ADHESION OF BIOCOMPATIBLE TiNb COATING

Preparation of a coating with a high quality requires good adhesion of the film to the substrate. The paper deals with the adhesion of biocompatible TiNb coating with different base materials. Several materials such as titanium CP grade 2, titanium alloys Ti6Al4V and stainless steel AISI 316L were measured. Testing samples were made in the shape of small discs. Those samples were coated with a TiNb layer by using the PVD method (magnetron sputtering). Onto the measured layer of TiNb an assistant cylinder was stuck using a high strength epoxy adhesive E1100S. The sample with the assistant cylinder was fixed into a special fixture and the whole assembly underwent pull-off testing for adhesion. The main result of this experiment was determining the strength needed to peel the layer and morphology and size of the breakaway. As a result, we will be able to determine the best base material and conditions where the coating will be remain intact with the base material

Design of Linear Quadratic Regulator (LQR) Based on Genetic Algorithm for Inverted Pendulum

One of the crucial problems in the dynamics and automatic control theory is balancing of an invertedpendulum robot by moving a cart along a horizontal path. This task is often used as a benchmark for di erentmethod comparison. In the practical use of the LQR method, the key problem is how to choose weight matricesQ and R correctly. To obtain satisfying results the experiments should be repeated many times with di erentparameters of weight matrices. These LQR parameters can be tuned by a Genetic Algorithm (GA) techniquefor getting better results. In our paper, the LQR parameters weight matrices Q and R which were tuned usingthe Genetic Algorithm. The simulations of the control problem are designed using MATLAB script code andMATLAB Simulink on an inverted pendulum model. The results show that the Genetic Algorithm is suitablefor tuning the parameters to give an optimal response. The control problem of the inverted pendulum was solvedsuccessfully

Blood Arsenic Levels as a Marker of Breast Cancer Risk among BRCA1 Carriers

Funding Information: Funding: The study was funded by the National Centre for Research and Development Projects. INNOMED/1/16/NCBR/2014 and PBS3/B7/26/2015. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.An important group of breast cancers is those associated with inherited susceptibility. In women, several predisposing mutations in genes involved in DNA repair have been discovered. Women with a germline pathogenic variant in BRCA1 have a lifetime cancer risk of 70%. As part of a larger prospective study on heavy metals, our aim was to investigate if blood arsenic levels are associated with breast cancer risk among women with inherited BRCA1 mutations. A total of 1084 participants with pathogenic variants in BRCA1 were enrolled in this study. Subjects were followed from 2011 to 2020 (mean follow-up time: 3.75 years). During that time, 90 cancers were diagnosed, including 67 breast and 10 ovarian cancers. The group was stratified into two categories (lower and higher blood As levels), divided at the median (<0.85 µg/L and ≥0.85 µg/L) As level among all unaffected participants. Cox proportional hazards models were used to model the association between As levels and cancer incidence. A high blood As level (≥0.85 µg/L) was associated with a significantly increased risk of developing breast cancer (HR = 2.05; 95%CI: 1.18–3.56; p = 0.01) and of any cancer (HR = 1.73; 95%CI: 1.09–2.74; p = 0.02). These findings suggest a possible role of environmental arsenic in the development of cancers among women with germline pathogenic variants in BRCA1.Peer reviewe

Free analyte atom distribution, reactions and analyte reatomization in quartz tube hydride atomizers for atomic absorption spectrometry.

Available from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Stabilization of Higher Periodic Orbits of Chaotic maps using Permutation-selective Objective Function

International audienceThis paper deals with the design of an advanced objective function capable of proper evaluation of the solutions during the process of chaotic trajectory stabilisation into stable periodic motion by means of evolutionary metaheuristic optimization. The challenging problem of stabilisation of chaotic systems generates many unexpected difficulties. One of them is the evaluation of a sample stabilized run during optimization. Even more so, when the target state of the chaotic system is a stable cycle oscillating periodically between several target positions. In this study, a two-dimensional dynamical system, known as the Hénon map was used. The system is stabilized using Extended Time Delayed Auto Synchronization (ETDAS) method with Genetic Algorithm (GA) optimization. The solutions are evaluated by a permutation-selective objective function, which achieves significantly better results than conventional evaluation methods based on a common objective function

Management of arrhythmia in sepsis and septic shock

The occurrence of supraventricular arrhythmias is associated with an unfavourable prognosis in septic shock. Available trials are difficult to apply in sepsis and septic shock patients due to included cohorts, control groups and because “one size does not fit all“. The priorities in the critically ill are maintenance of the sinus rhythm and diastolic ventricular filling. The rate control modality should be reserved for chronic AF and in situations when the sinus rhythm is difficult to maintain due to extreme stress conditions resulting from a high dosage of vasoactive agents. Electric cardioversion is indicated in unstable patients with an absence of contraindications and is more feasible in combination with an antiarrhythmic agent. Besides amiodarone being preferred for its lower cardiodepressant side effect compared to other agents, drugs with a different degree of betablocking activity are very useful in supraventricular arrhythmias and septic shock, providing echocardiography is routinely used to support their indications within the current summary of product characteristics. A typical patient benefiting from propafenone is without significant structural heart disease, i.e. typically with normal to moderately reduced left ventricular systolic function. Future research should be channelled towards echocardiography-guided prospective controlled trials on antiarrhythmic therapy which may clarify the issue of rhythm versus rate control, the effects of various antiarrhythmic drugs, and a place for electric cardioversion in critically ill patients in septic shock

Lung Point Sign in Ultrasound Diagnostics of Pneumothorax: Imitations and Variants

Background. Pulmonary ultrasound plays a key role in the diagnosis of pneumothorax in emergency and intensive-care medicine. The lung point sign has been generally considered a pathognomonic diagnostic sign. Recently, several other situations have been published that can mimic the lung point, as well as a few different variants of the true lung point sign. Materials and Methods. Based on years of monitoring the literature and collecting our database of ultrasound findings, we prepared a review of ultrasound findings mimicking the lung point sign and ultrasound variants of the true lung point sign. Results. We present four imitations of the lung point sign (physiological lung point sign, pseudo-lung point sign, bleb point sign, and pleurofascial point sign) and two variants of the true lung point sign (double lung point sign and hydro point sign) documented by images and video records. Conclusions. Knowledge of ultrasound imitations and variants of the lung point sign may increase the reliability of pneumothorax diagnosis and may reduce the risk of performing unindicated interventions

Vasopressin in Patients with Septic Shock and Dynamic Left Ventricular Outflow Tract Obstruction

Purpose Left ventricular outflow tract obstruction (LVOTO) is a relatively uncommon but severe condition that may lead to hemodynamic impairment. It can be elicited by morphological (left ventricular hypertrophy, sigmoid septum, prominent papillary muscle, prolonged anterior mitral valve leaflet) and functional (hypovolemia, low afterload, hypercontractility, catecholamines) factors. We sought to determine the incidence of the most severe form of LVOTO in septic shock patients and describe the therapeutic effects of vasopressin. Methods Over a period of 29 months, 527 patients in septic shock were screened for LVOTO. All were mechanically ventilated and treated according to sepsis bundles, including pre-load optimization and norepinephrine infusion. Vasopressin was added in addition to norepinephrine to reduce the adrenergic burden and decrease LVOTO. Results Ten patients were diagnosed with the most severe form of LVOTO, including systolic anterior mitral valve motion (SAM) and severe mitral regurgitation (MR) with pulmonary oedema. The median norepinephrine dosage to obtain a mean arterial pressure of >= 70 mmHg was 0.58 mcg/Kg/min (IQR 0.40-0.78). All patients had a hyper-contractile left ventricle, septal hypertrophy, significant LVOTO (peak gradient 78 [56-123] mmHg) associated with SAM and severe MR with pulmonary oedema. Vasopressin (median 4 IU/h) allowed a significant reduction of norepinephrine (0.18 [0.14-0.30] mcg/kg/min; p = 0.01), LVOT gradient (35 [24-60] mmHg; p = 0.01) and MR with a significant paO(2)/FiO(2) increase (174 [125-213] mmHg; p = 0.01). Conclusion Vasopressin allowed a reduction of norepinephrine with subsequent LVOTO reduction and hemodynamic improvement of the most severe form of LVOTO, which represented 1.9% of all septic shock patients