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   90篇
  免费   17篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2015年   5篇
  2014年   3篇
  2013年   5篇
  2012年   4篇
  2011年   9篇
  2010年   3篇
  2009年   2篇
  2008年   2篇
  2007年   3篇
  2006年   3篇
  2005年   3篇
  2004年   2篇
  2003年   1篇
  2000年   1篇
  1999年   4篇
  1998年   4篇
  1997年   3篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1992年   2篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1987年   2篇
  1986年   2篇
  1984年   6篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1970年   2篇
  1969年   4篇
  1967年   1篇
  1966年   1篇
排序方式: 共有107条查询结果,搜索用时 31 毫秒
51.
52.
Proopiomelanocortin (POMC) contains several interesting, behaviorally active peptides. Release patterns of these fragments have been related to bizarre episodes of self-injurious behavior (SIB) among autistic individuals. Moreover, elevation in beta-endorphin (betaE) but not ACTH levels was associated with a positive response to an acutely administered, centrally acting opioid blocker among autistic individuals exhibiting SIB. In the present study, POMC fragments were measured in 12 self-injurious patients before and after long term (3 month) treatment with an opiate blocker naltrexone (NTX). POMC fragments were sampled from blood collected at the beginning of the baseline and placebo-controlled treatment phases of the study. Results indicated that the co-release (coupling) of POMC fragments were stable over time and the profile of POMC fragments in plasma predicted the effectiveness of a CNS acting drug in autistic subjects who self-injure.  相似文献   
53.
A variety of high-throughput methods have made it possible to generate detailed temporal expression data for a single gene or large numbers of genes. Common methods for analysis of these large data sets can be problematic. One challenge is the comparison of temporal expression data obtained from different growth conditions where the patterns of expression may be shifted in time. We propose the use of wavelet analysis to transform the data obtained under different growth conditions to permit comparison of expression patterns from experiments that have time shifts or delays. We demonstrate this approach using detailed temporal data for a single bacterial gene obtained under 72 different growth conditions. This general strategy can be applied in the analysis of data sets of thousands of genes under different conditions.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]  相似文献   
54.
55.
BackgroundThe diagnosis of tuberculosis (TB) in young children can be challenging, especially in severely malnourished children. There is a critical need for improved diagnostics for children. Thus, we sought to evaluate the performance of a technique that measures antibodies in lymphocyte supernatant (ALS) for the diagnosis of TB in severely malnourished children presenting with suspected pneumonia.MethodsChildren less than 5 years with severe acute malnutrition and radiological features of pneumonia admitted to the Dhaka Hospital of International Centre for Diarrhoeal Disease Research, Bangladesh, were enrolled consecutively following informed written consent. In addition to clinical and radiological assessment, samples taken for TB diagnosis included gastric lavage fluid and induced sputum for microbiological confirmation. ALS was measured from venous blood, and results were evaluated in children classified as “confirmed”, “non-confirmed TB” or “not TB”.ResultsAmong 224 children who had ALS analysis, 12 (5.4%) children had microbiologically “confirmed TB”, a further 41 (18%) had clinically diagnosed “non-confirmed TB” and the remaining 168 (75%) were considered not to have TB. ALS was positive in 89 (40%) and negative in 85 (39%) of children, with a large number (47 or 21%) reported as “borderline”. These proportions were similar between the three diagnostic groups. The sensitivity and specificity of ALS when comparing “Confirmed TB” to “Not TB” was only 67% (95% CI: 31–91%) and 51% (95% CI: 42–60%), respectively.

Conclusions and Significance

Our data suggest that ALS is not sufficiently accurate to improve the diagnosis of TB in children with severe malnutrition.  相似文献   
56.
57.
Lai WK  Buck MJ 《Genome biology》2010,11(12):R126-10
To facilitate identification and characterization of genomic functional elements, we have developed a chromatin architecture alignment algorithm (ArchAlign). ArchAlign identifies shared chromatin structural patterns from high-resolution chromatin structural datasets derived from next-generation sequencing or tiled microarray approaches for user defined regions of interest. We validated ArchAlign using well characterized functional elements, and used it to explore the chromatin structural architecture at CTCF binding sites in the human genome. ArchAlign is freely available at http://www.acsu.buffalo.edu/~mjbuck/ArchAlign.html.  相似文献   
58.
The mechanism of enterovirus inactivation by marine bacteria was investigated using poliovirus type 1 as a model virus and with strains of Pseudomonas and Vibrio isolated from the marine environment. Treatment of virus with cell-free filtrates from late log phase bacterial cultures produced alterations in the viral capsid as shown by a reduction in efficiency of adsorption to host cells, increased sensitivity to ribonuclease, and by the release of ribonucleic acid from the treated virions. Filtration of 14C-labelled, treated virus through 25-nm filters revealed that the majority of the isotope (85-96%) passed the filters, indicating extensive capsid disruption. However, the most rapid and pronounced change observed during virus inactivation was the loss of infectivity, suggesting that enzymatic degradation is not the first event in the poliovirus inactivation process by marine bacteria.  相似文献   
59.
The function of the ubiquitous actin-binding protein, caldesmon (l-CaD) in mammalian non-muscle cells remains elusive. During mitosis, l-CaD becomes markedly phosphorylated at Ser497 and Ser527 (in the rat sequence), therefore, it has been suggested that l-CaD is involved in cytokinesis by inhibiting the actomyosin interaction until it is phosphorylated, although direct in vivo evidence is still missing. In the present study, we used F-actin staining and specific antibodies against these two phosphorylation sites of l-CaD to simultaneously monitor actin assembly and l-CaD phosphorylation. Our observations demonstrated that the level of l-CaD phosphorylation undergoes dynamic changes during the cell cycle. The spatial and temporal distributions of phospho-CaD do not correlate with cytokinesis per se, but rather, with the level of actin bundles in a reciprocal manner. The highest l-CaD phosphorylation level coincides with the disassembly of actin cytoskeleton during mitotic cell rounding. Ser-to-Ala mutations at these two positions prevent stress fibers from disassembly upon migratory stimulation. In addition, phospho-CaD appears to colocalize with nascent focal adhesion complexes during postmitotic spreading. These findings suggest that l-CaD phosphorylation plays an important role not only in cytoskeleton remodeling during cell shape changes, but also in cell spreading and migration.  相似文献   
60.
Heat lysis is a very reliable method for high-throughput labs to decrease costs and increase throughput with little sacrifice in quality of sequence data compared to typically used two-plate or magnetic-bead DNA purification methods. Laboratories employing this procedure on high-copy plasmids, using a sequencing reaction with a 1/8th Big Dye (Applied Biosystems) dilution, have reported generating data with 85% of all wells having read lengths of at least 600 bases with quality value (QV) 20 or above.1We have adopted this procedure in our laboratory and optimized it for sequencing from various in-house cDNA and genomic shotgun libraries cloned into high-copy plasmids, as well as for libraries constructed outside of our sequencing center. To fully develop the procedure, we utilized a number of culture plates, testing different plate volumes, well shapes, and growth times. Also, we tested various volumes of resuspension buffer in order to generate the highest sequencing success rates and read lengths. To further cut costs, we optimized the sequencing reactions by testing various dilutions of Big Dye and template amounts.Based upon over 55,000 reads, we have been able to consistently generate sequencing results with average success rates of 90–95% and read lengths of over 700 bases with QV 20 or above. Our past protocol employed a standard two-plate DNA preparation method with a 1/16th Big Dye dilution in the sequencing reaction. In contrast, we now use the optimized heat lysis protocol combined with a 1/32nd Big Dye dilution. These changes have increased throughput and produced the high-quality sequencing results stated above, yet reduced our consumables cost by over 55%.  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