全文获取类型
| 收费全文 | 4482370篇 |
| 免费 | 355561篇 |
| 国内免费 | 15635篇 |
专业分类
| 耳鼻咽喉 | 61161篇 |
| 儿科学 | 142820篇 |
| 妇产科学 | 116789篇 |
| 基础医学 | 682060篇 |
| 口腔科学 | 124249篇 |
| 临床医学 | 408031篇 |
| 内科学 | 811923篇 |
| 皮肤病学 | 109507篇 |
| 神经病学 | 372020篇 |
| 特种医学 | 175723篇 |
| 外国民族医学 | 523篇 |
| 外科学 | 682960篇 |
| 综合类 | 133586篇 |
| 现状与发展 | 24篇 |
| 一般理论 | 2598篇 |
| 预防医学 | 372180篇 |
| 眼科学 | 106606篇 |
| 药学 | 314778篇 |
| 28篇 | |
| 中国医学 | 12682篇 |
| 肿瘤学 | 223318篇 |
出版年
| 2021年 | 57001篇 |
| 2020年 | 36140篇 |
| 2019年 | 59399篇 |
| 2018年 | 75254篇 |
| 2017年 | 57428篇 |
| 2016年 | 63780篇 |
| 2015年 | 76823篇 |
| 2014年 | 111481篇 |
| 2013年 | 177198篇 |
| 2012年 | 124855篇 |
| 2011年 | 130321篇 |
| 2010年 | 127200篇 |
| 2009年 | 128129篇 |
| 2008年 | 115572篇 |
| 2007年 | 123166篇 |
| 2006年 | 131215篇 |
| 2005年 | 125783篇 |
| 2004年 | 127045篇 |
| 2003年 | 116484篇 |
| 2002年 | 105147篇 |
| 2001年 | 173690篇 |
| 2000年 | 169501篇 |
| 1999年 | 153752篇 |
| 1998年 | 73396篇 |
| 1997年 | 68744篇 |
| 1996年 | 66830篇 |
| 1995年 | 62493篇 |
| 1994年 | 56416篇 |
| 1993年 | 52433篇 |
| 1992年 | 112201篇 |
| 1991年 | 107873篇 |
| 1990年 | 103217篇 |
| 1989年 | 100400篇 |
| 1988年 | 92457篇 |
| 1987年 | 90498篇 |
| 1986年 | 85589篇 |
| 1985年 | 83890篇 |
| 1984年 | 69716篇 |
| 1983年 | 61673篇 |
| 1982年 | 48934篇 |
| 1981年 | 45452篇 |
| 1980年 | 42690篇 |
| 1979年 | 59521篇 |
| 1978年 | 47821篇 |
| 1977年 | 42597篇 |
| 1976年 | 39345篇 |
| 1975年 | 39138篇 |
| 1974年 | 43003篇 |
| 1973年 | 41413篇 |
| 1972年 | 38668篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
101.
AbstractPurpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.
- Implications for rehabilitation
This proposed system will help the visually impaired to
ensure secure navigation
be independent of the others
develop self confidence.
overcome the training, affordability of wearable/ handheld devices.
102.
Christopher R. LaFever 《Death Studies》2020,44(12):819-822
103.
104.
105.
Jeroen M. van de Pol Jurjen G. Geljon Svetlana V. Belitser Geert W.J. Frederix Anke M. Hövels Marcel L. Bouvy 《Research in social & administrative pharmacy》2019,15(1):70-76
Introduction
The nature of community pharmacy is changing, shifting from the preparation and distribution of medicines to the provision of cognitive pharmaceutical services (CPS); however, often the provision of traditional services leaves little time for innovative services. This study investigated the time community pharmacists spend on the tasks and activities of daily practice and to what extent they are able to implement CPS-related services in daily practice.Methods
Self-reporting work sampling was used to register the activities of community pharmacists. A smartphone application, designed specifically for this purpose, alerted participants to register their current activity five times per working day for 6 weeks. Participants also completed an online survey about baseline characteristics.Results
Ninety-one Dutch community pharmacists provided work-sampling data (7848 registered activities). Overall, 51.5% of their time was spent on professional activities, 35.4% on semi-professional activities, and 13.1% on non-professional activities. The proportion of time devoted to CPS decreased during the workweek, whereas the time spent on traditional task increased.Discussion and conclusion
This study shows it is feasible to collect work-sampling data using smartphone technology. Community pharmacists spent almost half of their time on semi-professional and non-professional activities, activities that could be delegated to other staff members. In practice, the transition to CPS is hampered by competing traditional tasks, which prevents community pharmacists from profiling themselves as pharmaceutical experts in daily practice. 相似文献106.
107.
108.
J. Rodríguez-Carrio A. Martínez-Zapico I. Cabezas-Rodríguez L. Benavente Á.I. Pérez-Álvarez P. López J.B. Cannata-Andía M. Naves-Díaz A. Suárez 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):135-143
Background and aims
Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.Methods and results
In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.Conclusion
SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE. 相似文献109.
Maggie L. Westfal David C. Chang Cassandra M. Kelleher 《Journal of pediatric surgery》2019,54(1):140-144
Purpose
The purpose of this study was to evaluate trends in demographics and outcomes of pediatric breast cancer in a United States population-based cohort.Methods
The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant breast tumors between 1973 and 2014. Analysis was performed using Stata Statistical Software version 13.1. Associations between categorical variables were made using X2 test. Log-rank test was used for univariate survival analysis. Kaplan–Meier analysis investigated five-year survival rates across several variables. Adjusted analysis was performed using a Cox Proportional-Hazards regression.Results
134 patients with breast malignancies were identified. Carcinoma was the most prevalent histology (48.5%), followed by fibroepithelial tumors (FETs) (35.1%), and sarcoma (14.2%). FETs were twice as common in black compared to nonblack patients (56.3% vs. 29.0%, p?<?0.01). Analyzing histology by stage revealed that 100% of FETs were early stage disease (p?<?0.0001). 46.7% of the tumors tested were ER/PR negative, more than twice as many compared to the published adult estimate of 20.0%. Unadjusted survival analysis revealed worse survival for patients with adenocarcinoma/sarcomas, advanced stage, and high grade disease, without a survival difference between races.Conclusion
Breast cancer remains a rare malignancy among pediatric patients. Although black patients were found to have more noncarcinomatous tumors with less advanced disease, this did not confer a survival advantage.Type of study
Retrospective cohort study.Level of evidence
Level III. 相似文献110.
A. Ríos A.I. López-Navas M.A. Ayala G. Garrido M.J. Sebastián J. Carrillo Á. Sánchez J. Flores-Medina J.J. Ruiz-Manzanera A.M. Hernández P. Ramírez P. Parrilla 《Transplantation proceedings》2019,51(2):258-260
The Latin American population has a double way of immigration, one toward the United States by proximity and another toward Spain by sociocultural affinity. This population increase is affecting organ donation and transplantation in receiving countries.