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crystal structure transporter

Simon Yves, Romain Fleury, Thomas Berthelot, Mathias Fink, Fabrice Lemoult, Geoffroy Lerosey
The exciting discovery of topological condensed matter systems has lately triggered a search for their photonic analogues, motivated by the possibility of robust backscattering-immune light transport. However, topological photonic phases have so far only been observed in photonic crystals and waveguide arrays, which are inherently physically wavelength scaled, hindering their application in compact subwavelength systems. In this letter, we tackle this problem by patterning the deep subwavelength resonant elements of metamaterials onto specific lattices, and create crystalline metamaterials that can develop complex nonlocal properties due to multiple scattering, despite their very subwavelength spatial scale that usually implies to disregard their structure...
July 18, 2017: Nature Communications
Lin Mei, Jiantie Xu, Zengxi Wei, Huakun Liu, Yutao Li, Jianmin Ma, Shixue Dou
With the large-scale applications of electric vehicles in recent years, future batteries are required to be higher in power and possess higher energy densities, be more environmental friendly, and have longer cycling life, lower cost, and greater safety than current batteries. Therefore, to develop alternative electrode materials for advanced batteries is an important research direction. Recently, the Chevrel phase Mo6 T8 (T = S, Se) has attracted increasing attention as electrode candidate for advanced batteries, including monovalent (e...
July 18, 2017: Small
Samuel Álvarez-Almazán, Martiniano Bello, Feliciano Tamay-Cach, Marlet Martínez-Archundia, Diana Alemán-González-Duhart, José Correa-Basurto, Jessica Elena Mendieta-Wejebe
Diabetes mellitus is a chronic disease characterized by hyperglycemia, insulin resistance and hyperlipidemia. Glitazones or thiazolidinediones (TZD) are drugs that act as insulin-sensitizing agents whose molecular target is the peroxisome proliferator-activated receptor gamma (PPARγ). The euglycemic action of TZD has been linked with the induction of type 4 glucose transporter. However, it has been shown that the effect of TZD depends on the specific stereoisomer that interacts with PPARγ. Therefore, this work is focused on exploring the interactions and geometry adopted by glitazone's stereoisomers and one endogenous ligand on different conformations of the six crystals of the PPARγ protein using molecular docking and molecular dynamics (MD) simulations accompanied by the MMGBSA approach...
July 14, 2017: Biochemical Pharmacology
Yong Kyu Lee, Kyunghan Ahn, Joonil Cha, Chongjian Zhou, Hyo Seok Kim, Garam Choi, Sue In Chae, Jae-Hyuk Park, Yeseul Lee, Cheol-Hee Park, Sung-Pyo Cho, Sang Hyun Park, Yung-Eun Sung, Won Bo Lee, Taeghwan Hyeon, In Chung
SnSe emerges as a new class of thermoelectric materials since recent discovery of an ultrahigh thermoelectric figure of merit in its single crystals. Achieving such performance in the polycrystalline counterpart is still challenging and requires fundamental understandings of its electrical and thermal transport properties as well as structural chemistry. Here we demonstrate a new strategy of improving conversion efficiency of bulk polycrystalline SnSe thermoelectrics. We show that PbSe alloying decreases the transition temperature between Pnma and Cmcm phases and thereby can serve as a means of controlling its onset temperature...
July 14, 2017: Journal of the American Chemical Society
Thomas P Wyche, René F Ramos Alvarenga, Jeff S Piotrowski, Megan N Duster, Simone R Warrack, Gabriel Cornilescu, Travis J De Wolfe, Yanpeng Hou, Doug R Braun, Gregory A Ellis, Scott W Simpkins, Justin Nelson, Chad L Myers, James Steele, Hirotada Mori, Nasia Safdar, John L Markley, Scott Raymond Rajski, Tim S Bugni
A polyether antibiotic, ecteinamycin (1) was isolated from a marine Actinomadura sp., cultivated from the ascidian Ectein-ascidia turbinata. 13C-enrichment, high resolution NMR spectroscopy and molecular modeling enabled elucidation of the structure of 1 which was validated on the basis of comparisons with its recently reported crystal structure. Importantly, ec-teinamycin demonstrated potent activity against the toxigenic strain of Clostridium difficile NAP1/B1/027 (MIC = 59 ng/μL), as well as other toxigenic and non-toxigenic C...
July 14, 2017: ACS Chemical Biology
Shaojie Liu, Xunlu Zhang, Changjin Ou, Shulei Wang, Xinli Yang, XinHui Zhou, Baoxiu Mi, Dapeng Cao, Zhi Qiang Gao
In this paper, two new pyridazine based donor-acceptor type materials, i.e., 3CzPyaPy: 9,9'-(3-(6-(9H-carbazol-9-yl)pyridazin-3-yl)pyridine-2,6-diyl)bis(9H-carbazole) and 4CzPyPyaPy: 3,6-bis(2,6-di(9H-carbazol-9-yl)pyridin-3-yl)pyridazine, were synthesized with high yields. These two materials exhibited strong absorption/emission with high molar extinction coefficients and moderate photoluminescence quantum yield. The glass transition temperature of 3CzPyaPy was detected to be as high as 131°C, showing its high thermal stability...
July 14, 2017: ACS Applied Materials & Interfaces
Ying Yang, Beth Rice, Xingyuan Shi, Jochen R Brandt, Rosenildo Correa da Costa, Gordon J Hedley, Detlef-M Smilgies, Jarvist M Frost, Ifor D W Samuel, Alberto Otero-de-la-Roza, Erin R Johnson, Kim E Jelfs, Jenny Nelson, Alasdair J Campbell, Matthew J Fuchter
Chiral molecules exist as pairs of non-superimposable mirror images; a fundamental symmetry property vastly underexplored in organic electronic devices. Here, we show that organic field-effect transistors (OFETs) made from the helically chiral molecule 1-aza[6]helicene can display up to an 80-fold difference in hole mobility, together with differences in thin-film photophysics and morphology, solely depending on whether a single handedness or a 1:1 mixture of left and right handed molecules is employed under analogous fabrication conditions...
July 11, 2017: ACS Nano
Christopher D Radka, Lawrence J DeLucas, Landon S Wilson, Matthew B Lawrenz, Robert D Perry, Stephen G Aller
Gram-negative bacteria use siderophores, outer membrane receptors, inner membrane transporters and substrate-binding proteins (SBPs) to transport transition metals through the periplasm. The SBPs share a similar protein fold that has undergone significant structural evolution to communicate with a variety of differentially regulated transporters in the cell. In Yersinia pestis, the causative agent of plague, YfeA (YPO2439, y1897), an SBP, is important for full virulence during mammalian infection. To better understand the role of YfeA in infection, crystal structures were determined under several environmental conditions with respect to transition-metal levels...
July 1, 2017: Acta Crystallographica. Section D, Structural Biology
Kelvin H L Zhang, Rui Wu, Fengzai Tang, Weiwei Li, Freddy Oropeza, Liang Qiao, Vlado Lazarov, Yingge Du, David J Payne, Judith L MacManus-Driscoll, Mark Blamire
Understanding the energetics at the interface including the alignment of valence and conduction bands, built-in potentials, and ionic and electronic reconstructions, is an important challenge in designing oxide interfaces that have controllable multi-functionalities for novel (opto-)electronic devices. In this work, we report detailed investigations on the hetero-interface of wide bandgap p-type NiO and n-type SrTiO3 (STO). We show that despite a large lattice mismatch (~7%) and dissimilar crystal structure, high-quality NiO and Li doped NiO (LNO) thin films can be epitaxially grown on STO(001) substrates through a domain matching epitaxy (DME) mechanism...
July 11, 2017: ACS Applied Materials & Interfaces
Tobias Egle, Cédric Barroo, Nare Janvelyan, Andreas C Baumgaertel, Austin J Akey, Monika M Biener, Cynthia M Friend, David C Bell, Juergen Biener
Many application-relevant properties of nanoporous metals critically depend on their multiscale architecture. For example, the intrinsically high step-edge density of curved surfaces at the nanoscale provides highly reactive sites for catalysis, whereas the macroscale pore and grain morphology determines the macroscopic properties, such as mass transport, electrical conductivity, or mechanical properties. In this work, we systematically study the effects of alloy composition and dealloying conditions on the multiscale morphology of nanoporous copper (np-Cu) made from various commercial Zn-Cu precursor alloys...
July 19, 2017: ACS Applied Materials & Interfaces
Jianhua Han, Xuewen Yin, Hui Nan, Yu Zhou, Zhibo Yao, Jianbao Li, Dan Oron, Hong Lin
The combination of perovskite solar cells and quantum dot solar cells has significant potential due to the complementary nature of the two constituent materials. In this study, solar cells (SCs) with a hybrid CH3 NH3 PbI3 /SnS quantum dots (QDs) absorber layer are fabricated by a facile and universal in situ crystallization method, enabling easy embedding of the QDs in perovskite layer. Compared with SCs based on CH3 NH3 PbI3 , SCs using CH3 NH3 PbI3 /SnS QDs hybrid films as absorber achieves a 25% enhancement in efficiency, giving rise to an efficiency of 16...
July 10, 2017: Small
Tao Dong, Lei Lv, Linlin Feng, Yu Xia, Wei Deng, Pan Ye, Bei Yang, Shang Ding, Antonio Facchetti, Huanli Dong, Hui Huang
Noncovalent conformational locks are broadly employed to construct highly planar π-conjugated semiconductors exhibiting substantial charge transport characteristics. However, current chalcogen-based conformational lock strategies for organic semiconductors are limited to S···X (X = O, N, halide) weak interactions. An easily accessible (minimal synthetic steps) and structurally planar selenophene-based building block, 1,2-diethoxy-1,2-bisselenylvinylene (DESVS), with novel Se···O noncovalent conformational locks is designed and synthesized...
July 10, 2017: Advanced Materials
Michal Košťál, Jaroslav Šoltés, Ladislav Viererbl, Zdeněk Matěj, František Cvachovec, Vojtěch Rypar, Evžen Losa
A well-defined neutron spectrum is an essential tool for calibration and tests of spectrometry and dosimetry detectors, and evaluation methods for spectra processing. Many of the nowadays used neutron standards are calibrated against a fission spectrum which has a rather smooth energy dependence. In recent time, at the LVR-15 research reactor in Rez, an alternative approach was tested for the needs of fast neutron spectrometry detector calibration. This process comprises detector tests in a neutron beam, filtered by one meter of single-crystalline silicon, which contains several significant peaks in the fast neutron energy range...
June 27, 2017: Applied Radiation and Isotopes
Kai Liu, Lifei Zheng, Chao Ma, Robert Göstl, Andreas Herrmann
Over the last few years, DNA-surfactant complexes have gained traction as unique and powerful materials for potential applications ranging from optoelectronics to biomedicine because they self-assemble with outstanding flexibility spanning packing modes from ordered lamellar, hexagonal and cubic structures to disordered isotropic phases. These materials consist of a DNA backbone from which the surfactants protrude as non-covalently bound side chains. Their formation is electrostatically driven and they form bulk films, lyotropic as well as thermotropic liquid crystals and hydrogels...
July 7, 2017: Chemical Society Reviews
Lijie Sun, Hao Xie, Jean C Ingram, Ryan J Hope, Stephen A Baldwin, Simon G Patching
The concentrative nucleoside transporter (CNT) family of proteins mediate uptake of nucleosides into cells driven by a cation gradient, which then enter salvage pathways for nucleic acid synthesis. In humans they also transport hydrophilic anti-cancer and anti-viral nucleoside analogue drugs into cells and tissues where they exert their pharmacological effects. Escherichia coli CNT NupC (400 residues) is pyrimidine-specific and driven by a proton gradient. We have used computational, biochemical and biophysical methods to characterise evolutionary relationships, conservation of residues, structural domains, transmembrane helices and residues involved in nucleoside binding and/or transport activity in NupC compared with sodium-driven Vibrio cholerae CNT (vcCNT) and human CNTs (hCNT1-3)...
July 6, 2017: Biochemistry
Michał Falkowski, Andre M Strydom
The results of the magnetic, electron transport, heat capacity and heat conduction measurements on the new rhombohedral ternary compound Pr<sub>2</sub>Rh<sub>3</sub>Ge have been investigated. The synthesized polycrystalline compound was found to crystallize in the ternary ordered variant of the cubic Laves phase MgCu<sub>2</sub>-type of structure with the space group <i>R</i>-3<i>m</i>, as previously reported. Pr<sub>2</sub>Rh<sub>3</sub>Ge exhibits a ferromagnetic behaviour below T<sub>C</sub> = 8...
July 6, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Javid Khan, Jiuwang Gu, Shiman He, Xiaohui Li, Gulzar Ahmed, Zhongwu Liu, Muhammad Nadeem Akhtar, Wenjie Mai, Mingmei Wu
A tri-layered photoelectrode for dye-sensitized solar cells (DSSCs) is assembled using single crystal hollow TiO2 nanoparticles (HTNPs), sub-micro hollow TiO2 mesospheres (SHTMSs) and hierarchical TiO2 microspheres (HTMSs). The bottom layer composed of single crystal hollow TiO2 nanoparticles serves to absorb dye molecules, harvest light due to its hollow structure and keep a better mechanical contact with FTO conducting glass; the middle layer consisting of sub-micro hollow mesospheres works as a multifunctional layer due to its high dye adsorption ability, strong light trapping and scattering ability and slow recombination rates; and the top layer consisting of hierarchical microspheres enhances light scattering...
July 5, 2017: Nanoscale
Sukrit Sucharitakul, Gaihua Ye, Walter R L Lambrecht, Churna Bhandari, Axel Gross, Rui He, Hilde Poelman, Xuan P A Gao
V2O5 with a layered van der Waals (vdW) structure has been widely studied because of the material's potential in applications such as battery electrodes. In this work, microelectronic devices were fabricated to study the electrical and optical properties of mechanically exfoliated multilayered V2O5 flakes. Raman spectroscopy was used to determine the crystal structure axes of the nanoflakes and revealed that the intensities of the Raman modes depend strongly on the relative orientation between the crystal axes and the polarization directions of incident/scattered light...
July 19, 2017: ACS Applied Materials & Interfaces
Masataka Yamashita, Koki Kawano, Akinobu Matsumoto, Naoki Aratani, Hironobu Hayashi, Mitsuharu Suzuki, Lei Zhang, Alejandro L Briseno, Hiroko Yamada
Air-stable organic semiconductors based on tetrathiafuluvalene (TTF) were developed by synthesising a series of dinaphthotetrathiafulvalene bisimides (DNTTF-Im) using electron-donating TTF, -extended naphthalene, and electron withdrawing imide. Electron spin resonance spectroscopy and X-ray single crystal structure analysis of aryl-substituted DNTTF-Im radical cations confirmed that localization of the spin resides on the electron donating TTF moiety. The organic field-effect transistor properties derived from the use of highly crystalline n-butyl(C4) and n-hexyl(C6)-substituted DNTTF-Im were assessed...
July 4, 2017: Chemistry: a European Journal
Kathrin Michel, Jens-Peter Eufinger, Gregor Ulbrich, Martin Lerch, Juergen Janek, Matthias T Elm
Solid solutions of ceria and praseodymia are highly relevant for electrochemical applications as the incorporation of praseodymium into the ceria lattice shifts the range of mixed ionic electronic conductivity to higher oxygen partial pressures. To better understand the influence of praseodymium substitution on the transport processes and oxygen storage capacity in ceria, single crystals of ceria substituted with 14 mol% praseodymium have been investigated, obtaining the bulk properties without the influence of grain boundaries...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
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