scholarly journals Porous surfaces: stability and recovery of coronaviruses

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucy Owen ◽  
Maitreyi Shivkumar ◽  
Richard B. M. Cross ◽  
Katie Laird
Keyword(s):  
Surface Properties ◽  
Close Contact ◽  
Indirect Contact ◽  
Indirect Transmission ◽  
Hydrophobic Materials ◽  
Porous Surfaces ◽  
Potential Risks ◽  
The Stability ◽  
Review Current

The role of indirect contact in the transmission of SARS-CoV-2 is not clear. SARS-CoV-2 persists on dry surfaces for hours to days; published studies have largely focused on hard surfaces with less research being conducted on different porous surfaces, such as textiles. Understanding the potential risks of indirect transmission of COVID-19 is useful for settings where there is close contact with textiles, including healthcare, manufacturing and retail environments. This article aims to review current research on porous surfaces in relation to their potential as fomites of coronaviruses compared to non-porous surfaces. Current methodologies for assessing the stability and recovery of coronaviruses from surfaces are also explored. Coronaviruses are often less stable on porous surfaces than non-porous surfaces, for example, SARS-CoV-2 persists for 0.5 h–5 days on paper and 3–21 days on plastic; however, stability is dependent on the type of surface. In particular, the surface properties of textiles differ widely depending on their construction, leading to variation in the stability of coronaviruses, with longer persistence on more hydrophobic materials such as polyester (1–3 days) compared to highly absorbent cotton (2 h–4 days). These findings should be considered where there is close contact with potentially contaminated textiles.

scholarly journals Historical Discoveries on Viruses in the Environment and Their Impact on Public Health

Intervirology ◽  
2020 ◽  
Vol 63 (1-6) ◽  
pp. 17-32
Author(s):  
Thomas Labadie ◽  
Christophe Batéjat ◽  
India Leclercq ◽  
Jean-Claude Manuguerra
Keyword(s):  
Public Health ◽  
Influenza Virus ◽  
Ebola Virus ◽  
Close Contact ◽  
Abiotic Factors ◽  
Virus Transmission ◽  
Human Coronavirus ◽  
Indirect Transmission ◽  
Droplet Sizes

<b><i>Background:</i></b> Transmission of many viruses occurs by direct transmission during a close contact between two hosts, or by an indirect transmission through the environment. Several and often interconnected factors, both abiotic and biotic, determine the persistence of these viruses released in the environment, which can last from a few seconds to several years. Moreover, viruses in the environment are able to travel short to very long distances, especially in the air or in water. <b><i>Summary:</i></b> Although well described now, the role of these environments as intermediaries or as reservoirs in virus transmission has been extensively studied and debated in the last century. The majority of these discoveries, such as the pioneer work on bacteria transmission, the progressive discoveries of viruses, as well as the persistence of the influenza virus in the air varying along with droplet sizes, or the role of water in the transmission of poliovirus, have contributed to the improvement of public health. Recent outbreaks of human coronavirus, influenza virus, and Ebola virus have also demonstrated the contemporaneity of these research studies and the need to study virus persistence in the environment. <b><i>Key Messages:</i></b> In this review, we discuss historical discoveries that contributed to describe biotic and abiotic factors determining viral persistence in the environment.

scholarly journals Prolonged viability of SARS-CoV-2 in fomites

2020 ◽  
Author(s):  
Boris Pastorino ◽  
Franck Touret ◽  
Magali Gilles ◽  
Xavier de Lamballerie ◽  
Remi N Charrel
Keyword(s):  
Culture Medium ◽  
Limit Of Detection ◽  
Surface Cleaning ◽  
Type I ◽  
Surface Type ◽  
Indirect Transmission ◽  
Viral Particles ◽  
The Stability ◽  
Mucosal Secretions

SARS-CoV-2 has spread worldwide, demonstrating a great potential for direct and indirect transmission between humans. Whether coronaviruses can keep their infectivity in fomites through remaining viable on dry surfaces for periods exceeding hours, as shown for SARS-CoV and MERS-CoV, remains debated (1). Whether this is also true for SARS-CoV-2 remains uncertain; specifically there is no data about the role of proteins on virus viability in the environment. We evaluated the stability and infectivity of SARS-CoV-2 deposited on polystyrene plastic, aluminum and glass for 96 hours at 45-55% relative humidity and 19-21°C temperature range using a 106 TCID50/mL inoculum; these experiments were conducted with and without bovine serum albumine (BSA, 10g/L) for mimicking the protein content (interfering substance) within body fluids of the respiratory system such as cough droplets, sputum, and airways mucosal secretions (2). Briefly, 50μL of virus was deposited on the various surfaces and recovered sequentially by adding 150µl of cell culture medium; infectiousness was immediately quantified by end-point titration on Vero E6 cells. Each experiment was replicated three times. The limit of detection was about 100.5 TCID50/mL. Regardless the type of surface, virus viability decreased of approximately one log10 within 2 hours; afterwards, three drastically different profiles were observed depending of surface type: (i) steady viability with a &lt;1 log10 drop over 92 hours on polystyrene plastic, (ii) a 3.5 log10 decrease along 44 hours on glass, and (iii) a sharp 6 log10 drop in less than 4 hours on aluminum (3, 4). The probable adsorption of viral particles onto polystyrene surface was associated with prolonged viability, whereas the drastic drop on aluminum suggests an intrinsic virucidal activity of this metal (3). Interestingly, SARS-CoV-2 viability was remarkably preserved in the presence of BSA regardless the type of surface. The 10g/L BSA condition used in our study is closely mimicking respiratory fluids (mucus, airways secretions, sputum) possessing protein concentrations higher than 10g/L (2). This resembles what happens when a COVID-19 patient is coughing or depositing infected airways secretions on surfaces. In conclusions we showed that even moderate protein concentrations in droplets increased drastically the viability of SARS-CoV-2 as for other viruses (5). Accordingly, it is plausible that contaminated fomites containing viable SARS-CoV-2 play a significant role in the person-to-person dissemination. This supports surface cleaning as a necessary action to be enforced and repeated since it may play a key role in halting SARS-CoV-2 transmission and mitigating the COVID-19 pandemic.

The Role of Shared Decision-Making in Audiologic Rehabilitation

2014 ◽  
Vol 21 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Helen Pryce ◽  
Amanda Hall
Keyword(s):  
Decision Making ◽  
Shared Decision Making ◽  
Behavior Changes ◽  
Shared Decision ◽  
Patient Centered ◽  
Treatment Information ◽  
Centered Care ◽  
Potential Risks ◽  
Audiologic Rehabilitation

Shared decision-making (SDM), a component of patient-centered care, is the process in which the clinician and patient both participate in decision-making about treatment; information is shared between the parties and both agree with the decision. Shared decision-making is appropriate for health care conditions in which there is more than one evidence-based treatment or management option that have different benefits and risks. The patient's involvement ensures that the decisions regarding treatment are sensitive to the patient's values and preferences. Audiologic rehabilitation requires substantial behavior changes on the part of patients and includes benefits to their communication as well as compromises and potential risks. This article identifies the importance of shared decision-making in audiologic rehabilitation and the changes required to implement it effectively.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

SARS-COV2 virus and Coronavirus disease (COVID-19)

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 977-982
Author(s):  
Mohamed J. Saadh ◽  
Bashar Haj Rashid M ◽  
Roa’a Matar ◽  
Sajeda Riyad Aldibs ◽  
Hala Sbaih ◽  
...  
Keyword(s):  
Close Contact ◽  
Antiviral Agents ◽  
Health Concern ◽  
The Novel ◽  
Global Public Health ◽  
Fatal Disease ◽  
Mild Disease ◽  
Life Threatening ◽  
Novel Coronavirus

SARS-COV2 virus causes Coronavirus disease (COVID-19) and represents the causative agent of a potentially fatal disease that is of great global public health concern. The novel coronavirus (2019) was discovered in 2019 in Wuhan, the market of the wet animal, China with viral pneumonia cases and is life-threatening. Today, WHO announces COVID-19 outbreak as a pandemic. COVID-19 is likely to be zoonotic. It is transmitted from bats as intermediary animals to human. Also, the virus is transmitted from human to human who is in close contact with others. The computerized tomographic chest scan is usually abnormal even in those with no symptoms or mild disease. Treatment is nearly supportive; the role of antiviral agents is yet to be established. The SARS-COV2 virus spreads faster than its two ancestors, the SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), but has lower fatality. In this article, we aimed to summarize the transmission, symptoms, pathogenesis, diagnosis, treatment, and vaccine to control the spread of this fatal disease.

LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

2017 ◽  
Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Models ◽  
Stable State ◽  
Landslide Risk ◽  
Kuibyshev Reservoir ◽  
Stepped Surface ◽  
The Stability ◽  
Landslide Slope ◽  
The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

Short-Term Ultramicronized Palmitoylethanolamide Therapy in Patients with Myasthenia Gravis: a Pilot Study to Possible Future Implications of Treatment

2019 ◽  
Vol 18 (3) ◽  
pp. 232-238 ◽  
Author(s):  
Emanuela Onesti ◽  
Vittorio Frasca ◽  
Marco Ceccanti ◽  
Giorgio Tartaglia ◽  
Maria Cristina Gori ◽  
...  
Keyword(s):  
Pilot Study ◽  
Myasthenia Gravis ◽  
Repetitive Nerve Stimulation ◽  
Beneficial Effects ◽  
Antibody Titers ◽  
The Stability ◽  
Ultramicronized Palmitoylethanolamide ◽  
Open Pilot

Background: The cannabinoid system may be involved in the humoral mechanisms at the neuromuscular junction. Ultramicronized-palmitoylethanolamide (μm-PEA) has recently been shown to reduce the desensitization of Acetylcholine (ACh)-evoked currents in denervated patients modifying the stability of ACh receptor (AChR) function. <p> Objective: To analyze the possible beneficial effects of μm-PEA in patients with myasthenia gravis (MG) on muscular fatigue and neurophysiological changes. <p> Method: The duration of this open pilot study, which included an intra-individual control, was three weeks. Each patient was assigned to a 1-week treatment period with μm-PEA 600 mg twice a day. A neurophysiological examination based on repetitive nerve stimulation (RNS) of the masseteric and the axillary nerves was performed, and the quantitative MG (QMG) score was calculated in 22 MG patients every week in a three-week follow-up period. AChR antibody titer was investigated to analyze a possible immunomodulatory effect of PEA in MG patients. <p> Results: PEA had a significant effect on the QMG score (p=0.03418) and on RNS of the masseteric nerve (p=0.01763), thus indicating that PEA reduces the level of disability and decremental muscle response. Antibody titers did not change significantly after treatment. <p> Conclusion: According to our observations, μm-PEA as an add-on therapy could improve muscular response to fatigue in MG. The possible modulation of AChR currents as a means of eliciting a direct effect from PEA on the conformation of ACh receptors should be investigated. The co-role of cytokines also warrants an analysis. Given the rapidity and reversibility of the response, we suppose that PEA acts directly on AChR, though further studies are needed to confirm this hypothesis.

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