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   6408篇
  免费   485篇
  国内免费   88篇
耳鼻咽喉   126篇
儿科学   260篇
妇产科学   111篇
基础医学   578篇
口腔科学   147篇
临床医学   838篇
内科学   988篇
皮肤病学   189篇
神经病学   289篇
特种医学   187篇
外科学   1241篇
综合类   427篇
一般理论   1篇
预防医学   783篇
眼科学   96篇
药学   218篇
中国医学   53篇
肿瘤学   449篇
  2023年   149篇
  2022年   159篇
  2021年   305篇
  2020年   283篇
  2019年   434篇
  2018年   358篇
  2017年   291篇
  2016年   223篇
  2015年   209篇
  2014年   355篇
  2013年   438篇
  2012年   263篇
  2011年   286篇
  2010年   242篇
  2009年   254篇
  2008年   261篇
  2007年   274篇
  2006年   235篇
  2005年   179篇
  2004年   166篇
  2003年   146篇
  2002年   128篇
  2001年   103篇
  2000年   97篇
  1999年   94篇
  1998年   67篇
  1997年   51篇
  1996年   58篇
  1995年   46篇
  1994年   46篇
  1993年   46篇
  1992年   53篇
  1991年   37篇
  1990年   30篇
  1989年   33篇
  1988年   28篇
  1987年   28篇
  1986年   25篇
  1985年   63篇
  1984年   77篇
  1983年   46篇
  1982年   64篇
  1981年   70篇
  1980年   44篇
  1979年   36篇
  1978年   31篇
  1977年   25篇
  1976年   18篇
  1974年   7篇
  1973年   4篇
排序方式: 共有6981条查询结果,搜索用时 15 毫秒
1.
2.
目的了解发达国家医学生器官捐献意愿研究的目的、结果、障碍因素和解决对策。 方法以主题词和自由词联合的方式对PubMed、Web of Science、Ovid MEDLINE、Ovid EMBASE(Excerpta Medica)、EBSCOhost Complete和Cochrane Library等已发表文献数据库,以及灰色文献数据库York Centre for Reviews and Dissemination、Open Grey、ProQuest Dissertation and Theses和Mednar进行系统、全面地检索,并采用Arksey和O′Malley提出的范围综述框架进行文献资料整合。 结果共纳入17项发达国家医学生器官捐献意愿研究。研究背景主要为医学生未来对于公众器官捐献有着重要影响。研究结果表明,大多数医学生器官捐献意愿性良好,但不同亚组的研究结果不一;其最主要的障碍因素为医学生器官捐献相关知识的缺乏;解决对策主要为施予系统化、结构化和可评价的教育课程。 结论21世纪以来发达国家医学生器官捐献意愿研究方兴未艾,其研究的多层面、多角度以及揭示的问题、寻求的解决对策,可对我国现阶段医学生器官捐献的研究提供一定参考。  相似文献   
3.
4.
《Value in health》2022,25(9):1480-1488
ObjectivesInvolvement of patients and medical professionals in assessment of relative effectiveness (relative effectiveness assessment) contributes to an efficient and effective health technology assessment (HTA) process and supports acceptance and implementation of the outcome. This study aimed to analyze stakeholder involvement in assessing relative effectiveness and how the parties involved value this collaboration.MethodsThis is a document analysis of all drug assessments completed in 2019 (20) by the public HTA agency of The Netherlands, enriched with semistructured interviews with employees of the HTA agency (18) and representatives of patient (5) and medical (11) associations involved in these assessments. Data were analyzed, coded, and categorized.ResultsIn almost half of the assessments, there was no coordination with the medical associations at the start of the relative effectiveness assessment and no patient associations involved in this phase. During the assessment procedure, patient and medical associations were always asked to comment on the draft report. Nevertheless, the strict 5-day deadline that the HTA agency uses as a response period often hampered a proper response and involvement. According to interviewees of the HTA agency, this leads to a great diversity in the substantive quality of their input. Patient and medical associations indicated that the HTA agency relies too much on “paper knowledge,” which leads to a (perceived) lack of alignment with clinical practice.ConclusionsThe limited involvement results in a lack of coordination and mutual trust. Optimizing involvement of patients and medical professionals in HTA practice requires effort from all parties involved. Procedural adjustments and better coordination, especially at the start of the assessment, would probably improve cooperation.  相似文献   
5.
6.
目的 利用MRI技术连续采集头颈部肿瘤患者吞咽时图像,观察并测量软腭、舌、喉的运动规律及最大活动度。方法 随机选取2018年7月-10月在中国医学科学院肿瘤医院接受调强放疗的原发头颈部恶性肿瘤20例患者,其中男17例、女3例,中位年龄58.5岁(28~78岁)。20例患者中鼻咽癌7例,口腔癌3例,口咽癌5例,下咽癌3例,鼻腔鼻旁窦2例。根据AJCC第八版分期Ⅰ-Ⅱ期患者2例,Ⅲ期8例,Ⅳ期10例。结果 吞咽时软腭向上移动移动距离为(1.06±0.31) cm且服从正态分布,向后移动距离为(0.83±0.24) cm且近似正态分布。舌体向后移动距离为(0.77±0.22) cm,且服从正态分布。含压舌板行图像采集患者舌上移位移为0,无压舌板患者舌体中位上移距离为1.23 cm (0.59~1.41 cm)。喉向上移动距离为(1.14±0.22) cm且服从正态分布,向前移动的中位距离为0.4 cm (0.27~0.90 cm)。结论 吞咽运动有可能发生于头颈部肿瘤患者放疗过程中,并引起大体肿瘤体积(GTV)及周围正常组织移动;因此在制定放疗计划时应注意GTV至PGTV的个体化外放距离,以保证肿瘤处方剂量。  相似文献   
7.
Managing traumatic liver injury (TLI) is always challenging and demands precise clinical judgment. Currently, treatment of TLI in most circumstances is non-operative; however, surgical therapy might be required for severe TLI, particularly those that result in extensive blood loss. In the current institutional study carried out from June 1995 to April 2017, we describe our experience with 5 patients who received an orthotopic liver transplant for severe TLI. One patient passed away postoperatively from cerebral edema; 1 patient died of renal failure 4 years after the liver transplantation, and 3 patients are still alive. Based on our experience, we conclude that in patients with TLI, especially those with uncontrollable bleeding or those who develop liver failure, liver transplantation should be taken into consideration.  相似文献   
8.

Objectives

We describe the Canadian results of the Ascyrus Medical Dissection Stent (AMDS), a novel partially uncovered aortic arch hybrid graft implanted antegrade during hypothermic circulatory arrest to promote true lumen expansion and enhance aortic remodeling.

Methods

From March 2017 to February 2018, 16 consecutive patients (66 ± 12 years; 38% female) presented with acute type A aortic dissections and underwent emergent surgical aortic repair with AMDS implantation. All patients presented with DeBakey I aortic dissection, with evidence of malperfusion in 50% (n = 8) of patients. All cases were performed under hypothermic circulatory arrest with an additional average duration for AMDS implantation time of 2.1 minutes.

Results

All 16 device implantations were successful. Overall 30-day mortality was 6.3% (n = 1) and stroke occurred in 6.3% (n = 1) of cases. There was no incidence of device-related aortic injury or aortic arch branch vessel occlusion. During the follow-up period, 12 patients had completed at least 1 postoperative computed tomography scan. At initial follow-up computed tomography scan, complete or partial thrombosis, and remodeling of the aortic arch occurred in 91.7% of cases (n = 11/12) and in the proximal descending thoracic aorta, complete or partial thrombosis, and remodeling occurred in 91.7% (n = 11/12).

Conclusions

Preliminary results suggest that the AMDS is a safe, feasible and reproducible adjunct to current surgical approaches for acute DeBakey I aortic dissection repair. Further, the AMDS manages malperfusion and promotes early positive remodeling in the aortic arch and distal dissected segments, with favorable FL closure rates at follow-up. Ongoing follow-up will provide additional insight into the long-term effects of the AMDS.  相似文献   
9.
10.
《Radiography》2022,28(3):746-750
IntroductionIn response to advice from The National Institute for Health and Care Excellence (1) to reduce hospital visits during COVID-19, standard headrests were introduced for head and neck radiotherapy within Northern Centre for Cancer Care (NCCC). The standard headrest requires one mould room appointment compared to 3 appointments with customised headrests.MethodsTwo groups of 10 patients treated between December 2019 and June 2020 were retrospectively analysed by 1 observer. Groups were stratified according to age, sex and tumour site. One group had customised headrest and the other had standard headrest. Five hundred and forty seven cone beam computed tomography images were reviewed. A 6 Degree of Freedom match was performed then chin, shoulder and spine position were assessed using dosimetrist drawn structures. Structures out of the tolerance were recorded. A chi-squared test was used for statistical analysis.ResultsThe out of tolerance chin position count recorded was 21 for customised headrest and 36 for standard headrest, p-value 0.046. The shoulder position count was 13 for customised headrest and 77 for standard headrest p-value <0.001. The spine position count was 3 for CHR and 21 for standard headrest, p-value <0.001. This means the headrests compared are not equivalent in terms of set up reproducibility. Overall the standard headrest group had 10 set-up re-scans and no set up re-scans were recorded in the customised headrest group.ConclusionFewer hospital visits with SHR reduce patient exposure to COVID-19. However, CHR provided a more reliable level of immobilisation in this study.Implications for practiceThe radiotherapy service will be reviewed in line with these findings.  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