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   56192篇
  免费   3809篇
  国内免费   948篇
耳鼻咽喉   430篇
儿科学   1447篇
妇产科学   1437篇
基础医学   6944篇
口腔科学   885篇
临床医学   4934篇
内科学   13137篇
皮肤病学   883篇
神经病学   5358篇
特种医学   1969篇
外国民族医学   2篇
外科学   7188篇
综合类   2122篇
现状与发展   1篇
一般理论   2篇
预防医学   3146篇
眼科学   786篇
药学   4596篇
  8篇
中国医学   969篇
肿瘤学   4705篇
  2023年   459篇
  2022年   953篇
  2021年   1920篇
  2020年   1216篇
  2019年   1396篇
  2018年   1614篇
  2017年   1253篇
  2016年   1295篇
  2015年   1648篇
  2014年   2199篇
  2013年   2727篇
  2012年   3788篇
  2011年   3805篇
  2010年   2221篇
  2009年   2108篇
  2008年   3226篇
  2007年   3290篇
  2006年   2994篇
  2005年   2873篇
  2004年   2598篇
  2003年   2327篇
  2002年   2133篇
  2001年   1470篇
  2000年   1388篇
  1999年   1300篇
  1998年   540篇
  1997年   425篇
  1996年   423篇
  1995年   323篇
  1994年   298篇
  1993年   249篇
  1992年   689篇
  1991年   582篇
  1990年   548篇
  1989年   558篇
  1988年   465篇
  1987年   426篇
  1986年   409篇
  1985年   322篇
  1984年   263篇
  1983年   214篇
  1982年   121篇
  1979年   214篇
  1978年   131篇
  1977年   112篇
  1974年   123篇
  1973年   129篇
  1972年   123篇
  1971年   111篇
  1969年   103篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
The presence of cellular retinoic acid binding protein (cRABP) was analyzed in 13 consecutive patients with large bowel cancer (one right colon and 12 rectum-sigmoid, classified as three Duke B, eight C, and two D). Specimens of neoplastic tissue and of adjacent mucosa were obtained at surgery, and cRABP was determined by an assay based on incubation of partially purified cytosol with labeled retinoic acid and ultracentrifugation in sucrose density gradients. Sixty-one percent of tumors contained detectable levels of cRABP, whereas 58.3% of normal mucosal specimens were positive for cRABP. Among the positive tumors 62.5% contained cRABP also in the corresponding mucosa; in the group of cRABP-negative tumors, 40% showed cRABP in the adjacent mucosa. No correlation could be established with the grading or the stage of the tumors; however, interestingly, 100% (three cases) of gelatinous carcinomas were cRABP positive. Since cRABP seems to be a character of neoplastic cells contrary to normal ones, it would be interesting to investigate the conditions that influence the presence of this protein in normal appearing mucosa adjacent to carcinoma.  相似文献   
53.
54.
Most of the techniques described in the literature for the repair of chronic partial ACL tears, don’t spare the intact portion of the ligament. The aim of this study was to perform a prospective analysis of the results of augmentation surgery using gracilis and semitendinosus tendons to treat partial sub-acute lesions of the ACL. This technique involves an “over the top” femoral passage, which enables salvage and strengthening of the intact portion of the ACL. The study included 47 patients treated consecutively at our institute from 1993 to 1998, with a mean injury-surgery interval of 18 weeks (range 12–36). The patients were followed up by clinical and instrumental assessment criteria at 3 months, 1 and 5 years after surgery. Clinical assessment was performed using the IKDC form. Subjective and functional parameters were assessed by the Tegner activity scale. Instrumental evaluation was done using the KT-2000 instrument: the 30-pound passive test and the manual maximum displacement test were performed. We obtained good or excellent results in 95.7% of cases. No recurrences in ligamentous laxity were observed. We believe that the described technique has the advantage of being compatible with ACL anatomy, and enables very rapid functional recovery.  相似文献   
55.
A case of gastric tube bleeding after an Ivor-Lewis esophagectomy with gastroesophageal anastomosis is reported. During the early postoperative course, the patient had a gastric tube stasis that improved progressively. The subsequent onset of a serious and intermittent hematemesis, which was endoscopically deemed to be the result of a hemorrhagic gastritis, required multiple blood transfusions. The evolution to a severe hemodynamic instability obliged us to reoperate on the patient. During surgery, a band-related obstruction of the first jejunal loop with local signs of vascular hypertension was noted. As soon as the obstruction was solved, the gastric bleeding stopped. The authors discuss the clinical aspects and physiopathology of the gastric tube bleeding and, in particular, they evaluate the influence of the intestinal obstruction with vascular involvement on the development of this exceptional and severe complication.  相似文献   
56.
57.
58.
59.
目的我们应用平衡法门控心血池显像技术对不同Killip分级的前壁心肌梗死患者进行左室总体和局部收缩和舒张功能参数的对比分析。方法对照组15例(G0),前壁心肌梗死KillipⅠ级17例(G1),前壁心肌梗死KillipⅡⅢ级12例(G2)。利用平衡法门控心血池显像技术评价3组的左室总体和局部的收缩与舒张功能。结果①左室整体收缩功能,在LVEF,ESC 2个参数中,G1比G0有显著差异(P<0.05),G2分别比G1和G0有显著差异(P<0.05)。在PER、1/3EF、1/3ER 3个参数中,G2分别比G1和G0显著下降(P<0.05)。②左室总体舒张功能,在PFR、1/3FF、1/3FR、EDC中,G1比G0有显著差异(P<0.05),G2分别比G1和G0有显著差异(P<0.05)。③左室局部收缩功能,在以LVREF为参数时,G1在4个节段比G0显著差异(P<0.05),G2在所有6个节段中比G1和G0均显著下降(P<0.05)。④左室局部舒张功能,在以LVR1/3FF为参数时,G1在4个节段比G0显著下降(P<0.05),G2在所有6个节段比G0和G1均显著下降(P<0.05)。结论前壁心肌梗死后出现心功能受损或心力衰竭的主要原因为左室重构。  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