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   4898182篇
  免费   395342篇
  国内免费   16182篇
耳鼻咽喉   70883篇
儿科学   155783篇
妇产科学   131338篇
基础医学   733950篇
口腔科学   138399篇
临床医学   444654篇
内科学   895053篇
皮肤病学   115360篇
神经病学   411090篇
特种医学   194844篇
外国民族医学   1197篇
外科学   745718篇
综合类   140310篇
现状与发展   23篇
一般理论   2730篇
预防医学   412728篇
眼科学   116606篇
药学   349744篇
  25篇
中国医学   12663篇
肿瘤学   236608篇
  2021年   56478篇
  2019年   59297篇
  2018年   75411篇
  2017年   57620篇
  2016年   64133篇
  2015年   77007篇
  2014年   112009篇
  2013年   177770篇
  2012年   134254篇
  2011年   140793篇
  2010年   128655篇
  2009年   129909篇
  2008年   127787篇
  2007年   137419篇
  2006年   145637篇
  2005年   140984篇
  2004年   141472篇
  2003年   131758篇
  2002年   122673篇
  2001年   184149篇
  2000年   181301篇
  1999年   164696篇
  1998年   75138篇
  1997年   70274篇
  1996年   68272篇
  1995年   63989篇
  1994年   58117篇
  1993年   53785篇
  1992年   124052篇
  1991年   119720篇
  1990年   115294篇
  1989年   112120篇
  1988年   104452篇
  1987年   102384篇
  1986年   97416篇
  1985年   95263篇
  1984年   78042篇
  1983年   69074篇
  1982年   52272篇
  1981年   48390篇
  1980年   45471篇
  1979年   70184篇
  1978年   55014篇
  1977年   48210篇
  1976年   45122篇
  1975年   45774篇
  1974年   52202篇
  1973年   50027篇
  1972年   47200篇
  1971年   43518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