Annual Variation of PM2.5 Chemical Composition in Ho Chi Minh City, Vietnam Including the COVID-19 Outbreak Period

PM2.5 was continuously collected in Ho Chi Minh City (HCMC), Vietnam, during the period from September 2019 to August 2020, which included the period of socioeconomic suppression caused by restrictions imposed in the face of the coronavirus disease of 2019. The concentrations of PM2.5 mass, water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were determined to evaluate the seasonal variations in PM2.5, the effect of socioeconomic suppression on PM2.5, and potential PM2.5 sources in HCMC. The PM2.5 mass concentration during the sampling period was 28.44 +/- 11.55 mu g m(-3) (average +/- standard deviation). OC, EC, and total WSIs accounted for 30.7 +/- 6.6%, 9.7 +/- 2.9%, and 24.9 +/- 6.6% of the PM2.5 mass, respectively. WSOC contributed 46.4 +/- 10.1% to OC mass. NO3-, SO42-, and NH4+ were the dominant species in WSIs (72.7 +/- 17.7% of the total WSIs' mass). The concentrations of PM2.5 mass and total WSIs during the rainy season were lower than those during the dry season, whereas the concentrations of carbonaceous species during the rainy season were higher. The concentrations of PM2.5 mass and chemical species during the socioeconomic suppression period significantly decreased by 45%-61% compared to the values before this period. The OC/EC ratio (3.28 +/- 0.61) and char-EC/soot-EC (4.88 +/- 2.72) suggested that biomass burning, coal combustion, vehicle emissions, cooking activities are major PM2.5 sources in HCMC. Furthermore, the results of a concentration-weighted trajectory analysis suggested that the geological sources of PM2.5 were in the local areas of HCMC and the northeast provinces of Vietnam (where coal-fired power plants are located).

A study of pharmacists' resilience-enhancing behaviours to improve pharmacy student resiliency in Japan

Background: The word "resilience" has been trending since recent devastating natural disasters and the COVID-19 worldwide pandemic. This study sought to uncover how Japanese pharmacists perceive and define resiliency and quantify their resilient behaviours for the purpose of enhancing pharmacy education. Methods: A four-part, online questionnaire that included the 10 Factor Resilient Behavior Scale (F10RBS) was sent to pharmacists around Japan. Results: Pharmacists defined resilience as "bouncing back" and "a positive adaptation after trauma". An exploratory factor analysis of the resilience-enhancing behaviours led to three factors: personal health and well-being, altruism, and a positive outlook. Conclusion: The results of this study revealed that resilience is strengthened through experience and previously established behaviours and skills. This understanding of resilient behaviours can be integrated into pharmacy education by encouraging university students to maintain a healthy lifestyle and make choices that will nurture resilience before experiencing a traumatic event or the stress of professional work.

Thymidine derivatives as inhibitors against novel coronavirus (SARS-COV-2) main protease: Theoretical and computational investigations

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a beta coronavirus that was first found during the Wuhan COVID-19 (coronavirus disease 2019) epidemic in 2019 and listed as a potential global health threat by WHO due to high mortality. The main protease of SARS-CoV-2 is one of the best targets to design and develop antiviral drugs. Nucleoside agents have been under investigation for many years and some of the most clinically effective antiviral agents currently in use are purine or pyrimidine nucleoside derivatives. For example, ribavirin, a synthetic nucleoside similar in structure to guanosine and inosine, has potent in vitro activity against a broad spectrum of viruses, including the epidemic respiratory viruses. Azidothymidine (AZT) is one of the most popular antiviral drugs in which 3'-hydroxyl (-OH) of thymidine is modified by an azide group and now it is used worldwide for the treatment of HIV infection. In this study, several thymidine derivatives with different aliphatic and aromatic groups were subjected to quantum mechanical calculation (QMC), PASS (prediction of activity spectra for substances) antiviral divination, molecular docking, and pharmacokinetic characterization to assess the binding affinity and interaction of thymidine derivatives against main protease (Mpro) of SARS-CoV-2. Density functional theory (DFT) at the B3LYP/3-21G level of theory was employed to enumerate charge distribution, polarizability, and thermodynamic properties such as frontier orbital energy, Gibbs free energy, enthalpy, electronic energy, heat capacity, entropy, of modified derivatives to evaluate the effect of certain groups (aliphatic and aromatic) on the drug properties and found that all derivatives were thermodynamically more stable than the parent molecule thymidine. PASS antiviral parameters of the modified derivatives revealed promising drug properties in comparison to standard antiviral drugs. Molecular docking is performed using AutoDock Vina to determine the binding affinities and interactions between the thymidine derivatives and the SARS-CoV-2 main protease. The modified derivatives strongly interact with the prime Cys145 and His41 residues. Finally, the pharmacokinetic characterization of the optimized inhibitor demonstrates that these thymidine derivatives appear to be safer inhibitors and a combination of in silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) prediction and drug-likeness had promising results due to their improved kinetic properties. After all, our comprehensive computational and statistical analysis shows that these selected thymidine derivatives can be used as potential inhibitors against the SARS-CoV-2. © 2021 Nova Science Publishers, Inc.

Effect of Covid-19 and Lock-down on the Electricity Sector in Bangladesh

Coronavirus disease (COVID-19) has brought unprecedented global health and economic crisis in the year 2020. The energy sector is also severely affected by this crisis, which has slowed transport, trade and economic activities across the globe. Many of the countries had to adopt full and/or partial lock-down measures for a significant duration in order to prevent the spread of this highly contagious virus, which in turn had profound impact on the dynamics of the most favorable mode of final energy, electricity. In this paper, we analyze the impact of covid-19 and reduced economic activity due to lockdown on Bangladesh electricity sector in detail. Reduction of electricity demand, system load factor, load curve, fuel cost for generation from fossil fuels, changes in generation mix and growth of on-grid renewable electricity generation have been analyzed. In addition, current government plan for the continued growth and development of the sector has been reviewed to justify the resiliency of the system to overcome major obstacles. Several policy recommendations have been made to improve system efficiency and economic performance for sustainable development.

Pharmacokinetics and Molecular Docking Studies of Uridine Derivatives as SARS-COV-2 M-pro Inhibitors

Various clinical trials are undergoing to identify specific drugs for the treatment of new global threat viruses. The main protease of SARS-CoV-2 is one of the significant targets to design and amplify antiviral drugs. In this investigation, we optimized a nucleoside, uridine, and some of its acylated derivatives (2-14) using density functional theory (DFT) at the B3LYP/3-21G level of theory. Charge distribution, polarizability, and thermodynamic properties such as free energy, heat capacity, entropy, of modified compounds were studied in the subsequent analysis to evaluate how certain groups (aliphatic and aromatic) impact the drug properties. It was observed that all derivatives were thermodynamically more stable than the parent ligand, uridine, and some of them were more chemically reactive than others. Then, molecular docking was performed against SARS-CoV-2 main protease (PDB: 6Y84 and 6LU7) to investigate the binding mode (s) and binding affinities of the selected uridine derivatives. Most of the compounds studied here could bind near the crucial catalytic residues, HIS41 and CYS145 of the main protease and surrounded by other active site residues such as GLY143, MET49, MET165, HIS163, PRO168, GLU166, GLN189 and SER144. Significant binding affinities (-6.0 to -7.8 kcal mol(-1)) for 6LU7 and (-5.9 to -7.7 kcal mol(-1)) for 6Y84 were found which revealed the potency of inhibition of uridine derivatives against SARS-CoV-2 M-pro. Finally, all the modified uridine derivatives were analyzed in silico ADMET and drug-like properties. Overall, the present study could be helpful for the development of uridine-based novel potential inhibitors against the SARS-CoV-2 M-pro.