目的探讨补充益生菌对根除慢性胃炎患者幽门螺旋杆菌(Helicobacter pylori, Hp)的临床效果及其胃黏膜病理损伤转归的影响。方法收集2017年1月1日—2017年8月31日在广东药科大学附属第二医院确诊的慢性胃炎伴Hp感染患者104例,按随机数字...目的探讨补充益生菌对根除慢性胃炎患者幽门螺旋杆菌(Helicobacter pylori, Hp)的临床效果及其胃黏膜病理损伤转归的影响。方法收集2017年1月1日—2017年8月31日在广东药科大学附属第二医院确诊的慢性胃炎伴Hp感染患者104例,按随机数字表法将患者分为对照组和实验组,每组52例,对照组患者仅根除Hp,实验组患者予根除Hp同时补充益生菌治疗,对比分析2组患者干预前和干预6个月后的临床症状、胃镜下胃黏膜表现、Hp根除率以及胃黏膜病理变化(包括炎症、萎缩、肠化生和异型增生)情况。结果根除Hp对2组患者的临床症状和病理损伤均有不同程度的改善,但实验组患者的临床疗效和Hp根除率优于对照组(90.38%vs. 78.85%,P=0.036;90.38%vs. 75.00%,P=0.038),实验组患者干预后胃黏膜病理总评分低于对照组(4.15±1.02 vs. 5.92±1.75,P<0.05),其中胃黏膜炎症和肠化生病理改善疗效显著优于对照组(0.87±0.12 vs. 1.46±0.37,P<0.05;1.27±0.45 vs. 1.81±0.58,P<0.05)。结论根除幽门螺旋杆菌能使大多数慢性胃炎患者临床获益,补充益生菌可有效提高患者的临床疗效和Hp根除率,并减轻胃黏膜的病理损伤。展开更多
The effects of pulsed magnetic field on the solidified microstructure of Mg-Gd-Y-Zr alloy were investigated. Fine uniform equiaxed grains are acquired in the whole ingot by the pulsed magnetic field treatment,and the ...The effects of pulsed magnetic field on the solidified microstructure of Mg-Gd-Y-Zr alloy were investigated. Fine uniform equiaxed grains are acquired in the whole ingot by the pulsed magnetic field treatment,and the average grain size of the as-cast φ50 mm and φ100 mm ingots is refined to 37 μm and 47 μm with the pulsed magnetic field.The macrosegregation of solute elements of Mg-Gd-Y-Zr alloy is also reduced by the pulsed magnetic field treatment. Structure refinement is due to the electromagnetic undercooling zone in front of the solid/liquid interface by the magnetic pressure,and reduction of temperature gradient by the vibration of melt resulted from the pulsed magnetic field,which increases the nucleation rate and prohibits dendrite growth.In addition,primary α-Mg dendrites break into fine crystals, resulting in a refined solidification structure of the magnesium alloys.The Joule heat effect induced in the melt also strengthens the grain refinement effect and the spheroidization of dendrite arms.展开更多
A macroscopic thermal field calculation and a microstructure simulation are performed to investigate the directional solidification of a nickel-based superalloy with applied direct current in this study.The heat effec...A macroscopic thermal field calculation and a microstructure simulation are performed to investigate the directional solidification of a nickel-based superalloy with applied direct current in this study.The heat effects of electric current passing through the solidification interface as Joule heat and Peltier heat are investigated in the calculations.The calculated result shows that the Joule heat improves the temperature gradient in the solidification interface,while the effect of Peltier heat is negligible for macroscopic thermal field.The directional growth of dendrites under the influence of Joule heat is investigated with simulation.It is found that under the influence of Joule heat,the dendrites are provided with self-adjustment ability of coordinating growth to achieve flat interface in macroscale during directional solidification with the direct electric current.This interesting phenomenon is brought by the crowdedly passing through the dendrite of electric current in the solidification interface for the large difference of the electrical resistivity between solid state and melt of the superalloy.展开更多
Effect of a low-voltage pulsed magnetic field(LVPMF)on the solidified microstructure and mechanical properties of Mg-Al-Zn alloy was studied.When the LVPMF is applied during solidification,the as-cast microstructure i...Effect of a low-voltage pulsed magnetic field(LVPMF)on the solidified microstructure and mechanical properties of Mg-Al-Zn alloy was studied.When the LVPMF is applied during solidification,the as-cast microstructure is significantly refined and a-Mg is modified from developed dendrite to fine rosette.This morphology modification is caused by the accumulation of Joule heat on dendrite tip.Accumulation of Joule heat on dendrite tip melts the dendrite tip and increases the radius of curvature.The increased radius of curvature at the dendrite tip lowers the growth rate and results in the formation of rosette a-Mg.With the application of the LVPMF,β precipitates,formed in the interdendritic liquid region,are connected to each other due to the smaller dimension of the primary and secondary arms and larger volume fraction of the β precipitates between the dendrites.Experimental results indicate that the yield strength and ultimate tensile strength are both increased under with the application of the LVPMF.However,elongation is slightly decreased with the application of the LVPMF due to the continuous β precipitates.展开更多
文摘目的探讨补充益生菌对根除慢性胃炎患者幽门螺旋杆菌(Helicobacter pylori, Hp)的临床效果及其胃黏膜病理损伤转归的影响。方法收集2017年1月1日—2017年8月31日在广东药科大学附属第二医院确诊的慢性胃炎伴Hp感染患者104例,按随机数字表法将患者分为对照组和实验组,每组52例,对照组患者仅根除Hp,实验组患者予根除Hp同时补充益生菌治疗,对比分析2组患者干预前和干预6个月后的临床症状、胃镜下胃黏膜表现、Hp根除率以及胃黏膜病理变化(包括炎症、萎缩、肠化生和异型增生)情况。结果根除Hp对2组患者的临床症状和病理损伤均有不同程度的改善,但实验组患者的临床疗效和Hp根除率优于对照组(90.38%vs. 78.85%,P=0.036;90.38%vs. 75.00%,P=0.038),实验组患者干预后胃黏膜病理总评分低于对照组(4.15±1.02 vs. 5.92±1.75,P<0.05),其中胃黏膜炎症和肠化生病理改善疗效显著优于对照组(0.87±0.12 vs. 1.46±0.37,P<0.05;1.27±0.45 vs. 1.81±0.58,P<0.05)。结论根除幽门螺旋杆菌能使大多数慢性胃炎患者临床获益,补充益生菌可有效提高患者的临床疗效和Hp根除率,并减轻胃黏膜的病理损伤。
基金Item Sponsored by Zhejiang Province Science Foundation of China[No.LQ12E05006]
文摘The effects of pulsed magnetic field on the solidified microstructure of Mg-Gd-Y-Zr alloy were investigated. Fine uniform equiaxed grains are acquired in the whole ingot by the pulsed magnetic field treatment,and the average grain size of the as-cast φ50 mm and φ100 mm ingots is refined to 37 μm and 47 μm with the pulsed magnetic field.The macrosegregation of solute elements of Mg-Gd-Y-Zr alloy is also reduced by the pulsed magnetic field treatment. Structure refinement is due to the electromagnetic undercooling zone in front of the solid/liquid interface by the magnetic pressure,and reduction of temperature gradient by the vibration of melt resulted from the pulsed magnetic field,which increases the nucleation rate and prohibits dendrite growth.In addition,primary α-Mg dendrites break into fine crystals, resulting in a refined solidification structure of the magnesium alloys.The Joule heat effect induced in the melt also strengthens the grain refinement effect and the spheroidization of dendrite arms.
基金Item Sponsored by National Natural Science Foundation of China[No.50931004]the National Basic Research Program of China[No.2010CB631205]
文摘A macroscopic thermal field calculation and a microstructure simulation are performed to investigate the directional solidification of a nickel-based superalloy with applied direct current in this study.The heat effects of electric current passing through the solidification interface as Joule heat and Peltier heat are investigated in the calculations.The calculated result shows that the Joule heat improves the temperature gradient in the solidification interface,while the effect of Peltier heat is negligible for macroscopic thermal field.The directional growth of dendrites under the influence of Joule heat is investigated with simulation.It is found that under the influence of Joule heat,the dendrites are provided with self-adjustment ability of coordinating growth to achieve flat interface in macroscale during directional solidification with the direct electric current.This interesting phenomenon is brought by the crowdedly passing through the dendrite of electric current in the solidification interface for the large difference of the electrical resistivity between solid state and melt of the superalloy.
基金Item Sponsored by National Natural Science Foundation of China[No.50774075 and 51034012]
文摘Effect of a low-voltage pulsed magnetic field(LVPMF)on the solidified microstructure and mechanical properties of Mg-Al-Zn alloy was studied.When the LVPMF is applied during solidification,the as-cast microstructure is significantly refined and a-Mg is modified from developed dendrite to fine rosette.This morphology modification is caused by the accumulation of Joule heat on dendrite tip.Accumulation of Joule heat on dendrite tip melts the dendrite tip and increases the radius of curvature.The increased radius of curvature at the dendrite tip lowers the growth rate and results in the formation of rosette a-Mg.With the application of the LVPMF,β precipitates,formed in the interdendritic liquid region,are connected to each other due to the smaller dimension of the primary and secondary arms and larger volume fraction of the β precipitates between the dendrites.Experimental results indicate that the yield strength and ultimate tensile strength are both increased under with the application of the LVPMF.However,elongation is slightly decreased with the application of the LVPMF due to the continuous β precipitates.
