Fecal Microbiota Transplantation during and Post-COVID-19 Pandemic

COVID-19 is a major pandemic facing the world today, which has implications on current microbiome-based treatments such as fecal microbiota transplantation (FMT) used for recurrent Clostridioides difficile infections. The bidirectional relationship between the inhabitants of our gut, the gut microbiota, and COVID-19 pathogenesis, as well as the underlying mechanism involved, must be elucidated in order to increase FMT safety and efficacy. In this perspective, we discuss the crucial cross-talk between the gut microbiota and the lungs, known as the gut–lung axis, during COVID-19 infection, as well as the putative effect of these microorganisms and their functional activity (i.e., short chain fatty acids and bile acids) on FMT treatment. In addition, we highlight the urgent need to investigate the possible impact of COVID-19 on FMT safety and efficacy, as well as instilling stringent screening protocols of donors and recipients during COVID-19 and post-COVID-19 pandemic to produce a cohesive and optimized FMT treatment plan across all centers and in all countries across the globe.     

Field Enhancement in Metamaterial Split Ring Resonator Aperture Nano-Antenna with Spherical Nano-Particle Arrangement

Silicon - In this paper, we present a split ring resonator (SRR) for a nano-aperture antenna for biomedical and spectroscopy applications. We have shown that while the graphene coat layer is...     

Extended beam search for non-exhaustive state space analysis

State space explosion is a major problem in both qualitative and quantitative model checking. This article focuses on using beam search, a heuristic search algorithm, for pruning weighted state spaces while generating. The original beam search is adapted to the state space generation setting and two new variants, motivated by practical case studies, are devised. These beam searches have been implemented in the μCRL toolset and applied on several case studies reported in the article.     

Effect of Eryngium caeruleum essential oil on microbial and sensory quality of minced fish and fate of Listeria monocytogenes during the storage at 4°C

The present study investigated in vitro antimicrobial activity of Eryngium caeruleum essential oil (EEO) against five foodborne pathogenic bacteria based on microdilution and disk diffusion methods. Moreover, its effects on specific spoilage microorganisms, inoculated Listeria monocytogenes, and its sensory changes in minced fish were evaluated during 12 days of storage at refrigeration temperature. The results showed that Staphylococcus aureus and Escherichia coli were the most sensitive and the most resistant bacteria with a minimum inhibitory concentration of 0.125 and 1 mg/ml, as well as inhibition zones of 15.66 and 11.66 mm, respectively. Regarding the antimicrobial effect of EEO on the microbial profile and inoculated L. monocytogenes, treating with 0.4% EEO caused a significant decrease in the studied microorganisms when compared to the control group (p < 0.05). In addition, considering the sensory evaluation, the best scores were observed for the samples treated with 0.2% and 0.4% EEO. However, none of the groups obtained acceptable scores until the final day of storage except for the color attribute. In general, sensory evaluation and its correlation with microbial counting indicated that the treatment with 0.4% EEO was able to preserve the microbial quality of the minced fish at refrigeration temperature without any undesirable sensory effects.     

A comparative study of group delay equalizers for satellite communications

This article presents a comparative study of four different group delay (GD) equalizers with a narrow band filter used as input multiplexer for a Ku‐band satellite transponder. A dual mode cylindrical filter with 36 MHz bandwidth is designed and fabricated. The filter GD is measured and two types of group‐delay equalizers are designed to fulfill the requirements of the transponder's GD mask. Two rectangular and two cylindrical equalizers are designed and their performance parameters, such as insertion loss and equalized bandwidth, are compared. In addition, a comparison between the designed first order (C‐section) and second order (D‐section) GD equalizers is done.     

Simulation of reversible chain transfer catalyzed polymerization (RTCP): effect of different iodide based catalysts

Monte Carlo kinetic simulation method was performed to study the reversible chain transfer catalyzed polymerization (RTCP) of styrene in 80°C. The effect of different iodide based catalysts (AI) was investigated on RTCP systems by simulating the chain length distribution, the depletion rate of polymerization ingredients, average molecular weights and the monomer conversion. In RTCP systems a narrow distribution was obtained compared to iodide-mediated polymerization. Superior reversible chain transfer reaction constants (k_a and k_da) led to a more uniform chain length distribution and a faster PDI decrement. In each RTCP system k_da/k_a ratio, designates the concentration of A* by dictating the dominant side of exchange equilibriums which specifies the number of cross-termination reactions. Addition of cross-termination reactions to the iodide-mediated polymerization system decreases the number of combination reactions leading to lower average molecular weights. Higher k_da/k_a ratios also consequences in faster catalyst depletions and lessen monomer conversions. On the other hand, PhE-I was found to deplete rapidly in RTCP systems, changing the nonlinear increase of the number average molecular weight to a linear pattern. The Monte Carlo simulation results were in a fine agreement with experimental data which were obtained from different RTCP systems.     

Economic feasibility of solid oxide fuel cell (SOFC) for power generation in Iran

Supply utilities needed in site with the lowest cost and emission and highest efficiency are considered one of the main concerns of the process industry’s owners that requires doing more research in this area. In this research, during a case study, first comprehensive site of producing utility is optimized, and then the energy and environmental analysis of fuel cell system is taken place. Then fuel cell integration with utility site during two scenarios of entire supply of steam generated by HRSG of gas turbine and entire supply of gas turbine generated power was evaluated. According to the evaluation done, if the target is the entire supply of steam generated by HRSG of gas turbine, selecting solid oxide fuel cell (SOFC) system is economically and environmentally more affordable. So if the target is preheating, selecting the system is based on entire supply of steam generated by the boilers, and the number of eight SOFC systems will be required by which a power about 22 MW can be produced.     

An innovative approach to fabricate a thermosensitive melatonin-loaded conductive pluronic/chitosan hydrogel for myocardial tissue engineering

This study aimed at designing and fabrication of a novel injectable and thermosensitive melatonin-loaded pluronic/chitosan hydrogel containing gold nanoparticles (GNPs) and poly glycerol sebacate (PGS) for myocardial tissue engineering. The PGS nanoparticles were used as the melatonin (drug model) carrier. The gelation time, syringeability, stability, and swelling of the hydrogel were scrutinized. Rheological properties, chemical composition, and morphology of the samples were also investigated. The effect of GNPs addition on the electrical conductivity of hydrogel was assessed. The cytotoxicity of hydrogels was assessed through MTT assay in the exposure of H9C2 cells up to 7 days. Scanning electron microscopy was applied to evaluate the morphology of seeded cells. The synthesis parameters of PGS nanoparticles were optimized through which 2.5%w/v of PGS and 1:10 organic phase to aqueous phase (O/A) ratio were found desirable. The optimum hydrogel illustrated 2 min gelation time and was stable up to 20 days with 5% swelling in the first 12 h into phosphate buffered saline. The GNPs with a uniform distribution rendered the hydrogel electrically conductive (1500 μS/cm). According to the MTT assay results, 3.125 μM melatonin was considered as the suitable concentration by which a significant increase in the cell viability was observed. The results exhibited that the prepared hydrogel composed of pluronic/chitosan/GNPs, and 3.125 μM melatonin-loaded PGS nanoparticles could be applied as a promising scaffold for myocardial tissue engineering.