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   863021篇
  免费   70650篇
  国内免费   1834篇
耳鼻咽喉   12819篇
儿科学   24642篇
妇产科学   25131篇
基础医学   124288篇
口腔科学   25498篇
临床医学   75399篇
内科学   164862篇
皮肤病学   17005篇
神经病学   70193篇
特种医学   35216篇
外国民族医学   171篇
外科学   136230篇
综合类   24609篇
现状与发展   2篇
一般理论   263篇
预防医学   66901篇
眼科学   20534篇
药学   64746篇
  14篇
中国医学   1595篇
肿瘤学   45387篇
  2018年   7338篇
  2015年   7735篇
  2014年   11127篇
  2013年   16781篇
  2012年   22725篇
  2011年   23831篇
  2010年   13873篇
  2009年   13073篇
  2008年   22578篇
  2007年   24639篇
  2006年   24504篇
  2005年   24154篇
  2004年   23714篇
  2003年   22841篇
  2002年   21936篇
  2001年   35834篇
  2000年   36476篇
  1999年   30914篇
  1998年   9226篇
  1997年   8550篇
  1996年   8480篇
  1995年   8010篇
  1994年   7727篇
  1992年   26664篇
  1991年   26103篇
  1990年   25621篇
  1989年   24681篇
  1988年   23230篇
  1987年   22888篇
  1986年   21744篇
  1985年   21098篇
  1984年   16386篇
  1983年   13998篇
  1982年   8854篇
  1981年   8203篇
  1980年   7672篇
  1979年   16742篇
  1978年   12116篇
  1977年   10182篇
  1976年   9330篇
  1975年   10150篇
  1974年   12642篇
  1973年   12136篇
  1972年   11541篇
  1971年   10689篇
  1970年   10218篇
  1969年   9911篇
  1968年   8901篇
  1967年   8231篇
  1966年   7656篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
While some individuals can defy the lure of temptation, many others find appetizing food irresistible. The goal of this study was to investigate the neuropsychological mechanisms that increase individuals' vulnerability to cue‐induced eating. Using ERPs, a direct measure of brain activity, we showed that individuals with larger late positive potentials in response to food‐related cues than to erotic images are more susceptible to cue‐induced eating and, in the presence of a palatable food option, eat more than twice as much as individuals with the opposite brain reactivity profile. By highlighting the presence of individual brain reactivity profiles associated with susceptibility to cue‐induced eating, these findings contribute to the understanding of the neurobiological basis of vulnerability to obesity.  相似文献   
92.
93.
94.
95.
96.
97.
The oxytocinase subfamily of M1 aminopeptidases plays an important role in processing and trimming of peptides for presentation on major histocompatibility (MHC) Class I molecules. Several large-scale genomic studies have identified association of members of this family of enzymes, most notably ERAP1 and ERAP2, with immune-mediated diseases including ankylosing spondylitis, psoriasis and birdshot chorioretinopathy. Much is now known about the genetics of these enzymes and how genetic variants alter their function, but how these variants contribute to disease remains largely unresolved. Here we discuss what is known about their structure and function and highlight some of the knowledge gaps that affect development of drugs targeting these enzymes.  相似文献   
98.
Fifty Veterans of the first Gulf War in 1991 exposed to depleted uranium (DU) were studied for glycosylphosphatidylinositol-anchor (GPIa) deficient T-cell mutants on three occasions during the years 2009, 2011, and 2013. GPIa deficiency was determined in two ways: cloning assays employing aerolysin selection and cytometry using the FLAER reagent for positive staining of GPIa cell surface proteins. Subsequent molecular analyses of deficient isolates recovered from cloning assays (Nicklas JA et al. [2019]: Environ Mol Mutagen) revealed apparent incomplete selection in some cloning assays, necessitating correction of original data to afford a more realistic estimate of GPIa deficient mutant frequency (MF) values. GPIa deficient variant frequencies (VFs) determined by cytometry were determined in the years 2011 and 2013. A positive but nonsignificant association was observed between MF and VF values determined on the same blood samples during 2013. Exposure to DU had no effect on either GPIa deficient MF or VFs. Environ. Mol. Mutagen. 60:494–504, 2019. © 2019 Wiley Periodicals, Inc.  相似文献   
99.
Journal of Digital Imaging - A lay-language glossary of radiology, built to help patients better understand the content of their radiology reports, has been analyzed for its coverage and...  相似文献   
100.
We have identified a discrete, focal telomere DNA expansion phenotype in the photoreceptor cell layer of normal, non‐neoplastic human retinas. This phenotype is similar to that observed in a subset of human cancers, including a large fraction of tumors of the central nervous system, which maintain their telomeres via the non‐telomerase‐mediated alternative lengthening of telomeres (ALT) mechanism. We observed that these large, ultra‐bright telomere DNA foci are restricted to the rod photoreceptors and are not observed in other cell types. Additionally, focus‐positive rod cells are dispersed homogeneously throughout the posterior retinal photoreceptor cell layer and appear to be human‐specific. We examined 108 normal human retinas obtained at autopsy from a wide range of ages. These large, ultra‐bright telomere DNA foci were not observed in infants before 6 months of age; however, the prevalence of focus‐positive rod cells dramatically increased throughout life. To investigate associations between this phenotype and retinal pathology, we assessed adult glaucoma (N = 29) and diabetic retinopathy (N = 38) cases. Focus‐positive rod cells were prominent in these diseases. When compared to the normal group, after adjusting for age, logistic regression modeling revealed significantly increased odds of falling in the high category of focus‐positive rod cells for glaucoma and diabetic retinopathy. In summary, we have identified a dramatic telomere alteration associated with aging and diseases affecting the retina.  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