全文获取类型
收费全文 | 4726篇 |
免费 | 269篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 87篇 |
妇产科学 | 78篇 |
基础医学 | 474篇 |
口腔科学 | 70篇 |
临床医学 | 489篇 |
内科学 | 1048篇 |
皮肤病学 | 40篇 |
神经病学 | 557篇 |
特种医学 | 155篇 |
外科学 | 580篇 |
综合类 | 67篇 |
一般理论 | 5篇 |
预防医学 | 436篇 |
眼科学 | 294篇 |
药学 | 282篇 |
中国医学 | 2篇 |
肿瘤学 | 297篇 |
出版年
2022年 | 26篇 |
2021年 | 68篇 |
2020年 | 57篇 |
2019年 | 60篇 |
2018年 | 80篇 |
2017年 | 65篇 |
2016年 | 83篇 |
2015年 | 78篇 |
2014年 | 119篇 |
2013年 | 176篇 |
2012年 | 274篇 |
2011年 | 289篇 |
2010年 | 143篇 |
2009年 | 140篇 |
2008年 | 244篇 |
2007年 | 249篇 |
2006年 | 252篇 |
2005年 | 223篇 |
2004年 | 186篇 |
2003年 | 219篇 |
2002年 | 202篇 |
2001年 | 125篇 |
2000年 | 138篇 |
1999年 | 100篇 |
1998年 | 46篇 |
1997年 | 44篇 |
1996年 | 30篇 |
1995年 | 28篇 |
1994年 | 31篇 |
1993年 | 23篇 |
1992年 | 81篇 |
1991年 | 52篇 |
1990年 | 56篇 |
1989年 | 57篇 |
1988年 | 48篇 |
1987年 | 54篇 |
1986年 | 70篇 |
1985年 | 61篇 |
1984年 | 51篇 |
1983年 | 47篇 |
1982年 | 27篇 |
1980年 | 24篇 |
1979年 | 46篇 |
1978年 | 26篇 |
1975年 | 24篇 |
1974年 | 23篇 |
1973年 | 25篇 |
1938年 | 21篇 |
1935年 | 22篇 |
1933年 | 26篇 |
排序方式: 共有5002条查询结果,搜索用时 15 毫秒
1.
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
2.
Julie A. Schmidt Georgina K. Fensom Sabina Rinaldi Augustin Scalbert Paul N. Appleby David Achaintre Audrey Gicquiau Marc J. Gunter Pietro Ferrari Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Anna Karakatsani Eleni Peppa Domenico Palli Sabina Sieri Rosario Tumino Bas Bueno-de-Mesquita Antonio Agudo Maria-Jose Sánchez María-Dolores Chirlaque Eva Ardanaz Nerea Larrañaga Aurora Perez-Cornago Nada Assi Elio Riboli Konstantinos K. Tsilidis Timothy J. Key Ruth C. Travis 《International journal of cancer. Journal international du cancer》2020,146(3):720-730
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer. 相似文献
3.
4.
5.
M C Post J G L M Luermans H W M Plokker W Budts 《Catheterization and cardiovascular interventions》2007,69(1):9-14
Migraine is a common neurological disorder with a great impact on the quality of life and social activities. The patent foramen ovale (PFO) is an intra-atrial right-to-left shunt with a prevalence of 25% in the general population. An increased prevalence is found in patients with migraine, especially in migraine with aura. Percutaneous PFO closure might decrease the prevalence of migraine. However, most of these observational studies were retrospective without a randomized design and the results need to be interpreted with caution. In this review we describe the association between PFO and migraine and the different pathophysiological hypotheses, which have been proposed to explain this relationship. 相似文献
6.
A new method is presented for studying mediator release in isolated peritoneal cells of the rat. Using a superfusion technique, cells can be maintained in a continuously cleared medium. Cells were stimulated with antigen, compound 48/80 or A23187 to characterize this preparation. In addition, inhibitory effects of theophylline, isoprenaline and cromoglycate on compound 48/80-induced histamine release were studied. We conclude that superfusion is a valid alternative to study mediator release from isolated peritoneal cells. 相似文献
7.
Organic nitrates are used for the treatment of angina pectoris symptoms, acute coronary syndrome and for acute and chronic heart insufficiency. In spite of the proven effectiveness of organic nitrates for acute cases, long-term therapy is limited by to the development of tolerance. Recent animal experiments, as well as clinical data, show that an endothelial dysfunction is also induced, a disquieting point, especially considering the negative prognostic impact of endothelial dysfunction. Due to these side effects, the published guidelines of the American Heart Association and the American College of Physicians do not recommend the use of long-term nitrates, such as mono- and dinitrate, for the treatment of stable angina pectoris. Rather, if good left ventricular function is present the calcium antagonist amlodipine should be used. In cases of appreciably reduced left ventricular function, there is a current discussion, based on the recently published A-HeFT study, as to whether a combination therapy with organic nitrates and the effective arteriole dilator hydralazine is beneficial for patients with severe heart insufficiency. 相似文献
8.
Lawrence T. Post 《American journal of ophthalmology》1943,26(6):629-631
9.
Cholecystokinin (CCK )isa polypeptidehor monecontaining 33aminoacidsresiduewithgastroin testinal,biliarandbrainactivities Itiswidelydis tributedinthevertebratecentralnervoussystem ,anditcanstimulateextensivelytheliberationofinsulinandglucagonfromtheLangerhansislets GreateffortshavebeendevotedtothesynthesisofCCK 8,itsderivativesandanalogues Amongthedifferentmethods ,theenzymaticmethodisthemosteffectiveonewithmanyadvantagesoverconventionalchemicalmethodologies :enzymespecificitysuppress essid… 相似文献
10.