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   3447663篇
  免费   305255篇
  国内免费   13859篇
耳鼻咽喉   47436篇
儿科学   109133篇
妇产科学   87880篇
基础医学   550523篇
口腔科学   93293篇
临床医学   313176篇
内科学   612951篇
皮肤病学   89447篇
神经病学   297872篇
特种医学   138299篇
外国民族医学   300篇
外科学   534735篇
综合类   106072篇
现状与发展   24篇
一般理论   2301篇
预防医学   294040篇
眼科学   78867篇
药学   237964篇
  24篇
中国医学   9559篇
肿瘤学   162881篇
  2021年   55119篇
  2020年   35082篇
  2019年   58099篇
  2018年   71375篇
  2017年   54318篇
  2016年   60019篇
  2015年   74155篇
  2014年   108451篇
  2013年   173539篇
  2012年   92590篇
  2011年   92662篇
  2010年   116720篇
  2009年   121112篇
  2008年   79700篇
  2007年   82920篇
  2006年   93468篇
  2005年   89018篇
  2004年   91030篇
  2003年   81928篇
  2002年   71135篇
  2001年   111041篇
  2000年   104631篇
  1999年   102210篇
  1998年   66200篇
  1997年   63812篇
  1996年   62018篇
  1995年   57763篇
  1994年   51771篇
  1993年   48378篇
  1992年   73503篇
  1991年   70224篇
  1990年   66552篇
  1989年   65119篇
  1988年   60374篇
  1987年   59045篇
  1986年   55864篇
  1985年   55980篇
  1984年   50440篇
  1983年   45768篇
  1982年   42575篇
  1981年   39980篇
  1980年   37685篇
  1979年   41774篇
  1978年   36574篇
  1977年   33132篇
  1976年   30466篇
  1975年   29036篇
  1974年   30281篇
  1973年   29035篇
  1972年   27046篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health.  相似文献   
172.
173.
174.
We report a Chinese family with members affected by epidermolytic ichthyosis (EI), caused by KRT gene mutations. The proband was a 14‐year‐old boy who had simultaneous appearance of nephroblastoma and epidermolytic ichthyosis (EI). Both the patient and his mother exhibited the specific clinical and pathological manifestations of EI. We analysed all exons and flanking sequences of the KRT1 and KRT10 genes using PCR, and found that the proband and his mother had a G>C transition at nucleotide position 1432 in exon 7 of KRT1, resulting in an amino acid substitution of glutamate (GAA) to glutamine (CAA) at codon 478 (E478Q). The KRT10 gene had no mutations.  相似文献   
175.
176.
177.
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   
178.
179.
180.
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   
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