No abstract

We report on high magnetic fields (up to 40 T) cyclotron resonance, quantum Hall effect and Shubnikov-de-Hass measurements in high frequency transistors based on Si-doped GaN–AlGaN heterojunctions. A simple way of precise modelling of the cyclotron absorption in these heterojunctions is presented. We clearly establish two-dimensional electrons to be the dominant conducting carriers and determine precisely their in-plane effective mass to be 0.230±0.005 of the free electron effective mass. The increase of the effective mass with an increase of two-dimensional carrier density is observed and explained by the nonparabolicity effect.

The role of TDRG1 in tumorigenesis and the progression of seminoma, as well as its role in regulating chemosensitivity of seminoma to cisplatin through the PI3K/Akt/mTOR signaling pathway, has been previously defined. However, the detailed mechanism underlying TDRG1 expression and concomitant chemoresistance conditions are unknown. Furthermore, it has been reported that non‐protein‐coding RNAs play an important role in a variety of vital processes including cellular chemosensitivity. However, the role of non‐protein‐coding RNAs in regulating the chemosensitivity of seminoma remains unknown. In this study, using microarray analysis, we found that long non‐coding RNA H19 was upregulated while miRNA‐106b‐5p was downregulated in an established cisplatin‐resistant TCam‐2 cell line. Moreover, H19 acts as a miRNA‐106b‐5p sponge and thus impairs the function of miRNA‐106b‐5p on its target gene, TDRG1. Based on these findings, we propose that H19 promotes the expression of TDRG1 by sequestering miRNA‐106b‐5p and uses this mechanism to facilitate cell survival in cisplatin‐based chemotherapeutic conditions. These findings elucidate the mechanisms, at least partially, applied to deregulate TDRG1 and cisplatin sensitivity, and may provide new therapeutic possibilities for chemoresistant seminoma.

Testicular germ cell tumours (TGCTs) are the most common malignancy and the leading cause of death from solid tumours in young men. 1,2 These tumours peak during the third decade of life, and an increasing incidence has been reported widely. 3 Histologically, TGCTs are subdivided into various elements. Type II TGCT refers to seminomas and non-seminomas of (predominantly) adolescents

Tin oxide nanowires have been grown on p-type silicon substrates using a gold-catalyst-assisted vapor-liquid-solid growth process. The nanowires were annealed in the presence of oxygen at 700 degrees C for different time intervals. The changes in material properties of the nanowires after annealing were investigated using various characterization techniques. Annealing improves the crystal quality of the nanowires as seen from Raman spectroscopy analysis. Photoluminescence (PL) data indicates a decrease in the oxygen vacancies and defects after annealing, affecting the luminescence from the nanowires. In addition, x-ray photoelectron spectroscopy (XPS) was used to obtain the changes in the tin and oxygen atomic concentrations before and after annealing, from which the stoichiometry was calculated.