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   2654篇
  免费   284篇
  国内免费   20篇
耳鼻咽喉   28篇
儿科学   84篇
妇产科学   34篇
基础医学   359篇
口腔科学   45篇
临床医学   305篇
内科学   482篇
皮肤病学   405篇
神经病学   114篇
特种医学   160篇
外科学   287篇
综合类   107篇
现状与发展   30篇
一般理论   2篇
预防医学   103篇
眼科学   23篇
药学   107篇
中国医学   3篇
肿瘤学   280篇
  2024年   15篇
  2023年   181篇
  2022年   21篇
  2021年   28篇
  2020年   61篇
  2019年   30篇
  2018年   64篇
  2017年   61篇
  2016年   58篇
  2015年   79篇
  2014年   104篇
  2013年   99篇
  2012年   70篇
  2011年   76篇
  2010年   103篇
  2009年   113篇
  2008年   89篇
  2007年   101篇
  2006年   78篇
  2005年   88篇
  2004年   96篇
  2003年   81篇
  2002年   86篇
  2001年   75篇
  2000年   69篇
  1999年   77篇
  1998年   51篇
  1997年   75篇
  1996年   63篇
  1995年   55篇
  1994年   44篇
  1993年   45篇
  1992年   55篇
  1991年   49篇
  1990年   44篇
  1989年   45篇
  1988年   46篇
  1987年   38篇
  1986年   23篇
  1985年   24篇
  1984年   28篇
  1982年   16篇
  1981年   16篇
  1979年   19篇
  1978年   16篇
  1976年   22篇
  1975年   21篇
  1974年   22篇
  1973年   19篇
  1970年   16篇
排序方式: 共有2958条查询结果,搜索用时 46 毫秒
51.
应用改进的眼震图检查先天性眼球震颤   总被引:2,自引:0,他引:2  
目的评价改进后的眼震图对先天性眼球震颤波形的分析,为其手术治疗提供较为精确的量化标准.方法改进电生理仪的视网膜电图(EOG)程序,分别记录68例患者33cm原在位、右5°、10°、15°、20°,左5°、10°、15°、20°,3m原在位及闭眼的波形,并对其中28例手术患者术前和术后的眼震图进行比较.结果68例患者中,跳动型48例,其中水平跳动46例,垂直跳动2例;水平钟摆型20例.跳动型中,有代偿头位的40例,钟摆型无明显代偿头位.28例手术患者中,水平跳动型26例,水平钟摆型2例.26例跳动型患者均有中间位和代偿头位.术后20例代偿头位消失,6例代偿头位在左5°~10°.按震频、振幅、震强的分组中,处于中等震频、振幅、震强范围内的多见.结论改进的眼震图可以对眼震的振幅、震频、震强、中间位进行量化的检测,从而指导其治疗.  相似文献   
52.
Antifungal activity of natural products is being studied widely. Saponins are known to be antifungal and antibacterial. We have isolated eight steroid saponins from Tribulus terrestris L. , namely TTS-8, TTS-9, TTS-10, TTS-11, TTS-12, TTS-13, TTS-14 and TTS-15. TTS-12 and TTS-15 were identified as tigogenin-3-O-β-D-xylopyranosyl(1→ 2)-[-β-D-xylopyranosyl( 1 → 3 ) 3-β- D-glucopyranosyl ( 1 → 4 )- 1- α-L-rhamnopyranosyl ( 1 → 2 ) 3-β-D-galactopyranoside and tigogenin-3-O-β-D-glucopyranpyranosyl(1→2)-[-β-D-xylopyranosyl(1→ 3)3-β-D-glucopyranosyl(1→4)-β-D-galactopyranoside, respectively. The in vitro antifungal activities of the eight saponins against six fluconazole-resistant yeasts, Candida albicans, Candida glabrata, Candida para psilosis , Candida tropicalis , Candida krusei , and Cryptococcus neo f ormans were studied using microbroth dilution assay. The results showed that TTS-12 and TTS-15 were very effective against several pathogenic candidal species and C. neoformans in vitro. It is noteworthy that TTS-12 and TTS-15 were very active against fluconazole-resistant C. albicans (MIC80 = 4.4, 9.4 mg/ml), C. neoformans (MIC80 =10.7, 18.7 mg/ml) and inherently resistant C. krusei (MIC80 =8.8, 18.4 mg/ml). So in vivo activity of TTS-12 in a vaginal infection model with fluconazole-resistant C. albicans was studied in particular. Our studies revealed TTS-12 also showed in vivo activities against fluconazole-resistant yeasts. In conclusion, steroid saponins TTS-12 and TTS-15 from Tribulus terrestris L. have significant in vitro antifungal activity against fluconazole-resistant fungi, especially TTS-12 also showed in vivo activity against fluconazole-resistant C. albicans.  相似文献   
53.
54.
55.
56.
57.
58.
59.
Mutations affecting recombination activation genes RAG1 and RAG2 are associated with variable phenotypes, depending on the residual recombinase activity. The aim of this study is to describe a variety of clinical phenotypes in RAG-deficient patients from the highly consanguineous Egyptian population. Thirty-one patients with RAG mutations (from 28 families) were included from 2013 to 2017. On the basis of clinical, immunological and genetic data, patients were subdivided into three groups; classical TB severe combined immunodeficiency (SCID), Omenn syndrome (OS) and atypical SCID. Nineteen patients presented with typical TBSCID; among these, five patients carried a homozygous RAG2 mutation G35V and five others carried two homozygous RAG2 mutations (T215I and R229Q) that were detected together. Four novel mutations were reported in the TBSCID group; three in RAG1 (A565P, N591Pfs*14 and K621E) and one in RAG2 (F29S). Seven patients presented with OS and a novel RAG2 mutation (C419W) was documented in one patient. The atypical SCID group comprised five patients. Two had normal B cell counts; one had a previously undescribed RAG2 mutation (V327D). The other three patients presented with autoimmune cytopaenias and features of combined immunodeficiency and were diagnosed at a relatively late age and with a substantial diagnostic delay; one patient had a novel RAG1 mutation (C335R). PID disorders are frequent among Egyptian children because of the high consanguinity. RAG mutations stand behind several variable phenotypes, including classical SCID, OS, atypical SCID with autoimmunity and TB+ CID.  相似文献   
60.
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