In the internet of battlefield things, ammunition is becoming networked and intelligent, which depends on location information. Therefore, this paper focuses on the self-organized network collaborative localization of...In the internet of battlefield things, ammunition is becoming networked and intelligent, which depends on location information. Therefore, this paper focuses on the self-organized network collaborative localization of munitions with an aerial three-dimensional(3D) highly-dynamic topographic structure under a satellite denied environment. As for aerial networked munitions, the measurement of munitions is objectively incomplete due to the degenerated and interrupted link of munitions. For this reason, a cluster-oriented collaborative localization method is put forward in this paper. Multidimensional scaling(MDS) was first integrated with a trilateration localization method(TLM) to construct a relative localization algorithm for determining the relative location of a mobile cluster network. The information related to relative velocity was then combined into a collaborative localization framework to devise a TLM-vMDS algorithm. Finally, an iterative refinement algorithm based on scaling by majorizing a complicated function(SMACOF) was employed to effectively eliminate the influence of incomplete link observation on localization accuracy. Compared with the currently available advanced algorithms, the proposed TLM-vMDS algorithm achieves higher localization accuracy and faster convergence for a cluster of extensively networked munitions, and also offers better numerical stability and robustness for highspeed motion models.展开更多
Dimethyl sulfide(DMS)has been historically recognized as a metabolite of the marine microorganism or a disgusting component for the smell of halitosis patients.In our recent study,DMS has been identified as a cytoprot...Dimethyl sulfide(DMS)has been historically recognized as a metabolite of the marine microorganism or a disgusting component for the smell of halitosis patients.In our recent study,DMS has been identified as a cytoprotectant that protects against oxidative-stress induced cell death and aging.We found that at near-physiological concentrations,DMS reduced reactive oxygen species(ROS)in cultured PC12 cells and alleviated oxidative stress.The radical-scavenging capacity of DMS at near-physiological concentration was equivalent to endogenous methionine(Met)-centered antioxidant defense.Methionine sulfoxidereductase A(MsrA),the key antioxidant enzyme in Met-centered defense,bound to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72,Tyr103,Glu115,followed by the release of dimethyl sulfoxide(DMSO).MTT assay and trypan blue test indicated that supplement of DMS exhibited cytoprotection against 6-hydroxydopamine and MPP+induced cell apoptosis.Furthermore,Msr A knockdown abolished the cytoprotective effect of DMS at near-physiological concentrations.The present study reveals new insight into the potential therapeutic value of DMS in Parkinson disease.展开更多
文摘In the internet of battlefield things, ammunition is becoming networked and intelligent, which depends on location information. Therefore, this paper focuses on the self-organized network collaborative localization of munitions with an aerial three-dimensional(3D) highly-dynamic topographic structure under a satellite denied environment. As for aerial networked munitions, the measurement of munitions is objectively incomplete due to the degenerated and interrupted link of munitions. For this reason, a cluster-oriented collaborative localization method is put forward in this paper. Multidimensional scaling(MDS) was first integrated with a trilateration localization method(TLM) to construct a relative localization algorithm for determining the relative location of a mobile cluster network. The information related to relative velocity was then combined into a collaborative localization framework to devise a TLM-vMDS algorithm. Finally, an iterative refinement algorithm based on scaling by majorizing a complicated function(SMACOF) was employed to effectively eliminate the influence of incomplete link observation on localization accuracy. Compared with the currently available advanced algorithms, the proposed TLM-vMDS algorithm achieves higher localization accuracy and faster convergence for a cluster of extensively networked munitions, and also offers better numerical stability and robustness for highspeed motion models.
文摘Dimethyl sulfide(DMS)has been historically recognized as a metabolite of the marine microorganism or a disgusting component for the smell of halitosis patients.In our recent study,DMS has been identified as a cytoprotectant that protects against oxidative-stress induced cell death and aging.We found that at near-physiological concentrations,DMS reduced reactive oxygen species(ROS)in cultured PC12 cells and alleviated oxidative stress.The radical-scavenging capacity of DMS at near-physiological concentration was equivalent to endogenous methionine(Met)-centered antioxidant defense.Methionine sulfoxidereductase A(MsrA),the key antioxidant enzyme in Met-centered defense,bound to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72,Tyr103,Glu115,followed by the release of dimethyl sulfoxide(DMSO).MTT assay and trypan blue test indicated that supplement of DMS exhibited cytoprotection against 6-hydroxydopamine and MPP+induced cell apoptosis.Furthermore,Msr A knockdown abolished the cytoprotective effect of DMS at near-physiological concentrations.The present study reveals new insight into the potential therapeutic value of DMS in Parkinson disease.
