36 research outputs found

    Synthetic Resin Reinforcement of Timber Joints Deteriorated by Termites

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    Timber has been widely adopted as a global structural material. However, timber sometimes deteriorates due to various factors such as termite infestation, which may reduce its strength and durability. It is difficult to ascertain the degree of deterioration of timbers by visual inspection because deterioration by termites causes severe damage to the inner parts of the timber. Therefore, the damage is often discovered after the deterioration progresses. The restoration and refurbishment method currently implemented is removing the degraded parts and partially replacing them with new healthy wood. Although it is as desirable to reinforce the original part as it is to restore its strength, especially for historical timber structures, this approach has not yet been put into practical use. This study investigates the possibility of restoring timber deteriorated by termites with little changes in its appearance by using resin filling. Deterioration by termites occurs at the base of the timber. Therefore, the specimen is assumed to be the joint of a foundation and column. First, the deteriorated specimen was filled with epoxy resin, and then, the effectiveness of the filling was confirmed by a nondestructive test method using ultrasonic pulse velocity. Finally, shear strength test was performed for the joint. As a result, ultrasonic velocity significantly increased because of the resin filling. The strength of the specimen filled with epoxy resin was restored and was close to the strength of a healthy one. It was confirmed that this strengthening method with resin filling was useful for improving the structural performance of timber deteriorated by termites with little change in appearance

    CACNA1A variants may modify the epileptic phenotype of Dravet syndrome

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    Dravet syndrome is an intractable epileptic syndrome beginning in the first year of life. De novo mutations of SCN1A, which encode the Na(v)1.1 neuronal voltage-gated sodium channel, are considered the major cause of Dravet syndrome. In this study, we investigated genetic modifiers of this syndrome. We performed a mutational analysis of all coding exons of CACNA1A in 48 subjects with Dravet syndrome. To assess the effects of CACNA1A variants on the epileptic phenotypes of Dravet syndrome, we compared clinical features in two genotype groups: 1) subjects harboring SCN1A mutations but no CACNA1A variants (n=20) and 2) subjects with SCN1A mutations plus CACNA1A variants (n=20). CACNA1A variants detected in patients were studied using heterologous expression of recombinant human Ca(v)2.1 in HEK 293 cells and whole-cell patch-clamp recording. Nine CACNA1A variants, including six novel ones, were detected in 21 of the 48 subjects (43.8%). Based on the incidence of variants in healthy controls, most of the variants seemed to be common polymorphisms. However, the subjects harboring SCN1A mutations and CACNA1A variants had absence seizures more frequently than the patients with only SCN1A mutations (8/20 vs. 0/20, p=0.002). Moreover, the former group of subjects exhibited earlier onset of seizures and more frequent prolonged seizures before one year of age, compared to the latter group of subjects. The electrophysiological properties of four of the five novel Ca(v)2.1 variants exhibited biophysical changes consistent with gain-of-function. We conclude that CACNA1A variants in some persons with Dravet syndrome may modify the epileptic phenotypes

    Influence of primary and secondary prevention indications on anxiety about the implantable cardioverter-defibrillator

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    AbstractBackgroundImplantable cardioverter-defibrillators (ICDs) have been established for primary and secondary prevention of fatal arrhythmias. However, little is known about the influence of ICD indications on quality of life (QOL) and psychological disturbances. This study aimed to examine whether there were differences in QOL and psychological distress in patients that have an ICD for primary or secondary prevention of fatal arrhythmias.MethodsA multicenter survey of 179 consecutive outpatients (29.1% primary prevention) with ICD implantations completed the Short Form-8 (SF-8), Beck Depression Inventory (BDI), Impact of Event Scale-Revised (IES-R), State-Trait Anxiety Inventory (STAI), and Worries about ICD (WAICD).ResultsPatients with an ICD for primary prevention had a higher trait anxiety score and worries about ICD score than patients with an ICD for secondary prevention (41.7±12.4 vs. 34.7±12.3, p=0.001 and 39.6±18.0 vs. 30.0±18.9, p=0.002, respectively), even after adjusting for demographic and clinical characteristics. In multivariable analysis of variance, primary prevention ICD recipients reported a poorer QOL on the vitality subscale of the SF-8.ConclusionsIn our study population, which mostly consisted of New York Heart Association (NYHA) class I and II subjects, primary prevention ICD recipients were more prone to experience worries about their ICD, anxiety, and a poorer QOL compared to secondary prevention ICD recipients. In clinical practice, primary prevention ICD patients should be closely monitored. If warranted, they should be offered psychological intervention, as anxiety and low QOL were predictors of mortality

    Pronuclear injection-based mouse targeted transgenesis for reproducible and highly efficient transgene expression

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    Mouse transgenesis has proven invaluable for analysis of gene function and generation of human disease models. We describe here the development of a pronuclear injection-based targeted transgenesis (PITT) system, involving site-specific integration in fertilized eggs. The system was applied to two different genomic target loci to generate a series of transgenic lines including fluorescent mice, which reproducibly displayed strong, ubiquitous and stable transgene expression. We also demonstrated that knockdown mice could be readily generated by PITT by taking advantage of the reproducible and highly efficient expression system. The PITT system, which circumvents the problem of unpredictable and unstable transgene expression of conventional random-integration transgenic mice, reduces the time, cost and effort needed to generate transgenic mice, and is potentially applicable to both in vivo ‘gain-of-function’ and ‘loss-of-function’ studies
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