The defect structure of as-grown SrF2 and nonstoichiometric phases Sr1 – xLaxF2 + x (x = 0.11, 0.20, 0.32, 0.37, 0.47) single crystals, grown from a melt under identical conditions, has been studied by X-ray diffraction analysis. All crystals belong to the CaF2-type structure, sp. gr. $$Fm\bar {3}m$$
 . Deficit of fluorine anions is found in the 8c site in SrF2. Interstitial anions are not visualized in SrF2 in difference electron-density maps. The Sr1 – xLaxF2 + x phases exhibit the presence of vacancies in the main anion motif and interstitial fluorine ions of three types: in two sites 32f (w, w, w) with different coordinates w and in one site 4b. A model of the defect structure of Sr1 – xLaxF2 + x phase is proposed, according to which interstitial fluorine ions and impurity cations La3+ are grouped into clusters of the [Sr1 – nLanF26] tetrahedral configuration. Calculations based on structural data revealed that the average number of La3+ ions per cluster linearly increases from 2.6 to 3.13 with an increase in the LaF3 concentration. The average crystal volume corresponding to one cluster decreases from 1170.6(3) to 336.1(5) A3. The volume of the anion cluster core decreases from 2.52(7) to 2.42(7) A3, passing through a minimum in the composition with x = 0.32, which is similar to that of congruently melting phase, and then increases to 2.44(9) A3 at х = 0.47. Dynamic thermal displacement of matrix anions in Sr1 – xLaxF2 + x is observed in the [111] direction towards the cubic void center in the anion sublattice. Therefore, according to the mechanism of electrical conductivity, anion jumps are most likely in this direction.

Nanostructured Crystals of Fluorite Phases Sr1 – xRxF2 + x (R Are Rare-Earth Elements) and Their Ordering. 13: Crystal Structure of SrF2 and Concentration Dependence of the Defect Structure of Nonstoichiometric Phase Sr1 – xLaxF2 + x As Grown (x = 0.11, 0.20, 0.32, 0.37, 0.47)

The effect of high-energy (150 eV) electron irradiation in an electron microscope column on crystals of fluorides of alkaline earth elements CaF2, SrF2, and BaF2 is studied. During structural investigations by electron diffraction and electron microscopy, the electron irradiation causes chemical changes in MF2 crystals such as the desorption of fluorine and the accumulation of oxygen in the irradiated area with the formation of oxide MO. The fluorine desorption rate increases significantly when the electron-beam density exceeds the threshold value of ∼2 × 103 pA/cm2). In BaF2 samples, the transformation of BaO into Ba(OH)2 was observed when irradiation stopped. The renewal of irradiation is accompanied by the inverse transformation of Ba(OH)2 into BaO. In the initial stage of irradiation of all MF2 compounds, the oxide phase is in the single-crystal state with a lattice highly matched with the MF2 matrix. When the irradiation dose is increased, the oxide phase passes to the polycrystalline phase. Gaseous products of MF2 destruction (in the form of bubbles several nanometers in diameter) form a rectangular array with a period of ∼20 nm in the sample.

Effect of high-energy electron irradiation in an electron microscope column on fluorides of alkaline earth elements (CaF2, SrF2, and BaF2)

The heat capacity Cp(T) of cadmium fluoride, strontium fluoride, and the Cd05Sr05F2 solid solution has been studied experimentally (2–300 K) We have detected deviations ΔCp(T) of the Cp(T) data from additivity The low-temperature (2–50 K), positive deviations ΔCp(T) have been tentatively attributed to the effect of two-level systems associated with the glasslike character of the low-temperature thermal properties of the solution due to disorder in the Cd–Sr sublattice The high-temperature (100–300 K), negative deviations ΔCp(T) are caused by the effect of anharmonicity of lattice vibrations, whose increasing role is also associated with the disordered arrangement of atoms in the crystal lattice upon formation of the solution The Cp(T) data for the solution of the system studied have been analyzed in the Debye–Einstein model We have determined model parameters: characteristic temperatures Θi and the fractions of different contributions, ai, to total thermal characteristics of the substances studied

Structural Disorder and Heat Capacity of a Solid Solution between Cadmium and Strontium Fluorides

Electron paramagnetic resonance of Ca1 − x − y Y x Gd y F2 + x + y single crystals has revealed spectra that are not typical of gadolinium-doped CaF2 crystals. These spectra have a nearly tetragonal symmetry and are most probably caused by Gd3+ ions localized in yttrium clusters. Weak spectra of tetragonal Gd3+ centers, whose parameters are close to those of a cubic gadolinium center caused by an isolated Gd3+ ion, have been also detected. These centers are attributed to isolated Gd3+ ions localized near octahedral rare-earth clusters or their associations.

/pdf/electron-paramagnetic-resonance-of-gd-3-ions-in-ca-1-x-y-y-x-2ta4kgkbtn.pdf

Electron paramagnetic resonance of Gd 3+ ions in Ca 1 − x − y Y x Gd y F 2 + x + y crystals

The focus on the interests of children has always been inherent in the Russian State, but the most effective measures have been implemented already in this century: 4 years before WHO announced the Global Strategy for Mothers and Children in 2016, Russian President Vladimir Putin signed the Decree on the National Strategy for Children for 2012–2017, in 2017. The President announced the “Decade of Childhood”, and in 2020 The priority of childhood was enshrined in the Constitution of the Russian Federation. In the Russian Federation, the most child-oriented system of children’s healthcare has been built, in medical and scientific organizations of the pediatric profile of the Russian Federation, specialists with medical, biomedical, psychological, pedagogical, and social education are specially trained to work with children of different ages, and scientific research in the field of pediatrics is carried out by specialized researchers within the framework of special programs focused on the needs of children’s healthcare. A detailed analysis of the structure and content of the projects implemented in 2022 has been carried out. Scientific projects involving children compared to 2018, when the implementation of the “Decade of Childhood” program began, which indicates that scientific research in the field of children’s health and development is voluminous, but uncoordinated. Many topics are carried out simultaneously by several scientific and medical or educational organizations, but they are not coordinated in unified scientific and methodological approaches. At the same time, there are systemic problems, to solve which it is necessary to switch to network scientific research of population health; to strengthen the integration of research teams both in the context of interdepartmental cooperation (the Ministry of Education and Science of the Russian Federation and the Ministry of Health of the Russian Federation — Rospotrebnadzor — Federal Medical and Biological Agency), and joint scientific work with other ministries (the Ministry of Education of the Russian Federation, the Ministry of Sports of the Russian Federation, the Ministry of Culture of the Russian Federation, etc.); as well as to improve financial mechanisms for managing scientific activities.

Scientific Research in the Field of Children’s Health and Development

The structures of as-grown Cd0.90R0.10F2.10 (R = Sm-Lu and Y) crystals are determined and related to the CaF2 structure type. It is assumed that in all the crystals R3+ and Cd2+ ions form clusters with the tetrahedral configuration of the [Cd2R2F26] and [CdR3F26] cations. The concentration of [Cd2R2F26] cations in crystals with R = Er-Lu and Y is considerably higher that in crystals with R = Sm-Ho. The tendency to a decrease in the coordination number of R3+ toward the end of the rare earth series manifests itself in the fact that the Yb3+ ions in Cd0.90Yb0.10F2.10 occupy both tetrahedral (c.n. 10) and octahedral (c.n. 8) clusters. The Yb3+ ions in tetrahedral clusters are displaced from their basic positions by 0.15 A along the 〈100〉 directions. In Cd1−xR x F2+x the relaxation of the anion sublattice of the fluorite matrix around clusters is much more pronounced than in the Ca1−xR x F2+x phases having similar geometry.

/pdf/growth-and-defect-crystal-structure-of-cdf2-and-1v4l5m9fz9.pdf

Growth and defect crystal structure of CdF2 and nonstoichiometric Cd1−x R x F2+x phases (R = rare earth elements and In). Part 3. Crystal structure of As-grown Cd0.90 R 0.10F2.10(R = Sm-Lu, Y) single crystals

   Treatment of patients with high-risk neuroblastoma (NB) is a complex challenge, and it is based on response to certain elements of therapy. The development and introduction of new treatment approaches, such as GD2-targeted immunotherapy (IT), leads to improved survival in this cohort of patients.   The aim of the study was to retrospectively assess the effectiveness of therapy in patients with high-risk NB before the introduction of IT into clinical practice.   We retrospectively analyzed the data of 151 NB patients stratified into a high-risk group who had received treatment in accordance with the modified NB2004 protocol of the German Society for Pediatric Oncology and Hematology (GPOH) at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology from 01.2012 to 12.2017. This study was approved by the Independent Ethics Committee and the Academic Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. All the study subjects (or their legal representatives) signed a voluntary informed consent form indicating their agreement to treatment and use of their data for research purposes. Overall survival (OS), event-free survival (EFS), and risk factors were analyzed in the patients with high-risk NB including those who had completed multimodal therapy with autologous hematopoietic stem cell transplantation and post-consolidation therapy with isotretinoin and had achieved a satisfactory response to induction therapy (complete response (CR), very good partial response (VGPR), partial response (PR)) (population of special interest). The main unfavorable prognostic clinical and molecular genetic factors affecting survival in the high-risk NB patients were older age, MYCN gene amplification, and stage 4 of the disease. The use of the modified GPOH NB2004 protocol resulted in a satisfactory response (CR/VGPR/PR) to the induction therapy in most patients: 124/151 (82.1 %). Surgery (other than primary tumor biopsy) led to improved survival, with no statistical difference between macroscopic radical surgery and macroscopic residual tumor. At the same time, radiation therapy (RT), as the second element of local control, had a significant impact on EFS in the group of the patients with stage 4 disease: the 3-year EFS was 39.4 % (95 % confidence interval (CI) 23.1–55.4) in the patients with RT versus 25.7 % (95 % CI 17.5–34.7) in the patients without RT (p = 0.0295). The introduction of a new high-dose TreoMel chemotherapy regimen did not result in worse survival rates but led to a decrease in transplant-related toxicity. The 5-year OS and 5-year EFS were 49.4 % (95 % CI 40.9–57.3 %) and 33.3 % (95 % CI 25.9–40.9) respectively for all the study subjects, and 81.6 % (95 % CI 70.3–88.9) and 55.1 % (95 % CI 43.1–65.5) respectively for the patients from the population of special interest. The analysis of the results of therapy in the high-risk NB patients who had received treatment at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, yielded results comparable to those of the original GPOH NB2004 protocol. The patients with CR/VGPR/PR to the induction therapy who had completed the protocol treatment with autologous hematopoietic stem cell transplantation and isotretinoin post-consolidation therapy demonstrated higher 5-year EFS rates. However, there remains a need to develop more effective treatment regimens for high-risk NB.

/pdf/the-results-of-therapy-in-patients-with-high-risk-2x2s0n72.pdf

The results of therapy in patients with high-risk neuroblastoma: the experience of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology

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Growth and defect crystal structure of CdF2 and nonstoichiometric Cd1−x R x F2+x phases (R = rare earth elements and In). Part 3. Crystal structure of As-grown Cd0.90 R 0.10F2.10(R = Sm-Lu, Y) single crystals

The results of therapy in patients with high-risk neuroblastoma: the experience of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology