Endorepellin plays a key role in the regulation of angiogenesis,but its effects on angiogenesis after traumatic brain injury are unclear.This study explored the effects of endorepellin on angiogenesis and neurobehavio...Endorepellin plays a key role in the regulation of angiogenesis,but its effects on angiogenesis after traumatic brain injury are unclear.This study explored the effects of endorepellin on angiogenesis and neurobehavioral outcomes after traumatic brain injury in mice.Mice were randomly divided into four groups:sham,controlled cortical impact only,adeno-associated virus(AAV)-green fluorescent protein,and AAV-shEndorepellin-green fluorescent protein groups.In the controlled cortical impact model,the transduction of AAV-shEndorepellin-green fluorescent protein downregulated endorepellin while increasing the number of CD31+/Ki-67+proliferating endothelial cells and the functional microvessel density in mouse brain.These changes resulted in improved neurological function compared with controlled cortical impact mice.Western blotting revealed increased expression of vascular endothelial growth factor and angiopoietin-1 in mice treated with AAV-shEndorepellin-green fluorescent protein.Synchrotron radiation angiography showed that endorepellin downregulation promoted angiogenesis and increased cortical neovascularization,which may further improve neurobehavioral outcomes.Furthermore,an in vitro study showed that downregulation of endorepellin increased tube formation by human umbilical vein endothelial cells compared with a control.Mechanistic analysis found that endorepellin downregulation may mediate angiogenesis by activating vascular endothelial growth factor-and angiopoietin-1-related signaling pathways.展开更多
Despite the industrial significance of grain size for enhancing mechanical properties and formability,the in-depth deformation mechanisms at elevated temperature are still unclear.To investigate the functions of grain...Despite the industrial significance of grain size for enhancing mechanical properties and formability,the in-depth deformation mechanisms at elevated temperature are still unclear.To investigate the functions of grain size on hot workability and deformation mechanisms,three groups of Mg-1.2Zn-0.2Y alloy specimens with different grain sizes were hot compressed and then studied by combining constitutive model,processing map and microstructural observations.The results showed that the enhanced hot workability accompanying low deformation activation energy and small instability regime was obtained with refined grain size.During hot deformation,the decreased grain size in Mg1.2Zn-0.2Y alloy mainly improved the plastic deformation homogeneity,especially for the weakened local straining around grain boundaries.As a result,the dynamic recrystallization nucleation and texture development at lower strain level were influenced by the initial grain size.At higher strain magnitude,the growth and coarsening of dynamic recrystallized grains would further release strain localization and improve hot workability,while the texture was less impacted.Further,unlike the primary basal slip and deformation twinning in the specimen with coarse grain at low temperature,non-basal slips of dislocations were initiated with less deformation twins in the specimens with refined grain size.展开更多
In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/wa...In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/water suspensions were chosen as the subject of this research. The particulate fouling characteristics of γ-Al_2O_3/water suspensions on the surface of stainless steel have been experimentally studied by varying the heat flux and the inlet temperature under single-phase flow and subcooled-flow boiling conditions. The results show that in the condition of single-phase flow, the asymptotic value of fouling resistance decreases with increasing of heat flux and inlet temperature. The asymptotic value of fouling resistance under single-phase flow is much higher than for the subcooled-flow boiling condition. The effect of heat flux on the fouling resistance under the two flow states has an inverse relationship, and there exists a minimum value of fouling resistance between these two states. For subcooled-flow boiling, the asymptotic value of fouling resistance increases with increasing heat flux, whereas the effect on fouling resistance by the inlet temperature is negligible.展开更多
A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by posi...A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by positive-and negative-ion electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results of negative-ion ESI FT-ICR MS showed that the N1 class species was the most abundant and the multifunctional group compounds,such as N1 O1,N1 O2,N1 S1,N1 S2,and N2 class species became abundant as the SFEF fraction became heavier.In positive-ion ESI mode,the relative abundance of N1 class species decreased gradually in the heavy SFEF fractions while that of multifunctional group compounds increased.The relative abundance of N4 V1 O1 increased dramatically in heavy fractions and the end-cut.The distributions of polar heteroatom species of VR derived from oilsands bitumen were similar with those of VR derived from the Venezuela Orinoco extra heavy oil.展开更多
Objective:To investigate the differences in small intestinal toxicity and taxonomic composition,diversity,and functional pathways of gut microbiome and metabolome after different radiotherapies in mouse colorectal can...Objective:To investigate the differences in small intestinal toxicity and taxonomic composition,diversity,and functional pathways of gut microbiome and metabolome after different radiotherapies in mouse colorectal cancer(CRC)model.Methods:Azoxymethane/dextran sodium sulfate(AOM/DSS)-induced mouse CRC model was treated with single pulse FLASH-RT(dose rate 100 Gy/s)or CONV-RT(dose rate 2 Gy/min)at whole abdomen.At 12 d after radiotherapy,sections of small intestinal tract tissue were dissected for hematoxylin and eosin(HE)staining and the fresh feces were collected for 16S ribosomal RNA(rRNA)microbiome sequencing and liquid chromatography and mass spectrometry(LC-MS)metabolomics sequencing to assess changes in the gut microbiota and metabolites.Microbial high-throughput 16S rRNA data was analyzed with QIIME2 and LEfSe softwares.ProteoWizard,XCMS and Ropls softwares were used for LC-MS analysis.Results:HE staining showed that FLASH-RT maintained small intestinal integrity and reduced the radiotherapyinduced injury.Sequencing analysis of gut fecal microbiome showed that phylum Bacteroidetes and genera Prevotella and Lactobacillus of microbial community were increased after FLASH-RT.Metabolomics sequencing analysis revealed that the metabolites after FLASH-RT were enriched in amino acid metabolism,while cholesterol metabolism was top enriched after CONV-RT.Conclusions:FLASH-RT significantly mitigates the small intestine tissue damage compared with CONV-RT.FLASHRT and CONV-RT have different impact on gut microbiota and its metabolites.Our results provide a theoretical basis for the early evaluation,prediction and individualized treatment of the irradiation effect after novel FLASHRT on tumors through the evaluation of intestinal microbiota and metabolites.展开更多
An integrated Eulerian model for fouling in turbulent flow was developed to simulate the particle fouling charac-teristics.The model comprises a deposition process and removal process.The deposition process considers ...An integrated Eulerian model for fouling in turbulent flow was developed to simulate the particle fouling charac-teristics.The model comprises a deposition process and removal process.The deposition process considers four various factors affecting the particle deposition which are Brownian and eddy diffusion,gravity,thermophoretic,and turbophoretic forces.This study compares the Lagrangian and Eulerian approaches under the same operat-ing conditions with an emphasis on their performance in predicting particle deposition.The deposition height calculated by using the Eulerian approach is in good agreement with the experimental data and the deposition morphology is similar to that observed in experiments.Furthermore,this paper explores the deposition charac-teristics and predicts the deposition morphology under different particle sizes.展开更多
This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. pr...This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. programming and concave optimization over a polyhedron. Considering that the super-level sets of concave piecewise linear functions are polyhedra, we propose the Hill Tunneling via Weighted Simplex Centroid(HTWSC) algorithm, which can escape a local optimum to reach the other side of its contour surface by cutting across the super-level set. The searching path for hill tunneling is established via the weighted centroid of a constructed simplex. In the numerical experiments, different weighting methods are studied first, and the best is chosen for the proposed HTWSC algorithm. Then, the HTWSC algorithm is compared with the hill detouring method and the software CPLEX for the equivalent mixed integer programming, with results indicating its superior performance in terms of numerical efficiency and the global search capability.展开更多
This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear(CPWL) programming with generalization of hinging hyperplane objective and linear constraints. CPWL programmin...This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear(CPWL) programming with generalization of hinging hyperplane objective and linear constraints. CPWL programming is popular since it can be equivalently transformed into difference of convex functions programming or concave optimization. Inspired by the concavity of the concave CPWL functions, we propose an Objective Variation Simplex Algorithm(OVSA), which is able to find a local optimum in a reasonable time. Computational results are presented for further insights into the performance of the OVSA compared with two other algorithms on random test problems.展开更多
In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l_0 norm minimization problem. In this pa...In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l_0 norm minimization problem. In this paper, we equivalently transform the l_0 norm minimization into a concave continuous piecewise linear programming,and propose an optimization algorithm based on a modified interior point method. Numerical experiments demonstrate that our algorithm improves the sufficient number of measurements, relaxes the restrictions of the sensing matrix to some extent, and performs robustly in the noisy scenarios.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81801236(to ZX),81974189(to HT)a grant from Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,No.ynlc201719(to QZ).
文摘Endorepellin plays a key role in the regulation of angiogenesis,but its effects on angiogenesis after traumatic brain injury are unclear.This study explored the effects of endorepellin on angiogenesis and neurobehavioral outcomes after traumatic brain injury in mice.Mice were randomly divided into four groups:sham,controlled cortical impact only,adeno-associated virus(AAV)-green fluorescent protein,and AAV-shEndorepellin-green fluorescent protein groups.In the controlled cortical impact model,the transduction of AAV-shEndorepellin-green fluorescent protein downregulated endorepellin while increasing the number of CD31+/Ki-67+proliferating endothelial cells and the functional microvessel density in mouse brain.These changes resulted in improved neurological function compared with controlled cortical impact mice.Western blotting revealed increased expression of vascular endothelial growth factor and angiopoietin-1 in mice treated with AAV-shEndorepellin-green fluorescent protein.Synchrotron radiation angiography showed that endorepellin downregulation promoted angiogenesis and increased cortical neovascularization,which may further improve neurobehavioral outcomes.Furthermore,an in vitro study showed that downregulation of endorepellin increased tube formation by human umbilical vein endothelial cells compared with a control.Mechanistic analysis found that endorepellin downregulation may mediate angiogenesis by activating vascular endothelial growth factor-and angiopoietin-1-related signaling pathways.
基金supported by the National Natural Science Foundation of China(51774124,52074114)Hunan Provincial Natural Science Foundation of China(2019JJ40017,2020JJ5062)+1 种基金Key Technologies R&D in Strategic Emerging Industries and Transformation in High-tech Achievements Program of Hunan Province(2019GK4045)Graduate Training and Innovation Practice Base of Hunan Province.
文摘Despite the industrial significance of grain size for enhancing mechanical properties and formability,the in-depth deformation mechanisms at elevated temperature are still unclear.To investigate the functions of grain size on hot workability and deformation mechanisms,three groups of Mg-1.2Zn-0.2Y alloy specimens with different grain sizes were hot compressed and then studied by combining constitutive model,processing map and microstructural observations.The results showed that the enhanced hot workability accompanying low deformation activation energy and small instability regime was obtained with refined grain size.During hot deformation,the decreased grain size in Mg1.2Zn-0.2Y alloy mainly improved the plastic deformation homogeneity,especially for the weakened local straining around grain boundaries.As a result,the dynamic recrystallization nucleation and texture development at lower strain level were influenced by the initial grain size.At higher strain magnitude,the growth and coarsening of dynamic recrystallized grains would further release strain localization and improve hot workability,while the texture was less impacted.Further,unlike the primary basal slip and deformation twinning in the specimen with coarse grain at low temperature,non-basal slips of dislocations were initiated with less deformation twins in the specimens with refined grain size.
基金Supported by the National Natural Science Foundation of China(51476025)
文摘In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/water suspensions were chosen as the subject of this research. The particulate fouling characteristics of γ-Al_2O_3/water suspensions on the surface of stainless steel have been experimentally studied by varying the heat flux and the inlet temperature under single-phase flow and subcooled-flow boiling conditions. The results show that in the condition of single-phase flow, the asymptotic value of fouling resistance decreases with increasing of heat flux and inlet temperature. The asymptotic value of fouling resistance under single-phase flow is much higher than for the subcooled-flow boiling condition. The effect of heat flux on the fouling resistance under the two flow states has an inverse relationship, and there exists a minimum value of fouling resistance between these two states. For subcooled-flow boiling, the asymptotic value of fouling resistance increases with increasing heat flux, whereas the effect on fouling resistance by the inlet temperature is negligible.
文摘A Canadian in situ oilsands bitumen-derived vacuum residue(VR)was subjected to supercritical fluid extraction and fractionation(SFEF)into 13 extractable fractions and an unextractable end-cut and characterized by positive-and negative-ion electrospray ionization(ESI)Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS).The results of negative-ion ESI FT-ICR MS showed that the N1 class species was the most abundant and the multifunctional group compounds,such as N1 O1,N1 O2,N1 S1,N1 S2,and N2 class species became abundant as the SFEF fraction became heavier.In positive-ion ESI mode,the relative abundance of N1 class species decreased gradually in the heavy SFEF fractions while that of multifunctional group compounds increased.The relative abundance of N4 V1 O1 increased dramatically in heavy fractions and the end-cut.The distributions of polar heteroatom species of VR derived from oilsands bitumen were similar with those of VR derived from the Venezuela Orinoco extra heavy oil.
基金The study was supported by the Project from State Key Laboratory of Radiation Medicine and Protection(GZK1202221)the Nuclear Technology Application Excellent Experts Program of the Second Affiliated Hospital of Soochow University(XKTJ-HRC2021002),China.
文摘Objective:To investigate the differences in small intestinal toxicity and taxonomic composition,diversity,and functional pathways of gut microbiome and metabolome after different radiotherapies in mouse colorectal cancer(CRC)model.Methods:Azoxymethane/dextran sodium sulfate(AOM/DSS)-induced mouse CRC model was treated with single pulse FLASH-RT(dose rate 100 Gy/s)or CONV-RT(dose rate 2 Gy/min)at whole abdomen.At 12 d after radiotherapy,sections of small intestinal tract tissue were dissected for hematoxylin and eosin(HE)staining and the fresh feces were collected for 16S ribosomal RNA(rRNA)microbiome sequencing and liquid chromatography and mass spectrometry(LC-MS)metabolomics sequencing to assess changes in the gut microbiota and metabolites.Microbial high-throughput 16S rRNA data was analyzed with QIIME2 and LEfSe softwares.ProteoWizard,XCMS and Ropls softwares were used for LC-MS analysis.Results:HE staining showed that FLASH-RT maintained small intestinal integrity and reduced the radiotherapyinduced injury.Sequencing analysis of gut fecal microbiome showed that phylum Bacteroidetes and genera Prevotella and Lactobacillus of microbial community were increased after FLASH-RT.Metabolomics sequencing analysis revealed that the metabolites after FLASH-RT were enriched in amino acid metabolism,while cholesterol metabolism was top enriched after CONV-RT.Conclusions:FLASH-RT significantly mitigates the small intestine tissue damage compared with CONV-RT.FLASHRT and CONV-RT have different impact on gut microbiota and its metabolites.Our results provide a theoretical basis for the early evaluation,prediction and individualized treatment of the irradiation effect after novel FLASHRT on tumors through the evaluation of intestinal microbiota and metabolites.
基金supported by the National Key R&D Program of China(2020YFA0308800 and 2021YFA1400100)the National Natural Science Foundation of China(12074212)+7 种基金supported by the National Natural Science Foundation of China(12174214 and 92065205)the National Key R&D Program of China(2018YFA0306504)the Innovation Program for Quantum Science and Technology(2021ZD0302100)supported by the National Natural Science Foundation of China(12274252)the National Key R&D Program of China(2018YFA0307100)supported by the National Natural Science Foundation of China(21975140 and 51991343)Fundamental Research Funds for the Central Universities(Buctrc202212)supported by funds from the University of Toronto。
基金the National Natural Sci-ence Foundation of China(No.51976028)for its financial support.
文摘An integrated Eulerian model for fouling in turbulent flow was developed to simulate the particle fouling charac-teristics.The model comprises a deposition process and removal process.The deposition process considers four various factors affecting the particle deposition which are Brownian and eddy diffusion,gravity,thermophoretic,and turbophoretic forces.This study compares the Lagrangian and Eulerian approaches under the same operat-ing conditions with an emphasis on their performance in predicting particle deposition.The deposition height calculated by using the Eulerian approach is in good agreement with the experimental data and the deposition morphology is similar to that observed in experiments.Furthermore,this paper explores the deposition charac-teristics and predicts the deposition morphology under different particle sizes.
基金jointly supported by the National Key Basic Research and Development (973) Program of China (No. 2012CB720505)the National Natural Science Foundation of China (Nos. 61473165 and 61134012)
文摘This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. programming and concave optimization over a polyhedron. Considering that the super-level sets of concave piecewise linear functions are polyhedra, we propose the Hill Tunneling via Weighted Simplex Centroid(HTWSC) algorithm, which can escape a local optimum to reach the other side of its contour surface by cutting across the super-level set. The searching path for hill tunneling is established via the weighted centroid of a constructed simplex. In the numerical experiments, different weighting methods are studied first, and the best is chosen for the proposed HTWSC algorithm. Then, the HTWSC algorithm is compared with the hill detouring method and the software CPLEX for the equivalent mixed integer programming, with results indicating its superior performance in terms of numerical efficiency and the global search capability.
基金supported by the National Natural Science Foundation of China (Nos. 61473165 and 61134012)the National Key Basic Research and Development (973) Program of China (No. 2012CB720505)
文摘This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear(CPWL) programming with generalization of hinging hyperplane objective and linear constraints. CPWL programming is popular since it can be equivalently transformed into difference of convex functions programming or concave optimization. Inspired by the concavity of the concave CPWL functions, we propose an Objective Variation Simplex Algorithm(OVSA), which is able to find a local optimum in a reasonable time. Computational results are presented for further insights into the performance of the OVSA compared with two other algorithms on random test problems.
基金supported by the National Natural Science Foundation of China(Nos.61473165 and 61134012)the National Key Basic Research and Development(973)Program of China(No.2012CB720505)
文摘In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l_0 norm minimization problem. In this paper, we equivalently transform the l_0 norm minimization into a concave continuous piecewise linear programming,and propose an optimization algorithm based on a modified interior point method. Numerical experiments demonstrate that our algorithm improves the sufficient number of measurements, relaxes the restrictions of the sensing matrix to some extent, and performs robustly in the noisy scenarios.
