Nanosized spinel ferrites MFe2O4(M = Ni, Co, and Zn) have been prepared by sol-gel autocombustion method using citric acid as a fuel agent. The materials are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The spinel ferrites have been applied for Congo-Red (CR) dye adsorption using batch technique. Different kinetic and equilibrium models have been fitted by nonlinear regression to analyze the adsorption data. In accordance with Langmuir isotherm, the maximum adsorption capacity at 293 K is 14.06 mg/g for CoFe2O4and 17.13 mg/g for NiFe2O4. The values of mean free energy determined from Dubinin-Radushkevich isotherm are higher than 8 (kJ mol−1), indicating a chemisorption mechanism. Based on the calculated thermodynamic parameters (free energy, enthalpy, and entropy) the adsorption of CR onto ferrites is a spontaneous and endothermic process. Response surface methodology has been applied to construct the multiple regression models for prediction of the adsorption capacity and removal efficiency. The model-based optimization has been performed using genetic algorithms and desirability function approach. The single-objective optimization has yielded a maximum value of color removal efficiency of 98.995%, using NiFe2O4adsorbent. The multiobjective optimization has resulted in the improvement of both removal efficiency and adsorption capacity.

Rectal cancer is a significant part of colorectal cancers, being one of the most common causes of death in the world. The goal of this study is to achieve information about anatomical aspects of neovascularization in inferior rectal cancer. The study was performed on a group of 10 patients, imagistic investigated and diagnosed with inferior rectal tumors. The method used consist of comparing the results of CT and MRI images with in vitro arteriographies on resected specimens. In conclusion we tried to make a predictive and reproducible model for inferior rectal cancer which can refocus surgical procedures and oncologic treatment. Paraneoplastic neoangiogenesis processes allow staging of colorectal formations, but the problem arises on the neoangiogenesis staging; the excised lower rectal tumors which presented a reduced neovascularization, respectively a small number of vascular condensation nucleus had a better prognosis and a simple postoperative evolution.

The photocatalytic activity of zinc oxide, prepared by precipitation followed by calcination, was tested using rhodamine 6G as a rebel organic compound. The experiments were planned in order to allow an optimization procedure, by investigating the effects of different parameters such as the preparative method of the solid, amount of photocatalyst, pH of the reaction medium, and initial concentration of the dye. The results were compared with those obtained on P-25 Titania, and one of the samples had similar performances in terms of dye degradation degree, but needed higher pH values to prevent the photocatalyst degradation.

Background: The influence of the early COVID-19 pandemic on non-COVID-19 emergencies is uncertain. We conducted a systematic review and a meta-analysis to evaluate the impact of the first months of the COVID-19 pandemic on the presentation, management, and prognosis of patients presenting with ST-segment elevation myocardial infarction (STEMI). Methods: We searched the PubMed, Scopus, and Embase databases from January to August 2020. A meta-analysis of studies comparing the profile, STEMI severity at presentation, reperfusion delay, and in-hospital mortality for patients presenting before and during the early COVID-19 pandemic was conducted. Fifteen cross-sectional observational studies including 20,528 STEMI patients from the pre-COVID period and 2190 patients diagnosed and treated during the first months of the COVID-19 pandemic met the inclusion criteria. Results: Patients presenting with STEMI during the pandemic were younger and had a higher comorbidity burden. The time interval between symptoms and first medical contact increased from 93.22 ± 137.37 min to 142 ± 281.60 min (p < 0.001). Door-to-balloon time did not differ significantly between the two periods (p = 0.293). The pooled odds ratio (OR) for low left ventricular ejection fraction at presentation during the pandemic was 2.24 (95% confidence interval (CI) 1.54–3.26) and for a presentation delay >24 h was 2.9 (95% CI 1.54–5.45) relative to before the pandemic. In-hospital mortality did not increase significantly during the outbreak (p = 0.97). Conclusion: During the first months of the COVID-19 pandemic, patients presenting with STEMI were addressed later in the course of the disease with more severe left ventricular impairment. In-hospital emergency circuits and care functioned properly with no increase in door-to-balloon time and early mortality.

This paper deals with the practical implementation of cleaner technologies in the chemical industry, using two case studies as an illustration. The first case study deals with the removal of NOx and N2O gases over an iron-doped ZSM-5 catalyst developed for tail gas treatment in nitric acid manufacturing. The aim for this case study was to investigate the efficiency of the zeolitic catalyst in the DeNOx process and to compare its catalytic activity with the conventional vanadia-titania. By the experiments carried out, it can be concluded that the new technological developments could significantly contribute to a decrease in environmental pollution. The second case study focuses on zeolite-based catalysts prepared from zeolitic tuff by the impregnation method, for biodiesel production from waste sunflower vegetable oil. The effects of operating and processing variables such as reaction temperature and time were investigated. The results showed that the highest biodiesel yield was 96.7% at an 11.5 MeOH/oil molar ratio, in the presence of 6.4 wt % catalyst at a 50 °C reaction temperature and reaction time of 2 h. The properties of the biodiesel that was produced, such as the viscosity, meet the required specifications of standard JUS EN14214. The common feature of the two different case studies is that both technologies use zeolite catalysts, namely naturally-occurring zeolitic tuff and synthetic ZSM type zeolite catalyst. The examples shown emphasize the importance of the zeolites in clean chemical technologies, which contribute to the protection of the environment.