Interactions between apolipoprotein E (apo E) and amyloid beta (Aβ) are associated with the peripheral clearance of Aβ and are important to the development of neurodegenerative diseases. Interests in acute phase pro...Interactions between apolipoprotein E (apo E) and amyloid beta (Aβ) are associated with the peripheral clearance of Aβ and are important to the development of neurodegenerative diseases. Interests in acute phase proteins (APP) as biomarkers for the early progression of Alzheimer’s disease indicate that the peripheral Aβ metabolism is perturbed and the role of nutritional diets are important to reduce APPs to maintain peripheral Aβ clearance with relevance to hepatic cholesterol homeostasis and brain amyloidosis. The role of nutriproteomic diets that reverse the effects of high fat diets are associated with the reduction in APPs, cholesterol homeostasis and improved clearance of Aβ. Nutritional diets that reduce the increase in plasma endotoxins (gut microbiotica) such as lipopolysaccarides (LPS) reduce the effects of LPS on cell membranes and increase the cellular uptake of Aβ by interactions with apo E. LPS alter hepatic lipid metabolism with an increase hepatic cytokines and APPs in plasma. Interactions between apo E and Aβ are altered by LPS with increased binding of LPS to apo E with effects on electrostatic alterations in Aβ oligomers. The role of LPS in neurodegenerative diseases includes the effects of LPS on alpha-synuclein metabolism with relevance to Parkinson’s disease and Alzheimer’s展开更多
Well-crystallized zeolite beta was synthesized by using acid-leached metakaolin as the silica-alumina source and tetraethylammonium hydroxide structure-directing agent.The influence of the composition of the reaction ...Well-crystallized zeolite beta was synthesized by using acid-leached metakaolin as the silica-alumina source and tetraethylammonium hydroxide structure-directing agent.The influence of the composition of the reaction mixture on product crystallinity was investigated,and the crystallization process was studied by examining solid samples obtained at different synthesis times.Results showed that the acid-leached metakaolin was fully converted into soluble aluminum and silicon species,which is crucial for the formation of well-crystallized zeolite beta.At the beginning of the crystallization process,these soluble aluminum and silicon species formed a aluminum-rich intermediate structure with layer morphology.With the crystallization proceeding,more silicon species were incorporated into the zeolite beta framework and the layered structure was changed into spherical particles of zeolite beta with high SiO 2 /Al 2 O 3 ratio and crystallinity.展开更多
A cued search algorithm with uncertain detection performance is proposed for phased array radars. Firstly, a target search model based on the information gain criterion is presented with known detection performance, a...A cued search algorithm with uncertain detection performance is proposed for phased array radars. Firstly, a target search model based on the information gain criterion is presented with known detection performance, and the statistical characteristic of the detection probability is calculated by using the fluctuant model of the target radar cross section （RCS）. Secondly, when the detection probability is completely unknown, its probability density function is modeled with a beta distribution, and its posterior probability distribution with the radar observation is derived based on the Bayesian theory. Finally simulation results show that the cued search algorithm with a known RCS fluctuant model can achieve the best performance, and the algorithm with the detection probability modeled as a beta distribution is better than that with a random selected detection probability because the model parameters can be updated by the radar observation to approach to the real value of the detection probability.展开更多
目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状...目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。展开更多
Low thermal expansion superalloys have been used for a number of years in a variety of applications, including gas turbine engines. The low thermal expansion characteristics of the most widely used class of materials ...Low thermal expansion superalloys have been used for a number of years in a variety of applications, including gas turbine engines. The low thermal expansion characteristics of the most widely used class of materials are derived from the ferromagnetic characteristics of Ni, Fe, and Co-based austenitic matrices containing little or no Cr.Alloy developments have been aimed at improving the oxidation resistance and stress accelerated grain boundary oxygen (SAGBO) attack.INCONEL alloy 783 is an oxidation resistant, low coefficient of thermal expansion superalloy developed for gas turbine applications. Alloy 783 represents a culmination in the development, of an alloy system with very high alumtnum content that, in addition to forming γ′,causes βaluminide phase precipitation in the austenitic matrix.This type of structure can be processed to resist both SAGBO and general oxidation,while providing low thermal expansion and useful mechanical properties up to 700℃.Key aspects of the alloy's development are presented.展开更多
Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo...Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo2O8 by the Rietveld method. The orthorhombic phase belonged to Pmn21 space group and the cell parameters were ao=0.597 1(9) nm, bo=0.730 6(1) nm, co=0.912 7(1) nm, Rp%=9.37; wRp%=11.81. The TEM images were also given. The comparison was made between precursor-heated and precursor-microwave routes. Metastable polymorphic phase was favorably formed by the latter method.展开更多
文摘Interactions between apolipoprotein E (apo E) and amyloid beta (Aβ) are associated with the peripheral clearance of Aβ and are important to the development of neurodegenerative diseases. Interests in acute phase proteins (APP) as biomarkers for the early progression of Alzheimer’s disease indicate that the peripheral Aβ metabolism is perturbed and the role of nutritional diets are important to reduce APPs to maintain peripheral Aβ clearance with relevance to hepatic cholesterol homeostasis and brain amyloidosis. The role of nutriproteomic diets that reverse the effects of high fat diets are associated with the reduction in APPs, cholesterol homeostasis and improved clearance of Aβ. Nutritional diets that reduce the increase in plasma endotoxins (gut microbiotica) such as lipopolysaccarides (LPS) reduce the effects of LPS on cell membranes and increase the cellular uptake of Aβ by interactions with apo E. LPS alter hepatic lipid metabolism with an increase hepatic cytokines and APPs in plasma. Interactions between apo E and Aβ are altered by LPS with increased binding of LPS to apo E with effects on electrostatic alterations in Aβ oligomers. The role of LPS in neurodegenerative diseases includes the effects of LPS on alpha-synuclein metabolism with relevance to Parkinson’s disease and Alzheimer’s
基金supported by Beijing Natural Science Foundation (Grant No.2093043)the National Natural Science Foundation of China (Grant No.20606038)
文摘Well-crystallized zeolite beta was synthesized by using acid-leached metakaolin as the silica-alumina source and tetraethylammonium hydroxide structure-directing agent.The influence of the composition of the reaction mixture on product crystallinity was investigated,and the crystallization process was studied by examining solid samples obtained at different synthesis times.Results showed that the acid-leached metakaolin was fully converted into soluble aluminum and silicon species,which is crucial for the formation of well-crystallized zeolite beta.At the beginning of the crystallization process,these soluble aluminum and silicon species formed a aluminum-rich intermediate structure with layer morphology.With the crystallization proceeding,more silicon species were incorporated into the zeolite beta framework and the layered structure was changed into spherical particles of zeolite beta with high SiO 2 /Al 2 O 3 ratio and crystallinity.
基金supported by the National Natural Science Foundation of China (61372165)the Postdoctoral Science Foundation of China (201150M15462012T50874)
文摘A cued search algorithm with uncertain detection performance is proposed for phased array radars. Firstly, a target search model based on the information gain criterion is presented with known detection performance, and the statistical characteristic of the detection probability is calculated by using the fluctuant model of the target radar cross section （RCS）. Secondly, when the detection probability is completely unknown, its probability density function is modeled with a beta distribution, and its posterior probability distribution with the radar observation is derived based on the Bayesian theory. Finally simulation results show that the cued search algorithm with a known RCS fluctuant model can achieve the best performance, and the algorithm with the detection probability modeled as a beta distribution is better than that with a random selected detection probability because the model parameters can be updated by the radar observation to approach to the real value of the detection probability.
文摘目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。
文摘Low thermal expansion superalloys have been used for a number of years in a variety of applications, including gas turbine engines. The low thermal expansion characteristics of the most widely used class of materials are derived from the ferromagnetic characteristics of Ni, Fe, and Co-based austenitic matrices containing little or no Cr.Alloy developments have been aimed at improving the oxidation resistance and stress accelerated grain boundary oxygen (SAGBO) attack.INCONEL alloy 783 is an oxidation resistant, low coefficient of thermal expansion superalloy developed for gas turbine applications. Alloy 783 represents a culmination in the development, of an alloy system with very high alumtnum content that, in addition to forming γ′,causes βaluminide phase precipitation in the austenitic matrix.This type of structure can be processed to resist both SAGBO and general oxidation,while providing low thermal expansion and useful mechanical properties up to 700℃.Key aspects of the alloy's development are presented.
文摘Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo2O8 by the Rietveld method. The orthorhombic phase belonged to Pmn21 space group and the cell parameters were ao=0.597 1(9) nm, bo=0.730 6(1) nm, co=0.912 7(1) nm, Rp%=9.37; wRp%=11.81. The TEM images were also given. The comparison was made between precursor-heated and precursor-microwave routes. Metastable polymorphic phase was favorably formed by the latter method.
