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   148篇
  免费   17篇
  165篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2016年   1篇
  2015年   4篇
  2014年   7篇
  2013年   10篇
  2012年   12篇
  2011年   12篇
  2010年   4篇
  2009年   12篇
  2008年   10篇
  2007年   11篇
  2006年   9篇
  2005年   8篇
  2004年   10篇
  2003年   5篇
  2002年   7篇
  2001年   7篇
  2000年   5篇
  1999年   3篇
  1998年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1982年   1篇
排序方式: 共有165条查询结果,搜索用时 0 毫秒
161.
As the pathogenesis of the HELLP-syndrome is unknown, a complex consideration regarding the changes in the plasma as the main transport medium in the body is of great benefit because it is well available and can rapidly be investigated in the clinics. Besides that, the liver which is early affected in HELLP-syndrome produces the main part of plasma proteins. For the purpose of our study plasma protein abundances from patients with HELLP-syndrome and from control individuals were determined before and after delivery. In the differential analysis using two-dimensional gel electrophoresis, six areas with variable protein spot intensities were detected. The reference gel that we developed for HELLP plasma samples integrates the changes of plasma proteins when comparing HELLP patients to healthy women prior to and after delivery. A specific plasma protein profile for the HELLP-syndrome was generated involving protein areas that contain inter-alpha-trypsin inhibitor heavy chain H4, kininogen 1, fibrinogen gamma chain, transthyretin, haptoglobins, and serum amyloid A with statistically significant expression differences when compared to controls. The most striking difference between the majority of the gels from HELLP patients and the gels from non-HELLP samples were clearly overexpressed protein spots at about 11 kDa which were identified as serum amyloid A (SAA). This differential expression was validated and quantitatively assayed by ELISA measurements against human SAA in plasma. Our results show that significant differences in SAA expressions between healthy controls and HELLP patients were obtained, that could function as markers for the HELLP-syndrome. According to our data it is possible to draw a line of separation with no overlap between the HELLP group for which SAA plasma levels were found to be above 3.51 mg/L and the non-HELLP groups in which SAA plasma levels were below 3.51 mg/L. It now is possible to clinically elucidate if the differentially expressed proteins are suited for longitudinal studies concerning both, to function as markers or perhaps even as disease predictors that might become relevant for diagnostic tests.  相似文献   
162.

Background

Codon usage plays a crucial role when recombinant proteins are expressed in different organisms. This is especially the case if the codon usage frequency of the organism of origin and the target host organism differ significantly, for example when a human gene is expressed in E. coli. Therefore, to enable or enhance efficient gene expression it is of great importance to identify rare codons in any given DNA sequence and subsequently mutate these to codons which are more frequently used in the expression host.

Results

We describe an open-source web-based application, ATGme, which can in a first step identify rare and highly rare codons from most organisms, and secondly gives the user the possibility to optimize the sequence.

Conclusions

This application provides a simple user-friendly interface utilizing three optimization strategies: 1. one-click optimization, 2. bulk optimization (by codon-type), 3. individualized custom (codon-by-codon) optimization. ATGme is an open-source application which is freely available at: http://atgme.org  相似文献   
163.
The chemical composition and vertical distribution of sediment phosphorus (P) in shallow coastal sediments of the northeastern Baltic Sea (BS) were characterized by sequential extraction. Different P forms were related to chemical and physical properties of the sediments and the chemistry of pore water and near-bottom water. Sediment P composition varied among the sampling sites located in the Archipelago Sea (AS) and along the northern coast of the Gulf of Finland (GoF): the organic rich sites were high in organic P (OP), while apatite-P dominated in the area affected by sediment transportation. Although the near-bottom water was oxic, the sediments released P. Release of P was most pronounced at the site with high sediment OP and reduced conditions in the sediment-water interface, indicating that P had its origins in organic sources as well as in reducible iron (Fe) oxyhydroxides. The results suggest that even though these coastal areas are shallow enough to lack salinity stratification typical for the brackish BS, they are vulnerable to seasonal oxygen (O2) depletion and P release because of their patchy bottom topography, which restricts mixing of water. Furthermore, coastal basins accumulate organic matter (OM) and OP, degradation of which further diminishes O2 and creates the potential for P release from the sediment. In these conditions, an abundance of labile OP may cause marked efflux of P from sediment reserves in the long-term.  相似文献   
164.
Objective: We determined whether fat accumulation in the liver is associated with features of insulin resistance independent of obesity. Research Methods and Procedures: We recruited 27 obese nondiabetic women in whom liver fat (LFAT) content was determined by proton spectroscopy, intra-abdominal and subcutaneous fat by magnetic resonance imaging, and insulin sensitivity by the euglycemic insulin clamp technique. The women were divided based on their median LFAT content (5%) to groups with low (3.2 ± 0.3%) and high (9.8 ± 1.5%) liver fat. The groups were almost identical with respect to age (36 ± 1 vs. 38 ± 1 years in low vs. high-LFAT), body mass index (32.2 ± 0.6 vs. 32.8 ± 0.5 kg/m2), waist-to-hip ratio, intra-abdominal, subcutaneous, and total fat content. Results: Women with high LFAT had features of insulin resistance including higher fasting serum triglyceride (1.93 ± 0.21 vs. 1.11 ± 0.09 mM, p < 0.01) and insulin (14 ± 3 vs. 10 ± 1 mU/L, p < 0.05) concentrations than women with low LFAT. The group with high LFAT also had higher 24-hour blood pressures, and lower whole-body insulin sensitivity compared with the low-LFAT group. Discussion: In obese women with previous gestational diabetes, LFAT, rather than any measure of body composition, is associated with features of insulin resistance.  相似文献   
165.
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