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   1302篇
  免费   188篇
  国内免费   18篇
耳鼻咽喉   20篇
儿科学   52篇
妇产科学   20篇
基础医学   97篇
口腔科学   39篇
临床医学   211篇
内科学   284篇
皮肤病学   109篇
神经病学   42篇
特种医学   132篇
外科学   192篇
综合类   95篇
现状与发展   30篇
预防医学   58篇
眼科学   17篇
药学   34篇
中国医学   3篇
肿瘤学   73篇
  2024年   18篇
  2023年   179篇
  2022年   13篇
  2021年   17篇
  2020年   55篇
  2019年   21篇
  2018年   52篇
  2017年   48篇
  2016年   42篇
  2015年   58篇
  2014年   88篇
  2013年   63篇
  2012年   27篇
  2011年   34篇
  2010年   75篇
  2009年   93篇
  2008年   33篇
  2007年   52篇
  2006年   20篇
  2005年   18篇
  2004年   10篇
  2003年   14篇
  2002年   17篇
  2001年   11篇
  2000年   13篇
  1999年   27篇
  1998年   35篇
  1997年   49篇
  1996年   41篇
  1995年   36篇
  1994年   29篇
  1993年   34篇
  1992年   8篇
  1991年   7篇
  1990年   9篇
  1989年   24篇
  1988年   20篇
  1987年   17篇
  1986年   6篇
  1985年   11篇
  1984年   5篇
  1983年   3篇
  1982年   8篇
  1981年   10篇
  1980年   12篇
  1978年   6篇
  1977年   3篇
  1976年   13篇
  1975年   10篇
  1974年   3篇
排序方式: 共有1508条查询结果,搜索用时 0 毫秒
11.
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   
12.
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   
13.
14.
15.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.  相似文献   
16.
Background: Impaired intestinal mucosal barrier (IMB) function is common in traumatic brain injury (TBI), but dopamine receptors (DRs) change in intestinal mucosa after TBI, and effects of enteral nutrition (EN) and supplements on IMB function remain unclear. Our purpose was to study the effects of EN and supplements on intestinal mucosal permeability (IMPB) and the expression of DRs DRD1 and DRD2 in the intestinal mucosa of rats with TBI. Methods: Forty‐eight rats were divided into 8 groups; control, animals with TBI, dopamine group, animals with TBI treated with dopamine antagonist, EN alone, or EN combined with glutamine, probiotics, or a combination of probiotics and glutamine daily after TBI. Results: The IMPB was improved in the glutamine, probiotics, and combination groups. Including probiotics improved IMPB more than adding glutamine, and bacterial translocation in the intestines after TBI was reduced in the probiotics and combination groups (all Ps < .01). TBI led to elevated DRD1 and DRD2 mRNA and protein levels, which were reduced in the DA antagonist, glutamine, probiotics, and combination groups. DRD2 mRNA and protein levels in the probiotics and combination groups were decreased more than in the DA antagonist group (all Ps < .01). The increased IMPB after TBI correlated with increased DRD1 and DRD2 levels in the rat intestinal mucosa. Conclusion: EN supplemented with probiotics or combining glutamine and probiotics lowers the increased IMPB, bacterial translocation, and DRD1 and DRD2 mRNA and protein expression in rat intestinal mucosa caused by TBI.  相似文献   
17.
18.
19.
Udden  MM; Umeda  M; Hirano  Y; Marcus  DM 《Blood》1987,69(1):52-57
The In(Lu) phenotype is inherited as an autosomal dominant trait and is characterized by suppression of the Lutheran, P1, i, and Aua erythrocyte blood group antigens. We have developed a monoclonal antibody (L21) that strongly agglutinates all erythrocytes except In(Lu), and we have identified eight In(Lu) individuals among 42,000 blood donors tested. Studies of two families confirmed the dominant mode of inheritance and revealed several new features of this phenotype. The erythrocytes of all five affected individuals from the two families exhibited diminished hemagglutination by the lectin concanavalin A, although they reacted normally with several other lectins. The erythrocytes of two affected individuals in one family exhibited marked acanthocytosis. The erythrocytes of the proposita of the other family exhibited a mild degree of poikilocytosis, but the cells of the other two affected individuals in this family had normal morphology. The osmotic fragility of fresh In(Lu) erythrocytes was normal, but after incubation for 24 hours at 37 degrees C in plasma the In(Lu) cells exhibited a marked increase in resistance to osmotic lysis. During the incubation period the erythrocytes lost K+ and their total cation content was diminished. These data indicate that in addition to the suppression of blood group antigens noted previously, the In(Lu) phenotype includes a variety of morphological abnormalities and a defect in electrolyte metabolism. The use of L21 and similar monoclonal antibodies provides a more sensitive means of detecting In(Lu) erythrocytes than typing with human anti-Lub antisera.  相似文献   
20.
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