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   2349篇
  免费   232篇
  国内免费   19篇
耳鼻咽喉   4篇
儿科学   121篇
妇产科学   56篇
基础医学   360篇
口腔科学   76篇
临床医学   224篇
内科学   383篇
皮肤病学   158篇
神经病学   164篇
特种医学   275篇
外科学   177篇
综合类   83篇
一般理论   1篇
预防医学   209篇
眼科学   47篇
药学   104篇
  1篇
肿瘤学   157篇
  2021年   19篇
  2020年   19篇
  2019年   29篇
  2018年   23篇
  2017年   16篇
  2016年   29篇
  2015年   43篇
  2014年   43篇
  2013年   85篇
  2012年   59篇
  2011年   70篇
  2010年   93篇
  2009年   79篇
  2008年   58篇
  2007年   82篇
  2006年   71篇
  2005年   94篇
  2004年   71篇
  2003年   75篇
  2002年   70篇
  2001年   45篇
  2000年   51篇
  1999年   68篇
  1998年   98篇
  1997年   92篇
  1996年   70篇
  1995年   65篇
  1994年   49篇
  1993年   56篇
  1992年   40篇
  1991年   53篇
  1990年   47篇
  1989年   75篇
  1988年   64篇
  1987年   50篇
  1986年   41篇
  1985年   44篇
  1984年   38篇
  1983年   36篇
  1982年   35篇
  1981年   38篇
  1980年   30篇
  1979年   21篇
  1978年   25篇
  1977年   25篇
  1976年   17篇
  1975年   17篇
  1970年   14篇
  1969年   16篇
  1968年   17篇
排序方式: 共有2600条查询结果,搜索用时 15 毫秒
1.
2.
3.
BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.  相似文献   
4.
Background: Laparoscopic stapling was found to be a viable option for attaching epimysial electrodes onto the abdominal surface of the diaphragm. Stapling was preferable to suturing due to its simplicity and speed. Methods: Of the two staplers tested in this study, the Ethicon Endopath was preferred over the Autosuture Endo Hernia because the staples did not penetrate the diaphragm when an electrode tab thickness greater than 0.75 mm was used. Results: The thickness of the electrode tab was an important factor in determining staple penetration but large variation in penetration depth indicated that other factors may also play a role. An electrode tab thickness of 1.0–1.25 mm was suggested to minimize the risk of diaphragm perforation. Conclusions: The histological reaction to staples implanted up to 14 months was unremarkable, reflecting the safety of laparoscopic staples for permanently anchoring electrodes on the diaphragm. Received: 2 April 1996/Accepted: 12 June 1996  相似文献   
5.
6.
In male rats, there is an age-associated decline in the capacity of cardiac sympathetic nerves to release norepinephrine. To investigate whether this phenomenon also occurs in female rats, we examined adrenergic neurochemical transmission in the hearts of female and male Fischer 344 rats. Rats aged 6, 12, and 24 months were employed. Hearts with the right cardiac sympathetic nerve intact were isolated and perfused with Krebs-Ringer solution. Stimulations were performed following the administration of cocaine or metanephrine separately and in combination or following the combination of cocaine, metanephrine, and yohimbine. Cocaine (1 microM) was used to block uptake 1, metanephrine (1 x 10(-5) M) to block uptake 2, and yohimbine (3 microM) to block alpha 2 receptor presynaptically. The nerve was stimulated with frequencies of 2, 6, and 12 Hz, and norepinephrine amount in the effluent was determined by high performance liquid chromatography/electrochemical detection methods. Neither norepinephrine release nor the effects of yohimbine, cocaine, or metanephrine were found to be affected in older female rats (24 month). This suggests that age-related changes in adrenergic neurochemical transmission in the heart of female rats differ from those seen in older male rats.  相似文献   
7.
A lump on the midface of a child can pose as a diagnostic dilemma. There is a wide variety of possible differential diagnoses, ranging from simple benign conditions such as a sebaceous cyst, dermoid cyst, lipoma, neuroma and neurofibroma, to potentially devastating conditions such as odontogenic myxoma.A case of a child in which the formulation of a definite diagnosis was clinically and histologically challenging is presented.  相似文献   
8.
9.
10.
BACKGROUND: Acquired cerebriform intradermal naevus (CIN) is a rare form of pseudo cutis verticis gyrata. CASE REPORT: A case of acquired CIN of the scalp in a 46-year-old male patient is presented. The clinical and histopathological presentations of CIN are described and the therapeutic possibilities are discussed. CONCLUSIONS: In each individual case the physician must decide whether to do surgery or follow a wait-and-see policy. There is little risk of malignant change of CIN, and surgical excision of such lesions often involves evident mutilation.  相似文献   
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