全文获取类型
收费全文 | 167篇 |
免费 | 9篇 |
国内免费 | 115篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2021年 | 2篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 12篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 6篇 |
2009年 | 4篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 15篇 |
2005年 | 21篇 |
2004年 | 24篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 6篇 |
1997年 | 10篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1980年 | 1篇 |
1959年 | 7篇 |
1958年 | 6篇 |
1956年 | 3篇 |
1955年 | 4篇 |
1954年 | 7篇 |
1953年 | 3篇 |
1952年 | 1篇 |
1951年 | 7篇 |
1950年 | 2篇 |
1949年 | 2篇 |
1944年 | 1篇 |
1943年 | 1篇 |
1941年 | 1篇 |
1940年 | 5篇 |
1939年 | 2篇 |
1938年 | 2篇 |
排序方式: 共有291条查询结果,搜索用时 265 毫秒
91.
92.
93.
94.
95.
Yoo SA Bae DG Ryoo JW Kim HR Park GS Cho CS Chae CB Kim WU 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(9):5846-5855
Vascular endothelial growth factor (VEGF) has been suggested to play a critical role in the pathogenesis of rheumatoid arthritis (RA). We previously identified a novel RRKRRR hexapeptide that blocked the interaction between VEGF and its receptor through the screening of peptide libraries. In this study, we investigated whether anti-VEGF peptide RRKRRR (dRK6) could suppress collagen-induced arthritis (CIA) and regulate the activation of mononuclear cells of RA patients. A s.c. injection of dRK6 resulted in a dose-dependent decrease in the severity and incidence of CIA and suppressed synovial infiltration of inflammatory cells in DBA/1 mice. In these mice, the T cell responses to type II collagen (CII) in lymph node cells and circulating IgG Abs to CII were also dose-dependently inhibited by the peptides. In addition, VEGF directly increased the production of TNF-alpha and IL-6 from human PBMC. Synovial fluid mononuclear cells of RA patients showed a greater response to VEGF stimulation than the PBMC of healthy controls. The major cell types responding to VEGF were monocytes. Moreover, anti-VEGF dRK6 inhibited the VEGF-induced production of TNF-alpha and IL-6 from synovial fluid mononuclear cells of RA patients and decreased serum IL-6 levels in CIA mice. In summary, we observed first that dRK6 suppressed the ongoing paw inflammation in mice and blocked the VEGF-induced production of proinflammatory cytokines. These data suggest that dRK6 may be an effective strategy in the treatment of RA, and could be applied to modulate various chronic VEGF-dependent inflammatory diseases. 相似文献
96.
Geographical and altitudinal population genetic structure of two dung fly species with contrasting mobility and temperature preference 总被引:2,自引:0,他引:2
Local adaptation of populations requires some degree of spatio-temporal isolation. Previous studies of the two dung fly species Scathophaga stercoraria and Sepsis cynipsea have revealed low levels of geographic and altitudinal genetic differentiation in quantitative life history and morphological traits, but instead high degrees of phenotypic plasticity. These patterns suggest that gene flow is extensive despite considerable geographic barriers and large spatio-temporal variation in selection on body size and related traits. In this study we addressed this hypothesis by investigating genetic differentiation of dung fly populations throughout Switzerland based on the same 10 electrophoretic loci in each species. Overall, we found no significant geographic differentiation of populations for either species. This is inconsistent with the higher rates of gene flow expected due to better flying capacity of the larger S. stercoraria. However, heterozygote deficiencies within populations indicated structuring on a finer scale, seen for several loci in S. cynipsea, and for the locus PGM (Phosphoglucomutase) in S. stercoraria. Additionally, S. cynipsea showed a tendency towards a greater gene diversity at higher altitudes, mediated primarily by the locus MDH (malate dehydrogenase), at which a second allele was only present in populations above 1000 m. This may be caused by increased environmental stress at higher altitudes in this warm-adapted species. MDH might thus be a candidate locus subject to thermal selection in this species, but this remains to be corroborated by direct evidence. In S. stercoraria, no altitudinal variation was found. 相似文献
97.
Radiation sensitivity of lymphocytes from healthy individuals and cancer patients as measured by the comet assay 总被引:4,自引:0,他引:4
Müller WU Bauch T Stüben G Sack H Streffer C 《Radiation and environmental biophysics》2001,40(1):83-89
Lymphocytes of healthy volunteers (n=24) and of tumour patients (n=30, 18 of whom had experienced severe side-effects) were irradiated with x-rays in vitro. DNA damage was analysed after 0.25–2
Gy and DNA repair after 2 Gy, and quantification of both endpoints was done by the comet assay. The individual differences
in radiation-induced DNA damage as well as in the repair kinetics were observed to be striking for both healthy donors and
tumour patients. After a repair time of 3 h, following 2 Gy x-irradiation, some of the healthy volunteers showed no residual
DNA damage at all in their lymphocytes, whereas others revealed about 30%. There was no indication that our results were affected
by either age, gender or smoking habits. Slow repair kinetics and high amounts of residual damage were characteristic for
many but not all tumour patients who had experienced severe side-effects in their normal tissues during or after radiotherapy
(n=18). Our conclusion is that those individuals showing poor DNA repair characteristics in the lymphocytes following in vitro
irradiation, have a high probability of being radiosensitive. The opposite conclusion is not necessarily true: if repair is
effective, this does not mean that the individual is radioresistant, because factors other than impaired repair may cause
radiosensitivity.
Received: 3 May 2000 / Accepted: 1 December 2000 相似文献
98.
Emerging studies support that RNA-binding proteins(RBPs)play critical roles in human biology and pathogenesis.RBPs are essential players in RNA processing and metabolism,including pre-mRNA splicing,polyadenylation,transport,surveillance,mRNA localization,mRNA stability control,translational control and editing of various types of RNAs.Aberrant expression of and mutations in RBP genes affect various steps of RNA processing,altering target gene function.RBPs have been associated with various diseases,including neurological diseases.Here,we mainly focus on selected RNA-binding proteins including Nova-1/Nova-2,HuR/HuB/HuC/HuD,TDP-43,Fus,Rbfox1/Rbfox2,QKI and FMRP,discussing their function and roles in human diseases. 相似文献
99.
100.
LI XiWen GAO HuanHuan WANG YiTao SONG JingYuan HENRY Robert WU HeZhen HU ZhiGang YAO Hui LUO HongMei LUO Kun PAN HongLin CHEN ShiLin 《中国科学:生命科学英文版》2013,56(2):189-198
Magnolia grandiflora is an important medicinal,ornamental and horticultural plant species.The chloroplast(cp) genome of M.grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species.The complete cp genome of M.grandiflora was 159623 bp in length and contained a pair of inverted repeats(IR) of 26563 bp separated by large and small single copy(LSC,SSC) regions of 87757 and 18740 bp,respectively.A total of 129 genes were successfully annotated,18 of which included introns.The identity,number and GC content of M.grandiflora cp genes were similar to those of other Magnoliaceae species genomes.Analysis revealed 218 simple sequence repeat(SSR) loci,most composed of A or T,contributing to a bias in base composition.The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M.grandiflora cp genome vectors.In addition,results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycf1 gene.Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony(MP) and maximum likelihood(ML) methods provided strong support for the phylogenetic position of Magnolia.The availability of the complete cp genome sequence of M.grandiflora provides valuable information for breeding of desirable varieties,cp genetic engineering,developing useful molecular markers and phylogenetic analyses in Magnoliaceae. 相似文献