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   1683篇
  免费   150篇
  国内免费   23篇
耳鼻咽喉   18篇
儿科学   57篇
妇产科学   14篇
基础医学   127篇
口腔科学   23篇
临床医学   191篇
内科学   252篇
皮肤病学   11篇
神经病学   113篇
特种医学   39篇
外科学   208篇
综合类   201篇
预防医学   178篇
眼科学   8篇
药学   239篇
  4篇
中国医学   135篇
肿瘤学   38篇
  2024年   8篇
  2023年   64篇
  2022年   67篇
  2021年   133篇
  2020年   132篇
  2019年   99篇
  2018年   97篇
  2017年   108篇
  2016年   96篇
  2015年   75篇
  2014年   110篇
  2013年   139篇
  2012年   93篇
  2011年   91篇
  2010年   66篇
  2009年   67篇
  2008年   44篇
  2007年   43篇
  2006年   49篇
  2005年   38篇
  2004年   33篇
  2003年   23篇
  2002年   25篇
  2001年   23篇
  2000年   16篇
  1999年   12篇
  1998年   9篇
  1997年   8篇
  1996年   5篇
  1995年   7篇
  1994年   7篇
  1993年   6篇
  1992年   7篇
  1991年   4篇
  1990年   4篇
  1989年   8篇
  1988年   7篇
  1987年   6篇
  1986年   3篇
  1985年   6篇
  1984年   4篇
  1983年   3篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1971年   1篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有1856条查询结果,搜索用时 15 毫秒
11.
Simultaneous measurements of skin potential (SP) and skin resistance (SR) obtained from 20 male and 20 female adult subjects during 2 sessions held 2 to 9 days apart were used in studying (1) the correlation of change measurements and prestimulus level in the two measures, and (2) the amount of correlation between SP and SR using both simple difference and residual change scores in which the regression of poststimulus values on initial level (prestimulus) has been controlled. Correlations within Ss and correlations among Ss showed large individual variability, correlation differences between males and females, and high correlation between SP and SR change scores. Although the law of initial value (LIV) seemed to have little applicability to the measurement of electrodermal responses, the results underscored the need to control for contamination of change measures by initial level regardless of direction.  相似文献   
12.
《Value in health》2022,25(7):1218-1226
ObjectivesThis study aimed to develop the Indian 5-level version EQ-5D (EQ-5D-5L) value set, which is a key input in health technology assessment for resource allocation in healthcare.MethodsA cross-sectional survey using the EuroQol Group’s Valuation Technology was undertaken in a representative sample of 3548 adult respondents, selected from 5 different states of India using a multistage stratified random sampling technique. The participants were interviewed using a computer-assisted personal interviewing technique. This study adopted a novel extended EuroQol Group’s Valuation Technology design that included 18 blocks of 10 composite time trade-off (c-TTO) tasks, comprising 150 unique health states, and 36 blocks of 7 discrete choice experiment (DCE) tasks, comprising 252 DCE pairs. Different models were explored for their predictive performance. Hybrid modeling approach using both c-TTO and DCE data was used to estimate the value set.ResultsA total of 2409 interviews were included in the analysis. The hybrid heteroscedastic model with censoring at ?1 combining c-TTO and DCE data yielded the most consistent results and was used for the generation of the value set. The predicted values for all 3125 health states ranged from ?0.923 to 1. The preference values were most affected by the pain/discomfort dimension.ConclusionsThis is the largest EQ-5D-5L valuation study conducted so far in the world. The Indian EQ-5D-5L value set will promote the effective conduct of health technology assessment studies in India, thereby generating credible evidence for efficient resource use in healthcare.  相似文献   
13.
Intensive care is a specialist area of the hospital with concentration of resources and expertise to look after critically unwell patients. No set criteria exist for admission to intensive care, although patients usually have severe illness associated with physiological dysfunction and actual or impending organ failure. There are multiple scoring systems designed to assess severity of illness, all with significant limitations. The National Early Warning Score 2 (NEWS-2) is a commonly used ‘track and trigger’ system designed to detect and respond to the unwell or deteriorating patient. NEWS-2 is marker of physiological disturbance and high scores correlate with intensive care admission and mortality. Looking at the elective and emergency surgical population, patients at high risk of complications should be admitted to intensive care postoperatively. Increasing age, comorbidities, poor exercise tolerance and major surgical intervention are associated with adverse outcomes. Admission to intensive care often requires difficult time-critical decisions to be made with limited information. Intensive care admission can be the difference between life and death, but there are both physical and psychological harm associated with invasive organ support. The four pillars of medical ethics – autonomy, beneficence, non-maleficence and justice – can be used to guide these decisions.  相似文献   
14.
15.
BackgroundThe surgical treatment of moderate-advanced hallux rigidus is controversial. Cheilectomy is widely used but has recurrence rates of up to 30%. Dorsal oblique metatarsal osteotomy (DOO) has also shown good results, however, there is no study comparing outcomes of the DOO against cheilectomy.MethodsThis was a retrospective propensity score matched study based on registry data from a single tertiary institution. Between 2007 and 2017, all patients who had undergone dorsal cheilectomy or DOO for hallux rigidus were included. Patients with previous foot surgery, revision surgeries, and concomitant surgical procedures were excluded. Clinical outcomes, complication rates, revision rates and patient satisfaction were assessed at 2 years postoperatively.ResultsThere were 44 patients (34 cheilectomy, 10 DOO). After propensity score matching, 17 cheilectomy and all 10 DOO cases were selected for comparison. Patients in both groups had a significant improvement in visual analogue pain scores (VAS) and AOFAS 1st toe scores 2-years post-operatively (P < 0.001) with high levels of post-operative satisfaction (85.1%). Overall there were no statistically significant differences in post-operative scores, improvement in scores, complication rates, revision rates, and levels of patient satisfaction between groups.ConclusionsBoth the DOO and cheilectomy give similarly good outcomes for moderate-advanced hallux rigidus. Further studies are needed to elucidate differences in indications for each procedure.  相似文献   
16.
功能性消化不良患者胃排空功能与症状分型的关系   总被引:4,自引:2,他引:2  
目的 通过 99m Tc植酸钠固体餐检测胃排空 ,了解功能性消化不良 (functional dyspepsia,FD)患者各临床亚型胃运动的情况 .方法  99m Tc植酸钠标记固体餐 ,对 30例 FD患者 (其中溃疡样型 10例 ,动力障碍型 10例 ,非特异型 10例 )及 10名健康对照者进行了核素检测分析 .结果 运动障碍样型及非特异型 FD患者胃半排空时间延迟 (87± 2 8min,89± 2 6 min vs6 1± 9min,P<0 .0 5 ) ,2 h胃排空率明显减少(6 3.0± 11.5 % ,5 7.7± 15 .5 % vs87.0± 10 .3% ,P<0 .0 1) ,而溃疡样型 FD与正常人比无差异 (P>0 .0 5 ) .结论 胃排空延迟在运动障碍样型及非特异型 FD病因中占重要地位 ,FD三个临床亚型之间发病机制既相同又略有不同 ;FD患者中有症状与胃排空之间存在不一致现象 ,所以核素胃排空检查在 FD胃运动功能的判定及指导治疗上有重要意义 .  相似文献   
17.
本文选取我校医学检验系93~96年级170余名本科在校学生作为调查研究对象(第一专业志愿与非第一专业志愿考生比例约为1:2),通过对这两部分学生专业志愿与在校专业思想,学习成绩及政治表现等综合素质方面的关系调查分析,结果表明:专业志愿不是影响学生专业思想、学习成绩和综合素质的主要因素,学生在校专业思想受在校教育和多种因素影响。提示招生录取新生时不应歧视非第一专业志愿考生。  相似文献   
18.
Summary One hundred and fifty patients suffering from Parkinson's disease were analysed for the expression of the motor symptoms during optimum response to levodopa therapy (subscale III of the Unified Parkinson's Disease Rating Scale). Patients were grouped according to age (64, 65–74, 75 years). Disease duration and daily levodopa dosage were similar in the three groups. Pooled residual scores for posture and gait impairment (PGI), tremor (T), rigidity (R) and distal motor impairment (DMI; hand and foot movements) increased with age (Kruskal-Wallis ANOVA). The parkinsonian scores were significantly higher than the scores of 150 age-matched normal controls (Mann-Whitney U test). The differences between the patients' scores and the scores of the age-matched controls increased with age. In spite of a significant increase in the daily levodopa dosage with disease duration (linear regression), PGI aggravated age-dependently, and DMI age-independently with symptom duration (Spearman rank correlation). In contrast, T and R did not increase with disease duration.  相似文献   
19.
Some investigators have expressed concern--especially for psychiatric disorders--that bilineal pedigrees should not be included in linkage studies. This study compares the "informativeness" of bilineal and unilineal families for a homogeneous single-gene disorder. Three approaches were used: (1) simulation studies of three-generation pedigrees, (2) calculation of expected lod scores (ELODs) in nuclear families, and (3) calculation of Fisher's information number I(theta) in nuclear families. The simulation studies in (1) permitted a realistic comparison between bilineal datasets and purely unilineal ones. The calculations in nuclear families in (2) and (3) then made it possible to analyze the sources of information loss in bilineal families. Overall, in datasets of five three-generation pedigrees each, the drop in mean maximum lod score was approximately 50% from purely unilineal datasets to extremely bilineal ones. In less-extreme bilineal datasets, which are closer to most real data than the extremely bilineal ones, the drops in lod score were very small--less than 10% in some, and practically zero in others. The details will vary, depending on size and structure of the pedigree, genetic model, true value of the recombination fraction, and informativeness of the marker. However, these results imply that the information loss due to bilineality is not necessarily very great. The nuclear-family calculations showed that for phase-known matings there is relatively little information loss in bilineal families, but for phase-unknown matings there the loss is much greater. In conclusion, for single-gene disorders with no genetic heterogeneity, whereas bilineal families can be less informative than comparable unilineal families, they are not so much less informative that they should automatically be discarded from linkage datasets. The implications of bilineal pedigrees for linkage studies of heterogeneous disorders are also discussed.  相似文献   
20.
This paper uses the standard error of measurement (SEM) and the standard error of the difference (S(diff)) in relation to data on individuals with amyotrophic lateral sclerosis (ALS) to calculate the minimum change scores required by statistical criteria for each dimension of the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40). Data collected from a longitudinal study was used to evaluate the usefulness of SEM and S(diff) criteria and to compare these criteria with an anchor-based approach in determining meaningful change. Questionnaires were completed on two occasions, 3 months apart. 764 questionnaires were returned. Questionnaires included the ALSAQ-40 and dimension specific transition items. The ALSAQ-40 is a disease specific health-related quality of life instrument for use in studies of patients with ALS or other motor neuron diseases. For all dimensions of the ALSAQ-40 the patterns of SEMs were similar over time. The results suggest that, for example, six points change on a 0-100 transformed scoring of the physical mobility dimension may be considered on distributional grounds a minimum meaningful change. The demonstrated consistency of SEMs for the dimensions of the ALSAQ-40 is empirical evidence of the theoretically claimed advantage of this measure of sample independence, and supports use of this distributional approach to calculate meaningful change.  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