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   6334篇
  免费   606篇
  国内免费   14篇
耳鼻咽喉   26篇
儿科学   265篇
妇产科学   454篇
基础医学   565篇
口腔科学   127篇
临床医学   1231篇
内科学   1217篇
皮肤病学   167篇
神经病学   470篇
特种医学   574篇
外国民族医学   7篇
外科学   652篇
综合类   150篇
一般理论   2篇
预防医学   421篇
眼科学   84篇
药学   253篇
中国医学   7篇
肿瘤学   282篇
  2021年   56篇
  2020年   72篇
  2019年   71篇
  2018年   117篇
  2017年   129篇
  2016年   123篇
  2015年   143篇
  2014年   179篇
  2013年   208篇
  2012年   227篇
  2011年   253篇
  2010年   208篇
  2009年   186篇
  2008年   187篇
  2007年   198篇
  2006年   222篇
  2005年   200篇
  2004年   193篇
  2003年   185篇
  2002年   164篇
  2001年   180篇
  2000年   170篇
  1999年   188篇
  1998年   145篇
  1997年   161篇
  1996年   136篇
  1995年   126篇
  1994年   96篇
  1993年   79篇
  1992年   148篇
  1991年   129篇
  1990年   129篇
  1989年   138篇
  1988年   145篇
  1987年   126篇
  1986年   128篇
  1985年   133篇
  1984年   97篇
  1983年   90篇
  1982年   63篇
  1981年   55篇
  1980年   63篇
  1979年   72篇
  1978年   76篇
  1977年   59篇
  1976年   63篇
  1975年   66篇
  1974年   58篇
  1973年   75篇
  1972年   84篇
排序方式: 共有6954条查询结果,搜索用时 16 毫秒
11.
Administration of an elemental diet to rats given methotrexate (MTX), 20 mg/kg intraperitoneally (ip), results in 100% mortality from severe enterocolitis. Previous studies indicate that glutamine (GLN), which is not present in elemental diets, is the preferred oxidative substrate for the gut and may facilitate intestinal recovery after injury. This study investigated the effects of a glutamine-supplemented elemental diet (GLN-ED) on nutritional status, intestinal morphometry, bacterial translocation and survival in this lethal model of intestinal injury. Three experiments were performed. In the first experiment, rats received an intragastric elemental diet supplemented with either 2% GLN or an equivalent amount of glycine (Control). After 4 days animals received either MTX, 20 mg/kg ip, or saline ip and were killed 3 days later. The GLN-ED resulted in significantly decreased weight loss, improved nitrogen retention, and increased mucosal weight, protein, and DNA content of the jejunum and colon. In the second experiment rats were assigned to diet as in the first experiment, but all animals received MTX. Control diet animals died within 120 hrs of MTX administration. The GLN-ED group had significantly longer survival time and decreased mortality. In the third experiment animals were assigned to diet and MTX as in the first experiment. Ninety-six hrs later aortic blood cultures revealed enteric bacteremia in animals administered MTX. GLN-ED resulted in a significant reduction in the incidence of bacteremia. These experiments showed that a GLN-ED significantly improved nutritional status, decreased intestinal injury, decreased bacterial translocation, and resulted in improved survival in a lethal model of enterocolitis.  相似文献   
12.
AIMS: Autoimmune disorders co-exist in the same individuals and in families, implying a shared aetiology. The aim of this study was to compare the prevalence of the common autoimmune diseases in the parents of siblings from the Type 1 diabetes Warren repository with the general population. METHODS: Between 1989 and 1996, 505 British families with at least two siblings affected by Type 1 diabetes were recruited. Clinical information was collected regarding the presence of autoimmune disease in the parents and the prevalence of disease in the parents was compared with that expected in the general population. RESULTS: The prevalence of autoimmune disease in the parents was significantly higher in the repository compared with that expected in the general population [P-value = 1.98 x 10(-5) (female), P-value = 1.1 x 10(-8) (male)]. Type 1 diabetes was recorded in 63/1010 (6.2%) parents with a marked paternal preponderance (9.5 vs. 3%P = 0.002). Other autoimmune diseases affected 27% of parents with diabetes and 13.2% of parents without diabetes (P < 0.01). CONCLUSION: These data confirm the importance of family history as a significant risk factor for the development of Type 1 diabetes and support the hypothesis that the common autoimmune diseases share at least some aetiological mechanisms.  相似文献   
13.
BACKGROUND Dermatologic procedures often cause some degree of pain. A self-warming patch containing lidocaine and tetracaine (L/T) was developed to provide topical local anesthesia prior to painful procedures.
OBJECTIVES To evaluate the safety and efficacy of a self-warming L/T patch to provide anesthesia in adult patients undergoing minor dermatologic procedures.
METHODS An active or placebo study drug was placed on adults 30 minutes prior to minor dermatologic surgical procedures in a prospectively randomized, double-blinded manner. Subcutaneous lidocaine injection was available during the procedure as a rescue medication if requested by the subject. Immediately following the procedure, the subjects, the investigator, and an independent observer rated pain intensity and adverse events were recorded.
RESULTS Patient-reported pain intensity was significantly lower in the L/T patch group (   p < .001  ). Investigators and an independent observer rated the pain in the L/T patch group to be less than in the placebo patch group (   p = .004  and   p < .001  , respectively). Forty-nine percent of patients in the placebo group required rescue subcutaneous lidocaine compared with 22% in the L/T patch study group (   p = .008  ). One patient in the L/T patch group reported a transient moderate burning sensation.
CONCLUSION The self-warming L/T patch was effective in providing clinically useful local anesthesia for minor dermatologic procedures in adult patients.
ZARS, INC., PROVIDED SUPPORT VIA A SPONSORED RESEARCH GRANT TO THE UNIVERSITY OF MIAMI.  相似文献   
14.
Society is currently on the threshold of a new revolution in understanding the interaction of genes and the environment. This research has profound implications for understanding occupational disease and will present ethical challenges to occupational health practice. The public must be educated about the potential promise, as well as the threats, posed by emerging genetic technologies.  相似文献   
15.
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.  相似文献   
16.
17.
18.
19.
20.
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