Beginning with the explicitly covariant Maxwell equations in media, we deduce an explicitly covariant stress-energy-momentum balance equation in material media. Proceeding in this way we avoid mixing external fields a...Beginning with the explicitly covariant Maxwell equations in media, we deduce an explicitly covariant stress-energy-momentum balance equation in material media. Proceeding in this way we avoid mixing external fields and self fields, as occurs if one begins with Lorentz＇s law, the most usual approach appearing in textbooks. Indeed our deduction implies a generalized force density in which the total fields appear. As an application of the present deduction, we discuss briefly the Abraham-Minkowski controversy, showing its relation to open or closed electromagnetic systems. This approach will be interesting for scholars as well as graduate students interested in conceptual problems of relativistic electromagnetism.展开更多
The tensile properties of a series of soybean protein yarns are tested in USTER THINKPAID Ⅲ. A nonlinear viscoelastic model has been proposed to describe the tensile behavior of soybean protein yarns. The model is co...The tensile properties of a series of soybean protein yarns are tested in USTER THINKPAID Ⅲ. A nonlinear viscoelastic model has been proposed to describe the tensile behavior of soybean protein yarns. The model is composed of a Maxwell element, a linear spring and a nonlinear spring. The tensile properties of soybean protein yam are analyzed. The stress-strain curves of the yams are fitted. The average breaking tenacity and specific work of rupture are calculated using the average breaking strain. Comparisons indicate that theoretical predictions conform the experimental results very well.展开更多
This study was carried out in the Wistar rats to investigate the effect of Tang herb on the pharmacokinetics of the antiretroviral drug lopinavir （LPV） following single oral administration. Rats were randomly divide...This study was carried out in the Wistar rats to investigate the effect of Tang herb on the pharmacokinetics of the antiretroviral drug lopinavir （LPV） following single oral administration. Rats were randomly divided into LPV group （36 mg/kg） and LPV combining with Tang herb group （LPV： 36 mg/kg, Tang herb： 864 mg/kg）. The blood concentrations of lopinavir at 0, 0.5, 1, 2, 4, 8, 10, 12, 14, 16, 22 h after administration were determined by HPLC and the pharmacokinetic parameters were investigated. The results showed that Tang herb significantly increased the Cmax and A UC （P〈0.05） while slightly increased the t1/2z and Tmax of lopinavir （P〉0.05）. The present study suggests that Tang herb may delay the absorption, increase the time to reach the maximum concentration, and improve the bioavailability of LPV. Further evaluation of the possible interaction mechanism between Tang herb and LPV needs to be studied.展开更多
In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human ...In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human plasma. Entecavir was used as an internal standard, and plasma samples were prepared by solid-phase extraction performed on Phenomenex Strata cartridges （30 mg）. The mobile phase consisted of 10 mM ammonium acetate in water and methanol （60：40, v/v）. The chromatographic separation was performed isocratically on a Phenomenex C18 （4.6 mm×150 mm, 5 μm）, and analytes were analyzed in multiple reaction monitoring （MRM） mode with positive electrospray ionization （ESI） interface using the respective [M＋H] ＋ ions, m/z 288.2→m/z 176.1 for tenofovir and m/z 278.1→m/z 152 for entecavir. The calibration curve （r2 = 0.9962） of tenofovir was established within the range of 4.096-1000 μg/L. The intra- and inter-day precisions were less than 10%. This validated method was successfully applied to a pharmacokinetic study in 12 healthy Chinese volunteers after the oral administration of tenofovir disonroxil fumarate.展开更多
Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations ...Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations and f(R) gravity by a natural holographic approach,the quasi-static condition is necessary.We also find the surface stress tensor and the surface electric current,surface magnetic current on a holographic screen for f(R) gravity and Maxwell's theory,respectively.展开更多
A tablet consisting of direct-acting antiviral agents,ledipasvir（a NS5 A protein inhibitor） and sofosbuvir（a NS5 B polymerase inhibitor）,is the first fixed-dose preparation used in the antiviral therapy of hepatit...A tablet consisting of direct-acting antiviral agents,ledipasvir（a NS5 A protein inhibitor） and sofosbuvir（a NS5 B polymerase inhibitor）,is the first fixed-dose preparation used in the antiviral therapy of hepatitis C.A model-based meta-analysis of ledipasvir and GS331007,the primary metabolite of sofosbuvir,enabled the integration of pharmacokinetic（PK） information from separate clinical trials and the quantitative characterization of the population pharmacokinetics of these two drugs.A systematic publication search was conducted for the clinical studies of ledipasvir and sofosbuvir.A total of 401 arm-level aggregate concentrations of GS331007 and 188 concentrations of ledipasvir were used for PK modeling.A two-compartment disposition model was used for both ledipasvir and GS331007.Zero-order absorption was applied for ledipasvir PK modeling,and a combined zero- and first-order absorption was used for the modeling of GS331007.Absorption lag was observed in concentration-time profiles of both ledipasvir and GS331007.To aid the development of direct-acting antiviral drugs,our established PK models provided a basis for the further PK-viral kinetic studies of ledipasvir and sofosbuvir.展开更多
In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure incl...In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure includes a new analytical method and high accurate finite element simulations. In the part of theoretical analysis, three-dimensional Maxwell stress functions are employed in order to derive three-dimensional crack tip fields. Based on the theoretical analysis, an equation which can describe the relationship among the three-dimensional J-integral J(z), the stress intensity factor K(z) and the tri-axial stress constraint level Tz(z) is derived first. In the part of finite element simulations, a fine mesh including 153360 elements is constructed to compute the stress field near the crack front, J(z) and Tz(z). Numerical results show that in the plane very close to the free surface, the K field solution is still valid for in-plane stresses. Comparison with the numerical results shows that the analytical results are valid.展开更多
In this paper an investigation into dust acoustic sofitary waves （DASWs） in the presence of superthermM electrons and ions in a magnetized plasma with cold dust gains and trapped electrons is discussed. The dynamic ...In this paper an investigation into dust acoustic sofitary waves （DASWs） in the presence of superthermM electrons and ions in a magnetized plasma with cold dust gains and trapped electrons is discussed. The dynamic of both electrons and ions is simulated by the generalized Lorentzian （κ） distribution function （DF）. The dust grains are cold and their dynamics are studied by hydrodynamic equations. The basic set of fluid equations is reduced to modified Korteweg-de Vries （mKdV） equation using Reductive Perturbation Theory （RPT）. Two types of solitary waves, fast and slow dust acoustic soliton （DAS） exist in this plasma. Caiculations reveal that compressive solitary structures are possibly propagated in the plasma where dust grains are negatively （or positively） charged. The properties of DASs are also investigated numerically.展开更多
The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-tr...The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-trivial way.Moreover,asymptotic index and distribution parameter of current density are calculated by using black hole solution,some new features of this solution are briefly discussed.展开更多
文摘Beginning with the explicitly covariant Maxwell equations in media, we deduce an explicitly covariant stress-energy-momentum balance equation in material media. Proceeding in this way we avoid mixing external fields and self fields, as occurs if one begins with Lorentz＇s law, the most usual approach appearing in textbooks. Indeed our deduction implies a generalized force density in which the total fields appear. As an application of the present deduction, we discuss briefly the Abraham-Minkowski controversy, showing its relation to open or closed electromagnetic systems. This approach will be interesting for scholars as well as graduate students interested in conceptual problems of relativistic electromagnetism.
文摘The tensile properties of a series of soybean protein yarns are tested in USTER THINKPAID Ⅲ. A nonlinear viscoelastic model has been proposed to describe the tensile behavior of soybean protein yarns. The model is composed of a Maxwell element, a linear spring and a nonlinear spring. The tensile properties of soybean protein yam are analyzed. The stress-strain curves of the yams are fitted. The average breaking tenacity and specific work of rupture are calculated using the average breaking strain. Comparisons indicate that theoretical predictions conform the experimental results very well.
基金Major New Drug Discovery Science and Technology Group(Grant No.2012ZX09303013)
文摘This study was carried out in the Wistar rats to investigate the effect of Tang herb on the pharmacokinetics of the antiretroviral drug lopinavir （LPV） following single oral administration. Rats were randomly divided into LPV group （36 mg/kg） and LPV combining with Tang herb group （LPV： 36 mg/kg, Tang herb： 864 mg/kg）. The blood concentrations of lopinavir at 0, 0.5, 1, 2, 4, 8, 10, 12, 14, 16, 22 h after administration were determined by HPLC and the pharmacokinetic parameters were investigated. The results showed that Tang herb significantly increased the Cmax and A UC （P〈0.05） while slightly increased the t1/2z and Tmax of lopinavir （P〉0.05）. The present study suggests that Tang herb may delay the absorption, increase the time to reach the maximum concentration, and improve the bioavailability of LPV. Further evaluation of the possible interaction mechanism between Tang herb and LPV needs to be studied.
基金The Science and Technology Development Plan Project of Wujin District,Changzhou City,Jiangsu Province(Grant No.WS201413)the Research Funds for the Teachers of Central South University(Grant No.2014JSJJ028)
文摘In the present study, we developed and validated a selective, specific and sensitive liquid chromatography-electrospray ionization mass spectrometry （LC-ESI-MS/MS） method for the determination of tenofovir in human plasma. Entecavir was used as an internal standard, and plasma samples were prepared by solid-phase extraction performed on Phenomenex Strata cartridges （30 mg）. The mobile phase consisted of 10 mM ammonium acetate in water and methanol （60：40, v/v）. The chromatographic separation was performed isocratically on a Phenomenex C18 （4.6 mm×150 mm, 5 μm）, and analytes were analyzed in multiple reaction monitoring （MRM） mode with positive electrospray ionization （ESI） interface using the respective [M＋H] ＋ ions, m/z 288.2→m/z 176.1 for tenofovir and m/z 278.1→m/z 152 for entecavir. The calibration curve （r2 = 0.9962） of tenofovir was established within the range of 4.096-1000 μg/L. The intra- and inter-day precisions were less than 10%. This validated method was successfully applied to a pharmacokinetic study in 12 healthy Chinese volunteers after the oral administration of tenofovir disonroxil fumarate.
基金supported by the National Natural Science Foundation ofChina (Grant Nos. 10535060,A050207,10975172 and 10821504)the National Basic Research Program of China (Grant No. 2007CB815401)
文摘Extending the holographic program of our previous work,we derive f(R) gravity and the Maxwell equations from the holographic principle,using time-like holographic screens.We find that to derive the Einstein equations and f(R) gravity by a natural holographic approach,the quasi-static condition is necessary.We also find the surface stress tensor and the surface electric current,surface magnetic current on a holographic screen for f(R) gravity and Maxwell's theory,respectively.
基金Janssen Research & DevelopmentChina，Pfizer Scholarship for Pharmacometrics during this project
文摘A tablet consisting of direct-acting antiviral agents,ledipasvir（a NS5 A protein inhibitor） and sofosbuvir（a NS5 B polymerase inhibitor）,is the first fixed-dose preparation used in the antiviral therapy of hepatitis C.A model-based meta-analysis of ledipasvir and GS331007,the primary metabolite of sofosbuvir,enabled the integration of pharmacokinetic（PK） information from separate clinical trials and the quantitative characterization of the population pharmacokinetics of these two drugs.A systematic publication search was conducted for the clinical studies of ledipasvir and sofosbuvir.A total of 401 arm-level aggregate concentrations of GS331007 and 188 concentrations of ledipasvir were used for PK modeling.A two-compartment disposition model was used for both ledipasvir and GS331007.Zero-order absorption was applied for ledipasvir PK modeling,and a combined zero- and first-order absorption was used for the modeling of GS331007.Absorption lag was observed in concentration-time profiles of both ledipasvir and GS331007.To aid the development of direct-acting antiviral drugs,our established PK models provided a basis for the further PK-viral kinetic studies of ledipasvir and sofosbuvir.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2014B1801)
文摘In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure includes a new analytical method and high accurate finite element simulations. In the part of theoretical analysis, three-dimensional Maxwell stress functions are employed in order to derive three-dimensional crack tip fields. Based on the theoretical analysis, an equation which can describe the relationship among the three-dimensional J-integral J(z), the stress intensity factor K(z) and the tri-axial stress constraint level Tz(z) is derived first. In the part of finite element simulations, a fine mesh including 153360 elements is constructed to compute the stress field near the crack front, J(z) and Tz(z). Numerical results show that in the plane very close to the free surface, the K field solution is still valid for in-plane stresses. Comparison with the numerical results shows that the analytical results are valid.
文摘In this paper an investigation into dust acoustic sofitary waves （DASWs） in the presence of superthermM electrons and ions in a magnetized plasma with cold dust gains and trapped electrons is discussed. The dynamic of both electrons and ions is simulated by the generalized Lorentzian （κ） distribution function （DF）. The dust grains are cold and their dynamics are studied by hydrodynamic equations. The basic set of fluid equations is reduced to modified Korteweg-de Vries （mKdV） equation using Reductive Perturbation Theory （RPT）. Two types of solitary waves, fast and slow dust acoustic soliton （DAS） exist in this plasma. Caiculations reveal that compressive solitary structures are possibly propagated in the plasma where dust grains are negatively （or positively） charged. The properties of DASs are also investigated numerically.
基金Supported by Natural Science Foundation of Sichuan Education Committee under Grant No. 11ZA100Scientific Research Foundation for Graduate Student of Sichuan Normal University under Grant No. 20113
文摘The (2+1)-dimensional Maxwell-Chern-Simons gravity with phantom dilaton field coupling is studied in this paper.It is shown that black hole solution to exist when electromagnetic coupled to dilaton field in the non-trivial way.Moreover,asymptotic index and distribution parameter of current density are calculated by using black hole solution,some new features of this solution are briefly discussed.
