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   462篇
  免费   30篇
  国内免费   61篇
耳鼻咽喉   1篇
儿科学   29篇
妇产科学   9篇
基础医学   61篇
口腔科学   7篇
临床医学   76篇
内科学   79篇
皮肤病学   12篇
神经病学   23篇
特种医学   86篇
外科学   53篇
综合类   22篇
预防医学   14篇
眼科学   7篇
药学   51篇
中国医学   1篇
肿瘤学   22篇
  2022年   3篇
  2021年   10篇
  2019年   3篇
  2018年   6篇
  2017年   6篇
  2016年   6篇
  2015年   12篇
  2014年   13篇
  2013年   14篇
  2012年   12篇
  2011年   10篇
  2010年   14篇
  2009年   21篇
  2008年   5篇
  2007年   49篇
  2006年   18篇
  2005年   19篇
  2004年   5篇
  2003年   5篇
  2002年   8篇
  2001年   9篇
  2000年   7篇
  1999年   14篇
  1998年   28篇
  1997年   38篇
  1996年   27篇
  1995年   22篇
  1994年   12篇
  1993年   24篇
  1991年   6篇
  1990年   7篇
  1989年   19篇
  1988年   8篇
  1987年   10篇
  1986年   7篇
  1985年   4篇
  1984年   8篇
  1983年   4篇
  1982年   4篇
  1981年   5篇
  1980年   12篇
  1979年   2篇
  1978年   3篇
  1977年   3篇
  1976年   3篇
  1975年   4篇
  1974年   2篇
  1972年   3篇
  1968年   2篇
  1966年   4篇
排序方式: 共有553条查询结果,搜索用时 31 毫秒
101.
Mixed payment systems have become a prominent alternative to paying physicians through fee‐for‐service and capitation. While theory shows mixed payment systems to be superior, causal effects on physicians' behavior when introducing mixed systems are not well understood empirically. We systematically analyze the influence of fee‐for‐service, capitation, and mixed payment systems on physicians' service provision. In a controlled laboratory setting, we implement an exogenous variation of the payment method. Medical and non‐medical students in the role of physicians in the lab (N = 213) choose quantities of medical services affecting patients' health outside the lab. Behavioral data reveal significant overprovision of medical services under fee‐for‐service and significant underprovision under capitation, although less than predicted when assuming profit maximization. Introducing mixed payment systems significantly reduces deviations from patient‐optimal treatment. Although medical students tend to be more patient regarding, our results hold for both medical and non‐medical students. Responses to incentive systems can be explained by a behavioral model capturing individual altruism. In particular, we find support that altruism plays a role in service provision and can partially mitigate agency problems, but altruism is heterogeneous in the population. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
102.
Introduction: Acute and chronic graft rejection continues to be an important problem after solid organ transplantation. With the introduction of potent immunosuppressive agents such as calcineurin inhibitors, the risk of rejection has been significantly reduced. However, the adverse effects of life-long immunosuppression remain a concern, and there exist a fine balance between over-immunosuppression and risk of rejection.

Areas covered: In this review, the current standard of care in immunosuppressive therapy, including the use of steroids, calcineurin inhibitors, mycophenolate prodrugs and mammalian target of rapamycin inhibitors, will be discussed. Newer immunosuppressive agents showing promising early data after liver and kidney transplantation will also be explored.

Expert Opinion: Currently, calcineurin inhibitors continue to be a vital component of immunosuppressive therapy after solid organ transplantation. Although minimization and avoidance strategies have been developed, the ultimate goal of inducing tolerance remains elusive. Newer emerging agents should have potent and specific immunosuppressive activity, with minimal associated side effects. An individualized approach should be adopted to tailor immunosuppression according to the different needs of recipients.  相似文献   

103.
Renal allograft loss from chronic rejection or cyclosporine toxicity (CsAT) is characterized by progressive interstitial fibrosis, yet the protein composition of these lesions is unknown. The normal tubular basement membrane (TBM) contains laminin (LM), collagen IV (containing collagen IV alpha chain 1 [COL4A1] and COL4A2), thrombospondin (TSP), and fibronectin (FN). Only TSP and FN extend beyond the TBM into the interstitial space. Very scanty amounts of interstitial collagens (I and III) are detected in the interstitium. In a pilot study of human renal allograft biopsy specimens, three patterns of extracellular matrix (ECM) composition were identified. Pattern 1 showed no change in ECM composition; pattern 2 showed generalized accumulation of collagens I and III in the interstitium; and pattern 3 showed new expression of COL4A3 and LM-beta2 in the proximal TBM. Criteria were established for the clinicopathological diagnosis of CsAT and rejection. These diagnoses were correlated with the ECM composition in 22 renal allograft biopsy specimens. Control groups were examined in a similar manner and included native kidney biopsy specimens from patients with other allografts (n = 7), renal biopsy specimens from patients with glomerular disease (n = 9), and renal allograft biopsy specimens from patients without clinicopathological evidence of renal disease. These data show that rejection is associated with pattern 3 and CsAT is associated with pattern 2. Thus, detection of ECM composition may be a useful adjunct to standard microscopy in distinguishing rejection from CsAT in renal allograft biopsy specimens. These data suggest that interstitial fibrosis associated with rejection and CsAT result from different pathogenic mechanisms.  相似文献   
104.
105.
立位X线胸片可敏感而特异地显示膈下游离气体 ,对开放性结肠直肠切除术后空腔脏器出现破损是一项有效的检查 ,但由于剖腹术后气腹自然吸收所需要的时间未知 ,其作用尚未被确定。本次试验的目的即在于确定这一时间。   3个月内连续 92例接受了连续性结肠直肠切除术的病人 (8例拒绝合作 ,9例采用了腹腔镜技术 )中的 75例参与了这次试验 (平均年龄 6 2 1岁 ,男∶女 =1 3∶1) ,手术指征分别为直肠癌 6例 ,憩室病 2例 ,肠道炎症 2例 ,放疗引起狭窄 3例 ,功能性疾患 (慢性运输性便秘 ,直肠脱垂 ) 2例 ,其它 (家族性腺瘤息肉、乙状结肠扭转、短…  相似文献   
106.
树突状细胞与肝脏疾病   总被引:9,自引:3,他引:6  
免疫反应的产生首先是由抗原提呈细胞(antigenpresenting cells,APC)捕获抗原,经其加工处理后将抗原信息传递给T,B淋巴细胞,从而引发一系列的特异性免疫应答.APC包括树突状细胞(dendritic cells,DC)、巨噬细胞(MΦ)、B细胞等,其中DC是人体内最具潜能的抗原提呈细胞(APC),能在体内外直接激活纯真(naive)T细胞,提呈抗原给MHC-Ⅰ类限制性CD8+和MHC-Ⅱ类限制性CD4+T淋巴细胞,诱导特异性免疫应答[1-6].  相似文献   
107.
108.

Objective

The study examined parent stress and health‐related quality of life (HRQOL) among families of children with congenital heart disease (CHD) referred for psychological services.

Methods

Parents of 54 children (85% boys) aged 3 to 13 (Mage = 7.48, SD = 2.38) completed measures to assess parenting stress (Parenting Stress Index – Short Form; Pediatric Inventory for Parents) and the PedsQL Family Impact Module. Medical information was retrieved from medical record review.

Results

Half of parents of children with single ventricle anatomy had clinically significant levels of parenting stress. Parents of children with single ventricle anatomy reported more frequent illness‐related stress and more difficulty dealing with illness‐related stress than parents of children with two ventricle anatomy. Younger gestational age at birth and referral for attention or behavior problems were associated with greater likelihood of parent at‐risk psychosocial functioning.

Conclusions

Among children referred for psychological services, many parents report significant stress and significant negative impact of the child's medical condition on the family. Results underscore the need to consider assessing parent psychosocial functioning and providing additional support for parents of children with CHD.  相似文献   
109.
Background and Objectives: Children with congenital heart disease (CHD) are at risk for neurodevelopmental (ND) delays. The purpose of this study is to compare the ND testing results of children with CHD at 2 and 4 years of age and determine if rates of ND delays change over time.
Methods: Children with CHD completed the Bayley Scales of Infant Development‐III (BSID‐III) at 2 years of age, and standardized neuropsychological measures at 4 years. Scores were compared with test norms and were classified as: average (within one SD of test mean); at risk (1‐2 SDs from the test mean); and delayed (>2 SD from test mean). Pearson correlations and McNemar’s exact tests were performed to deter‐ mine the relationship between test scores at the two times of assessment.
Results: Sixty‐four patients completed evaluations at 24 ± 3 months of age and 4 years of age. BSID‐III cognitive and fine motor scores were correlated with pre‐ school IQ and fine motor scores, r = .75 to .87, P < .0001. Agreement in score catego‐ ries was 79% for cognitive and 61% for fine motor. More patients had at risk or delayed scores at age 4 vs age 2 (P≤.01).
Conclusion(s): Despite significant correlations between 2‐ and 4‐year‐old test scores, many patients who scored in the average range at age 2 showed deficits at age 4. BSID‐III scores at age 2 may underestimate delays. Therefore, longitudinal ND as‐ sessment is recommended.  相似文献   
110.
AIM: To evaluate the effectiveness and safety of acupuncture for the treatment of obesity by reviewing currently available randomised controlled trials. METHODS: This review followed the Cochrane Handbook for Systematic Reviews of Interventions. Fifteen English and three Chinese databases were searched from their respective inceptions until July 2014. Key words used in the search consisted of acupuncture, needles, obesity, overweight, randomised trial and their synonyms. The risk of bias of included studies was assessed. The differences in effect size between acupuncture and control (including sham, no treatment, western medicine and dietary therapy/exercise) groups were compared using Cochrane Collaboration’s RevMan 5.3 software. RESULTS: Two thousand six hundred and twenty-one records were identified; after full-text articles assessed for eligibility, 9 of them met inclusion criteria. Majority of included studies had unclear or high risk of bias across all domains. All included studies had high or unclear risk of bias in randomisation, blinding and outcome data. Meta-analysis showed that acupuncture was more effective for reducing body weight and body mass index than no treatment group. Manual acupuncture was also superior to dietary therapy alone for decreasing body weight. With dietary therapy as co-intervention, combined acupuncture group achieved lower body mass index than combined sham acupuncture group or dietary therapy alone group at the end of treatment period. No severe adverse events from acupuncture group were reported from all included studies. CONCLUSION: Due to the poor quality of included studies the effectiveness of acupuncture cannot be concluded. Better-designed, large-scale, randomised, sham-controlled clinical trials with long-term follow-up are needed.  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