全文获取类型
收费全文 | 167413篇 |
免费 | 14584篇 |
国内免费 | 11409篇 |
专业分类
耳鼻咽喉 | 1370篇 |
儿科学 | 1988篇 |
妇产科学 | 2851篇 |
基础医学 | 19732篇 |
口腔科学 | 2970篇 |
临床医学 | 21843篇 |
内科学 | 26673篇 |
皮肤病学 | 1916篇 |
神经病学 | 9005篇 |
特种医学 | 5885篇 |
外国民族医学 | 86篇 |
外科学 | 17319篇 |
综合类 | 26133篇 |
现状与发展 | 36篇 |
一般理论 | 11篇 |
预防医学 | 10613篇 |
眼科学 | 4779篇 |
药学 | 17012篇 |
140篇 | |
中国医学 | 8594篇 |
肿瘤学 | 14450篇 |
出版年
2024年 | 484篇 |
2023年 | 2405篇 |
2022年 | 6245篇 |
2021年 | 7854篇 |
2020年 | 5715篇 |
2019年 | 5320篇 |
2018年 | 5513篇 |
2017年 | 4972篇 |
2016年 | 4622篇 |
2015年 | 6986篇 |
2014年 | 8795篇 |
2013年 | 8073篇 |
2012年 | 11784篇 |
2011年 | 12945篇 |
2010年 | 7874篇 |
2009年 | 6332篇 |
2008年 | 8544篇 |
2007年 | 8632篇 |
2006年 | 8651篇 |
2005年 | 8366篇 |
2004年 | 6043篇 |
2003年 | 5919篇 |
2002年 | 5097篇 |
2001年 | 4529篇 |
2000年 | 4454篇 |
1999年 | 4687篇 |
1998年 | 3057篇 |
1997年 | 2923篇 |
1996年 | 2166篇 |
1995年 | 2010篇 |
1994年 | 1757篇 |
1993年 | 1050篇 |
1992年 | 1554篇 |
1991年 | 1342篇 |
1990年 | 1183篇 |
1989年 | 1023篇 |
1988年 | 915篇 |
1987年 | 829篇 |
1986年 | 649篇 |
1985年 | 550篇 |
1984年 | 320篇 |
1983年 | 207篇 |
1982年 | 132篇 |
1981年 | 131篇 |
1980年 | 90篇 |
1979年 | 125篇 |
1978年 | 61篇 |
1976年 | 52篇 |
1975年 | 55篇 |
1974年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
Liver fibrosis was induced in rats by repeated peritoneal injections of carbon tetrachloride (CCl4) over a period of 2-11 weeks. Serum procollagen III peptide (SPIIINP), prolidase (SP) and alanine aminotransferase (SALT) levels were monitored during the period of induction. The extent of fibrosis was semi-quantitatively estimated after collagen staining, and the anti-fibrotic effects of 16,16-dimethyl prostaglandin E2 (DMPGE2), colchicine, and zinc sulphate were studied. SPIIINP and SP were increased the first 2 weeks after CCl4 administration and peaked at 6 weeks. Alterations in SPIIINP and SP correlated well to the semi-quantitative histological score of liver sections during the first 6 weeks, and SP was positively related to SPIIINP throughout the whole induction period. DMPGE2 decreased SPIIINP, SP and SALT significantly in addition to a markedly decreased formation of liver collagens. Colchicine had a similar but less dramatic effect, whereas zinc sulphate only reduced SPIIINP without influencing liver damage. In conclusion SPIIINP seems to be a valuable indicator of liver fibrogenesis, and SP may play a limited role in indicating accelerated collagen metabolism in the liver. DMPGE2 obviously inhibited the production of collagens induced by CCl4. Colchicine also had an apparent effect on liver fibrosis, whereas zinc sulphate merely seemed to postpone it. 相似文献
103.
本文报道老年非何杰金氏淋巴瘤(NHL)59例并与同期非老年患者138例相比。老年患者占同期NHL总数的29.9%。59例中有结内型43例,结外型16例;低度恶性与中度恶性各12例,高度恶性35例。与非老年组比较,老年组的就诊原因、病变部位、恶性程度、细胞类型和预后等方面无何差别,提示年龄对上述特征无明显影响。 相似文献
104.
105.
Minzhong Yu Lezheng Wu Dezheng Wu 《Documenta ophthalmologica. Advances in ophthalmology》1990,76(1):37-46
The visual pursuit test is a method that collects and analyzes the characteristics of pursuit eye movements and examines the function of the eye movement system. This paper analyzes the model parameters of the smooth pursuit eye movement system in order to explore a method for improving the analysis. The input-output relationship of the smooth pursuit system can be expressed by a quasilinear model. We compute the model parameters (gain, phase, spectral purity, cross covariance) by digital signal processing. Eye movement is recorded by electrooculogram. Both eyes are tested individually. The visual target moves at frequencies of 0.2, 0.4, 0.8, 1.2, and 1.6 Hz. Ranges are gain, 1.01 to 0.70; phase, -0.1 ° to -66 °; spectral purity, 0.97 to 0.70; and cross covariance, 0.99 to 0.26. We tested 40 normal subjects as well as patients with ataxia (8), vertigo (18), and ophthalmoplegia (9). The oculomotor system of normal subjects functions as a linear system in the performance of this test at 0.2 to 0.8 Hz. The spectral purity dropped to about 0.70 at 1.6 Hz. The variability of all measures increases greatly at 1.6 Hz, which indicates that this target motion exceeds the tracking ability of many normal subjects and that the oculomotor system of normal subjects functions as a nonlinear system in this condition. Statistical tests show no significant differences between sex, age, and the two eyes. The model parameters tentatively proved effective in clinical application. 相似文献
106.
应用免疫细胞化学技术及酶联免疫吸附试验(ELISA)对大鼠腹腔肥大细胞合成和释放肿瘤坏死因子(TNF)的状况进行了观测。结果:新鲜分离纯化的大鼠腹腔肥大细胞胞浆呈TNF蛋白阳性。单纯肥大细胞培养早期(2~4 h),上清液中未能检测到TNF,随着培养时间延长,上清液中TNF含量增多;盐酸吗啡与肥大细胞共同培养2h时,上清液中出现可测TNF。四甲基偶氮唑盐(MTT)比色分析试验表明,肥大细胞培养上清液具体有TNF的抗肿瘤活性中。提示:大鼠腹腔肥大细胞能合成和释放TNF,盐酸吗啡能促进肥大细胞释放TNF。 相似文献
107.
本文在分析黑龙江省妇幼保健机构设置现状的基础上,论述了在社会主义市场经济新形势下,妇幼保健机构发展的指导思想、模式与对策。 相似文献
108.
At extreme altitude of 5,620 m, cardiac function was examined with electrical impedance at rest and during exercise. Mountaineers as subjects of experiment were divided into two groups: 15 subjects were Tibetan natives, and 10 subjects were Han visitors of expedition (both were young healthy males). The results showed that no significant difference was seen between the two groups in cardiac pump function at rest. In the Han visitors during exercise, HR increase was restricted, SV and CO were decreased, and PEP/LVET ratio was increased. In the Tibetan natives, HR increased gradually with increased work load, SV tended to be stable CO increased significantly under higher work load, and PEP/LVET ratio decreased gradually. These results suggest that the Tibetan natives were adapted to hypoxic environment much better than the immigrants because their cardiac reserve capacity and maximal oxygen uptake were better than the immigrants at extreme altitude. 相似文献
109.
110.
传统腺样体切除术后腺样体残留情况调查 总被引:39,自引:0,他引:39
体统的腺样体手术为腺样体刮除术,为非直视下的手术,虽然多数患者手术后症状得得缓解,但临床上也常常看到手术后短时间内症状复发或者缓解不彻底的患儿,这类情况往往和腺样体手术切除不彻底有关。本院自2003年1月-2004年9月间对腺样体切除术后复发再次手术患者,以鼻内镜观察记录腺样体残留情况,对初次手术患者在进行传统腺样体刮除术并止血后,立即进行鼻内镜检查,了解腺样体残留情况并进行鼻内镜下处理,报告如下。 相似文献