目的:比较臭氧(O3)联合再矿化与单纯O3、单纯再矿化处理对离体乳牙脱矿牙本质显微硬度及表层微结构的影响。方法:根据纳入和排除标准筛选出经无创伤修复治疗法去腐后包埋纵剖的40例离体乳牙样本,随机分为4组,分别进行40 s O3处理(A组);1...目的:比较臭氧(O3)联合再矿化与单纯O3、单纯再矿化处理对离体乳牙脱矿牙本质显微硬度及表层微结构的影响。方法:根据纳入和排除标准筛选出经无创伤修复治疗法去腐后包埋纵剖的40例离体乳牙样本,随机分为4组,分别进行40 s O3处理(A组);1 min再矿化液涂布(B组)及40 s O3联合1 min再矿化处理(C组)及对照组(D组)。用维氏显微硬度值(Vikers Microhardness Number,VHN)和扫描电镜(Scanningelectron microscope,SEM)评价效果。结果:本实验采取析因设计,经方差分析显示,A、B两组VHN与对照组相比差异有统计学意义(P<0.05),C组VHN虽有升高,但其交互作用无统计学意义(P>0.05);扫描电镜显示:A组和C组较B组及D组(对照组)清洁度高。结论:40 s O3联合1 min再矿化处理可显著提高乳牙脱矿牙本质的VHN,但VHN的升高主要是因O3对牙本质有较强的脱水作用,改变了牙本质弹性模量而引起的。O3的负压状态有利于清除牙本质碎屑,暴露牙本质小管。展开更多
A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which i...A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which is aimed at efficient operation of the overall system considering the operational characteristic of the components and taking the curves of engine, hydraulic pump/motor and hydrau- lic pump as the main design basis; regenerative control strategy which makes regenerative brake sys- tem and frictional brake system work harmoniously is designed to raise recovery rate of regenerative brake energy. System dynamic modeling and simulation results show that the energy control strategy designed here is able to adapt system to changes of working condition and switch the operating mode reasonably. The regenerative braking control strategy is effective in raising the utilization of energy and improving fuel economy.展开更多
Objectives. To compare the effects of losartan, enalapril and their combination in the prevention ofleft ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in the rat. Methods. AMI model was induced...Objectives. To compare the effects of losartan, enalapril and their combination in the prevention ofleft ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in the rat. Methods. AMI model was induced in female SD rats by ligating left coronary artery. Forty-eight hours after the procedure, 83 surviving rats were randomized into one of the following 4 groups: 1 ) AMI control group (n =19), 2) losartan group (n= 22, 3 mg @ kg - 1 @ d - 1 ), 3 ) enalapril group (n = 20, 1 mg @ kg - 1 @ d - 1 ), 4) losartan - enalapril combinative group (n = 22, 3 and 1 mg @ kg- 1 @ d - 1 respectively). 5 ) sham-operated group ( n =10) and 6) normal rats group (n = 10) were selected randomly to serve as non-infarction controls. Losartan and enalapril were delivered by direct gastric gavage. After 4 weeks of medical therapy, hemodynamic studies were performed in each group, then the rat hearts were fixed with 10% formalin and pathologic analysis on them was performed. Complete experimental data was obtained in 56 rats, comprising 1 ) AMI controls (n = 11 ), 2) losartan group (n = 10), 3 ) enalapril group (n = 10), 4) the combination of losartan and enalapril group (n = 11 ),5) sham - operated group (n = 6) and 6) normal controls (n=8). Results. There were no significant differences among the 4 AMI groups in MI size (41.7% ～ 43.4%, all P＞ 0.05). Compared with sham group, the left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV), long and short axis length (L and D), as well as LV absolute and relative weight (LVAW and LVRW)in AMI group were all significantly increased ( P ＜0.05 ～ 0. 001 ); whereas the maximum left ventricular pressure rising and droping rates ( + dp/dt) and their corrected values by LV systolic pressure ( + dp/dt/LVSP)were significantly reduced (all P ＜0.001 ), indicating LVRM occurred and LV systolic and diastolic function impaired after AMI. Compared with AMI group , LVEDP, LVV, LVAW and LVRW were all significantly decreased (P ＜0.05～0.001 ); while + dp/dt/LVSP were significantly enhanced in all 3 treatment groups (P ＜0.05～0.001 ) except -dp/dt/LVSP in losartan group (P＞ 0. 05 ). There were no significant differences in the above indices among the 3 treatment groups (all P＞ 0.05). Conclusion. Both losartan and enalapril can prevent from LVRM after AMI in the rat and improve LV function with equivalent effects. There seems no additive effect when the 2 drugs are used in combination.展开更多
文摘目的:比较臭氧(O3)联合再矿化与单纯O3、单纯再矿化处理对离体乳牙脱矿牙本质显微硬度及表层微结构的影响。方法:根据纳入和排除标准筛选出经无创伤修复治疗法去腐后包埋纵剖的40例离体乳牙样本,随机分为4组,分别进行40 s O3处理(A组);1 min再矿化液涂布(B组)及40 s O3联合1 min再矿化处理(C组)及对照组(D组)。用维氏显微硬度值(Vikers Microhardness Number,VHN)和扫描电镜(Scanningelectron microscope,SEM)评价效果。结果:本实验采取析因设计,经方差分析显示,A、B两组VHN与对照组相比差异有统计学意义(P<0.05),C组VHN虽有升高,但其交互作用无统计学意义(P>0.05);扫描电镜显示:A组和C组较B组及D组(对照组)清洁度高。结论:40 s O3联合1 min再矿化处理可显著提高乳牙脱矿牙本质的VHN,但VHN的升高主要是因O3对牙本质有较强的脱水作用,改变了牙本质弹性模量而引起的。O3的负压状态有利于清除牙本质碎屑,暴露牙本质小管。
基金Supported by the National Natural Science Foundation of China(No.50875054)Weihai Science and Technology Development Plan Project(No.2012DXGJ13)
文摘A series-parallel hydraulic hybrid system applied to public buses is put torwaro, ano parameters of key components are analyzed and determined. Energy management strategy based on logic thresh- old is designed which is aimed at efficient operation of the overall system considering the operational characteristic of the components and taking the curves of engine, hydraulic pump/motor and hydrau- lic pump as the main design basis; regenerative control strategy which makes regenerative brake sys- tem and frictional brake system work harmoniously is designed to raise recovery rate of regenerative brake energy. System dynamic modeling and simulation results show that the energy control strategy designed here is able to adapt system to changes of working condition and switch the operating mode reasonably. The regenerative braking control strategy is effective in raising the utilization of energy and improving fuel economy.
文摘Objectives. To compare the effects of losartan, enalapril and their combination in the prevention ofleft ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in the rat. Methods. AMI model was induced in female SD rats by ligating left coronary artery. Forty-eight hours after the procedure, 83 surviving rats were randomized into one of the following 4 groups: 1 ) AMI control group (n =19), 2) losartan group (n= 22, 3 mg @ kg - 1 @ d - 1 ), 3 ) enalapril group (n = 20, 1 mg @ kg - 1 @ d - 1 ), 4) losartan - enalapril combinative group (n = 22, 3 and 1 mg @ kg- 1 @ d - 1 respectively). 5 ) sham-operated group ( n =10) and 6) normal rats group (n = 10) were selected randomly to serve as non-infarction controls. Losartan and enalapril were delivered by direct gastric gavage. After 4 weeks of medical therapy, hemodynamic studies were performed in each group, then the rat hearts were fixed with 10% formalin and pathologic analysis on them was performed. Complete experimental data was obtained in 56 rats, comprising 1 ) AMI controls (n = 11 ), 2) losartan group (n = 10), 3 ) enalapril group (n = 10), 4) the combination of losartan and enalapril group (n = 11 ),5) sham - operated group (n = 6) and 6) normal controls (n=8). Results. There were no significant differences among the 4 AMI groups in MI size (41.7% ～ 43.4%, all P＞ 0.05). Compared with sham group, the left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV), long and short axis length (L and D), as well as LV absolute and relative weight (LVAW and LVRW)in AMI group were all significantly increased ( P ＜0.05 ～ 0. 001 ); whereas the maximum left ventricular pressure rising and droping rates ( + dp/dt) and their corrected values by LV systolic pressure ( + dp/dt/LVSP)were significantly reduced (all P ＜0.001 ), indicating LVRM occurred and LV systolic and diastolic function impaired after AMI. Compared with AMI group , LVEDP, LVV, LVAW and LVRW were all significantly decreased (P ＜0.05～0.001 ); while + dp/dt/LVSP were significantly enhanced in all 3 treatment groups (P ＜0.05～0.001 ) except -dp/dt/LVSP in losartan group (P＞ 0. 05 ). There were no significant differences in the above indices among the 3 treatment groups (all P＞ 0.05). Conclusion. Both losartan and enalapril can prevent from LVRM after AMI in the rat and improve LV function with equivalent effects. There seems no additive effect when the 2 drugs are used in combination.
