全文获取类型
收费全文 | 348篇 |
免费 | 75篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 10篇 |
妇产科学 | 19篇 |
基础医学 | 33篇 |
口腔科学 | 5篇 |
临床医学 | 72篇 |
内科学 | 68篇 |
皮肤病学 | 17篇 |
神经病学 | 11篇 |
特种医学 | 84篇 |
外科学 | 32篇 |
综合类 | 5篇 |
现状与发展 | 1篇 |
预防医学 | 25篇 |
眼科学 | 2篇 |
药学 | 9篇 |
肿瘤学 | 35篇 |
出版年
2024年 | 4篇 |
2023年 | 24篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 16篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 20篇 |
2016年 | 20篇 |
2015年 | 10篇 |
2014年 | 18篇 |
2013年 | 16篇 |
2012年 | 5篇 |
2011年 | 2篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 4篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 16篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 20篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
排序方式: 共有432条查询结果,搜索用时 15 毫秒
1.
2.
Ross BD; Jacobson S; Villamil F; Korula J; Kreis R; Ernst T; Shonk T; Moats RA 《Radiology》1994,193(2):457
3.
4.
Nichols SM Bavister BD Brenner CA Didier PJ Harrison RM Kubisch HM 《Human reproduction (Oxford, England)》2005,20(1):79-83
BACKGROUND: A decline in fertility is evident in human females past their middle thirties. This 'reproductive senescence', marked by a sharp decline in pregnancy rates, may be attributed to reductions in numbers of available oocytes and their quality. Because Old World primates exhibit ovarian morphology and physiological control and timing of menstrual cycles closely resembling those of humans, the current study investigated the rhesus macaque as a potential model for human reproductive senescence. METHODS: Ovaries collected from females aged 1-25 years and divided into five age groups were analysed histologically. RESULTS: General ovarian morphology demonstrated significant changes as the females approached menopause. The proportions of primordial and primary follicles all demonstrated significant differences across age groups (primordial: 77.1, 79.9, 69.7, 62.9, 55.1%; primary: 21.5, 18.8, 28.5, 35.2, 43.1% for age groups 1 to 5 respectively; P<0.0001 for both). Samples from females approaching or undergoing the menopausal transition (aged 20-25 years) demonstrated evidence of ovarian senescence, having scattered and atretic follicles, low numbers of primordial follicles and reduced stromal tissue. CONCLUSION: This study supports the value of the rhesus monkey as a model for reproductive ageing because its ovary undergoes follicular reservoir depletion similar to that seen in humans. 相似文献
5.
BD White A Kong E Khoo AM Southcott 《Journal of Medical Imaging and Radiation Oncology》2005,49(4):319-321
Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease characterized by the presence of osseous and cartilaginous submucosal nodules projecting into the tracheobronchial tree. Most cases are asymptomatic and discovered incidentally at post‐mortem. We identified a case of TO on thoracic spiral CT and confirmed the diagnosis on bronchoscopy. This article reviews the imaging characteristics of TO, and shows the 3‐D virtual bronchoscopic and multiplanar reconstruction appearances of TO. 相似文献
6.
WBG Macdonald AP Patrikeos RI Thompson BD Adler AA Van Der Schaaf 《Journal of Medical Imaging and Radiation Oncology》2005,49(1):32-38
The present study compared the accuracy of ventilation perfusion scintigraphy (VQS) and CT pulmonary angiography (CTPA) for the diagnosis of pulmonary embolism. This was a prospective observational study of 112 patients with suspected pulmonary embolism (PE) who could be studied with both investigations within 24 h. Results were compared to final diagnosis at completion of 6-month follow up, using receiver operating characteristic (ROC) analysis. Pulmonary embolism was diagnosed in 27 referred patients (24%). The sensitivity and specificity of VQS and CTPA were similar to that reported from the literature. A normal VQ scan had the highest negative predictive value (100%), while a high-probability VQ scan had the highest positive predictive value (92%). There was no overall difference (area under the ROC curve (AUC)) between VQS (AUC (95% CI) = 0.82 (0.75,0.89)) and CTPA (AUC = 0.88 (0.81,0.94)) for the diagnosis of PE. Among patients with abnormal chest X-rays, CTPA (AUC 0.90 (0.83,0.97)) appeared somewhat better than VQS (AUC 0.78 (0.68,0.88)) but this difference did not reach statistical significance. In this instance, CTPA is at least as accurate as VQS and may provide an opportunity to make alternative diagnoses. 相似文献
7.
8.
9.
10.