首页 | 官方网站   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   132307篇
  免费   44099篇
  国内免费   285篇
医药卫生   176691篇
  2023年   572篇
  2022年   1111篇
  2021年   3167篇
  2020年   6118篇
  2019年   12217篇
  2018年   11782篇
  2017年   12641篇
  2016年   13444篇
  2015年   13520篇
  2014年   14023篇
  2013年   15164篇
  2012年   8464篇
  2011年   8411篇
  2010年   11082篇
  2009年   7336篇
  2008年   5519篇
  2007年   4316篇
  2006年   4095篇
  2005年   3837篇
  2004年   3348篇
  2003年   3090篇
  2002年   2928篇
  2001年   1494篇
  2000年   1307篇
  1999年   890篇
  1998年   506篇
  1997年   379篇
  1996年   343篇
  1995年   296篇
  1994年   274篇
  1993年   218篇
  1992年   363篇
  1991年   324篇
  1990年   264篇
  1989年   264篇
  1988年   263篇
  1987年   262篇
  1986年   247篇
  1985年   202篇
  1984年   177篇
  1983年   164篇
  1982年   135篇
  1981年   98篇
  1980年   99篇
  1979年   125篇
  1978年   104篇
  1977年   102篇
  1975年   105篇
  1974年   106篇
  1973年   111篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
3.
4.
5.
6.
7.
8.
9.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
10.
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-23

京公网安备 11010802026262号