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   2367215篇
  免费   158325篇
  国内免费   3240篇
耳鼻咽喉   32224篇
儿科学   75921篇
妇产科学   62685篇
基础医学   348450篇
口腔科学   63707篇
临床医学   211804篇
内科学   458318篇
皮肤病学   51773篇
神经病学   185841篇
特种医学   88079篇
外国民族医学   489篇
外科学   354124篇
综合类   47519篇
现状与发展   12篇
一般理论   848篇
预防医学   182939篇
眼科学   54441篇
药学   175363篇
  58篇
中国医学   4581篇
肿瘤学   129604篇
  2021年   19362篇
  2019年   20274篇
  2018年   27143篇
  2017年   20425篇
  2016年   22822篇
  2015年   25654篇
  2014年   36104篇
  2013年   53952篇
  2012年   74676篇
  2011年   79406篇
  2010年   47056篇
  2009年   44566篇
  2008年   74608篇
  2007年   79476篇
  2006年   80295篇
  2005年   77779篇
  2004年   74367篇
  2003年   71692篇
  2002年   69366篇
  2001年   108737篇
  2000年   111451篇
  1999年   93494篇
  1998年   26992篇
  1997年   23658篇
  1996年   24054篇
  1995年   22715篇
  1994年   20894篇
  1993年   19712篇
  1992年   72001篇
  1991年   70070篇
  1990年   68391篇
  1989年   65664篇
  1988年   60302篇
  1987年   59125篇
  1986年   55218篇
  1985年   53004篇
  1984年   39311篇
  1983年   33396篇
  1982年   19858篇
  1979年   35866篇
  1978年   25651篇
  1977年   21230篇
  1976年   20332篇
  1975年   21816篇
  1974年   26148篇
  1973年   24802篇
  1972年   23200篇
  1971年   22037篇
  1970年   20247篇
  1969年   19315篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.

Aims

To obtain an overview of the management and outcomes of children aged 18 years or younger diagnosed with differentiated thyroid carcinoma of follicular cell origin across the UK, by collecting and analysing data from the limited number of centres treating these patients. This multicentre data might provide a more realistic perspective than single-institution series.

Materials and methods

Six centres submitted data extracted from historical records on patients aged 18 years or younger, diagnosed between 1964 and 2017. The univariate and multivariable Cox proportional hazard model was used to identify potential predictors of progression-free survival, using national data as a control.

Results

Data on 166 patients were available for analysis. Females (74%) were predominant, and the age ranged from 3 to 19 years at diagnosis, mean 14.1 years. Nodal metastases were present in 51%; 12% had distant metastases. After surgery, 95% received radioactive iodine (39% on more than one occasion) and 4% received external beam radiotherapy. With a median follow-up duration of 5 years, 69% are alive with no evidence of disease; 20% are alive with a raised thyroglobulin level as the only evidence of residual disease; 6% have residual structural disease detectable on imaging; 2% have died, from cerebral metastases.

Conclusion

Despite most patients having advanced disease at presentation, outcomes are very good. A national prospective registry should allow systematic collection of good-quality data and may facilitate research to further improve outcomes.  相似文献   
72.

Introduction

Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.

Methods

Data were collected from subjects undergoing cytoreductive surgery for MPM from specialist centers in Hyõgo, Japan, and Sydney, Australia, between 1991 and 2016. The CART model was applied using the combination of clinical variables to stratify subjects into risk groups (1 through 4); survival characteristics were then compared.

Results

Two hundred eighty-nine cases were included (205 from Australia, 84 from Japan). Overall median survival was 34.6 (interquartile range: 17.5–56.1) months; median age was 63.0 (interquartile range: 57.0–67.8) years, and 83.0% (n = 240) were male. There were no clinically meaningful differences between the two cohorts. Survival across the four risk groups was significantly different (p < 0.0001); the model stratified survival well with a Harrell's concordance statistic of 0.62 (95% confidence interval: 0.57–0.66) at 36 months. The group with the longest survival (median, 82.5 months) had: no weight loss, hemoglobin > 153 g/L and serum albumin > 43 g/L at time of referral to the surgical center.

Conclusions

Using routinely available clinical variables, the CART model was able to stratify surgical patients into risk groups with statistically different survival characteristics with fair to good performance. Presence of weight loss, anemia, and low albumin should confer caution when considering surgical therapy for MPM.  相似文献   
73.
74.
75.
76.
77.
78.
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