Spin state crossover in Co3BO5

We have investigated the spin and oxidation states of Co in Co3BO5 using x-ray magnetic circular dichroism (XMCD) and dc magnetic susceptibility measurements. At low temperatures, XMCD experiments have been performed at the Co K-edge in Co3BO5 and Co2FeBO5 single crystals in the fully ferrimagnetically ordered phase. The Co (K-edge) XMCD signal is found to be related to the Co2+ magnetic sublattices in both compounds, providing strong experimental support for the low-spin (LS) Co3+ scenario. The paramagnetic susceptibility is highly anisotropic. An estimation of the effective magnetic moment in the temperature range 100-250 K correlates well with two Co2+ ions in the high-spin (HS) state and some orbital contribution, while Co3+ remains in the LS state. The crystal structure of the Co3BO5 single crystal has been solved in detail at the T range 296-703 K. The unit cell parameters and volume show anomalies at 500 and 700 K. The octahedral environment of the Co4 site strongly changes with heating. The generalized gradient approximation with Hubbard U correction calculations have revealed that, at low-temperatures, the system is insulating with a band gap of 1.4 eV, and the Co2+ ions are in the HS state, while Co3+ are in the LS state. At high temperatures (T > 700 K), the charge ordering disappears, and the system becomes metallic with all Co ions in 3d7 electronic configuration and HS state. © 2021 American Physical Society

ПОЛУЧЕНИЕ НАНОПОРОШКА ДИОКСИДА КРЕМНИЯ НА ОСНОВЕ ГИДРОТЕРМАЛЬНОГО РАСТВОРА КРИОХИМИЧЕСКОЙ ВАКУУМНОЙ СУБЛИМАЦИИ

The paper considers the model of choice by high-school optimal solutions for the distribution of sets of entrants in its branches

MECHANICAL VENTILATION WITH A TARGET TIDAL VOLUME IN NEWBORNS AND CHILDRENWITH VARIOUS LUNG DISEASES AT EARLY AGES: PROTOCOL FOR PREPARATION OF THERESPIRATORY EQUIPMENT AND VENTILATIVE CONTROL

One of the leading trends in modern medicine is the principle of prevention, which consists in preventing the formation of diseases and complications of therapy. The main damaging factor during respiratory support in patients with inhomogeneous lung tissue injury is tidal volume (TV). With traditional pressure controlled mechanical ventilation (PCMV), controlling the TV delivered to the child is difficult due to the variable mechanical properties of the lung tissue. PCMV algorithms with targeted TV, used in neonatology and in young children, make it possible to adjust the parameters of endotracheal respiratory support automatically. Thus, the principle of prevention is observed from inspiration to inspiration, and TV values become more constant, despite the changing respiratory mechanics. This protects the lungs from volumotrauma and ensures favorable outcomes. The purpose of this work is to review the existing recommendations on the use of dual-control modes of ventilation in newborns and young children and to present a protocol for preparing the breathing apparatus and controlling parameters when using PCMV with guaranteed TV. © 2022, Pediatria Ltd. All rights reserved

Pulmonary alveolar microlithiasis: A literature review and case report of a lung biopsy-confirmed disease in an infant

The article provides up-to-date information on epidemiology, etiology, genetics, pathogenesis, pathomorphology, clinical manifestation, X-ray and computed tomography (CT) semiotics, features in childhood, treatment of a rare genetic interstitial lung disease pulmonary alveolar microlithiasis (PAM). A clinical observation of a child with PAM manifestation, confirmed by lung biopsy in infancy, is presented. The results of X-ray and CT of the patient's chest organs are presented, the unique features of the course of the disease are listed. © 2021, Pediatria Ltd.. All rights reserved

POSSIBILITIES OF EARLY DIAGNOSIS OF PRIMARY CILIARY DYSKINESIA

Despite the manifestations of primary ciliary dyskinesia (PCD) in the neonatal period or in the first year of life, the diagnosis of this rare disease is usually established at the age of 4–7 years. The aim of the study was to search for reserves for early diagnosis of PCD. Materials and methods of research: 17 patients were observed with PCD, confirmed on the basis of the PICADAR scale, high-speed light video microscopy (all patients) and transmission electron microscopy (in 3 patients) of the mucous biopsy of the respiratory membrane using a genetic study (in one patient). Results: all patients were born full-term; neonatal respiratory distress syndrome (RDS) was observed in 71% of patients; the median duration of mechanical ventilation/oxygen therapy was 14 [7; 21] days; lateralization abnormalities were found in 35% of patients; all patients had persistent nasal congestion and/or rhinorrhea, 94% had chronic or recurrent sinusitis, otitis, recurrent pneumonia, chest x-ray and computed tomography (CT) scans in 71% had atelectasis with constant localization in the middle lobe, 12 of 15 patients, traced in the follow-up, – bronchiectasis (BE), also mainly in the middle lobe (in 9 patients). The average age at diagnosis was 5 [1.75; 7] years, patients with an established diagnosis over the age of 3 years were more often diagnosed with BE. The median of PICADAR scores was 7 [6; 8] points. Conclusions: to establish early diagnosis of PCD, it is important to consider neonatal RDS, lateralization of organs, difficulty in nasal breathing, starting from the first half of life. © 2022, Pediatria Ltd. All rights reserved