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   1511篇
  免费   88篇
  国内免费   6篇
耳鼻咽喉   3篇
儿科学   119篇
妇产科学   64篇
基础医学   177篇
口腔科学   28篇
临床医学   133篇
内科学   222篇
皮肤病学   107篇
神经病学   98篇
特种医学   31篇
外科学   100篇
综合类   36篇
一般理论   6篇
预防医学   101篇
眼科学   48篇
药学   133篇
中国医学   3篇
肿瘤学   196篇
  2023年   15篇
  2022年   18篇
  2021年   76篇
  2020年   54篇
  2019年   43篇
  2018年   56篇
  2017年   48篇
  2016年   70篇
  2015年   57篇
  2014年   71篇
  2013年   86篇
  2012年   169篇
  2011年   155篇
  2010年   71篇
  2009年   53篇
  2008年   85篇
  2007年   75篇
  2006年   70篇
  2005年   82篇
  2004年   63篇
  2003年   55篇
  2002年   49篇
  2001年   6篇
  2000年   3篇
  1999年   5篇
  1998年   12篇
  1997年   12篇
  1996年   5篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1991年   1篇
  1990年   3篇
  1988年   3篇
  1983年   1篇
  1982年   4篇
  1980年   1篇
  1974年   1篇
  1973年   3篇
  1971年   3篇
  1970年   4篇
  1969年   3篇
  1968年   2篇
  1967年   2篇
排序方式: 共有1605条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Early Stroke Recognition: Developing an Out-of-hospital NIH Stroke Scale   总被引:1,自引:0,他引:1  
Objective : To develop an abbreviated and practical neurologic scale that could assist emergency medical services or triage personnel in identifying patients with stroke.
Methods : A prospective, observational, cohort study was performed at university-based EDs. Participants were 74 patients treated in a thrombolytic stroke trial and 225 consecutive non-stroke patients evaluated during 4 random 12-hour shifts in the ED. Scores on the NIH Stroke Scale were obtained for all patients by physicians. Items of this scale were modified and recoded to a binomial (normal or abnormal) scale. Serial univariate analyses using χ2 were performed to rank items. Recursive partitioning was then performed to develop the decision rule for predicting the presence of stroke.
Results : Three items identified 100% of patients with stroke: facial palsy, motor arm, and dysarthria. An Abbreviated NIH Stroke Scale based on these items had a sensitivity of 100% and a specificity of 92%. A proposed Out-of-hospital NIH Stroke Scale consisting of facial palsy, motor arm, and a combination of dysarthria and best language items (abnormal speech) had a sensitivity of 100% and a specificity of 88%.
Conclusion : Using the derivation data set, a proposed Out-of-hospital NIH Stroke Scale had a high sensitivity and specificity for identifying patients with stroke when performed by physicians in this group of 299 ED patients. Prospective studies of other health care professionals using the scale in the out-of-hospital arena are needed.  相似文献   
5.
BACKGROUND: Abnormalities in the limbic-hypothalamic-pituitary-adrenal (LHPA) axis have been implicated in the pathogenesis of obsessive-compulsive disorder (OCD). To our knowledge, however, no prior study has measured pituitary gland volume in OCD. METHODS: Volumetric magnetic resonance imaging studies were conducted in 31 psychotropic drug-na?ve children (10 boys, 21 girls) aged 8-17 years and 31 case-matched healthy comparison subjects. RESULTS: Pituitary volume was significantly smaller in patients with OCD as compared with healthy control subjects (11% smaller). Smaller pituitary volume in patients with OCD was associated with increased compulsive but not obsessive symptom severity. Boys with OCD had smaller pituitary gland volumes compared with control boys (20% smaller). No significant differences in pituitary volume were observed between girls with OCD and control girls. Boys with OCD had significantly smaller pituitary volumes than girls with OCD (31% smaller), whereas control boys also had smaller pituitary gland volumes compared with control girls (21% smaller). CONCLUSIONS: These findings provide new evidence of reduced pituitary volume in pediatric OCD that seems to be more prominent in male patients. The observed alterations in pituitary volume are consistent with neuroendocrine studies that have reported abnormalities in the LHPA axis in OCD.  相似文献   
6.
Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.  相似文献   
7.
Retinoic acid receptor beta (RARB) variants are heavily linked to pathologies of neural crest cell migration. The purpose of this report is to present a 23‐month‐old male with the previously described R387C RARB gain‐of‐function variant whose gastrointestinal issues and long‐term constipation lead to the discovery of colonic hypoganglionosis. This case further delineates the pattern of malformation associated with RARB variants. The findings are also consistent with the known etiology of aganglionic colon due to failed neural crest cell migration.  相似文献   
8.
Insular carcinoma of thyroid (ICT) is a rare tumor, which accounts for 4-6% of thyroid malignancies. ICT arising from follicular cells of thyroid shows a characteristic insular growth pattern characterized by solid nests of tumor cells separated by vessels. A 52-year-old female presented with a huge swelling in midline of the neck with retrosternal extension. The patient was euthyroid. Near total thyroidectomy was done. Grossly, the tumour was involving both the lobes and isthmus of thyroid. Microscopic examination revealed features of insular carcinoma. On immunohistochemistry, tumour cells were positive for thyroglobulin and negative for calcitonin.  相似文献   
9.
Primary nasal septal adenocarcinoma is a rare lesion. A sporadic case of septal adenocarcinoma in a 22 years old male is being described along with review of literature.  相似文献   
10.
Alveolar overdistension during mechanical ventilation causes leukocyte sequestration, leading to lung injury. However, underlying endothelial cell (EC) mechanisms are undefined. In a new approach, we exposed isolated blood-perfused rat lungs to high tidal volume ventilation (HV) for 2 h, then obtained fresh lung endothelial cells (FLEC) by immunosorting at 4 degrees C. Immunoblotting experiments indicated that as compared with FLEC derived from lungs ventilated at low volume (LV), HV markedly enhanced tyrosine phosphorylation (TyrP). The tyrosine kinase blocker, genistein, inhibited this response. HV also induced focal adhesion (FA) formation in FLEC, as detected by immunofluorescent aggregates of the alpha(v)beta(3) integrin that co-localized with aggregations of focal adhesion kinase (FAK). Immunoprecipitation and blotting experiments revealed that HV increased TyrP of the FA protein, paxillin. In addition, HV induced a paxillin-associated P-selectin expression on FLEC that was also inhibited by genistein. However, HV did not increase lung water. These results indicate that in HV, EC signaling in situ causes FA formation and induces TyrP-dependent P-selectin expression. These signaling mechanisms may promote leukocyte-mediated responses in HV.  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