With the development of the integration of aviation safety and artificial intelligence,research on the combination of risk assessment and artificial intelligence is particularly important in the field of risk manageme...With the development of the integration of aviation safety and artificial intelligence,research on the combination of risk assessment and artificial intelligence is particularly important in the field of risk management,but searching for an efficient and accurate risk assessment algorithm has become a challenge for the civil aviation industry.Therefore,an improved risk assessment algorithm(PS-AE-LSTM)based on long short-term memory network(LSTM)with autoencoder(AE)is proposed for the various supervised deep learning algorithms in flight safety that cannot adequately address the problem of the quality on risk level labels.Firstly,based on the normal distribution characteristics of flight data,a probability severity(PS)model is established to enhance the quality of risk assessment labels.Secondly,autoencoder is introduced to reconstruct the flight parameter data to improve the data quality.Finally,utilizing the time-series nature of flight data,a long and short-termmemory network is used to classify the risk level and improve the accuracy of risk assessment.Thus,a risk assessment experimentwas conducted to analyze a fleet landing phase dataset using the PS-AE-LSTMalgorithm to assess the risk level associated with aircraft hard landing events.The results show that the proposed algorithm achieves an accuracy of 86.45%compared with seven baseline models and has excellent risk assessment capability.展开更多
L-malic acid(L-MA)is an important intermediate in the tricarboxylic acid cycle and a crucial bulk chemical with various applications in the food,pharmaceutical,and chemical industries.With the rapid advancements in me...L-malic acid(L-MA)is an important intermediate in the tricarboxylic acid cycle and a crucial bulk chemical with various applications in the food,pharmaceutical,and chemical industries.With the rapid advancements in metabolic engineering technology and the global commitment toward fostering a green economy and sustainable development,the large-scale production of L-MA is gradually transitioning from conventional petroleum-based approaches to microbial fermentation.This comprehensive review aims to provide a thorough overview of the historical background and recent advancements in the microbial fermentation production of L-MA,encompassing an in-depth introduction to diverse biosynthetic pathways and host strains.Moreover,this review elucidates the challenges encountered in the industrialization of microbial fermentation production of L-MA,offering a summary of potential solutions and prospects for future research directions.The anticipated outcome of this review is to contribute valuable theoretical guidance toward promoting technological innovation in L-MA production.展开更多
Disaccharide phosphorylases(DSPs)are carbohydrate-active enzymes with outstanding potential for the biocatalytic conversion of common table sugar into products with attractive properties.They are modular enzymes that ...Disaccharide phosphorylases(DSPs)are carbohydrate-active enzymes with outstanding potential for the biocatalytic conversion of common table sugar into products with attractive properties.They are modular enzymes that form active homo-oligomers.From a mechanistic as well as a structural point of view,they are similar to glycoside hydrolases or glycosyltransferases.As the majority of DSPs show strict stereo-and regiospecificities,these enzymes were used to synthesize specific disaccharides.Currently,protein engineering of DSPs is pursued in different laboratories to broaden the donor and acceptor substrate specificities or improve the industrial particularity of naturally existing enzymes,to eventually generate a toolbox of new catalysts for glycoside synthesis.Herein we review the characteristics and classifications of reported DSPs and the glycoside products that they have been used to synthesize.展开更多
AIM: To describe the involution patterns of vessel growth of retina through fluorescein angiography(FA) of children, who had been under treatment up to 1 y previously intravitreal ranibizumab(IVR) as monotherapy for r...AIM: To describe the involution patterns of vessel growth of retina through fluorescein angiography(FA) of children, who had been under treatment up to 1 y previously intravitreal ranibizumab(IVR) as monotherapy for retinopathy of prematurity(ROP). METHODS: This is a retrospective study. The medical information and FA of 17 children(34 eyes) whose area of avascular retina from the ora serrata was more than two disc diameters(DD) were analyzed. RESULTS: Among 34 eyes, all were the presence of finger-shaped vessels and arteriolar-venular shunts(100%,34/34 eyes). Popcorn abnormalities were found in most of the eyes(94.1%, 32/34 eyes). Furthermore, in many cases(23.5%, 8/34 eyes), there were leakage persisting in the region of the junction between avascular and vascular retina. In contrast, just 2 eyes(5.9%) showed damage of retinal capillary bed and 3 eyes(8.8%) showed large area of retinal pigment epithelium(RPE) atrophy. CONCLUSION: Although IVR can be very effective in ROP, we should remain cautious as infants may remain avascular peripheral retinas and abnormal vessel. FA allows accurate visualization of vessel abnormalities in eyes with ROP, which will be helpful to affect assessment of disease activity and therapeutic effect.展开更多
The unified hardening(UH)model proposed by Yao et al.(Geotechnique 2009)is the constitutive model which can consider the influence of the complex stress path and stress history on the deformation and strength of clays...The unified hardening(UH)model proposed by Yao et al.(Geotechnique 2009)is the constitutive model which can consider the influence of the complex stress path and stress history on the deformation and strength of clays reasonably.Firstly,the loading-unloading criterion of material model is defined as the change law of the intersection of current yield surface and the p axis,which makes the loading-unloading in the process of hardening and softening can be unified considered in UH model.Then,the Newton-Raphson method is adopted to attain the nonlinear problems solution in the finite element method of UH model,and the semi-implicit return mapping method is adopted to update stress.The application of the UH model in the finite element is realized.And then,the analyses of triaxial test are performed using the unit prediction and finite element method.The results of the unit prediction method are compared with the experimental results to illustrate the rationality of the UH model.Comparing the results with the unit prediction method and the finite element method,the correctness of the finite element program of the UH model is iUusttated.Further,Ae three-dimensional firdte element andysis of embankment on soft soil is performed by the program.The comparison between the results calculated by the UH model and the modified Cam-clay(MCC)model and the experimental data shows that the UH model is rational in analyzing the actual embankment engineering on soft soil.展开更多
Enzyme cascade reactions play significant roles in bioelectrochemical processes because they permit more complex reactions. Co-immobilization of multienzyme on the electrode could help to facilitate substrate/intermed...Enzyme cascade reactions play significant roles in bioelectrochemical processes because they permit more complex reactions. Co-immobilization of multienzyme on the electrode could help to facilitate substrate/intermediate transfer among different enzymes and electron transfer from enzyme active sites to the electrode with high stability and retrievability. Different co-immobilization strategies to construct multienzyme bioelectrodes have been widely reported, however, up to now, they have barely been reviewed. In this review, we focus on recent state-of-the-art techniques for constructing co-immobilized multienzyme electrodes including random and positional co-immobilization. Particular attention is given to strategies such as multienzyme complex and surface display. Cofactor co-immobilization on the electrode is also crucial for the enhancement of catalytic reaction and electron transfer, yet, few studies have been reported. The up-to-date advances in bioelectrochemical applications of multienzyme bioelectrodes are also presented. Finally, key challenges and future perspectives are discussed.展开更多
In February 2006,a large amount of unknown floating microorganisms appeared in the Hailang River(HR) in the City of Hailin,Heilongjiang Province,China.The microorganisms caused the river water fouling and threatened t...In February 2006,a large amount of unknown floating microorganisms appeared in the Hailang River(HR) in the City of Hailin,Heilongjiang Province,China.The microorganisms caused the river water fouling and threatened the clean water supply of the city.To identify the unknown floating organisms,morphological and histological inspection,PCR,cloning and sequence analysis were conducted.The results revealed that the unknown floating organisms in the river were a novel species that likely belonged to oomycetes in Saprolegniales.The organisms were named Saprolegnia sp.HL0602.展开更多
The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea.Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic lev...The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea.Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic level.Variations in fatty acid compositions among different species were observed but were unclear.Different dietary structures could be traced from molecular isotopes of selected fatty acids in the Shiba shrimp(Matapenaeus joyneri),the coastal mud shrimp(Solenocera crassicomis) and the northern Maoxia shrimp(Acetes chinensis).Both M.joyneri and S.crassicomis are mainly benthos feeders,while A.chinensis is a pelagic species,although they have a similar fatty acid composition.There was a good correlation for isotopes of arachidonic acid(C20:4n6;ARA) and docosahexaenoic acid(C22:6n3;DHA)among pelagic species from higher trophic levels.The isotopic compositions of DHA in benthic species were more negative than those of pelagic species at the same trophic level.The fact that the diet of benthic species contains more degraded items,the carbon isotopes of which are derived from a large biochemical fraction,may be the reason for this variation.A comparative study of benthic and pelagic species demonstrated the different carbon sources in potential food items and the presence of a more complex system at the watersediment interface.展开更多
基金the National Natural Science Foundation of China(U2033213)the Fundamental Research Funds for the Central Universities(FZ2021ZZ01,FZ2022ZX50).
文摘With the development of the integration of aviation safety and artificial intelligence,research on the combination of risk assessment and artificial intelligence is particularly important in the field of risk management,but searching for an efficient and accurate risk assessment algorithm has become a challenge for the civil aviation industry.Therefore,an improved risk assessment algorithm(PS-AE-LSTM)based on long short-term memory network(LSTM)with autoencoder(AE)is proposed for the various supervised deep learning algorithms in flight safety that cannot adequately address the problem of the quality on risk level labels.Firstly,based on the normal distribution characteristics of flight data,a probability severity(PS)model is established to enhance the quality of risk assessment labels.Secondly,autoencoder is introduced to reconstruct the flight parameter data to improve the data quality.Finally,utilizing the time-series nature of flight data,a long and short-termmemory network is used to classify the risk level and improve the accuracy of risk assessment.Thus,a risk assessment experimentwas conducted to analyze a fleet landing phase dataset using the PS-AE-LSTMalgorithm to assess the risk level associated with aircraft hard landing events.The results show that the proposed algorithm achieves an accuracy of 86.45%compared with seven baseline models and has excellent risk assessment capability.
基金financially supported by the National Key R&D Program of China(2019YFA0904900)the National Science Fund for Distinguished Young Scholars(No.32225031)the General Program of National Nature Science Foundation of China(No.32271482).
文摘L-malic acid(L-MA)is an important intermediate in the tricarboxylic acid cycle and a crucial bulk chemical with various applications in the food,pharmaceutical,and chemical industries.With the rapid advancements in metabolic engineering technology and the global commitment toward fostering a green economy and sustainable development,the large-scale production of L-MA is gradually transitioning from conventional petroleum-based approaches to microbial fermentation.This comprehensive review aims to provide a thorough overview of the historical background and recent advancements in the microbial fermentation production of L-MA,encompassing an in-depth introduction to diverse biosynthetic pathways and host strains.Moreover,this review elucidates the challenges encountered in the industrialization of microbial fermentation production of L-MA,offering a summary of potential solutions and prospects for future research directions.The anticipated outcome of this review is to contribute valuable theoretical guidance toward promoting technological innovation in L-MA production.
基金This work was supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-ZS-2016-3)the National Natural Science Foundation of China(Grant No.21778073)Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(Grant No.TSBICIP-KJGG-003).
文摘Disaccharide phosphorylases(DSPs)are carbohydrate-active enzymes with outstanding potential for the biocatalytic conversion of common table sugar into products with attractive properties.They are modular enzymes that form active homo-oligomers.From a mechanistic as well as a structural point of view,they are similar to glycoside hydrolases or glycosyltransferases.As the majority of DSPs show strict stereo-and regiospecificities,these enzymes were used to synthesize specific disaccharides.Currently,protein engineering of DSPs is pursued in different laboratories to broaden the donor and acceptor substrate specificities or improve the industrial particularity of naturally existing enzymes,to eventually generate a toolbox of new catalysts for glycoside synthesis.Herein we review the characteristics and classifications of reported DSPs and the glycoside products that they have been used to synthesize.
文摘AIM: To describe the involution patterns of vessel growth of retina through fluorescein angiography(FA) of children, who had been under treatment up to 1 y previously intravitreal ranibizumab(IVR) as monotherapy for retinopathy of prematurity(ROP). METHODS: This is a retrospective study. The medical information and FA of 17 children(34 eyes) whose area of avascular retina from the ora serrata was more than two disc diameters(DD) were analyzed. RESULTS: Among 34 eyes, all were the presence of finger-shaped vessels and arteriolar-venular shunts(100%,34/34 eyes). Popcorn abnormalities were found in most of the eyes(94.1%, 32/34 eyes). Furthermore, in many cases(23.5%, 8/34 eyes), there were leakage persisting in the region of the junction between avascular and vascular retina. In contrast, just 2 eyes(5.9%) showed damage of retinal capillary bed and 3 eyes(8.8%) showed large area of retinal pigment epithelium(RPE) atrophy. CONCLUSION: Although IVR can be very effective in ROP, we should remain cautious as infants may remain avascular peripheral retinas and abnormal vessel. FA allows accurate visualization of vessel abnormalities in eyes with ROP, which will be helpful to affect assessment of disease activity and therapeutic effect.
基金supported by the National Natural Science Foundation of China(Grants 11672015,51808547,and 51808548)the Central University Basic Scientific Research Business Expenses Funded Project(Grant 3122014C014)+1 种基金the Civil Aviation University Airport Engineering Base Open Fund(Grant JCGC2019KFJJ003)Tianjin Municipal Education Commission Scientific Research Project(Grant 2019KJ124)。
文摘The unified hardening(UH)model proposed by Yao et al.(Geotechnique 2009)is the constitutive model which can consider the influence of the complex stress path and stress history on the deformation and strength of clays reasonably.Firstly,the loading-unloading criterion of material model is defined as the change law of the intersection of current yield surface and the p axis,which makes the loading-unloading in the process of hardening and softening can be unified considered in UH model.Then,the Newton-Raphson method is adopted to attain the nonlinear problems solution in the finite element method of UH model,and the semi-implicit return mapping method is adopted to update stress.The application of the UH model in the finite element is realized.And then,the analyses of triaxial test are performed using the unit prediction and finite element method.The results of the unit prediction method are compared with the experimental results to illustrate the rationality of the UH model.Comparing the results with the unit prediction method and the finite element method,the correctness of the finite element program of the UH model is iUusttated.Further,Ae three-dimensional firdte element andysis of embankment on soft soil is performed by the program.The comparison between the results calculated by the UH model and the modified Cam-clay(MCC)model and the experimental data shows that the UH model is rational in analyzing the actual embankment engineering on soft soil.
基金supported by the National Natural Science Foundation of China(21878324,21706273)the CAS Pioneer Hundred Talent Program(Type C,reference#2016-081)。
文摘Enzyme cascade reactions play significant roles in bioelectrochemical processes because they permit more complex reactions. Co-immobilization of multienzyme on the electrode could help to facilitate substrate/intermediate transfer among different enzymes and electron transfer from enzyme active sites to the electrode with high stability and retrievability. Different co-immobilization strategies to construct multienzyme bioelectrodes have been widely reported, however, up to now, they have barely been reviewed. In this review, we focus on recent state-of-the-art techniques for constructing co-immobilized multienzyme electrodes including random and positional co-immobilization. Particular attention is given to strategies such as multienzyme complex and surface display. Cofactor co-immobilization on the electrode is also crucial for the enhancement of catalytic reaction and electron transfer, yet, few studies have been reported. The up-to-date advances in bioelectrochemical applications of multienzyme bioelectrodes are also presented. Finally, key challenges and future perspectives are discussed.
基金Supported by Infectious Diseases Special Project,Minister of Health of China(2008ZX10004-001)
文摘In February 2006,a large amount of unknown floating microorganisms appeared in the Hailang River(HR) in the City of Hailin,Heilongjiang Province,China.The microorganisms caused the river water fouling and threatened the clean water supply of the city.To identify the unknown floating organisms,morphological and histological inspection,PCR,cloning and sequence analysis were conducted.The results revealed that the unknown floating organisms in the river were a novel species that likely belonged to oomycetes in Saprolegniales.The organisms were named Saprolegnia sp.HL0602.
基金Supported by the National Basic Research Program of China(973 Program)(Nos.2011CB409801,2014CB441502)
文摘The composition and compound-specific isotopes of fatty acids were studied within food webs in the East China Sea.Lipid-normalized stable carbon isotopes of total organic carbon had a good correlation with trophic level.Variations in fatty acid compositions among different species were observed but were unclear.Different dietary structures could be traced from molecular isotopes of selected fatty acids in the Shiba shrimp(Matapenaeus joyneri),the coastal mud shrimp(Solenocera crassicomis) and the northern Maoxia shrimp(Acetes chinensis).Both M.joyneri and S.crassicomis are mainly benthos feeders,while A.chinensis is a pelagic species,although they have a similar fatty acid composition.There was a good correlation for isotopes of arachidonic acid(C20:4n6;ARA) and docosahexaenoic acid(C22:6n3;DHA)among pelagic species from higher trophic levels.The isotopic compositions of DHA in benthic species were more negative than those of pelagic species at the same trophic level.The fact that the diet of benthic species contains more degraded items,the carbon isotopes of which are derived from a large biochemical fraction,may be the reason for this variation.A comparative study of benthic and pelagic species demonstrated the different carbon sources in potential food items and the presence of a more complex system at the watersediment interface.
