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   5189篇
  免费   310篇
  国内免费   51篇
耳鼻咽喉   106篇
儿科学   165篇
妇产科学   53篇
基础医学   739篇
口腔科学   79篇
临床医学   544篇
内科学   1061篇
皮肤病学   109篇
神经病学   425篇
特种医学   460篇
外国民族医学   1篇
外科学   725篇
综合类   63篇
一般理论   2篇
预防医学   320篇
眼科学   40篇
药学   404篇
中国医学   1篇
肿瘤学   253篇
  2021年   49篇
  2020年   47篇
  2019年   65篇
  2018年   77篇
  2017年   76篇
  2016年   84篇
  2015年   84篇
  2014年   112篇
  2013年   158篇
  2012年   213篇
  2011年   240篇
  2010年   174篇
  2009年   141篇
  2008年   217篇
  2007年   232篇
  2006年   257篇
  2005年   221篇
  2004年   223篇
  2003年   163篇
  2002年   205篇
  2001年   184篇
  2000年   184篇
  1999年   129篇
  1998年   84篇
  1997年   73篇
  1996年   76篇
  1995年   73篇
  1994年   66篇
  1993年   50篇
  1992年   93篇
  1991年   100篇
  1990年   97篇
  1989年   114篇
  1988年   100篇
  1987年   72篇
  1986年   69篇
  1985年   74篇
  1984年   51篇
  1983年   37篇
  1981年   41篇
  1980年   32篇
  1979年   39篇
  1978年   37篇
  1977年   30篇
  1975年   36篇
  1974年   30篇
  1973年   28篇
  1972年   28篇
  1971年   27篇
  1970年   32篇
排序方式: 共有5550条查询结果,搜索用时 15 毫秒
991.

Objectives

The aim of the study was to determine whether behaviourally informed short message service (SMS) primer and reminder messages could increase the return rate of HIV self‐sampling kits ordered online.

Methods

The study was a 2 × 2 factorial design randomized control trial. A total of 9585 individuals who ordered a self‐sampling kit from www.freetesting.hiv different SMS combinations: 1) standard reminders sent days 3 and 7 after dispatch (control); 2) primer sent 1 day after dispatch plus standard reminders; 3) behavioural insights (BI) reminders (no primer); or 4) primer plus BI reminders. The analysis was restricted to individuals who received all messages (n = 8999). We used logistic regression to investigate independent effects of the primer and BI reminders and their interaction. We explored the impact of sociodemographic characteristics on kit return as a secondary analysis.

Results

Those who received the primer and BI reminders had a return rate 4% higher than that of those who received the standard messages. We found strong evidence of a positive effect of the BI reminders (odds ratio 1.13; 95% confidence interval 1.04–1.23; P = 0.003) but no evidence for an effect of the primer, or for an interaction between the two interventions. Odds of kit return increased with age, with those aged ≥ 65 years being almost 2.5 times more likely to return the kit than those aged 25–34 years. Men who have sex with men were 1.5–4.5 times more likely to return the kit compared with other sexual behaviour and gender identity groups. Non‐African black clients were 25% less likely to return the kit compared with other ethnicities.

Conclusions

Adding BI to reminder messages was successful in improving return rates at no additional cost.  相似文献   
992.
Purpose

Research shows that the prevalence of psychiatric problems is higher in ethnic minority youth compared to native youth. This school-based screening study of early adolescents’ mental health in the Netherlands examined differences in prevalence of psychotic experiences in ethnic minority youth compared to their Dutch peers. Moreover, we investigated the association between psychotic experiences, ethnic identity, and perceived discrimination.

Methods

A cohort of 1194 ethnic majority and minority adolescents (mean age 13.72, SD 0.63) filled-out questionnaires on psychotic experiences (including delusional and hallucinatory experiences), perceived group and personal discrimination, and ethnic identity.

Results

Apart from lower levels of hallucinatory experiences in Turkish–Dutch adolescents, prevalence of psychotic experiences did not differ between ethnic minority and majority adolescents. Perceived personal discrimination was associated with the presence of psychotic experiences (including delusional and hallucinatory experiences) (OR 2.30, 95% CI 1.22–4.34). This association was stronger for delusional experiences (OR 2.94, 95% CI 1.43–6.06) than for hallucinatory experiences (OR 1.65, 95% CI 0.73–3.72). No significant associations were found between perceived group discrimination and psychotic experiences. A weak ethnic identity was associated with higher risk for reporting psychotic experiences (OR 2.04, 95% CI 1.14–3.66), particularly hallucinatory experiences (OR 3.15, 95% CI 1.54–6.44). When looking at specific ethnic identity categories, marginalization, compared to separation, was associated with a threefold risk for reporting psychotic experiences (OR 3.26, 95% CI 1.33–8.03). Both marginalisation (OR 3.17, 95% CI 1.04–9.63) and assimilation (OR 3.25, 95% CI 1.30–8.13) were associated with a higher risk for hallucinatory experiences.

Conclusions

These results underline the protective effect of ethnic identity against mental health problems. Future research should focus on interventions that focus on strengthen social identity.

  相似文献   
993.
994.

Background

The Yale New Haven Readmission Risk Score (YNHRRS) for pneumonia is a clinical prediction tool developed to assess risk for 30-day readmission. This tool was validated in a cohort of Medicare patients; generalizability to a broader patient population has not been evaluated. In addition, it lacks indicators of functional status or social support, which have been shown in other studies to be predictors of readmission. The objective of this study was to evaluate the generalizability of the YNHRRS for pneumonia in a general population of hospitalized patients, and assess the impact of incorporating measures of functional status and social support on its predictive value.

Methods

This retrospective chart review comprised all patients admitted to a 563-bed academic medical center with a primary diagnosis of pneumonia between March 2014 and March 2015. Abstraction of clinical variables allowed calculation of the YNHRRS and additional indicators of functional status and social support. The primary outcome was 30-day readmission rate. We created a logistic regression model to predict readmission using the YNHRRS, functional status, and social support as covariates.

Results

Among 270 discharges with pneumonia, the observed readmission rate was 23%. The YNHRRS was a significant predictor of readmission in our multivariate model, with an odds ratio of 2.20 (95% confidence interval, 1.29-3.73) for each 10% increase in calculated risk. Indicators of functional status and social support were not significant predictors of readmission.

Conclusions

The YNHRRS can be applied to an unselected population as a tool to predict patients with pneumonia at risk for readmission.  相似文献   
995.
从业医师时常报道下肢溃疡病人坚持治疗非常困难,尽管对治疗难度有多大了解较少。本文介绍了从业医师如何提供关于下肢溃疡病人有效护理,讨论了压迫疗法的选择,如何影响一致性。评估和一致性从业者常发现处理如下问题较困难:病人不接受治疗方案、病情治疗困难和病人缺乏进步思想。促进一致性需要从业医师去养成一个与患者敏锐的医患关系,认识患者的问题。选择合适的疗法一篇关于压迫疗法综述的结论是:①在压迫治疗方面有较高的压力(35~45mmHg)优于低的压力(15~25 mmHg);②具有弹性和无弹性的多层绷带方法,优于单层方法,对特定的病人用最佳…  相似文献   
996.
Diffusion modeling of dermal absorption relies in large part on high quality input data. Currently, estimates of corneocyte-phase partitioning are based on an analysis of a dataset of limited size and diversity. Therefore, we have updated and broadened the analysis. For this purpose, binding coefficients to different keratins, namely, bovine hoof and horn, human delipidized callus, human delipidized stratum corneum (SC), human nail, human hair, and sheep wool were collected from the literature. In addition, binding coefficients to hoof/horn and delipidized SC were measured for eight hydrophilic compounds including three ionizable compounds that were measured at different pH values. Important results are: (i) only hoof/horn, callus, and delipidized SC are suitable keratins for estimating corneocyte protein binding; (ii) binding coefficients to hoof/horn, callus, and delipidized SC can be predicted from the octanol-water partition coefficients log K(o/w) confirming the analysis of the limited dataset; (iii) binding of ionizable compounds can be predicted by correcting log K(o/w) for pH; (iv) the correlation derived for the extended database is steeper than the relationship derived for the limited dataset. This has consequences for the estimates of SC partition and diffusion coefficients for diffusion modeling of dermal absorption. .  相似文献   
997.
998.
Objective Although Parkinson??s disease is a common disorder in the elderly, there have been very few studies of the role of the pharmaceutical care services in detecting and reducing problems associated with drug treatment in community settings. The aim of this study was therefore to investigate the type and frequency of drug-related problems identified in patients with Parkinson??s disease by community pharmacists over an 8-month period and to assess the pharmaceutical service interventions, the type and frequency of intervention outcomes and the clinical benefits for the patients. Setting Community pharmacies in Germany. Method Thirty-two community pharmacists recruited 113 outpatients with idiopathic Parkinson??s disease who were receiving anti-Parkinsonian medication. Main outcome measure Drug-related problems. Results A total of 331 drug-related problems were identified by the pharmacists. Patients not receiving a medication, despite the presence of an indication or symptom, accounted for the highest proportion of drug-related problems (26.3%). The pharmacists proposed a total of 474 interventions, the most common of which was giving the patient treatment advice (19.6%). Intervention outcomes were recorded for 215 of the 331 drug-related problems, for which there were 553 individual outcome results. Adjustments of the drug regimen accounted for the highest percentage of individual results (43.6%). Conclusion Structured pharmaceutical care processes by community pharmacists have the potential to make a valuable contribution to health care and enhance the health outcomes of patients with Parkinson??s disease.  相似文献   
999.
1000.
(Headache 2011;51:533‐543) Objective.— To evaluate the efficacy and tolerability of telcagepant when co‐administered with ibuprofen or acetaminophen for the acute treatment of migraine. Background.— Telcagepant is an oral calcitonin gene‐related peptide receptor antagonist which is being evaluated for the acute treatment of migraine. Combining telcagepant with analgesics that have a different mechanism of action could produce greater efficacy. Methods.— Randomized, double‐blind, placebo‐controlled study. Patients were randomized to treat a moderate or severe migraine headache with either telcagepant 280 mg + ibuprofen 400 mg (N = 171), telcagepant 280 mg + acetaminophen 1000 mg (N = 171), telcagepant 280 mg (N = 170), or placebo (N = 171). The primary efficacy endpoint was 2‐hour pain freedom. The study had approximately 88% power to detect an additive effect of at least 15 percentage points (telcagepant combination vs telcagepant monotherapy) and 48% power to detect an additive effect of at least 10 percentage points. Safety and tolerability were assessed by adverse events and laboratory tests. Results.— The percentages of patients with 2‐hour pain freedom were greater in each active treatment group compared to placebo (P < .001): telcagepant + ibuprofen = 35.2%, telcagepant + acetaminophen = 38.3%, telcagepant = 31.2%, placebo = 10.9%. No significant differences were seen for either of the combination groups vs telcagepant monotherapy, but both were numerically larger than telcagepant monotherapy. All the active treatments were generally well tolerated. The percentage of patients reporting any adverse event within 48 hours was higher in the active treatment groups than placebo: telcagepant + ibuprofen = 30.3%, telcagepant + acetaminophen = 31.6%, telcagepant = 24.8%, placebo = 18.2%. The most common adverse events reported by ≥4 patients in one or more of the treatment groups that included telcagepant were fatigue, nausea, dizziness, somnolence, dry mouth, and tremor. Conclusions.— The combination of telcagepant 280 mg with either ibuprofen 400 mg or acetaminophen 1000 mg did not show a statistically significant difference from telcagepant alone. Numerically greater treatment effects in the combination treatment groups over the telcagepant 280 mg monotherapy suggest that telcagepant combination treatments may merit further evaluation in studies powered to detect smaller additive benefits. (Clinicaltrials.gov; NCT00758836).  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