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Background: Monoamine oxidase B (MAOB), a flavin monoamine oxidase, regulates biogenic and xenobiotic amine oxidative deaminization. We demonstrate MAOB expression in head and neck epithelium and its biological importance in head and neck squamous cell carcinoma (HNSCC) development. Methods: First, we found a possible MAOB downregulation in HNSCC using bioinformatic analysis. Second, we validated MAOB expression changes in vitro and assessed its tumorigenicity in HNSCC. Finally, preclinical xenograft models further confirmed our findings. Results: Results proved that MAOB was significantly reduced in HNSCC tissues and cell lines. By comparing MAOB localization in patient specimens, we found that epithelial basal cells express MAOB and that it changes throughout HNSCC development. We observed that MAOB overexpression inhibited HNSCC cell malignancy via lentiviral transfection. We additionally discovered that selegiline partly counter‐regulated MAOB overexpression‐induced phenotypes in HNSCC cells. Conclusions: We found that MAOB is a potent biomarker and a unique and essential indication of HNSCC carcinogenesis. [ABSTRACT FROM AUTHOR]

Compared to silicon devices, silicon carbide (SiC) devices have much lower C(oss) and Q(g); they can switch at much higher speed, SiC power modules are thus more sensitive to stray parameters. Large stray inductance may result in high voltage spikes and cause severe electro-magnetic interference (EMI) issues; unbalanced stray inductance may contribute to uneven current sharing between parallel devices. Low and symmetrical inductance is a necessity to fully utilise the superior characteristics of SiC devices. This paper first studies the current sharing and voltage spike mechanisms of multichip power modules (MCPMs). Stray inductance distribution, current sharing as well as voltage spikes under different direct bonded copper (DBC) layout conditions are investigated using finite element modelling software. A round symmetrical DBC layout is then proposed. Compared with conventional ones, the proposed structure is symmetrical in stray inductance distribution; thus improving the consistency among chips. To reduce the total equivalent stray inductance and tackle the voltage spike problem, this study further presents an improved 3D structure on the basis of the round symmetrical DBC. The stray inductance extraction and double pulse simulation results verify the effectiveness of the improved 3D structure in current sharing as well as voltage spike reduction.

The nonreciprocal Josephson junction, the Josephson diode, opens a door for superconducting circuit technology. Here, we report on nonreciprocal behaviors in Nb/Au/NbSe2 Josephson junctions. The strong asymmetry could be seen in the current–voltage characteristics, which most likely arises from time symmetry breaking due to Abrikosov vortices, indicated by an asymmetric Fraunhofer pattern. The nonreciprocal microwave responses are systematically investigated compared to a numerical simulation based on a resistively and capacitively shunted junction model, which could well capture the asymmetric behaviors and rule out some artifacts such as other parasitic Josephson-like structures. Based on the nonreciprocal microwave responses, we put forward a proposal for a switchable Josephson diode controlled by an external microwave, which might provide an opportunity for next-generation microwave-related superconducting circuits. [ABSTRACT FROM AUTHOR]

In a harsh environment, power modules have to be subjected to deep power cycling, which causes large temperature fluctuations and, hence, leads to fatigue stresses. Reducing the junction temperature fluctuation of chips can significantly improve power module reliability. This article proposes a power module design with considerably reduced junction temperature fluctuation by using phase change material (PCM) as a part of thermal management. Cyclical power is applied to the proposed power module, and experiment results show that the reduction of junction temperature fluctuation is effective in a certain range of power periods. Thermodynamic simulations are used to illustrate the mechanism of PCM in reducing junction temperature fluctuation and the factors influencing the optimal range of power periods. With the significant reduction of junction temperature fluctuation, the reliability of the proposed power module is enhanced. The approach is significant to improve the reliability of power modules in power fluctuating conditions. [ABSTRACT FROM AUTHOR]