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   34899篇
  免费   2698篇
  国内免费   97篇
耳鼻咽喉   369篇
儿科学   1224篇
妇产科学   694篇
基础医学   4225篇
口腔科学   869篇
临床医学   3778篇
内科学   7400篇
皮肤病学   560篇
神经病学   3298篇
特种医学   1145篇
外国民族医学   8篇
外科学   5315篇
综合类   529篇
一般理论   19篇
预防医学   2907篇
眼科学   760篇
药学   2532篇
中国医学   21篇
肿瘤学   2041篇
  2022年   247篇
  2021年   634篇
  2020年   361篇
  2019年   667篇
  2018年   761篇
  2017年   555篇
  2016年   557篇
  2015年   673篇
  2014年   1001篇
  2013年   1371篇
  2012年   2153篇
  2011年   2147篇
  2010年   1170篇
  2009年   1072篇
  2008年   1938篇
  2007年   2015篇
  2006年   2053篇
  2005年   1999篇
  2004年   1936篇
  2003年   1695篇
  2002年   1570篇
  2001年   691篇
  2000年   633篇
  1999年   659篇
  1998年   372篇
  1997年   296篇
  1996年   278篇
  1995年   238篇
  1994年   260篇
  1993年   224篇
  1992年   474篇
  1991年   458篇
  1990年   444篇
  1989年   426篇
  1988年   381篇
  1987年   383篇
  1986年   359篇
  1985年   368篇
  1984年   309篇
  1983年   261篇
  1982年   195篇
  1981年   187篇
  1980年   166篇
  1979年   295篇
  1978年   228篇
  1977年   200篇
  1975年   203篇
  1974年   215篇
  1973年   206篇
  1972年   205篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.

Purpose

A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).

Methods and Materials

A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.

Results

The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.

Conclusions

Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making.  相似文献   
4.
5.
6.
Quality of Life Research - This study investigated the PROMIS Self-Efficacy Measure for Managing Chronic Conditions (PROMIS-SE) domain distributions and examined the factor structure of the...  相似文献   
7.
8.
9.
Despite numerous studies of approach- and avoidant mindsets, relatively little research has addressed the impact of such motivational orientations on performance and emotion in a real-time, multi-task setting. A laboratory simulation is reported that examines the influence of an induced approach-centered, an avoidance-centered, and a “neutral” motivational mindset upon multiple aspects of task performance, self-regulatory cognition, and affect. Undergraduate females randomly assigned to one of three mindset conditions performed a simulated automobile drive across one practice and two experimental trials. Dependent measures included divided attention, behavioral indicators of driving “cautiousness” in relatively safe straight roadway sections as well as during more risk-filled driving, multiple aspects of self-regulatory thinking (including self-monitoring, intended effort, and self-administered consequences), and positive and negative affect. Results revealed that the avoidant mindset produced poorer executive attention (i.e., fewer correctly detected divided attention events), more “cautious” driving behavior and reduced performance variability (i.e., greater control) when driving on presumably safe, straight roadway sections, lower self-reports of intended effort, and greater negative affect relative to the approach mindset. Results are intepreted within a self-regulation-centered motivational framework. Implications of the multi-task simulation for the study of normal and disordered adjustment are considered.  相似文献   
10.
BACKGROUND: Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery. METHODS: We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D. RESULTS: Mean patient age was 43 +/- 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level 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