首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   50篇
  免费   1篇
  51篇
  2021年   1篇
  2020年   2篇
  2019年   1篇
  2018年   4篇
  2017年   5篇
  2016年   1篇
  2015年   5篇
  2014年   1篇
  2013年   1篇
  2012年   3篇
  2011年   2篇
  2010年   2篇
  2009年   1篇
  2007年   1篇
  2004年   6篇
  2003年   1篇
  2002年   2篇
  2001年   2篇
  2000年   6篇
  1998年   1篇
  1989年   2篇
  1988年   1篇
排序方式: 共有51条查询结果,搜索用时 0 毫秒
1.
The cleavable homobifunctional reagent dichloro[N,N,N',N'-tetrakis(2-aminoethyl)-1,6-hexamethylenediamminedi platinum (II)] dichloride was used for studying rRNA-protein cross-links in free 35S-labelled 70 S ribosomes and within initiation complex ribosome.AUGU6.fMet-tRNA(fMet). It was shown that the sets of proteins cross-linked to 16 S and 23 S rRNA in free 70 S ribosomes and in 70 S initiation complex do not differ significantly. The authors are the first to demonstrate most of the 23 S rRNA-protein cross-links and some 16 S rRNA-protein cross-links, in particular those with L7/L12 protein.  相似文献   
2.
Probiotics and Antimicrobial Proteins - Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is...  相似文献   
3.
Probiotics and Antimicrobial Proteins - A promising approach for slowing down the rate of reproductive aging is the use of probiotic bacteria as a feed additive. In the current study was...  相似文献   
4.
In T-10 experiments, attempts were made to significantly exceed the Greenwald limit $\bar n_{Gr} $ during high-power (P ab=750 kW) electron-cyclotron resonance heating (ECRH) and gas puffing. Formally, the density limit $(\bar n_e )_{\lim } $ exceeding the Greenwald limit $({{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }} = 1.8)$ was achieved for q L=8.2. However, as q L decreased, the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ also decreased, approaching unity at q L≈3. It was suggested that the “current radius” (i.e., the radius of the magnetic surface enclosing the bulk of the plasma current I p), rather than the limiter radius, was the parameter governing the value of $(\bar n_e )_{\lim } $ . In the ECRH experiments, no substantial degradation of plasma confinement was observed up to $\bar n_e \sim 0.9(\bar n_e )_{\lim } $ regardless of the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ . In different scenarios of the density growth up to $(\bar n_e )_{\lim } $ , two types of disruptions related to the density limit were observed.  相似文献   
5.
Results are presented from studies of the time evolution of the ion temperature in the T-10 tokamak in the course of injection of several (up to five) deuterium pellets into a deuterium plasma the electron component of which is heated at the second harmonic of the electron gyrofrequency. It is shown that, at an electron cyclotron heating power of 900 kW, the injection of five pellets is accompanied by an increase in the ion temperature to 1200 keV, which is a record value for T-10. It is noted that energy exchange between the electron and ion components in these experiments is a purely classical, Coulomb process.  相似文献   
6.
7.
Endotoxin tolerance (ET) represents a state of an altered immune response induced by multiple stimulations of a cell, a tissue, or an organism with lipopolysaccharide. Characteristics of ET include downregulation of induction of proinflammatory genes (TNFα, IL6, and others) and enhancement of induction of antiinflammatory genes (IL10, TGFβ). ET generally has protective functions; nevertheless, it might result in a state of innate immune deficiency and cause negative outcomes. A current issue is the search for the mechanisms controlling the level of inflammation in the course of endotoxin tolerance. In this work, we investigated the change in cyclooxygenase 2 (Cox2) expression in the model of endotoxin tolerance in astrocytes and analyzed the possibility of regulating this process applying nuclear receptor PPAR agonists. Our results indicate that: 1) endotoxin tolerance can be induced in astrocytes and results in TNFα and Cox2 mRNA induction decrease upon secondary stimulation; 2) tolerance is revealed on the level of TNFα release and Cox2 protein expression; 3) PPAR agonists GW7647, L-165041, and rosiglitazone control Cox2 mRNA expression levels under conditions of endotoxin tolerance. In particular, rosiglitazone (a PPARγ agonist) induces Cox2 mRNA expression, while GW7647 (a PPARα agonist) and L-165041 (a PPARβ agonist) suppress the expression. Our results demonstrate that Cox2 can be upand downregulated during endotoxin tolerance in astrocytes, and PPAR agonists might be effective for controlling this target under conditions of multiple proinflammatory stimulations of brain tissues with endotoxin.  相似文献   
8.
The importance of six theoretically calculated molecular parameters in the antigibberellin (retardant) activity of quaternary ammonium salts is studied using a regression analysis. A bioassay system based on cell culture of fungus Gibberella fujikuroi is used to determine the activity. In the case of N,N,N-trimethyl-N-(2-hydroxyethyl)ammonium chloride (choline) and N,N,N-triethyl-N-(2-hydroxyethyl)ammonium chloride (N,N,N-triethylcholine) derivatives with linear structure, the polarizability, proton acceptor activity, and lipophilicity of these compounds exert the largest effect on the antigibberellin activity. The antigibberellin activity of more sterically hindered N,N-dialkylpiperidinium salts was mainly defined by the steric parameter, while the polarizability, proton acceptor activity, and (through them) lipophilicity exert a lesser effect. Other parameters are of minor importance for the three groups of compounds studied.  相似文献   
9.
Probiotics and Antimicrobial Proteins - The study aims at elucidating the effect of bacilli probiotic preparations on the physiology of laying hens and roosters. Probiotic formulations were...  相似文献   
10.
One of the important components of the concept of aging-phenoptosis (programmed aging) is the notion of aging as an accelerator of evolution having the rank of subconcept. For many reasons, the main being the problematic experimental testing of evolutionary hypotheses, verification of the above-mentioned subconcept can be based primarily on analysis of the internal inconsistency of heuristic models and their correspondence to undisputedly observed facts. To illustrate the acceleration mechanism, and most importantly to structure the evolutionary process in communities that include naturally weakened individuals, V. P. Skulachev offered in 2003 a conceptual model that he later called a “fable about hares”. Despite its simplicity, this model has undoubted internal logic. The natural trend in the development of conceptual models is their translation into the language of mathematics. The purpose of the present work was to create a variation of the known multi-agent model “predator–prey” that would allow us to “see” how the presence in the prey population of naturally weakened (old) members stimulates the selection of individuals with traits whose adaptive potential is not devaluated with age. The model (http://homebear.ru/PD) was developed on the Java platform, version 6, NetBeans development environment 8.2. Statistical analysis and preparation of illustrative materials were carried out using environment R, version 3.4.1. The results of numerical experiments set using our model correspond in principle to the provisions of the heuristic model of Skulachev and, consequently, confirm the absence in it of logical contradictions.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号