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.