全文获取类型
收费全文 | 384166篇 |
免费 | 25460篇 |
国内免费 | 3136篇 |
专业分类
耳鼻咽喉 | 5219篇 |
儿科学 | 8272篇 |
妇产科学 | 10223篇 |
基础医学 | 53840篇 |
口腔科学 | 11855篇 |
临床医学 | 30824篇 |
内科学 | 79236篇 |
皮肤病学 | 8605篇 |
神经病学 | 27573篇 |
特种医学 | 14162篇 |
外国民族医学 | 85篇 |
外科学 | 61152篇 |
综合类 | 10792篇 |
现状与发展 | 2篇 |
一般理论 | 66篇 |
预防医学 | 17733篇 |
眼科学 | 9577篇 |
药学 | 31633篇 |
6篇 | |
中国医学 | 2481篇 |
肿瘤学 | 29426篇 |
出版年
2021年 | 2953篇 |
2019年 | 2977篇 |
2018年 | 4769篇 |
2017年 | 3633篇 |
2016年 | 3679篇 |
2015年 | 4340篇 |
2014年 | 6048篇 |
2013年 | 7683篇 |
2012年 | 10520篇 |
2011年 | 10698篇 |
2010年 | 6468篇 |
2009年 | 6039篇 |
2008年 | 9706篇 |
2007年 | 10538篇 |
2006年 | 10487篇 |
2005年 | 9604篇 |
2004年 | 8929篇 |
2003年 | 8666篇 |
2002年 | 8307篇 |
2001年 | 28353篇 |
2000年 | 28865篇 |
1999年 | 23752篇 |
1998年 | 5211篇 |
1997年 | 4299篇 |
1996年 | 3877篇 |
1995年 | 3518篇 |
1994年 | 3156篇 |
1993年 | 2861篇 |
1992年 | 16087篇 |
1991年 | 14852篇 |
1990年 | 14184篇 |
1989年 | 13986篇 |
1988年 | 12600篇 |
1987年 | 12084篇 |
1986年 | 11113篇 |
1985年 | 10335篇 |
1984年 | 6928篇 |
1983年 | 5604篇 |
1982年 | 2726篇 |
1979年 | 5482篇 |
1978年 | 3357篇 |
1977年 | 2974篇 |
1975年 | 2643篇 |
1974年 | 3066篇 |
1973年 | 2875篇 |
1972年 | 2834篇 |
1971年 | 2777篇 |
1970年 | 2513篇 |
1969年 | 2547篇 |
1968年 | 2254篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
42.
Harinakshi Sanikini David C. Muller Marisa Sophiea Sabina Rinaldi Antonio Agudo Eric J. Duell Elisabete Weiderpass Kim Overvad Anne Tjønneland Jytte Halkjær Marie-Christine Boutron-Ruault Franck Carbonnel Iris Cervenka Heiner Boeing Rudolf Kaaks Tilman Kühn Antonia Trichopoulou Georgia Martimianaki Anna Karakatsani Valeria Pala Domenico Palli Amalia Mattiello Rosario Tumino Carlotta Sacerdote Guri Skeie Charlotta Rylander María-Dolores Chirlaque López Maria-Jose Sánchez Eva Ardanaz Sara Regnér Tanja Stocks Bas Bueno-de-Mesquita Roel C.H. Vermeulen Dagfinn Aune Tammy Y.N. Tong Nathalie Kliemann Neil Murphy Marc Chadeau-Hyam Marc J. Gunter Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers. 相似文献
43.
44.
Pediatric dermatology is one of the smallest subspecialties, and expanding the availability of care is of great interest. Teledermatology has been proposed as a way to expand access and improve care delivery, but no current assessment of pediatric teledermatology exists. The objective of the current study was to assess usage and perspectives on pediatric teledermatology. Surveys were distributed electronically to all 226 board‐certified U.S. pediatric dermatologists; 44% (100/226) responded. Nearly all respondents (89%) have experience with teledermatology. Formal teledermatology reimbursement success rates have increased to 35%. Respondents were positive about teledermatology's present and future prospects, and 41% want to use teledermatology more often, although they viewed teledermatology as somewhat inferior to in‐person care regarding accuracy of diagnosis and appropriation of management plans. Significant differences were found between formal teledermatology users and nonusers in salary structure, practice environment, sex, and region. Substantial increases in pediatric teledermatology have occurred in the last 5 to 10 years, and there remains cause for optimism for teledermatology's future. Concerns about diagnostic confidence and care quality indicate that teledermatology may be best for care of patients with characteristic clinical presentations or management of patients with established diagnoses. 相似文献
45.
46.
47.
BackgroundWomen suffering from kidney disease are more prone to fertility problems, due to uremia. Fortunately, their fertility rate increases dramatically after renal transplantation. This study analyzes the predictors/risk factors of successful pregnancy with live birth outcome while presenting an overview of the 7-year experience of a single center.MethodsThis retrospective cohort study includes 239 women of reproductive age (18–40 years) who underwent renal transplantation in a tertiary Turkish clinic between October 1, 2011, and August 24, 2017. The subjects were invited to take part in a survey questioning their obstetric characteristics and they were assessed in 2 groups: fertile and infertile. Multivariable linear regression analysis was conducted to determine the predictors of a successful pregnancy.ResultsThirty-five 35 patients wished to become pregnant: 12 got pregnant spontaneously, while 21 failed to become pregnant (spontaneously). The mean age of the patients at the survey was 34 ± 7. Regular menstrual cycles after renal transplantation, tacrolimus-mycophenolate mofetil maintenance protocol, and age at transplantation were found to be predictors of spontaneous pregnancy. The duration of peritoneal dialysis was significantly longer in the infertile group (48 vs 12 months).ConclusionEnd-stage renal disease's negative impacts, including menstrual abnormality and fertility problems, can be overcome by successful kidney transplantation with appropriate immunosuppression. Minimizing the duration of peritoneal dialysis, particularly in patients who desire future fertility, may be accepted as a logical management strategy. 相似文献
48.
49.
50.