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   3632篇
  免费   279篇
  国内免费   8篇
耳鼻咽喉   27篇
儿科学   100篇
妇产科学   92篇
基础医学   482篇
口腔科学   42篇
临床医学   492篇
内科学   547篇
皮肤病学   18篇
神经病学   554篇
特种医学   65篇
外科学   453篇
综合类   82篇
一般理论   3篇
预防医学   472篇
眼科学   37篇
药学   261篇
中国医学   1篇
肿瘤学   191篇
  2023年   23篇
  2022年   50篇
  2021年   87篇
  2020年   47篇
  2019年   74篇
  2018年   90篇
  2017年   70篇
  2016年   79篇
  2015年   77篇
  2014年   121篇
  2013年   147篇
  2012年   234篇
  2011年   226篇
  2010年   130篇
  2009年   112篇
  2008年   159篇
  2007年   209篇
  2006年   167篇
  2005年   204篇
  2004年   164篇
  2003年   166篇
  2002年   151篇
  2001年   93篇
  2000年   84篇
  1999年   77篇
  1998年   36篇
  1997年   20篇
  1996年   23篇
  1995年   27篇
  1994年   22篇
  1993年   24篇
  1992年   74篇
  1991年   45篇
  1990年   54篇
  1989年   41篇
  1988年   57篇
  1987年   51篇
  1986年   37篇
  1985年   40篇
  1984年   42篇
  1983年   21篇
  1982年   20篇
  1981年   17篇
  1980年   15篇
  1978年   19篇
  1977年   18篇
  1974年   15篇
  1972年   19篇
  1970年   14篇
  1968年   13篇
排序方式: 共有3919条查询结果,搜索用时 15 毫秒
1.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
2.
3.
4.

Purpose

The purpose of this study was to evaluate trends in demographics and outcomes of pediatric breast cancer in a United States population-based cohort.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant breast tumors between 1973 and 2014. Analysis was performed using Stata Statistical Software version 13.1. Associations between categorical variables were made using X2 test. Log-rank test was used for univariate survival analysis. Kaplan–Meier analysis investigated five-year survival rates across several variables. Adjusted analysis was performed using a Cox Proportional-Hazards regression.

Results

134 patients with breast malignancies were identified. Carcinoma was the most prevalent histology (48.5%), followed by fibroepithelial tumors (FETs) (35.1%), and sarcoma (14.2%). FETs were twice as common in black compared to nonblack patients (56.3% vs. 29.0%, p?<?0.01). Analyzing histology by stage revealed that 100% of FETs were early stage disease (p?<?0.0001). 46.7% of the tumors tested were ER/PR negative, more than twice as many compared to the published adult estimate of 20.0%. Unadjusted survival analysis revealed worse survival for patients with adenocarcinoma/sarcomas, advanced stage, and high grade disease, without a survival difference between races.

Conclusion

Breast cancer remains a rare malignancy among pediatric patients. Although black patients were found to have more noncarcinomatous tumors with less advanced disease, this did not confer a survival advantage.

Type of study

Retrospective cohort study.

Level of evidence

Level III.  相似文献   
5.
Background. It has been reported that gender differences in cardiovascular outcomes found in adults also are present in children who undergo surgical repair for congenital heart disease. Methods. California statewide hospital discharge data 1989–99 were used to study outcomes in children <18 years undergoing cardiac surgery. Hospital discharge data were linked to death registry data to study postdischarge death within 30 days of discharge. We used logistic regression to evaluate the effect of gender on mortality controlling for age, race and ethnicity, type of insurance, household income, date and month of surgery, type of admission, hospital case volume, and various types of procedures. Results. There were 25 402 cardiac surgery cases with 1505 in‐hospital deaths (mortality rate of 5.92%). An additional 37 deaths occurred within 30 days after hospital discharge. Crude mortality rates for males (5.99%) and females (5.84%) were not significantly different. However, fewer neonates were female and females underwent a higher proportion of low‐risk procedures than males. Logistic regression revealed that females, compared with males, had a significantly higher odds ratio (OR) for in‐hospital mortality (OR = 1.18, P < .01) and overall (up to 30 days post discharge) mortality (OR = 1.18, P < .01). The risk‐adjusted length of hospital stay was similar between females and males while charges per hospital day were slightly higher in females than males. The prevalence of Down syndrome, pulmonary hypertension, and failure to thrive were higher in females. Conclusions. Female gender is associated with an 18% higher in‐hospital and 30‐day postdischarge mortality as compared with male gender. There was no difference in length of hospital stay between males and females. The mechanism by which female gender acts as a risk factor requires further investigation.  相似文献   
6.
7.
8.
9.
This article focuses on possible psychopharmacological interventions in the immediate post disaster setting. As there is little evidence for the efficacy or effectiveness of such interventions-given the difficulty in performing randomized, double-blind, placebo controlled studies with these populations-the article will delineate the neurobiological basis for pathological sequelae and theoretical drug interventions targeting putative disease mechanisms.  相似文献   
10.
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