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   106篇
  免费   1篇
  2022年   1篇
  2017年   5篇
  2016年   2篇
  2015年   3篇
  2014年   1篇
  2013年   3篇
  2012年   3篇
  2011年   8篇
  2010年   9篇
  2009年   1篇
  2008年   2篇
  2007年   3篇
  2006年   1篇
  2005年   10篇
  2004年   6篇
  2003年   5篇
  2002年   3篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1992年   4篇
  1991年   6篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   4篇
  1986年   1篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1964年   1篇
排序方式: 共有107条查询结果,搜索用时 218 毫秒
1.
2.
3.
It was demonstrated that several 5'-phosphonates of 4'-thio-5-ethyl-2'-deoxyuridine possessed antiviral activity in vitro and in the murine model of herpes simplex virus type 1 infection. It was shown that the derivatives after intraabdominal administration penetrated effectively into the brain tissue. The agents provided statistically significant increase of the average life span, lower virus titre in the brain and lower lethality when compared to the control group of the animals. It is emphasized that the derivatives were less toxic than the original compound.  相似文献   
4.

Background  

Several cell lines and primary cultures benefit from the use of positively charged extracellular matrix proteins or polymers that enhance their ability to attach to culture plates. Polyethyleneimine is a positively charged polymer that has gained recent attention as a transfection reagent. A less known use of this cationic polymer as an attachment factor was explored with several cell lines.  相似文献   
5.
A number of new 5"-phosphonate derivatives of 4"-thio-5-ethyl-2"-deoxyuridine (TEDU) were synthesized. These compounds displayed a low cytotoxicity and, except for TEDU 5"-fluorophosphate, antiherpes activity similar to that of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir) and 9-(1,3-dihydroxy-2-propoxymethyl)guanine (pencyclovir). 5"-Ethoxycarbonylphosphonate and 5"-aminocarbonylphosphonate of TEDU were also found to suppress the reproduction of herpes simplex type 1 virus, which is resistant to acyclovir.  相似文献   
6.
Phosphonate derivatives of acyclovir containing phosphorous acid and ethoxycarbonylphosphonic acid residues as well as their isopropyl esters were prepared. They selectively inhibited the herpes simplex virus 1 reproduction in Vero cell culture, the efficacy of esters being 3-4 times higher than that of ACV. The hydrolysis of the synthesized compounds was studied in the PBS buffer and human blood serum.  相似文献   
7.
The aims of the present study were to investigate the relationship of aerobic and anaerobic parameters with 400 m performance, and establish which variable better explains long distance performance in swimming. Twenty-two swimmers (19.1±1.5 years, height 173.9±10.0 cm, body mass 71.2±10.2 kg; 76.6±5.3% of 400 m world record) underwent a lactate minimum test to determine lactate minimum speed (LMS) (i.e., aerobic capacity index). Moreover, the swimmers performed a 400 m maximal effort to determine mean speed (S400m), peak oxygen uptake (V.O2PEAK) and total anaerobic contribution (CANA). The CANA was assumed as the sum of alactic and lactic contributions. Physiological parameters of 400 m were determined using the backward extrapolation technique (V.O2PEAK and alactic contributions of CANA) and blood lactate concentration analysis (lactic anaerobic contributions of CANA). The Pearson correlation test and backward multiple regression analysis were used to verify the possible correlations between the physiological indices (predictor factors) and S400m (independent variable) (p < 0.05). Values are presented as mean ± standard deviation. Significant correlations were observed between S400m (1.4±0.1 m·s-1) and LMS (1.3±0.1 m·s-1; r = 0.80), V.O2PEAK (4.5±3.9 L·min-1; r = 0.72) and CANA (4.7±1.5 L·O2; r= 0.44). The best model constructed using multiple regression analysis demonstrated that LMS and V.O2PEAK explained 85% of the 400 m performance variance. When backward multiple regression analysis was performed, CANA lost significance. Thus, the results demonstrated that both aerobic parameters (capacity and power) can be used to predict 400 m swimming performance.  相似文献   
8.

Background

Genetic markers and maps are instrumental in quantitative trait locus (QTL) mapping in segregating populations. The resolution of QTL localization depends on the number of informative recombinations in the population and how well they are tagged by markers. Larger populations and denser marker maps are better for detecting and locating QTLs. Marker maps that are initially too sparse can be saturated or derived de novo from high-throughput omics data, (e.g. gene expression, protein or metabolite abundance). If these molecular phenotypes are affected by genetic variation due to a major QTL they will show a clear multimodal distribution. Using this information, phenotypes can be converted into genetic markers.

Results

The Pheno2Geno tool uses mixture modeling to select phenotypes and transform them into genetic markers suitable for construction and/or saturation of a genetic map. Pheno2Geno excludes candidate genetic markers that show evidence for multiple possibly epistatically interacting QTL and/or interaction with the environment, in order to provide a set of robust markers for follow-up QTL mapping.We demonstrate the use of Pheno2Geno on gene expression data of 370,000 probes in 148 A. thaliana recombinant inbred lines. Pheno2Geno is able to saturate the existing genetic map, decreasing the average distance between markers from 7.1 cM to 0.89 cM, close to the theoretical limit of 0.68 cM (with 148 individuals we expect a recombination every 100/148=0.68 cM); this pinpointed almost all of the informative recombinations in the population.

Conclusion

The Pheno2Geno package makes use of genome-wide molecular profiling and provides a tool for high-throughput de novo map construction and saturation of existing genetic maps. Processing of the showcase dataset takes less than 30 minutes on an average desktop PC. Pheno2Geno improves QTL mapping results at no additional laboratory cost and with minimum computational effort. Its results are formatted for direct use in R/qtl, the leading R package for QTL studies. Pheno2Geno is freely available on CRAN under “GNU GPL v3”. The Pheno2Geno package as well as the tutorial can also be found at: http://pheno2geno.nl.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-015-0475-6) contains supplementary material, which is available to authorized users.  相似文献   
9.
Thymidine kinase UL23 gene (EC 2.7.1.145) from the L2 acyclovir-sensitive strain of herpes simplex virus type 1 was cloned and expressed in E. coli. The enzyme was purified by chromatography to the purity of 90% according to PAG electrophoresis data. The Michaelis constants for the reactions with thymidine and acyclovir were determined. The enzyme was found to phosphorylate modified nucleosides, particularly 3′-deoxythymidine, 3′-deoxy-2′,3′-didehydrothymidine, 2′,3′-dideoxycytidine, 9-[(hydroxyethyl)methyl]guanine, E-5-(2-bromovinyl-2′-deoxyuridine, 9-(1,3-dihydroxy-2-propoxymethyl)guanine, 2′,3′-dideoxydehydrothymidine, β-L-2′,3′-dideoxy-3′-thiacytidine, and 3′-fluoro-3′-deoxythymidine. Some properties of the purified enzyme were compared with those of thymidine kinases of other herpes simplex virus strains. It was shown that acyclovir H-phosphonate inhibited the enzyme.  相似文献   
10.
The antiviral activity against HIV and HSV and the chemical stability of ACV phosphoramidate derivatives were studied. The phosphoramidates of ACV demonstrated moderate activity. The best compound appeared to be 9-(2-hydroxymethyl)guanine phosphoromonomorpholidate (7), which inhibited virus replication in pseudo-HIV-1 particles by 50% at 50 μM. It also inhibited replication of wild-type HSV-1 (9.7 μM) as well as an acyclovir-resistant strain (25 μM). None of the synthesised compounds showed any cytotoxicity.  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