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Introduction: Atrial fibrillation (AF) is the most common sustained arrhythmia, and catheter ablation (CA) is a primary therapeutic option. However, the 30‐day all‐cause mortality risk associated with CA for AF may be underestimated due to selection bias. Our study aimed to assess 30‐day mortality in an unselected cohort of patients. Methods: Data from the National Health Fund‐Poland covered over 99% of nationwide radiofrequency ablation (RF) or cryoballoon ablation for AF, with 100% recorded deaths. The study included consecutive CA procedures in adult patients between 2012 and 2019. Thirty‐day mortality rates were calculated for each age group. Results: A total of 31 214 CAs for AF were performed on 26 767 patients (34.8% female). Forty‐four percent of patients had hypertension, 31.2% had coronary artery disease, 14.4% had heart failure, 11% had diabetes mellitus, 5.6% had malignant neoplasms, 2.7% had a previous myocardial infarction, 2.5% had a previous stroke, and 2.2% had kidney disease. Thirty‐two deaths (0.1%) occurred within 30 days, with the highest mortality in the oldest age group (>80 years). Statistical analysis revealed higher incidences of kidney disease (p < 0.001) and heart failure (p = 0.001) in patients who died within 30 days. Mortality risk did not significantly differ between cryoballoon and RF ablation, as well as first and subsequent ablation for AF. The risk of death within 7 days postablation for AF was 1 in 2750 procedures, while the risk of death on the same day postablation was 1 in 6250 procedures. Conclusions: The 30‐day mortality rate in a large, unselected AF ablation cohort, covering 99% of procedures in the country, is low except for the oldest patients. This factor should be taken into consideration when offering CA for AF. [ABSTRACT FROM AUTHOR]

The paper presents the influence of the temperature of the sintering process on the microstructure and selected properties of boron carbide/TiB2/SiC composites obtained in situ by spark plasma sintering (SPS). The homogeneous mixture of boron carbide and 5% vol. Ti5Si3 micropowders were used as the initial material. Spark plasma sintering was conducted at 1700 °C, 1800 °C, and 1900 °C for 10 min after the initial pressing at 35 MPa. The heating and cooling rate was 200 °C/min. The obtained boron carbide composites were subjected to density measurement, an analysis of the chemical and phase composition, microstructure examination, and dry friction-wear tests in ball-on-disc geometry using WC as a counterpart material. The phase compositions of the produced composites differed from the composition of the initial powder mixture. Instead of titanium silicide, two new phases appeared: TiB2 and SiC. The complete disappearance of Ti5Si3 was accompanied by a decrease in the boron carbide content of the stoichiometry formula B13C2 and an increase in the content of TiB2, while the SiC content was almost constant. The relative density of the obtained boron carbide composites, as well as their hardness and resistance to wear, increased with the sintering temperature and TiB2 content. Unfortunately, the reactions occurring during sintering did not allow us to obtain composites with high density and hardness. The relative density was 76–85.2% of the theoretical one, while the Vickers hardness was in the range of 4–12 GPa. The mechanism wear of boron carbide composites tested in friction contact with WC was abrasive. The volumetric wear rate (Wv) of composites decreased with increasing sintering temperature and TiB2 content. The average value of coefficient of friction (CoF) was in the range of 0.54–0.61, i.e., it did not differ significantly from the value for B4C sinters. [ABSTRACT FROM AUTHOR]

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The design of transparent conductive electrodes (TCEs) for optoelectronic devices requires a trade‐off between high conductivity and transmittivity, limiting their efficiency. This paper demonstrates the best ever achieved TCEs with the novel approach to fabricating TCEs that effectively alleviates this trade‐off: a monolithic high contrast grating integrated with metal (metalMHCG). The metalMHCG enables higher electrical conductivity than other TCEs, while providing transmissive and antireflective properties. It focuses on infrared spectrum TCEs, which are essential for sensing, thermal imaging, and automotive applications. However, due to elevated free carrier absorption, they are much more demanding than TCEs for the visible spectrum. It demonstrates a record 75% absolute transmittiance of unpolarized light, resulting in a record 108% transmittance relative to plain GaAs substrate. It achieves even larger absolute transmittance of polarized light, reaching 92% or 133% relative transmittance. Despite the record high transmittance, the sheet resistance of the metalMHCG is the best ever reported, several times lower than any other TCE, ranging from 0.5 to 1 Ω Sq−1. [ABSTRACT FROM AUTHOR]

Most systems used in quantum physics experiments require the efficient and simultaneous recording different multi-photon coincidence detection events. In such experiments, the single-photon gated counting systems can be applicable. The main sources of errors in these systems are both instability of the clock source and their imperfect synchronization with the excitation source. Below, we propose a solution for improvement of the metrological parameters of such measuring systems. Thus, we designed a novel integrated circuit dedicated to registration of signals from a photon number resolving detectors including a phase synchronizer module. This paper presents the architecture of a high-resolution (~60 ps) digital phase synchronizer module cooperating with a multi-channel coincidence counter. The main characteristic feature of the presented system is its ability to fast synchronization (requiring only one clock period) with the measuring process. Therefore, it is designed to work with various excitation sources of a very wide frequency range. Implementation of the phase synchronizer module in an FPGA device enabled to reduce the synchronization error value from 2.857 ns to 214.8 ps.