A synapse with low power consumption based on MoTe2/SnS2heterostructure.

The use of two-dimensional materials and van der Waals heterostructures holds great potential for improving the performance of memristors Here, we present SnS2/MoTe2heterostructure synaptic transistors. Benefiting from the ultra-low dark current of the heterojunction, the power consumption of the synapse is only 19pJ per switching under 0.1 V bias, comparable to that of biological synapses. The synaptic device based on the SnS2/MoTe2demonstrates various synaptic functionalities, including short-term plasticity, long-term plasticity, and paired-pulse facilitation. In particular, the synaptic weight of the excitatory postsynaptic current can reach 109.8%. In addition, the controllability of the long-term potentiation and long-term depression are discussed. The dynamic range (Gmax/Gmin) and the symmetricity values of the synaptic devices are approximately 16.22 and 6.37, and the non-linearity is 1.79. Our study provides the possibility for the application of 2D material synaptic devices in the field of low-power information storage.

Phase-Regulated Active Hydrogen Behavior on Molybdenum Disulfide for Electrochemical Nitrate-to-Ammonia Conversion.

Electrochemical reduction of nitrate waste is promising for environmental remediation and ammonia preparation. This process includes multiple hydrogenation steps, and thus the active hydrogen behavior on the surface of the catalyst is crucial. The crystal phase referred to the atomic arrangements in crystals has a great effect on active hydrogen, but the influence of the crystal phase on nitrate reduction is still unclear. Herein, enzyme-mimicking MoS2 in different crystal phases (1T and 2H) are used as models. The Faradaic efficiency of ammonia reaches ≈90 % over 1T-MoS2 , obviously outperforming that of 2H-MoS2 (27.31 %). In situ Raman spectra and theoretical calculations reveal that 1T-MoS2 produces more active hydrogen on edge S sites at a more positive potential and conducts an effortless pathway from nitrate to ammonia instead of multiple energetically demanding hydrogenation steps (such as *HNO to *HNOH) performed on 2H-MoS2 .

[Mechanism of Xianglian Pills in improving dyslipidemia in obese mice induced by high-fat diet based on network pharmacology and intestinal flora].

The present study aimed to investigate the effect of Xianglian Pills(XLP) on lipid metabolism in obese mice and explore the underlying mechanism based on network pharmacology and intestinal flora. Firstly, network pharmacology was used to predict the possible effect of XLP on obesity. Secondly, an obese mouse model induced by a high-fat diet was established to observe changes in mouse body weight, adiposity index, liver and adipose tissue pathology. Lipid profiles, liver and kidney function markers, insulin content, and the expression of recombinant uncoupling protein 1(UCP-1) and PR structural domain protein 16(PRDM16) were measured. The 16S rRNA gene sequencing technology was used to analyze the changes in the intestinal flora. Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis showed that XLP mainly played a role in improving obesity by regulating lipolysis, type 2 diabetes mellitus, and insulin resistance. The results of animal experiments showed that XLP significantly reduced body weight, adiposity, blood lipid levels, and serum insulin levels in obese mice, while enhancing the expression of UCP-1 and PRDM16 in adipose tissue without causing damage to the liver or kidneys. The 16S rRNA gene sequencing results showed that XLP decreased the Firmicutes/Bacteroidetes(F/B) ratio at the phylum level, increased the relative abundance of Akkermansia and Bacteroides at the family and genus levels, and reduced the abundance of Allobaculum. Therefore, XLP can effectively improve lipid metabolism disorders in high-fat diet-induced obese mice, and the mechanism is related to the improvement of brown adipose function, the browning of white fat, the accelerated lipid metabolism, and the improvement of intestinal flora. However, its effect on promoting the conversion of white adipose to brown adipose still needs to be further studied.

Synthesis and anti-inflammatory activity of paeonol derivatives with etherized aryl urea by regulating TLR4/MyD88 signaling pathway in RAW264.7 cell.

Thirty-three novel paeonol etherized aryl urea derivatives (PEUs) were synthesized via a bromination-Williamson Ether Synthesis-deprotection-nucleophilic addition reaction sequence. The structures of PEUs were characterized by LC-MS, HRMS, 1H NMR and 13C NMR spectra. The levels of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages were initially employed to evaluate the anti-inflammatory effects of all compounds. Remarkably, b16 exhibited a good anti-inflammatory activity at 2.5 µm which is the same as the potency of paeonol at 20 µm. The results of mechanism research displayed that the anti-inflammatory effect of b16 was ascribed to the inhibition of the TLR4/MyD88 signaling pathway and inflammatory factors. Additionally, b16 distinctly reduced the generation of free radicals in macrophages and strikingly increased the mitochondrial membrane potential. According to the structure-activity relationships (SAR) of PEUs, the incorporation of halogens on the benzene ring and the hydrogen of phenol hydroxyl substituted by aryl urea, were beneficial to enhance the anti-inflammatory activities. Molecular docking results illustrated that the binding ability of b16 to TLR4 was stronger than that of paeonol. In summary, the novel aryl urea-derivied paeonol b16 could be a new promising candidate for the treatment of inflammation-related diseases.

Scalable Electrosynthesis of Formamide through C-N Coupling at the Industrially Relevant Current Density of 120†mA cm-2.

The scalable and durable electrosynthesis of high-valued organonitrogen compounds from carbon- and nitrogen-containing small molecules, especially operating at a high current density, is highly desirable. Here, a one-pot electrooxidation method to synthesize formamide (HCONH2 ) from methanol and ammonia over a commercial boron-doped diamond (BDD) catalyst is reported. The formamide selectivity from methanol and formamide Faradaic efficiency (FE HCONH 2 ${{_{{\rm HCONH}{_{2}}}}}$ ) achieve 73.2 % and 41.2 % at the current density of 120 mA cm-2 with high durability. The C-N bond originates from the nucleophilic attack of ammonia on an aldehyde-like intermediate. Impressively, an 8 L electrolyzer is employed for the pilot plant test over a 2200 cm2 BDD electrode, which exhibits 33.5 % FE HCONH 2 ${{_{{\rm HCONH}{_{2}}}}}$ at 120 mA cm-2 (current: 264 A) with a yield rate of 36.9 g h-1 , demonstrating the potential of this technique for large-scale electrosynthesis of formamide.

Implantation energy- and size-dependent light output of enhanced-efficiency micro-LED arrays fabricated by ion implantation.

A new process is presented for fabricating enhanced-efficiency micro-pixelated vertical-structured light-emitting diode (µVLED) arrays based on ion-implantation technology. High-resistivity selective regions are locally introduced in the n-GaN layer by ion implantation and then used as effective and non-destructive electrical isolation for realizing µVLED arrays with ultra-small pixel diameters. The implantation energy-dependent and size-dependent opto-electrical characteristics of fluorine (F-) implanted µVLED arrays are investigated systematically. The results show that the optimally designed F- ion implantation not only can achieve smaller reverse leakage current but also can realize ion-induced thermal relaxation effectively and is more suited for fabricating high-resolution µVLED arrays with higher optical output power. For the F--implanted µVLED array with pixel diameters of 10 µm, a measured output power density reaches a value of 82.1 W cm-2 at a high injection current density of 220 A cm-2, before power saturation. Further, the output power densities and external quantum efficiencies of F--implanted µVLED arrays with pixel diameters less than 10µm show strong dependences on pixel size due to the presence of defects-related SRH process. So, the high-efficiency µVLED arrays with ultra-small pixel sizes could be fabricated by an appropriately designed ion implantation combined with control of defect densities to meet the industrial requirement of microdisplay applications.

Research of nanopore structure of Ga2O3 film in MOCVD for improving the performance of UV photoresponse.

Using the mechanism of self-reactive etching between Ga and Ga2O3, Ga2O3 nanopore films were fabricated. The self-reactive etching effects based on as-grown and annealed Ga2O3 films by metal organic chemical vapor deposition were compared. It was found that the nanopore film based on as-grown Ga2O3 film has a uniform size, high density and a small diameter. Ultraviolet-visible light reflection spectra and transmission spectra show that the nanopore film could effectively reduce the reflectivity of light and enhance the light absorption. Based on the as-grown Ga2O3 film and its nanopore film, metal-semiconductor-metal structure solar blind ultraviolet photodetectors (PD) were fabricated. Under 5 V bias, the light-dark current ratio of the nanopore film PD is about 2.5 × 102 times that of the film PD, the peak responsivity of the nanopore film PD is about 49 times that of the film PD. The rejection ratio is 4.6 × 103, about 1.15 × 102 times that of the film PD. The nanopore structure effectively increases the surface-volume ratio of film. The photoelectric detection performance and response performance of the nanopore film PD could be significantly enhanced.

Parallel Polarization Illumination with a Multifocal Axicon Metalens for Improved Polarization Imaging.

Polarization imaging is an important branch of the microscopy technique that can provide additional information and enhanced contrast. The illumination system of a polarization microscope enables many different polarizations but makes the setup bulky, complicated, and slow. Here, we design and fabricate an ultrathin planar axicon metalens that also enables parallel illumination with different polarizations. Our results reveal a diffraction-limited size and high degree of linear polarization. To verify our approach, we accurately map the polarization angle of an aluminum grating, which is used as a polarizer. Furthermore, we demonstrate that elliptical polarization can be generated without additional design. A single metalens has the same capabilities as a conventional illumination module containing a polarizer, compensator, and rotation-stage/optical modulator. In addition, our device has the potential to enable rapid super-resolution polarization imaging. The new method could be useful in many applications and areas, including, e.g., materials research and biomedicine.

Self-catalyzed metal organic chemical vapor deposition growth of vertical ß-Ga2O3 nanowire arrays.

Self-catalyzed metal organic chemical vapor deposition (MOCVD) growth of Ga2O3 nanowires on GaN layers prepared on a sapphire substrate has been studied. Nanowire orientations are found to be growth temperature dominated. The vertical yields over total (VOT) curve shows a maximum peak beyond 70% around 480 °C, based on scanning electron microscope observations. X-ray diffraction patterns revealed a primary ß-(-201) normal orientation of as grown nanowires all over the studied temperature interval. Further transmission electron microscopy characterization had confirmed ß-(-201) normal axial orientation of these vertical nanowires, which have well crystallinity. The ß-(010)//GaN(110) in-plane epitaxial relationship is consistent with reported Ga2O3 film/nanowire growth. Nanowires crystallized in ß-[001] axial orientation were considered to be the inclined ones. Based on contrast experiments, the temperature dominated growth behavior is considered a thermodynamic process. The two observed crystalline orientation might have distinguishable but similar system energy, which results in coexistence of multi orientation nanowires over a large temperature span and an optimum temperature window for vertical ß-(-201) normal orientation. The presented optimized ß-Ga2O3 nanowire arrays with highest VOT close to 90% should effectively promote development of reliable high performance devices based on Ga2O3 nanowires.

Four active monomers from Moutan Cortex exert inhibitory effects against oxidative stress by activating Nrf2/Keap1 signaling pathway.

Paeonol, quercetin, ß-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and antitumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H2O2) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl4). Monomers protected against oxidative stress in HepG2 cells in a doseresponse manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelchlike ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of ß-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl4. In HepG2 cells, paeonol, quercetin, ß-sitosterol, and gallic acid play a defensive role against H2O2-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

Enhanced performance of vertical-structured InGaN micro-pixelated light-emitting-diode array fabricated using an ion implantation process.

In this Letter, a new approach to fabricating a high-efficiency vertical-structured InGaN micro-pixelated light-emitting diode (µVLED) is presented. The high-resistivity selective areas are intentionally created in the n-GaN layer through a fluorine (F) ion-implantation process and then used as the electrical isolation regions for realizing a µVLED array consisting of 25×25 pixels with a diameter of 10 µm. The results prove that the dual-energy F- ion implantations not only can improve the uniformity of carrier distribution but also can effectively prevent current from leaking along the etched sidewalls, which in turn realize a more efficient carrier injection into the mesa area. More notably, the current-handling capability and corresponding optical output power density of the µVLED array are substantially higher than those of conventional vertical-structured broad-area LEDs. A measured output light power density of the F- ion-implanted µVLED array reaches a maximum value of 43 W cm-2 at 3.06 kA cm-2, before power saturation. The improved luminescence performances of the µVLED array can be attributed to an effective ion-induced heat relaxation and associated lower junction temperature.

Steep-slope field-effect transistors with AlGaN/GaN HEMT and oxide-based threshold switching device.

We report the demonstration of a steep-slope field-effect transistor with AlGaN/GaN MIS-HEMTs employing SiO2-based threshold switching devices in series with the source. The SiO2-based threshold switching devices exhibited steep slope when changing resistance states. The integrated steep-slope transistor showed a low subthreshold swing of sub-5 mV/dec with a transition range of over 105 in the transfer characteristics in both sweep directions at room temperature, as well as the low leakage current (10-5 µA µm-1) and a high I ON/I OFF ratio (>107). Moreover, with the SiO2-based threshold switching devices we also observed a positive shift of threshold voltages of the integrated device. Results from more than 50 transfer characteristics measurements also indicate the good repeatability and practicability of such a steep-switching device, where the average steep slopes are below 10 mV/decade. This steep-slope transistor with oxide-based threshold switching devices can be further extended to various transistor platforms like Si and III-V and are of potential interest for the development of power switching and high frequency devices.

Observation of terahertz plasmon and plasmon-polariton splitting in a grating-coupled AlGaN/GaN heterostructure.

Plasmon in two-dimensional electron gas (2DEG) has long been considered as a promising active medium for terahertz emitters and detectors. However, the efficiency of terahertz plasmonic devices is severely limited by the high damping rate of plasma wave in solid state. In addition to the enhancement of plasmon lifetime by using 2DEGs with higher carrier mobility, engineering on the boundary condition and electromagnetic environment of plasmon cavity helps to preserve the plasmon states. Here we report on terahertz reflection spectroscopy of plasmon states in a grating-coupled AlGaN/GaN-2DEG plasmonic device at 7 K in equilibrium with ambient blackbody irradiation. Localized plasmon states and plasmon-polariton states were observed when the core plasmonic device is integrated with a silicon lens and when it is embedded in a terahertz Fabry-Pérot cavity, respectively. Simulation results including the reflection spectra and total reflection power agree well with the measured results. The Rabi splitting is found to be inversely proportional to the resonance frequency, and follows a linear relation with the square root of the sheet electron density. A normalized coupling ratio, ΩRω0≈0.13, is achieved between the Rabi splitting ΩR and the resonance frequency ω0. The coupling ratio could be further increased to allow for ultrastrong coupling between terahertz photons and plasmons.

Synthesis and anti-inflammatory activity of paeonol analogues in the murine model of complete Freund's adjuvant induced arthritis.

A new series of paeonol alkyl ether analogues were synthesized and confirmed with IR, 1H NMR, 13C NMR and HRMS spectra. They have shown anti-inflammatory activities by scavenging mediator of free radicals and inhibiting lipid mediator of inflammation on complete Freund's adjuvant (CFA) induced arthritis in mice. The in vitro and in vivo scavenging ability of free radicals was determined by using chemical analysis and commercial assay kits, respectively. The in vivo inhibiting lipid mediator of inflammation was examined by ELISA. Our results indicated that the substitution of the hydrogen in hydroxyl group at C2 position of paeonol 1 by short carbon chain, in the presence or absence of bromo atom at C5 position, decreased its scavenging ability on radicals (3a or 4a vs 1), while the long alkyl substitution (Cn>14) increased the activity. Compared with 3a or 4a, scavenging abilities of 3a-h or 4a-h gradually increased following the length elongation of alkyl carbon chain. Compounds 3h and 4h showed great scavenging ability on OH, O2-, DPPH, ATBS+ and MDA, and good promotion on T-AOC and SOD. The results of the in vivo inhibiting lipid mediator of inflammation also demonstrated that 3h, 4h exhibited substantial inhibition on enzyme activity of COX-2, PGE2. Therefore, 3h and 4h have great potential to be the novel anti-inflammatory drug candidates for the therapy of arthritis.

Recent progress in marine chondroitin sulfate, dermatan sulfate, and chondroitin sulfate/dermatan sulfate hybrid chains as potential functional foods and therapeutic agents.

Chondroitin sulfate (CS), dermatan sulfate (DS), and CS/DS hybrid chains are natural complex glycosaminoglycans with high structural diversity and widely distributed in marine organisms, such as fish, shrimp, starfish, and sea cucumber. Numerous CS, DS, and CS/DS hybrid chains with various structures and activities have been obtained from marine animals and have received extensive attention. However, only a few of these hybrid chains have been well-characterized and commercially developed. This review presents information on the extraction, purification, structural characterization, biological activities, potential action mechanisms, and structure-activity relationships of marine CS, DS, and CS/DS hybrid chains. We also discuss the challenges and perspectives in the research of CS, DS, and CS/DS hybrid chains. This review may provide a useful reference for the further investigation, development, and application of CS, DS, and CS/DS hybrid chains in the fields of functional foods and therapeutic agents.

Linoelaidic acid gavage has more severe consequences on triglycerides accumulation, inflammation and intestinal microbiota in mice than elaidic acid.

This work aims to study the effects of oral gavage (0.2 mg/g body weight) of elaidic acid (C18:1-9 t, EA) and linoelaidic acid (C18:2-9 t,12 t, LEA) on lipid metabolism, inflammation and gut homeostasis of mice. Results showed that both EA and LEA gavage significantly increased LDL-c, TC and oxidative stress levels in the liver and serum and may stimulate liver inflammation via NF-κB and MAPK signaling pathway. Compared with EA, LEA gavage significantly promoted TAG accumulation and inflammatory signaling. Serum lipidomics revealed that LEA intake significantly increased the concentration of ∼50 TAGs, while EA gavage primarily caused significant decreases in several SMs. 16S rRNA demonstrated that LEA ingestion markedly changed fecal microbiota by enriching Lactobacillus (phylum Firmicutes), however, EA treatment did not affect it. Overall, LEA gavage has more severe consequences on TAG accumulation, inflammation and microbial structure than EA, highlighting that the number of trans double bonds affects these processes.

Diosmetin ameliorates psoriasis-associated inflammation and keratinocyte hyperproliferation by modulation of PGC-1α / YAP signaling pathway.

Psoriasis, characterized by aberrant epidermal keratinocyte proliferation and differentiation, is a chronic inflammatory immune-related skin disease. Diosmetin (Dios), derived from citrus fruits, exhibits anti-inflammatory and anti-proliferative properties. In this study, IL-17A-induced HaCaT cell model and Imiquimod (IMQ)-induced mouse model were utilized to investigate the effects of Dios against psoriasis. The morphology and biomarkers of psoriasis were regarded as the preliminary evaluation including PASI score, skin thickness, H&E staining, EdU staining and inflammatory factors. Transcriptomics analysis revealed PGC-1α as a key target for Dios in ameliorating psoriasis. Specifically, Dios, through PGC-1α, suppressed YAP-mediated proliferation and inflammatory responses in psoriatic keratinocytes. In conclusion, Dios shows promise in psoriasis treatment and holds potential for development as targeted medications for application in psoriasis.

Structural elucidation and anti-psoriasis activity of a novel polysaccharide from Saussurea Costus.

PSCP, a novel water-soluble polysaccharide, was extracted from the root of Saussurea costus and subsequently purified using DEAE-52 cellulose and Sephadax G-50 columns. The elucidation of its structure involved various techniques including HPGPC, FT-IR, HPLC-ELSD, GC-MS, NMR, AFM, and SEM. The results show that PSCP was a homogeneous heteropoly saccharide having molecular weight of 4131 Da and mainly composed of 1-α-D-Glcp-(-2-ß-D-Fruf-1-)23-2-ß-D-Fruf. The anti-psoriasis activity of PSCP was evaluated in imiquimod-induced psoriasis in Balb/C mice. This study revealed that treatment with PSCP resulted in a significant improvement in the pathological morphology of the skin and a reduction in the PASI score. Analysis of liver RNA-Seq data indicated that the MAPK signaling pathway may play a crucial role in the ability of PSCP to ameliorate psoriasis. PSCP was found to effectively inhibit the phosphorylation of JNK, ERK, and p38, as well as down-regulate the expression of the transcription factor AP-1 (c-fos and c-jun) in the nucleus, thereby reducing the expression of inflammatory factors. These findings suggest that PSCP holds promise as a novel therapeutic approach for the treatment of psoriasis.

High-Speed and Ultrasensitive Solar-Blind Ultraviolet Photodetectors Based on In Situ Grown ß-Ga2O3 Single-Crystal Films.

Deep-level defects in ß-Ga2O3 that worsen the response speed and dark current (Id) of photodetectors (PDs) have been a long-standing issue for its application. Herein, an in situ grown single-crystal Ga2O3 nanoparticle seed layer (NPSL) was used to shorten the response time and reduce the Id of metal-semiconductor-metal (MSM) PDs. With the NPSL, the Id was reduced by 4 magnitudes from 0.389 µA to 81.03 pA, and the decay time (τd1/τd2) decreased from 258/1690 to 62/142 µs at -5 V. In addition, the PDs with the NPSL also exhibit a high responsivity (43.5 A W-1), high specific detectivity (2.81 × 1014 Jones), and large linear dynamic range (61 dB) under 254 nm illumination. The mechanism behind the performance improvement can be attributed to the suppression of the deep-level defects (i.e., self-trapped holes) and increase of the Schottky barrier. The barrier height extracted is increased by 0.18 eV compared with the case without the NPSL. Our work contributes to understanding the relationship between defects and the performance of PDs based on heteroepitaxial ß-Ga2O3 thin films and provides an important reference for the development of high-speed and ultrasensitive deep ultraviolet PDs.

Comparative Analysis of the GaN Nonpolar Plane Morphology by Wet Treatment and Its Effect on Electrical Properties in Trench MOSFET.

The morphological characteristics of the GaN nonpolar sidewalls with different crystal plane orientations were studied under various TMAH wet treatment conditions, and the effect of different morphological features on device carrier mobility was modeled and analyzed. After TMAH wet treatment, the morphology of the a-plane sidewall presents multiplied zigzag triangular prisms along the [0001] direction, which consist of two adjacent m-plane and c-plane on top. While along the [112̅0] direction, the m-plane sidewall is represented by thin, striped prisms with three m-plane and a c-plane on the side. The density and size of sidewall prisms were studied by varying the solution temperature and immersion period. The prism density decreases linearly as the solution temperature rises. With increased immersion time, both a-plane and m-plane sidewalls show smaller prism sizes. Vertical GaN trench MOSFET with nonpolar a- and m-plane sidewall channels were fabricated and characterized. By properly treated in TMAH solution, transistors with an a-plane sidewall conduction channel exhibit higher current density, from 241 to 423 A cm-2@VDS = 10 V, VGS = 20 V, and higher mobility, from 2.9 to 2.0 cm2 (V s)-1, compared to those of m-plane sidewall devices. The temperature dependence on mobility is also discussed, and a modeling analysis for the difference in carrier mobility is then performed.