Destruction mechanisms of ozone over SARS-CoV-2.

In this pandemic SARS-CoV-2 crisis, any attempt to contain and eliminate the virus will also stop its spread and consequently decrease the risk of severe illness and death. While ozone treatment has been suggested as an effective disinfection process, no precise mechanism of action has been previously reported. This study aimed to further investigate the effect of ozone treatment on SARS-CoV-2. Therefore, virus collected from nasopharyngeal and oropharyngeal swab and sputum samples from symptomatic patients was exposed to ozone for different exposure times. The virus morphology and structure were monitored and analyzed through Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Atomic Absorption Spectroscopy (AAS), and ATR-FTIR. The obtained results showed that ozone treatment not only unsettles the virus morphology but also alters the virus proteins' structure and conformation through amino acid disturbance and Zn ion release from the virus non-structural proteins. These results could provide a clearer pathway for virus elimination and therapeutics preparation.

Nanogel-based natural polymers as smart carriers for the controlled delivery of Timolol Maleate through the cornea for glaucoma.

Despite frequent scientific efforts, efficient ocular drug delivery is a major challenge for pharmaceutical scientists. Poor bioavailability of ophthalmic solutions can be overcome by using smart ophthalmic drug-delivery systems. In this research, loading and delivery of Timolol Maleate (TM) through the cornea by synthesized nanoparticles based on biopolymers (chitosan-alginate) were studied. The physico-chemical properties of these nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS). Loading and release were evaluated by a UV-vis spectrometer and the ex vivo permeation study was carried out using the Franz Diffusion Cell and fluorescent microscopy studies. The results indicated that morphology and size of nanoparticles were spherical and in the range of 80-100nm. The loading capacity and encapsulation efficiency were about 42% and 94% respectively. They illustrated a burst release in the first hour followed by a slower and more sustained drug release during the next 24h. Also, the results indicated that the cornea penetration of TM loaded in nanoparticles was twice than that of TM. Hence, this nanocarrier can be considered as a suitable candidate for controlled TM delivery and release through the cornea.

Humic substances-enhanced electroremediation of heavy metals contaminated soil.

The effects of catholyte conditioning and the use of humic acids (HAs) and fulvic acids (FAs) as chelating agents to improve electrokinetic (EK) remediation efficiency were investigated using a real and highly contaminated soil. By applying a constant voltage (2.0V/cm) to the soil, pH and current changes and heavy metals (HMs) concentration were investigated through a range of durations and positions. The observations demonstrated that both catholyte conditioning with 0.1N HNO3 and using humic substances (HSs) enhance remediation efficiency. After 20 days of EK treatment, the removal efficiency of HMs in HS-enhanced EK remediation was about 2.0-3.0 times greater than when unenhanced. The quantity of HMs moving toward the cathode exceeded the anode, from which it could be reasonably inferred that most negatively charged HM-HS complexes were moved by electroosmotic forces. Further, free HM cations and positively charged complexed HMs migrated to the catholyte compartment by electromigration. The results obtained in this study, demonstrate the suitability of HS-enhanced EK remediation in HMs contaminated soil.

Effects of temperature treatment on corn cob composting and reducing of composting time: a comparative study.

This study focuses on the effect of temperature on the compost quality and the processing time. Two temperature, namely 46°C (high temperature) and 30°C (low temperature) were considered for the composting trials. A mixture of 60% ground corn cob, 30% dried sports grass and 10% bio-activator was used as composting material. The composting process lasted for 120 days. The maturity indices at the end of composting indicate that, for the high-temperature treatment, the compost show an improved quality as compared to the low-temperature treatment. The maturity indices, namely carbon to nitrogen ratio, water extractable organic carbon, ratio of cation exchange capacity to total organic carbon and germination index, determined for the high temperature treatment are: 13.9, 1.48 mg mL⁻¹, 2.21, and 86%, respectively. On the basis of the compost characteristics, the processing time for the high- and low-temperature treatments was 75 days and 105 days, respectively. It can be concluded that treatment at the high-temperature level considered in this study presents a more suitable option for improvement of composting.