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排序方式: 共有3437条查询结果,搜索用时 46 毫秒
91.
Michael J. Dube Dennis Bollea William R. Jones Jr. Mario Marchetti Mark J. Jansen 《Tribology Letters》2003,14(1):3-8
Synthetic hydrocarbon liquid lubricants (based on polyalphaolefins) have been developed for use in space applications. These materials have been fully characterized and their physical properties reported which include: kinematic and absolute viscosity, viscosity index, vapor pressure, evaporation, specific gravity, pour point, coefficient of thermal expansion, refractive index, and flow activation energy. In addition, tribological properties under ultrahigh vacuum conditions have been determined. These include: lubricated lifetimes using a spiral orbit tribometer (SOT) and vacuum four-ball wear rates. These values are compared to existing state-of-the-art space lubricants. 相似文献
92.
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94.
This paper considers the fixed-structure, discrete-time mixed H 2 / H X controller synthesis problem in the delta operator (difference operator) framework. The differential operator and shift operator versions of the problem are reviewed for comparison, and necessary conditions are derived for all three formulations. A quasi-Newton/continuation algorithm is then used to obtain approximate solutions to these equations. Controllers are synthesized for two numerical examples, and the performance of the algorithm on the differential, difference and shift operator versions of the problems is compared. 相似文献
95.
Stefan Alexander Tennigkeit Raziye Karapinar Till Rudack Max-Aylmer Dreier Philipp Althoff Dennis Eickelbeck Tatjana Surdin Michelle Grömmke Melanie D. Mark Katharina Spoida Mathias Lübben Udo Höweler Prof. Dr. Stefan Herlitze Prof. Dr. Klaus Gerwert 《Chembiochem : a European journal of chemical biology》2019,20(14):1766-1771
The primary goal of optogenetics is the light-controlled noninvasive and specific manipulation of various cellular processes. Herein, we present a hybrid strategy for targeted protein engineering combining computational techniques with electrophysiological and UV/visible spectroscopic experiments. We validated our concept for channelrhodopsin-2 and applied it to modify the less-well-studied vertebrate opsin melanopsin. Melanopsin is a promising optogenetic tool that functions as a selective molecular light switch for G protein-coupled receptor pathways. Thus, we constructed a model of the melanopsin Gq protein complex and predicted an absorption maximum shift of the Y211F variant. This variant displays a narrow blue-shifted action spectrum and twofold faster deactivation kinetics compared to wild-type melanopsin on G protein-coupled inward rectifying K+ (GIRK) channels in HEK293 cells. Furthermore, we verified the in vivo activity and optogenetic potential for the variant in mice. Thus, we propose that our developed concept will be generally applicable to designing optogenetic tools. 相似文献
96.
Otis Smart Douglas MausEric Marsh Dennis DlugosBrian Litt Kimford Meador 《Expert systems with applications》2012,39(8):7355-7370
Localizing an epileptic network is essential for guiding neurosurgery and antiepileptic medical devices as well as elucidating mechanisms that may explain seizure-generation and epilepsy. There is increasing evidence that pathological oscillations may be specific to diseased networks in patients with epilepsy and that these oscillations may be a key biomarker for generating and indentifying epileptic networks. We present a semi-automated method that detects, maps, and mines pathological gamma (30-100 Hz) oscillations (PGOs) in human epileptic brain to possibly localize epileptic networks. We apply the method to standard clinical iEEG (<100 Hz) with interictal PGOs and seizures from six patients with medically refractory epilepsy. We demonstrate that electrodes with consistent PGO discharges do not always coincide with clinically determined seizure onset zone (SOZ) electrodes but at times PGO-dense electrodes include secondary seizure-areas (SS) or even areas without seizures (NS). In 4/5 patients with epilepsy surgery, we observe poor (Engel Class 4) postsurgical outcomes and identify more PGO-activity in SS or NS than in SOZ. Additional studies are needed to further clarify the role of PGOs in epileptic brain. 相似文献
97.
Daniel Stubba Dr. Dennis Bensinger Janika Steinbacher Lilia Proskurjakov Álvaro Salcedo Gómez Dr. Uwe Schmidt Prof. Dr. Stefan Roth Prof. Dr. Katja Schmitz Prof. Dr. Boris Schmidt 《ChemMedChem》2019,14(23):2005-2022
The ubiquitin-proteasome system (UPS) is an established therapeutic target for approved drugs to treat selected hematologic malignancies. While drug discovery targeting the UPS focuses on irreversibly binding epoxyketones and slowly-reversibly binding boronates, optimization of novel covalent-reversibly binding warheads remains largely unattended. We previously reported α-ketoamides to be a promising reversible lead motif, yet the cytotoxic activity required further optimization. This work focuses on the lead optimization of phenoxy-substituted α-ketoamides combining the structure-activity relationships from the primed and the non-primed site of the proteasome β5 subunit. Our optimization strategy is accompanied by molecular modeling, suggesting occupation of P1′ by a 3-phenoxy group to increase β5 inhibition and cytotoxic activity in leukemia cell lines. Key compounds were further profiled for time-dependent inhibition of cellular substrate conversion. Furthermore, the α-ketoamide lead structure 27 does not affect escape response behavior in Danio rerio embryos, in contrast to bortezomib, which suggests increased target specificity. 相似文献
98.
Beierlein Dennis Häussermann Dorothea Traa Yvonne Klemm Elias 《Catalysis Letters》2022,152(10):2908-2919
Catalysis Letters - We developed a rapid aging method for Ni/Al2O3 methanation catalysts mimicking the real aging in the actual application. The method is based on hydrothermal deactivation of the... 相似文献
99.
Although theoretically necessary, social capital is usually not considered within the process of asset allocation for private
investors. Both the lack of appropriate practical valuation concepts and the effort of providing and processing the required
information as input for a valuation have been obstacles to properly include social capital in this process. However, first
theoretical financial models for the evaluation of social capital have recently become available. Moreover, the fast growth
of business community websites and the technological progress in Web 2.0 tools that allow and acquire the active involvement
of users, facilitate the provision and processing of valuation-relevant information. In this paper we focus on this second
aspect and propose a social software-based concept that allows for an integration of social capital in the asset allocation
process. 相似文献
100.
Taste perception and purchase intent of oil‐in‐water spreads: effects of oil types and salt (NaCl or KCl) concentrations 下载免费PDF全文
Wilfredo Alejandro Cerrato Rodriguez Damir Dennis Torrico Luis Fernando Osorio Jorge Cardona Witoon Prinyawiwatkul 《International Journal of Food Science & Technology》2017,52(10):2138-2147
Associations of sodium intake with heart‐related problems are creating awareness towards reducing sodium. Potassium chloride (KCl), a substitute for sodium chloride (NaCl), has the disadvantage of imparting bitterness at high concentrations. We evaluated physical characteristics, taste perception and purchase intent of KCl and NaCl in oil‐in‐water spreads/emulsions composed by olive, rice bran and soya bean oils. Consumers (N = 300) evaluated saltiness/bitterness of emulsions prepared with 65% oil, and NaCl (0.5% and 1.0%) or KCl (0.75% and 1.5%). Olive oil spreads (104.07–107.43 Pa s) had higher viscosity compared to other spreads (59.16–74.96 Pa s). Type of oil had significant effects on bitterness, overall taste liking and viscosity. Taste liking decreased due to bitterness of olive oil spreads (mean drop=1.72–2.43). Purchase intent was positively associated with saltiness and pH and increased with oil claims (increase = 1.3%–22.1%) compared to sodium claims (increase = 0.0%–12.9%). These findings are useful for understanding taste perception of emulsions. 相似文献