全文获取类型
收费全文 | 13464篇 |
免费 | 1390篇 |
国内免费 | 212篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 135篇 |
妇产科学 | 117篇 |
基础医学 | 1706篇 |
口腔科学 | 346篇 |
临床医学 | 1461篇 |
内科学 | 656篇 |
皮肤病学 | 49篇 |
神经病学 | 981篇 |
特种医学 | 310篇 |
外科学 | 486篇 |
综合类 | 3462篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 3360篇 |
眼科学 | 139篇 |
药学 | 964篇 |
13篇 | |
中国医学 | 441篇 |
肿瘤学 | 370篇 |
出版年
2024年 | 13篇 |
2023年 | 175篇 |
2022年 | 304篇 |
2021年 | 555篇 |
2020年 | 569篇 |
2019年 | 449篇 |
2018年 | 437篇 |
2017年 | 442篇 |
2016年 | 506篇 |
2015年 | 570篇 |
2014年 | 1152篇 |
2013年 | 1187篇 |
2012年 | 1050篇 |
2011年 | 1085篇 |
2010年 | 858篇 |
2009年 | 743篇 |
2008年 | 869篇 |
2007年 | 660篇 |
2006年 | 614篇 |
2005年 | 496篇 |
2004年 | 391篇 |
2003年 | 361篇 |
2002年 | 252篇 |
2001年 | 169篇 |
2000年 | 161篇 |
1999年 | 105篇 |
1998年 | 111篇 |
1997年 | 81篇 |
1996年 | 61篇 |
1995年 | 62篇 |
1994年 | 57篇 |
1993年 | 41篇 |
1992年 | 42篇 |
1991年 | 52篇 |
1990年 | 24篇 |
1989年 | 35篇 |
1988年 | 34篇 |
1987年 | 32篇 |
1986年 | 22篇 |
1985年 | 34篇 |
1984年 | 36篇 |
1983年 | 29篇 |
1982年 | 27篇 |
1981年 | 28篇 |
1980年 | 22篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1977年 | 7篇 |
1975年 | 6篇 |
1974年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
《Gait & posture》2021
BackgroundMeasuring dynamic vertical ground reaction force allows for assessment of important clinical and physical capacity factors such as weight bearing asymmetry, force distribution, and rate of force development. However, current technologies for accurately assessing ground reaction force are typically expensive.Research QuestionThe aim of this study was to examine the validity and reliability of obtaining static and dynamic ground reaction force data from low-cost modified digital bathroom scales.MethodsFour modified bathroom scales, two units each of two different brands, were examined. Repeated mechanical loading trials were performed with known loads ranging from 0.01 to 65 kg, with acquired data compared against the known loading to calculate accuracy, hysteresis, and non-linearity. Dynamic trials consisting of 5 times sit-to-stand and weight-shifting were performed by 32 adults. Absolute and relative agreement intraclass correlation coefficient, and Pearson’s and Spearman’s correlations were performed to determine validity and reliability for the mechanical tests. Bland-Altmann plots were created for each comparison. Mean absolute error (MAE) and unbiased cross-correlation were performed on the dynamic data, comparing the calibrated data to the known values from a Bertec force platform.ResultsHysteresis and non-linearity were excellent (<0.2 % full-scale), and mechanical test results showed excellent reliability and validity. Cross-correlation results for the dynamic data were excellent, however MAE for the more rapid sit-to-stand task was higher than the slower weight-shifting test. This may have been due to the low default sampling rate for the lowest noise setting of the HX711 amplifier (10 Hz).SignificanceIn summary, our results suggest that digital bathroom scales can be easily and inexpensively modified to obtain accurate vertical ground reaction force data, with sensitivity to detect changes of as little as 0.01 kg. 相似文献
52.
53.
《Health & place》2019
Within the growing body of research linking neighbourhood environmental attributes with physical activity, associations between recreational destinations and non-walking leisure-time physical activity (LTPA) are rarely studied, and to date, not across multiple cities. We examined six potential associations of objectively-measured access to private recreational facilities (e.g., fitness centres, swimming pools) and parks with adults’ non-walking LTPA (e.g., swimming, cycling, tennis), using data gathered with consistent methods from adults living in international cities with a range of environment attributes. The potential effects of socio-demographic moderators and between-city variations were also examined. Data from 6725 adults from 10 cities (6 countries) were gathered. Adults were more likely to engage in non-walking LTPA if they had a greater number of private recreational facilities within 0.5 or 1 km of the home, particularly in women, and if they lived closer to a park. The amount of non-zero LTPA was only associated (positively) with the number of recreational facilities within 1 km. Relationships between amount of LTPA and park proximity appear complex, with likely contextual and cultural differences. Improving access to private recreational facilities could promote non-walking LTPA, especially in women. 相似文献
54.
目的:探讨醛-酮还原酶家族7成员A3(AKR7A3)在肺腺癌中的异常表达及与临床病理特征的关系,并探究其临床意义。方法:采用生物信息学数据库分析、免疫组化、Western Blot、Real-time PCR等方法对肺腺癌组织及不同细胞中AKR7A3的表达进行检测与分析。结果:Oncomine数据库分析结果显示,在肺腺癌中,AKR7A3的表达普遍高于正常肺组织,分别为正常肺组织的1.811倍(P=0.022)、1.356倍(P<0.01)、1.413倍(P=0.002)。Kaplan-Meier Plotter数据库分析结果显示,AKR7A3高表达的患者较低表达的患者生存时间缩短,差异具有统计学意义(P=0.003 7)。免疫组化染色显示肺腺癌组织中AKR7A3的表达较癌旁增高,在与临床病理特征的相关性分析中,发现其与肿瘤分化程度(P<0.01)、淋巴结转移情况(P=0.029)以及TNM分期(P<0.01)相关,且会造成患者生存时间缩短(P=0.031)。Cox多因素分析表明AKR7A3可能是影响肺腺癌患者预后的独立危险因素(P=0.012)。Western Blot及Real-time PCR实验提示不同肺腺癌细胞中AKR7A3蛋白及mRNA表达普遍增高。结论:AKR7A3在肺腺癌中表达增高,对预后有不良影响,有促进肿瘤发生发展的作用。 相似文献
55.
56.
《Gait & posture》2019
BackgroundSpine posture, range of motion (ROM) and movement asymmetry can contribute to low back pain (LBP). These variables may have greater impact in populations required to perform repetitive spine movements, such as dancers; however, there is limited evidence to support this.Research questionWhat is the influence of dance and LBP on spinal kinematics?MethodsIn this cross-sectional study, multi-segment spinal kinematics were examined in 60 female participants, including dancers (n = 21) and non-dancers (n = 39) with LBP (n = 33) and without LBP (n = 27). A nine-camera motion analysis system sampling at 100 Hz was used to assess standing posture, as well as ROM and movement asymmetry for side bend and trunk rotation tasks. A two-way ANOVA was performed for each of the outcome variables to detect any differences between dancers and non-dancers, or individuals with and without LBP.ResultsCompared to non-dancers, dancers displayed a flatter upper lumbar angle when standing (p < 0.01, ηp2 = 0.15), and achieved greater frontal plane ROM for the upper lumbar (p = 0.04, ηp2 = 0.08) and lower thoracic (p = 0.02, ηp2 = 0.09) segments. There were no differences between dancers and non-dancers for transverse plane ROM (p > 0.05) or movement asymmetry (p > 0.05). There was no main effect for LBP symptoms on any kinematic measures, and no interaction effect for dance group and LBP on spinal kinematics (p > 0.05).SignificanceFemale dancers displayed a flatter spine posture and increased spine ROM compared to non-dancers for a select number of spine segments and movement tasks. However, the overall number of differences was small, and no relationship was observed between LBP and spinal kinematics. This suggests that these simple, static posture, ROM, and asymmetry measures often used in clinical practice can provide only limited generalisable information about the impact of dance or LBP on spinal kinematics. 相似文献
57.
疫情背景下社交媒体信息过载的影响及应对研究综述 《医学教育管理》2020,6(3):220-224
信息过载指由于所接受的信息的数量过大、导致人们在一定时间内不能有效处理和使用信息的一种现象。疫情背景下,除了疫情本身可能会对个体心理产生影响外,长时间暴露于社交媒体中过量的、重复的、真假不一且来源多样的信息下同样有可能导致一系列不良的认知、情绪和行为后果。本研究对社交媒体信息过载的类型、影响、成因等相关研究进行了综述,并对可能的应对策略进行了总结。 相似文献
58.
YouTube as a source of medical information on the novel coronavirus 2019 disease (COVID-19) pandemic
Ryan S. D’Souza Shawn D’Souza Natalie Strand Alexandra Anderson Matthew N. P. Vogt Oludare Olatoye 《Global public health》2020,15(7):935-942
ABSTRACT Media coverage on coronavirus disease 2019 (COVID-19) has been extensive, yet large gaps remain in our understanding of the role of social media platforms during worldwide health crisis. The purpose of this study was to assess the most viewed YouTube videos on COVID-19 for medical content. We coded video characteristics, source, and medical content of the 113 most-widely viewed videos about COVID-19. Seventy-nine (69.9%) videos were classified as useful, and 10 (8.8%) videos were classified as misleading. Independent users were more likely to post misleading videos than useful videos (60.0% vs 21.5%, P?=?0.009). News agencies were more likely to post useful videos than misleading videos (72.2% vs 40.0%, P?=?0.039). Useful videos were more likely to present any information on prevalence or incidence (79.7% vs 20.0%, P?<?0.001), as well as information on outcomes or prognosis (84.8% vs 30.0%, P?<?0.001) compared to misleading videos. The World Health Organization contributed one useful video (1.3%), while no videos from the Center for Disease Control were included. Although YouTube generally is a useful source of medical information on the COVID-19 pandemic, increased efforts to disseminate accurate information from reputable sources is desired to help mitigate disease spread and decrease unnecessary panic in the general population. 相似文献
59.
Melinda Boss Peter Hartmann Jennifer Turner Douglas Pritchard Rafael Prez‐Escamilla Rhonda Clifford 《Maternal & child nutrition》2020,16(3)
During the last decade, there have been several publications highlighting the need for consistent terminology in breastfeeding research. Standard terms and definitions are essential for the comparison and interpretation of scientific studies that, in turn, support evidence‐based education, consistency of health care, and breastfeeding policy. Inconsistent advice is commonly reported by mothers to contribute to early weaning. A standard language is the fundamental starting point required for the provision of consistent advice. LactaPedia ( www.lactapedia.com ) is a comprehensive lactation glossary of over 500 terms and definitions created during the development of LactaMap ( www.lactamap.com ), an online lactation care support system. This paper describes the development of LactaPedia, a website that is accessible free of charge to anyone with access to the Internet. Multiple methodological frameworks were incorporated in LactaPedia's development in order to meet the needs of a glossary to support both consistent health care and scientific research. The resulting LactaPedia methodology is a six‐stage process that was developed inductively and includes framework to guide vetting and extension of its content using public feedback via discussion forums. The discussion forums support ongoing usability and refinement of the glossary. The development of LactaPedia provides a fundamental first step towards improving breastfeeding outcomes that are currently well below World Health Organisation recommendations globally. 相似文献
60.