共查询到20条相似文献,搜索用时 31 毫秒
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Volker Presser Lifeng Zhang Jun Jie Niu John McDonough Carlos Perez Hao Fong Yury Gogotsi 《Liver Transplantation》2011,1(3):423-430
Nano‐fibrous felts (nano‐felts) of carbide‐derived carbon (CDC) have been developed from the precursor of electrospun titanium carbide (TiC) nano‐felts. Conformal transformation of TiC into CDC conserves main features of the precursor including the high interconnectivity and structural integrity; the developed TiC‐CDC nano‐felts are mechanically flexible/resilient, and can be used as electrode material for supercapacitor application without the addition of any binder. After synthesis through chlorination of the precursor at 600 °C, the TiC‐CDC nano‐fibers show an average pore size of ~1nm, a high specific surface area of 1390 m2/g; and the nano‐fibers have graphitic carbon ribbons embedded in a highly disordered carbon matrix. Graphitic carbon is preserved from the precursor nano‐fibers where a few graphene layers surround TiC nanocrystallites. Electrochemical measurements show a high gravimetric capacitance of 110 F/g in aqueous electrolyte (1 M H2SO4) and 65 F/g in organic electrolyte (1.5 M TEA‐BF4 in acetonitrile). Because of the unique microstructure of TiC‐CDC nano‐felts, a fade of the capacitance of merely 50% at a high scan rate of 5 V/s is observed. A fade of just 15% is observed for nano‐felt film electrodes tested in 1 M H2 SO4 at 1 V/s, resulting in a high gravimetric capacitance of 94 F/g. Such a high rate performance is only known for graphene or carbon‐onion based supercapacitors, whereas binders have to be used for the fabrication of those supercapacitors. 相似文献
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Micro‐ and Mesoporous Carbide‐Derived Carbon–Selenium Cathodes for High‐Performance Lithium Selenium Batteries 下载免费PDF全文
Jung Tae Lee Hyea Kim Martin Oschatz Dong‐Chan Lee Feixiang Wu Huan‐Ting Lin Bogdan Zdyrko Won Il Cho Stefan Kaskel Gleb Yushin 《Liver Transplantation》2015,5(1)
Nanocomposites of selenium (Se) and ordered mesoporous silicon carbide‐derived carbon (OM‐SiC‐CDC) are prepared for the first time and studied as cathodes for lithium‐selenium (Li‐Se) batteries. The higher concentration of Li salt in the electrolytes greatly improves Se utilization and cell cycle stability. Se‐CDC shows significantly better performance characteristics than Se‐activated carbon nanocomposites with similar physical properties. Se‐CDC also exhibits better rate performance and cycle stability compared to similarly produced sulfur (S)–CDC for Li/S batteries. 相似文献
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Tetiana Serdiuk Vladimir Lysenko Barbara Mognetti Valery Skryshevsky Alain Géloën 《Journal of biophotonics》2013,6(3):291-297
Semiconductor nanoparticles (NPs) became important and wide‐used tool for cell imaging because of their unique remarkable properties. Nevertheless, all previous investigations in this area were done on proliferating cells. For the first time, this work demonstrates strong influence of cell active proliferation/contact inhibition of proliferation on uptake of NPs. In addition, we show that cell division plays key‐role in penetration of silicon carbide based NPs (SiC NPs) inside the cell nucleus. This may very likely concern other types of NPs able to reach the cell nuclei. In particular, observed effect of cell division gives perspectives for future selective cancer treatment with NPs. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Hierarchical Carbide‐Derived Carbon Foams with Advanced Mesostructure as a Versatile Electrochemical Energy‐Storage Material 下载免费PDF全文
Martin Oschatz Lars Borchardt Katja Pinkert Sören Thieme Martin R. Lohe Claudia Hoffmann Matthias Benusch Florian M. Wisser Christoph Ziegler Lars Giebeler Mark H. Rümmeli Jürgen Eckert Alexander Eychmüller Stefan Kaskel 《Liver Transplantation》2014,4(2)
Highly porous carbide‐derived carbon (CDC) mesofoams (DUT‐70) are prepared by nanocasting of mesocellular silica foams with a polycarbosilane precursor. Ceramic conversion followed by silica removal and high‐temperature chlorine treatment yields CDCs with a hierarchical micro‐mesopore arrangement. This new type of polymer‐based CDC is characterized by specific surface areas as high as 2700 m2 g?1, coupled with ultrahigh micro‐ and mesopore volumes up to 2.6 cm3 g?1. The relationship between synthesis conditions and the properties of the resulting carbon materials is described in detail, allowing precise control of the properties of DUT‐70. Since the hierarchical pore system ensures both efficient mass transfer and high capacities, the novel CDC shows outstanding performance as an electrode material in electrochemical double‐layer capacitors (EDLCs) with specific capacities above 240 F g?1 when measured in a symmetrical two‐electrode configuration. Remarkable capacities of 175 F g?1 can be retained even at high current densities of 20 A g?1 as a result of the enhanced ion‐transport pathways provided by the cellular mesostructure. Moreover, DUT‐70 can be infiltrated with sulfur and host the active material in lithium–sulfur battery cathodes. Reversible capacities of 790 mAh g?1 are achieved at a current rate of C/10 after 100 cycles, which renders DUT‐70 an ideal support material for electrochemical energy‐storage applications. 相似文献
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Beaudelaire Kemvoufo Ponou Rémy Bertrand Teponno Massimo Ricciutelli Télesphore Bénoit Nguelefack Luana Quassinti Massimo Bramucci Giulio Lupidi Luciano Barboni Léon Azefack Tapondjou 《化学与生物多样性》2011,8(7):1301-1309
Two new oleanane‐type triterpenes named ivorengenin A (=3‐oxo‐2α,19α,24‐trihydroxyolean‐12‐en‐28‐oic acid; 1 ) and ivorengenin B (=4‐oxo‐19α‐hydroxy‐3,24‐dinor‐2,4‐secoolean‐12‐ene‐2,28‐dioic acid; 2 ), together with five known compounds, arjungenin, arjunic acid, betulinic acid, sericic acid, and oleanolic acid, were isolated from the barks of Terminalia ivorensis A. Chev . (Combretaceae). Their structures were established on the basis of 1D‐ and 2D‐NMR data, and mass spectrometry. A biogenetic pathway to the formation of these compounds from sericic acid, isolated as the major compound from this plant, was proposed. The antioxidant activities of different compounds were investigated by means of the 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assays, and IC50 values were calculated and compared with Trolox activity. Antiproliferative activities of the isolated compounds were also evaluated against MDA‐MB‐231, PC3, HCT116, and T98G human cancer cell lines, against which the compounds showed significant cytotoxic activities. 相似文献
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《Chirality》2017,29(1):33-37
Dehydrative cyclization of 4‐(D‐altro ‐pentitol‐1‐yl)2‐phenyl‐2H ‐1,2,3‐triazole in basic medium with one moler equivalent of p‐toluene sulfonyl chloride in pyridine solution gave the homo‐C‐ nucleoside 4‐(2,5‐anhydro‐D‐altro ‐1‐yl)‐2‐phenyl‐2H ‐1,2,3‐triazole. The structure and anomeric configuration was determined by acylation, nuclear magnetic resonance (NMR), and mass spectroscopy. The stereochemistry at the carbon bridge of homo‐C‐ nucleoside 2‐phenyl‐2H ‐1,2,3‐triazoles was determined by circular dichroism (CD) spectroscopy. 相似文献
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Seong‐Min Bak Ruimin Qiao Wanli Yang Sungsik Lee Xiqian Yu Babak Anasori Hungsui Lee Yury Gogotsi Xiao‐Qing Yang 《Liver Transplantation》2017,7(20)
2D vanadium carbide MXene containing surface functional groups (denoted as V2CTx , where Tx are surface functional groups) is synthesized and studied as anode material for Na‐ion batteries. V2CTx anode exhibits reversible charge storage with good cycling stability and high rate capability through electrochemical test. The charge storage mechanism of V2CTx material during Na+ intercalation/deintercalation and the redox reaction of vanadium are studied using a combination of synchrotron based X‐ray diffraction, hard X‐ray absorption near edge spectroscopy (XANES), and soft X‐ray absorption spectroscopy (sXAS). Experimental evidence of a major contribution of redox reaction of vanadium to the charge storage and the reversible capacity of V2CTx during sodiation/desodiation process are provided through V K ‐edge XANES and V L 2,3‐edge sXAS results. A correlation between the CO32? content and the Na+ intercalation/deintercalation states in the V2CTx electrode observed from C and O K ‐edge in sXAS results implies that some additional charge storage reactions may take place between the Na+‐intercalated V2CTx and the carbonate‐based nonaqueous electrolyte. The results of this study provide valuable information for the further studies on V2CTx as anode material for Na‐ion batteries and capacitors. 相似文献
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Dariusz Brzezinski Marcin Kowiel David R. Cooper Marcin Cymborowski Marek Grabowski Alexander Wlodawer Zbigniew Dauter Ivan G. Shabalin Miroslaw Gilski Bernhard Rupp Mariusz Jaskolski Wladek Minor 《Protein science : a publication of the Protein Society》2021,30(1):115-124
The COVID‐19 pandemic has triggered numerous scientific activities aimed at understanding the SARS‐CoV‐2 virus and ultimately developing treatments. Structural biologists have already determined hundreds of experimental X‐ray, cryo‐EM, and NMR structures of proteins and nucleic acids related to this coronavirus, and this number is still growing. To help biomedical researchers, who may not necessarily be experts in structural biology, navigate through the flood of structural models, we have created an online resource, covid19.bioreproducibility.org, that aggregates expert‐verified information about SARS‐CoV‐2‐related macromolecular models. In this article, we describe this web resource along with the suite of tools and methodologies used for assessing the structures presented therein. 相似文献
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Ovidiu Paun 《Botanical journal of the Linnean Society. Linnean Society of London》2012,170(1):132-133
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《Journal of cellular biochemistry》2009,108(1):337-337
During the corresponding author's transfer from Dongguk University to Sungkyunkwan University in March 2006, data from the previous University was transferred to the corresponding author's new computer. During this data transfer there was a mixing of EMSA data from experiments involving Quercetin (QC), Ochnaflavone (OC), Tanshinone (TS), Crytotanshinone (CT), BMK, and natural extracts. The mixed EMSA data was inadvertently incorporated in more than one publication. Figure 6 has been corrected to new data with re‐confirmation. J. Cell. Biochem. 108: 337, 2009. © 2009 Wiley‐Liss, Inc.
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Novel ordered hierarchical mesoporous/microporous carbon (OHMMC) derived from mesoporous titanium‐carbide/carbon composites was prepared for the first time by synthesizing ordered mesoporous nanocrystalline titanium‐carbide/carbon composites, followed by chlorination of titanium carbides. The mesostructure and microstructure can be conveniently tuned by controlling the TiC contents of mesoporous TiC/C composite precursor, and chlorination temperature. By optimal condition, the OHMMC has a high surface area (1917 m2g?1), large pore volumes (1.24 cm3g?1), narrow mesopore‐size distributions (centered at about 3 nm), and micropore size of 0.69 and 1.25 nm, and shows a great potential as electrode for supercapacitor applications: it exhibits a high capacitance of 146 Fg?1 in noaqueous electrolyte and excellent rate capability. The ordered mesoporous channel pores are favorable for retention and immersion of the electrolyte, providing a more favorable path for electrolyte penetration and transportation to achieve promising rate capability performance. Meanwhile, the micropores drilled on the mesopore‐walls can increase the specific surface area to provide more sites for charge storage. 相似文献