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Eight undescribed phenylpropanoid-dihydrochalcone hybrids, namely (+)- and (-)-malahupin A, (+)- and (-)-malahupin B, (±)-malahupin C, malahupinosides A and B, 7‴-epi-malahupinoside B, together with two known compounds, phloretin and phlorizin, were isolated from the leaves of the folk medicinal plant Malus hupehensis. Their structures were elucidated by extensive NMR and MS spectroscopic methods, chiral-phase analysis, and ECD calculations. Compounds (+)-malahupin B and malahupinoside B showed weak inhibition activities against the nitric oxide production in liposaccharide-induced murine RAW264.7 macrophages with IC

To explore the impacts of time delay on nonlinear dynamics of consensus models, we incorporate time-varying delay into a two-agent system to study its long-time behaviors. By the classical 3/2 stability theory, we establish a sufficient condition for the system to experience unconditional consensus. Numerical examples show the effectiveness of the proposed protocols and present possible Hopf bifurcations when the time delay changes.

A symmetric monoterpenoid indole alkaloid trimer, bousangustine A, is reported for the first time, as well as the dimeric alkaloids bousangustines B and C; these were isolated from the trunks of Bousigonia angustifolia. The structures, which feature a symmetric 6/9/5/6 ring system, were elucidated using comprehensive spectroscopic analysis. Their absolute configurations were determined via X-ray crystal diffraction, as well as computational chemistry. They can be constructed through Friedel–Crafts and free radical reactions, respectively. These compounds exhibited significant cytotoxicity against tumor cells.

The problems of lack of stability and difficult sealing of gas drainage boreholes in soft-coal seams directly affect the efficient extraction of gas in these soft-coal seams. After the holes are drilled, the collapsed holes lead to the failure to seal in time, which brings hidden dangers to mine production and causes time and economic waste. In this paper, the viscoelastic mechanics model is used to solve the force of the coal body in the fractured area of the orifice, combined with the theory of the external conditions affecting the collapse of the orifice of the soft-coal seam. The reason for the easy collapse of the borehole of the soft-coal seam is studied, and a reasonable solution is proposed. "Concentric ring" reinforced sealing technology, elaborated from the physical model, technical principles, and processes, was finally carried out in an on-site application test at the N2106 working face of a mining area in Shanxi. The results show that the fracture zone of the soft-coal seam easily enters a stage of rapid deformation under the effect of time. Its strong adsorption behavior, easy expansion, and other characteristics, combined with the violent disturbance of the drill pipe when the drilling is offset, eventually cause the hole to retreat, making it easy to deform and collapse afterward. The test boreholes reinforced and sealed with "concentric rings" have no problem of collapsed holes after retreating. The gas concentration remained above 30% in the first 30 days. The maximum gas purity of the borehole on the 30th day of extraction flow rate reached 0.053 m

Continued interest in bioactive alkaloids led to the isolation of two undescribed alkaloids, ophiorrhines F (

In this study, low-velocity impact and interfacial bonding properties of weft-knitted ultra-high-molecular-weight-polyethylene (UHMWPE) filaments reinforced epoxy resin and vinyl ester resin composites were investigated. UHMWPE filament yarns of 600 D were applied to fabricate three weft-knitted structures of plain stitch, interlock air space stitch and swiss double pique. Vacuum-assisted resin infusion (VARI) technology was utilized to combine resin and fabric to form inter-ply hybrid rigid composites. The basic mechanics, impact resistance and puncture performance of the hybrid composites were evaluated and their interfacial bonding was analyzed. It was revealed that composites with interlock air space stitch reinforcement exhibited the highest mechanical properties and puncture resistance. Under the same weft-knitted reinforcement, the tensile and flexural properties of the epoxy matrix composites were better than vinyl ester matrix composites. However, their low-velocity impact resistance was a bit inferior. The interfacial bonding ability between vinyl ester resin and weft knitting structure reinforcement was stronger because of the similar material structure between resin and reinforcement. This process is important for determining the optimum bonding method to achieve extensive application and improve the shelf life of UHMWPE composites.

This work focuses on the fixed-time consensus problem for multi-agent systems. By employing an improved fixed-time stability theorem and Lyapunov functions, it is proved that the proposed protocols can achieve fixed-time consensus when the interaction topology is strongly connected and detail-balanced. In particular, the settling time of the presented protocols is less than that of the existing ones, which is illustrated by both theoretical analysis and numerical simulations.

This paper solves the robust fixed-time consensus problem for multi-agent systems with nonlinear state measurements. Sufficient conditions are established for the proposed protocol to reach fixed-time consensus under time-varying undirected and fixed directed topology with the aid of Lyapunov functions. It is proved that the finite settling time of the presented protocol for robust consensus is uniformly bounded for any initial condition, which makes it possible for people to design and estimate the convergence time off-line. Numerical simulations are preformed to show the effectiveness of our proposed protocol.

Fifteen undescribed Stemona alkaloids, named as stemarines A-O (1-15), along with 25 known alkaloids (16-40), were isolated and identified from the roots of Stemona mairei (H.Lév.)K.Krause (Stemonaceae). Their structures were elucidated through the analysis of the NMR spectra, mass data, and computational chemistry. All the hitherto undescribed compounds possess a pyrrolo[1,2-α]azepine core structure but differ in important structural features, which reflects their nematocidal activities. Alkaloids 3-6 featured a carboxylic side chain and exhibited significant nematocidal activity against the nematode Caenorhabditis elegans. Transections of fresh roots combined with application of the Dragendorff' reagent on the tissue indicated accumulation of alkaloids mainly in the epidermis and the pith. These results suggest the key pharmacophore of these alkaloids lies in the aliphatic side chain of these compounds and its spatial distribution in the roots indicate protective effects against underground herbivores.

Highlights Ti3C2Tx MXene-based coaxial zinc-ion hybrid fiber supercapacitors (FSCs) were fabricated with braided structure, which can be prepared continuously and present excellent flexibility and ultrastability. A sports watch driven by the watch belts which weaved uses the obtained zinc-ion hybrid FSC and LED arrays lighted by the FSCs under embedding into textiles, demonstrating the great potential application in smart wearable textiles. Abstract Zinc-ion hybrid fiber supercapacitors (FSCs) are promising energy storages for wearable electronics owing to their high energy density, good flexibility, and weavability. However, it is still a critical challenge to optimize the structure of the designed FSC to improve energy density and realize the continuous fabrication of super-long FSCs. Herein, we propose a braided coaxial zinc-ion hybrid FSC with several meters of Ti3C2Tx MXene cathode as core electrodes, and shell zinc fiber anode was braided on the surface of the Ti3C2Tx MXene fibers across the solid electrolytes. According to the simulated results using ANSYS Maxwell software, the braided structures revealed a higher capacitance compared to the spring-like structures. The resulting FSCs exhibited a high areal capacitance of 214 mF cm–2, the energy density of 42.8 μWh cm−2 at 5 mV s−1, and excellent cycling stability with 83.58% capacity retention after 5000 cycles. The coaxial FSC was tied several kinds of knots, proving a shape-controllable fiber energy storage. Furthermore, the knitted FSC showed superior stability and weavability, which can be woven into watch belts or embedded into textiles to power smart watches and LED arrays for a few days.

The cell‐to‐cell transfer of α‐synuclein (α‐Syn) greatly contributes to Parkinson's disease (PD) pathogenesis and underlies the spread of α‐Syn pathology. During this process, extracellular α‐Syn can activate microglia and neuroinflammation, which plays an important role in PD. However, the effect of extracellular α‐Syn on microglia autophagy is poorly understood. In the present study, we reported that extracellular α‐Syn inhibited the autophagy initiation, as indicated by LC3‐II reduction and p62 protein elevation in BV2 and cultured primary microglia. The in vitro findings were verified in microglia‐enriched population isolated from α‐Syn‐overexpressing mice induced by adeno‐associated virus (AAV2/9)‐encoded wildtype human α‐Syn injection into the substantia nigra (SN). Mechanistically, α‐Syn led to microglial autophagic impairment through activating toll‐like receptor 4 (Tlr4) and its downstream p38 and Akt‐mTOR signaling because Tlr4 knockout and inhibition of p38, Akt as well as mTOR prevented α‐Syn‐induced autophagy inhibition. Moreover, inhibition of Akt reversed the mTOR activation but failed to affect p38 phosphorylation triggered by α‐Syn. Functionally, the in vivo evidence showed that lysozyme 2 Cre (Lyz2 cre)‐mediated depletion of autophagy‐related gene 5 (Atg5) in microglia aggravated the neuroinflammation and dopaminergic neuron losses in the SN and exacerbated the locomotor deficit in α‐Syn‐overexpressing mice. Taken together, the results suggest that extracellular α‐Syn, via Tlr4‐dependent p38 and Akt‐mTOR signaling cascades, disrupts microglial autophagy activity which synergistically contributes to neuroinflammation and PD development., Autophagy‐dependent and independent machinery synergistically contribute to hα‐Syn‐caused neuroinflammation in PD. The basal autophagy activity restricts microglia inflammation. Extracellular hα‐Syn interacts with and activates Tlr4, resulting in inflammatory responses, as well as autophagy suppression in microglia via Tlr4‐dependent p38 and Akt/mTOR signaling cascades. This impairs the inhibitory effect of autophagy on inflammation, and thus aggravating hα‐Syn‐induced inflammatory responses.

The instability and sealing difficulty confronted by gas drainage boreholes in a soft coal seam weakens the drainage efficiency. To address this problem, the instability characteristics of the sealing section of boreholes are investigated. On the basis of the findings of the mechanical properties of the borehole around the sealing section and in view of the physical and mechanical properties of the soft coal seam, a theoretical analysis was performed. A system consisting of the YYL200 electronic persistent creep test system and the DNS-200 electronic universal tester was used to observe the borehole under different filling conditions. The samples were subjected to a graded loading test, and the Kelvin-Voigt model was selected for parameter inversion and law analysis of the test results. The results show that the collapse of the broken area and the stress concentration and instability of the sealing section after the sealing of the soft coal seam are directly attributable to the instability of the soft coal seam and the sealing difficulty. The mechanical properties of the grouting sealing material are directly related to the loading of the hole-containing sample and dead load displacement. The maximal overall displacement of the sample in group B is close to 1.4 mm. The instantaneous deformation capacity and deformation space reflected by the generalized Kelvin model parameters