BACKGROUND Intracranial and extracranial artery stenosis is associated with cerebral infarction.Vascular calcification and atherosclerosis are the main causes of stenosis and major risk factors for cardiovascular and ...BACKGROUND Intracranial and extracranial artery stenosis is associated with cerebral infarction.Vascular calcification and atherosclerosis are the main causes of stenosis and major risk factors for cardiovascular and cerebrovascular events in patients with type 2 diabetes mellitus(T2DM).Bone turnover biomarkers(BTMs)are associated with vascular calcification,atherosclerosis,glucose,and lipid metabolism.AIM To investigate the association of circulating BTM levels with severe intracranial and extracranial artery stenosis in patients with T2DM.METHODS For this cross-sectional study including 257 T2DM patients,levels of the BTMs serum osteocalcin(OC),C-terminal cross-linked telopeptide of type I collagen(CTX),and procollagen type I N-peptide were measured by electrical chemiluminescent immunoassay,and artery stenosis was assessed by color Doppler and transcranial Doppler.Patients were grouped according to the existence and location(intracranial vs.extracranial)of artery stenosis.Correlations between BTM levels,previous stroke,stenosis location,and glucose and lipid metabolism were analyzed.RESULTS T2DM patients with severe artery stenosis had a higher frequency of previous stroke and levels of all three tested BTMs(all P<0.05)than patients without.Some differences in OC and CTX levels were observed according to the location of artery stenosis.Significant associations were also observed between BTM levels and some glucose and lipid homeostasis parameters.On multivariate logistic regression analysis,all BTMs were significant predictors of artery stenosis in T2DM patients with and without adjustment for confounding factors(all P<0.001),and receiver operating characteristic curve analysis demonstrated the ability of BTM levels to predict artery stenosis in T2DM patients.CONCLUSION BTM levels were found to be independent risk factors for severe intracranial and extracranial artery stenosis and were differentially associated with glucose and lipid metabolism in patients with T2DM.Therefore,BTMs may be promising biomarkers and potential therapeutic targets for artery stenosis.展开更多
As major contributor to the blue carbon sink,intertidal zones play a crucial role in the global carbon cycle.In recent years,more attention has been given to the carbon cycle in intertidal wetlands.However,due to high...As major contributor to the blue carbon sink,intertidal zones play a crucial role in the global carbon cycle.In recent years,more attention has been given to the carbon cycle in intertidal wetlands.However,due to highly variable and uncertain environmental conditions,it is difficult to clarify the quantitative relationship between soil respiration and environmental factors through in-situ experiments.In this study,the response of soil respiration characteristics to variations in the temperature and water table was investigated using a monitoring apparatus of CO_(2)flux at the soil-air interface in the intertidal zone.The results showed that soil respiration flux was significantly correlated with temperature,and the correlation best fitted the DoseResp function.Meanwhile,the respiration flux was enhanced with the descent of water table,a relationship could be described by a quadratic function.The effect of the water table on soil respiration became more pronounced with the rise of temperature.These results provide significant clarification of the impact of human activities on the carbon cycle in bare intertidal zones and as well as support for numerical simulations of the carbon cycle in bare intertidal zones.展开更多
This paper presents and verifies a new idea for constructing an ultrasonic motor (USM). The stator contains several vibrators fabricated by bonding piezoelectric ceramics (PZTs) to a metal base. When two alternati...This paper presents and verifies a new idea for constructing an ultrasonic motor (USM). The stator contains several vibrators fabricated by bonding piezoelectric ceramics (PZTs) to a metal base. When two alternating current (AC) voltages with a 90° phase difference are applied to the PZTs, longitudinal and bending modes are excited in the vibrator. The bending vibrations of the vibrators are stacked to form the torsional vibration of the stator, ultimately generating longitudinal-torsional composite vibration. Both vibrators and the stator are excited to the resonance state. A standing wave is formed by superposition of longitudinal and torsional modes. The proposed motor is an in-plane vibration motor because the vibrations of the stator are in the circumferential plane. The finite element method (FEM) is used to validate the feasibility of the proposed motor. The fabricated stator contains five vibrators. The tested resonance frequencies of longitudinal and torsional modes are 44.42 kHz and 43.83 kHz, respectively. The stall torque is 0.3 N'm and no-load speed is 45 r/min. The highest efficiency is 30%. The applied driving voltage is 100 Vo.p (peak voltage) at 43.9 kHz. The designed motor is a parallel-actuated integral motor. It allows the vibrators to operate synchronously, and overcomes asynchronous issues that occur in traditional multi-vibrator motors.展开更多
In this paper, in-situ coagulation of 0.9Al_2O_3–0.1TiO_2 suspension and microwave dielectric properties of 0.9Al_2O_3–0.1TiO_2 ceramics prepared by a novel direct coagulation casting via high valence counter ions(D...In this paper, in-situ coagulation of 0.9Al_2O_3–0.1TiO_2 suspension and microwave dielectric properties of 0.9Al_2O_3–0.1TiO_2 ceramics prepared by a novel direct coagulation casting via high valence counter ions(DCC-HVCI) method were proposed. The 0.9Al_2O_3–0.1TiO_2 suspension could be coagulated via controlled release of calcium ions from calcium iodate at an elevated temperature. The influence of tri-ammonium citrate(TAC) content, solid loading, and calcium iodate content on the rheological properties of the suspension was investigated. In addition, the influence of coagulation temperature on coagulation time and properties of green bodies was also studied. It was found that the stable 0.9Al_2O_3–0.1TiO_2 suspension could be successfully prepared by adding 0.3 wt% TAC and adjusting pH value to 10–12 at room temperature. 0.9Al_2O_3–0.1TiO_2 green bodies with uniform microstructures were coagulated by adding 8.0 g/L calcium iodate after treating at 70 ℃ for 1 h. 0.9Al_2O_3–0.1TiO_2 ceramics, sintered at 1500 ℃ for 4 h and annealed at 1100 ℃ for 5 h, showed uniform microstructures with density of 3.62±0.02 g/cm^3. The microwave dielectric properties of 0.9Al_2O_3–0.1TiO_2 ceramics prepared by DCC-HVCI method were: ε_r = 11.26±0.06, Q×f = 11569± 629 GHz, τ_t = 0.93±0.60 ppm/℃. The DCC-HVCI method is a novel and promising route without binder removal process to prepare complex-shaped microwave dielectric ceramics with uniform microstructures and good microwave dielectric properties.展开更多
基金Supported by Beijing Municipal Hospital Management Center“Cultivation Plan”,No.PX2022032.
文摘BACKGROUND Intracranial and extracranial artery stenosis is associated with cerebral infarction.Vascular calcification and atherosclerosis are the main causes of stenosis and major risk factors for cardiovascular and cerebrovascular events in patients with type 2 diabetes mellitus(T2DM).Bone turnover biomarkers(BTMs)are associated with vascular calcification,atherosclerosis,glucose,and lipid metabolism.AIM To investigate the association of circulating BTM levels with severe intracranial and extracranial artery stenosis in patients with T2DM.METHODS For this cross-sectional study including 257 T2DM patients,levels of the BTMs serum osteocalcin(OC),C-terminal cross-linked telopeptide of type I collagen(CTX),and procollagen type I N-peptide were measured by electrical chemiluminescent immunoassay,and artery stenosis was assessed by color Doppler and transcranial Doppler.Patients were grouped according to the existence and location(intracranial vs.extracranial)of artery stenosis.Correlations between BTM levels,previous stroke,stenosis location,and glucose and lipid metabolism were analyzed.RESULTS T2DM patients with severe artery stenosis had a higher frequency of previous stroke and levels of all three tested BTMs(all P<0.05)than patients without.Some differences in OC and CTX levels were observed according to the location of artery stenosis.Significant associations were also observed between BTM levels and some glucose and lipid homeostasis parameters.On multivariate logistic regression analysis,all BTMs were significant predictors of artery stenosis in T2DM patients with and without adjustment for confounding factors(all P<0.001),and receiver operating characteristic curve analysis demonstrated the ability of BTM levels to predict artery stenosis in T2DM patients.CONCLUSION BTM levels were found to be independent risk factors for severe intracranial and extracranial artery stenosis and were differentially associated with glucose and lipid metabolism in patients with T2DM.Therefore,BTMs may be promising biomarkers and potential therapeutic targets for artery stenosis.
基金supported by the National Natural Science Foundation of China(Grant No.U2040209)the Open Funds of the Key Laboratory of Ocean Space Resource Management Technology of Ministry of Natural Resources(Grant No.KF-2021-108)the Fundamental Research Funds for the Central Universities(Grant No.B210204001).
文摘As major contributor to the blue carbon sink,intertidal zones play a crucial role in the global carbon cycle.In recent years,more attention has been given to the carbon cycle in intertidal wetlands.However,due to highly variable and uncertain environmental conditions,it is difficult to clarify the quantitative relationship between soil respiration and environmental factors through in-situ experiments.In this study,the response of soil respiration characteristics to variations in the temperature and water table was investigated using a monitoring apparatus of CO_(2)flux at the soil-air interface in the intertidal zone.The results showed that soil respiration flux was significantly correlated with temperature,and the correlation best fitted the DoseResp function.Meanwhile,the respiration flux was enhanced with the descent of water table,a relationship could be described by a quadratic function.The effect of the water table on soil respiration became more pronounced with the rise of temperature.These results provide significant clarification of the impact of human activities on the carbon cycle in bare intertidal zones and as well as support for numerical simulations of the carbon cycle in bare intertidal zones.
基金Project supported by the National Natural Science Foundation of China (No. 11174206), the Open Fund of State Key Laboratory of Ocean Engineering (No. 0507), and the Shanghai Aerospace Science and Technology Innovation Fund (No. 201347), China
文摘This paper presents and verifies a new idea for constructing an ultrasonic motor (USM). The stator contains several vibrators fabricated by bonding piezoelectric ceramics (PZTs) to a metal base. When two alternating current (AC) voltages with a 90° phase difference are applied to the PZTs, longitudinal and bending modes are excited in the vibrator. The bending vibrations of the vibrators are stacked to form the torsional vibration of the stator, ultimately generating longitudinal-torsional composite vibration. Both vibrators and the stator are excited to the resonance state. A standing wave is formed by superposition of longitudinal and torsional modes. The proposed motor is an in-plane vibration motor because the vibrations of the stator are in the circumferential plane. The finite element method (FEM) is used to validate the feasibility of the proposed motor. The fabricated stator contains five vibrators. The tested resonance frequencies of longitudinal and torsional modes are 44.42 kHz and 43.83 kHz, respectively. The stall torque is 0.3 N'm and no-load speed is 45 r/min. The highest efficiency is 30%. The applied driving voltage is 100 Vo.p (peak voltage) at 43.9 kHz. The designed motor is a parallel-actuated integral motor. It allows the vibrators to operate synchronously, and overcomes asynchronous issues that occur in traditional multi-vibrator motors.
基金supported by National Natural Science Foundation of China(No.51501066)China Postdoctoral Science Foundation(Nos.2015M572136,2017T100550,and 2016M602290)the Fundamental Research Funds for the Central University(No.2017JYCXJJ002)
文摘In this paper, in-situ coagulation of 0.9Al_2O_3–0.1TiO_2 suspension and microwave dielectric properties of 0.9Al_2O_3–0.1TiO_2 ceramics prepared by a novel direct coagulation casting via high valence counter ions(DCC-HVCI) method were proposed. The 0.9Al_2O_3–0.1TiO_2 suspension could be coagulated via controlled release of calcium ions from calcium iodate at an elevated temperature. The influence of tri-ammonium citrate(TAC) content, solid loading, and calcium iodate content on the rheological properties of the suspension was investigated. In addition, the influence of coagulation temperature on coagulation time and properties of green bodies was also studied. It was found that the stable 0.9Al_2O_3–0.1TiO_2 suspension could be successfully prepared by adding 0.3 wt% TAC and adjusting pH value to 10–12 at room temperature. 0.9Al_2O_3–0.1TiO_2 green bodies with uniform microstructures were coagulated by adding 8.0 g/L calcium iodate after treating at 70 ℃ for 1 h. 0.9Al_2O_3–0.1TiO_2 ceramics, sintered at 1500 ℃ for 4 h and annealed at 1100 ℃ for 5 h, showed uniform microstructures with density of 3.62±0.02 g/cm^3. The microwave dielectric properties of 0.9Al_2O_3–0.1TiO_2 ceramics prepared by DCC-HVCI method were: ε_r = 11.26±0.06, Q×f = 11569± 629 GHz, τ_t = 0.93±0.60 ppm/℃. The DCC-HVCI method is a novel and promising route without binder removal process to prepare complex-shaped microwave dielectric ceramics with uniform microstructures and good microwave dielectric properties.