仿生种植牙应力分布的有限元分析

以上颌中切牙为解剖学基础 ,提出了仿生种植牙模型。相同载荷分别作用于天然牙、仿生牙及骨性结合种植牙模型 ,用二维有限元法计算得到牙周膜和仿生牙周膜的应力分布 ,对三种模型骨界面上的应力分布进行了比较研究     

天然牙与种植体联合支持附着体连接式固定桥的骨组织应力分析

为了研究天然牙与种植体联合支持附着体连接式固定桥的骨组织应力分布情况,选择一左侧下颌第一磨牙缺失病例,分别设计刚性连接(模型Ⅰ)和Ceka附着体连接(模型Ⅱ)天然牙与种植体联合支持固定桥模型.分别在分散垂直和分散斜向两种载荷情况下,采用三维有限元法分析基牙及种植体周围骨组织的应力分布情况.研究结果表明,在两种载荷情况下,种植体周围骨组织的应力值都大于天然牙周围骨组织的应力值,模型Ⅰ中的种植体周围骨组织的应力值明显大于模型Ⅱ中的种植体周围骨组织的应力值,而天然牙周围骨组织的应力值在两组模型中变化不大.因此可以认为,Ceka附着体能缓冲种植体周围骨组织的部分应力,但对垂直应力和侧向应力的缓冲能力区别不大.进行天然牙与种植体联合支持固定桥修复时,可以设计附着体连接体,以缓冲种植体周围骨组织的应力水平,防止或减轻种植体支持组织的损伤.     

Cochlear implants in the inclusive classroom: a case study

This article presents a case study of a child aged 12 years with a cochlear implant who is attending a mainstream educational setting in Skopje, FYR Macedonia. The study, which uses both qualitative and quantitative data, took place over a period of 12 months. It illustrates the importance of professional development and training of teachers and a need to emphasise a range of intervention strategies. It also highlights the challenges facing children and young people with cochlear implants in schools and suggests a range of systemic approaches to addressing the issues raised.     

Parental Involvement in Children’s Learning: The Case of Cochlear Implantation—Parents as Educators?

Extensive research emphasises the importance of parental involvement for children’s learning and academic achievement. This paper reports from a Norwegian study researching parents’ experiences on follow-up after their child’s cochlear implantation. Within this context, parental involvement is suggested to be of major importance for the child’s language learning. The study explores the parents’ talk on their involvement in the child’s language after implantation. Data consist of 27 written parental accounts and interviews with 14 of these parents. The analysis shows the parents’ extensive involvement in the child’s language learning. The study brings into conversation how understandings of learning influence parental involvement, leading to implications for the parents and children involved. It addresses a need for debate on how parents can support children’s learning, whilst avoiding parenthood becoming a series of educational tasks.     

地下鼠听觉机制研究的进展

地下鼠是由环境特化的物种,在长期的地下适应过程中,其听觉系统出现一系列的适应性进化,总结起来,其听觉敏感频率偏于中低频,与声波在地下洞道中的传播能力相一致。听觉机制的核心问题是耳蜗活动机制的研究。本文从耳蜗解剖学基础研究、离子通道研究、地下鼠震动通讯研究、听域分析研究等几个方面进行综述,为地下啮齿类物种特殊的适听机制提供更进一步研究的参考。     

人工耳蜗儿童与助听器儿童选择性听取能力的比较研究

本研究采用三因素混合实验设计,比较了人工耳蜗儿童(CI)与助听器儿童(HA)在不同信噪比条件下(SNR=10,5,0),对不同难度材料(双音节词和短句)的选择性听取能力.研究结果表明:(1)在重建听阈与补偿听阈相似时,人工耳蜗儿童与助听器儿童的选择性听取能力的差异不显著;(2)两类儿童对词语和短句的选择性听取能力差异显著;(3)在不同信噪比条件下两类儿童的择性听取能力差异显著.本研究结果提示,若助听器能补偿到最适宜水平,则没有必要进行人工耳蜗植入.     

顺铂对耳蜗毒性的实验研究

目的 :探讨顺铂对耳蜗毒性的影响。方法 :将豚鼠 12只随机分成顺铂组、对照组 ,每组 6只。顺铂组连续 5d腹腔注射顺铂 ,2ml·kg- 1·d- 1;对照组连续 5d腹腔注射生理盐水 ,2ml·kg- 1·d- 1。两组豚鼠均于实验结束后测耳蜗血流、耳蜗电图 ,断头 ,取耳蜗 ,用不同方法染色固定 ,铺片及电镜观察。结果 :顺铂组动物在给药后体重减轻 ,耳廓反射减退 ,耳蜗血流下降 ,阈值提高 ,毛细胞大片缺失 ,两组比较 ,差异有显著性 (P <0 .0 1)。顺铂组血管纹较对照组血管纹明显扩张 ,红细胞聚集。扫描电镜下观察 ,顺铂组的绝大部分内、外毛细胞的纤毛散乱 ,倒伏 ,甚至缺失 ;透射电镜下观察 ,顺铂组血管纹线粒体水肿变性。结论 :顺铂对耳蜗有损坏作用。     

20MnMo钢的焊接冷裂纹敏感性研究

采用焊接冷裂纹插销试验方法,研究了20MnMo钢的焊接冷裂纹的敏感性。研究结果表明：采用E6015-D1焊条,在热输入E=15KJ/cm的情况下,该钢的室温临界应力σcr=180MPa;当预热150℃,σcr=300MPa。预热可以明显改善20MnMo钢的焊接性。     

Negotiating reassurance: parents’ narratives on follow-up after cochlear implantation

This study presents an analysis of parental experiences on follow-up after cochlear implantation. Data were constructed in semi-structured, individual interviews with the parents of 14 children who use cochlear implants. Drawing on narrative analysis, the study explores parental responses to insecurity concerning children’s learning and development, as well as the meaning professional support holds for parents. In their response to insecurity, the parents handle the ‘trouble’ of insecurity through constructing two narratives of self: the parent-as-learner and the parent-as-teacher. The parents use these narrative constructions to negotiate reassurance, holding themselves responsible for future outcomes. The parents’ stories reflect a language of instrumentality, inducing a burden of responsibility. The study addresses the need to question to which extent parents should act as teachers and cautions that, while acknowledging the importance of parents’ involvement for children’s learning and development, this should not reduce the relationship to a functional, pedagogical one. The contribution of the study is to bring into conversation how the language of instrumentality affects the parents and how this invokes a need for rethinking parent support. Suggestions for further research are given.