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https://www.readbyqxmd.com/read/27906228/holographic-imaging-with-a-hard-x-ray-nanoprobe-ptychographic-versus-conventional-phase-retrieval
#1
A-L Robisch, J Wallentin, A Pacureanu, P Cloetens, T Salditt
We have performed near-field x-ray imaging with simultaneous object and probe reconstruction. By an advanced ptychographic algorithm based on longitudinal and lateral translations, full-field images of nanoscale objects are reconstructed with quantitative contrast values, along with the extended wavefronts used to illuminate the objects. The imaging scheme makes idealizing assumptions on the probe obsolete, and efficiently disentangles phase shifts related to the object from the imperfections in the illumination...
December 1, 2016: Optics Letters
https://www.readbyqxmd.com/read/27900454/intact-imaging-of-human-heart-structure-using-x-ray-phase-contrast-tomography
#2
Yukihiro Kaneko, Gen Shinohara, Masato Hoshino, Hiroyuki Morishita, Kiyozo Morita, Yoshihiro Oshima, Masashi Takahashi, Naoto Yagi, Yutaka Okita, Takuro Tsukube
Structural examination of human heart specimens at the microscopic level is a prerequisite for understanding congenital heart diseases. It is desirable not to destroy or alter the properties of such specimens because of their scarcity. However, many of the currently available imaging techniques either destroy the specimen through sectioning or alter the chemical and mechanical properties of the specimen through staining and contrast agent injection. As a result, subsequent studies may not be possible. X-ray phase-contrast tomography is an imaging modality for biological soft tissues that does not destroy or alter the properties of the specimen...
November 30, 2016: Pediatric Cardiology
https://www.readbyqxmd.com/read/27897249/visualization-and-pathological-characteristics-of-hepatic-alveolar-echinococcosis-with-synchrotron-based-x-ray-phase-sensitive-micro-tomography
#3
Huiqiang Liu, Xuewen Ji, Li Sun, Tiqiao Xiao, Honglan Xie, Yanan Fu, Yuan Zhao, Wenya Liu, Xueliang Zhang, Renyong Lin
Propagation-based phase-contrast computed tomography (PPCT) utilizes highly sensitive phase-contrast technology applied to X-ray micro-tomography, especially with the extensive use of synchrotron radiation (SR). Performing phase retrieval (PR) on the acquired angular projections can enhance image contrast and enable quantitative imaging. We employed the combination of SR-PPCT and PR for the histopathological evaluation of hepatic alveolar echinococcosis (HAE) disease and demonstrated the validity and superiority of PR-based SR-PPCT...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27893445/a-method-for-high-energy-low-dose-mammography-using-edge-illumination-x-ray-phase-contrast-imaging
#4
Paul C Diemoz, Alberto Bravin, Anikó Sztrókay-Gaul, Marie Ruat, Susanne Grandl, Doris Mayr, Sigrid Auweter, Alberto Mittone, Emmanuel Brun, Cyril Ponchut, Maximilian F Reiser, Paola Coan, Alessandro Olivo
Since the breast is one of the most radiosensitive organs, mammography is arguably the area where lowering radiation dose is of the uttermost importance. Phase-based x-ray imaging methods can provide opportunities in this sense, since they do not require x-rays to be stopped in tissue for image contrast to be generated. Therefore, x-ray energy can be considerably increased compared to those usually exploited by conventional mammography. In this article we show how a novel, optimized approach can lead to considerable dose reductions...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27883131/photo-induced-magnetization-and-first-principles-calculations-of-a-two-dimensional-cyanide-bridged-co-w-bimetal-assembly
#5
Y Miyamoto, T Nasu, N Ozaki, Y Umeta, H Tokoro, K Nakabayashi, S Ohkoshi
A two-dimensional cyanide-bridged Co-W bimetal assembly, (H5O2(+))[Co(4-bromopyridine)2{W(CN)8}], was prepared. A synchrotron radiation (SR) X-ray single-crystal measurement shows that the crystal structure is monoclinic in the P21/c space group. Magnetic and spectroscopic measurements show that this assembly takes Co(S = 0)-W(IV)(S = 0) in the temperature range of 2-390 K. Such a wide temperature range Co-W(IV) phase has not been reported so far. First-principles calculations show that the band gap is composed of a W(IV) valence band and a Co(III) conduction band...
November 24, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/27883014/first-in-flight-synchrotron-x-ray-absorption-and-photoemission-study-of-carbon-soot-nanoparticles
#6
F-X Ouf, P Parent, C Laffon, I Marhaba, D Ferry, B Marcillaud, E Antonsson, S Benkoula, X-J Liu, C Nicolas, E Robert, M Patanen, F-A Barreda, O Sublemontier, A Coppalle, J Yon, F Miserque, T Mostefaoui, T Z Regier, J-B A Mitchell, C Miron
Many studies have been conducted on the environmental impacts of combustion generated aerosols. Due to their complex composition and morphology, their chemical reactivity is not well understood and new developments of analysis methods are needed. We report the first demonstration of in-flight X-ray based characterizations of freshly emitted soot particles, which is of paramount importance for understanding the role of one of the main anthropogenic particulate contributors to global climate change. Soot particles, produced by a burner for several air-to-fuel ratios, were injected through an aerodynamic lens, focusing them to a region where they interacted with synchrotron radiation...
November 24, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27873287/non-invasive-and-non-destructive-examination-of-artistic-pigments-paints-and-paintings-by-means-of-x-ray-methods
#7
REVIEW
Koen Janssens, Geert Van der Snickt, Frederik Vanmeert, Stijn Legrand, Gert Nuyts, Matthias Alfeld, Letizia Monico, Willemien Anaf, Wout De Nolf, Marc Vermeulen, Jo Verbeeck, Karolien De Wael
Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS)...
December 2016: Topics in Current Chemistry (Journal)
https://www.readbyqxmd.com/read/27866899/potential-of-compact-compton-sources-in-the-medical-field
#8
Marie Jacquet
The exceptional improvement of high power lasers and optical cavity finesses in the last fifteen years allows today the development of X-ray sources based on inverse Compton scattering. These compact sources will provide high intensity beams, with a tunable energy in the range 20-100keV, that can be used in several application including material sciences, structural biology, cultural heritage research and preservation and medical or biomedical preclinical and clinical research. The access to these devices will be easier...
November 17, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27866898/optimizing-dose-enhancement-with-ta2o5-nanoparticles-for-synchrotron-microbeam-activated-radiation-therapy
#9
Elette Engels, Stéphanie Corde, Sally McKinnon, Sébastien Incerti, Konstantin Konstantinov, Anatoly Rosenfeld, Moeava Tehei, Michael Lerch, Susanna Guatelli
Microbeam Radiation Therapy (MRT) exploits tumour selectivity and normal tissue sparing with spatially fractionated kilovoltage X-ray microbeams through the dose volume effect. Experimental measurements with Ta2O5 nanoparticles (NPs) in 9L gliosarcoma treated with MRT at the Australian Synchrotron, increased the treatment efficiency. Ta2O5 NPs were observed to form shells around cell nuclei which may be the reason for their efficiency in MRT. In this article, our experimental observation of NP shell formation is the basis of a Geant4 radiation transport study to characterise dose enhancement by Ta2O5 NPs in MRT...
November 17, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27847197/synchrotron-radiation-micro-ct-as-a-novel-tool-to-evaluate-the-effect-of-agomir-210-in-a-rat-spinal-cord-injury-model
#10
Yong Cao, Tian-Ding Wu, Hao Wu, Ye Lang, Dong-Zhe Li, Shuang-Fei Ni, Hong-Bin Lu, Jian-Zhong Hu
MicroRNA-210 (miR-210) was initially reported to be associated with hypoxia and plays a vital role in modulating angiogenesis. However, the potential effect and underlying mechanisms of miR-210 activity in rat spinal cord injury (SCI) have not yet been fully illuminated. In the present study, differential microRNA expression after SCI was determined by Microarray analysis. To explore the effect of miR-210 after SCI, we intrathecally injected agomir-210 with Alzet Osmotic Pumps to up-regulated the endogenous miR-210 expression...
November 12, 2016: Brain Research
https://www.readbyqxmd.com/read/27845939/multiscale-and-multimodality-computed-tomography-for-cortical-bone-analysis
#11
A Ostertag, F Peyrin, P J Gouttenoire, J D Laredo, M C DeVernejoul, M Cohen Solal, C Chappard
In clinical studies, high resolution peripheral quantitative computed tomography (HR-pQCT) is used to separately evaluate cortical bone and trabecular bone with an isotropic voxel of 82 µm(3), and typical cortical parameters are cortical density (D.comp), thickness (Ct.Th), and porosity (Ct.Po). In vitro, micro-computed tomography (micro-CT) is used to explore the internal cortical bone micro-structure with isotropic voxels and high resolution synchrotron radiation (SR); micro-CT is considered the 'gold standard'...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27845039/crystal-structure-analysis-of-a-hypothetical-protein-mj0366-from-methanocaldococcus-jannaschii-revealed-a-novel-topological-arrangement-of-the-knot-fold
#12
Viswanathan Thiruselvam, Thirumananseri Kumarevel, Ponnuraj Karthe, Seiki Kuramitsu, Shigeyuki Yokoyama, Mondikalipudur Nanjappagounder Ponnuswamy
The crystal structure of a hypothetical protein MJ0366, derived from Methanocaldococcus jannaschii was solved at 1.9 Å resolution using synchrotron radiation. MJ0366 was crystallized as a monomer and has knot structural arrangement. Intriguingly, the solved structure consists of novel 'KNOT' fold conformation. The 31 trefoil knot was observed in the structure. The N-terminal and C-terminal ends did not participate in knot formation.
November 12, 2016: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/27836805/cementum-structure-in-beluga-whale-teeth
#13
S R Stock, L A Finney, A Telser, E Maxey, S Vogt, J S Okasinski
: A large fraction of the volume of Beluga whale (Delphinapterus leucas) teeth consists of cementum, a mineralized tissue which grows throughout the life of the animal and to which the periodontal ligaments attach. Annular growth bands or growth layer groups (GLGs) form within Beluga cementum, and this study investigates GLG structure using x-ray fluorescence mapping and x-ray diffraction mapping with microbeams of synchrotron radiation. The Ca and Zn fluorescent intensities and carbonated hydroxyapatite (cAp) diffracted intensities rise and fall together and match the light-dark bands visible in transmitted light micrographs...
November 8, 2016: Acta Biomaterialia
https://www.readbyqxmd.com/read/27836637/a-single-image-retrieval-method-for-edge-illumination-x-ray-phase-contrast-imaging-application-and-noise-analysis
#14
Paul C Diémoz, Fabio A Vittoria, Charlotte K Hagen, Marco Endrizzi, Paola Coan, Alberto Bravin, Ulrich H Wagner, Christoph Rau, Ian K Robinson, Alessandro Olivo
PURPOSE: Edge illumination (EI) X-ray phase-contrast imaging (XPCI) has been under development at University College London in recent years, and has shown great potential for both laboratory and synchrotron applications. In this work, we propose a new acquisition and processing scheme. Contrary to existing retrieval methods for EI, which require as input two images acquired in different setup configurations, the proposed approach can retrieve an approximate map of the X-ray phase from a single image, thus significantly simplifying the acquisition procedure and reducing data collection times...
November 8, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27834761/three-dimensional-visualization-of-human-cardiac-conduction-tissue-in-whole-heart-specimens-by-high-resolution-phase-contrast-ct-imaging-using-synchrotron-radiation
#15
Gen Shinohara, Kiyozo Morita, Masato Hoshino, Yoshihiro Ko, Takuro Tsukube, Yukihiro Kaneko, Hiroyuki Morishita, Yoshihiro Oshima, Hironori Matsuhisa, Ryuma Iwaki, Masashi Takahashi, Takaaki Matsuyama, Kazuhiro Hashimoto, Naoto Yagi
BACKGROUND: The feasibility of synchrotron radiation-based phase-contrast computed tomography (PCCT) for visualization of the atrioventricular (AV) conduction axis in human whole heart specimens was tested using four postmortem structurally normal newborn hearts obtained at autopsy. METHODS: A PCCT imaging system at the beamline BL20B2 in a SPring-8 synchrotron radiation facility was used. The PCCT imaging of the conduction system was performed with "virtual" slicing of the three-dimensional reconstructed images...
November 2016: World Journal for Pediatric & Congenital Heart Surgery
https://www.readbyqxmd.com/read/27828382/spatial-coherence-determination-from-the-fourier-analysis-of-a-resonant-soft-x-ray-magnetic-speckle-pattern
#16
Kai Bagschik, Robert Frömter, Leonard Müller, Wojciech Roseker, Judith Bach, Philipp Staeck, Carsten Thönnißen, Stefan Schleitzer, Magnus Hårdensson Berntsen, Christian Weier, Roman Adam, Jens Viefhaus, Claus Michael Schneider, Gerhard Grübel, Hans Peter Oepen
We present a method to determine the two-dimensional spatial coherence of synchrotron radiation in the soft X-ray regime by analyzing the Fourier transform of the magnetic speckle pattern from a ferromagnetic film in a multidomain state. To corroborate the results, a Young's double-pinhole experiment has been performed. The transverse coherence lengths in vertical and horizontal direction of both approaches are in a good agreement. The method presented here is simple and gives a direct access to the coherence properties of synchrotron radiation without nanostructured test objects...
October 3, 2016: Optics Express
https://www.readbyqxmd.com/read/27824451/frequency-comb-spectrum-of-periodic-patterned-signals
#17
Johannes L Steinmann, Edmund Blomley, Miriam Brosi, Erik Bründermann, Michele Caselle, Jeffrey L Hesler, Nicole Hiller, Benjamin Kehrer, Yves-Laurent Mathis, Michael J Nasse, Juliane Raasch, Manuel Schedler, Patrik Schönfeldt, Marcel Schuh, Markus Schwarz, Michael Siegel, Nigel Smale, Marc Weber, Anke-Susanne Müller
Using arbitrary periodic pulse patterns we show the enhancement of specific frequencies in a frequency comb. The envelope of a regular frequency comb originates from equally spaced, identical pulses and mimics the single pulse spectrum. We investigated spectra originating from the periodic emission of pulse trains with gaps and individual pulse heights, which are commonly observed, for example, at high-repetition-rate free electron lasers, high power lasers, and synchrotrons. The ANKA synchrotron light source was filled with defined patterns of short electron bunches generating coherent synchrotron radiation in the terahertz range...
October 21, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27824194/investigation-of-the-enhanced-photocathodic-activity-of-la5ti2cus5o7-photocathodes-in-h2-evolution-by-synchrotron-radiation-nanospectroscopy
#18
Enju Sakai, Naoka Nagamura, Jingyuan Liu, Takashi Hisatomi, Taro Yamada, Kazunari Domen, Masaharu Oshima
The local electronic structures of La5Ti2MS5O7 (M = Cu, Ag) particulate photoelectrodes with and without Ga doping were investigated, using a photoemission spectroscopy system with a lateral resolution of approximately 100 nm. The band alignments for La5Ti2MS5O7 were determined on the basis of pinpoint photoemission spectra acquired at optimal positions on the sample surfaces. A clear upward chemical potential shift of approximately 0.35 eV was observed in the case of Ga-doped La5Ti2CuS5O7. On the other hand, the electronic structure of La5Ti2AgS5O7 remained almost unaffected by Ga doping...
December 7, 2016: Nanoscale
https://www.readbyqxmd.com/read/27819254/full-beam-performances-of-a-pet-detector-with-synchrotron-therapeutic-proton-beams
#19
M A Piliero, F Pennazio, M G Bisogni, N Camarlinghi, P G Cerello, A Del Guerra, V Ferrero, E Fiorina, G Giraudo, M Morrocchi, C Peroni, G Pirrone, G Sportelli, R Wheadon
Treatment quality assessment is a crucial feature for both present and next-generation ion therapy facilities. Several approaches are being explored, based on prompt radiation emission or on PET signals by [Formula: see text]-decaying isotopes generated by beam interactions with the body. In-beam PET monitoring at synchrotron-based ion therapy facilities has already been performed, either based on inter-spill data only, to avoid the influence of the prompt radiation, or including both in-spill and inter-spill data...
December 7, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27812371/combined-operando-x-ray-diffraction-raman-spectroscopy-of-catalytic-solids-in-the-laboratory-the-co-tio2-fischer-tropsch-synthesis-catalyst-showcase
#20
Korneel H Cats, Bert M Weckhuysen
A novel laboratory setup for combined operando X-ray diffraction and Raman spectroscopy of catalytic solids with online product analysis by gas chromatography is presented. The setup can be used with a laboratory-based X-ray source, which results in important advantages in terms of time-on-stream that can be measured, compared to synchrotron-based experiments. The data quality was much improved by the use of a relatively high-energy MoKα radiation instead of the more conventional CuKα radiation. We have applied the instrument to study the long-term deactivation of Co/TiO2 Fischer-Tropsch synthesis (FTS) catalysts...
April 20, 2016: ChemCatChem
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