A green, eco-friendly approach to biosynthesizing silver nanoparticles has been reported for marine macroalga (Cystoseira myrica) extract as a reducing agent. Different pH and temperature impact the green synthesis of silver nanoparticles suggesting that the synthesis depends greatly on pH and temperature. The structure and characters of synthesized nanoparticles were confirmed using HR-TEM, DLS, XRD, and FTIR. Cytotoxicity was indicated using provided cell lines of breast carcinoma cells (MCF-7) and human hepatocellular carcinoma cells (HepG2). Shape of silver nanoparticles at pH 9 and 75°C for 30 min was found to be suitable for the biosynthesis process and the AgNPs exhibited a characteristic absorption peak at 434 nm. High Resolution Electron Microscope Transmission reported polydisperse and spherical shapes ranging from 8 to 15 nm. High attractive and repulsive forces between each nanoparticle were recorded with an average zeta-potential value of approximately −29.3 mV. The X-ray diffraction study revealed the crystalline structure of silver nanoparticles. FTIR has shown the bioreduction of silver ions to silver nanoparticles through biomolecules found in algal extract. Silver nanoparticles have been found to have anticancer activity. The cytotoxicity assay was studied against MCF-7 and HepG2 at various concentrations (100, 50, 25, 12.5, 6.25, 3.125, 1.56, 0.78, 0.39, 0.2, and 0.1 μg/mL). By increasing the concentration of AgNPs from 0.1 to 100 μg/mL, the maximum percentage of viability against MCF-7 and HepG2 cell line decreased from 94.55 ± 7.55 to 19.879 ± 0.503 and from 78.56 ± 11.36 to 25.81 ± 2.66 after time exposure, respectively.

The production of sodium hypochlorite (NaOCl) from salty wastewater using an electrochemical cell has several advantages over other methods that often require hazardous chemicals and generate toxic waste, being more sustainable and environmentally friendly. However, the process of producing sodium hypochlorite using an electrochemical cell requires careful control of the operating conditions, such as the current density, flow rate, inert electrode spacing, and electrolyte concentration, to optimize the conversion efficiency and prevent electrode fouling and degradation. In this study, NaOCl was produced via a bench-scale electrochemical cell using a flowing porous graphite electrode in a continuous flow system from salty wastewater collected from the Suez Canal in Egypt. The aim of the investigation was to examine the factors that affect the concentration of NaOCl and energy consumption, such as anodic current density, salinity, inert electrode spacing, and influent feed flow rate. A lab-scale reactor with two electrodes was used to conduct the experiments. The highest NaOCl yield of 20.6% was achieved with a graphite electrode, which had high current efficiency and rigidity at a flow rate of 4.5 mL/min, a current density of 3.183 mA/cm2, an electrode space of 0.5 cm, salinity of 40,000 ppm, and a pH of 6.4. The power consumption under these conditions was 0.0137 kwh. Additionally, a statistical and least square multivariate regression technique was employed to establish a correlation for predicting the % NaOCl production. The obtained correlation had an R2 value of 98.4%. Overall, this investigation provides valuable insights into the production of NaOCl using a continuous flow system from salty wastewater, which could have potential for industrial applications in various sectors such as textiles, detergents, paper, and pulp.

Coronaviruses (CoVs) are a broad family of potentially serious RNA viruses that are now causing an outbreak of respiratory disease known as CoV disease 2019 . Melatonin is a pineal hormone that is predominantly produced and released at night from the amino acid tryptophan. Melatonin and its metabolites are also important in immunomodulation, and they have antioxidative properties due to their capacity to scavenge reactive oxygen species both directly and indirectly. COVID-19 leads to changes of altered consciousness levels in about 15% of hospitalized patients, starting from somnolence to disorientation, delirium, stupor, and coma. Melatonin can decrease the molecules that cause delirium in the elderly and central respiratory depression, such as benzodiazepines and antipsychotics. Melatonin may help alleviate infection-induced acute respiratory distress as well as its diverse effects, which include anti-inflammatory, antioxidative, and immune-enhancing properties. Its supplemental dose may be able to prevent SARS-COV-2 infections by reversing aerobic glycolysis via suppression of both HIF-1 and mTOR, allowing pyruvate dehydrogenase complex activity to be suppressed and acetyl-coenzyme A to be produced. When mitochondrion-produced and parenteral melatonin are combined, the cytokine storm is reduced, and COVID-19 infection-induced damage is alleviated. In conclusion, melatonin could have an important role in the management of COVID-19.