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   486篇
  免费   41篇
耳鼻咽喉   6篇
儿科学   10篇
妇产科学   7篇
基础医学   72篇
口腔科学   21篇
临床医学   46篇
内科学   171篇
皮肤病学   9篇
神经病学   31篇
特种医学   8篇
外科学   52篇
综合类   4篇
一般理论   3篇
预防医学   20篇
眼科学   15篇
药学   27篇
中国医学   4篇
肿瘤学   21篇
  2022年   4篇
  2021年   8篇
  2020年   11篇
  2019年   17篇
  2018年   12篇
  2017年   8篇
  2016年   4篇
  2015年   9篇
  2014年   16篇
  2013年   21篇
  2012年   38篇
  2011年   36篇
  2010年   11篇
  2009年   11篇
  2008年   21篇
  2007年   24篇
  2006年   18篇
  2005年   20篇
  2004年   15篇
  2003年   14篇
  2002年   13篇
  1998年   4篇
  1997年   4篇
  1992年   5篇
  1990年   3篇
  1988年   5篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1984年   3篇
  1982年   3篇
  1979年   3篇
  1978年   7篇
  1977年   5篇
  1976年   4篇
  1975年   3篇
  1974年   10篇
  1973年   7篇
  1972年   9篇
  1971年   8篇
  1970年   8篇
  1969年   3篇
  1968年   7篇
  1965年   3篇
  1943年   6篇
  1942年   11篇
  1941年   7篇
  1927年   3篇
  1926年   5篇
  1924年   3篇
排序方式: 共有527条查询结果,搜索用时 109 毫秒
1.
Left ventricular outflow obstruction can be divided into three distinct categories: valvular aortic stenosis, the most common form; supravalvular aortic stenosis, which is often seen in early childhood; and subvalvular stenosis, which can be further subdivided into muscular, tunnel, and fibromembranous subtypes. All may be found in a patient seen with symptoms of angina, syncope, or heart failure as a precursor to sudden death. Prompt clinical recognition is essential as is a high degree of suspicion when these signs are associated with a systolic ejection murmur on clinical examination. Echocardiography and a meticulous Doppler examination are very useful in the diagnosis of these disorders as well as in further distinguishing among the different subtypes. The authors describe the case of a 40-year-old woman with chest pain refractory to medical therapy and a long systolic ejection murmur.  相似文献   
2.
We investigated whether Notch signaling pathways have a role in human developmental hematopoiesis. In situ histochemistry analysis revealed that Notch1, 2, and 4 and Notch ligand (Delta1-4, and Jagged1) proteins were not expressed in the yolk sac blood islands, the para-aortic splanchnopleure, the hematopoietic aortic clusters, and at the early stages of embryonic liver hematopoiesis. Notch1-2, and Delta4 were eventually detected in the embryonic liver, from 34 until 38 days postconception. Fluorescence-activated cell sorter analysis showed that first-trimester embryonic liver CD34(+)CD38(low) cells expressed both Notch1 and Notch2. When these cells were cultured on S17 stroma stably expressing Delta4, a 2.6-fold increase in BFU-E number was observed at day 7, as compared with cultures with control stroma, and this effect was maintained for 2 weeks. Importantly, exposure of these cells to Delta4 under these conditions maintained the original frequency and quality of long-term culture-initiating cells (LTC-ICs), while control cultures quickly resulted in the extinction of this LTC-IC potential. Furthermore, short-term exposure of embryonic liver adherent cells to erythropoietin resulted in a dose-dependent increase in Delta4 expression, almost doubling the expression observed with untreated stroma. This suggests that Delta4 has a role in the regulation of hematopoiesis after a hypoxic stress in the fetus.  相似文献   
3.
Fabry''s disease     
Fifteen hemizygotes and 30 heterozygotes have been diagnosed since our investigations of Fabry's disease were started 10 years ago. They belong mainly to three Danish families. Genetic counseling and prenatal diagnoses have been performed, and in vitro studies of cultured fibroblasts and endothelial cells have been made with special reference to enzyme therapy.  相似文献   
4.
5.
6.
7.
8.
J Oral Pathol Med (2011) 40 : 111–120 Background: In juvenile idiopathic arthritis involvement of the temporomandibular joints (TMJs) is often associated with mandibular growth deviations. The relation between the growth deviations and severity of the inflammation, condylar shape, the micro‐architecture, and the quality of the bone has not previously been investigated. This paper studies the effect on the bony structures in mandibular condylar development in rabbits with antigen‐induced arthritis. Methods: Included were 42 juvenile rabbits with ovalbumin‐induced arthritis of the TMJs treated with intraarticular saline, intraarticular etanercept or subcutaneous etanercept. A TMJ from each animal was scanned using micro‐computed tomography and structural parameters were calculated. Three‐dimensional reconstructions of the mandibular condyle were scored blindly as normal or abnormal. TMJs were stratified for condylar morphology and were evaluated against data on trabecular structural parameters, inflammation, degree of mineralization, overall mandibular growth, and mineral apposition rate. Results: Abnormal morphology were seen in 15/32 animals available for data analysis. Erosions were an uncommon finding. Abnormal morphology was strongly related to the degree of inflammation. The trabecular separation was larger in group with abnormal morphology than in the group with normal morphology. Abnormal condylar morphology was not associated with overall mandibular growth. No differences were observed in mineral apposition rate. No differences in structural parameters were seen according to treatment modality. Conclusion: We showed that severe inflammation in the TMJs during mandibular development was associated with morphological changes in the mandibular condyle. These changes were predominantly seen at the macro‐morphological level and only very few differences were structural.  相似文献   
9.
10.
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