全文获取类型
收费全文 | 193867篇 |
免费 | 3996篇 |
国内免费 | 435篇 |
专业分类
耳鼻咽喉 | 2747篇 |
儿科学 | 7453篇 |
妇产科学 | 5851篇 |
基础医学 | 25044篇 |
口腔科学 | 5741篇 |
临床医学 | 15192篇 |
内科学 | 34712篇 |
皮肤病学 | 4491篇 |
神经病学 | 11664篇 |
特种医学 | 10597篇 |
外国民族医学 | 103篇 |
外科学 | 29087篇 |
综合类 | 1080篇 |
一般理论 | 7篇 |
预防医学 | 16248篇 |
眼科学 | 4266篇 |
药学 | 13435篇 |
2篇 | |
中国医学 | 140篇 |
肿瘤学 | 10438篇 |
出版年
2018年 | 3497篇 |
2017年 | 3868篇 |
2016年 | 3153篇 |
2015年 | 4830篇 |
2014年 | 4260篇 |
2013年 | 3324篇 |
2012年 | 9756篇 |
2011年 | 4625篇 |
2010年 | 2166篇 |
2009年 | 3843篇 |
2008年 | 2015篇 |
2007年 | 2713篇 |
2006年 | 3001篇 |
2005年 | 11098篇 |
2004年 | 12585篇 |
2003年 | 8174篇 |
2002年 | 3394篇 |
2001年 | 4312篇 |
2000年 | 1669篇 |
1999年 | 5820篇 |
1998年 | 519篇 |
1995年 | 389篇 |
1992年 | 6859篇 |
1991年 | 7095篇 |
1990年 | 7341篇 |
1989年 | 6945篇 |
1988年 | 6470篇 |
1987年 | 6229篇 |
1986年 | 5959篇 |
1985年 | 5241篇 |
1984年 | 3590篇 |
1983年 | 2910篇 |
1982年 | 1002篇 |
1981年 | 766篇 |
1980年 | 835篇 |
1979年 | 3828篇 |
1978年 | 2363篇 |
1977年 | 1785篇 |
1976年 | 1559篇 |
1975年 | 2474篇 |
1974年 | 3106篇 |
1973年 | 2739篇 |
1972年 | 2757篇 |
1971年 | 2742篇 |
1970年 | 2556篇 |
1969年 | 2465篇 |
1968年 | 2237篇 |
1967年 | 2163篇 |
1966年 | 1898篇 |
1965年 | 1131篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
The purpose of the present paper was to demonstrate the antitumor activity of lymphocytes and antibodies in the antibody-dependent cell-mediated cytotoxicity test (ADCC) in relation to the tumor growth in adult and aging rats bearing a methylcholanthrene-induced sarcoma (MC-Sa). In the syngeneic system using the ADCC test effector spleen lymphocytes, 51Cr labeled MC-Sa target cells and anti-MC-Sa serum were derived from inbred male Wistar rats. It was found that adult and aging tumor-bearing rats possessed lymphocytes (LSa) and antibodies (Ab) which were active in ADCC. In comparative studies between the groups of adult and aging rats a reverse relationship between tumor growth and activity of LSa and Ab in the ADCC test has been found. Thus, the larger weight of tumors in the group of adult rats was followed by lower LSa and Ab activities in the ADCC test. On the other hand, the smaller tumor growth in the group of aging rats was followed by higher activities of LSa and Ab in this test. We suggest that the ADCC phenomenon could be one of the antitumor mechanisms especially effective in aging rats. 相似文献
992.
J A Represa J A De Diego L M Molina I Delgado M G Calvo J F Ca?izo A Menchero M Gea 《The Journal of cardiovascular surgery》1986,27(4):426-430
Three cases of popliteal artery entrapment syndrome, one of them bilateral, are presented with a review of the literature, with special reference to the embryological development of the popliteal space and the diagnostic and therapeutic problems presented by this syndrome. 相似文献
993.
Effects of androgens and estrogens on the vasopressin and oxytocin innervation of the adult rat brain 总被引:5,自引:0,他引:5
Geert J. De Vries Wouter Duetz Ruud M. Buijs Joop van Heerikhuize Jan T.M. Vreeburg 《Brain research》1986,399(2):296-302
Recently we reported that castration of rats eliminates vasopressin immunoreactivity in the lateral septum and other areas that appear to receive vasopressin innervation from the bed nucleus of the stria terminalis. Testosterone treatment counteracts this effect of castration. In the present study, we investigated whether this action of testosterone depends on its androgenic or estrogenic metabolites by treating long-term castrated rats with estradiol (E) and/or 5 alpha-dihydrotestosterone (DHT) or testosterone. The brains were then processed for immunocytochemistry or radioimmunoassay. DHT did not increase vasopressin staining in the lateral septum, although it fully restored the size of the seminal vesicles. E did restore the original fiber density, but individual fibers stained more weakly than in sham-operated males. Only treatment with both E and DHT fully restored the vasopressin innervation. This pattern was also reflected in the radioimmunoassay data. The vasopressin content of the lateral septum decreased about 90% after castration but was fully restored by either testosterone or E + DHT treatment. E alone, however, was only half as effective as E + DHT. The treatments had no effect on the oxytocin content of the septum, or on the vasopressin or oxytocin content of the dorsal vagal complex. The results suggest that E mediates most of the effects of testosterone on the vasopressin innervation of the lateral septum. DHT enhances the response to E but has little effect on its own. 相似文献
994.
995.
996.
997.
998.
999.
1000.