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Koshonna Brown, Ted Thurn, Lun Xin, William Liu, Remon Bazak, Si Chen, Barry Lai, Stefan Vogt, Chris Jacobsen, Tatjana Paunesku, Gayle E Woloschak
Titanium dioxide (TiO2 ) nanoparticles are produced for many different purposes, including development of therapeutic and diagnostic nanoparticles for cancer detection and treatment, drug delivery, induction of DNA double-strand breaks, and imaging of specific cells and subcellular structures. Currently, the use of optical microscopy, an imaging technique most accessible to biology and medical pathology, to detect TiO2 nanoparticles in cells and tissues ex vivo is limited with low detection limits, while more sensitive imaging methods (transmission electron microscopy, X-ray fluorescence microscopy, etc...
January 2018: Nano Research
Linji Zhang, Yang Ren, Xiuru Liu, Fei Han, Kenneth Evans-Lutterodt, Hongyan Wang, Yali He, Junlong Wang, Yong Zhao, Wenge Yang
Amorphous sulfur was prepared by rapid compression of liquid sulfur at temperatures above the λ-transition for to preserve the high-temperature liquid structure. We conducted synchrotron high-energy X-ray diffraction and Raman spectroscopy to diagnose the structural evolution of amorphous sulfur from room temperature to post-λ-transition temperature. Discontinuous changes of the first and second peaks in atomic pair-distribution-function, g(r), were observed during the transition from amorphous to liquid sulfur...
March 14, 2018: Scientific Reports
Erik B Watkins, Shelli L Frey, Eva Y Chi, Kathleen D Cao, Tadeusz Pacuszka, Jaroslaw Majewski, Ka Yee C Lee
The influence of carbohydrate structure on the ordering of glycosphingolipids (GSLs) and surrounding phospholipids was investigated in monolayers at the air-water interface. Binary mixtures composed of GSLs, chosen to span a range of carbohydrate complexity, and zwitterionic dipalmitoylphosphatidylcholine phospholipid, were studied. X-ray reflectivity was used to measure the out-of-plane structure of the monolayers and characterize the extension and conformation of the GSL carbohydrates. Using synchrotron grazing incidence x-ray diffraction, the in-plane packing of the lipid acyl chains and the area per molecule within ordered domains were characterized at different mole ratios of the two components...
March 13, 2018: Biophysical Journal
Mimi Gao, Melanie Berghaus, Simone Möbitz, Vitor Schuabb, Nelli Erwin, Marius Herzog, Karin Julius, Christian Sternemann, Roland Winter
For over 50 years, it has been known that the mitosis of eukaryotic cells is inhibited already at high hydrostatic pressure conditions of 30 MPa. This effect has been attributed to the disorganization of microtubules, the main component of the spindle apparatus. However, the structural details of the depolymerization and the origin of the pressure sensitivity have remained elusive. It has also been a puzzle how complex organisms could still successfully inhabit extreme high-pressure environments such as those encountered in the depth of oceans...
March 13, 2018: Biophysical Journal
Rui Zhang, Qianlei Zhang, Youxin Ji, Fengmei Su, Lingpu Meng, Zeming Qi, Yuanfei Lin, Xueyu Li, Xiaowei Chen, Fei Lv, Liangbin Li
Fibrillation and the complexation reaction between poly(vinyl alcohol) (PVA)-iodine (i) complexes have been studied with in situ synchrotron radiation small- and wide-angle X-ray scattering (SAXS and WAXS) during the uniaxial stretching of PVA films in KI/I2 aqueous solution. SAXS results show that stretching induces the formation of nanofibrils, which pack periodically in the later stage of stretching with an average inter-fibrillar distance of around 10 nm. The onset strains for fibrillation and the appearance of periodicity of nanofibrils are located at the beginning and the end of the stress plateau, and decrease with increasing iodine concentration...
March 14, 2018: Soft Matter
Ricardo Araújo, Vincent Fernandez, Richard D Rabbitt, Eric G Ekdale, Miguel T Antunes, Rui Castanhinha, Jörg Fröbisch, Rui M S Martins
The semicircular canal (SC) system of the inner ear detects head angular accelerations and is essential for navigation and spatial awareness in vertebrates. Because the bony labyrinth encloses the membranous labyrinth SCs, it can be used as a proxy for animal behavior. The bony labyrinth of dicynodonts, a clade of herbivorous non-mammalian synapsids, has only been described in a handful of individuals and remains particularly obscure. Here we describe the bony labyrinth anatomy of three Endothiodon cf. bathystoma specimens from Mozambique based on digital reconstructions from propagation phase-contrast synchrotron micro-computed tomography...
2018: PloS One
Sumit Agrawal, Nadine Schart-Morén, Wei Liu, Hanif M Ladak, Helge Rask-Andersen, Hao Li
OBJECTIVE: We used synchrotron radiation phase contrast imaging (SR-PCI) to study the 3D microanatomy of the basilar membrane (BM) and its attachment to the spiral ligament (SL) (with a conceivable secondary spiral lamina [SSL] or secondary spiral plate) at the round window membrane (RWM) in the human cochlea. The conception of this complex anatomy may be essential for accomplishing structural preservation at cochlear implant surgery. MATERIAL AND METHODS: Sixteen freshly fixed human temporal bones were used to reproduce the BM, SL, primary and secondary osseous spiral laminae (OSL), and RWM using volume-rendering software...
March 14, 2018: Upsala Journal of Medical Sciences
Udo Bauer, Florian Späth, Fabian Düll, Philipp Bachmann, Johann Steinhauer, Hans-Peter Steinrück, Christian Papp
We have investigated the adsorption and thermal reactivity of CO and C2H4 on well-defined bimetallic PtxAg1-x/Pt(111) surface alloys (with x = 0.67, 0.50, 0.38 and 0.32) using in situ synchrotron-based high resolution X-ray photoelectron spectroscopy. During low temperature (140 K) adsorption of CO, we find population of the energetically more stable Pt on-top site followed by the Pt bridge site, as known from clean Pt(111); CO does not adsorb on Ag facets under the applied conditions. The total CO coverage linearly decreases with Ag surface content...
March 14, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Gustavo A Garcia, Bérenger Gans, Julia Krüger, Fabian Holzmeier, Anja Röder, Allan Lopes, Christa Fittschen, Christian Alcaraz, Jean-Christophe Loison
We present the photoelectron spectra of C3 Hx (x = 0-3) formed in a microwave discharge flow-tube reactor by consecutive H abstractions from C3 H4 (C3 Hx + F → C3 Hx-1 + HF (x = 1-4)), but also from F + CH4 schemes by secondary reactions. The spectra were obtained combining tunable VUV synchrotron radiation with double imaging electron/ion coincidence techniques, yielding mass-selected threshold photoelectron spectra. The obtained results complement not only existing ones, but for the first time the photoelectron spectra of C3 , cyclic and linear C3 H (c,l-C3 H) as well as of the excited states of C3 H3 are reported...
March 14, 2018: Physical Chemistry Chemical Physics: PCCP
Dennis F A E Voeten, Jorge Cubo, Emmanuel de Margerie, Martin Röper, Vincent Beyrand, Stanislav Bureš, Paul Tafforeau, Sophie Sanchez
Archaeopteryx is an iconic fossil taxon with feathered wings from the Late Jurassic of Germany that occupies a crucial position for understanding the early evolution of avian flight. After over 150 years of study, its mosaic anatomy unifying characters of both non-flying dinosaurs and flying birds has remained challenging to interpret in a locomotory context. Here, we compare new data from three Archaeopteryx specimens obtained through phase-contrast synchrotron microtomography to a representative sample of archosaurs employing a diverse array of locomotory strategies...
March 13, 2018: Nature Communications
Jonathan M Grimes, David R Hall, Alun W Ashton, Gwyndaf Evans, Robin L Owen, Armin Wagner, Katherine E McAuley, Frank von Delft, Allen M Orville, Thomas Sorensen, Martin A Walsh, Helen M Ginn, David I Stuart
Macromolecular crystallography (MX) has been a motor for biology for over half a century and this continues apace. A series of revolutions, including the production of recombinant proteins and cryo-crystallography, have meant that MX has repeatedly reinvented itself to dramatically increase its reach. Over the last 30 years synchrotron radiation has nucleated a succession of advances, ranging from detectors to optics and automation. These advances, in turn, open up opportunities. For instance, a further order of magnitude could perhaps be gained in signal to noise for general synchrotron experiments...
February 1, 2018: Acta Crystallographica. Section D, Structural Biology
Naoya Yamaguchi, Shinya Anraku, Erwan Paineau, Cyrus R Safinya, Patrick Davidson, Laurent J Michot, Nobuyoshi Miyamoto
Exploring the interaction of nucleic acids with clay minerals is important to understand such issues as the persistence in soils of biomolecules and the appearance of genetic polymers in prebiotic environments. Colloidal dispersions of double stranded DNA and clay nanosheets may also provide interesting model systems to study the statistical physics of mixtures of semi-flexible rods and plates. Here, we show that adding very small amounts of DNA to liquid-crystalline montmorillonite and beidellite smectite clay suspensions strongly widens the isotropic/nematic phase coexistence region...
March 12, 2018: Scientific Reports
Joshua A Hammons, Fan Zhang, Jan Ilavsky
HYPOTHESIS: Many applications of deep eutectic solvents (DES) rely on exploitation of their unique yet complex liquid structures. Due to the ionic nature of the DES components, their diffuse structures are perturbed in the presence of a charged surface. We hypothesize that it is possible to perturb the bulk DES structure far (>100 nm) from a curved, charged surface with mesoscopic dimensions. EXPERIMENTS: We performed in situ, synchrotron-based ultra-small angle X-ray scattering (USAXS) experiments to study the solvent distribution near the surface of charged mesoporous silica particles (MPS) (≈0...
March 3, 2018: Journal of Colloid and Interface Science
Shuangfei Ni, Yong Cao, Liyuan Jiang, Zixiang Luo, Hongbin Lu, Jianzhong Hu, Tianding Wu
STUDY DESIGN: The efficacy of estrogen on vessel angiogenesis in acute spinal cord injury in a rat model were evaluated by synchrotron radiation. OBJECTIVE: Here, we investigate the change in injured spinal cord vessels and used the synchrotron radiation to investigate the effect of estrogen on vessel angiogenesis and functional recovery in a rat model of SCI. SUMMARY OF BACKGROUND DATE: The promotion of angiogenesis after spinal cord injury (SCI) may be a therapeutic target in the treatment of SCI...
March 9, 2018: Spine
Yudai Izumi, Koichi Matsuo, Hirofumi Namatame
We report structural alterations of histone H3 proteins induced by lysine-4 (K4) monomethylation, dimethylation, and trimethylation identified by using synchrotron radiation circular dichroism spectroscopy. Compared with unmethylated H3, monomethylation and dimethylation induced increases in α-helix structures and decreases in β-strand structures. In contrast, trimethylation decreased α-helix content but increased β-strand content. The structural differences among K4-unmethylated/methylated H3 may allow epigenetic enzymes to discriminate the substrates both chemically and sterically...
March 12, 2018: Chirality
Satyendra Nath Gupta, Anjali Singh, Koushik Pal, D Victor S Muthu, Chandra Shekhar, Moaz A ElGhazali, Pavel Naumov, Sergey Medvedev, Claudia Felser, Umesh V Waghmare, A K Sooda
High pressure Raman, resistivity and synchrotron x-ray diffraction studies on Weyl semimetals NbAs and TaAs have been carried out along with density functional theoretical (DFT) analysis to explain pressure-induced structural and electronic topological phase transitions. The frequencies of first order Raman modes harden with increasing pressure, exhibiting a slope change at P<sub>c</sub><sup>Nb</sup> ~15 GPa for NbAs and P<sub>c</sub><sup>Ta</sup> ~16 GPa for TaAs...
March 12, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
D Mihrin, P W Jakobsen, A Voute, L Manceron, R Wugt Larsen
The high-resolution terahertz absorption spectrum of the large-amplitude intermolecular donor librational band ν of the homodimer (HCN)2 has been recorded by means of long-path static gas-phase Fourier transform spectroscopy at 207 K employing a highly brilliant electron storage ring source. The rovibrational structure of the ν band has the typical appearance of a perpendicular type band of a Σ-Π transition for a linear polyatomic molecule. The generated terahertz spectrum is analyzed employing a standard semi-rigid linear molecule Hamiltonian, yielding a band origin ν0 of 119...
March 12, 2018: Physical Chemistry Chemical Physics: PCCP
Tianqi Niu, Jing Lu, Rahim Munir, Jianbo Li, Dounya Barrit, Xu Zhang, Hanlin Hu, Zhou Yang, Aram Amassian, Kui Zhao, Shengzhong Frank Liu
The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high-performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron-based grazing-incidence X-ray scattering to explore the film formation mechanism...
March 12, 2018: Advanced Materials
Bing Wang, Dongyue Tan, Tung Lik Lee, Jia Chuan Khong, Feng Wang, Dmitry Eskin, Thomas Connolley, Kamel Fezzaa, Jiawei Mi
The data presented in this article are related to the paper entitled 'Ultrafast synchrotron X-ray imaging studies of microstructure fragmentation in solidification under ultrasound' [Wang et al., Acta Mater. 144 (2018) 505-515]. This data article provides further supporting information and analytical methods, including the data from both experimental and numerical simulation, as well as the Matlab code for processing the X-ray images. Six videos constructed from the processed synchrotron X-ray images are also provided...
April 2018: Data in Brief
Paolo Ruzza, Rosa Maria Vitale, Rohanah Hussain, Alessia Montini, Claudia Honisch, Alice Pozzebon, Charlotte S Hughes, Barbara Biondi, Pietro Amodeo, GianPietro Sechi, Giuliano Siligardi
BACKGROUND: Lysozyme is a widely distributed enzyme present in a variety of tissue and body fluids. Human and hen egg white lysozyme are used as validated model to study protein folding and stability and to understand protein misfolding and aggregation. We recently found that ceftriaxone, a β-lactam antibiotic able to overcome the blood-brain barrier, successfully eliminated the cellular toxic effects of misfolded proteins as Glial Fibrillary Acidic Protein and α-synuclein. To further understand the anti-amyloidogenic properties of ceftriaxone, we studied its activity towards lysozyme aggregation with the aim to investigate a possible chaperone-like activity of this molecule...
March 7, 2018: Biochimica et Biophysica Acta
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