全文获取类型
收费全文 | 374353篇 |
免费 | 34845篇 |
国内免费 | 26007篇 |
专业分类
耳鼻咽喉 | 2845篇 |
儿科学 | 4899篇 |
妇产科学 | 4195篇 |
基础医学 | 41037篇 |
口腔科学 | 6126篇 |
临床医学 | 52862篇 |
内科学 | 50692篇 |
皮肤病学 | 4137篇 |
神经病学 | 18166篇 |
特种医学 | 13776篇 |
外国民族医学 | 224篇 |
外科学 | 33087篇 |
综合类 | 69942篇 |
现状与发展 | 86篇 |
一般理论 | 31篇 |
预防医学 | 27565篇 |
眼科学 | 10673篇 |
药学 | 40666篇 |
432篇 | |
中国医学 | 24364篇 |
肿瘤学 | 29400篇 |
出版年
2024年 | 1273篇 |
2023年 | 5462篇 |
2022年 | 14383篇 |
2021年 | 18246篇 |
2020年 | 14411篇 |
2019年 | 11690篇 |
2018年 | 12168篇 |
2017年 | 11673篇 |
2016年 | 10779篇 |
2015年 | 16831篇 |
2014年 | 20948篇 |
2013年 | 19056篇 |
2012年 | 28357篇 |
2011年 | 31878篇 |
2010年 | 21502篇 |
2009年 | 17503篇 |
2008年 | 21392篇 |
2007年 | 21110篇 |
2006年 | 20142篇 |
2005年 | 19225篇 |
2004年 | 12702篇 |
2003年 | 12231篇 |
2002年 | 10005篇 |
2001年 | 8533篇 |
2000年 | 8319篇 |
1999年 | 8394篇 |
1998年 | 5302篇 |
1997年 | 5093篇 |
1996年 | 3958篇 |
1995年 | 3713篇 |
1994年 | 3135篇 |
1993年 | 2028篇 |
1992年 | 2426篇 |
1991年 | 2126篇 |
1990年 | 1792篇 |
1989年 | 1556篇 |
1988年 | 1283篇 |
1987年 | 1183篇 |
1986年 | 955篇 |
1985年 | 676篇 |
1984年 | 369篇 |
1983年 | 271篇 |
1982年 | 142篇 |
1981年 | 169篇 |
1980年 | 115篇 |
1979年 | 154篇 |
1978年 | 73篇 |
1977年 | 53篇 |
1974年 | 42篇 |
1972年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
从蝮蛇毒中提取磷酸二酯酶,用此酶免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞Fo融合,以间接ELISA检测杂交瘤细胞培养上清液和小鼠腹水中的特异性抗体,其效价分别为1∶128和1∶51 200.抗原阻断试验结果表明,此抗体对蛇毒磷酸二酯酶具有特异性.该杂交瘤细胞株定为G_8,该株单抗属鼠IgG_(2a)亚型,经体外持续培养6个月,其分泌抗体性能稳定. 相似文献
993.
本文对52例涎腺恶性肿瘤进行了回顾性研究。52例中发生于腮腺者27例(51.9%);病理类型以腺样囊性癌和粘液表皮样癌最多见;随访2~8年,死亡19例,病死率最高者为腺癌(5/8)和鳞癌(3/5)。作者对腺样囊性癌的病理分型提出了不同看法。 相似文献
994.
Antidepressant-like effects of trazodone on a behavioral screen are mediated by trazodone, not the metabolite m-chlorophenylpiperazine 总被引:1,自引:0,他引:1
Trazodone is an atypical antidepressant drug (i.e. blocks neither monoamine uptake nor monoamine oxidase) which tests as an antidepressant drug on the differential-reinforcement-of-low-rate 72-s (DRL 72-s) schedule of reinforcement by increasing the reinforcement rate and decreasing the response rate. m-Chlorophenylpiperazine (m-CPP) is a 5-HT1B and 5-HT1C agonist, weak 5-HT2 antagonist, and trazodone metabolite. It has been suggested that formation of m-CPP is responsible for the antidepressant action of trazodone. Administration of m-CPP (1-10 mg/kg i.p.) 60, 30 or 10 min before the behavioral session did not mimic the reinforcement rate-increasing effects of trazodone (10-20 mg/kg i.p.) on rats performing under the DRL 72-s schedule of water reinforcement. Pretreatment with proadifen (50 mg/kg i.p.), an inhibitor of trazodone metabolism, caused a greater than 30-fold leftward shift in the dose-response curve for both the reinforcement rate and the response rate. These results suggest that the parent compound and not the trazodone metabolite m-CPP, mediates the antidepressant-like effects of trazodone on DRL 72-s behavior. 相似文献
995.
用免疫组织化学PAP法显示实验性脾虚组和正常对照组大鼠胰岛B细胞(胰岛素细胞)、A细胞(胰高血糖素细胞)和D细胞(生长抑素细胞).结果显示,实验组胰岛素分泌升高(P<0.01),胰高血糖素和生长抑素分泌下降(P<0.05)。实验结果提示大鼠胰岛A、B和D细胞分泌活动的变化与脾虚证的症候可能有密切关系。 相似文献
996.
A Kunkl D Fenoglio F Manca G Li Pira C Cambiaggi R Strom F Celada 《International immunology》1992,4(6):627-636
The murine antibody response to Escherichia coli beta-galactosidase (GZ) was analyzed in vivo and in vitro by focusing on two families of antibodies that exert distinct conformational/functional activity on the antigen. Activating antibodies--defined by their capacity to increase the enzymatic activity of defective GZ produced by mutant strains of E. coli--are detected early after secondary challenge. Inhibiting antibodies, which interfere with antibody-mediated enzyme activation, appear later and cause the abrupt fall of activating titer, a scenario suggesting either idiotype/anti-idiotype interaction or opposite pulsions exerted on the antigen molecule. Supporting the latter mechanism, the confrontation of mAbs of the two families produced classical competitive inhibition curves when the readout was enzyme activation, although they recognize two different epitopes of the same molecule: the activating mAb a quaternary conformation-dependent site of wild-type GZ, the inhibiting mAb a sequential determinant exposed only in denatured or in defective enzyme. The different timing of generation of these antibodies during the response may depend on a processing step necessary for unfolding of native antigen and consequent display of certain cryptic epitopes before they can trigger specific B cells. A picture emerges where the response to the various epitopes of a complex antigen is sequentially connected and where the uptake by antigen-presenting cells of antigen complexed with antibodies specific for the exposed epitopes may favor revelation of the cryptic ones. 相似文献
997.
用结合^131碘和化疗药物的明胶微球作肝动脉... 总被引:1,自引:0,他引:1
Nine patients with inoperable hepatoma were treated by using hepatic arterial embolization 131I and chemotherapeutic agent gelatin microsphere (131I-CA-GM). The emission CT after operation detected that the microspheres were concentrated on tumor area. The ratio between the radioactivity in tumor and that in liver was 4.1:1. A case died of ictopic embolization; the others survived 3, 4, 5, 19, 24, 7, 8, and 12 months respectively. Three of them were still alive. 131I-CA-GM has triple anticarcinogenic actions, including the arterial occlusion, targeting chemotherapy and internal radiation. The microspheres can selectively accumulate in the tumor artery and can be easily traced by gamma-camera or emission CT. 131I-CA-GM is a hopeful embolic agent for the treatment of liver cancer, but some problems about ectopic arterial embolization should be further studied. 相似文献
998.
999.
The external subdivision of the lateral parabrachial nucleus (LPBE) shows strong Fos-like immunoreactivity (FLI) following anorectic doses of the indirect serotonin agonist dexfenfluramine (DFEN). In an effort to determine the contribution of the LPBE to DFEN-induced anorexia, bilateral ibotenate lesions were made in the LPBE, and the effects of the lesion on DFEN-induced anorexia and FLI as well as c-June-like immunoreactivity (JLI) were examined. It was found that LPBE lesion significantly attenuated DFEN anorexia: in a 1-h food intake test following 24-h food deprivation, DFEN (2 mg/kg) suppressed food intake by 60% in intact rats but only 34% in rats with LPBE lesions. In addition to this behavioral change, LPBE lesion completely abolished DFEN-induced FLI and JLI in the lateral subdivision of the central nucleus of the amygdala (CeL) and laterodorsal subdivision of the bed nucleus of stria terminalis (BSTLD), both of which showed strong FLI and JLI in intact rats. DFEN-induced FLI and JLI in other brain regions were not affected by LPBE lesion, including the ventromedial and lateral hypothalamus, caudate-putamen, and the nucleus of the solitary tract (NST). The parallel loss of DFEN-induced anorexia and FLI/JLI following LPBE lesion raises the novel possibility that LPBE-CeL/BSTLD pathway may be involved in DFEN anorexia. 相似文献
1000.
L D Klentzeris T C Li P Dockery I D Cooke 《European journal of obstetrics, gynecology, and reproductive biology》1992,45(2):119-124
To investigate whether or not there is any relation between endometrial morphology and subsequent pregnancy rate, 47 couples with unexplained infertility were followed up for 3 years after they had had an endometrial biopsy. Each woman had an LH-timed endometrial biopsy performed in the luteal phase of the cycle. The biopsy was dated chronologically according to the luteinizing hormone (LH) surge and histologically using morphometric criteria. None of the women received any form of treatment in the endometrial biopsy cycle. Of 47 women with unexplained infertility, 36 (76.6%) (Group I) had 'in phase' endometrial development and 11 (23.4%) (Group II) had retarded endometrium. Women with normal endometrial development had a higher pregnancy rate than women with retarded endometrial development (50% vs. 9%; P less than 0.02). The fecundability during treatment cycles was higher in Group I than in Group II (0.051 vs. 0.008; P less than 0.05). In women with 'in phase' endometrium, treatment increased the monthly probability of conception (0.051 vs. 0.006; P less than 0.001). A precisely timed endometrial biopsy should be considered as part of the investigations for women with unexplained reproductive failure, to help determine prognosis. 相似文献