全文获取类型
收费全文 | 124篇 |
免费 | 19篇 |
出版年
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 25篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2002年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1992年 | 2篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1975年 | 2篇 |
1948年 | 1篇 |
1943年 | 1篇 |
1929年 | 1篇 |
1926年 | 1篇 |
1925年 | 1篇 |
1924年 | 1篇 |
1921年 | 1篇 |
1920年 | 1篇 |
1915年 | 2篇 |
1914年 | 1篇 |
1909年 | 1篇 |
1902年 | 1篇 |
1901年 | 1篇 |
1897年 | 2篇 |
1892年 | 1篇 |
1891年 | 1篇 |
1889年 | 1篇 |
1888年 | 1篇 |
1887年 | 1篇 |
1883年 | 3篇 |
1882年 | 5篇 |
1881年 | 2篇 |
1880年 | 1篇 |
1879年 | 6篇 |
1878年 | 2篇 |
1877年 | 2篇 |
1876年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Fowler CJ Vedin V Sjöberg E 《Biochemical and biophysical research communications》1999,257(2):629-634
In the present study, the effects of the thiol oxidising agent diamide upon the properties of rat brain beta1-adrenergic and human platelet serotonin2A receptor recognition sites have been investigated using [3H](-)CGP-12177 (in the presence of ICI-118551) and [3H]LSD as ligands. (-)Isoprenaline inhibited [3H](-)CGP-12177 binding with nH values of 0.87, 0.67, and 0.56 for added Mg2+ concentrations of 0, 2.5, and 25 mM, respectively. Pretreatment with diamide increased the nH to above unity for the inhibition of the binding by (-)isoprenaline, without a concomitant effect on the inhibition of the binding by (-)propranolol. In contrast, diamide reduced the affinity of human platelet serotonin2A-receptors for antagonists, but did not consistently induce nH values above unity for the inhibition of antagonist binding by serotonin. These results suggest that cooperative interactions reported for cardiac muscarinic receptors may also occur for beta1-adrenergic receptors in the rat brain. 相似文献
5.
6.
Volatile odorous chemicals are detected by around a thousand different G protein-coupled odorant receptors in the mouse. We demonstrated that exposure of the behaving mouse to odorant for a few minutes led to induction of the immediate early gene c-fos for several hours in a fraction of the olfactory sensory neurones in the nasal cavity. Associated with this odorant-specific induction event was activation of extracellular-regulated kinase (ERK)1/2 that preceded increased c-fos expression. The distribution of odorant-activated neurones mimicked the scattered and spatially limited distribution of neurones expressing a single odorant receptor gene. A small change in odorant chemical structure caused a zonal shift in the spatial distribution of activated neurones, suggesting that the gene expression change resulted from specific receptor interaction. Repeated exposure to odorant or use of different concentrations did not change the pattern of c-fos induction. These results indicate that odorant-induced c-fos expression can be used to visualize odorant representations in the olfactory epithelium that reflect late cellular events regulated by adequate odorant receptor stimulation. 相似文献
7.
Background
Distance-based methods are popular for reconstructing evolutionary trees thanks to their speed and generality. A number of methods exist for estimating distances from sequence alignments, which often involves some sort of correction for multiple substitutions. The problem is to accurately estimate the number of true substitutions given an observed alignment. So far, the most accurate protein distance estimators have looked for the optimal matrix in a series of transition probability matrices, e.g. the Dayhoff series. The evolutionary distance between two aligned sequences is here estimated as the evolutionary distance of the optimal matrix. The optimal matrix can be found either by an iterative search for the Maximum Likelihood matrix, or by integration to find the Expected Distance. As a consequence, these methods are more complex to implement and computationally heavier than correction-based methods. Another problem is that the result may vary substantially depending on the evolutionary model used for the matrices. An ideal distance estimator should produce consistent and accurate distances independent of the evolutionary model used. 相似文献8.
Background
Profile hidden Markov model (HMM) techniques are among the most powerful methods for protein homology detection. Yet, the critical features for successful modelling are not fully known. In the present work we approached this by using two of the most popular HMM packages: SAM and HMMER. The programs' abilities to build models and score sequences were compared on a SCOP/Pfam based test set. The comparison was done separately for local and global HMM scoring. 相似文献9.
Vedin I Cederholm T Freund-Levi Y Basun H Garlind A Irving GF Eriksdotter-Jönhagen M Wahlund LO Dahlman I Palmblad J 《PloS one》2012,7(4):e35425
Background
Dietary fish oil, rich in n-3 fatty acids (n-3 FAs), e.g. docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), regulate inflammatory reactions by various mechanisms, e.g. gene activation. However, the effects of long-term treatment with DHA and EPA in humans, using genome wide techniques, are poorly described. Hence, our aim was to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global gene expression in peripheral blood mononuclear cells.Methods and Findings
In the present study, blood samples were obtained from a subgroup of 16 patients originating from the randomized double-blind, placebo-controlled OmegAD study, where 174 Alzheimer disease (AD) patients received daily either 1.7 g of DHA and 0.6 g EPA or placebo for 6 months. In blood samples obtained from 11 patients receiving n-3 FA and five placebo, expressions of approximately 8000 genes were assessed by gene array. Significant changes were confirmed by real-time PCR. At 6 months, the n-3 FAs group displayed significant rises of DHA and EPA plasma concentrations, as well as up- and down-regulation of nine and ten genes, respectively, was noticed. Many of these genes are involved in inflammation regulation and neurodegeneration, e.g. CD63, MAN2A1, CASP4, LOC399491, NAIP, and SORL1 and in ubiqutination processes, e.g. ANAPC5 and UBE2V1. Down-regulations of ANAPC5 and RHOB correlated to increases of plasma DHA and EPA levels.Conclusions
We suggest that 6 months of dietary n-3 FA supplementation affected expression of genes that might influence inflammatory processes and could be of significance for AD.Trial Registration
ClinicalTrials.gov NCT00211159相似文献10.