Basic Study of Synchronization in a Two Degree of Freedom, Duffing Based System

The issue of synchronization has been analyzed from many points of view since it was first described in 17th century. Nowadays the theory that stands behind it is so developed, it might be difficult to understand where it all comes from. This paper reminds the key concepts of synchronization by examination of two coupled Duffing oscillators. It describes also the origins of Duffing equation and proves its ability to behave chaotically

Implementation of the New Control Methods in Simplification of a Multidimensional Control and Optimization of a Control System Parameters.

The main purpose of this text is to present application of the Largest Lyapunov Exponent (LLE) as a criterion for optimization of the new type of simple controller parameters. Investigated controller is the part of numerically simulated control system. The calculation of LLE was done with a new method [2]. Introduction contains reference to previous publications on inverted pendulum control and Lyapunov stability. Application of the new simple formula for LLE estimation in control systems is discussed. In the next part simulated dynamical system is described and new type of simple controller allowing to control multidimensional system is introduced. In the last part results of the simulation are shown along with conclusions to whole dynamics analysis. Comparison of the proposed regulator with the linearquadratic regulator (LQR) was verified and its better effectiveness with respect to LQR was proved

Optimization of the Control System Parameters with Use of the New Simple Method of the Largest Lyapunov Exponent Estimation.

This text covers application of Largest Lapunov Exponent (LLE) as a criterion for control performance assessment (CPA) in a simulated control system. The main task is to find a simple and effective method to search for the best configuration of a controller in a control system. In this context, CPA criterion based on calculation of LLE by means of a new method [3] is compared to classical CPA criteria used in control engineering [1]. Introduction contains references to previous publications on Lyapunov stability. Later on, description of classical criteria for CPA along with formulae is presented. Significance of LLE in control systems is explained. Moreover, new efficient formula for calculation of LLE [3] is shown. In the second part simulation of the control system used for experiment is described. The next part contains results of the simulation in which typical criteria for CPA are compared with criterion based on value of LLE. In the last part results of the experiment are summed up and conclusions are drawn

Application of the Lyapunov Exponent Based on Current Vibration Control Parameter (CVC) in Control of an Industrial Robot.

Controlling dynamics of industrial robots is one of the most important and complicated tasks in robotics. In some works[3,7], there are algorithms of the manipulators steering with flexible joints or arms. However, introducing them to calculation of trajectory results in complicated equations and a longer time of counting. On the other hand, works [4,5,6]show that improvement of the tool path is possible thanks to the previousidentification of the robot errors and their compensation. This text covers application of Largest Lyapunov Exponent (LLE) as a criterion for control performance assessment (CPA) in a real control system. The main task is to find a simple and effective method to search for the best configuration of a controller in a control system. In this context, CPA criterion based on calculation of LLE by means of a new method [9–11] is presented in the article

Karnoprawna ochrona przed mobbingiem w prawie polskim – uwagi de lege lata i postulaty de lege ferenda

Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00

Naczyniakomięsak serca — pułapki diagnostyczne

Primary tumours of the heart are extremely rare. Sarcomas are considered to be the most frequent histological type. This study presents two cases with a two-week and two-month history of fatigue, fever and shortness of breath. In both cases, cardiac tumours with pericardial effusion were diagnosed by means of echocardiography, being responsible for the above-mentioned symptoms. At the beginning of the diagnostic process, sarcomas seemed to be the likeliest cause of these symptoms. Establishment of the histopathological diagnosis based on the tumour biopsy turned out to be very difficult, and this delayed further therapeutic procedures

Rheological properties of erythrocytes in patients infected with Clostridium difficile

Clostridium difficile infection (CDI) is a bacterial infection of the digestive tract. Acute infections are accompanied by increased risk for venous thromboembolism (VTE). To date, there have been no studies of the rheological properties of blood during the course of digestive tract infections. The aim of our study was to examine the effects of CDI on red blood cell (RBC) rheology, specifically RBC deformability, RBC aggregation, and plasma viscosity. In addition, the activity of glucose 6 phosphate dehydrogenase (G6PD) and acetylcholinesterase (AChE) in RBC was studied. Our study group included 20 patients with CDI, 20 healthy persons comprised the control group. We examined the effects of CDI on the rheology of RBCs, their deformability and aggregation, using a Laser–assisted Optical Rotational Cell Analyzer (LORCA). Plasma viscosity was determined using a capillary tube plasma viscosymeter. Moreover, we estimated the activity of AChE and G6PD in RBC using spectrophotometric method. A statistically significant increase was found in the aggregation index, viscosity and activity of G6PD whereas the amount of time to reach half of maximum aggregation (t½) and the amplitude of aggregation (AMP) both showed statistically significantly decreases among patients with CDI compared to the control group. We also observed that the Elongation Index (EI) was decreased when shear stress values were low, between 0.3 Pa and 0.58 Pa, whereas EI was increased for shear stress in the range of 1.13 - 59.97 Pa. These observations were statistically significant. We report for the first time that acute infection of the gastrointestinal tract with Clostridium difficile is associated with abnormalities in rheological properties of blood, increased serum viscosity as well as increased aggregation of RBCs, which correlated with severity of inflammation. These abnormalities may be an additional mechanism causing increased incidence of VTE in CDI

Risk factors of atrial fibrillation recurrence despite successful radiofrequency ablation of accessory pathway: At 11 years of follow-up

Background: Previous reports on patients with radiofrequency catheter ablation (RFCA) of accessorypathway (AP) and atrial fibrillation (AF) include only short follow-up periods. The aim of this studywas to analyze predictors of recurrence of AF in patients after successful RFCA of APs over long termfollow-up periods.Methods: Of the 1,007 patients who underwent non-pharmacological treatment of APs (between theyears 1993–2008), data of 100 consecutive patients were retrospectively analyzed (75 men, mean age43.6 ± 14.7), with the longest period of follow-up (mean 11.3 ± 3.5 years) after successful RFCA ofAP. In Group 1, there were 72 patients (54 men, mean age 40.66 ± 13.85 years) without documentedepisodes of AF after RFCA of AP. Group 2 consisted of 28 patients (21 men, mean age 50.79 ± 14.49years) with AF episodes despite successful elimination of AP.Results: In univariate analysis, patients from Group 1 were significantly younger at the time of ablationthan patients from Group 2 (40.66 ± 13.85 vs. 50.79 ± 14.49 years; p = 0.002), had shorter historyof AF episodes (4.11 ± 4.07 vs. 8.25 ± 7.50 years; p = 0.024) and had less frequently documentedatrial tachycardia (AT) prior to ablation (3.39 vs. 20.00%; p = 0.022). In multivariate analysis, thehistory of AF in years (p = 0.043), was an independent risk factor for AF recurrences.Conclusions: Older patient age, longer history of AF and AT prior to RFCA of APs identified a subgroupof patients who required additional treatment. In the multivariate analysis, the history of AF inyears (p = 0.043) was a risk factor for AF recurrence

Conduction disturbances and permanent cardiac pacing after transcatheter implantation of the CoreValve aortic bioprosthesis: initial single centre experience

Background: The rate of significant conduction disturbances requiring permanent pacemaker implantation (PPI) following surgical aortic valve replacement (AVR) is 2&#8211;8%. Transcatheter aortic valve implantation (TAVI) is an alternative management approach in patients with severe aortic stenosis who are not considered candidates for AVR. The TAVI using the CoreValve (CV) bioprosthesis is associated with a nearly 30% rate of conduction disturbances requiring postprocedural PPI. Aim: To provide an initial evaluation of the rate of conduction disturbances and the need for PPI, and to analyse factors that increase the risk of this complication in patients undergoing TAVI using CV bioprosthesis. In addition, we evaluated the rate of permanent conduction disturbances in patients who underwent PPI at one year after TAVI. Methods: We studies 22 initial patients in a single centre who underwent CV bioprosthesis implantation in 2009&#8211;2010. After exclusion of 6 patients with preprocedural PPI, we ultimately evaluated 16 patients. Uni- and multivariate analyses were performed using &chi;2, Fisher, and Wilcoxon tests, and logistic regression analysis was performed using the SAS software. Results: Overall, 8 (50%) patients in our study group required PPI after TAVI (TAVI + PPI), and the remaining 8 patients did not require PPI (TAVI). The most common indication for PPI was complete heart block. The decision to implant a pacemaker was made on average at 9 &#177; 7 days following TAVI (range 3 to 22 days). When we analysed risk factors for PPI that were unrelated to the TAVI procedure, we found that the TAVI + PPI group was characterised (vs the TAVI group) by a significantly larger diameter of the native aortic valve (p = 0.03) and a larger left ventricular outflow tract (LVOT) dimension in the frontal (p = 0.02) and the corresponding frontal dimension in the transverse view (p = 0.01) by computed tomography angiography. Logistic regression analysis showed that the risk of PPI increased more than 2.5 times for each increase in the aortic annulus diameter by 1 mm (OR 2.64; 95% CI 0.90&#8211;7.74). None of the risk factors related to TAVI resulted in a significant increase in the rate of PPI. Among the patients who underwent PPI, we only noted a trend for a larger valvulotomy balloon diameter (p = 0.08), shorter procedure duration (p = 0.06), and deeper CV insertion within LVOT (p = 0.09). In addition, the bioprosthesis was inserted deeper in those patients who developed new LBBB after TAVI (p = 0.06). The ECG analysis at one day after the procedure showed a significant prolongation of PR, QRS, QT, and QTc intervals, and increased left axis deviation in the TAVI + + PPI group. In addition, the TAVI + PPI group showed increased QRS duration (p = 0.03) and increased left axis deviation (p = 0.049) compared to the TAVI group. Each increase in QRS duration by 10 ms was associated with 2.5-fold increase in the risk of PPI (OR 1.10; 95% CI 0.97&#8211;1.22), and each increase in PR interval duration by 10 ms with a 23% increase in risk (OR 1.02; 95% CI 0.99&#8211;1.05). New LBBB following CV implantation was noted significantly more frequently in the TAVI + PPI group vs the TAVI group (p < 0.0003). Pacemaker interrogation at one year after TAVI showed that the mean percentage of ventricular pacing in all patients with a pacemaker (DDD and VVI) pacing was 41%, and it was less than 10% in 2 patients. Conclusions: 1. Transcatheter implantation of a CV bioprosthesis is associated with an increased risk of persistent conduction disturbances and subsequent PPI. 2. New LBBB after TAVI may predict the need for PPI. 3. Careful ECG monitoring is necessary for one week after CV bioprosthesis implantation due to a risk of atrioventricular conduction disturbances and the need for PPI. 4. Patients at an increased risk of postprocedural PPI may be those with deep bioprosthesis insertion in LVOT, larger LVOT diameter, and larger aortic annulus diameter in the frontal view. These observations require confirmation in a larger group of patients.Background: The rate of significant conduction disturbances requiring permanent pacemaker implantation (PPI) following surgical aortic valve replacement (AVR) is 2&#8211;8%. Transcatheter aortic valve implantation (TAVI) is an alternative management approach in patients with severe aortic stenosis who are not considered candidates for AVR. The TAVI using the CoreValve (CV) bioprosthesis is associated with a nearly 30% rate of conduction disturbances requiring postprocedural PPI. Aim: To provide an initial evaluation of the rate of conduction disturbances and the need for PPI, and to analyse factors that increase the risk of this complication in patients undergoing TAVI using CV bioprosthesis. In addition, we evaluated the rate of permanent conduction disturbances in patients who underwent PPI at one year after TAVI. Methods: We studies 22 initial patients in a single centre who underwent CV bioprosthesis implantation in 2009&#8211;2010. After exclusion of 6 patients with preprocedural PPI, we ultimately evaluated 16 patients. Uni- and multivariate analyses were performed using &#967; 2, Fisher, and Wilcoxon tests, and logistic regression analysis was performed using the SAS software. Results: Overall, 8 (50%) patients in our study group required PPI after TAVI (TAVI + PPI), and the remaining 8 patients did not require PPI (TAVI). The most common indication for PPI was complete heart block. The decision to implant a pacemaker was made on average at 9 +- 7 days following TAVI (range 3 to 22 days). When we analysed risk factors for PPI that were unrelated to the TAVI procedure, we found that the TAVI + PPI group was characterised (vs the TAVI group) by a significantly larger diameter of the native aortic valve (p = 0.03) and a larger left ventricular outflow tract (LVOT) dimension in the frontal (p = 0.02) and the corresponding frontal dimension in the transverse view (p = 0.01) by computed tomography angiography. Logistic regression analysis showed that the risk of PPI increased more than 2.5 times for each increase in the aortic annulus diameter by 1 mm (OR 2.64; 95% CI 0.90&#8211;7.74). None of the risk factors related to TAVI resulted in a significant increase in the rate of PPI. Among the patients who underwent PPI, we only noted a trend for a larger valvulotomy balloon diameter (p = 0.08), shorter procedure duration (p = 0.06), and deeper CV insertion within LVOT (p = 0.09). In addition, the bioprosthesis was inserted deeper in those patients who developed new LBBB after TAVI (p = 0.06). The ECG analysis at one day after the procedure showed a significant prolongation of PR, QRS, QT, and QTc intervals, and increased left axis deviation in the TAVI + PPI group. In addition, the TAVI + PPI group showed increased QRS duration (p = 0.03) and increased left axis deviation (p = 0.049) compared to the TAVI group. Each increase in QRS duration by 10 ms was associated with 2.5-fold increase in the risk of PPI (OR 1.10; 95% CI 0.97&#8211;1.22), and each increase in PR interval duration by 10 ms with a 23% increase in risk (OR 1.02; 95% CI 0.99&#8211;1.05). New LBBB following CV implantation was noted significantly more frequently in the TAVI + PPI group vs the TAVI group (p < 0.0003). Pacemaker interrogation at one year after TAVI showed that the mean percentage of ventricular pacing in all patients with a pacemaker (DDD and VVI) pacing was 41%, and it was less than 10% in 2 patients. Conclusions: 1. Transcatheter implantation of a CV bioprosthesis is associated with an increased risk of persistent conduction disturbances and subsequent PPI. 2. New LBBB after TAVI may predict the need for PPI. 3. Careful ECG monitoring is necessary for one week after CV bioprosthesis implantation due to a risk of atrioventricular conduction disturbances and the need for PPI. 4. Patients at an increased risk of postprocedural PPI may be those with deep bioprosthesis insertion in LVOT, larger LVOT diameter, and larger aortic annulus diameter in the frontal view. These observations require confirmation in a larger group of patients

Doustne antykoagulanty nowej generacji — aspekty praktyczne. Stanowisko Sekcji Farmakoterapii Sercowo-Naczyniowej Polskiego Towarzystwa Kardiologicznego

This document is a statement from Cardiovascular Pharmacotherapy Section of the Polish Cardiac Society regarding the practical approach to therapy with novel oral anticoagulants — thrombin antagonists and Xa antagonists, based upon most recent scientific information including European Society of Cardiology guidelines 2016 and recommendations from European Heart Rhythm Association.    Niniejszy dokument jest stanowiskiem Sekcji Farmakoterapii Sercowo-Naczyniowej Polskiego Towarzystwa Kardiologicznego na temat praktycznego stosowania nowych doustnych antykoagulantów — antagonistów trombiny i czynnika Xa, z uwzględnieniem najnowszych danych, w tym wytycznych Europejskiego Towarzystwa Kardiologicznego i rekomendacji Europejskiej Asocjacji Rytmu Serca.