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   996篇
  免费   58篇
  国内免费   7篇
耳鼻咽喉   7篇
儿科学   10篇
妇产科学   12篇
基础医学   129篇
口腔科学   9篇
临床医学   90篇
内科学   251篇
皮肤病学   5篇
神经病学   100篇
特种医学   32篇
外科学   44篇
综合类   17篇
一般理论   2篇
预防医学   61篇
眼科学   14篇
药学   73篇
肿瘤学   205篇
  2023年   8篇
  2022年   10篇
  2021年   19篇
  2020年   17篇
  2019年   29篇
  2018年   18篇
  2017年   20篇
  2016年   26篇
  2015年   19篇
  2014年   31篇
  2013年   49篇
  2012年   68篇
  2011年   71篇
  2010年   42篇
  2009年   34篇
  2008年   66篇
  2007年   52篇
  2006年   60篇
  2005年   44篇
  2004年   33篇
  2003年   32篇
  2002年   30篇
  2001年   15篇
  2000年   13篇
  1999年   26篇
  1998年   16篇
  1997年   11篇
  1996年   16篇
  1995年   15篇
  1994年   18篇
  1993年   9篇
  1992年   20篇
  1991年   11篇
  1990年   10篇
  1989年   12篇
  1988年   9篇
  1987年   23篇
  1986年   9篇
  1985年   10篇
  1984年   9篇
  1983年   9篇
  1982年   6篇
  1981年   5篇
  1980年   1篇
  1979年   5篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1968年   1篇
  1922年   1篇
排序方式: 共有1061条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
It is frequently suggested that younger adults are negative in their attitudes toward elderly people. There are also claims that such attitudes develop as a result of the socially constructed phenomenon of ageism. This paper briefly addresses the concept as it is presented in the literature and goes on to describe an attitudinal study which supports the existence of ageism. An Attitudes Toward the Elderly inventory was administered to secondary school pupils during their final 2 years of schooling, to student nurses at the very beginning of their training and to qualified nurses. It was found that the subjects did demonstrate negative attitudes and that there appeared to be a definite gender socialization influence, with females demonstrating less negative attitudes than males. Contrary to expectations, entry into nursing did not lead to more positive attitudes but had the converse effect. The influence of ageism and more specific professional socialization processes are suggested as explanations for these patterns. Implications for nursing and other occupational groups involved in caring for the elderly are discussed.  相似文献   
75.
Side rails are commonly used in the care of the older person. They can be classified as a physical restraint if they restrict the movement of an individual and also if the individual has an inability to have them removed/lowered at will. Advanced age should not be an indicator for side rail use and an individualized approach in patient assessment is advised.  相似文献   
76.
Morphine, the recommended drug for the management of moderate to severe cancer pain, is metabolized predominantly to the glucuronides morphine-6-glucuronide (M6G) and morphine-3-glucuronide (M3G). The quantitative clinical importance of these metabolites following the administration of oral morphine is unclear. This study investigates the relationship between plasma concentrations of morphine (M), M6G, M3G and clinical effects in patients receiving sustained release oral morphine for cancer-related pain. Peak and trough plasma concentrations of morphine and its metabolites were determined by high-performance liquid chromatography (HPLC). At corresponding time points, pain [Visual Analogue Scales (VAS), Verbal Rating Scales (VRS), Pain Relief Scores (PRS)] and toxicity (VAS and VRS) were assessed. Renal and liver function tests were performed. Forty-six patients were included in the study. There was a significant correlation between dose and both peak and trough plasma M, M6G and M3G (r > 0.60, P < 0.001 for each). Differences between peak and trough M, M6G, M3G, M+M6G, M6G:M, M3G:M and M3G:M6G were all significant (P < 0.001 for each). Pain was generally well controlled in the group, with a median VAS of 15 mm at the peak blood sampling time point. The differences between peak and trough values for VAS pain, VAS nausea and VAS drowsiness were not statistically significant (P = 0.078, 0.45 and 0.099, respectively). There were no differences in peak or trough morphine and metabolite concentrations or ratios between patients with low (< median) or high pain scores. Similarly, there was no significant relationship between high and low plasma concentrations and clinical effect. This study did not identify a simple relationship between plasma concentrations of morphine, morphine metabolites or metabolite ratios and clinical effects in patients with cancer and pain who were receiving chronic oral morphine therapy. Although overall pain control was good, there was marked interpatient variability in the dose of morphine and the plasma concentrations necessary to achieve this degree of analgesia.  相似文献   
77.
Arthrogryposis, Renal dysfunction and Cholestasis (ARC) syndrome is a multi-system autosomal recessive disorder caused by germline mutations in VPS33B. The detection of germline VPS33B mutations removes the need for diagnostic organ biopsies (these carry a>50% risk of life-threatening haemorrhage due to platelet dysfunction); however, VPS33B mutations are not detectable in approximately 25% of patients. In order further to define the molecular basis of ARC we performed mutation analysis and mRNA and protein studies in patients with a clinical diagnosis of ARC. Here we report novel mutations in VPS33B in patients from Eastern Europe and South East Asia. One of the mutations was present in 7 unrelated Korean patients. Reduced expression of VPS33B and cellular phenotype was detected in fibroblasts from patients clinically diagnosed with ARC with and without known VPS33B mutations. One mutation-negative patient was found to have normal mRNA and protein levels. This patient's clinical condition improved and he is alive at the age of 2.5 years. Thus we show that all patients with a classical clinical course of ARC had decreased expression of VPS33B whereas normal VPS33B expression was associated with good prognosis despite initial diagnosis of ARC.  相似文献   
78.
Familial biparental hydatidiform mole (FBHM) is a maternal‐effect autosomal recessive disorder in which recurrent pregnancy failure with molar degeneration occurs. The phenotype mimics molar pregnancy due to androgenesis, despite the normal genetic makeup of the conceptus. FBHM appears to result from a failure to establish correct maternal epigenetic identity at imprinted loci during oogenesis. Several women affected with FBHM have previously been shown to have biallelic mutations in the NLRP7 gene (NALP7). Here, we present the results of epigenetic and mutational analysis on FBHM patients from 11 families, 10 of them novel. We demonstrate a methylation defect at imprinted loci in tissue from four new FBHM cases. Biallelic NLRP7 mutations, including eight previously undescribed mutations, were found in all but one family. These results indicate for the first time that maternal imprints at some loci may be correctly specified in FBHM conceptions, since differential methylation of SGCE/PEG10 was preserved in all four cases. © 2009 Wiley‐Liss, Inc.  相似文献   
79.
Impact of pregnancy and parturition on the anal sphincters and pelvic floor   总被引:1,自引:0,他引:1  
Incontinence and defecatory difficulties are commonly reported among women and are often ascribed to traumas sustained during childbirth. Specifically, injuries to the anal sphincters (tears) and conformational changes in the various structures that comprise the pelvic floor (prolapse and perineal descent) have been considered as important contributors to the development of anal incontinence, or difficult defaecation (straining, incomplete evacuation), in later life. An understanding of both the effects of pregnancy and parturition on these structures and the natural history of any traumas sustained are, therefore, of key importance. Unfortunately, the literature on these issues, though vast, is far from complete. While it is evident that pregnancy, per se, imposes changes, primarily through hormonal influences, on colonic, ano-rectal and pelvic floor physiology, the long-term impact of such effects is far from clear. Risk factors for the occurrence of significant, though often occult, anal sphincter injuries during birth have been identified and the role of these tears in the etiology of post-partum incontinence has been well delineated. In contrast, the contribution of such intra-partum events to the later onset of incontinence is far from clear and may well have been over-estimated.  相似文献   
80.
OBJECTIVES: A model based on the associative strength of object evaluations is tested to explain why those who score higher on health anxiety have a better memory for health-related words. METHOD: Sixty participants observed health and nonhealth words. A recognition memory task followed a free recall task and finally subjects provided evaluations (emotionality, imageability, and frequency) for all the words. Hit rates for health words, d', c, and psychological response times (PRTs) for evaluations were examined using multi-level modelling (MLM) and regression. RESULTS: Health words had a higher hit rate, which was greater for those with higher levels of health anxiety. The higher hit rate for health words is partly mediated by the extent to which health words are evaluated as emotionally unpleasant, and this was stronger for (moderated by) those with higher levels of health anxiety. Consistent with the associative strength model, those with higher levels of health anxiety demonstrated faster PRTs when making emotional evaluations of health words compared to nonhealth words, while those lower in health anxiety were slower to evaluate health words. CONCLUSIONS: Emotional evaluations speed the recognition of health words for high health anxious individuals. These findings are discussed with respect to the wider literature on cognitive processes in health anxiety, automatic processing, implicit attitudes, and emotions in decision making.  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