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   657篇
  免费   77篇
耳鼻咽喉   2篇
儿科学   53篇
妇产科学   9篇
基础医学   96篇
口腔科学   9篇
临床医学   70篇
内科学   229篇
皮肤病学   1篇
神经病学   18篇
特种医学   6篇
外科学   89篇
综合类   7篇
预防医学   27篇
眼科学   7篇
药学   34篇
肿瘤学   77篇
  2023年   6篇
  2022年   12篇
  2021年   12篇
  2020年   16篇
  2019年   19篇
  2018年   27篇
  2017年   14篇
  2016年   21篇
  2015年   28篇
  2014年   28篇
  2013年   27篇
  2012年   23篇
  2011年   30篇
  2010年   28篇
  2009年   14篇
  2008年   30篇
  2007年   30篇
  2006年   33篇
  2005年   20篇
  2004年   29篇
  2003年   18篇
  2002年   31篇
  2001年   27篇
  2000年   21篇
  1999年   23篇
  1998年   9篇
  1997年   5篇
  1996年   8篇
  1995年   6篇
  1994年   8篇
  1993年   12篇
  1992年   16篇
  1991年   10篇
  1990年   6篇
  1989年   8篇
  1988年   5篇
  1987年   6篇
  1986年   6篇
  1985年   6篇
  1984年   5篇
  1983年   5篇
  1982年   2篇
  1980年   5篇
  1969年   2篇
  1939年   3篇
  1938年   2篇
  1932年   2篇
  1913年   2篇
  1912年   2篇
  1898年   2篇
排序方式: 共有734条查询结果,搜索用时 15 毫秒
731.

Background

Many patients with myelodysplastic syndromes (MDS) need repeated red blood cell transfusions which entails a risk of immunization and antibody formation. Associations between alloantibodies, autoantibodies and increased transfusion requirements have been reported, but their relationship remains unclear. In this study, we analyzed factors potentially associated with red blood cell alloimmunization, as well as changes in transfusion intensity and post-transfusion hemoglobin increments.

Methods

In a retrospective cohort study, we linked Swedish MDS patients diagnosed between 2003 and 2017 to transfusion and immunohematology data. Potentially associated factors were analyzed using Cox proportional hazards regression. The transfusion rate after detected alloimmunization was analyzed using a fixed effects Poisson regression. Post-transfusion hemoglobin increments before and after alloimmunization were compared using a mixed effects regression.

Results

Alloantibodies following MDS diagnosis were detected in 50 out of 429 patients (11.7%). Female sex and a positive direct antiglobulin test (DAT) were independently associated with alloimmunization, with hazard ratios of 2.02 (95% confidence interval [CI] 1.08–3.78) and 9.72 (95% CI, 5.31–17.74), respectively. The transfusion rate following alloimmunization was increased with an incidence rate ratio of 1.33 (95% CI, 0.98–1.80) and the post-transfusion hemoglobin increment after alloimmunization was 1.40 g/L (95% CI, 0.52–2.28) lower per red blood cell unit (p = .002) compared to before alloimmunization, in multivariable analyses.

Discussion

Alloimmunization against blood group antigens was associated with sex, DAT-positivity, increased transfusion needs, and lower post-transfusion hemoglobin increments. These findings warrant further investigation to evaluate the clinical significance of up-front typing and prophylactic antigen matching in patients with MDS.  相似文献   
732.

Background

Gasless laparoscopy (GL) emerged to overcome the clinical and financial challenges of pneumoperitoneum and is often seen as a viable option for use in resource-limited settings as a means of saving costs and resources. This study aims to systematically review the evidence available on the safety and efficiency of GL compared with conventional laparoscopy (CL) and laparotomy.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, Medline, Embase, Web of Science and Cochrane databases were searched. Variables of interest were determined a priori and Covidence software was used to screen studies for inclusion without demographic preference. The quality of studies was assessed using the Cochrane Risk Assessment tool.

Results

Of the 1080 studies screened, a total of 43 studies were included. Laparoscopic cholecystectomy was by far the most studied intervention in randomised studies. In these, the mean setup time for gasless and CL was 13.14 (95% CI −0.16 to 26.44) and 12.8 (95% CI −10.86 to 36.47) minutes, respectively. The mean duration of surgery for gasless and CL was 89.39 (95% CI 77.44 to 101.34) and 72.59 (95% CI 63.44 to 81.74) minutes, respectively, and the mean length of stay was 4.25 (95% CI 2.02 to 6.48) and 4.04 (95% CI 1.72 to 6.36) days, respectively. Most reported complications were haemorrhage and infection with no assessable statistical difference.

Conclusions

Although GL seems to be a feasible approach for many general surgery interventions, the observed outcomes based on safety and efficiency are not sufficient to recommend GL as an alternative to CL or laparotomy. Larger randomised trials with a low risk of bias are warranted.  相似文献   
733.

Background

Many children with tic disorders outgrow their tics, but little is known about the proportion of individuals who will continue to require specialist services in adulthood and which variables are associated with tic persistence.

Objectives

The aims were to estimate the proportion of individuals first diagnosed with tic disorders in childhood who continued to receive tic disorder diagnoses after age 18 years and to identify risk factors for persistence.

Methods

In this Swedish nationwide cohort study including 3761 individuals diagnosed with tic disorders in childhood, we calculated the proportion of individuals whose diagnoses persisted into adulthood. Minimally adjusted logistic regression models examined the associations between sociodemographic, clinical, and family variables and tic disorder persistence. A multivariable model was then fitted, including only variables that were statistically significant in the minimally adjusted models.

Results

Seven hundred and fifty-four (20%) children with tic disorders received a diagnosis of a chronic tic disorder in adulthood. Psychiatric comorbidity in childhood (particularly attention-deficit hyperactivity disorder, obsessive-compulsive disorder, pervasive developmental disorders, and anxiety disorders) and psychiatric disorders in first-degree relatives (particularly tic and anxiety disorders) were the strongest risk factors for persistence. We did not observe statistically significant associations with socioeconomic variables, perinatal complications, comorbid autoimmune diseases, or family history of autoimmune diseases. All statistically significant variables combined explained approximately 10% of the variance in tic disorder persistence (P < 0.0001).

Conclusions

Childhood psychiatric comorbidities and family history of psychiatric disorders were the strongest risk factors associated with tic disorder persistence into adulthood. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.  相似文献   
734.

Background and Aims

Growing evidence supports an association between fatty liver disease (FLD) and cardiac dysfunction and remodelling, leading to cardiovascular disease and heart failure. Herein, we investigated the independent contribution of FLD to cardiac dysfunction and remodelling in participants from the UK Biobank with cardiac magnetic resonance (CMR) data available.

Methods

A total of 18 848 Europeans without chronic viral hepatitis and valvular heart diseases, with liver magnetic resonance imaging and CMR data were included in the analyses. Clinical, laboratory and imaging data were collected using standardized procedures. Multivariable regression models were used to test the association between FLD and CMR endpoints, after adjusting for several cardiometabolic risk factors. Linear regression models with regularization (Least Absolute Shrinkage and Selection Operator [LASSO], Ridge and Elastic Net) were used to generate predictive models for heart-related endpoints.

Results

FLD was independently associated with higher average heart rate, higher cardiac remodelling (higher eccentricity ratio and lower remodelling index), lower left and right ventricular volumes (end-systolic, end-diastolic and stroke volumes) as well as with lower left and right atrial maximal volumes (p < 0.001). FLD was the strongest positive predictor for average heart rate, followed by age, hypertension and type 2 diabetes. Male sex was the strongest positive predictor for eccentricity ratio followed by FLD, age, hypertension and BMI. For LV volumes, FLD was the strongest negative predictor along with age.

Conclusions

FLD is an independent predictor of higher heart rate and early cardiac remodelling associated with reduced ventricular volumes.  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