全文获取类型
收费全文 | 1361篇 |
免费 | 143篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 51篇 |
妇产科学 | 27篇 |
基础医学 | 157篇 |
口腔科学 | 35篇 |
临床医学 | 198篇 |
内科学 | 229篇 |
皮肤病学 | 10篇 |
神经病学 | 86篇 |
特种医学 | 135篇 |
外科学 | 191篇 |
综合类 | 48篇 |
一般理论 | 1篇 |
预防医学 | 102篇 |
眼科学 | 143篇 |
药学 | 129篇 |
中国医学 | 3篇 |
肿瘤学 | 50篇 |
出版年
2021年 | 15篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 15篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 28篇 |
2013年 | 45篇 |
2012年 | 40篇 |
2011年 | 48篇 |
2010年 | 39篇 |
2009年 | 44篇 |
2008年 | 51篇 |
2007年 | 96篇 |
2006年 | 54篇 |
2005年 | 58篇 |
2004年 | 42篇 |
2003年 | 36篇 |
2002年 | 34篇 |
2001年 | 49篇 |
2000年 | 35篇 |
1999年 | 41篇 |
1998年 | 52篇 |
1997年 | 44篇 |
1996年 | 44篇 |
1995年 | 45篇 |
1994年 | 40篇 |
1993年 | 46篇 |
1992年 | 21篇 |
1991年 | 35篇 |
1990年 | 26篇 |
1989年 | 43篇 |
1988年 | 42篇 |
1987年 | 34篇 |
1986年 | 35篇 |
1985年 | 32篇 |
1984年 | 22篇 |
1983年 | 15篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 22篇 |
1979年 | 16篇 |
1978年 | 10篇 |
1977年 | 17篇 |
1976年 | 10篇 |
1975年 | 14篇 |
1973年 | 14篇 |
1972年 | 10篇 |
1969年 | 12篇 |
1968年 | 9篇 |
排序方式: 共有1608条查询结果,搜索用时 434 毫秒
71.
72.
73.
A 10-year-old male was referred with difficulties at school. He had particular difficulty with reading long words, following the sequence of text down a page, writing words in the correct order, writing words in line, and copying from the blackboard. He had a history of infective endocarditis complicated by intracerebral haemorrhage at the age of three years. Detailed history taking revealed symptoms typical of 'dorsal stream' pathology, namely a deficit of 'vision for action'. This included a spatial disorder of attention (simultanagnosia), defective hand and foot movements under visual control (optic ataxia), and acquired oculomotor apraxia which are consistent with Balint's syndrome. Strategies were suggested for coping with the symptoms and one year later a distinct improvement in adapting to the disability was found. 相似文献
74.
BACKGROUND: There is no simple way to assess the injured patient after a loss of consciousness. Computed tomographic scanning is required to rule out anatomic injuries, and invasive intracranial pressure monitoring is needed for the patient with severe traumatic brain injury (TBI). We hypothesized that a noninvasive acoustic monitoring system could provide useful clinical data on the severity and progression of TBI. METHODS: Twenty-eight consecutive patients with severe TBI and an indication for invasive intracranial pressure monitoring were studied using the Brain Acoustic Monitor (BAM). Monitoring occurred for 1- to 3-hour time periods on the day of enrollment and each day until the patient's condition stabilized. BAM signals were categorized on the basis of amplitude and positive-to-negative deflection ratio, and then compared with the patient's clinical outcome. RESULTS: BAM signal correlated very strongly with clinical outcome: in 27 of 29 sessions with a normal signal, patients were discharged at a Glasgow Coma Scale score > 13, whereas in 36 of 42 sessions with an abnormal signal, the patient either died or left the hospital with a Glasgow Coma Scale score < 9 (p < 0.00001). The correlation between clinical outcome and initial BAM reading was even stronger: 10 of 10 patients with a normal signal did well, as compared with 3 of 18 patients with an abnormal signal. CONCLUSION: Noninvasive monitoring of the injured brain can discriminate those patients who will have a poor clinical outcome from those who will do well. Further trials of the BAM are indicated. 相似文献
75.
Dutton DG 《Journal of psychiatric practice》2002,8(4):216-228
A new theory is proposed to account for individual differences in the tendency to be abusive, assaultive, or homicidal in intimate relationships. The focus of this theory is on men whose abuse is specific to intimate relationships and is manifested through cyclical mood swings. This group, which appears to comprise about 40% of all men who present for treatment for wife assault, appears to have a borderline personality structure. For these men, abusiveness is triggered by internal mood states rather than by external events. Several studies are cited indicating that intimate attachment generates rage in wife assaulters. The origins of this attachment-rage are traced to early development. This template generates a complex of perceptions (attributions and projections) and behaviors (abusiveness) specific to intimate relationships. A personality profile of intimately abusive males has been strongly related to intimate partners' reports of psychological abusiveness in several samples of males, including physically assaultive males, non-violent controls, clinical outpatients, college students, and gay males. 相似文献
76.
BACKGROUND AND AIM OF THE STUDY: The accuracy of the Gorlin equation when applied to mixed valve pathology has not been investigated. An in-vitro study was performed to determine how a range of valve regurgitations and stenoses affects the Gorlin aortic valve area. METHODS: Various combinations of stenosis and regurgitation were simulated by placement of constricting orifices and minimal blockage reflux tubes within a 29-mm prosthetic pericardial valve. The orifice areas ranged from 0.7 cm2 to 1.75 cm2, and regurgitant fraction (RF) ranged from 0 to 0.35. Twenty-eight tests were performed at 70 beats/min, cardiac output of 5 l/min and systole 33-36% of the cycle. The mean pressure drops across the valve were adjusted to a value appropriate to blood density. Peripheral resistance was set to give a mean value of 1,537 dyn.s.cm(-5). RESULTS: The Gorlin area varied up to 0.55 cm2 from the geometric orifice area over the range of regurgitant fractions and stenoses. To improve the Gorlin equation, an amended mean volumetric forward flow rate was obtained by multiplying the cardiac output in the equation by the factor (1 - RF)(-1), to reconcile the equation for valvular regurgitation. The area predicted by the modified equation differed by <0.15 cm2 from the non-regurgitant valve geometric orifice area over the range of regurgitation and stenoses simulated. CONCLUSION: The study supports the validity of the Gorlin equation predicting pure aortic valve stenosis (areas <1.3 cm2); however, the equation overestimates the severity of stenoses when regurgitation is present. A modified equation is proposed, which includes regurgitant fraction. The new equation improves the calculation of valve geometric area in the presence of regurgitation and may be useful in cardiac catheterization laboratories where mixed aortic valve pathology is being evaluated. 相似文献
77.
78.
Valyasevi RW Jyonouchi SC Dutton CM Munsakul N Bahn RS 《The Journal of clinical endocrinology and metabolism》2001,86(2):903-908
Graves' ophthalmopathy (GO) is an orbital autoimmune disease that is closely associated with Graves' hyperthyroidism. Examination of retroorbital tissues in GO reveals an accumulation of glycosaminoglycans, increased fat volume, lymphocytic infiltration, and the presence of several inflammatory cytokines. A subpopulation of human orbital fibroblasts can be differentiated in vitro into cells with the morphologic features of adipocytes. We demonstrated recently that these differentiated cultures show increased expression of functional TSH receptor (TSHr). To determine whether the presence of inflammatory cytokines might impact adipogenesis or TSHr expression in these cultures, we treated orbital fibroblasts from normal individuals or GO patients with tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), or transforming growth factor-beta. We found that each of these cytokines inhibits TSH-dependent cAMP production and TSHr gene expression, and that TNF-alpha and IFN-gamma also inhibit morphological adipocyte differentiation. When cytokines were added after differentiation, the inhibition was less pronounced. Our results suggest that TNF-alpha, IFN-gamma, and transforming growth factor-beta may act within the orbit in GO to modulate expression of the putative orbital autoantigen, TSHr. In addition, the former two cytokines may play a role in determining the extent to which the volume of the orbital adipose tissue increases in this condition. 相似文献
79.
Nurses' perceived barriers to the implementation of a Fall Prevention Clinical Practice Guideline in Singapore hospitals 总被引:1,自引:0,他引:1
Serena SL Koh Elizabeth Manias Alison M Hutchinson Susan Donath Linda Johnston 《BMC health services research》2008,8(1):105
Background
Theories of behavior change indicate that an analysis of barriers to change is helpful when trying to influence professional practice. The aim of this study was to assess the perceived barriers to practice change by eliciting nurses' opinions with regard to barriers to, and facilitators of, implementation of a Fall Prevention clinical practice guideline in five acute care hospitals in Singapore. 相似文献80.