Contains recognition pattern of the html/infected.webpage.gen 3 html script virus

Take the notorious Iloveyou worm : When it went off, it hit nearly every email user in the world, overloaded phone systems with fraudulently sent texts , brought down television networks, and even delayed my daily afternoon paper for half a day. What makes an effective worm so devastating is its ability to spread without end-user action. Viruses, by contrast, require that an end-user at least kick it off, before it can try to infect other innocent files and users.

Worms exploit other files and programs to do the dirty work. For example, the SQL Slammer worm used a patched vulnerability in Microsoft SQL to incur buffer overflows on nearly every unpatched SQL server connected to the internet in about 10 minutes, a speed record that still stands today. Computer worms have been replaced by Trojan malware programs as the weapon of choice for hackers.

Trojans masquerade as legitimate programs, but they contain malicious instructions. They've been around forever, even longer than computer viruses, but have taken hold of current computers more than any other type of malware. A Trojan must be executed by its victim to do its work. Trojans usually arrive via email or are pushed on users when they visit infected websites. The most popular Trojan type is the fake antivirus program, which pops up and claims you're infected, then instructs you to run a program to clean your PC.

Users swallow the bait and the Trojan takes root. Remote access Trojans RATs in particular have become popular among cybercriminals. RATs allow the attacker to take remote control over the victim's computer, often with the intent to move laterally and infect an entire network. This type of Trojan is designed to avoid detection. Threat actors don't even need to write their own. Hundred of off-the-shelf RATs are available in underground marketplaces. Trojans are hard to defend against for two reasons: They're easy to write cyber criminals routinely produce and hawk Trojan-building kits and spread by tricking end-users — which a patch, firewall, and other traditional defense cannot stop.

Malware writers pump out Trojans by the millions each month. Antimalware vendors try their best to fight Trojans, but there are too many signatures to keep up with. Today, most malware is a combination of traditional malicious programs, often including parts of Trojans and worms and occasionally a virus.

Skip directly to site content Skip directly to page options Skip directly to A-Z link. Section Navigation. Important update: Healthcare facilities. Learn more. Updated Jan. Without depending on the high density of small pores, the filter thickness can be reduced and the removal efficiency can be maintained under a continuous airflow with a low-pressure drop.

Three charging techniques, namely, in situ charging, corona charging, and tribocharging, can be used to fabricate electret membranes [ ]. The electrospinning process for the fabrication of nanofibrous membranes can in situ charge the nanofibres through introducing charge storage enhancers into electrospinning solutions. Nanoparticles, such as polytetrafluoroethylene, silicon nitride, magnesium stearate, titanium dioxide, boehmite, and SiO 2 , are usually employed as charge enhancers, and various hybrid electret filters have been developed via the in situ charging technology of electrospinning [ , — ].

A polyvinylidene fluoride nanofibrous membrane doped with well-dispersed SiO 2 nanoparticles demonstrated a remarkable electret effect with a surface potential of Besides electrospinning, corona treatment is another approach to charge fibrous membranes under an external electric field. Zhang et al. A fatal drawback of the in situ and corona-charged electret membranes is the poor stability of filtration efficiency due to the rapid dissipation of the surface charges when the membranes are in contact with moisture or oil droplets under a hazy environment [ ].

Electret membranes fabricated by a tribocharging strategy with constant charge supply can solve the problem of charge dissipating, leading to enhanced stability and prolonged service life of the filters.

Very recently, a triboelectric nanogenerator TENG has been combined with nanofibrous air filters for high-efficiency particulate removal [ , ]. TENG is a newly invented technology which is used for harvesting energy from various mechanical movements such as wind, water wave, and human motion [ ].

The large open-circuit voltage up to several hundred volts generated by TENG based on triboelectrification and electrostatic induction effect makes it a popular candidate for application in various self-powered wearable devices [ ].

Using this technology, the same group later developed a self-powered electrostatic adsorption face mask SEA-FM from electrospun poly vinylidene fluoride membrane equipped with a TENG driven by human respiration Figure 10 d [ ].

The removal efficiency is stable under a high humidity environment and displayed no obvious deterioration after five cleaning cycles. Hence, the triboelectric air filters are highly effective and stable with a long service life, paying the way for the fabrication of face masks and other health protection applications. Metal-organic frameworks MOFs are a class of porous crystalline materials that are composed of transition-metal cations and coordinately bonded multidentate organic linkers.

With high porosity, tunable pore size, rich functionalities, and good thermal stability, MOFs hold great promise for applications as filtration materials [ ]. As MOF crystals are in a light powder form, they are usually grown on porous substrates or embedded in polymer fibrous membranes to form MOF-based filters.

Due to the unbalanced metal ions and defects on the surface, MOFs can offer positive charge to polarize the PM surface, leading to improved electrostatic adsorption of PM pollutants.

Inspired by the promising results, the same group further employed a roll-to-roll hot-pressing method for mass production of MOF-based filters on various commercially available flexible substrates i. It can be easily washed with tap water and ethanol and reused three times without apparent efficiency loss, which is quite promising for application in residential pollution control.

Koo et al. Hao et al. Though air filters discussed above show excellent capture efficiency for particular matters PM , microorganisms or bioaerosols , such as bacteria, viruses, and fungi in the air, adhere to the filter surface, remain viable, and may reproduce within the filter media, which pose a risk of second airborne contamination. Meanwhile, the accumulation of microorganisms in the filter also blocks the filter, leading to reduced ventilation volume and deterioration of the filter [ — ].

Thus, it is highly desirable to develop air filters with antimicrobial properties, especially when the filters are used for respiratory protection, such as masks, and for indoor air purification. Up to now, a wide range of antimicrobial agents, such as natural products, nanoparticles of metal and metal oxide, metal-organic frameworks MOFs , graphene, and its derivatives, have been investigated to impart air filters with biocidal properties.

Antimicrobial extracts of natural products have been widely studied as antimicrobial agents for air filters owing to their high antimicrobial activity, low toxicity, low-cost, and gentleness to the environment [ — ].

The microbial toxicity of natural product extracts is generally accredited to the flavonoids they may contain, which kill microbes via the damage of cell membrane function and inhibition of DNA gyrase [ , ]. Herbal extracts, such as tea tree oils [ ], extract of olive [ ], extract of Euscaphis japonica [ ], grapefruit seed extract [ ], mangosteen extracts [ ], and especially Sophora flavescens [ — ], have been sprayed on the surfaces of fibrous polymeric filter for antimicrobial properties, and the herbal extract-coated filter demonstrated good antimicrobial activity.

Recently, Sim et al. However, the high antimicrobial activity of these surface-coated filters is often delivered at a high loading of antimicrobial herbal extracts, which would lead to much increased pressure drop [ , , ]. To solve this problem, Choi et al. Owing to the uniform dispersion of antimicrobial ingredient across the polymeric nanofibres, the fabricated hybrid nanofibrous filter exhibited excellent filtration efficiency However, the durability of natural product extracts is still a concern, when it comes to a real application as the antibacterial activity may be affected by temperature, or degraded due to a natural oxidation process [ , , ].

This can be complemented by nonnatural antimicrobial substances. Apart from natural herbal extracts, metals and their compounds have also been extensively studied for their antimicrobial application. Nanoparticles of metal and their compounds have garnered huge attention as a potent antimicrobial agent due to their high surface-to-volume ratios compared with their bulky counterparts [ , ]. A synergistic antimicrobial performance is also revealed via their combination with other biocidal agents, such as carbon nanotubes [ , , ].

Apart from antimicrobial air filters, multifunctional air filters, which simultaneously remove PM, microorganisms, and volatile organic compounds VOCs , have drawn increasing research attention recently [ , ].

The integrated multifunctional air filter provides a promising solution to address the high-pressure drop often caused by multiple filters with different functions used in current air filters.

Feng et al. In another study, Zhao et al. The antimicrobial functionality of Ag nanoparticles, as well as their catalytic performance for formaldehyde degradation, were greatly enhanced when loaded on high surface area of CNTs.

Copper nanoparticles are strong microbicides for a broad spectrum of microorganisms [ ]. Very recently, they have been demonstrated to be effective against the newly emerged coronavirus COVID , which is threatening the whole world [ , ]. Though copper-polymer nanocomposites have been explored for antimicrobial applications, the integration of copper nanoparticles to filters for personal protection or air filtration has not been reported yet.

With appropriate technologies to effectively deposit copper nanoparticles onto fibrous filter matrix, more advancement for copper nanoparticles as antimicrobial coating in air filters is expected. MOFs, as an emerging new class of antimicrobials, are superior compared with metals due to their high surface area, uniform distribution of metal active sites, and adjustable porous structures [ , ].

There has been rapid progress in recent years on the research of antimicrobial behavior of MOFs, along with the antimicrobial application of MOFs and their composites [ , ]. The antimicrobial mechanism of MOFs is mainly accredited to the inherent biocidal nature from their metal ions and may also be from the antimicrobial organic ligands [ , — ]. Ma et al. Very recently, inspired by the extremely tunable photocatalytic properties of MOFs, Li et al. ZIF-8 nanocrystals were integrated to nonwoven fabrics via hot pressing.

The established MOFilter achieved This work sheds light on the photocatalytic biocidal action of MOFs and provides valuable insights for their potential antimicrobial applications in air disinfection. Though there have been numerous studies on antimicrobial materials and their antimicrobial application, the integration of antimicrobial substances with filters for air purification is still at a preliminary stage, especially for the newly emerging antimicrobial nanoparticles.

In view of rising air pollution, and the severe coronavirus COVID pandemic, there would be increasing attention on air filters with antimicrobial properties. To achieve high-performance antimicrobial air filters, the choice of highly efficient and biologically safe antimicrobial ingredients, the structural design for good gas permeation, and a simple and economic preparation method are key for their ultimate commercialization to provide protection for public health.

While face masks can offer some form of protection against airborne and droplet-borne pathogens entering our airway through the mouth and nose, contact with the outer layer of the mask, such as with hands during mask adjustment, removal, or even disposal, can nonetheless result in self-inoculation of pathogenic microbes. A recent study showed that the SARS-CoV-2 virus can remain infectious on the outer layer of the surgical mask even after 6 days [ ].

Disinfection of masks, especially reusable ones, is therefore crucial. Cloth masks may be disinfected by washing with detergents and bleach whereas surgical and N95 masks may be disinfected via UV [ ] or heat treatment [ , ]. Such treatments are nonetheless discrete, and masks are easily contaminated with pathogenic microbes again once in use.

Thus, masks with antimicrobial activity that can automatically destroy or inactivate infectious microbes may reduce the risk of contamination. With increased awareness of epidemics, research on methods to incorporate antimicrobial activity onto masks have intensified.

Antimicrobial air filter materials discussed in the previous section Section 6. Alternatively, masks may also be treated or coated with antimicrobial agents. Many classes of antimicrobial agents, including metal nanoparticles, organic compounds, and even common household chemicals, have demonstrated antimicrobial activity in masks.

Notably, several of these masks are commercially available today; these examples will be highlighted in their respective sections. Herein, some common antimicrobial agents that may be used to treat masks will be discussed. Metal-based nanoparticles NPs are a growing field in the fight against microbes due to their low toxicity towards humans at concentrations effective for pathogen inactivation [ — ].

Due to their broad spectrum of biocidal activity and high potency, most do not induce resistance and are effective against multiresistant bacteria [ , ]. There have been several reports of AgNPs conferring antimicrobial properties to masks. One method is to introduce AgNPs onto the materials used to make masks. US Pat. The yarn showed antimicrobial activity against multiple bacteria genus, including Bacillus , Staphylococcus , Chlamydia , Escherichia , and Pseudomonas , and fungi, such as Candida albicans even after dying and times of washing [ ].

Anson Nanobiotechnology Zhuhai uses this fabric between the electret filter and the inner layer of the mask to produce nanosilver antibacterial surgical masks [ 99 , ].

Other methods of loading AgNPs onto fabric for mask materials have been described [ — ]. A more facile method could be to coat AgNPs directly onto surgical masks; More et al. Cu and copper oxide both have potent biocidal properties and have been incorporated into textiles and other products with antimicrobial and antiviral properties [ 21 , — ].

Borkow and coworkers from Cupron Inc. These Cu x O-impregnated masks showed not only Mask safety was also evaluated: the masks did not cause skin irritation nor poisoning through inhalation or saliva ingestion. The mask inactivated Copper oxide impregnated fibres have similarly been used in reusable masks. Cupron Inc. Copper Clothing Ltd. Several other copper fibre manufacturers, e. Photocatalysts typically inactivate microbes by producing ROS via light-catalysed redox reactions [ — ].

Masks with a surface titanium oxide- TiO 2 - apatite layer on the outer nonwoven fabric layer have shown good filtration and photocatalytic activity [ , ].

A recent study showed that even metal-organic frameworks MOFs could be used as mask filters. Despite the high antimicrobial activity of photocatalyst-impregnated masks, it must be noted that they are only effective when sufficient light energy is applied. The wide usage of some metal NPs, especially silver, has led to some bacterial resistance against these agents [ , ].

Combinations of multiple NP species may be beneficial to the biocidal efficiency. However, due to the nanofibre filter, the mask should not be laundered. Acid-based media, such as citric acid, cause inactivation and aggregation of hemagglutinin HA glycoprotein spikes in virus membranes, thus rendering the virus unable to enter cells [ , ].

The application of citric acid as a coating on the outer layer of face masks was patented as early as [ ] and is currently widely in use. Even coating the PP filtration layer with simple table salt NaCl can confer virucidal activity [ ]. In vivo studies with mice exposed to the H1N1 and H5N1 viruses through NaCl-coated filters showed drastically reduced lung virus titer and increased survival rate compared to the control.

Tea polyphenols possess antiviral properties due to the ability of catechin, theaflavin, and their derivatives to damage virus membranes and bind to viral nucleic acids, inhibiting replication in influenza A H1N1 and H3N2 and B viruses [ , ].

Catel-Ferreira et al. While catechin at this concentration did not inhibit E. When used as a filter layer in Kolmi M mask, Cationic ammonium polymers have also been studied: Tiliket et al. When used as a filter layer in a Kolmi M mask, The effectiveness of organic acids also led to the development of acidic polymers for mask materials. Graphene, the superstar of 2D materials, has been most explored as an antimicrobial in various areas [ ].

Graphene and its derivatives have also been widely used with other antimicrobial agents, taking advantage of their large surface area, for a synergistic effect to enhance antimicrobial efficacy [ , ]. Recently, the excellent photothermal properties of graphene in NIR regions have been utilized to increase the surface temperature and thus inactivate microorganisms [ , ].

Other 2D materials, such as MoS 2 [ — ] and graphitic carbon nitride g-C 3 N 4 [ — ], also show attractive antimicrobial performance, while their potential antimicrobial application in air filtration needs to be further explored.

Several masks have also integrated more than one class of antimicrobial agents across multiple layers. US patent disclosed that treating the outer nonwoven layer with antimicrobial agents comprising polyhexamethylene biguanide, citric acid, and N -alkyl polyglycoside, as well as other known antimicrobial agents, can deactivate Both antiviral masks inactivated It has been tested for continuous use for up to 8 hours.

Similar technology has also been described elsewhere [ ]. In summary, multiple types of biocidal agents have been incorporated into masks, giving them the added ability to kill pathogenic microbes while not adversely affecting their basic performance. To date, many masks, some including more than one type of antimicrobial agent, are commercially available as summarised in Table 3. However, it must be noted that mask antimicrobial activities have only been studied under strict laboratory conditions; the actual performance of the masks during day-to-day usage may vary.

For example, the time required to achieve high biocidal activity may be dependent on the amount of light, especially for photocatalytic biocidal agents, humidity, or airflow.

The performance of reusable masks after repeated washing, especially after laundering with surfactants and at high temperatures, may also differ from the laboratory tests. Hence, while antimicrobial masks can offer additional protection against microbes, basic hygiene practices such as not touching the mask surface and washing of hands should still be observed. Increasingly, wearing of face masks is becoming the new norm in our lives.

In an attempt to curb the spread of the virus, more than 50 countries have made face masks mandatory in public spaces during the COVID pandemic, such as China, Singapore, Spain, and France [ ]. In other places, medical experts highly encourage the use of face masks for the protection of the community and oneself against viral transmission.

As international travel bans gradually lift, airlines require passengers to don masks at all times. Experts are anticipating a prolonged period of such measures as the world battles the disease. Even when we leave the shadows of the COVID pandemic, we prepare and anticipate future health crises, especially those of a respiratory and infectious nature.

We could perhaps no longer treat mask-wearing as a temporary solution but to adapt to having face masks as part of our staple of accessories. To note also is the matter of cost—as a temporary transient accessory or a surgical PPE, currently mask manufacturing tends to aim at driving the cost down, at producing cheap disposable units. With it becoming a staple, people may be convinced to invest more in sophisticated, multifunctional reusable variants, and cost-per-wear will help justify the addition of these attributes.

In addition to their antimicrobial activities, functionalized graphene and graphene-based composites have been reported to confer superhydrophobicity onto material surfaces.

Very recently, Zhong et al. The graphene-deposited mask exhibited outstanding superhydrophobic and photothermal performance.

More impressively, the roll-to-roll laser production system can be integrated with current roll-to-roll surgical mask production lines, and the cost of raw materials is low, which makes the technology promising for commercial applications. Furthermore, the graphene-coated masks can be further recycled for solar-driven desalination.

There are three main categories of social needs that require a transparent quality to our everyday face mask: the hearing-impaired, the digital face-recognition technology, and the human-facing industry. There are an estimated million in the world suffering from deafness or hearing loss [ ], who heavily depend on lip-reading for communication.

With the loss of partial face visibility, a substantial population of the hearing-impaired will be adversely affected in speech perception. Face recognition algorithms have not been optimised for the mask-wearing era, and the lack of which directly threatens societal security. Lastly, for the human-facing industry or population, reading of facial expressions can be crucial [ , ], for instance, interpreters and translators, caretakers for people with illnesses, confusion and anxiety, customer-facing staff including medical staff where medical miscommunication may occur , interacting with people who speak a different language, or the elderly and the young.

As tech companies attempt to resolve the second category of digital recognition using enhanced algorithms such as the Israeli Corsight and the Chinese Hanvon for covered faces [ , ], we envisage a transparent mask as a straight-forward solution to the aforementioned needs. The challenge is threefold for a transparent mask material—it needs to be nonpermeable to liquids and fluids, it should provide two-way protection against transmission of viral shedding , and it has to be breathable for human wear.

There have been numerous transparent face mask patents in the market [ — ], for instance, one from that in particular highlights a disposable transparent antimicrobial face mask [ ]. For medical purposes, it consists of highly porous transparent film, with nonporous microvented laminae to provide controlled gas permeation but liquid-proof. The transparent panel is said to be made from thermoplastic films such as polyethylene terephthalate PET and polyvinylidene fluoride PVDF , with perforations and pleats incorporated.

The antimicrobial used here is a Si-QAC biocide that provides mechanical contact kill, to prevent chemical leaching from conventional antimicrobials. The inventor J. The bactericides and deodorant solutions are either embedded in the resin or coated on the resin sheet. More recently, commercial product ClearMask claims to be the first fully transparent face mask, patent-pending at the time of writing [ ], for ease of connecting and communicating with people, focusing on a human-centric experience.

With prolonged wearing of masks being necessary, such as for hours on flights and enclosed or confined spaces, offices, and workplaces, the inconvenience and discomfort, especially for children and the elderly, are amplified by current mask designs.

For instance, Konda et al. The studies found hybrid fabrics are better at filtering out particles, likely due to the combined mechanical and electrostatic filtration ability of the materials. Cloth or homemade masks also tend to fit less well, further reducing their filtration efficiencies. Other efficacy studies indicate a similar trend of commercial surgical masks being a preferred viral barrier to homemade masks [ 12 , 17 , ]. Materials and designs promising of better breathability, durability, and comfort have been proposed and invented for mask use.

Several suggest the use of microporous membranes, or films with interconnected pores, for ventilation and breathability. The material resolidifies as it releases the energy to the ambient air during inhalation. The process can then be cycled. Such material is coated in a discontinuous pattern so as not to reduce coverage of the liquid-resistant barrier material.

A cooling function is especially critical in a tropical climate [ , ]. The reusable mask comes with removable filters. Another design by BDCI involves a simple 3D-printed skeleton to reinforce the mask shape firmly, preventing negative air pressure from collapsing the mask cup during inhalation, hence improving the ease of breathing [ ]. The ability to self-clean is certainly desirable.

Disposable masks are usually not environmentally friendly and require constant manufacturing and purchasing. Apart from the aforementioned antimicrobial properties, a few self-cleaning or self-sterilizing approaches are available for repeated prolonged or repeated use of masks. Stanford et al. The LIG has a high surface area and traps microbes whose proliferation is inhibited on the graphene. Cycles of Joule heating then kills the microorganisms and pathogens, and the high thermal stability of LIG allows it to be reused.

Arnusch et al. Zhong et al. The graphene coating functions as an aqueous-resistant layer on the mask surface. One other common approach is the use of ultraviolet UV light. One early demonstration by inventor Ricci showed a germicidal mask [ ], where the air breathed in by the user has been exposed to inbuilt UV radiation, killing pathogens and viruses.

When realised, this would make efficient reusable face masks. We live in a constantly image-conscious world of consumerism, social media, and complicated human psyche. As we transit into the new postpandemic age, we cannot ignore the social and psychological aspects of donning additional apparel. Aesthetics, trends, and fashion are important factors in everyday living, as we already see reusable fabric masks sporting various patterns and designs.

Multiple functions, way beyond the essential medical needs and convenience, would be desired. Masks now provide a ready platform to incorporate gadgets, electronics, good-to-haves, and a canvas for novel ideas.

As our postpandemic lifestyle evolves, it is appropriate to consider the fashion, function, and future of masking up. It is inspiring to take creative design approaches into consideration when evaluating the next-generation protective masks. Yanko Design has gathered many innovative technology ideas along this line.

The setup when charged can run for hours and is said to be more spacious and comfortable [ ]. Another designer Joe Doucet takes on a fashionable stand with a sleek face mask-shield-visor all in one [ ]. Such features also help to enhance communication between the everyday mask-wearing population, when our voices are muffled by the mask materials.

There are several reports of nanosensors embedded in surgical masks for monitoring human breathing rate, most of which use materials which produce electrical outputs in response to humidity during human breathing [ — ]. The Laboratory for Embedded and Programmable Systems UC Davis has also embedded oxygen, carbon dioxide, and flow sensor into an elevation training mask Training Mask 2.

Abnormal breath patterns can indicate poor health or even lung disease [ , ]. Xiaomi Inc. From these data, the mask can calculate its pollutant absorption quantity and signal to the user when the mask should be replaced; the mask is expected to be commercially available soon.

Zhou et. Using negatively charged electrospun PEI as the nonwoven electret, The PEI electret can be loosely sandwiched between 2 iron Fe net electrodes to form a nanogenerator and incorporated into a commercial mask; during exhalation, the airflow causes movement of the electret between the Fe electrodes, generating alternating electricity to power a small LCD screen, which can display the measured breathing rate. As the surface charge of the PEI electret decreases, removal efficiency and power generated will decrease; thus, when breathing can no longer power the LCD, the mask should be replaced.

Face mask sampling has been used by Williams and coworkers to detect M. This method is noninvasive and enabled early detection of tuberculosis in people whose tuberculous burden is too low to be detected by conventional sputum tests.

Another team of researchers led by Collins developed a paper-based colorimetric sensor for the detection of Zika virus RNA [ ]. The scientists are now designing a face mask which can detect SARS-CoV-2 virus and produce a fluorescent output [ ].

Prototyping is in progress at the time of writing [ ]. This generated a demand for raw materials and environmental impact. A recent study from UCL suggests that if every person in the UK uses one single-use mask each day for a year, 66, tonnes of contaminated plastic waste would be generated, without counting the waste from packaging [ ]. Assuming the same disposal rate for every affected country, the medical waste generated at a global scale is going to be substantial, with a negative impact on our ecosystem and human health [ ].

Apart from physical waste, greenhouse gas GHG emission across the mask life cycle is another concern. GHG is emitted at every stage of the face mask life cycle, from the production of polymer resin, nonwoven sheet conversion, face mask assembly, and transportation to the end of life EoL treatments by incineration or landfill.

Based on the UCL projection of 66, tonnes of mask waste generated each year in the UK at the current high mask disposable rate, , tonnes of GHG could be released into the environment per year solely from the resin production stage. The subsequent energy-intensive manufacturing process such as melt-blown, transportation, and incineration is expected to further increase the carbon footprint of mask to a large extend.

To have a clear picture of the exact impact being imposed by face masks, comprehensive life cycle assessment LCA , a well-adopted methodology for analysing the environmental impact of an industrial system from cradle to grave, should be used. There is no doubt that the sudden increase in mask manufacturing and usage will cast more pressure to the already alarming global environmental issues originated from plastic products.

On the one hand, more masks are needed for reducing the risk of the virus spreading part of the preparations for economic reopening. On the other hand, reducing mask production, usage, and disposal is preferred for environmental reasons. Facing such a dilemma, tackling both challenges may need synergistic efforts from policymakers, industry players, researchers, and the general public. These efforts include strategies to reuse disposable masks, a search for alternative mask material with low GHG emission, etc.

Amid the crisis, we are seeing promising initiatives from the industrial and research communities. The reuse of single-use face masks provides a straightforward way to reduce the disposal rate.

In this regard, appropriate disinfection processes for safe and frequent reuse of masks without composing the mask filtration efficiency need to be determined. This has been discussed in detail in the previous section Section 5. Besides recycling commercial masks, DIY reusable masks also help to alleviate the supply shortage, with possible environmental benefits. As discussed in Section 4 , with the right choice of materials, appropriate design, and assembly, a DIY reusable mask may function as well as commercially manufactured surgical ones.

Using easily available household materials such as reusable nonwoven bag, dried hypoallergenic wet wipe, and a thin cotton cloth as the outer hydrophobic, middle filtering, and inner adsorbent layers, respectively, researchers from A STAR, Singapore, successfully designed a DIY mask with essential properties comparable to a surgical mask [ ].

As the performance of DIY masks depends on the materials used and how it is they are assembled, the public should not have the misconception that DIY masks can serve as a surgical mask alternative. A changeable filter layer that can be fitted inside the masks prevails as a viable option in improving the performance of a self-improvised mask.

The replaceable layer of fibrous material filters out viruses and other pathogens and allows the mask to be washed and reused. The changeable filter endows the various grass-root production of masks over the past few months with up-to-standard filtration performance.

In addition to the essential filtering function, incorporating multifunctionality into mask design or mask materials opens up opportunities for masks with advanced features. Some of these innovative efforts have been described in Section 6. Spurred by the outbreak of COVID, many companies are transitioning to mask production to meet the vast demand, such as global gaming hardware manufacturing company Razer Inc.

Yet, this ambitious effort has run into a bottleneck, the deficit of melt-blown fabric. Putting supply availability aside, the life cycle GHG emission level of the raw materials poses another set of challenges.

The filter membrane exhibited a high efficiency of It was found that the presence of soy particulates on fibre surface enhanced its water absorption and colourability properties while retaining the feel of natural fibres. More recently, researchers from the BioProducts Institute at the University of British Columbia have developed a fully compostable and biodegradable medical N95 mask, named Can-Mask, using wood fibres from sources such as pine, spruce, cedar, and other softwoods [ ].

Although a large range of thermoplastic resins can be processed by spun-bond and melt-blown technology, an essential part of the mask structure, PP remains the major resin being used for its ease in processing, especially in terms of viscosity control.

Hence, proper control of the rheological behavior using modifiers will assist in the production of non-PP melt-blown fabric that meets the requirement for medical applications. Natural materials such as cellulose, cotton, and commercial resins such as Bioplast could become potential candidates after issues regarding their poor thermal stability have been addressed.

Recent efforts have demonstrated the potential of reusable mask development enabled by material innovation and technology advancement in addressing the mask shortage while reducing the GHG emissions and negative environmental impact. However, continuous efforts are needed to ensure feasible developments can be transit to existing manufacturing facilities. Also, there are more scientific opportunities to develop novel and environmentally friendly mask materials with functions of interests such as self-sanitising and degradable materials and to develop a low energy consumption technique or process for a nonwoven fibre that could replace a carbon-intensive melt-blown process in the near future.

This does not undermine the role of a single-use mask as an immediate measure to protect those at high risk of infection healthcare professionals. Till date, COVID is still on the rise worldwide, the use of mask may become a norm and the demand will remain high.

Hence, continuous efforts are required for a closely integrated experimental and theoretical investigation aiming to progress upon the current state of understanding and perpetuate the development of innovative solutions for the mask crisis amid the pandemic.

The COVID pandemic has forced the global population to adopt new ways of living, including the wearing of masks as a new norm. This review therefore provides a holistic summary of the A to Z of face masks, to give readers a broad-view understanding of masks from the perspective of public health to the domains of material development. The importance of mask-wearing in preventing the spread of airborne and droplet-borne infections was discussed early in this review.

Thereafter, the protection mechanism, production, and performance testing of commercial masks were described. We then explored the effectiveness of DIY homemade masks as an alternative to commercial masks.

To overcome the issue of mask shortage, methods to decontaminate used masks were introduced and elaborated. The review then discussed research advances in the development of materials with improved filtering capacity and antimicrobial activity. Finally, the environmental implications of widespread mask-wearing and increased mask production were deliberated upon as efforts towards finding more sustainable solutions to support long-term mask-wearing, even after the end of the pandemic, were explored.

As mentioned in the very beginning, the fight against any infectious diseases requires efforts and solutions in prevention, detection, diagnosis, and treatment. Note : The data is shown in the browser as intended, because the browser will interpret the HTML escaped symbols. In this case, the browser will first un- htmlspecialchars the value, and then pass the URL on.

Although most browsers will recover if you forget this, this isn't always possible. Because foo. That is, the periods are replaced with underscores. So, you'd access these variables like any other described within the section on retrieving variables from external sources.

Note : Spaces in request variable names are converted to underscores. If you do not specify the keys, the array gets filled in the order the elements appear in the form. Our first example will contain keys 0, 1, 2 and 3. The select multiple tag in an HTML construct allows users to select multiple items from a list.