全文获取类型
收费全文 | 213569篇 |
免费 | 28839篇 |
国内免费 | 7481篇 |
专业分类
耳鼻咽喉 | 1703篇 |
儿科学 | 1664篇 |
妇产科学 | 5156篇 |
基础医学 | 15534篇 |
口腔科学 | 2185篇 |
临床医学 | 16994篇 |
内科学 | 21981篇 |
皮肤病学 | 1373篇 |
神经病学 | 1214篇 |
特种医学 | 6174篇 |
外国民族医学 | 270篇 |
外科学 | 30513篇 |
综合类 | 28537篇 |
现状与发展 | 39篇 |
一般理论 | 3篇 |
预防医学 | 9894篇 |
眼科学 | 120篇 |
药学 | 15315篇 |
140篇 | |
中国医学 | 5652篇 |
肿瘤学 | 85428篇 |
出版年
2024年 | 253篇 |
2023年 | 4322篇 |
2022年 | 6137篇 |
2021年 | 11253篇 |
2020年 | 10737篇 |
2019年 | 9698篇 |
2018年 | 9278篇 |
2017年 | 9783篇 |
2016年 | 10533篇 |
2015年 | 12124篇 |
2014年 | 17542篇 |
2013年 | 17579篇 |
2012年 | 14048篇 |
2011年 | 14281篇 |
2010年 | 10413篇 |
2009年 | 10606篇 |
2008年 | 10936篇 |
2007年 | 10416篇 |
2006年 | 9114篇 |
2005年 | 7532篇 |
2004年 | 6236篇 |
2003年 | 5197篇 |
2002年 | 4440篇 |
2001年 | 4117篇 |
2000年 | 3501篇 |
1999年 | 2925篇 |
1998年 | 2465篇 |
1997年 | 2174篇 |
1996年 | 1612篇 |
1995年 | 1719篇 |
1994年 | 1435篇 |
1993年 | 1089篇 |
1992年 | 946篇 |
1991年 | 886篇 |
1990年 | 670篇 |
1989年 | 616篇 |
1988年 | 522篇 |
1987年 | 434篇 |
1986年 | 311篇 |
1985年 | 401篇 |
1984年 | 343篇 |
1983年 | 219篇 |
1982年 | 227篇 |
1981年 | 206篇 |
1980年 | 186篇 |
1979年 | 123篇 |
1978年 | 82篇 |
1977年 | 74篇 |
1976年 | 65篇 |
1975年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 906 毫秒
101.
102.
《The British journal of oral & maxillofacial surgery》2020,58(1):3-24
Medical practitioners’ (MP) role is pivotal in primary prevention, early diagnosis, prompt referral and effective management of oral and oropharyngeal carcinomas (OC/OPC), which raises the importance of their effective OC/OPC education at all levels of medical education. The purpose of this systematic review was to summarise the available scientific evidence about their educational competence in dealing with OC/OPC. We made a systematic search of papers in the English language in MEDLINE, Scopus, Cochrane Library CENTRAL and CINAHL databases from their inception until December 2018. Overall, 23 cross-sectional and three interventional studies have been selected for the systematic review and 18 of these were included in the meta-analyses. Excluding tobacco use (synthesised estimate of 95% of respondents identified tobacco as an OC/OPC risk factor, 95% CI of synthesised estimate 92% to 97%) and alcohol consumption (65%, 95%CI 52% to 77%), less than half of MP (approximately) were knowledgeable about important OC/OPC risk factors including human papilloma virus (42%, 95% CI 30% to 54%), poor diet (34%, 95% CI 17% to 54%), and advancing age (45%, 95% CI 21% to 70%). There was a low to moderate level of awareness among MP regarding common precancerous oral lesions involving leukoplakia (56%, 95% CI 32% to 79%), erythroplakia (30%, 95% CI 8% to 58%), and oral lichen planus (13%, 95% CI 0 to 41%). Moderate knowledge was also recorded about frequent sites of OC development involving the tongue (48%, 95% CI 33% to 64%) and floor of the mouth (37%, 95% CI 19% to 57%). Most MP enquired about tobacco use (86%, 95% CI 74% to 96%), and alcohol consumption (73%, 95% CI 47% to 94%) during history taking, and expressed willingness to be given supplementary OC/OPC education (78%, 95% CI 54% to 96%), as well. With regard to the incidence of intraoral screening, 27% of MP (95% CI 12% to 46%) make an intraoral examination as a routine. Interestingly, studies from each continent yielded significantly different outcomes to some research questions in the review. From the MP’s perspective, clinical time restrictions and deficiencies in organised training were recognised as the main barriers towards their OC/OPC educational competence. The findings of this systematic review indicated the existence of deficiencies in knowledge and misconceptions, neglected preventive responsibilities, and associated barriers towards OC/OPC. A need for improved OC/OPC training at all levels of medical education is required to increase competence worldwide. 相似文献
103.
Nicole D. Facompre Pavithra Rajagopalan Varun Sahu Alexander T. Pearson Kathleen T. Montone Claire D. James Frederico O. Gleber-Netto Gregory S. Weinstein Jalal Jalaly Alexander Lin Anil K. Rustgi Hiroshi Nakagawa Joseph A. Califano Curtis R. Pickering Elizabeth A. White Bradford E. Windle Iain M. Morgan Roger B. Cohen Phyllis A. Gimotty Devraj Basu 《International journal of cancer. Journal international du cancer》2020,147(11):3236-3249
104.
Guo-Chao Zhong Yang Peng Kang Wang Lun Wan You-Qi-Le Wu Fa-Bao Hao Jie-Jun Hu Hai-Tao Gu 《International journal of cancer. Journal international du cancer》2020,147(6):1577-1586
Epidemiological studies on magnesium intake and primary liver cancer (PLC) are scarce, and no prospective studies have examined the associations of magnesium intake with PLC incidence and mortality. We sought to clarify whether higher magnesium intake from diet and supplements was associated with lower risks of PLC incidence and mortality in the US population. Magnesium intake from diet and supplements was evaluated through a food frequency questionnaire in a cohort of 104,025 participants. Cox regression was employed to calculate hazard ratios for PLC incidence and competing risk regression was employed to calculate subdistribution hazard ratios for PLC mortality. Restricted cubic spline regression was employed to test nonlinearity. We documented 116 PLC cases during 1,193,513.5 person-years of follow-up and 100 PLC deaths during 1,198,021.3 person-years of follow-up. Total (diet + supplements) magnesium intake was found to be inversely associated with risks of PLC incidence (hazard ratiotertile 3 vs. 1: 0.44; 95% confidence interval: 0.24, 0.80; ptrend = 0.0065) and mortality (subdistribution hazard ratiotertile 3 vs. 1: 0.37; 95% confidence interval: 0.19, 0.71; ptrend = 0.0008). Similar results were obtained for dietary magnesium intake. Nonlinear inverse dose–response associations with PLC incidence and mortality were observed for both total and dietary magnesium intakes (all pnonlinearity < 0.05). In summary, in the US population, a high magnesium intake is associated with decreased risks of PLC incidence and mortality in a nonlinear dose–response manner. These findings support that increasing the consumption of foods rich in magnesium may be beneficial in reducing PLC incidence and mortality. 相似文献
105.
Susanna Zanutto Chiara Maura Ciniselli Antonino Belfiore Mara Lecchi Enzo Masci Gabriele Delconte Massimo Primignani Giulia Tosetti Marco Dal Fante Linda Fazzini Aldo Airoldi Marcello Vangeli Francesca Turpini Giovanni Giuseppe Rubis Passoni Paolo Viaggi Monica Arena Roberta Ilaria Olimpia Motta Anna Maria Cantù Cristiano Crosta Giuseppe De Roberto Francesca Iannuzzi Andrea Cassinotti Valentina Dall'Olio Laura Tizzoni Gabriella Sozzi Emanuele Meroni Luigi Bisanti Marco Alessandro Pierotti Paolo Verderio Manuela Gariboldi 《International journal of cancer. Journal international du cancer》2020,146(4):1164-1173
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most. 相似文献
106.
Li Bai Saeha Shin Richard T. Burnett Jeffrey C. Kwong Perry Hystad Aaron van Donkelaar Mark S. Goldberg Eric Lavigne Scott Weichenthal Randall V. Martin Ray Copes Alexander Kopp Hong Chen 《International journal of cancer. Journal international du cancer》2020,146(9):2450-2459
Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM2.5) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO2) and ozone (O3). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population-based cohort study to investigate the associations of chronic exposure to PM2.5, NO2, O3 and redox-weighted average of NO2 and O3 (Ox) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long-term residents aged 35–85 years who lived in Ontario, Canada, 2001–2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow-up. We used Cox proportional-hazards models adjusting for personal- and neighborhood-level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow-up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM2.5 (hazard ratio [HR] = 1.02 [95% CI: 1.01–1.05] per 5.3 μg/m3) and NO2 (HR = 1.05 [95% CI: 1.03–1.07] per 14 ppb). No associations with lung cancer were observed for O3 or Ox. Relationships between PM2.5 and NO2 with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer. 相似文献
107.
Tianyu Zeng Yijia Hua Chunxiao Sun Yuchen Zhang Fan Yang Mengzhu Yang Yiqi Yang Jun Li Xiang Huang Hao Wu Ziyi Fu Wei Li Yongmei Yin 《International journal of cancer. Journal international du cancer》2020,147(11):3007-3018
tRNA-derived fragments, a class of small noncoding RNAs (sncRNAs), have been identified in numerous studies in recent years. tRNA-derived fragments are classified into two main groups, including tRNA halves (tiRNAs) and tRNA-derived small RNA fragments (tRFs), according to different cleavage positions of the precursor or mature tRNAs. Instead of random tRNA degradation debris, a growing body of evidence has shown that tRNA-derived fragments are precise products of specific tRNA modifications and play important roles in biological activities, such as regulating protein translation, affecting gene expression, and altering immune signaling. Recently, the relations between tRNA-derived fragments and the occurrence of human diseases, especially cancers, have generated wide interest. It has been demonstrated that tRNA-derived fragments are involved in cancer cell proliferation, metastasis, progression and survival. In this review, we will describe the biogenesis of tRNA-derived fragments, the distinct expression and function of tRNA-derived fragments in the development of cancers, and their emerging roles as diagnostic and prognostic biomarkers and precise targets of future treatments. 相似文献
108.
Hélène Person Francis Guillemin Thierry Conroy Michel Velten Christine Rotonda 《International journal of cancer. Journal international du cancer》2020,146(7):1827-1835
Women with breast cancer are increasingly being cured of the disease but fatigue remains the most frequently reported symptom. The aims of our study were to identify distinct trajectories in four fatigue dimensions during 2 years after breast cancer surgery and to explore the demographic, clinical and personality characteristics associated with these profiles. We included women from the prospective longitudinal multicenter FATSEIN cohort in France. They completed the Multidimensional Fatigue Inventory for nine follow-ups over 24 months after surgery. A group-based trajectory model identified distinct trajectories in each fatigue dimension. Multinomial logistic regression determined the factors associated with each profile. From the 459 women followed, 3–5 fatigue trajectories were revealed in each fatigue dimension, from its absence to its severest degree. In our multivariate analysis, the risk of severe fatigue was decreased in all dimensions by a high quality of life before surgery (measured by the European Organization for Research and Treatment of Cancer 30-item QoL questionnaire; e.g., for general and physical fatigue: OR = 0.93, 95% CI 0.91, 0.96), especially a high physical and emotional functions for general and physical fatigue, and a high cognitive function for mental fatigue. Both severe mental fatigue and severely reduced motivation worsened with low optimism before surgery (e.g., for mental fatigue: OR = 0.93, 95% CI 0.89, 0.97). Severely reduced activities increased by having chemotherapy (OR = 9.41, 95% CI 2.28, 38.79). Targeting women at risk for severe fatigue can provide early preventive and curative treatment and appropriate psychological support. 相似文献
109.
110.