全文获取类型
收费全文 | 31467篇 |
免费 | 4340篇 |
国内免费 | 131篇 |
专业分类
耳鼻咽喉 | 483篇 |
儿科学 | 824篇 |
妇产科学 | 751篇 |
基础医学 | 3448篇 |
口腔科学 | 765篇 |
临床医学 | 5514篇 |
内科学 | 6760篇 |
皮肤病学 | 487篇 |
神经病学 | 3297篇 |
特种医学 | 890篇 |
外科学 | 5067篇 |
综合类 | 312篇 |
一般理论 | 18篇 |
预防医学 | 3041篇 |
眼科学 | 1014篇 |
药学 | 1327篇 |
中国医学 | 39篇 |
肿瘤学 | 1901篇 |
出版年
2024年 | 111篇 |
2023年 | 693篇 |
2022年 | 548篇 |
2021年 | 1108篇 |
2020年 | 821篇 |
2019年 | 840篇 |
2018年 | 1446篇 |
2017年 | 1244篇 |
2016年 | 1196篇 |
2015年 | 1306篇 |
2014年 | 1629篇 |
2013年 | 1898篇 |
2012年 | 1884篇 |
2011年 | 1898篇 |
2010年 | 1375篇 |
2009年 | 1424篇 |
2008年 | 1606篇 |
2007年 | 1500篇 |
2006年 | 1534篇 |
2005年 | 1400篇 |
2004年 | 1242篇 |
2003年 | 1080篇 |
2002年 | 1075篇 |
2001年 | 350篇 |
2000年 | 216篇 |
1999年 | 352篇 |
1998年 | 444篇 |
1997年 | 418篇 |
1996年 | 437篇 |
1995年 | 345篇 |
1994年 | 340篇 |
1993年 | 284篇 |
1992年 | 246篇 |
1991年 | 213篇 |
1990年 | 181篇 |
1989年 | 172篇 |
1988年 | 174篇 |
1987年 | 179篇 |
1986年 | 139篇 |
1985年 | 144篇 |
1984年 | 146篇 |
1983年 | 128篇 |
1982年 | 171篇 |
1981年 | 149篇 |
1980年 | 183篇 |
1979年 | 92篇 |
1978年 | 100篇 |
1977年 | 89篇 |
1976年 | 87篇 |
1974年 | 80篇 |
排序方式: 共有10000条查询结果,搜索用时 26 毫秒
1.
2.
3.
Allison J. Cowin PhD ; Nicholas Hatzirodos BSc ; Justin Rigden PhD ; Robert Fitridge FRACS ; David A. Belford PhD 《Wound repair and regeneration》2006,14(4):421-426
High levels of tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, are present in the wound fluid of chronic nonhealing wounds. This leads to increased inflammation, cytokine expression, and ultimately results in impaired wound healing and tissue destruction. Etanercept is a recombinant fusion protein that consists of the soluble TNF receptor (p75) linked to the Fc portion of human IgG1. It is an effective inhibitor of TNF-alpha and has been shown to provide rapid and sustained improvement in rheumatoid arthritis by acting as a soluble receptor binding TNF-alpha and preventing its proinflammatory activities. Therefore, the aim of this study was to determine whether Etanercept could inhibit TNF-alpha activity in chronic wound fluid. Wound fluid was collected from the venous leg ulcers of 16 different patients. The effect of Etanercept on TNF-alpha activity was evaluated using both a TNF-alpha bioassay and an enzyme-linked immunoassay. Etanercept was found to reduce the cytotoxic effect of chronic wound fluid on L929 fibroblasts by approximately 30% and neutralized TNF-alpha binding in the enzyme-linked immunoassay by up to 80%. Direct application of Etanercept to chronic wounds may therefore reduce the inflammatory activity of TNF-alpha, which could reduce the chronicity of venous leg ulcers and thus aid in the healing of these wounds. 相似文献
4.
Peter Stone MD FRNZCOG FRCOG David Cook FRNZCOG MRCOG John Hutton PhD FRNZCOG FRCOG Gordon Purdie BSc Henry Murray MD FRNZCOG MRCOG Lauren Harcourt MPP BA 《The Australian & New Zealand journal of obstetrics & gynaecology》1995,35(1):32-37
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects. 相似文献
5.
A prospective, randomized controlled study of computer-assisted learning in parasitology. 总被引:1,自引:0,他引:1
PURPOSE: To compare, using a prospective, randomized controlled study, three methods of teaching a medical school parasitology course: computer-based instruction, traditional lecture-based instruction, and a combination of computer-based and lecture-based instruction. METHOD: A single class of the University of Utah School of Medicine was randomized into three study groups for the second-year parasitology course. The computer group (n = 29) used a locally developed interactive parasitology computer program; the lecture group (n = 32) had traditional lectures, and the combined group (n = 33) used both the computer program and lectures. Students' knowledge was assessed using a pretest, a final examination, and a posttest administered four months after the course. Students also used logs to track the amounts of time they spent studying. Their impressions and course evaluations were collected using a standardized course-evaluation form. RESULTS: The groups' scores on the pretest, final examination, and posttest were not statistically significantly different. Students in the computer group averaged 26.8 hours of studying over the two-week course compared with 32.1 hours in the lecture group and 32.7 hours in the combined group. The difference in study times between the computer and combined groups yielded a significant p value of 0.036. Students were generally positive about the course and the computer program. CONCLUSION: Students can learn parasitology from computer-based instruction as effectively as from traditional lecture-based instruction, and they can do so in less time. 相似文献
6.
Hippocampal pathology in refractory temporal lobe epilepsy: T2-weighted signal change reflects dentate gliosis. 总被引:11,自引:0,他引:11
Regula S Briellmann Renate M Kalnins Samuel F Berkovic Graeme D Jackson 《Neurology》2002,58(2):265-271
BACKGROUND: The MR and pathologic features of hippocampal sclerosis (HS) are well described and include volume decrease and T2-weighted signal increase for MRI, and neuron cell loss and gliosis for pathology. OBJECTIVE: To confirm the established correlation between hippocampal volumes and neuron cell counts, and to study the still controversial association between signal change and gliosis. METHODS: The authors studied 44 patients (22 men and 22 women; mean age at surgery, 37 years) with refractory temporal lobe epilepsy. Quantitative assessment of hippocampal volumes and T2 relaxometry, and neuron and glial cell count in the region CA1 and molecular layer of the dentate gyrus was performed. The proportion of glial fibrillary acidic protein (GFAP)-positive glial cells (reactive astrocytes) was indicated. RESULTS: In a stepwise regression, the ipsilateral hippocampal volume was predicted best by the neuron cell count in the dentate gyrus (p = 0.005, r = 0.4). Hippocampal T2 time, however, was predicted best by the glial cell count in the dentate gyrus (p = 0.01, r = 0.4). None of the other cell counts contributed to either model. In the dentate, 31% of the glial cells were reactive astrocytes, whereas in CA1, 5% were reactive. CONCLUSION: The results confirmed the correlation between hippocampal volumes and neuron cell counts. T2-weighted signal increase in the hippocampus was mainly influenced by gliosis in the dentate gyrus, where a high proportion of glial cells show abnormal activity. This activity may reflect changes important in the development of hippocampal epileptogenicity. 相似文献
7.
8.
9.
10.