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排序方式: 共有479条查询结果,搜索用时 31 毫秒
181.
Jitendra N. Tiwari Ahmad M. Harzandi Miran Ha Siraj Sultan Chang Woo Myung Hyo Ju Park Dong Yeon Kim Pandiarajan Thangavel Aditya Narayan Singh Pankaj Sharma Selvaraj Selva Chandrasekaran Foad Salehnia Ji‐Wook Jang Hyeon Suk Shin Zonghoon Lee Kwang S. Kim 《Liver Transplantation》2019,9(26)
The most efficient electrocatalyst for the hydrogen evolution reaction (HER) is a Pt‐based catalyst, but its high cost and nonperfect efficiency hinder wide‐ranging industrial/technological applications. Here, an electrocatalyst of both ruthenium (Ru) single atoms (SAs) and N‐doped‐graphitic(GN)‐shell‐covered nitrided‐Ru nanoparticles (NPs) (having a Ru‐Nx shell) embedded on melamine‐derived GN matrix { 1 : [Ru(SA)+Ru(NP)@RuNx@GN]/GN}, which exhibits superior HER activity in both acidic and basic media, is presented. In 0.5 m H2SO4/1 m KOH solutions, 1 shows diminutive “negative overpotentials” (?η = |η| = 10/7 mV at 10 mA cm?2, lowest ever) and high exchange current densities (4.70/1.96 mA cm?2). The remarkable HER performance is attributed to the near‐zero free energies for hydrogen adsorption/desorption on Ru(SAs) and the increased conductivity of melamine‐derived GN sheets by the presence of nitrided‐Ru(NPs). The nitridation process forming nitrided‐Ru(NPs), which are imperfectly covered by a GN shell, allows superb long‐term operation durability. The catalyst splits water into molecular oxygen and hydrogen at 1.50/1.40 V (in 0.1 m HClO4/1 m KOH), demonstrating its potential as a ready‐to‐use, highly effective energy device for industrial applications. 相似文献
182.
Dinesh Jaishankar Abraam M. Yakoub Anita Bogdanov Tibor Valyi-Nagy Deepak Shukla 《Journal of virology》2015,89(3):1932-1938
Uncontrolled herpes simplex virus 1 (HSV-1) infection can advance to serious conditions, including corneal blindness or fatal encephalitis. Here, we describe a highly potent anti-HSV-1 peptide (DG2) that inhibits HSV-1 entry into host cells and blocks all aspects of infection. Importantly, DG2 is highly resistant to proteases and shows minimal toxicity, paving the way for prophylactic or therapeutic application of the peptide in vivo. 相似文献
183.
Santi M. Mandal Denial Mahata Ludovico Migliolo Aditya Parekh Partha S. Addy Mahitosh Mandal Amit Basak 《The Journal of biological chemistry》2014,289(37):25468-25473
Effects of glucose on the susceptibility of antifungal agents were investigated against Candida spp. Increasing the concentration of glucose decreased the activity of antifungal agents; voriconazole was the most affected drugs followed by amphotericin B. No significant change has been observed for anidulafungin. Biophysical interactions between antifungal agents with glucose molecules were investigated using isothermal titration calorimetry, Fourier transform infrared, and 1H NMR. Glucose has a higher affinity to bind with voriconazole by hydrogen bonding and decrease the susceptibility of antifungal agents during chemotherapy. In addition to confirming the results observed in vitro, theoretical docking studies demonstrated that voriconazole presented three important hydrogen bonds and amphotericin B presented two hydrogen bonds that stabilized the glucose. In vivo results also suggest that the physiologically relevant higher glucose level in the bloodstream of diabetes mellitus mice might interact with the available selective agents during antifungal therapy, thus decreasing glucose activity by complex formation. Thus, proper selection of drugs for diabetes mellitus patients is important to control infectious diseases. 相似文献
184.
Chang Seok Lee Dimitra K. Georgiou Adan Dagnino-Acosta Jianjun Xu Iskander I. Ismailov Mark Knoblauch Tanner O. Monroe RuiRui Ji Amy D. Hanna Aditya D. Joshi Cheng Long Joshua Oakes Ted Tran Benjamin T. Corona Sabina Lorca Christopher P. Ingalls Vihang A. Narkar Johanna T. Lanner J. Henri Bayle William J. Durham Susan L. Hamilton 《The Journal of biological chemistry》2014,289(37):25556-25570
Rapamycin at high doses (2–10 mg/kg body weight) inhibits mammalian target of rapamycin complex 1 (mTORC1) and protein synthesis in mice. In contrast, low doses of rapamycin (10 μg/kg) increase mTORC1 activity and protein synthesis in skeletal muscle. Similar changes are found with SLF (synthetic ligand for FKBP12, which does not inhibit mTORC1) and in mice with a skeletal muscle-specific FKBP12 deficiency. These interventions also increase Ca2+ influx to enhance refilling of sarcoplasmic reticulum Ca2+ stores, slow muscle fatigue, and increase running endurance without negatively impacting cardiac function. FKBP12 deficiency or longer treatments with low dose rapamycin or SLF increase the percentage of type I fibers, further adding to fatigue resistance. We demonstrate that FKBP12 and its ligands impact multiple aspects of muscle function. 相似文献
185.
Aditya Iyer Nils?O. Petersen Mireille?M.A.E. Claessens Vinod Subramaniam 《Biophysical journal》2014,106(12):2585-2594
Interactions of monomeric alpha-synuclein (αS) with lipid membranes have been suggested to play an important role in initiating aggregation of αS. We have systematically analyzed the distribution and self-assembly of monomeric αS on supported lipid bilayers. We observe that at protein/lipid ratios higher than 1:10, αS forms micrometer-sized clusters, leading to observable membrane defects and decrease in lateral diffusion of both lipids and proteins. An αS deletion mutant lacking amino-acid residues 71–82 binds to membranes, but does not observably affect membrane integrity. Although this deletion mutant cannot form amyloid, significant amyloid formation is observed in the wild-type αS clusters. These results suggest that the process of amyloid formation, rather than binding of αS on membranes, is crucial in compromising membrane integrity. 相似文献
186.
Aditya Bharadwaj 《Ethnos》2014,79(1):84-107
Drawing on Foucault's notion of subject formation or subjectification, this article shows how a process of experimental subjectification, a wilful submission and participation in seemingly experimental treatments, produces both empowering and life-affirming experiences as well as a critique of established scientific norms and practices. The article examines processes of experimental subjectification in the narratives of patients pursuing clinical application of human embryonic stem cells in India to treat chronic spinal cord injury and in the narrative of the director of the clinic providing the treatment. The article addresses how the clinic's director and patients from around the globe continue to successfully pursue embryonic stem cell therapies, despite intense media speculation and scientific scrutiny labelling the clinic as a maverick experimental site. 相似文献
187.
Satish Srinivas Kitambi Enrique M. Toledo Dmitry Usoskin Shimei Wee Aditya Harisankar Richard Svensson Kristmundur Sigmundsson Christina Kalderén Mia Niklasson Soumi Kundu Sergi Aranda Bengt Westermark Lene Uhrbom Michael Andäng Peter Damberg Sven Nelander Ernest Arenas Per Artursson Julian Walfridsson Karin Forsberg Nilsson Lars G.J. Hammarström Patrik Ernfors 《Cell》2014
188.
189.
Michael D. Madritch Clayton C. Kingdon Aditya Singh Karen E. Mock Richard L. Lindroth Philip A. Townsend 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1643)
Fine-scale biodiversity is increasingly recognized as important to ecosystem-level processes. Remote sensing technologies have great potential to estimate both biodiversity and ecosystem function over large spatial scales. Here, we demonstrate the capacity of imaging spectroscopy to discriminate among genotypes of Populus tremuloides (trembling aspen), one of the most genetically diverse and widespread forest species in North America. We combine imaging spectroscopy (AVIRIS) data with genetic, phytochemical, microbial and biogeochemical data to determine how intraspecific plant genetic variation influences below-ground processes at landscape scales. We demonstrate that both canopy chemistry and below-ground processes vary over large spatial scales (continental) according to aspen genotype. Imaging spectrometer data distinguish aspen genotypes through variation in canopy spectral signature. In addition, foliar spectral variation correlates well with variation in canopy chemistry, especially condensed tannins. Variation in aspen canopy chemistry, in turn, is correlated with variation in below-ground processes. Variation in spectra also correlates well with variation in soil traits. These findings indicate that forest tree species can create spatial mosaics of ecosystem functioning across large spatial scales and that these patterns can be quantified via remote sensing techniques. Moreover, they demonstrate the utility of using optical properties as proxies for fine-scale measurements of biodiversity over large spatial scales. 相似文献
190.
Zeng Y Kulkarni A Yang Z Patil PB Zhou W Chi X Van Lanen S Chen S 《ACS chemical biology》2012,7(9):1565-1575
"Trojan horse" antibiotic albomycins are peptidyl nucleosides consisting of a highly modified 4'-thiofuranosyl cytosine moiety and a ferrichrome siderophore that are linked by a peptide bond via a serine residue. While the latter component serves to sequester iron from the environment, the seryl nucleoside portion is a potent inhibitor of bacterial seryl-tRNA synthetases, resulting in broad-spectrum antimicrobial activities of albomycin δ(2). The isolation of albomycins has revealed this biological activity is optimized only following two unusual cytosine modifications, N4-carbamoylation and N3-methylation. We identified a genetic locus (named abm) for albomycin production in Streptomyces sp. ATCC 700974. Gene deletion and complementation experiments along with bioinformatic analysis suggested 18 genes are responsible for albomycin biosynthesis and resistance, allowing us to propose a potential biosynthetic pathway for installing the novel chemical features. The gene abmI, encoding a putative methyltransferase, was functionally assigned in vitro and shown to modify the N3 of a variety of cytosine-containing nucleosides and antibiotics such as blasticidin S. Furthermore, a ΔabmI mutant was shown to produce the descarbamoyl-desmethyl albomycin analogue, supporting that the N3-methylation occurs before the N4-carbamoylation in the biosynthesis of albomycin δ(2). The combined genetic information was utilized to identify an abm-related locus (named ctj) from the draft genome of Streptomyces sp. C. Cross-complementation experiments and in vitro studies with CtjF, the AbmI homologue, suggest the production of a similar 4'-thiofuranosyl cytosine in this organism. In total, the genetic and biochemical data provide a biosynthetic template for assembling siderophore-inhibitor conjugates and modifying the albomycin scaffold to generate new derivatives. 相似文献