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   1577篇
  免费   191篇
  国内免费   20篇
耳鼻咽喉   20篇
儿科学   59篇
妇产科学   25篇
基础医学   114篇
口腔科学   41篇
临床医学   225篇
内科学   308篇
皮肤病学   104篇
神经病学   54篇
特种医学   134篇
外科学   295篇
综合类   104篇
现状与发展   30篇
预防医学   139篇
眼科学   15篇
药学   36篇
中国医学   3篇
肿瘤学   82篇
  2024年   15篇
  2023年   178篇
  2022年   11篇
  2021年   20篇
  2020年   56篇
  2019年   25篇
  2018年   57篇
  2017年   46篇
  2016年   42篇
  2015年   58篇
  2014年   87篇
  2013年   67篇
  2012年   37篇
  2011年   50篇
  2010年   82篇
  2009年   98篇
  2008年   46篇
  2007年   65篇
  2006年   35篇
  2005年   35篇
  2004年   28篇
  2003年   33篇
  2002年   36篇
  2001年   19篇
  2000年   30篇
  1999年   40篇
  1998年   37篇
  1997年   51篇
  1996年   43篇
  1995年   37篇
  1994年   32篇
  1993年   36篇
  1992年   18篇
  1991年   14篇
  1990年   20篇
  1989年   32篇
  1988年   24篇
  1987年   20篇
  1986年   12篇
  1985年   11篇
  1984年   10篇
  1983年   5篇
  1982年   9篇
  1981年   10篇
  1980年   12篇
  1978年   8篇
  1977年   5篇
  1976年   14篇
  1975年   16篇
  1974年   7篇
排序方式: 共有1788条查询结果,搜索用时 31 毫秒
31.
The Brachmann de Lange syndrome (BDLS), first described in its full clinical presentation by Brachmann (1916) and Cornelia de Lange (1933) is a multi-system syndrome involving congenital malformations, growth retardation and neurodevelopmental delay. We describe here twelve Egyptian cases with this syndrome with emphasis on the orodental, ear and eye abnormalities and their relation to the severity of expreseion of the disorder. The crodental anomalies were high arched palate, Iong philtrum, micrognathia, macrostomia hypoplasia of upper anterior teceth, fissured tongue macroglossia. Ear malformations were low-set large ears. Otoscopy revealed normal drum appearance. Audiogram revealed conductive, sensorineural or mixed hearing loss. Ocular manifestations were nystagmus, convergentt squint, enophthalmos, myopia 8 blue scleca. The study emphasizes certain eye, ear and crodental anomalies as diagnostic features of the BDLS which correlate with the severity of expression of the syndrome. None of the cases had chromosomal aberrations and the parental consanguinity rate was not increased thus supporting dominant mutations or minor chromosomal etiology.  相似文献   
32.
33.
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   
34.
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   
35.
36.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder afflicting about one in every 68 children. It is behaviorally diagnosed based on a triad of symptoms, including impairment in communication, impairment in sociability and abnormal and stereotypic behavior. The subjectivity of behavioral diagnosis urges the need for clinical biomarker tests to improve and complement ASD diagnosis and treatment. Over the past two decades, researchers garnered a broad range of biomarkers associated with ASD and often correlating with the severity of ASD, which includes metabolic and genetic biomarkers or neuroimaging abnormalities. Metabolic biomarkers are either involved in key pathways such as a trans-sulfuration pathway or produced due to the derangement of these pathways in the case of oxidative stress. Recent studies reported several genetic abnormalities related to ASD, encompassing various mechanisms, from copy number variations (CNVs) and single nucleotide polymorphisms (SNPs) to chromosomal anomalies. However, it is still premature to consider these genetic variants as true biomarkers for ASD, due to their low reproducibility and regional-specific nature. Herein, we comprehensively review state of the art about major biomarkers reported in ASD and the association of some biomarkers with ASD symptoms and severity. It is important to establish those biomarkers to be able to help in the diagnosis and to optimize the treatment of ASD.  相似文献   
37.
38.
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