22 research outputs found
Total Occlusion of the Infarct-Related Artery in Non-ST-Elevation Myocardial Infarction (NSTEMI)-How Can We Identify These Patients?
Background and Objectives: Regardless of the improvement in key recommendations in non-ST-elevation myocardial infarction (NSTEMI), the prevalence of total occlusion (TO) of infarct-related artery (IRA), and the impact of TO of IRA on outcomes in patients with NSTEMI, remain unclear. Aim: The study aimed to assess the incidence and predictors of TO of IRA in patients with NSTEMI, and its clinical significance. Material and Methods: The study was a single-center retrospective cohort analysis of 399 consecutive patients with NSTEMI (293 male, mean age: 71 10.1 years) undergoing percutaneous coronary intervention. The study population was categorized into patients with TO and non-TO of IRA on coronary angiography. In-hospital and one-year mortality were analyzed. Results: TO of IRA in the NSTEMI population occurred in 138 (34.6%) patients. Multivariate analysis identified the following independent predictors of TO of IRA: left ventricular ejection fraction (odds ratio (OR) 0.949, p < 0.001); family history of coronary artery disease (CAD) (OR 2.652, p < 0.001); and high-density lipoprotein (HDL) level (OR 0.972, p = 0.002). In-hospital and one-year mortality
were significantly higher in the TO group than the non-TO group (2.8% vs. 1.1%, p = 0.007 and 18.1% vs. 6.5%, p < 0.001, respectively). The independent predictors of in-hospital mortality were: left ventricular ejection fraction (LVEF) at admission (OR 0.768, p = 0.004); and TO of IRA (OR 1.863, p = 0.005). Conclusions: In the population of patients with NSTEMI, TO of IRA represents a considerably frequent phenomenon, and corresponds with impaired outcomes. Therefore, the utmost caution should be paid to prevent delay of coronary angiography in NSTEMI patients with impaired left ventricular systolic function, metabolic isturbances, and a family history of CAD, who are at increased risk of TO of IRA
Analysis of the impact of sex and age on the variation in the prevalence of antinuclear autoantibodies in Polish population : a nationwide observational, cross-sectional study
The detection of antinuclear autoantibody (ANA) is dependent on many factors and varies between the populations. The aim of the study was first to assess the prevalence of ANA in the Polish adult population depending on age, sex and the cutoff threshold used for the results obtained. Second, we estimated the occurrence of individual types of ANA-staining patterns. We tested 1731 patient samples using commercially available IIFA using two cutoff thresholds of 1:100 and 1:160. We found ANA in 260 participants (15.0%), but the percentage of positive results strongly depended on the cutoff level. For a cutoff threshold 1:100, the positive population was 19.5% and for the 1:160 cutoff threshold, it was 11.7%. The most prevalent ANA-staining pattern was AC-2 Dense Fine speckled (50%), followed by AC-21 Reticular/AMA (14.38%) ANA more common in women (72%); 64% of ANA-positive patients were over 50 years of age. ANA prevalence in the Polish population is at a level observed in other highly developed countries and is more prevalent in women and elderly individuals. To reduce the number of positive results released, we suggest that Polish laboratories should set 1:160 as the cutoff threshold. © 2021, The Author(s). **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Fadi Charchar" is provided in this record*
Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress
Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress. Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing. Results: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P =.038) and 11% lower concentration of UA (P =.005). TOS was 20% lower (P =.014). The activity of SOD was up to 5% higher (P =.037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity. Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes
O odsprzęganiu liniowych układów dynamicznych MIMO z zapewnieniem stabilności
In the paper methods for decoupling of dynamic multivariable systems are presented. There is discussed both static and dynamic decoupling of systems for open-loop control. The designed elements of the system provides elimination of interactions between specific plants inputs and outputs in a steady and transition state respectively. Results of considerations are illustrated by a numerical example.W artykule omawia się sposoby odsprzęgania dynamicznych wielowymiarowych układów liniowych do celów sterowania nimi w otwartej pętli. Rozważa się zarówno odsprzęganie statyczne eliminujące interakcje między poszczególnymi wyjściami obiektu w stanach ustalonych jak i odsprzęganie dynamiczne pozwalające na eliminację tych oddziaływań również w stanach przejściowych. Rozważania zilustrowano przykładem obliczeniowym
Adaptive control in multivariable dynamic systems
W pracy omawia się problemy wystepujące przy projektowaniu i realizacji w dziedzinie czasowej adaptacyjnych układów sterowania w wielowymiarowych układach dynamicznych ze sprzężeniem zwrotnym, wykorzystujących technikę lokowania biegunów (z ang. Pole Placement). Na tle ogólnych wymagań stawianych wielowymiarowym układom ze sprzężeniem zwrotnym rozpatruje się przypadki sterowania modalnego z wykorzystaniem obserwatorów Luenbergera pełnego rzędu i obserwatorów funkcjonalnych zredukowanego rzędu. Podaje się sposoby projektowania regulatorów modalnych w dziedzinach operatorowych "s" lub "z" oraz ich realizacji w dziedzinach czasowych, przydatnych do celów sterowania adaptacyjnego. Całość rozważań ilustruje przykład obliczeniowy przeprowadzony dla obiektu 4 rzędu o 3 wejściach i 2 wyjściach.The paper deals with problems encountered when designing and implementing (in time domain) adaptive control systems in feedback multivariable dynamic systems employing the pole placement approach. Some cases of modal control using full-order functional reduced-order Luenberger observers are considered against the backgroung of general requirements that are imposed on multivariable feedback-based systems. Techniques for designing modal controllers in the s-domain or z-domain and their implementation in time-domain beging suitable for adaptive conterol are given. The considerations are illustrated by an example of the design procedure carried out for a control plant of the 4th order with 3 inputs and 2 outputs
On control of nonlinear dynamic MIMO plants using a switchable structure of linear modal controllers
W artykule przedstawia się wieloregulatorową, przełączalną strukturę układu sterowania nieliniowymi obiektami dynamicznymi MIMO na przykładzie sterowania położeniem statku wiertniczego z wykorzystaniem nieliniowego modelu wolnozmiennych ruchów statku nad punktem wiercenia w trzech stopniach swobody ruchu (3DOF). W proponowanej strukturze układu wykorzystuje się zestaw liniowych regulatorów modalnych współpracujących z dodatkowym układem sterowania w pętli otwartej, odsprzęgniętym statycznie lub dynamicznie. Syntezy układu dokonuje się poprzez linearyzację przyjętego opisu obiektu sterowania w nominalnych "punktach pracy", zależnych od zadawanego kąta kursowego statku i wartości prądu morskiego. Prezentowane wyniki badań dotyczą trzech odmian przełączalnej struktury układu: (i) klasycznej, z regulatorami modalnymi przełączanymi w momencie zmiany wartości sygnałów odniesienia gdy powodują one zmianę "punktu pracy" układu oraz nieklasycznej, w której regulatory modalne są przełączane dopiero po zadziałaniu pomocniczego układu sterowania, odsprzęgniętego (ii) statycznie lub (iii) dynamicznie. Działanie zaproponowanych odmian układów sterowania zilustrowano przykładami symulacji z nieliniowym modelem ruchów statku wiertniczego WIMPEY SEALAB w środowisku MATLAB/Simulink.In the paper a multicontroller-based switchable control system structure is proposed to control nonlinear MIMO plants. The considered structure contains a set of linear feedback controllers operating together with an additional, decoupled loop of the control system. The nonlinear model of low-frequency (LF) motions of a drilling vessel in three degrees of freedom (3DOF) on the sea surface is used as a MIMO plant to be controlled. The system synthesis is carried out by linearisation of the adopted nonlinear plant model at its nominal "working points" that depend on the preset ship yaw angle and the see current velocity. The investigation results presented concern three types of switched structures: (i) the classic one with a set of (stable) modal controllers switched at the moment of changing the reference signals with subsequent changes of the system "working point", and the non-classic structure in which modal controllers are switched after running an auxiliary decoupled control loop either statically (ii) or dynamically (iii). Performance of the proposed control systems is illustrated by examples of simulation results carried out in MATLAB/Simulink using the nonlinear model of motions of the WIMPEY SEALAB drilling vessel
Linear adaptive structure for control of a nonlinear MIMO dynamic plant
In the paper an adaptive linear control system structure with modal controllers for a MIMO nonlinear dynamic process is presented and various methods for synthesis of those controllers are analyzed. The problems under study are exemplified by the synthesis of a position and yaw angle control system for a drillship described by a 3DOF nonlinear mathematical model of low-frequency motions made by the drillship over the drilling point. In the proposed control system, use is made of a set of (stable) linear modal controllers that create a linear adaptive controller with variable parameters tuned appropriately to operation conditions chosen on the basis of two measured auxiliary signals. These are the ship’s current forward speed measured in reference to the water and the systematically calculated difference between the course angle and the sea current (yaw angle). The system synthesis is carried out by means of four different methods for system pole placement after having linearized the model of low-frequency motions made by the vessel at its nominal “operating points” in steady states that are dependent on the specified yaw angle and the sea current velocity. The final part of the paper includes simulation results of system operation with an adaptive controller of (stepwise) varying parameters along with conclusions and final remarks
Design of a multivariable neural controller for control of a nonlinear MIMO plant
The paper presents the training problem of a set of neural nets to obtain a (gain-scheduling, adaptive) multivariable neural controller for control of a nonlinear MIMO dynamic process represented by a mathematical model of Low-Frequency (LF) motions of a drillship over the drilling point at the sea bottom. The designed neural controller contains a set of neural nets that determine values of its parameters chosen on the basis of two measured auxiliary signals. These are the ship’s current forward speed measured with respect to water and the systematically calculated difference between the course angle and the sea current (yaw angle). Four different methods for synthesis of multivariable modal controllers are used to obtain source data for training the neural controller with parameters reproduced by neural networks. Neural networks are designed on the basis of 3650 modal controllers obtained with the use of the pole placement technique after having linearized the model of LF motions made by the vessel at its nominal operating points in steady states that are dependent on the specified yaw angle and the sea current velocity. The final part of the paper includes simulation results of system operation with a neural controller along with conclusions and final remarks
A comparative and experimental study on gradient and genetic optimization algorithms for parameter identification of linear MIMO models of a drilling vessel
The paper presents algorithms for parameter identification of linear vessel models being in force for the current operating point of a ship. Advantages and disadvantages of gradient and genetic algorithms in identifying the model parameters are discussed. The study is supported by presentation of identification results for a nonlinear model of a drilling vessel