No abstract

To replace mechanical ventilation (MV), which represents the cornerstone therapy in severe COVID-19 cases, high-flow nasal oxygen (HFNO) therapy has recently emerged as a less-invasive therapeutic possibility for those patients. Respecting the risk of MV delay as a result of HFNO use, we aimed to evaluate which parameters could determine the risk of in-hospital mortality in HFNO-treated COVID-19 patients. This single-center cohort study included 102 COVID-19-positive patients treated with HFNO. Standard therapeutic methods and up-to-date protocols were used. Patients who underwent a fatal event (41.2%) were significantly older, mostly male patients, and had higher comorbidity burdens measured by CCI. In a univariate analysis, older age, shorter HFNO duration, ventilator initiation, higher CCI and lower ROX index all emerged as significant predictors of adverse events (p < 0.05). Variables were dichotomized and included in the multivariate analysis to define their relative weights in the computed risk score model. Based on this, a risk score model for the prediction of in-hospital mortality in COVID-19 patients treated with HFNO consisting of four variables was defined: CCI > 4, ROX index ≤ 4.11, LDH-to-WBC ratio, age > 65 years (CROW-65). The main purpose of CROW-65 is to address whether HFNO should be initiated in the subgroup of patients with a high risk of in-hospital mortality.

&lt;p&gt;Historical disposal sites of red mud can be found all around Europe, most notably at Sardinia, in Hungary, or at many locations in East-Southeast Europe. Red mud contains dominantly iron, aluminum, and silicon oxides, with races of various metals and compounds that can still be reprocessed if appropriate methods are applied. Some of the promising methods include microorganisms, and in particular bacteria.&lt;/p&gt;&lt;p&gt;The main objective of the study was to determine whether prolonged bacterial activity changes the geochemistry of the red mud. The bacteria for the experiment were isolated through several selective steps from activated sludge of wastewater treatment plant and red mud from three different locations: Dobro Selo and Zvornik (Bosnia and Herzegovina), and Alm&amp;#225;sf&amp;#252;zit&amp;#337; (Hungary).&lt;/p&gt;&lt;p&gt;After successful isolation, the bacteria were applied to the homogenized red mud samples, with nutrient media and water added in different combinations and ratios. The experiment lasted for 6 months after the bacteria were first applied to the red mud samples. During this period, geochemical analyses of the red mud were carried out twice, after 4 weeks and after 24 weeks, while the analysis of bacterial survival and quantity in the red mud samples were carried after 4, 8, and 24 weeks. The goal of geochemical analyses was to determine whether the bacteria caused changes in the concentrations of the elements of interest in the red mud when used as cultivating substrate and whether the elements of interest became more available to the bacteria due to their growth and adaptation to the red mud.&lt;/p&gt;&lt;p&gt;Prior to geochemical analysis, subsamples were heated at 100&amp;#176;C for 60 minutes to induce bacteriolysis and filtered twice with MiliQ water (red band filter paper). The eluates were stored in plastic cuvettes and kept in a dark place at 4&amp;#176;C until analysis (HR-ICP-MS). The filter papers containing the treated red mud were dried, sealed, and stored for further geochemical analysis of total major and trace element concentrations by ICP-MS and mineralogical (XRPD) analyses. Detailed results of the geochemical and mineralogical analyses are pending.&lt;/p&gt;&lt;p&gt;This work has been supported by EIT Raw Materials project RIS-RESTORE, project number 19269.&lt;/p&gt;