The temperature of powder bed is very important for selective laser sintering system(SLS),because it directly affects the quality of part.Furthermore,the temperature of powder bed should alter according to the slicing...The temperature of powder bed is very important for selective laser sintering system(SLS),because it directly affects the quality of part.Furthermore,the temperature of powder bed should alter according to the slicing section contour of model in order to ensure that the integration is successful and intelligent.Namely,the temperature of powder bed should change with shape of CAD model at different height.The paper illuminates how to distinguish the slicing contour loops from adjacent region.In this way,the temperature can be adaptively adjusted with altering of the sectional contours.展开更多
An adaptive heat source mode is proposed to account for the keyhole effect and the characteristics of volumetric distribution along the direction of the workpiece thickness. Finite element analysis of the temperature ...An adaptive heat source mode is proposed to account for the keyhole effect and the characteristics of volumetric distribution along the direction of the workpiece thickness. Finite element analysis of the temperature field in keyhole plasma arc welding is conducted and the weld geometry is obtained. The predicted results are in agreement with the measured ones.展开更多
I first met Constantine Dafermos in August 1974, at a meeting at Brown University, where I was invited because my former advisor （Jacques-Louis LIONS） could not come, and he had proposed my name. I was happily surpr...I first met Constantine Dafermos in August 1974, at a meeting at Brown University, where I was invited because my former advisor （Jacques-Louis LIONS） could not come, and he had proposed my name. I was happily surprised that Constantine greeted me as if he knew me well, and since for many years now I have considered him as if he was an older brother, I wonder when this feeling started.展开更多
Although both protein arginine methylation(PRMT)and jasmonate(JA)signaling are crucial for regulating plant development,the relationship between these processes in the control of spikelet development remains unclear.I...Although both protein arginine methylation(PRMT)and jasmonate(JA)signaling are crucial for regulating plant development,the relationship between these processes in the control of spikelet development remains unclear.In this study,we used the CRISPR/Cas9 technology to generate two OsPRMT6a loss-of-function mutants that exhibit various abnormal spikelet structures.Interestingly,we found that OsPRMT6a can methylate arginine residues in JA signal repressors OsJAZ1 and OsJAZ7.We showed that arginine methylation of OsJAZ1 enhances the binding affinity of OsJAZ1 with the JA receptors OsCOI1a and OsCOI1b in the presence of JAs,thereby promoting the ubiquitination of OsJAZ1 by the SCF^(OsCOI1a/OsCOI1b) complex and degradation via the 26S proteasome.This process ultimately releases OsMYC2,a core transcriptional regulator in the JA signaling pathway,to activate or repress JA-responsive genes,thereby maintaining normal plant(spikelet)development.However,in the osprmt6a-1 mutant,reduced arginine methylation of OsJAZ1 impaires the interaction between OsJAZ1 and OsCOI1a/OsCOI1b in the presence of JAs.As a result,OsJAZ1 proteins become more stable,repressing JA responses,thus causing the formation of abnormal spikelet structures.Moreover,we discovered that JA signaling reduces the OsPRMT6a mRNA level in an OsMYC2-dependent manner,thereby establishing a negative feedback loop to balance JA signaling.We further found that OsPRMT6a-mediated arginine methylation of OsJAZ1 likely serves as a switch to tune JA signaling to maintain normal spikelet development under harsh environmental conditions such as high temperatures.Collectively,our study establishes a direct molecular link between arginine methylation and JA signaling in rice.展开更多
The shoot apical meristem(SAM)is responsible for overall shoot growth by generating all aboveground structures.Recent research has revealed that the SAM displays an autonomous heat stress(HS)memory of a previous non-l...The shoot apical meristem(SAM)is responsible for overall shoot growth by generating all aboveground structures.Recent research has revealed that the SAM displays an autonomous heat stress(HS)memory of a previous non-lethal HS event.Considering the importance of the SAM for plant growth,it is essential to determine how its thermomemory is mechanistically controlled.Here,we report that HEAT SHOCK TRAN-SCRIPTION FACTOR A7b(HSFA7b)plays a crucial role in this process in Arabidopsis,as the absence of functional HSFA7b results in the temporal suppression of SAM activity after thermopriming.We found that HSFA7b directly regulates ethylene response at the SAM by binding to the promoter of the key ethylene signaling gene ETHYLENE-INSENSITIVE 3 to establish thermotolerance.Moreover,we demonstrated that HSFA7b regulates the expression of ETHYLENE OVERPRODUCER 1(ETO1)and ETO1-LIKE 1,both of which encode ethylene biosynthesis repressors,thereby ensuring ethylene homeostasis at the SAM.Taken together,these results reveal a crucial and tissue-specic role for HSFA7b in thermomemory at the Arabidopsis SAM.展开更多
Purpose The aim of this study was to confirm the impact of heat acclimation on aerobic performance in hot conditions and elucidate the transfer of heat adaptations to cool and hypoxic environments.Methods Ten males(VO...Purpose The aim of this study was to confirm the impact of heat acclimation on aerobic performance in hot conditions and elucidate the transfer of heat adaptations to cool and hypoxic environments.Methods Ten males(VO_(2peak):4.50±0.50 L/min)completed two three-week interventions consisting of heat acclimation(HA:36℃ and 59%RH)and temperate training(TEMP:18℃ and 60%RH)in a counter-balanced crossover design.Train-ing weeks consisted of four work-matched controlled heart rate sessions interspersed with one intermittent sprint session,and two rest days.Before and after the interventionsVO_(2peak) and 20-min time trial performance were evaluated in COOL(18℃),HOT(35℃)and hypoxic(HYP:18℃ andFiO_(2):15.4%)conditions.Results Following HA,VO_(2peak) increased significantly in HOT(0.24 L/min[0.01,0.47],P=0.040)but not COOL(P=0.431)or HYP(P=0.411),whereas TEMP had no influence onVO_(2peak)(P≥0.424).Mean time trial power output increased sig-nificantly in HOT(20 W[11,28],P<0.001)and COOL(12 W[4,21],P=0.004),but not HYP(7 W[-1,16],P=0.075)after HA,whereas TEMP had no influence on mean power output(P≥0.110).Rectal(-0.13℃[-0.23,-0.03],P=0.009)and skin(-0.7℃[-1.2,-0.3],P<0.001)temperature were lower during the time trial in HOT after HA,whereas mean heart rate did not differ(P=0.339).Conclusions HA improved aerobic performance in HOT in conjunction with lower thermal strain and enhanced cardiovas-cular stability(similar heart rate for higher workload),whereas the mechanistic pathways improving performance in COOL and HYP remain unclear.展开更多
Against the background of global climate change, the increasing heat health risk from the combined effect of changes in high temperature, exposure, vulnerability, and other factors has become a growing concern.Yet the...Against the background of global climate change, the increasing heat health risk from the combined effect of changes in high temperature, exposure, vulnerability, and other factors has become a growing concern.Yet the low number of temperature observation stations is insufficient to represent the complex changes in urban heatwaves, and subdistrict-scale(town, township, neighborhood committee, and equivalent) heat health risk and adaptability assessments are still limited. In this study, we built daytime and nighttime high-temperature interpolation models supported by data from 225 meteorological stations in Beijing.The models performed well at interpolating the cumulative hours of high temperature and the interpolation quality at night was better than that during the day. We further established a methodological framework for heat health risk and adaptability assessments based on heat hazard, population exposure, social vulnerability, and adaptability at the subdistrict scale in Beijing. Our results show that the heat health risk hotspots were mainly located in the central urban area,with 81 hotspots during the day and 76 at night. The average value of the heat health risk index of urban areas was 5.60 times higher than that of suburban areas in the daytime,and 6.70 times higher than that of suburban areas in the night. Greater population density and higher intensity of heat hazards were the main reasons for the high risk in most heat health risk hotspots. Combined with a heat-adaptive-capacity evaluation for hotspot areas, this study suggests that 11high-risk and low-adaptation subdistricts are priority areas for government action to reduce heat health risk in policy formulation and urban development.展开更多
基金Sponsored by the 863 Inportant Science and Technology Subject Foundation(Grant No.2002AA6Z3081).
文摘The temperature of powder bed is very important for selective laser sintering system(SLS),because it directly affects the quality of part.Furthermore,the temperature of powder bed should alter according to the slicing section contour of model in order to ensure that the integration is successful and intelligent.Namely,the temperature of powder bed should change with shape of CAD model at different height.The paper illuminates how to distinguish the slicing contour loops from adjacent region.In this way,the temperature can be adaptively adjusted with altering of the sectional contours.
文摘An adaptive heat source mode is proposed to account for the keyhole effect and the characteristics of volumetric distribution along the direction of the workpiece thickness. Finite element analysis of the temperature field in keyhole plasma arc welding is conducted and the weld geometry is obtained. The predicted results are in agreement with the measured ones.
文摘I first met Constantine Dafermos in August 1974, at a meeting at Brown University, where I was invited because my former advisor （Jacques-Louis LIONS） could not come, and he had proposed my name. I was happily surprised that Constantine greeted me as if he knew me well, and since for many years now I have considered him as if he was an older brother, I wonder when this feeling started.
基金We thank Prof.Qiang Cai(College of Life Sciences,Wuhan University)and Prof.Zheng Yuan(School of Life Sciences and Biotechnology,Shanghai Jiao Tong University)for providing morphology data for the eg1-1 and eg2-1D mutants.This work was supported by grants from the National Key R&D Program of China(2022YFD1200100)STI2030-Major Projects(2023ZD0406802)the National Natural Science Foundation of China(no.92035301 and no.31771765).
文摘Although both protein arginine methylation(PRMT)and jasmonate(JA)signaling are crucial for regulating plant development,the relationship between these processes in the control of spikelet development remains unclear.In this study,we used the CRISPR/Cas9 technology to generate two OsPRMT6a loss-of-function mutants that exhibit various abnormal spikelet structures.Interestingly,we found that OsPRMT6a can methylate arginine residues in JA signal repressors OsJAZ1 and OsJAZ7.We showed that arginine methylation of OsJAZ1 enhances the binding affinity of OsJAZ1 with the JA receptors OsCOI1a and OsCOI1b in the presence of JAs,thereby promoting the ubiquitination of OsJAZ1 by the SCF^(OsCOI1a/OsCOI1b) complex and degradation via the 26S proteasome.This process ultimately releases OsMYC2,a core transcriptional regulator in the JA signaling pathway,to activate or repress JA-responsive genes,thereby maintaining normal plant(spikelet)development.However,in the osprmt6a-1 mutant,reduced arginine methylation of OsJAZ1 impaires the interaction between OsJAZ1 and OsCOI1a/OsCOI1b in the presence of JAs.As a result,OsJAZ1 proteins become more stable,repressing JA responses,thus causing the formation of abnormal spikelet structures.Moreover,we discovered that JA signaling reduces the OsPRMT6a mRNA level in an OsMYC2-dependent manner,thereby establishing a negative feedback loop to balance JA signaling.We further found that OsPRMT6a-mediated arginine methylation of OsJAZ1 likely serves as a switch to tune JA signaling to maintain normal spikelet development under harsh environmental conditions such as high temperatures.Collectively,our study establishes a direct molecular link between arginine methylation and JA signaling in rice.
基金funding Collaborative Research Centre 973"Priming and Memory of Organismic Responses to Stress" (www.sfb973.de)the European Union’s Horizon 2020 Research and Innovation Programme for funding project PlantaSYST (SGA-CSA No.739582 under FPA No.664620)+1 种基金the European Regional Development Fund for funding project BG05M2OP001-1.003-001-C01 through the Bulgarian"Science and Education for Smart Growth"Operational Programme,and the MPI-MP and the University of Potsdam for financial support.B.M.-R.and S.J.thank the International Max Planck Research School"Primary Metabolism and Plant Growth" (IMPRS-PMPG)for support.J.J.O.thanks the DFG (OL 767/1-1)Leibniz Institute of Vegetable and Ornamental Crops for funding.
文摘The shoot apical meristem(SAM)is responsible for overall shoot growth by generating all aboveground structures.Recent research has revealed that the SAM displays an autonomous heat stress(HS)memory of a previous non-lethal HS event.Considering the importance of the SAM for plant growth,it is essential to determine how its thermomemory is mechanistically controlled.Here,we report that HEAT SHOCK TRAN-SCRIPTION FACTOR A7b(HSFA7b)plays a crucial role in this process in Arabidopsis,as the absence of functional HSFA7b results in the temporal suppression of SAM activity after thermopriming.We found that HSFA7b directly regulates ethylene response at the SAM by binding to the promoter of the key ethylene signaling gene ETHYLENE-INSENSITIVE 3 to establish thermotolerance.Moreover,we demonstrated that HSFA7b regulates the expression of ETHYLENE OVERPRODUCER 1(ETO1)and ETO1-LIKE 1,both of which encode ethylene biosynthesis repressors,thereby ensuring ethylene homeostasis at the SAM.Taken together,these results reveal a crucial and tissue-specic role for HSFA7b in thermomemory at the Arabidopsis SAM.
文摘Purpose The aim of this study was to confirm the impact of heat acclimation on aerobic performance in hot conditions and elucidate the transfer of heat adaptations to cool and hypoxic environments.Methods Ten males(VO_(2peak):4.50±0.50 L/min)completed two three-week interventions consisting of heat acclimation(HA:36℃ and 59%RH)and temperate training(TEMP:18℃ and 60%RH)in a counter-balanced crossover design.Train-ing weeks consisted of four work-matched controlled heart rate sessions interspersed with one intermittent sprint session,and two rest days.Before and after the interventionsVO_(2peak) and 20-min time trial performance were evaluated in COOL(18℃),HOT(35℃)and hypoxic(HYP:18℃ andFiO_(2):15.4%)conditions.Results Following HA,VO_(2peak) increased significantly in HOT(0.24 L/min[0.01,0.47],P=0.040)but not COOL(P=0.431)or HYP(P=0.411),whereas TEMP had no influence onVO_(2peak)(P≥0.424).Mean time trial power output increased sig-nificantly in HOT(20 W[11,28],P<0.001)and COOL(12 W[4,21],P=0.004),but not HYP(7 W[-1,16],P=0.075)after HA,whereas TEMP had no influence on mean power output(P≥0.110).Rectal(-0.13℃[-0.23,-0.03],P=0.009)and skin(-0.7℃[-1.2,-0.3],P<0.001)temperature were lower during the time trial in HOT after HA,whereas mean heart rate did not differ(P=0.339).Conclusions HA improved aerobic performance in HOT in conjunction with lower thermal strain and enhanced cardiovas-cular stability(similar heart rate for higher workload),whereas the mechanistic pathways improving performance in COOL and HYP remain unclear.
基金This work was jointly supported by the National Key Research and Development Program of China(2019YFC0507805)the Strategic Leading Science and Technology Program of the Chinese Academy of Sciences(XDA20020202).We express our sincere appreciation to the anonymous reviewers for their constructive comments.
文摘Against the background of global climate change, the increasing heat health risk from the combined effect of changes in high temperature, exposure, vulnerability, and other factors has become a growing concern.Yet the low number of temperature observation stations is insufficient to represent the complex changes in urban heatwaves, and subdistrict-scale(town, township, neighborhood committee, and equivalent) heat health risk and adaptability assessments are still limited. In this study, we built daytime and nighttime high-temperature interpolation models supported by data from 225 meteorological stations in Beijing.The models performed well at interpolating the cumulative hours of high temperature and the interpolation quality at night was better than that during the day. We further established a methodological framework for heat health risk and adaptability assessments based on heat hazard, population exposure, social vulnerability, and adaptability at the subdistrict scale in Beijing. Our results show that the heat health risk hotspots were mainly located in the central urban area,with 81 hotspots during the day and 76 at night. The average value of the heat health risk index of urban areas was 5.60 times higher than that of suburban areas in the daytime,and 6.70 times higher than that of suburban areas in the night. Greater population density and higher intensity of heat hazards were the main reasons for the high risk in most heat health risk hotspots. Combined with a heat-adaptive-capacity evaluation for hotspot areas, this study suggests that 11high-risk and low-adaptation subdistricts are priority areas for government action to reduce heat health risk in policy formulation and urban development.
