全文获取类型
收费全文 | 3983篇 |
免费 | 239篇 |
国内免费 | 2篇 |
出版年
2021年 | 27篇 |
2019年 | 28篇 |
2018年 | 43篇 |
2017年 | 26篇 |
2016年 | 52篇 |
2015年 | 98篇 |
2014年 | 99篇 |
2013年 | 279篇 |
2012年 | 200篇 |
2011年 | 171篇 |
2010年 | 104篇 |
2009年 | 122篇 |
2008年 | 202篇 |
2007年 | 216篇 |
2006年 | 208篇 |
2005年 | 213篇 |
2004年 | 201篇 |
2003年 | 206篇 |
2002年 | 185篇 |
2001年 | 87篇 |
2000年 | 78篇 |
1999年 | 76篇 |
1998年 | 62篇 |
1997年 | 49篇 |
1996年 | 59篇 |
1995年 | 51篇 |
1994年 | 47篇 |
1993年 | 56篇 |
1992年 | 71篇 |
1991年 | 64篇 |
1990年 | 58篇 |
1989年 | 58篇 |
1988年 | 61篇 |
1987年 | 41篇 |
1986年 | 32篇 |
1985年 | 60篇 |
1984年 | 31篇 |
1983年 | 34篇 |
1982年 | 43篇 |
1981年 | 57篇 |
1980年 | 31篇 |
1979年 | 32篇 |
1978年 | 45篇 |
1977年 | 28篇 |
1976年 | 32篇 |
1975年 | 18篇 |
1969年 | 16篇 |
1968年 | 17篇 |
1967年 | 17篇 |
1966年 | 15篇 |
排序方式: 共有4224条查询结果,搜索用时 15 毫秒
1.
2.
3.
Tomonori Murakami Kenji Hiraoka Takeshi Mikami Tatsuji Matsumoto Susumu Katagiri Kunihiro Shinagawa Masuko Suzuki 《FEMS microbiology letters》1993,107(2-3):179-183
Abstract Flagellar antigen of Bacillus cereus H.1 was purified and tested for serodiagnostic antigen by ELISA. The antibody against the flagellar antigen of B. cereus H.1 reacted not only with the homologous specific antigen but also reacted with the flagellar antigens of 23 strains of B. cereus . This common flagellar antigen of B. cereus was found to be due to 61-kDa protein by SDS-PAGE and immunoblot assay. Monoclonal antibody H15A5 against common antigenic epitope of B. cereus also reacted with flagellar antigens of 21 strains of Bacillus thuringiensis by ELISA. This monoclonal antibody reacted with the 61-kDa protein of the flagella of B. cereus H.1 and H.2 and B. thuringiensis Kurstaki HD1, Alesti and Aizawai juroi by immunoblot analysis. These results indicated that the common antigenic epitope of the 61-kDa protein existed in the flagella both of B. cereus and B. thuringiensis . 相似文献
4.
Glucanase-treatment of yeast cells was shown to increase the glucose fermenting activity, and decrease the sucrose and maltose fermenting activity. Also, lipase–and phospholipase–treatment decreased the fermenting activity on these sugars. However, the effects on the disaccharide fermenting activity could be reversed under various growth conditions of the yeast cells.From these results, structural factors envolved in the transport of fermentable sugars into yeast cells are discussed. 相似文献
5.
Haruhide Kawabe Hiroshi Naganawa Shinichi Kondo Hamao Umezawa Susumu Mitsuhashi 《Microbiology and immunology》1978,22(9):515-521
A clinical isolate of Staphylococcus aureus resistant to gentamicin, kanamycin and 3′,4′-dideoxykanamycin B contained two enzymes capable of inactivating gentamicin, i.e., an aminoglycoside 2″-phosphotransferase and aminoglycoside acetyltransferase. 相似文献
6.
7.
The degree of methylation at the c-myc proto-oncogene was found to change in human lymphoproliferative diseases, when examined using a methylation-sensitive restriction enzyme. In peripheral blood mononuclear cells (PBMC) c-myc DNA showed hypomethylation in human lymphoproliferative diseases, in comparison to normal subjects matched in age and sex. In cases of chronic lymphocytic leukemia (CLL), the change was amplified in the crisis. When the DNA was examined at the actin gene, no significant change was observed. The results suggest that the change in c-myc proto-oncogene methylation might become an important clue in understanding the relationship between levels of gene expression and methylation in human lymphoproliferative diseases. 相似文献
8.
Primary structures of human protein kinase C beta I and beta II differ only in their C-terminal sequences 总被引:5,自引:0,他引:5
Two types of cDNA clones encoding human protein kinase C (PKC) were isolated from a spleen cDNA library using rabbit protein kinase C beta I/beta II cDNA as a hybridization probe. Nucleotide sequence analyses of these cDNA inserts revealed complete primary structures of two distinct types of human protein kinase C beta I and beta II which differ only in their C-terminal 50 or 52 amino acid residues. It was concluded that there exist four distinct types of PKC, PKC alpha, beta I, beta II and gamma, in human as well as rabbit, and that the corresponding sequences are strictly conserved among mammalian species. 相似文献
9.
Koichi Suzuki Shinobu Imajoh Yasufumi Emori Hiroshi Kawasaki Yasufumi Minami Shigeo Ohno 《FEBS letters》1987,220(2):271-277
The structures of calcium-activated neutral protease (CANP) and its endogenous inhibitor elucidated recently have revealed novel features with respect to their structure-function relationship and enzyme activity regulation. The protease is regarded as a proenzyme which can be activated at the cell membrane in the presence of Ca2+ and phospholipid, and presumably regulates the functions of proteins, especially membrane-associated proteins, by limited proteolysis. Protein kinase C is hydrolysed and activated by CANP at the cell membrane to a cofactor-independent form. These results are reviewed and the possible involvement of CANP in signal transduction is discussed. 相似文献
10.
Summary The purpose of this paper is to describe the immunocytochemical localization of M protein of vesicular stomatitis virus (VSV) in infected cells. Vero cells, MDBK cells, Swiss 3T3 cells, and BHK cells were examined at various times after infection. For immunofluorescent staining, the cells were fixed with PLP fixative and then treated with 0.05% Triton X-100 before incubation with antibodies. Three hours after infection, M protein exhibited diffuse immunostaining throughout the cytoplasm and later accumulated along the cell membrane. The localization of M protein differed from the granular localization of the nucleocapsid N protein of VSV in the cytoplasm. For electron microscopy, the cells were fixed first in a mixture of 2% paraformaldehyde and 0.05% glutaraldehyde and then with PLP fixative, this being followed by treatment with 0.05% saponin. They were then immunostained using the immunoperoxidase method. The M protein was found to be distributed throughout the cytoplasm and later under the cell membrane, especially at virus budding sites. We also used postembedding immunostaining and freeze-fracture immunostaining to avoid the translocation of M protein caused by the detergent treatment. These techniques confirmed our previous results. Our findings are consistent with the view that the M protein of VSV is synthesized on free ribosomes and is then associated with the cell membrane where viral assembly may occur.S. Ohno was a visiting fellow from the Fogarty International Center at the National Institutes of Health, USA, from September 1981 to August 1983, while some parts of this work were in progress. 相似文献