scholarly journals SARS-CoV-2 Survival on Surfaces and the Effect of UV-C Light

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 408
Author(s):  
Anna Gidari ◽  
Samuele Sabbatini ◽  
Sabrina Bastianelli ◽  
Sara Pierucci ◽  
Chiara Busti ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Severe Acute Respiratory Syndrome ◽  
Half Life ◽  
Virus Titer ◽  
Viral Inactivation ◽  
Viral Spread ◽  
Drop Drying ◽  
Important Means ◽  
Uv C ◽  
Higher Doses

The aim of this study was to establish the persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on inanimate surfaces such as plastic, stainless steel, and glass during UV-C irradiation which is a physical means commonly utilized in sanitization procedures. The viral inactivation rate, virus half-life, and percentage of titer reduction after UV-C irradiation were assessed. Infectivity was maintained on plastic and glass until 120 h and on stainless steel until 72 h. The virus half-life was 5.3, 4.4, and 4.2 h on plastic, stainless steel, and glass, respectively. In all cases, titer decay was >99% after drop drying. UV-C irradiation efficiently reduced virus titer (99.99%), with doses ranging from 10.25 to 23.71 mJ/cm2. Plastic and stainless steel needed higher doses to achieve target reduction. The total inactivation of SARS-CoV-2 on glass was obtained with the lower dose applied. SARS-CoV-2 survival can be long lasting on inanimate surfaces. It is worth recommending efficient disinfection protocols as a measure of prevention of viral spread. UV-C can provide rapid, efficient and sustainable sanitization procedures of different materials and surfaces. The dosages and mode of irradiation are important parameters to consider in their implementation as an important means to fight the SARS-CoV-2 pandemic.

scholarly journals Distinct uptake, amplification, and release of SARS-CoV-2 by M1 and M2 alveolar macrophages

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiadi Lv ◽  
Zhenfeng Wang ◽  
Yajin Qu ◽  
Hua Zhu ◽  
Qiangqiang Zhu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Mouse Model ◽  
Alveolar Macrophages ◽  
Transgenic Mouse Model ◽  
Lysosomal Ph ◽  
Viral Spread ◽  
Lysosomal System ◽  
Endosomal Ph ◽  
Alternatively Activated ◽  
Classically Activated

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the alveoli, where abundant alveolar macrophages (AMs) reside. How AMs respond to SARS-CoV-2 invasion remains elusive. Here, we show that classically activated M1 AMs facilitate viral spread; however, alternatively activated M2 AMs limit the spread. M1 AMs utilize cellular softness to efficiently take up SARS-CoV-2. Subsequently, the invaded viruses take over the endo-lysosomal system to escape. M1 AMs have a lower endosomal pH, favoring membrane fusion and allowing the entry of viral RNA from the endosomes into the cytoplasm, where the virus achieves replication and is packaged to be released. In contrast, M2 AMs have a higher endosomal pH but a lower lysosomal pH, thus delivering the virus to lysosomes for degradation. In hACE2 transgenic mouse model, M1 AMs are found to facilitate SARS-CoV-2 infection of the lungs. These findings provide insights into the complex roles of AMs during SARS-CoV-2 infection, along with potential therapeutic targets.

Updated picture of SARS-CoV-2 variants and mutations

Diagnosis ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Giuseppe Lippi ◽  
Camilla Mattiuzzi ◽  
Brandon M. Henry
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Preventive Measures ◽  
Definitive Treatment ◽  
Social Distancing ◽  
Viral Spread ◽  
Limited Efficacy ◽  
Highly Virulent ◽  
New Mutations

Abstract The worldwide burden of coronavirus disease 2019 (COVID-19) is still unremittingly prosecuting, with nearly 300 million infections and over 5.3 million deaths recorded so far since the origin of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic at the end of the year 2019. The fight against this new highly virulent beta coronavirus appears one of the most strenuous and long challenges that humanity has ever faced, since a definitive treatment has not been identified so far. The adoption of potentially useful physical preventive measures such as lockdowns, social distancing and face masking seems only partially effective for mitigating viral spread, though efficacy and continuation of such measures on the long term is questionable, due to many social and economic reasons. Many COVID-19 vaccines have been developed and are now widely used, though their effectiveness is challenged by several aspects such as low uptake and limited efficacy in some specific populations, as well as by continuous emergence of new mutations in the SARS-CoV-2 genome, accompanying the origin and spread of new variants, which in turn may contribute to further decrease the effectiveness of current vaccines and treatments. This article is hence aimed to provide an updated picture of SARS-CoV-2 variants and mutations that have emerged from November 2019 to present time (i.e., early December 2021).

scholarly journals UJI FOTOSTABILITAS PIGMEN BIXIN PADA BENTONIT DAN BENTONIT TERPILAR-TiO2

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Nelly - Wahyuni
Keyword(s):  
Half Life ◽  
The Other ◽  
Uv C

One of the characteristics of the bixin pigment is its low photostability, which causes its limitations. There are many methods to improve the photostability of bixin. This study aims to study the rate of degradation of bixin in the form of an extract that will be impregnated in bentonite and TiO2 pillared bentonite. The photostability test was carried out by continuously illuminating the sample with ultraviolet (UV C) light for nine h. Bixin concentration was observed using a UV-spectrophotometer. The results showed that the impregnation of bixin extract on bentonite could increase the photostability of bixin from 14.4 h to 138.6 h. On the other, impregnation of bixin on TiO2 pillared bentonite increases the rate of bixin degradation. The half-life of bixin offered to this material is only 3.7 h. TiO2 pillared bentonite enrolls as a photocatalyst, which is enhanced photodegradation of bixin pigment. Keywords: bixin, bentonite, photostability, pigment, TiO2-pillared bentonite 

scholarly journals Mapping of UV-C dose and SARS-CoV-2 viral inactivation across N95 respirators during decontamination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alisha Geldert ◽  
Alison Su ◽  
Allison W. Roberts ◽  
Guillaume Golovkine ◽  
Samantha M. Grist ◽  
...  
Keyword(s):  
Optical Simulation ◽  
Pathogen Inactivation ◽  
Viral Inactivation ◽  
Flexible Form ◽  
Measurement Tools ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Uv C ◽  
Dose Difference

AbstractDuring public health crises like the COVID-19 pandemic, ultraviolet-C (UV-C) decontamination of N95 respirators for emergency reuse has been implemented to mitigate shortages. Pathogen photoinactivation efficacy depends critically on UV-C dose, which is distance- and angle-dependent and thus varies substantially across N95 surfaces within a decontamination system. Due to nonuniform and system-dependent UV-C dose distributions, characterizing UV-C dose and resulting pathogen inactivation with sufficient spatial resolution on-N95 is key to designing and validating UV-C decontamination protocols. However, robust quantification of UV-C dose across N95 facepieces presents challenges, as few UV-C measurement tools have sufficient (1) small, flexible form factor, and (2) angular response. To address this gap, we combine optical modeling and quantitative photochromic indicator (PCI) dosimetry with viral inactivation assays to generate high-resolution maps of “on-N95” UV-C dose and concomitant SARS-CoV-2 viral inactivation across N95 facepieces within a commercial decontamination chamber. Using modeling to rapidly identify on-N95 locations of interest, in-situ measurements report a 17.4 ± 5.0-fold dose difference across N95 facepieces in the chamber, yielding 2.9 ± 0.2-log variation in SARS-CoV-2 inactivation. UV-C dose at several on-N95 locations was lower than the lowest-dose locations on the chamber floor, highlighting the importance of on-N95 dose validation. Overall, we integrate optical simulation with in-situ PCI dosimetry to relate UV-C dose and viral inactivation at specific on-N95 locations, establishing a versatile approach to characterize UV-C photoinactivation of pathogens contaminating complex substrates such as N95s.

scholarly journals First-in-Woman Safety, Tolerability, and Pharmacokinetics of Orally Administered GS-441524: A Broad-Spectrum Antiviral Treatment for COVID-19

2021 ◽  
Author(s):  
Victoria Yan
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Broad Spectrum ◽  
Half Life ◽  
Maximum Concentration ◽  
Viral Infections ◽  
Clinical Laboratory ◽  
Antiviral Treatment ◽  
Oral Solution ◽  
Healthy Human

GS-441524 is a nucleoside analogue with broad-spectrum antiviral activity against RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and feline coronavirus (FCoV). GS-441524 is the main circulating metabolite following intravenous administration of remdesivir (Veklury®), with a plasma half-life of approximately 24 hours. The safety, tolerability, and pharmacokinetics of GS-441524 was evaluated in a healthy human volunteer (N=1) when administered directly as an oral solution (750 mg) once daily for 7 days (Part 1) and 3 times daily for 3 days (Part 2). In Part 1 of the study, the effect of food on the absorption of GS-441524 was also evaluated. GS-441524 appeared rapidly in plasma, with an average time of maximum concentration of 0.5 hours during once-per-day dosing and exhibited an initial half-life phase of approximately 3.3 hours in the fasted state. Negligible accumulation was observed during part 1 of the multiday study. In Part 2 of the study, GS-441524 was administered 3 times daily, every 3 hours. A 2-4-fold accumulation of GS-441524 was observed approximately 3 hours after the third dose was administered, with a time of maximum concentration of 9 hours and a maximum concentration of 12.01 µM, exceeding the concentration reported to eradicate SARS-CoV-2 in vitro. For the duration of the study, GS-441524 was well-tolerated. There were no treatment-related adverse events and no clinically significant findings in clinical laboratory, vital signs, or electrocardiography. Taken together, these results demonstrate the safety and viability of orally administered GS-441524 for the treatment of COVID-19 and emerging viral infections.

Challenges post-COVID-19: planning strategies to resume elective dentistry and allied surgical specialities

2020 ◽  
Vol 26 (6) ◽  
pp. 1-4
Author(s):  
Melissa Loh ◽  
Karthikeyan Iyengar ◽  
William YC Loh
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Surgical Management ◽  
Personal Protective Equipment ◽  
Dental Treatment ◽  
Protective Equipment ◽  
Limited Availability ◽  
Viral Spread ◽  
Elective Treatment ◽  
Planning Strategies ◽  
The Uk

The effect of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on the NHS in the UK has been profound and unprecedented. Many surgical specialities, including dentistry, throughout the country have not been exempt from this effect. As there are many aerosol-generating procedures and aerosol-generating exposures in surgical specialities, there has been a substantial cancellation of elective treatment. This has been in part because of the limited availability of personal protective equipment for surgeons as this is being use elsewhere by clinicians to aid the reduction of viral spread in the community. As the UK is preparing to emerge from the ‘lockdown’ during the pandemic, restarting elective surgical and dental treatment is an expected challenge. This article looks at the possible roadmap to recovery of elective surgical management and dentistry, taking into consideration possible predicted further peaks and troughs of COVID-19 infections.

scholarly journals Predicting SARS-CoV-2 Infection Trend Using Technical Analysis Indicators

2020 ◽  
pp. 1-5
Author(s):  
Marino Paroli ◽  
Maria Isabella Sirinian
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Financial Market ◽  
Moving Average ◽  
Technical Analysis ◽  
Price Trend ◽  
Subsequent Change ◽  
Change Of Direction ◽  
Viral Spread ◽  
Combined Use ◽  
Security Price

ABSTRACT Objectives: Coronavirus disease 2019 (COVID-19) pandemic is a global health emergency caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to evaluate whether technical analysis (TA) indicators, commonly used in the financial market to spot security price trend reversals, might be proficiently used also to anticipate a possible increase of SARS-Cov-2 spread. Methods: Analysis was performed on datasets from Italy, Iran, and Brazil. TA indicators tested were: (1) the combined use of a faster (3-d) and a slower (20-d) simple moving averages (SMA), (2) the moving average converge/divergence (MACD), and (3) the divergence in the direction of the number of new daily cases trend and the corresponding MACD histogram. Results: We found that the use of both fast/slow SMAs and MACD provided a reliable signal of trend inversion of SARS-Cov-2 spread. Results were consistent for all the 3 countries considered. The trend reversals signaled by the indicators were always followed by a sustained trend persistence until a new signal of reversal appeared. Conclusions: TA indicators tested here proved to be reliable tools to identify in the short mid-term a subsequent change of direction of viral spread trend either downward, upward, or sideward.

scholarly journals Louvain Natural Radiocarbon Measurements XI

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 358-362 ◽  
Author(s):  
E. Gilot ◽  
P. C. Capron
Keyword(s):  
Stainless Steel ◽  
Sample Preparation ◽  
Calculation Method ◽  
Half Life ◽  
Counting Procedure ◽  
Standard Deviations

The following list comprises selected measurements obtained by counting methane at 3 atm pressure in a 0.6 L stainless steel counter. Sample preparation, counting procedure, and calculation method are described in previous lists. Dates are reported in terms of the Libby half-life. The quoted errors are the experimental standard deviations including uncertainty on samples and standards.

scholarly journals Riken Natural Radiocarbon Measurements IV

Radiocarbon ◽  
1968 ◽  
Vol 10 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Fumio Yamasaki ◽  
Tatsuji Hamada ◽  
Chikako Fujiyama
Keyword(s):  
Stainless Steel ◽  
Oxalic Acid ◽  
Fresh Water ◽  
Half Life ◽  
Water Shell ◽  
Calcareous Deposits ◽  
Modern Standard

The C14 dates given below are a continuation of the work presented in our previous list (RIKEN III), and have been obtained by counting CO2 at ca. 2 atm pressure in a 2.7 L stainless steel counter. Results obtained mainly during 1967 are described.Shell samples were treated with 1% HCl to remove the outer 10%. Calcareous deposits on the surface, when observed, were removed by mechanical means.Dates were calculated on the basis of the C14 half-life of 5568 yr and 95% NBS oxalic acid as modern standard. No correction was applied even for fresh water shell samples.

Influence of salts and montmorillonite upon heat inactivation of poliovirus in sterile water

1995 ◽  
Vol 31 (5-6) ◽  
pp. 177-180 ◽  
Author(s):  
F. Quignon ◽  
L. Schwartzbrod
Keyword(s):  
Regression Line ◽  
Virus Titer ◽  
Decay Rates ◽  
Heat Inactivation ◽  
Sterile Water ◽  
Excellent Correlation ◽  
Viral Inactivation ◽  
Different Temperatures ◽  
Line Following

Using semi-purified type-1 poliovirus we show that the viral inactivation rate in sterile deionised water is not influenced by the initial virus titer, remains unaffected by the saline concentration (ionic strength) of the medium nor by the valency of the introduced cations. In the presence of purified Na-montmorillonite and in similar conditions we observe the same viral decay rates. In particular the presence of clay (at least up to 205 mg.l−1) does not provide viruses with any protective effect against heat, as experiments carried out at different temperatures do not reveal any difference between viral inactivation rates due to the presence of montmorillonite. Furthermore viral decay rates obtained with or without clay both plot against temperature on the same regression line, following an Arrhenius-like equation with an excellent correlation coefficient.

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