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   3442225篇
  免费   297348篇
  国内免费   13589篇
耳鼻咽喉   48338篇
儿科学   111834篇
妇产科学   89274篇
基础医学   546790篇
口腔科学   90834篇
临床医学   307465篇
内科学   616812篇
皮肤病学   91132篇
神经病学   293833篇
特种医学   137289篇
外国民族医学   686篇
外科学   536223篇
综合类   102682篇
现状与发展   23篇
一般理论   2270篇
预防医学   289078篇
眼科学   78817篇
药学   237710篇
  23篇
中国医学   9654篇
肿瘤学   162395篇
  2021年   54959篇
  2020年   35028篇
  2019年   58066篇
  2018年   71166篇
  2017年   54206篇
  2016年   59803篇
  2015年   73961篇
  2014年   108112篇
  2013年   173277篇
  2012年   91809篇
  2011年   91695篇
  2010年   116568篇
  2009年   121144篇
  2008年   79661篇
  2007年   83060篇
  2006年   93726篇
  2005年   89274篇
  2004年   91424篇
  2003年   82563篇
  2002年   72772篇
  2001年   110020篇
  2000年   104079篇
  1999年   102881篇
  1998年   66072篇
  1997年   63490篇
  1996年   61437篇
  1995年   56887篇
  1994年   51143篇
  1993年   47677篇
  1992年   72815篇
  1991年   69875篇
  1990年   66377篇
  1989年   64844篇
  1988年   60005篇
  1987年   58803篇
  1986年   55199篇
  1985年   55207篇
  1984年   49831篇
  1983年   45397篇
  1982年   41899篇
  1981年   39669篇
  1980年   37189篇
  1979年   40812篇
  1978年   35728篇
  1977年   32697篇
  1976年   30039篇
  1975年   28948篇
  1974年   29661篇
  1973年   28570篇
  1972年   26525篇
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
971.
972.
973.
974.
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   
975.
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   
976.
977.
978.
979.
980.
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   
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