A review of deciphering the successes and learning from the failures in preventive and health policies to stop the COVID-19 pandemic

The COVID-19 pandemic and occupational health-transitioning to the new normal

The coronavirus disease 2019 (COVID-19) pandemic had a profound impact on workers’ health and well-being. There are significant implications for Occupational Safety and Health (OSH) as we transit to the new normal, including the adoption of digital health solutions, emergence of remote work and the need to review our perspectives on the traditional OSH framework in tackling workplace hazards in a pandemic. This will better prepare us for the inevitable next global pandemic.

Identification of new dihydrophenanthrene derivatives as promising anti-SARS-CoV-2 drugs through in silico investigations

To research, evaluate, and invent novel compounds that inhibit SARS-CoV-2 activity, a series of reported 39 substituted 9, 10-dihydrophenanthrene derivatives were subjected to a quantitative structure-activity relationship (QSAR) study. Gaussian 09 and ChemOffice programs were used to calculate the molecular descriptors employed to determine their impact on the studied activity. Then we reduced the number of descriptors by eliminating the redundant information using principal component analysis (PCA). The creation of molecular models was done by using multiple linear regression (MLR) according to the principles established by the Organization for Economic Co-operation and Development (OECD) and the validation by using external and internal validation, Y-randomization tests, and domain of applicability. Moreover, we evaluated the toxicity of developed compounds using ADMET and Molecular docking to determine their optimal position to form a stable complex. As a result, four molecules may be used to develop a novel drug that can inhibit SARS-CoV-2 without causing the side effect.

Biogenic synthesis of reduced graphene oxide from Ziziphus spina-christi (Christ's thorn jujube) extracts for catalytic, antimicrobial, and antioxidant potentialities

In the current work, various concentrations of the aqueous extract of Ziziphus spina-christi were employed for the phytoreduction of graphene oxide (GO). The green synthesized reduced graphene oxide (rGO) was characterized through UV-Vis spectrometry, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDX). Gas chromatography-mass spectrometry (GC-MS) denoted the presence of numerous phytoconstituents including ketones, terpenoids, fatty acids, esters, and flavonoids, which acted as reducing and capping agents. The obtained results indicated the increase in rGO yield and shape with increasing the extract concentration. The optimized rGO was instantaneously ~100% removed methylene blue (MB) from the water at 5 mg L-1. However, the removal efficiency was slightly declined to reach 73.55 and 65.1% at 10 and 15 mg L-1, respectively. A powerful antibacterial activity for rGO particularly against gram-negative bacteria with a high concentration of 2 × 108 CFU mL-1 was confirmed. Furthermore, rGO demonstrated promising and comparable antioxidant efficiency with vitamin C against DPPH free radical scavenging. While vitamin C recorded 13.45 and 48.4%, the optimized rGO attained 13.30 and 45.20% at 12 and 50 μg mL-1, respectively.