Role of mast cells in the pathogenesis of severe lung damage in COVID-19 patients.

BACKGROUND: There is still insufficient knowledge with regard to the potential involvement of mast cells (MCs) and their mediators in the pathology of coronavirus disease-2019 (COVID-19). Therefore, our study aimed to investigate the role of MCs, their activation and protease profiles in the pathogenesis of early and late lung damage in COVID-19 patients. METHODS: Formalin-fixed and paraffin embedded lung specimens from 30 patients who died from COVID-19 and 9 controls were used for histological detection of MCs and their proteases (tryptase, chymase) followed by morphometric quantification. RESULTS: Our results demonstrated increased numbers of MCs at early stage and further augmentation of MCs number during the late stage of alveolar damage in COVID-19 patients, as compared to the control group. Importantly, the percentage of degranulated (activated) MCs was higher during both stages of alveolar lesions in comparison to the controls. While there was no prominent alteration in the profile of tryptase-positive MCs, our data revealed a significant elevation in the number of chymase-positive MCs in the lungs of COVID-19 patients, compared to the controls. CONCLUSIONS: MCs are characterized by dysregulated accumulation and increased activation in the lungs of patients suffering from COVID-19. However, future profound studies are needed for precise analysis of the role of these immune cells in the context of novel coronavirus disease.

Thermal Conductivity of FLiNaK in a Molten State.

Although the thermal conductivity of molten salt mixtures is of interest for many potential technological applications, precise values are often hard to obtain. In this study, the thermal diffusivity of FliNaK was studied in a molten state using the laser flash method and found to be very slightly dependent on temperature. The heat capacity of FliNaK was measured using the DSC method. There was a minor difference between our results and data from the literature. From calculations based on thermal diffusivity, density and heat capacity values, thermal conductivity was shown to decrease with temperature.

Reduce Adverse Effects of Laparoscopic Cholecystectomy with Pulse Width Modulated LED Light (625 nm, 76 Hz, 23% Duty Cycle).

OBJECTIVE: Reducing adverse effects in laparoscopic cholecystectomy (LCE) is important to avoid complications. After removal, the porta hepatis and gallbladder bed of liver were treated with pulse width modulated (PWM) red LED light with parameters λ = 625 ± 5 nm, full width at half maximum 17 nm, 76 Hz, duty cycle 23%, 15-30 mW/cm2, and 0.9-1.8 J/cm2. The changes of eight blood parameters were studied: red blood cell, hemoglobin, white blood cell, erythrocyte sedimentation rate (ESR), bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), and amylase. BACKGROUND DATA: Other current methods of reducing undesirable effects of LCE significantly affect surgery and are not commonly used in practice. MATERIALS AND METHODS: Before LCE, 263 patients were randomized into the control and test groups. Patients in the test group were treated with light radiated for 2 min during the surgery on the bed of the removed gallbladder and porta hepatis. Blood samples were taken before surgery and on the third day after surgery, studied, and compared by nonparametric statistical methods. RESULTS: The test group revealed significant reduction in postsurgery gain of levels of ALT, AST, and ESR compared with the control group. CONCLUSIONS: Treatment of the removed gallbladder bed and porta hepatis by red LED PWM radiation during LCE significantly reduces the adverse effects of surgery while increasing its time insignificantly and does not affect the surgical best practices deployed.

Heat capacity of molten halides.

The heat capacities of molten salts are very important for their practical use. Experimental investigation of this property is challenging because of the high temperatures involved and the corrosive nature of these materials. It is preferable to combine experimental investigations with empirical relationships, which allows for the evaluation of the heat capacity of molten salt mixtures. The isobaric molar heat capacities of all molten alkali and alkaline-earth halides were found to be constant for each group of salts. The value depends on the number of atoms in the salt, and the molar heat capacity per atom is constant for all molten halide salts with the exception of the lithium halides. The molar heat capacities of molten halides do not change when the anions are changed.

Interaction between SiO2 and a KF-KCl-K2SiF6 Melt.

The solubility mechanism of silica in a fluoride-chloride melt has been determined in situ using Raman spectroscopy. The spectroscopy data revealed that the silica solubility process involved Si-O bond breakage and Si-F bond formation. The process results in the formation of silicate complexes, fluorine-bearing silicate complexes, and silicon tetrafluoride in the melt. Mass spectrometry of the vapor phase over the KF-KCl-K2SiF6 and KF-KCl-K2SiF6-SiO2 melts and differential scanning calorimetry coupled with thermal gravimetric analysis of these melts were performed to verify the silica solubility mechanism.