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   4468546篇
  免费   359032篇
  国内免费   15350篇
耳鼻咽喉   62170篇
儿科学   144120篇
妇产科学   118307篇
基础医学   678960篇
口腔科学   121806篇
临床医学   404184篇
内科学   814707篇
皮肤病学   110649篇
神经病学   369424篇
特种医学   175926篇
外国民族医学   888篇
外科学   685337篇
综合类   129699篇
现状与发展   23篇
一般理论   2575篇
预防医学   367594篇
眼科学   106555篇
药学   313979篇
  26篇
中国医学   12654篇
肿瘤学   223345篇
  2021年   56329篇
  2020年   35852篇
  2019年   59088篇
  2018年   74719篇
  2017年   57127篇
  2016年   63226篇
  2015年   76372篇
  2014年   110745篇
  2013年   176432篇
  2012年   123485篇
  2011年   128542篇
  2010年   126533篇
  2009年   127709篇
  2008年   115124篇
  2007年   122704篇
  2006年   130919篇
  2005年   125600篇
  2004年   127049篇
  2003年   116827篇
  2002年   106170篇
  2001年   173750篇
  2000年   169576篇
  1999年   155107篇
  1998年   73232篇
  1997年   68489篇
  1996年   66378篇
  1995年   61809篇
  1994年   55974篇
  1993年   51908篇
  1992年   112409篇
  1991年   108235篇
  1990年   103553篇
  1989年   100750篇
  1988年   92793篇
  1987年   90814篇
  1986年   85548篇
  1985年   83646篇
  1984年   69497篇
  1983年   61594篇
  1982年   48499篇
  1981年   45260篇
  1980年   42300篇
  1979年   59026篇
  1978年   47211篇
  1977年   42296篇
  1976年   38971篇
  1975年   39120篇
  1974年   42774篇
  1973年   41000篇
  1972年   38300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