全文获取类型
收费全文 | 50808篇 |
免费 | 4135篇 |
国内免费 | 1373篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 1446篇 |
妇产科学 | 257篇 |
基础医学 | 3462篇 |
口腔科学 | 85篇 |
临床医学 | 6769篇 |
内科学 | 16027篇 |
皮肤病学 | 216篇 |
神经病学 | 398篇 |
特种医学 | 2042篇 |
外国民族医学 | 8篇 |
外科学 | 3556篇 |
综合类 | 10497篇 |
现状与发展 | 7篇 |
预防医学 | 3722篇 |
眼科学 | 144篇 |
药学 | 4640篇 |
60篇 | |
中国医学 | 1960篇 |
肿瘤学 | 930篇 |
出版年
2024年 | 115篇 |
2023年 | 753篇 |
2022年 | 1249篇 |
2021年 | 2315篇 |
2020年 | 2282篇 |
2019年 | 1917篇 |
2018年 | 1930篇 |
2017年 | 1965篇 |
2016年 | 2165篇 |
2015年 | 2212篇 |
2014年 | 3695篇 |
2013年 | 4091篇 |
2012年 | 3375篇 |
2011年 | 3467篇 |
2010年 | 2789篇 |
2009年 | 2434篇 |
2008年 | 2326篇 |
2007年 | 2425篇 |
2006年 | 2235篇 |
2005年 | 1911篇 |
2004年 | 1523篇 |
2003年 | 1267篇 |
2002年 | 1018篇 |
2001年 | 887篇 |
2000年 | 758篇 |
1999年 | 649篇 |
1998年 | 527篇 |
1997年 | 509篇 |
1996年 | 491篇 |
1995年 | 421篇 |
1994年 | 371篇 |
1993年 | 286篇 |
1992年 | 283篇 |
1991年 | 215篇 |
1990年 | 210篇 |
1989年 | 168篇 |
1988年 | 161篇 |
1987年 | 132篇 |
1986年 | 119篇 |
1985年 | 149篇 |
1984年 | 119篇 |
1983年 | 63篇 |
1982年 | 61篇 |
1981年 | 58篇 |
1980年 | 52篇 |
1979年 | 39篇 |
1978年 | 28篇 |
1977年 | 27篇 |
1976年 | 25篇 |
1975年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
62.
Anne-Marie Selzler Veronica Moore Razanne Habash Lauren Ellerton Erica Lenton Roger Goldstein 《COPD》2020,17(4):452-461
Abstract The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest. 相似文献
63.
A hypothesis for reactivation of pulmonary tuberculosis: How thoracic wall shape affects the epidemiology of tuberculosis 下载免费PDF全文
Aaron R. Casha Liberato Camilleri Alexander Manché Ruben Gatt Daphne Attard Wiktor Wolak Krzysztof Dudek Marilyn Gauci Christopher Giordimaina Joseph N. Grima 《Clinical anatomy (New York, N.Y.)》2015,28(5):614-620
This study was aimed at determining the cause for the high incidence of tuberculosis (TB) reactivation occurring in males with a low body mass index (BMI). Current thinking about pulmonary TB describes infection in the lung apex resulting in cavitation after reactivation. A different hypothesis is put forward for TB infection, suggesting that this occurs in subclinical apical cavities caused by increased pleural stress due to a low BMI body habitus. A finite element analysis (FEA) model of a lung was constructed including indentations for the first rib guided by paramedian sagittal CT reconstructions, and simulations were conducted with varying antero‐posterior (AP) diameters to mimic chests with a different thoracic index (ratio of AP to the transverse chest diameters). A Pubmed search was conducted about gender and thoracic index, and the effects of BMI on TB. FEA modeling revealed a tenfold increase in stress levels at the lung apex in low BMI chests, and a four‐fold increase with a low thoracic index, r2 = 0.9748 P < 0.001. Low thoracic index was related to BMI, P = 0.001. The mean thoracic index was statistically significantly lower in males, P = 0.001, and increased with age in both genders. This article is the first to suggest a possible mechanism linking pulmonary TB reactivation to low BMI due to the flattened thoracic wall shape of young male adults. The low thoracic index in young males may promote TB reactivation due to tissue destruction in the lung apex from high pleural stress levels. Clin. Anat. 28:614–620, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
64.
Leonardo Jönck Staub Roberta Rodolfo Mazzali Biscaro Erikson Kaszubowski Rosemeri Maurici 《The Journal of emergency medicine》2019,56(1):53-69
Background
Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.Objective
Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.Methods
PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).Results
Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.Conclusion
Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. 相似文献65.
66.
目的探讨先天性中枢性低通气综合征(CCHS)的临床和基因变异特征。方法分析1例首发表现为不明原因肺动脉高压的CCHS患儿的临床资料,并总结国内外文献中CCHS病例的临床特点、致病机制和基因变异情况。结果11月龄女婴,主要表现为浮肿、尿少、低血压、嗜睡、发绀、抽搐及颅内压增高。B型脑利钠肽、丙氨酸氨基转移酶升高,凝血酶原时间延长。颅脑磁共振示右侧额叶出血;超声心动图示中重度肺动脉高压。靶向捕获二代测序未发现可能的致病基因。采用Sanger法验证示患儿PHOX 2 B基因第3外显子存在多聚丙氨酸重复扩展变异,基因型为20/25。患儿入院后采用无创通气,睡眠时呼吸浅慢、微弱,伴血氧下降;血气分析提示二氧化碳潴留。随后改用夜间无创通气、降肺压药物治疗。复查肺动脉压力明显下降,生命体征稳定。随访至24月龄,夜间只需较低压力水平的无创通气,生长发育无异常。结论对于不明原因的肺动脉高压伴撤机困难患儿,需警惕CCHS。疑诊者应尽早针对CCHS相关基因进行靶向捕获二代测序及PHOX 2 B基因Sanger法验证。早期给予无创通气有望改善预后。 相似文献
67.
结核病是由结核分枝杆菌复合群引起的传染性疾病,是全球主要的流行病种之一。利福平是当前最主要的一线抗结核药物,因其长期应用和不规范治疗,利福平耐药逐渐增加,利福喷丁、利福布汀等利福霉素类衍生物在抗结核治疗方面起到了重要作用。基于利福霉素类药物的药理及药动学特性,对该类药物在结核病治疗中进行最优用药选择分析,并对该类药物与其他抗结核药物联用进行综述,旨在为利福霉素类抗结核药物的临床用药提供文献依据。 相似文献
68.
重症心源性肺水肿伴休克患者的机械通气治疗 总被引:3,自引:0,他引:3
目的研究重症心源性肺水肿伴休克患者机械通气(MV)治疗时通气压力的选择对预后的影响。方法将符合标准的22例患者分为两组对照组9例,常规给予较低通气压力和加强药物治疗;治疗组13例,适当增加通气压力。观察血压、临床症状和动脉血气的变化。结果调整MV后30分钟时,治疗组收缩压迅速由(95±12)mmHg升至(130±15)mmHg(P<0.001),呼吸频率(RR)由(38±11)次/min降至(27±6)次/min(P<0.005),心率(HR)由(126±15)次/min降至(105±12)次/min(P<0.001);对照组上述指标变化不明显。2小时后治疗组的升压药用量减少(70±15)%,对照组则增加(20±5)%;同时在吸氧浓度不变的情况下,治疗组的PaO2由(81±12)mmHg升至(140±15)mmHg(P<0.001),明显高于对照组PaO2的改善。24~48小时内治疗组11例患者(85%)停用升压药,对照组2例(22%)停用。最终治疗组100%的患者好转出院,对照组为45%(P<0.05)。结论与低压力通气相比,适当增加MV通气压力不仅可迅速改善重症心源性水肺肿伴休克患者的低氧血症,也可迅速升高血压,改善心功能,降低病死率。 相似文献
69.
目的了解结核病患者的心理状态,并给予相应治疗,以观察其疗效。方法采用医院焦虑抑郁情绪调查表,对2004年1月—2005年1月收治的130名结核病患者进行心理测评,对心理治疗前后患者心态的变化进行u检验。结果回收有效问卷123份,调查发现心理状态变异者占90.2%(111/123),其中焦虑型患者占56.1%(69/123),抑郁型患者占21.1%(26/123),无所用心型患者占13.0%(16/123),心理状态稳定者仅占9.8%(12/123)。给予相应心理治疗后患者心态较治疗前显著改善(P<0.01),心理状态变异者由治疗前的90.2%减少为治疗后的11.4%(14/123),心理状态稳定者由治疗前的9.8%提高到治疗后的88.6%(109/123)。结论结核病患者存在严重的心理问题,在治疗过程中开展心理治疗是十分必要的。 相似文献
70.