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This paper details the fabrication of GaN-based microdisks with a single porous n-GaN layer positioned beneath the multiple quantum wells region on a modified green light-emitting diode epiwafer. Simulations of the longitudinal light field distribution reveal effective confinement of the light field within the multiple quantum wells region due to the presence of the single porous layer. The porous layer also demonstrates sufficient conductivity as determined through calculations and serves as an effective method for thermal dispersion. Under optical pumping, all microdisks exhibit clear whispering gallery mode (WGM) lasing at room temperature, with the lowest threshold of 13.50 μJ/cm2 achieved in a 2-μm-diameter microdisk. These findings suggest that integrating the single porous layer into GaN microdisks is a highly promising approach for achieving high-efficiency WGM micro-laser diodes with effective electrical injection and heat dispersion. [ABSTRACT FROM AUTHOR]

Autophagy plays a key role in the metabolism of macromolecules via the degradative abilities of the lysosome. Transcription factor EB (TFEB) regulates autophagosome biogenesis and lysosome function, and promoting TFEB activity has emerged as a potential strategy for the treatment of metabolic disorders. Herein, we report that cetrimonium bromide (CTAB; a quaternary ammonium compound) promotes autophagy and lysosomal biogenesis by inducing the nuclear translocation of TFEB in hepatic cells. Knockdown of TFEB mediated by short hairpin RNA inhibits CTAB-induced autophagy and lysosomal biogenesis. Mechanistically, CTAB treatment inhibits the Akt--mTORC1 signaling pathway. Moreover, CTAB treatment significantly increases lipid metabolism in both palmitate- and oleate-treated HepG2 cells, and this increase was attenuated by knockdown of TFEB. Collectively, our results indicate that CTAB activates the autophagosome--lysosome pathway via inducing the nuclear translocation of TFEB by inhibiting the mTORC1 signaling pathway. These results add to the collective understanding of TFEB function and provide new insights into CTAB-mediated lipid metabolism. Key words: cetrimonium bromide, TFEB, autophagy, mTORC1 signaling, lipid metabolism. L'autophagie joue un rôle clé dans le métabolisme des macromolécules par la machinerie de dégradation lysosomale. Le facteur de transcription EB (TFEB) régule la biogenèse des autophagosomes et la fonction des lysosomes, et la promotion de l'activité du TFEB est apparue comme une stratégie potentielle pour le traitement des troubles métaboliques. Les auteurs décrivent ici que le bromure de cétrimonium (CTAB), un ammonium quaternaire, favorise l'autophagie et la biogenèse lysosomale en induisant la translocation nucléaire du TFEB dans les cellules hépatiques. Le silençage de TFEB par un ARN court en épingle à cheveux inhibe l'autophagie et la biogenèse lysosomale induites par le CTAB. Sur le plan mécanique, le traitement par le CTAB inhibe la voie de signalisation Akt--mTORC1. De plus, le traitement par le CTAB stimule nettement le métabolisme des lipides dans les cellules HepG2 traitées par le palmitate et l'oléate, et cette stimulation était atténuée par la déplétion du TFEB. Dans l'ensemble, ces résultats indiquent que le CTAB active la voie autophagie--lysosome en induisant la translocation nucléaire du TFEB par l'inhibition de la signalisation mTORC1. Ces résultats approfondissent notre compréhension de la fonction du TFEB et apportent de nouvelles connaissances sur le métabolisme des lipides médié par le CTAB. [Traduit par la Rédaction] Mots-clés : bromure de cétrimonium, TFEB, autophagie, signalisation mTORC1, métabolisme des lipides., Introduction Autophagy is a highly conserved degradation process by which components of the cell are degraded in lysosomes (Klionsky and Emr 2000). The autophagosome--lysosome pathway plays a key role in [...]

According to Milankovitch's theory, periodic climate change in Earth's history is controlled by the periodic changes in the Earth's orbit and axis of rotation. Milankovitch cycle include eccentricity, obliquity, and precession cycles. In addition to them, there are also some amplitude modulation (AM) cycles that affect the climate system through a series of "nonlinear" feedback processes, such as the 173 kyr obliquity AM cycle. Previous studies have demonstrated that the -170 kyr cycle modulate the paleoclimate and carbon cycle at mid- high latitude regions in the Meso-Cenozoic. However, due to the limitation of astronomical solutions and the lack of high-resolution geological records, the -170 kyr cycle has been less reported in the Paleozoic Era. In this study, cyclostratigraphic analysis of natural gamma ray (GR) logging data from four wells (Ji30, Ji31, Ji32, and Ji174) and total organic carbon (TOC) data from well Ji174 penetrating the Early Permian Lucaogou Formation in Jimusar Sag, Junggar Basin suggests preservation of eccentricity, obliquity, and precession cycles, and the -170 kyr AM cycle. Through the astronomical tuning of GR logging data obtained from four wells to eccentricity target cycles, we established the floating astronomical time scale (ATS). The results indicate an average sedimentation rate ranging from 7.4 to 9.5 cm/kyr and a duration from 2.8 to 3.2 million years (Myr) for the Lucaogou Formation. The differences in sedimentation rate and duration among these four wells may result from different well locations. Moreover, the -170 kyr cycle signal has been identified in the detrended GR logging and TOC data series, and its obliquity AM series. This signal might be attributed to the obliquity AM cycles originated from the interaction between s3 and s6 (s3 and s6 represent the precession of nodes of Earth and Saturn), which was recorded in the GR logging and TOC data time series due to nonlinear responses within the depositional system. [ABSTRACT FROM AUTHOR]

Mixed‐dimensional heterostructures provide additional freedom to construct diverse functional electronic and optoelectronic devices, gaining significant interest. Herein, highly‐aligned pseudo‐1D tellurium is epitaxially grown on 2D monolayer transition metal dichalcogenides (TMDs), including MoSe2, MoS2, and WS2. A one‐pot chemical vapor deposition (CVD) technique eliminates the normally required transfer steps, thereby producing mixed‐dimensional heterostructures with an ultraclean interface. The controllable epitaxial growth of Te/TMD heterostructures are verified by Raman, scanning probe microscopy (SPM), and transmission electron microscopy (TEM) observation. The photoluminescence results indicate that the emission from TMDs is quenched in the heterostructure, confirming the efficient transfer of photogenerated carriers from TMDs to Te. Additionally, the mixed‐dimensional p‐n Te/MoSe2 heterojunction photodetector presents self‐driven behavior with high responsivity (328 mA W−1), external quantum efficiency (79%), and specific detectivity (8.2 × 109 Jones). The modified facile synthesis strategy and proposed growth mechanism in this study shed light on synthesizing mixed‐dimensional heterojunctions. This opens avenues for fabricating functional devices with reduced sizes and high densities, further enabling miniaturization and integration opportunities. [ABSTRACT FROM AUTHOR]

A new reactive force field based on quantum mechanical data for describing formation of the Zn electrode‐electrolyte interface (EEI) chemistry in aqueous zinc‐ion batteries (ZIBs) is developed. This is the first demonstration in which Reactive Molecular Dynamics (RMD) simulation is used to follow the Zn reduction and anode structural evolution at the EEI. It is found that under axial pressure, Zn dendrite formation is inhibited. This is associated with accelerated ion transport and reduction while increasing preference towards horizontal (002) plane growth. Pressure‐induced desolvation of Zn ions within the electric double layer, which promotes faster reduction kinetics is observed. It is found that axial pressure stabilizes adatoms on the (002) plane by decreasing axial atom stress during nucleation and by increasing favorable lateral adatom diffusion, which reduces atomic scale dendrite formation. Finally, these are confirmed results by experimental characterization and electrochemical tests. [ABSTRACT FROM AUTHOR]

Dual-atom catalysts (DACs) have recently emerged as promising and high-activity catalysts for the oxygen reduction reaction (ORR), a key process in many electrochemical energy conversion devices. However, the ORR mechanism and kinetics on DACs has not yet been established. To address this problem, we employed grand canonical potential kinetics (GCP-K) with CANDLE solvation. The behavior of the free energy and grand canonical potential for ORR and hydrogen evolution reaction (HER) intermediates (OO*, OOH*, O*, OH*, and H*) and their corresponding transition states at constant charges were calculated and converted to free energy as a function of applied potential to predict current density as a function of applied potential for ORR (through the associative pathway) and the competitive HER on iron–nickel DAC (FeNiN6-DAC). We find a Tafel slope of 281 mV dec−1 for ORR, comparable with the experimental Tafel slope of 169 mV dec−1 at the current density of −1.7 mA cm−2. The change in concentration of ORR reaction intermediates on FeNiN6-DAC as a function of applied potentials indicates that the dominant intermediate is OH* at potentials >0.25 V vs. RHE. The charge transfer and spin density of Fe active sites reaches a maximum during each proton transfer step. The partial density of states of 3d orbitals on the Fe site indicates that the 3dx2−y2 orbital is near the Fermi level, while the position of the 3dz2 orbital and Fermi level reaches a minimum along the first reaction step of These insights into the fundamental aspects of ORR on DACs provide guidance for the design of efficient catalysts. [ABSTRACT FROM AUTHOR]