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   89286篇
  免费   6464篇
  国内免费   275篇
耳鼻咽喉   1023篇
儿科学   2129篇
妇产科学   1372篇
基础医学   11114篇
口腔科学   1309篇
临床医学   9353篇
内科学   18824篇
皮肤病学   1480篇
神经病学   8633篇
特种医学   3175篇
外国民族医学   6篇
外科学   15357篇
综合类   1034篇
一般理论   107篇
预防医学   6607篇
眼科学   2076篇
药学   6122篇
中国医学   89篇
肿瘤学   6215篇
  2023年   588篇
  2022年   1030篇
  2021年   2338篇
  2020年   1428篇
  2019年   2125篇
  2018年   2595篇
  2017年   1880篇
  2016年   2016篇
  2015年   2306篇
  2014年   3376篇
  2013年   4354篇
  2012年   6723篇
  2011年   6963篇
  2010年   3787篇
  2009年   3471篇
  2008年   5858篇
  2007年   5993篇
  2006年   5765篇
  2005年   5633篇
  2004年   5157篇
  2003年   4906篇
  2002年   4521篇
  2001年   816篇
  2000年   630篇
  1999年   726篇
  1998年   952篇
  1997年   789篇
  1996年   658篇
  1995年   591篇
  1994年   522篇
  1993年   498篇
  1992年   475篇
  1991年   410篇
  1990年   350篇
  1989年   337篇
  1988年   313篇
  1987年   287篇
  1986年   273篇
  1985年   304篇
  1984年   332篇
  1983年   313篇
  1982年   352篇
  1981年   351篇
  1980年   314篇
  1979年   209篇
  1978年   223篇
  1977年   214篇
  1976年   148篇
  1975年   157篇
  1974年   173篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
Erosive pustular dermatosis of the scalp (EPDS) is an uncommon chronic inflammatory response to scalp trauma that usually resolves with cicatricial alopecia. It most commonly affects elderly patients with a history of actinic damage. Herein, we describe a 16‐year‐old girl with acrofacial dysostosis type 1 presenting after surgery with crusting purulent scalp lesions, whose clinical presentation and histopathologic findings were consistent with EPDS. A review of the literature on EPDS in children is also detailed.  相似文献   
2.
Henna, derived from a combination of natural leaves and coloring additives, is a common decorative dye traditionally used in many Islamic religious celebrations. Para‐phenylenediamine (PPD), a major component of black henna tattoo, is a strong sensitizer and common allergen. We report a case of severe connubial allergic contact dermatitis after black henna heterotransfer in a girl.  相似文献   
3.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  相似文献   
4.
5.
BackgroundThe optimal management of community acquired pneumonia (CAP) depends on the clinical and microbiological profile in the locality.ObjectivesTo determine the clinical and microbiological profile of patients admitted with CAP in Ilorin, Nigeria.MethodsOne hundred and two consenting consecutively selected patients with clinical and radiologic confirmation of CAP were recruited in 12 months. The socio-demographic, physical examination and laboratory/radiologic parameters were documented in a questionnaire. Microbiological evaluation of their sputum was done and blood samples were taken for complete blood count, culture, serum urea and serological evaluation for atypical bacteria and some viral pathogens.ResultsCAP constituted 5.9% of the total medical admissions during the one-year study period. The mean age of the patients was 49 ± 22 years with the largest frequency in those aged 65 years and above. The commonest symptoms were shortness of breath (96.1%) and cough (94.1%), with a median duration of 3 days from symptom onset to admission. Systemic hypertension was the commonest comorbid illness (25/102; 24.5%). Klebsiella pneumoniae was the predominant pathogen isolated (20/102; 28.1%). The susceptible antibiotics were Imipenem, Ceftazidime and Ceftriaxone. Intra-hospital mortality was 17.6%. CURB – 65 score of ≥ 2 and the presence of complications of CAP were the independent predictors of mortality.ConclusionCAP constitutes a significant disease burden in Ilorin, Nigeria. Typical bacteria accounted for over half of the pathogens isolated from the patients with gram negative agents predominating. This highlights a possible shift in the microbiological profile which could guide empirical treatment.  相似文献   
6.
7.
8.
9.
10.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  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