全文获取类型
收费全文 | 220203篇 |
免费 | 4148篇 |
国内免费 | 202篇 |
专业分类
耳鼻咽喉 | 1654篇 |
儿科学 | 8047篇 |
妇产科学 | 3608篇 |
基础医学 | 22072篇 |
口腔科学 | 2169篇 |
临床医学 | 16766篇 |
内科学 | 41134篇 |
皮肤病学 | 1516篇 |
神经病学 | 20496篇 |
特种医学 | 10663篇 |
外科学 | 36632篇 |
综合类 | 2679篇 |
一般理论 | 81篇 |
预防医学 | 21175篇 |
眼科学 | 3917篇 |
药学 | 11850篇 |
中国医学 | 672篇 |
肿瘤学 | 19422篇 |
出版年
2023年 | 364篇 |
2022年 | 714篇 |
2021年 | 1654篇 |
2020年 | 826篇 |
2019年 | 1362篇 |
2018年 | 23334篇 |
2017年 | 18327篇 |
2016年 | 20558篇 |
2015年 | 2207篇 |
2014年 | 2617篇 |
2013年 | 2903篇 |
2012年 | 10532篇 |
2011年 | 24471篇 |
2010年 | 20643篇 |
2009年 | 13223篇 |
2008年 | 22346篇 |
2007年 | 24494篇 |
2006年 | 3416篇 |
2005年 | 4847篇 |
2004年 | 5976篇 |
2003年 | 6571篇 |
2002年 | 4576篇 |
2001年 | 812篇 |
2000年 | 889篇 |
1999年 | 657篇 |
1998年 | 649篇 |
1997年 | 565篇 |
1996年 | 371篇 |
1995年 | 369篇 |
1994年 | 297篇 |
1993年 | 267篇 |
1992年 | 299篇 |
1991年 | 329篇 |
1990年 | 341篇 |
1989年 | 273篇 |
1988年 | 196篇 |
1987年 | 189篇 |
1986年 | 155篇 |
1985年 | 166篇 |
1984年 | 140篇 |
1983年 | 145篇 |
1982年 | 145篇 |
1981年 | 93篇 |
1980年 | 113篇 |
1979年 | 83篇 |
1978年 | 73篇 |
1977年 | 66篇 |
1974年 | 58篇 |
1973年 | 57篇 |
1938年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Karl Johnson Katherine W. Saylor Isabella Guynn Karen Hicklin Jonathan S. Berg Kristen Hassmiller Lich 《Genetics in medicine》2022,24(2):262-288
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing. 相似文献
2.
3.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome. 相似文献
4.
Abd-Allah H. El Ashmawy Kathleen Dowson Ahmed El-Bakoury Hazem A.H. Hosny Rathan Yarlagadda Jonathan Keenan 《The Journal of arthroplasty》2021,36(3):816-822.e1
BackgroundTotal hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients’ satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic.MethodsA total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up.ResultsThe VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients’ satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up.ConclusionVJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients. 相似文献
5.
6.
Clinical & Experimental Metastasis - 相似文献
7.
Vasundhara Sridharan Yuichi Shoda Jaimee L. Heffner Jonathan Bricker 《Substance use & misuse》2019,54(7):1086-1095
Background: Lay belief systems about the malleability of human attributes have been shown to impact behavior change in multiple domains. Addiction mindset—i.e., beliefs about the permanence (vs. malleability) of addiction — may affect cigarette smokers’ ability to quit, but this has never been examined. Objectives: The aims of the present research were to develop a measure of addiction mindset (study 1) and examine its associations with various psychological aspects of quitting smoking (study 2). Methods: In Study 1, using factor analysis of current smokers’ and nonsmokers’ (n?=?600) responses to 22 items designed to measure addiction mindset, we developed a reliable six-item Addiction Mindset Scale (AMS). In Study 2, adult smokers (n?=?200) completed the AMS, and measures of a number of psychological processes related to smoking. Results: Higher scores on the AMS, indicative of the belief that addiction is malleable (referred to as a growth mindset), were positively and significantly associated with greater motivation to quit, greater commitment to quitting, greater self-efficacy to abstain, less attribution of failure to lack of ability to change addiction, and fewer self-reported barriers to cessation (all p’s < .05). Conclusions: The results of this study show a relationship between the beliefs about the permanence of addiction and psychological processes relevant to quitting smoking. The findings underscore the potential of future research exploring how addiction mindsets relate to successful smoking cessation as well as other types of addictive behavior and how they can be applied to change people’s behavior. 相似文献
8.
9.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
10.