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   3492142篇
  免费   295546篇
  国内免费   15937篇
耳鼻咽喉   47303篇
儿科学   111658篇
妇产科学   91180篇
基础医学   556908篇
口腔科学   93965篇
临床医学   322440篇
内科学   615668篇
皮肤病学   90863篇
神经病学   300953篇
特种医学   135189篇
外国民族医学   392篇
外科学   529048篇
综合类   106329篇
现状与发展   23篇
一般理论   2290篇
预防医学   303030篇
眼科学   79284篇
药学   240134篇
  27篇
中国医学   10470篇
肿瘤学   166471篇
  2021年   55427篇
  2020年   35325篇
  2019年   58340篇
  2018年   72057篇
  2017年   54942篇
  2016年   60500篇
  2015年   74530篇
  2014年   108825篇
  2013年   174392篇
  2012年   99140篇
  2011年   100292篇
  2010年   118974篇
  2009年   122411篇
  2008年   86046篇
  2007年   89343篇
  2006年   99666篇
  2005年   94776篇
  2004年   95975篇
  2003年   86289篇
  2002年   75942篇
  2001年   107406篇
  2000年   100746篇
  1999年   99475篇
  1998年   65679篇
  1997年   63528篇
  1996年   61217篇
  1995年   56828篇
  1994年   50987篇
  1993年   47574篇
  1992年   70753篇
  1991年   67868篇
  1990年   64417篇
  1989年   62803篇
  1988年   58390篇
  1987年   56991篇
  1986年   54398篇
  1985年   54270篇
  1984年   49242篇
  1983年   44867篇
  1982年   42006篇
  1981年   39586篇
  1980年   37221篇
  1979年   40756篇
  1978年   35913篇
  1977年   32460篇
  1976年   30302篇
  1975年   28542篇
  1974年   30014篇
  1973年   28910篇
  1972年   27056篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
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   
994.
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   
995.
996.
997.
998.
999.
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   
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