Universal field-tunable terahertz emission by ultrafast photoinduced demagnetization in Fe, Ni, and Co ferromagnetic films

We report a universal terahertz (THz) emission behavior from simple Ni, Fe, and Co metallic ferromagnetic films, triggered by the femtosecond laser pulse and subsequent photoinduced demagnetization on an ultrafast time scale. THz emission behavior in ferromagnetic films is found to be consistent with initial magnetization states controlled by external fields, where the hysteresis of the maximal THz emission signal is observed to be well-matched with the magnetic hysteresis curve. It is experimentally demonstrated that the ultrafast THz emission by the photoinduced demagnetization is controllable in a simple way by external fields as well as pump fluences. © 2020, The Author(s).1

Methylsulfonylmethane Suppresses Breast Cancer Growth by Down-Regulating STAT3 and STAT5b Pathways

Breast cancer is the most aggressive form of all cancers, with high incidence and mortality rates. The purpose of the present study was to investigate the molecular mechanism by which methylsulfonylmethane (MSM) inhibits breast cancer growth in mice xenografts. MSM is an organic sulfur-containing natural compound without any toxicity. In this study, we demonstrated that MSM substantially decreased the viability of human breast cancer cells in a dose-dependent manner. MSM also suppressed the phosphorylation of STAT3, STAT5b, expression of IGF-1R, HIF-1α, VEGF, BrK, and p-IGF-1R and inhibited triple-negative receptor expression in receptor-positive cell lines. Moreover, MSM decreased the DNA-binding activities of STAT5b and STAT3, to the target gene promoters in MDA-MB 231 or co-transfected COS-7 cells. We confirmed that MSM significantly decreased the relative luciferase activities indicating crosstalk between STAT5b/IGF-1R, STAT5b/HSP90α, and STAT3/VEGF. To confirm these findings in vivo, xenografts were established in Balb/c athymic nude mice with MDA-MB 231 cells and MSM was administered for 30 days. Concurring to our in vitro analysis, these xenografts showed decreased expression of STAT3, STAT5b, IGF-1R and VEGF. Through in vitro and in vivo analysis, we confirmed that MSM can effectively regulate multiple targets including STAT3/VEGF and STAT5b/IGF-1R. These are the major molecules involved in tumor development, progression, and metastasis. Thus, we strongly recommend the use of MSM as a trial drug for treating all types of breast cancers including triple-negative cancers

Superamphiphobic Surface by Nanotransfer Molding and Isotropic Etching

We present a novel method of fabricating superhydrophobic and superoleophobic surfaces with nanoscale reentrant curvature by nanotransfer molding and controlled wet etching of the facile undercut. This method produces completely ordered re-entrant nanostructures and prevents capillary-induced bundling effects. The mushroom-like, re-entrant, overhanging structure demonstrates superhydrophobic and superoleophobic characteristics, as tested by water droplet bouncing and contact angle measurements, and has high transparency on a flexible substrate. Widespread use as self-cleaning surfaces is expected in the near future

Glutamyl-Prolyl-tRNA Synthetase Regulates Epithelial Expression of Mesenchymal Markers and Extracellular Matrix Proteins: Implications for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), a chronic disease of unknown cause, is characterized by abnormal accumulation of extracellular matrix (ECM) in fibrotic foci in the lung. Previous studies have shown that the transforming growth factor β1 (TGFβ1) and signal transducers and activators of transcription (STAT) pathways play roles in IPF pathogenesis. Glutamyl-prolyl-tRNA-synthetase (EPRS) has been identified as a target for anti-fibrosis therapy, but the link between EPRS and TGFβ1-mediated IPF pathogenesis remains unknown. Here, we studied the role of EPRS in the development of fibrotic phenotypes in A549 alveolar epithelial cells and bleomycin-treated animal models. We found that EPRS knockdown inhibited the TGFβ1-mediated upregulation of fibronectin and collagen I and the mesenchymal proteins α-smooth muscle actin (α-SMA) and snail 1. TGFβ1-mediated transcription of collagen I-α1 and laminin γ2 in A549 cells was also down-regulated by EPRS suppression, indicating that EPRS is required for ECM protein transcriptions. Activation of STAT signaling in TGFβ1-induced ECM expression was dependent on EPRS. TGFβ1 treatment resulted in EPRS-dependent in vitro formation of a multi-protein complex consisting of the TGFβ1 receptor, EPRS, Janus tyrosine kinases (JAKs), and STATs. In vivo lung tissue from bleomycin-treated mice showed EPRS-dependent STAT6 phosphorylation and ECM production. Our results suggest that epithelial EPRS regulates the expression of mesenchymal markers and ECM proteins via the TGFβ1/STAT signaling pathway. Therefore, epithelial EPRS can be used as a potential target to develop anti-IPF treatments

Metastable defect curing by alkaline earth metal in chalcogenide thin-film solar cells

This study investigates the use of an alkaline earth metal precursor (MgF2) to enhance the performance of chalcogenide-based Cu(In,Ga)Se2 (CIGS) solar cells with a chemically bath deposited-Zn(O,S) (CBD-Zn(O,S)) buffer layer via post-deposited treatment (PDT). The optimal substrate temperature and layer thickness are 570 °C and 5 nm, and the light soaking (LS) treatment does not be required in this condition. The morphological properties and chemical reaction at the p-n junction of CIGS/CBD-Zn(O,S) are examined as a function of MgF2 PDT layer thickness. As the MgF2 PDT layer thickness increases, the CIGS surface becomes rough with vigorously agglomerated Cu clusters owing to the substantially high substrate temperature, which increases the incorporation of In-Se bonds and the oxygenation rate of MgF2. Density functional theory (DFT) clarifies the improved cell efficiency without the need for LS treatment (MgF2 PDT, 5 nm) by calculating the defect-related electronic behavior. The MgF2 phase effectively passivates metastable defect Cu-Se vacancy defects (VCu-Se), related to the LS effect without the additional formation of deep-level defect states into the CIGS bandgap. Moreover, VCu-Se states exert the most influence on the LS effect, and the control of defect states in the CIGS layer (not the buffer layer) is crucial for cell efficiency

Real-Time Correlation Detection via Online Learning of a Spiking Neural Network with a Conductive-Bridge Neuron

© 2022 The Authors.The neuronal density of complementary metal-oxide-semiconductor field-effect transistor-based neurons is limited because of the use of capacitors. Therefore, a novel neuron is fabricated using a conductive-bridge-neuron device, current-mirror-type sense amplifier, latch, micro-controller-unit, and digital-analog-converters. This neuron exhibits a typical integrate-and-fire function; in particular, the generation frequency of the fire spikes at the neuron exponentially increases with the input-voltage-spike amplitude. Using the proposed designed neuron in combination with an input spike generation and spike-timing-dependent-plasticity algorithm, a real-time correlation detection based on online learning is realized. With the increase in the number of learning iterations, the weight of synapses for 100 correlated input neurons gradually increase, whereas that for 900 uncorrelated input neurons steadily reduce. In addition, after 700 learning iterations, the output neuron is almost synchronized with the 100 correlated input neurons, thereby achieving correlation detection for cognitive functions in neuromorphic architectures and demonstrating the possibility of development of a neuromorphic chip based on the conductive-bridge neurons and synapses.N