Functionality of immune cells in COVID-19 infection: development of cell-based therapeutics.

Introduction: In late December 2019, a sudden severe respiratory illness of unknown origin was reported in China. In early January 2020, the cause of COVID-19 infection was announced a new coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Examination of the SARS-CoV-2 genome sequence revealed a close resemblance to the previously reported SARS-CoV and coronavirus Middle East respiratory syndrome (MERS-CoV). However, initial testing of drugs used against SARS-CoV and MERS-CoV has been ineffective in controlling SARS-CoV-2. One of the key strategies to fight the virus is to look at how the immune system works against the virus, which has led to a better understanding of the disease and the development of new therapies and vaccine designs. Methods: This review discussed the innate and acquired immune system responses and how immune cells function against the virus to shed light on the human body's defense strategies. Results: Although immune responses have been revealed critical to eradicating infections caused by coronaviruses, dysregulated immune responses can lead to immune pathologies thoroughly investigated. Also, the benefit of mesenchymal stem cells, NK cells, Treg cells, specific T cells, and platelet lysates have been submitted as promising solutions to prevent the effects of infection in patients with COVID-19. Conclusion: It has been concluded that none of the above has undoubtedly been approved for the treatment or prevention of COVID-19, but clinical trials are underway better to understand the efficacy and safety of these cellular therapies.

Modification of photocatalytic property of BaTiO3 perovskite structure by Fe2O3 nanoparticles for CO2 reduction in gas phase.

In this work, perovskite structure of BaTiO3 was coupled with Fe2O3 in different molar ratios achieving the best photocatalytic performance of CO2 reduction in the presence of CH4 as reducing agent; both of them are main greenhouse gases. The photocatalysts were synthesized by facile hydrothermal method. The samples were characterized by XRD, FTIR, FESEM, EDX, UV-Vis DRS, and photoluminescence (PL) analyses. The BaTiO3 synthesized in this research showed a weak PL signal which is due to the intrinsic ferroelectric property as has been observed in previous reports. Compared to the pure BaTiO3 and Fe2O3, the heterojunctions exhibited enhanced photocatalytic activity. The maximum CO2 reduction under visible light irradiation was obtained to be 22% during 60 min process time. The enhanced photocatalytic activity could be attributed to the increased optical absorption, the good separation, and immigration of photogenerated charge carriers that decreased the recombination rate of charge carriers in the n-n heterojunction.

One-Year Clinical Success of Embrace Hydrophilic and Helioseal-F Hydrophobic Sealants in Permanent First Molars: A Clinical Trial.

OBJECTIVES: This study sought to compare the one-year clinical success of a hydrophilic and a hydrophobic fissure sealant in permanent first molars. MATERIALS AND METHODS: This split-mouth clinical trial was conducted on 23 six to nine year olds who had four fully erupted sound first molars. Helioseal-F and Embrace sealants were randomly applied on the first molars, and follow-ups were scheduled at three, six and 12 months to examine the teeth according to USPHS criteria (retention, marginal adaptation, color match, surface smoothness and caries recurrence). The Wilcoxon signed rank test, the Friedman test and the Mann Whitney test were applied for statistical analyses (P<0.05). RESULTS: No significant differences were noted between Embrace and Helioseal-F in retention, smoothness of surface, marginal adaptation, color match or caries at three, six or 12 months (all P>0.05). In addition, the retention of sealants between the maxilla and mandible was not significantly different (P>0.05). Friedman test revealed no significant difference in any of the five parameters at different time points in any sealant group (P>0.05). CONCLUSIONS: Embrace hydrophilic and Helioseal-F hydrophobic sealants have the same one-year clinical success rate.