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   9682篇
  免费   922篇
  国内免费   14篇
耳鼻咽喉   39篇
儿科学   306篇
妇产科学   159篇
基础医学   1206篇
口腔科学   215篇
临床医学   1260篇
内科学   1737篇
皮肤病学   91篇
神经病学   666篇
特种医学   550篇
外科学   1138篇
综合类   191篇
一般理论   4篇
预防医学   902篇
眼科学   820篇
药学   832篇
  1篇
中国医学   8篇
肿瘤学   493篇
  2021年   115篇
  2020年   93篇
  2019年   151篇
  2018年   147篇
  2017年   117篇
  2016年   144篇
  2015年   164篇
  2014年   224篇
  2013年   348篇
  2012年   426篇
  2011年   397篇
  2010年   271篇
  2009年   239篇
  2008年   460篇
  2007年   438篇
  2006年   412篇
  2005年   424篇
  2004年   399篇
  2003年   340篇
  2002年   332篇
  2001年   297篇
  2000年   329篇
  1999年   267篇
  1998年   171篇
  1997年   169篇
  1996年   168篇
  1995年   146篇
  1994年   131篇
  1993年   111篇
  1992年   246篇
  1991年   214篇
  1990年   198篇
  1989年   202篇
  1988年   189篇
  1987年   206篇
  1986年   157篇
  1985年   190篇
  1984年   144篇
  1983年   109篇
  1982年   84篇
  1981年   67篇
  1979年   89篇
  1978年   83篇
  1977年   77篇
  1976年   66篇
  1975年   61篇
  1974年   69篇
  1973年   64篇
  1972年   59篇
  1971年   58篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Parastomal hernia.   总被引:1,自引:0,他引:1       下载免费PDF全文
Parastomal herniation is a common complication after stoma formation. The incidence can be reduced by using an extraperitoneal technique, limiting the size of the trephine to 1.5-2.0 cm or by strengthening with a mesh. If an intraperitoneal technique is used the intestine should be brought out through the rectus muscle. Generally, the symptoms are easily controlled with a support belt. Various techniques have been advocated for surgical repair. Fascial repair alone should no longer be performed owing to an unacceptably high recurrence rate, but should be combined with a prosthetic mesh. Relocation of the stoma should be performed for primary repairs.  相似文献   
53.
One goal of supportive housing is to enlarge and improve the functioning of the social support networks of residents. The networks of a convenience sample of 42 residents were assessed using scales developed by Barrera. The size of the networks (11.5) was no larger than that reported for similar clients living in other types of community settings but the composition differed. Staff and co-residents appear to partially replace rather than add to family and friends. This is of concern because friends are uniquely important determinants of satisfaction. An association between perceived need for support and network size was also found. These findings suggest some positive influences but also raise questions about unintended negative consequences of living in artificially constructed social environments.When this project was undertaken, Dr. Goering, Janet Durbin, Bill Lancee and Taras Babiak were all members of the Social and Community Psychiatry Section, Clarke Institute. Robert Foster was Executive Director of Regeneration House, Inc., where Susan Boyles is Assistant Executive Director.  相似文献   
54.
55.
Uroscopy in the 21st century: high-field NMR spectroscopy   总被引:1,自引:1,他引:0  
From the experiments described, it can be seen that there are different research approaches that can be taken and these are summarized in Table 1. Whereas much scientific research is principally hypothesis led, there remains, nevertheless, an important place for exploratory research. High resolution NMR can measure, directly and simultaneously, a wide range of endogenous metabolites in biological fluids and has the unique capability of providing structural information on the metabolites detected. It has proved to be a powerful research tool with which to study inherited metabolic diseases, renal disease, drug metabolism, and toxicity, and can be used to monitor the effects of drug therapy. For instance, by using a library of experimental toxins one can map the metabolic profile of site-specific nephron injury. With this approach in man one could eventually take an unknown disease such as Balkan nephropathy and predict the initial site of tubular injury, the mode of injury and therefore the kind of toxin capable of producing that injury. NMR spectroscopic techniques are still advancing rapidly, with ever increasing sensitivity and sophistication of NMR pulse sequences to enhance structural elucidation in complex mixtures. Given the advances in directly coupled HPLC-NMR and even HPLC-NMR-mass spectroscopy it is likely that these technologies in conjunction with pattern recognition will make major contribution to our understanding of renal processes and provide new diagnostic insights in the 21st century.   相似文献   
56.
57.
Leukotriene B4 (LTB4) and the protein kinase C activator, 4-beta-phorbol dibutyrate (PDBu), both induced a pronounced and concentration-dependent stimulation of hydrogen peroxide (H2O2) generation by purified guinea pig peritoneal eosinophils in the concentration range 1 nM-1 microM. The LTB4 response was inhibited competitively by the specific LTB4 receptor antagonist, U-75302, with a KB of 25 nM, while the concentration-response curves for both stimuli were shifted rightwards (3.8-fold and 2.8-fold for LTB4 and PDBu, respectively) by the competitive protein kinase C inhibitor, 1-O-hexadecyl-2-O-methylglycerol at a concentration of 300 microM. LTB4 appears, therefore, to induce respiratory burst in eosinophils via a receptor-mediated mechanism involving protein kinase C.  相似文献   
58.
Using WHO definitions of visual loss and a standardised methodology, 256 children were examined in schools for the blind in Thailand (1 school) and the Philippines (3 schools). 244 (95%) were blind (BL) or severely visually impaired (SVI). Causes of SVI and blindness were classified anatomically and aetiologically, and avoidable causes identified. Causes of visual loss in Khon Kaen, Thailand (n = 65) and Manila, Philippines, (n = 113) were similar, with conditions of the whole globe accounting for 27.7 and 27.4% of SVI/BL; retinal disease 29.2 and 23.0%; cataract 16.9 and 16.8%; corneal disease 12.3 and 13.4%; and optic nerve disease and glaucoma 6.2 and 8.8%. Perinatal factors accounted for 20.0 and 23.0% of SVI/BL; hereditary disease 13.8 and 17.7%; and 12.3 and 15.0% was due to events occurring during childhood. The underlying aetiology could not be determined in 50.8 and 41.6% of cases, respectively. In the two schools together twenty six children (15%) were blind from retinopathy of prematurity (ROP) and 16 (9%) from corneal scarring attributed to Vitamin A deficiency. 103 of 178 (58%) children had avoidable causes of visual loss. In the Filipino towns of Baguio and Davao (n = 66), the causes of visual loss were different from those in Khon Kaen and Manila, with 54.8 and 42.9% of SVI/BL being due to corneal disease, and only 3.2 and 8.5% to retinal disease. Childhood factors were more important (61.3 and 57.1%) than hereditary (9.7 and 17.1%) or perinatal factors (0 and 2.9%). Thirty one children (47%) had SVI/BL attributed to Vitamin A deficiency. No child was blind from ROP. 42 of 66 (64%) of children had avoidable causes of blindness. Overall 60% of children with SVI/BL had avoidable causes of visual loss in these 4 schools. Approximately half could have been prevented by primary health and eye care services and half could have been managed by surgical ophthalmological procedures. The causes of blindness identified in this blind school study suggest that the major causes are different for schools serving rural populations compared to those serving urban communities. Different control strategies are required for the different situations.  相似文献   
59.
60.
Fifty mothers and 44 well siblings of children and adolescents with cystic fibrosis (CF) participated in this study to identify correlates of maternal well-being. Participants completed postal questionnaires which assessed maternal well-being, problems experienced surrounding the illness and treatment and the nature of the sibling relationship. Due to the demanding nature of treatment and the fact that CF is both genetic and incurable at present we anticipate mothers of these children will experience higher levels of stress and consequently poorer well-being than the normal population. In addition, illness severity, problems with adherence to treatment, child communication, maternal support and the sibling relationship are expected to relate to maternal well-being. Mothers in this sample did not rate their well-being as any different to the normal population. Results suggest that mothers are likely to rate their own well-being as poor when they report more frequent problems surrounding the illness and treatment and well children rate their sibling relationship as having frequent disagreements and aggression. This study highlights factors that are related to maternal well-being in families where one child has CF. These mothers as a group do not appear to be experiencing more stress in their daily lives than the normal population but certain illness and family variables are related to their well-being when examining the mothers on certain dimensions.  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