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Presents a study which demonstrated a heterojunction bipolar transistor using a novel compound collector design that allows a low-knee voltage and high-breakdown voltage to be obtained simultaneously. Advantages of double-heterojunction bipolar transistors; Methodology; Results.

Atomic layer epitaxy (ALE) has successfully been used to grow epitaxial layers over chemically etched grooves and dry etched sidewalls formed on GaAs(100) substrates. GaAs/InGaAs multilayers were deposited on V-shaped and inverted trapezoid-shaped grooves that were 4–5 μm deep and 8–20 μm wide. Growth conforming to the original sidewall surfaces was accomplished both on the chemically etched and on ion beam assisted etched surfaces. These features show distinct improvement over similar attempts by metalorganic chemical vapor deposition or molecular beam epitaxy. The ability of ALE to proceed in a self-limiting fashion on such structures is expected to lead to the realization of novel device concepts. [ABSTRACT FROM AUTHOR]

Ga-As-In-As superalloy has been grown by atomic epitaxy on InP substrates. This has been achieved by sequential exposure of the substrate to trimethylgallium, arsine, triethylindium, and arsine. The thickness of the deposited film is in excellent agreement with the predicted value based on the number of exposure cycles. These results demonstrate that atomic layer epitaxy offers the ultimate control for depositing thin films. The superalloy films have been characterized by transmission electron microscopy and photoluminescence. [ABSTRACT FROM AUTHOR]

Objective: Regulation of anabolic and catabolic factors is considered essential in maintaining the homoeostasis of healthy articular cartilage. In this study we investigated the influence of RNA binding proteins (RNABPs) in this process., Design: Using small interfering RNA (siRNA), RNABP expression was knocked down in SW1353 chondrosarcoma cells and human articular chondrocytes. Gene expression and messenger RNA (mRNA) decay of anabolic (SOX9, Aggrecan) and catabolic (matrix metalloproteinase (MMP)13) factors were analysed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). RNA-electromobility shift assays (EMSAs) were used to investigate RNABP interactions with the SOX9 mRNA 3' untranslated region (UTR). Immunohistochemical localisation of MMP13 and the RNABP human antigen R (HuR) was performed in E13.5 and E16.5 mouse embryo sections., Results: SOX9 mRNA, mRNA half-life and protein expression were increased with siRNA targeting the RNABP tristetraprolin (TTP) in both HACs and SW1353s. TTP knockdown also stimulated aggrecan mRNA expression but did not affect its stability. RNA-EMSAs demonstrated that adenine uracil (AU)-rich elements in the SOX9 mRNA 3'UTR interacted with chondrocyte proteins with three specific elements interacting with TTP. HuR knockdown significantly increased MMP13 expression and also regulated the expression of a number of known transcriptional repressors of MMP13. HuR was ubiquitously expressed within mouse embryos yet displayed regional down-regulation within developing skeletal structures., Conclusion: This study demonstrates for the first time how RNABPs are able to affect the balance of anabolic and catabolic gene expression in human chondrocytes. The post-transcriptional mechanisms controlled by RNABPs present novel avenues of regulation and potential points of intervention for controlling the expression of SOX9 and MMP13 in chondrocytes., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)