全文获取类型
收费全文 | 708篇 |
免费 | 29篇 |
专业分类
737篇 |
出版年
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 25篇 |
2014年 | 27篇 |
2013年 | 26篇 |
2012年 | 53篇 |
2011年 | 40篇 |
2010年 | 23篇 |
2009年 | 28篇 |
2008年 | 54篇 |
2007年 | 54篇 |
2006年 | 47篇 |
2005年 | 48篇 |
2004年 | 46篇 |
2003年 | 50篇 |
2002年 | 60篇 |
2001年 | 15篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有737条查询结果,搜索用时 0 毫秒
731.
Kenji Kawaguchi Jonghyuk Park Takahiro Masaki Yoshihiro Mezaki Sae Ochi Tomokazu Matsuura 《Biochemistry and Biophysics Reports》2020
Astrocytes are major glial cells that play a critical role in brain homeostasis. Abnormalities in astrocytic function, such as hepatic encephalopathy (HE) during acute liver failure, can result in brain death following brain edema and the associated astrocyte swelling. Recently, we have identified alpha 1-antichymotripsin (ACT) to be a biomarker candidate for HE. ACT induces astrocyte swelling by upregulating aquaporin 4 (AQP4); however, the causal connection between these proteins is not clear yet. In this study, we utilized a microarray profile to screen the differentially expressed genes (DEGs) in astrocytes treated with ACT. We then performed Gene Ontology, REACTOME, and the comprehensive resource of mammalian protein complexes (CORUM) enrichment analyses of the identified DEGs. The results of these analyses indicated that the DEGs were enriched in pathways activating adenylate cyclase (AC)-coupled G protein-coupled receptors (GPCRs) and therefore were involved in the cyclic adenosine monophosphate (cAMP) signaling. These results indicate that ACT may act as a ligand of Gs-GPCRs and subsequently upregulate cAMP. As cAMP is known to upregulate AQP4 in astrocytes, these results suggest that ACT may upregulate AQP4 by activating AC GPCRs and therefore serve as a therapeutic target for acute HE. 相似文献
732.
Vancomycin possesses the unusual property of promoting the aggregation of proteins. It also binds to itself (dimerization). Both properties may be related to its antimicrobial activity and we report here procedures to measure them. The position of the negative ellipticity band in the near ultraviolet circular dichroism spectrum of the vancomycin monomer shifts as a function of antibiotic concentration and can be used to readily determine the monomer-dimer equilibrium constant. These measurements complement those performed by high-resolution gel filtration to measure the same process. Aggregation of purified proteins was determined by turbidity measurements. Both dimerization and protein aggregation are influenced by anions whose effectiveness is related to their carboxyl pKa values, thus linking these two properties. 相似文献
733.
Ichiro Azuma Kazuhisa Sugimura Tadayoshi Taniyama Aminkham A. Aladin Yuichi Yamamura 《Microbiology and immunology》1975,19(4):265-275
The chemical and immunological properties of the cell walls prepared from the cells of anaerobic coryneforms, Propionibacterium acnes C7 and Corynebacterium parvum ATCC 11829, were partially investigated. The cell walls prepared from P. acnes C7 and C. parvum ATCC 11829 were composed of fatty acids, polysaccharides consisting glucose, galactose and mannose and mucopeptides consisting mainly of alanine, glutamic acid, a, ε-diaminopimelic acid, glycine, muramic acid and glucosamine. As the fatty acid constituents of the cell wall of P. acnes C7, iso-pentadecanoic acid and iso-heptadecanoic acid were detected as major components. Both cell walls prepared from P. acnes C7 and C. parvum ATCC 11829 showed potent adjuvant activity on the formation of circulating antibody and development of delayed type hypersensitivity in vivo and on the primary immune response to sheep erythrocytes in vitro, however, could not augment helper function of carrier-primed T cells and on the development of cell-mediated cytotoxicity to mastocytoma P815-X2 cells in C57BL/6J mice. It is also shown that the cell walls of P. acnes C7 and C. parvum ATCC 11829 act on mouse spleen cells as mitogen. 相似文献
734.
Yan-Chao Li Wan-Zhu Bai Kazuhisa Sakai Tsutomu Hashikawa 《The journal of histochemistry and cytochemistry》2009,57(8):741-751
The organization of F-actin in the ventricular system has been reported to display pronounced regional differences with respect to shape, size, and development. However, the real roles played by F-actin in these cells cannot be understood unless the precise localization of F-actin is defined. In the present study, we used double-fluorescence labeling to further examine the localization of F-actin in the ependymocytes and its spatial relation to the other two cytoskeletal components, microtubules and intermediate filaments. Then we converted fluorescence signals for F-actin to peroxidase/DAB reaction products by use of a phalloidin-based FITC-anti-FITC system. This detection technique provided an overview of the distribution of F-actin in the ependymocytes at the ultrastructural level, and has been proven to be helpful in correlating light and electron microscopic investigations. (J Histochem Cytochem 57:741–751, 2009) 相似文献
735.
Steven T. Swift Irene Y. Najita Kazuhisa Ohtaguchi A. G. Fredrickson 《Microbial ecology》1982,8(3):201-215
Feeding, growth, and reproductive responses of the suspension-feeding protozoanTetrahymena pyriformis to shifts up or down of the density of its bacterial food were observed. The rates of feeding, growth, and reproduction were determined by measuring the rates of uptake of viable bacterial cells, of change of mean volume of the protozoan cells, and of change of number of protozoan cells, respectively. The effects of the nutritional status of the protozoans at the time of shifting were observed also. Results are interpreted in terms of the limited polymorphism exhibited in the life cycle of this organism. Responses in all cases seem to reflect a strategy for exploiting a patchy, transient environment, a conclusion already reached by several earlier investigators. 相似文献
736.
Tohru Mizushima Yoshihisa Ohtsuka Takeyoshi Miki Kazuhisa Sekimizu 《FEMS microbiology letters》1994,121(3):333-336
Abstract We previously reported that plasmid DNA in Escherichia coli cells growing under aerobic conditions relaxed immediately and transiently after heat shock (Mizushima, T., Natori, S. and Sekimizu, K., Mol. Gen. Genet. (1993) 238, 1–5). We next examined DNA relaxation and induction of heat shock proteins after heat shock in cells growing under anaerobic conditions. DNA in these cells relaxed rapidly (2 min) after heat shock (42°C), as was the case with aerobically growing cells, but full superhelicity was not recovered. The relaxed state of DNA topology was maintained for 60 min after heat shock. Induction of DnaK and GroEL proteins, which was transient in aerobically growing cells, was continuous in anaerobically growing cells. Therefore, induction of heat shock proteins correlated with DNA relaxation in both aerobic and anaerobic conditions. 相似文献
737.
Yukitaka Murakami Satoshi Shizukuishi Akira Tsunemitsu Kazuhisa Nakashima Yukio Kato Saburo Aimoto 《FEMS microbiology letters》1991,82(3):253-256
Porphyromonas gingivalis 381 cells were incubated with 125I-histidine-rich polypeptide (histatin) 5 in the presence or absence of unlabeled histatin 5, to evaluate the histatin-binding capacity of the cells. The binding of histatin 5 was rapid, reversible, saturable and specific. The number of histatin 5-binding sites per cell was 3,600, and the dissociation constant (Kd) was in the order of 10(-6) M. These findings suggest that histatin interacts with certain bacterial cells through specific binding sites on their surface, and will allow the development of a histatin radioreceptor assay. 相似文献