The relationship between inflammation, oxidant stress and cardiovascular damage in children with ... more The relationship between inflammation, oxidant stress and cardiovascular damage in children with chronic renal failure (CRF) has not previously been investigated. The aim of this study was to investigate markers of oxidative stress, inflammation and early cardiovascular abnormalities. Therefore, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities; blood glutathione (GSH) and serum malondialdehyde (MDA) levels; C-reactive protein (CRP) and proinflammatory cytokines (IL-6, TNF-α,); and left ventricular masses (LVM) and intima media thicknesses (IMT) were measured in children with CRF. A total of 29 children with CRF (19 nondialysis, 10 peritoneal dialysis) were included. The control group consisted of 25 healthy subjects. CRF children had significantly increased IL-6, TNF-α, CRP and MDA concentrations and decreased SOD, CAT and GSH levels compared with controls (P<0.05). Nondialysis and peritoneal dialysis subgroups had similar oxidative stress and inflammation biomarkers (P>0.05). Erythrocyte CAT was positively correlated with CRP, TNF-α, and IL2-R in the study group. Positive correlations were found between cytokine concentrations, CRP and urea/creatinine levels. Significantly increased LVM and IMT values were found in CRF children (P<0.05). In conclusion, increased oxidant stress and inflammation together with early cardiovascular damage were found in CRF children. Further studies with more patients are needed to verify these results.
Magnetosphere of the Earth is formed in the process of turbulent solar wind flow around the obsta... more Magnetosphere of the Earth is formed in the process of turbulent solar wind flow around the obstacle -magnetic field of the Earth. The level of turbulence in the magnetosheath and geo-magnetic tail is very high even during periods of comparatively stable solar wind parameters. Such situation requires checking of the most popular concepts of the nature of magnetospheric activity. Properties of magnetosheath and magnetospheric turbulence are analyzed in connec-tion with the problem of the nature of substorms and localization of substorm onset. The large-scale picture of the plasma velocity fluctuations obtained using data of INTERBALL and Geotail observations is analyzed. It is shown that it is possible to select surrounding the Earth at geocentric distances from 7Re till 10Re plasma ring with comparatively low level of fluctuations. Results of observations demonstrating isolated substorm onset inside this ring are summarized. It is shown that the non-contradictory picture of large-scale magnetospheric convection and substorm dynamics can be obtained taking into account high level of magne-tosheath and magnetospheric turbulence.
Identification of electromechanical systems operating in open-loop or closed-loop conditions has ... more Identification of electromechanical systems operating in open-loop or closed-loop conditions has long been of prime interest in industrial applications. This paper presents experimental on-line identification of an electromechanical system represented by a digital input/output model. The paper also bridges the theory and practice gap for applied researchers. Studies are carried out by formulating the mathematical model using differential equations and experimental discrete-time identification using on-line plant input-output data. A recursive least-squares method is used to estimate the unknown parameters of the system. Discrete-time data for the parameter identification are obtained experimentally from a setup constructed in the laboratory. A root-mean-square error criterion is used for model validation. Results are presented which show variations in parameters of the electromechanical system. It is demonstrated that identified model output and actual system output match. All tests are performed with no previous results from finite element simulations.
Abstract This study investigated the effects of four different types of modified wheat and corn s... more Abstract This study investigated the effects of four different types of modified wheat and corn starches (pregelatinized, thinned with acid, cross-linked, dextrinized and intact form) on the cake quality. The starches were added to the cake formulations at levels of 0, 10, 20 and ...
In this study, a sliding mode control system with a proportional+integral+derivative (PID) slidin... more In this study, a sliding mode control system with a proportional+integral+derivative (PID) sliding surface is adopted to control the speed of an electromechanical plant. A robust sliding mode controller is derived so that the actual trajectory tracks the desired trajectory despite uncertainty, nonlinear dynamics, and external disturbances. The proposed sliding mode controller is chosen to ensure the stability of overall dynamics during the reaching phase and sliding phase. The stability of the system is guaranteed in the sense of the Lyapunov stability theorem. The chattering problem is overcome using a hyperbolic function for the sliding surface. Experimental results that are compared with the results of conventional PID verify that the proposed sliding mode controller can achieve favorable tracking performance, and it is robust with regard to uncertainties and disturbances.
The relationship between inflammation, oxidant stress and cardiovascular damage in children with ... more The relationship between inflammation, oxidant stress and cardiovascular damage in children with chronic renal failure (CRF) has not previously been investigated. The aim of this study was to investigate markers of oxidative stress, inflammation and early cardiovascular abnormalities. Therefore, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities; blood glutathione (GSH) and serum malondialdehyde (MDA) levels; C-reactive protein (CRP) and proinflammatory cytokines (IL-6, TNF-α,); and left ventricular masses (LVM) and intima media thicknesses (IMT) were measured in children with CRF. A total of 29 children with CRF (19 nondialysis, 10 peritoneal dialysis) were included. The control group consisted of 25 healthy subjects. CRF children had significantly increased IL-6, TNF-α, CRP and MDA concentrations and decreased SOD, CAT and GSH levels compared with controls (P<0.05). Nondialysis and peritoneal dialysis subgroups had similar oxidative stress and inflammation biomarkers (P>0.05). Erythrocyte CAT was positively correlated with CRP, TNF-α, and IL2-R in the study group. Positive correlations were found between cytokine concentrations, CRP and urea/creatinine levels. Significantly increased LVM and IMT values were found in CRF children (P<0.05). In conclusion, increased oxidant stress and inflammation together with early cardiovascular damage were found in CRF children. Further studies with more patients are needed to verify these results.
Magnetosphere of the Earth is formed in the process of turbulent solar wind flow around the obsta... more Magnetosphere of the Earth is formed in the process of turbulent solar wind flow around the obstacle -magnetic field of the Earth. The level of turbulence in the magnetosheath and geo-magnetic tail is very high even during periods of comparatively stable solar wind parameters. Such situation requires checking of the most popular concepts of the nature of magnetospheric activity. Properties of magnetosheath and magnetospheric turbulence are analyzed in connec-tion with the problem of the nature of substorms and localization of substorm onset. The large-scale picture of the plasma velocity fluctuations obtained using data of INTERBALL and Geotail observations is analyzed. It is shown that it is possible to select surrounding the Earth at geocentric distances from 7Re till 10Re plasma ring with comparatively low level of fluctuations. Results of observations demonstrating isolated substorm onset inside this ring are summarized. It is shown that the non-contradictory picture of large-scale magnetospheric convection and substorm dynamics can be obtained taking into account high level of magne-tosheath and magnetospheric turbulence.
Identification of electromechanical systems operating in open-loop or closed-loop conditions has ... more Identification of electromechanical systems operating in open-loop or closed-loop conditions has long been of prime interest in industrial applications. This paper presents experimental on-line identification of an electromechanical system represented by a digital input/output model. The paper also bridges the theory and practice gap for applied researchers. Studies are carried out by formulating the mathematical model using differential equations and experimental discrete-time identification using on-line plant input-output data. A recursive least-squares method is used to estimate the unknown parameters of the system. Discrete-time data for the parameter identification are obtained experimentally from a setup constructed in the laboratory. A root-mean-square error criterion is used for model validation. Results are presented which show variations in parameters of the electromechanical system. It is demonstrated that identified model output and actual system output match. All tests are performed with no previous results from finite element simulations.
Abstract This study investigated the effects of four different types of modified wheat and corn s... more Abstract This study investigated the effects of four different types of modified wheat and corn starches (pregelatinized, thinned with acid, cross-linked, dextrinized and intact form) on the cake quality. The starches were added to the cake formulations at levels of 0, 10, 20 and ...
In this study, a sliding mode control system with a proportional+integral+derivative (PID) slidin... more In this study, a sliding mode control system with a proportional+integral+derivative (PID) sliding surface is adopted to control the speed of an electromechanical plant. A robust sliding mode controller is derived so that the actual trajectory tracks the desired trajectory despite uncertainty, nonlinear dynamics, and external disturbances. The proposed sliding mode controller is chosen to ensure the stability of overall dynamics during the reaching phase and sliding phase. The stability of the system is guaranteed in the sense of the Lyapunov stability theorem. The chattering problem is overcome using a hyperbolic function for the sliding surface. Experimental results that are compared with the results of conventional PID verify that the proposed sliding mode controller can achieve favorable tracking performance, and it is robust with regard to uncertainties and disturbances.
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