Structure of F2(-) centers in K2YF5 and their relation to thermoluminescence below room temperature

X-ray irradiation at 77 K produces signals from several trapped hole and/or electron centers in the electron-paramagnetic-resonance (EPR) spectra of rare-earth-doped K2YF5. Five of the spectral components have a structure typical of a center with electron spin S=1/2 exhibiting a strong hyperfine interaction with two nearly equivalent F-19 nuclei. They are identified as V- or H-type intrinsic-trapped hole centers, having the F-2(-) molecular anion as their core. Three centers are characterized by monoclinic g and F-19 self-hyperfine tensors, i.e., with one principal axis along the crystal's twofold screw axis, the two others are triclinic. Plausible models for these five centers are discussed and via thermal-annealing experiments, in which EPR and thermoluminescence (TL) spectra are simultaneously monitored, their role in the TL processes below room temperature is investigated

Electron paramagnetic resonance study of Eu2+ centers in melt-grown CsBr single crystals

The structure of Eu2+ monomer centers in CsBr single crystals is investigated using electron paramagnetic resonance (EPR) spectroscopy. These centers are produced by heating the melt-grown crystals above 600 K in vacuum followed by a rapid quench to room temperature (RT) or 77 K. The angular dependence of their EPR spectrum demonstrates that these centers have cubic symmetry. At RT the EPR spectrum decays by aggregation of the Eu2+ ions. This strongly contrasts with the situation for CsBr:Eu needle image plates synthesized by physical vapor deposition, where the Eu2+-related EPR spectrum was observed to exhibit long-term stability at RT

Classification of Schoolchildren on Professional Trajectories using Experience of Successful Specialists

In the paper, we propose a new approach to vocational guidance of schoolchildren based on classification of pupil wishes between given professional trajectories, which are presented by profiles of successful professionals. Both wishes and profiles are replies in free text form on a questionnaire proposed by skilled psychologists. Such an approach avoids the well-known deficiencies of traditional methods including binary questioning, talks about concrete professions, and interviews with school psychologists. We use the simple terms selection for preprocessing and the traditional method of voting for classification. The mentioned procedures are discussed and the proposed approach is preliminary checked on invited specialists. This joint Russian-Irish research has been carried out with Moscow schoolchildren (2 schools) and Moscow specialists (2 trajectories). The results of presented pilot study look very promising. It is the basis for current applied research in Moscow and the future activities in Dublin

ENDOR in field-frequency space: orientation, species and quantum state selection

Due to its specific detection method, via saturation of the EPR spectrum at a certain magnetic field position, ENDOR measurements are highly selective. Already in the late sixties Rist and Hyde recognized the possibilities of obtaining angular dependent information from powder specimens by recording the field-dependence of the ENDOR spectrum, by grace of the orientation selection principle.1 However, also for single crystal samples it makes sense to record ENDOR spectra in the two-dimensional field-frequency space (FF-ENDOR). Next to orientation selectivity – when several symmetry-related orientations of the same paramagnetic species are simultaneously detected in the EPR spectrum – such measurements feature species selectivity and, for systems with S > ½ and/or I > ½, also quantum state selectivity. The former facilitates the interpretation of multi- composite EPR spectra, as illustrated in the figure below. Quantum state selectivity offers possibilities of determining the relative signs of spin Hamiltonian parameters, e.g. zero-field splitting and hyperfine, or hyperfine and quadrupole principal values. All these effects will be illustrated through recent examples in or research of radiation-induced radicals in sugars and high-spin transition ion or rare-earth doped fluoride crystals

Serological diagnostics of myocardium diseases based on multivariate analysis of cardiotrophic autoantibodies' profiles

ABSTRACT We analyzed profiles of IgG autoantibodies to 16 cardiac specific proteins and their main immunogenic region B-epitopes, in the groups of already verified cardiac pathology: acute and chronic lymphocytic myocarditis, ST elevation myocardial infarction, postinfarction remodeling of myocardium, dilated cardiomyopathy and in healthy controls along with patients, suffered from gastritis (to evaluate immune response against cross-reactive B-epitopes). AAB specific patterns allowed us to distinguish cases among themselves by means of multiparametrical canonical discriminant analysis in approximately 95% of cases. Positive predictive value in the group of MYO reached 95%, in the STEMI-89%, in the PIR-99%, in the DCM-99%, in the group of gastritis-88%. Principal component analysis of mentioned cardiac pathologies extended current clinical knowledge of their immunopathogenesis. Obtained data markedly proved a usability of serum AAB profiling for non invasive screening, differential diagnostics and working hypothesis composition

Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study

Background Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave. Methods This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs. Results Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates. Conclusions Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility. Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)