scholarly journals Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Hiroshi Ueki ◽  
Yuri Furusawa ◽  
Kiyoko Iwatsuki-Horimoto ◽  
Masaki Imai ◽  
Hiroki Kabata ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Protective Effect ◽  
Protective Efficiency ◽  
Airborne Transmission ◽  
Simulation Experiments ◽  
Additional Equipment ◽  
Human Respiration ◽  
Surgical Masks ◽  
And Performance

ABSTRACT Guidelines from the CDC and the WHO recommend the wearing of face masks to prevent the spread of coronavirus (CoV) disease 2019 (COVID-19); however, the protective efficiency of such masks against airborne transmission of infectious severe acute respiratory syndrome CoV-2 (SARS-CoV-2) droplets/aerosols is unknown. Here, we developed an airborne transmission simulator of infectious SARS-CoV-2-containing droplets/aerosols produced by human respiration and coughs and assessed the transmissibility of the infectious droplets/aerosols and the ability of various types of face masks to block the transmission. We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of SARS-CoV-2 and that the protective efficiency was higher when masks were worn by a virus spreader. Importantly, medical masks (surgical masks and even N95 masks) were not able to completely block the transmission of virus droplets/aerosols even when completely sealed. Our data will help medical workers understand the proper use and performance of masks and determine whether they need additional equipment to protect themselves from infected patients. IMPORTANCE Airborne simulation experiments showed that cotton masks, surgical masks, and N95 masks provide some protection from the transmission of infective SARS-CoV-2 droplets/aerosols; however, medical masks (surgical masks and even N95 masks) could not completely block the transmission of virus droplets/aerosols even when sealed.

scholarly journals The new coronavirus disease: what do we know so far?

2020 ◽  
Vol 12 (5) ◽  
pp. 193-201 ◽  
Author(s):  
Sammer Tang ◽  
Mike Brady ◽  
Jo Mildenhall ◽  
Ursula Rolfe ◽  
Alexandra Bowles ◽  
...  
Keyword(s):  
Risk Factors ◽  
Severe Acute Respiratory Syndrome ◽  
Drug Treatment ◽  
Clinical Assessment ◽  
Older Age ◽  
New Disease ◽  
Airborne Transmission ◽  
Clinical Guidance ◽  
Novel Coronavirus ◽  
Respiratory Droplets

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that causes the new disease COVID-19. Symptoms range from mild to severe with a higher incidence of severe cases in patients with risk factors such as older age and comorbidities. COVID-19 is mainly spread through the inhalation of respiratory droplets from coughing or sneezing or via contact with droplet-contaminated surfaces. Paramedics should be aware that some aerosol-generating procedures may put them at a higher risk of contracting the virus via possible airborne transmission. Use of remote triage clinical assessment is likely to increase as a result of the pandemic. There is no curative drug treatment for the virus and some medications may exacerbate its effects or make patients more susceptible to it. Evidence and guidelines are evolving on SARS-CoV-2 and COVID-19. Paramedics should keep up to date with the latest clinical guidance from their employers.

Research on Data Destruction Mechanism with Security Level in HDFS

2013 ◽  
Vol 834-836 ◽  
pp. 1795-1798
Author(s):  
Jun Qin ◽  
Ya Ping Zhang ◽  
Ping Zong
Keyword(s):  
Data Security ◽  
Cloud Storage ◽  
Storage System ◽  
Security Requirements ◽  
Security Level ◽  
Primary Concern ◽  
Simulation Experiments ◽  
Performance Requirements ◽  
Destruction Mechanism ◽  
And Performance

In cloud computing applications, the data security is a primary concern of user. In this paper, for the problem that data of the HDFS cannot be destroyed completely in open source cloud storage system, which may lead to data leakage, it designs a destruction mechanism of HDFS with multiple security level. This mechanism make data effectively destroyed by the method of data overwrite which makes a balance between security requirements and performance requirements. The Simulation experiments show that the mechanism can override a Block file in HDFS environment effectively to achieve the purpose of data destroying. At the same the overhead of different overwrite algorithm is different also which can ensure the security and efficiency is balanced.

scholarly journals Development of a standardized method to evaluate the protective efficiency of cosmetic packaging against microbial contamination

2020 ◽  
Author(s):  
Chloe Catovic ◽  
Sylvia Martin ◽  
Sephane Desaint ◽  
Christine Borges ◽  
Helene Lesouhaitier ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Microbial Contamination ◽  
Performance Characteristics ◽  
Protective Efficiency ◽  
Cosmetic Product ◽  
And Performance ◽  
The Right ◽  
Preservative Free ◽  
Different Origin

Abstract Doubts surrounding the potential adverse effects of antimicrobial preservatives have modified the demand of consumers, who increasingly insist on the production of low-level and even preservative-free cosmetics. Protection of the product against microbial contamination is therefore focused on the packaging. This has prompted the emergence of a highly diverse array of so-called “protective”, “overprotective”, and “barrier” packaging. However, these designations are not normalized and the choice of the right packaging adapted to each cosmetic product is still essentially empirical, hazardous, and time consuming. The Cosmetic Valleys cluster has launched a commission to define a complete and experimentally-validated method to classify the level of protection of cosmetic packaging against microbial contamination. As reported herein, this required the development a specific bacteriostatic medium that can be used for seven days and an in vitro procedure that reproduces in-use contamination and consumer practices. Based on tests performed on over 800 packages of different origin and performance characteristics, we propose a classification, divided into six grades, to differentiate the protective efficiency of cosmetic packaging. This work can be considered as a first step towards a regulatory text.

scholarly journals Modular Robotic Design and Reconfiguring Path Planning

2022 ◽  
Vol 12 (2) ◽  
pp. 723
Author(s):  
Ye Dai ◽  
Chao-Fang Xiang ◽  
Zhao-Xu Liu ◽  
Zhao-Long Li ◽  
Wen-Yin Qu ◽  
...  
Keyword(s):  
Path Planning ◽  
Industrial Application ◽  
Ant Colony Algorithm ◽  
Ant Colony ◽  
Configuration Design ◽  
Functional Modules ◽  
Simulation Experiments ◽  
Innovative Design ◽  
And Performance ◽  
Robot Configurations

The modular robot is becoming a prevalent research object in robots because of its unique configuration advantages and performance characteristics. It is possible to form robot configurations with different functions by reconfiguring functional modules. This paper focuses on studying the modular robot’s configuration design and self-reconfiguration process and hopes to realize the industrial application of the modular self-reconfiguration robot to a certain extent. We design robotic configurations with different DOF based on the cellular module of the hexahedron and perform the kinematic analysis of the structure. An innovative design of a modular reconfiguration platform for conformational reorganization is presented, and the collaborative path planning between different modules in the reconfiguration platform is investigated. We propose an optimized ant colony algorithm for reconfiguration path planning and verify the superiority and rationality of this algorithm compared with the traditional ant colony algorithm for platform path planning through simulation experiments.

scholarly journals Effect of face mask use on cardioventilatoryand performance parameters: a systematic review

2021 ◽  
Author(s):  
Mayara Jeronymo Uébe Mansur ◽  
Bárbara Vieira Bolckau Miranda ◽  
Paloma Priscila Porreca ◽  
Victor Paes Dias Gonçalves ◽  
Anderson Pontes Morales ◽  
...  
Keyword(s):  
Physical Activity ◽  
Systematic Review ◽  
Face Mask ◽  
Performance Parameters ◽  
Public Places ◽  
Surgical Masks ◽  
Significant Difference ◽  
Physiological Impact ◽  
And Performance ◽  
The Impact

The main way to combat and prevent the spread of COVID-19 is through the use of face masksin all situations, whether in public places or workspaces and also during physical activity or exercise. However, recommendations for the use of face masks during exercise vary globally and the physiological impact of using tissue or surgical masks duringthis activity is not well understood. Thus, the objective of this work is to carry out a systematic review to investigate the impact of using a mask during physical activity or exercise in the parameters: ventilatory, physiological, and performance. A structured search was performed following the guidelines of the Preferred Reporting Items for Systematic Review (PRISMA) in the Medline / PubMed and Web of Science, Scopus and Bireme / Lilacs / BVS databases until May 2021. Seven published studies were included in the systematic review. All studies were randomized controlled and crossover clinical trials, seven studies used a surgical mask in their analysis, three studies used a P95 mask, and two studies used a cloth mask. When analyzing the results, four studies showed no significant difference in the use of surgical masks in relation to performance, ventilatory and hemodynamic function parameters; three studies showed a significant worsening with the condition of using a mask in ventilatory, cardiorespiratoryand performance parameters. It was concluded that the findings of the evaluated studies showed divergences in ventilatory, physiological and performance parameters. It is believed that it may be related to the types of exercise protocols used in the assessment. In addition, the study methods had a low risk of bia

scholarly journals Transmission of SARS-CoV-2 in Public Transportation Vehicles: A Case Study in Hunan Province, China

2020 ◽  
Vol 7 (10) ◽  
Author(s):  
Kaiwei Luo ◽  
Zhao Lei ◽  
Zheng Hai ◽  
Shanliang Xiao ◽  
Jia Rui ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Public Transportation ◽  
Close Contact ◽  
Control Strategies ◽  
Index Patient ◽  
Hunan Province ◽  
Closed Space ◽  
Airborne Transmission ◽  
Retrospective Investigation

Abstract Here we report a case study of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak event during bus trips of an index patient in Hunan Province, China. This retrospective investigation suggests potential airborne transmission of SARS-CoV-2 and the possibility of superspreading events in certain close contact and closed space settings, which should be taken into account when control strategies are planned.

scholarly journals Evidence of Airborne Transmission of the Severe Acute Respiratory Syndrome Virus

2004 ◽  
Vol 350 (17) ◽  
pp. 1731-1739 ◽  
Author(s):  
Ignatius T.S. Yu ◽  
Yuguo Li ◽  
Tze Wai Wong ◽  
Wilson Tam ◽  
Andy T. Chan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Respiratory Syndrome Virus ◽  
Airborne Transmission

scholarly journals Protective effect of resveratrol against corticosterone-induced neurotoxicity in PC12 cells

2019 ◽  
Vol 10 (1) ◽  
pp. 235-240 ◽  
Author(s):  
Ye Zhang ◽  
Yun He ◽  
Ning Deng ◽  
Yan Chen ◽  
Jiecong Huang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Protective Effect ◽  
Cell Viability ◽  
Pc12 Cells ◽  
Caspase 3 ◽  
Annexin V ◽  
Cell Counting ◽  
Depressant Effect ◽  
Protective Efficiency ◽  
Related Proteins

Abstract Objective Resveratrol(RES) is a natural polyphenol which possesses an anti-depressant effect. However, the mechanisms of its anti-depressant effect remain unclear. The aim of the study is to investigate the potential mechanisms in the neuro-protective efficiency in the corticosterone-induced pheochromacytoma 12 (PC12) cells. Methods PC12 cells were treated with 200 μM of corticosterone in the absence or presence of different concentrations of RES for 24 h. Then, cell viability was measured by Cell Counting Kit-8 assay. Apoptosis of PC12 cells was measured by Annexin V-FITC and Propidium iodide (PI) labelling. The expression of apoptosis-related proteins including Bax, Bcl-2, caspase-3 was determined by western blotting. Results The results showed that treatment with 200 μM of corticosterone induced cytotoxicity in PC12 cells. However, different concentrations of RES (2.5μmol/L, 5μmol/L and 10 μmol/L) significantly increased the cell viability, suppressed the apoptosis of PC12 cells, down-regulated Bax and caspase-3 protein expression, and up-regulated Bcl-2 protein expression, compared to the model group (p<0.05). Conclusion Resveratrol has a protective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to the apoptosis via inhibition of apoptosis-related proteins and displays the antidepressant-like effect.

scholarly journals DOA-Based Localization Method with Multiple Screening K-Means Clustering for Multiple Sources

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yankui Zhang ◽  
Daming Wang ◽  
Weijia Cui ◽  
Jiangdong You ◽  
Hao Li ◽  
...  
Keyword(s):  
Cost Function ◽  
Complexity Analysis ◽  
Multiple Target ◽  
Clustering Method ◽  
Multiple Sources ◽  
Simulation Experiments ◽  
Complete Set ◽  
And Performance ◽  
The Cost ◽  
Fuzzy Target

The existing angle-based localization methods are mainly suitable for the single source. Actually, there often exists situation which contains multiple target sources. To solve the problem of localization of multitarget sources, this paper presents a K-means clustering method based on multiple screening, which can effectively realize the localization of multiple sources based on DOA (direction of arrival) parameters. The method firstly establishes a cost function of position coordinates by using DOA parameters from the measuring position coordinates and then solves the cost function to obtain a complete set of real position coordinates and fuzzy position coordinates. As the distribution of real target coordinates is concentrated and the fuzzy target positions are scattered, the K-means clustering method is adopted to classify the coordinate set. In order to improve the positioning accuracy, a multiscreening process is introduced to screen the input samples before each clustering, and it can be finally concluded that clustering centers are the position coordinates of the target sources. Meanwhile, the complexity analysis and performance verification of this method are proposed. Simulation experiments show that this method can efficiently realize ambiguity-free, highly precise localization of multitarget sources.

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