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   1441633篇
  免费   106919篇
  国内免费   4553篇
耳鼻咽喉   18517篇
儿科学   46721篇
妇产科学   38790篇
基础医学   212221篇
口腔科学   39782篇
临床医学   136432篇
内科学   284587篇
皮肤病学   30004篇
神经病学   120474篇
特种医学   50647篇
外国民族医学   368篇
外科学   197200篇
综合类   29410篇
现状与发展   1篇
一般理论   493篇
预防医学   125037篇
眼科学   31524篇
药学   106437篇
  6篇
中国医学   3696篇
肿瘤学   80758篇
  2021年   13385篇
  2019年   14309篇
  2018年   20583篇
  2017年   14786篇
  2016年   15540篇
  2015年   17793篇
  2014年   23907篇
  2013年   36624篇
  2012年   52190篇
  2011年   55322篇
  2010年   31442篇
  2009年   28062篇
  2008年   49407篇
  2007年   52189篇
  2006年   51818篇
  2005年   50092篇
  2004年   47253篇
  2003年   44844篇
  2002年   43387篇
  2001年   63491篇
  2000年   65547篇
  1999年   54571篇
  1998年   15052篇
  1997年   13606篇
  1996年   13400篇
  1995年   12688篇
  1994年   11801篇
  1993年   11086篇
  1992年   42471篇
  1991年   41524篇
  1990年   40134篇
  1989年   37951篇
  1988年   35103篇
  1987年   34212篇
  1986年   32646篇
  1985年   31079篇
  1984年   23362篇
  1983年   19866篇
  1982年   11878篇
  1979年   21086篇
  1978年   14998篇
  1977年   12239篇
  1976年   12056篇
  1975年   12348篇
  1974年   15092篇
  1973年   14769篇
  1972年   13611篇
  1971年   12696篇
  1970年   11752篇
  1969年   10670篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  相似文献   
103.
104.
105.
In 1963, Goffman argued that forming a group based on shared stigma may provide benefits. However, there is no empirical research on whether perception that a separate, unique, coherent group exists (i.e., group entitativity) influences coping, such as educating others or secrecy, for the stigmatized individual or his or her spouse. Further, little is known about how spouses influence each other in terms of promoting the education of others about a stigmatizing condition, especially when it comes to the role of believing that stigma-based groups, to which they may both belong, exist. This study provides a step toward bridging this gap in the research by applying the label management model in efforts to understand coping for couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). This study included 50 married couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). We found that group entitativity related to those with AATD counterbalanced the influence of genetic stigma on spouses’ intentions to keep the diagnosis secret or to educate others about it. Intrapersonal and interpersonal influences appeared among spouses. Attention is needed on the power of creating groups for stigmatized persons and their relatives. Indeed, people live within a dynamic world of group entities, and multiple social identities including spousal and familial. While attention has been paid to the diffusion of stigmas to loved ones, less has been paid to the uplift of group entities for them.  相似文献   
106.
107.
108.
ABSTRACT

Domestic chickens (Gallus gallus domesticus) were exposed to imidacloprid by gavage once daily for 7 consecutive days at 0, 0.03, 0.34, 3.42, 10.25, and 15.5 mg/kg/day (n = 20 per group; 5 6-week-old males, 5 6-week-old females, 5 9-week-old males, and 5 9-week-old females). The severity and duration of neurobehavioral abnormalities were recorded. Components of the innate and adaptive immune system were assessed with 7 standard functional assays. Temporary neurobehavioral abnormalities were observed in a dose-dependent manner, including muscle tremors, ataxia, and depressed mentation. Based upon mean clinical severity scores, the no observed adverse effect level (NOAEL) was 3.42 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 10.25 mg/kg/day. The effective dose value for the presence of any neurobehavioral abnormalities in 50% of the test group (ED50) was 4.62 ± 0.98 mg/kg/day. The ED50 for an adjusted score that included both severity and duration of neurobehavioral abnormalities was 11.24 ± 9.33 mg/kg/day. These ED50 values are equivalent to a 1 kg bird ingesting 29 or 70 imidacloprid treated soybean seeds respectively. Immunotoxicity was not documented, possible causes include the assays were insensitive, relevant immune functions were not examined, or imidacloprid is not immunotoxic at this dosing schedule in this species. Neurobehavioral abnormalities were a more sensitive indicator of the sublethal effects of imidacloprid than immunotoxicity.  相似文献   
109.
110.
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