全文获取类型
收费全文 | 31455篇 |
免费 | 4137篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 387篇 |
儿科学 | 875篇 |
妇产科学 | 834篇 |
基础医学 | 3476篇 |
口腔科学 | 577篇 |
临床医学 | 6079篇 |
内科学 | 5780篇 |
皮肤病学 | 640篇 |
神经病学 | 3409篇 |
特种医学 | 852篇 |
外国民族医学 | 5篇 |
外科学 | 4007篇 |
综合类 | 180篇 |
一般理论 | 16篇 |
预防医学 | 3856篇 |
眼科学 | 774篇 |
药学 | 1555篇 |
中国医学 | 38篇 |
肿瘤学 | 2354篇 |
出版年
2024年 | 114篇 |
2023年 | 766篇 |
2022年 | 637篇 |
2021年 | 1196篇 |
2020年 | 898篇 |
2019年 | 1076篇 |
2018年 | 1635篇 |
2017年 | 1423篇 |
2016年 | 1441篇 |
2015年 | 1519篇 |
2014年 | 1896篇 |
2013年 | 2133篇 |
2012年 | 2325篇 |
2011年 | 2322篇 |
2010年 | 1517篇 |
2009年 | 1530篇 |
2008年 | 1671篇 |
2007年 | 1587篇 |
2006年 | 1509篇 |
2005年 | 1353篇 |
2004年 | 1176篇 |
2003年 | 968篇 |
2002年 | 924篇 |
2001年 | 291篇 |
2000年 | 163篇 |
1999年 | 274篇 |
1998年 | 421篇 |
1997年 | 350篇 |
1996年 | 385篇 |
1995年 | 274篇 |
1994年 | 285篇 |
1993年 | 219篇 |
1992年 | 179篇 |
1991年 | 144篇 |
1990年 | 87篇 |
1989年 | 107篇 |
1988年 | 95篇 |
1987年 | 96篇 |
1986年 | 79篇 |
1985年 | 53篇 |
1984年 | 58篇 |
1983年 | 46篇 |
1982年 | 51篇 |
1981年 | 28篇 |
1980年 | 31篇 |
1979年 | 23篇 |
1978年 | 21篇 |
1976年 | 25篇 |
1974年 | 25篇 |
1971年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Kienbaum Peter Schaefer Maximilian S. Weibel Stephanie Schlesinger Tobias Meybohm Patrick Eberhart Leopold H. Kranke Peter 《Der Anaesthesist》2022,71(2):123-128
Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster... 相似文献
2.
Kuo-yi Jade Chang MHealthEc MHM BSc Lisa Lorraine Dillon MSpecEd BPsych Lil Deverell COMS PhD MEd GradDipO&M BEd Mei Ying Boon PhD BOptom FAAO Lisa Keay PhD MPH BOptom 《Clinical & experimental optometry》2020,103(4):434-448
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual. 相似文献
3.
4.
Stephanie Kay Kolar 《Addiction Research & Theory》2016,24(1):25-31
Aims: Relapse rates among cigarette smokers are high. Few studies have examined time-to-relapse using survival analysis in racially/ethnically diverse smokers and initial abstinence criteria have been inconsistent or unspecified. This study compared survival curves using two common definitions of initial abstinence. We hypothesized greater relapse rates among participants abstinent for only 24 hours (h) at the end-of-therapy (EOT) compared with 7 days. Methods: Adult smokers (59% Black, 22% Hispanic and 17% White) received 8-sessions of group cognitive behavioural therapy (CBT) plus transdermal nicotine patches and were assessed monthly up to 12 months post-EOT. Participants reporting abstinence (7-day point prevalence abstinence [ppa] or 24-h ppa) at the EOT were included in Kaplan–Meier curves. Results: Of 301 participants, 120 (40%) reported 7-day ppa at the EOT and an additional 29 (10%) reported 24-h ppa only. Over the 12-month follow-up period, nearly 50% remained abstinent. Of those who resumed smoking, most relapses occurred within the first three months. Survival curves indicated that median survival was 207 and 225 days for 7-day and 24-h definitions of abstinence, respectively. The difference in time-to-relapse between participants abstinent for 24?h at the EOT versus 7-days was not significant (p?=?0.14). Conclusions: Operationalization of initial abstinence is important for relapse analyses and comparisons of survival curves across samples. Participants reported high rates of abstinence and relapse rates were relatively low. Contrary to expectations, 24-h ppa at the EOT was not associated with greater relapse than 7-day abstinence. This suggests either measure may be utilized in relapse prevention research in racially/ethnically diverse treatment-seekers. 相似文献
5.
A mixed‐method study of effects of a therapeutic play intervention for children on parental anxiety and parents' perceptions of the intervention
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
6.
Haya Mohammed BSc MChB M. Yousuf Salmasi MRCS Massimo Caputo PhD Gianni D. Angelini PhD Hunaid A. Vohra PhD 《Journal of cardiac surgery》2020,35(6):1209-1219
Background
Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.Methods
PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.Results
Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.Conclusions
MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.7.
Toidi Adekambi Chris C. Ibegbu Stephanie Cagle Ameeta S. Kalokhe Yun F. Wang Yijuan Hu Cheryl L. Day Susan M. Ray Jyothi Rengarajan 《The Journal of clinical investigation》2015,125(5):1827-1838
BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection.METHODS. Using polychromatic flow cytometry, we evaluated the expression of immune activation markers on Mtb-specific CD4+ T cells from individuals with asymptomatic latent Mtb infection (LTBI) and ATB as well as from ATB patients undergoing anti-TB treatment.RESULTS. Frequencies of Mtb-specific IFN-γ+CD4+ T cells that expressed immune activation markers CD38 and HLA-DR as well as intracellular proliferation marker Ki-67 were substantially higher in subjects with ATB compared with those with LTBI. These markers accurately classified ATB and LTBI status, with cutoff values of 18%, 60%, and 5% for CD38+IFN-γ+, HLA-DR+IFN-γ+, and Ki-67+IFN-γ+, respectively, with 100% specificity and greater than 96% sensitivity. These markers also distinguished individuals with untreated ATB from those who had successfully completed anti-TB treatment and correlated with decreasing mycobacterial loads during treatment.CONCLUSION. We have identified host blood-based biomarkers on Mtb-specific CD4+ T cells that discriminate between ATB and LTBI and provide a set of tools for monitoring treatment response and cure.TRIAL REGISTRATION. Registration is not required for observational studies.FUNDING. This study was funded by Emory University, the NIH, and the Yerkes National Primate Center. 相似文献
8.
9.
Evaluation of training nurses to perform semi‐automated three‐dimensional left ventricular ejection fraction using a customised workstation‐based training protocol
下载免费PDF全文
![点击此处可从《Journal of clinical nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
10.