全文获取类型
收费全文 | 899篇 |
免费 | 77篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 33篇 |
妇产科学 | 38篇 |
基础医学 | 94篇 |
口腔科学 | 59篇 |
临床医学 | 130篇 |
内科学 | 128篇 |
皮肤病学 | 17篇 |
神经病学 | 62篇 |
特种医学 | 35篇 |
外国民族医学 | 1篇 |
外科学 | 81篇 |
预防医学 | 101篇 |
眼科学 | 9篇 |
药学 | 76篇 |
中国医学 | 1篇 |
肿瘤学 | 109篇 |
出版年
2024年 | 4篇 |
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 25篇 |
2019年 | 23篇 |
2018年 | 40篇 |
2017年 | 30篇 |
2016年 | 24篇 |
2015年 | 23篇 |
2014年 | 26篇 |
2013年 | 56篇 |
2012年 | 70篇 |
2011年 | 67篇 |
2010年 | 26篇 |
2009年 | 24篇 |
2008年 | 53篇 |
2007年 | 49篇 |
2006年 | 53篇 |
2005年 | 59篇 |
2004年 | 40篇 |
2003年 | 35篇 |
2002年 | 36篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1976年 | 3篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 7篇 |
1969年 | 3篇 |
排序方式: 共有977条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
Solveig B. Larsen Aleksander Giwercman Marcello Spanò Jens P. Bonde The ASCLEPIOS Study Group 《Reproductive toxicology (Elmsford, N.Y.)》1998,12(6):391-589
It was hypothesized that occupational exposure to pesticides during a spraying season causes changes in semen quality that might be detected in a longitudinal study. We analyzed the within-person changes in semen quality and reproductive hormones across a spraying season in groups of farmers using and not using pesticides. A total of 248 men collected two semen samples (participation rate: 32%). The median sperm concentration declined significantly from the first to the second sample in both groups, but there was no statistical difference in the decline between the two groups, unadjusted or adjusted. Only minor changes were found in sperm morphology, vitality, motility, sperm chromatin denaturation (SCSA), and reproductive hormones, and the differences in changes between the two groups were nonsignificant, or, in the opposite direction to the expected. There was no relation between the changes in sperm parameters in relation to pesticide exposure variables. In conclusion, use of pesticides by Danish farmers is not a likely cause of short-term effects on semen quality and reproductive hormones. 相似文献
4.
E S Haug P Romundstad S Aune T B J Hayes H O Myhre 《European journal of vascular and endovascular surgery》2005,29(5):489-495
OBJECTIVES: To study early mortality and long-term survival of patients more than 80 years of age having elective open repair for abdominal aortic aneurysm (AAA). DESIGN: Retrospective multicenter cohort study. MATERIAL: One hundred and five patients, 23 women and 82 men, with a median age of 82 years, operated at three Norwegian hospitals during the period 1983-2002. METHOD: Survival analyses were based on data from medical records and the Norwegian Registrar's Office of Births and Deaths. Expected survival was based on mortality rates of the general population, matched by age, sex, and calendar period. Relative survival was calculated as the ratio between the observed and the expected survival. RESULTS: During the study period there has been a 10 fold increase in octogenarians treated with open operation for AAA. Early mortality (30-day) for the whole group of patients was 10.5% (95% confidence interval (95% CI) 5.3-18.0), and similar for both genders. The 5-year survival rate was 47% (95% CI 35.9-57.4), and not significantly different from that of a matched group in the general population. Patients aged 84 years or more had a median survival time of 35 months (95% CI 18.5-51.6). CONCLUSION: The number of AAA operations in octogenarians has increased considerably during 20 years. Octogenarians operated electively for AAA has higher 30-day mortality as compared to younger patients. Their long-term survival appears similar to a matched control group. The benefit of surgery must be carefully considered against the perioperative risk, especially for the oldest octogenarians. 相似文献
5.
Glial cell expression of hepatocyte growth factor in vitreoretinal proliferative disease 总被引:5,自引:0,他引:5
Hollborn M Krausse C Iandiev I Yafai Y Tenckhoff S Bigl M Schnurrbusch UE Limb GA Reichenbach A Kohen L Wolf S Wiedemann P Bringmann A 《Laboratory investigation; a journal of technical methods and pathology》2004,84(8):963-972
The hepatocyte growth factor (HGF) has been crucially implicated in the development of proliferative retinal diseases; however, it is unclear whether retinal glial cells express or respond to HGF. Therefore, we examined the expression of HGF and of the receptor for HGF, c-Met, by immunohistochemical costaining with glial fibrillary acidic protein (GFAP) in epiretinal membranes of patients with proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), respectively. Furthermore, it was determined whether cells of the human retinal glial cell line, MIO-M1, secrete HGF protein, and whether HGF stimulates proliferation and chemotaxis, and secretion of the vascular endothelial growth factor (VEGF). Neuroretinas of patients with PVR express elevated mRNA level for HGF in comparison to control retinas. In epiretinal membranes of patients with PVR or PDR, immunoreactivity for HGF and for c-Met, respectively, partially colocalized with immunoreactivity for GFAP. Fetal bovine serum and basic fibroblast growth factor, but not heparin-binding epidermal or platelet-derived growth factors, evoked HGF secretion by cultured retinal glial cells. HGF displayed only a marginal effect on cell proliferation while it stimulated chemotaxis. HGF promoted the secretion of VEGF, via activation of the phosphatidylinositol-3 kinase. It is concluded that glial cells in epiretinal membranes express both HGF protein and c-Met receptors. The results suggest an autocrine/paracrine role of HGF in glial cell responses during proliferative vitreoretinal disorders as well as in retinal neovascularization, by stimulating of VEGF release. 相似文献
6.
Dadi Helgason Solveig Helgadottir Anders Ahlsson Jarmo Gunn Vibeke Hjortdal Emma C. Hansson Anders Jeppsson Ari Mennander Shahab Nozohoor Igor Zindovic Christian Olsson Stefan Orri Ragnarsson Martin I. Sigurdsson Arnar Geirsson Tomas Gudbjartsson 《The Annals of thoracic surgery》2021,111(4):1292-1298
7.
Solveig R. M. Johansson R. G. G. Andersson 《Naunyn-Schmiedeberg's archives of pharmacology》1981,316(2):190-193
Summary Diazoxide significantly decreased the blood pressure and relaxed the uterine muscle in anaesthetized normotensive rats. A marked elevation of blood glucose followed the intravenous injection of diazoxide. The hyperglycemic and the uterine relaxing response could be significantly decreased by injection of propranolol prior to diazoxide. The hypotensive effect was not diminished by propranolol, however. In liver and uterus the content of cAMP was increased following diazoxide treatment in vivo. The rise in cAMP could be completely inhibited by propranolol, indicating a -receptor stimulation being the cause of the cAMP elevation. 相似文献
8.
Ana-Maria Bamberger Solveig Aupers Karin Milde-Langosch Thomas L?ning 《International journal of gynecological pathology》2003,22(2):156-161
In this study, a specific monoclonal antibody was used to immunohistochemically investigate correlated expression of the cell cycle promoter cyclin E and the proliferation marker Ki-67 in benign extravillous trophoblast and gestational trophoblastic lesions. Our data show that cyclin E is expressed in the normal extravillous trophoblast, with strongest levels of expression in the cell columns of anchoring villi. Differences could be observed in expression of Ki-67 in both normal extravillous trophoblast and gestational trophoblastic lesions. In the extravillous trophoblast of the cell columns, expression of cyclin E started more distal compared with Ki-67 and was maintained (with less intensity) into the deeper layers of interstitial trophoblast. In the benign trophoblastic lesions (exaggerated placental site [EPS] and placental site nodule [PSN]) and in the trophoblast proliferations on the surface of hydropic villi of hydatidiform moles (HM), the percentage of cells expressing cyclin E was higher than of those expressing Ki-67. The same observation could be made for a case of placental site trophoblastic tumor (PSTT). In contrast, choriocarcinomas (N=8), which are definitely malignant tumors, showed an opposite pattern, with a much higher percentage of strongly Ki-67-positive cells compared with cyclin E-positive cells. We conclude that cyclin E is expressed in benign extravillous trophoblast and gestational trophoblastic lesions, where a ratio cyclin E/Ki-67<1 characterizes choriocarcinomas, whereas PSTT and the benign lesions (HM, EPS, PSN) show expression of cyclin E in a higher percentage of cells than Ki-67 (cyclin E/Ki-67 ratio >1). 相似文献
9.
10.