全文获取类型
收费全文 | 583篇 |
免费 | 20篇 |
国内免费 | 1篇 |
出版年
2021年 | 3篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 23篇 |
2014年 | 10篇 |
2013年 | 44篇 |
2012年 | 25篇 |
2011年 | 20篇 |
2010年 | 19篇 |
2009年 | 21篇 |
2008年 | 28篇 |
2007年 | 20篇 |
2006年 | 30篇 |
2005年 | 30篇 |
2004年 | 38篇 |
2003年 | 30篇 |
2002年 | 21篇 |
2001年 | 4篇 |
1999年 | 13篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 16篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1965年 | 2篇 |
1963年 | 3篇 |
1957年 | 2篇 |
排序方式: 共有604条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
Kazuyasu Onozuka Teruo Kirikae Fumiko Kirikae Yasuo Suda Shoichi Kusumoto Shunsuke Yamamoto Tadakatsu Shimamura Masayasu Nakano 《Microbiology and immunology》1997,41(10):765-772
The role of CD14 in the phagocytosis and killing of microorganisms was investigated using macrophage-like cell lines, CD14-positive J774.1 cells and CD14-negative mutant J7.DEF3 cells derived from J744.1 cells. The cells were infected with Salmonella typhimurium organisms of the smooth (S)-form LT2, mutant rough (R)-form TV148 or Staphylococcus aureus 248βH. At 30 or 180 min incubation, the cells were washed and disrupted. Colony-forming units (CFUs) liberated from the disrupted cells were determined by quantitative cultivation, and the phagocytic index and killing rate were calculated. Both the phagocytic index and killing rate of J774.1 cells against LT2 organisms were greater than those of J7.DEF.3 cells. However, the index and rate of J774.1 cells against TV148 and 248βH organisms were similar to those of the J7.DEF.3 cells. The phagocytosis of LT2 organisms by J774.1 cells was partially inhibited by S-form LPS (S-LPS) and anti-CD14 antibody, but not by R-chemotype LPS (R-LPS). These results suggest that CD14 participates in the phagocytosis of S-form Salmonella. 相似文献
95.
Masahito Hashimoto Fumiko Kirikae Taeko Dohi Seizi Adachi Shoichi Kusumoto Yasuo Suda Tsuyoshi Fujita Hideo Naoki Teruo Kirikae 《European journal of biochemistry》2002,269(15):3715-3721
Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction. Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids. The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction. The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: [-->4)alpha-L-Rhap(1-->3)beta-D-Manp(1-->]. 相似文献
96.
97.
98.
Yamakawa H Oyama S Mitsuhashi H Sasagawa N Uchino S Kohsaka S Ishiura S 《Biochemical and biophysical research communications》2007,355(1):41-46
Recently, neuroligins (NLs)3 and 4X have received much attention as autism-related genes. Here, we identified syntrophin-gamma2 (SNTG2) as a de novo binding partner of NL3. SNTG2 also bound to NL4X and NL4Y. Interestingly, the binding was influenced by autism-related mutations, implying that the impaired interaction between NLs and SNTG2 contributes to the etiology of autism. 相似文献
99.
Berberine alters the processing of Alzheimer's amyloid precursor protein to decrease Abeta secretion 总被引:2,自引:0,他引:2
Asai M Iwata N Yoshikawa A Aizaki Y Ishiura S Saido TC Maruyama K 《Biochemical and biophysical research communications》2007,352(2):498-502
Berberine is an isoquinoline alkaloid isolated from Coptidis rhizoma, a major herb widely used in Chinese herbal medicine. Berberine's biological activity includes antidiarrheal, antimicrobial, and anti-inflammatory effects. Recent findings show that berberine prevents neuronal damage due to ischemia or oxidative stress and that it might act as a novel cholesterol-lowering compound. The accumulation of amyloid-beta peptide (Abeta) derived from amyloid precursor protein (APP) is a triggering event leading to the pathological cascade of Alzheimer's disease (AD); therefore the inhibition of Abeta production should be a rational therapeutic strategy in the prevention and treatment of AD. Here, we report that berberine reduces Abeta levels by modulating APP processing in human neuroglioma H4 cells stably expressing Swedish-type of APP at the range of berberine concentration without cellular toxicity. Our results indicate that berberine would be a promising candidate for the treatment of AD. 相似文献
100.
Benthic moss pillars in Antarctic lakes 总被引:2,自引:0,他引:2
Unique pillar-like colonies of aquatic mosses, rising from cyanobacterial and algal mats, have been discovered in some freshwater
lakes in the vicinity of Syowa Station (69°00′S, 39°35′E), continental Antarctica. These moss pillars are about 40 cm in diameter
and up to 60 cm high and occur at the lake bottoms mainly between 3 and 5 m depth. The primary component is a species of Leptobryum, a genus unknown in the continental Antarctic terrestrial bryoflora and as an aquatic genus elsewhere in the world. Bryum pseudotriquetrum is often an associated species. In longitudinal section the pillars reveal several whitish layers formed by mineral sediment
and dead cyanobacteria. It is speculated that the biomass of aquatic mosses at the bottom of many Antarctic lakes is considerably
greater than that previously estimated.
Accepted: 11 April 1999 相似文献