Search

Thermodynamics of boehmite formation upon hydrothermal treatment of micron-size particles of hydrargillite and γ-Al2O3 at 200°C in various media has been studied at various treatment times. The presence of surface-bound water with low evaporation enthalpy value at the initial stages of precursor hydrothermal treatment has been revealed. It has been shown that, irrespective of precursor and hydrothermal treatment medium, the prepared boehmite has similar properties [ABSTRACT FROM AUTHOR]

Introduction: It is known that many psychopharmacological drugs have anti-inflammatory, as well as antibacterial and antiviral effects. Objectives: To investigate the association between the severity and duration criteria of COVID-19 with psychopharmacotherapy in double-diagnosed patients. Methods: A total of 169 case histories from a specialized infectious psychiatric department (May 2020 to January 2021) were evaluated. Progression indicators of severe and mild COVID-19, along with the duration of persistent SARS-CoV-2 viral shedding, were assessed in correlation with the administration of antidepressants, antipsychotics, and acid sphingomyelinase inhibitors (FIASMA-active drugs). Results: The use of any psychotropic agents was associated with a 0.9% increase in the risk of severe course of COVID-19 for each unit increase in the systemic inflammation index PLR, specifically in patients with intellectual disability (ICD-10 codes F70-79), when compared to patients with schizophrenia (ICD-10 codes F20-29): R²McF=0.138; AIC=181; χ²=25.8; df=9; p=0.002. High PLR values and the use of FIASMA-active drugs were associated with prolonged COVID-19 duration, while antidepressant therapy and elevated C-reactive protein levels were associated with a reduced predicted duration of viral shedding in 13.8% of variance: R²=0.0864; AIC=1299; F=5.2(3), p=0.002. Including the nosology of psychiatric disorders in the regression model increased the proportion of explained variance to 22.8%. Conclusions: Thymoanaleptic therapy for individuals with psychiatric disorders may act as a protective factor against COVID-19. There is no evidence suggesting adverse effects of antipsychotics on the severity and duration of COVID-19. Further research is necessary to investigate the effects of FIASMA-active psychopharmacological agents within nosologically homogeneous groups. Disclosure of Interest: None Declared [ABSTRACT FROM AUTHOR]

We propose a mechanism capable of describing phase transformations during the hydrothermal treatment of micron- and nanometer-sized γ-Al2O3 and Al(OH)3 powders, identify the steps of the process, and demonstrate the role of water with a small heat of vaporization in the hydrothermal treatment process. [ABSTRACT FROM AUTHOR]

We have studied the kinetics of boehmite nanopowder formation during hydrothermal treatment of γ-Al2O3 nanopowder in a 1.5% HCl solution at 200, 170, and 150°C. The results demonstrate that the temperature-dependent reaction rate constant follows the Arrhenius equation. The Ea of the process has been determined to be 84 kJ/mol. The thermodynamics of γ-Al2O3 nanopowder conversion into boehmite during hydrothermal treatment at 150°C has been studied by differential scanning calorimetry. The heat of vaporization of water from a two-phase nanosystem (γ-Al2O3 + forming boehmite) has been determined to be 8, 16, and 22 kJ/mol H2O, which points to an active role of water with a low heat of vaporization in the initial stages of the hydrothermal treatment of the γ-Al2O3 nanopowder. The heat effect of the АlООН → γ-Al2O3 conversion in the nanopowders is lower than the reference value by 7 kJ/mol AlOOH, which is attributable to the small particle size and low structural perfection of the synthesized boehmite (AlOOH). [ABSTRACT FROM AUTHOR]

The new compound Аl2(SO4)3 ⋅ 8(CH3)2SO, which cannot be prepared by direct synthesis, has been synthesized from an Аl2(SO4)3 ⋅ 8(CH3)2SO ⋅ 3Н2О glass. The compound has been identified by X-ray diffraction. Based on IR spectra, it has been concluded that the Al3+ ion has mixed coordination to dimethylsulfoxide (DMSO) molecules, and the ligands are linked to each other through the S and O atoms. [ABSTRACT FROM AUTHOR]

A new method for producing a nanosized γ-Al2O3 powder was proposed, by which a saturated solution of aluminum oxychloride and sucrose was subjected to sequential heat treatment to 350°C to form a transient species and then to 800°C to form a nanosized γ-Al2O3 powder. The optimal treatment parameters were determined. Stages of the process were identified. The transient species and the nanosized γ-Al2O3 powder were studied. [ABSTRACT FROM AUTHOR]

Water-acetone solutions in the AlCl3-(CH3)2CO-H2O and AlCl3-(CH3)2CO-H2O-HCl systems were obtained and studied. In both cases, the solution separated into layers to form liquid fractions of lower and higher density. The IR spectra of the fractions were studied. In the light fraction, no AlCl3 was present, but hydrogen-bonded acetone-water complexes were detected. The spectra of the heavy fraction exhibited a broad band at ~3020-3040 cm-1 corresponding to the OH groups of water from aluminum hexahydrate. As the solvent is evaporated, the band narrows down, with its position being retained. The IR spectrum of the obtained solid becomes identical to the IR spectrum of the crystal hydrate AlCl3.(H2O)6. The structures and spectral and energetic parameters of Al(H2O)63+, Al(H2O)6+123+, Al((CH3)2CO)63+, Al((CH3)2CO)43+, and (CH3)2CO.H2O were calculated by the density functional theory method (B3LYP/6-31++G(d,p)). Relying on the results, an explanation was proposed for the experimentlly observed absence of acetone molecules in the Al3+ first coordination shell. [ABSTRACT FROM AUTHOR]