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   1269881篇
  免费   99760篇
  国内免费   1980篇
耳鼻咽喉   18405篇
儿科学   44239篇
妇产科学   34993篇
基础医学   180939篇
口腔科学   33557篇
临床医学   110630篇
内科学   256149篇
皮肤病学   28005篇
神经病学   99712篇
特种医学   51170篇
外国民族医学   660篇
外科学   195759篇
综合类   27022篇
现状与发展   1篇
一般理论   377篇
预防医学   95143篇
眼科学   27796篇
药学   94537篇
  2篇
中国医学   2336篇
肿瘤学   70189篇
  2018年   13129篇
  2017年   9963篇
  2016年   10899篇
  2015年   12372篇
  2014年   17171篇
  2013年   26217篇
  2012年   36032篇
  2011年   38055篇
  2010年   22805篇
  2009年   21818篇
  2008年   36639篇
  2007年   39261篇
  2006年   39505篇
  2005年   38452篇
  2004年   37590篇
  2003年   36347篇
  2002年   35702篇
  2001年   63890篇
  2000年   66319篇
  1999年   56061篇
  1998年   14354篇
  1997年   12988篇
  1996年   13406篇
  1995年   13386篇
  1994年   12721篇
  1993年   11725篇
  1992年   44503篇
  1991年   43456篇
  1990年   42203篇
  1989年   40092篇
  1988年   36867篇
  1987年   36220篇
  1986年   33594篇
  1985年   32264篇
  1984年   24120篇
  1983年   20218篇
  1982年   11683篇
  1981年   10641篇
  1980年   9460篇
  1979年   21300篇
  1978年   14787篇
  1977年   12490篇
  1976年   11668篇
  1975年   12601篇
  1974年   14645篇
  1973年   14102篇
  1972年   12940篇
  1971年   11714篇
  1970年   11039篇
  1969年   10013篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
991.
Neuroscience and Behavioral Physiology - The effects of prenatal stress (PNS) on the formation of the orexinergic and dopaminergic systems of the brain were studied in 14- and 30-day-old rat pups...  相似文献   
992.
The etiology of distal site cancers in inflammatory bowel disease (IBD) is not well understood and requires further study. We investigated whether pediatric IBD patients' blood cells exhibit elevated levels of genomic damage by measuring the frequency of mutant phenotype (CD59-/CD55-) reticulocytes (MUT RET) as a reporter of PIG-A mutation, and the frequency of micronucleated reticulocytes (MN-RET) as an indicator of chromosomal damage. IBD patients (n = 18 new-onset disease, 46 established disease) were compared to age-matched controls (constipation or irritable bowel syndrome patients from the same clinic, n = 30) and young healthy adults age 19–24 (n = 25). IBD patients showed no indication of elevated MUT RET relative to controls (mean ± SD = 3.1 ± 2.3 × 10−6 vs. 3.6 ± 5.6 x 10−6, respectively). In contrast, 59 IBD patients where %MN-RET measurements were obtained, 10 exceeded the upper bound 90% tolerance interval derived from control subjects (i.e., 0.42%). Furthermore, each of the 10 IBD patients with elevated MN-RET had established disease (10/42), none were new-onset (0/17) (p = .049). Interestingly, each of the subjects with increased chromosomal damage was receiving anti-TNF based monotherapy at the time blood was collected (10/10, 100%), whereas this therapy was less common (20/32, 63%) among patients that exhibited ≤0.42% MN-RET (p = .040). The results clearly indicate the need for further work to understand whether the results presented herein are reproducible and if so, to elucidate the causative factor(s) responsible for elevated MN-RET frequencies in some IBD patients.  相似文献   
993.
994.
995.
996.
997.
998.
999.
The profile and trajectory of cognitive impairment in mitochondrial disease are poorly defined. This systematic review sought to evaluate the current literature on cognition in mitochondrial disease, and to determine future research directions. A systematic review was conducted, employing PubMed, Medline, Psycinfo, Embase and Web of Science, and 360‐degree citation methods. English language papers on adult patients were included. The literature search yielded 2421 articles, of which 167 met inclusion criteria. Case reports and reviews of medical reports of patients yielded broad diagnoses of dementia, cognitive impairment and cognitive decline. In contrast, systematic investigations of cognitive functioning using detailed cognitive batteries identified focal cognitive rather than global deficits. Results were variable, but included visuospatial functioning, memory, attention, processing speed and executive functions. Conclusions from studies have been hampered by small sample sizes, variation in genotype and the breadth and depth of assessments undertaken. Comprehensive cognitive research with concurrent functional neuroimaging and physical correlates of mitochondrial disease in larger samples of well‐characterized patients may discern the aetiology and progression of cognitive deficits. These data provide insights into the pattern and trajectory of cognitive impairments, which are invaluable for clinical monitoring, health planning and clinical trial readiness.  相似文献   
1000.
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