The synthesis route was investigated and optimized for the preparation of iminodiacetic acid-polyethylene glycol (IDA-PEG) for immobilized metal ion affinity partitioning in aqueous two-phase systems. IDA-PEG was synt...The synthesis route was investigated and optimized for the preparation of iminodiacetic acid-polyethylene glycol (IDA-PEG) for immobilized metal ion affinity partitioning in aqueous two-phase systems. IDA-PEG was synthesized from PEG in two steps by the reaction of iminodiacetic acid with a monosubstituted derivative of epichlorohydrin-activated PEG. The Cu2+ content combined with IDA-PEG was determined by atomic absorption spectrometry as 0.5 mol·mol^-1 (PEG). Furthermore, the affinity partitioning behavior of lactate dehydrogenase in polyethylene glycol/hydroxypropyl starch aqueous two-phase systems was studied to clarify the affinity effect of the Cu(Ⅱ)-IDA-PEG.展开更多
A custom built dynamic oxygen uptake tester was used to study theinfluence of nitrogen compounds on the oxidation characteristics ofthe saturate fractions from mineral base oils. Experimental resultsindicate that nitr...A custom built dynamic oxygen uptake tester was used to study theinfluence of nitrogen compounds on the oxidation characteristics ofthe saturate fractions from mineral base oils. Experimental resultsindicate that nitrogen compounds, especially quinoline and indole,take part in the oxidation of saturates. It is also found that indoleis more active than quinoline. The latter can be oxidized partly intoketoimine, and the former is more rapidly oxidized into acylamide.The oxidation products, ketoimine or acylamide, could inhibit theoxidation of the saturates by decomposing hydroperoxide.展开更多
Even though in IR and Raman spectra of liquid methanol there is always an apparent feature for the asymmetric stretching mode of the CH3 group around 2970 cm^-1, this feature has not been observed in the Sum Frequency...Even though in IR and Raman spectra of liquid methanol there is always an apparent feature for the asymmetric stretching mode of the CH3 group around 2970 cm^-1, this feature has not been observed in the Sum Frequency Generation Vibrational Spectroscopy (SFG-VS) in any polarizations from the air/methanol interface. Here we present a treatment based on a corrected bond additivity model to quantitatively interpret the SFG-VS of the air/methanol interface from the IR and Raman spectra of liquid methanol.展开更多
The α-Fe nanoparticles with oxide shell were prepared by the complete reduction of iron oxide ones with hydrogen, followed by the selective surface oxidation as a thin layer. As-treated α-Fe nanoparticles preserved ...The α-Fe nanoparticles with oxide shell were prepared by the complete reduction of iron oxide ones with hydrogen, followed by the selective surface oxidation as a thin layer. As-treated α-Fe nanoparticles preserved their saturation magnetization and metal α-Fe phase for at least 80 days in the air. In comparison, the unstabilized α-Fe nanoparticles protected only by their silica shell were oxidized instantly in the air and the saturation magnetization of the unstabilized α-Fe nanoparticles was decreased drastically. Since the stabilization procedure was carried out under dry conditions using silica-coated iron oxide nanoparticles as precursors, it could be applied to nanoparticles of various sizes and shapes to obtain a stable α-Fe phase.展开更多
The effect of microwave (MW) heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the ...The effect of microwave (MW) heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven (850 W, 2.450 MHz) for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil (203 nm, 230 nm, 269 nm and 278 nm) dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil's c' oscillates around the origin value in greater rate. Dielectric loss e" decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher's power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.展开更多
Suda (2012) extended the ErdSs-Ko-Rado theorem to designs in strongly regularized semilattices. In this paper we generalize Suda's results in regularized semilattices and partition regularized semilattices, give ma...Suda (2012) extended the ErdSs-Ko-Rado theorem to designs in strongly regularized semilattices. In this paper we generalize Suda's results in regularized semilattices and partition regularized semilattices, give many examples for these semilattices and obtain their intersection theorems.展开更多
It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis(ACE) to study receptor-ligand interactions or to screen natural products and compounds synt...It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis(ACE) to study receptor-ligand interactions or to screen natural products and compounds synthesized by combinatorial chemistry. In this paper, we developed a new method of immobilizing HEK293 cells on the inner wall of a capillary column. Four important experimental conditions were optimized, including cell injection density, PLL concentration, cell culturing time and sterile processing method. Immobilized cell-coated capillary columns prepared under the optimized experimental conditions exhibited good uniformity, stability and durability, which were suitable for capillary electrophoresis. The method could also be used to immobilize HEK293 cells over-expressing certain membrane receptors on the inner wall of a capillary. In this way, cell-coated capillary columns could be applied to ACE drug screening targeting certain membrane proteins.展开更多
Infections of patients from consumption of contaminated pharmaceutical products constituted major health risk problems. Medicinal products are liable to microbial intrusion during in-use application. The current study...Infections of patients from consumption of contaminated pharmaceutical products constituted major health risk problems. Medicinal products are liable to microbial intrusion during in-use application. The current study focused on repeated contamination with constant level of microbiological burden by two bacteria viz. Staphylococcus aureus and Pseudomonas aeruginosa were used as dose-response models for infection through two different routes of administration. Nine different forms of insulin vials were subjected to this type of simulation study at constant assumed level of contaminations, preservative efficacy test(PET) and dose potency. Multi-spot contamination imitation study showed that initial fast rise in contamination, followed shortly by longer but steeper slope which finally turned into higher rate of contamination during the few last doses of the unit dosage forms, where the volume of the product became increasingly and progressively very small. When the probability of infection curves was constructed, both S. aureus and P. aeruginosa showed same pattern, with notably higher risk from septicemia route of the latter rather than subcutaneous route of the former. The present simulation study showed that continuous use of the same contaminated syringe progressively increased the risk of infection, especially at final few doses(between 3th and 10 th last doses depending on the dosage form sizes in the vials and the administration volumes) of the product. Small volume parenterals(SVP) are especially products at higher risk than the larger volume ones.展开更多
The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alt...The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alternative approach for theoretically dealing with chemical dissolution front (CDF) propagation in fluid-saturated carbonate rocks. Note that the CDF is represented by the porosity front in this study. In this new approach, the porosity, pore-fluid velocity and acid concentration are directly used as independent variables. To illustrate how to use the present new approach, an aeidization dissolution system (ADS) consisting of carbonate rocks, which belongs to one of the many general chemical dissolution systems (CDSs), is taken as an application example. When the acid dissolution capacity (ADC) number (that is defined as the ratio of the volume of the carbonate rock dissolved by an acid to that of the acid) approaches zero, the present new approach can be used to obtain analytical solutions for the stable ADS. However, if the ADC number is a nonzero finite number, then numerical solutions can be only obtained for the ADS, especially when the ADS is in an unstable state. The related theoretical results have demonstrated that: (1) When the ADS is in a stable state and in the case of the ADC number approaching zero, the present new approach is mathematically equivalent to the previous approach, in which the porosity, pore-fluid pressure and acid concentration are used as independent variables. However, when the ADS is in an unstable state, the use of the present new approach leads to a free parameter that needs to be determined by some other ways. (2) The existence of a non-step-type dissolution front within a transient region should at least satisfy that none of the ADC number, injected acid velocity and reciprocal of the dissolution reaction rate is equal to zero in the stable ADS.展开更多
An important property of the reproducing kernel of D2(Ω,ρ) is obtained and the reproducing kernels for D2(Ω,ρ) are calculated when Ω = Bn × Bn and ρ are some special functions.A reproducing kernel is used t...An important property of the reproducing kernel of D2(Ω,ρ) is obtained and the reproducing kernels for D2(Ω,ρ) are calculated when Ω = Bn × Bn and ρ are some special functions.A reproducing kernel is used to construct a semi-positive definite matrix and a distance function defined on Ω×Ω.An inequality is obtained about the distance function and the pseudo-distance induced by the matrix.展开更多
A 3×3 matrix Lie algebra is first introduced, its subalgebras and the generated Lie algebras are obtained, respectively. Applications of a few Lie subalgebras give rise to two integrable nonlinear hierarchies of ...A 3×3 matrix Lie algebra is first introduced, its subalgebras and the generated Lie algebras are obtained, respectively. Applications of a few Lie subalgebras give rise to two integrable nonlinear hierarchies of evolution equations from their reductions we obtain the nonlinear Schroedinger equations, the mKdV equations, the Broer-Kaup (1310 equation and its generalized equation, etc. The linear and nonlinear integrable couplings of one integrable hierarchy presented in the paper are worked out by casting a 3×3 Lie subalgebra into a 2×2 matrix Lie algebra. Finally, we discuss the elliptic variable solutions of a generalized BK equation.展开更多
In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the st...In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the steadycavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order methodwith adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure fielddownstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (correspondingto the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motionof bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamicbehaviors of bubble different from those in previous papers are displayed. In addition, the internal relationshipbetween bubble dynamics and process intensification is also discussed. The simulation results reported in thiswork reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundationfor the practical application of hydrodynamic cavitation technology.展开更多
基金Supported by the National Natural Science Foundation of China(No.29736180).
文摘The synthesis route was investigated and optimized for the preparation of iminodiacetic acid-polyethylene glycol (IDA-PEG) for immobilized metal ion affinity partitioning in aqueous two-phase systems. IDA-PEG was synthesized from PEG in two steps by the reaction of iminodiacetic acid with a monosubstituted derivative of epichlorohydrin-activated PEG. The Cu2+ content combined with IDA-PEG was determined by atomic absorption spectrometry as 0.5 mol·mol^-1 (PEG). Furthermore, the affinity partitioning behavior of lactate dehydrogenase in polyethylene glycol/hydroxypropyl starch aqueous two-phase systems was studied to clarify the affinity effect of the Cu(Ⅱ)-IDA-PEG.
文摘A custom built dynamic oxygen uptake tester was used to study theinfluence of nitrogen compounds on the oxidation characteristics ofthe saturate fractions from mineral base oils. Experimental resultsindicate that nitrogen compounds, especially quinoline and indole,take part in the oxidation of saturates. It is also found that indoleis more active than quinoline. The latter can be oxidized partly intoketoimine, and the former is more rapidly oxidized into acylamide.The oxidation products, ketoimine or acylamide, could inhibit theoxidation of the saturates by decomposing hydroperoxide.
文摘Even though in IR and Raman spectra of liquid methanol there is always an apparent feature for the asymmetric stretching mode of the CH3 group around 2970 cm^-1, this feature has not been observed in the Sum Frequency Generation Vibrational Spectroscopy (SFG-VS) in any polarizations from the air/methanol interface. Here we present a treatment based on a corrected bond additivity model to quantitatively interpret the SFG-VS of the air/methanol interface from the IR and Raman spectra of liquid methanol.
文摘The α-Fe nanoparticles with oxide shell were prepared by the complete reduction of iron oxide ones with hydrogen, followed by the selective surface oxidation as a thin layer. As-treated α-Fe nanoparticles preserved their saturation magnetization and metal α-Fe phase for at least 80 days in the air. In comparison, the unstabilized α-Fe nanoparticles protected only by their silica shell were oxidized instantly in the air and the saturation magnetization of the unstabilized α-Fe nanoparticles was decreased drastically. Since the stabilization procedure was carried out under dry conditions using silica-coated iron oxide nanoparticles as precursors, it could be applied to nanoparticles of various sizes and shapes to obtain a stable α-Fe phase.
文摘The effect of microwave (MW) heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven (850 W, 2.450 MHz) for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil (203 nm, 230 nm, 269 nm and 278 nm) dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil's c' oscillates around the origin value in greater rate. Dielectric loss e" decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher's power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.
基金supported by National Natural Science Foundation of China(Grant Nos.11271047 and 10971052)Natural Science Foundation of Hebei Province(Grant Nos.A2012408003 and A2012205079)+3 种基金the Talent Project Fund of Hebei Province(Grant No.2011-11)the Doctoral Fund from Hebei Normal University(Grant No.L2011B02)Scientific Research Fund of the Department of Education of Hebei Education Department(Grant No.ZH2012082)the Fundamental Research Funds for the Central University of China
文摘Suda (2012) extended the ErdSs-Ko-Rado theorem to designs in strongly regularized semilattices. In this paper we generalize Suda's results in regularized semilattices and partition regularized semilattices, give many examples for these semilattices and obtain their intersection theorems.
基金The National Natural Science Foundation(Grant No.81373372)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20130001110059)
文摘It is a new strategy to immobilize cells on the inner wall of a capillary column and use affinity capillary electrophoresis(ACE) to study receptor-ligand interactions or to screen natural products and compounds synthesized by combinatorial chemistry. In this paper, we developed a new method of immobilizing HEK293 cells on the inner wall of a capillary column. Four important experimental conditions were optimized, including cell injection density, PLL concentration, cell culturing time and sterile processing method. Immobilized cell-coated capillary columns prepared under the optimized experimental conditions exhibited good uniformity, stability and durability, which were suitable for capillary electrophoresis. The method could also be used to immobilize HEK293 cells over-expressing certain membrane receptors on the inner wall of a capillary. In this way, cell-coated capillary columns could be applied to ACE drug screening targeting certain membrane proteins.
基金supported and partially financially by HIKMA Pharma Pharmaceutical Company-2nd Industrial Zone-6th of October city,Egypt
文摘Infections of patients from consumption of contaminated pharmaceutical products constituted major health risk problems. Medicinal products are liable to microbial intrusion during in-use application. The current study focused on repeated contamination with constant level of microbiological burden by two bacteria viz. Staphylococcus aureus and Pseudomonas aeruginosa were used as dose-response models for infection through two different routes of administration. Nine different forms of insulin vials were subjected to this type of simulation study at constant assumed level of contaminations, preservative efficacy test(PET) and dose potency. Multi-spot contamination imitation study showed that initial fast rise in contamination, followed shortly by longer but steeper slope which finally turned into higher rate of contamination during the few last doses of the unit dosage forms, where the volume of the product became increasingly and progressively very small. When the probability of infection curves was constructed, both S. aureus and P. aeruginosa showed same pattern, with notably higher risk from septicemia route of the latter rather than subcutaneous route of the former. The present simulation study showed that continuous use of the same contaminated syringe progressively increased the risk of infection, especially at final few doses(between 3th and 10 th last doses depending on the dosage form sizes in the vials and the administration volumes) of the product. Small volume parenterals(SVP) are especially products at higher risk than the larger volume ones.
基金supported by the National Natural Science Foundation of China(Grant No.11272359)
文摘The natural phenomenon associated with the chemical dissolution of dissolvable minerals of rocks can be employed to develop innovative technology in mining and oil extracting engineering. This paper presents a new alternative approach for theoretically dealing with chemical dissolution front (CDF) propagation in fluid-saturated carbonate rocks. Note that the CDF is represented by the porosity front in this study. In this new approach, the porosity, pore-fluid velocity and acid concentration are directly used as independent variables. To illustrate how to use the present new approach, an aeidization dissolution system (ADS) consisting of carbonate rocks, which belongs to one of the many general chemical dissolution systems (CDSs), is taken as an application example. When the acid dissolution capacity (ADC) number (that is defined as the ratio of the volume of the carbonate rock dissolved by an acid to that of the acid) approaches zero, the present new approach can be used to obtain analytical solutions for the stable ADS. However, if the ADC number is a nonzero finite number, then numerical solutions can be only obtained for the ADS, especially when the ADS is in an unstable state. The related theoretical results have demonstrated that: (1) When the ADS is in a stable state and in the case of the ADC number approaching zero, the present new approach is mathematically equivalent to the previous approach, in which the porosity, pore-fluid pressure and acid concentration are used as independent variables. However, when the ADS is in an unstable state, the use of the present new approach leads to a free parameter that needs to be determined by some other ways. (2) The existence of a non-step-type dissolution front within a transient region should at least satisfy that none of the ADC number, injected acid velocity and reciprocal of the dissolution reaction rate is equal to zero in the stable ADS.
基金the National Natural Science Foundation of China(No.10401024)
文摘An important property of the reproducing kernel of D2(Ω,ρ) is obtained and the reproducing kernels for D2(Ω,ρ) are calculated when Ω = Bn × Bn and ρ are some special functions.A reproducing kernel is used to construct a semi-positive definite matrix and a distance function defined on Ω×Ω.An inequality is obtained about the distance function and the pseudo-distance induced by the matrix.
基金Supported by Natural Science Foundation of Liaoning Province under Grant No. 20092171
文摘A 3×3 matrix Lie algebra is first introduced, its subalgebras and the generated Lie algebras are obtained, respectively. Applications of a few Lie subalgebras give rise to two integrable nonlinear hierarchies of evolution equations from their reductions we obtain the nonlinear Schroedinger equations, the mKdV equations, the Broer-Kaup (1310 equation and its generalized equation, etc. The linear and nonlinear integrable couplings of one integrable hierarchy presented in the paper are worked out by casting a 3×3 Lie subalgebra into a 2×2 matrix Lie algebra. Finally, we discuss the elliptic variable solutions of a generalized BK equation.
基金support of the National Natural Science Foundation of China (Grant No. 50806078)the National High-Tech Research and Development Program of China (863 Program, Grant No. 2006AA05Z203).
文摘In this paper, by introducing the flow velocity item into the classical Rayleigh-Plesset dynamic equation, a newequation, which does not involve the time term and can describe the motion of cavitation bubble in the steadycavitating flow, has been obtained. By solving the new motion equation using Runge-Kutta fourth order methodwith adaptive step size control, the dynamic behaviors of cavitation bubble driven by the varying pressure fielddownstream of a venturi cavitation reactor are numerically simulated. The effects of liquid temperature (correspondingto the saturated vapor pressure of liquid), cavitation number and inlet pressure of venturi on radial motionof bubble and pressure pulse due to the radial motion are analyzed and discussed in detail. Some dynamicbehaviors of bubble different from those in previous papers are displayed. In addition, the internal relationshipbetween bubble dynamics and process intensification is also discussed. The simulation results reported in thiswork reveal the variation laws of cavitation intensity with the flow conditions of liquid, and will lay a foundationfor the practical application of hydrodynamic cavitation technology.