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   36821篇
  免费   1803篇
  国内免费   211篇
耳鼻咽喉   382篇
儿科学   844篇
妇产科学   432篇
基础医学   4606篇
口腔科学   950篇
临床医学   2506篇
内科学   9928篇
皮肤病学   562篇
神经病学   2514篇
特种医学   1393篇
外科学   6588篇
综合类   174篇
一般理论   3篇
预防医学   1081篇
眼科学   426篇
药学   2432篇
中国医学   102篇
肿瘤学   3912篇
  2023年   290篇
  2022年   518篇
  2021年   873篇
  2020年   440篇
  2019年   601篇
  2018年   763篇
  2017年   611篇
  2016年   662篇
  2015年   628篇
  2014年   889篇
  2013年   1060篇
  2012年   1730篇
  2011年   1792篇
  2010年   1068篇
  2009年   906篇
  2008年   1639篇
  2007年   1738篇
  2006年   1719篇
  2005年   1801篇
  2004年   1706篇
  2003年   1669篇
  2002年   1554篇
  2001年   1217篇
  2000年   1294篇
  1999年   1142篇
  1998年   486篇
  1997年   354篇
  1996年   355篇
  1995年   311篇
  1994年   264篇
  1993年   275篇
  1992年   788篇
  1991年   728篇
  1990年   682篇
  1989年   734篇
  1988年   653篇
  1987年   606篇
  1986年   552篇
  1985年   520篇
  1984年   340篇
  1983年   283篇
  1979年   261篇
  1978年   190篇
  1977年   162篇
  1974年   156篇
  1973年   172篇
  1972年   166篇
  1971年   157篇
  1970年   158篇
  1968年   148篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Liver histopathology in clinical Reye syndrome   总被引:1,自引:0,他引:1  
Analysis of the liver histopathology in 19 children with clinical Reye syndrome (RS) revealed that nine had diffuse panlobular steatosis, one giant cell hepatitis, one a mild choledochal cyst with inflammation, two multifocal spotty necrosis and one multiple centrilobular necrosis, the other five being normal. Four of the nine patients with diffuse panlobular steatosis showed microvesicular fatty droplets with central nuclei, which was consistent with findings characteristic for typical RS. Two cases showed a periportal area dominant macrovesicular fatty change, which was highly suggestive for metabolic disorder. In the other three cases, the findings were so variable in terms of the size of lipid droplets and the location of nuclei in hepatocytes that it was not possible to provide any clue for defining a diagnosis. These results confirmed the legitimacy of the diagnostic criteria of RS which included a liver biopsy as one of the mandatory conditions. They also indicated that RS-mimicking clinical pictures can be presented by miscellaneous conditions in which liver histology does not necessarily helpful in establishing definite diagnosis.  相似文献   
12.
In order to examine the cholecystohepatic circulation of trichloroethylene (TRI) and its metabolites, we injected the gallbladder with TRI and its metabolites, i.e. chloral hydrate (CH), free-trichloroethanol (F-TCE), trichloroacetic acid (TCA) and conjugated-trichloroethanol (Conj-TCE), using anesthetized dogs. The absorption rates of water from the gallbladder were 25-30% 2 h after administration for all substances. The absorption rates of substances were 65-70% in the CH, F-TCE and TRI groups, and 40-50% in the Conj-TCE and TCA groups 2 h after the administration. Conj-TCE in the blood absorbed from the gallbladder has a tendency to be directly transported to the venous system rather than to be taken into hepatocytes in the liver. All of the administered substances, in particular, F-TCE might be metabolized to other substances in the gallbladder.  相似文献   
13.
14.
15.
16.
Iron deficiency (ID) is one of the most commonly known forms of nutritional deficiencies. Low body iron is thought to induce neurologic defects but may also play a protective role against cancer development by cell growth arrest. Thus, ID may affect cellular pathways controlling cell growth and proliferation, the mechanism of which is still not fully understood. The serine/threonine protein kinase Akt and its downstream target, the mammalian Target of Rapamycin (mTOR), is known to play a crucial role in the regulation of cell growth and survival. Therefore, we hypothesized that Akt/mTOR pathway could be influenced by ID. Three-week-old male Wistar-strain rats were divided into 3 groups and the 2 groups had free access to a control diet (C group) or an iron-deficient diet (D group). The third group (PF group) were pair-fed the control diet to the mean intake of the D group. After 4 weeks, rats were killed and their brains were sampled. In separate experiments, COS-1 cells were cultured with or without the iron chelator deferoxamine. Western blots of brain samples and COS-1 lysates were used to analyze the expression and phosphorylation state of Akt, TSC2, mTOR, and S6 kinase proteins implicated in the Akt/mTOR pathway. Using 2 different ID models, we show for the first time that iron deficiency depresses Akt activity in rats and in COS-1 cells, leading to a decrease in mTOR activity.  相似文献   
17.
18.
CASE REPORT: A 12-year-old boy who had a history of Kawasaki disease 9 years ago experienced a subarachnoid hemorrhage by ruptured right posterior cerebral artery aneurysm. On day 1 operation, as the aneurysm was very fragile and bled easily, two intraoperative ruptures, including a very premature rupture, were encountered. As a result, a left hemiparesis especially severe in the left hand was caused by the right anterior thalamic infarction due to the occlusion of a thalamo-perforating artery arising near the neck of the aneurysm. DISCUSSION: The histopathological examination of the intraoperative excised aneurysmal dome disclosed the thickening of the endothelial inner due to the endothelial hypertrophy and the invasion of inflammatory cells. This finding of the aneurysm was partially mimicking the finding of the coronary artery of the patients with Kawasaki disease. The combination of cerebral aneurysm and Kawasaki disease has never been reported until now, and the etiology of the aneurysm of this patient is unclear.  相似文献   
19.
Since 1998, we have performed minimum incision endoscopic surgery (MIES) for renal cell carcinoma (RCC). For seven dialysis patients with bilateral RCC, we have performed sequential bilateral MIES radical nephrectomy. It was carried out by retroperitoneal approach through a single minimum incision that narrowly permitted extraction of the specimen using endoscopy and direct stereovision, without trocar ports, without gas insufflation and without the insertion of the hands of operators into the operative field. Although six of the seven patients had multiple complications in addition to chronic renal failure (CRF), bilateral kidneys were successfully removed by sequential MIES radical nephrectomy without major operative complication. Postoperative recovery was prompt with all patients resuming oral feeding and walking by the second postoperative day. Sequential bilateral MIES radical nephrectomy, leaving the peritoneal cavity intact and without imposing circulatory stress caused by gas insufflation, is a feasible treatment for bilateral RCCs in dialysis patients.  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