The yield of a comprehensive investigation protocol for the diagnosis of true idiopathic ventricular fibrillation in a real-life clinical setting.

Traditionally, aborted cardiac arrest (ACA) due to documented ventricular fibrillation (VF) in the absence of structural heart disease has been termed idiopathic VF. By careful evaluation, a specific etiology can be found in a substantial proportion of patients. The aim of this survey was to assess the yield of an advanced diagnostic work-up to reveal a causative etiology in a real-life clinical setting. Patients from the University Hospital Brno's ACA database were analyzed (514 patients in total). Forty-six patients (31 males) fulfilled the inclusion criteria, which were: (1) absence of structural pathology on echocardiography; (2) absence of coronary artery disease; and (3) absence of reversible cause of ACA. The diagnostic work-up consisted in cardiac magnetic resonance imaging, stress testing, sodium channel blocker challenge, and genetic testing according to the availability of the method and patient compliance. A specific disease was found in 17 individuals (37.0%), although at least one diagnostic step was refused by 13 patients (28.3%). True idiopathic VF was confirmed in 7 patients (15.2%), for whom the entire diagnostic work-up did not reveal any specific pathology. Our real-life survey shows that, even with an incomplete diagnostic work-up (due to the unavailability of a particular method or variable patient compliance), a specific diagnosis can be identified in more than one third of the cases of "idiopathic" VF, which can thus enable targeted treatment and family screening.

Additive Manufacturing of WC-Co Specimens with Internal Channels.

Most material removal in modern manufacturing is currently performed using tools with indexable inserts. Additive manufacturing allows for the creation of new, experimental insert shapes and, more importantly, internal structures, such as channels for coolant. This study deals with developing a process for efficiently manufacturing WC-Co specimens with internal coolant channels with a focus on obtaining a suitable microstructure and surface finish, especially inside the channels. The first part of this study covers the development of process parameters to achieve a microstructure without cracks and with minimal porosity. The next stage focuses solely on improving the surface quality of the parts. Special attention is given to the internal channels, where true surface area and surface quality are evaluated, as these characteristics greatly influence coolant flow. To conclude, WC-Co specimens were successfully manufactured and a microstructure with low porosity and no cracks was achieved and an effective parameter set was found. We have developed a process that produces parts with a surface roughness comparable to those of standard SLS manufacturing of steel parts, while still providing a high-quality internal microstructure. The most suitable parameter set resulted in a profile surface roughness of Ra 4 µm and Rz 31 µm and areal surface roughness of Sa 7 µm and Sz 125 µm.

Developing a large-scale dataset of flood fatalities for territories in the Euro-Mediterranean region, FFEM-DB.

This data paper describes the multinational Database of Flood Fatalities from the Euro-Mediterranean region FFEM-DB that hosts data of 2,875 flood fatalities from 12 territories (nine of which represent entire countries) in Europe and the broader Mediterranean region from 1980 to 2020. The FFEM-DB database provides data on fatalities' profiles, location, and contributing circumstances, allowing researchers and flood risk managers to explore demographic, behavioral, and situational factors, as well as environmental features of flood-related mortality. The standardized data collection and classification methodology enable comparison between regions beyond administrative boundaries. The FFEM-DB is expandable, regularly updated, publicly available, and with anonymized data. The key advantages of the FFEM-DB compared to existing datasets containing flood fatalities are its high level of detail, data accuracy, record completeness, and the large sample size from an extended area.

Thermodynamics and Mechanics of Thermal Spraying of Steel EN 10060 Substrate with NiCrBSi Alloy after Milling.

The objective of this paper is to present a new way of identifying and predicting the relationship between thermodynamic and physical-mechanical parameters in the formation of a layer after spraying on a substrate with NiCrBSi alloy and its subsequent processing by milling. The milling of the spherical surface of the EN 10060 material after spraying was performed on the DMU 40 eVolinear linear milling centre. The experimental part of the article is focused on investigating the influence of cutting parameters when machining a selected combination of materials (substrate-coating: EN 10060 steel-NiCrBSi alloy). The experiment is based on the results of direct measurements of three basic cutting parameters, namely: cutting speed vc (m∙min-1), feed per tooth fz (mm), and the depth of cut ap (mm). The new distribution functions of selected cutting parameters were derived. The analytical results of the thermodynamic calculations performed on nickel-based alloy can be used for accurate predictions of the technological parameters of milling a spherical substrate made of EN 10060 steel after HVOF spraying, and also for both sample preparation and the subsequent production of high-quality coatings.

Investigation of Surface Roughness and Predictive Modelling of Machining Stellite 6.

The aim of the paper was to examine the influence of cutting conditions on the roughness of surfaces machined by longitudinal turning, namely of surfaces coated with Stellite 6 prepared by high-velocity oxygen fuel (HVOF) technology and applied onto a standard structural steel substrate. From the results of measurements of the cutting parameters, a prediction model of the roughness parameters was created using mathematical and statistical methods. Based on a more detailed analysis and data comparison, a new method for prediction of parameters of longitudinal turning technology was obtained. The main aim of the paper was to identify the mutual discrete relationships between the substrate roughness and the machining parameters. These were the feed rate vc (m·min-1), in the case of turning and milling, and the feed rate f (mm·rev-1) and the depth of cut ap (mm). The paper compared and verified two approaches of this method, namely the mathematical statistical approach, the analytical approach and measured dates. From the evaluated and interpreted results, new equations were formulated, enabling prediction of the material parameters of the workpiece, the technological parameters and the parameters of surface quality.