Immune and bioinformatics identification of T cell and B cell epitopes in the protein structure of SARS-CoV-2: A systematic review

The beginning of 2020 was marked as the emergence of a COVID-19 outbreak caused by a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, there is no vaccine or approved treatment for this infectious virus so the invention of an efficient vaccine is certainly a high priority. Some studies have employed several techniques to facilitate the combination of the immunoinformatics approach and comparative genomic approach in order to determine the potential peptides for designing the T-cell epitope-based peptide vaccine using the 2019-nCoV envelope protein as a target. Via screening the bioimmunoinformatic SARS-CoV2 derived B-cell and T-cell epitopes within the basic immunogenic of SARS-CoV2 proteins, we presented a set of inferred B-cell and T-cell epitopes from the spike (S) and nucleocapsid (N) proteins with high antigenicity and without allergenic property or toxic effects. Our findings provide a screened set of epitopes that can be introduced as potential targets for developing peptide vaccines against the SARS-CoV-2 virus

Mechanisms of spinal cord injury regeneration in zebrafish: A systematic review

Objective(s): To determine the molecular and cellular mechanisms of spinal cord regeneration in zebrafish. Materials and Methods: Medical databases of PubMed and Scopus were searched with following key words: Zebrafish; spinal cord injuries; regeneration; recovery of function. The map of mechanisms was performed using Xmind software. Results: Wnt/�-catenin signaling, L1.1, L1.2, Major vault protein (MVP), contactin-2 and High mobility group box1 (HMGB1) had positive promoting effects on axonal re-growth while Ptena had an inhibitory effect. Neurogenesis is stimulated by Wnt/�-catenin signaling as well as HMGB1, but inhibited by Notch signaling. Glial cells proliferate in response to fibroblast growth factor (fgf) signaling and Lysophosphatidic acid (LPA). Furthermore, fgf signaling pathway causes glia bridge formation in favor of axonal regeneration. LPA and HMGB1 in acute phase stimulate inflammatory responses around injury and suppress regeneration. LPA also induces microglia activation and neuronal death in addition to glia cell proliferation, but prevents neurite sprouting. Conclusion: This study provides a comprehensive review of the known molecules and mechanisms in the current literature involved in the spinal cord injury (SCI) regeneration in zebrafish, in a time course manner. A better understanding of the whole determining mechanisms for the SCI regeneration should be considered as a main goal for future studies. © 2017, Mashhad University of Medical Sciences. All rights reserved

Optimized adsorption of 4-chlorophenol onto activated carbon derived from milk vetch utilizing response surface methodology

In the present study, the adsorption of 4-chlrorophenol (4-CP) from aqueous solutions was investigated using activated carbon prepared from milk vetch. Scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier transform infrared were carried out to characterize as-prepared activated carbon. The adsorption process was optimized by response surface methodology based on central composite design. Accordingly, a 4-CP removal of 89.52 was obtained with a reaction time of 49min, initial 4-CP concentration of 56mg/L, adsorbent dosage of 1g/L, and initial pH of 7. Among various operational parameters, the adsorbent dosage (F-value=139.5) produced the largest effect on 4-CP removal (), while initial pH (F-value=0.620) presented the lowest effect. The pseudo-second-order kinetic equation described the process reasonably well (R-2=0.9996). The process followed Langmuir isotherm (R-2=0.9969) with a maximum adsorption capacity of about 87mg/g. For chemical regeneration, during three-stage regeneration runs, the removal efficiency () of 4-CP decreased from 87.45 to 61.15, while, in the case of thermal regeneration, it decreased from 87.45 to 77.68, respectively. Overall, activated carbon derived from milk vetch can be applied as an efficient adsorbent for sequestering 4-CP from aqueous phase with relatively high reusability potential

The application of ZnO/SiO2 nanocomposite for the photocatalytic degradation of a textile dye in aqueous solutions in comparison with pure ZnO nanoparticles

One of the major disadvantages of the application of ZnO nanoparticles as photocatalyst in photocatalytic systems is photoinstability due to the photocorrosion under UV light irradiation resulting in the significant reduction in their photocatalytic activity. Therefore, in the present study, SiO2 nanopowders were incorporated into the ZnO nanoparticles to enhance their photocatalytic activity for the decolorization of methylene blue (MB) dye in comparison with pure ZnO/UV process. The efficiency of UV/ZnO/SiO2 process was compared with UV/ZnO process for the decolorization of MB dye and the removal of chemical oxygen demand (COD). The effect of various amounts of SiO2 (5, 10, and 15) incorporated into ZnO nanoparticles was studied. At optimal SiO2 loading of 10, the decolorization efficiency of MB and the removal of COD were obtained to be 100 and 81, respectively. However, using UV/ZnO process at the same operational conditions, the decolorization efficiency of MB and the removal of COD were 66 and 44, respectively. An initial pH of 7 and initial dye concentration of 25mg/L were chosen as optimal experimental conditions. It can be stated that the incorporation of SiO2 nanopowders into the ZnO nanoparticles would be beneficial for enhancing their photocatalytic activity

Removal of methylene blue and acid orange 7 from aqueous solutions by activated carbon coated with zinc oxide (ZnO) nanoparticles: equilibrium, kinetic, and thermodynamic study

Various industries like textile, plastic, pulp, and paper produce dye containing wastewaters that have harmful effects on the environment as well as human health. The aim of this study was to investigate the effect of granular activated carbon (AC) coated by zinc oxide nanoparticles (ZnO-np) in the removal of dyes, methylene blue (MB) and acid orange 7 (AO7), from aqueous solutions. The morphology of the AC and AC-ZnO was determined by SEM and theFTIRspectraconfirmedthe stronginteraction between AC and ZnO. The effect of various parameters, such as nanoparticles loading onto the AC, pH, contact time, dye concentration, ion strength, temperature, and adsorbent regeneration, was studied on the adsorption. The results showed that the surface structure of the raw AC was porous and had irregular shapes, but the surface of the modified AC (AC-ZnO) due to the homogenous coating of the ZnO-np onto the AC was approximately uniform and regular. The sorption capacity and optimum contact time for the removal of MB (32.22 mg/g) and AO7 (32.13 mg/g) by AC-ZnO were obtained as 32.22 mg/g during 120 min and 32.13 mg/g over 150 min, respectively. The optimum pH for the sorption of MB occurred at pH 11 and for AO7 was obtained at pH 3. The results also showed that Langmuir isotherm and pseudo-second-order kinetic models fitted the experimental data better than other isotherm and kinetic models. It is obviously clear that AC-ZnO, in comparison with raw AC, was more efficient sorbent for the removal of MB and AO7 and it can be proposed for the removal of these dyes from aqueous solutions

Improved performance of immobilized TiO2 under visible light for the commercial surfactant degradation: Role of carbon doped TiO2 and anatase/rutile ratio

Nanoparticles of TiO2 with different ratios of anatase (A)/rutile (R) phases were successfully synthesized via solgel method. Carbon-doped TiO2 (CDT) was supported on the surfaces of granular activated carbon (GAC) for photocatalytic degradation and mineralization of the commercial nonylphenol (NP) surfactant under visible light irradiation. The physicochemical characteristics of the synthesized composites (TiO2, CDT, and CDT/GAC) were determined in detail by X-ray diffraction, scanning electron microscopy, elemental mapping, Brunauer-Emmett-Teller, UV-Vis absorption and PL spectra. The results indicated that the band gap decreased from 3.17 eV to 2.72 eV after C doping, and to 2.66 eV by changing the calcination temperature from 475 degrees C to 600 degrees C; the visible light absorption also increased. This study demonstrates that the CDT/GAC photocatalyst with an A (53.06)/R (46.94) ratio exhibited high degradation efficiency. COD and TOC removal of 99 and 89, respectively, and 80 NP decrease within 60 min. The NP degradation increases with increasing temperature and light intensity. The Langmuir-Hinshelwood kinetic model fitted with the experimental data. In addition, it is reported that the synthesized photocatalyst became stable and highly active, even after five cycles. The results also showed that the values of the carbon oxidation state (COS) and the average oxidation state (AOS) were highly increased after the decomposition of NP by the Xenon/CDT (A/R)/GAC process over 3.37 and 3.87, respectively

EFFECT OF PRAESTOL AS A COAGULANT-AID TO IMPROVE COAGULATION-FLOCCULATION IN DYE CONTAINING WASTEWATERS

This study was conducted to investigate the effect of praestol, as a coagulant-aid, to improve coagulation-flocculation process in the removal of disperse red 60 from aqueous solutions. The effect of various parameters including coagulants dose (10-1000 mg l(-1)), praestol dose (0-1000 mg l(-1)), solution pH (3-11), initial dye concentration (100-500 mg l(-1)), flocculation speed (30-60 rpm), flocculation time (15-30 min), settling time (5-60 min) and ionic strength (0-6 mg l(-1)) was evaluated on the dye removal. The dye removal efficiency was substantially increased by using praestol in the concentration of 80 mg l(-1) and 400 mg l(-1) for coagulation with alum and polyaluminum chloride (PACl), respectively. The maximum dye removal by alum coupled with praestol (Al-P) and PACl coupled with praestol (PA-P) was found to be 97.8 and 98.7, respectively that were occurred at pH 7. The results showed that the application of PA-P or Al-P can be effectively used to remove disperse red 60 (DR 60) in aqueous solutions

A systematic review of possible airborne transmission of the COVID-19 virus (SARS-CoV-2) in the indoor air environment

At the end of December 2019, the rapid spread of the COVID-19 (SARS-CoV-2) disease and, subsequently, deaths around the world, lead to the declaration of the pandemic situation in the world. At the beginning of the epidemic, much attention is paid to person-to-person transmission, disinfection of virus-contaminated surfaces, and social distancing. However, there is much debate about the routes of disease transmission, including airborne transmission, so it is important to elucidate the exact route of transmission of the COVID-19 disease. To this end, the first systematic review study was conducted to comprehensively search all databases to collect studies on airborne transmission of SARS-CoV-2 in indoor air environments. In total, 14 relevant and eligible studies were included. Based on the findings, there is a great possibility of airborne transmission of SARS-CoV-2 in indoor air environments. Therefore, some procedures are presented such as improving ventilation, especially in hospitals and crowded places, and observing the interpersonal distance of more than 2 m so that experts in indoor air quality consider them to improve the indoor air environments. Finally, in addition to the recommendations of the centers and official authorities such as hand washing and observing social distancing, the route of air transmission should also be considered to further protect health personnel, patients in hospitals, and the public in other Public Buildings

Simultaneous adsorption of heavy metals from aqueous matrices by nanocomposites: A first systematic review of the evidence

Background: Nanocomposites have received remarkable attention as effective adsorbents for removal of coexisting pollutants over the last decades. The presence of heavy metals (HMs) in wastewater has caused a global health concern. Therefore, the aim of this study was to review the most relevant publications reporting the use of nanostructures to simultaneous adsorption of HMs in mixed aqueous systems. Methods: In this systematic review, 9 studies were included through a systematic search in the three databases (ISI, Scopus, and PubMed) during 1990-2021. The optimal value of simultaneous adsorption parameters such as initial concentration, contact time, adsorbent dosage, and pH was discussed. Results: Findings indicate that the Langmuir and Freundlich models and the pseudo-second-order kinetic model have been widely used and the most popular models to describe the equilibrium of HMs by nanoadsorbents. This study confirmed that the simultaneous removal rate of HMs decreased with an increase in pH value. It was found that the major mechanisms of HMs adsorption onto nanostructures were electrostatic interactions and precipitation. Conclusion: Nanocomposites have remarkable adsorption performance for HMs with the highest adsorption capacity (qe(mg/g))

Association between air pollution and Multiple Sclerosis: A systematic review

Air pollution is a major public health threat. The present study is the first systematic review (SR) to determine the association of exposure to air pollution and Multiple Sclerosis (MS) Progression. A Literature search was carried out using relevant keywords within several international databases. A comprehensive literature search was carried out systematically and yielded 24 eligible studies concerning the relationship of exposure to air pollution including criteria air pollutants such as particulate matter, NOx and SOx, CO2, traffic noise, etc. and MS disease. The results of the included studies reveal that there was a significant relationship between exposure to air pollution and MS development and progression. Although the effect of air pollution in the pathogenesis of MS is notfully known, according to the results of the included studies exposure to polluted air can stimulate several mechanisms that act as risk factors for developing MS and for having disease relapses or neurological disability. The major potential mechanism is Dysimmune inflammatory responses subsequent oxidative stress (OS), which leads to neuroinflammation and breakdown of the normal balance between immunity and self-tolerance. Air pollutants induce and sustain chemical reactions that produce reactive oxygen species (ROSs) and nitrogen reactive species (RNSs) which can initiate inflammatory cascades via the redox-sensitive mitogen-activated protein kinase (MAPK) and NF-kappaB that recruit and activate neutrophils, monocytes, and dendritic cells that stimulate the adaptive immune responses such as Th1 and Th17 in fl ammatory responses. The uncontrolled inflammatory responses following these events cause cell death and the release of self-antigens capable of stimulating the production of auto-aggressive T-cells via enhancing antigen presentation and facilitate entry of these cells to the central nervous system. Thus, oxidative stress is the culprit in the systemic inflammation and immune imbalance development and progression, powerful risk factors in MS