Temperature and E-Poling Evolution of Structural, Vibrational, Dielectric, and Ferroelectric Properties of Ba1-xSrxTiO3 Ceramics (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.45).

Lead-free Ba1-xSrxTiO3 (BST) (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.45) ceramics were successfully prepared via the solid-state reaction route. A pure perovskite crystalline structure was identified for all compositions by X-ray diffraction analysis. The basic phase transition temperatures in these ceramics were studied over a wide temperature range. A change in symmetry from a tetragonal to cubic phase was detected, which was further proven by phonon anomalies in composition/temperature-dependent Raman spectra. The incorporation of Sr2+ into BaTiO3 (BT) lead to a shift in the phase transitions to lower temperatures, suppressing the ferroelectric properties and inducing relaxor-like behavior. Therefore, it was reasonable to suppose that the materials progressively lack long-range ordering. The initial second-harmonic generation (SHG) measurements demonstrated that the cubic phase of BST ceramics is not purely centrosymmetric over a wide temperature interval. We discussed the possible origin of the observed effects, and showed that electric field poling seems to reconstruct the structural ordering destroyed by the introduction of Sr2+ to BT. In the first approximation, substitution of Sr for larger Ba simply reduced the space for the off-central shift in Ti in the lattice and hence the domain polarization. A-site cation ordering in BST and its influence on the density of electronic states were also explored. The effect of doping with strontium ions in the BST compound on the density of electronic states was investigated using ab initio methods. As the calculations showed, doping BT with Sr2+ atoms led to an increase in the bandgap. The proposed calculations will also be used in the subsequent search for materials optimal for applications in photovoltaics.

A randomized crossover comparison of the bébé VieScope and direct laryngoscope for pediatric airway management by nurses in medical simulation settings.

BACKGROUND: Airway management in life-threatening emergencies is essential for children, and endotracheal intubation is the gold standard. It protects against regurgitation and enables mechanical ventilation. New types of airway management equipment are being developed and implemented to meet the needs of medical personnel. RESEARCH DESIGN AND METHODS: This prospective, randomized, cross-over simulation trial evaluated the success of endotracheal intubation in three scenarios: normal airway (scenario-A), tongue edema (scenario-B), and continuous chest compression (scenario-C), using the bébé Vie Scope™ laryngoscope (VieScope) and the Macintosh blade laryngoscope (MAC) as a comparative tool performed by nurses with limited tracheal intubation experience. RESULTS: The results of the study showed that in scenario-A, there were no significant differences in the first attempt success rate or endotracheal intubation time between VieScope and MAC. However, VieScope was associated with better visualization of the glottis. In scenarios B and C, VieScope was significantly more effective than MAC in terms of first-pass success rate, time to intubate, Cormack-Lehane grade, POGO score, and ease of endotracheal intubation. CONCLUSIONS: Bébé VieScope may be useful for endotracheal intubation in pediatric patients, particularly in cases of tongue edema and ongoing chest compression, providing a higher first-pass success rate than conventional laryngoscopes.

ETView SL versus Macintosh Direct Laryngoscope for Endotracheal Intubation Amid Simulated COVID-19 Cardiac Arrest: A Randomized Crossover Study.

Airway management procedures, such as endotracheal intubation (ETI), pose a significant risk of aerosol generation, requiring robust personal protective equipment (PPE) against aerosol-generating procedures (AGP). This study aimed to assess the impact of PPE-AGP on intubation success rates, time to intubation, and glottic visualization using ETView and a standard Macintosh laryngoscope (MAC). A total of 52 physicians participated in this prospective, observational, randomized crossover study conducted in a medical simulation setting. Participants included COVID-19 patients with cardiac arrest scenarios with and without PPE-AGP who were intubated with ETView and MAC. During intubation without PPE-AGP, ETView showed a similar first-pass success rate (FPS) but had a shorter intubation time and better glottal hydration compared to MAC. In scenario B (with PPE-AGP), ETView outperformed MAC in FPS, initiation time, and glottic visualization. The use of PPE-AGP had little impact on ETView's performance. However, it negatively affected the Macintosh laryngoscope, reducing FPS and glottic visibility. Participants found intubation with ETView easier in both scenarios. In conclusion, as compared to the Macintosh laryngoscope, ETView demonstrated higher performance under the circumstances of the simulation, especially when PPE-AGP was used.

Impact of VieScope® on first-attempt success during simulated COVID-19 patients intubation: A randomized cross-over simulation trial.

BACKGROUND: The purpose of our study was to determine the efficacy of intubation with VieScope® and Macintosh laryngoscope in different scenarios of simulated COVID-19 patients by paramedics wearing personal protective equipment (PPE) for aerosol gener-ating procedures (AGPs). METHODS: Study was designed as a prospective, observational, randomized, crossover simulation trial. 37 paramedics took part in the study. They performed endotracheal intubation (ETI) of a person suspected of COVID-19. Intubation was performed using VieS-cope® and Macintosh laryngoscopes in two research scenarios: Scenario A - normal airway and Scenario B - difficult airway. Both the order of participants and the methods of intubation were random. RESULTS: In Scenario A, time to intubation using VieScope® and Macintosh laryngoscope amounted to 35.3 (IQR; 32-40) seconds and 35.8 (IQR: 30-40)s, respectively. Nearly all participants performed ETI successfully both with VieScope® and Macintosh laryngo-scope (100% vs. 94.6%). In scenario B, intubation with the VieScope®, compared to the Macintosh laryngoscope, was associated with a shorter intubation time (p<0.001), a higher success rate of the first intubation attempt (p<0.001), a better visualization degree glottis (p=0.012) and ease of intubation (p<0.001). CONCLUSION: Our analysis suggests that the use of a VieScope® compared to Macintosh laryngoscope in difficult airway intuba-tion performed by paramedics wearing PPE-AGP is associated with shorter intubation times, greater intubation efficiency as well as better visualization of the glottis. Additional clinical trials are necessary to confirm the obtained results.

Ceramic Matrix Composites Obtained by the Reactive Sintering of Boron Carbide with Intermetallic Compounds from the Ti-Si System.

In this study, we investigated the effect of adding two different intermetallics, Ti5Si3 and TiSi2, for the preparation of TiB2-SiC-B4C composites. As part of the research, stoichiometric composites consisting only of two phases TiB2 and SiC were obtained. The TiB2-SiC-B4C composites were prepared via pressureless sintering. The presence of the phases in the sintered composites was confirmed using X-ray diffraction and scanning electron microscopy. The SEM-EDS examination revealed that the TiB2 and SiC phases were formed during the composite process synthesis and were distributed homogeneously in the B4C matrix. The obtained results allowed us to usually exceed 2000 °C and the use of specialized equipment for firing, that is, vacuum or protective atmosphere furnaces as well as control and measurement equipment. Such an approach generates high costs that are decisive for the economics of the technological processes. In the case of our compositions, it is possible to lower the temperature to 1650 °C. The TiB2-SiC-B4C composites were classified as UHTCs.

Minimum Query Set for Decision Tree Construction.

A new two-stage method for the construction of a decision tree is developed. The first stage is based on the definition of a minimum query set, which is the smallest set of attribute-value pairs for which any two objects can be distinguished. To obtain this set, an appropriate linear programming model is proposed. The queries from this set are building blocks of the second stage in which we try to find an optimal decision tree using a genetic algorithm. In a series of experiments, we show that for some databases, our approach should be considered as an alternative method to classical ones (CART, C4.5) and other heuristic approaches in terms of classification quality.

Efficacy and Safety of Tranexamic Acid in Emergency Trauma: A Systematic Review and Meta-Analysis.

In trauma patients, bleeding can lead to coagulopathy, hemorrhagic shock, and multiorgan failure, and therefore is of fundamental significance in regard to early morbidity. We conducted a meta-analysis to evaluate the efficacy and safety of tranexamic acid (TXA) in civil and military settings and its impact on in-hospital mortality (survival to hospital discharge or 30-day survival), intensive care unit and hospital length of stay, incidence of adverse events (myocardial infarct and neurological complications), and volume of blood product transfusion. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic review of the literature using PubMed, Scopus, EMBASE, Web of Science, and the Cochrane Central Register and Controlled Trials (CENTRAL) database was conducted from inception to 10 January 2021. In-hospital mortality was reported in 14 studies and was 15.5% for the TXA group as compared with 16.4% for the non-TXA group (OR = 0.81, 95% CI 0.62-1.06, I2 = 83%, p = 0.12). In a civilian TXA application, in-hospital mortality in the TXA and non-TXA groups amounted to 15.0% and 17.1%, respectively (OR = 0.69, 95% CI 0.51-0.93, p = 0.02, I2 = 78%). A subgroup analysis of the randomized control trial (RCT) studies showed a statistically significant reduction in in-hospital mortality in the TXA group (14.3%) as compared with the non-TXA group (15.7%, OR = 0.89, 95% CI 0.83-0.96, p = 0.003, I2 = 0%). To summarize, TXA used in civilian application reduces in-hospital mortality. Application of TXA is beneficial for severely injured patients who undergoing shock and require massive blood transfusions. Patients who undergo treatment with TXA should be monitored for clinical signs of thromboembolism, since TXA is a standalone risk factor of a thromboembolic event and the D-dimers in traumatic patients are almost always elevated.

Efficacy of Targeted Temperature Management after Pediatric Cardiac Arrest: A Meta-Analysis of 2002 Patients.

Cardiac arrest (CA) is associated with high mortality and poor life quality. Targeted temperature management (TTM) or therapeutic hypothermia is a therapy increasing the survival of adult patients after CA. The study aim was to assess the feasibility of therapeutic hypothermia after pediatric CA. We performed a systematic review and meta-analysis of randomized controlled trials and observational studies evaluating the use of TTM after pediatric CA. The primary outcome was survival to hospital discharge or 30-day survival. Secondary outcomes included a one-year survival rate, survival with a Vineland adaptive behavior scale (VABS-II) score ≥ 70, and occurrence of adverse events. Ten articles (n = 2002 patients) were included, comparing TTM patients (n = 638) with controls (n = 1364). In a fixed-effects meta-analysis, survival to hospital discharge in the TTM group was 49.7%, which was higher than in the non-TTM group (43.5%; odds ratio, OR = 1.22; 95% confidence interval, CI: 1.00, 1.50; p = 0.06). There were no differences in the one-year survival rate or the occurrence of adverse events between the TTM and non-TTM groups. Altogether, the use of TTM was associated with a higher survival to hospital discharge; however, it did not significantly increase the annual survival. Additional high-quality prospective studies are necessary to confer additional TTM benefits.

Impact of diabetes mellitus on in-hospital mortality in adult patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) has spread worldwide since the beginning of 2020, placing the heavy burden on the health systems all over the world. The population that particularly has been affected by the pandemic is the group of patients suffering from diabetes mellitus. Having taken the public health in considerations, we have decided to perform a systematic review and meta-analysis of diabetes mellitus on in-hospital mortality in patients with COVID-19. METHODS: A systematic literature review (MEDLINE, EMBASE, Web of Science, Scopus, Cochrane) including all published clinical trials or observational studies published till December 10, 2020, was performed using following terms "diabetes mellitus" OR "diabetes" OR "DM" AND "survival" OR "mortality" AND "SARS-CoV-2" OR "COVID-19". RESULTS: Nineteen studies were included out of the 7327 initially identified studies. Mortality of DM patients vs non-DM patients was 21.3 versus 6.1%, respectively (OR = 2.39; 95%CI: 1.65, 3.64; P < 0.001), while severe disease in DM and non-DM group varied and amounted to 34.8% versus 22.8% (OR = 1.43; 95%CI: 0.82, 2.50; P = 0.20). In the DM group, the complications were observed far more often when compared with non-DM group, both in acute respiratory distress (31.4 vs. 17.2%; OR = 2.38; 95%CI:1.80, 3.13; P < 0.001), acute cardiac injury (22.0% vs. 12.8%; OR = 2.59; 95%CI: 1.81, 3.73; P < 0.001), and acute kidney injury (19.1 vs. 10.2%; OR = 1.97; 95%CI: 1.36, 2.85; P < 0.001). CONCLUSIONS: Based on the findings, we shall conclude that diabetes is an independent risk factor of the severity of COVID-19 in-hospital settings; therefore, patients with diabetes shall aim to reduce the exposure to the potential infection of COVID-19.

Factors influencing high-quality chest compressions during cardiopulmonary resuscitation scenario, according to 2015 American Heart Association Guidelines.

BACKGROUND AND AIM: Recent American Heart Association guidelines from 2010 and 2015 stressed the importance of high-quality chest compression and defined standards for compression rate, depth, recoil, and maximal acceptable time for interruptions. High-quality cardiopulmonary resuscitation (CPR) is the "cornerstone" of a system of care that can optimise outcomes beyond the return of spontaneous circulation. METHODS: One hundred medical students were enrolled to the study. Study participants, after attending a Basic Life Support Course according to American Heart Association 2015 guidelines, performed 2-min CPR on a Resusci Anne® QCPR Mani-kin. The following data were collected: age, sex, and health status. The study made use of a Tanita MC-980 MA for body composition analysis. RESULTS: Mean height of participants was 170.2 ± 8.3 cm, and mean weight was 65 ± 11.8 kg. Mean body mass index was 22.1 ± 2.7, and mean fat-free mass (FFM) was 50.1 ± 10.5 kg. The mean fat mass (FAT%) was 22.9 ± 7.6. Basal metabolic rate, FFM, trunk muscle mass, left arm muscle mass, and right arm muscle mass were positively correlated with compression depth (all p for trend < 0.05). Mean compression depth was 49.7 ± 8.4 (for female 48.7 ± 7.9 mm, for male 42.4 ± 9.5 mm; p = 0.144). Compression rate for males and females was the same, at 114 ×/min (p = 0.769). CONCLUSIONS: In our study, basal metabolic rate, FFM, trunk muscle mass, and left and right arm muscle mass were positively correlated with compression depth. Moreover, an arm muscle mass rise of 1 kg caused a rise of compression depth param-eter of 7.3 mm, while when chest compression was performed by females, a fall of compression depth of 3.3 mm was seen.

Which position should we take during newborn resuscitation? A prospective, randomised, multicentre simulation trial.

BACKGROUND: Early bystander cardiopulmonary resuscitation (CPR) for cardiac arrest is crucial in the chain of survival. Cardiac arrest in infants is rare, but CPR is also performed in severe bradycardia. European Resuscitation Council and American Heart Association guidelines recommend continuing CPR until the heart muscle is sufficiently oxygenated and regains sufficient contractility and function. The most common and recommended CPR techniques that can be applied in newborns are the two-finger technique and two-thumb technique. AIM: We sought to assess the quality of CPR performed in newborns with the two-finger technique depending on the posi-tion of the rescuer during resuscitation. METHODS: This was a prospective, randomised, crossover, simulated study. It involved 93 nurses who were required to perform a two-minute CPR using the two-finger technique in three scenarios: (A) with the newborn lying on the floor; (B) on a table; and (C) with the newborn on the rescuer's forearm. The Newborn Tory® S2210 manikin was used to simulate a neonatal patient in cardiac arrest. The following parameters were measured: chest compression (CC) depth, CC rate, no-flow time, percentage of full release, ventilation rate, and ventilation volume, as well as the number of effective compressions and effective ventilations. RESULTS: Statistical analysis showed significant differences in CC rates between scenarios A and B (p < 0.001) and between scenarios B and C (p = 0.002). Significant differences were also observed between the median CC depth. The median per-centage of no-flow-fraction was the highest for scenario A (55%), followed by scenario B (48%), and scenario C (46%). There were significant differences between the values of no-flow-fraction between scenarios A and B (p < 0.001), and between scenarios A and C (p < 0.001). The percentage of chest full releases for scenarios A, B, and C amounted to 94%, 1%, and 92%, respectively. Significant differences in the number of effective CCs between scenarios A and B (p < 0.001) as well as B and C (p < 0.001) were revealed. The median ventilation rate was highest for scenario B (13 × min-1), and lowest for scenario A (9 × min-1). The highest tidal volume was obtained in scenario A (27 mL), and the lowest in scenario C (26 mL). The most effective CPR was performed when resuscitation was carried out on the rescuer's forearm. CONCLUSIONS: The quality of CCs in newborns depends on the location of the patient and the rescuer. The optimal form of resuscitation of newborns is resuscitation on the rescuer's forearm.