Light exposure required for optimum conversion of light activated resin systems

OBJECTIVE: The aim of this study was to evaluate the relationship between the degree of conversion (DC) of composites and the light intensity using LED-curing units and also to determine the amount of exposure required to achieve optimal curing. METHOD: The light outputs of light-curing units and the depths of cure of composites exposed to these units were determined using the methods outlined in modified ISO standards, ISO/TS10650 and ISO 4049, respectively. The distributions of DC in composites were investigated by IR spectra of microareas obtained at various depths from the irradiated surface of thin specimens cut out from the cured composites. IR spectra were measured using a Fourier transform infrared spectrometer equipped with a microscopic unit. DC was calculated from the changes in the amount of C=C double bonds in the IR spectra. RESULTS: The light intensity at various depths through the cured composite was calculated from the attenuation coefficient of each material, obtained from the linear relationship between the depth of cure and the logarithm of the amount of exposure, which is defined as the product of the irradiance and irradiation time. There was a third or fourth order regression relationship between DC and the logarithm of total light energy at a particular depth. SIGNIFICANCE: The minimum light energy required to produce a saturated DC was about 1000 s mW/cm2.     

安吉复口服液的耐缺氧,耐低温和抗疲劳作用

采用缺氧、寒冷和负重游泳等方法,观察了安吉复口服液(0.025、0.1和0.4mg·kg~(-1),ig,qd×14d)对小鼠的耐缺氧、耐低温及抗疲劳作用.结果表明,安吉复口服液0.1、0.4mg·kg~(-1)可延长KCN中毒小鼠的存活时间及延长小鼠在寒冷环境中存活时间,而0.4mg·kg~(-1)可延长常压缺氧条件下小鼠存活时间及延长小鼠负重游泳时间.     

介入治疗并发症的发生与防治

介入治疗是融合了内科药物治疗、外科手术治疗及医学影像学的一种特殊的治疗体系 ,其疗效受到世人瞩目并成为目前发展最为迅速的学科之一。但是 ,再好的方法也会存在不足之处 ,介入治疗也不例外。随着介入治疗在各家医院的普遍应用 ,并发症的发生也会越来越多 ,迫使人们关注这个问题。所谓介入治疗并发症 ,是指因血管造影及 (或 )血管内治疗所引起、需要一定治疗、使病人的治疗复杂化或延长病人住院时间的不良反应 ,就其全身多系统而言 ,介入治疗引发并发症的原因大致可归纳为两个主要因素即介入器材操作和引入人体内的物质(包括介入治疗所…     

77例出院后精神分裂症患者心理调查分析

研究目的调查分析出院后精神分裂症患者的心理状况，了解存在的问题并探讨解决的对策。研究方法对77例出院后精神分裂症病人就22项心理问题进行调查统计，并对比男女患者差异。结果男性易发脾气、借酒消愁、因病影响工作安排的现象较女性突出，而女性的婚姻状况较紧性明显。结论社区防治的病人心理问题较繁杂，因此防治工作应重视患者的心理特点，解决患者的实际问题。     

Modification des styles d'attachement après le premier amour

The newborn are subject to the bond between infants and their caregivers. The newborn receives the imprint of a style of attachment of which the function involves “proximity-maintenance” and “separation-protest”. The “secure-base” uses the attachment as a base from which the newly born is able to explore his environment. The continuity between childhood and adult relationships changes when romantic love and sexual appetite appear. A new kind of attachment with the love partner must develop and it has to support both attachment and sexuality. The youngster produces the same secure, avoiding, ambivalent or confused attachment as when he was an infant but, as opposed to that with his family, when the young person is attached to his partner he doesn't want to leave. In order to assess the link between the attachment with caregivers and the attachment with the first love, we proposed a questionnaire, a kind of “Love quiz”. First, the representation of attachment with their parents was assessed by four columns of ten questions. Each question referred to a style of attachment, for instance at the end of the interview, the column asking questions about avoidance displayed seven answers, whereas the secure column showed only three answers and the confused only one. Later, the same questionnaire was submitted in order to describe the new attachment with the first love. Results showed that the commitment to romantic love was similar to those observed among infants. But, after a while, the scores obtained in each column evolved: Fourteen out of twenty symptomatic adolescents improved their secure score; three remained in the same style of attachment and three others felt their first love as a traumatism. Out of eighteen no-symptomatic adolescents, fourteen were secure. Only four were insecure. After the first love, the rate of insecure adolescents increased to eight; four others were traumatised. The first love probably sets up a sensitive period in which biology, emotion and culture converge to enable us to be imprinted by a partner. An affect regulation with romantic partners is negotiated like a transaction between two styles of attachment. What is surprising is that the population of insecure adolescents benefited more from romantic love than the secure population by increasing their score in the attachment style. Adult relationships can be understood in terms of attachment. The first attachment is acquired during early interactions, and when the beginnings of life are difficult the first love gives them a second chance.     

Curing efficiency and ocular hazards of dental photopolymerization sources

The spectral distributions of a range of dental photocuring sources were measured at the exit window and at a distance of 10 cm. The former enabled the evaluation of a newly proposed photocuring efficiency index which correlates well with the depth of cure of the photopolymerized resins, thus providing a basis for the comparison of different photocuring sources. The spectral irradiante of the sources obeyed the inversesquare law, allowing a comparison with the ACGIH threshold limit values. According to these criteria, no ocular hazard is posed to the patient or clinician by u.v.-A or u.v.-B radiation nor to the patient by the visible light when momentarily exposed to the sources. Similarly the ACGIH criterion indicates that the clinician does not risk chorioretinal injury provided the exposure is restricted to less than 140 s in a 3 h period.     

论生物技术在医药领域的应用

生物技术是一门新兴的、综合的学科。生物技术在医药领域的应用涉及到新药开发、新诊断技术、预防措施及新的治疗技术。文章就以上方面做了扼要综述,展示了其广阔的应用前景。     

高技术条件下战场救治的特点及医德要求

高技术条件下战争的特殊性给战场救治带来了新的挑战。通过分析高技术条件下的战场救治的特点,提出了要圆满完成战场救治任务,军队医务人员必须承担的医德责任和应具备的身心素质。     

H级无溶剂浸渍绝缘漆制备研究

以改性二苯醚树脂为原料,合成了一种新颖不饱和聚酯型无溶剂浸渍绝缘漆。它耐高温达到Ｈ级,固化速度快,贮存周期长,挥发率低。讨论了促进剂和挥发分抑制剂对无溶剂浸渍漆性能的影响,以及促进机理和抑制机理。结果证明了促进剂可以大大缩短固化时间,挥发分抑制剂在适当配比下,能够降低苯乙烯的挥发。