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31.
Mesoporous TiO2‐Sn/C Core‐Shell Nanowire Arrays as High‐Performance 3D Anodes for Li‐Ion Batteries 下载免费PDF全文
Three‐dimensional mesoporous TiO2‐Sn/C core‐shell nanowire arrays are prepared on Ti foil as anodes for lithium‐ion batteries. Sn formed by a reduction of SnO2 is encapsulated into TiO2 nanowires and the carbon layer is coated onto it. For additive‐free, self‐supported anodes in Li‐ion batteries, this unique core‐shell composite structure can effectively buffer the volume change, suppress cracking, and improve the conductivity of the electrode during the discharge‐charge process, thus resulting in superior rate capability and excellent long‐term cycling stability. Specifically, the TiO2‐Sn/C nanowire arrays display rechargeable discharge capacities of 769, 663, 365, 193, and 90 mA h g?1 at 0.1C, 0.5C, 2C 10C, and 30C, respectively (1C = 335 mA g?1). Furthermore, the TiO2‐Sn/C nanowire arrays exhibit a capacity retention rate of 84.8% with a discharge capacity of over 160 mA h g?1, even after 100 cycles at a high current rate of 10C. 相似文献
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33.
Benjamin E. Blass Pravin Iyer Magid Abou-Gharbia Wayne E. Childers John C. Gordon Mercy Ramanjulu George Morton Premkumar Arumugam Joshodeep Boruwa John Ellingboe Sayan Mitra Rajashekar Reddy Nimmareddy Shalini Paliwal Jamallamudi Rajasekhar Savithiri Shivakumar Pratima Srivastava Raghuram S. Tangirala Konda Venkataramanaiah L. Krishnakanth Reddy 《Bioorganic & medicinal chemistry letters》2018,28(13):2270-2274
The synthesis of steroid hormones is critical to human physiology and improper regulation of either the synthesis of these key molecules or activation of the associated receptors can lead to disease states. This has led to intense interest in developing compounds capable of modulating the synthesis of steroid hormones. Compounds capable of inhibiting Cyp19 (Aromatase), a key enzyme in the synthesis of estrogens, have been successfully employed as breast cancer therapies, while inhibitors of Cyp17 (17α-hydroxylase-17,20-lyase), a key enzyme in the synthesis of glucocorticoids, mineralocorticoids and steroidal sex hormones, are a key component of prostate cancer therapy. Inhibition of CYP17 has also been suggested as a possible target for the treatment of Cushing Syndrome and Metabolic Syndrome. We have identified two novel series of stilbene based CYP17 inhibitors and demonstrated that exemplary compounds in these series have pharmacokinetic properties consistent with orally delivered drugs. These findings suggest that compounds in these classes may be useful for the treatment of diseases and conditions associated with improper regulation of glucocorticoids synthesis and glucocorticoids receptor activation. 相似文献
34.
A unique 3D hybrid sponge with chemically coupled nickel disulfide‐reduced graphene oxide (NiS2‐RGO) framework is rationally developed as an effective polysulfide reservoir through a biomolecule‐assisted self‐assembly synthesis. An optimized amount of NiS2 (≈18 wt%) with porous nanoflower‐like morphology is uniformly in situ grown on the RGO substrate, providing abundant active sites to adsorb and localize polysulfides. The improved polysulfide adsorptivity from sulfiphilic NiS2 is confirmed by experimental data and first‐principle calculations. Moreover, due to the chemical coupling between NiS2 and RGO formed during the in situ synthesis, the conductive RGO substrate offers a 3D electron pathway to facilitate charge transfer toward the NiS2‐polysulfide adsorption interface, triggering a fast redox kinetics of polysulfide conversion and excellent rate performance (C/20–4C). Therefore, the self‐assembled hybrid structure simultaneously promotes static polysulfide‐trapping capability and dynamic polysulfide‐conversion reversibility. As a result, the 3D porous sponge enables a high sulfur content (75 wt%) and a remarkably high sulfur loading (up to 21 mg cm?2) and areal capacity (up to 16 mAh cm?2), exceeding most of the reported values in the literature involving either RGO or metal sulfides/other metal compounds (sulfur content of <60 wt% and sulfur loading of <3 mg cm?2). 相似文献
35.
A Lithium–Sulfur Cell Based on Reversible Lithium Deposition from a Li2S Cathode Host onto a Hostless‐Anode Substrate 下载免费PDF全文
The development of lithium–sulfur batteries necessitates a thorough understanding of the lithium‐deposition process. A novel full‐cell configuration comprising an Li2S cathode and a bare copper foil on the anode side is presented here. The absence of excess lithium allows for the realization of a truly lithium‐limited Li–S battery, which operates by reversible plating and stripping of lithium on the hostless‐anode substrate (copper foil). Its performance is closely tied to the efficiency of lithium deposition, generating valuable insights on the role and dynamic behavior of lithium anode. The Li2S full cell shows reasonable capacity retention with a Coulombic efficiency of 96% over 100 cycles, which is a tremendous improvement over that of a similar lithium‐plating‐based full cell with LiFePO4 cathodes. The exceptional robustness of the Li2S system is attributed to an intrinsic stabilization of the lithium‐deposition process, which is mediated by polysulfide intermediates that form protective Li2S and Li2S2 regions on the deposited lithium. Combined with the large improvements in energy density and safety by the elimination of a metallic lithium anode, the stability and electrochemical performance of the lithium‐plating‐based Li2S full cell establish it as an important trajectory for Li–S battery research, focusing on practical realization of reversible lithium anodes. 相似文献
36.
David Yang-Wei Fann Yun-An Lim Yi-Lin Cheng Ker-Zhing Lok Prasad Chunduri Sang-Ha Baik Grant R. Drummond S. Thameem Dheen Christopher G. Sobey Dong-Gyu Jo Christopher Li-Hsian Chen Thiruma V. Arumugam 《Molecular neurobiology》2018,55(2):1082-1096
Multi-protein complexes, termed “inflammasomes,” are known to contribute to neuronal cell death and brain injury following ischemic stroke. Ischemic stroke increases the expression and activation of nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) Pyrin domain containing 1 and 3 (NLRP1 and NLRP3) inflammasome proteins and both interleukin (IL)-1β and IL-18 in neurons. In this study, we provide evidence that activation of either the NF-κB and MAPK signaling pathways was partly responsible for inducing the expression and activation of NLRP1 and NLRP3 inflammasome proteins and that these effects can be attenuated using pharmacological inhibitors of these two pathways in neurons and brain tissue under in vitro and in vivo ischemic conditions, respectively. Moreover, these findings provided supporting evidence that treatment with intravenous immunoglobulin (IVIg) preparation can reduce activation of the NF-κB and MAPK signaling pathways resulting in decreased expression and activation of NLRP1 and NLRP3 inflammasomes, as well as increasing expression of anti-apoptotic proteins, Bcl-2 and Bcl-xL, in primary cortical neurons and/or cerebral tissue under in vitro and in vivo ischemic conditions. In summary, these results provide compelling evidence that both the NF-κB and MAPK signaling pathways play a pivotal role in regulating the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons and brain tissue under ischemic conditions. In addition, treatment with IVIg preparation decreased the activation of the NF-κB and MAPK signaling pathways, and thus attenuated the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons under ischemic conditions. Hence, these findings suggest that therapeutic interventions that target inflammasome activation in neurons may provide new opportunities in the future treatment of ischemic stroke. 相似文献
37.
Neutrophil extracellular traps in acrolein promoted hepatic ischemia reperfusion injury: Therapeutic potential of NOX2 and p38MAPK inhibitors 下载免费PDF全文
38.
The advent of whole genome sequencing leads to increasing number of proteins with known amino acid sequences. Despite many efforts, the number of proteins with resolved three dimensional structures is still low. One of the challenging tasks the structural biologists face is the prediction of the interaction of metal ion with any protein for which the structure is unknown. Based on the information available in Protein Data Bank, a site (METALACTIVE INTERACTION) has been generated which displays information for significant high preferential and low‐preferential combination of endogenous ligands for 49 metal ions. User can also gain information about the residues present in the first and second coordination sphere as it plays a major role in maintaining the structure and function of metalloproteins in biological system. In this paper, a novel computational tool (ZINCCLUSTER) is developed, which can predict the zinc metal binding sites of proteins even if only the primary sequence is known. The purpose of this tool is to predict the active site cluster of an uncharacterized protein based on its primary sequence or a 3D structure. The tool can predict amino acids interacting with a metal or vice versa. This tool is based on the occurrence of significant triplets and it is tested to have higher prediction accuracy when compared to that of other available techniques. 相似文献
39.
S. Thiyagarajan M. Arumugam N. Senthil S. Vellaikumar S. Kathiresan 《Biotechnology letters》2018,40(3):577-584
Objectives
To express a Δ6-desaturase gene and produce gamma-linolenic acid (GLA) and stearidonic acid (SDA) in prokaryotic expression system (Escherichia coli), and analyze its substrate specificity in the omega-3 fatty acid biosynthetic pathway.Results
Full-length ORF (1448 bp) of Δ6Des-Iso was isolated from Isochrysis sp. and characterized using multiple sequence alignment, phylogenetic analysis, transmembrane domain, and protein tertiary structure. Δ6Des-Iso is a front-end desaturase consisting of three conserved histidine domains and a cytochrome b5 domain. Δ6Des-Iso was cloned and expressed in E. coli with the production of GLA and SDA. Recombinant E. coli utilized 27 and 8% of exogenously supplied alpha-linolenic acid (ALA) and linoleic acid (LA) to produce 6.3% of SDA and 2.3% of GLA, respectively, suggesting that isolated Δ6Des-Iso is specific to the omega-3 pathway.Conclusion
For the first time production of GLA and SDA in a prokaryotic system was achieved.40.
Manjula Arumugam Jaime Jacqueline Jayapalan Puteri Shafinaz Abdul-Rahman Onn Haji Hashim 《Biological Rhythm Research》2018,49(1):93-102
Disorganized redox homeostasis is a main factor causing a number of diseases and it is imperative to comprehend the orchestration of circadian clock under oxidative stress in the organism, Drosophila melanogaster. This investigation analyses the influence of hesperidin on the circadian rhythms of lipid peroxidation products and antioxidants during rotenone-stimulated oxidative stress in fruit fly. The characteristics of rhythms of thiobarbituric acid reactive substances (TBARS), antioxidants (superoxide dismutase (SOD) and catalase (CAT)) were noticeably decreased in rotenone administered flies. Supplementation of hesperidin to rotenone-treated flies increased the mesor and modulated the amplitudes of antioxidants and conspicuously decreased the mesor values of TBARS. In addition, delays in acrophase in rotenone-induced flies were reversed by hesperidin treatment. Thus, treatment of hesperidin caused normalization of the altered rhythms. Disorganization of 24 h rhythms in markers of redox homeostasis was observed during rotenone treatment and the impairment is severe in circadian clock mutant (Cryb) flies. Reversibility of rhythms was prominent subsequent to hesperidin treatment in wild-type flies than (Cryb) flies. These observations denote a role of circadian clock in redox homeostasis and the use of Drosophila model in screening putative antioxidative phytomedicines prior to their usage in mammalian systems. 相似文献