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   258篇
  免费   5篇
耳鼻咽喉   10篇
儿科学   7篇
妇产科学   9篇
基础医学   63篇
口腔科学   6篇
临床医学   9篇
内科学   64篇
皮肤病学   1篇
神经病学   14篇
特种医学   8篇
外科学   9篇
综合类   1篇
预防医学   26篇
眼科学   20篇
药学   15篇
肿瘤学   1篇
  2021年   2篇
  2020年   3篇
  2019年   2篇
  2018年   5篇
  2017年   5篇
  2016年   2篇
  2015年   4篇
  2014年   13篇
  2013年   4篇
  2012年   9篇
  2011年   16篇
  2010年   14篇
  2009年   2篇
  2008年   20篇
  2007年   17篇
  2006年   8篇
  2005年   21篇
  2004年   7篇
  2003年   14篇
  2002年   5篇
  2001年   5篇
  2000年   7篇
  1999年   2篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1988年   2篇
  1987年   3篇
  1986年   5篇
  1985年   3篇
  1984年   1篇
  1983年   4篇
  1982年   2篇
  1979年   2篇
  1978年   2篇
  1977年   5篇
  1976年   1篇
  1975年   3篇
  1974年   3篇
  1973年   1篇
  1972年   5篇
  1971年   3篇
  1970年   6篇
  1969年   4篇
  1968年   1篇
  1967年   6篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1941年   1篇
排序方式: 共有263条查询结果,搜索用时 31 毫秒
1.
Prestomal teeth of flies in the families Calliphoridae (Chrysomya pinguis, Chrysomya villeneuvi, and Chrysomya chani), Muscidae (Hydrotaea (= Ophyra) chalcogaster) and Sarcophagidae (Boettcherisca peregrina) were presented using scanning electron microscopy. The slight to deep bifurcation of the tips of their teeth were similarly observed in all species examined. The anatomical feature of prestomal teeth of the flies examined may contribute to the understanding of their feeding behavior and the medical importance of their role in the future.  相似文献   
2.
Factor XIII (FXIII) deficiency is a very rare severe autosomal bleeding disorder with a frequency of 1:2,000,000 in the general population and only a few patients have been genetically characterized so far. We report a phenotype-genotype characterization of 10 unrelated Iranian patients. Two FXIII (transglutaminase) activity assays showed no FXIII activity, except a conserved residual activity in patients receiving prophylactic substitution treatment. FXIII antigen concentrations measured by two immunoassays were comparable. Genotype characterization identified four novel mutations (2 missense and 2 small deletions) and two previously reported missense mutations in the FXIII A subunit gene (F13A). Molecular modeling was carried out to reveal the structural consequences of the missense mutations, that caused the replacement of an arginine residue involved in the formation of structurally important extensive hydrogen-bonded network. The replacements [c.320G>A (p.Arg77His) in the beta-sandwich, c.868C>T (p.Arg260Cys), c.869G>A (p.Arg260His) and c.1236G>T (p.Arg382Ser) in the core domain] resulted in the loss or impairment of such H-bonded network. Energy decomposition analysis demonstrated that this situation leads to the instability and perhaps to the incorrect folding of the A subunit, that would explain the development of severe FXIII deficiency.  相似文献   
3.
4.
Inflammopharmacology - Ulcerative colitis is a form of inflammatory bowel disease that is characterized by acute and chronic inflammation. The aim of this work was to evaluate the efficacy of...  相似文献   
5.
Parasitology Research - Maggot debridement therapy (MDT) is an application of sterile laboratory-reared blow fly larvae to remove necrotic tissue and disinfect wounds for medical conditions. For...  相似文献   
6.
Distribution and occurrence of blow flies of forensic importance was performed during 2007 and 2008 in Chiang Mai and Lampang Provinces, northern Thailand. Surveys were conducted in forested areas for 30 minutes using a sweep net to collected flies attracted to a bait. A total of 2,115 blow flies belonging to six genera and 14 species were collected; Chrysomya megacephala (Fabricius) (44.7%), C. pinguis (Walker) (15.1%), C. chani Kurahashi (9.3%), C. thanomthini Kurahashi & Tumrasvin (0.3%); Achoetandrus rufifacies (Macquart) (10.5%), A. villeneuvi (Patton) (2.2%); Lucilia papuensis Macquart (2.2%), L. porphyrina (Walker) (12.4%), L. sinensis Aubertin (0.7%); Hemipyrellia ligurriens (Wiedemann) (1.3%), H. pulchra (Wiedemann) (0.1%); Hypopygiopsis infumata (Bigot) (0.6%), Hy. tumrasvini Kurahashi (0.2%) and Ceylonomyia nigripes Aubertin (0.4%). Among them, C. megacephala was the predominant species collected, particularly in the summer. The species likely to prevail in highland areas are C. pinguis, C. thanomthini, Hy. tumrasvini, L. papuensis and L. porphyrina.  相似文献   
7.

Background

Left ventricular (LV) diastolic dysfunction is common in systemic sclerosis (SSc). Less is known, however, about left atrial (LA) mechanics in this context. The aim of this study was to investigate the correlation between LV diastolic function and LA mechanics in SSc patients with the use of volumetric and 2-dimensional speckle tracking–derived strain techniques and to compare the results with those obtained in healthy subjects.

Methods and Results

Seventy-two SSc patients and 30 healthy volunteers (H) were investigated. LV diastolic function was classified as normal (I), impaired relaxation (II), and pseudonormal pattern (III). LA reservoir (H: 51.8?±?7.4%; I: 45.1?±?8.1%; II: 42.2?±?6.6%; III: 36.6?±?7.3%; analysis of variance: P?<?.001) and contractile strain (H: 24.8?±?4.9%; I: 18.2?±?4.4%; II: 21.5?±?2.8%; III: 16.8?±?3.6%; P?<?.001) already showed significant worsening in SSc patients with preserved LV diastolic function compared with healthy subjects. LA conduit strain (H: 27.1?±?4.6%; I: 26.9?±?5.7%; II: 20.6?±?6.1%; III: 19.5?±?5.3%; P?<?.001) was preserved in this early phase. Further deterioration of reservoir strain was pronounced in the pseudonormal group only. LA contractile strain increased significantly in the impaired relaxation group and then decreased with the further worsening of the LV diastolic function. Regarding phasic volume indices, the differences between groups were not always statistically significant.

Conclusion

LA mechanics strongly reflects the changes in LV diastolic function in SSc. On the other hand, strain parameters of the LA reservoir and contractile function already show significant worsening in SSc patients with preserved LV diastolic function, suggesting that impairment of the LA mechanics is an early sign of myocardial involvement in SSc.  相似文献   
8.
In this paper, an algorithm for detection of suspicious masses from mammographic images is presented. The proposed algorithm was tested on a database of 61 mammograms on which masses had previously been marked by experienced radiologists. Results show that the proposed method exhibits for mass detection, a sensitivity of 95.91%. The area under receiver operating characteristic (ROC) Az was 0.946 when enhancement of the original image was performed before detection and 0.938 otherwise. Furthermore in some cases, we could detect some masses that the radiologists were not able to mark out.  相似文献   
9.
Although increasingly complex models have been proposed in mediation literature, there is no model nor software that incorporates the multiple possible generalizations of the simple mediation model jointly. We propose a flexible moderated mediation model allowing for (1) a hierarchical structure of clustered data, (2) more and possibly correlated mediators, and (3) an ordinal outcome. The motivating data set is obtained from a European study in nursing research. Patients' willingness to recommend their treating hospital was recorded in an ordinal way. The research question is whether such recommendation directly depends on system‐level features in the organization of nursing care, or whether these associations are mediated by 2 measurements of nursing care left undone and possibly moderated by nurse education. We have developed a Bayesian approach and accompanying program that takes all the above generalizations into account.  相似文献   
10.
The efficacy of crude pineapple juice obtained from Ananus comosus in digesting fish for the harvesting of trematode metacercariae was investigated. No significant difference was found between the total number of metacercariae detected from fish (Cirrhina jullieni) digested by acid pepsin and those digested by freshly prepared pineapple juice that was kept for 15 days at a temperature of either -4 degrees C or -75 degrees C. However, fewer metacercariae were found when using juice that had been kept for more than 30 days. This study showed that freshly prepared pineapple juice kept frozen for 15 days could be used instead of commercial acid pepsin to digest fish for harvesting metacercariae, some of which could be used for further biological studies.  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