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   1326篇
  免费   103篇
  国内免费   6篇
耳鼻咽喉   10篇
儿科学   32篇
妇产科学   22篇
基础医学   143篇
口腔科学   23篇
临床医学   146篇
内科学   297篇
皮肤病学   30篇
神经病学   106篇
特种医学   34篇
外科学   216篇
综合类   22篇
一般理论   9篇
预防医学   126篇
眼科学   42篇
药学   94篇
中国医学   30篇
肿瘤学   53篇
  2024年   6篇
  2023年   31篇
  2022年   44篇
  2021年   92篇
  2020年   68篇
  2019年   62篇
  2018年   81篇
  2017年   54篇
  2016年   58篇
  2015年   71篇
  2014年   75篇
  2013年   100篇
  2012年   117篇
  2011年   108篇
  2010年   57篇
  2009年   47篇
  2008年   62篇
  2007年   63篇
  2006年   61篇
  2005年   46篇
  2004年   42篇
  2003年   21篇
  2002年   11篇
  2001年   7篇
  2000年   6篇
  1999年   7篇
  1998年   7篇
  1997年   1篇
  1996年   4篇
  1994年   2篇
  1992年   3篇
  1991年   2篇
  1990年   4篇
  1987年   1篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1979年   2篇
  1972年   2篇
  1969年   1篇
  1966年   2篇
  1965年   1篇
排序方式: 共有1435条查询结果,搜索用时 15 毫秒
11.

Rational

A growing body of evidence illustrates that 5-HT3 receptor antagonist drugs may be of benefit in the treatment of negative symptoms in schizophrenia.

Objective

The objective of this study was to assess the efficacy and tolerability of tropisetron add-on to risperidone on negative symptoms in patients with chronic stable schizophrenia.

Methods

In a double-blind, placebo-controlled 8-week trial, 40 patients with chronic schizophrenia who were stabilized on risperidone were randomized into tropisetron or placebo add-on groups. Psychotic symptoms were measured using the Positive and Negative Syndrome Scale (PANSS) every 2 weeks. Furthermore, extrapyramidal and depressive symptoms as well as side effects were assessed. The primary outcome measure was the difference in change from baseline of negative subscale scores between the two groups at week 8.

Results

Tropisetron resulted in greater improvement of the total PANSS scores [F(1.860,70.699)?=?37.366, p?<?0.001] as well as negative scores [F(2.439,92.675)?=?16.623, p?<?0.001] and general psychopathology [F(1.767,67.158)?=?4.602, p?=?0.017], but not positive subscale scores [F(1.348, 51.218)?=?0.048, p?=?0.893] compared to placebo. In a multiple regression analysis controlling for positive, extrapyramidal, and depressive symptoms, treatment group (standardized β?=??0.640) significantly predicted changes in primary negative symptoms. The side effect profile did not differ significantly between the two groups.

Conclusion

Tropisetron add-on to risperidone improves the primary negative symptoms of patients with chronic stable schizophrenia.  相似文献   
12.
13.
A comprehensive approach to understand the mechanical behavior of materials involves costly and time-consuming experiments. Recent advances in machine learning and in the field of computational material science could significantly reduce the need for experiments by enabling the prediction of a material’s mechanical behavior. In this paper, a reliable data pipeline consisting of experimentally validated phase field simulations and finite element analysis was created to generate a dataset of dual-phase steel microstructures and mechanical behaviors under different heat treatment conditions. Afterwards, a deep learning-based method was presented, which was the hybridization of two well-known transfer-learning approaches, ResNet50 and VGG16. Hyper parameter optimization (HPO) and fine-tuning were also implemented to train and boost both methods for the hybrid network. By fusing the hybrid model and the feature extractor, the dual-phase steels’ yield stress, ultimate stress, and fracture strain under new treatment conditions were predicted with an error of less than 1%.  相似文献   
14.
15.
Patients with hemophilia suffer from low bone mineral density (BMD) due to several risk factors including arthropathy and resulting immobility. Recent studies have shown variable frequency of low BMD in this group of patients. This study attempts to assess the prevalence of low BMD (osteoporosis and osteopenia) and the associated risk factors in a group of Iranian hemophilia patients. Patients with moderate or severe hemophilia underwent BMD measurement by dual energy X-ray absorptiometry. The results were correlated with other variables including physical activity, calcium intake and demographic data. Forty two patients with the mean age of 31 years (range 18–72) completed the study. The prevalence of osteoporosis in the spine and the left femoral neck was 23.8 and 14.6 %, respectively, and osteopenia in the spine and femoral neck was seen in 45.2 and 31.7 % of the patients, respectively based on the WHO T-score criteria. We found only cigarette smoking to be significantly related to low BMD (P < 0.001). There were two cases of pathologic fracture at femoral neck and forearm (4.8 %). Low BMD is very common in patients with hemophilia. Appropriate assessment of BMD and control of predisposing factors such as prophylactic factor replacement (to prevent hemarthrosis) and cessation of cigarette smoking are warranted.  相似文献   
16.
17.
18.
19.
The aim of this study is to determine safe fasting plasma glucose (FPG) levels. We included data on 5,960 individuals aged ≥20?years at baseline with at least one follow-up examination. Diabetes was ascertained in accordance with American Diabetes Association criteria, using standard 2-h post-challenge plasma glucose test. Multivariate restricted cubic splines Weibull regression was implemented for interval-censored survival data on incident diabetes. We used Harrell’s C statistic for discrimination, Nam-D’Agostino χ2 for calibration, and Royston’s R 2 for variations in the outcome explained by models. During a 6-year median follow-up, 369 incident cases of diabetes were ascertained. Family history of diabetes, systolic blood pressure, waist-to-height ratio, and triglyceride-to-high-density lipoprotein cholesterol ratio, independent of FPG and each other remained associated with incident diabetes. The cubic splines model achieved good calibration (χ2?=?12.1) and discrimination (C?=?0.828) and explained 75% of variation in the time until incident diabetes. A J-shaped FPG-diabetes relationship was observed. Descending arm of the dose–response relationship curve corresponded to increasing FPG levels up to 4.0?mmol?l?1, where it started increasing. The risk of incident diabetes decreased with decreasing levels of FPG down to 4.0?mmol?l?1, where the risk stopped decreasing. Multivariate-adjusted risk of incident diabetes was zero at FPG?=?5.05?mmol?l?1. Although currently there is no firm evidence to show that early intervention among individuals with the elevated FPG levels could prevent or delay onset of diabetes, individuals with FPG levels below 5.05?mmol?l?1 could be safely reassured about their near-term risk of developing incident diabetes and screened on a less frequent basis.  相似文献   
20.
Here, we present a 20-year-old man who presented with painful inguinal and femoral masses. He gave a history of sexual contact with a mare 14 days before his recent illness. He was diagnosed with lymphogranuloma venereum based on the histopathological findings and a high titre of IgG (1:1400).  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