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   1167篇
  免费   102篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   56篇
妇产科学   11篇
基础医学   108篇
口腔科学   30篇
临床医学   103篇
内科学   375篇
皮肤病学   19篇
神经病学   63篇
特种医学   10篇
外科学   104篇
综合类   22篇
一般理论   1篇
预防医学   38篇
眼科学   22篇
药学   88篇
中国医学   4篇
肿瘤学   211篇
  2024年   1篇
  2023年   13篇
  2022年   29篇
  2021年   56篇
  2020年   34篇
  2019年   36篇
  2018年   46篇
  2017年   31篇
  2016年   44篇
  2015年   39篇
  2014年   55篇
  2013年   53篇
  2012年   101篇
  2011年   86篇
  2010年   52篇
  2009年   50篇
  2008年   79篇
  2007年   74篇
  2006年   64篇
  2005年   61篇
  2004年   52篇
  2003年   55篇
  2002年   35篇
  2001年   26篇
  2000年   14篇
  1999年   22篇
  1998年   5篇
  1997年   4篇
  1996年   7篇
  1995年   3篇
  1994年   4篇
  1993年   2篇
  1992年   9篇
  1991年   3篇
  1990年   1篇
  1989年   6篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   3篇
  1981年   1篇
  1979年   5篇
  1976年   2篇
  1975年   1篇
  1966年   1篇
排序方式: 共有1272条查询结果,搜索用时 15 毫秒
991.
This paper discusses some of the key aspects of human factors in anaesthesia for the improvement of patient safety. Medical errors have emerged as a serious issue in healthcare delivery. There has been new interest in human factors as a means of reducing these errors. Human factors are important contributors to critical incidents and crises in anaesthesia. It has been shown that the prevalence of human factors in anaesthesia can be as high as 83%. Cognitive thinking process and biases involved are important in understanding human factors. Errors of cognition linked with human factors lead to anaesthetic errors and crisis. Multiple errors in the cognitive thinking process, known as "Cognitive dispositions to respond" have been identified leading to errors. These errors classified into latent or active can be easily identified in the clinical vignettes of serious medical errors. Application of the knowledge on human factors and use of cognitive de-biasing strategies can avoid human errors. These strategies could involve use of checklists, strategies to cope with stress and fatigue and the use of standard operating procedures. A safety culture and health care model designed to promote patient safety can compliment this further. Incorporation of these strategies strengthens the defence layers against the "Swiss Cheese" models, which exist in the health care industry.  相似文献   
992.
We analyzed the outcomes following initial relapse or refractory disease in systemic light chain amyloidosis (AL) and the impact of type of therapy employed.A total of 1327 patients with AL seen at Mayo Clinic within 90 days of diagnosis, between 2006 and 2015, were reviewed. The study included 366 patients experiencing a documented hematological or organ relapse or refractory disease requiring start of second line therapy. Overall survival (OS) and time to next treatment (TTNT) were calculated from start of second line treatment.The median time to require second line treatment was 16.2 months (1‐93) from the start of first line therapy. At relapse, patients received proteasome inhibitors (PI; 45.1%), immunomodulators (IMiD; 22.7%), alkylators (9%), PI and IMiD combination (4.1%), autologous transplant (3.8%), steroids and other therapies (4.9%). Among these, 124 (33.9%) required change or reinstitution of therapy. The median time to require third line treatment was 31 months (95% CI; 24, 40.5) and the median overall survival (OS) was 38.8 months (95% CI; 29.6, 52.6) from the start of second line treatment. Retreatment with same therapy at relapse significantly reduced TTNT (22 m vs 32.3 m; P = .01) as compared to different therapy; but did not have any impact OS (30.8 m vs 51.1 m; P = .5). In conclusion, this study provides important information about outcomes of patients with AL who require second line treatment for relapsed/refractory disease . Treatment with a different therapy at relapse improves time to next therapy but does not impact OS.  相似文献   
993.
Objectives: To identify the prevalence and correlates of bipolar I patients with a lifetime history of suicide attempt.

Materials and methods: Bipolar I disorder was diagnosed in 150 patients as per DSM-IV-TR criteria. Their lifetime suicide risk was assessed using the Columbia Suicide Severity Rating Scale. NIMH retrospective Life Chart Methodology was used to chart the illness course. Medication Adherence Rating Scale (MARS) and Pittsburgh Sleep Quality Index (PSQI) were used to assess the recent adherence and subjective sleep quality, respectively. The suicide attempters were compared with non-attempters on individual variables.

Results: Around 23% had a positive lifetime history of suicide attempt. They were predominantly female, had an index (first ever) episode of depression, spent more proportion of time being ill, especially in depressive or mixed episode phase. Comorbid substance use disorder along with suicidal attempts was seen only in males. Suicide attempters displayed poor medication adherence attitudes for medications taken during the past week and reported impaired sleep quality for the previous month.

Conclusions: A positive history of lifetime suicide attempt was significantly associated with a worse course of bipolar I disorder. Effective treatment of depressive episodes, addressing non-adherence, substance use and sleep problems can reduce the suicide risk in such patients. Retrospective design of the study and recall bias are some of the limitations.  相似文献   

994.
A single monoclonal protein typically characterizes monoclonal gammopathies, but a small proportion may have more than one M protein identifiable. In the setting of symptomatic multiple myeloma (MM), the development of a new monoclonal protein following therapy is associated with better outcomes. As for the precursor conditions, monoclonal gammopathy undetermined significance (MGUS) and smoldering multiple myeloma (SMM), there is limited information on the impact of a second monoclonal protein on the disease course, including progression and response to treatment. The outcomes of patients with MGUS and SMM with more than one monoclonal protein, after identifying 539 patients with biclonal proteins on electrophoresis and/or immunofixation, were reported. About 22 of 393 patients with MGUS/biclonal gammopathy of undetermined significance (BGUS) progressed to SMM (6), MM (11), AL (3), or WM (2), and 5 of 16 patients with biclonal SMM progressed to MM. The rate of progression for BGUS was approximately 1% per year, which is similar to MGUS with one monoclonal protein. The median estimated time of progression of biclonal SMM was 2.6 years; similar to monoclonal SMM. For patients with biclonal MM, both M spikes responded to treatment and, upon relapse, the original dominant M protein remained dominant as the disease progressed. In conclusion, the presence of a second monoclonal protein does not appear to affect the progression of precursor states and suggests multiple monoclonal proteins do not clinically impact one another in the course of the disease. Am. J. Hematol. 91:473–475, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   
995.

Background

Hereditary cancers account for 5–10% of cancers. In this study BRCA1, BRCA2 and CHEK2*(1100delC) were analyzed for mutations in 91 HBOC/HBC/HOC families and early onset breast and early onset ovarian cancer cases.

Methods

PCR-DHPLC was used for mutation screening followed by DNA sequencing for identification and confirmation of mutations. Kaplan-Meier survival probabilities were computed for five-year survival data on Breast and Ovarian cancer cases separately, and differences were tested using the Log-rank test.

Results

Fifteen (16%) pathogenic mutations (12 in BRCA1 and 3 in BRCA2), of which six were novel BRCA1 mutations were identified. None of the cases showed CHEK2*1100delC mutation. Many reported polymorphisms in the exonic and intronic regions of BRCA1 and BRCA2 were also seen. The mutation status and the polymorphisms were analyzed for association with the clinico-pathological features like age, stage, grade, histology, disease status, survival (overall and disease free) and with prognostic molecular markers (ER, PR, c-erbB2 and p53).

Conclusion

The stage of the disease at diagnosis was the only statistically significant (p < 0.0035) prognostic parameter. The mutation frequency and the polymorphisms were similar to reports on other ethnic populations. The lack of association between the clinico-pathological variables, mutation status and the disease status is likely to be due to the small numbers.  相似文献   
996.
BackgroundThere are limited data on the outcomes of acute myocardial infarction–cardiogenic shock (AMI-CS) in patients with concomitant cancer.MethodsA retrospective cohort of adult AMI-CS admissions was identified from the National Inpatient Sample (2000–2017) and stratified by active cancer, historical cancer, and no cancer. Outcomes of interest included in-hospital mortality, use of coronary angiography, use of percutaneous coronary intervention, do-not-resuscitate status, palliative care use, hospitalization costs, and hospital length of stay.ResultsOf the 557,974 AMI-CS admissions during this 18-year period, active and historical cancers were noted in 14,826 (2.6%) and 27,073 (4.8%), respectively. From 2000 to 2017, there was a decline in active cancers (adjusted odds ratio, 0.70 [95% CI, 0.63–0.79]; P < .001) and an increase in historical cancer (adjusted odds ratio, 2.06 [95% CI, 1.89–2.25]; P < .001). Compared with patients with no cancer, patients with active and historical cancer received less-frequent coronary angiography (57%, 67%, and 70%, respectively) and percutaneous coronary intervention (40%, 47%, and 49%%, respectively) and had higher do-not-resuscitate status (13%, 15%, 7%%, respectively) and palliative care use (12%, 10%, 6%%, respectively) (P < .001). Compared with those without cancer, higher in-hospital mortality was found in admissions with active cancer (45.9% vs 37.0%; adjusted odds ratio, 1.29 [95% CI, 1.24–1.34]; P < .001) but not historical cancer (40.1% vs 37.0%; adjusted odds ratio, 1.01 [95% CI, 0.98–1.04]; P = .39). AMI-CS admissions with cancer had a shorter hospitalization duration and lower costs (all P < .001).ConclusionConcomitant cancer was associated with less use of guideline-directed procedures. Active, but not historical, cancer was associated with higher mortality in patients with AMI-CS.  相似文献   
997.
Aim:To assess the expression of PGC1-α and PGC1-β in Oral squamous cell carcinoma in the presence and absence of hyperglycemia. Materials and Methods:Fresh tissue samples were collected from 14 well differentiated OSCC patients with hyperglycemia, 14 OSCC patients without hyperglycemia and 14 healthy controls and subjected to quantitative real-time PCR to assess expression of PGC1-α and PGC1-β. The relative gene expression of PGC1-α and PGC1-β was calculated using the double delta Ct method. A two-fold difference was defined as over or under- expression. To further evaluate clinicopathological association, Independent t-test was employed. Results:The expression of both PGC1-α and PGC1-β were increased in OSCC patients when compared to healthy controls and similar findings were observed on calculating the fold change healthy controls and OSCC study groups. On assessing the expression of target genes within study groups, they did not present with significant fold change and the hyperglycemic status of the individual did not contribute to the expression of the target genes as P value obtained for PGC1-α and PGC1-β were >0.05. Conclusion:The hyperglycemic status of the individual does not influence the expression of PGC1-α and PGC1-β in OSCC tissues and the cause for over-expression of the study targets in OSCC tissues must be further evaluated to assess their potential as possible candidates for targeted therapy in OSCC patients.Key Words: Diabetes mellitus, Hyperglycemia, Oral cancer, PGC1-α- PGC1-β  相似文献   
998.
BACKGROUNDWe performed a meta-analysis on observational studies since randomized control trials are not available. We studied intracoronary brachytherapy (ICBT) and recurrent drug eluting stent in-stent restenosis (DES-ISR) to evaluate the procedural success, target lesion revascularization (TLR), incidence of myocardial infarction (MI) and all-cause mortality at 2 years follow-up.AIMTo perform meta-analysis for patients undergoing ICBT for recurrent DES-ISR.METHODSWe performed a systematic search of the PubMed/MEDLINE, Cochrane and DARE databases to identify relevant articles. Studies were excluded if intra-coronary brachytherapy was used as a treatment modality for initial ISR and studies with bare metal stents. We used a random-effect model with DerSimonian & Laird method to calculate summary estimates. Heterogeneity was assessed using I2 statistics.RESULTSA total of 6 observational studies were included in the final analysis. Procedural angiographic success following intra-coronary brachytherapy was 99.8%. Incidence of MI at 1-year was 2% and 4.1% at 2-years, respectively. The incidence of TLR 14.1% at 1-year and 22.7% at 2-years, respectively. All-cause mortality at 1- and 2-year follow-up was 3% and 7.5%, respectively.CONCLUSIONGiven the observational nature of the studies included in the analysis, heterogeneity was significantly higher for outcomes. While there are no randomized controlled trials or definitive guidelines available for recurrent ISR associated with DES, this analysis suggests that brachytherapy might be the alternative approach for recurrent DES-ISR. Randomized controlled trials are required to confirm results from this study.  相似文献   
999.
1000.
Coronavirus disease 2019 (COVID-19) pneumonia outbreak started in December 2019. On March 12, 2020, the World Health Organization (WHO) declared that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitutes a pandemic, and as of May 2021, SARS-CoV-2 has infected over 167.3 million patients, including 3.4 million deaths, reported to WHO. In this review, we will focus on the relationship between SARS-CoV-2 infection and the liver. We will discuss how chronic liver diseases affect the COVID-19 disease course and outcomes. We will also discuss the SARS-CoV-2 effects on the liver, mechanisms of acute liver injury, and potential management plans.  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