现有交通信号灯控制策略大多针对单一交叉口展开分析,该策略仅考虑车流量的单一因素,难以适应动态的路网状态。对此,提出了一种结合模糊控制的深度强化学习交通灯控制策略,利用SAC(soft actor critic)深度强化学习对两交叉口的交通信号...现有交通信号灯控制策略大多针对单一交叉口展开分析,该策略仅考虑车流量的单一因素,难以适应动态的路网状态。对此,提出了一种结合模糊控制的深度强化学习交通灯控制策略,利用SAC(soft actor critic)深度强化学习对两交叉口的交通信号灯相位选择及配时进行联合优化,同时考虑车辆速度、路段车辆排队长度等因素,利用模糊控制对SAC的惩罚函数进行处理。实验结果表明,与固定循环周期策略、SAC控制策略和DDPG(deep deterministic policy gradient)控制策略相比,提出的交通信号灯控制策略能获得更快的车辆通行速度,车辆的油耗和尾气排放情况也得到了改善。展开更多
Hawthorns are important medicinal and edible plants with a long history of health protection in China.Besides cultivated hawthorn,other wild hawthorns may also have excellent medicinal and edible value,such as Crataeg...Hawthorns are important medicinal and edible plants with a long history of health protection in China.Besides cultivated hawthorn,other wild hawthorns may also have excellent medicinal and edible value,such as Crataegus chungtienensis,an endemic species distributed in the Southwest of China.In this study,by integrating the flavor-related metabolome and transcriptome data of the ripening fruit of C.chungtienensis,we have developed an understanding of the formation of hawthorn fruit quality.The results show that a total of 849 metabolites were detected in the young and mature fruit of C.chungtienensis,of which flavonoids were the most detected metabolites.Among the differentially accumulated metabolites,stachyose,maltotetraose and cis-aconitic acid were significantly increased during fruit ripening,and these may be important metabolites affecting fruit flavor change.Moreover,several flavonoids and terpenoids were reduced after fruit ripening compared with young fruit.Therefore,using the unripe fruit of C.chungtienensis may allow us to obtain more medicinal active ingredients such as flavonoids and terpenoids.Furthermore,we screened out some differentially expressed genes(DEGs)related to fruit quality formation,which had important relationships with differentially accumulated sugars,acids,flavonoids and terpenoids.Our study provides new insights into flavor formation in wild hawthorn during fruit development and ripening,and at the same time this study lays the foundation for the improvement of hawthorn fruit flavor.展开更多
Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenoli...Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenolics.However,their origin,evolution,and differential roles during plant development and land colonization are unclear.We performed the phylogeny,domain,amino acids,compositional biases,and intron analyses to clarify the origin and evolution of COs and LACs,and analysed the structure,selective pressure,and chloroplast targeting to understand the species-dependent distribution of COs.We found that Streptophyta COs were not homologous to the Chlorophyta tyrosinases(TYRs),and might have been acquired by horizontal gene transfer from bacteria.COs expanded in bryophytes.Structural-functionality and selective pressure were partially responsible for the species-dependent retention of COs in embryophytes.LACs emerged in Zygnemaphyceae,having evolved from ascorbate oxidases(AAOs),and prevailed in the vascular plants and strongly expanded in seed plants.COs and LACs coevolved with the phenolic metabolism pathway genes.These results suggested that TYRs and AAOs were the first-stage phenoloxidases in Chlorophyta.COs might be the second key for the early land colonization.LACs were the third one(dominating in the vascular plants)and might be advantageous for diversified phenol substrates and the erect growth of plants.This work provided new insights into how phenoloxidases evolved and were devoted to plant evolution.展开更多
Novel promoters that confer root-specific expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain rea...Novel promoters that confer root-specific expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-specific expression in rice. The isolation and characterization of upstream promoter regions of five selected genes rice root-specific promoter （rRSP） 1 to 5 （rRSP1-rRSP5） and A2P （the promoter of OsAct2） revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-specific activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-specific enhancement of target gene（s）.展开更多
Software-defined networks (SDN) have been widely used in Cloud Data Centers in recent years. With the development of cloud technologies, different organizations need to share network resources to achieve common busine...Software-defined networks (SDN) have been widely used in Cloud Data Centers in recent years. With the development of cloud technologies, different organizations need to share network resources to achieve common business goals, which requires distributed SDN controllers to collaboratively manage cloud networks and realize cross-domain routing. However, existing distributed controller cooperative routing schemes require a third-party trust center to establish trusted relationships for controllers. Since both trust centers and certified entities are vulnerable to various attacks and security risks, the existing works cannot effectively ensure cross-domain routing is credible. To address this problem, Blockchain is employed to establish trusted relationships between distributed controllers, then a cross-domain routing mechanism was devised based on the trusted relationships. Security analysis and experiments indicate that the proposed scheme can establish trust relationships and provide credible cross-domain routing cooperation for distributed SDN controllers. Besides, the required overhead of storage and bandwidth are very limited, which implies good practicability.展开更多
Although PD-L1/PD-1 blockade therapy has been approved to treat many types of cancers,the majority of patients with solid tumors do not respond well,but the underlying reason remains unclear.Here,we studied ovarian ca...Although PD-L1/PD-1 blockade therapy has been approved to treat many types of cancers,the majority of patients with solid tumors do not respond well,but the underlying reason remains unclear.Here,we studied ovarian cancer(OvCa),a tumor type generally resistant to current immunotherapies,to investigate PD-1-independent immunosuppression.We found that PD-L1 was not highly expressed in the tumor microenvironment(TME)of human OvCa.Instead,B7-H3,another checkpoint molecule,was highly expressed by both tumor cells and tumor-infiltrating antigen-presenting cells(APCs),which correlated with T-cell exhaustion in patients.Using ID8 OvCa mouse models,we found that B7-H3 expressed on tumor cells,but not host cells,had a dominant role in suppressing antitumor immunity.Therapeutically,B7-H3 blockade,but not PD-1 blockade,prolonged the survival of ID8 tumorbearing mice.Collectively,our results demonstrate that tumor-expressed B7-H3 inhibits the function of CD8^(+)T cells and suggest that B7-H3 may be a target in patients who are not responsive to PD-L1/PD-1 inhibition,particularly OvCa patients.展开更多
Cultivated hawthorn(Crataegus pinnatifida var.major)is an important medicinal and edible plant with a long history of use for health protection in China.Herein,we provide a de novo chromosomelevel genome sequence of t...Cultivated hawthorn(Crataegus pinnatifida var.major)is an important medicinal and edible plant with a long history of use for health protection in China.Herein,we provide a de novo chromosomelevel genome sequence of the hawthorn cultivar“Qiu Jinxing.”We assembled an 823.41 Mb genome encoding 40571 genes and further anchored the779.24 Mb sequence into 17 pseudo-chromosomes,which account for 94.64%of the assembled genome.Phylogenomic analyses revealed that cultivated hawthorn diverged from other species within the Maleae(apple tribe)at approximately 35.4 Mya.Notably,genes involved in the flavonoid and triterpenoid biosynthetic pathways have been significantly amplified in the hawthorn genome.In addition,our results indicated that the Maleae share a unique ancient tetraploidization event;however,no recent independent whole-genome duplication event was specifically detected in hawthorn.The amplification of non-specific long terminal repeat retrotransposons contributed the most to the expansion of the hawthorn genome.Furthermore,we identified two paleo-sub-genomes in extant species of Maleae and found that these two sub-genomes showed different rearrangement mechanisms.We also reconstructed the ancestral chromosomes of Rosaceae and discussed two possible paleopolyploid origin patterns(autopolyploidization or allopolyploidization)of Maleae.Overall,our study provides an improved context for understanding the evolution of Maleae species,and this new highquality reference genome provides a useful resource for the horticultural improvement of hawthorn.展开更多
基金supported by the National Natural Science Foundation of China(32260094,32060237 to T.Z.,82260739 to G.L.,and 32060085 to Q.Q.)the Major Science and Technology Project of Yunnan Province(202102AE090031)to G.L.
文摘Hawthorns are important medicinal and edible plants with a long history of health protection in China.Besides cultivated hawthorn,other wild hawthorns may also have excellent medicinal and edible value,such as Crataegus chungtienensis,an endemic species distributed in the Southwest of China.In this study,by integrating the flavor-related metabolome and transcriptome data of the ripening fruit of C.chungtienensis,we have developed an understanding of the formation of hawthorn fruit quality.The results show that a total of 849 metabolites were detected in the young and mature fruit of C.chungtienensis,of which flavonoids were the most detected metabolites.Among the differentially accumulated metabolites,stachyose,maltotetraose and cis-aconitic acid were significantly increased during fruit ripening,and these may be important metabolites affecting fruit flavor change.Moreover,several flavonoids and terpenoids were reduced after fruit ripening compared with young fruit.Therefore,using the unripe fruit of C.chungtienensis may allow us to obtain more medicinal active ingredients such as flavonoids and terpenoids.Furthermore,we screened out some differentially expressed genes(DEGs)related to fruit quality formation,which had important relationships with differentially accumulated sugars,acids,flavonoids and terpenoids.Our study provides new insights into flavor formation in wild hawthorn during fruit development and ripening,and at the same time this study lays the foundation for the improvement of hawthorn fruit flavor.
基金This work received financial support from the National Natural Science Foundation in China(Grant No.32060175 and 32060043)Fundamental Research Projects of Yunnan Province(2022530401740002).
文摘Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenolics.However,their origin,evolution,and differential roles during plant development and land colonization are unclear.We performed the phylogeny,domain,amino acids,compositional biases,and intron analyses to clarify the origin and evolution of COs and LACs,and analysed the structure,selective pressure,and chloroplast targeting to understand the species-dependent distribution of COs.We found that Streptophyta COs were not homologous to the Chlorophyta tyrosinases(TYRs),and might have been acquired by horizontal gene transfer from bacteria.COs expanded in bryophytes.Structural-functionality and selective pressure were partially responsible for the species-dependent retention of COs in embryophytes.LACs emerged in Zygnemaphyceae,having evolved from ascorbate oxidases(AAOs),and prevailed in the vascular plants and strongly expanded in seed plants.COs and LACs coevolved with the phenolic metabolism pathway genes.These results suggested that TYRs and AAOs were the first-stage phenoloxidases in Chlorophyta.COs might be the second key for the early land colonization.LACs were the third one(dominating in the vascular plants)and might be advantageous for diversified phenol substrates and the erect growth of plants.This work provided new insights into how phenoloxidases evolved and were devoted to plant evolution.
基金supported by the National Natural Science Foundation of China (31271694)the National Transgenic Plant Program of China (2011ZX08001-003)
文摘Novel promoters that confer root-specific expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-specific expression in rice. The isolation and characterization of upstream promoter regions of five selected genes rice root-specific promoter （rRSP） 1 to 5 （rRSP1-rRSP5） and A2P （the promoter of OsAct2） revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-specific activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-specific enhancement of target gene（s）.
基金National Natural Science Foundation of China (Grant Nos. U1708262, U1736203, 61772173, 61672413)ational Key R&D Program of China (2017YFB0801805)he Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University.
文摘Software-defined networks (SDN) have been widely used in Cloud Data Centers in recent years. With the development of cloud technologies, different organizations need to share network resources to achieve common business goals, which requires distributed SDN controllers to collaboratively manage cloud networks and realize cross-domain routing. However, existing distributed controller cooperative routing schemes require a third-party trust center to establish trusted relationships for controllers. Since both trust centers and certified entities are vulnerable to various attacks and security risks, the existing works cannot effectively ensure cross-domain routing is credible. To address this problem, Blockchain is employed to establish trusted relationships between distributed controllers, then a cross-domain routing mechanism was devised based on the trusted relationships. Security analysis and experiments indicate that the proposed scheme can establish trust relationships and provide credible cross-domain routing cooperation for distributed SDN controllers. Besides, the required overhead of storage and bandwidth are very limited, which implies good practicability.
基金The authors are grateful to Dr.Xueguang Zhang(Soochow University,China)and Jiajia Li(Fudan University Shanghai Cancer Center)for providing the mouse and human OvCa cell lines.This project was funded in part by the Key Program of the National Natural Science Foundation of China(81730039&81671460 to L.-P.J.)the National Key Research and Development Program of China(2017YFC1001401 to L.-P.J.)+2 种基金Beijing Municipal Science and Technology Projects(Z181100006318015 and Z181100001318007 to C.D.)Shanghai Municipal Medical and Health Discipline Construction Projects(2017ZZ02015 to L.-P.J.)the National Basic Research Program of China(2015CB943300 to L.-P.J.).
文摘Although PD-L1/PD-1 blockade therapy has been approved to treat many types of cancers,the majority of patients with solid tumors do not respond well,but the underlying reason remains unclear.Here,we studied ovarian cancer(OvCa),a tumor type generally resistant to current immunotherapies,to investigate PD-1-independent immunosuppression.We found that PD-L1 was not highly expressed in the tumor microenvironment(TME)of human OvCa.Instead,B7-H3,another checkpoint molecule,was highly expressed by both tumor cells and tumor-infiltrating antigen-presenting cells(APCs),which correlated with T-cell exhaustion in patients.Using ID8 OvCa mouse models,we found that B7-H3 expressed on tumor cells,but not host cells,had a dominant role in suppressing antitumor immunity.Therapeutically,B7-H3 blockade,but not PD-1 blockade,prolonged the survival of ID8 tumorbearing mice.Collectively,our results demonstrate that tumor-expressed B7-H3 inhibits the function of CD8^(+)T cells and suggest that B7-H3 may be a target in patients who are not responsive to PD-L1/PD-1 inhibition,particularly OvCa patients.
基金supported by grants from National Natural Science Foundation of China(32060237 to T.Z.and 32060085 to Q.Q.)funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(No.833522)from Ghent University(Methusalem funding,BOF.MET.2021.0005.01)。
文摘Cultivated hawthorn(Crataegus pinnatifida var.major)is an important medicinal and edible plant with a long history of use for health protection in China.Herein,we provide a de novo chromosomelevel genome sequence of the hawthorn cultivar“Qiu Jinxing.”We assembled an 823.41 Mb genome encoding 40571 genes and further anchored the779.24 Mb sequence into 17 pseudo-chromosomes,which account for 94.64%of the assembled genome.Phylogenomic analyses revealed that cultivated hawthorn diverged from other species within the Maleae(apple tribe)at approximately 35.4 Mya.Notably,genes involved in the flavonoid and triterpenoid biosynthetic pathways have been significantly amplified in the hawthorn genome.In addition,our results indicated that the Maleae share a unique ancient tetraploidization event;however,no recent independent whole-genome duplication event was specifically detected in hawthorn.The amplification of non-specific long terminal repeat retrotransposons contributed the most to the expansion of the hawthorn genome.Furthermore,we identified two paleo-sub-genomes in extant species of Maleae and found that these two sub-genomes showed different rearrangement mechanisms.We also reconstructed the ancestral chromosomes of Rosaceae and discussed two possible paleopolyploid origin patterns(autopolyploidization or allopolyploidization)of Maleae.Overall,our study provides an improved context for understanding the evolution of Maleae species,and this new highquality reference genome provides a useful resource for the horticultural improvement of hawthorn.
