全文获取类型
收费全文 | 360680篇 |
免费 | 28029篇 |
国内免费 | 92篇 |
专业分类
388801篇 |
出版年
2018年 | 4183篇 |
2017年 | 4034篇 |
2016年 | 5093篇 |
2015年 | 4957篇 |
2014年 | 6608篇 |
2013年 | 9473篇 |
2012年 | 11067篇 |
2011年 | 11919篇 |
2010年 | 8298篇 |
2009年 | 7314篇 |
2008年 | 10596篇 |
2007年 | 11074篇 |
2006年 | 10582篇 |
2005年 | 9875篇 |
2004年 | 10100篇 |
2003年 | 9733篇 |
2002年 | 9710篇 |
2001年 | 15829篇 |
2000年 | 15707篇 |
1999年 | 12021篇 |
1998年 | 3817篇 |
1997年 | 3774篇 |
1996年 | 3427篇 |
1995年 | 3164篇 |
1992年 | 9531篇 |
1991年 | 9726篇 |
1990年 | 9487篇 |
1989年 | 9491篇 |
1988年 | 8753篇 |
1987年 | 8245篇 |
1986年 | 7530篇 |
1985年 | 7852篇 |
1984年 | 6333篇 |
1983年 | 5317篇 |
1982年 | 3614篇 |
1981年 | 3180篇 |
1980年 | 3132篇 |
1979年 | 5962篇 |
1978年 | 4646篇 |
1977年 | 4230篇 |
1976年 | 3993篇 |
1975年 | 4803篇 |
1974年 | 5313篇 |
1973年 | 5269篇 |
1972年 | 4790篇 |
1971年 | 4485篇 |
1970年 | 3896篇 |
1969年 | 3795篇 |
1968年 | 3554篇 |
1967年 | 3201篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
V M Morogova R Sh Magazov A V Dulina D V Krutilina R S Shafeeva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(12):65-67
The production of virus-neutralizing antibodies in high titers has been found to occur in persons immunized with tissue-culture rabies vaccines, concentrated and non concentrated, intramuscularly in a dose of 1 ml in accordance with reduced immunization schedules. 相似文献
972.
Iu I Afanas'ev O i Mikha?lov V I Nozdrin G V Nikitenkova M I Rytikova 《Biulleten' eksperimental'no? biologii i meditsiny》1986,101(1):22-24
Human and animal blood smear staining with PAPh has revealed mononuclear leukocyte-erythrocyte aggregates. Administration of retinoic acid increased concentration and dimensions of these aggregates and was followed by preferential accumulation of PAPh-negative osmotically unstable erythrocytes. Similar changes were detected in the blood samples of women engaged in the production of retinoic acid. Aggregate concentration showed positive correlation with erythrocyte sedimentation rate and no correlation with prothrombin time. 相似文献
973.
O A Bogoslovskaia L V Andreev E B Burlakova N N Glushchenko V F Koniukhov 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1984,(12):65-68
Experiments on E. coli used as a model have revealed that fatty-acid composition is one of the characteristics which determine the viability of bacteria in the air. The viability of microbial cells in the air has been shown to increase with the increase of the pool of cyclopropane acids and the palmitic acid/palmitoleic acid ratio in the cells, irrespective of their genotype and the phase of their growth. 相似文献
974.
975.
976.
N G Kalina S I Elkina V V Sergeev 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1984,(12):107-110
The stimulating influence of glucose-containing muramyldipeptide (GMDP) on the nonspecific resistance of mice was shown to depend on the features of the pathogenesis of the infection. Thus, the intraperitoneal injection of GMDP increased the survival rate of mice infected with Escherichia coli, but had no stimulating effect on the resistance of the animals to Salmonella typhimurium natural infection in whose pathogenesis macrophages played an essential role. Experiments demonstrated that GMDP was capable of enhancing the ingestive function of macrophages, but did not increase their bactericidal activity with respect to this infection. 相似文献
977.
The peculiarities of the primary immune response, the formation of immunological memory and the secondary immune response to serogroup A and C meningococcal polysaccharides were studied in 7 strains of inbred mice, hybrids F1 and in noninbred animals. The passive local hemolysis test and the passive hemagglutination test indicated that the intensity of immune response to A and C polysacchardies depended on the genotype of the animals: both antigens induced the most intense response in CBA and BALB/c mice. The primary immune response to the both antigens was characterized by a short latent period, a rapid (by days 4-5) increase in the amount of antibody-producing cells in the spleen and in antibody titer in the blood serum to the maximum level, and a pronounced decrease inantibody formation by days 6-7 followed by a gradual extinction of the response. A single injection of A and C polysaccharides in a dose of 0.5 microgram induced the formation of immunological memory in mice, persisting for at least 4 weeks and manifesting after reimmunization as the increased or more prolonged synthesis of IgM and IgG. 相似文献
978.
979.
S C Tsai R Adamik V C Manganiello M Vaughan 《Biochemical and biophysical research communications》1981,100(2):637-643
A new amino acid was isolated from the cuticle collagen of and characterized by ultraviolet, mass and nmr spectroscopies and chemical degradation. The results indicate that the compound is an isomer of trityrosine, having an ether linkage. The name “isotrityrosine” is proposed. Its structure suggests that it serves as a crosslink and plays a role in the organization of the collagen structure. 相似文献
980.
In the past, it has been difficult to grow human diploid fibroblast cells at clonal densities. Newly devised cell culture media and rigorously controlled environmental conditions have greatly increased the ease with which such cells can be cloned. The present work was undertaken to determine whether, under appropriate conditions, diploid fibroblast cells from human embryonic lung, grow as well at clonal densities as in mass culture. The parameters studied were: (1) population doubling time, (2) in vitro proliferative capacity, (3) attachment, (4) percentage of non-dividing cells. In all cases essentially the same results were obtained for cultures at clonal densities and mass cultures. These results indicate that the behavior of these types of cells in clonal culture can be used to infer the behavior of individual cells and clones within a mass culture. 相似文献