A robotic fish, BASEMACK1, is designed and fabricated by mimicking the shape of a live mackerel. Three DC servo-motors are serially linked together and actuated to mimic the mackerel＇s Carangiform motion. Hydrodynami...A robotic fish, BASEMACK1, is designed and fabricated by mimicking the shape of a live mackerel. Three DC servo-motors are serially linked together and actuated to mimic the mackerel＇s Carangiform motion. Hydrodynamic characteristics of a fish-mimetic test model are experimentally identified and utilized in order to numerically simulate fish swimming. The discrete set of kinematic and dynamic parameters are obtained by considering required horizontal and lateral forces and minimum energy consumption. Using the optimized parameter set, optimal control of the robot is studied.展开更多
BACKGROUND Older men are more vulnerable to fatal falls than women,and gait disturbances contribute to the risk of falls.Studies have assessed the association between arterial stiffness and gait dysfunction,but the re...BACKGROUND Older men are more vulnerable to fatal falls than women,and gait disturbances contribute to the risk of falls.Studies have assessed the association between arterial stiffness and gait dysfunction,but the results have been inconclusive.This study aimed to conduct a cross-sectional analysis to evaluate the association between brachial–ankle pulse wave velocity(baPWV)and gait assessment in older men.METHODS Data from the 2014–2015 Korea Institute of Sport Science Fitness Standards project were used for the analysis.The inclusion criteria were men aged>65 years with gait assessment[the 30-s chair stand test(30s-CST),the timed up and go(TUG)test,the figure-of-8 walk(F8W)test,the 2-min step test(2MST),and the 6-min walk test(6MWT)]and baPWV measurement data.Generalized linear regression analysis was conducted with multiple confounding factor adjustments,including lower extremity isometric strength.RESULTS A total of 291 participants were included in the analysis.The mean age was 71.38±4.40 years.The mean values were as follows:(1)30s-CST,17.48±5.00;(2)TUG test,6.01±1.10 s;(3)F8W test,25.65±4.71 s;(4)2MST,102.40±18.83 per 2 min;and(5)6MWT,500.02±85.65 m.After multivariable adjustment,baPWV was associated with the 6MWT(β=−0.037,95%CI:−0.072–−0.002),TUG test(β=0,95%CI:0.000–0.001),and F8W test(β=0.002,95%CI:0.000–0.004).baPWV was not associated with the 30s-CST and 2MST.CONCLUSIONS The current study showed a statistically significant association between gait assessments and arterial stiffness,independent of lower extremity strength.However,this association was modest.Future prospective studies are needed to elucidate the complex relationship between arterial stiffness and gait dysfunction.展开更多
Health monitoring with wearable pulse oximetry(PO)paves the way for personalized,point-of-care health management.Organic PO(OPO)sensors are particularly promising for wearable POs due to their excellent compatibility ...Health monitoring with wearable pulse oximetry(PO)paves the way for personalized,point-of-care health management.Organic PO(OPO)sensors are particularly promising for wearable POs due to their excellent compatibility with flexible,lightweight form factors and design freedom,enabling low power consumption comparable to or even surpassing that of conventional inorganic systems.However,further power reductions are crucial for wearable systems with limited onboard power,and achieving sufficient signal strength at minimal luminance is essential for extended operation.Here,we propose an OPO structure with both ultralow power consumption and low luminance operation.By combining a ring-shaped,vertically stacked two-color organic light-emitting diode(OLED)with a circular organic photodiode(OPD)filling the interior and exterior of the OLED ring,we demonstrate OPO sensors requiring only a fewμW to drive the OLEDs and operable at a few tens of cd/m^(2),demonstrating potentials for continuous health monitoring with extended long-term operation.展开更多
Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms t...Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms to date contain gaps and missing sequences.Here,we report the assembly and analysis of gap-free reference genome sequences for two elite O.sativa xian/indica rice varieties,Zhenshan 97 and Minghui 63,which are being used as a model system for studying heterosis and yield.Gap-free reference genomes provide the opportunity for a global view of the structure and function of centromeres.We show that all rice centromeric regions share conserved centromere-specific satellite motifs with different copy numbers and structures.In addition,the similarity of CentO repeats in the same chromosome is higher than across chromosomes,supporting a model of local expansion and homogenization.Both genomes have over 395 non-TE genes located in centromere regions,of which∼41%are actively transcribed.Two large structural variants at the end of chromosome 11 affect the copy number of resistance genes between the two genomes.The availability of the two gap-free genomes lays a solid foundation for further understanding genome structure and function in plants and breeding climate-resilient varieties.展开更多
Let γ be a hyperbolic closed orbit of a C1 vector field X on a compact C∞ manifold M of dimension n ≥ 3, and let Hx（γ） be the homoclinic class of X containing γ. In this paper, we provethat Cl-generically, if ...Let γ be a hyperbolic closed orbit of a C1 vector field X on a compact C∞ manifold M of dimension n ≥ 3, and let Hx（γ） be the homoclinic class of X containing γ. In this paper, we provethat Cl-generically, if Hx （γ） is expansive and isolated, then it is hyperbolic.展开更多
文摘A robotic fish, BASEMACK1, is designed and fabricated by mimicking the shape of a live mackerel. Three DC servo-motors are serially linked together and actuated to mimic the mackerel＇s Carangiform motion. Hydrodynamic characteristics of a fish-mimetic test model are experimentally identified and utilized in order to numerically simulate fish swimming. The discrete set of kinematic and dynamic parameters are obtained by considering required horizontal and lateral forces and minimum energy consumption. Using the optimized parameter set, optimal control of the robot is studied.
基金supported by the Korea Sport Promotion Foundation。
文摘BACKGROUND Older men are more vulnerable to fatal falls than women,and gait disturbances contribute to the risk of falls.Studies have assessed the association between arterial stiffness and gait dysfunction,but the results have been inconclusive.This study aimed to conduct a cross-sectional analysis to evaluate the association between brachial–ankle pulse wave velocity(baPWV)and gait assessment in older men.METHODS Data from the 2014–2015 Korea Institute of Sport Science Fitness Standards project were used for the analysis.The inclusion criteria were men aged>65 years with gait assessment[the 30-s chair stand test(30s-CST),the timed up and go(TUG)test,the figure-of-8 walk(F8W)test,the 2-min step test(2MST),and the 6-min walk test(6MWT)]and baPWV measurement data.Generalized linear regression analysis was conducted with multiple confounding factor adjustments,including lower extremity isometric strength.RESULTS A total of 291 participants were included in the analysis.The mean age was 71.38±4.40 years.The mean values were as follows:(1)30s-CST,17.48±5.00;(2)TUG test,6.01±1.10 s;(3)F8W test,25.65±4.71 s;(4)2MST,102.40±18.83 per 2 min;and(5)6MWT,500.02±85.65 m.After multivariable adjustment,baPWV was associated with the 6MWT(β=−0.037,95%CI:−0.072–−0.002),TUG test(β=0,95%CI:0.000–0.001),and F8W test(β=0.002,95%CI:0.000–0.004).baPWV was not associated with the 30s-CST and 2MST.CONCLUSIONS The current study showed a statistically significant association between gait assessments and arterial stiffness,independent of lower extremity strength.However,this association was modest.Future prospective studies are needed to elucidate the complex relationship between arterial stiffness and gait dysfunction.
基金supported by the Technology Innovation Program(20018954)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by Nano·Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning(NRF-2016M3A7B4910631)the Engineering Research Center of Excellence(ERC)Program supported by National Research Foundation(NRF),Korean Ministry of Science&ICT(MSIT)(Grant No.NRF-2017R1A5A1014708).
文摘Health monitoring with wearable pulse oximetry(PO)paves the way for personalized,point-of-care health management.Organic PO(OPO)sensors are particularly promising for wearable POs due to their excellent compatibility with flexible,lightweight form factors and design freedom,enabling low power consumption comparable to or even surpassing that of conventional inorganic systems.However,further power reductions are crucial for wearable systems with limited onboard power,and achieving sufficient signal strength at minimal luminance is essential for extended operation.Here,we propose an OPO structure with both ultralow power consumption and low luminance operation.By combining a ring-shaped,vertically stacked two-color organic light-emitting diode(OLED)with a circular organic photodiode(OPD)filling the interior and exterior of the OLED ring,we demonstrate OPO sensors requiring only a fewμW to drive the OLEDs and operable at a few tens of cd/m^(2),demonstrating potentials for continuous health monitoring with extended long-term operation.
基金This research was supported by the Natinal Key Research and Development Program of China(2016YFD0100904 and 2016YFD0100802)the National Natural Science Foundation of China(31871269)+1 种基金the Hubei Provincial Natural Science Foundation of China(2019CFA014)Fundamental Research Funds for the Central Universities(2662020SKPY010 to J.Z.).
文摘Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms to date contain gaps and missing sequences.Here,we report the assembly and analysis of gap-free reference genome sequences for two elite O.sativa xian/indica rice varieties,Zhenshan 97 and Minghui 63,which are being used as a model system for studying heterosis and yield.Gap-free reference genomes provide the opportunity for a global view of the structure and function of centromeres.We show that all rice centromeric regions share conserved centromere-specific satellite motifs with different copy numbers and structures.In addition,the similarity of CentO repeats in the same chromosome is higher than across chromosomes,supporting a model of local expansion and homogenization.Both genomes have over 395 non-TE genes located in centromere regions,of which∼41%are actively transcribed.Two large structural variants at the end of chromosome 11 affect the copy number of resistance genes between the two genomes.The availability of the two gap-free genomes lays a solid foundation for further understanding genome structure and function in plants and breeding climate-resilient varieties.
基金supported by Math Vision 2020 Project by the National Research Foundation of Korea(NRF)
文摘Let γ be a hyperbolic closed orbit of a C1 vector field X on a compact C∞ manifold M of dimension n ≥ 3, and let Hx（γ） be the homoclinic class of X containing γ. In this paper, we provethat Cl-generically, if Hx （γ） is expansive and isolated, then it is hyperbolic.
