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   1179篇
  免费   78篇
  国内免费   16篇
耳鼻咽喉   4篇
儿科学   69篇
妇产科学   35篇
基础医学   134篇
口腔科学   12篇
临床医学   107篇
内科学   254篇
皮肤病学   17篇
神经病学   41篇
特种医学   152篇
外科学   81篇
综合类   117篇
预防医学   89篇
眼科学   4篇
药学   53篇
中国医学   1篇
肿瘤学   103篇
  2022年   7篇
  2021年   10篇
  2019年   7篇
  2018年   8篇
  2017年   14篇
  2016年   19篇
  2015年   27篇
  2014年   35篇
  2013年   43篇
  2012年   53篇
  2011年   39篇
  2010年   55篇
  2009年   46篇
  2008年   66篇
  2007年   61篇
  2006年   43篇
  2005年   32篇
  2004年   32篇
  2003年   29篇
  2002年   31篇
  2001年   35篇
  2000年   27篇
  1999年   42篇
  1998年   50篇
  1997年   41篇
  1996年   34篇
  1995年   25篇
  1994年   31篇
  1993年   24篇
  1992年   19篇
  1991年   12篇
  1990年   25篇
  1989年   20篇
  1988年   27篇
  1987年   31篇
  1986年   19篇
  1985年   20篇
  1984年   7篇
  1983年   11篇
  1982年   17篇
  1981年   8篇
  1980年   6篇
  1979年   11篇
  1978年   12篇
  1977年   6篇
  1976年   8篇
  1975年   8篇
  1974年   8篇
  1973年   7篇
  1972年   5篇
排序方式: 共有1273条查询结果,搜索用时 15 毫秒
61.
62.
Background Post‐inflammatory hyperpigmentation (PIH) is a common occurrence in patients with acne vulgaris, particularly in those with skin of colour. Aims A previous study has demonstrated the benefit of tretinoin (retinoic acid) in the treatment of PIH; however, there is currently no standard protocol to evaluate change in PIH following treatment. Based on these findings, we performed a pilot, exploratory, blinded, intraindividual‐controlled methodology study that consisted of a photographic assessment protocol with facial mapping. Materials and methods The study was based on a secondary analysis of a phase 4, community‐based trial of 544 acne patients who were treated with tretinoin gel microsphere 0.04% or 0.1%. Only patients with Fitzpatrick types III–V (skin of colour) were included in the study; subjects with Fitzpatrick skin type VI were excluded because the photographic assessment did not allow for proper evaluation. Results Despite the small number of subjects evaluated (n = 25), the results revealed consistent assessment of improvement in PIH between two independent graders (weighted κ = 0.84). Conclusion Further study with a larger population is recommended to validate the accuracy of this method.  相似文献   
63.
King PT  Rosalion A  McMillan J  Buist M  Holmes PW 《Lancet》2000,356(9223):45-46
We describe the use of extracorporeal membrane oxygenation in pregnancy. There were no major complications, and the outcome was successful for mother and baby.  相似文献   
64.
65.
Remission following an elemental diet or prednisolone in Crohn's disease   总被引:1,自引:0,他引:1  
The short- and long-term effects of an elemental diet in children with acute Crohn's disease were compared with those of prednisolone in historical controls. Clinical remission was induced in 25 of 30 and in 18 of 28 episodes treated for six weeks with an elemental diet and prednisolone. Patients with proximal disease had longer remission after treatment with an elemental diet (p < 0.05) than did patients with colonic disease after treatment with prednisolone (p < 0.01). Disease activity index score improved in both groups compared with the pretreatment scores (p < 0.05). However, the improvement in the elemental diet group was significantly better than in the prednisolone group (p < 0.001). Changes in linear growth were better after treatment with an elemental diet compared with steroids (p < 0.001). Serum albumin and haematocrit concentrations all improved significantly in the children treated with an elemental diet (p < 0.001) but not in those treated with steroids. Thus an elemental diet was better than prednisolone in proximal disease and confirmed improved growth and nutritional status.  相似文献   
66.
Pelvic ultrasound findings in different forms of sexual precocity   总被引:2,自引:0,他引:2  
Recently produced reference curves for various ultrasound dimensions were used to retrospectively assess 67 pelvic ultrasound scans carried out at the initial presentation in girls with sexual precocity. At presentation the group with precocious puberty had significantly increased uterine lengths and ovarian volumes compared with the normal population, and a significantly increased fundal–cervical ratio. Ovarian volume was also significantly increased in thelarche and thelarche variant. The fundal–cervical ratio was significantly increased in thelarche variant. There was considerable overlap between individuals with sexual precocity and normal subjects. The ultrasound findings that best discriminated early or precocious puberty from other forms of sexual precocity were the presence of a midline endometrial echo, and a uterine length above the 97th centile for age. An entirely normal pelvic ultrasound at presentation did not rule out the possibility of precocious puberty.  相似文献   
67.
We report 8 infants with immediate hypersensitivity reactions to foods (milk, egg, or peanut), occurring at the first-known exposure. Each developed symptoms within the first hour, but these generally settled within 2 hours. Sensitisation to the food concerned was demonstrated by positive immediate allergen skin prick tests in every case. Symptoms experienced included irritability, erythematous rash, urticaria, angio-oedema, vomiting, rhinorrhoea, and cough. Five infants were being followed prospectively and 4 were clinically tolerant of the food by age 16 months. The most likely route of sensitisation was via breast milk. None of the infants experienced similar reactions while being breast fed, suggesting that the reaction was dose dependent. As 5 out of a group of 80 infants being followed prospectively developed an immediate reaction at their first known exposure to a food, this appeared to be a not uncommon presentation of food hypersensitivity in infancy.  相似文献   
68.
The cloning of novel G protein-coupled receptors and the search for their natural ligands, a process called reverse pharmacology, is an excellent opportunity to discover novel hormones and neurotransmitters. Based on a degenerate primer approach we have cloned a G protein-coupled receptor whose mRNA expression profile indicates highest expression in the dorsal root ganglia, specifically in the subset of small neurons, suggesting a role in nociception. In addition, moderate expression was found in lung, hypothalamus, peripheral blood leukocytes, and ovaries. Guided by a receptor-activation bioassay, we identified adenine as the endogenous ligand, which activated the receptor potently and with high structural stringency. Therefore, we propose to name this receptor as the adenine receptor. Hormonal functions have already been demonstrated for adenine derivatives like 6-benzylaminopurine in plants and 1-methyladenine in lower animals. Here, we demonstrate that adenine functions as a signaling molecule in mammals. This finding adds a third family besides P1 and P2 receptors to the class of purinergic receptors.  相似文献   
69.

Background  

Uganda began to implement the prevention of mother-to-child transmission (PMTCT) of HIV programme in 2000, and by the end of 2003 it had expanded to cover 38 of the 56 districts including Mbale District. However, reports from Mbale Hospital showed that less than 10% of pregnant women accepted antenatal HIV testing. We therefore conducted a study to determine the proportion of pregnant women who tested for HIV and the gaps and barriers in PMTCT implementation.  相似文献   
70.
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