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   1110994篇
  免费   65633篇
  国内免费   2351篇
耳鼻咽喉   14048篇
儿科学   36462篇
妇产科学   29994篇
基础医学   150008篇
口腔科学   26458篇
临床医学   91402篇
内科学   220395篇
皮肤病学   20126篇
神经病学   90458篇
特种医学   46156篇
外国民族医学   336篇
外科学   176605篇
综合类   21886篇
一般理论   283篇
预防医学   85940篇
眼科学   23084篇
药学   75544篇
  2篇
中国医学   2428篇
肿瘤学   67363篇
  2018年   32527篇
  2017年   25924篇
  2016年   29487篇
  2015年   10166篇
  2014年   13789篇
  2013年   20874篇
  2012年   34004篇
  2011年   50447篇
  2010年   36582篇
  2009年   28659篇
  2008年   48754篇
  2007年   53932篇
  2006年   29818篇
  2005年   31581篇
  2004年   31973篇
  2003年   32728篇
  2002年   29900篇
  2001年   41956篇
  2000年   43381篇
  1999年   36675篇
  1998年   10464篇
  1997年   9675篇
  1996年   9433篇
  1995年   8778篇
  1994年   8436篇
  1993年   7846篇
  1992年   28407篇
  1991年   27226篇
  1990年   26674篇
  1989年   25537篇
  1988年   23749篇
  1987年   23370篇
  1986年   22422篇
  1985年   21321篇
  1984年   15939篇
  1983年   13595篇
  1982年   8249篇
  1981年   7134篇
  1979年   14729篇
  1978年   10315篇
  1977年   8677篇
  1976年   8232篇
  1975年   8985篇
  1974年   10763篇
  1973年   10219篇
  1972年   9676篇
  1971年   8933篇
  1970年   8625篇
  1969年   8067篇
  1968年   7721篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.

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   
104.
105.
106.
Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA.  相似文献   
107.
108.
109.

Objective

To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.

Data Source

Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.

Study Design

We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.

Principal Findings

In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.

Conclusions

Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships.  相似文献   
110.
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