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   4098376篇
  免费   337635篇
  国内免费   14804篇
耳鼻咽喉   56479篇
儿科学   126980篇
妇产科学   106993篇
基础医学   634526篇
口腔科学   113074篇
临床医学   369306篇
内科学   741824篇
皮肤病学   103278篇
神经病学   345913篇
特种医学   160083篇
外国民族医学   562篇
外科学   633770篇
综合类   118859篇
现状与发展   24篇
一般理论   2464篇
预防医学   336434篇
眼科学   95387篇
药学   287775篇
  24篇
中国医学   11709篇
肿瘤学   205351篇
  2021年   55572篇
  2020年   35390篇
  2019年   58481篇
  2018年   72976篇
  2017年   55829篇
  2016年   61736篇
  2015年   75261篇
  2014年   109580篇
  2013年   174814篇
  2012年   111947篇
  2011年   114596篇
  2010年   121864篇
  2009年   124928篇
  2008年   101988篇
  2007年   107355篇
  2006年   117080篇
  2005年   112084篇
  2004年   113210篇
  2003年   103534篇
  2002年   93050篇
  2001年   156017篇
  2000年   150949篇
  1999年   139340篇
  1998年   70474篇
  1997年   66873篇
  1996年   64716篇
  1995年   60103篇
  1994年   53928篇
  1993年   50203篇
  1992年   99484篇
  1991年   94491篇
  1990年   89747篇
  1989年   87884篇
  1988年   80880篇
  1987年   79101篇
  1986年   74242篇
  1985年   73381篇
  1984年   62188篇
  1983年   55619篇
  1982年   46221篇
  1981年   42952篇
  1980年   40335篇
  1979年   52116篇
  1978年   42809篇
  1977年   38507篇
  1976年   34986篇
  1975年   34310篇
  1974年   37059篇
  1973年   35536篇
  1972年   33386篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
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   
995.
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   
996.
997.
998.
999.
1000.
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