In five-axis machining,tool orientation above a blade stream surface may lead to tool collision and a decrease in workpiece rigidity.Hence,collisionless tool orientation smoothing(TOS)becomes an important issue.On the...In five-axis machining,tool orientation above a blade stream surface may lead to tool collision and a decrease in workpiece rigidity.Hence,collisionless tool orientation smoothing(TOS)becomes an important issue.On the basis of a constant scallop height tool path,the triangular facets in the faces,vertices format are constructed from cutter contact(CC)using the Voronoi incremental algorithm.The cutter location(CL)points candidate set is represented by an oblique elliptic cone whose vertex lies at CC using NURBS envelope.Whether the CL point is above its CC is judged by the dot product between the normal vector and the point on triangulation nearest to the CL point.The curvatures at CC are obtained by fitting a moving least square(MLS) quadratic patch to the local neighborhood of a vertex and calculating eigenvectors and eigenvalues of the Hessian matrix.Triangular surface elastic energy is employed as the weight in selection from the NURBS envelope.The collision is judged by NURBS surface intersection.TOS can then be expressed by selecting a CL point for each CC point and converted into a numerical control(NC)code automatically according to the postprocessor type of the machine center.The proposed method is verified by finishing of a cryogenic turboexpander impeller of air separation equipment.展开更多
Background:The potential human-to-human transmission of the coronavirus pneumonia(coronavirus disease 2019[COVID-19])has caused an outbreak of acute respiratory illness.Xuebijing injection is recommended as first-line...Background:The potential human-to-human transmission of the coronavirus pneumonia(coronavirus disease 2019[COVID-19])has caused an outbreak of acute respiratory illness.Xuebijing injection is recommended as first-line treatment for the severe and critical patients with COVID-19.The aim of present study is to interpret the pharmacological mechanisms and molecular connections of Xuebijing injection against COVID-19 by utilizing the approaches of network pharmacology and molecular docking.Materials and Methods:Active ingredients of Xuebijing injection were collected by Traditional Chinese Medicine Systems Pharmacology(TCMSP)database,and putative therapeutic targets were screened from TCMSP,Swiss Target Prediction,and STITCH databases.Moreover,the protein–protein interactions,topological analysis,and pathway enrichment were established to distinguish the hub targets and pathways by employing STRING database,Cytoscape software,DAVID database,respectively.In addition,the potential interaction and binding activity of candidate ingredients in Xuebijing injection with core targets were revealed by molecular docking simulation(Auto Dock software).Results:A total of 115 bioactive components in Xuebijing injection were collected,and416 targets including AKT1,TP53,VEGFA,ALB,TNF and so on were responsible for treating COVID-19.Bioinformatics analysis revealed that matching core targets were closely associated with the inhibition of cytokine storm for its clinical beneficial effects in severe cases.The results of enrichment analysis indicated that PI3 K-Akt signaling pathway,human T-cell leukemia virus type 1 infection,mitogen-activated protein kinase signaling pathway,tuberculosis,focal adhesion,TNF signaling pathway,and small-cell lung cancer were represented pathways of Xuebijing injection against COVID-19 in terms of lung inflammation,virus infection,and lung injury.Meanwhile,the active ingredients of Xuebijing injection exerted superior binding activities with 3 CLpro and angiotensin-converting enzyme 2 as observed via molecular docking simulation.Conclusions:Through the comprehensive analysis of network pharmacology,the current research preliminarily elaborated the molecular regulation of therapeutic mechanisms for Xuebijing injection against COVID-19 and binding activity between active components and core targets,which provided scientific evidence to facilitate the development of Xuebijing injection and clinical treatment for COVID-19.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 2011CB706506)the National Science and Technology Major Project of China (Nos. 2011ZX04014-131 and 2012ZX04010 011)the National Science Foundation for Young Scholars of China (No. 51005204)
文摘In five-axis machining,tool orientation above a blade stream surface may lead to tool collision and a decrease in workpiece rigidity.Hence,collisionless tool orientation smoothing(TOS)becomes an important issue.On the basis of a constant scallop height tool path,the triangular facets in the faces,vertices format are constructed from cutter contact(CC)using the Voronoi incremental algorithm.The cutter location(CL)points candidate set is represented by an oblique elliptic cone whose vertex lies at CC using NURBS envelope.Whether the CL point is above its CC is judged by the dot product between the normal vector and the point on triangulation nearest to the CL point.The curvatures at CC are obtained by fitting a moving least square(MLS) quadratic patch to the local neighborhood of a vertex and calculating eigenvectors and eigenvalues of the Hessian matrix.Triangular surface elastic energy is employed as the weight in selection from the NURBS envelope.The collision is judged by NURBS surface intersection.TOS can then be expressed by selecting a CL point for each CC point and converted into a numerical control(NC)code automatically according to the postprocessor type of the machine center.The proposed method is verified by finishing of a cryogenic turboexpander impeller of air separation equipment.
基金supported by the National Natural Science Foundation of China to BZ(Grant No.81874349)the Programs Foundation for Leading Talents in State Administration of TCM of China-“Qihuang scholars”Project(10400633210004)the National Special Support Plan for High-level Talents(Plan of ten thousand people),Famous Teacher Program to Professor Bing Zhang。
文摘Background:The potential human-to-human transmission of the coronavirus pneumonia(coronavirus disease 2019[COVID-19])has caused an outbreak of acute respiratory illness.Xuebijing injection is recommended as first-line treatment for the severe and critical patients with COVID-19.The aim of present study is to interpret the pharmacological mechanisms and molecular connections of Xuebijing injection against COVID-19 by utilizing the approaches of network pharmacology and molecular docking.Materials and Methods:Active ingredients of Xuebijing injection were collected by Traditional Chinese Medicine Systems Pharmacology(TCMSP)database,and putative therapeutic targets were screened from TCMSP,Swiss Target Prediction,and STITCH databases.Moreover,the protein–protein interactions,topological analysis,and pathway enrichment were established to distinguish the hub targets and pathways by employing STRING database,Cytoscape software,DAVID database,respectively.In addition,the potential interaction and binding activity of candidate ingredients in Xuebijing injection with core targets were revealed by molecular docking simulation(Auto Dock software).Results:A total of 115 bioactive components in Xuebijing injection were collected,and416 targets including AKT1,TP53,VEGFA,ALB,TNF and so on were responsible for treating COVID-19.Bioinformatics analysis revealed that matching core targets were closely associated with the inhibition of cytokine storm for its clinical beneficial effects in severe cases.The results of enrichment analysis indicated that PI3 K-Akt signaling pathway,human T-cell leukemia virus type 1 infection,mitogen-activated protein kinase signaling pathway,tuberculosis,focal adhesion,TNF signaling pathway,and small-cell lung cancer were represented pathways of Xuebijing injection against COVID-19 in terms of lung inflammation,virus infection,and lung injury.Meanwhile,the active ingredients of Xuebijing injection exerted superior binding activities with 3 CLpro and angiotensin-converting enzyme 2 as observed via molecular docking simulation.Conclusions:Through the comprehensive analysis of network pharmacology,the current research preliminarily elaborated the molecular regulation of therapeutic mechanisms for Xuebijing injection against COVID-19 and binding activity between active components and core targets,which provided scientific evidence to facilitate the development of Xuebijing injection and clinical treatment for COVID-19.
