In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a n...In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a new order parameter φ to quantify the degree of order in the spatial distribution of particles. The results show that the spatial distribution order parameter can effectively describe the transition from a disorderly moving phase to a phase with a coherent motion of the particle distribution and the same conclusion could be obtained for systems with different sizes. Furthermore, we develop a powerful molecular dynamic graph network(MDGNet) model to realize the long-term prediction of the self-propelled collective system solely from the initial particle positions and movement angles. Employing this model, we successfully predict the order parameters of the specified time step. And the model can also be applied to analyze other types of complex systems with local interactions.展开更多
Long noncoding RNAs(lncRNAs)are important in abiotic stress tolerance.Here,we identified salt-responsive genes and lncRNAs in the roots and leaves of Betula platyphylla Suk.(birch),and characterized their lncRNAs func...Long noncoding RNAs(lncRNAs)are important in abiotic stress tolerance.Here,we identified salt-responsive genes and lncRNAs in the roots and leaves of Betula platyphylla Suk.(birch),and characterized their lncRNAs functions.In total,2660 mRNAs and 539 lncRNAs responding to salt treatment were identified using RNA-seq.The salt-responsive genes were substantially enriched in‘cell wall biogenesis’and‘wood development’in the roots and were enriched in‘photosynthesis’and‘response to stimulus’in the leaves.Meanwhile,the potential target genes of the salt-responsive lncRNAs in roots and leaves were both enriched in‘nitrogen compound metabolic process’and‘response to stimulus’.We further built a method for quickly identifying abiotic stress tolerance of lncRNAs,which employed transient transformation for overexpression and knock-down of the lncRNA,enabling gain-and loss-of-function analysis.Using this method,11 randomly selected salt-responsive lncRNAs were characterized.Among them,six lncRNAs confer salt tolerance,two lncRNAs confer salt sensitivity,and the other three lncRNAs are not involved in salt tolerance.In addition,a lncRNA,LncY1,was further characterized,which improves salt tolerance by regulating two transcription factors,BpMYB96 and BpCDF3.Taken together,our results suggested that lncRNAs play important roles in the salt response of birch plants.展开更多
Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction(ORR/OER) is paramount for metal–air batteries. Metal–organic frameworks(MOFs)-based materials hav...Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction(ORR/OER) is paramount for metal–air batteries. Metal–organic frameworks(MOFs)-based materials have attracted a great deal of attention as the potential candidate for effectively catalyzing ORR/OER due to their adjustable composition and porous structure. Herein, we first introduce the Mn species into zeolitic-imidazole frameworks(ZIFs) and then further pyrolyze the Mn-containing bimetallic ZIFs to synthesize core-shell-structured Co@Co4N nanoparticles embedded into MnO-modified porous N-doped carbon nanocubes(Co@Co4N/MnO–NC). Co@Co4N/MnO–NC exhibits the outstanding catalytic activity toward ORR and OER which is attributed to its abundant pyridinic/graphitic N and Co4N,the optimized content of MnO species, highly dispersed catalytic sites and porous carbon matrix. As a result, the Co@Co4N/MnO–NC-based Zn–air battery exhibits enhanced performances, including the high discharge capacity(762 mA h gZn-1), large power density(200.5 mW cm-2), stable potential profile over 72 h, low overpotential(<1.0 V) and superior cycling life(2800 cycles). Moreover, the belt-shaped Co@Co4N/MnO–NC cathode-based Zn–air batteries are also designed which exhibit the superb electrochemical properties at different bending/twisting conditions.展开更多
A rapid and sensitive liquid chromatography tandem mass spectrometry method was established and validated for determination of melatonin in dog plasma using desvenlafaxine as an internal standard (IS). Plasma samples ...A rapid and sensitive liquid chromatography tandem mass spectrometry method was established and validated for determination of melatonin in dog plasma using desvenlafaxine as an internal standard (IS). Plasma samples were pretreated by liquid–liquid extraction with ethyl acetate. Chromatographic separation was carried out on a C18 column at a flow rate of 0.2 ml/min by an isocratic mobile phase of methanol : 5 m M ammonium acetate : formic acid (40:60:0.1, v/v/v). Positive ion mode detection was performed using multiple reaction monitoring (MRM) at m/z 233.2→174.2 for melatonin and m/z 264.2→58.2 for desvenlafaxine.The method was linear in the concentration range of 0.020–10 ng/ml with a correlation coefficient ≥0.996. The intra-and inter-assay precision (%RSD) values were within 12.6% (LLOQ15.2%), and accuracy (%RE) ranged from -1.8% to 5.0% (LLOQ ±16.5%). The total analysis time was 3.0 min. The method was fully validated and successfully applied to a pharmacokinetic study of melatonin prolonged-release tablet in Beagle dogs. The values of half-life and Tmax were similar to the corresponding data reported before.展开更多
[Objectives]To explore the active components and mechanism of Bupleurum and Asarum in the treatment of traumatic brain injury(TBI).[Methods]All the active components and potential action targets of Bupleurum and Asaru...[Objectives]To explore the active components and mechanism of Bupleurum and Asarum in the treatment of traumatic brain injury(TBI).[Methods]All the active components and potential action targets of Bupleurum and Asarum pairs were collected by online platform Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)database and literature search.Target genes related to traumatic brain injury were obtained by Online Mendelian Inheritance in Man(OMMI),Therapeutic Target Database(TTD),PharmGKB,Genecards and Drugbank.The"drug-ingredient-target"network diagram was constructed by using Cytoscape software.Venny 2.1.0 was used to integrate the intersection targets of drug targets and disease targets,and the String platform was used to construct a target protein-protein interaction network(PPI).Topological analysis and core target screening of the constructed PPI network were performed using the"CytoNCA"plug-in in Cytoscape software.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis were performed on the intersection targets using the DAVID database.Finally,Autodock and Pymol software were used to simulate the binding activity of key candidate active components and core genes.[Results]25 active components were screened from Bupleurum-Asarum and 111 potential targets involved in the disease process.GO analysis and KEGG results showed that potential therapeutic targets were mainly enriched in biological processes such as inflammatory response,oxidative stress,cell membrane repair,and cytokine regulation.Network analysis and molecular docking showed that the key compounds of Bupleurum and Asarum were kaempferol and quercetin,which were well docked with the active pockets of four core genes of traumatic brain injury.[Conclusions]Bupleurum and Asarum may be involved in the regulation of inflammatory response,oxidative stress,cell membrane repair through multiple targets and multiple pathways in the treatment of traumatic brain injury.展开更多
:This article first analyzes the problems existing in the teaching about diagnosing and removing automobile’s failure,and then discusses some specific teaching strategies on diagnosing and removing automobile’s fail...:This article first analyzes the problems existing in the teaching about diagnosing and removing automobile’s failure,and then discusses some specific teaching strategies on diagnosing and removing automobile’s failure to provide some effective reference for the related staff.展开更多
Automobile Inspection and Maintenance Course is relatively practical and professional.Therefore,teachers need to provide students with opportunities for practice as much as possible,so that students can realize the in...Automobile Inspection and Maintenance Course is relatively practical and professional.Therefore,teachers need to provide students with opportunities for practice as much as possible,so that students can realize the integration of theory and practice,improve teaching efficiency.Project-oriented teaching design can enable students to participate in the practical training and maintenance of automotive engines,which helps students understand the theories in the book.This article mainly analyzes the strategies for teaching design of project-oriented Automobile Inspection and Maintenance Course.展开更多
In some clinical features, the failure of the couple to reproduce may be related to the chromosome abnormality of the patient. This report was based on one example about the topic.
Modulating Tankyrases(TNKS),interactions with USP25 to promote TNKS degradation,rather than inhibiting their enzymatic activities,is emerging as an alternative/specific approach to inhibit the Wnt/β-catenin pathway.H...Modulating Tankyrases(TNKS),interactions with USP25 to promote TNKS degradation,rather than inhibiting their enzymatic activities,is emerging as an alternative/specific approach to inhibit the Wnt/β-catenin pathway.Here,we identified UAT-B,a novel neoantimycin analog isolated from Streptomyces conglobatus,as a small-molecule inhibitor of TNKS-USP25 protein-protein interaction(PPI)to overcome multi-drug resistance in colorectal cancer(CRC).The disruption of TNKS-USP25 complex formation by UAT-B led to a significant decrease in TNKS levels,triggering cell apoptosis through modulation of the Wnt/β-catenin pathway.Importantly,UAT-B successfully inhibited the CRC cells growth that harbored high TNKS levels,as demonstrated in various in vitro and in vivo studies utilizing cell line-based and patient-derived xenografts,as well as APC^(min/+)spontaneous CRC models.Collectively,these findings suggest that targeting the TNKS-USP25 PPI using a small-molecule inhibitor represents a compelling therapeutic strategy for CRC treatment,and UAT-B emerges as a promising candidate for further preclinical and clinical investigations.展开更多
Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten th...Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.展开更多
The loess accumulation process has great potential to record patterns of atmospheric circulation change,paleoclimate,and paleoenvironmental evolution.South-eastern Xizang is a climatically sensitive region and here,we...The loess accumulation process has great potential to record patterns of atmospheric circulation change,paleoclimate,and paleoenvironmental evolution.South-eastern Xizang is a climatically sensitive region and here,we analyze a loess profile at Ranwu in order to explore the processes and interactions of dust transport and paleoclimate evolution in the region.Based on parametric grain size end-member analysis,optically stimulated luminescence(OSL)dating,and environmental proxies we show that the Ranwu loess profile comprises five end members(EMs).EM1 represents the fine silt fraction transported by high-altitude westerly winds over long distances;EM2 represents the medium silt fraction accumulated by glacier winds;EM3 is the coarse silt fraction transported by local dust storms under the action of strong glacier winds;EM4 represents the very fine sand fraction transported by strong local dust storms,different wind strengths controls the relative proportion of EM3 and EM4 over time.EM5 is the coarse sand fraction formed from the product of strong weathering of gravels.OSL dating shows loess sedimentation at Ranwu started around 11.16 ka.The prevailing climate was generally warm and wet between 11.6 and 4.2 ka,with four cooling events at 10.50,9.18,7.85,and 6.37 ka.Extensive paleosol development between 8.2 and 4.2 ka,a change to dry and cold climate conditions was favorable for loess formation after 4.2 ka.The palaeoenvironmental changes and abrupt climate events recorded in the Ranwu loess sequence are consistent with Holocene global environmental changes.展开更多
Dual atom catalysts(DACs),are promising electrocatalysts for oxygen reduction reaction(ORR)on account of the potential dual-atom active sites for the optimized adsorption of catalytic intermediates and the lower react...Dual atom catalysts(DACs),are promising electrocatalysts for oxygen reduction reaction(ORR)on account of the potential dual-atom active sites for the optimized adsorption of catalytic intermediates and the lower reaction energy barriers.Herein,spatial confinement strategy to fabricate DACs with well-defined Fe,Co dual-atom active site is proposed by implanting zeolitic imidazolate frameworks inside the pores of highly porous carbon nanospheres(Fe/Co-SAs-Nx-PCNSs).The atomically dispersed dual-atom active sites facilitate the adsorption/desorption of intermediates.Furthermore,the spatial confinement effect protects metal atoms aggregating.Benefiting from the rich accessible dual-atom active sites and boosted mass transport,we achieve remarkable ORR performance with half-wave potential up to 0.91 and 0.8 V(vs.reversible hydrogen electrode(RHE)),and long-term stability up to 10 h in both alkaline and acidic electrolytes.The remarkably enhanced ORR catalytic property of our as-developed DACs is in the rank of excellence for 1%.The as-developed rechargeable Zn-air battery(ZAB)with Fe/Co-SAs-Nx-PCNSs air cathode delivers ultrahigh power density of 216 mW·cm^(−2),outstanding specific capacity of 813 mAh·g^(−1),and promising cycling operation durability over 160 h.The flexible Zn-air battery also exhibits excellent specific capacity,cycling stability,and flexibility performance.This work opens up a new pathway for the multiscale design of efficient electrocatalysts with atomically dispersed multiple active sites.展开更多
Norfloxacin(NOR), an ionizable antibiotic frequently used in the aquaculture industry, has aroused public concern due to its persistence, bacterial resistance, and environmental ubiquity.Therefore, we investigated the...Norfloxacin(NOR), an ionizable antibiotic frequently used in the aquaculture industry, has aroused public concern due to its persistence, bacterial resistance, and environmental ubiquity.Therefore, we investigated the photolysis of different species of NOR and the impact of a ubiquitous component of natural water — dissolved organic matter(DOM), which has a special photochemical activity and normally acts as a sensitizer or inhibiter in the photolysis of diverse organics; furthermore, scavenging experiments combined with electron paramagnetic resonance(EPR) were performed to evaluate the transformation of NOR in water. The results demonstated that NOR underwent direct photolysis and self-sensitized photolysis via hydroxyl radical(U OH) and singlet oxygen(1O2) based on the scavenging experiments. In addition, DOM was found to influence the photolysis of different NOR species, and its impact was related to the concentration of DOM and type of NOR species. Photolysis of cationic NOR was photosensitized by DOM at low concentration, while zwitterionic and anionic NOR were photoinhibited by DOM, where quenching of U OH predominated according to EPR experiments, accompanied by possible participation of excited triplet-state NOR and1O2. Photo-intermediate identification of different NOR species in solutions with/without DOM indicated that NOR underwent different photodegradation pathways including dechlorination, cleavage of the piperazine side chain and photooxidation, and DOM had little impact on the distribution but influenced the concentration evolution of photolysis intermediates. The results implied that for accurate ecological risk assessment of emerging ionizable pollutants, the impact of DOM on the environmental photochemical behavior of all dissociated species should not be ignored.展开更多
It is important to develop efficient technologies on removal of perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS)from water due to their wide distribution and potential threat to human health.In this wor...It is important to develop efficient technologies on removal of perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS)from water due to their wide distribution and potential threat to human health.In this work,a durable and convenient electrosorption device was designed in continuous flow mode to investigate the adsorption of PFOX(X=A and S)on multiwalled carbon nanotubes(MWNTs)from water under electrochemical assistance.The electrosorption experiments were conducted under different influent and electrolyte concentrations,hydraulic retention time(HRT)and electrode distance to optimize the operation.The results showed that the highest removal efficiencies toward both PFOA and PFOS could come up to 90%at 1 V.Compared with open circuit(OC)adsorption under the same conditions,the removal efficiencies were improved by 4.9 times(PFOA)and 4.2 times(PFOS)respectively.In addition,the MWNTs electrode was found to be reusable.These findings provide an efficient method to remove PFOX from water by electrosorption in continuous flow mode.展开更多
The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would un...The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would undertake electrophilic substitution generating mono-or di-halogenated products,which would be oxidized to esters and further hydrolyzed to phenol derivatives.The generated catechol intermediate would be transformed into furan-like heterocyclic product.The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent.When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions,most of brominated byproducts could be detected,and the acute toxicity significantly increased as well.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical...Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.展开更多
Cathodic reduction of CO_2 and anodic oxidation of organic matters are crucial to methaneproducing microbial electrolysis cell(MEC) applied in anaerobic digestion of waste activated sludge. However, cathodic CO_2 redu...Cathodic reduction of CO_2 and anodic oxidation of organic matters are crucial to methaneproducing microbial electrolysis cell(MEC) applied in anaerobic digestion of waste activated sludge. However, cathodic CO_2 reduction is usually restrained by slow metabolism rates of H_2-utilizing methanogens and low electron-capturing capacity of CO_2, which consequently slows down the anodic oxidation that participates to sludge disintegration. Herein, a strategy with adding nitrate as electron acceptor to foster electronic transfer between the anode and cathode was proposed to improve anodic oxidation. Results showed that the average efficiency of anodic oxidation in the nitrate-added MEC increased by 55.9%. Accordingly,volatile suspended solid removal efficiency in the nitrate-added MEC was 21.9% higher than that of control MEC. Although the initial cumulative methane production in the nitrateadded MEC was lower than that of control MEC, the cumulative methane production in 24 days was 8.9% higher. Fourier transform infrared spectroscopy analysis indicated that anodic oxidation of MEC with nitrate accelerated the disintegration of sludge flocs and cell walls. Calculation on current signal further revealed that anodic oxidation driven by cathodic nitrate reduction was the main mechanism responsible for the improved sludge digestion.展开更多
The United States is a leading nation in the development of synthetic biology,an emerging engineering discipline to create,control and reprogram biological systems.With strategic investment from its government agencie...The United States is a leading nation in the development of synthetic biology,an emerging engineering discipline to create,control and reprogram biological systems.With strategic investment from its government agencies,the U.S.has established numerous research centers and programs in synthetic biology,enabling significant advances in foundational tool development and practical applications ranging from bioenergy,biomanufacturing,to biomedicine.To maintain its leadership in synthetic biology,U.S,has conducted several roadmap studies to provide strategic visions and action recommendations.Here we will provide a brief overview of the major research programs and roadmap studies of synthetic biology in the U.S.展开更多
Overproduction of polyketides has been a challenge for metabolic engineering for decades.However,recent studies have demonstrated that in both native host and heterologous host,engineeringβ-oxidation pathways can lea...Overproduction of polyketides has been a challenge for metabolic engineering for decades.However,recent studies have demonstrated that in both native host and heterologous host,engineeringβ-oxidation pathways can lead to dramatic improvement of polyketide production.展开更多
基金the National Natural Science Foundation of China (Grant No. 11702289)Key core technology and generic technology research and development project of Shanxi Province of China (Grant No. 2020XXX013)the National Key Research and Development Project of China。
文摘In the past few decades, the study of collective motion phase transition process has made great progress. It is also important for the description of the spatial distribution of particles. In this work, we propose a new order parameter φ to quantify the degree of order in the spatial distribution of particles. The results show that the spatial distribution order parameter can effectively describe the transition from a disorderly moving phase to a phase with a coherent motion of the particle distribution and the same conclusion could be obtained for systems with different sizes. Furthermore, we develop a powerful molecular dynamic graph network(MDGNet) model to realize the long-term prediction of the self-propelled collective system solely from the initial particle positions and movement angles. Employing this model, we successfully predict the order parameters of the specified time step. And the model can also be applied to analyze other types of complex systems with local interactions.
基金supported by the Xingliao Talent Plan Project XLYC1902007Funds for Guiding Local Scientific and Technological Development by the Central Government 202JH6/10500071.
文摘Long noncoding RNAs(lncRNAs)are important in abiotic stress tolerance.Here,we identified salt-responsive genes and lncRNAs in the roots and leaves of Betula platyphylla Suk.(birch),and characterized their lncRNAs functions.In total,2660 mRNAs and 539 lncRNAs responding to salt treatment were identified using RNA-seq.The salt-responsive genes were substantially enriched in‘cell wall biogenesis’and‘wood development’in the roots and were enriched in‘photosynthesis’and‘response to stimulus’in the leaves.Meanwhile,the potential target genes of the salt-responsive lncRNAs in roots and leaves were both enriched in‘nitrogen compound metabolic process’and‘response to stimulus’.We further built a method for quickly identifying abiotic stress tolerance of lncRNAs,which employed transient transformation for overexpression and knock-down of the lncRNA,enabling gain-and loss-of-function analysis.Using this method,11 randomly selected salt-responsive lncRNAs were characterized.Among them,six lncRNAs confer salt tolerance,two lncRNAs confer salt sensitivity,and the other three lncRNAs are not involved in salt tolerance.In addition,a lncRNA,LncY1,was further characterized,which improves salt tolerance by regulating two transcription factors,BpMYB96 and BpCDF3.Taken together,our results suggested that lncRNAs play important roles in the salt response of birch plants.
基金the National Natural Science Foundation of China(21905151 and 51772162)Outstanding Youth Foundation of Shandong Province,China(ZR2019JQ14)+4 种基金the Natural Science Foundation of Shandong Province(ZR2018BB034)Taishan Scholar Young Talent ProgramMajor Scientific and Technological Innovation Project(2019JZZY020405)China Postdoctoral Science Foundation(2019M652499)the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University(2019-23)。
文摘Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction(ORR/OER) is paramount for metal–air batteries. Metal–organic frameworks(MOFs)-based materials have attracted a great deal of attention as the potential candidate for effectively catalyzing ORR/OER due to their adjustable composition and porous structure. Herein, we first introduce the Mn species into zeolitic-imidazole frameworks(ZIFs) and then further pyrolyze the Mn-containing bimetallic ZIFs to synthesize core-shell-structured Co@Co4N nanoparticles embedded into MnO-modified porous N-doped carbon nanocubes(Co@Co4N/MnO–NC). Co@Co4N/MnO–NC exhibits the outstanding catalytic activity toward ORR and OER which is attributed to its abundant pyridinic/graphitic N and Co4N,the optimized content of MnO species, highly dispersed catalytic sites and porous carbon matrix. As a result, the Co@Co4N/MnO–NC-based Zn–air battery exhibits enhanced performances, including the high discharge capacity(762 mA h gZn-1), large power density(200.5 mW cm-2), stable potential profile over 72 h, low overpotential(<1.0 V) and superior cycling life(2800 cycles). Moreover, the belt-shaped Co@Co4N/MnO–NC cathode-based Zn–air batteries are also designed which exhibit the superb electrochemical properties at different bending/twisting conditions.
文摘A rapid and sensitive liquid chromatography tandem mass spectrometry method was established and validated for determination of melatonin in dog plasma using desvenlafaxine as an internal standard (IS). Plasma samples were pretreated by liquid–liquid extraction with ethyl acetate. Chromatographic separation was carried out on a C18 column at a flow rate of 0.2 ml/min by an isocratic mobile phase of methanol : 5 m M ammonium acetate : formic acid (40:60:0.1, v/v/v). Positive ion mode detection was performed using multiple reaction monitoring (MRM) at m/z 233.2→174.2 for melatonin and m/z 264.2→58.2 for desvenlafaxine.The method was linear in the concentration range of 0.020–10 ng/ml with a correlation coefficient ≥0.996. The intra-and inter-assay precision (%RSD) values were within 12.6% (LLOQ15.2%), and accuracy (%RE) ranged from -1.8% to 5.0% (LLOQ ±16.5%). The total analysis time was 3.0 min. The method was fully validated and successfully applied to a pharmacokinetic study of melatonin prolonged-release tablet in Beagle dogs. The values of half-life and Tmax were similar to the corresponding data reported before.
基金Supported by Program of Guangxi Natural Science Foundation (2018GXNSFBA050069&2022GXNSFAA035459)the R&D Project of Guangxi Zhuang Autonomous Region Key Trauma Surgery
文摘[Objectives]To explore the active components and mechanism of Bupleurum and Asarum in the treatment of traumatic brain injury(TBI).[Methods]All the active components and potential action targets of Bupleurum and Asarum pairs were collected by online platform Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)database and literature search.Target genes related to traumatic brain injury were obtained by Online Mendelian Inheritance in Man(OMMI),Therapeutic Target Database(TTD),PharmGKB,Genecards and Drugbank.The"drug-ingredient-target"network diagram was constructed by using Cytoscape software.Venny 2.1.0 was used to integrate the intersection targets of drug targets and disease targets,and the String platform was used to construct a target protein-protein interaction network(PPI).Topological analysis and core target screening of the constructed PPI network were performed using the"CytoNCA"plug-in in Cytoscape software.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis were performed on the intersection targets using the DAVID database.Finally,Autodock and Pymol software were used to simulate the binding activity of key candidate active components and core genes.[Results]25 active components were screened from Bupleurum-Asarum and 111 potential targets involved in the disease process.GO analysis and KEGG results showed that potential therapeutic targets were mainly enriched in biological processes such as inflammatory response,oxidative stress,cell membrane repair,and cytokine regulation.Network analysis and molecular docking showed that the key compounds of Bupleurum and Asarum were kaempferol and quercetin,which were well docked with the active pockets of four core genes of traumatic brain injury.[Conclusions]Bupleurum and Asarum may be involved in the regulation of inflammatory response,oxidative stress,cell membrane repair through multiple targets and multiple pathways in the treatment of traumatic brain injury.
文摘:This article first analyzes the problems existing in the teaching about diagnosing and removing automobile’s failure,and then discusses some specific teaching strategies on diagnosing and removing automobile’s failure to provide some effective reference for the related staff.
文摘Automobile Inspection and Maintenance Course is relatively practical and professional.Therefore,teachers need to provide students with opportunities for practice as much as possible,so that students can realize the integration of theory and practice,improve teaching efficiency.Project-oriented teaching design can enable students to participate in the practical training and maintenance of automotive engines,which helps students understand the theories in the book.This article mainly analyzes the strategies for teaching design of project-oriented Automobile Inspection and Maintenance Course.
文摘In some clinical features, the failure of the couple to reproduce may be related to the chromosome abnormality of the patient. This report was based on one example about the topic.
基金This study was financially supported by the National Key Research and Development Program of China(2022YFC2804100,2021YFF0502400,2022YFC2804300)National Natural Science Foundation of China(82073713,22137006,82104033,82173730,81903499,32070070,82160669)Innovative research team of highlevel local universities in Shanghai(SHSMU-ZDCX20212702,China).We thank Dr.Juncheng Su from Shanghai Jiao-Tong University School of Medicine(Shanghai,China)for providing the LoVo and COLO 320DM cell lines.
文摘Modulating Tankyrases(TNKS),interactions with USP25 to promote TNKS degradation,rather than inhibiting their enzymatic activities,is emerging as an alternative/specific approach to inhibit the Wnt/β-catenin pathway.Here,we identified UAT-B,a novel neoantimycin analog isolated from Streptomyces conglobatus,as a small-molecule inhibitor of TNKS-USP25 protein-protein interaction(PPI)to overcome multi-drug resistance in colorectal cancer(CRC).The disruption of TNKS-USP25 complex formation by UAT-B led to a significant decrease in TNKS levels,triggering cell apoptosis through modulation of the Wnt/β-catenin pathway.Importantly,UAT-B successfully inhibited the CRC cells growth that harbored high TNKS levels,as demonstrated in various in vitro and in vivo studies utilizing cell line-based and patient-derived xenografts,as well as APC^(min/+)spontaneous CRC models.Collectively,these findings suggest that targeting the TNKS-USP25 PPI using a small-molecule inhibitor represents a compelling therapeutic strategy for CRC treatment,and UAT-B emerges as a promising candidate for further preclinical and clinical investigations.
基金supported by National Natural Science Foundation of China under Grant 51977066。
文摘Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.
基金supported by the National Natural Science Foundation of China(Grant No.41807448).
文摘The loess accumulation process has great potential to record patterns of atmospheric circulation change,paleoclimate,and paleoenvironmental evolution.South-eastern Xizang is a climatically sensitive region and here,we analyze a loess profile at Ranwu in order to explore the processes and interactions of dust transport and paleoclimate evolution in the region.Based on parametric grain size end-member analysis,optically stimulated luminescence(OSL)dating,and environmental proxies we show that the Ranwu loess profile comprises five end members(EMs).EM1 represents the fine silt fraction transported by high-altitude westerly winds over long distances;EM2 represents the medium silt fraction accumulated by glacier winds;EM3 is the coarse silt fraction transported by local dust storms under the action of strong glacier winds;EM4 represents the very fine sand fraction transported by strong local dust storms,different wind strengths controls the relative proportion of EM3 and EM4 over time.EM5 is the coarse sand fraction formed from the product of strong weathering of gravels.OSL dating shows loess sedimentation at Ranwu started around 11.16 ka.The prevailing climate was generally warm and wet between 11.6 and 4.2 ka,with four cooling events at 10.50,9.18,7.85,and 6.37 ka.Extensive paleosol development between 8.2 and 4.2 ka,a change to dry and cold climate conditions was favorable for loess formation after 4.2 ka.The palaeoenvironmental changes and abrupt climate events recorded in the Ranwu loess sequence are consistent with Holocene global environmental changes.
基金supported financially by the National Natural Science Foundation of China(Nos.52172208,52072197,and 21971132)Natural Science Foundation of Shandong Province(No.ZR2019MB042).
文摘Dual atom catalysts(DACs),are promising electrocatalysts for oxygen reduction reaction(ORR)on account of the potential dual-atom active sites for the optimized adsorption of catalytic intermediates and the lower reaction energy barriers.Herein,spatial confinement strategy to fabricate DACs with well-defined Fe,Co dual-atom active site is proposed by implanting zeolitic imidazolate frameworks inside the pores of highly porous carbon nanospheres(Fe/Co-SAs-Nx-PCNSs).The atomically dispersed dual-atom active sites facilitate the adsorption/desorption of intermediates.Furthermore,the spatial confinement effect protects metal atoms aggregating.Benefiting from the rich accessible dual-atom active sites and boosted mass transport,we achieve remarkable ORR performance with half-wave potential up to 0.91 and 0.8 V(vs.reversible hydrogen electrode(RHE)),and long-term stability up to 10 h in both alkaline and acidic electrolytes.The remarkably enhanced ORR catalytic property of our as-developed DACs is in the rank of excellence for 1%.The as-developed rechargeable Zn-air battery(ZAB)with Fe/Co-SAs-Nx-PCNSs air cathode delivers ultrahigh power density of 216 mW·cm^(−2),outstanding specific capacity of 813 mAh·g^(−1),and promising cycling operation durability over 160 h.The flexible Zn-air battery also exhibits excellent specific capacity,cycling stability,and flexibility performance.This work opens up a new pathway for the multiscale design of efficient electrocatalysts with atomically dispersed multiple active sites.
基金supported by the National Basic Research Program (973) of China (No. 2013CB430403)
文摘Norfloxacin(NOR), an ionizable antibiotic frequently used in the aquaculture industry, has aroused public concern due to its persistence, bacterial resistance, and environmental ubiquity.Therefore, we investigated the photolysis of different species of NOR and the impact of a ubiquitous component of natural water — dissolved organic matter(DOM), which has a special photochemical activity and normally acts as a sensitizer or inhibiter in the photolysis of diverse organics; furthermore, scavenging experiments combined with electron paramagnetic resonance(EPR) were performed to evaluate the transformation of NOR in water. The results demonstated that NOR underwent direct photolysis and self-sensitized photolysis via hydroxyl radical(U OH) and singlet oxygen(1O2) based on the scavenging experiments. In addition, DOM was found to influence the photolysis of different NOR species, and its impact was related to the concentration of DOM and type of NOR species. Photolysis of cationic NOR was photosensitized by DOM at low concentration, while zwitterionic and anionic NOR were photoinhibited by DOM, where quenching of U OH predominated according to EPR experiments, accompanied by possible participation of excited triplet-state NOR and1O2. Photo-intermediate identification of different NOR species in solutions with/without DOM indicated that NOR underwent different photodegradation pathways including dechlorination, cleavage of the piperazine side chain and photooxidation, and DOM had little impact on the distribution but influenced the concentration evolution of photolysis intermediates. The results implied that for accurate ecological risk assessment of emerging ionizable pollutants, the impact of DOM on the environmental photochemical behavior of all dissociated species should not be ignored.
基金supported by the National Crucial Research Project for Water Pollution Control of China (2012ZX07202006)the Fundamental Research Funds for the Central Universities of China (DUT14QY01 and DUT13LK19)
文摘It is important to develop efficient technologies on removal of perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS)from water due to their wide distribution and potential threat to human health.In this work,a durable and convenient electrosorption device was designed in continuous flow mode to investigate the adsorption of PFOX(X=A and S)on multiwalled carbon nanotubes(MWNTs)from water under electrochemical assistance.The electrosorption experiments were conducted under different influent and electrolyte concentrations,hydraulic retention time(HRT)and electrode distance to optimize the operation.The results showed that the highest removal efficiencies toward both PFOA and PFOS could come up to 90%at 1 V.Compared with open circuit(OC)adsorption under the same conditions,the removal efficiencies were improved by 4.9 times(PFOA)and 4.2 times(PFOS)respectively.In addition,the MWNTs electrode was found to be reusable.These findings provide an efficient method to remove PFOX from water by electrosorption in continuous flow mode.
基金supported by the National Natural Science Foundation of China(Nos.20877090,21077123,21377143)
文摘The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would undertake electrophilic substitution generating mono-or di-halogenated products,which would be oxidized to esters and further hydrolyzed to phenol derivatives.The generated catechol intermediate would be transformed into furan-like heterocyclic product.The product species were p H-dependent,while benzophenone-4 elimination was chlorine dose-dependent.When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions,most of brominated byproducts could be detected,and the acute toxicity significantly increased as well.
基金the financial support from the Research Grants Council of Hong Kong(No.15304519)the National Natural Science Foundation of China(No.11904306)+2 种基金the Hong Kong Polytechnic University(No.1-ZVH9)The authors also thank the Fundamental Research Funds for the Central Universities(Nos.2019B02414 and 2019B44214)PAPD,and Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering,MOE(No.KLIEEE-18-02).
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.
基金supported by the National Natural Scientific Foundation of China(No.51578105)
文摘Cathodic reduction of CO_2 and anodic oxidation of organic matters are crucial to methaneproducing microbial electrolysis cell(MEC) applied in anaerobic digestion of waste activated sludge. However, cathodic CO_2 reduction is usually restrained by slow metabolism rates of H_2-utilizing methanogens and low electron-capturing capacity of CO_2, which consequently slows down the anodic oxidation that participates to sludge disintegration. Herein, a strategy with adding nitrate as electron acceptor to foster electronic transfer between the anode and cathode was proposed to improve anodic oxidation. Results showed that the average efficiency of anodic oxidation in the nitrate-added MEC increased by 55.9%. Accordingly,volatile suspended solid removal efficiency in the nitrate-added MEC was 21.9% higher than that of control MEC. Although the initial cumulative methane production in the nitrateadded MEC was lower than that of control MEC, the cumulative methane production in 24 days was 8.9% higher. Fourier transform infrared spectroscopy analysis indicated that anodic oxidation of MEC with nitrate accelerated the disintegration of sludge flocs and cell walls. Calculation on current signal further revealed that anodic oxidation driven by cathodic nitrate reduction was the main mechanism responsible for the improved sludge digestion.
基金We thank the U.S.National Institutes of Health(GM077596)Roy J.Carver Charitable Trust(13-4257)+1 种基金U.S.Department of Energy(ER65474)Carl R.Woese Institute for Genomic Biology at the University of Illinois at Urbana-Champaign,and the Energy Efficiency&Resources Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry&Energy,Republic of Korea(20153030091450)for financial support in our development and application of synthetic biology technologies.In addition,we state that there is no conflict of interest.
文摘The United States is a leading nation in the development of synthetic biology,an emerging engineering discipline to create,control and reprogram biological systems.With strategic investment from its government agencies,the U.S.has established numerous research centers and programs in synthetic biology,enabling significant advances in foundational tool development and practical applications ranging from bioenergy,biomanufacturing,to biomedicine.To maintain its leadership in synthetic biology,U.S,has conducted several roadmap studies to provide strategic visions and action recommendations.Here we will provide a brief overview of the major research programs and roadmap studies of synthetic biology in the U.S.
基金This work was supported by award AI144967(to H.Z.)from the U.S.National Institutes of Health(NIH)and awards DE-SC0018260 and DESC0018420(to H.Z.)from the U.S.Department of Energy.
文摘Overproduction of polyketides has been a challenge for metabolic engineering for decades.However,recent studies have demonstrated that in both native host and heterologous host,engineeringβ-oxidation pathways can lead to dramatic improvement of polyketide production.
