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   1848374篇
  免费   136065篇
  国内免费   6701篇
耳鼻咽喉   23156篇
儿科学   59773篇
妇产科学   48030篇
基础医学   267798篇
口腔科学   47165篇
临床医学   166014篇
内科学   369851篇
皮肤病学   41935篇
神经病学   146054篇
特种医学   75298篇
外国民族医学   323篇
外科学   287786篇
综合类   38408篇
现状与发展   4篇
一般理论   509篇
预防医学   146643篇
眼科学   39147篇
药学   131189篇
  6篇
中国医学   3158篇
肿瘤学   98893篇
  2018年   27458篇
  2017年   21637篇
  2016年   26092篇
  2015年   18794篇
  2014年   25770篇
  2013年   38345篇
  2012年   51377篇
  2011年   61438篇
  2010年   39243篇
  2009年   36095篇
  2008年   57953篇
  2007年   63890篇
  2006年   53597篇
  2005年   53206篇
  2004年   51898篇
  2003年   51652篇
  2002年   48376篇
  2001年   83031篇
  2000年   85467篇
  1999年   71062篇
  1998年   21016篇
  1997年   18698篇
  1996年   19536篇
  1995年   19499篇
  1994年   18093篇
  1993年   17072篇
  1992年   58225篇
  1991年   58344篇
  1990年   56591篇
  1989年   54407篇
  1988年   50277篇
  1987年   49673篇
  1986年   46560篇
  1985年   44926篇
  1984年   34037篇
  1983年   28740篇
  1982年   17356篇
  1981年   15582篇
  1979年   31011篇
  1978年   22430篇
  1977年   18677篇
  1976年   17875篇
  1975年   19351篇
  1974年   22491篇
  1973年   21508篇
  1972年   19843篇
  1971年   18444篇
  1970年   17065篇
  1969年   15957篇
  1968年   14920篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
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   
43.
44.
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   
45.
46.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
47.
48.
49.
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment.  相似文献   
50.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  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