全文获取类型
收费全文 | 144003篇 |
免费 | 13790篇 |
国内免费 | 8553篇 |
专业分类
耳鼻咽喉 | 1096篇 |
儿科学 | 1840篇 |
妇产科学 | 1580篇 |
基础医学 | 21482篇 |
口腔科学 | 2515篇 |
临床医学 | 17321篇 |
内科学 | 20100篇 |
皮肤病学 | 1575篇 |
神经病学 | 7008篇 |
特种医学 | 4946篇 |
外国民族医学 | 65篇 |
外科学 | 13757篇 |
综合类 | 23475篇 |
现状与发展 | 31篇 |
一般理论 | 12篇 |
预防医学 | 10132篇 |
眼科学 | 3472篇 |
药学 | 16586篇 |
122篇 | |
中国医学 | 7875篇 |
肿瘤学 | 11356篇 |
出版年
2024年 | 577篇 |
2023年 | 2245篇 |
2022年 | 5776篇 |
2021年 | 7293篇 |
2020年 | 5336篇 |
2019年 | 4766篇 |
2018年 | 4974篇 |
2017年 | 4565篇 |
2016年 | 4353篇 |
2015年 | 6325篇 |
2014年 | 7831篇 |
2013年 | 7598篇 |
2012年 | 10647篇 |
2011年 | 11291篇 |
2010年 | 7926篇 |
2009年 | 6396篇 |
2008年 | 7715篇 |
2007年 | 7712篇 |
2006年 | 7023篇 |
2005年 | 6353篇 |
2004年 | 4958篇 |
2003年 | 4830篇 |
2002年 | 4118篇 |
2001年 | 3423篇 |
2000年 | 2952篇 |
1999年 | 2619篇 |
1998年 | 1659篇 |
1997年 | 1786篇 |
1996年 | 1251篇 |
1995年 | 1191篇 |
1994年 | 1084篇 |
1993年 | 762篇 |
1992年 | 967篇 |
1991年 | 885篇 |
1990年 | 790篇 |
1989年 | 726篇 |
1988年 | 653篇 |
1987年 | 562篇 |
1986年 | 528篇 |
1985年 | 424篇 |
1984年 | 369篇 |
1983年 | 302篇 |
1982年 | 268篇 |
1981年 | 229篇 |
1980年 | 196篇 |
1979年 | 198篇 |
1978年 | 192篇 |
1977年 | 211篇 |
1976年 | 191篇 |
1974年 | 156篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
组织扩张术皮肤胶原的代谢改变 总被引:4,自引:0,他引:4
目的:研究常规扩张(ITE)和持续快速扩张(CTE)对皮肤胶原代谢的影响。方法用白色小家猪制作组织扩张术动物模型,用Gordeladze法测定血清和扩张组织的羟脯氨酸(HP)含量,藻酸盐印模材膜片法测量标记区面积;光镜测量真皮厚度。结果:ITE组血清HP含量升高,0.8倍,CTE组升高1.2倍,ITE和CTE组皮肤含量与正常皮肤相同,组织中HP总量均明显升高,持续扩张皮瓣组(CTEF)术后4wk皮 相似文献
32.
33.
Human bladder cancer cell lines, J82, Yen-87, Shen-87 and Zoa-88, and murine bladder cancer cell lines, MBT-2 and M1660, were used as target cells for dye-sensitized photoinactivation study in using methylene blue. Normal fibroblast cells, FB-1 and FB8490, were used as control group. The cytoplasmic activity of lactic dehydrogenase, soft agar clonogenic assay, and in vivo tumor growth, survival rate and tumor taking rate with or without photoinactivation were monitored and compared between different cell lines. Efficacy of photoinactivation was time-related and more than 90 per cent of cytotoxicity could be obtained within 60 minutes of illumination. The plateau of cytotoxicity curve could be achieved after staining for 30 minutes by methylene blue under the same illumination time. Normal fibroblasts had the same features with cancer cells. Photoinactivation of tumor cells showed significant inhibition of tumor growth and tumor taking rate in experimental animals. Survival rate was also significantly prolonged in the animals with tumor cells receiving photoinactivation. These results suggest that methylene blue-sensitized photoinactivation may be useful as an adjuvant photochemotherapy for superficial bladder cancer. 相似文献
34.
35.
Satomi Kitagawa Yu Yamaguchi Emiko Sameshima Masaru Kunitomo 《Clinical and experimental pharmacology & physiology》1994,21(12):963-970
1. Endothelium-dependent relaxation in response to acetylcholine (ACh) and the calcium ionophore A 23187 was examined in aorta, coronary, basilar and renal arteries isolated from Watanabe heritable hyperlipidaemic (WHHL) rabbits of 2, 6 and 12 months of age, with normolipidaemic heterozygous WHHL rabbits as controls. 2. In the rings of WHHL rabbit aortae and coronary arteries preconstricted with vasoconstrictors, endothelium-dependent relaxation in response to ACh was attenuated with age compared to the heterozygous WHHL rabbits. A significant negative correlation was found between the total cholesterol content and the relaxation response to ACh in the aortae or coronary arteries from 6 and 12 month old WHHL rabbits. 3. In the rings of basilar arteries, endothelium-dependent relaxations to ACh were not modified with age. Similarly, in the rings of renal arteries, the relaxation response to ACh was not changed with age, but in the 6 and 12 month preparations, after the age of 6 months, a contraction following the relaxation appeared at higher concentrations of ACh (10?7 to 10?6 mol/L). The contraction was endothelium-dependent and inhibited by indomethacin. 4. A 23187-induced endothelium-dependent relaxations were also markedly attenuated in the aorta and significantly in the coronary artery with age. 5. Endothelium-independent relaxation to sodium nitroprusside was not changed in all arteries from WHHL rabbits of different ages. 6. These findings indicate that in the aorta and coronary artery of the WHHL rabbit, the endothelium-dependent relaxation to ACh and A 23187 becomes impaired with increasing age (i.e., with the progression of cholesterol deposition in the arterial wall) but is preserved in the basilar and renal artery. 相似文献
36.
37.
Pharmaceutical Chemistry Journal - 相似文献
38.
B. B. Aleksandrov M. S. Gavrilov R. Z. Dautova R. Kh. Niyazov V. D. Sviridov N. D. Chkanikova B. Ya. Syropyatov V. S. Shklyaev Yu. V. Shklyaev 《Pharmaceutical Chemistry Journal》1992,26(1):57-58
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 26, No. 1, pp. 44–45, January, 1992. 相似文献
39.
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
40.