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   1296篇
  免费   165篇
  国内免费   10篇
耳鼻咽喉   20篇
儿科学   99篇
妇产科学   15篇
基础医学   157篇
口腔科学   39篇
临床医学   191篇
内科学   280篇
皮肤病学   13篇
神经病学   125篇
特种医学   188篇
外科学   170篇
综合类   34篇
预防医学   45篇
眼科学   2篇
药学   25篇
中国医学   5篇
肿瘤学   63篇
  2021年   12篇
  2020年   9篇
  2019年   12篇
  2018年   36篇
  2017年   43篇
  2016年   37篇
  2015年   39篇
  2014年   40篇
  2013年   67篇
  2012年   41篇
  2011年   44篇
  2010年   66篇
  2009年   62篇
  2008年   40篇
  2007年   37篇
  2006年   40篇
  2005年   26篇
  2004年   23篇
  2003年   23篇
  2002年   19篇
  2001年   33篇
  2000年   29篇
  1999年   15篇
  1998年   63篇
  1997年   65篇
  1996年   57篇
  1995年   52篇
  1994年   30篇
  1993年   42篇
  1992年   31篇
  1991年   26篇
  1990年   25篇
  1989年   25篇
  1988年   34篇
  1987年   27篇
  1986年   26篇
  1985年   20篇
  1984年   14篇
  1983年   20篇
  1981年   18篇
  1980年   8篇
  1979年   6篇
  1978年   6篇
  1977年   14篇
  1976年   11篇
  1974年   10篇
  1973年   5篇
  1972年   4篇
  1970年   5篇
  1967年   4篇
排序方式: 共有1471条查询结果,搜索用时 15 毫秒
41.
42.
OBJECTIVE: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive fatal prion disorder with typical clinical findings of dementia, motor dysfunction, and myoclonus and characteristic electroencephalographic (EEG) findings of bilateral synchronous periodic sharp waves. Advances in neuroimaging capabilities with diffusion-weighted and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) techniques have shown promise in the non-invasive diagnosis of CJD. This series illustrates the correlation between the lateralized and focal clinical, EEG, and MRI FLAIR sequence abnormalities in 8 patients (7 men and one woman 55-73 years old) with CJD. METHODS: A case series of 8 patients, evaluated at Mayo Clinic, who had a history of rapidly progressive lateralized or focal neurologic dysfunction and laboratory findings consistent with CJD between 1996 and 1999 were identified. EEG, MRI of the head with FLAIR sequence, and cerebrospinal fluid studies were performed in all patients. RESULTS: Mean time to death from symptom onset was 4 months. Symptoms were lateralized to the left hemisphere in 5 patients and to the right hemisphere in two. One patient showed bilateral occipital lobe involvement. In all patients, the EEG showed lateralized or focal periodic sharp waves that colocalized with clinical cerebral dysfunction. FLAIR MRI images revealed increased signal in the cortical ribbon and deep gray matter corresponding to the lateralized clinical and EEG findings in 7 patients. The other patient had bilateral occipital increased signal on FLAIR MRI. CONCLUSIONS: CJD may present with lateralized or focal cortical syndromes with colocalizing EEG and MRI findings. With the appropriate clinical history and laboratory evaluation, the corresponding areas of increased signal on FLAIR MRI provide supportive evidence of the disease. SIGNIFICANCE: CJD can sometimes present with more focal or lateralized clinical findings, and the colocalizing EEG and MRI findings can help make or confirm the diagnosis of CJD.  相似文献   
43.
44.
45.
A new serological test, diffusion in gel-enzyme-linked immunosorbent assay (DIG-ELISA) was developed and compared with the microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis. The results suggest that DIG-ELISA is a viable alternative to the MAT because of its simplicity, sensitivity, versatility and potential for standardisation.  相似文献   
46.
Spontaneously elevated nociceptive threshold levels were markedly diminished after Naloxone injections in 4 patients with congenital insensitivity to pain. This finding suggested the hypothesis of a relation between congenital insensitivity to pain and permanent hyperfunction of an endomorphinic system. Radio-immunoassay of CSF beta-endorphin was performed in all 4 cases. The normal or only slightly elevated levels cannot explain electrophysiologic findings, but as a function of the multiplicity of endogenous opioid systems, hyperactivity of another endomorphinic system cannot be excluded. Other hypotheses may also be proposed.  相似文献   
47.
48.
49.
50.
El‐Hattab AW, Bournat J, Eng PA, Wu JBS, Walker BA, Stankiewicz P, Cheung SW, Brown CW. Microduplication of Xp11.23p11.3 with effects on cognition, behavior, and craniofacial development. We report an ~1.3 Mb tandem duplication at Xp11.23p11.3 in an 11‐year‐old boy with pleasant personality, hyperactivity, learning and visual‐spatial difficulties, relative microcephaly, long face, stellate iris pattern, and periorbital fullness. This clinical presentation is milder and distinct from that of patients with partially overlapping Xp11.22p11.23 duplications which have been described in males and females with intellectual disability, language delay, autistic behaviors, and seizures. The duplicated region harbors three known X‐linked mental retardation genes: FTSJ1, ZNF81, and SYN1. Quantitative polymerase chain reaction from whole blood total RNA showed increased expression of three genes located in the duplicated region: EBP, WDR13, and ZNF81. Thus, over‐expression of genes in the interval may contribute to the observed phenotype. Many of the features seen in this patient are present in individuals with Williams‐Beuren syndrome (WBS). Interestingly, the SYN1 gene within the duplicated interval, as well as the STX1A gene, within the WBS critical region, co‐localize to presynaptic active zones, and play important roles in neurotransmitter release.  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