Objective:To clarify the anti-depressive potential mechanisms of Kaixin Powder(KP),a drug that helps to prevent and treat depression and other mentaldiseases,from genome-wide transcriptome profiling.Methods:Transcript...Objective:To clarify the anti-depressive potential mechanisms of Kaixin Powder(KP),a drug that helps to prevent and treat depression and other mentaldiseases,from genome-wide transcriptome profiling.Methods:Transcriptome and KEGG pathway analysis were conducted on the hippocampus of depressed rats,then the differentially expressed genes were validated and serum concentration of lipid parameters were identified by enzymatic assays.Furthermore,high-fat diets induced depression-like behaviors in Syrian golden hamsters were conducted to verify the predicted molecular mechanisms acquired from the transcriptome analysis.Results:Transcriptome results revealed that the 24 differentially expressed genes(DEGs)in chronic mild stress(CMS)rats could be reversed after two weeks of KP treatment.The mechanisms of KP in treating depression firstly involved the regulation of several pathology modules,including lipid metabolism,synapse function and inflammation.KP could regulate imbalances of lipid homeostasis in high-fat diet induced depressive symptoms.Furthermore,it was validated that cholesterol metabolism dysfunction can be ameliorated by KP,which was correlated with upregulation of the AdipoR1-BDNF(brainderived neurotrophic factor)co-regulatory pathway.Conclusion:Taken together,our results demonstrated that KP not only alleviates depression via traditional mental illness targets,but it may also simulates the cholesterol metabolism and adiponectin signaling with multi-target characteristics.展开更多
Structural optimization technologies are increasingly applied to lightweight automotive structural design.In a body-inwhite(BIW)development project,optimization technologies are applied in three steps that are seamles...Structural optimization technologies are increasingly applied to lightweight automotive structural design.In a body-inwhite(BIW)development project,optimization technologies are applied in three steps that are seamlessly integrated into engineering practice.By following a design-driven approach,an innovative design that was 50.65 kg lighter than the base design was achieved.First,topology optimization was used to investigate the optimal material distribution in a given design space,and helped in extracting the main load path,while considering crashworthiness,NVH,and static stiffness performance requirements.In the second step,the effective design of a beam cross-section and feasible joints was carried out based on optimization technology and expert knowledge.In this step,the deep involvement of manufacturing process experts on stamping and joint connection feasibility analysis increased the chance of success remarkably.The sensitivity analysis,topography optimization,and gauge optimization of the created draft 3D BIW frame comprised the last step before finalizing the initial design.The new design was validated by full load case simulations,including full vehicle crashworthiness analysis,mode frequency,and body mount point dynamic stiffness analysis,and BIW stiffness and component attachment stiffness analysis.The validation results indicate that the new BIW design achieves the performance goal,while being 13.3%lighter than the base design.展开更多
Scallop ice is a special phenomenon that occurs during swept wing aircraft passing through icing clouds.It poses a great challenge for the icing safety assessment that the complex scallop ice shape feature and its mec...Scallop ice is a special phenomenon that occurs during swept wing aircraft passing through icing clouds.It poses a great challenge for the icing safety assessment that the complex scallop ice shape feature and its mechanism are still unclear.In this work,a large-scale icing wind tunnel experiment of swept wing designed by NACA0012 airfoil is conducted in the Icing Wind Tunnel of China Aerodynamics Research and Development Center.The detailed three-dimensional ice shapes under 0°,15°,30°and 45°swept angles are obtained by laser scanning technology.The experimental results show that with the swept angle increasing from 0°to 45°,the 2D double ice horn structures show certain spanwise variation,and finally transform into complete scallop ice with ice thickness greatly enhanced in the stagnation line region.The empirical mode decomposition of the spanwise ice curve captures the high-frequency fluctuation on the scallop ice caused by the small-scale roughness element,while the trend with low frequency is not obvious.Based on the experimental data,a new complete scallop ice geometric model,named 5Points-5Lines-2Arcs(5P-5L-2A)model,is proposed,which can provide important basis for the quantitative description of complex scallop ice shape.展开更多
In situ ultrafine TiC dispersion reinforced Inconel 718 alloy with enhanced mechanical properties was fabricated by the technique of reactive hot-press sintering Ti2AlC and In718 powders.The effect of Ti2AlC precursor...In situ ultrafine TiC dispersion reinforced Inconel 718 alloy with enhanced mechanical properties was fabricated by the technique of reactive hot-press sintering Ti2AlC and In718 powders.The effect of Ti2AlC precursor additions(5 vol.%,10 vol.%,15 vol.%)on microstructure and mechanical properties of TiC/In718 composites were investigated.A relationship of microstructural characteristics,room and elevated temperature mechanical performance,and underlying strengthening mechanisms were analyzed.The results show that initial Ti2AlC precursor transformed completely into ultrafine TiC particulate(~230 nm)and distributed uniformly in the matrix after sintering 5 and 10 vol.%Ti2AlC/In718.However,TiC particulates tended to aggregate to stripes with the addition of Ti2AlC up to 15 vol.%,which,in adverse,weaken the properties of In718.The 5 vol.%Ti2AlC/In718 sample showed a higher tensile strength of 1404±13 MPa with a noticeable elongation of 9.8%at room temperature compared to the pure In718(ultimate tensile strength(UTS)=1310 MPa,elongation=21.5%).At 600℃,700℃,800℃and 900℃,tensile strength of the as-sintered 5 vol.%Ti2AlC/In718 composite was determined to be 1333±13 MPa,1010±10 MPa,685±25 MPa and 276±3 MPa,increased by 9.2%,14.6%,14.2%and 55%,respectively,compared with that of monolithic In718 alloy.The excellent tensile properties of TiC/In718 composite can be ascribed to the combined mechanisms in term of increased dislocation density,dispersive Orowan and load transfer mechanisms.展开更多
基金supported by National Natural Science Foundation of China(No.81573876 and 81973502)。
文摘Objective:To clarify the anti-depressive potential mechanisms of Kaixin Powder(KP),a drug that helps to prevent and treat depression and other mentaldiseases,from genome-wide transcriptome profiling.Methods:Transcriptome and KEGG pathway analysis were conducted on the hippocampus of depressed rats,then the differentially expressed genes were validated and serum concentration of lipid parameters were identified by enzymatic assays.Furthermore,high-fat diets induced depression-like behaviors in Syrian golden hamsters were conducted to verify the predicted molecular mechanisms acquired from the transcriptome analysis.Results:Transcriptome results revealed that the 24 differentially expressed genes(DEGs)in chronic mild stress(CMS)rats could be reversed after two weeks of KP treatment.The mechanisms of KP in treating depression firstly involved the regulation of several pathology modules,including lipid metabolism,synapse function and inflammation.KP could regulate imbalances of lipid homeostasis in high-fat diet induced depressive symptoms.Furthermore,it was validated that cholesterol metabolism dysfunction can be ameliorated by KP,which was correlated with upregulation of the AdipoR1-BDNF(brainderived neurotrophic factor)co-regulatory pathway.Conclusion:Taken together,our results demonstrated that KP not only alleviates depression via traditional mental illness targets,but it may also simulates the cholesterol metabolism and adiponectin signaling with multi-target characteristics.
文摘Structural optimization technologies are increasingly applied to lightweight automotive structural design.In a body-inwhite(BIW)development project,optimization technologies are applied in three steps that are seamlessly integrated into engineering practice.By following a design-driven approach,an innovative design that was 50.65 kg lighter than the base design was achieved.First,topology optimization was used to investigate the optimal material distribution in a given design space,and helped in extracting the main load path,while considering crashworthiness,NVH,and static stiffness performance requirements.In the second step,the effective design of a beam cross-section and feasible joints was carried out based on optimization technology and expert knowledge.In this step,the deep involvement of manufacturing process experts on stamping and joint connection feasibility analysis increased the chance of success remarkably.The sensitivity analysis,topography optimization,and gauge optimization of the created draft 3D BIW frame comprised the last step before finalizing the initial design.The new design was validated by full load case simulations,including full vehicle crashworthiness analysis,mode frequency,and body mount point dynamic stiffness analysis,and BIW stiffness and component attachment stiffness analysis.The validation results indicate that the new BIW design achieves the performance goal,while being 13.3%lighter than the base design.
基金co-supported by the National Natural Science Foundation of China (Nos. 12172372 and 12132019)the National Major Science and Technology Projects of China (No. J2019-III-0010-0054)
文摘Scallop ice is a special phenomenon that occurs during swept wing aircraft passing through icing clouds.It poses a great challenge for the icing safety assessment that the complex scallop ice shape feature and its mechanism are still unclear.In this work,a large-scale icing wind tunnel experiment of swept wing designed by NACA0012 airfoil is conducted in the Icing Wind Tunnel of China Aerodynamics Research and Development Center.The detailed three-dimensional ice shapes under 0°,15°,30°and 45°swept angles are obtained by laser scanning technology.The experimental results show that with the swept angle increasing from 0°to 45°,the 2D double ice horn structures show certain spanwise variation,and finally transform into complete scallop ice with ice thickness greatly enhanced in the stagnation line region.The empirical mode decomposition of the spanwise ice curve captures the high-frequency fluctuation on the scallop ice caused by the small-scale roughness element,while the trend with low frequency is not obvious.Based on the experimental data,a new complete scallop ice geometric model,named 5Points-5Lines-2Arcs(5P-5L-2A)model,is proposed,which can provide important basis for the quantitative description of complex scallop ice shape.
基金supported financially by the National Natural Science Foundation of China(Nos.51871011,51572017 and 51301013)the Beijing Government Funds for the Constructive Project of Central Universitiesthe Fundamental Research Funds for the Central Universities(No.2018YJS144)。
文摘In situ ultrafine TiC dispersion reinforced Inconel 718 alloy with enhanced mechanical properties was fabricated by the technique of reactive hot-press sintering Ti2AlC and In718 powders.The effect of Ti2AlC precursor additions(5 vol.%,10 vol.%,15 vol.%)on microstructure and mechanical properties of TiC/In718 composites were investigated.A relationship of microstructural characteristics,room and elevated temperature mechanical performance,and underlying strengthening mechanisms were analyzed.The results show that initial Ti2AlC precursor transformed completely into ultrafine TiC particulate(~230 nm)and distributed uniformly in the matrix after sintering 5 and 10 vol.%Ti2AlC/In718.However,TiC particulates tended to aggregate to stripes with the addition of Ti2AlC up to 15 vol.%,which,in adverse,weaken the properties of In718.The 5 vol.%Ti2AlC/In718 sample showed a higher tensile strength of 1404±13 MPa with a noticeable elongation of 9.8%at room temperature compared to the pure In718(ultimate tensile strength(UTS)=1310 MPa,elongation=21.5%).At 600℃,700℃,800℃and 900℃,tensile strength of the as-sintered 5 vol.%Ti2AlC/In718 composite was determined to be 1333±13 MPa,1010±10 MPa,685±25 MPa and 276±3 MPa,increased by 9.2%,14.6%,14.2%and 55%,respectively,compared with that of monolithic In718 alloy.The excellent tensile properties of TiC/In718 composite can be ascribed to the combined mechanisms in term of increased dislocation density,dispersive Orowan and load transfer mechanisms.