Decreased Expression of Plakophilin-2 and αT-Catenin in Arrhythmogenic Right Ventricular Cardiomyopathy: Potential Markers for Diagnosis

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary disease of the heart muscle. Clinical challenges remain, however, in identifying patients with ARVC in the early or concealed stages with subtle clinical manifestations. Therefore, we wanted to identify potential targets by immunohistochemical (IHC) analysis in comparison with controls. Pathogenic mutations were identified in 11 of 37 autopsied patients with ARVC. As observed from IHC analysis of the RV, expression of αT-catenin and plakophilin-2 is significantly decreased in autopsied patients with ARVC as compared to controls, and the decreased expression is consistent in patients with and without pathogenic mutations. Furthermore, ARVC specimens demonstrated a reduced localization of αT-catenin, desmocollin-2, desmoglein-2, desmoplakin, and plakophilin-2 on intercalated discs. These findings have been validated by comparing RV specimens obtained via endomyocardial biopsy between patients with ARVC and those without. The pathogenic mutation was present in 3 of 5 clinical patients with ARVC. In HL-1 myocytes, siRNA was used to knockdown CTNNA3, and western blotting analysis demonstrated that the decline in αT-catenin expression was accompanied by a significant decline in the expression of plakophilin-2. The aforementioned effect was directed towards protein degradation rather than mRNA stability. Plakophilin-2 expression decreases concurrently with the decline in CTNNA3 expression. Therefore, the expression of αT-catenin and plakophilin-2 could be potential surrogates for the diagnosis of ARVC.     

Influence of the copper ion on aging rate of oil-paper insulation in a power transformer

To identify the influence of copper ion on the aging rate of oil-paper insulation, accelerated thermal aging experiments on oil-paper insulation were designed and performed at two significant temperatures. A set of characteristic parameters, including dissolved gases, degree of polymerisation, furfural content, water content and acid number of oil, was tested. The experiments- results reveal that copper ion has a different influence on insulation paper and oil during the aging process of the insulation system. On the one hand, it delays the degradation of insulation paper, reducing the ratio of CO₂/CO by about 11% at 80%C and by more than 50% at 130%C. On the other hand, copper ion promotes the oxidation of oil and thus accelerates the aging rate.     

Preparation and properties of a novel bone repair composite: nano-hydroxyapatite/chitosan/carboxymethyl cellulose

Nano-hydroxyapatite/chitosan/carboxymethyl cellulose (n-HA/CS/CMC) composites with weight ratios of 70/10/20, 70/15/15 and 70/20/10 were prepared through a co-solution method. The properties of the composites were characterized by means of burn-out test, IR, XRD, TEM and universal material testing machine. The degradation and bioactivity were also investigated by in vitro test in a simulated body fluid (SBF) for 8 weeks. The results showed that n-HA particles were dispersed uniformly in organic phase, and strong chemical interactions formed among the three phases. Moreover, the composites were similar to natural bone in morphology and size. In addition, the compressive strength was improved compared with n-HA/CS composite. The biodegradation rate was controllable by altering weight ratio of the CS/CMC. Meanwhile, the composites could induce apatite particles to deposit in SBF. All the above results indicate that the novel composites of n-HA/CS/CMC have a promising prospect used for bone repair materials in view of the good mechanical property, adjustable biodegradation rate and bioactivity in SBF. Additionally, the study would provide a good guide to exploit clinical application of natural cellulose.     

Bad-scenario-set robust scheduling for a job shop to hedge against processing time uncertainty

This paper proposed two robust scheduling formulations in real manufacturing systems based on the concept of bad scenario set to hedge against processing time uncertainty, which is described by discrete scenarios. Two proposed robust scheduling formulations are applied to an uncertain job-shop scheduling problem with the makespan as the performance criterion. The united-scenario neighbourhood (UN) structure is constructed based on bad scenario set for the scenario job-shop scheduling problem. A tabu search (TS) algorithm with the UN structure is developed to solve the proposed robust scheduling problem. An extensive experiment was conducted. The computational results show that the first robust scheduling formulation could be preferred to the second one for the discussed problem. It is also verified that the obtained robust solutions could hedge against the processing time uncertainty through decreasing the number of bad scenarios and the degree of performance degradation on bad scenarios. Moreover, the computational results demonstrate that the developed TS algorithm is competitive for the proposed robust scheduling formulations.