Chemicals play a crucial role in neurophysiological and neuropathological *** regulating the concentration of specific chemicals,receptors on the neuron cell membrane can be modulated to activate or inhibit,thereby in...
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Chemicals play a crucial role in neurophysiological and neuropathological *** regulating the concentration of specific chemicals,receptors on the neuron cell membrane can be modulated to activate or inhibit,thereby influencing specific ion channels and facilitating *** review introduces several chemical modulation techniques,such as microinjection,electrode/nanoparticle-based chemical delivery methods,in situ electrochemical synthesis and *** these techniques show promise in expanding the application of chemical neuromodulation,they currently exhibit different degrees of shortcomings and room for *** review summarizes the opportunities and challenges for chemical neuromodulation methods and provide an outlook for their prospects in the future.
The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely ***,the question of the“trade-off”be...
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The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely ***,the question of the“trade-off”between AEM ionic conductivity and dimensional stability remains *** strategy of inducing microphase separation to improve the performance of AEM has attracted much attention recently,but the design of optimal molecular structures is still being ***,this work introduced different ratios of 3-bromo-1,1,1-trifluoroacetone(x=40,50,and 60)into the main chain of poly(p-terphenylene isatin).Because fluorinated groups have excellent hydrophobicity,hydrophilic hydroxyl-containing side chains are introduced to jointly adjust the formation of phase separation *** results show that PTI-PTF_(50)-NOH AEM with the appropriate fluorinated group ratio has the best ionic conductivity and alkali stability under the combined effect of *** has an ionic conductivity of 133.83 mS cm^(-1)at 80°*** addition,the OH-conductivity remains at 89%of the initial value at 80°C and 3 M KOH for 1056 h of *** cell polarization curve based on PTI-PTF_(50)-NOH shows a power density of 734.76 mW cm^(-2)at a current density of 1807.7 mA cm^(-2).
Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature ...
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Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature treatment were conducted with a ϕ75 mm split Hopkinson tension bar (SHTB) to investigate the mesoscopic fracture and damage properties of rock. An improved scanning electron microscopy (SEM) experimental method was used to analyze the tensile fracture surfaces of rock samples. Qualitative and quantitative analyses were performed to assess evolution of mesoscopic damage of heat-damaged rock under tensile loading. A constitutive model describing the mesoscopic fractal damage under thermo-mechanical coupling was established. The results showed that the high temperatures significantly reduced the tensile strength and fracture surface roughness of the red sandstone. The three-dimensional (3D) reconstruction of the fracture surface of the samples that experienced tensile failure at 900 °C showed a flat surface. The standard deviation of elevation and slope angle of specimen fracture surface first increased and then decreased with increasing temperature. The threshold for brittle fracture of the heat-damaged red sandstone specimens was 600 °C. Beyond this threshold temperature, local ductile fracture occurred, resulting in plastic deformation of the fracture surface during tensile fracturing. With increase of temperature, the internal meso-structure of samples was strengthened slightly at first and then deteriorated gradually, which was consistent with the change of macroscopic mechanical properties of red sandstone. The mesoscopic characteristics, such as the number, mean side length, maximum area, porosity, and fractal dimension of crack, exhibited an initial decline, followed by a gradual increase. The development of microcracks in samples had significant influence on mesoscopic fractal dimension. The mesoscopic fractal characteristics were used to establis
Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO2capture and *** organic framework materials,as a kind of materials with high porosity and designa...
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Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO2capture and *** organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other *** review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO2capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit ***,the main challenges associated with porous frameworks for CO2capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and *** review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.
Pyrrolobenzoxazines are a rare terpene-amino acid family of natural products with potent biological ***,we reported the full biosynthetic pathway of paeciloxazine(1),a typical pyrrolobenzoxazine,with significant insec...
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Pyrrolobenzoxazines are a rare terpene-amino acid family of natural products with potent biological ***,we reported the full biosynthetic pathway of paeciloxazine(1),a typical pyrrolobenzoxazine,with significant insecticidal *** on heterologous expression,chemical complement experiment,and in vitro biochemical assays,we demonstrated the sesquiterpene portion of 1 derived from discontinuously oxidations of amorphdiene,in which P450 monooxygenase PaxH catalyzed a cascade of hydroxylation and epoxidation,while two flavin dependent monooxygenases are involved in the transformation of the esterified tryptophan into a pyrrolobenzoxazine ***,a total of 15 compounds were generated through heterologous expression,of which 13,17 and 20 showed potential antiepileptic *** study fully elucidated the biosynthetic pathway of paeciloxazine(1)and showed the diversity and complexity of constructing natural products by organisms.
Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the ...
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Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil ***,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in ***,producing hydrogen on an industrial scale is challenging due to the high production *** present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater *** the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater *** the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater ***,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.
This study investigates the morphological and mineralogical characteristics of proto-dolomite induced by two specific microorganisms with varying lifestyles:the extremely halophilic bacterium Vibrio harveyi QPL2 and t...
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This study investigates the morphological and mineralogical characteristics of proto-dolomite induced by two specific microorganisms with varying lifestyles:the extremely halophilic bacterium Vibrio harveyi QPL2 and the cyanobacterium Leptolyngbya boryana. Halophilic bacterially-induced proto-dolomite(HBD) and cyanobacterially-induced proto-dolomite (CBD) were subjected to comprehensive characterization techniques, including x-ray diffraction, scanning electron microscopy, Focused Ion Beam, thermogravimetric analysis, and x-ray photoelectron spectroscopy. The results indicate that both HBD and CBD exhibit a low degree of crystallinity and possess comparable molar ratios of MgCO3to CaCO3. Moreover, neither of them exhibits the ordered structure of ideal dolomite. HBD and CBD exhibit notable distinctions in external morphology and internal structure. HBD forms a subunit aggregate with a less dense surface and numerous pinhole structures resulting from bacterial survival. In contrast, CBD adopts a bispherical shape with a relatively dense surface and minimal indications of cyanobacterial survival. Both HBD and CBD have an internal hollow structure. However, HBD is characterized by sparse population and loosely arranged subunits, while CBD features only a central cavity. Additionally, HBD particles are smaller compared to CBD particles. These morphological differences suggest that HBD primarily grows through bacterial surface-dependent processes,whereas the growth of CBD is not directly reliant on the surface of cyanobacteria. Compositionally, the weightpercentage of crystalline water in CBD exceeded that of HBD with a value of 29.42%compared to 5.9%. This increase in internal crystalline water enables a faster conversion of CBD to the ordered ideal dolomite in a specific diagenetic environment. This study implies that the morphology and composition of microbial protodolomite may aid in identifying the type of dolomite-inducing microbes.
Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized *** and delineation of genera within this family have varied *** three-subfamily classification o...
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Dryopteridaceae are the largest fern family and include nearly 20%of extant fern diversity,with 24 currently recognized *** and delineation of genera within this family have varied *** three-subfamily classification of Dryopteridaceae was based primarily on molecular phylogenetic relationships but lacked morphological evidence,and the phylogenetic relationships of the subfamilies and genera of Dryopteridaceae are only partially resolved.A comprehensive and robust phylogeny is urgently *** heterogeneous morphology of the current members of Dryopteridaceae makes the family and its subfamilies difficult to define by single morphological characteristics or even character *** carried out phylogenetic analyses to reconstruct a highly supported phylogeny of *** analyses recovered 24 strongly supported clades grouped into seven major clades of *** morphological characters including habit,rhizome shape,frond morphology,rachis-costae architecture,appendages on stipe base and lamina,and soral arrangement were found to be informative for identifying different major clades and clades in *** on phylogenetic reconstruction and morphological analysis,we presented an updated infra-familial classification of Dryopteridaceae with seven subfamilies and 24 genera including four newly proposed subfamilies(Ctenitidoideae,Lastreopsidoideae,Pleocnemioideae,and Polystichopsidoideae).Morphological character combinations of each subfamily are summarized,and a key is *** genera sensu PPG I are recognized,with Stigmatopetris reclassified into Dryopteridoideae and Arthrobotrya considered a synonym of Teratophyllum.A new genus Pseudarachniodes is *** revised classification will serve as a foundational framework for future investigations on taxonomy,biogeography,and diversification of the most species-rich Dryopteridaceae in ferns.
The ultra-high-energy（UHE） gamma-ray source 1LHAASO j0007+7303u is positionally associated with the composite SNR CTA1 that is located at high Galactic Latitude b ≈ 10.5°. This provides a rare opportunity to spati...
The ultra-high-energy（UHE） gamma-ray source 1LHAASO j0007+7303u is positionally associated with the composite SNR CTA1 that is located at high Galactic Latitude b ≈ 10.5°. This provides a rare opportunity to spatially resolve the component of the pulsar wind nebula（PWN） and supernova remnant（SNR） at UHE. This paper conducted a dedicated data analysis of 1LHAASO j0007+7303u using the data collected from December 2019 to july 2023. This source is well detected with significances of 21σ and 17σ at 8-100 TeV and >100 TeV, respectively. The corresponding extensions are determined to be 0.23°±0.03°and 0.17°±0.03°. The emission is proposed to originate from the relativistic electrons accelerated within the PWN of PSR j0007+7303. The energy spectrum is well described by a power-law with an exponential cutoff function dN/dE =（42.4 ± 4.1）(E/（20 TeV）)-2.31±0.11exp(-E/（110±25 TeV）) TeV-1cm-2s-1in the energy range from 8 to 300 TeV, implying a steady-state parent electron spectrum dNe/dEe∝(Ee/（100 TeV）)-3.13±0.16exp[(-Ee/（373±70 TeV）)2] at energies above ≈ 50 TeV. The cutoff energy of the electron spectrum is roughly equal to the expected current maximum energy of particles accelerated at the PWN terminal shock. Combining the x-ray and gamma-ray emission, the current space-averaged magnetic field can be limited to≈ 4.5 μG. To satisfy the multi-wavelength spectrum and the γ-ray extensions, the transport of relativistic particles within the PWN is likely dominated by the advection process under the free-expansion phase assumption.
We report the detection of an extended very-high-energy(VHE) γ-ray source coincident with the location of middle-aged(62.4 kyr) pulsar PSR j0248+6021, by using the LHAASO-WCDA data of live 796 d and LHAASO-KM2A data ...
We report the detection of an extended very-high-energy(VHE) γ-ray source coincident with the location of middle-aged(62.4 kyr) pulsar PSR j0248+6021, by using the LHAASO-WCDA data of live 796 d and LHAASO-KM2A data of live 1216d. A significant excess of γ-ray induced showers is observed both by WCDA in energy bands of 1-25 Te V and KM2A in energy bands of >25 TeV with 7.3σ and 13.5σ, respectively. The best-fit position derived through WCDA data is R.A. = 42.06°± 0.12°and Dec. = 60.24°± 0.13°with an extension of 0.69°±0.15°and that of the KM2A data is R.A.= 42.29°± 0.13°and Dec. =60.38°± 0.07°with an extension of 0.37°±0.07°. No clear extended multiwavelength counterpart of this LHAASO source has been found from the radio band to the GeV band. The most plausible explanation of the VHE γ-ray emission is the inverse Compton process of highly relativistic electrons and positrons injected by the pulsar. These electrons/positrons are hypothesized to be either confined within the pulsar wind nebula or to have already escaped into the interstellar medium, forming a pulsar halo.
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