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Eleven flavonoids including one new flavonol glycoside, quercetin-3-O-(2-α-L-rhamnopyranosyl)-β-D-glucuronopyranosyl methyl ester (1), were isolated for the first time from the fruits of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their structures were determined by extensive spectroscopic data. The known flavonoids, quercetin-3-O-β-D-glucuronide methyl ester (3), quercetin-3-O-(2''-α-L-rhamnopyranosyl-6''-O-α-L-rhamno pyranosyl)-β-D-glucopyranoside (5), myricetin (9), and 6-methoxy-naringenin (11) were isolated for the first time from the genus Phyllanthus. Flavonoids 4, 6 and 9 (IC50 = 6.01, 6.32, and 7.84 μM, respectively) showed stronger α-glucosidase inhibitory activities than the positive control, acarbose (IC50 = 306.45 μM). The fruits of P. acidus might be further developed as an anti-diabetic food supplement.

Lithium sulfur battery is one of the most promising applicants for the next generation of energy storage devices whose commercial applications are impeded by the key issue of shuttle effect. To overcome this obstacle, various of two-dimensional (2D) carbon-based metal-free compounds have been proposed to serve as anchoring materials for immobilizing soluble lithium polysulfides (LiPs), which however suffered from low electronic conductivity implying unsatisfactory performance for catalyzing sulfur redox. Therefore, we predicted metallic C5N monolayers, possessing hexagonal (H) and orthorhombic (O) phases, which exhibit excellent performances for suppressing the shuttle effect. First principles simulations demonstrate that O-C5N could serve as bifunctional anchoring material due to its strong adsorption capability to LiPs and excellent catalytic performance for sulfur redox with active sites from both basal plane and zigzag edges. Furthermore, the rate of Li2S oxidation over O-C5N is fast due to low energy barrier of 0.93eV for Li2S decomposition. While for H-C5N only N atoms locating at the armchair edges can efficiently trap LiPs and boost the formation and dissociation of Li2S during discharge and charge processes, respectively. The current work opens an avenue of designing 2D metallic carbon-based anchoring materials for Lithium sulfur battery, which deserves further experimental research efforts.

The two-step strategy screening based high throughput calculation is an effective method to search for highly active single atom catalysts (SACs) for efficient nitrogen reduction reaction (NRR), sharing a common feature of active metal centers MN4. However, this method faces the lack of descriptor for designing SACs due to limited data. Herein we proposed a robust empirical rule to estimate 312 credible limiting potentials for NRR over 104 C3N-supported SACs. It is found that the limiting potential scales clearly with the adsorption free energies of two key reaction intermediates (∗N2H and ∗NH2), which are significantly dependent on the structure relating descriptor φ, and the activity of SACs with and without N coordination exhibits similar catalytic efficiency. We identified four high-performance SACs having moieties of CrC2N2, CrC4, MnC4 and OsC4 with high selectivity towards NRR and competitive limiting potentials of −0.40, −0.45, −0.53 and −0.54 V, respectively. The φ values for these four SACs are around 19–25 which fall within its optimal ranges of 20–25 validating its prediction fidelity. This work broadens the discovery of two-dimensional carbon-nitrides supported SACs free of N coordination towards efficient N2 reduction and opens a new route of descriptor-guided design of efficient SACs for electrocatalysis process.

Phyllaciduloids E (1) and F (2), two new cleistanthane diterpenoids, were isolated from the leaves of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their planar structures were established by spectroscopic analysis and comparison with literature values. The relative configurations of phyllaciduloids E and F were confirmed by DFT-NMR chemical shift calculations and subsequent CP3 probability methods. Phyllaciduloids E and F were evaluated for their cytotoxicity. However, no significant activities were detected at concentrations up to 40 μM.

Eleven flavonoids including one new flavonol glycoside, quercetin-3

Accumulation of amyloid-β (Aβ) is implicated in the pathogenesis and development of Alzheimer's disease (AD) and it is a prime suspect for causing neuronal loss and cognitive deficits during AD. To...

Silicon carbide (SiC) is enabling the next generation of semiconductor power devices, with performance orders-of-magnitude beyond silicon. The most important power switching device is the SiC power MOSFET, whose performance is limited by three main resistance elements: the channel, drift layer, and substrate. For blocking voltages in the range of 400-900V, substrate resistance is a major limitation. Wafer thinning is currently used to reduce the substrate resistance, but this also reduces the strength of the wafers. We report on a waffle substrate technique that relies on wafer thinning and inductively coupled plasma (ICP) etching to reduce the substrate resistance below levels achievable by thinning alone, while retaining the mechanical stability of a moderately-thinned substrate. This technique can be applied to any SiC device for which substrate resistance is a limitation.

Lithium-sulfur battery is one of the most promising applicants for the next generation of energy storage devices whose commercial applications are impeded by the key issue of the shuttle effect. To overcome this obstacle, various two-dimensional (2D) carbon-based metal-free compounds have been proposed to serve as anchoring materials for immobilizing soluble lithium polysulfides (LiPs), which however suffer from low electronic conductivity implying unsatisfactory performance for catalyzing sulfur redox. Therefore, we have predicted metallic C

The sulfur redox kinetics critically matters to superior lithium-sulfur (Li-S) batteries, for which single atom catalysts (SACs) take effect on promoting Li2 S redox process and mitigating the shuttle behavior of lithium polysulfide (LiPs). However, conventional trial-and-error strategy significantly slows down the development of SACs in Li-S batteries. Here, the Li2 S oxidation processes over MN4 @G catalysts are fully explored and energy barrier of Li2 S decomposition (Eb ) is identified to correlate strongly with three parameters of energy difference between initial and final states of Li2 S decomposition, reaction energy of Li2 S oxidation and LiS bond strength. These three parameters can serve as efficient descriptors by which two excellent SACs of MoN4 @G and WN4 @G are screened which give rise to Eb values of 0.58 and 0.55 eV, respectively, outperforming other analogues in adsorbing LiPs and accelerating the redox kinetics of Li2 S. This method can be extended to a wider range of SACs by coupling MN4 moiety with heterostructures and heteroatoms beyond N where WN4 @G/TiS2 heterointerface is predicted to exhibit enhanced catalytic performance for Li2 S decomposition with Eb of 0.40 eV. This work will help accelerate the process of designing a wider range of efficient catalysts in Li-S batteries and even beyond, e.g. alkali-ion-Chalcogen batteries.

Alzheimer's disease (AD) ranks as the leading cause of dementia. MicroRNA (miR)-212-3p has been identified to exert neuroprotective effects on brain disorders. The current study analyzed the protective role of miR-212-3p in AD rats via regulating the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)/Caspase-1 signaling pathway. The AD rat model was established via injection of amyloid-β 1-42 (Aβ1-42), followed by the Morris water maze test. The morphology and functions of neurons were observed. Furthermore, miR-212-3p, NLRP3, cleaved Caspase-1, gasdermin D N-terminus, interleukin (IL)-1β and IL-18 expressions were measured. H19-7 cells were treated with Aβ1-42 to establish the AD cell model, followed by an assessment of cell viability and pyroptosis. Downstream targets of miR-212-3p and specificity protein 1 (SP1), as well as beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) were predicted by databases and testified using dual-luciferase and chromatin immunoprecipitation assays. miR-212-3p was weakly expressed in AD rats. miR-212-3p overexpression was linked to improved learning and memory capacities of AD rats and reduced neuronal pyroptosis linked to neuroinflammation attenuation. In vitro, miR-212-3p improved viability and suppressed pyroptosis of neurons via inhibiting NLRP3/Caspase-1. Overall, miR-212-3p inhibited SP1 expression to block BACE1-induced activation of NLRP3/Caspase-1, thereby attenuating neuroinflammation of AD rats.

Developing low-cost and efficient oxygen evolution electrocatalysts is key to decarbonization. A facile, surfactant-free, and gram-level biomass-assisted fast heating and cooling synthesis method is reported for synthesizing a series of carbon-encapsulated dense and uniform FeNi nanoalloys with a single-phase face-centered-cubic solid-solution crystalline structure and an average particle size of sub-5 nm. This method also enables precise control of both size and composition. Electrochemical measurements show that among Fex Ni(1- x ) nanoalloys, Fe0.5 Ni0.5 has the best performance. Density functional theory calculations support the experimental findings and reveal that the optimally positioned d-band center of O-covered Fe0.5 Ni0.5 renders a half-filled antibonding state, resulting in moderate binding energies of key reaction intermediates. By increasing the total metal content from 25 to 60 wt%, the 60% Fe0.5 Ni0.5 /40% C shows an extraordinarily low overpotential of 219 mV at 10 mA cm-2 with a small Tafel slope of 23.2 mV dec-1 for the oxygen evolution reaction, which are much lower than most other FeNi-based electrocatalysts and even the state-of-the-art RuO2 . It also shows robust durability in an alkaline environment for at least 50 h. The gram-level fast heating and cooling synthesis method is extendable to a wide range of binary, ternary, quaternary nanoalloys, as well as quinary and denary high-entropy-alloy nanoparticles. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) National Research Foundation (NRF) Submitted/Accepted version The authors acknowledge the help of Dr. Yang Bai and Huiqing Xie from the Institute of Materials Research and Engineering for XPS characterization. This work was supported by the Ministry of Education (MOE) Singapore Tier 1 FG79/20. K.H. acknowledges funding from the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science, Technology and Research under Grant No. A1898b0043. K.H. also acknowledges support from the NRF Fellowship Grant No. NRFNRFF13-2021-0011.

Phyllaciduloids E (

As metal-free carbon based catalysts, boron (B)-doped carbonaceous materials have proved to exhibit superior catalytic performance toward nitrogen reduction reaction. However, this strategy of heteroatom doping encounters the synthesis challenges of precise control of the doping level and homogeneous distribution of the dopants, and in particular, these materials cannot be utilized in electrochemical N2 reduction because of poor electrical conductivity. Accordingly, via first-principles calculations, we here predicted two stable two-dimensional crystalline compounds: BC6N2 and BC4N, which have small band gaps and uniform distribution of NRR active sp2-B species and holey structures. Between them, the BC6N2 monolayer originally possesses nice NRR activity with limiting potentials of -0.47 V. In the proton-rich acid medium, the electronic properties of these two B-C-N monolayers could be further tailored to exhibit a metallic characteristic by H pre-adsorption. This drastically improves the conductivity and enhances their NRR performances as reflected by the limiting potentials of -0.15, -0.34, and -0.34 V for BC6N2 via enzymatic, distal, and alternating mechanisms, respectively. Besides, NRR on BC4N through enzymatic mechanism proceeds as the limiting potential moderated from -1.20 to -0.90 V. More than that, the competing hydrogen evolution reaction can be effectively suppressed. The current investigation opens an avenue of designing a 2D crystalline phase of MFC catalysts independent of heteroatom doping and gives insightful views of surface functionalization as an impactful strategy to improve the electrocatalytic activity of metal-free catalysts.

Phytochemical investigation on the nonpolar extracts of P. acidus leaves afforded three new cleistanthane diterpenoids, named phyllanacidins A–C (1–3), in addition to three known ones (4–6). Among them, compounds 2 and 3 represent the first examples of 17-nor cleistanthane diterpenoids. Their structures including absolute configurations were elucidated on the basis of extensive spectroscopic data and single crystal X-ray diffraction analysis. All the isolated cleistanthane diterpenoids were evaluated for their cytotoxic activities against five human cancer cell lines. Compounds 4–6 exhibited moderate cytotoxicity with IC50 values ranging from 16.11 to 30.82 μM.

Recently, the integration of Edge computing and Wireless power transmission has provided low delay information processing and sustained green energy in IOT system. However, the constraint of system energy consumption remains the key factor which limits performance of IOT system. In this letter, we propose an energy-efficiency based resource allocation and power control algorithm (EE-RAPC) to Wireless Power Transfer and Edge Computing system (WPT-EC-IoT) in time division duplex-orthogonal frequency division multiple access mode (TDD-OFDMA). The algorithm optimizes distribution of subchannels, assigns different power to each subchannel to obtain local optimum of system energy consumption under the condition of specific time allocation coefficient and then adjust time allocation coefficient to get the global optimum. Numerical results demonstrate that the proposed algorithm maintains good performance in energy consumption of IOT system.