4 research outputs found
Self-Cleaning and Antibacterial Properties of the Cement Mortar with ZnO/Hydroxyapatite Powders
According to literature data, different micro- and nanopowders have been used as a partial substitute for cement mortar due to their small size and large specific surface area. The aim of the work is to develop innovative materials based on cement mortar with antibacterial and self-cleaning properties, which can be used in the long-term maintenance of clean spaces. First, zinc oxide/hydroxyapatite (ZnO/Hap) powder denoted as ZH was synthesized by the hydrothermal method; then it was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM)/ energy dispersive spectroscopy (EDS), and adsorption–desorption isotherms. The second step was the cement mortar preparation: one plain, denoted E, and one with ZH powder inside, denoted MZH. Both mortars were subjected to self-cleaning and antibacterial tests. In the self-cleaning tests, two concentrated solutions of rhodamine B and methylene blue were used. MZH showed a better decolorating after 24 h of UV light than plain cement mortar denoted E for both solutions. In order to highlight the antibacterial effect of cement mortars on some strains of Gram-positive and Gram-negative bacteria, the direct contact method was used. The study revealed that, after 24 h of incubation, the planktonic growth of the E. coli strain is significantly inhibited in the presence of the MZH sample, compared to the control strain. MZH cement mortar exhibits a better growth inhibitory property than the plain cement mortar E
Self-Cleaning and Antibacterial Properties of the Cement Mortar with ZnO/Hydroxyapatite Powders
According to literature data, different micro- and nanopowders have been used as a partial substitute for cement mortar due to their small size and large specific surface area. The aim of the work is to develop innovative materials based on cement mortar with antibacterial and self-cleaning properties, which can be used in the long-term maintenance of clean spaces. First, zinc oxide/hydroxyapatite (ZnO/Hap) powder denoted as ZH was synthesized by the hydrothermal method; then it was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM)/ energy dispersive spectroscopy (EDS), and adsorption–desorption isotherms. The second step was the cement mortar preparation: one plain, denoted E, and one with ZH powder inside, denoted MZH. Both mortars were subjected to self-cleaning and antibacterial tests. In the self-cleaning tests, two concentrated solutions of rhodamine B and methylene blue were used. MZH showed a better decolorating after 24 h of UV light than plain cement mortar denoted E for both solutions. In order to highlight the antibacterial effect of cement mortars on some strains of Gram-positive and Gram-negative bacteria, the direct contact method was used. The study revealed that, after 24 h of incubation, the planktonic growth of the E. coli strain is significantly inhibited in the presence of the MZH sample, compared to the control strain. MZH cement mortar exhibits a better growth inhibitory property than the plain cement mortar E
Neutrophil-to-Lymphocyte Ratio as an Independent Predictor of In-Hospital Mortality in Patients with Acute Intracerebral Hemorrhage
Background and Objectives: Neutrophil-to-lymphocyte ratio (NLR), a very low cost, widely available marker of systemic inflammation, has been proposed as a potential predictor of short-term outcome in patients with intracerebral hemorrhage (ICH). Methods: Patients with ICH admitted to the Neurology Department during a two-year period were screened for inclusion. Based on eligibility criteria, 201 patients were included in the present analysis. Clinical, imaging, and laboratory characteristics were collected in a prespecified manner. Logistic regression models and receiver operating characteristics (ROC) curves were used to assess the performance of NLR assessed at admission (admission NLR) and 72 h later (three-day NLR) in predicting in-hospital death. Results: The median age of the study population was 70 years (IQR: 61–79), median admission NIHSS was 16 (IQR: 6–24), and median hematoma volume was 13.7 mL (IQR: 4.6–35.2 mL). Ninety patients (44.8%) died during hospitalization, and for 35 patients (17.4%) death occurred during the first three days. Several common predictors were significantly associated with in-hospital mortality in univariate analysis, including NLR assessed at admission (OR: 1.11; 95% CI: 1.04–1.18; p = 0.002). However, in multivariate analysis admission, NLR was not an independent predictor of in-hospital mortality (OR: 1.04; 95% CI: 0.9–1.1; p = 0.3). The subgroup analysis of 112 patients who survived the first 72 h of hospitalization showed that three-day NLR (OR: 1.2; 95% CI: 1.09–1.4; p < 0.001) and age (OR: 1.05; 95% CI: 1.02–1.08; p = 0.02) were the only independent predictors of in-hospital mortality. ROC curve analysis yielded an optimal cut-off value of three-day NLR for the prediction of in-hospital mortality of ≥6.3 (AUC = 0.819; 95% CI: 0.735–0.885; p < 0.0001) and Kaplan–Meier analysis proved that ICH patients with three-day NLR ≥6.3 had significantly higher odds of in-hospital death (HR: 7.37; 95% CI: 3.62–15; log-rank test; p < 0.0001). Conclusion: NLR assessed 72 h after admission is an independent predictor of in-hospital mortality in ICH patients and could be widely used in clinical practice to identify the patients at high risk of in-hospital death. Further studies to confirm this finding are needed
Modeling and Characterization of Complex Concentrated Alloys with Reduced Content of Critical Raw Materials
The continuous development of society has increased the demand for critical raw materials (CRMs) by using them in different industrial applications. Since 2010, the European Commission has compiled a list of CRMs and potential consumption scenarios with significant economic and environmental impacts. Various efforts were made to reduce or replace the CRM content used in the obtaining process of high-performance materials. Complex concentrated alloys (CCAs) are an innovative solution due to their multitude of attractive characteristics, which make them suitable to be used in a wide range of industrial applications. In order to demonstrate their efficiency in use, materials should have improved recyclability, good mechanical or biocompatible properties, and/or oxidation resistance, according to their destination. In order to predict the formation of solid solutions in CCAs and provide the optimal compositions, thermodynamic and kinetic simulations were performed. The selected compositions were formed in an induction furnace and then structurally characterized with different techniques. The empirical results indicate that the obtained CCAs are suitable to be used in advanced applications, providing original contributions, both in terms of scientific and technological fields, which can open new perspectives for the selection, design, and development of new materials with reduced CRM contents