Among the three types of accelerated life testing, that is, the constantstress accelerated life testing, the step stress accelerated life testing, and the progressive stress accelerated life testing, the last one is t...Among the three types of accelerated life testing, that is, the constantstress accelerated life testing, the step stress accelerated life testing, and the progressive stress accelerated life testing, the last one is the most effective and economical way to get the failure times of products in a short period of time. In this article a deficiency in the classical approach is pointed out and a new method for the statistical analysis of life data, especially for electronic products, under progressive stress (voltage) V(t)=Kt is given. Using the Bayesian method, for certain choices of the prior distribution, several forms of estimators of the parameters in the normal stress Weibull distribution and the inverse power law model are derived. In particular, when the new shape parameter of the distribution under progressive stress is given (or estimated in advance), the closed forms of these estimators are relatively simple and are numerically accessible on computers. The formulations are given for the general case and are illustrated for a special simple case. Comparison with the classical approach using pseudorandom data as well as real data on solid tantatum electrolytic capacitors shows that the proposed method is better and more effective.展开更多
NAD+/NADH redox state has been implicated in many diseases such as cancer and diabetes aswell as in the regulation of embryonic development and aging,To fluorimetrically sssthemitochondrial redox state,Dr.Chance and c...NAD+/NADH redox state has been implicated in many diseases such as cancer and diabetes aswell as in the regulation of embryonic development and aging,To fluorimetrically sssthemitochondrial redox state,Dr.Chance and co-workers measured the fluorescence of NADH andoxidized flavoproteins(Fp)including favin-adenine-dinucleotide(FAD)and demonstrated theirratio(i.e.the redox ratio)is a sensitive indicator of the mitochondrial redox states.,The Chanceredox sca mer was built to simult aneously measure NADH and Fp in tisue at submilimeter scalein 3D using the freeze-trap protocol.This paper summarizes our recent research experience,development and new applications of the redox scanning technique in collaboration with Dr.Chance beginning in 2005.Dr.Chance initiated or actively involved in many of the projectsduring the last several years of his life.We advanced the redox scanning technigue by measuringthe nominal concentrations(in reference to the frozen solution standards)of the endogenousfuorescent analy tes,i.e.,[NADH]and[rp]to quantify the redox ratios in various biologicaltissues.The advancement has enabled us to identify an array of the redox indices as quantitativeimaging,biomarkers(including[NADH],[Fp],[Fp]/[NADH]+[Fp],[NADH]/[Fp],and theirstandard deviations)for studying some important biological questions on cancer and normaltsue metabolism.We found that the redox indices were asociated or changed with(NADH)tumorigenesis(cancer versus non-cancer of human breast tisue biopsies);(2)tumor metastaticpotential;(3)tumor glucose uptake;(4)tumor p53 stat us;(5)PI3K pathway activation in pre-malignant tissue;(6)therapeutic ffects on tumors;(7)embryonic stem cell diferentiation;(8)the heart under fasting,Together,our work demonstrated that the tisue redox indices obtainedfrom the redox scanning technique may provide usefil information about tisue met abolism and physiology status in normal and diseased tissues.The Chance redox scanner and other redoximaging techniques may have wide-ranging potential applications in many fields,such as cancer,diabetes,developmental process,mitochondrial diseases,neurodegenerative diseases,and aging.展开更多
前瞻性临床研究显示,患者首次脑卒中的发病率同患有心肌梗死、非脑卒中患者的血压有直接的关系,而经抗高血压临床治疗对照试验,可知舒张压的下降同高血压患者脑卒中再发的几率呈线性关系,平均每降低5~6 mm Hg,发病几率则减少30%~40%。...前瞻性临床研究显示,患者首次脑卒中的发病率同患有心肌梗死、非脑卒中患者的血压有直接的关系,而经抗高血压临床治疗对照试验,可知舒张压的下降同高血压患者脑卒中再发的几率呈线性关系,平均每降低5~6 mm Hg,发病几率则减少30%~40%。针对高血压人群及非高血压人群进行降压治疗,可以有效预防脑卒中再发,可以通过临床PROGRESS、PATS试验进行验证。通过研究降压治疗对脑卒中再发预防的研究,分析PROGRESS和PATS试验及其临床意义,以期通过降压治疗的方式,控制脑卒中的发病率,改善脑血管疾病患者的生活质量,更好的指导临床治疗。展开更多
今年2月5日,位于西部非洲的布基纳法索以原执政的争取人民民主组织——劳动运动为基础,联合其他10个政党和另外2个政党的部分人,共同组建了一个新党——争取民主和进步大会党(CONGRES POUR LADEMOCRATIE ET LE PROGRES),属于社会民主党...今年2月5日,位于西部非洲的布基纳法索以原执政的争取人民民主组织——劳动运动为基础,联合其他10个政党和另外2个政党的部分人,共同组建了一个新党——争取民主和进步大会党(CONGRES POUR LADEMOCRATIE ET LE PROGRES),属于社会民主党性质。展开更多
文摘Among the three types of accelerated life testing, that is, the constantstress accelerated life testing, the step stress accelerated life testing, and the progressive stress accelerated life testing, the last one is the most effective and economical way to get the failure times of products in a short period of time. In this article a deficiency in the classical approach is pointed out and a new method for the statistical analysis of life data, especially for electronic products, under progressive stress (voltage) V(t)=Kt is given. Using the Bayesian method, for certain choices of the prior distribution, several forms of estimators of the parameters in the normal stress Weibull distribution and the inverse power law model are derived. In particular, when the new shape parameter of the distribution under progressive stress is given (or estimated in advance), the closed forms of these estimators are relatively simple and are numerically accessible on computers. The formulations are given for the general case and are illustrated for a special simple case. Comparison with the classical approach using pseudorandom data as well as real data on solid tantatum electrolytic capacitors shows that the proposed method is better and more effective.
基金made possible by the financial support of National Institute of Health(R01 CA155348(L.Z.Li))。
文摘NAD+/NADH redox state has been implicated in many diseases such as cancer and diabetes aswell as in the regulation of embryonic development and aging,To fluorimetrically sssthemitochondrial redox state,Dr.Chance and co-workers measured the fluorescence of NADH andoxidized flavoproteins(Fp)including favin-adenine-dinucleotide(FAD)and demonstrated theirratio(i.e.the redox ratio)is a sensitive indicator of the mitochondrial redox states.,The Chanceredox sca mer was built to simult aneously measure NADH and Fp in tisue at submilimeter scalein 3D using the freeze-trap protocol.This paper summarizes our recent research experience,development and new applications of the redox scanning technique in collaboration with Dr.Chance beginning in 2005.Dr.Chance initiated or actively involved in many of the projectsduring the last several years of his life.We advanced the redox scanning technigue by measuringthe nominal concentrations(in reference to the frozen solution standards)of the endogenousfuorescent analy tes,i.e.,[NADH]and[rp]to quantify the redox ratios in various biologicaltissues.The advancement has enabled us to identify an array of the redox indices as quantitativeimaging,biomarkers(including[NADH],[Fp],[Fp]/[NADH]+[Fp],[NADH]/[Fp],and theirstandard deviations)for studying some important biological questions on cancer and normaltsue metabolism.We found that the redox indices were asociated or changed with(NADH)tumorigenesis(cancer versus non-cancer of human breast tisue biopsies);(2)tumor metastaticpotential;(3)tumor glucose uptake;(4)tumor p53 stat us;(5)PI3K pathway activation in pre-malignant tissue;(6)therapeutic ffects on tumors;(7)embryonic stem cell diferentiation;(8)the heart under fasting,Together,our work demonstrated that the tisue redox indices obtainedfrom the redox scanning technique may provide usefil information about tisue met abolism and physiology status in normal and diseased tissues.The Chance redox scanner and other redoximaging techniques may have wide-ranging potential applications in many fields,such as cancer,diabetes,developmental process,mitochondrial diseases,neurodegenerative diseases,and aging.
文摘前瞻性临床研究显示,患者首次脑卒中的发病率同患有心肌梗死、非脑卒中患者的血压有直接的关系,而经抗高血压临床治疗对照试验,可知舒张压的下降同高血压患者脑卒中再发的几率呈线性关系,平均每降低5~6 mm Hg,发病几率则减少30%~40%。针对高血压人群及非高血压人群进行降压治疗,可以有效预防脑卒中再发,可以通过临床PROGRESS、PATS试验进行验证。通过研究降压治疗对脑卒中再发预防的研究,分析PROGRESS和PATS试验及其临床意义,以期通过降压治疗的方式,控制脑卒中的发病率,改善脑血管疾病患者的生活质量,更好的指导临床治疗。
