RESULTS OF ORTHOPEDIC TREATMENT IN CANCER PATIENTS WITH MAXILLOFACIAL DEFECTS

The fates of 450 patients with different defects of the upper jaw and midfacial tissues were traced after maxillofacial replacement were traced. The follow-up was 1 to 15 years. The immediate and late results of orthopedic treatment were studied using the follow-up and assessed from both the underlying disease and the degree of functional and cosmetic efficiency of orthopedic apparatuses

Comparative study of the influence of pulsed and continuous wave laser heating on the mobilization of carbon and its chemical reaction with iron in a diamond anvil cell

Laser heating in a diamond anvil cell (DAC) is a common method for studying material behavior at high-pressure and high-temperature conditions. It has been previously proven that during continuous wave (CW) laser heating of a sample, carbon of the diamond anvils is mobilized, and its diffusion into the sample can lead to undesirable chemical reactions, which, if not detected, may cause misinterpretations of the results of the experiment. Minimizing the heating time with the use of a pulsed laser (PL) is thought to reduce the risk of possible carbon contamination of the sample; however, this has not been proven experimentally. Here, we report the results of our comparative study of the effect of pulsed and continuous wave (CW) laser heating on the mobilization of carbon and its chemical interaction with iron in a diamond anvil cell. Using X-ray absorption near edge structure spectroscopy, Synchrotron Mössbauer Source spectroscopy, and Synchrotron X-ray diffraction, we examined iron samples that were laser heated in DACs in various pressure transmitting media (neon, argon, and potassium chloride). According to our results, the use of the PL heating does not prevent the sample from carbon contamination. A reaction between carbon and iron happens within a few seconds even at moderate temperatures. We found that one analytical technique was generally insufficient to fully characterize the phase composition of the laser-heated samples

PATIENTS’ PSYCHOSOMATIC STATUS BEFORE AND AFTER ORTHOPEDIC CORRECTION OF MAXILLOFACIAL DEFECTS

A medicopsychological study of the time course of psychic changes was conducted in 88 cancer patients with defects of facial soft tissues (n = 38) and maxilla (n = 50). Since the patients’ visit to an oncologist, the diagnostic-stage depth of mental disorders was rather various: from mild asthenia to depression. Thus, 88 (100 %) patients were found to have an anxious feeling, 16 (18.2 %) had affective-shock reactions; 7 (7.9 %) had reactive depression. In the postoperative period, anxiety-depressive syndrome gave way to astheno-depressive one. After hospital discharge, the reactive state became less tense during psychosocial readaptation, the characteriological personality changes were increasingly more pronounced in the forefront in the patients. They became anxious, suspicious, unconfident about themselves, sensitive, tried to avoid difficult situations in life. The circle of interests was limited to thoughts on their own health. Combination therapy with psychotropic drugs was used to correct the mental status of patients with acquired maxillary defects in the study group. The dosage of the drugs was individually adjusted according to the degree of psychopathological manifestations

Revealing the Complex Nature of Bonding in the Binary High-Pressure Compound FeO2_{2}

Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe$_{2}$O$_{3}$ and the appearance of FeO$_{2}$. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory+dynamical mean-field theory calculations, we demonstrate that iron in high-pressure cubic FeO$_{2}$ and isostructural FeO$_{2}$H$_{0.5}$ is ferric (Fe$^{3+}$), and oxygen has a formal valence less than 2. Reduction of oxygen valence from 2, common for oxides, down to 1.5 can be explained by a formation of a localized hole at oxygen sites

Aromatic hexazine [N6]4−[N_6]^{4−} anion featured in the complex structure of the high-pressure potassium nitrogen compound K9N56K_9N_{56}

The recent high-pressure synthesis of pentazolates and the subsequent stabilization of the aromatic $[N_5]^−$ anion at atmospheric pressure have had an immense impact on nitrogen chemistry. Other aromatic nitrogen species have also been actively sought, including the hexaazabenzene $N_6$ring. Although a variety of configurations and geometries have been proposed based on ab initio calculations, one that stands out as a likely candidate is the aromatic hexazine anion $[N_6]^{4−}$. Here we present the synthesis of this species, realized in the high-pressure potassium nitrogen compound $K_9N_{56}$ formed at high pressures (46 and 61 GPa) and high temperature (estimated to be above 2,000 K) by direct reaction between nitrogen and $KN_3$ in a laser-heated diamond anvil cell. The complex structure of $K_9N_{56}$—composed of 520 atoms per unit cell—was solved based on synchrotron single-crystal X-ray diffraction and corroborated by density functional theory calculations. The observed hexazine anion $[N_6]^{4−}$ is planar and proposed to be aromatic