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排序方式: 共有1929条查询结果,搜索用时 15 毫秒
961.
Boris Brumshtein Matilde Aguilar‐Moncayo M. Isabel García‐Moreno Dr. Carmen Ortiz Mellet Prof. José M. García Fernández Prof. Israel Silman Prof. Yoseph Shaaltiel Dr. David Aviezer Dr. Joel L. Sussman Prof. Anthony H. Futerman Prof. 《Chembiochem : a European journal of chemical biology》2009,10(9):1480-1485
6‐Amino‐6‐deoxy‐5,6‐di‐ N ‐( N ′‐octyliminomethylidene)nojirimycin , a reducing analogue of N‐nonyl‐1‐deoxynojirimycin, proved to be a potent and very selective inhibitor of β‐glucosidases, including human acid β‐glucosidase. Structural studies of the enzyme–inhibitor complex showed a binding mode in which the anomeric hydroxy group is accommodated in the “wrong” α configuration.
962.
V. M. Titov L. A. Merzhievskii S. M. Karakhanov S. A. Bordzilovskii 《Combustion, Explosion, and Shock Waves》1999,35(3):338-340
The interaction of dense and porous cylinders with incident plates is studied experimentally at collision velocities of 3.3–4.6 km/sec. Qualitative differences in the deformation mechanics of compact porous bodies are elucidated. The compression of porous samples is found to take place in two stages. These data can be invoked to explain the structural features of impact craters on planetary surfaces. Translated fromFizika Goreniya i Vzryva, Vol. 35, No. 3, pp. 133–135, May–June 1999. 相似文献
963.
Boris Dyatkin Matthew Laskoski William K. Edelen III Syed B. Qadri Teddy M. Keller 《International Journal of Applied Ceramic Technology》2021,18(2):457-471
We report on a novel polymer-derived synthesis approach that yields boron carbide monoliths and metal-reinforced B4C cermets. This single-step approach relies on a preceramic powder blend of boron and an acetylenic resin with a high char yield. At low temperatures below 1500°C and without applied pressures, preceramic precursor reaction bond together and form nanocrystalline refractory B4C matrices. Resulting near net shape boron, carbide monoliths exhibit small crystal grain sizes, maintain chemical purity, and exhibit morphological homogeneity. We reinforce the refractory carbide with five different metals and demonstrate the influence of each on the density, hardness, oxidation stability, and electronic conductivity of resulting cermet composites. We assess the optimal synthesis and reinforcement strategies that tailor these nanostructured materials for inexpensive and high-performing engineering applications. 相似文献
964.
Dr. Maria Duca Dr. Dennis Gillingham Prof. Dr. Christian Adam Olsen Prof. Dr. Gianluca Sbardella Dr. Philip R. Skaanderup Prof. Dr. Mario van der Stelt Prof. Dr. Boris Vauzeilles Prof. Dr. Olalla Vázquez Dr. Yves P. Auberson 《Chembiochem : a European journal of chemical biology》2021,22(19):2823-2825
The E uropean F ederation for M edicinal chemistry and C hemical biology (EFMC) is a federation of learned societies. It groups organizations of European scientists working in a dynamic field spanning chemical biology and medicinal chemistry. New ideas, tools, and technologies emerging from a wide array of scientific disciplines continuously energize this rapidly evolving area. Medicinal chemistry is the design, synthesis, and optimization of biologically active molecules aimed at discovering new drug candidates – a mission that in many ways overlaps with the scope of chemical biology. Chemical biology is by now a mature field of science for which a more precise definition of what it encompasses, in the frame of EFMC, is timely. This article discusses chemical biology as currently understood by EFMC, including all activities dealing with the design and synthesis of biologically active chemical tools and their use to probe, characterize, or influence biological systems. 相似文献
965.
Violetta V. Kravtsova Inna I. Paramonova Natalia A. Vilchinskaya Maria V. Tishkova Vladimir V. Matchkov Boris S. Shenkman Igor I. Krivoi 《International journal of molecular sciences》2021,22(8)
Sustained sarcolemma depolarization due to loss of the Na,K-ATPase function is characteristic for skeletal muscle motor dysfunction. Ouabain, a specific ligand of the Na,K-ATPase, has a circulating endogenous analogue. We hypothesized that the Na,K-ATPase targeted by the elevated level of circulating ouabain modulates skeletal muscle electrogenesis and prevents its disuse-induced disturbances. Isolated soleus muscles from rats intraperitoneally injected with ouabain alone or subsequently exposed to muscle disuse by 6-h hindlimb suspension (HS) were studied. Conventional electrophysiology, Western blotting, and confocal microscopy with cytochemistry were used. Acutely applied 10 nM ouabain hyperpolarized the membrane. However, a single injection of ouabain (1 µg/kg) prior HS was unable to prevent the HS-induced membrane depolarization. Chronic administration of ouabain for four days did not change the α1 and α2 Na,K-ATPase protein content, however it partially prevented the HS-induced loss of the Na,K-ATPase electrogenic activity and sarcolemma depolarization. These changes were associated with increased phosphorylation levels of AMP-activated protein kinase (AMPK), its substrate acetyl-CoA carboxylase and p70 protein, accompanied with increased mRNA expression of interleikin-6 (IL-6) and IL-6 receptor. Considering the role of AMPK in regulation of the Na,K-ATPase, we suggest an IL-6/AMPK contribution to prevent the effects of chronic ouabain under skeletal muscle disuse. 相似文献
966.
967.
To fully understand particle interactions with both substrate and neighboring particles in cold spray, ultrasound wave generation and ultrasonic monitoring of particle impacts were studied. The multi-channel ultrasonic system works in pulse-echo and passive modes. In pauses between pulse-echo data acquisition frames the system is in the passive mode receiving the signals generated by the particle impacts. The particles being deposited generate the ultrasonic signals in a very wideband frequency range at more than 40?dB signal-to-noise ratio. The particle impact signals are considered as a sum of the background wideband noise and the sparse strong pulses observed when the nozzle passes over the location of the transducer. It was shown that these components of the particle impact signal can be separated by threshold processing. The results of the passive monitoring are confirmed by the ultrasonic pulse-echo and direct measurements of a deposited coating geometry. 相似文献
968.
Boris A. Trofimov Marina V. Markova Lyudmila V. Morozova Al’bina I. Mikhaleva Lyubov’ N. Sobenina Ol’ga V. Petrova Tamara I. Vakul'skaya Galina F. Myachina Konstantin B. Petrushenko 《Synthetic Metals》2010,160(13-14):1539-1543
Cationic polymerization of N-vinyl-2-phenylpyrrole (catalysts: Me3SiCl, CF3COOH, BF3·OEt2, HCl, WCl6, FeCl3, complex LiBF4–dimethoxyethane, catalysts concentration 1–2 wt%, 20–70 °C, 24–48 h) affords oligomers (molecular weight 1400–1700) of a unexpected structure with alternating 2-phenylpyrrole and ethylydene units, the yields reaching 63%. The oligomers structure has been supported by isolation and identification of the corresponding dimer, N-vinyl-2-phenyl-5-[N-(2-phenyl-1H-pyrrol-1-yl)ethyl]-1H-pyrrole. Radical polymerization of the same monomer (AIBN, 1.5–4 wt%, 60–80 °C, 40–60 h or UV irradiation or both) gives oligomers (molecular weight 2100–3000) of normal structure having polyethene backbone with pendant 2-phenylpyrrole groups in up to 40% yields. The oligomers of both types are semiconductors (1.3 × 10?6–3.6 × 10?6 S/cm) after doping with I2, paramagnetic (4.2 × 1017–8.7 × 1017 g?1) and fluorescent in a near UV region (λ 355–363 nm, acetonitrile). 相似文献
969.
The kinetics of poly(butylene succinate) synthesis and the influence of molar mass on its thermal properties 下载免费PDF全文
The synthesis of poly(butylene succinate) (PBS) of Mw ranging from 4000 to 180,000 g mol?1 is realized with molar ratios [COOH]0/[OH]0 of 1 and 0.98, and varying amounts of titanium (IV) tetrabutoxide (TBT) catalyst. Polycondensation kinetics are followed by chemical titration of carboxylic groups, and the kinetic rate constants of self‐catalyzed and external‐catalyzed reactions are calculated. The synthesis of PBS with high molar mass follows the classical Flory theory. The effect of molar mass on PBS thermal properties is also studied. A faster crystallization rate and a higher temperature of crystallization are observed, for very high molar masses. This behavior could be due to a memory effect of the polymer. Complex melting behavior of PBS is induced by a continuous reorganization of the crystalline phase, as observed by MTDSC. DSC measurements also reveal that the crystallinity—and so the amorphous phase—is limited to about 35% when the molar mass Mn is higher than 40,000 g mol?1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40639. 相似文献
970.
Exploring the Arabidopsis Proteome: Influence of Protein Solubilization Buffers on Proteome Coverage
Claudius Marondedze Aloysius Wong Arnoud Groen Natalia Serrano Boris Jankovic Kathryn Lilley Christoph Gehring Ludivine Thomas 《International journal of molecular sciences》2015,16(1):857-870
The study of proteomes provides new insights into stimulus-specific responses of protein synthesis and turnover, and the role of post-translational modifications at the systems level. Due to the diverse chemical nature of proteins and shortcomings in the analytical techniques used in their study, only a partial display of the proteome is achieved in any study, and this holds particularly true for plant proteomes. Here we show that different solubilization and separation methods have profound effects on the resulting proteome. In particular, we observed that the type of detergents employed in the solubilization buffer preferentially enriches proteins in different functional categories. These include proteins with a role in signaling, transport, response to temperature stimuli and metabolism. This data may offer a functional bias on comparative analysis studies. In order to obtain a broader coverage, we propose a two-step solubilization protocol with first a detergent-free buffer and then a second step utilizing a combination of two detergents to solubilize proteins. 相似文献