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   760篇
  免费   60篇
  国内免费   7篇
耳鼻咽喉   5篇
儿科学   7篇
妇产科学   6篇
基础医学   133篇
口腔科学   10篇
临床医学   57篇
内科学   271篇
皮肤病学   5篇
神经病学   52篇
特种医学   12篇
外科学   68篇
综合类   1篇
预防医学   26篇
眼科学   7篇
药学   62篇
中国医学   4篇
肿瘤学   101篇
  2024年   1篇
  2023年   13篇
  2022年   36篇
  2021年   64篇
  2020年   24篇
  2019年   31篇
  2018年   33篇
  2017年   25篇
  2016年   27篇
  2015年   26篇
  2014年   33篇
  2013年   50篇
  2012年   65篇
  2011年   59篇
  2010年   26篇
  2009年   33篇
  2008年   46篇
  2007年   56篇
  2006年   40篇
  2005年   40篇
  2004年   29篇
  2003年   29篇
  2002年   17篇
  2001年   4篇
  1999年   3篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1981年   2篇
  1980年   1篇
排序方式: 共有827条查询结果,搜索用时 15 毫秒
691.
692.
693.

Background

Alcohol problems are a major health issue in Nepal and remain under diagnosed. Increase in consumption are due to many factors, including advertising, pricing and availability, but accurate information is lacking on the prevalence of current alcohol use disorders. The AUDIT (Alcohol Use Disorder Identification Test) questionnaire developed by WHO identifies individuals along the full spectrum of alcohol misuse and hence provides an opportunity for early intervention in non-specialty settings. This study aims to validate a Nepali version of AUDIT among patients attending a university hospital and assess the prevalence of alcohol use disorders along the full spectrum of alcohol misuse.

Methods

This cross-sectional study was conducted in patients attending the medicine out-patient department of a university hospital. DSM-IV diagnostic categories (alcohol abuse and alcohol dependence) were used as the gold standard to calculate the diagnostic parameters of the AUDIT. Hazardous drinking was defined as self reported consumption of ≥21 standard drink units per week for males and ≥14 standard drink units per week for females.

Results

A total of 1068 individuals successfully completed the study. According to DSM-IV, drinkers were classified as follows: No alcohol problem (n=562; 59.5%), alcohol abusers (n= 78; 8.3%) and alcohol dependent (n=304; 32.2%). The prevalence of hazardous drinker was 67.1%. The Nepali version of AUDIT is a reliable and valid screening tool to identify individuals with alcohol use disorders in the Nepalese population. AUDIT showed a good capacity to discriminate dependent patients (with AUDIT ≥11 for both the gender) and hazardous drinkers (with AUDIT ≥5 for males and ≥4 for females). For alcohol dependence/abuse the cut off values was ≥9 for both males and females.

Conclusion

The AUDIT questionnaire is a good screening instrument for detecting alcohol use disorders in patients attending a university hospital. This study also reveals a very high prevalence of alcohol use disorders in Nepal.  相似文献   
694.
One of the major impediments in human aging research is the absence of a comprehensive and actionable set of biomarkers that may be targeted and measured to track the effectiveness of therapeutic interventions. In this study, we designed a modular ensemble of 21 deep neural networks (DNNs) of varying depth, structure and optimization to predict human chronological age using a basic blood test. To train the DNNs, we used over 60,000 samples from common blood biochemistry and cell count tests from routine health exams performed by a single laboratory and linked to chronological age and sex. The best performing DNN in the ensemble demonstrated 81.5 % epsilon-accuracy r = 0.90 with R2 = 0.80 and MAE = 6.07 years in predicting chronological age within a 10 year frame, while the entire ensemble achieved 83.5% epsilon-accuracy r = 0.91 with R2 = 0.82 and MAE = 5.55 years. The ensemble also identified the 5 most important markers for predicting human chronological age: albumin, glucose, alkaline phosphatase, urea and erythrocytes. To allow for public testing and evaluate real-life performance of the predictor, we developed an online system available at http://www.aging.ai. The ensemble approach may facilitate integration of multi-modal data linked to chronological age and sex that may lead to simple, minimally invasive, and affordable methods of tracking integrated biomarkers of aging in humans and performing cross-species feature importance analysis.  相似文献   
695.
BACKGROUND: Two recent large genetic studies in the US population have reported association between genetic variation in gamma-amino butyric acid alpha2 receptor subtype (GABRA2) and risk for alcohol dependence. The goal of this study was to test whether GABRA2 is associated with alcohol dependence in a sample of Russian alcohol-dependent men. METHODS: A total of 113 Russian alcohol-dependent men and 100 male population control subjects were recruited in St. Petersburg and genotyped for seven GABRA2 single-nucleotide polymorphisms (SNPs) using real-time PCR (TaqMan). Six SNPs were located in a GABRA2 haplotype block previously associated with alcohol dependence (AD) in the US population. SNPs and haplotypes were tested for an association to AD using chi analysis and a likelihood ratio-based statistic implemented in the software COCAPHASE. RESULTS: Significant associations between two SNPs and AD were observed (p < 0.05). In addition, a trend-level association was observed between AD and three adjacent SNPs (p < 0.1). Associated alleles were carried in a haplotype that was present at frequencies of 0.37 and 0.48 in the control and alcohol-dependent populations, respectively (p < 0.06). Tight linkage disequilibrium spanning from the central portion of the gene to the 3' end was observed in this population. Comparison of the findings to the previously published studies in the US population revealed a highly similar linkage disequilibrium pattern in this population. CONCLUSIONS: These findings suggest that genetic variants of GABRA2 increase risk for AD in the Russian population and provide additional support to the hypothesis that polymorphic variation at the GABRA2 locus plays an important role in predisposing to AD at least in European-ancestry populations.  相似文献   
696.
The next‐generation sequencing (NGS) has become a routine method for diagnostics of inherited disorders. However, assessment of the discovered variants may be challenging, especially when they are not predicted to change the protein sequence. Here we performed a functional analysis of 20 novel or rare intronic and synonymous glucokinase (GCK) gene variants identified by targeted NGS in 1,130 patients with maturity‐onset diabetes of the young. Human Splicing Finder, ver 3.1 and a precomputed index of splicing variants (SPIDEX) were used for in silico prediction. In vitro effects of GCK gene variants on splicing were tested using a minigene expression approach. In vitro effect on splicing was shown for 9 of 20 variants, including two synonymous substitutions. In silico and in vitro results matched in about 50% of cases. The results demonstrate that novel or rare apparently benign GCK gene variants should be regarded as potential splicing mutations.  相似文献   
697.
This study assessed the safety and preliminary efficacy of escalated dose subcutaneous alemtuzumab in combination with rituximab in chronic lymphocytic leukemia. Twenty-eight patients with relapsed refractory chronic lymphocytic leukemia were treated on four dosing cohorts of weekly rituximab at 375 mg/m2 and alemtuzumab doses that started at 30 mg three times per week and escalated to weekly dosing over four weeks, culminating with 90 mg weekly. One dose limiting toxicity of a rituximab infusion reaction was seen in cohort 2, but the regimen was otherwise well tolerated without evidence of differential toxicity by cohort. The overall response rate by National Cancer Institute-Working Group criteria was 61%, and the rate of complete bone marrow response was 43%, most of whom were negative for minimal residual disease. The addition of CT scan evaluation per International Workshop on Chronic Lymphocytic Leukemia 2008 criteria reduced the overall response rate to 14%. Median overall survival was 35 months, with 12 patients able to proceed to stem cell transplantation. Pharmacokinetic studies showed that chronic lymphocytic leukemia involving more than 80% of the bone marrow at study start was associated with lower trough concentrations of alemtuzumab and rituximab, and that higher trough serum concentrations of alemtuzumab were associated with complete bone marrow clearance. We conclude that escalated subcutaneous doses of alemtuzumab given weekly are well tolerated and result in excellent bone marrow clearance of chronic lymphocytic leukemia, helping patients to proceed to stem cell transplantation. This study is registered at ClinicalTrials.gov (Identifier:00330252).  相似文献   
698.
ObjectivesThe goal of the present study was to investigate the potential for acoustic microscopy techniques to characterize the cement–dentin interface in restored teeth.MethodsSpecial flat-parallel specimens and whole extracted teeth with restorations were scanned using a high-frequency (50 MHz) focused ultrasonic transducer. Visual acoustic images (B- and C-scans) of the cement–dentin interface were obtained nondestructively, analyzed and compared with optical images taken after the samples were cut along the scanning axis. The shear bonding strength of a subsection of specimens was tested in a Lloyd material testing machine.ResultsAn essential distinction between the acoustical properties associated with good and failed bonding has been shown. In the case of failed adhesion, the ultrasound signal reflection from the cement–dentin interface is up to four to seven times higher in magnitude than in the case of good bonding. The comparison of the ultrasound imaging data with the data obtained using an optical microscope revealed a strong correspondence with the acoustical and optical results with respect to the presence, position and dimensions of the defects. The specimens showing higher ultrasound reflection from cement/dentin interface have also shown lower shear bonding strength.SignificanceThe results demonstrate that acoustic scanning with a high-frequency focused ultrasonic probe is a valuable method for nondestructive morpho-mechanical analysis of cement/dentin interface for either experimental models or whole restored teeth. An appropriately expanded approach can be widely used for the pre-clinical evaluation of dental materials. Further, this method may prove beneficial in the design of new diagnostic ultrasound devices and techniques for use within clinical dentistry.  相似文献   
699.
700.
Briefly incubated agar cultures from positive blood cultures were used for antimicrobial susceptibility testing (AST) by Vitek 2. The cultivation time until inoculation was 3.8 h for Gram-positive cocci and 2.4 h for Gram-negative rods. The error rates were low, providing early and reliable AST without additional time or cost expenditure.  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