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   44915篇
  免费   3642篇
  国内免费   100篇
耳鼻咽喉   732篇
儿科学   1565篇
妇产科学   1230篇
基础医学   6055篇
口腔科学   1153篇
临床医学   3959篇
内科学   10205篇
皮肤病学   983篇
神经病学   4516篇
特种医学   1515篇
外国民族医学   3篇
外科学   6169篇
综合类   750篇
一般理论   56篇
预防医学   3310篇
眼科学   1001篇
药学   2534篇
中国医学   15篇
肿瘤学   2906篇
  2021年   589篇
  2020年   392篇
  2019年   661篇
  2018年   730篇
  2017年   529篇
  2016年   580篇
  2015年   726篇
  2014年   996篇
  2013年   1607篇
  2012年   2028篇
  2011年   2200篇
  2010年   1235篇
  2009年   1103篇
  2008年   2070篇
  2007年   2229篇
  2006年   2192篇
  2005年   2177篇
  2004年   2082篇
  2003年   1957篇
  2002年   2025篇
  2001年   1231篇
  2000年   1273篇
  1999年   1101篇
  1998年   550篇
  1997年   447篇
  1996年   453篇
  1995年   429篇
  1994年   397篇
  1993年   412篇
  1992年   944篇
  1991年   887篇
  1990年   755篇
  1989年   798篇
  1988年   763篇
  1987年   763篇
  1986年   723篇
  1985年   738篇
  1984年   627篇
  1983年   558篇
  1982年   422篇
  1981年   346篇
  1980年   379篇
  1979年   529篇
  1978年   380篇
  1977年   337篇
  1976年   357篇
  1975年   333篇
  1974年   355篇
  1973年   362篇
  1972年   309篇
排序方式: 共有10000条查询结果,搜索用时 640 毫秒
1.
European Surgery - Treatment of pilonidal sinus disease (PSD) requires a tailored approach. A national guideline was published in 2014. The current status of surgical PSD therapy...  相似文献   
2.
3.
4.
5.
6.
The term “oligometastatic prostate cancer” refers to a heterogeneous group of disease states currently defined solely on the basis of clinical features. Oligorecurrent disease, de novo oligometastases, and oligoprogressive disease likely have unique biologic underpinnings and natural histories. Evidence suggesting the existence of a subset of patients who harbor prostate cancer with limited metastatic potential currently includes disparate and overwhelmingly retrospective reports. Nevertheless, emerging prospective data have corroborated the “better-than-expected,” retrospectively observed outcomes, particularly in the setting of oligorecurrent prostate cancer. Improved functional imaging with prostate-specific membrane antigen-targeted strategies may enhance the identification of patients with oligometastatic prostate cancer in the short term. In the long term, refinement of the oligometastatic case definition likely will require biologic risk-stratification schemes. To determine optimal treatment strategies and identify patients most likely to benefit from metastasis-directed therapy, future efforts should focus on conducting high-quality, prospective trials with much-needed molecular correlative studies.  相似文献   
7.

Background

Payers frequently rely on budget impact model (BIM) results to help determine drug coverage policy and its effect on their bottom line. It is unclear whether BIMs typically overestimate or underestimate real-world budget impact.

Objective

We examined how different modeling assumptions influenced the results of 6 BIMs from the Institute for Clinical and Economic Review (ICER).

Study Design

Retrospective analysis of pharmaceutical sales data.

Methods

From ICER reports issued before 2016, we collected estimates of 3 BIM outputs: aggregate therapy cost (ie, cost to treat the patient population with a particular therapy), therapy uptake, and price. We compared these against real-world estimates that we generated using drug sales data. We considered 2 classes of BIM estimates: those forecasting future uptake of new agents, which assumed “unmanaged uptake,” and those describing the contemporaneous market state (ie, estimates of current, managed uptake and budget impact for compounds already on the market).

Results

Differences between ICER's estimates and our own were largest for forecasted studies. Here, ICER's uptake estimates exceeded real-world estimates by factors ranging from 7.4 (sacubitril/valsartan) to 54 (hepatitis C treatments). The “unmanaged uptake” assumption (removed from ICER's approach in 2017) yields large deviations between BIM estimates and real-world consumption. Nevertheless, in some cases, ICER's BIMs that relied on current market estimates also deviated substantially from real-world sales data.

Conclusions

This study highlights challenges with forecasting budget impact. In particular, assumptions about uptake and data source selection can greatly influence the accuracy of results.  相似文献   
8.

Introduction

Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.

Innovation

An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.

Outcomes

A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.

Comments

We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes.  相似文献   
9.
Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain.  相似文献   
10.
We present the case of 7‐year‐old African American girl with loose anagen syndrome. Although this is a common cause of hair loss in Caucasian children, and there have been reports of cases occurring in dark‐skinned children of North African and Middle Eastern descent, to our knowledge there have been no cases reported in black children of sub‐Saharan African ancestry. We present this case to broaden the differential diagnosis of hair loss in African Americans.  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