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   4884篇
  免费   229篇
  国内免费   18篇
耳鼻咽喉   14篇
儿科学   53篇
妇产科学   65篇
基础医学   517篇
口腔科学   84篇
临床医学   590篇
内科学   1497篇
皮肤病学   53篇
神经病学   577篇
特种医学   101篇
外科学   424篇
综合类   13篇
预防医学   460篇
眼科学   36篇
药学   362篇
中国医学   3篇
肿瘤学   282篇
  2024年   5篇
  2023年   25篇
  2022年   85篇
  2021年   179篇
  2020年   92篇
  2019年   157篇
  2018年   198篇
  2017年   118篇
  2016年   118篇
  2015年   126篇
  2014年   220篇
  2013年   261篇
  2012年   414篇
  2011年   431篇
  2010年   262篇
  2009年   211篇
  2008年   324篇
  2007年   301篇
  2006年   316篇
  2005年   286篇
  2004年   260篇
  2003年   232篇
  2002年   204篇
  2001年   29篇
  2000年   22篇
  1999年   30篇
  1998年   39篇
  1997年   33篇
  1996年   23篇
  1995年   27篇
  1994年   18篇
  1993年   7篇
  1992年   7篇
  1991年   9篇
  1990年   12篇
  1989年   7篇
  1988年   8篇
  1987年   4篇
  1986年   5篇
  1985年   7篇
  1982年   2篇
  1981年   4篇
  1979年   1篇
  1971年   1篇
  1964年   1篇
  1962年   2篇
  1961年   1篇
  1960年   3篇
  1933年   1篇
  1929年   1篇
排序方式: 共有5131条查询结果,搜索用时 0 毫秒
71.

Background

The EQ-5D has been frequently used in national health surveys. This study is a head-to-head comparison to assess how expanding the number of levels from three (EQ-5D-3L) to five in the new EQ-5D-5L version has improved its distribution, discriminatory power, and validity in the general population.

Methods

A representative sample (N?=?7554) from the Catalan Health Interview Survey 2011–2012, aged ≥18, answered both EQ-5D versions, and we evaluated the response redistribution and inconsistencies between them. To assess validity of this redistribution, we calculated the mean of the Visual Analogue Scale (VAS), which measures perceived health. The discriminatory power was examined with Shannon Indices, calculated for each dimension separately. Spanish preference value sets were applied to obtain utility indices, examining their distribution with statistics of central tendency and dispersion. We estimated the proportion of individuals reporting the best health state in EQ-5D-5L and EQ-5D-3L within groups of specific chronic conditions and their VAS mean.

Results

A very small reduction in the percentage of individuals with the best health state was observed, from 61.8% in EQ-5D-3L to 60.8% in EQ-5D-5L. In contrast, a large proportion of individuals reporting extreme problems in the 3 L version moved to severe problems (level 4) in the 5 L version, particularly for pain/discomfort (75.5%) and anxiety/depression (66.4%). The average proportion of inconsistencies was 0.9%. The pattern of the perceived health VAS mean confirmed the hypothesis established a priori, supporting the validity of the observed redistribution. Shannon index showed that absolute informativity was higher in the 5 L version for all dimensions. The means (SD) of the Spanish EQ-5D-3L and EQ-5D-5L indices were 0.87 (0.25) and 0.89 (0.22). The proportion of individuals with the best health state within each specific chronic condition was very similar, regardless of the EQ-5D version (≤?30% in half of the 28 chronic conditions).

Conclusion

Although the proportion of individuals with the best possible health state is still very high, our findings support that the increase of levels provided by the EQ-5D-5L contributed to the validity and discriminatory power of this new version to measure health in general population, as in the national health surveys.
  相似文献   
72.
OBJECTIVE: To assess whether combination antibiotic therapy improves outcome of severe community-acquired pneumonia in the subset of patients with shock. DESIGN: Secondary analysis of a prospective observational, cohort study. SETTING: Thirty-three intensive care units (ICUs) in Spain. PATIENTS: Patients were 529 adults with community-acquired pneumonia requiring ICU admission. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Two hundred and seventy (51%) patients required vasoactive drugs and were categorized as having shock. The effects of combination antibiotic therapy and monotherapy on survival were compared using univariate analysis and a Cox regression model. The adjusted 28-day in-ICU mortality was similar (p = .99) for combination antibiotic therapy and monotherapy in the absence of shock. However, in patients with shock, combination antibiotic therapy was associated with significantly higher adjusted 28-day in-ICU survival (hazard ratio, 1.69; 95% confidence interval, 1.09-2.60; p = .01) in a Cox hazard regression model. Even when monotherapy was appropriate, it achieved a lower 28-day in-ICU survival than an adequate antibiotic combination (hazard ratio, 1.64; 95% confidence interval, 1.01-2.64). CONCLUSIONS: Combination antibiotic therapy does not seem to increase ICU survival in all patients with severe community-acquired pneumonia. However, in the subset of patients with shock, combination antibiotic therapy improves survival rates.  相似文献   
73.
Consistent induction of donor‐specific unresponsiveness in the absence of continuous immunosuppressive therapy and toxic effects remains a difficult task in clinical organ transplantation. Transplant immunologists have developed numerous experimental treatments that target antigen‐presentation (signal 1), costimulation (signal 2), and cytokine production (signal 3) to establish transplantation tolerance. While promising results have been obtained using therapeutic approaches that predominantly target the adaptive immune response, the long‐term graft survival rates remain suboptimal. This suggests the existence of unrecognized allograft rejection mechanisms that contribute to organ failure. We postulate that trained immunity stimulatory pathways are critical to the immune response that mediates graft loss. Trained immunity is a recently discovered functional program of the innate immune system, which is characterized by nonpermanent epigenetic and metabolic reprogramming of macrophages. Since trained macrophages upregulate costimulatory molecules (signal 2) and produce pro‐inflammatory cytokines (signal 3), they contribute to potent graft reactive immune responses and organ transplant rejection. In this review, we summarize the detrimental effects of trained immunity in the context of organ transplantation and describe pathways that induce macrophage training associated with graft rejection.  相似文献   
74.
75.
Objective: This study explored the clinical features of physicians and nurses with dual diagnosis.

 Methods: We conducted a retrospective review of 150 medical records of physicians (n = 120) and nurses (n = 30) admitted from February 2008 to February 2011 to the Barcelona Psychiatric Inpatient Unit for Health Professionals. Routine intake included the Spanish version of the Psychiatric Research Interview for Substance and Mental Disorders (PRISM-IV) and a clinical interview.

 Results: The mean age of participants was 48.59 (SD = 8.9) years and 57.3% were male. Patients experienced substance dependence with alcohol (n = 112, 74.7%), sedatives (n = 59, 39.3%), cocaine (n = 24, 16%), other stimulants (n = 15, 10%), and opiates other than heroin (n = 16, 10.7%). About 41% (n = 61) also met criteria for a mental health disorder, mainly major depressive disorder (n = 42, 28%), while 8% (n = 12) had attention deficit hyperactivity disorder. A high proportion of physicians (n = 95, 79.2%) and nurses (n = 25, 83.3%) had nicotine dependence. The most common comorbidity was alcohol dependence and major depressive disorder. No differences were found between groups in the prevalence of substance use disorders, mental health disorders, and dual diagnosis.

 Conclusions: Dual diagnosis is a common condition among inpatient physicians and nurses with substance use disorders and its clinical presentation may be similar in both groups.  相似文献   

76.

Purpose

To assess whether the correction dose recommended by the summary of product characteristics was adequate and to confirm the adequacy of the recommended conversion dosing strategies from shorter-acting erythropoiesis-stimulating agents (ESAs) to continuous erythropoietin receptor activator (C.E.R.A) in anaemic chronic kidney disease (CKD) patients in the clinical setting.

Methods

This was a 12-month, multicenter, prospective, observational study in anaemic CKD patients on haemodialysis and not on dialysis receiving C.E.R.A (at least one dose).

Results

A total of 227 patients were included (not on dialysis; n = 142; haemodialysis: n = 85). The present analysis was conducted on ESA-naïve patients (not on dialysis: n = 31) and patients switched from other ESA (not on dialysis: n = 63; haemodialysis: n = 57). Both on and not on dialysis patients switched from other ESA received lower starting C.E.R.A doses than those recommended, and remained stable during the 12-month period. The higher the previous ESA dose was, the more beneficial the C.E.R.A dose conversion factor was. The proportion of patients with stable haemoglobin within the target range (11–13 g/dL) did not vary during the 12-month period both in nondialysis CKD patients and in those undergoing dialysis [baseline: 42 (66.7 %) and 34 (59.6 %); month 6: 21 (55.3 %) and 26 (50.0 %); month 12: 20 (64.5 %) and 25 (69.4 %), respectively]. In naïve patients, the mean weight-adjusted C.E.R.A dose during the study (1.19 ± 0.49 µg/kg/month) was similar to the recommended one. C.E.R.A was well tolerated.

Conclusions

Conversion from shorter-acting ESAs to C.E.R.A doses lower than those recommended can efficiently maintain target haemoglobin levels both in nondialysis and haemodialysis CKD patients, particularly when switching from higher ESA doses. A monthly C.E.R.A dose of 1.2 µg/Kg seems adequate for anaemia correction.  相似文献   
77.
The objective of this retrospective study was to evaluate our results with one-stage revision using cementless femoral stem for infected hip arthroplasties. Twenty-four patients were included in the study. The acetabular component was cemented in 9 cases. In 2 patients a structured bone allograft was necessary to fill an acetabular defect. After a mean follow-up of 44.6 months, 23 patients showed no signs of infection (95.8%), the mean functional response according to the Merle d’Aubigné scale was 13.8 and the mean Harris Hip Score was 65.4. One-stage revision hip arthroplasty using cementless femoral stem was associated with a high success rate.  相似文献   
78.
The preparation of well-defined d-xylo and d-ribo glycosides represents a synthetic challenge due to the limited configurational availability of starting materials and the laborious synthesis of homogeneous 2-deoxy-β-glycosidic linkages, in particular that of the sugar-steroid motif, which represents the “stereoselective determining step” of the overall synthesis. Herein we describe the use of 2-deoxy-2-iodo-glycopyranosyl sulfoxides accessible from widely available d-xylose and d-ribose monosaccharides as privileged glycosyl donors that permit activation at very low temperature. This ensures a precise kinetic control for a complete 1,2-trans stereoselective glycosylation of particularly challenging steroidal aglycones.

Highly stereoselective synthesis of challenging steroidal 2-deoxy-β-glycosides with d-xylo and d-ribo configurations enabled by low temperature activation of 2-deoxy-2-iodoglycopyranosyl sulfoxides.  相似文献   
79.
80.
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