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   182593篇
  免费   14175篇
  国内免费   4151篇
耳鼻咽喉   1481篇
儿科学   2681篇
妇产科学   3167篇
基础医学   23464篇
口腔科学   3684篇
临床医学   12927篇
内科学   22794篇
皮肤病学   2472篇
神经病学   12334篇
特种医学   6523篇
外国民族医学   1篇
外科学   15308篇
综合类   24583篇
现状与发展   21篇
一般理论   8篇
预防医学   15448篇
眼科学   2287篇
药学   25682篇
  55篇
中国医学   13063篇
肿瘤学   12936篇
  2024年   149篇
  2023年   2391篇
  2022年   3402篇
  2021年   7347篇
  2020年   6491篇
  2019年   6500篇
  2018年   6511篇
  2017年   7022篇
  2016年   6990篇
  2015年   6534篇
  2014年   7622篇
  2013年   11490篇
  2012年   9298篇
  2011年   11205篇
  2010年   7035篇
  2009年   7119篇
  2008年   8605篇
  2007年   9576篇
  2006年   9053篇
  2005年   8355篇
  2004年   7157篇
  2003年   6433篇
  2002年   5001篇
  2001年   4535篇
  2000年   3816篇
  1999年   3191篇
  1998年   2368篇
  1997年   2446篇
  1996年   2254篇
  1995年   2088篇
  1994年   2030篇
  1993年   1697篇
  1992年   1567篇
  1991年   1466篇
  1990年   1274篇
  1989年   1042篇
  1988年   998篇
  1987年   908篇
  1986年   834篇
  1985年   1217篇
  1984年   975篇
  1983年   733篇
  1982年   756篇
  1981年   621篇
  1980年   603篇
  1979年   479篇
  1978年   299篇
  1977年   261篇
  1976年   246篇
  1975年   190篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
21.
The aim of the study was to compare automated and manually conducted (slice-by-slice) virtual orbital wall reconstruction in terms of PSI design, manufacture, and clinical application for orbital fracture management.Patients with orbital wall fractures were evaluated for the potential for treatment with PSI, based on automated virtual wall reconstruction; these formed the main group. The surgical outcomes of these main-group patients' treatments were compared with those of the control group, which comprised patients randomly selected for this study, each of whom had the same orbital trauma patterns and were also managed with PSI. However, the control group patients were treated using ‘slice-by-slice’ virtual orbital reconstruction.Mean volume differences between the intact and reconstructed orbit were 0.65 ± 0.26 cm3 in the main group (n = 23) and 0.57 ± 0.23 cm3 in the control (n = 27; p = 0.837). In both groups, no cases of implant malposition or enophthalmos were detected after surgery. Orbital shape difference was similar for the main group and the control, at ?3.3 ± 3.5% and 3.25 ± 2.5%, respectively (p = 0.929). Diplopia was diagnosed at the 3-month follow-up in 13.0% of the main group and in 11.1% of the control (p = 0.651). The average times spent on computer-aided design (CAD) procedures, including segmentation, virtual orbital reconstruction, and PSI design, were 36.7 ± 6.9 min in the main group and 72.9 ± 7.7 min in the control group (p < 0.001).Within the limitations of the study it seems that PSI based on automated virtual reconstruction is a relevant alternative treatment option for orbital fractures because of its clinical efficacy that is similar to PSI based on a ‘slice-by-slice’ CAD protocol.  相似文献   
22.
《Saudi Dental Journal》2022,34(7):596-603
ObjectiveStudies have shown that gingival crevices may be a significant route for SARS-CoV-2 entry. However, the role of oral health in the acquisition and severity of COVID-19 is not known.DesignA retrospective analysis was performed using electronic health record data from a large urban academic medical center between 12/1/2019 and 8/24/2020. A total of 387 COVID-19 positive cases were identified and matched 1:1 by age, sex, and race to 387 controls without COVID-19 diagnoses. Demographics, number of missing teeth and alveolar crestal height were determined from radiographs and medical/dental charts. In a subgroup of 107 cases and controls, we also examined the rate of change in alveolar crestal height. A conditional logistic regression model was utilized to assess association between alveolar crestal height and missing teeth with COVID-19 status and with hospitalization status among COVID-19 cases.ResultsIncreased alveolar bone loss, OR = 4.302 (2.510 – 7.376), fewer missing teeth, OR = 0.897 (0.835–0.965) and lack of smoking history distinguished COVID-19 cases from controls. After adjusting for time between examinations, cases with COVID-19 had greater alveolar bone loss compared to controls (0.641 ± 0.613 mm vs 0.260 ± 0.631 mm, p < 0.01.) Among cases with COVID-19, increased number of missing teeth OR = 2.1871 (1.146– 4.174) was significantly associated with hospitalization.ConclusionsAlveolar bone loss and missing teeth are positively associated with the acquisition and severity of COVID-19 disease, respectively.  相似文献   
23.
ObjectivesSeveral implementation strategies can reduce potentially inappropriate medication (PIM) prescribing. Although use of PIMs has declined in recent years, it remains prevalent. Various strategies exist to improve the appropriateness of medication use. However, little is known about the processes of these different implementation strategies. This scoping review aims to investigate how the process evaluation of implementation strategies for reducing PIM prescribing in the older population has been studied.MethodsWe searched for process evaluations of implementation strategies for reducing PIM prescribing in PUBMED, SCOPUS and Web of Science published between January 2000 and November 2019 in English. We applied the following inclusion criteria: patients aged ≥65 years, validated PIM criteria, and implementation process evaluated. The review focuses on decision support for health care professionals. We described the findings of the process evaluations, and compared the authors’ concepts of process evaluation of the included publications to those of Proctor et al.( 2010).ResultOf 9131 publications screened, 29 met our inclusion criteria. Different process evaluation conceptualizations were identified. Most process evaluations took place in the initial stages of the process (acceptability, adoption, appropriateness, and feasibility) and sustainability and implementation costs were seldom evaluated. None of the included publications evaluated fidelity.Multifaceted interventions were the most studied implementation strategies. Medication review was more common in acceptability evaluations, multidisciplinary interventions in adoption evaluations, and computerized systems and educational interventions in feasibility evaluations. Process evaluations were studied from the health care professionals’ viewpoint in most of the included publications, but the management viewpoint was missing.DiscussionThe conceptualization of process evaluation in the field of PIM prescribing is indeterminate. There is also a current gap in the knowledge of sustainability and implementation costs. Clarifying the conceptualization of implementation process evaluation is essential in order to effectively translate research knowledge into practice.  相似文献   
24.
《Molecular therapy》2022,30(2):519-533
  1. Download : Download high-res image (159KB)
  2. Download : Download full-size image
  相似文献   
25.
Network meta-analyses (NMAs) simultaneously estimate the effects of multiple possible treatment options for a given clinical presentation. For allergists to benefit optimally from NMAs, they must understand the process and be able to interpret the results. Through a worked example published in Pediatric Allergy and Immunology, we summarize how to identify credible NMAs and interpret them with a focus on recent innovations in the GRADE approach (Grading of Recommendations Assessment, Development, and Evaluation). NMAs build on traditional systematic reviews and meta-analyses that consider only direct paired comparisons by including indirect evidence, thus allowing the simultaneous assessment of the relative effect of all pairs of competing alternatives. Our framework informs clinicians of how to identify credible NMAs and address the certainty of the evidence. Trustworthy NMAs fill a critical gap in providing key inferences using direct and indirect evidence to inform clinical decision making when faced with more than two competing courses of treatment options. This document will help allergists to identify trustworthy NMAs to enhance patient care.  相似文献   
26.
Background/purposeAtypical clubfeet are distinct from idiopathic clubfeet. It is resistant to correction by conventional casting methods and often requires a modification of Ponseti's casting technique. Although the initial correction rates are reasonable, relapse and complications are frequent. There is limited literature on the results of modified Ponseti casting of these feet. We conducted this meta-analysis to study a few important aspects of atypical/complex clubfeet treatment by the modified Ponseti technique.Research questionWhat are the results of atypical or complex clubfeet after treatment by the modified Ponseti technique?MethodologyFive electronic databases (PubMed, Embase, Scopus, Ovid, and Cochrane Library) were searched for articles reporting on the results of atypical/complex clubfeet treated by the modified Ponseti technique. Details of the number of casts required for correction, rate of percutaneous Achilles tenotomy (PAT), other soft tissue procedures required, complications, and relapse rates were extracted into spreadsheets, and meta-analysis was carried out using OpenMeta Analyst software.ResultsTen studies were included for analysis with a total of 240 patients with 354 clubfeet. The initial correction was achieved in all feet. A pooled analysis of the data showed that a mean of six casts was required for the initial correction. The rate of PAT was 98.3%. The overall complication rate was 16.8%. 7.2% required an additional soft tissue procedure apart from the PAT, and relapse of the deformity was observed in a mean of 19.8% cases.ConclusionModified Ponseti technique is effective in the initial management of atypical/complex clubfeet. Although the PAT rate is slightly higher in the Modified Ponseti technique, the remaining result parameters are comparable with the results of idiopathic clubfoot managed with the Ponseti method of casting. However, these children should be kept under follow-up for a longer duration to find the exact relapse rates.  相似文献   
27.
28.
The discussion paper will focus on continuity of care relating to previous NZ research, specifically to transitioning complex preterm infants from NICU to home based on parent experiences, and on the practice developments that have occurred, to ensure optimal health outcomes. Previous NZ research discovered parent desire a consistent service delivery for the entire transition journey from NICU and at home.An informative and comprehensive opportunity has occurred for reflective professional practice, evaluation, development and implementation which have transpired in positive change through innovative practice developments and support change implementation in Wellington, NZ. This has resulted in the articulation of a model of care that has both embraced and integrated parental desires for a continuity of care process for complex preterm infants. This has been achieved by having the same Discharge Facilitator/Key Case Manager present within the NICU and external to the NICU for Home-based infants for the entire transition journey.The paper will focus and emphasis additional practice development changes and furthermore, will present a real purpose, for other countries to learn of such practice developments that have exemplified a celebratory success for families of Wellington, NZ.  相似文献   
29.
30.
肥厚型心肌病(HCM)是一种常见的遗传性心脏病,是青少年及年轻运动员心源性猝死的最主要原因之一,其分子遗传学基础为基因突变。TNNC1是HCM的重要致病基因之一,目前仅发现其少量非同义单核苷酸多态性(nsSNPs)位点与HCM发病相关,但该基因其他nsSNPs数量较多,结合临床进行实验遗传检测其基因型与表型的关系,工作量巨大,尚不可行。因此,采用生物信息学方法,从dbSNP数据库中筛选出TNNC1基因全部的nsSNPs,联合4款(Mutation Taster、PolyPhen-2、PhD-SNP和MutPred)专业软件,进行有害性分级筛选和致病关联预测,最后进行突变蛋白三维结构建模及可视化分析。结果显示,首次从TNNC1基因102个nsSNPs位点中预测出疾病相关的18个(G159D、S69R、P52R、D149G、D3V、G140E、N51K、D151V、M47R、G110C、A23D、G140R、K158N、C35Y、R147C、L48P、F74C和V44G)高风险nsSNPs。基于生物信息学方法,以TNNC1基因的nsSNPs为示范,分析其nsSNPs与疾病表型的关系,这为其他遗传疾病致病基因nsSNPs的关联分析打下理论研究基础,具有重要的参考价值。  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