The effect of Glycyrrhiza uralensis Fisch (GRZ) aqueous extract and one of its active principles Glycyrrhetinic acid (GRT) on hepatic cytochrome P450 in mice were investigated. Oral administration of GRZ at 10g/kg/d o...The effect of Glycyrrhiza uralensis Fisch (GRZ) aqueous extract and one of its active principles Glycyrrhetinic acid (GRT) on hepatic cytochrome P450 in mice were investigated. Oral administration of GRZ at 10g/kg/d or GRT at 50 mg/kg/d for 7 days was foulld to increase the P450 contents up to 4.6 fold compared with the controls. The activities of aryl hydrocarbon hydroxylase (AHH,3. 1 and 3. 3 fold), aminopyrine N-demethylase (ADM, 4. 2 and 3. 2 folds), and 7-ethoxycumarin O-deethylase (ECOD, 2. 8 and 2. 5 fold) were also shown to be increased. Westem blot analysis showed that the subtypes of P450 isoforms induced selectively by GRZ and GRT included CYP1A1 (1. 8 and 1. 5 fold over that of the control, respectively), CYP2B1 (both 1.3 fold), and CYP2C11(3 .2 and 3 .0 fold). Moreover, significant positive correlation between the P450 content or the isoforms and the corresponding enzyme activities mentioned above was observed.展开更多
Given an irreducible plane algebraic curve of degree d 〉 3, we compute its numerical singular points, determine their multiplicities, and count the number of distinct tangents at each to decide whether the singular p...Given an irreducible plane algebraic curve of degree d 〉 3, we compute its numerical singular points, determine their multiplicities, and count the number of distinct tangents at each to decide whether the singular points are ordinary. The numerical procedures rely on computing numerical solutions of polynomial systems by homotopy continuation method and a reliable method that calculates multiple roots of the univariate polynomials accurately using standard machine precision. It is completely different from the traditional symbolic computation and provides singular points and their related properties of some plane algebraic curves that the symbolic software Maple cannot work out. Without using multiprecision arithmetic, extensive numerical experiments show that our numerical procedures are accurate, efficient and robust, even if the coefficients of plane algebraic curves are inexact.展开更多
文摘The effect of Glycyrrhiza uralensis Fisch (GRZ) aqueous extract and one of its active principles Glycyrrhetinic acid (GRT) on hepatic cytochrome P450 in mice were investigated. Oral administration of GRZ at 10g/kg/d or GRT at 50 mg/kg/d for 7 days was foulld to increase the P450 contents up to 4.6 fold compared with the controls. The activities of aryl hydrocarbon hydroxylase (AHH,3. 1 and 3. 3 fold), aminopyrine N-demethylase (ADM, 4. 2 and 3. 2 folds), and 7-ethoxycumarin O-deethylase (ECOD, 2. 8 and 2. 5 fold) were also shown to be increased. Westem blot analysis showed that the subtypes of P450 isoforms induced selectively by GRZ and GRT included CYP1A1 (1. 8 and 1. 5 fold over that of the control, respectively), CYP2B1 (both 1.3 fold), and CYP2C11(3 .2 and 3 .0 fold). Moreover, significant positive correlation between the P450 content or the isoforms and the corresponding enzyme activities mentioned above was observed.
基金The NSF (61033012,10801023,11171052,10771028) of China
文摘Given an irreducible plane algebraic curve of degree d 〉 3, we compute its numerical singular points, determine their multiplicities, and count the number of distinct tangents at each to decide whether the singular points are ordinary. The numerical procedures rely on computing numerical solutions of polynomial systems by homotopy continuation method and a reliable method that calculates multiple roots of the univariate polynomials accurately using standard machine precision. It is completely different from the traditional symbolic computation and provides singular points and their related properties of some plane algebraic curves that the symbolic software Maple cannot work out. Without using multiprecision arithmetic, extensive numerical experiments show that our numerical procedures are accurate, efficient and robust, even if the coefficients of plane algebraic curves are inexact.
