全文获取类型
收费全文 | 459篇 |
免费 | 28篇 |
国内免费 | 2篇 |
专业分类
儿科学 | 8篇 |
妇产科学 | 21篇 |
基础医学 | 35篇 |
口腔科学 | 16篇 |
临床医学 | 31篇 |
内科学 | 164篇 |
皮肤病学 | 1篇 |
神经病学 | 75篇 |
特种医学 | 12篇 |
外科学 | 41篇 |
综合类 | 5篇 |
预防医学 | 65篇 |
眼科学 | 1篇 |
药学 | 11篇 |
肿瘤学 | 3篇 |
出版年
2021年 | 6篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 6篇 |
2014年 | 11篇 |
2013年 | 10篇 |
2012年 | 43篇 |
2011年 | 28篇 |
2010年 | 12篇 |
2009年 | 10篇 |
2008年 | 25篇 |
2007年 | 36篇 |
2006年 | 29篇 |
2005年 | 32篇 |
2004年 | 26篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 12篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 12篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 3篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1958年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有489条查询结果,搜索用时 140 毫秒
1.
2.
Choroid plexus papilloma in the posterior fossa 总被引:2,自引:0,他引:2
Choroid plexus papillomas in the posterior fossa can present with different clinical signs and symptoms. The tumors in the patients we discuss in this article originated from different sites of the choroid plexus. One patient, who had a fourth ventricle papilloma, experienced unsteady gait and episodes of dizziness over many years. The tumor was cystic an calcified, and adherent to the brain-stem. The second patient had only signs of increased intracranial pressure. A soft tumor was located in the cerebellomedullary cistern. The third patient, with a papilloma in the cerebellopontine angle, complained of hearing loss. This tumor was firmly adherent to the dura mater and looked exactly like a meningioma. The appearance on computed tomography scan, the macroscopic aspect, and the vascular supply of a papilloma in the posterior fossa can vary considerably. 相似文献
3.
Ossewaarde ME Bots ML van der Schouw YT de Kleijn MJ Wilmink HW Bak AA Planellas J Banga JD Grobbee DE 《Maturitas》2003,45(1):47-54
OBJECTIVES: To determine whether improvement in endothelial function of the brachial artery observed in women treated with hormone replacement therapy (HRT) may be explained by changes in lipid profile or blood pressure, information was used obtained in a single-centre, randomised, double blind, placebo-controlled trial. METHODS: Hundred-and-five healthy postmenopausal women, aged 50-65 years, were treated with 0.625 mg conjugated equine estrogens (CEE) combined with 2.5 mg medroxyprogesterone acetate (MPA) (CEE+MPA), 2.5 mg tibolone or placebo for 3 months. At baseline and after 3 months, endothelial function was assessed using flow-mediated dilatation (FMD) and nitro glycerine-mediated dilatation (NMD). Furthermore, lipids were measured. Multivariate linear regression analysis was applied to address the research question. RESULTS: Treatment with CEE+MPA resulted in an improvement in FMD of 2.0% (95% CI: -0.1; 4.1). CEE/MPA reduced total cholesterol with 13% (95% CI: -18%; -7%), LDL-cholesterol with 23% (95% CI: -30%; -15%) and lipoprotein(a) (Lp(a)) with 14% (95% CI: -26%; -2%). The magnitude of the relation of CEE/MPA with endothelial function was attenuated to from 2.0 to 1.6% when change in Lp(a) was taken into account. Adjustments for other lipids or blood pressure did not attenuate the association. CONCLUSIONS: The improvement in endothelial function in postmenopausal women treated with CEE+MPA appears to be partially mediated by change in Lp(a), and apparently not by changes in other lipids. 相似文献
4.
Hormone replacement therapy and intima-media thickness of the common carotid artery: the Rotterdam study 总被引:4,自引:0,他引:4
Westendorp IC in 't Veld BA Bots ML Akkerhuis JM Hofman A Grobbee DE Witteman JC 《Stroke; a journal of cerebral circulation》1999,30(12):2562-2567
BACKGROUND AND PURPOSE: Observational data suggest that hormone replacement therapy (HRT) reduces morbidity and mortality from cardiovascular disease in healthy postmenopausal women. The mechanisms underlying this protection are not entirely clear but may include inhibition of the atherosclerotic process. METHODS: We studied the association between ever use of HRT and intima-media thickness (IMT) of the common carotid artery in 1103 naturally menopausal women, aged 55 to 80 years, in the Rotterdam Study, a community-based cohort study in a suburban area of Rotterdam, Netherlands. Mean and maximum IMT of the common carotid artery were measured noninvasively with B-mode ultrasound. RESULTS: Ever use of HRT for >/=1 year was associated with a decreased mean and maximum IMT compared with never users (mean IMT, 0.719 mm [SE 0.01] versus 0. 742 mm [SE 0.004], P=0.03; maximum IMT, 0.952 mm [SE 0.015] versus 0. 983 mm [SE 0.006], P=0.04), after adjustment for age, smoking, educational level, systolic blood pressure, and body mass index. No association was found for use <1 year (mean IMT, 0.739 mm [SE 0.013] versus 0.742 mm [SE 0.004], P=0.69; maximum IMT, 0.990 mm [SE 0.019] versus 0.983 mm [SE 0.006], P=0.75). Additional adjustment for diabetes, frequency of visits to healthcare facilities, or total and HDL cholesterol did not change these results. CONCLUSIONS: The findings of this population-based study show that ever use of HRT is associated with a decreased IMT in the common carotid artery in elderly women. 相似文献
5.
van der Bom JG Bots ML Haverkate F Meyer P Hofman A Grobbee DE Kluft C 《Thrombosis and haemostasis》1999,81(2):275-280
Increased concentrations of plasminogen activator inhibitor type 1 (PAI-1) and of D-dimer have jointly been found in subjects with cardiovascular disease. To understand this apparent paradox of increased inhibition of fibrinolysis (high PAI-1) combined with increased fibrinolytic activity (high D-dimer), we examined the relation between D-dimer, PAI-1 and the activator of fibrinolysis, tissue type plasminogen activator (t-PA) in subjects with varying severity of peripheral atherosclerosis. In 325 subjects selected from the Rotterdam Study, a cohort of 7983 men and women aged 55 years and over, the ankle to brachial systolic blood pressure ratio, t-PA antigen and activity, PAI-1 antigen and D-dimer were measured. T-PA antigen and t-PA activity were, independent from each other, increased with degree of atherosclerosis; t-PA antigen increased with 3.5 ng/ml (SE 1.7, p = 0.04) and t-PA activity with 0.46 IU/ml (0.20, p = 0.02) per unit decrease in ankle to brachial pressure ratio (i.e. increase in atherosclerosis). PAI-1 antigen was not related to atherosclerosis. More marked atherosclerosis was associated with increased D-dimer, mainly in subgroups with PAI-1 antigen below 50 ng/ml, t-PA antigen below 10 ng/ml, or t-PA activity above 1.5 IU/ml. In contrast to current beliefs, we found that only a fraction of the variation of t-PA antigen was due to the variation in circulating PAI-1 antigen. A slight positive association was observed between t-PA antigen and D-dimer. PAI-1 and t-PA activity were not associated with D-dimer concentration. In conclusion, in subjects with peripheral atherosclerosis PAI-1 antigen is not increased, but low PAI-1 levels (and possibly also low levels of t-PA antigen and high levels of t-PA activity) appear to be required to increase circulating D-dimer. This suggests that increased D-dimer levels in subjects with atherosclerosis do not reflect increased inhibition, but rather reflect increased fibrinolysis. 相似文献
6.
7.
Majke H.D. van Bommel Marieke Arts de Jong Miranda P. Steenbeek Michiel L. Bots Liselore L.M. van Westerop Maria T.E. Hopman Nicoline Hoogerbrugge Joanne A. de Hullu Angela H.E.M. Maas 《Journal of cardiology》2021,77(6):570-575
BackgroundBRCA1/2 mutation carriers are generally exposed to early menopause due to risk-reducing salpingo-oophorectomy (RRSO) around the age of 40 years. This risk-reducing intervention is based on a 10–40% life-time risk of ovarian cancer in this population. Although effective, premature and acute menopause induces non-cancer related morbidity in both the short and long term. Little is known about the impact of RRSO on the cardiovascular system.MethodsThis cross-sectional study explored the relationship between time since RRSO and signs of subclinical atherosclerosis, as measured by carotid intima-media thickness (CIMT) and pulse wave velocity (PWV), in 165 BRCA1/2 mutation carriers. All participants, aged 40 to 63 years, underwent RRSO before the age of 45 years, and at least 5 years ago. Cardiovascular risk factors were assessed by questionnaires and a single screening visit. Data were analyzed using linear regression models.ResultsMean CIMT was 692.7 μm (SD 87.0), and mean central PWV 6.40 m/s (SD 1.42). After adjustment for age and several relevant cardiovascular risk factors, time since RRSO was not associated with CIMT (β=0.68 μm; 95% CI –4.02, 5.38) and PWV (β=44 mm/s; 95% CI –32, 120). Compared to women of a reference group from the general population, lower systolic blood pressure [mean difference 12 mmHg; 95% confidence interval (CI) 10, 14] was found in BRCA1/2 mutation carriers.ConclusionsWe found that, in BRCA1/2 mutation carriers, at 5 to 24 years follow-up, time since RRSO is not related to development of subclinical atherosclerosis. However, the follow-up period in these relatively young women might have been too short. 相似文献
8.
9.