Background Mitochondrial dysfunction induced by excessive mitochondrial reactive oxygen species(ROS)damages embryonic development and leads to growth arrest.Objective The purpose of this study is to elucidate whether ...Background Mitochondrial dysfunction induced by excessive mitochondrial reactive oxygen species(ROS)damages embryonic development and leads to growth arrest.Objective The purpose of this study is to elucidate whether maternal zinc(Zn)exert protective effect on oxidative stress targeting mitochondrial function using an avian model.Result In ovo injected tert-butyl hydroperoxide(BHP)increases(P<0.05)hepatic mitochondrial ROS,malondialdehyde(MDA)and 8-hydroxy-2-deoxyguanosine(8-OHdG),and decreases(P<0.05)mitochondrial membrane potential(MMP),mitochondrial DNA(mtDNA)copy number and adenosine triphosphate(ATP)content,contributing to mitochondrial dysfunction.In vivo and in vitro studies revealed that Zn addition enhances(P<0.05)ATP synthesis and metallothionein 4(MT4)content and expression as well as alleviates(P<0.05)the BHP-induced mitochondrial ROS generation,oxidative damage and dysfunction,exerting a protective effect on mitochondrial function by enhancing antioxidant capacity and upregulating the mRNA and protein expressions of Nrf2 and PGC-1α.Conclusions The present study provides a new way to protect offspring against oxidative damage by maternal Zn supplementation through the process of targeting mitochondria involving the activation of Nrf2/PGC-1αsignaling.展开更多
Background Ochratoxin A(OTA)is a mycotoxin widely present in raw food and feed materials and is mainly pro-duced by Aspergillus ochraceus and Penicillium verrucosum.Our previous study showed that OTA principally induc...Background Ochratoxin A(OTA)is a mycotoxin widely present in raw food and feed materials and is mainly pro-duced by Aspergillus ochraceus and Penicillium verrucosum.Our previous study showed that OTA principally induces liver inflammation by causing intestinal flora disorder,especially Bacteroides plebeius(B.plebeius)overgrowth.However,whether OTA or B.plebeius alteration leads to abnormal tryptophan-related metabolism in the intestine and liver is largely unknown.This study aimed to elucidate the metabolic changes in the intestine and liver induced by OTA and the tryptophan-related metabolic pathway in the liver.Materials and methods A total of 30 healthy 1-day-old male Cherry Valley ducks were randomly divided into 2 groups.The control group was given 0.1 mol/L NaHCO3 solution,and the OTA group was given 235μg/kg body weight OTA for 14 consecutive days.Tryptophan metabolites were determined by intestinal chyme metabolomics and liver tryptophan-targeted metabolomics.AMPK-related signaling pathway factors were analyzed by Western blot-ting and mRNA expression.Results Metabolomic analysis of the intestinal chyme showed that OTA treatment resulted in a decrease in intesti-nal nicotinuric acid levels,the downstream product of tryptophan metabolism,which were significantly negatively correlated with B.plebeius abundance.In contrast,OTA induced a significant increase in indole-3-acetamide levels,which were positively correlated with B.plebeius abundance.Simultaneously,OTA decreased the levels of ATP,NAD+and dipeptidase in the liver.Liver tryptophan metabolomics analysis showed that OTA inhibited the kynurenine metabolic pathway and reduced the levels of kynurenine,anthranilic acid and nicotinic acid.Moreover,OTA increased the phosphorylation of AMPK protein and decreased the phosphorylation of mTOR protein.Conclusion OTA decreased the level of nicotinuric acid in the intestinal tract,which was negatively correlated with B.plebeius abundance.The abnormal metabolism of tryptophan led to a deficiency of NAD+and ATP in the liver,which in turn activated the AMPK signaling pathway.Our results provide new insights into the toxic mechanism of OTA,and tryptophan metabolism might be a target for prevention and treatment.展开更多
An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missi...An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missile (SAM) tactical unit. The accomplishment process of target assignment (TA) task is analyzed. A firing advantage degree (FAD) concept of fire unit (FU) intercepting targets is put forward and its evaluation model is established by using a linear weighted synthetic method. A TA optimization model is presented and its solving algorithms are designed respectively based on ACO and SA. A hybrid optimization strategy is presented and developed synthesizing the merits of ACO and SA. The simulation examples show that the model and algorithms can meet the solving requirement of TAP in AD combat.展开更多
Air traffic is exhibiting the characteristics of high density,high volume,and unmanned operations.To ensure smooth,efficient,safe,and reliable operations,it is necessary to promote the digital transformation of Air Tr...Air traffic is exhibiting the characteristics of high density,high volume,and unmanned operations.To ensure smooth,efficient,safe,and reliable operations,it is necessary to promote the digital transformation of Air Traffic Management(ATM)with digitalization,autonomy,and collaboration as its typical features.This article,based on the background of current and foreseeable future ATM needs,deeply analyzes the challenges and opportunities faced by traditional ATM.It explores and proposes to further investigate the commonalities,characteristics,and evolution of air traffic,the interaction mechanism of"human-machine-environment"in air traffic,the integrated design of airborne avionics and ATM systems,the comprehensive integration of ATM based on vulnerability analysis,airspace classification management,air traffic flow management,key technologies of"perception-collision avoidance",wake vortex monitoring and interval reduction,unmanned aerial vehicle management,and the expansion of ATM capabilities in the"high frontier".The research suggests strengthening top-level planning,building an open,mutually beneficial,and win-win digital ATM ecological framework based on multi-party collaboration,coordinating the research and application of new digital ATM technologies,accelerating the occupation of the new track of low-altitude economy,and enhancing ATM capabilities driven by the digital transformation of ATM.展开更多
Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning,flight scheduling,airport operation,and passenger service.Flight delay is affected by nu...Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning,flight scheduling,airport operation,and passenger service.Flight delay is affected by numerous factors and irregularly propagates in air transportation networks owing to flight connectivity,which brings critical challenges to accurate flight delay prediction.In recent years,Graph Convolutional Networks(GCNs)have become popular in flight delay prediction due to the advantage in extracting complicated relationships.However,most of the existing GCN-based methods have failed to effectively capture the spatial-temporal information in flight delay prediction.In this paper,a Geographical and Operational Graph Convolutional Network(GOGCN)is proposed for multi-airport flight delay prediction.The GOGCN is a GCN-based spatial-temporal model that improves node feature representation ability with geographical and operational spatial-temporal interactions in a graph.Specifically,an operational aggregator is designed to extract global operational information based on the graph structure,while a geographical aggregator is developed to capture the similar nature among spatially close airports.Extensive experiments on a real-world dataset demonstrate that the proposed approach outperforms the state-of-the-art methods with a satisfying accuracy improvement.展开更多
Hepatic lipid and fatty acid(FA)metabolism are critical for regulating energetic homeostasis during embryogenesis.At present,it remains unclear how an exogenous FA intervention affects embryonic development in an avia...Hepatic lipid and fatty acid(FA)metabolism are critical for regulating energetic homeostasis during embryogenesis.At present,it remains unclear how an exogenous FA intervention affects embryonic development in an avian embryo model.In Exp.1,30 fertilized eggs were sampled on embryonic days(E)16,19,22,25,28,31 and the day of hatch(DOH)to determine the critical period of lipid metabolism.In Exp.2,a total of 120 fertilized eggs were divided into two groups(60 eggs/group)for in ovo feeding(IOF)procedures on E25.Eggs were injected into the yolk sac with PBS as the control group and with oleic acid(OA)as the IOF-OA treatment group.Samples were collected on E28 and E31.In Exp.1,hepatic triacylglycerol(TG)and cholesterol(CHO)contents increased while serum TG content decreased from E16 to DOH(P<0.05).Both serum and liver displayed an increase in unsaturated FA and a decrease in saturated FA(P<0.05).There was a quadratic increase in the target gene and protein expression related to hepatic FA de novo synthesis and oxidation(P<0.05),whose inflection period was between E22 and E28.In Exp.2,compared with the control embryos,IOF-OA embryos had an increased yolk sac TG content on E28 and E31,and a decreased serum TG and CHO content on E28(P<0.05).The IOF-OA embryos had less OA in the yolk sac and liver on E28,and less unsaturated FA in the serum and liver on E31 than did the control embryos(P<0.05).Hepatic gene mRNA expression related to FA uptake,synthesis,and oxidation on E28 was lower in IOF-OA than in control embryos(P<0.05),not on E31(P>0.05).Maximal metabolic changes in lipid and FA metabolism occurred on E22-E28 in Muscovy duck embryogenesis,along with the altered target gene and protein expression related to lipogenesis and lipolysis.IOF-OA intervention on E25 could inhibit the target gene expression related to FA uptake,synthesis,and oxidation,which may influence the normal FA metabolism on E28 during embryogenesis.展开更多
基金sponsored by the National Key R&D Program of China(2022YFD1301800 and1300400)National Natural Science Foundation of China(31802080 and 3197200131)+1 种基金Key Open Laboratory of Chinese Veterinary Medicine of State Ethnic Affairs Commission&National Local Joint Engineering Research Centre for the Separation and Purification Technology of Ethnic Chinese Veterinary Medicine([2022]09)Guangdong Provincial Science and Technology Special Foundation(210723106900762 and 2021020103-2)。
文摘Background Mitochondrial dysfunction induced by excessive mitochondrial reactive oxygen species(ROS)damages embryonic development and leads to growth arrest.Objective The purpose of this study is to elucidate whether maternal zinc(Zn)exert protective effect on oxidative stress targeting mitochondrial function using an avian model.Result In ovo injected tert-butyl hydroperoxide(BHP)increases(P<0.05)hepatic mitochondrial ROS,malondialdehyde(MDA)and 8-hydroxy-2-deoxyguanosine(8-OHdG),and decreases(P<0.05)mitochondrial membrane potential(MMP),mitochondrial DNA(mtDNA)copy number and adenosine triphosphate(ATP)content,contributing to mitochondrial dysfunction.In vivo and in vitro studies revealed that Zn addition enhances(P<0.05)ATP synthesis and metallothionein 4(MT4)content and expression as well as alleviates(P<0.05)the BHP-induced mitochondrial ROS generation,oxidative damage and dysfunction,exerting a protective effect on mitochondrial function by enhancing antioxidant capacity and upregulating the mRNA and protein expressions of Nrf2 and PGC-1α.Conclusions The present study provides a new way to protect offspring against oxidative damage by maternal Zn supplementation through the process of targeting mitochondria involving the activation of Nrf2/PGC-1αsignaling.
基金Guangdong Province Natural Science Funds for Distinguished Young Scholar(2022B1515020016)the National Science Fund for Outstanding Young Scholars(32222080)+5 种基金National Key Research Program(2021YFD1300404)National Science Fund Project of China(32072751)Guangdong Basic and Applied Basic Research Foundation(2022B1515130003)China Agriculture Research System(CARS-42-15)Modern Agricultural Industrial Technology System Innovation Team of Guangdong Province(2022KJ137)Natural Science Foundation of Guangdong Province(2019B1515210012).
文摘Background Ochratoxin A(OTA)is a mycotoxin widely present in raw food and feed materials and is mainly pro-duced by Aspergillus ochraceus and Penicillium verrucosum.Our previous study showed that OTA principally induces liver inflammation by causing intestinal flora disorder,especially Bacteroides plebeius(B.plebeius)overgrowth.However,whether OTA or B.plebeius alteration leads to abnormal tryptophan-related metabolism in the intestine and liver is largely unknown.This study aimed to elucidate the metabolic changes in the intestine and liver induced by OTA and the tryptophan-related metabolic pathway in the liver.Materials and methods A total of 30 healthy 1-day-old male Cherry Valley ducks were randomly divided into 2 groups.The control group was given 0.1 mol/L NaHCO3 solution,and the OTA group was given 235μg/kg body weight OTA for 14 consecutive days.Tryptophan metabolites were determined by intestinal chyme metabolomics and liver tryptophan-targeted metabolomics.AMPK-related signaling pathway factors were analyzed by Western blot-ting and mRNA expression.Results Metabolomic analysis of the intestinal chyme showed that OTA treatment resulted in a decrease in intesti-nal nicotinuric acid levels,the downstream product of tryptophan metabolism,which were significantly negatively correlated with B.plebeius abundance.In contrast,OTA induced a significant increase in indole-3-acetamide levels,which were positively correlated with B.plebeius abundance.Simultaneously,OTA decreased the levels of ATP,NAD+and dipeptidase in the liver.Liver tryptophan metabolomics analysis showed that OTA inhibited the kynurenine metabolic pathway and reduced the levels of kynurenine,anthranilic acid and nicotinic acid.Moreover,OTA increased the phosphorylation of AMPK protein and decreased the phosphorylation of mTOR protein.Conclusion OTA decreased the level of nicotinuric acid in the intestinal tract,which was negatively correlated with B.plebeius abundance.The abnormal metabolism of tryptophan led to a deficiency of NAD+and ATP in the liver,which in turn activated the AMPK signaling pathway.Our results provide new insights into the toxic mechanism of OTA,and tryptophan metabolism might be a target for prevention and treatment.
基金supported by the National Aviation Science Foundation of China(20090196002)
文摘An ant colony optimization (ACO)-simulated annealing (SA)-based algorithm is developed for the target assignment problem (TAP) in the air defense (AD) command and control (C2) system of surface to air missile (SAM) tactical unit. The accomplishment process of target assignment (TA) task is analyzed. A firing advantage degree (FAD) concept of fire unit (FU) intercepting targets is put forward and its evaluation model is established by using a linear weighted synthetic method. A TA optimization model is presented and its solving algorithms are designed respectively based on ACO and SA. A hybrid optimization strategy is presented and developed synthesizing the merits of ACO and SA. The simulation examples show that the model and algorithms can meet the solving requirement of TAP in AD combat.
基金supported by the National Key R&D Program of China(No.2022YFB4300900).
文摘Air traffic is exhibiting the characteristics of high density,high volume,and unmanned operations.To ensure smooth,efficient,safe,and reliable operations,it is necessary to promote the digital transformation of Air Traffic Management(ATM)with digitalization,autonomy,and collaboration as its typical features.This article,based on the background of current and foreseeable future ATM needs,deeply analyzes the challenges and opportunities faced by traditional ATM.It explores and proposes to further investigate the commonalities,characteristics,and evolution of air traffic,the interaction mechanism of"human-machine-environment"in air traffic,the integrated design of airborne avionics and ATM systems,the comprehensive integration of ATM based on vulnerability analysis,airspace classification management,air traffic flow management,key technologies of"perception-collision avoidance",wake vortex monitoring and interval reduction,unmanned aerial vehicle management,and the expansion of ATM capabilities in the"high frontier".The research suggests strengthening top-level planning,building an open,mutually beneficial,and win-win digital ATM ecological framework based on multi-party collaboration,coordinating the research and application of new digital ATM technologies,accelerating the occupation of the new track of low-altitude economy,and enhancing ATM capabilities driven by the digital transformation of ATM.
基金supported by the National Natural Science Foundation of China(Nos.71731001,U2133210,and U2033215,61822102)。
文摘Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning,flight scheduling,airport operation,and passenger service.Flight delay is affected by numerous factors and irregularly propagates in air transportation networks owing to flight connectivity,which brings critical challenges to accurate flight delay prediction.In recent years,Graph Convolutional Networks(GCNs)have become popular in flight delay prediction due to the advantage in extracting complicated relationships.However,most of the existing GCN-based methods have failed to effectively capture the spatial-temporal information in flight delay prediction.In this paper,a Geographical and Operational Graph Convolutional Network(GOGCN)is proposed for multi-airport flight delay prediction.The GOGCN is a GCN-based spatial-temporal model that improves node feature representation ability with geographical and operational spatial-temporal interactions in a graph.Specifically,an operational aggregator is designed to extract global operational information based on the graph structure,while a geographical aggregator is developed to capture the similar nature among spatially close airports.Extensive experiments on a real-world dataset demonstrate that the proposed approach outperforms the state-of-the-art methods with a satisfying accuracy improvement.
基金This study was sponsored by National Natural Science Foundation of China(31972584)China Agriculture Research System of MOF and MARA(CARS-42-15).
文摘Hepatic lipid and fatty acid(FA)metabolism are critical for regulating energetic homeostasis during embryogenesis.At present,it remains unclear how an exogenous FA intervention affects embryonic development in an avian embryo model.In Exp.1,30 fertilized eggs were sampled on embryonic days(E)16,19,22,25,28,31 and the day of hatch(DOH)to determine the critical period of lipid metabolism.In Exp.2,a total of 120 fertilized eggs were divided into two groups(60 eggs/group)for in ovo feeding(IOF)procedures on E25.Eggs were injected into the yolk sac with PBS as the control group and with oleic acid(OA)as the IOF-OA treatment group.Samples were collected on E28 and E31.In Exp.1,hepatic triacylglycerol(TG)and cholesterol(CHO)contents increased while serum TG content decreased from E16 to DOH(P<0.05).Both serum and liver displayed an increase in unsaturated FA and a decrease in saturated FA(P<0.05).There was a quadratic increase in the target gene and protein expression related to hepatic FA de novo synthesis and oxidation(P<0.05),whose inflection period was between E22 and E28.In Exp.2,compared with the control embryos,IOF-OA embryos had an increased yolk sac TG content on E28 and E31,and a decreased serum TG and CHO content on E28(P<0.05).The IOF-OA embryos had less OA in the yolk sac and liver on E28,and less unsaturated FA in the serum and liver on E31 than did the control embryos(P<0.05).Hepatic gene mRNA expression related to FA uptake,synthesis,and oxidation on E28 was lower in IOF-OA than in control embryos(P<0.05),not on E31(P>0.05).Maximal metabolic changes in lipid and FA metabolism occurred on E22-E28 in Muscovy duck embryogenesis,along with the altered target gene and protein expression related to lipogenesis and lipolysis.IOF-OA intervention on E25 could inhibit the target gene expression related to FA uptake,synthesis,and oxidation,which may influence the normal FA metabolism on E28 during embryogenesis.