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https://www.readbyqxmd.com/read/28340456/macroscopic-and-microscopic-investigation-of-adsorption-and-precipitation-of-zn-on-%C3%AE-alumina-in-the-absence-and-presence-of-as
#1
Yu-Jun Wang, Ting-Ting Fan, Cun Liu, Wei Li, Meng-Qiang Zhu, Jian-Xin Fan, Hua Gong, Dong-Mei Zhou, Donald L Sparks
Contaminants zinc (Zn) and arsenate (As) often coexist in soils. However, little is known concerning the impacts of coexisting As on Zn adsorption and precipitation on soil minerals. In the present study, adsorption and precipitation of Zn on γ-alumina in the absence and presence of arsenate was investigated employing batch experiments and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. Results indicated that Zn formed edge-sharing tetrahedral surface complexes at pH 5.5 and Zn-Al LDH-like (layered double hydroxide) precipitates at pH 7...
March 21, 2017: Chemosphere
https://www.readbyqxmd.com/read/28337116/assessment-of-usefulness-of-synchrotron-radiation-techniques-to-determine-arsenic-species-in-hair-and-rice-grain-samples
#2
Jun Lin, Guo-Fang Lin, Yu-Lan Li, Xiao-Yan Gao, Hui Du, Chao-Gang Jia, Hong-Chao Lu, Klaus Golka, Jian-Hua Shen
The arseniasis in Southwest Guizhou, China has been identified as a unique case of endemic arseniasis caused by exposure to indoor combustion of high As-content coal. Present investigation targeted the microdistribution and speciation of the element arsenic in human hair and environmental samples collected in one of the hyper-endemic villages of arseniasis in the area. Analyses were performed by micro-beam X-ray fluorescence (μ-XRF) and X-ray absorption fine structure (XAFS). The total As level in hair samples of diagnosed patients was detected at almost the same level as in their asymptomatic neighbors...
2017: EXCLI journal
https://www.readbyqxmd.com/read/28335367/investigating-polymer-metal-interfaces-by-grazing-incidence-small-angle-x-ray-scattering-from-gradients-to-real-time-studies
#3
REVIEW
Matthias Schwartzkopf, Stephan V Roth
Tailoring the polymer-metal interface is crucial for advanced material design. Vacuum deposition methods for metal layer coating are widely used in industry and research. They allow for installing a variety of nanostructures, often making use of the selective interaction of the metal atoms with the underlying polymer thin film. The polymer thin film may eventually be nanostructured, too, in order to create a hierarchy in length scales. Grazing incidence X-ray scattering is an advanced method to characterize and investigate polymer-metal interfaces...
December 10, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334658/extraction-of-the-3d-local-orientation-of-myocytes-in-human-cardiac-tissue-using-x-ray-phase-contrast-micro-tomography-and-multi-scale-analysis
#4
François Varray, Iulia Mirea, Max Langer, Françoise Peyrin, Laurent Fanton, Isabelle E Magnin
This paper presents a methodology to access the 3D local myocyte arrangements in fresh human post-mortem heart samples. We investigated the cardiac micro-structure at a high and isotropic resolution of 3.5 µm in three dimensions using X-ray phase micro-tomography at the European Synchrotron Radiation Facility. We then processed the reconstructed volumes to extract the 3D local orientation of the myocytes using a multi-scale approach with no segmentation. We created a simplified 3D model of tissue sample made of simulated myocytes with known size and orientations, to evaluate our orientation extraction method...
February 20, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28333689/computational-modelling-of-the-cerebral-cortical-microvasculature-effect-of-x-ray-microbeams-versus-broad-beam-irradiation
#5
Andreas Merrem, Stefan Bartzsch, Jean Laissue, Uwe Oelfke
Microbeam Radiation Therapy is an innovative pre-clinical strategy which uses arrays of parallel, tens of micrometre wide kilo-voltage photon beams to treat tumours. These X-ray beams are typically generated on a synchrotron source. It was shown that these beam geometries allow exceptional normal tissue sparing from radiation damage while still being effective in tumour ablation. A final biological explanation for this enhanced therapeutic ratio has still not been found, some experimental data support an important role of the vasculature...
March 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28332562/new-insights-on-the-biomineralisation-process-developing-in-human-lungs-around-inhaled-asbestos-fibres
#6
Fabrizio Bardelli, Giulia Veronesi, Silvana Capella, Donata Bellis, Laurent Charlet, Alessia Cedola, Elena Belluso
Once penetrated into the lungs of exposed people, asbestos induces an in vivo biomineralisation process that leads to the formation of a ferruginous coating embedding the fibres. The ensemble of the fibre and the coating is referred to as asbestos body and is believed to be responsible for the high toxicological outcome of asbestos. Lung tissue of two individuals subjected to prolonged occupational exposure to crocidolite asbestos was investigated using synchrotron radiation micro-probe tools. The distribution of K and of elements heavier than Fe (Zn, Cu, As, and Ba) in the asbestos bodies was observed for the first time...
March 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28329054/whole-heart-detailed-and-quantitative-anatomy-myofibre-structure-and-vasculature-from-x-ray-phase-contrast-synchrotron-radiation-based-micro-computed-tomography
#7
Anna Gonzalez-Tendero, Chong Zhang, Vedrana Balicevic, Rubén Cárdenes, Sven Loncaric, Constantine Butakoff, Bruno Paun, Anne Bonnin, Patricia Garcia-Cañadilla, Emma Muñoz-Moreno, Eduard Gratacós, Fatima Crispi, Bart Bijnens
Background: While individual cardiac myocytes only have a limited ability to shorten, the heart efficiently pumps a large volume-fraction thanks to a cell organization in a complex 3D fibre structure. Subclinical subtle cardiac structural remodelling is often present before symptoms arise. Understanding and early detection of these subtle changes is crucial for diagnosis and prevention. Additionally, personalized computational modelling requires knowledge on the multi-scale structure of the whole heart and vessels...
March 15, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28328028/large-area-elemental-imaging-reveals-van-eyck-s-original-paint-layers-on-the-ghent-altarpiece-1432-rescoping-its-conservation-treatment
#8
Geert Van der Snickt, Hélène Dubois, Jana Sanyova, Stijn Legrand, Alexia Coudray, Cécile Glaude, Marie Postec, Piet Van Espen, Koen Janssens
A combination of large-scale and micro-scale elemental imaging, yielding elemental distribution maps obtained by, respectively non-invasive macroscopic X-ray fluorescence (MA-XRF) and by secondary electron microscopy/energy dispersive X-ray analysis (SEM-EDX) and synchrotron radiation-based micro-XRF (SR μ-XRF) imaging was employed to reorient and optimize the conservation strategy of van Eyck's renowned Ghent Altarpiece. By exploiting the penetrative properties of X-rays together with the elemental specificity offered by XRF, it was possible to visualize the original paint layers by van Eyck hidden below the overpainted surface and to simultaneously assess their condition...
March 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28323518/synthesis-crystallization-and-preliminary-crystallographic-analysis-of-a-52-nucleotide-dna-2-ome-rna-oligomer-mimicking-10-23-dnazyme-in-the-complex-with-a-substrate
#9
Rafał Dolot, Milena Sobczak, Barbara Mikołajczyk, Barbara Nawrot
A 52-nucleotide DNA/2'-OMe-RNA oligomer mimicking 10-23 DNAzyme in the complex with its substrate was synthesized, purified and crystallized by the hanging-drop method using 0.8 M sodium potassium tartrate as a precipitant. A data set to 1.21 Å resolution was collected from a monocrystal at 100 K using synchrotron radiation on a beamline BL14.1 at BESSY. The crystal belonged to the P21 group with unit-cell a = 49.42, b = 24.69, c = 50.23, β = 118.48.
March 21, 2017: Nucleosides, Nucleotides & Nucleic Acids
https://www.readbyqxmd.com/read/28316816/crystal-structure-of-9-20-dimethyl-1-8-12-19-tetra-aza-tetra-cyclo-17-3-1-0-2-7-0-13-18-tricosane-dihydrate-from-synchrotron-x-ray-data
#10
Dohyun Moon, Jong-Ha Choi
The structure of the title compound, C21H40N4·2H2O, has been determined from synchrotron X-ray radiation data. The asymmetric unit comprises one 12-membered macropolycycle and two lattice water mol-ecules. The macropolycycle contains two cyclo-hexane rings and one 1,3-di-aza-cyclo-hexane ring, all in chair conformations. The C-N and C-C bond lengths are in the ranges 1.4526 (16)-1.4786 (17) and 1.517 (2)-1.5414 (17) Å, respectively. One intra-molecular N-H⋯N hydrogen bond helps to stabilize the mol-ecular conformation while medium-strength inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds involving the lattice water mol-ecules connect the components into a three-dimensional network...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28315820/evaluating-differential-nuclear-dna-yield-rates-and-osteocyte-numbers-among-human-bone-tissue-types-a-synchrotron-radiation-micro-ct-approach
#11
Janna M Andronowski, Amy Z Mundorff, Isaac V Pratt, Jon M Davoren, David M L Cooper
Molecular human identification has conventionally focused on DNA sampling from dense, weight-bearing cortical bone tissue, typically from femora or tibiae. A comparison of skeletal elements from three contemporary individuals demonstrated that elements with high quantities of cancellous bone yielded nuclear DNA at the highest rates, suggesting that preferentially sampling cortical bone may be suboptimal (Mundorff & Davoren, 2014). Despite these findings, the reason for the differential DNA yields between cortical and cancellous bone tissues remains unknown...
March 6, 2017: Forensic Science International. Genetics
https://www.readbyqxmd.com/read/28294350/high-resolution-fiber-optic-dosimeters-for-microbeam-radiation-therapy
#12
James Archer, Enbang Li, Marco Petasecca, Michael Lerch, Anatoly Rosenfeld, Martin Carolan
PURPOSE: A high resolution, water equivalent, optical and passive x-ray dosimeter has been constructed using plastic scintillator and optical fiber. This dosimeter has a peak edge-on spatial resolution of 100 μm in one dimension, with a 10 μm resolution dosimeter under investigation. The dosimeter design has a potential application in synchrotron x-ray microbeam radiation therapy where a high resolution is vital for accurate dose measurements and quality assurance. METHODS: BC-400 plastic scintillator, of thickness 100 μm, was optically coupled to an optical fiber with core diameter 1 mm...
March 14, 2017: Medical Physics
https://www.readbyqxmd.com/read/28294065/tetramethylpyrazine-facilitates-functional-recovery-after-spinal-cord-injury-by-inhibiting-mmp2-mmp9-and-vascular-endothelial-cell-apoptosis
#13
Jian-Zhong Hu, Xiao-Kai Wang, Yong Cao, Dong-Zhe Li, Tian-Ding Wu, Tao Zhang, Da-Qi Xu, Hong-Bin Lu
BACKGROUND: Spinal cord injury (SCI) is a major public health issue that leads to neurological dysfunctions and morbidities in patients. Tetramethylpyrazine (TMP) plays a neuroprotective role in SCI; however, the underlying mechanism has not been fully elucidated. Objective In the present study, we aimed to investigate the mechanisms and therapeutic effects of TMP on SCI. METHODS: A contusion SCI model was established that used a modified Allen's method. In the TMP group, TMP (200 mg/kg) was injected daily for 5 days post-injury, while in the Negative Control (NC) group, an equal volume of normal saline was injected...
March 13, 2017: Current Neurovascular Research
https://www.readbyqxmd.com/read/28287226/the-effect-of-sr-oh-2-on-the-hydrogen-storage-properties-of-the-mg-nh2-2-2lih-system
#14
Hujun Cao, Han Wang, Claudio Pistidda, Chiara Milanese, Weijin Zhang, Anna-Lisa Chaudhary, Antonio Santoru, Sebastiano Garroni, Jozef Bednarcik, Hanns-Peter Liermann, Ping Chen, Thomas Klassen, Martin Dornheim
The doping effect of Sr(OH)2 on the Mg(NH2)2-2LiH system is investigated considering different amounts of added Sr(OH)2 in the range of 0.05 to 0.2 mol. Experimental results show that both the thermodynamic and the kinetic properties of Mg(NH2)2-2LiH are influenced by the presence of Sr(OH)2. The addition of 0.1 mol Sr(OH)2 leads to a decrease in both the dehydrogenation onset and peak temperatures of ca. 70 and 13 °C, respectively, and an acceleration in the de/re-hydrogenation rates of one time at 150 °C compared to Mg(NH2)2-2LiH alone...
March 13, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28283856/effects-of-nintedanib-on-the-microvascular-architecture-in-a-lung-fibrosis-model
#15
Maximilian Ackermann, Yong Ook Kim, Willi L Wagner, Detlef Schuppan, Cristian D Valenzuela, Steven J Mentzer, Sebastian Kreuz, Detlef Stiller, Lutz Wollin, Moritz A Konerding
Nintedanib, a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis, has anti-fibrotic, anti-inflammatory, and anti-angiogenic activity. We explored the impact of nintedanib on microvascular architecture in a pulmonary fibrosis model. Lung fibrosis was induced in C57Bl/6 mice by intratracheal bleomycin (0.5 mg/kg). Nintedanib was started after the onset of lung pathology (50 mg/kg twice daily, orally). Micro-computed tomography was performed via volumetric assessment. Static lung compliance and forced vital capacity were determined by invasive measurements...
March 10, 2017: Angiogenesis
https://www.readbyqxmd.com/read/28281635/aluminum-induced-dreierketten-chain-cross-links-increase-the-mechanical-properties-of-nanocrystalline-calcium-aluminosilicate-hydrate
#16
Guoqing Geng, Rupert J Myers, Jiaqi Li, Roya Maboudian, Carlo Carraro, David A Shapiro, Paulo J M Monteiro
The incorporation of Al and increased curing temperature promotes the crystallization and cross-linking of calcium (alumino)silicate hydrate (C-(A-)S-H), which is the primary binding phase in most contemporary concrete materials. However, the influence of Al-induced structural changes on the mechanical properties at atomistic scale is not well understood. Herein, synchrotron radiation-based high-pressure X-ray diffraction is used to quantify the influence of dreierketten chain cross-linking on the anisotropic mechanical behavior of C-(A-)S-H...
March 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28281358/synchrotron-microtomography-to-evaluate-effects-of-different-polychemotherapy-drugs-to-cortical-bone-structure
#17
L P Nogueira, R Alessio, A Mantuano, G Sena, C E de Almeida, G Tromba, A P Almeida, C Salata, M V G Colaço, D Braz, R C Barroso
PURPOSE: In the present work, femur diaphysis of rats, treated with two different chemotherapy drugs, AC (doxorubicin + cyclophosphamide) and TC (docetaxel + cyclophosphamide) were evaluated by 3D morphological analysis using synchrotron radiation microtomography. MATERIALS AND METHODS: Wistar rats were classified into three groups. One group received doses of docetaxel and cyclophosphamide (G1) - TC regimen; another group received doses of doxorubicin and cyclophosphamide (G2) - AC regimen; while control group (G0) received no further treatment...
March 10, 2017: International Journal of Radiation Biology
https://www.readbyqxmd.com/read/28279178/validation-of-diffusion-tensor-mri-measurements-of-cardiac-microstructure-with-structure-tensor-synchrotron-radiation-imaging
#18
Irvin Teh, Darryl McClymont, Marie-Christine Zdora, Hannah J Whittington, Valentina Davidoiu, Jack Lee, Craig A Lygate, Christoph Rau, Irene Zanette, Jürgen E Schneider
BACKGROUND: Diffusion tensor imaging (DTI) is widely used to assess tissue microstructure non-invasively. Cardiac DTI enables inference of cell and sheetlet orientations, which are altered under pathological conditions. However, DTI is affected by many factors, therefore robust validation is critical. Existing histological validation is intrinsically flawed, since it requires further tissue processing leading to sample distortion, is routinely limited in field-of-view and requires reconstruction of three-dimensional volumes from two-dimensional images...
March 10, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28276680/isolation-of-cu-atoms-in-pd-lattice-forming-highly-selective-sites-for-photocatalytic-conversion-of-co2-to-ch4
#19
Ran Long, Yu Li, Yan Liu, Shuangming Chen, Xusheng Zheng, Chao Gao, Chaohua He, Nanshan Chen, Zeming Qi, Li Song, Jun Jiang, Junfa Zhu, Yujie Xiong
Photocatalytic conversion of CO2 to CH4 - a carbon-neutral fuel represents an appealing approach to remedy the current energy and environmental crisis; however, it suffers from the large production of CO and H2 by side reactions. The design of catalytic sites for CO2 adsorption and activation holds the key to address this grand challenge. In this article, we develop highly selective sites for photocatalytic conversion of CO2 to CH4 by isolating Cu atoms in Pd lattice. According to our synchrotron-radiation characterizations and theoretical simulations, the isolation of Cu atoms in Pd lattice can play dual roles in the enhancement of CO2-to-CH4 conversion: (1) providing the paired Cu-Pd sites for the enhanced CO2 adsorption and the suppressed H2 evolution; and (2) elevating the d-band center of Cu sites for the improved CO2 activation...
March 9, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28271891/highly-sensitive-and-selective-uranium-detection-in-natural-water-systems-using-a-luminescent-mesoporous-metal-organic-framework-equipped-with-abundant-lewis-basic-sites-a-combined-batch-x-ray-absorption-spectroscopy-and-first-principles-simulation-investigation
#20
Wei Liu, Xing Dai, Zhuanling Bai, Yanlong Wang, Zaixing Yang, Linjuan Zhang, Lin Xu, Lanhua Chen, Yuxiang Li, Daxiang Gui, Juan Diwu, Jianqiang Wang, Ruhong Zhou, Zhifang Chai, Shuao Wang
Uranium is not only a strategic resource for the nuclear industry but also a global contaminant with high toxicity. Although several strategies have been established for detecting uranyl ions in water, searching for new uranium sensor material with great sensitivity, selectivity, and stability remains a challenge. We introduce here a hydrolytically stable mesoporous terbium(III)-based MOF material compound 1, whose channels are as large as 27 Å × 23 Å and are equipped with abundant exposed Lewis basic sites, the luminescence intensity of which can be efficiently and selectively quenched by uranyl ions...
March 17, 2017: Environmental Science & Technology
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