全文获取类型
收费全文 | 603篇 |
免费 | 22篇 |
国内免费 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 24篇 |
2014年 | 12篇 |
2013年 | 45篇 |
2012年 | 25篇 |
2011年 | 23篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 30篇 |
2007年 | 18篇 |
2006年 | 25篇 |
2005年 | 30篇 |
2004年 | 37篇 |
2003年 | 31篇 |
2002年 | 22篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 16篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1973年 | 5篇 |
1967年 | 3篇 |
1963年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有626条查询结果,搜索用时 31 毫秒
461.
Shoichi Ozaki Hitoshi Honda Naoki Maruyama Sachiko Hirose Masaru Hamaoki Hidetoshi Sato Professor Toshikazu Shirai 《Immunogenetics》1983,18(3):241-254
The incidences of positive anti-erythrocyte autoantibodies (AEA) in New Zealand Black (NZB), C57BL/6, their F1, F2 hybrid, and the F1 × NZB backcross mice were 100, 0, 0, 17, and 51%, respectively. This finding is in keeping with the idea that a combined effect of one to three dominant predisposing NZB gene(s) and a single dominant modifying C57BL/6 gene regulates the AEA production. Studies suggested that the modifying locusAem-1 is loosely linked toMup-1 locus on chromosome 4, and the gene order isAem-1: Mup-1: Gpd-1. We analyzed the effects of theAem-1 locus on other autoimmune traits and found that the gene action ofAem-1 is unrelated to the spontaneous productions of dsDNA-specific antibodies, the retroviral gp70-anti-gp70 immune complexes and natural thymocytotoxic autoantibod ies and to the serum level of retroviral gp70. A significant association was observed between the negative AEA and the low (normal) serum IgM level in (C57BL/6 × NZB)F1 × NZB backcross mice. It remains to be determined whether theAem-1 locus also controls the serum IgM level.Abbreviations used in this paper AEA
anti-erythrocyte autoantibody
- NTA
natural thymocytotoxic autoantibody
- gp70
major glycoprotein constituent of the murine C type retrovirus envelope
-
Mup-1
major urinary protein complex-1
-
Gpd-1
glucose-6-phosphate dehydrogenase-1
-
Akp-1
alkaline phosphatase-1
-
Es-1
esterase-1
-
Igh-1
immunoglobulin (IgG2a) heavy chain-1 相似文献
462.
Kunio Ohmiya Shuya Tanimura Takeshi Kobayashi Shoichi Shimizu 《Biotechnology and bioengineering》1978,20(1):1-15
High activity alkaline protease was obtained when the enzyme was immobilized on Dowex MWA-1 (mesh 20–50) with 10% glutaraldehyde in chilled phosphate buffer (M/15, pH 6.5). Activity yields of the protease and rennet were 27 and 29, respectively. The highest activities appeared at 60°C, pH 10 for alkaline protease and 50°C, pH 4.0 for rennet. The properties of both proteases were not essentially changed by the immobilization except that the Km values of both enzymes were increased about tenfold as a result of immobilization. Both proteases in the immobilized state were more stable than those in the free state at 60°C. Other peptide hydrolases, β-galactosidase, invertase, and glucoamylase, were successfully immobilized with high activities, but lipase, hexokinase, glucose-6-phosphate dehydrogenase, and xanthine oxidase became inactive. 相似文献
463.
Shoichi Nakakuki 《Primates; journal of primatology》1994,35(4):513-517
In the lung of the crab-eating monkey (Macaca fascicularis), the right pulmonary artery runs across the ventral side of the right upper lobe bronchiole and the dorsal side of the right
middle lobe bronchiole. Thereafter, it courses along the dorso-lateral side of the right bronchus, between the dorsal and
lateral bronchiole systems. During this course, the right pulmonary artery gives off arterial branches running mainly along
the dorsal or lateral side of each bronchiole. The left pulmonary artery runs across the dorsal side of the left middle lobe
bronchiole, and is then distributed as in the right lower lobe. The pulmonary veins run mainly along the ventral or medial
side of the bronchiole in the upper and middle lobes whereas, in the lower lobe, they run ventrally, and between the bronchioles.
Finally they enter the left atrium as four large veins. 相似文献
464.
Zabta Khan Shinwari Hidetoshi Kato Ryohei Terauchi Shoichi Kawano 《Plant Systematics and Evolution》1994,192(3-4):263-277
The chloroplast gene encoding ribulose-1,5-bisphosphate-carboxylase (rbcL) was sequenced for phylogenetic analysis of 13 species (10 genera) in the tribePolygonatae s.l. of theLiliaceae-Asparagoideae. The data were analysed using maximum parsimony and neighbour-joining methods. There were 233 phylogenetically informative sites out of 1368 base pairs compared. The results suggest that there are three monophyletic groups withinPolygonatae s.l. with high bootstrap confidence values. Group A representsPolygonatae s.str., with generaMaianthemum, Smilacina, Convallaria, Disporopsis, andPolygonatum. Group B containsUvularia andDisporum and group C includesStreptopus, Tricyrtis, Clintonia, andProsartes. The study suggests thatPolygonatae s.l. are not a monophyletic group, including at least three groups of different phylogenetic origin. Monophyly of the taxa within groups A, B, and C is supported by the high bootstrap confidence values (85–100%) of the bootstrap replications for both parsimony and neighbour-joining methods. The differences between each group (calculated as 100x base substitutions per site) were 6.99–9.03 for group A and B, 4.92–7.35 for A and C, and 6.66–7.57 for B and C. 相似文献
465.
Morita T Yamashita A Kashima I Ogata K Ishiura S Ohno S 《The Journal of biological chemistry》2007,282(11):7799-7808
Phosphatidylinositol 3-kinase-related kinases (PIKKs) consisting of SMG-1, ATM, ATR, DNA-PKcs, and mTOR are a family of proteins involved in the surveillance of gene expression in eukaryotic cells. They are involved in mechanisms responsible for genome stability, mRNA quality, and translation. They share a large N-terminal domain and a C-terminal FATC domain in addition to the unique serine/threonine protein kinase (PIKK) domain that is different from classical protein kinases. However, structure-function relationships of PIKKs remain unclear. Here we have focused on one of the PIKK members, SMG-1, which is involved in RNA surveillance, termed nonsense-mediated mRNA decay (NMD), to analyze the roles of conserved and SMG-1-specific sequences on the intrinsic kinase activity. Analyses of sets of point and deletion mutants of SMG-1 in a purified system and intact cells revealed that the long N-terminal region and the conserved leucine in the FATC domain were essential for SMG-1 kinase activity. However, the conserved tryptophan in the TOR SMG-1 (TS) homology domain and the FATC domain was not. In addition, the long insertion region between PIKK and FATC domains was not essential for SMG-1 kinase activity. These results indicated an unexpected feature of SMG-1, i.e. that distantly located N- and C-terminal sequences were essential for the intrinsic kinase activity. 相似文献
466.
Raben N Takikita S Pittis MG Bembi B Marie SK Roberts A Page L Kishnani PS Schoser BG Chien YH Ralston E Nagaraju K Plotz PH 《Autophagy》2007,3(6):546-552
Autophagy is a major pathway for delivery of proteins and organelles to lysosomes where they are degraded and recycled. We have previously shown excessive autophagy in a mouse model of Pompe disease (glycogen storage disease type II), a devastating myopathy caused by a deficiency of the glycogen-degrading lysosomal enzyme acid alpha-glucosidase. The autophagic buildup constituted a major pathological component in skeletal muscle and interfered with delivery of the therapeutic enzyme. To assess the role of autophagy in the pathogenesis of the human disease, we have analyzed vesicles of the lysosomal-degradative pathway in isolated single muscle fibers from Pompe patients. Human myofibers showed abundant autophagosome formation and areas of autophagic buildup of a wide range of sizes. In patients, as in the mouse model, the enormous autophagic buildup causes greater skeletal muscle damage than the enlarged, glycogenfilled lysosomes outside the autophagic regions. Clearing or preventing autophagic buildup seems, therefore, a necessary target of Pompe disease therapy. 相似文献
467.
The variation in Fas localization and the changes in Fas expression level upon stimulation with growth factors 总被引:2,自引:0,他引:2
Although Fas (APO-1/CD95) is well known as a death receptor, its stimulation occasionally fails to induce apoptosis in malignant cells. On the contrary, Fas is reported to advance the cell cycle in cancer cells. Therefore, we investigated roles of Fas in cell growth and apoptosis using human lung cancer cell lines. Fas was localized in the cytoplasm in exponentially growing cells, whereas only confluent cells expressed Fas on the cell membrane. A stimulation of confluent cells by either of EGF, IGF-I or VEGF induced once a decrease in Fas expression level and its sequential recovery. Fas expression levels in confluent cells were negatively correlated with cell doubling times (r=0.757, p=0.0088). Fas remained on the cell membrane of IgM-treated cells even after the growth factor stimulation, leading to apoptosis with abnormal mitosis, whereas the same stimulation induced Fas internalization in IgG(1)-treated cells. From these results, we suggest that Fas remaining on the cell membrane amplifies to induce apoptosis. Conversely, Fas internalization may enable cancer cells to escape from apoptosis. Our results suggest that growth factor may contribute to the resistance of cancer cells to Fas-mediated apoptosis in an autocrine or paracrine fashion. 相似文献
468.
Population structure and dynamics of a riparian canopy species, Aesculus turbinata (Japanese horse chestnut), were analyzed based on the census data collected for the 8 years from 1989 to 1996 in temperate deciduous forests in Ashiu, Kyoto Prefecture, Japan. The censuses were conducted in three permanently established study plots over an environmental gradient that included the lower hill slope, river terrace, and floodplain of a riparian area within a forest stand of approximately 3 ha. Transition matrix based on the data from 1989 to 1996 was provided for the total population made by pooling population data from all subpopulations in three different habitats (i.e. slope, terrace, floodplain). The total Aesculus population showed positive population growth (λ = 1.0298). From the elasticity analysis, larger elasticity values were obtained with increasing size- or stage-classes. A combined transition matrix was also constructed for the life-history processes consisting of three subpopulations developed on an environmental gradient. This whole population linked by seed flow showed an increase in population size (λ = 1.0286). The elasticity matrix showed the relative importance of the slope subpopulation, suggesting its significant role as a mainland source population. Log-linear analyses were carried out to examine spatiotemporal variations of life-history parameters; significant effects of stage and plot were recognized, while no effect of year was detected on any life-history parameters except for fecundity. 相似文献
469.
Suppression of macrophage activation by peritoneal fluid from patients with endometriosis 总被引:2,自引:0,他引:2
Shigeki Takeshita Kazuyoshi Dobashi Shigeru Abe Shigeru Tansho Hideyo Yamaguchi Shoichi Okinaga Hiroyuki Mori 《FEMS immunology and medical microbiology》1998,20(4):243-248
To investigate the effects of peritoneal fluid from patients with endometriosis on mouse peritoneal macrophages (Mφ), peritoneal fluid from endometriosis patients (n=15) were added to a monolayer of C3H/HeJ mouse peritoneal Mφ. Tumor necrosis factor-producing activity was measured by the L929 assay activated with FK-23 (a preparation of heat-killed Enterococcus faecalis). Tumor necrosis factor-producing activity of C3H/HeJ mouse peritoneal Mφ incubated with peritoneal fluid was suppressed in 14 endometriosis patients. Interestingly, in nine endometriosis patients, tumor necrosis factor-producing activity was much lower than seen with mouse peritoneal Mφ incubated with corticosterone. Peritoneal fluid contains suppressive properties for the activation of peritoneal Mφ, which might allow the implantation of free endometrial cells or the metaplastic phenomena stimulated by retrograde menstruation. 相似文献
470.
Okajima K Yoshihara S Fukushima Y Geng X Katayama M Higashi S Watanabe M Sato S Tabata S Shibata Y Itoh S Ikeuchi M 《Journal of biochemistry》2005,137(6):741-750
BLUF (a sensor of Blue-Light Using FAD) is a novel putative photoreceptor domain that is found in many bacteria and some eukaryotic algae. As found on genome analysis, certain cyanobacteria have BLUF proteins with a short C-terminal extension. As typical examples, Tll0078 from thermophilic Thermosynechococcus elongatus BP-1 and Slr1694 from mesophilic Synechocystis sp. PCC 6803 were comparatively studied. FAD of both proteins was hardly reduced by exogenous reductants or mediators except methylviologen but showed a typical spectral shift to a longer wavelength upon excitation with blue light. In particular, freshly prepared Tll0078 protein showed slow but reversible aggregation, indicative of light-induced conformational changes in the protein structure. Tll0078 is far more stable as to heat treatment than Slr1694, as judged from flavin fluorescence. The slr1694-disruptant showed phototactic motility away from the light source (negative phototaxis), while the wild type Synechocystis showed positive phototaxis toward the source. Yeast two-hybrid screening with slr1694 showed self-interaction of Slr1694 (PixD) with itself and interaction with a novel PatA-like response regulator, Slr1693 (PixE). These results were discussed in relation to the signaling mechanism of the "short" BLUF proteins in the regulation of cyanobacterial phototaxis. 相似文献