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   4265980篇
  免费   360689篇
  国内免费   15248篇
耳鼻咽喉   60887篇
儿科学   132878篇
妇产科学   111723篇
基础医学   654532篇
口腔科学   118674篇
临床医学   387392篇
内科学   774787篇
皮肤病学   103200篇
神经病学   366137篇
特种医学   170484篇
外国民族医学   912篇
外科学   651545篇
综合类   126078篇
现状与发展   23篇
一般理论   2590篇
预防医学   362039篇
眼科学   100377篇
药学   301648篇
  24篇
中国医学   11353篇
肿瘤学   204634篇
  2021年   55620篇
  2020年   35453篇
  2019年   58557篇
  2018年   73123篇
  2017年   55846篇
  2016年   62149篇
  2015年   75458篇
  2014年   110176篇
  2013年   175498篇
  2012年   117157篇
  2011年   120156篇
  2010年   122739篇
  2009年   125942篇
  2008年   107393篇
  2007年   113878篇
  2006年   123433篇
  2005年   118583篇
  2004年   119542篇
  2003年   110275篇
  2002年   100910篇
  2001年   154279篇
  2000年   150437篇
  1999年   139528篇
  1998年   71272篇
  1997年   67779篇
  1996年   65672篇
  1995年   61504篇
  1994年   55582篇
  1993年   51623篇
  1992年   103575篇
  1991年   98956篇
  1990年   94051篇
  1989年   91694篇
  1988年   85319篇
  1987年   83777篇
  1986年   79470篇
  1985年   77907篇
  1984年   65939篇
  1983年   58852篇
  1982年   48141篇
  1981年   44878篇
  1980年   42177篇
  1979年   57830篇
  1978年   47031篇
  1977年   41595篇
  1976年   38657篇
  1975年   37846篇
  1974年   42423篇
  1973年   40546篇
  1972年   38016篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
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   
993.
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   
994.
995.
996.
997.
998.
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   
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