputtered onto siliconmonoxide and carbon support films on molybdenum transmission electron microscope (TEM) grids and observed during in situ annealing in a TEM heating stage at 250∘C. The evolution of crystallization is consistent with a classical model of homogeneous nucleation and isotropic grain growth. The two-dimensional grain morphology of the TEM foil allowed straightforward recognition of amorphous and crystallized regions of the films, for measurement of crystalline volume fraction and grain number density. By assuming that the kinetic parameters remain constant beyond the onset of crystallization, the final average grain size was computed, using an analytical extrapolation to the fully crystallized state. Electron diffractio... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2882951 Mon, 12 Oct 2009 15:20:27 +0100 2882951 http://www.medworm.com/index.php?rid=2747890&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F614301.html Protein self-assembly into highly ordered fibrillar aggregates has attracted increasing attention over recent years, due primarily to its association with disease states such as Alzheimer's. More recently, however, research has focused on understanding the generic behavior of protein self-assembly where fibrillation is typically induced under harsh conditions of low pH and/or high temperature. Moreover the inherent properties of these fibrils, including their nanoscale dimension, environmental responsiveness, and biological compatibility, are attracting substantial interest for exploiting these fibrils for the creation of new materials. Here we will show how protein fibrils can be formed under physiological conditions and their subsequent gelation driven using the ionic strength of cel... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2747890 Mon, 31 Aug 2009 14:02:06 +0100 2747890 http://www.medworm.com/index.php?rid=2645201&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F373986.html The influence of different activation conditions, including activating agent/CNFs ratio, activation temperature, and He flow rate, on the pore structure development of herringbone carbon nanofibers (CNFs) was studied. The best results of activated CNFs with larger specific surface area can be achieved using the following optimized factors: RbOH/CNFs ratio = 4/1, activation temperature = 900∘C ,and a He flow rate = 850 ml/min. The optimization of these three factors leads to high CNFs micropore volume, being the surface area increased by a factor of 3 compared to the raw CNFs. It is important to note that only the creation of micropores (ultramicropores principally) took place, and mesopores were not generated if compared with raw CNFs. (Source: Research Letters in Nanotechnol... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2645201 Tue, 28 Jul 2009 12:43:38 +0100 2645201 http://www.medworm.com/index.php?rid=2593076&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F313962.html Preparation and electrocatalytic reactions of nanoporous materials in biodegradable fluids were studied. Electrochemical etching was conducted to selectively extract metallic elements from alloys to form porous structures. Electrocatalytic properties of the porous electrodes were characterized. Comparative studies on the electrochemical activities of the nanoporous metallic electrodes with bulk metallic wire catalysts were performed. It is found that the current density at the nanoporous electrode is three times higher than that of the bulk electrode. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2593076 Sun, 12 Jul 2009 12:20:10 +0100 2593076 http://www.medworm.com/index.php?rid=2580133&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F405153.abs.html The significant factor that determines the improvement of properties in rubber by the incorporation of nanoclay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nanoclay will not contribute for the good dispersion of nanofiller in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nanoclay in the matrix polymer. Epoxidized natural rubber and organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay employed in this study is Cloisite 20A. The obtained nanocomposites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray dif... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2580133 Wed, 08 Jul 2009 12:31:14 +0100 2580133 http://www.medworm.com/index.php?rid=2469022&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F827174.html We report a method of patterning the 1D and 2D arrays of gold nanoparticles on the DNA self-assembled scaffolds. The 5 nm gold nanoparticle was well positioned at the center of each 4×4 tile motif of the DNA scaffold. The precisely located gold particles can form 1D and 2D arrays. This controllable scaffolding technology may become a promising tool for nanoscaled fabrication of electronics and photonic devices. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469022 Wed, 10 Jun 2009 08:26:04 +0100 2469022 http://www.medworm.com/index.php?rid=2469021&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F527294.html This report describes the viability of a strategy for manipulating the assembly/disassembly processes of DNA-Au nanoparticles by molecular intervention. Using the temperature-induced assembly and disassembly processes of DNAs and gold nanoparticles as a model system, the introduction of a molecular recognition probe is demonstrated to lead to the intervention of the assembly/disassembly processes depending on its specific biorecognition. This process can be detected by monitoring the change in the optical properties of gold nanoparticles and their DNA assemblies. Implications of the preliminary results to exploration of the resulting nanostructures for fine-tuning of the interfacial reactivities in DNA-based bioassays and biomaterial engineering are also discussed. (Source: Research Letter... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469021 Wed, 10 Jun 2009 08:26:04 +0100 2469021 http://www.medworm.com/index.php?rid=2469020&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F853253.html Inelastic electron tunneling spectroscopy (IETS) is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nanoelectronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable system... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469020 Wed, 10 Jun 2009 08:26:04 +0100 2469020 http://www.medworm.com/index.php?rid=2469019&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F789153.html Devices based on nanomaterials are emerging as a powerful and general class of ultrasensitive sensors for the direct detection of biological and chemical species. In this work, we report the preparation and the full characterization of nanomaterials such as gold nanowires and TiO2 nanostructured films to be used for assembling of electrochemical biosensors. Gold nanowires were prepared by electroless deposition within the pores of polycarbonate particle track-etched membranes (PTMs). Glucose oxidase was deposited onto the nanowires using self-assembling monolayer as an anchor layer for the enzyme molecules. Finally, cyclic voltammetry was performed for different enzymes to test the applicability of gold nanowires as biosensors. Considering another interesting nanomaterial, the realization ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469019 Wed, 10 Jun 2009 08:26:04 +0100 2469019 http://www.medworm.com/index.php?rid=2469018&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F756843.html Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray-pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order-of-magnitude (from 200 to 20 nm) smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469018 Wed, 10 Jun 2009 08:26:04 +0100 2469018 http://www.medworm.com/index.php?rid=2469017&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F974072.html The fluorescence of emitters embedded in a photonic crystal is known to be inhibited by the presence of an incomplete photonic band gap or pseudogap acting in their emission range. Here, we present a study of the angular dependence of the fluorescence emission of emitters embedded in a photonic crystal. Our results clearly show an angular dependence of the fluorescence emission, which is caused by the presence of an incomplete 3D band gap. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469017 Wed, 10 Jun 2009 08:26:04 +0100 2469017 http://www.medworm.com/index.php?rid=2469016&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F296928.html An apparent enhanced solubility of single-wall carbon nanotubes (SWNTs) in the deuterated form of the standard 3 : 1 sulfuric (H2SO4) to nitric (HNO3) acid mixture treatment is reported and attributed to the stronger interaction of deuterium bonds with the single-wall carbon nanotube surface. UV-Visible spectroscopy was used to characterize the apparent enhanced solubility of the SWNTs treated in deuterated forms of the acid mixture in comparison to the standard acid mix, while FTIR was used to analyze the nature of the functional groups generated on the SWNTs as a result of the different acid treatments. The apparent enhanced solubility reported here is consistent with the limited number of computational and experimental results published in the literature regarding the interaction of car... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469016 Wed, 10 Jun 2009 08:26:04 +0100 2469016 http://www.medworm.com/index.php?rid=2469014&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F516478.html The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, and N2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumi... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469014 Wed, 10 Jun 2009 08:26:04 +0100 2469014 http://www.medworm.com/index.php?rid=2469012&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F765398.html Discrete track media (DTM) fabricated by nanoimprint lithography (NIL) is considered as a potential technology for future hard disk drives (HDD). In the fabrication of a master mold for NIL, patterning the resist tracks with a narrow distribution in the width is the first critical step. This paper reports the challenges involved in the fabrication of high aspect ratio discrete tracks on Polymethylmethacrylate (PMMA) resist by means of electron beam lithography. It was observed that fabrication parameters applied for successful patterning of discrete tracks in nanoscale length were not directly suitable for the patterning of discrete tracks in micron scale. Hence different approaches such as thick layer resist coating, introducing of post exposure baking process, and varying of exposure par... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469012 Wed, 10 Jun 2009 08:26:04 +0100 2469012 http://www.medworm.com/index.php?rid=2469011&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F156358.html The possibility of using single-walled carbon nanotubes (SWCNTs) aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV-11 on single-walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant (k) for S.aureus and E.coli determined from batch adsorption study was found to be 9×108 and 2×108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The res... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469011 Wed, 10 Jun 2009 08:26:04 +0100 2469011 http://www.medworm.com/index.php?rid=2469010&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F389512.html Polyethylene terephthalate-polylactic acid copolymer (PET-PLA) was synthesized from bis (2-hydroxyethyl terephthalate) and L-lactic acid oligomer in the presence of manganese antimony glycoxide as a catalyst. The synthesized PET-PLA copolymer was used for controlled drug release systems with gold nanoparticles. Fluorouracil containing PET-PLA nanocapsules was prepared in the presence of gold nanoparticles by solvent evaporation method. The morphologies of the nanocapsules were characterized using scanning electron microscopy and transmission electron microscopy. Controlled release of Fu and Fu@Au was carried out in 0.1 M phosphate buffer (pH 7.4) and 0.1 M HCl solution. The results indicated that the drug release for gold nanoparticles/fluorouracil (Au@Fu) incorporated PET-PL... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469010 Wed, 10 Jun 2009 08:26:04 +0100 2469010 http://www.medworm.com/index.php?rid=2469009&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F138468.html In this work, TiO2 nanocrystals were synthesized by the sol-gel method. These materials were annealed at 200 and 500∘C; and characterized by the XRD-Rietveld refinement; and by BET and TEM. As for the low-temperature-treated sample (200∘C), nanocrystals with small crystallite sizes (7 nm) and high abundance of anatase, coexisting with the brookite phase, were obtained. Meanwhile, the sample annealed at 500∘C showed an increased crystallite size (22 nm) and an important polymorphic increment. The sample annealed at 200∘C showed a high activity in the photocatalytic decomposition of acetaldehyde. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469009 Wed, 10 Jun 2009 08:26:04 +0100 2469009 http://www.medworm.com/index.php?rid=2469008&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F217510.html The molybdenum trioxide (MoO3) thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469008 Wed, 10 Jun 2009 08:26:04 +0100 2469008 http://www.medworm.com/index.php?rid=2469007&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F492478.html A convenient lithographic technique is proposed in this paper, which can be used to produce subdiffraction-limit arrays of nanopatterns over large areas (about several square centimeters). An array of polystyrene spheres (PS) is arranged on the surface of a layer of silver which has a thickness of about tens of nanometers. With the normal illumination light of wavelength 365 nm perpendicular to the substrate, PS can generate an array of optical patterns with high intensity at their contact points with silver. By designing the silver slab, the evanescent waves that carry subwavelength information about the optical patterns are substantially enhanced, while propagating components are restrained. In the photoresist which is on the other side of silver, the optical intensity is redistri... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469007 Wed, 10 Jun 2009 08:26:04 +0100 2469007 http://www.medworm.com/index.php?rid=2469005&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F734940.html FeTi clusters with a diameter of less than 10 nm and covered with a graphitic layer have been preferentially produced in an H2 gas atmosphere at pressures of 10 and 26.6 kPa by the simultaneous evaporation of Fe and Ti wires from a concave carbon boat. To compare this result with cluster formation in an inert gas atmosphere, the result for an Ar gas pressure of 10 kPa is also discussed. The formation of disordered FeNi clusters predominately took place in an H2 gas atmosphere. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469005 Wed, 10 Jun 2009 08:26:04 +0100 2469005 http://www.medworm.com/index.php?rid=2469004&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2008%2F701813.html Zinc oxide nanorods with 100 nm diameter and 900 nm length were grown on the surface of a silver wire (0.25 mm in diameter) with the aim to produce electrochemical nanosensors. It is shown that the ZnO nanorods exhibit a Ca2+-dependent electrochemical potentiometric behavior in an aqueous solution. The potential difference was found to be linear over a large logarithmic concentration range (1 μM to 0.1 M) using Ag/AgCl as a reference electrode and the response time was less than one minute. In order to adapt the sensors for calcium ion measurements in biological fluids with sufficient selectivity and stability, plastic membrane coatings containing ionophores were applied. These functionalized ZnO nanorods sensors showed a high sensitivity (26.55&#x... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469004 Wed, 10 Jun 2009 08:26:04 +0100 2469004 http://www.medworm.com/index.php?rid=2469003&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F971423.html A new single source approach was developed to synthesize Pd-Co nanoparticles using a bimetallic compound, [Et3NH]2[CoPd2(μ-4-I-3,5-Me2pz)4Cl4] (CoPd2), as a molecular precursor to obtain dispersed catalyst on highly ordered pyrolytic graphite (HOPG) surface, in view of preparing oxygen reduction catalysts for low temperature fuel cells. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques were employed to characterize the nanostructure formations and to determine the composition and morphology of the complex on the HOPG. Results of high resolution XPS analysis (HR-XPS) revealed the binding energies corresponding to the atomic constituents of the precursor. When the precursor solution was placed on the surface of the HOPG, the bimetall... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469003 Wed, 10 Jun 2009 08:26:04 +0100 2469003 http://www.medworm.com/index.php?rid=2469002&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Frlnt%2F2009%2F540257.html We have measured temperature-dependent (between 20 and 80∘C) electrical conductivity and molecular structure (Raman spectroscopy) of DNA-lipid cast film. Our findings show that the conductivity is strongly influenced by premelting effects in the molecular structure starting near physiological temperatures (∼40∘C), prior to the global DNA denaturation. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2469002 Wed, 10 Jun 2009 08:26:04 +0100 2469002 http://www.medworm.com/index.php?rid=2301888&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2009%2F971423 A new single source approach was developed to synthesize Pd-Co nanoparticles using a bimetallic compound, [Et3NH]2[CoPd2(μ-4-I-3,5-Me2pz)4Cl4] (CoPd2), as a molecular precursor to obtain dispersed catalyst on highly ordered pyrolytic graphite (HOPG) surface, in view of preparing oxygen reduction catalysts for low temperature fuel cells. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques were employed to characterize the nanostructure formations and to determine the composition and morphology of the complex on the HOPG. Results of high resolution XPS analysis (HR-XPS) revealed the binding energies corresponding to the atomic constituents of the precursor. When the precursor solution was placed on the surface of the HOPG, the bimetall... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2301888 Sun, 05 Apr 2009 17:39:15 +0100 2301888 http://www.medworm.com/index.php?rid=2301887&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2009%2F540257 We have measured temperature-dependent (between 20 and 80∘C) electrical conductivity and molecular structure (Raman spectroscopy) of DNA-lipid cast film. Our findings show that the conductivity is strongly influenced by premelting effects in the molecular structure starting near physiological temperatures (∼40∘C), prior to the global DNA denaturation. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2301887 Sun, 05 Apr 2009 17:39:15 +0100 2301887 http://www.medworm.com/index.php?rid=2087671&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F701813 Zinc oxide nanorods with 100 nm diameter and 900 nm length were grown on the surface of a silver wire (0.25 mm in diameter) with the aim to produce electrochemical nanosensors. It is shown that the ZnO nanorods exhibit a Ca2+-dependent electrochemical potentiometric behavior in an aqueous solution. The potential difference was found to be linear over a large logarithmic concentration range (1 μM to 0.1 M) using Ag/AgCl as a reference electrode and the response time was less than one minute. In order to adapt the sensors for calcium ion measurements in biological fluids with sufficient selectivity and stability, plastic membrane coatings containing ionophores were applied. These functionalized ZnO nanorods sensors showed a high sensitivity (26.55&#x... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2087671 Thu, 08 Jan 2009 12:41:50 +0100 2087671 http://www.medworm.com/index.php?rid=2056658&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F734940 FeTi clusters with a diameter of less than 10 nm and covered with a graphitic layer have been preferentially produced in an H2 gas atmosphere at pressures of 10 and 26.6 kPa by the simultaneous evaporation of Fe and Ti wires from a concave carbon boat. To compare this result with cluster formation in an inert gas atmosphere, the result for an Ar gas pressure of 10 kPa is also discussed. The formation of disordered FeNi clusters predominately took place in an H2 gas atmosphere. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2056658 Mon, 22 Dec 2008 13:35:53 +0100 2056658 http://www.medworm.com/index.php?rid=2036165&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F492478 A convenient lithographic technique is proposed in this paper, which can be used to produce subdiffraction-limit arrays of nanopatterns over large areas (about several square centimeters). An array of polystyrene spheres (PS) is arranged on the surface of a layer of silver which has a thickness of about tens of nanometers. With the normal illumination light of wavelength 365 nm perpendicular to the substrate, PS can generate an array of optical patterns with high intensity at their contact points with silver. By designing the silver slab, the evanescent waves that carry subwavelength information about the optical patterns are substantially enhanced, while propagating components are restrained. In the photoresist which is on the other side of silver, the optical intensity is redistri... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2036165 Mon, 15 Dec 2008 13:17:15 +0100 2036165 http://www.medworm.com/index.php?rid=2012057&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F217510 The molybdenum trioxide (MoO3) thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=2012057 Thu, 04 Dec 2008 17:38:39 +0100 2012057 http://www.medworm.com/index.php?rid=1677642&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F138468 In this work, TiO2 nanocrystals were synthesized by the sol-gel method. These materials were annealed at 200 and 500∘C; and characterized by the XRD-Rietveld refinement; and by BET and TEM. As for the low-temperature-treated sample (200∘C), nanocrystals with small crystallite sizes (7 nm) and high abundance of anatase, coexisting with the brookite phase, were obtained. Meanwhile, the sample annealed at 500∘C showed an increased crystallite size (22 nm) and an important polymorphic increment. The sample annealed at 200∘C showed a high activity in the photocatalytic decomposition of acetaldehyde. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1677642 Mon, 04 Aug 2008 15:20:19 +0100 1677642 http://www.medworm.com/index.php?rid=1618803&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F827174 We report a method of patterning the 1D and 2D arrays of gold nanoparticles on the DNA self-assembled scaffolds. The 5 nm gold nanoparticle was well positioned at the center of each 4×4 tile motif of the DNA scaffold. The precisely located gold particles can form 1D and 2D arrays. This controllable scaffolding technology may become a promising tool for nanoscaled fabrication of electronics and photonic devices. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618803 Mon, 14 Jul 2008 14:41:36 +0100 1618803 http://www.medworm.com/index.php?rid=1618802&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F527294 This report describes the viability of a strategy for manipulating the assembly/disassembly processes of DNA-Au nanoparticles by molecular intervention. Using the temperature-induced assembly and disassembly processes of DNAs and gold nanoparticles as a model system, the introduction of a molecular recognition probe is demonstrated to lead to the intervention of the assembly/disassembly processes depending on its specific biorecognition. This process can be detected by monitoring the change in the optical properties of gold nanoparticles and their DNA assemblies. Implications of the preliminary results to exploration of the resulting nanostructures for fine-tuning of the interfacial reactivities in DNA-based bioassays and biomaterial engineering are also discussed. (Source: Research Letter... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618802 Mon, 14 Jul 2008 14:41:36 +0100 1618802 http://www.medworm.com/index.php?rid=1618801&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F853253 Inelastic electron tunneling spectroscopy (IETS) is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nanoelectronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable system... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618801 Mon, 14 Jul 2008 14:41:36 +0100 1618801 http://www.medworm.com/index.php?rid=1618800&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F789153 Devices based on nanomaterials are emerging as a powerful and general class of ultrasensitive sensors for the direct detection of biological and chemical species. In this work, we report the preparation and the full characterization of nanomaterials such as gold nanowires and TiO2 nanostructured films to be used for assembling of electrochemical biosensors. Gold nanowires were prepared by electroless deposition within the pores of polycarbonate particle track-etched membranes (PTMs). Glucose oxidase was deposited onto the nanowires using self-assembling monolayer as an anchor layer for the enzyme molecules. Finally, cyclic voltammetry was performed for different enzymes to test the applicability of gold nanowires as biosensors. Considering another interesting nanomaterial, the realization ... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618800 Mon, 14 Jul 2008 14:41:36 +0100 1618800 http://www.medworm.com/index.php?rid=1618799&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F756843 Ammonium nitrate was added to the spraying solution as a foaming agent to reduce the particle size of nanoparticles synthesized in the spray-pyrolysis process. Ammonium nitrate was effective in breaking the aerosol droplet size and generating nanoparticles that were of approximately one order-of-magnitude (from 200 to 20 nm) smaller diameter than those created in the absence of ammonium nitrate in the feed solution. This technique makes it possible to control the particle diameter of metallic nanoparticles below 20 nm. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618799 Mon, 14 Jul 2008 14:41:36 +0100 1618799 http://www.medworm.com/index.php?rid=1618798&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F974072 The fluorescence of emitters embedded in a photonic crystal is known to be inhibited by the presence of an incomplete photonic band gap or pseudogap acting in their emission range. Here, we present a study of the angular dependence of the fluorescence emission of emitters embedded in a photonic crystal. Our results clearly show an angular dependence of the fluorescence emission, which is caused by the presence of an incomplete 3D band gap. (Source: Research Letters in Nanotechnology) Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618798 Mon, 14 Jul 2008 14:41:36 +0100 1618798 http://www.medworm.com/index.php?rid=1618797&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F296928 An apparent enhanced solubility of single-wall carbon nanotubes (SWNTs) in the deuterated form of the standard 3 : 1 sulfuric (H2SO4) to nitric (HNO3) acid mixture treatment is reported and attributed to the stronger interaction of deuterium bonds with the single-wall carbon nanotube surface. UV-Visible spectroscopy was used to characterize the apparent enhanced solubility of the SWNTs treated in deuterated forms of the acid mixture in comparison to the standard acid mix, while FTIR was used to analyze the nature of the functional groups generated on the SWNTs as a result of the different acid treatments. The apparent enhanced solubility reported here is consistent with the limited number of computational and experimental results published in the literature regarding the interaction of car... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618797 Mon, 14 Jul 2008 14:41:36 +0100 1618797 http://www.medworm.com/index.php?rid=1618796&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F516478 The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, and N2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumi... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618796 Mon, 14 Jul 2008 14:41:36 +0100 1618796 http://www.medworm.com/index.php?rid=1618795&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F765398 Discrete track media (DTM) fabricated by nanoimprint lithography (NIL) is considered as a potential technology for future hard disk drives (HDD). In the fabrication of a master mold for NIL, patterning the resist tracks with a narrow distribution in the width is the first critical step. This paper reports the challenges involved in the fabrication of high aspect ratio discrete tracks on Polymethylmethacrylate (PMMA) resist by means of electron beam lithography. It was observed that fabrication parameters applied for successful patterning of discrete tracks in nanoscale length were not directly suitable for the patterning of discrete tracks in micron scale. Hence different approaches such as thick layer resist coating, introducing of post exposure baking process, and varying of exposure par... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618795 Mon, 14 Jul 2008 14:41:36 +0100 1618795 http://www.medworm.com/index.php?rid=1618794&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F156358 The possibility of using single-walled carbon nanotubes (SWCNTs) aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV-11 on single-walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant (k) for S.aureus and E.coli determined from batch adsorption study was found to be 9×108 and 2×108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The res... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618794 Mon, 14 Jul 2008 14:41:36 +0100 1618794 http://www.medworm.com/index.php?rid=1618793&cid=s_37733_174_f&fid=37733&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F389512 Polyethylene terephthalate-polylactic acid copolymer (PET-PLA) was synthesized from bis (2-hydroxyethyl terephthalate) and L-lactic acid oligomer in the presence of manganese antimony glycoxide as a catalyst. The synthesized PET-PLA copolymer was used for controlled drug release systems with gold nanoparticles. Fluorouracil containing PET-PLA nanocapsules was prepared in the presence of gold nanoparticles by solvent evaporation method. The morphologies of the nanocapsules were characterized using scanning electron microscopy and transmission electron microscopy. Controlled release of Fu and Fu@Au was carried out in 0.1 M phosphate buffer (pH 7.4) and 0.1 M HCl solution. The results indicated that the drug release for gold nanoparticles/fluorouracil (Au@Fu) incorporated PET-PL... Research Letters in Nanotechnology journals http://www.medworm.com/rss/comments.php?id=1618793 Mon, 14 Jul 2008 14:41:36 +0100 1618793