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   3770379篇
  免费   312135篇
  国内免费   14691篇
耳鼻咽喉   50745篇
儿科学   119461篇
妇产科学   97728篇
基础医学   590896篇
口腔科学   102425篇
临床医学   340292篇
内科学   674130篇
皮肤病学   98527篇
神经病学   316922篇
特种医学   146991篇
外国民族医学   264篇
外科学   581630篇
综合类   114159篇
现状与发展   23篇
一般理论   2362篇
预防医学   311022篇
眼科学   89077篇
药学   261161篇
  26篇
中国医学   11454篇
肿瘤学   187910篇
  2021年   55858篇
  2020年   35530篇
  2019年   58649篇
  2018年   72982篇
  2017年   55636篇
  2016年   61539篇
  2015年   75240篇
  2014年   109533篇
  2013年   174972篇
  2012年   104912篇
  2011年   106762篇
  2010年   120905篇
  2009年   123807篇
  2008年   93136篇
  2007年   97717篇
  2006年   107184篇
  2005年   101916篇
  2004年   103624篇
  2003年   93484篇
  2002年   82850篇
  2001年   136078篇
  2000年   129636篇
  1999年   121999篇
  1998年   68597篇
  1997年   65266篇
  1996年   63003篇
  1995年   58546篇
  1994年   52532篇
  1993年   48891篇
  1992年   85024篇
  1991年   80952篇
  1990年   76660篇
  1989年   75101篇
  1988年   69009篇
  1987年   67201篇
  1986年   63542篇
  1985年   62764篇
  1984年   54875篇
  1983年   49573篇
  1982年   43618篇
  1981年   40993篇
  1980年   38455篇
  1979年   44846篇
  1978年   38237篇
  1977年   34915篇
  1976年   31958篇
  1975年   30783篇
  1974年   32478篇
  1973年   31178篇
  1972年   29033篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
983.
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   
984.
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   
985.
986.
987.
988.
989.
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   
990.
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