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   38998篇
  免费   1885篇
  国内免费   179篇
耳鼻咽喉   306篇
儿科学   723篇
妇产科学   630篇
基础医学   4962篇
口腔科学   991篇
临床医学   2595篇
内科学   9590篇
皮肤病学   605篇
神经病学   2786篇
特种医学   1428篇
外科学   7290篇
综合类   184篇
预防医学   1276篇
眼科学   450篇
药学   2840篇
中国医学   132篇
肿瘤学   4274篇
  2023年   191篇
  2022年   364篇
  2021年   673篇
  2020年   391篇
  2019年   534篇
  2018年   673篇
  2017年   526篇
  2016年   607篇
  2015年   687篇
  2014年   890篇
  2013年   1044篇
  2012年   1647篇
  2011年   1741篇
  2010年   993篇
  2009年   811篇
  2008年   1550篇
  2007年   1651篇
  2006年   1650篇
  2005年   1700篇
  2004年   1731篇
  2003年   1649篇
  2002年   1655篇
  2001年   1668篇
  2000年   1612篇
  1999年   1543篇
  1998年   549篇
  1997年   450篇
  1996年   397篇
  1995年   349篇
  1994年   337篇
  1993年   299篇
  1992年   989篇
  1991年   931篇
  1990年   812篇
  1989年   901篇
  1988年   778篇
  1987年   705篇
  1986年   748篇
  1985年   685篇
  1984年   433篇
  1983年   378篇
  1982年   193篇
  1981年   189篇
  1979年   310篇
  1978年   241篇
  1977年   214篇
  1975年   211篇
  1974年   185篇
  1973年   173篇
  1971年   176篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
The interaction between oxyhemoglobin (oxyHb) and 5-hydroxytryptamine (5-HT) was investigated in an experimental model of isolated canine internal and common carotid arteries with insertion of stainless steel cannulae. Extraluminal application of 10(-5) M oxyHb induced marked and long-lasting vasoconstriction in the internal carotid but not in the common carotid arteries. The 5-HT-induced vasoconstriction was potentiated significantly in both the internal and common carotid arteries. These potentiations were not influenced by the presence or absence of endothelium, a finding which was confirmed by vascular responses to intraluminal acetylcholine. It is concluded that the interaction between extraluminal oxyHb and intraluminal 5-HT may be one of the possible etiological factors behind the chronic phase of vascular spasm following subarachnoid hemorrhage.  相似文献   
83.
A 66-year-old woman time of 10 days. One month after radicalmastectomy, there was local recurrence, followed by multiplepulmonary metastases, and the patient died of respiratory failure5 months after surgery. The gray-white-colored tumor measured13x12x;10 cm, and its border was well defined. The tumor wascomposed of diffusely growing round or polygonal cells withvesicular nuclei, prominent nucleoli, and ample cytoplasm containingeosinophilic inclusions. Lymph node involvement was widespread.Both vimentin and keratin were clearly demonstrated by immunohistochemicalstaining. Ultrastructural studies revealed that the MRT cellscontained cytoplasmic whorls of intermediate filaments.  相似文献   
84.
85.
86.
A 60-year-old man suffered from paraplegia after the operation for thoracic aortic aneurysm and died 10 months after the operation. Detailed examination on the distribution of spinal cord lesions and of the locations of anterior radicular arteries revealed that the spinal cord ischemia occurred at the mid-thoracic segments between T-6 and T-10; the artery of Adamkiewicz entered at T-12; another radicular artery entered at T-4. We concluded that the spinal cord ischemia was caused by the interruption of the radicular artery at T-4 and that the segments nourished by the blood flow of the artery of Adamkiewicz were intact. We suggest that in some patients important radicular arteries other than the artery of Adamkiewicz are essential to preserve blood flow to the upper or middle thoracic spinal segments.  相似文献   
87.
88.
89.
90.
A 72-year-old man with recurrent pancreatitis and a horseshoe-shaped anomaly of the pancreas is described. The diagnosis was made by endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography scan; laparotomy was confirmatory. The abnormal duct branched to the lower left from an enlarged Santorini's duct; a thin Wirsung's duct was joined at its distal portion to the junction of the abnormal duct. The anomaly was associated with a cystic dilatation of the common bile duct with stone and cholecystolithiasis. This anomaly is considered to be a variation of the dominant dorsal duct syndrome.  相似文献   
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