Junction Barrier Research Articles

Chronic stress and corticosterone exacerbate alcohol-induced tissue injury in the gut-liver-brain axis

Alcohol use disorders are associated with altered stress responses, but the impact of stress or stress hormones on alcohol-associated tissue injury remain unknown. We evaluated the effects of chronic restraint stress on alcohol-induced gut barrier dysfunction and liver damage in mice. To determine whether corticosterone is the stress hormone associated with the stress-induced effects, we evaluated the effect of chronic corticosterone treatment on alcoholic tissue injury at the Gut-Liver-Brain (GLB) axis. Chronic restraint stress synergized alcohol-induced epithelial tight junction disruption and mucosal barrier dysfunction in the mouse intestine. These effects of stress on the gut were reproduced by corticosterone treatment. Corticosterone synergized alcohol-induced expression of inflammatory cytokines and chemokines in the colonic mucosa, and it potentiated the alcohol-induced endotoxemia and systemic inflammation. Corticosterone also potentiated alcohol-induced liver damage and neuroinflammation. Metagenomic analyses of 16S RNA from fecal samples indicated that corticosterone modulates alcohol-induced changes in the diversity and abundance of gut microbiota. In Caco-2 cell monolayers, corticosterone dose-dependently potentiated ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. These data indicate that chronic stress and corticosterone exacerbate alcohol-induced mucosal barrier dysfunction, endotoxemia, and systemic alcohol responses. Corticosterone-mediated promotion of alcohol-induced intestinal epithelial barrier dysfunction and modulation of gut microbiota may play a crucial role in the mechanism of stress-induced promotion of alcohol-associated tissue injury at the GLB axis.

Adverse effects of LPS on membrane proteins in lactating bovine mammary epithelial cells.

Mastitis causes a decrease in milk yield and abnormalities in milk components from dairy cows. Escherichia coli and the E. coli lipopolysaccharide (LPS) cell wall component directly downregulate milk production in bovine mammary epithelial cells (BMECs). However, the detailed mechanism by which this occurs in BMECs remains unclear. Various membrane proteins, such as immune sensors (Toll-like receptors, TLR), nutrient transporters (glucose transporter and aquaporin), and tight junction proteins (claudin and occludin) are involved in the onset of mastitis or milk production in BMECs. In this study, we investigated the influence of LPS on membrane proteins using an in vitro culture model. This mastitis model demonstrated a loss of glucose transporter-1 and aquaporin-3 at lateral membranes and a decrease in milk production in response to LPS treatment. LPS disrupted the tight junction barrier and caused compositional changes in localization of claudin-3 and claudin-4, although tight junctions were maintained to separate the apical membrane domains and the basolateral membrane domains. LPS did not significantly affect the expression level and subcellular localization of epidermal growth factor receptor in lactating BMECs with no detectable changes in MEK1/2-ERK1/2 signaling. In contrast, NFκB was concurrently activated with temporal translocation of TLR-4 in the apical membranes, whereas TLR-2 was not significantly influenced by LPS treatment. These findings indicate the importance of investigating the subcellular localization of membrane proteins to understand the molecular mechanism of LPS in milk production in mastitis.

Discriminatory {040}-Reduction Facet/Ag0 Schottky Barrier Coupled {040/110}-BiVO4@Ag@CoAl-LDH Z-Scheme Isotype Heterostructure.

Crystal facet engineering, a trending technique to acquire superior exciton pair anti-recombination and interfacial charge pair separation via an inherent functional exposed facet isotype junction, is the current research hotspot. Selectively controlling facet exposure factor with Schottky energy barrier architecture across discerned exposed functional facet attested to facilitate electron injection-separation via a shorter barrier height and closer surface distance. In this context, a {040/110}-BiVO4@Ag@CoAl-LDH Z-scheme isotype heterostructure with elevated {040} facet exposure factor tailored a {040/110} crystal facet isotype junction, and {040}-BiVO4 functional facet/metallic Ag0 nano-island semiconductor-metal selective Schottky contact was fabricated meticulously via a three-step reflux, photoreduction, followed by an in situ co-precipitation method. Inherent attribution of crystal facet isotype junction and minor semiconductor-metal Schottky barrier toward the nature of exciton pair separation and elevated photoredox activity was neatly demonstrated and well inferred, which is the novelty of the present research. The ternary isotype heterostructure corroborates impressive gemifloxacin detoxification (89.72%, 90 min) and O2 generation (768 μmol, 120 min), which are multiple folds that of respective pure and binary isotype heterostructures. The bottom-up photoredox activity was well ascribed to shorter Schottky barrier hot electron channelization provoked superior exciton pair separation and well attested via linear sweep voltammetry (315 μA), photoluminescence, electrochemical impedance spectroscopy, Bode, carrier density, and transient photocurrent analysis. The research illustrates a novel insight and scientific basis for the rational design of crystal facet isotype junction and selective Schottky contact vectorial electron shuttling promoted Z-scheme charge transfer dynamics isotype heterostructure systems toward photocatalytic energy-environmental remediation.

An In Vitro Assay to Monitor Sertoli Cell Blood-Testis Barrier (BTB) Integrity.

In this chapter, we detail a reliable, effective, and easy to perform assay to monitor the Sertoli cell blood-testis barrier (BTB) integrity. While the BTB in the testis is composed of the tight junction (TJ) barrier and basal ES (ectoplasmic specialization, a testis-specific actin-rich adherens junction (AJ) type), this method is applicable to all other blood-tissue barrier in vitro, including endothelial TJ-barrier of the blood-brain barrier (BBB). Furthermore, this method does not require expensive set up, and can be rapidly performed by any standard biochemistry/cell biology/molecular biology laboratory. The basic idea is built on the concept that a functional blood-tissue barrier, such as the BTB conferred by Sertoli cells in the testis, is capable of blocking the diffusion of a small membrane impermeable biotin (e.g., EZ-Link Sulfo-NHS-LC-biotin, Mr. 556.59) across the barrier. However, when this barrier is compromised, such as following treatment with a toxicant or knockdown of a relevant gene necessary to confer the TJ-barrier function, the biotin will permeate the barrier, reaching the Sertoli cell cytosol. Biotin can be subsequently visualized by using streptavidin conjugated to a fluorescence tag such as Alexa Fluor 488 (green fluorescence) which can be easily visualized by a standard fluorescence microscope.

High Single-Event Burnout Resistance 4H-SiC Junction Barrier Schottky Diode

This paper presents a single-event burnout (SEB) resistance method for 4H-SiC Junction Barrier Schottky Diode (JBS) under high bias voltage and linear energy transfer (LET) conditions. The method is validated via two-dimensional numerical simulations. The analysis and comparison of conventional 4H-SiC JBS and 4H-SiC Multi-Buffer Layer JBS (MBL-JBS) diodes verify the resistance tolerance of the latter device to SEB. Silvaco TCAD simulation results prove that the 4H-SiC MBL-JBS modulates the drift region's electric field distribution and disperses the high-peak electric field at the N-/N+ junction. Moreover, it reduces the impact generation rate at the Schottky, PN and N-/N+ junctions to achieve SEB tolerance. The device's SEB performance is optimized by adjusting the 4H-SiC MBL-JBS structure parameters, and the SEB threshold voltage is significantly improved compared with the traditional structure.

A reliable and accurate model of photoelectron yield spectrum and its applications

Experimental and theoretical research on photoelectron yield spectrum play a crucial role in electronic and photo-electronic materials and devices, and the reliable and precise estimation of photoelectron yield via photon energy is very important for detecting microscopic electrical information in photo-electronic materials and devices. Photoelectron yield is defined as the number of electrons emitted by per incident photon. Before this work, the technique was based on the interception of a plot of square root of photoelectron yield versus photon energy for metal-insulator hetero-junction, and that of a plot of cube root of photoelectron yield variation with photon energy for insulator-semiconductor hetero-junction. But, how to intercept the relationship between photoelectron yield and photon energy for semiconductor-semiconductor and metal-semiconductor hetero-junctions has not been known. Besides, many experimental plots of square root and cube root of photoelectron yield against photon energy are available, but none of them is a straight line. In order to obtain a more accurate and reliable barrier height, electrical structure of the junction, the energy level distribution of the energy band offset, defect density in the junction, and the valence band profile through the photoelectric yield spectrum, a reliable and accurate model of photoelectron yield spectrum is established via combining the solution to a differential equation and experimental results. A method is proposed to naturally determine the junction barrier height by using the experimental results of the internal current yield varying with the photon energy. The this method can be used to calculate the junction barrier height as accurately and reliably as possible, and the density and energy level distributions of the effective occupancy states of the electrons in the four junctions are obtained by using this photoelectric yield spectrum model, In addition, based on this model, this paper proves mathematically that the density and energy level distribution of the effective occupancy state of electrons present a peak shape. Therefore, the application prospects of this photoelectric yield spectrum model are demonstrated.

Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling.

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

Effects of housing systems and glucose oxidase on growth performance and intestinal health of Beijing You Chickens

We investigated the effects of housing systems and dietary glucose oxidase (GOD) on the growth performance and intestinal health of Beijing You chickens (BYC). The experiment was designed as a factorial arrangement of 2 housing systems × 2 dietary treatments. Chickens were fed a basal diet or a diet with 200 U/kg GOD and were reared on the floor with deep litter or in the cages. Compared with the litter floor groups, the decreased average daily feed intake of 1 to 42 d, decreased feed conversion ratio (FCR), improved average daily gain of 42 to 77 d, and the whole period were identified in the cage rearing groups (P < 0.05). The FCR of 42 to 77 d and the whole period, the 42-d ileal pH, and 77-d jejunal and ileal pH decreased with the supplement of GOD (P < 0.05). Additionally, 16S rRNA gene of ileum contents was sequenced by high-throughput sequencing. Sequencing data indicated that the Firmicutes phylum of 42 d and the Bacteroidetes phylum were significantly higher in the litter group with GOD supplement (P < 0.05). The jejunal Occludin, Mucin-2 mRNA expression levels were higher in the litter floor groups than those in the cage rearing groups on 42 d (P < 0.05). The Mucin-2 and TNF-α mRNA expression levels increased with cage rearing on 77 d (P < 0.05). The Occludin and TLR-4 mRNA expression levels increased with the supplementation of GOD on 77 d (P < 0.05). Moreover, the upregulation effects of Occludin and ZO-1 mRNA expression levels were more obvious in the litter floor group fed with GOD diet on 77 d (P < 0.05). The serum endotoxin content of 42-day-old cage rearing groups were higher than that of the litter floor groups, and the serum endotoxin content significantly decreased with the supplement of GOD on 77 d. The results indicated that the litter floor systems were beneficial to the development of intestinal barrier junction in the early stage, but the cage systems were more conducive to the growth performance of BYC. The dietary GOD could inhibit the harmful bacteria and promote the beneficial bacteria, which might be related to the improvement of the growth performance and intestinal barrier function.

Blood-brain barrier genetic disruption leads to protective barrier formation at the Glia Limitans.

Inflammation of the central nervous system (CNS) induces endothelial blood-brain barrier (BBB) opening as well as the formation of a tight junction barrier between reactive astrocytes at the Glia Limitans. We hypothesized that the CNS parenchyma may acquire protection from the reactive astrocytic Glia Limitans not only during neuroinflammation but also when BBB integrity is compromised in the resting state. Previous studies found that astrocyte-derived Sonic hedgehog (SHH) stabilizes the BBB during CNS inflammatory disease, while endothelial-derived desert hedgehog (DHH) is expressed at the BBB under resting conditions. Here, we investigated the effects of endothelial Dhh on the integrity of the BBB and Glia Limitans. We first characterized DHH expression within endothelial cells at the BBB, then demonstrated that DHH is down-regulated during experimental autoimmune encephalomyelitis (EAE). Using a mouse model in which endothelial Dhh is inducibly deleted, we found that endothelial Dhh both opens the BBB via the modulation of forkhead box O1 (FoxO1) transcriptional activity and induces a tight junctional barrier at the Glia Limitans. We confirmed the relevance of this glial barrier system in human multiple sclerosis active lesions. These results provide evidence for the novel concept of "chronic neuroinflammatory tolerance" in which BBB opening in the resting state is sufficient to stimulate a protective barrier at the Glia Limitans that limits the severity of subsequent neuroinflammatory disease. In summary, genetic disruption of the BBB generates endothelial signals that drive the formation under resting conditions of a secondary barrier at the Glia Limitans with protective effects against subsequent CNS inflammation. The concept of a reciprocally regulated CNS double barrier system has implications for treatment strategies in both the acute and chronic phases of multiple sclerosis pathophysiology.

Research on wind barrier of canyon bridge-tunnel junction based on wind characteristics

Due to the acceleration effect of the wind by the special geographical location of the canyon bridge-tunnel junction, the traffic safety and stability of this section are difficult to be guaranteed, resulting in frequent traffic accidents. In order to ensure the safety and comfort of vehicles driving on this section, the numerical simulation method based on CFD is adopted to establish the numerical model of the canyon bridge-tunnel junction. The acceleration of the incoming wind speed in the bridge-tunnel junction with a guardrail that is 0.8 m high is analyzed from different canyon spacings, wind directions and heights from the bridge deck. Based on the characteristics of wind field above the bridge deck, two kinds of gradient wind barriers—trapezoidal and stepped—are proposed, and their wind reduction effects and turbulence intensity changes are analyzed. Then the aerodynamic performances of running vehicle are compared. The results show that the stepped wind barrier with 50% porosity and rectangular section railings has the best wind reduction effects, and can noticeably improve the comfort of driving. The aerodynamic coefficients of vehicle are lower with stepped wind barrier.

SiC Trenched Schottky Diode with Step-Shaped Junction Barrier for Superior Static Performance and Large Design Window

A novel silicon carbide (SiC) trenched schottky diode with step-shaped junction barrier is proposed for superior static performance and large design window. In the proposed diode, to improve tradeoff between specific on-resistance and surface peak electric field, the shape of the trenched-junction is modified to stair-step, without extra fabrication process. To investigate the performances of the SiC step-shaped trenched junction barrier schottky (SSTJBS) diode, numerical simulations are carried out through Silvaco TCAD. The results indicate that the proposed diode can accommodate highly doped drift region with no degradation of its reverse blocking characteristic. In comparison with the conventional SiC trenched junction barrier schottky (TJBS) diode, the proposed SiC SSTJBS diode shows a larger design window of drift region doping concentration from 7.9×1015cm-3 to 9.5×1015cm-3. In the design window, the specific on-resistance and surface peak electric field can be reduced by 12.9% and 11%, respectively.

The tight junction and the epithelial barrier in coeliac disease.

Epithelial barriers are essential to maintain multicellular organisms well compartmentalized and protected from external environment. In the intestine, the epithelial layer orchestrates a dynamic balance between nutrient absorption and prevention of microorganisms, and antigen intrusion. Intestinal barrier function has been shown to be altered in coeliac disease but whether it contributes to the pathogenesis development or if it is merely a phenomenon secondary to the aberrant immune response is still unknown. The tight junction complexes are multiprotein cell-cell adhesions that seal the epithelial intercellular space and regulate the paracellular permeability of ions and solutes. These structures have a fundamental role in epithelial barrier integrity as well as in signaling mechanisms that control epithelial-cell polarization, the formation of apical domains and cellular processes such as cell proliferation, migration, differentiation, and survival. In coeliac disease, the molecular structures and function of tight junctions appear disrupted and are not completely recovered after treatment with gluten-free diet. Moreover, zonulin, the only known physiological regulator of the tight junction permeability, appears augmented in autoimmune conditions associated with TJ dysfunction, including coeliac disease. This chapter will examine recent discoveries about the molecular architecture of tight junctions and their functions. We will discuss how different factors contribute to tight junction disruption and intestinal barrier impairment in coeliac disease. To conclude, new insights into zonulin-driven disruption of tight junction structures and barrier integrity in coeliac disease are presented together with the advancements in novel therapy to treat the barrier defect seen in pathogenesis.

Demonstration of β-Ga2O3 Junction Barrier Schottky Diodes With a Baliga's Figure of Merit of 0.85 GW/cm2 or a 5A/700 V Handling Capabilities

In this article, we report on demonstrating the first vertical β-Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> junction barrier Schottky (JBS) diode with the implementation of thermally oxidized p-type NiO to compensate for the dilemma of the forfeit of the p-type β-Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . With this wide-bandgap p-type NiOx, β-Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> JBS diodes with an area of 100 × 100 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> achieve a breakdown voltage (BV) and specific on-resistance Ron,sp of 1715 V and 3.45 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively, yielding a Baliga's figure of merit (FOM) of BV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /Ron,sp = 0.85 GW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which is the highest direct-current FOM value among all β-Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> diodes. Meanwhile, a large size JBS diode with the area of 1 × 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> shows a forward current IF and BV of 5 A/700 V, which is also the best IF and BV combinations (FOM = 64 MW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) among all published results about large-area Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> diodes. Dynamic switching characteristics reveal that the diode suffers from a negligible current collapse phenomenon even at a -600 V and 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> s stress, showing the great promise of implementing p-NiO in the future β-Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> power electronic devices.

A topological Josephson junction platform for creating, manipulating, and braiding Majorana bound states

As part of the intense effort toward identifying platforms in which Majorana bound states can be realized and manipulated to perform qubit operations, we propose a topological Josephson junction architecture that achieves these capabilities and which can be experimentally implemented. The platform uses conventional superconducting electrodes deposited on a topological insulator film to form networks of proximity-coupled lateral Josephson junctions. Magnetic fields threading the network of junction barriers create Josephson vortices that host Majorana bound states localized in the junction where the local phase difference is an odd multiple of π, i.e. attached to the cores of the Josephson vortices. This enables us to manipulate the Majorana states by moving the Josephson vortices, achieving functionality exclusive to these systems in contrast to others, such as those composed of topological superconductor nanowires. We describe protocols for: (1) braiding localized Majorana states by exchange, (2) controlling the separation and hence the coupling of adjacent localized Majorana states to effect non-Abelian rotations via hybridization of the Majorana modes, and (3) reading out changes in the non-local parity correlations induced by such operations. These schemes utilize current pulses and local magnetic field pulses to control the location of vortices, and measurements of the Josephson current–phase relation to reveal the presence of the Majorana bound states. Finally, we present brief discussions of readout schemes and viable experimental settings for realizing the platform.

Modeling of Current Mismatch and 1/f Noise for Halo-Implanted Drain-Extended MOSFETs

Drain-extended MOSFET (DEMOS) with halo implant induced laterally asymmetric channel doping shows anomalous characteristics across bias and temperature that cannot be captured by existing models. The transconductance (g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> ) maxima in the linear region is found to be not only a function of the peak mobility but also the halo doping density. In the saturation region, the g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> characteristics show a nonmonotonic “hump” induced by the haloregion/channel-region junction barrier. Another key careabout for analog design - the drain current (ID) mismatch, also exhibits unique characteristics with excess mismatch in the weak-inversion (WI) region, in particular at low temperature. In addition, the anomalous flicker noise (1/f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">noise</sub> ) trends in the presence of high-trap density in the halo region of halo-implanted DEMOS are also discussed. In this work, we propose an analytical model based on the equivalent conductance and impedance field theory to capture these effects. The proposed model is in good agreement with measurements and numerical device simulations using technology computer-aided design (TCAD) of DEMOS across a different oxide thickness, geometry, bias, and temperature.

Investigation of Electrical Contacts to p-Grid in SiC Power Devices Based on Charge Storage Effect and Dynamic Degradation

P-grid is a typical feature in power devices to block high off-state voltage. In power devices, the p-grid is routinely coupled to an external electrode with an Ohmic contact, but Schottky contact to the p-grid is also proposed/adopted for certain purposes. This work investigates the role of contact to p-grid in power devices based on the commonly adopted technology computer-aided design (TCAD) device simulations, with the silicon carbide (SiC) junction barrier Schottky (JBS) diode as a case study. The static characteristics of the JBS diode is independent of the nature of the contact to p-grid, including the forward voltage drop (VF) and the breakdown voltage (BV). However, during the switching process, a Schottky contact would cause storage of negative charges in the p-grid, which leads to an increased VF during switching operation. On the contrary, an Ohmic contact provides an effective discharging path for the stored negative charges in the p-grid, which eliminates the dynamic degradation issues. Therefore, the necessity of an Ohmic contact to p-grid in power devices is clarified.

Exogenous inositol ameliorates the effects of acute ammonia toxicity on intestinal oxidative status, immune response, apoptosis, and tight junction barriers of great blue-spotted mudskippers (Boleophthalmus pectinirostris)

Ammonia toxicity can disrupt the intestinal health of aquatic animals. It is important to find substances that alleviate these adverse effects. The present study explored the possible protective role of myo-inositol (MI) in ammonia-induced toxicity in the fish intestine. Great blue-spotted mudskippers (Boleophthalmus pectinirostris) accumulated in artificial seawater (15‰ salinity, n = 600) were randomly selected and intraperitoneally injected with NaCl (0.68%) or MI (2.5 mg/g fish in 0.68% NaCl) then exposed to artificial seawater alone (NaCl and MI group) or seawater containing 57.025 mmol/L ammonium chloride (NH3 and NH3 + MI group). After a 24-h experiment, it showed that ammonia exposure down-regulated the mRNA expression levels of intestinal barrier function proteins (Zo-1, Ocln, Cldn-5, Cldn-12, and Cldn-15) and anti-inflammatory cytokines (Tgf-β and Il-10) while the acute ammonia stress up-regulated the apoptosis genes (p53, Bax, Caspase-3, and Caspase-9) and pro-inflammatory cytokines (Tnf-α and Il-1β). Furthermore, ammonia challenge also induced oxidative stress, as the malondialdehyde and the protein carbonyl contents were increased. In addition, ammonia stress down-regulated the antioxidant enzymes (Cu/Zn-Sod, Cat, Gpx, and Gst) activities as well as their gene transcription levels. The administration of the exogenous myo-inositol greatly ameliorated the ammonia-induced changes in redox capacity, immune response, apoptosis, inflammation, and tight junction barrier function to levels similar to those of the NaCl group. Furthermore, fish injected with MI alone showed no significant changes compared with the NaCl group. Taken together, pretreatment with myo-inositol had no obvious side-effects and effectively protected the mudskippers' intestine from the toxicity caused by acute ammonia stress.

Mott barrier behavior of metal–TlGaSe2 layered semiconductor junction

We report on the characteristics of metal-p-type high resistance TlGaSe2 semiconductor junction barrier fabricated by deposition of indium and gold metals. The electrical properties of /TlGaSe2/ semiconductor contacts were monitored as a function of temperature in the range of ∼80–300 K using current–voltage () and capacitance–voltage () measurements. Device characteristics of /TlGaSe2/ showed rectification properties. From forward bias characteristics it was revealed that the increase of current is slower than the predictions by Schottky barrier theory. The rectification properties of /TlGaSe2/ semiconductor device were simulated by the Mott barrier model where the presence of an undoped layer on the semiconductor surface is assumed, and measurements and computational simulation agreed on the validity of this model. measurements showed that at higher temperatures /TlGaSe2/ barrier showed a capacitance from accumulation toward depletion mode, whereas at low temperatures the barrier capacitance degradation was found. The observed of /TlGaSe2/ does not significantly change over the entire bias range 30 V, confirming that the /TlGaSe2/ is fully depleted, thus the structures are Mott barrier.First-principles electronic band diagram calculations showed that introduction of -atom vacancies in the various sites of TlGaSe2 unit cell greatly affects the electronic band structure of this semiconductor in an increasing manner in band gaps with respect to stoichiometric compound. Consequently, the - vacancies localized inside the thin surface layer of TlGaSe2 are responsible for high average surface electrical resistivity of the material and could be proposed as a physical basis for the existence of native insulator layer on TlGaSe2 surface. Thus we propose a model for TlGaSe2 crystal which is comprised from an electrically conducting bulk semiconductor sandwiched between two high resistivity thin surface sheets. We suggest that the selenium vacancy defects on the surface of TlGaSe2 layered semiconductor are also responsible for the memristive behavior of this compound.

Interfacial resonant tunneling induced by folded bands and providing highly spin-polarized current in spinel-oxide barrier junctions

In spintronics, simultaneous realization of high tunneling magnetoresistance and low resistivity in magnetic tunnel junctions (MTJs) is challenging because insulating layers with higher barrier heights generally generate highly spin-polarized currents but increase resistivity. We overcome this trade-off relationship using Brillouin-zone-folded bands at the interfaces in the Fe/spinel ${\mathrm{MgGa}}_{2}{\mathrm{O}}_{4}/\mathrm{Fe}\phantom{\rule{0.16em}{0ex}}\mathrm{MTJ}$. Interfacial resonant states that enhance conductance are formed by folded bands, with Fe--O hybridization playing a key role in the resonant effect intensity at the Fermi level. The electronegativity of cation Ga in spinel oxide ${\mathrm{MgGa}}_{2}{\mathrm{O}}_{4}$ is found to be a crucial physical quantity to control an intensity of the interfacial-resonant effect from the comparative analysis with the ${\mathrm{MgAl}}_{2}{\mathrm{O}}_{4}$-based MTJ.

Role of Antimicrobial Peptides in Skin Barrier Repair in Individuals with Atopic Dermatitis.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that exhibits a complex interplay of skin barrier disruption and immune dysregulation. Patients with AD are susceptible to cutaneous infections that may progress to complications, including staphylococcal septicemia. Although most studies have focused on filaggrin mutations, the physical barrier and antimicrobial barrier also play critical roles in the pathogenesis of AD. Within the physical barrier, the stratum corneum and tight junctions play the most important roles. The tight junction barrier is involved in the pathogenesis of AD, as structural and functional defects in tight junctions not only disrupt the physical barrier but also contribute to immunological impairments. Furthermore, antimicrobial peptides, such as LL-37, human β-defensins, and S100A7, improve tight junction barrier function. Recent studies elucidating the pathogenesis of AD have led to the development of barrier repair therapy for skin barrier defects in patients with this disease. This review analyzes the association between skin barrier disruption in patients with AD and antimicrobial peptides to determine the effect of these peptides on skin barrier repair and to consider employing antimicrobial peptides in barrier repair strategies as an additional approach for AD management.