Development of heart motion reconstruction framework based on the 4D echocardiographic data

Abnormalities in heart motion can eventually lead to life threatening cardiac injuries therefore measurements of dynamic heart functions are of great clinical importance. The images of moving spatial heart structures can be efficiently acquired using 4D echocardiography. Unfortunately, because of the low quality such images do not allow for precise measurements. To overcome this problem images need to be further processed and moving structures have to be extracted. In this work we present a method for estimating heart motion from the 3D echocardiographic image sequence. On the basis of this method we have developed an application that enables qualitative and quantitative (i.e. volume changes, stroke volume, ejection fraction and cardiac output parameters) description of the heart wall motion. We provide a set of tools for denoising images using the anisotropic diffusion algorithm extended to the fourth dimension and the time averaging method based on non-linear registration efficiently parameterized using the B-spline based Free Form Deformation. We have also developed a non-linear deformable segmentation algorithm for extraction of the inner ventricular surface. The motion of the left ventricle is reconstructed in our approach by recovering deformations of the matter during the cardiac cycle. All the obtained results using our framework can be efficiently presented in 3D using a set of newly developed heart motion visualization tools

Effect of high-temperature exposure on the microstructure and mechanical properties of the Al5Ti5Co35Ni35Fe20 high-entropy alloy

Effect of high-temperature exposure on the microstructure and mechanical properties of the Al5Ti5Co35Ni35Fe20 High-Entropy Alloy was studied. High-entropy alloys belong to the group of multi-principal element alloys composed of at least five elements with a concentration between 5 and 35 atomic pct. Despite the multicomponent composition, the goal is to achieve a simple solid solution. The alloy was exposed to a temperature range of 650-900 degrees C for 168 h (7 days), after hot rolling and air-quenching. After hot rolling the investigated alloy was not fully supersaturated. The application of air cooling caused gamma' precipitation, which was uniformly distributed within the microstructure. High-temperature exposure caused the growth of gamma' particles. At 700 degrees C and higher, additional continuous and discontinuous precipitation of gamma' was observed. Finally, the microstructure of the investigated alloy consisted of gamma matrix and three types of gamma' precipitates, i.e. spherical gamma' phases with bimodal distribution within the grains and elongated DP gamma' phases present at the grain boundaries. The highest mechanical properties were obtained after exposure to 650 degrees C, which was caused by gamma' precipitation. Further increase in temperature decreased the mechanical properties.Web of Science9155955

Contests Hosting Service as a tool to teach programming

Computer science would not exist without the concept of algorithm. Therefore design of algorithms plays an important role in education while implementation is usually considered to be straightforward. Increasing variety of programming languages, wealth of possible constructions, programming environments and tools makes programming difficult for the beginners.Apart from the idea of problem solution, it is important to teach programming skills. Size of classes of 10-20 pupils and a limited number of lessons and their short time are the major problem. The teacher has to check solution of every pupil, compile it and run tests. This is definitely a time-consuming process which makes teaching difficult. In this paper the authors present the use of problem solutions validation systems during classes. With the help of such a system called Zawody WEB, the authors teach algorithms and programming for the secondary school students

Application of Pfortran and Co-Array Fortran in the parallelization of the GROMOS96 molecular dynamics module

After at least a decade of parallel tool development, parallelization of scientific applications remains a significant undertaking. Typically parallelization is a specialized activity supported only partially by the programming tool set, with the programmer involved with parallel issues in addition to sequential ones. The details of concern range from algorithm design down to low-level data movement details. The aim of parallel programming tools is to automate the latter without sacrificing performance and portability, allowing the programmer to focus on algorithm specification and development. We present our use of two similar parallelization tools, Pfortran and Cray's Co-Array Fortran, in the parallelization of the GROMOS96 molecular dynamics module. Our parallelization started from the GROMOS96 distribution's sharedmemory implementation of the replicated algorithm, but used little of that existing parallel structure. Consequently, our parallelization was close to starting with the sequential version. We found the intuitive extensions to Pfortran and Co-Array Fortran helpful in the rapid parallelization of the project. We present performance figures for both the Pfortran and CoArray Fortran parallelizations showing linear speedup within the range expected by these parallelization methods

Mortality in patients after acute myocardial infarction managed by cardiologists and primary care physicians : a systematic review

Introduction Mortality following acute myocardial infarction (AMI) remains high despite of progress in invasive and noninvasive treatments. Objectives This study aimed to compare the outcomes of ambulatory treatment provided by cardiologists versus general practitioners (GPs) in post‑AMI patients. Patients and methods We conducted a systematic search in 3 electronic databases for interventional and observational studies that reported all‑cause mortality, mortality from cardiovascular causes, stroke, and myocardial infarction at long‑term follow‑up following AMI. We assessed the risk of bias of the included studies using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS‑I) tool. For randomized trials, we used the revised Cochrane risk of bias tool (RoB 2.0). Results Two nonrandomized studies fulfilled the inclusion criteria. We assessed these studies as having a moderate risk of bias. We did not pool the results owing to significant heterogeneity between the studies. Patients consulted by both a cardiologist and a GP were at lower risk of all‑cause death as compared with patients consulted by a cardiologist only (risk ratio [RR], 0.92; 95% CI, 0.85–0.99). Patients consulted by a cardiologist with or without GP consultation were at lower risk of all‑cause death compared with those consulted by a GP only in both studies (RR, 0.8; 95% CI, 0.75–0.85 and RR, 0.44; 95% CI, 0.41–0.47). Conclusions Patients after AMI consulted by both a cardiologist and a GP may beat lower risk of death compared with patients consulted by a GP or a cardiologist only. However, these findings are based on moderate‑quality nonrandomized studies. We found no evidence on the relation between the specialization of the physician and the risk of cardiovascular death, stroke, or myocardial infarction in AMI survivors

THE INFLUENCE OF MICROSTRUCTURE OF 30MnB4 STEEL ON HYDROGEN-ASSISTED CRACKING

This paper analyzes the problem of susceptibility to hydrogen-assisted cracking (fracture behavior) of zinc-coated screws made of 30MnB4 steel. Two samples (screws) were compared after proper and improper heat treatment affecting hydrogen solubility during the further galvanic process and resulting in different fracture modes. Both samples were loaded to failure by torsion. The fracture surface and microstructure of the samples were examined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS)

Approximant-based orientation determination of quasicrystals using electron backscatter diffraction

Orientation mapping of quasicrystalline materials is demonstrated using crystalline approximant structures in the technique of electron backscatter diffraction (EBSD). The approximant-based orientations are symmetrised according to the rotational point group of the quasicrystal, including the visualization of orientation maps using proper colour keys for quasicrystal symmetries. Alternatively, approximant-based orientation data can also be treated using pseudosymmetry post-processing options in the EBSD system software, which enables basic grain size estimations. Approximant-based orientation analyses are demonstrated for icosahedral and decagonal quasicrystals