OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retros...OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retrospectively studied.Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements.In addition,brachial blood pressure was measured,and total arterial compliance,systemic vascular resistance,arterial elastance,and end-systolic LV elastance were calculated.The participants were divided into four groups according to the status of ascending aortic diameter and PP.RESULTS LV mass index increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrend<0.001).Total arterial compliance−1,arterial elastance,and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation,regardless of PP being lower or higher(P<0.01).Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[aortic dilatation with lower PP(OR=1.75,95%CI:1.01–3.04)and aortic dilatation with higher PP(OR=3.42,95%CI:2.03–5.77)].In the relation between PP and LV mass index(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by ascending aortic diameter(P<0.0001).CONCLUSIONS In Chinese elderly patients with hypertension,ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.展开更多
To investigate the shock response of cyclotetramethylene tetranitramine(HMX)single crystals at elevated temperatures(below the phase transition point),plate impact experiments at elevated temperatures were designed an...To investigate the shock response of cyclotetramethylene tetranitramine(HMX)single crystals at elevated temperatures(below the phase transition point),plate impact experiments at elevated temperatures were designed and conducted.The HMX/window interface particle velocities at temperatures of 300 K,373 K,and 423 K were measured by the velocity interferometry system for any reflector(VISAR)technique.To further analyze the related mesoscale deformation mechanisms,a nonlinear thermoelastic-viscoplastic model was developed,which considers thermal activation and phonon drag dislocation slip mechanisms.The proposed model could well reproduce the measured thermal hardening behavior of Hugoniot elastic limit(HEL)of HMX single crystals.At elevated temperatures,the reduced dislocation mobility was observed,which stems from both phonon scattering and radiative damping effects.Comparatively speaking,radiative damping contributes less than phonon scattering to thermal hardening behavior.The calibrated model was further used to predict shock response of HMX single crystals with different thicknesses at different initial temperatures.Both the stress relaxation and elastic precursor decrease with thickness are mainly due to the rapid dislocation generation.These insights shed light on the interplay between dislocation motion and dislocation generation in thermal hardening behavior,stress relaxation,and elastic precursor decay,which serves to reveal the mesoscale deformation mechanisms at elevated temperatures.展开更多
The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Her...The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Here,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae pv.tomato(Pst)DC3000 in tomato.The knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense response.Using exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense response.Elevated CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and temperature.The results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in tomato.These findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate.展开更多
Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by opti...Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by optical microscopy,scanning electron microscopy,electron back-scattered diffraction and transmission electron microscopy.The results show that true stress first rises to the peak point and then drops to the bottom value and increases again with further increasing strain at each temperature.Twinning dynamic recrystallization(DRX)and continuous DRX contribute to the formation of new fine grains at temperatures 450∼475℃ when the restoration is caused by both DRX and texture change due to extension twinning,resulting in the larger softening degrees compared with the softening effects owing to continuous DRX and discontinuous DRX at 500∼550℃ when twinning activation is suppressed.500℃ is the transition temperature denoting a significant decline in the contribution of twinning and TDRX to the strain with increasing temperature.The cuboid-shape phase exists in both homogenized and compressed samples,while the compositions are varied.展开更多
基金the National Key Research and Development Program of China(No.2018 YFC2000301)。
文摘OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retrospectively studied.Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements.In addition,brachial blood pressure was measured,and total arterial compliance,systemic vascular resistance,arterial elastance,and end-systolic LV elastance were calculated.The participants were divided into four groups according to the status of ascending aortic diameter and PP.RESULTS LV mass index increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrend<0.001).Total arterial compliance−1,arterial elastance,and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation,regardless of PP being lower or higher(P<0.01).Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[aortic dilatation with lower PP(OR=1.75,95%CI:1.01–3.04)and aortic dilatation with higher PP(OR=3.42,95%CI:2.03–5.77)].In the relation between PP and LV mass index(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by ascending aortic diameter(P<0.0001).CONCLUSIONS In Chinese elderly patients with hypertension,ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.
基金supported by the National Natural Science Foundation of China(No.12172051,No.11802024)Beijing Institute of Technology Research Fund Program for Young Scholars(WXJ2019).
文摘To investigate the shock response of cyclotetramethylene tetranitramine(HMX)single crystals at elevated temperatures(below the phase transition point),plate impact experiments at elevated temperatures were designed and conducted.The HMX/window interface particle velocities at temperatures of 300 K,373 K,and 423 K were measured by the velocity interferometry system for any reflector(VISAR)technique.To further analyze the related mesoscale deformation mechanisms,a nonlinear thermoelastic-viscoplastic model was developed,which considers thermal activation and phonon drag dislocation slip mechanisms.The proposed model could well reproduce the measured thermal hardening behavior of Hugoniot elastic limit(HEL)of HMX single crystals.At elevated temperatures,the reduced dislocation mobility was observed,which stems from both phonon scattering and radiative damping effects.Comparatively speaking,radiative damping contributes less than phonon scattering to thermal hardening behavior.The calibrated model was further used to predict shock response of HMX single crystals with different thicknesses at different initial temperatures.Both the stress relaxation and elastic precursor decrease with thickness are mainly due to the rapid dislocation generation.These insights shed light on the interplay between dislocation motion and dislocation generation in thermal hardening behavior,stress relaxation,and elastic precursor decay,which serves to reveal the mesoscale deformation mechanisms at elevated temperatures.
基金This work was supported by the Key Research and Development Program of Zhejiang Province(2021C02040)the National Natural Science Foundation of China(32172650,31902097)+1 种基金the Natural Science Foundation of Zhejiang Province(LR19C150001)the Starry Night Science Fund of Zhejiang University Shanghai Insti-tute for Advanced Study(SN-ZJU-SIAS-0011).
文摘The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Here,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae pv.tomato(Pst)DC3000 in tomato.The knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense response.Using exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense response.Elevated CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and temperature.The results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in tomato.These findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate.
基金This work was supported by the Changsha University Talent Introduction Project(50800-92808)the Excellent youth project of Hunan Provincial Department of Education(19B055,18B418,19C0156)the Natural Science Foundation of Hunan Province of China(2020JJ4645).
文摘Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by optical microscopy,scanning electron microscopy,electron back-scattered diffraction and transmission electron microscopy.The results show that true stress first rises to the peak point and then drops to the bottom value and increases again with further increasing strain at each temperature.Twinning dynamic recrystallization(DRX)and continuous DRX contribute to the formation of new fine grains at temperatures 450∼475℃ when the restoration is caused by both DRX and texture change due to extension twinning,resulting in the larger softening degrees compared with the softening effects owing to continuous DRX and discontinuous DRX at 500∼550℃ when twinning activation is suppressed.500℃ is the transition temperature denoting a significant decline in the contribution of twinning and TDRX to the strain with increasing temperature.The cuboid-shape phase exists in both homogenized and compressed samples,while the compositions are varied.
