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   175529篇
  免费   971篇
  国内免费   3篇
耳鼻咽喉   1129篇
儿科学   6617篇
妇产科学   2998篇
基础医学   16498篇
口腔科学   1536篇
临床医学   12312篇
内科学   30852篇
皮肤病学   662篇
神经病学   16393篇
特种医学   8957篇
外科学   28947篇
综合类   2310篇
预防医学   18038篇
眼科学   2762篇
药学   9477篇
中国医学   626篇
肿瘤学   16389篇
  2021年   38篇
  2020年   22篇
  2019年   44篇
  2018年   21939篇
  2017年   17384篇
  2016年   19522篇
  2015年   905篇
  2014年   803篇
  2013年   773篇
  2012年   6935篇
  2011年   20973篇
  2010年   18796篇
  2009年   11509篇
  2008年   19501篇
  2007年   21676篇
  2006年   530篇
  2005年   2142篇
  2004年   3349篇
  2003年   4315篇
  2002年   2462篇
  2001年   286篇
  2000年   425篇
  1999年   180篇
  1998年   207篇
  1997年   209篇
  1996年   99篇
  1995年   110篇
  1994年   101篇
  1993年   60篇
  1992年   54篇
  1991年   107篇
  1990年   145篇
  1989年   86篇
  1988年   69篇
  1987年   49篇
  1986年   30篇
  1985年   43篇
  1984年   26篇
  1983年   25篇
  1982年   24篇
  1980年   41篇
  1974年   22篇
  1970年   22篇
  1969年   22篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components showed cytotoxic activities comparable to doxorubicin (LC50 14–70 μg/ml).  相似文献   
102.
103.
104.
We report a case of groove pancreatitis (GP) associated with a true pancreatic cyst. An 81-year-old man who had suffered epigastric pain for 4 months was referred to Saisekai Kure Hospital. Computed tomography and endoscopic retrograde pancreatography showed a cystic lesion in the groove area of the pancreas. Serum amylase elevation and imaging findings suggested GP due to the cyst. Six weeks of medical treatment did not improve the clinical symptoms. Therefore, pancreatoduodenectomy was performed. Histologic examination revealed a true cyst with intraluminal necrosis, which produced a protein plug that obstructed the Santorini duct. The parenchyma surrounding the groove area showed marked fibrosis and inflammatory cell infiltration. GP due to true pancreatic cyst was diagnosed. Although GP is usually caused by overconsumption of alcohol, which leads to changes in the pancreatic juice and the ultimate blockage of pancreatic outflow, the histologic features in our patient suggest that true pancreatic cyst stands as a secondary cause of GP.  相似文献   
105.
The prevalence of primary headache (PH) in a multiple sclerosis (MS) sample vs. control healthy subjects was investigated at a neurological clinic in 2004–2005: 122 of 238 (51%) MS patients and 57 of 238 (23%) controls proved to be affected by headache. The groups did not differ for the rates of PH types. Headache types of MS patients were comparable to those of PH patients that were observed at the same institute in a case-control comparison. First symptoms of headache preceded those of MS in two thirds of cases. Headache features did not significantly change after MS onset. Comorbidity of MS and PH could be explained by some common clinical and biological traits.  相似文献   
106.

Background  

Cerebrospinal fluid (CSF) pleocytosis may be seen in asymptomatic HIV-infected individuals. This finding complicates interpretation of CSF abnormalities when such individuals are evaluated for other central nervous system infections. The goal of this study was to determine the relationship between CSF pleocytosis, central nervous system (CNS) antiretroviral penetration, adherence to antiretroviral medication regimens, neurological symptoms and performance on neuropsychological tests.  相似文献   
107.
Single-agent chemotherapy of metastatic breast cancer is the treatment of choice in patients with slow tumor progression and asymptomatic disease. In this patient group, the choice of drugs is based more on good tolerability than on efficacy. By contrast, symptomatic or rapidly progressing disease requires the use of highly active regimens where more weight is put on reliable antitumor activity. While anthraycline-based combination regimens have set the standard of effective treatment, the addition of docetaxel (and to a lesser extent paclitaxel) has improved tumor response, but failed to induce a consistent prolongation of survival. Based on retrospective analyses, it is hypothesised that the combined use of anthracyclines and taxanes in first-line therapy may be most beneficial in defined subgroups: after adjuvant chemotherapy, in patients with HER-2 gene amplification, possibly also in patients with rapidly progressing visceral disease.  相似文献   
108.
109.
110.
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