全文获取类型
收费全文 | 27913篇 |
免费 | 2922篇 |
国内免费 | 1120篇 |
专业分类
耳鼻咽喉 | 733篇 |
儿科学 | 305篇 |
妇产科学 | 327篇 |
基础医学 | 1010篇 |
口腔科学 | 152篇 |
临床医学 | 5859篇 |
内科学 | 3388篇 |
皮肤病学 | 60篇 |
神经病学 | 6845篇 |
特种医学 | 685篇 |
外科学 | 2114篇 |
综合类 | 4012篇 |
现状与发展 | 5篇 |
预防医学 | 1465篇 |
眼科学 | 218篇 |
药学 | 1753篇 |
33篇 | |
中国医学 | 2769篇 |
肿瘤学 | 222篇 |
出版年
2024年 | 56篇 |
2023年 | 680篇 |
2022年 | 1030篇 |
2021年 | 1788篇 |
2020年 | 1760篇 |
2019年 | 1511篇 |
2018年 | 1565篇 |
2017年 | 1482篇 |
2016年 | 1438篇 |
2015年 | 1224篇 |
2014年 | 2368篇 |
2013年 | 2618篇 |
2012年 | 1827篇 |
2011年 | 1733篇 |
2010年 | 1428篇 |
2009年 | 1166篇 |
2008年 | 1120篇 |
2007年 | 1121篇 |
2006年 | 1017篇 |
2005年 | 752篇 |
2004年 | 663篇 |
2003年 | 544篇 |
2002年 | 510篇 |
2001年 | 414篇 |
2000年 | 314篇 |
1999年 | 295篇 |
1998年 | 205篇 |
1997年 | 152篇 |
1996年 | 112篇 |
1995年 | 127篇 |
1994年 | 138篇 |
1993年 | 95篇 |
1992年 | 86篇 |
1991年 | 56篇 |
1990年 | 62篇 |
1989年 | 64篇 |
1988年 | 53篇 |
1987年 | 47篇 |
1986年 | 55篇 |
1985年 | 43篇 |
1984年 | 36篇 |
1983年 | 41篇 |
1982年 | 45篇 |
1981年 | 21篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 18篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
14.
Objective: To observe the effects and safety of Tongyan Spray (通咽喷雾剂) on the range and time of hyoid motion in patients with ischemic post-stroke dysphagia. Methods: Seventy-two patients with ischemic post-stroke dysphagia were selected and randomly assigned to a treatment group (36 cases) and a control group (36 cases) by a random number table from January 2013 to October 2014. All patients swallowed 4 kinds of barium meals with different traits respectively, and each patient underwent video fluoroscopy (VF) examination twice. In the treatment group, Tongyan Spray was sprayed to the pharynx on both sides and the middle part once respectively. The spray was applied 30 min before the second examination. Purified water at room temperature was used as placebo in the control group. The changes in the range and time of hyoid motion in both groups were observed before and after treatment. Results: Six patients dropped out in each group, and 60 patients completed the study and were included in the final analysis. Significant improvement was observed in the range of superior hyoid excursion distance and the time of hyoid motion in the treatment group compared with the control group (P<0.05). There were no obvious adverse reactions observed in oral mucosa in both groups during the whole study. Conclusion: Tongyan Spray was an effective and safe medicine for improving swallowing function in patients with ischemic post-stroke dysphagia. 相似文献
16.
Background:Acute ischemic stroke (AIS) is an important factor leading to adult death and disability globally. For AIS patients who meet certain conditions, recombinant tissue plasminogen activator (rt-PA) intravenous thrombolysis is an important method recommended by national guidelines to achieve vascular recanalization. However, complications such as hemorrhagic transformation and vascular reocclusion after thrombolysis are still unsolved problems in clinical. Several systematic reviews of clinical randomized controlled trials (RCTs) in the past have shown that Chinese herbal injections (CHIs) can improve the neurological function of patients, increase the tolerance of ischemic tissues to hypoxia, and inhibit platelet aggregation. Therefore, this study conducted a meta-analysis of AIS treatment with intravenous thrombolysis alone and compared it with the combined application of CHIs. To evaluate whether CHIs have a synergistic effect on thrombolytic therapy and provide a basis for clinical application.Methods:The following databases will be searched until September 2020: ①English databases: PubMed, Cochrane Library, Embase; ②Chinese databases: CNKI, Wanfang database, Weipu database, SinoMed. RCTs will be included to compare the efficacy of thrombolysis combined with CHIs and thrombolysis alone in the treatment of AIS. Data extraction and risk of bias assessments will be carried out by 2 verifiers independently. The risk of bias will be evaluated through the Cochrane risk of bias tool. Review Manager software 5.3 will be used for statistical analysis.Results:This study will provide comprehensive evidence for the treatment of AIS by CHIs combined with intravenous thrombolysis from multiple aspects.Conclusion:The conclusion of the meta-analysis will provide a basis for judging whether CHIs combined with intravenous thrombolysis is an effective measure for the treatment of AIS.Ethics and dissemination:Ethical approval is not needed because this study will be based on data that already published. We will publish the findings of this study in a peer-reviewed journal and related conferences.PROSPERO registration number:CRD42020215546. 相似文献
17.
《Diagnostic and interventional imaging》2021,102(10):629-639
PurposeTo investigate the reproducibility of diffusion-weighted (DW) MRI and 18F-Fluorodeoxyglucose (18F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.Materials and methodsTen women (median age, 67 years; range: 41.8–77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥ 1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients × 5 sites × 3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).ResultsFor both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained > 0.8 for PET/CT. Inter- and intra-observer ICCs were > 0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013–0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P = 0.0023, P< 0.0001 and P =0.0028, respectively).ConclusionWhile both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy. 相似文献
18.
19.
《Journal of the American College of Radiology》2021,18(6):820-833
PurposeNational guidelines recommend prompt identification of candidates for acute ischemic stroke (AIS) treatment, requiring timely neuroimaging with CT and/or MRI. CT is often preferred because of its widespread availability and rapid acquisition. Despite higher diagnostic accuracy of MRI, it commonly involves complex workflows that could potentially cause treatment time delays. The purpose of this study was to analyze the impact on outcomes of imaging utilization before treatment decisions at comprehensive stroke centers for patients presenting with suspected AIS in the anterior circulation with last-known-well-to-arrival time 0 to 24 hours.MethodsA decision simulation model based on the American Heart Association’s recommendations for AIS care pathways was developed from a health care perspective to compare initial imaging strategies: (1) stepwise-CT: noncontrast CT (NCCT) at the time of presentation, with CT angiography (CTA) ± CT perfusion (CTP) only in select patients (initial imaging to exclude hemorrhage and extensive ischemia) for mechanical thrombectomy (MT) evaluation; (2) stepwise-hybrid: NCCT at the time of presentation, with MR angiography (MRA) ± MR perfusion (MRP) only for MT evaluation; (3) stepwise-advanced: NCCT + CTA at presentation, with MR diffusion-weighted imaging (MR DWI) + MRP only for MT evaluation; (4) comprehensive-CT: NCCT + CTA + CTP at the time of presentation; and (5) comprehensive-MR: MR DWI + MRA + MRP at the time of presentation. Model parameters were defined using evidence-based data. Cost-effectiveness and sensitivity analyses were performed.ResultsThe cost-effectiveness analyses revealed that comprehensive-CT and comprehensive-MR yield the highest lifetime quality-adjusted life-years (QALYs) (4.81 and 4.82, respectively). However, the incremental cost-effectiveness ratio of comprehensive-MR is $233,000/QALY compared with comprehensive-CT. Stepwise-CT, stepwise-hybrid, and stepwise-advanced strategies are dominated, yielding lower QALYs and higher costs compared with comprehensive-CT.ConclusionsPerforming comprehensive-CT at presentation is the most cost-effective initial imaging strategy at comprehensive stroke centers. 相似文献
20.
Viviane Rostirola Elsner Lucieli Trevizol Isadora de Leon Marcos da Silva Thayn Weiss Milena Braga Daniela Pochmann Amanda Stolzenberg Blembeel Caroline Dani Elenice Boggio 《中国神经再生研究》2021,16(5):805
A growing body of evidence has suggested that the imbalance of epigenetic markers and oxidative stress appears to be involved in the pathophysiology and progression of stroke. Thus, strategies that modulate these biomarkers might be considered targets for neuroprotection and novel therapeutic opportunities for these patients. Physical exercise has been reported to induce changes in these epigenetic markers and improve clinical outcomes in different populations. However, little is reported on this in post-stroke patients. The purpose of this study was to investigate the effect of a single exercise session with Walk Aide functional electrical stimulation(FES) on cognitive performance, clinical functional parameters, oxidative stress and epigenetic modulation in post-stroke individuals. In this crossover design study, 12 post-stroke individuals aged 54–72 years of either sexes were included and subjected to a single session of exercise(45 minutes) without Walk Aide functional electrical stimulation(EXE alone group), followed by another single session of exercise(45 minutes) with Walk Aide functional electrical stimulation(EXE + FES group). The clinical functional outcome measures, cognitive performance and blood collections for biomarker measurements were assessed pre-and post-intervention. After intervention, higher Berg Balance Scale scores were obtained in the EXE + FES group than in the EXE alone group. There was no significant difference in the Timed Up and Go test results post-intervention between EXE alone and EXE + FES groups. After intervention, a better cognitive performance was found in both groups compared with before the intervention. After intervention, the Timed Up and Go test scores were higher in the EXE + FES group than in the EXE alone group. In addition, the intervention induced lower levels of lipid peroxidation. After intervention, carbonyl level was lower, superoxide dismutase activity and superoxide dismutase/catalase activity ratio were higher in the EXE + FES group, compared with the EXE group alone. In each group, both histone deacetylase(HDAC2) and histone acetyltransferase activities were increased after intervention compared with before the intervention. These findings suggest that a single exercise session with Walk Aide FES is more effective on balance ability and cognitive performance compared with conventional exercise alone in post-stroke patients. This is likely to be related to the regulation of oxidative stress markers. The present study was approved by the Research Ethics Committee of the Methodist University Center-IPA(approval No. 2.423.376) on December 7, 2017 and registered in the Brazilian Registry of Clinical Trials—Re BEC(RBR-9 phj2 q) on February 11, 2019. 相似文献