首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   69343篇
  免费   6266篇
  国内免费   5190篇
耳鼻咽喉   400篇
儿科学   721篇
妇产科学   876篇
基础医学   8715篇
口腔科学   1186篇
临床医学   9354篇
内科学   10563篇
皮肤病学   767篇
神经病学   3650篇
特种医学   2414篇
外国民族医学   41篇
外科学   7069篇
综合类   11971篇
现状与发展   17篇
一般理论   2篇
预防医学   4256篇
眼科学   1826篇
药学   7437篇
  74篇
中国医学   3685篇
肿瘤学   5775篇
  2024年   225篇
  2023年   1196篇
  2022年   2848篇
  2021年   3591篇
  2020年   2604篇
  2019年   2383篇
  2018年   2385篇
  2017年   2046篇
  2016年   2052篇
  2015年   3132篇
  2014年   3935篇
  2013年   3263篇
  2012年   4783篇
  2011年   5663篇
  2010年   3272篇
  2009年   2479篇
  2008年   3430篇
  2007年   3593篇
  2006年   3609篇
  2005年   3465篇
  2004年   2232篇
  2003年   2195篇
  2002年   1831篇
  2001年   1695篇
  2000年   1776篇
  1999年   1973篇
  1998年   1257篇
  1997年   1355篇
  1996年   1014篇
  1995年   895篇
  1994年   770篇
  1993年   496篇
  1992年   606篇
  1991年   529篇
  1990年   451篇
  1989年   398篇
  1988年   336篇
  1987年   284篇
  1986年   249篇
  1985年   173篇
  1984年   102篇
  1983年   71篇
  1982年   38篇
  1981年   52篇
  1980年   28篇
  1979年   38篇
  1963年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Summary In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane-fluidity induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However, the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding isotypic and idiotypic determinants of IgM on the cell membrane.  相似文献   
32.
33.
34.
X Y Zhu  H Y Yu 《中西医结合杂志》1990,10(8):485-7, 454
The immunosuppressive effect of cultured Cordyceps sinensis (Bei Lin Capsule) was studied in vitro and in vivo. When the drug was added from 0.6 mg/ml to 5 mg/ml a significant dose-dependent inhibition effect was shown in the following immune reactions of mice (P less than 0.05-0.01): phagocytic function of peripheral blood leucocytes assayed by chemiluminescence; mitogenic response of spleen lymphocytes to Con A; mixed lymphocyte culture and LPS induced interleukin-1 release of macrophages. The survival rate of mice spleen lymphocytes cultured with Cordyceps sinensis 5 mg/ml in 37 degrees C 5% CO2 for 5 days was more than 80%. Cordyceps sinensis 4 g/kg daily significantly prolonged the mice skin allograft survival time (12.7 +/- 2.2 days v.s. 8.3 +/- 0.7 days in the control, P less than 0.01) and its immunosuppressive effect was close to that of Cyclosporin A 5 mg/kg daily on skin allograft.  相似文献   
35.
本文探讨食管胃腔内弹力环扎吻合术的力学机理。这是一种不用任何缝合材料或吻合器进行胃食管吻合的新技术,我们已成功应用于临床。取临床所用的乳胶管按该材料多向异性特征、实验条件以及弹力环数目分为8组,每组3个样品进行各种体外力学试验。通过应力—应变(拉力—伸长)关系曲线和定伸长松驰试验确定它的力学特性是一种粘弹性材料。根据实验所得的应力换算为弹力环对食管和胃组织所施加的最佳压力(压强)是4.23±0.23Kg/cm~2,这样才能保证这一种新颖的吻合术可达到简便、安全、可靠的目的。  相似文献   
36.
5S ribosomal DNA (rDNA) was isolated and sequenced from the gibel carp Carassius auratus gibelio with 162 chromosomes and crucian carp Carassius auratus with 100 chromosomes, and fluorescent probes for chromosome localization were prepared to ascertain the ploidy origin and evolutionary relationship between the two species. Using fluorescence in-situ hybridization (FISH), major 5S rDNA signals were localized to the short arms of three subtelocentric chromosomes in the gibel carp and to the short arms of two subtelocentrics in the crucian carp. In addition, some minor signals were detected on other chromosomes of both species. Simultaneously, six chromosomes were microdissected from the gibel carp metaphase spreads using glass needles, and the isolated chromosomes were amplified in vitro by degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR). Significantly, when the DOP-PCR-generated probes prepared from each single chromosome were hybridized, three same-sized chromosomes were painted in each gibel carp metaphase, whereas only two painted chromosomes were observed in each crucian carp metaphase spread. The data indicate that gibel carp is of triploid origin in comparison with diploid crucian carp.  相似文献   
37.
糖尿病妇科手术92例的围手术期处理   总被引:1,自引:0,他引:1  
朱文昭 《医学争鸣》2005,26(4):367-367
2002-01/2004-01Ⅱ型糖尿病(DM)妇科手术患92例,年龄31~73(平均53.4)岁.有明确DM病史53例.病程1/12~21(平均6.9)a,入院后新诊断的DM39例空腹血糖为5.9—18.0(平均9.6)mmol/L,餐后血糖为9.3—22.6(平均16.5)mmol/L,术前准备时间平均为6.4d,术后住院时间平均为11.4d,术前有并存症72例.随机抽取同期住院非DM妇科手术92例,年龄22~65(平均41.5)岁,  相似文献   
38.
L Zhu  R K Crouch 《Cornea》1992,11(6):567-572
The action of hydrogen peroxide on soluble proteins of the rat cornea has been evaluated. Two major corneal proteins are found to be oxidized by 10 mM hydrogen peroxide. Protein sequence and antibody recognition has shown one of the proteins to be albumin. Treatment of pure rat or human albumin with hydrogen peroxide oxidizes the protein and decreases its affinity for its antibody. Because albumin is a major protein in the cornea, its ready oxidation suggests that a role for albumin in this tissue may be to act as a native antioxidant, scavenging hydrogen peroxide and thus preventing more extensive damage by this toxin. These data are relevant to the evaluation of the safety of contact lens disinfectants containing hydrogen peroxide and suggest that further study of the action of this oxidant is warranted.  相似文献   
39.
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号