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 'X-Ray Optics and Instrumentation' source. Wed, 17 Aug 2011 18:46:02 +0100 http://www.medworm.com/index.php?rid=4951664&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fchrp%2F2011%2F696208%2Fabs%2F Triple-negative breast cancer (TNBC), a subtype distinguished by negative immunohistochemical assays for expression of the estrogen and progesterone receptors (ER/PR) and human epidermal growth factor receptor-2(HER2) represents 15% of all breast cancers. Patients with TNBC generally experience a more aggressive clinical course with increased risk of disease progression and poorer overall survival. Furthermore, this subtype accounts for a disproportionate number of disease-related mortality in part due to its aggressive natural history and our lack of effective targeted agents beyond conventional cytotoxic chemotherapy. In this paper, we will review the epidemiology, risk factors, prognosis, and the molecular and clinicopathologic features that distinguish TNBC from other subtypes of ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=4951664 Tue, 21 Jun 2011 17:50:12 +0100 4951664 http://www.medworm.com/index.php?rid=4360398&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F156984.html The objective was specifically developed to match our needs and has few chromatic and geometric aberrations and high photometric performance. The scintillator assembly is constructed using a specific (patented) technique of assembling monolithic scintillating crystals. It replaces the segmented scintillator previously used at our facility and produces higher quality images (better resolution and no segmentation). The sensitivity, noise level, detection threshold and resolution of CrystalEyeCam were measured using an 18-MeV-bremsstrahlung spectrum, filtered with 10 cm of lead, and two 165 mm×165 mm BGO assemblies: 20 and 30 mm in thickness, respectively. In particular, with the 30 mm-thick BGO assembly, the measured detection threshold of the ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=4360398 Tue, 18 Jan 2011 21:22:33 +0100 4360398 http://www.medworm.com/index.php?rid=4035967&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F295095.html Silicon Pore Optics (SPO) is a new X-ray optics technology under development in Europe, forming the ESA baseline technology for the International X-ray Observatory candidate mission studied jointly by ESA, NASA, and JAXA. With its matrix-like structure, made of monocrystalline-bonded Silicon mirrors, it can achieve the required angular resolution and low mass density required for future large X-ray observatories. Glass-based Micro Pore Optics (MPO) achieve modest angular resolution compared to SPO, but are even lighter and have achieved sufficient maturity level to be accepted as the X-ray optic technology for instruments on board the Bepi-Colombo mission, due to visit the planet Mercury. Opportunities for technology transfer to ground-based applications include material science, security ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=4035967 Wed, 06 Oct 2010 22:18:43 +0100 4035967 http://www.medworm.com/index.php?rid=3942386&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F784732.html We describe the experimental procedures used when assembling and precisely shaping the mirrors, with special attention paid to laboratory testing of the mirror-temperature stabilization. For this purpose, the temperature dependence of the surface slope profile of a specially fabricated test mirror placed inside a temperature-controlled container was measured. We demonstrate that with active mirror-temperature stabilization, a change of the surrounding temperature by more than 3 K does not noticeably affect the mirror figure. Without temperature stabilization, the rms slope error is changed by approximately 1.5 μrad (primarily defocus) under the same conditions. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3942386 Wed, 08 Sep 2010 09:14:08 +0100 3942386 http://www.medworm.com/index.php?rid=3935727&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F479631.html This paper provides a comprehensive overview on the utilization of curved graded multilayer coatings as focusing elements for hard X-rays. It concentrates on the Kirkpatrick-Baez (KB) focusing setup that has been developed at 3rd generation synchrotron sources worldwide. The optical performance of these devices is evaluated applying analytical and numerical approaches. The essential role of the multilayer coating and its meridional d-spacing gradient are discussed as well as important technological issues. Experimental data and examples of operational KB focusing devices and applications complement the work. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3935727 Mon, 06 Sep 2010 08:55:55 +0100 3935727 http://www.medworm.com/index.php?rid=3912994&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F421945.html An overview is given of the study on X-ray focusing using the Fabry-Perot type multi-plate silicon crystal cavities consisting of compound refractive lenses. Silicon (12 4 0) is used as the back reflection for cavity resonance at the photon energy of 14.4388 keV. Measurements of focal length of the transmitted beam through the crystal cavities show enhanced focusing effect due to the presence of back diffraction. Also, an incident beam with ultrahigh energy resolution can improve the focusing owing to the wider acceptance angle of the back diffraction. Considerations based on the excitation of dispersion surface within the framework of X-ray dynamical diffraction theory are also presented to reveal the origin of this enhanced focusing. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3912994 Sun, 29 Aug 2010 09:22:13 +0100 3912994 http://www.medworm.com/index.php?rid=3880425&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F784732.html We describe the experimental procedures used when assembling and precisely shaping the mirrors, with special attention paid to laboratory testing of the mirror-temperature stabilization. For this purpose, the temperature dependence of the surface slope profile of a specially fabricated test mirror placed inside a temperature-controlled container was measured. We demonstrate that with active mirror-temperature stabilization, a change of the surrounding temperature by more than 3K does not noticeably affect the mirror figure. Without temperature stabilization, the rms slope error is changed by approximately 1.5 urad (primarily defocus) under the same conditions. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3880425 Thu, 19 Aug 2010 09:16:42 +0100 3880425 http://www.medworm.com/index.php?rid=3842797&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F583626.html This paper describes the design, crystal selection, and crystal testing for a vertical Johann spectrometer operating in the 13 keV range to measure ion Doppler broadening in inertial confinement plasmas. The spectrometer is designed to use thin, curved, mica crystals to achieve a resolving power of E/ΔE>2000. A number of natural mica crystals were screened for flatness and X-ray diffraction width to find samples of sufficient perfection for use in the instrument. Procedures to select and mount high quality mica samples are discussed. A diode-type X-ray source coupled to a dual goniometer arrangement was used to measure the crystal reflectivity curve. A procedure was developed for evaluating the goniometer performance using a set of diffraction grade Si crystals. This ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3842797 Mon, 09 Aug 2010 13:20:43 +0100 3842797 http://www.medworm.com/index.php?rid=3822535&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F856836.html The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is microstructured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to polycapillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the microprobing of biologic... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3822535 Thu, 05 Aug 2010 08:10:39 +0100 3822535 http://www.medworm.com/index.php?rid=3749792&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F824387.html A Fresnel zone plate (FZP) with 35 nm outermost zone width has been fabricated and tested in the hard X-ray region. The FZP was made by electron beam lithography and reactive ion etching technique. The performance test of the FZP was carried out by measuring the focused beam profile for coherent hard X-ray beam at the beamline 20XU of SPring-8. The full width at half maximum of the focused beam profile measured by knife-edge scan method is 34.9±2.7 nm, that agrees well with the theoretical value of diffraction-limited resolution. Applications to scanning microscopy were also carried out. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3749792 Wed, 14 Jul 2010 07:37:13 +0100 3749792 http://www.medworm.com/index.php?rid=3726426&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2010%2F317909.html Total-external-reflection Kirkpatrick-Baez mirror optics for high-energy X-rays have been applied to the X-ray microprobe at beamline 37XU of SPring-8. A focused beam size of 1.0 μm (V)×0.83 μm (H) has been achieved at an X-ray energy of 30 keV, and a total photon flux of the focused beam was about 5×109 photons/s. Micro-X-ray fluorescence (μ-XRF) analysis of the uranium distribution in rat kidneys has been performed with the mirror-focused beam. The sensitivity of uranium was evaluated from the XRF intensity of thin standard samples, and the minimum detection limit was estimated at 10 μg/g. The high-spatial-resolution analysis revealed that uranium was concentrated in the epithelium of the proximal tubules in the inner ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=3726426 Tue, 06 Jul 2010 07:38:35 +0100 3726426 http://www.medworm.com/index.php?rid=2468360&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F168237.html A custom processor based on reconfigurable hardware technology is proposed in order to compute the figure of merit used to measure the quality of the fit of X-ray diffraction peaks. As the experimental X-ray profiles can present many peaks severely overlapped, it is necessary to select the best model among a large set of reasonably good solutions. Determining the best solution is computationally intensive, because this is a hard combinatorial optimization problem. The proposed processors, working in parallel, increase the performance relative to a software implementation. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468360 Wed, 10 Jun 2009 05:16:20 +0100 2468360 http://www.medworm.com/index.php?rid=2468359&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F318171.html Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microfocus X-ray fluorescence (MμEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enables high-sensitivi... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468359 Wed, 10 Jun 2009 05:16:20 +0100 2468359 http://www.medworm.com/index.php?rid=2468358&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F792540.html We present two different types of collimation optimized for the production of low roughness curved mirrors and flat mirrors, respectively. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468358 Wed, 10 Jun 2009 05:16:20 +0100 2468358 http://www.medworm.com/index.php?rid=2468357&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F835172.html Recently, a novel data acquisition method has been proposed and experimentally implemented for differential phase-contrast computed tomography (DPC-CT), in which a conventional X-ray tube and a Talbot-Lau-type interferometer were utilized in data acquisition. The divergent nature of the data acquisition system requires a divergent-beam image reconstruction algorithm for DPC-CT. This paper focuses on addressing this image reconstruction issue. We have developed a filtered backprojection algorithm to directly reconstruct the DPC-CT images from acquired fan-beam data. The developed algorithm allows one to directly reconstruct the decrement of the real part of the refractive index from the measured data. In order to accurately reconstruct an image, the data need to be acquired over an angular ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468357 Wed, 10 Jun 2009 05:16:20 +0100 2468357 http://www.medworm.com/index.php?rid=2468356&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F408702.html The performance of parallel beam multilayer optics, including a parabolic multilayer Osmic MaxFlux GO-13N and a flat custom multilayer, was evaluated experimentally and compared to Bragg-Brentano and traditional ‘‘parallel beam’’ or ‘‘thin film’’ optical geometries. A novel arrangement of a parabolic multilayer in the incident beam with a flat multilayer in the diffracted beam functioning as an analyzer crystal was proven effective for powder diffraction applications. The dual-optic configuration improves resolution while eliminating sample displacement and transparency errors as expected for a configuration with equatorial divergence below 100 arcseconds. Fundamental parameters fitting showed that the parabolic multilayer can be accurately ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468356 Wed, 10 Jun 2009 05:16:20 +0100 2468356 http://www.medworm.com/index.php?rid=2468355&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F709692.html Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microbeam X-ray fluorescence (MμEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enable... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468355 Wed, 10 Jun 2009 05:16:20 +0100 2468355 http://www.medworm.com/index.php?rid=2468354&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2Fjournals%2Fxroi%2F2008%2F635024.html We present the first evaluation of such a filter for medical X-ray imaging. The experimental setup yields a 6.6 gain of flux at 20 keV, and we demonstrate tunability by altering the energy spectrum to center also around 17 and 23 keV. All measurements are found to agree well with ray-tracing and a proposed geometrical model. Compared to a model mammography system with absorption filtering, the experimental MPL filter reduces dose 13–25% for 3–7 cm breasts if the spectrum is centered around the optimal energy. Additionally, the resolution is improved 2.5 times for a 5 cm breast. The scan time is increased 3 times but can be reduced with a slightly decreased energy filtering and resolution. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=2468354 Wed, 10 Jun 2009 05:16:20 +0100 2468354 http://www.medworm.com/index.php?rid=1838190&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F709692 Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microbeam X-ray fluorescence (MμEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enable... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1838190 Tue, 30 Sep 2008 16:38:06 +0100 1838190 http://www.medworm.com/index.php?rid=1626369&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F408702 The performance of parallel beam multilayer optics, including a parabolic multilayer Osmic MaxFlux GO-13N and a flat custom multilayer, was evaluated experimentally and compared to Bragg-Brentano and traditional ‘‘parallel beam’’ or ‘‘thin film’’ optical geometries. A novel arrangement of a parabolic multilayer in the incident beam with a flat multilayer in the diffracted beam functioning as an analyzer crystal was proven effective for powder diffraction applications. The dual-optic configuration improves resolution while eliminating sample displacement and transparency errors as expected for a configuration with equatorial divergence below 100 arcseconds. Fundamental parameters fitting showed that the parabolic multilayer can be accurately ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1626369 Wed, 16 Jul 2008 14:59:46 +0100 1626369 http://www.medworm.com/index.php?rid=1618365&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F168237 A custom processor based on reconfigurable hardware technology is proposed in order to compute the figure of merit used to measure the quality of the fit of X-ray diffraction peaks. As the experimental X-ray profiles can present many peaks severely overlapped, it is necessary to select the best model among a large set of reasonably good solutions. Determining the best solution is computationally intensive, because this is a hard combinatorial optimization problem. The proposed processors, working in parallel, increase the performance relative to a software implementation. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1618365 Mon, 14 Jul 2008 14:03:03 +0100 1618365 http://www.medworm.com/index.php?rid=1618364&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F318171 Energy dispersive X-ray fluorescence (EDXRF) is a well-established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons. A particular EDXRF method, monochromatic microfocus X-ray fluorescence (MμEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state-of-the-art doubly curved crystal (DCC) X-ray optics, this technique enables high-sensitivi... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1618364 Mon, 14 Jul 2008 14:03:03 +0100 1618364 http://www.medworm.com/index.php?rid=1618363&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F792540 We present two different types of collimation optimized for the production of low roughness curved mirrors and flat mirrors, respectively. (Source: X-Ray Optics and Instrumentation) X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1618363 Mon, 14 Jul 2008 14:03:03 +0100 1618363 http://www.medworm.com/index.php?rid=1618362&cid=s_37730_75_f&fid=37730&url=http%3A%2F%2Fwww.hindawi.com%2FGetArticle.aspx%3Fdoi%3D10.1155%2F2008%2F835172 Recently, a novel data acquisition method has been proposed and experimentally implemented for differential phase-contrast computed tomography (DPC-CT), in which a conventional X-ray tube and a Talbot-Lau-type interferometer were utilized in data acquisition. The divergent nature of the data acquisition system requires a divergent-beam image reconstruction algorithm for DPC-CT. This paper focuses on addressing this image reconstruction issue. We have developed a filtered backprojection algorithm to directly reconstruct the DPC-CT images from acquired fan-beam data. The developed algorithm allows one to directly reconstruct the decrement of the real part of the refractive index from the measured data. In order to accurately reconstruct an image, the data need to be acquired over an angular ... X-Ray Optics and Instrumentation journals http://www.medworm.com/rss/comments.php?id=1618362 Mon, 14 Jul 2008 14:03:03 +0100 1618362