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排序方式: 共有218条查询结果,搜索用时 31 毫秒
51.
Mona TaghaviAuthor Vitae Nikita SchmidtAuthor Vitae 《Computer Standards & Interfaces》2012,34(1):162-170
This study presents an analysis of users' queries directed at different search engines to investigate trends and suggest better search engine capabilities. The query distribution among search engines that includes spawning of queries, number of terms per query and query lengths is discussed to highlight the principal factors affecting a user's choice of search engines and evaluate the reasons of varying the length of queries. The results could be used to develop long to short term business plans for search engine service providers to determine whether or not to opt for more focused topic specific search offerings to gain better market share. 相似文献
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53.
Yulia V. Vakhitova Tatiana S. Kalinina Liana F. Zainullina Anastasiya Yu. Lusta Anna V. Volkova Nikita V. Kudryashov Tatiana A. Gudasheva Alexander A. Shimshirt Ilya A. Kadnikov Mikhail V. Voronin Sergei B. Seredenin 《International journal of molecular sciences》2021,22(24)
Induction of BDNF-TrkB signaling is associated with the action mechanisms of conventional and fast-acting antidepressants. GSB-106, developed as a small dimeric dipeptide mimetic of BDNF, was previously shown to produce antidepressant-like effects in the mouse Porsolt test, tail suspension test, Nomura water wheel test, in the chronic social defeat stress model and in the inflammation-induced model of depression. In the present study, we evaluated the effect of chronic per os administration of GSB-106 to Balb/c mice under unpredictable chronic mild stress (UCMS). It was observed for the first time that long term GSB-106 treatment (1 mg/kg, 26 days) during ongoing UCMS procedure ameliorated the depressive-like behaviors in mice as indicated by the Porsolt test. In addition, chronic per os administration of GSB-106 resulted in an increase in BDNF levels, which were found to be decreased in the prefrontal cortex and hippocampus of mice after UCMS. Furthermore, prolonged GSB-106 treatment was accompanied by an increase in the content of pTrkB706/707 in the prefrontal cortex and by a pronounced increase in the level of pTrkB816 in both studied brain structures of mice subjected to UCMS procedure. In summary, the present data show that chronic GSB-106 treatment produces an antidepressant-like effect in the unpredictable chronic mild stress model, which is likely to be associated with the regulation of the BDNF-TrkB signaling. 相似文献
54.
Karin N. Westlund Marena A. Montera Aleyah E. Goins Sascha R. A. Alles Nikita Suri Sabrina L. McIlwrath Robyn Bartel Ravi V. Durvasula Adinarayana Kunamneni 《International journal of molecular sciences》2021,22(24)
Non-opioid single-chain variable fragment (scFv) small antibodies were generated as pain-reducing block of P2X4R receptor (P2X4R). A panel of scFvs targeting an extracellular peptide sequence of P2X4R was generated followed by cell-free ribosome display for recombinant antibody selection. After three rounds of bio-panning, a panel of recombinant antibodies was isolated and characterized by ELISA, cross-reactivity analysis, and immunoblotting/immunostaining. Generated scFv antibodies feature binding activity similar to monoclonal antibodies but with stronger affinity and increased tissue penetrability due to their ~30% smaller size. Two anti-P2X4R scFv clones (95, 12) with high specificity and affinity binding were selected for in vivo testing in male and female mice with trigeminal nerve chronic neuropathic pain (FRICT-ION model) persisting for several months in untreated BALBc mice. A single dose of P2X4R scFv (4 mg/kg, i.p.) successfully, completely, and permanently reversed chronic neuropathic pain-like measures in male mice only, providing retention of baseline behaviors indefinitely. Untreated mice retained hypersensitivity, and developed anxiety- and depression-like behaviors within 5 weeks. In vitro P2X4R scFv 95 treatment significantly increased the rheobase of larger-diameter (>25 µm) trigeminal ganglia (TG) neurons from FRICT-ION mice compared to controls. The data support use of engineered scFv antibodies as non-opioid biotherapeutic interventions for chronic pain. 相似文献
55.
Nikita M. Chernov Roman P. Kustin Yulia V. Pypa Sergej O. Anisimov Dar'ya V. Spiridonova Roman V. Shutov Igor P. Yakovlev 《Advanced Synthesis \u0026amp; Catalysis》2024,366(2):277-284
We studied a reaction of chromone-containing acrylonitriles and cyanoacrylates with acid hydrazides. This reaction turned out to be a method for the synthesis of salicyloyl-substituted 1,2,4-triazolo[1,5-a]pyridines. The synthesis developed is a tandem ring-opening/double ring-closing process. This synthetic approach is characterized by low toxic solvents (ethanol, butanol) and mediator (Et3N), 37–84% yields, non-chromatographic isolation of products, and substrate tolerance (59 examples). 相似文献
56.
Iliya Petriev Polina Pushankina Nikita Shostak Mikhail Baryshev 《International journal of molecular sciences》2022,23(1)
A method for obtaining composite gas-diffusion PdCu–Nb–PdCu membranes modified with a nanostructured crystalline coating was developed to increase the performance of Nb-based membranes. A modifying functional layer with a controlled size and composition was synthesized by electrochemical deposition, which made it possible to determine a certain geometric shape for palladium nanocrystallites. Developed PdCu–Nb–PdCu membranes have demonstrated flux values up to 0.232 mmol s−1 m−2 in the processes of diffusion purification of hydrogen at 400 °C. A very significant difference in the hydrogen fluxes through the modified and non-modified composite PdCu–Nb–PdCu membranes reached 1.73 times at the lower threshold temperature of 300 °C. Cu doping of protective layer did not affect the selective properties of the membranes, which was confirmed by the obtained high selectivity values up to 1323, and made it possible to reduce the noble metal content. The research data indicate that the modification of the membrane surface significantly accelerates the hydrogen transfer process at sufficiently low temperatures due to the acceleration of dissociative–associative processes on the surface. The reported approach demonstrates new possibilities for creating productive and cost-efficient membranes based on niobium. 相似文献
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58.
R. K. Mohanty Ravindra Kumar Nikita Setia 《International Journal for Computational Methods in Engineering Science and Mechanics》2021,22(1):45-59
Abstract We report a new cubic spline approximation based on half-step discretization of order 2 in y- and order 4 in x-directions, for 2D quasi-linear elliptic PDEs. We use only two extra half-step points in x-direction and a central point. The cubic spline method is directly obtained from the continuity of first derivative terms and is applicable to elliptic problems irrespective of coordinates, which is the main advantage of our work. The error analysis of a model problem is discussed in details. Some benchmark problems are solved in order to test the numerical stability and accuracy of the method. 相似文献
59.
This paper proposes a novel method of analysing trajectories followed by people while they perform navigational tasks. The
results indicate that modelling trajectories with Bézier curves provides a basis for the diagnosis of navigational patterns.
The method offers five indicators: goodness of fit, average curvature, number of inflexion points, lengths of straight line
segments, and area covered. Study results, obtained in a virtual environment show that these indicators carry important information
about user performance, specifically spatial knowledge acquisition.
Corina Sas is a Lecturer in the field of human–computer interaction in the Computing Department at Lancaster University. She holds bachelor
degrees in Computer Science and Psychology and an M.A. in Industrial Psychology from Romania. She received her Ph.D. degree
in Computer Science from University College Dublin in 2004. Her research interests include user modelling, adaptive systems,
data mining, spatial cognition, user studies and individual differences. She has published in various journals and international
conferences in these areas.
Nikita Schmidt is a Postdoctoral Research Fellow at University College Dublin (UCD). He received his Ph.D. degree from UCD in 2004 and M.Sc.
from St-Petersburg State University, Russia in 1994. His research interests include pervasive, ubiquitous and location-aware
computing, embedded systems, hardware-close software development and tree-structured data. His work experience is a mix of
industry and academia. 相似文献
60.
Nikita Kozhekin Vladimir Savchenko Mikhail Senin Ichiro Hagiwara 《The Visual computer》2003,19(7-8):549-564
In this paper, we discuss a novel, fast, practical algorithm for surface modification of geometric objects. A space-mapping technique is used to transform a given or damaged part of a surface into a different shape in a continuous manner. The proposed approach is used for surface-retouching and mesh-smoothing problems. The technique, in fact, is based on a local processing of polygonal data that can be applied to the fairing of 3D meshes. We consider shape transformation as a general type of operation for surface modification and attempt to approach the problem from a single point of view, namely, that of the space-mapping technique based on the implementation of radial-basis functions. Experimental results are included to demonstrate the functionality of our mesh-modeling tool. 相似文献