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   12433篇
  免费   625篇
  国内免费   56篇
耳鼻咽喉   140篇
儿科学   163篇
妇产科学   171篇
基础医学   1474篇
口腔科学   382篇
临床医学   798篇
内科学   2767篇
皮肤病学   162篇
神经病学   820篇
特种医学   526篇
外科学   2558篇
综合类   58篇
预防医学   274篇
眼科学   93篇
药学   997篇
中国医学   38篇
肿瘤学   1693篇
  2023年   63篇
  2022年   83篇
  2021年   278篇
  2020年   146篇
  2019年   218篇
  2018年   279篇
  2017年   254篇
  2016年   261篇
  2015年   263篇
  2014年   338篇
  2013年   436篇
  2012年   623篇
  2011年   741篇
  2010年   420篇
  2009年   380篇
  2008年   639篇
  2007年   720篇
  2006年   704篇
  2005年   685篇
  2004年   705篇
  2003年   702篇
  2002年   671篇
  2001年   283篇
  2000年   287篇
  1999年   264篇
  1998年   166篇
  1997年   132篇
  1996年   140篇
  1995年   107篇
  1994年   123篇
  1993年   98篇
  1992年   210篇
  1991年   179篇
  1990年   154篇
  1989年   164篇
  1988年   139篇
  1987年   140篇
  1986年   122篇
  1985年   124篇
  1984年   79篇
  1983年   67篇
  1982年   28篇
  1981年   28篇
  1979年   44篇
  1978年   33篇
  1977年   27篇
  1974年   27篇
  1973年   25篇
  1972年   27篇
  1970年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
2.
3.
4.
5.
Endoscopic nasobiliary drainage (ENBD) is a well established mode of biliary decompression. Although ENBD is certainly an uncomfortable procedure with the potential risk of spontaneous dislocation or removal of the drainage catheter by disoriented patients, it has several advantages over endoscopic biliary drainage (EBD) using an indwelling stent. The current indications for ENBD are: (i) temporary drainage to treat obstructive jaundice and cholangitis caused by malignant or benign biliary stricture; (ii) urgent drainage to treat suppurative cholangitis primarily caused by common bile duct stones; (iii) temporary drainage after stone removal in patients with suspected incomplete clearance and/or with cholangitis; and (iv) biliary leaks that occur primarily after surgery, as well as other indications. Different types of nasobiliary catheters are currently available that have been designed with various diameters, shapes, and materials. However, the current catheters are not considered by most endoscopists to be sufficient. Further improvements are needed to achieve better drainage and better maneuverability.  相似文献   
6.
1. The maximum activity of an antihuman hemolytic amboceptor may be obtained by employing the homologous or heterologous complement, according to the variable relations existing between the species furnishing the amboceptor and the one supplying the complement. Thus, some amboceptors are best reactivated by the complement of the same species, while others may act most strongly when reactivated with the complements of certain suitable heterologous species. 2. From the above it is clear that the complementary activity of a given serum may be very variable according to the varieties of amboceptors employed. In expressing the complementary activity of a serum, the species of the host of the amboceptor must always be stated. Thus, one serum may have many different complementary titers according to the amboceptors used. A similar variation in the titers of the amboceptors occurs when a variety of complements are employed. 3. Certain species of animals (pig and sheep) yield sera which are comparatively poor in reactivating most varieties of antihuman amboceptors. The complements of these species deteriorate rapidly. 4. The serum of chicken contained but little complement for the amboceptors derived from the mammalia, while the amboceptor from the chicken was only poorly, or not at all, reactivable by the complements contained in the mammalian sera. The serum of pig was the only variety which reactivated this amboceptor in a fair degree. 5. For the fixation tests guinea pig complement is the most favorable. This complement is also the most active and durable of those which have been studied. The complements of pig and sheep are quite fixable, but their weakness and rapid deterioration render them unsuitable for fixation purposes. Rabbit complement is quite active but is not easily fixable. Goat complement is, as already stated, difficult to fix, in spite of its strong complementary activity. The other complements are unsuitable because of their feeble complementary activity. 6. For fixation tests the antihuman amboceptors produced in the rabbit and guinea pig are suitable. They are, moreover, very active and do not cause the phenomenon of non-fixation. The amboceptors from other animals are unsuitable, as we cannot find a complement which strongly reactivates them. The amboceptor from the goat is unsuitable because of the danger of masking the fixation phenomenon by subsequent hemolysis. 7. In summing up, we arrive at the conclusion that the rabbit is the best animal for producing antihuman amboceptor, and the guinea pig for supplying complement. The guinea pig produces a good amboceptor, but its small size renders it second in choice. So far, no other animals have been found useful for the fixation experiments.  相似文献   
7.
8.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  相似文献   
9.
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