Current issues of body donation for teaching and research purposes and their use in the Czech Republic.

Since time immemorial, bodies of deceased have been an integral part of teaching anatomy, and therefore the study of medicine. Without them, the teaching of anatomy, clinical anatomy and many research projects could not be realized. Nowadays, the European countries allow to use exclusively bodies of the deceased donors. Recently, we have registered a growing trend in the needs of the bodies not only for the purposes of medical education, but also for those of clinical anatomy. The question also arose of the suitability of using COVID-19 positive donors or the legislative possibility of obtaining bodies in the absence of donors in the donor program. Our communication addresses current issues of body donation for teaching and research purposes and their use in the Czech Republic.

Sex differences in 1-year clinical outcomes after percutaneous coronary intervention with COMBO stents: From the COMBO collaboration.

BACKGROUND: The COMBO drug eluting stent is a novel device with luminal endothelial progenitor cell capture technology for rapid homogeneous endothelialization. METHODS AND RESULTS: We examined for sex differences in 1-year outcomes after COMBO stenting from the COMBO collaboration, a pooled patient-level dataset from the MASCOT and REMEDEE multicenter registries. The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, target vessel-myocardial infarction (TV-MI), or clinically driven target lesion revascularization (CD-TLR). Secondary outcomes included stent thrombosis (ST). Adjusted outcomes were assessed using Cox regression methods. The study included 861 (23.8%) women and 2,753 (76.2%) men. Women were older with higher prevalence of several comorbidities including diabetes mellitus. Risk of 1-year TLF was similar in both sexes (3.8% vs. 3.9%, HR 0.92, 95% CI 0.59-1.42, p = .70), without sex differences in the incidence of cardiac death (1.6% vs. 1.5%, p = .78), TV-MI (1.5% vs. 1.1%, p = .32), or CD-TLR (2.0% vs. 2.2%, p = .67). Definite or probable ST occurred in 0.4% women and 1.0% men (HR 0.26, 95% CI 0.06-1.11, p = .069). CONCLUSIONS: Despite greater clinical risks at baseline, women treated with COMBO stents had similarly low 1-year TLF and other ischemic outcomes compared to men.

Shape morphing technique can accurately predict pelvic bone landmarks.

Diffeomorphic shape registration allows for the seamless geometric alignment of shapes. In this study, we demonstrated the use of a registration algorithm to automatically seed anthropological landmarks on the CT images of the pelvis. We found a high correlation between manually and automatically seeded landmarks. The registration algorithm makes it possible to achieve a high degree of automation with the potential to reduce operator errors in the seeding of anthropological landmarks. The results of this study represent a promising step forward in effectively defining the anthropological measures of the human skeleton.

One-Year COMBO Stent Outcomes in Acute Coronary Syndrome: from the COMBO Collaboration.

PURPOSE: The COMBO biodegradable polymer sirolimus-eluting stent includes endothelial progenitor cell capture (EPC) technology for rapid endothelialization, which may offer advantage in acute coronary syndromes (ACS). We sought to analyze the performance of the COMBO stent by ACS status and ACS subtype. METHODS: The COMBO collaboration (n = 3614) is a patient-level pooled dataset from the MASCOT and REMEDEE registries. We evaluated outcomes by ACS status, and ACS subtype in patients with ST segment elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) versus unstable angina (UA). The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization. Secondary outcomes included stent thrombosis (ST). RESULTS: We compared 1965 (54%) ACS and 1649 (46.0%) non-ACS patients. ACS presentations included 40% (n = 789) STEMI, 31% (n = 600) NSTEMI, and 29% (n = 576) UA patients. Risk of 1-year TLF was greater in ACS patients (4.5% vs. 3.3%, HR 1.51 95% CI 1.01-2.25, p = 0.045) without significant differences in definite/probable ST (1.1% vs 0.5%, HR 2.40, 95% CI 0.91-6.31, p = 0.08). One-year TLF was similar in STEMI, NSTEMI, and UA (4.8% vs 4.8% vs. 3.7%, p = 0.60), but definite/probable ST was higher in STEMI patients (1.9% vs 0.5% vs 0.7%, p = 0.03). Adjusted outcomes were not different in MI versus UA patients. CONCLUSIONS: Despite the novel EPC capture technology, COMBO stent PCI was associated with somewhat greater risk of 1-year TLF in ACS than in non-ACS patients, without significant differences in stent thrombosis. No differences were observed in 1-year TLF among ACS subtypes.

Carotid artery plaque composition and distribution: near-infrared spectroscopy and intravascular ultrasound analysis.

Most atherosclerotic plaques (APs) form in typical predilection areas of low endothelial shear stress (ESS). On the contrary, previous data hinted that plaques rupture in their proximal parts where accelerated blood flow causes high ESS. It was postulated that high ESS plays an important role in the latter stages of AP formation and in its destabilization. Here, we used near-infrared spectroscopy (NIRS) to analyse the distribution of lipid core based on the presumed exposure to ESS. A total of 117 carotid arteries were evaluated using NIRS and intravascular ultrasound (IVUS) prior to carotid artery stenting. The point of minimal luminal area (MLA) was determined using IVUS. A stepwise analysis of the presence of lipid core was then performed using NIRS. The lipid core presence was quantified as the lipid core burden index (LCBI) within 2 mm wide segments both proximally and distally to the MLA. The analysed vessel was then divided into three 20 mm long thirds (proximal, middle, and distal) for further analysis. The maximal value of LCBI (231.9 ± 245.7) was noted in the segment localized just 2 mm proximally to MLA. The mean LCBI in the middle third was significantly higher than both the proximal (121.4 ± 185.6 vs. 47.0 ± 96.5, P < 0.01) and distal regions (121.4 ± 185.6 vs. 32.4 ± 89.6, P < 0.01). Lipid core was more common in the proximal region when compared with the distal region (mean LCBI 47.0 ± 96.5 vs. 32.4 ± 89.6, P < 0.01).

Coincidence of superficial brachiomedian artery and bitendinous palmaris longus: a case report.

We present a unique unilateral case of a superficial brachiomedian artery that coincides with a variable palmaris longus muscle in a male cadaver. The superficial brachiomedian artery branched at the distal part of the right arm and coursed superficially in the cubital and antebrachial regions. Then it passed through the carpal canal and formed a complete superficial palmar arch by joining the trunk of the ulnar artery. The variable bitendinous palmaris longus was composed of a central belly and two asymmetrical tendons inserting mainly on the ulnar side of the flexor retinaculum. The knowledge of this arterial variant is of high clinical relevance for the catheterization, for the harvesting of the forearm artery as a graft, for the collateral circulation in cases of arterial occlusion, for surgical management of the carpal tunnel syndrome, or in cases of injury of the superficially located variant artery.

[Detection of vulnerable atherosclerotic plaque with near-infrared spectroscopy: a systematic review]. / Význam vulnerabilních aterosklerotických plátu a moznosti jejich detekce pomocí intravaskulární spektroskopie.

The term vulnerable atherosclerotic plaque is used to describe an atherosclerotic lesion with a high probability of rupture and thrombosis causing an acute coronary event or stroke. Pathogenesis of the vulnerable plaque has been well described pathologically and on experimental models. Detection of vulnerable plaques in vivo has been limited so far. There has been lack of methods able to predict future event from certain lesion characteristics that were rigorously validated on prospective clinical trials. Intravascular near-infrared spectroscopy is a novel technique that has been intentionally developed for the identification of a lipid core within a plaque. Results from recent clinical trials seem promising. This review briefly summarizes current knowledge in the field of near-infrared spectroscopy.

The use of residual analysis to improve the error rate accuracy of machine translation.

The aim of the study is to compare two different approaches to machine translation-statistical and neural-using automatic MT metrics of error rate and residuals. We examined four available online MT systems (statistical Google Translate, neural Google Translate, and two European commission's MT tools-statistical mt@ec and neural eTranslation) through their products (MT outputs). We propose using residual analysis to improve the accuracy of machine translation error rate. Residuals represent a new approach to comparing the quality of statistical and neural MT outputs. The study provides new insights into evaluating machine translation quality from English and German into Slovak through automatic error rate metrics. In the category of prediction and syntactic-semantic correlativeness, statistical MT showed a significantly higher error rate than neural MT. Conversely, in the category of lexical semantics, neural MT showed a significantly higher error rate than statistical MT. The results indicate that relying solely on the reference when determining MT quality is insufficient. However, when combined with residuals, it offers a more objective view of MT quality and facilitates the comparison of statistical MT and neural MT.

In silico hemodynamical simulations show additional benefits of artery wall softening induced by antihypertensive drugs.

BACKGROUND AND OBJECTIVES: Age-related arterial stiffening increases peripheral resistance and decreases arterial distensibility, thus contributing to hypertension, an important risk factor of atherosclerosis. It causes abnormal blood flow, endothelial dysfunction, higher pulse wave velocity, and consequently elevated pressure wave amplitude. METHODS: This paper presents the influence of these changes via multiscale 3D-0D transient computational fluid dynamics simulations of blood flow in five patient-specific geometries of human carotid bifurcation using archetypal flow waveforms for young and old subjects. RESULTS: The proposed model shows a significant decrease in the time-averaged wall shear stress (TAWSS) for the old archetypal flow waveform. This is in good agreement with clinical data on a straight segment of common carotid arteries available for young and old subjects. Moreover, our study showed that the decrease of area-averaged TAWSS related to the old flow waveform is much more pronounced (2.5 ÷ 4.5 times higher) at risk areas (areas showing TAWSS below its threshold value of 0.48 Pa) than in straight segments commonly considered in clinical studies. CONCLUSIONS: Since arterial stiffness can be lowered through long-term usage of any of the five basic groups of antihypertensives, possible benefits of such medical therapy could be not only lowering blood pressure and peripheral resistance but also in increasing the TAWSS and thus attenuating an important mechanism of the atherosclerotic process.

Illumination of Interior Spaces through Structures Made of Unified Slabs of High-Performance Light-Transmitting Concrete with Embedded Optical Fibers.

Light-transmitting concrete as a building material already exists in many forms, but its light properties and the possibilities of using it to improve the lighting of interior spaces have not been investigated in detail yet. This paper focuses on the illumination of interior spaces using constructions made of light-transmitting concrete, which will allow light to pass between individual spaces. The experimental measurements carried out are divided into two typical situations using reduced room models. The first part of the paper focuses on the illumination of the room through the penetration of daylight through the ceiling made of light-transmitting concrete. The second part of the paper investigates the transmission of artificial light from one room to another through a non-load-bearing dividing structure composed of unified slabs of light-transmitting concrete. For the experiments, several models and samples were created for comparison. The first step of the experiment was to create slabs of light-transmitting concrete. While there are many options to produce such a slab, the best option is to use high-performance concrete with glass-fiber reinforcement, which improves the load transfer properties, and plastic optical fibers for light transmission. By adding optical fibers, we can achieve the transmission of light between any two spaces. For both of the experiments, we used reduced-scale models of rooms. Slabs with dimensions of 250 × 250 × 20 mm and 250 × 250 × 30 mm were used in three versions: concrete slabs with optical fibers, concrete slabs with air holes and solid slabs. The experiment measured and compared the level of illumination at several points in the model as it passed through each of the three different slabs. Based on the results of these experiments, it was concluded that the interior level of illumination of any space can be improved by using light-transmitting concrete, especially those without access to natural light. The experiment also assessed the strength properties of the slabs in relation to their intended use and compares them with the properties of stone slabs used as cladding.

Effect of twitter investor engagement on cryptocurrencies during the COVID-19 pandemic.

This study aims to examine whether the prices and returns of two cryptocurrencies, Dogecoin and Ethereum, are affected by Twitter engagement following the COVID-19 pandemic. We use the autoregressive integrated moving average with explanatory variables model to integrate the effects of investor attention and engagement on Dogecoin and Ethereum returns using data from December 31, 2020, to May 12, 2021. The results provide evidence supporting the hypothesis of a strong effect of Twitter investor engagement on Dogecoin returns; however, no potential impact is identified for Ethereum. These findings add to the growing evidence regarding the effect of social media on the cryptocurrency market and have useful implications for investors and corporate investment managers concerning investment decisions and trading strategies.

Reinforced L-Shaped Frame Made of Textile-Reinforced Concrete.

Textile-reinforced concrete is becoming more and more popular. The material enables the realization of very thin structures and shells, often with organic shapes. However, a problem with this reinforcement occurs when the structure is bent (contains a corner), and the flexural stiffness around this bent area is required. This article presents the design, solution, and load-bearing capacity of an L-shaped rigid frame made of textile-reinforced concrete. Basic material parameters of concrete matrix and carbon textile reinforcement were supplemented by a four-point bending test to calibrate fracture energy Gf, critical compressive displacement Wd, solver type, and other parameters of a numerical model created by Atena Engineering in specialized non-linear structural analysis software for reinforced concrete structures. The calibrated numerical model was used to evaluate different variants of carbon textile reinforcement of the L-shaped frame. The carbon textile reinforcement was homogenized using epoxy resin to ensure the interaction of all fibers, and its surface was modified with fine-grained silica sand to increase the cohesion with the concrete matrix. Specimens were produced based on the most effective variant of the L-shaped frame reinforcement to be experimentally tested. Thanks to the original shaping and anchoring of the reinforcement in the corner area, the frame with composite textile reinforcement is rigid and can transmit the bending stresses in both positive and negative directions. The results of the mechanical loading test on small experimental specimens correspond well to the results of numerical modeling using Atena Engineering software.

Woven Carbon-Fiber-Reinforced Polymer Tubular Mesh Reinforcement of Hollow High-Performance Concrete Beams.

This article presents woven carbon-fiber-reinforced polymer (CFRP) tubular mesh used as a reinforcement on the inner surface of hollow beams made of high-performance concrete (HPC). The tubular mesh was designed to serve as both the tensile and shear reinforcement of hollow beams intended for the construction of small self-supporting structures that could be assembled without mechanization. The reinforcement was prepared with a tri-axial weaving machine from carbon filament yarn and was homogenized using epoxy resin. The interaction of the composite reinforcement with the cementitious matrix was investigated, and the surface of the reinforcement was modified using silica sand and polyvinyl alcohol (PVA) fibers to improve cohesion. The sand coating enhanced bond strength, resulting in the significantly higher flexural strength of the hollow beam of 128%. The PVA fibers had a lower positive effect of 64% on the flexural strength but improved the ductility of the beam. Individual beams were connected by gluing steel parts directly inside the hollow core of the HPC beam. This procedure provides good interaction between the CFRP reinforcement and the glued steel insert and allows for the fast and simple assembly of structures. The weaving of additional layers of the CFRP reinforcement around HPC beams was also explored. A small structure made of the hollow HPC beams with inner composite reinforcement was constructed to demonstrate the possibilities of the presented technology.

[Ulnar Carpus Translation - our Experience]. / Ulnare Karpustranslation ­ unsere Erfahrungen.

The ulnar translation (UT) of the wrist is a rare but often missed injury. We report about our experiences in the treatment of 8 patients with an imminent (5), established (1), and chronic UT (2).

An interpretable system for predicting the impact of COVID-19 government interventions on stock market sectors.

Evaluating and understanding the financial impacts of COVID-19 has emerged as an urgent research agenda. Nevertheless, the impacts of government interventions on stock markets remain poorly understood. This study explores, for the first time, the impact of COVID-19 related government intervention policies on different stock market sectors using explainable machine learning-based prediction models. The empirical findings suggest that the LightGBM model provides excellent prediction accuracy while preserving computationally efficient and easy explainability of the model. We also find that COVID-19 government interventions are better predictors of stock market volatility than stock market returns. We further show that the observed effects of government intervention on the volatility and returns of ten stock market sectors are heterogeneous and asymmetrical. Our findings have important implications for policymakers and investors in terms of promoting balance and sustaining prosperity across industry sectors through government interventions.

Increased cardiovascular mortality in patients with mechanically expandable transcatheter aortic valve and without permanent pacemaker.

INTRODUCTION: Use of the mechanically expandable transcatheter aortic valve (MEV) has been recently linked to increased risks of valve dysfunction and cardiovascular mortality. The risk of developing conduction disturbance with the MEV valve is well known, and the negative prognostic impact of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation is another consideration. AIM: This study aimed to compare the mid-term survival of patients with MEV and self-expandable valves (SEV), and to examine survival of both groups according to the presence or absence of PPI. METHODS: This single-centre, retrospective, observational study examined data from MEV and SEV groups comprising 92 and 373 patients, respectively. The mean clinical follow-up was 2.5±1.7 years. Mortality information was obtained from the National Institutes of Health Information and Statistics. RESULTS: Baseline characteristics were comparable between the groups. The log-rank test showed higher cardiovascular mortality in the MEV group (p=0.042; the relative risk (RR) 1.594 (95% CI 1.013 to 2.508)). The Cox proportional hazards model identified MEV implantation as an independent predictor of cardiovascular mortality. The rate of PPI was twice as high in the MEV vs SEV group (33.7% vs 16.1%; p<0.001). We compared the survival of both groups according to the presence or absence of PPI and found higher mortality in the MEV group without PPI versus the SEV group without PPI (p=0.007; RR 2.156 (95% CI 1.213 to 3.831)). Survival did not differ in the groups with PPI. CONCLUSIONS: A higher mid-term cardiovascular mortality rate was observed with MEV versus SEV implants. Comparing both groups according to the presence or absence of PPI, we observed a higher mortality risk in patients with MEV without PPI than in SEV without PPI. In contrast, mortality did not differ between the groups when PPI was implanted.

High positive predictive value of PAPP-A for acute coronary syndrome diagnosis in heparin-naïve patients.

Pregnancy-associated plasma protein-A (PAPP-A) was studied as a marker of acute coronary syndrome (ACS). It has been shown that its levels are increased by heparin administration. Therefore, the aim of our study was to ascertain the diagnostic significance of PAPP-A in heparin-naïve patients and compare it with (TnI). We prospectively studied 67 heparin-naïve patients with acute chest pain. The patients were independently grouped according to the presence or absence of ACS. PAPP-A levels were significantly increased in ACS patients (8.6 vs. 7.3 mIU/l; P = 0.006) with high positive (95.7%) and lower negative predictive values (47.7%). In multivariate analysis, its levels were strongly predictive of a final diagnosis of ACS (OR 41.8; 95th CI 2.64-662.6; P = 0.008). The diagnostic significance of PAPP-A was not higher than TnI even within 6 h after the onset of chest pain [the area under the ROC curve (AUC) was 0.69 for PAPP-A and 0.91 for TnI, respectively; P = 0.08]. We observed no difference in the AUC in NSTE-ACS patients (0.73 for PAPP-A and 0.79 for TnI (P = 0.5)). PAPP-A levels were an independent predictor of ACS diagnosis in heparin-naïve patients. Its diagnostic significance was not higher than TnI even within a short period after the onset of chest pain. In troponin-negative NSTE-ACS patients, PAPP-A helped make the correct final diagnosis.

Combined approach to demonstrate acetylcholinesterase activity changes in the rat brain following tabun intoxication and its treatment.

Reactivation effects of K203 and currently available oximes (obidoxime, HI-6) in combination with atropine on acetylcholinesterase activities in the brain parts of rats poisoned with tabun were studied. The activity was determined by quantitative histochemical and biochemical methods correlating between them very well. The tabun-induced changes in acetylcholinsterase activity as well as in reactivation potency of reactivators used were different in various parts of the brain. Pontomedullar area seems to be important for observed changes following tabun intoxication and its treatment. From the oximes studied, the reactivation effect of K203 was comparable with obidoxime; HI-6 was ineffective. Combination of bio- and histochemical methods allow fine differentiation among the action of different oximes following tabun poisoning.

Fraud Detection in Mobile Payment Systems using an XGBoost-based Framework.

Mobile payment systems are becoming more popular due to the increase in the number of smartphones, which, in turn, attracts the interest of fraudsters. Extant research has therefore developed various fraud detection methods using supervised machine learning. However, sufficient labeled data are rarely available and their detection performance is negatively affected by the extreme class imbalance in financial fraud data. The purpose of this study is to propose an XGBoost-based fraud detection framework while considering the financial consequences of fraud detection systems. The framework was empirically validated on a large dataset of more than 6 million mobile transactions. To demonstrate the effectiveness of the proposed framework, we conducted a comparative evaluation of existing machine learning methods designed for modeling imbalanced data and outlier detection. The results suggest that in terms of standard classification measures, the proposed semi-supervised ensemble model integrating multiple unsupervised outlier detection algorithms and an XGBoost classifier achieves the best results, while the highest cost savings can be achieved by combining random under-sampling and XGBoost methods. This study has therefore financial implications for organizations to make appropriate decisions regarding the implementation of effective fraud detection systems.

Alkali-silica Reaction Elimination Potential of High-Performance Concrete Containing Glass Powder.

This study is mainly concerned with the assumption that glass powder can eliminate the potential alkali-silica reaction in high performance concrete. Glass is often land filled, produced as a secondary raw material or as a by-product of production. Chemical analyses were carried out, and the ecotoxicity of the material was investigated, serving as a basis for testing a potential alkali-silica reaction. High performance concrete (HPC) containing different types of waste powder (secondary raw material from production (SGP), jewelry production (SGJ), container waste glass (CWG), and glass from used photovoltaic panels (GPP)) are tested according to the international standard ASTM C1260 and the Czech technical condition TP 137. Newly designed mixtures are innocuous from the ASR point of view in the most cases, except SGP HPC.