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   1165篇
  免费   71篇
  国内免费   4篇
耳鼻咽喉   51篇
儿科学   35篇
妇产科学   14篇
基础医学   169篇
口腔科学   18篇
临床医学   157篇
内科学   295篇
皮肤病学   23篇
神经病学   44篇
特种医学   138篇
外科学   102篇
综合类   35篇
预防医学   55篇
眼科学   9篇
药学   57篇
肿瘤学   38篇
  2022年   8篇
  2021年   17篇
  2019年   10篇
  2018年   18篇
  2017年   8篇
  2016年   10篇
  2015年   19篇
  2014年   22篇
  2013年   35篇
  2012年   35篇
  2011年   31篇
  2010年   43篇
  2009年   45篇
  2008年   28篇
  2007年   21篇
  2006年   34篇
  2005年   24篇
  2004年   29篇
  2003年   35篇
  2002年   44篇
  2001年   24篇
  2000年   34篇
  1999年   27篇
  1998年   35篇
  1997年   33篇
  1996年   34篇
  1995年   30篇
  1994年   26篇
  1993年   25篇
  1992年   8篇
  1991年   25篇
  1990年   24篇
  1989年   35篇
  1988年   29篇
  1987年   22篇
  1986年   24篇
  1985年   24篇
  1984年   25篇
  1983年   21篇
  1982年   17篇
  1981年   18篇
  1980年   13篇
  1979年   16篇
  1978年   16篇
  1977年   23篇
  1976年   12篇
  1975年   17篇
  1970年   6篇
  1969年   7篇
  1967年   7篇
排序方式: 共有1240条查询结果,搜索用时 31 毫秒
991.
992.
Describing the health status of a population is difficult, especially in the case of irregular migrants who are now a growing population in western Countries. Data for children of these families are almost inexistent. In the absence of databases on this peculiar pediatric population, we analyzed drugs dispensation by a major Charity to have an insight into their health needs. This observational retrospective study was carried out during the entire 2015 and enrolled 628 undocumented children. A cohort of 8438 adult patients belonging to the same ethnic groups was used for comparison. Respiratory drugs were those most commonly prescribed, followed by those for skin and ocular diseases and by those for gastrointestinal disorders. Also in adults respiratory medications were the most dispensed, but almost in equal measure than cardiovascular drugs.To our knowledge this is the first study on the health needs of undocumented children residing in a western Country. The method we used seems to be a useful method for epidemiological analysis. As could be expected, respiratory and skin diseases ranked first, possibly owing to environmental factors.  相似文献   
993.
994.
Introduction: The aim of this study is to describe the frequency, nature, severity, and progression of cardiac abnormalities in a cohort of Dutch sarcoglycanopathy patients. Methods: In this cross‐sectional cohort study, patients were interviewed using a standardized questionnaire and assigned a functional score. Electrocardiography (ECG), echocardiography, and 24‐h ECG were performed. Results: Twenty‐four patients with sarcoglycanopathy had a median age of 25 years (range, 8–59 years). Beta blockers were used by 13%, and 17% used angiotensin‐converting enzyme inhibitors. ECG abnormalities were present in 5 (21%), and 4 (17%) fulfilled the criteria for dilated cardiomyopathy (DCM). There were no significant differences in median age or severity of disease between patients with or without DCM. Eleven patients were examined earlier. Median follow‐up time was 10 years. Two of the 11 patients (18%) developed DCM during follow‐up. Conclusions: Seventeen percent of the patients with sarcoglycanopathy were found to have dilated cardiomyopathy. We recommend biannual cardiac monitoring, including ECG and echocardiography. Muscle Nerve 50 : 909–913, 2014  相似文献   
995.
996.
Background Transplantation of autologous cultured pure melanocytes is a well‐established procedure for the treatment of refractory and stabilized vitiligo. However, there was no report specifically comparing the efficacy with the regard to defined age groups (children‐adolescence‐adult). Objective We analysed the efficacy of this procedure in the treatment of vitiligo in children and adolescents and compare it with the results in adults treated during the same period and using identical procedures. Methods Melanocytes were isolated from the roof of suction blister, cultured and expanded with Hu16 medium in vitro, and transplanted to laser‐denuded receipt area. A total of 12 children (8–12 years), 20 adolescents (13–17 years) and 70 adults with vitiligo were treated using this procedure. Results The patients obtained satisfactory results (repigmentation of 50% or more) results in children, adolescents and adults were 83.3%, 95.0% and 84.0% respectively. The mean extent of repigmentation in children, adolescents and adults was 80.7%, 78.9% and 76.6% respectively. There was no statistical difference in repigmentation among these three groups. After adjusting for all factors (gender, type of vitiligo, period of stability, location of the lesion or transplanted cell density) individually or totally using multiple regression analysis, age still did not correlate to the extent of repigmentation. Conclusions The satisfactory results obtained in the treatment of vitiligo in children and adolescents by transplantation of cultured autologous pure melanocytes are comparable with the results in adults. Therefore, this procedure can be considered in refractory and stable vitiligo in children and adolescents, especially in patients with large vitiliginous lesions.  相似文献   
997.

Background

Cardiovascular Magnetic Resonance (CMR) myocardial perfusion imaging has the potential to evolve into a method allowing full quantification of myocardial blood flow (MBF) in clinical routine. Multiple quantification pathways have been proposed. However at present it remains unclear which algorithm is the most accurate. An isolated perfused, magnetic resonance (MR) compatible pig heart model allows very accurate titration of MBF and in combination with high-resolution assessment of fluorescently-labeled microspheres represents a near optimal platform for validation. We sought to investigate which algorithm is most suited to quantify myocardial perfusion by CMR at 1.5 and 3 Tesla using state of the art CMR perfusion techniques and quantification algorithms.

Methods

First-pass perfusion CMR was performed in an MR compatible blood perfused pig heart model. We acquired perfusion images at physiological flow (“rest”), reduced flow (“ischaemia”) and during adenosine-induced hyperaemia (“hyperaemia”) as well as during coronary occlusion. Perfusion CMR was performed at 1.5 Tesla (n = 4 animals) and at 3 Tesla (n = 4 animals). Fluorescently-labeled microspheres and externally controlled coronary blood flow served as reference standards for comparison of different quantification strategies, namely Fermi function deconvolution (Fermi), autoregressive moving average modelling (ARMA), exponential basis deconvolution (Exponential) and B-spline basis deconvolution (B-spline).

Results

All CMR derived MBF estimates significantly correlated with microsphere results. The best correlation was achieved with Fermi function deconvolution both at 1.5 Tesla (r = 0.93, p < 0.001) and at 3 Tesla (r = 0.9, p < 0.001). Fermi correlated significantly better with the microspheres than all other methods at 3 Tesla (p < 0.002). B-spline performed worse than Fermi and Exponential at 1.5 Tesla and showed the weakest correlation to microspheres (r = 0.74, p < 0.001). All other comparisons were not significant. At 3 Tesla exponential deconvolution performed worst (r = 0.49, p < 0.001).

Conclusions

CMR derived quantitative blood flow estimates correlate with true myocardial blood flow in a controlled animal model. Amongst the different techniques, Fermi function deconvolution was the most accurate technique at both field strengths. Perfusion CMR based on Fermi function deconvolution may therefore emerge as a useful clinical tool providing accurate quantitative blood flow assessment.  相似文献   
998.
Orthotopic liver transplantation for alcoholic liver disease   总被引:4,自引:0,他引:4  
Alcohol abuse is the most common cause of end-stage liver disease in the United States, but many transplant centers are unwilling to accept alcoholic patients because of their supposed potential for recidivism, poor compliance with the required immunosuppression regimen and resulting failure of the allograft. There is also concern that alcohol-induced injury in other organs will preclude a good result. From July 1, 1982, to April 30, 1988, 73 patients received orthotopic liver transplants at the University of Pittsburgh for end-stage alcoholic liver disease. Fifty-two (71%) of these were alive at 25 +/- 9 mo (mean +/- S.D.) after transplantation, when a phone survey of these patients, their wives/husbands, and their physicians was performed to evaluate their subsequent use of alcohol, current medical condition and employment. Data obtained were compared with those for nonalcoholic patients selected as transplant controls. The recidivism rate has been 11.5%, with most patients drinking only socially. Fifty-four percent of the survivors are employed, 21% classify themselves as homemakers and only 11 (21%) are unable to work. Twenty-one patients died after transplantation; the most frequent cause of death was sepsis (43%), and intraoperative death was the next most common cause (28.6%). These data demonstrate that alcoholic patients can be transplanted successfully and achieve good health not significantly different from that of individuals transplanted for other causes. Thus orthotopic liver transplantation is a therapeutic option that should be considered for individuals with end-stage alcoholic liver disease who desire such therapy.  相似文献   
999.
BACKGROUND: Radioiodine therapy (131I) for the treatment of hyperthyroidism has been shown to be effective and safe. Despite the extensive experience with radioiodine therapy, the necessity for pretreatment with antithyroid drugs is controversial. Pretreatment is partly based on the concept that antithyroid drugs deplete the thyroidal hormonal stores, thereby reducing the risk of a radioiodine-induced aggravation of hyperthyroidism or thyroid storm. Few data are available on the frequency of clinically significant exacerbations of hyperthyroidism following 131I therapy without prior treatment with antithyroid drugs. The aim of the present study was to determine prospectively the early clinical and biochemical changes after 131I therapy in patients who were not pretreated with antithyroid drugs. METHODS: Patients with Graves' disease (n = 21), toxic multinodular goiter (n = 11) or toxic adenoma (n = 2) were studied before and after 131I therapy. Clinical and biochemical parameters of thyroid function were investigated before and 1, 2, 8, 11, 18 and 25 days after 131I treatment. Patients were given no antithyroid drugs prior to 131I therapy, all patients received beta-blocking agents for symptomatic relief. RESULTS: In 19 of 34 patients, a transient increase in thyroid hormone levels was observed, predominantly in the first week following 131I therapy. None of these patients experienced worsening of thyrotoxic symptoms. This transient increase in thyroid hormone levels was demonstrated in all patients with toxic multinodular goiter, whereas it was found in only six of 21 patients with Graves' disease. This difference could not readily be explained by differences in pretreatment thyroid hormone levels, administered dose or effectively absorbed dose of 131I. CONCLUSIONS: 131I treatment of hyperthyroidism without pretreatment with antithyroid drugs may cause a transient increase in thyroid hormone levels. Clinically significant exacerbations of hyperthyroidism were, however, not observed in our study population. Increased hormone levels following 131I therapy were more often seen in patients with toxic multinodular goiter than in patients with Graves' disease.  相似文献   
1000.
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