全文获取类型
收费全文 | 178643篇 |
免费 | 1293篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 1152篇 |
儿科学 | 6747篇 |
妇产科学 | 3158篇 |
基础医学 | 16928篇 |
口腔科学 | 1786篇 |
临床医学 | 12773篇 |
内科学 | 31336篇 |
皮肤病学 | 852篇 |
神经病学 | 16615篇 |
特种医学 | 8991篇 |
外国民族医学 | 1篇 |
外科学 | 29048篇 |
综合类 | 2382篇 |
一般理论 | 7篇 |
预防医学 | 18374篇 |
眼科学 | 2822篇 |
药学 | 9754篇 |
中国医学 | 674篇 |
肿瘤学 | 16567篇 |
出版年
2023年 | 114篇 |
2022年 | 209篇 |
2021年 | 340篇 |
2020年 | 227篇 |
2019年 | 335篇 |
2018年 | 22223篇 |
2017年 | 17547篇 |
2016年 | 19702篇 |
2015年 | 1106篇 |
2014年 | 1050篇 |
2013年 | 1033篇 |
2012年 | 7315篇 |
2011年 | 21279篇 |
2010年 | 18930篇 |
2009年 | 11606篇 |
2008年 | 19597篇 |
2007年 | 21784篇 |
2006年 | 606篇 |
2005年 | 2188篇 |
2004年 | 3382篇 |
2003年 | 4329篇 |
2002年 | 2478篇 |
2001年 | 266篇 |
2000年 | 405篇 |
1999年 | 165篇 |
1998年 | 195篇 |
1997年 | 202篇 |
1996年 | 84篇 |
1995年 | 98篇 |
1994年 | 95篇 |
1993年 | 60篇 |
1992年 | 41篇 |
1991年 | 84篇 |
1990年 | 126篇 |
1989年 | 77篇 |
1988年 | 50篇 |
1987年 | 38篇 |
1986年 | 21篇 |
1985年 | 30篇 |
1983年 | 21篇 |
1982年 | 24篇 |
1980年 | 39篇 |
1974年 | 22篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Background
Girl Scouting may offer a viable channel for health promotion and obesity prevention programs. This study evaluated the effectiveness of an intervention program delivered through Girl Scout Junior troops that was designed to foster healthful troop meeting environments and increase obesity prevention behaviors at home. 相似文献992.
Feng Xie Shu-Chuen Li Ron Goeree Jean-Eric Tarride Daria O’Reilly Ngai-Nung Lo Seng-Jin Yeo Kuang-Ying Yang Julian Thumboo 《Quality of life research》2008,17(4):595-601
Objective Our aim was to cross-culturally validate Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in
patients with knee osteoarthritis (OA) scheduled for total knee replacement in Singapore.
Methods Chinese WOMAC was translated from the original English version following standard guidelines. Patients were asked to complete
a questionnaire containing the WOMAC (twice within 6 days), the Short Form 36 (SF-36), and the EuroQoL EQ-5D. Reliability
was assessed using Cronbach’s alpha and intraclass correlation coefficients (ICC), dimensionality using item-to-domain correlations
and factor analyses. Convergent and discriminant construct validity was assessed using six each a priori hypotheses.
Results Chinese WOMAC was well accepted by the patients in the pilot test. The Chinese and English versions were therefore administered
to a consecutive sample of 131 Chinese- and 127 English-speaking subjects, respectively, with knee OA. Cronbach’s alpha exceeded
0.7 for all domains except for Chinese pain domain, whereas the ICC exceeded 0.7 for all domains. Hypothesized item-to-domain
correlations were observed for all items except for four items in Chinese physical function domain. The factor analyses yielded
seven and five factors with eigenvalues of more than 1.0 in the Chinese and English versions, respectively. A total of 10/12
a priori construct validity hypotheses were satisfied for the Chinese version. Weak correlations between WOMAC pain and SF-36
bodily pain and moderate correlation between WOMAC pain and EQ-5D anxiety/depression were observed.
Conclusions Chinese WOMAC was well accepted and demonstrated acceptable psychometric properties in Singaporean patients with severe knee
OA. 相似文献
993.
Hugenholtz NI Schaafsma FG Nieuwenhuijsen K van Dijk FJ 《International archives of occupational and environmental health》2008,82(1):107-115
OBJECTIVE: An intervention existing of an evidence-based medicine (EBM) course in combination with case method learning sessions (CMLSs) was designed to enhance the professional performance, self-efficacy and job satisfaction of occupational physicians. METHODS: A cluster randomized controlled trial was set up and data were collected through questionnaires at baseline (T0), directly after the intervention (T1) and 7 months after baseline (T2). The data of the intervention group [T0 (n = 49), T1 (n = 31), T2 (n = 29)] and control group [T0 (n = 49), T1 (n = 28), T2 (n = 28)] were analysed in mixed model analyses. Mean scores of the perceived value of the CMLS were calculated in the intervention group. RESULTS: The overall effect of the intervention over time comparing the intervention with the control group was statistically significant for professional performance (p < 0.001). Job satisfaction and self-efficacy changes were small and not statistically significant between the groups. The perceived value of the CMLS to gain new insights and to improve the quality of their performance increased with the number of sessions followed. CONCLUSION: An EBM course in combination with case method learning sessions is perceived as valuable and offers evidence to enhance the professional performance of occupational physicians. However, it does not seem to influence their self-efficacy and job satisfaction. 相似文献
994.
Background
Data on the effect of contraceptive methods, other than the condom, on HIV acquisition is not clear. The aim of this study was to describe hormonal contraceptive use, sexual behaviour and HIV prevalence among women in Cameroon in order to provide baseline information for future analytical studies. 相似文献995.
Annabelle M Wilson Anthea M Magarey Nadia Mastersson 《The international journal of behavioral nutrition and physical activity》2008,5(1):5
Background
Food behaviours, attitudes, environments and knowledge are relevant to professionals in childhood obesity prevention, as are dietary patterns which promote positive energy balance. There is a lack of valid and reliable tools to measure these parameters. The aim of this study was to determine the reliability and relative validity of a child nutrition questionnaire assessing all of these parameters, used in the evaluation of a community-based childhood obesity prevention project. 相似文献996.
Mohammad T. Yousafzai Maryam Alavi Heather Valerio Behzad Hajarizadeh Jason Grebely Gregory J. Dore 《Viruses》2022,14(7)
This study aimed to identify the factors associated with timely (within four weeks) HCV RNA testing and timely (within six months) DAA initiation following HCV notification in the DAA era. We conducted a cohort study of people with an HCV notification in NSW, Australia. Notifications of positive HCV serology were linked to administrative datasets. Weights were applied to account for spontaneous clearance. Logistic regression analyses were performed. Among 5582 people with an HCV notification during 2016–2017, 3867 (69%) were tested for HCV RNA, including 2770 (50%) who received timely testing. Among an estimated 3925 people with chronic HCV infection, 2372 (60%) initiated DAA therapy, including 1370 (35%) who received timely treatment. Factors associated with timely HCV RNA testing included age (≥30 years), female sex, non-Aboriginal ethnicity, country of birth being Australia, and no history of drug dependence. Factors associated with timely treatment were age (≥30 years), male sex, non-Aboriginal ethnicity, country of birth being Australia, no history of drug dependence, and HCV/HIV co-infection. In the DAA era, 50% of people with an HCV notification did not receive timely HCV RNA testing. Most people with an HCV infection received therapy; however, DAA initiation was delayed among many. 相似文献
997.
Vincent J. Major Simon A. Jones Narges Razavian Ashley Bagheri Felicia Mendoza Jay Stadelman Leora I. Horwitz Jonathan Austrian Yindalon Aphinyanaphongs 《Applied clinical informatics》2022,13(3):632
Background We previously developed and validated a predictive model to help clinicians identify hospitalized adults with coronavirus disease 2019 (COVID-19) who may be ready for discharge given their low risk of adverse events. Whether this algorithm can prompt more timely discharge for stable patients in practice is unknown. Objectives The aim of the study is to estimate the effect of displaying risk scores on length of stay (LOS). Methods We integrated model output into the electronic health record (EHR) at four hospitals in one health system by displaying a green/orange/red score indicating low/moderate/high-risk in a patient list column and a larger COVID-19 summary report visible for each patient. Display of the score was pseudo-randomized 1:1 into intervention and control arms using a patient identifier passed to the model execution code. Intervention effect was assessed by comparing LOS between intervention and control groups. Adverse safety outcomes of death, hospice, and re-presentation were tested separately and as a composite indicator. We tracked adoption and sustained use through daily counts of score displays. Results Enrolling 1,010 patients from May 15, 2020 to December 7, 2020, the trial found no detectable difference in LOS. The intervention had no impact on safety indicators of death, hospice or re-presentation after discharge. The scores were displayed consistently throughout the study period but the study lacks a causally linked process measure of provider actions based on the score. Secondary analysis revealed complex dynamics in LOS temporally, by primary symptom, and hospital location. Conclusion An AI-based COVID-19 risk score displayed passively to clinicians during routine care of hospitalized adults with COVID-19 was safe but had no detectable impact on LOS. Health technology challenges such as insufficient adoption, nonuniform use, and provider trust compounded with temporal factors of the COVID-19 pandemic may have contributed to the null result. Trial registration ClinicalTrials.gov identifier: . NCT04570488相似文献
998.
Seyed Ataollah Naghavi Haoyu Wang Swastina Nath Varma Maryam Tamaddon Arsalan Marghoub Rex Galbraith Jane Galbraith Mehran Moazen Jia Hua Wei Xu Chaozong Liu 《Materials》2022,15(14)
Additively manufactured Ti scaffolds have been used for bone replacement and orthopaedic applications. In these applications, both morphological and mechanical properties are important for their in vivo performance. Additively manufactured Ti6Al4V triply periodic minimal surface (TPMS) scaffolds with diamond and gyroid structures are known to have high stiffness and high osseointegration properties, respectively. However, morphological deviations between the as-designed and as-built types of these scaffolds have not been studied before. In this study, the morphological and mechanical properties of diamond and gyroid scaffolds at macro and microscales were examined. The results demonstrated that the mean printed strut thickness was greater than the designed target value. For diamond scaffolds, the deviation increased from 7.5 μm (2.5% excess) for vertical struts to 105.4 μm (35.1% excess) for horizontal struts. For the gyroid design, the corresponding deviations were larger, ranging from 12.6 μm (4.2% excess) to 198.6 μm (66.2% excess). The mean printed pore size was less than the designed target value. For diamonds, the deviation of the mean pore size from the designed value increased from 33.1 μm (−3.0% excess) for vertical struts to 92.8 μm (−8.4% excess) for horizontal struts. The corresponding deviation for gyroids was larger, ranging from 23.8 μm (−3.0% excess) to 168.7 μm (−21.1% excess). Compressive Young’s modulus of the bulk sample, gyroid and diamond scaffolds was calculated to be 35.8 GPa, 6.81 GPa and 7.59 GPa, respectively, via the global compression method. The corresponding yield strength of the samples was measured to be 1012, 108 and 134 MPa. Average microhardness and Young’s modulus from α and β phases of Ti6Al4V from scaffold struts were calculated to be 4.1 GPa and 131 GPa, respectively. The extracted morphology and mechanical properties in this study could help understand the deviation between the as-design and as-built matrices, which could help develop a design compensation strategy before the fabrication of the scaffolds. 相似文献
999.
1000.
Usama Afzal Muhammad Aslam Fatima Afzal Kanza Maryam Naveed Ahmad Qayyum Zafar Zahid Farooq 《RSC advances》2022,12(33):21297
Graphene is a 2D material with remarkable properties. The present study demonstrates the fabrication of a graphene-based sensor for measuring the temperature and humidity of a metal body. The graphene sensor was fabricated by depositing a thin film of graphene nanoparticles between silver electrodes (separated by ∼50 μm) on a glass substrate. The graphene thin film was characterized by XRD, Raman spectroscopy and UV-vis techniques. The capacitance and resistance for both the relative humidity (in the range of 0–100% RH) and temperature (in the range of 230–310 K) were measured using an LCR meter at 1 kHz in a controlled chamber. The graphene-based sensor expressed high sensitivity with fast response and recovery times for both humidity and temperature with long stability and low hysteresis curves. The sensor was also tested on a metal body, which expressed a good response time. Moreover, the measured data of capacitance and resistance was analyzed with classical and neutrosophic analysis as an application of modern material statistics. It was observed that neutrosophic analysis is more flexible for analyzing the capacitance and resistance of the fabricated sensor.Graphene is a 2D material with remarkable properties. 相似文献