全文获取类型
收费全文 | 174854篇 |
免费 | 16245篇 |
国内免费 | 10503篇 |
专业分类
耳鼻咽喉 | 1396篇 |
儿科学 | 2171篇 |
妇产科学 | 1729篇 |
基础医学 | 23967篇 |
口腔科学 | 3238篇 |
临床医学 | 20568篇 |
内科学 | 23322篇 |
皮肤病学 | 1942篇 |
神经病学 | 8493篇 |
特种医学 | 6575篇 |
外国民族医学 | 80篇 |
外科学 | 17534篇 |
综合类 | 30480篇 |
现状与发展 | 36篇 |
一般理论 | 22篇 |
预防医学 | 12586篇 |
眼科学 | 3844篇 |
药学 | 19976篇 |
156篇 | |
中国医学 | 10150篇 |
肿瘤学 | 13337篇 |
出版年
2024年 | 657篇 |
2023年 | 2558篇 |
2022年 | 6579篇 |
2021年 | 8309篇 |
2020年 | 6257篇 |
2019年 | 5450篇 |
2018年 | 5700篇 |
2017年 | 5390篇 |
2016年 | 5080篇 |
2015年 | 7619篇 |
2014年 | 9492篇 |
2013年 | 9511篇 |
2012年 | 13387篇 |
2011年 | 14310篇 |
2010年 | 10342篇 |
2009年 | 8601篇 |
2008年 | 10025篇 |
2007年 | 9963篇 |
2006年 | 9029篇 |
2005年 | 8095篇 |
2004年 | 6191篇 |
2003年 | 5921篇 |
2002年 | 4987篇 |
2001年 | 4024篇 |
2000年 | 3444篇 |
1999年 | 2950篇 |
1998年 | 1821篇 |
1997年 | 1942篇 |
1996年 | 1374篇 |
1995年 | 1281篇 |
1994年 | 1169篇 |
1993年 | 816篇 |
1992年 | 1010篇 |
1991年 | 940篇 |
1990年 | 833篇 |
1989年 | 758篇 |
1988年 | 670篇 |
1987年 | 579篇 |
1986年 | 553篇 |
1985年 | 444篇 |
1984年 | 381篇 |
1983年 | 306篇 |
1982年 | 273篇 |
1981年 | 235篇 |
1980年 | 197篇 |
1979年 | 201篇 |
1978年 | 193篇 |
1977年 | 212篇 |
1976年 | 193篇 |
1974年 | 159篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
95.
Previous studies have demonstrated variability in the phenotype of rat C6 glioma cells. In the present study, we compared morphology, growth rate, and beta-adrenergic regulation of gene expression in early (P39-47) and late (P55-90) passage C6 cells. Morphological changes were observed in five independently derived, late passage populations. In four of the five, the untreated cells were more polygonal than the fibroblast-like parental cells, and only a small fraction exhibited process outgrowth after dbcAMP treatment. Untreated cells from the fifth late passage population had longer cytoplasmic processes than parental cells and responded to dbcAMP with further process outgrowth. All late passage populations had shorter generation times than the parental cells. In early passage cells, treatment with the beta-adrenergic agonist, isoproterenol (IPR), resulted in an increase in c-fos mRNA and a decrease in c-jun mRNA (Gu-bits RM, Yu H: J Neurosci Res, 30:625-630, 1991). Both of these immediate early gene responses were irreversibly lost between P50 and P55. Additional differences in basal or IPR-induced mRNA levels were observed for beta-APP, GFAP, NGF, and PPE, but not for a number of other mRNAs. These results are discussed in relationship to previously described differences in the ability of early and late passage C6 cells to accumulate cAMP (Mallorga P, et al.: Biochim Biophys Acta 678:221-229, 1981). 相似文献
96.
E C Azmitia I Yu H M Akbari N Kheck P M Whitaker-Azmitia D R Marshak 《Journal of chemical neuroanatomy》1992,5(4):289-298
The availability of the primary amino acid sequence for a large number of molecules provides a fruitful opportunity for their cellular localization by utilizing the procedure of antipeptide antibody formation. This procedure permits a synthetic peptide sequence to be attached to a carrier molecule for the purpose of inoculating an animal to raise specific antibodies against the selected protein sequence. In this report we describe a number of steps that can be taken to increase the likelihood that the selected peptide sequence will be specific and antigenic. In addition, we describe how the peptides are synthesized, purified and coupled to keyhold limpet hemocyanin. The preparation of the antibody and its characterization are also presented in this method report. The immunocytochemical staining at both the light and ultrastructural level with serotonin (5-HT1A) receptor antipeptide antibodies is discussed. The advantages and disadvantages of this procedure are summarized. 相似文献
97.
The authors carried out research on breast volume and body surface anatomy of 125 women. As a result, an average breast volume
for Chinese women was obtained (325.36 ± 12.66 ml), and a table with several linear equations for calculating breast volume
was derived. The authors applied these results to their clinical work and succeeded in making mammaplasty more precise in
178 patients. 相似文献
98.
99.
E. V. Borisova D. Yu. Rusakov S. K. Sudakov 《Bulletin of experimental biology and medicine》1992,114(3):1328-1332
100.