Protective Effects of Common Masks against PM2.5

By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.

On the roads to H1N1 pandemic era:drive safe and fearless using colour-coded masks

Notwithstanding the end of 2009 H1N1 pandemic,the threat for its revisit still persists and WHO has warned to remain vigilant.During that lime the situation was more panicky than fatal.In this article,a suggestion to minimize the panic is provided by the usage of colour-coded masks and is proposed hereby as a "population segregation" approach in case of the revisit of HlNl or similar threatening respiratory viral infections.

Effect of face masks on speech understanding: A clinical perspective during speech audiometry

The objective was to measure the effect of various face masks on speech recognition threshold and the word recognition score in the presence of varying background noise levels.20 normal-hearing adult subjects(a total of 40 ears)participated.Pure tone audiometry followed by speech recognition threshold and word recognition score at the most comfortable level in varying signal-to-noise ratios(SNR0,SNR10,and SNR15)using surgical,pleated cloth,and N95 masks.Using surgical,cloth,and N95 masks,speech recognition thresholds increased by 1.8 dB,4.4 dB,and 5.05 dB,respectively.Word recognition scores decreased by 32%without a mask,43.7%in a surgical mask,46.3%in a cloth mask,and 46.7%in N95 mask conditions,between SNR15 and SNR0.The speech recognition threshold was negatively affected with cloth and N95 masks.Surgical masks do not affect the word recognition scores at lower background noise levels.However,as the signal-to-noise ratio decreased,even the surgical,cloth,and N95 masks significantly impacted the word recognition score even in normal-hearing individuals.

Conductive Polymer Composites Fabricated by Disposable Face Masks and Multi-Walled Carbon Nanotubes: Crystalline Structure and Enhancement Effect

Influenced by recent COVID-19,wearing face masks to block the spread of the epidemic has become the simplest and most effective way.However,after the people wear masks,thousands of tons of medical waste by used dis-posable masks will be generated every day in the world,causing great pressure on the environment.Herein,con-ductive polymer composites are fabricated by simple melt blending of mask fragments(mask polypropylene,short for mPP)and multi-walled carbon nanotubes(MWNTs).MWNTs were used as modifiers for composites because of their high strength and high conductivity.The crystalline structure,mechanical,electrical and thermal enhancement effect of the composites were investigated.MWNTs with high thermal stability acted the role of promoting the crystallisation of mPP by expediting the crystalline nucleation,leading to the improvement of amount for crystalline nucleus.MWNTs fibers interpenetrate with each other in mPP matrix to form conducting network.With 2.0 wt% MWNTs loading,the tensile strength and electrical conductivity of the composites were increased by 809% and 7 orders of magnitude.MWNTs fibers interpenetrate with each other in mPP matrix to form conducting network.Thus,more conducting paths were constructed to transport carriers.The findings may open a way for high value utilization of the disposable masks.

Running with Face Masks or Respirators Can Be Detrimental to the Respiratory and Cardiovascular Systems

Since the fi rst cases of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coro-navirus 2(SARS-CoV-2)were reported at the end of 2019,this infection has spread around the globe,becoming a pandemic.The use of face masks and respirators is an important public health measure to reduce or prevent transmission of SARS-CoV-2.Here we discuss the hypothetical mechanisms by which exercise with face masks or respirators can induce detrimental effects on the cardiovascular system,potentially explaining adverse events such as cardiac arrhythmias and spontaneous pneumothorax.Although sudden death associated with the wearing of a face mask during running is a rare event,the risk is higher especially in those with existing cardiac comorbidities.In such cases,a mask designed specifi cally for runners with no or few side effects of oxygen defi ciency should be considered instead.

Comparison of the clinical performance of i-gel and Ambu laryngeal masks in anaesthetised paediatric patients:A meta-analysis

BACKGROUND Paediatric supraglottic airway devices(SGAs)are widely used in routine anaesthesia and serve as primary or back-up devices for difficult airway management.The inflatable Ambu laryngeal masks and non-inflatable i-gel are two improvements of SGAs based on classic laryngeal masks.The clinical performance and safety of these two devices in paediatric patients are still unclear and warrant further investigation.AIM To perform a systematic review and meta-analysis on the clinical performance and safety of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients.METHODS MEDLINE,Embase,Web of Science and Cochrane Central Register of Controlled Trials were searched from inception dates to April 2020.We identified published randomised controlled trials(RCTs)in which the intervention involved the use of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients(age<18 years).We assessed the oropharyngeal leak pressure(OLP)as the primary outcome.The secondary outcomes were insertion time,success rate of insertion on the first attempt,and incidence of adverse events.RESULTS After searching for all relevant trials published up to April 2020,data from seven RCTs with a total of 667 paediatric patients(323 and 344 participants in the i-gel and Ambu groups,respectively)were evaluated.The mean OLP in anaesthetised paediatric patients was lower in the Ambu group[21.82 cmH2O for Ambu vs 23.98 cmH2O for i-gel,P=0.003,95%confidence interval(CI):-3.58 to-0.75,I2=68%,Mantel-Haenszel random model].We did not find any clear evidence of differences between the devices in terms of insertion time,success rate of insertion,and incidence of adverse events except for blood staining(risk ratio 5.86,95%CI:1.76 to 19.46,P=0.004,I2=0,fixed-effect model).CONCLUSION The i-gel airway may provide a better seal and is therefore probably more suitable than the Ambu laryngeal mask airway in anaesthetised paediatric patients.However,the evidence is insufficient to allow making firm conclusions or to guide clinical practice,owing to the small number of relevant published studies.

Method Investigation for Fabricating Micro-Optical Elements by Use of Half Tone Masks

Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerably high precision, but it is hard to operate from the viewpoint of operation. The method using contacting lithography technology or laser ablation can be easily operated with the cost of reducing fabrication precision and the trouble of choosing appropriate materials. For all of these methods, the coding of half tone masks with corrections for the nonlinear characteristics of coding, imaging and photoresist is recommended.

Katherine Mansfield＇s Art of Changing Masks in ＂Je ne parle pas frangais＂

In a letter to Vita Sackville-West dated 8 August 1931, eight years after Katherine Mansfield＇s death, Virginia Woolf confides that she ＂gave up＂ reading her literary rival＇s stories ＂because of their cheap sharp sentimentality＂. Woolf＇s observation invites us to question： is Mansfield a mere sentimentalist or is her characterisation technique misunderstood？ The first section of this paper demonstrates that attributing Mansfield＇ works as ＂sentimental＂ is erroneous since Mansfield＇s strategy is to change the masks of her characters within her stories, revealed in her letters and journal entries. Following the first section of this paper, I aim to explore how Mansfield extends this strategy of changing masks in daily life to her fictional characters in ＂Je ne parle pas fran^ais＂ （1918） by equipping them with different types of masks--speech and facial expressions, gender, and animality--to respond to changes in their situations and toward the characters around them. Particularly important to this exploration are Joan Riviere＇s insights into gender in her article, ＂Womanliness as Masquerade＂, Michael Goldman＇s theory of masks in acting in his The Actor＇s Freedom： Toward a Theory of Drama and Gilles Deleuze and Felix Guattari＇s concept of ＂becoming-animal＂ in KaJka.＂ Towards a Minor Literature.

Improper Disposal of Waste Water and Masks during COVID-19, and the Associated Increased Cycle of Infection to Human Health in Developing Countries: A Case Study of Tanzania

Since COVID-19 was declared by the World Health Organization (WHO), wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution are being applied globally to reduce the transmission rate. This study was intended to investigate handling of after wash waste water and masks among Tanzanian residents on the COVID-19 pandemic after it has been, declared by the World Health Organization (WHO) that, wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution should be applied globally to reduce the transmission rate. The assessment of health care waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste using open source software for collection (ODK). Data were analyzed using SPSS computer software. It has been indicated that before disposing the used mask, the best protocol is to spray 0.5% (5000 ppm) of chlorine disinfectant on the surface. In this study, about 46% consider used mask as normal municipal waste and 3% do not care they throw away the face masks in the street. Only 18% and 5% of reported to disposal as infectious and highly hazardous waste respectively. It is well documented that due to potential infectious disease like SARS-CoV-2, wastewater should be treated either on-site or conveyed off-site and treated in well-designed method or technology to kill the micro-organisms. The analysis revealed that majority of respondents (74.7%, 73.8%, 48.1% and 65% for healthcare center, district hospitals, regional hospitals and consultant hospitals respectively);dispose the waste in the open space. Continuous awareness creation programs about the negative impact of contaminated face masks and waste water on the health of individuals and introducing laws that can prohibit improper disposal are among the solutions that could help reduce the problem.

Colorful Peking Opera Masks

THE characteristically colorful Peking Opera masks emerged around 1894.A man of the Manchu ethnic group with the last name of Gui,who ardently loved Peking Opera.One day,he saw clay figurines in a temple fair,and at that moment an inspiration came to him to use a puddle to make a face-shaped mold.After making the mold,he dried it in the sun,and drew outlines and colored it according to the facial make-up of Peking Opera actors on the stage.For his creation,Gui became famous among Peking Opera fans in Beijing and was called“Painted face Gui”thereafter.

Applying “Masks” for Tubes

Corrosion control engineer: In the wilderness of the vast desert, accompanied by blowing sand, Chang Shuqiang has spent 14 of his youthful years along with the colorful paint that mirrors his splendid and sparkling life. With the spray gun as his "weapon" and the brush as his "painting brush", he applies warm and anti-aging "masks" on field facilities with wisdom and effort.

SARS-CoV-2, surgeons and surgical masks

The exact risk association of coronavirus disease 2019(COVID-19)for surgeons is not quantified which may be affected by their risk of exposure and individual factors.The objective of this review is to quantify the risk of COVID-19 among surgeons,and explore whether facemask can minimise the risk of COVID-19 among surgeons.A systematised review was carried out by searching MEDLINE to locate items on severe acute respiratory syndrome coronavirus 2 or COVID-19 in relation to health care workers(HCWs)especially those work in surgical specialities including surgical nurses and intensivists.Additionally,systematic reviews that assessed the effectiveness of facemask against viral respiratory infections,including COVID-19,among HCWs were identified.Data from identified articles were abstracted,synthesised and summarised.Fourteen primary studies that provided data on severe acute respiratory syndrome coronavirus 2 infection or experience among surgeons and 11 systematic reviews that provided evidence of the effectiveness of facemask(and other personal protective equipment)were summarised.Although the risk of COVID-19 could not be quantified precisely among surgeons,about 14%of HCWs including surgeons had COVID-19,there could be variations depending on settings.Facemask was found to be somewhat protective against COVID-19,but the HCWs’compliance was highly variable ranging from zero to 100%.Echoing surgical societies’guidelines we continue to recommend facemask use among surgeons to prevent COVID-19.

Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks

The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.

COVID-19:Masks do not influence neurocognitive performance during a shift at the emergency department

The COVID-19 pandemic has led to the widespread mandatory use of personal protective equipment(PPE),including filtering face pieces(FFP).Emergency medical care providers now commonly use this equipment.

Non-Contact Physiological Measurement System for Wearing Masks During the Epidemic

Physiological signals indicate a person’s physical and mental state at any given time.Accordingly,many studies extract physiological signals from the human body with non-contact methods,and most of them require facial feature points.However,under COVID-19,wearing a mask has become a must in many places,so how non-contact physiological information measurements can still be performed correctly even when a mask covers the facial information has become a focus of research.In this study,RGB and thermal infrared cameras were used to execute non-contact physiological information measurement systems for heart rate,blood pressure,respiratory rate,and forehead temperature for peoplewearing masks due to the pandemic.Using the green(G)minus red(R)signal in the RGB image,the region of interest(ROI)is established in the forehead and nose bridge regions.The photoplethysmography(PPG)waveforms of the two regions are obtained after the acquired PPG signal is subjected to the optical flow method,baseline drift calibration,normalization,and bandpass filtering.The relevant parameters in Deep Neural Networks(DNN)for the regression model can correctly predict the heartbeat and blood pressure.In addition,the temperature change in the ROI of the mask after thermal image processing and filtering can be used to correctly determine the number of breaths.Meanwhile,the thermal image can be used to read the temperature average of the ROI of the forehead,and the forehead temperature can be obtained smoothly.The experimental results show that the above-mentioned physiological signals of a subject can be obtained in 6-s images with the error for both heart rate and blood pressure within 2%∼3%and the error of forehead temperature within±0.5°C.

Optical transfer function analysis of circular-pupil wavefront coding systems with separable phase masks

This paper proposes a simple method to achieve the optical transfer function of a circular pupil wavefront coding system with a separable phase mask in Cartesian coordinates. Based on the stationary phase method, the optical transfer function of the circular pupil system can be easily obtained from the optical transfer function of the rectangular pupil system by modifying the cut-off frequency and the on-axial modulation transfer function. Finally, a system with a cubic phase mask is used as an example to illustrate the way to achieve the optical transfer function of the circular pupil system from the rectangular pupil system.

Effect of an E-Educational Poster on Improving the Knowledge, Attitude, and Practice on the Proper Use of Face Masks among School Students

Introduction: Two spread methods of Covid-19, namely airborne and respiratory droplets, can be prevented by proper use of face masks. However, it has been reported an inadequate knowledge attitude and practice of proper use of face masks among school students. Therefore, the knowledge, attitude, and practice of school students should be improved. Different approaches are used to improve knowledge, attitude, and practice. However, e-posters are rare, and the effect of e-posters on improving the knowledge, attitude, and practice of school students on the proper use of face masks has not been studied. Objectives: The objective of this study was to determine the effect of an e-educational poster on knowledge, attitude, and practice of the proper use of face masks among school students. Method: This study was conducted as a pre-test and post-test design. The sample was 364 grade 11 students of the Gampaha educational division, Sri Lanka. Data were collected using self-administered questionnaires distributed pre and post to the interventional e-education poster. Data analyses were conducted by using SPSS Software. Results: Results show no significant demographic difference (p = 0.446) between the pre and post-test groups. A significant increase was observed between the pre and post-test mean scores of knowledge (p ≤ 0.05), attitude (p ≤ 0.05), and practice (p ≤ 0.05) on the proper use of face masks. In pre-group knowledge (p = 0.155), attitude (p = 0.258) and practice (p = 0.211) shows no significant difference due to gender. Also post group knowledge (p = 0.079), attitude (p = 0.835) and practice (p = 0.435) shows no significant difference due to gender. Conclusions: The results suggest that e-educational posters may be useful to improve the knowledge, attitude, and practice on the proper use of face masks among school students. The improvement of knowledge, attitude, and practice on the proper use of face masks by e-educational posters among school students occurs irrespective of gender.

Single-Use Bag Valve Masks: Evaluation of Device Design and Residual Bioburden Analytical Methods

Background: A recent survey of in-hospital reprocessing in Tanzanian hospitals identified bag-valve masks (BVM) as a commonly reused single-use device. In low- and middle-income countries (LMIC), in-hospital reprocessing supports neonatal resuscitation strategies by helping to maintain adequate supplies of BVM. However, there is a need for device-specific protocols defining reprocessing procedures and inspection criteria to overcome variations in reprocessing practices between hospitals. The purposes of this study were: 1) to complete a comprehensive design review and identify challenges to reprocessing BVMs;and 2) to investigate three different residual bioburden analysis methods for assessing the efficacy of decontaminating a disposable BVM. Methods: New, unused bag-valve-masks were contaminated with Staphylococcus epidermidis and Artificial Mucus Soil to simulate the worst case soiling conditions. Devices underwent one of five disinfection protocols, including one currently used in a LMIC hospital. Three analytical (two quantitative and one qualitative) methods were selected to evaluate residual bioburden on the device following decontamination. Results: Of all protocols tested, only the positive control and the Soap and Bleach protocols met disinfection targets. Most cleaning outcomes were consistent from trial to trial for each protocol. However, cleaning outcomes varied greatly for the Alcohol Wipe protocol. For the residual bioburden analyses, the two quantitative methods produced similar results, but the qualitative measurement exhibited increased variability. Conclusion: While this study revealed positive disinfection outcomes for the Tanzanian hospital decontamination protocol, more studies are required to support these findings. Design features of the BVM mask presented challenges to cleaning and drying during different decontamination protocols, as seen in the variability in the Alcohol Wipe protocol performance. These findings support the case for a device-specific protocol for the BVM. Given proper hospital personnel training and available resources, in-hospital reprocessing could support neonatal resuscitation strategies and other demands for manual resuscitation by helping to maintain adequate supplies of BVM.

Exploring the Therapeutic Potential of Algae-Based Sheet Masks in Skincare: A Comprehensive Study of Cosmetological Benefits and Microbiome Balanced Interactions

Research in dermatology is exploring bio-compatible materials like alginate and calcium sulphate for use in skincare products, such as facial sheet masks. Alginate (from seaweed) has wound healing and hydration properties, while calcium assists in maintaining skin balance and protection. In this study we explore the effects of an algae-calcium based sheet mask on skin. Materials and Methods: In-vitro studies investigated the purpose, process and effectiveness of an algae-calcium dry sheet mask (Algae Mask-MedSkin Solutions Dr. Suwelack). The mask is made from brown algae and undergoes a lyophilization and stabilization process to form its final structure. The mask’s properties were tested using scanning electron microscopy (SEM) and its performance was assessed on human skin biopsies. Various tests were performed, such as measuring the release of ionic constituents and concentration of calcium ions, and the fibroblast cell-activating effect. Clinical evaluations and skin microbiome assessment were conducted on healthy volunteers to assess the mask’s effect on the skin. Results and Conclusion: The study validates the benefits of macro algae-based sheet masks for skincare, with significant cosmetic effects and high tolerance due to its composition. Notably, the algae based mask releases substantial calcium ions, hydrates, minimizes skin roughness and wrinkles, regulates pH levels, and maintains skin microbiome diversity. It also decreases Corynebacterium species found on the skin, suggesting potential to modify skin microbiome. .