全文获取类型
收费全文 | 282342篇 |
免费 | 25398篇 |
国内免费 | 19138篇 |
专业分类
耳鼻咽喉 | 2704篇 |
儿科学 | 2860篇 |
妇产科学 | 3394篇 |
基础医学 | 32724篇 |
口腔科学 | 4670篇 |
临床医学 | 37248篇 |
内科学 | 40514篇 |
皮肤病学 | 2937篇 |
神经病学 | 14858篇 |
特种医学 | 11262篇 |
外国民族医学 | 143篇 |
外科学 | 29927篇 |
综合类 | 48291篇 |
现状与发展 | 67篇 |
一般理论 | 22篇 |
预防医学 | 18125篇 |
眼科学 | 7825篇 |
药学 | 29222篇 |
246篇 | |
中国医学 | 16291篇 |
肿瘤学 | 23548篇 |
出版年
2024年 | 848篇 |
2023年 | 4131篇 |
2022年 | 10717篇 |
2021年 | 13742篇 |
2020年 | 10339篇 |
2019年 | 9040篇 |
2018年 | 9583篇 |
2017年 | 8782篇 |
2016年 | 8316篇 |
2015年 | 12847篇 |
2014年 | 15917篇 |
2013年 | 14539篇 |
2012年 | 21517篇 |
2011年 | 23676篇 |
2010年 | 15171篇 |
2009年 | 12188篇 |
2008年 | 15576篇 |
2007年 | 15427篇 |
2006年 | 15216篇 |
2005年 | 14636篇 |
2004年 | 9634篇 |
2003年 | 9199篇 |
2002年 | 7798篇 |
2001年 | 6599篇 |
2000年 | 6403篇 |
1999年 | 6308篇 |
1998年 | 3873篇 |
1997年 | 3843篇 |
1996年 | 3073篇 |
1995年 | 2801篇 |
1994年 | 2303篇 |
1993年 | 1472篇 |
1992年 | 1979篇 |
1991年 | 1688篇 |
1990年 | 1351篇 |
1989年 | 1144篇 |
1988年 | 1066篇 |
1987年 | 937篇 |
1986年 | 764篇 |
1985年 | 560篇 |
1984年 | 349篇 |
1983年 | 257篇 |
1982年 | 165篇 |
1981年 | 153篇 |
1980年 | 119篇 |
1979年 | 154篇 |
1978年 | 58篇 |
1977年 | 60篇 |
1975年 | 64篇 |
1974年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
11.
晶体玻璃体视网膜联合手术治疗复杂性视网膜脱离 总被引:6,自引:2,他引:4
目的探讨玻璃体视网膜手术(vitreretinalsurgery,VR术)联合晶体切除/超声粉碎的效果。方法对81例(81只眼)应用晶体玻璃体视网膜联合手术(lenticular-vitreoretinalsurgery,LVR术)治疗的复杂性视网膜脱离进行回顾性分析。结果解剖性成功者64只眼(79.01%),功能性成功者45只眼(55.56%);手术成功率显著降低的原因是前部增殖性玻璃体视网膜病变(proliferativevitreo-retinopathy,PVR)(成功率42.86%,P<0.01)和术中/术后眼内出血(成功率58.82%,P<0.025)。结论LVR术是治疗复杂性视网膜脱离的主要方法;显著影响手术预后的因素是前部PVR和术中/术后眼内出血。 相似文献
12.
人体蠕形螨的生物学研究 总被引:4,自引:0,他引:4
用透明胶带法观察蠕形螨在人体面部的寄生、逸出及其在体外的存活能力。结果表明:毛囊蠕形螨(Demod-exfoliculorum,D.f.)主要以颚体朝向毛囊底部寄生,且常常有多条群居现象,而皮脂蠕形螨,(Demodexbrevis,D.b.)一般为单条独居生活。两种人体蠕形螨昼夜均可主动爬出毛囊口出现在皮肤表面,D.f.以白天1000~1800为逸出高峰;D.b.则以夜间2200~200逸出最多。此外,蠕形螨在体外有较强的活动力和存活力。透明胶带法在人体蠕形螨的流行病学调查和生物学研究方面具有较高的应用价值 相似文献
13.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
14.
15.
16.
Geert Verreck Annelies Decorte Koen Heymans Jef Adriaensen Dirk Cleeren Adri Jacobs Dehua Liu David Tomasko Albertina Arien Jef Peeters Patrick Rombaut Guy Van den Mooter Marcus E Brewster 《European journal of pharmaceutical sciences》2005,26(3-4):349-358
The aim of the current research project was to explore the possibilities of combining pressurized carbon dioxide with hot stage extrusion during manufacturing of solid dispersions of itraconazole and polyvinylpyrrolidone-co-vinyl acetate 64 (PVP-VA 64) and to evaluate the ability of the pressurized gas to act as a temporary plasticizer as well as to produce a foamed extrudate. Pressurized carbon dioxide was injected into a Leistritz Micro 18 intermeshing co-rotating twin-screw melt extruder using an ISCO 260D syringe pump. The physicochemical characteristics of the extrudates with and without injection of carbon dioxide were evaluated with reference to the morphology of the solid dispersion and dissolution behaviour and particle properties. Carbon dioxide acted as plasticizer for itraconazole/PVP-VA 64, reducing the processing temperature during the hot stage extrusion process. Amorphous dispersions were obtained and the solid dispersion was not influenced by the carbon dioxide. Release of itraconazole from the solid dispersion could be controlled as a function of processing temperature and pressure. The macroscopic morphology changed to a foam-like structure due to expansion of the carbon dioxide at the extrusion die. This resulted in increased specific surface area, porosity, hygroscopicity and improved milling efficiency. 相似文献
17.
One of the consequences of increased intracellular calcium in response to a variety of physiological stimuli is the calcium activation of cytosolic proteases. Unlike lysosomal proteases with broad specificity, these calcium-activated neutral proteases show limited proteolysis of a restricted set of substrate proteins suggesting they may play a regulatory role in cellular physiology. In this study we show that the neural cell adhesion molecules NCAM-180 and N-cadherin are substrates for such endogenous calcium-activated neutral proteases. In contrast, a third neural cell adhesion molecule G4/L1 was not susceptible to calcium-activated proteolysis. The threshold for activation of NCAM and N-cadherin proteolysis is in the micromolar range of calcium suggesting that NCAM and N-cadherin are substrates for a mu-type calpain (calpain I). The site recognized by this protease is within intracellular domains of NCAM-180 and N-cadherin which are important for their interaction with cytoskeletal components. These results suggest that calcium-activated proteolysis at these sites in vivo could disrupt the linkage between extracellular ligand binding to these adhesion molecules and the normal intracellular effectors of such extracellular binding events. 相似文献
18.
本文对95例肾病综合征进行分析,探讨了性别、年龄、发病迁延时间、浮肿、蛋白尿、血尿、血压、尿素氮、血浆蛋白、血浆胆固醇、免疫球蛋白、补体C_3与激素反应及分型的关系。认为下列综合分析可做为判定难治性肾病综合征的参考。难治性肾病多分布在7岁以上,激素治疗4~8周血浆蛋白尚未恢复,尿镜检反复出现红细胞及颗粒管型,血清r—球蛋白不低,而补体C_3降低,提示难治性肾病。各种感染常常是造成肾病综合心难以控制,甚至死亡的重要因素。 相似文献
19.
Rolled finger gloves were used as ring tourniquets on a case of amputation injury of bilateral thumbs. Necrosis of soft tissue of the right thumb occurred due to mistakenly prolonged use of the tourniquet. Later the patient successfully underwent a toe-to-thumb transfer (modified wraparound procedure). The precautions in using finger tourniquets are stressed. 相似文献
20.