[Respiratory manifestations of post-COVID syndrome].

Overcoming infection with coronavirus disease 2019 (COVID-19) can lead to the persistence of various symptoms in some patients. The complex of symptoms causally related to severe acute respiratory coronavirus 2 infection is called post-COVID syndrome. One of the most common respiratory complications is pulmonary fibrosis, especially after critical course of the disease. In some patients, however, only the peripheral airways are affected by the air-trapping seen on high-resolution computed tomography scans. Less common respiratory complications include sarcoidosis and pneumatoceles. This narrative review summarizes current knowledge about pulmonary involvement as part of post-COVID syndrome.

Studies of aluminium coatings deposited by vacuum evaporation and magnetron sputtering.

The paper presents the results of investigations of the microstructures and properties of the aluminium coatings deposited by vacuum evaporation and magnetron sputtering. These coatings generally have a very refined microstructure with elongated nano-grains. However, the surface topography of the aluminium coating deposited by vacuum evaporation is more developed, its microstructure is less homogeneous and more porous. The residual tensile stresses in the aluminium coating deposited by magnetron sputtering are close to 130 MPa, and the texture is relatively pronounced. Vacuum evaporation does not induce residual stresses in the coatings and the texture is very weak. The results obtained indicate that the aluminium coatings produced by magnetron sputtering are more suitable for the diffusive Ti-Al intermetallic layers.

Sorption of cesium, cobalt and europium on low-rank coal and chitosan.

Potential low-cost sorbents of metals based on combined action of coal and chitosan have been investigated. Sorption of Cs, Co and Eu on oxidized coals in mixture with chitosan was studied as function of pH ( approximately 3-6) in batch experiments using radiotracer method. An improved sorption efficiency of the coal sorbents at neutral pH was obtained in mixture with chitosan, namely for oxihumolite at sorption of Eu and Co. Chitosan prevented deterioration of the sorption ability of coal with pH increase probably via retaining the soluble complexes with humic substances leached from coal by formation of an insoluble complex. The effect of chitosan addition was negligible or reverse in case of lignite upon acidification, where the interaction takes place preferentially on the coal surface and may restrict availability of the binding sites for metal ions.

Radiotracer analysis of cadmium speciation in soil solutions using electrophoresis, dialysis, centrifugation, and ultrafiltration.

Speciation of carrier-free 109Cd, added in cationic form to pre-filtered extracts obtained by leaching forest soil samples with distilled water, was analyzed using electrophoresis, dialysis, centrifugation, and ultrafiltration. Rapid establishment of isotopic equilibrium between the added 109Cd and stable cadmium present in the extracts was observed. All the data obtained indicated that 109Cd and also stable cadmium were present in the analyzed extracts in the form of neutral or negatively charged organic complexes or small colloids. The results of electrophoresis enabled the characterization, at least semiquantitative, of the abundance and electrophoretic mobility of the forms present. The incomplete dialysis of 109Cd from the soil extracts through cellophane membrane against water proved the presence of organic associates with molecular weights higher than 10(4). Dialysis against the same, but unlabeled extract was always complete, indicating the reversible (labile) nature of the organic forms of cadmium. Assessment of the stability constants of the organic forms using a simple discrete two-site model suggested that humate and/or fulvate complexes of cadmium were formed.

Effect of the heating temperature on the corrosion resistance of alkali-treated titanium.

The paper presents the results of examinations of the corrosion resistance of titanium after its being subjected to the surface modification by the alkali- and heat-treatments. The material examined was commercially pure titanium (grade 2). The samples were soaked in an aqueous 10M NaOH solution at 60 degrees C for 24 h and subsequently heated at 500, 600, or 700 degrees C for 1 h. The chemical composition of the surface layers was determined by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy. The phases present in the layers were identified by XRD. The corrosion resistance was evaluated by electrochemical methods (Stern's method, potentiodynamic method, and impedance spectroscopy) at a temperature of 37 degrees C after short- and long-time exposures. The 13 h exposure was aimed to allow the corrosion potential to stabilize. The aim of the long-term exposures was to examine how the corrosion resistance of the modified samples changes during the exposure. Under the conditions prevailing during the experiments, the highest corrosion resistance was achieved with the samples heated at a temperature of 700 degrees C.

Corrosion resistance and bioactivity of titanium after surface treatment by three different methods: ion implantation, alkaline treatment and anodic oxidation.

The paper compares the effects of various surface modifications, ion implantation, alkaline treatment and anodic oxidation, upon the corrosion resistance and bioactivity of titanium. The chemical composition of the surface layers thus produced was determined by XPS, SIMS and EDS coupled with SEM. The structure of the layers was examined by TEM, and their phase composition by XRD. The corrosion resistance was determined by electrochemical methods after the samples were exposed to the test conditions for 13 h. The bioactivity of titanium was evaluated in a simulated body fluid at a temperature of 37 degrees C after various exposure time.