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The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.
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Coronavirus Disease 2019 (COVID-19) is an emerging disease with a rapid increase in cases and deaths since its first discovery in December 2019, in Wuhan, China. Limited data are available on COVID-19 effects during pregnancy;however, information on diseases associated with other highly pathogenic coronaviruses (i.e. Severe Acute Respiratory Syndrome [SARS] and the Middle East respiratory syndrome [MERS]) may provide insight into the effects of COVID-19 during pregnancy. Coronaviruses cause illnesses ranging from the common cold to severe respiratory disease and death. The data indicate an average of 5 days incubation period (range: 2-14 days). The average age range of the hospitalized patients was 49-56 years, and a third to half of them have an underlying illness. Children were rarely mentioned. Within hospitalized cases, men were more frequent (54%-73%). Fever, cough, myalgia, vomiting, and diarrhea are common symptoms. This review aims at giving an in-depth understanding of COVID-19 by comparing its effects with SARS and MERS to evaluate its severity in pregnant women1. The results of varied studies show that COVID-19 affects pregnant women seriously and there is an alarming need to look into this aspect to prevent its harmful effects on the fetus.Copyright © 2020
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The interaction of the transmembrane domain of SARS-CoV-2 E-protein with glycyrrhizic acid in a model lipid bilayer (small isotropic bicelles) is demonstrated using various NMR techniques. Glycyrrhizic acid (GA) is the main active component of licorice root, and it shows antiviral activity against various enveloped viruses, including coronavirus. It is suggested that GA can influence the stage of fusion between the viral particle and the host cell by incorporating into the membrane. Using NMR spectroscopy, it was shown that the GA molecule penetrates into the lipid bilayer in a protonated state, but localizes on the bilayer surface in a deprotonated state. The transmembrane domain of SARS-CoV-2 E-protein facilitates deeper GA penetration into the hydrophobic region of bicelles at both acidic and neutral pH and promotes the self-association of GA at neutral pH. Phenylalanine residues of the E-protein interact with GA molecules inside the lipid bilayer at neutral pH. Furthermore, GA influences the mobility of the transmembrane domain of SARS-CoV-2 E-protein in the bilayer. These data provide deeper insight into the molecular mechanism of antiviral activity of glycyrrhizic acid.
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Extracorporeal membrane oxygenator (ECMO) is a valuable technology to support people with acute respiratory distress syndrome (ARDS) and is recommended for COVID-19 patients. This study aims to fabricate polymer-based composite membranes coated with ethylcellulose nanoparticles from waste paper and identify the performance of the composite as ECMO candidates. Composite membranes were made from four types of polymers, namely, nylon, PTFE (polytetrafluoroethylene), Pebax® MH-1657, and SBS (poly-(styrene-b-butadiene-b-styrene)). PDMS (polydimethylsiloxane) 1 wt.% and ethylcellulose nanoparticles (3% and 10 wt.%) were used as membrane coatings to increase their hydrophobic properties. The success of cellulose isolation and ethylcellulose synthesis from waste paper was confirmed by the FTIR and XRD analysis. The size of the synthesized ethylcellulose nanoparticles was 32.68 nm. The coating effect on composite membranes was studied by measuring the contact angle, membrane porosity, protein quantification tests, and single gas permeation of O2 and CO2. Based on the protein quantification test, the protein could not pass through the Pebax/PDMS and SBS/PDMS composites coated with 10 wt.% ethylcellulose;this indicated less risk of plasma leakage. The gas permeation test on nylon/PDMS, PTFE/PDMS, and SBS/PDMS composites coated with 10% ethylcellulose resulted high CO2/O2 selectivity, respectively, 2.17, 3.48, and 3.22 as good indication for extracorporeal oxygenation membrane.
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The global pandemic coronavirus pneumonia (COVID-19), the disease infected by the new coronavirus (SARS-CoV-2), is extremely contagious. It is mainly spread among people through respiratory droplets, aerosols, direct or indirect contact, fecal-oral transmission, and cold chain transportation. Especially, patients who are in the incubation period or have no obvious symptoms already have the ability to infect others. SARS-C0V-2 is a positive-sense single-stranded RNA virus, with a single linear RNA segment. Each SARS-CoV-2 virion is 60-140 mm in diameter. Like other coronaviruses, SARS-CoV-2 has four structural proteins, known as the spike (S), envelope(E), membrane (M), and nucleocapsid (N) proteins. To date, a variety of detection methods for the SARS-CoV-2 have been developed based on the virus structural basis and 'etiological characteristics, which would provide an effective guarantee for the diagnosis of COVID-19 patients and the control of the epidemic. In order to help for the early diagnosis and prevention of COVID-19, the pathogenic characteristics and recent progresses of detection base on nucleic acid, immunology and biosensors of the SARS-CoV-2 are reviewed in this paper.
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Separation membranes play a crucial role in the functioning of artificial organs, such as hemodialysis machines, membrane oxygenators, and artificial liver models. The current COVID-19 pandemic has highlighted the importance of these technologies in the medical community. However, membrane technology in artificial organs faces significant challenges, such as the clearance of low-middle-molecule and protein-bound toxins and limited blood compatibility. In this review, we will discuss the separation mechanisms, separation performance, and biocompatibility of different types of separation membranes used in artificial organs. We will also highlight the opportunities and challenges for next-generation membrane technology in this field, including the need for improved clearance of toxins and increased blood compatibility, as well as the potential for microfluidic devices.
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OBJECTIVE: COVID-19 has been reported to increase the risk of prematurity, however, due to the frequent absence of unaffected controls as well as inadequate accounting for confounders in many studies, the question requires further investigation. We sought to determine the impact of COVID-19 disease on preterm birth (PTB) overall, as well as related subcategories such as early prematurity, spontaneous, medically indicated preterm birth, and preterm labor (PTL). We assessed the impact of confounders such as COVID-19 risk factors, a-priori risk factors for PTB, symptomatology, and disease severity on rates of prematurity. METHODS: This was a retrospective cohort study of pregnant women from March 2020 till October 1st, 2020. The study included patients from 14 obstetric centers in Michigan, USA. Cases were defined as women diagnosed with COVID-19 at any point during their pregnancy. Cases were matched with uninfected women who delivered in the same unit, within 30 d of the delivery of the index case. Outcomes of interest were frequencies of prematurity overall and subcategories of preterm birth (early, spontaneous/medically indicated, preterm labor, and premature preterm rupture of membranes) in cases compared to controls. The impact of modifiers of these outcomes was documented with extensive control for potential confounders. A p value <.05 was used to infer significance. RESULTS: The rate of prematurity was 8.9% in controls, 9.4% in asymptomatic cases, 26.5% in symptomatic COVID-19 cases, and 58.8% among cases admitted to the ICU. Gestational age at delivery was noted to decrease with disease severity. Cases were at an increased risk of prematurity overall [adjusted relative risk (aRR) = 1.62 (1.2-2.18)] and of early prematurity (<34 weeks) [aRR = 1.8 (1.02-3.16)] when compared to controls. Medically indicated prematurity related to preeclampsia [aRR = 2.46 (1.47-4.12)] or other indications [aRR = 2.32 (1.12-4.79)], were the primary drivers of overall prematurity risk. Symptomatic cases were at an increased risk of preterm labor [aRR = 1.74 (1.04-2.8)] and spontaneous preterm birth due to premature preterm rupture of membranes [aRR = 2.2(1.05-4.55)] when compared to controls and asymptomatic cases combined. The gestational age at delivery followed a dose-response relation with disease severity, as more severe cases tended to deliver earlier (Wilcoxon p < .05). CONCLUSIONS: COVID-19 is an independent risk factor for preterm birth. The increased preterm birth rate in COVID-19 was primarily driven by medically indicated delivery, with preeclampsia as the principal risk factor. Symptomatic status and disease severity were significant drivers of preterm birth.
Subject(s)
COVID-19 , Obstetric Labor, Premature , Pre-Eclampsia , Premature Birth , Infant, Newborn , Female , Pregnancy , Humans , Premature Birth/epidemiology , Premature Birth/etiology , Retrospective Studies , Michigan/epidemiology , COVID-19/complications , COVID-19/epidemiology , SARS-CoV-2 , Pregnancy OutcomeABSTRACT
Background: Reports showed presence of SARS-CoV-2 genetic material in wastewater. Wastewater concentration methods are optimized for detection of non-enveloped viruses so need to be adopted for enveloped viruses and their genetic material. Methods: Conventional (cRT-PCR) and quantitative real time RT-PCR (qRT-PCR) were used as readouts to compare 4 water concentration methods namely, (A) filtration on negatively charged membrane followed by extracting RNA from it, (B) adsorbtion-elution method, (C) flocculation with skimmed milk and (D) polyethylene glycol precipitation, to detect SARS-CoV-2 RNA and 229E human coronavirus (229E-HCoV) as a model for spike-containing enveloped virus from fresh and wastewater. Results: On using cRT-PCR: recovery rate of SARS-CoV-2 RNA was better using method A then B for fresh water and method B then D for wastewater. 229E-HCoV recovery from fresh water was better using method C then A and methods B then D for wastewater. On using qRT-PCR, both methods A and B were better for SARS-CoV-2 RNA recovery from both fresh and wastewater. For the 229E-HCoV methods A was the most efficient for fresh water and method B for wastewater. Conclusion: Method B is recommended for SARS-CoV-2 RNA or whole 229E-HCoV recovery from wastewater.
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The poly(vinyl alcohol) (PVA) and starch-based polymeric films with a ratio of 2:8 were prepared using solution casting followed by a solvent evaporation method. Four types of membranes with varied concentrations of grapefruit seed extract (GSE) i.e., 2.5-10 wt% was incorporated in the films. The prepared membranes were assessed for transparency test, mechanical properties, surface morphology, permeability test for O2, and antimicrobial properties. The PVA/starch-10% GSE loaded film showed excellent mechanical properties showing highest 1344 ± 0.7% elongation at break but poor optical transparency with 53.8% to 68.61%. The Scanning Electron Microscopic study reveals the good compatibility between the PVA, Starch, and GSE. The gas permeability test reveals that the prepared films have shown good resistance to the O2 permeability 0.0326-0.316 Barrer at 20 kg/cm2 feed pressure for the prepared membranes showing excellent performance. By adding the little amount of GSE into the PVA/starch blend membranes showed promising antimicrobial efficacy against MNV-1. For 4 h. incubation, PVA/starch blend membranes containing 2.5%, 5%, and 10% GSE caused MNV-1 reductions of 0.92, 1.89, and 2.27 log PFU/ml, respectively. Similarly, after 24 h, the 5% and 10% GSE membranes reduced MNV-1 titers by 1.90 and 3.26 log PFU/ml, respectively. Antimicrobial tests have shown excellent performance to resist microorganisms. The water uptake capacity of the membrane is found 72% for the PVA/starch pristine membrane and is reduced to 32% for the 10% GSE embedded membrane. Since the current pandemic situation due to COVID-19 occurred by SARSCOV2, the prepared GSE incorporated polymeric blend films are the rays of hope in the packaging of food stuff.
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Background: Environmental concerns are increasing in and around us due to improper discharge of personal protective gear or equipment (PPEs) during the current pandemic with SARS-CoV-2. The residents of Salalah, under the Dhofar governorate of Oman, were hastening to take every possible measure to safeguard their health against the COVID-19 pandemic. In this scenario, improper discard of facemasks in the environment entails a significant problem for public health and aquatic environments. Objective: This study aims to assess how the SARS-CoV-2 virus disrupted the household waste management chain in the Sultanate of Oman. In addition, descriptive survey has also identified people's perception about the existing household waste management system. Methods: Total 200 respondents were personally selected under the purposive sampling category. Data were analyzed using SPSS version 26. The mean, standard deviation, and distribution shape were calculated based on the retrieved data. The variables and frequencies were tabulated for categorical variables. Results show negative impacts on the environment, wildlife, and public health. It was also observed that there was a significant difference when grouped according to residence location since the obtainedalso observed a significant difference when grouped according to residence location since the p-value of 0.007 was less than 0.05 alpha level. This means that the responses differ significantly. It shows from the test conducted that participants from the village experienced and observed a negative impact on the discarded face masks compared to those in the city. Conclusion and recommendation: This study illustrates the real impact of the COVID-19 face masks on the environment, wildlife, and public health. In addition, the new management of the user's face masks for eliminating or reducing the risks to human health and the environment has been suggested.
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Airborne particulate matter (PM) pollution has caused a public health threat, including nanoscale particles, especially with emerging infectious diseases and indoor and vehicular environmental pollution. However, most existing indoor air filtration units are expensive, energy-intensive, and bulky, and there is an unavoidable trade-off between low-efficiency PM0.3/pathogen interception, PM removal, and air resistance. Herein, we designed and synthesized a two-dimensional continuous cellulose-sheath/net with a unique dual-network corrugated architecture to manufacture high-efficiency air filters and even N95 particulate face mask. Combined with its sheath/net structured pores (size 100-200 nm) consisting of a cellulose framework (1-100 nm diameter), the cellulose sheath/net filter offers high-efficiency air filtration (>99.5338%, Extrafine particles; >99.9999%, PM2.5), low-pressure drops, and a robustness quality factor of >0.14 Pa-1, utilizing their ultralight weight of 30 mg/m2 and physical adhesion and sieving behaviors. Simultaneously, masks prepared with cellulose-sheath/net filters are more likely to capture and block smaller particles than the N95 standard. The synthesis of such materials with their nanoscale features and designed macrostructures may suggest new design criteria for a novel generation of high-efficiency air filter media for different applications such as personal protection products and industrial dust removal.
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At a global level, climate changes have been responsible for alterations in rainfall regimes. Numerous impacts resulting from such complex dynamics negatively affect peoples and nations. Desertification, sandification, floods, and droughts are some evident examples of the transformation the world is undergoing. In Brazil, the past few years have been characterized by long periods of drought in some regions. As a result, there have been considerable drops in the levels of reservoirs that supply important urban and economic axes in the country. Implications on the national economy and entire production chains aggravate the current scenario, along with two long years of the Sars-Cov-2 pandemic period. From this perspective, the present work aims to address the pressing need to adopt technologies and techniques for collecting and treating rainwater. To this end, specialized databases were accessed in order to evaluate ongoing research on the use of polymeric materials to achieve that goal. © 2022 Harrison Lourenço Corrêa;Licensee Lifescience Global.
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An effect of receptor-binding domain (RBD) of SARS-CoV-2 S-protein on structural parameters of model lipid membranes presented by dimyristoylphosphatidylcholine (DMPC) systems with cholesterol and melatonin impurities is studied by small angle neutron scattering (SANS). It is shown that an increase in melatonin concentration in the lipid membrane leads to a decrease in the thickness of the lipid bilayer, while an increase in the concentration of cholesterol leads to an increase in its thickness. It is suggested that increasing the concentration of melatonin in a membrane prevents the interaction of coronaviral S-protein with a lipid membrane of a cell. In the presence of cholesterol in the system, the interaction of a lipid membrane with an active part of S-protein occurs depending on a phase state of the lipid: in the case of a gel phase, there is no changes in structural parameters, but at higher temperatures in the case of a liquid crystal phase, an addition of RBD SARS-CoV-2 to the system causes a reduce in the membrane thickness. © 2023 Wiley-VCH GmbH.
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The global outbreak of COVID-19 results in the surge of disposable sanitary supplies, especially personal protective face masks. However, the charge dissipation of the electret meltblown nonwovens, which predominate in the commercial face mask filters, confines the durability and safety of commercial face masks. Furthermore, most of the face masks are made from nondegradable materials (such as PP) or part of their degradation products are toxic and contaminative to the environment. Herein, a type of face mask with biodegradable and highly effective PLA bi-layer complex fibrous membrane as filter core is reported. The prepared PLA complex membrane possesses a high-filtration efficiency of 99.1% for PM0.3 while providing a favorable pressure drop of 93.2 Pa. With the PLA complex membrane as the filter core, our face mask exhibits comparable or even higher wearability to commercial face masks, which further manifests our designed PLA complex membrane a promising filter media for face masks. © 2023, The Author(s), under exclusive licence to the Korean Fiber Society.
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Air pollution is one of the major global problems causing around 7 million dead per year. In fact, a connection between infectious disease transmission, including COVID-19, and air pollution has been proved: COVID-19 consequences on human health are found to be more severe in areas characterized by high levels of particulate matter (PM). Therefore, after the COVID-19 pandemic, the production of air filtration devices with high filtration efficiency has gained more and more attention. Herein, a review of the post-COVID-19 pandemic progress in nanofibrous polymeric membranes for air filtration is provided. First, a brief discussion on the different types of filtration mechanism and the key parameters of air filtration is proposed. The materials recently used for the production of nanofibrous filter membranes are presented, distinguishing between non-biodegradable polymeric materials and biodegradable ones. Subsequently, production technique proposed for the fabrication of nanofibrous membranes, i.e., electrospinning and solution blow spinning, are presented aiming to analyze and compare filtration efficiency, pressure drop, reusability and durability of the different polymeric system processed with different techniques. Finally, present challenges and future perspectives of nanofibrous polymeric membranes for air filtration are discussed with a particular emphasis on strategies to produce greener and more performant devices. © 2023 The Authors. Macromolecular Materials and Engineering published by Wiley-VCH GmbH.
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A dimensionless number Nr for the effective design of facial masks was derived and compared with other dimensionless numbers of fluid mechanics. Nr is found to closely resemble Euler's number (Eu). Nr is equal to the logarithmic function of the ratio of inertial force (Fi) of the air to the pressure force (Fp) of the air through the porous membrane of the mask. Nr is then introduced as a novel dimensionless number (Habib number) Ha in which the air flow through a facial mask is derived with parameters for an effective barrier from the COVID-19 virus (SARS COV 2). The introduction of Ha was not only for a comparison reason with other dimensionless numbers of fluid mechanics but also the number Ha is an essential extension of an early work on "Fluid mechanics of facial masks as personal protection equipment (PPE) of COVID-19 virus"[Rev. Sci. Instrum. 92, 074101 (2021)], in which the air flow through the mask is in its optimum design conditions to shield against the COVID-19 virus. As a result, an optimum Nr of expressing the flow of the O2 and N2 gases through the porous membrane was determined (Nr = NO2 = NN2 = Ha = -4.4). This was obtained when the N95 mask with specifications of a = 20 nm, l = 30 μm, and ϵ = 30% was used, with respect to the pressure gradient of the human lungs during exhaled and inhaled conditions, PAverage = 20 mm Hg (g cm-1 S-2), and to the size of the COVID-19 virus of about 125 nm (0.125 μm). In addition, a range of values of Nr was analyzed with respect to the optimum (Ha) value of Nr. On the one hand, when the range value of Nr falls between 0 ≥ Nr ≥ Ha, the mask has less resistance than Nr < -4.4, but not necessarily its optimum design conditions. On the other hand, when Nr = 0, the flow through the mask has no resistance at all, as if the mask does not exist. © 2023 Author(s).
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Cells produce nanosized lipid membrane-enclosed vesicles which play important roles in intercellular communication. Interestingly, a certain type of extracellular vesicle, termed exosomes, share physical, chemical, and biological properties with enveloped virus particles. To date, most similarities have been discovered with lentiviral particles, however, other virus species also frequently interact with exosomes. In this review, we will take a closer look at the similarities and differences between exosomes and enveloped viral particles, with a focus on events taking place at the vesicle or virus membrane. Since these structures present an area with an opportunity for interaction with target cells, this is relevant for basic biology as well as any potential research or medical applications.
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Membrane materials might be used for face protection because they can decontaminate the inhaled air from particle pollution and viruses like the SARS-Cov0-2 which damages our respiration system. In this study, plyethersulfone membranes (PES) were synthesized with green solvent at room temperature and its filtration effectiveness was investigated against nano-bacteria (size 0.05 to 0.2 µm) by measuring their Bacterial Filtration Efficiency (BFE) and micro aerosol size (0.3 µm), and Particulate Filtration Efficiency (PFE). The average SARS-CoV-2 diameters are between 50 nm to 160 nm. A series of experiments were performed to accomplish between 0.03 to 0.21 µm PES sponge like diameters so that can be used for SARS-CoV-2 filtration. Results showed that nanofiltration/ultrafiltration could filter 99.9% of bacteria and aerosol from contaminated air the size of the Covid-19 molecule.
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Extracellular vesicles (EVs) are nano-sized membranous particles secreted by cells. EVs have been classified into subpopulations according to their presumed biogenesis pathway, but their detailed biogenesis mechanisms still need to be fully elucidated. Enveloped viruses are another type of cell-derived nano-vesicles, and their biogenesis processes are much better known than that of EVs. Recently, studies on the similarity between enveloped viruses and EVs have been increasingly reported. The biogenesis of EVs could be better understood if these similarities are adequately investigated. In this study, we utilized a single vesicle imaging technique to visualize the protein expressions of individual nano-sized vesicles and analyzed expression patterns within single vesicles. Using this technique, we identified unique tetraspanin expression patterns in single EVs and that these patterns were closely related to their subcellular origins. The expression of CD9 or CD81 in EVs implied that they originated from the plasma membrane, and the expression of CD63 in EVs implied that they originated from endosomal organelles. We further analyzed the tetraspanin expressions of two different types of virus-like particles (VLPs) and demonstrated that the HIV-Gag-induced VLPs were more similar to EVs than SARS-CoV-2-NP/M/E-induced VLPs. In addition, HIV-Gag-GFP-expressing VLPs were highly colocalized with CD9, CD63, and CD81 signals, whereas SARS-CoV-NP-GFP-expressing VLPs were not. Based on these observations, we could assume that tetraspanin-expressing EVs might be produced through a similar process by which HIV is produced. © 2023
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The identification of the mechanisms by which T-cell receptors (TCRs) interact with human antigens provides a crucial opportunity to develop new vaccines, diagnostics and immunotherapies. However, the accurate prediction and recognition of TCR–antigen pairing represents a substantial computational challenge in immunology. Existing tools only learn the binding patterns of antigens from many known TCR binding repertoires and fail to recognize antigens that have never been presented to the immune system or for which only a few TCR binding repertoires are known. However, the binding specificity for neoantigens or exogenous peptides is crucial for immune studies and immunotherapy. Therefore, we developed Pan-Peptide Meta Learning (PanPep), a general and robust framework to recognize TCR–antigen binding, by combining the concepts of meta-learning and the neural Turing machine. The neural Turing machine adds external memory to avoid forgetting previously learned tasks, which is used here to accurately predict TCR binding specificity with any peptide, particularly unseen ones. We applied PanPep to various challenging clinical tasks, including (1) qualitatively measuring the clonal expansion of T cells;(2) efficiently sorting responsive T cells in tumour neoantigen therapy;and (3) accurately identifying immune-responsive TCRs in a large cohort from a COVID-19 study. Our comprehensive tests show that PanPep outperforms existing tools. PanPep also offers interpretability, revealing the nature of peptide and TCR interactions in 3D crystal structures. We believe PanPep can be a useful tool to decipher TCR–antigen interactions and that it has broad clinical applications. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.