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   3868979篇
  免费   312844篇
  国内免费   14532篇
耳鼻咽喉   53499篇
儿科学   121638篇
妇产科学   100983篇
基础医学   600785篇
口腔科学   105359篇
临床医学   345065篇
内科学   693664篇
皮肤病学   100147篇
神经病学   324071篇
特种医学   154023篇
外国民族医学   558篇
外科学   599052篇
综合类   113527篇
现状与发展   23篇
一般理论   2344篇
预防医学   316135篇
眼科学   89436篇
药学   273541篇
  27篇
中国医学   11218篇
肿瘤学   191260篇
  2021年   55487篇
  2020年   35369篇
  2019年   58319篇
  2018年   72267篇
  2017年   55301篇
  2016年   61199篇
  2015年   74936篇
  2014年   109204篇
  2013年   174534篇
  2012年   104080篇
  2011年   106262篇
  2010年   120382篇
  2009年   123752篇
  2008年   93434篇
  2007年   98277篇
  2006年   108047篇
  2005年   103282篇
  2004年   104599篇
  2003年   95510篇
  2002年   85223篇
  2001年   137185篇
  2000年   131425篇
  1999年   124741篇
  1998年   68316篇
  1997年   65234篇
  1996年   63090篇
  1995年   58458篇
  1994年   52400篇
  1993年   48867篇
  1992年   88301篇
  1991年   83926篇
  1990年   80670篇
  1989年   79007篇
  1988年   72812篇
  1987年   71006篇
  1986年   67663篇
  1985年   66461篇
  1984年   57343篇
  1983年   51480篇
  1982年   44472篇
  1981年   41412篇
  1980年   39178篇
  1979年   48342篇
  1978年   40124篇
  1977年   36823篇
  1976年   33458篇
  1975年   33261篇
  1974年   35284篇
  1973年   33936篇
  1972年   32001篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Nickel is the leading cause of allergic contact dermatitis (ACD) from early childhood through adolescence. Studies have shown that skin piercings and other nickel‐laden exposures can trigger the onset of nickel ACD in those who are susceptible. Nickel ACD causes a vast amount of cutaneous disease in children. Cases of nickel ACD in children have been reported in peer‐reviewed literature from 28 states. Common items that contain inciting nickel include jewelry, coins, zippers, belts, tools, toys, chair studs, cases for cell phones and tablets, and dental appliances. The diagnosis of nickel ACD has been routinely confirmed by patch testing in children older than 6 months suspected of ACD from nickel. Unlike in Europe, there are no mandatory restrictions legislated for nickel exposure in the United States. Denmark has demonstrated that regulation of the nickel content in metals can lower the risk of ACD and the associated health care–related costs that arise from excess nickel exposure. To further awareness, this article reviews the prominent role of nickel in pediatric skin disease in the United States. It discusses the need for a campaign by caretakers to reduce nickel‐related morbidity. Lastly, it promotes the model of European legislation as a successful intervention in the prevention of nickel ACD.  相似文献   
992.
A 3‐year‐old Arab boy with a history of hypoplastic left heart syndrome was referred to the pediatric dermatology clinic at Sheba Medical Center for evaluation of hypomelanosis, manifested by fair skin pigmentation and silvery‐grey hair, eyebrows, and eyelashes. The child had one older brother with similar hypopigmentation and another older brother who had died of congenital heart disease. The child had no history of neurologic deficits or immunodeficiency and no additional findings on clinical evaluation.  相似文献   
993.
994.
995.
996.
997.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.  相似文献   
998.
999.
1000.
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