Non-porous Surfaces Research Articles

Spontaneous directed leaching of slippery lubricant in self-stratified marine antifouling coatings for nonporous surfaces

The spontaneous directed leaching of lubricant can improve antifouling efficiency by minimizing adverse effects on marine life. Slippery lubricant-infused nonporous polydimethylsiloxane-based (PDMS-based) coatings with a self-stratified structure were prepared, using non-reactive phenylmethyl silicone oil as the lubricant. The coating adhered firmly to the substrate based on H-bonding interactions and maintained a low elastic modulus and surface free energy. The self-stratified structure ensured that the infused lubricant was centrally stored in the PDMS-cured region and could leach spontaneously and directionally onto the coating surface to enhance its antifouling capacity over time. The study finds that the instability of the unit mixed Gibbs free energy of the self-stratified coating led the lubricant leached onto the nonporous surface. This research widens the applicability of fouling release coatings with lubricant-infused nonporous surfaces from both theoretical and practical viewpoints.

Ultrafast inactivation of SARS-CoV-2 by 254-nm UV-C irradiation on porous and non-porous media of medical interest using an omnidirectional chamber

Covid-19 has spurred a renewed interest in decontamination techniques for air, objects and surfaces. Beginning in 2020, urgent effort was done to permit the reuse of UV-C for inactivating SARS-CoV-2. However, those studies diverged widely on the dose necessary to reach this goal; until today, the real value of the sensitivity of the virus to a 254-nm illumination is not known precisely. In this study, decontamination was performed in an original UV-C large decontamination chamber (UVCab, ON-LIGHT, France) delivering an omnidirectional irradiation with an average dose of 50 mJ/cm2 in 60 s. Viral inactivation was checked by both cell culture and PCR test. SARS-CoV-2 was inactivated by UV-C light within 3 s on both porous (disposable gown) and non-porous (stainless steel and apron) surfaces. For the porous surface, an irradiation of 5 min was needed to achieve a completely negative PCR signal. The Z value estimating the sensitivity of SARS-CoV-2 to UV-C in the experimental conditions of our cabinet was shown to be > 0.5820 m2/J. These results illustrate the ability of this apparatus to inactivate rapidly and definitively high loads of SARS-CoV-2 deposited on porous or non-porous supports and opens new perspectives on material decontamination using UV-C.

Fluorescent‐Dye‐Doped Nanoporous Silica Powder for Imaging of Latent Fingerprints (Levels 1–3) and Case Studies

AbstractNovel naphthalimide based fluorescent dye NI‐1 possess (i) high quantum yield, (ii) blue emission (λem=450 nm), (iii) CIE coordinate (x=0.21, y=0.35) with 39 % blue colour purity in solid state, (iv) photochemical and thermal stability up to 200 oC and (v) low cytotoxicity to normal cells L929. NI‐1 was doped in nano porous silica and used as fluorescent powder for imaging of latent fingerprints (LFPs) on coloured surfaces, barcode, wood, brick, leaf and engraved steel beside other common household porous and nonporous surfaces. We demonstrated visibility of levels 1–3 on ceramic tile, glass, paper, steel, iron and compact disc using NI‐1 doped fluorescent silica powder. Furthermore, LFPs developed with NI‐1 were successfully lifted from different surfaces using adhesive tape for documentation and archiving purposes. To mimic the automated fingerprint identification system (AFIS), we manually screened fingerprints from 16 subjects to identify the unknown subject. The unique minutiae points such as long hook, opposite bifurcation, crossbar, cross over, dock, triple bifurcation, lake and spikes were observed beside other 16 minutiae points.

Biomimetic super slippery surface with excellent and durable anti-icing property for immovable heritage conservation

The formation and accumulation of ice on solid surface is not only a potential threat to our daily life, but also a hazard to cultural heritages, such as murals, grottoes, monuments, ancient buildings. Inspired by slippery inner surface of Nepenthes, slippery liquid-infused porous surfaces (SLIPSs) for anti-icing attract a lot of attention recently. In this work, dip-coating approach is utilized to create a hydrophobic silica layer grafted with long-chain organic molecules. After infusing the oil phase, a three-layer Nepenthes-like structure is formed. The SLIPS shows excellent anti-icing property. It reduces the ice-surface adhesion strength to 0 kPa on non-porous surface and 6.83 kPa on porous surface (sandstone from Yungang Grottoes) respectively. After 35 icing/de-icing cycles, the SLIPS still shows good anti-icing ability. Our results show that the middle long-chain organic layer not only enhances the surface hydrophobicity but also increases its affinity with the oil phase to reduce lubricating oil loss, thus increasing its anti-icing durability. When the anti-icing ability decreases with time, simple re-infusing the oil phase can easily restore the anti-icing performance to its original level. The SLIPSs prepared in this work show outstanding hydrophobicity, ice repellency, durability and satisfying water vapor permeability on treated porous sandstones, which makes it potential to protect immovable cultural heritages from ice hazard.

Bacterial Polysaccharide-Stabilized Silver Nanoparticles Photocatalytically Decolorize Azo Dyes.

Bacterial polysaccharide is advantageous over plant, algal, and fungal polysaccharides in terms of stability, non-toxicity, and biodegradable nature. In addition, bacterial cell wall polysaccharide(CPs) is very little explored compared to exopolysaccharide. In this study, CPs have been isolated from thermotolerant Chryseobacterium geocarposphaerae DD3 (CPs3) from textile industry dye effluent. Structural characterization of the CPs was done by different techniques, viz., scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). CPs3 demonstrated compact non-porous amorphous surface composed of evenly distributed macromolecular lumps. TGA revealed a high thermostability (~ 350°C) of the polysaccharide. FTIR and NMR confirm the polysaccharidic nature of the polymer, consisting of glucose units linked by both β-(1 → 3) and β-(1 → 4) glycosidic bonds. The functional properties of CPs3 were evaluated for industrial use as additive, especially antibacterial, emulsification, and flocculation capacities. A single-step green synthesis of silver nanoparticle (AgNP) was performed using CPs3. AgNP was characterized using ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), AFM, and particle size analyses. The CPs3-stabilized AgNP exhibited potential photocatalytic activity against a broad range of azo dyes, congo red (88.33 ± 0.48%), methyl red (76.81 ± 1.03%), and malachite green (47.34 ± 0.90%) after only 3h of reaction. According to our knowledge, this is the first report on CPs from C. geocarposphaerae. The results demonstrated multifunctionality of CPs3 in both prospective, CPs3 as additive in biotechnology industry as well as Cps3-stabilized AgNP for bioremediation of azo dye.

Synthesis and Characterization of MC/TiO2 NPs Nanocomposite for Removal of Pb2+ and Reuse of Spent Adsorbent for Blood Fingerprint Detection.

The removal of toxic heavy metals from wastewater through the use of novel adsorbents is expensive. The challenge arises after the heavy metal is removed by the adsorbent, and the fate of the adsorbent is not taken care of. This may create secondary pollution. The study aimed to prepare mesoporous carbon (MC) from macadamia nutshells coated with titanium dioxide nanoparticles (TiO2 NPs) using a hydrothermal method to remove Pb2+ and to test the effectiveness of reusing the lead-loaded spent adsorbent (Pb2+-MC/TiO2 NP nanocomposite) in blood fingerprint detection. The samples were characterized using SEM, which confirmed spherical and flower-like structures of the nanomaterials, whereas TEM confirmed a particle size of 5 nm. The presence of functional groups such as C and Ti and a crystalline size of 4 nm were confirmed by FTIR and XRD, respectively. The surface area of 1283.822 m2/g for the MC/TiO2 NP nanocomposite was examined by BET. The removal of Pb2+ at pH 4 and the dosage of 1.6 g/L with the highest percentage removal of 98% were analyzed by ICP-OES. The Langmuir isotherm model best fit the experimental data, and the maximum adsorption capacity of the MC/TiO2 NP nanocomposite was 168.919 mg/g. The adsorption followed the pseudo-second-order kinetic model. The ΔH° (-54.783) represented the exothermic nature, and ΔG° (-0.133 to -4.743) indicated that the adsorption process is spontaneous. In the blood fingerprint detection, the fingerprint details were more visible after applying the Pb2+-MC/TiO2 NP nanocomposite than before the application. The reuse application experiments showed that the Pb2+-MC/TiO2 NP nanocomposite might be a useful alternative material for blood fingerprint enhancement when applied on nonporous surfaces, eliminating secondary pollution.

Waste Biomass Originated Biocompatible Fluorescent Graphene Nano-Sheets for Latent Fingerprints Detection in Versatile Surfaces

In recent years, the application of biocompatible and non-toxic nanomaterials for the detection of fingerprints has become the major interest in the forensic sector and crime investigation. In this study, waste chickpea seeds, as a natural resource, were bioprocessed and utilized for the synthesis of non-toxic graphene nano-sheets (GNSs) with high fluorescence. The graphene GNS were synthesized via pyrolysis at high temperatures and were characterized by TEM, XPS, fluorescence and UV-Vis spectroscopy, and FTIR analysis. The GNS exhibited excitation-independent emission at about 620 nm with a quantum yield of over 10% and showed more distinct blue light under a UV lamp. Biocompatibility of the synthesized GNS in terms of cell viability (88.28% and 74.19%) was observed even at high concentrations (50 and 100 mg/mL), respectively. In addition, the antimicrobial properties of the synthesized GNS-based coatings were tested with the pathogenic strain of Bacillus cereus via live/dead cell counts and a plate counting method confirming their biocompatible and antimicrobial nature for their potential use in safe fingerprint detection. The developed chickpea-originated fluorescent GNS-based spray coatings were tested on different surfaces, including plastic, glass, silicon, steel, and soft plastic for the detection of crime scene fingerprints. Results confirmed that GNS can be used for the detection of latent fingerprints on multiple non-porous surfaces and were easy to detect under a UV lamp at 395 nm. These findings reinforce the suggestion that the developed fluorescent GNS spray coating has a high potential to increase sensitive and stable crime traces for forensic latent fingerprint detection on nonporous surface material. Capitalizing on their color-tunable behavior, the developed chickpea-originated fluorescent GNS-based spray coating is ideal for the visual enhancement of latent fingerprints.

Variability in Donor Lung Culture and Relative Humidity Impact the Stability of 2009 Pandemic H1N1 Influenza Virus on Nonporous Surfaces.

Respiratory viruses can be transmitted by multiple modes, including contaminated surfaces, commonly referred to as fomites. Efficient fomite transmission requires that a virus remain infectious on a given surface material over a wide range of environmental conditions, including different relative humidities. Prior work examining the stability of influenza viruses on surfaces has relied upon virus grown in media or eggs, which does not mimic the composition of virus-containing droplets expelled from the human respiratory tract. In this study, we examined the stability of the 2009 pandemic H1N1 (H1N1pdm09) virus on a variety of nonporous surface materials at four different humidities. Importantly, we used virus grown in primary human bronchial epithelial cell (HBE) cultures from different donors to recapitulate the physiological microenvironment of expelled viruses. We observed rapid inactivation of H1N1pdm09 on copper under all experimental conditions. In contrast to copper, viruses were stable on polystyrene plastic, stainless steel, aluminum, and glass, at multiple relative humidities, but greater decay on acrylonitrile butadiene styrene (ABS) plastic was observed at short time points. However, the half-lives of viruses at 23% relative humidity were similar among noncopper surfaces and ranged from 4.5 to 5.9 h. Assessment of H1N1pdm09 longevity on nonporous surfaces revealed that virus persistence was governed more by differences among HBE culture donors than by surface material. Our findings highlight the potential role of an individual's respiratory fluid on viral persistence and could help explain heterogeneity in transmission dynamics. IMPORTANCE Seasonal epidemics and sporadic pandemics of influenza cause a large public health burden. Although influenza viruses disseminate through the environment in respiratory secretions expelled from infected individuals, they can also be transmitted by contaminated surfaces where virus-laden expulsions can be deposited. Understanding virus stability on surfaces within the indoor environment is critical to assessing influenza transmission risk. We found that influenza virus stability is affected by the host respiratory secretion in which the virus is expelled, the surface material on which the droplet lands, and the ambient relative humidity of the environment. Influenza viruses can remain infectious on many common surfaces for prolonged periods, with half-lives of 4.5 to 5.9 h. These data imply that influenza viruses are persistent in indoor environments in biologically relevant matrices. Decontamination and engineering controls should be used to mitigate influenza virus transmission.

In vitro inactivation of SARS-CoV-2 by ozonated water via novel hand hygiene device.

The COVID-19 pandemic has heightened awareness of the need for novel surface disinfectants and hand-hygiene modalities. Ozone gas is an effective surface disinfectant, but toxicity limits its use in human applications. Ozonated water is a safer means to use ozone for disinfection, especially for human antisepsis. However, there are little data available regarding the effectiveness of ozonated water in eliminating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This study utilizes a novel hand hygiene device that produces a stable ozone concentration of 0.5 +/-0.1ppm in water and applies it using a proprietary spray that controls droplet size, velocity, and direction. The Device was used to apply ozonated water to a known quantity of SARS-CoV-2 Delta Variant viral particles on a non-porous surface (glass) for seven seconds. Post-exposure growth was compared to the unexposed matched control utilizing the Spearman-Karber method. Compared to control, ozonated water decreased SARS-CoV-2 viral growth by a mean log10 reduction of 4.33, or>99.99%reduction. These results suggest that the ozonated water, when applied by a spray hand hygiene device, is highly effective at surface disinfection of SARS-CoV-2.

Antimicrobial efficiency of chlorine dioxide and its potential use as anti-SARS-CoV-2 agent: mechanisms of action and interactions with gut microbiota.

Chlorine dioxide (ClO2) is a disinfectant gas with strong antifungal, antibacterial, and antiviral activities. Applied on hard non-porous surfaces as an aqueous solution or gas, the ClO2 exerts antimicrobial activity through its interaction and destabilization of cell membrane proteins, as well as through DNA/RNA oxidation, triggering cell death. As for viruses, the ClO2 promotes protein denaturalization mechanisms preventing the union between the human cells and the viral envelope. Currently, ClO2 has been pointed out as a potential anti-SARS-CoV-2 clinical treatment for use in humans with the ability to oxidize the cysteine residues in the spike protein of SARS-CoV-2, inhibiting the subsequent binding with the Angiotensin-converting enzyme type 2 receptor, located in the alveolus cells. Orally administered ClO2 reaches the gut tract and exacerbates the symptoms of COVID-19 generating a dysbiosis with gut inflammation and diarrhea as side effects, and once absorbed, produces toxic effects including methemoglobinemia and hemoglobinuria which can trigger respiratory diseases. These effects are dose-dependent and may not be entirely consistent between individuals since the gut microbiota composition is highly heterogeneous. However, to support the use of ClO2 as an anti-SARS-CoV-2 agent, further studies focused on its effectiveness and safety both in healthy and immunocompromised individuals, are needed.

Surface-Localized Chemically Modified Reduced Graphene Oxide Nanocomposites as Flexible Conductive Surfaces for Space Applications.

Thermoplastic polymers are a compelling class of materials for emerging space exploration applications due to their wide range of mechanical properties and compatibility with a variety of processing methods, including additive manufacturing. However, despite these benefits, the use of thermoplastic polymers in a set of critical space applications is limited by their low electrical conductivity, which makes them susceptible to static charging and limits their ability to be used as active and passive components in electronic devices, including materials for static charge dissipation, resistive heaters, and electrodynamic dust shielding devices. Herein, we explore the microstructural evolution of electrically conductive, surface-localized nanocomposites (SLNCs) of chemically modified reduced graphene oxide and a set of thermoplastic polymers as a function of critical thermal properties of the substrate (melting temperature for semi-crystalline materials or glass transition temperature for amorphous materials). Selected offsets from critical substrate temperatures were used to produce SLNCs with conductivities between 0.6-3 S/cm and surface structures, which ranged from particle-rich, porous surfaces to polymer-rich, non-porous surfaces. We then demonstrate the physical durability of these electrically conductive SLNCs to expected stress conditions for flexible conductive materials in lunar applications including tension, flexion, and abrasion with lunar simulant. Small changes in resistance (R/R0 < 2) were measured under uniaxial tension up to 20% strain in high density polyethylene and up to 500 abrasion cycles in polysulfone, demonstrating the applicability of these materials as active and passive flexible conductors in exterior lunar applications. The tough, electrically conductive SLNCs developed here could greatly expand the use of polymeric materials in space applications, including lunar exploration, micro- and nano-satellites, and other orbital structures.

광학적 특성 평가기법을 이용한 지문현출 시약 1,2-IND와 BY40의 광발광 모드 최적조건에 대한 연구

Fingerprints are formed on various surfaces in crime scenes. Cyanoacrylate fuming with Basic Yellow 40 is usually used on non-porous surfaces and 1,2-Indanedione is the most common reagent for developing latent fingerprints. In general, developed fingerprints are observed using a light source and filter within corresponding wavelength range. This observation technique is called photoluminescence mode. Since the photoluminescence mode uses light sources and filters in the darkroom, it is easy to observe only the developed fingerprints. Therefore, many studies have been conducted to find best filter and light combination of latent fingerprint development reagents. But most of the studies on optimal photoluminescence conditions were based on visual evaluation methods such as the Home Office Grading System or SWGFAST. Since these visual evaluation criteria are based on the evaluator's visual judgment, the results may vary depending on the evaluator's competency, and it is difficult to compare if the difference in the degree of enhancement and appearance is small. To solve this problem, this study aims to quantify the quality of fingerprints and establish the optimal conditions for fingerprint development reagent(1,2-Indanedione, Basic Yellow 40) commonly used on porous and non-porous surfaces. Evaluation factors were set as optical characteristics that can affect the evaluation of the fingerprint, referring to previous studies. Brightness, contrast, signal to noise ratio were set as evaluation factors. More detailed comparison was possible using the optical characteristic evaluation technique, and the optimal light source and filter conditions according to the reagent could be found.

Characterization of Natural Cellulosic Fiber Obtained from the Flower Heads of Milk Thistle (Silybum marianum) as a Potential Polymer Reinforcement Material

ABSTRACT Natural fibers are being investigated as alternatives to synthetic fibers in composite materials. In this paper, the physical, chemical, thermal, and morphological characteristics of fibers derived from milk thistle flower heads were characterized as potential polymer reinforcement material using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The fibers were found to contain 42.9% cellulose, 21.2% hemicellulose, and a negligible lignin content. The fiber constituent functional groups were similar to those observed for other natural fibers. The crystallite size and the crystallinity index were found to be 2.23 nm and 84 ± 3%, respectively. The thermal stability of the fibers was found to be 220°C. The fibers start rapidly degrading above 290°C. Morphologically, the fibers appeared to have a nonporous surface with well-structured longitudinal parallel grooves. Cross sectionally, the fibers consisted of multiple hollow lumens interconnected with cell walls. The hollowed nature of the fibers explains the low value (0.33 ± 0.04 g mL−1) of their density. The tensile strength of the fibers was determined to be 22 ± 1 MPa. In conclusion, the fibers of the flower heads of milk thistle can be used as effective reinforcements in polymer matrices.

Preliminary Study: DNA Transfer and Persistence on Non-Porous Surfaces Submerged in Spring Water.

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat saliva of known DNA quantity was applied to glass slides and exposed to stagnant and flowing spring water to observe the effects on both DNA quantity and STR detection. Results supported that DNA deposited onto glass and subsequently submerged in water experienced a decrease in DNA quantity over time, yet submersion did not have as strong of a negative effect on the detected amplification product. Additionally, an increase in DNA quantity and detected amplification product from designated blank slides (no initial DNA added) could indicate the possibility of DNA transfer.

The microbiome of an outpatient rehabilitation clinic and predictors of contamination: A pilot study.

Understanding sources of microbial contamination in outpatient rehabilitation (REHAB) clinics is important to patients and healthcare providers. The purpose of this study was to characterize the microbiome of an outpatient REHAB clinic and examine relationships between clinic factors and contamination. Forty commonly contacted surfaces in an outpatient REHAB clinic were observed for frequency of contact and swiped using environmental sample collection kits. Surfaces were categorized based on frequency of contact and cleaning and surface type. Total bacterial and fungal load was assessed using primer sets specific for the 16S rRNA and ITS genes, respectively. Bacterial samples were sequenced using the Illumina system and analyzed using Illumina-utils, Minimum Entropy Decomposition, QIIME2 (for alpha and beta diversity), LEfSe and ANCOM-BC for taxonomic differential abundance and ADONIS to test for differences in beta diversity (p<0.05). Porous surfaces had more bacterial DNA compared to non-porous surfaces (median non-porous = 0.0016ng/μL, 95%CI = 0.0077-0.00024ng/μL, N = 15; porous = 0.0084 ng/μL, 95%CI = 0.0046-0.019 ng/μL, N = 18. p = 0.0066,DNA. Samples clustered by type of surface with non-porous surfaces further differentiated by those contacted by hand versus foot. ADONIS two-way ANOVA showed that the interaction of porosity and contact frequency (but neither alone) had a significant effect on 16S communities (F = 1.7234, R2 = 0.0609, p = 0.032). Porosity of surfaces and the way they are contacted may play an underestimated, but important role in microbial contamination. Additional research involving a broader range of clinics is required to confirm results. Results suggest that surface and contact-specific cleaning and hygiene measures may be needed for optimal sanitization in outpatient REHAB clinics.

Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures.

Low temperature is conducive to the survival of COVID-19. Some studies suggest that cold-chain environment may prolong the survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increase the risk of transmission. However, the effect of cold-chain environmental factors and packaging materials on SARS-CoV-2 stability remains unclear. This study aimed to reveal cold-chain environmental factors that preserve the stability of SARS-CoV-2 and further explore effective disinfection measures for SARS-CoV-2 in the cold-chain environment. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, on various types of packaging material surfaces, i.e., polyethylene plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of visible light (wavelength 450 nm-780 nm) and airflow on the stability of SARS-CoV-2 pseudovirus at -18°C was subsequently assessed. Experimental data show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surfaces than on nonporous surfaces, including polyethylene (PE) plastic, stainless steel, and Teflon. Compared with that at 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperatures. Seawater preserved viral stability both at -18°C and with repeated freeze-thaw cycles compared with that in deionized water. Visible light from light-emitting diode (LED) illumination and airflow at -18°C reduced SARS-CoV-2 pseudovirus stability. Our studies indicate that temperature and seawater in the cold chain are risk factors for SARS-CoV-2 transmission, and LED visible light irradiation and increased airflow may be used as disinfection measures for SARS-CoV-2 in the cold-chain environment.

Optimal Fast Integral Decontamination of Bacillus thuringiensis Aerosols and Fast Disinfection of Contaminated Surfaces.

Aerosolized anthrax (Bacillus anthracis) spores are of extreme health concern and can remain airborne for hours and contaminate all kinds of surfaces, constituting reservoirs from which resuspension is easily produced. The assessment of decontamination techniques must therefore consider both air and surfaces. In the present study, several kinds of disinfecting fogs were experimentally tested against Bacillus thuringiensis spores, which served as a surrogate for Bacillus anthracis, both as aerosols released into the air and spread on porous and non-porous surfaces with different positions and orientations. This technology removed Bacillus thuringiensis spores from the air in 20 min with just a 1 min application of fog. The dynamics and characteristics of the fog, related to aerosol and surface interactions, proved to be critical for optimal performance and decontamination. An optimal configuration could provide effective disinfection even on indirectly reached surfaces. In all cases, 8% hydrogen peroxide (H2O2) provided a higher disinfection rate than 2% glutaraldehyde.

Hydrophobic-oleophilic surfaces based on chemical modification of nanoporous alumina

Hydrophobic/oleophilic nanoporous anodic alumina substrates were fabricated by two-step anodization method following of chemical modification with 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane (FOTS). Surface morphology was characterized using a scanning electron microscopy. The influence of the topography and the pore size of the surface in the contact angle measurements with different solvents have been studied. The water repellence capacity of the nanoporous anodic alumina structure as fabricated depends on pore diameter but, there is a critical value of pore size beyond which the water contact angle decrease. After chemical modification of the surface, this effect is not observed. The porous topography of the material is not an advantage for the oleophibicity. The CA values for the non-porous surface using different solvents are lower than the structured surface.The results obtained in this study can be used to desire wettability properties. Modified NAA exhibit hydrophobicity and at the same time permeability for solvents with low surface tension.

Latent Fingerprint Development by Brick Powder

In forensic investigations, the relationship between the criminal, the victim, and the crime scene can be firmly established through the detection of latent finger marks. Fingerprints are avital and unique identity of a person. These are impressions left by the friction ridges of a human finger on contact with any surface. Many unique characteristics in the human body like a fingerprint, DNA, palm prints, iris patterns, voices, etc. So, Fingerprint is a unique characteristic of the human body, and every human’s different fingerprints between identical twins. As we know friction ridges develop in a 3-4 month of gestation duration time. Mayer, a German doctor, and anatomist were the first to write that friction ridge skin is unique. The fingerprint is the most important evidence at the Crime scene and identification of the criminal. Fingerprint identification is a method of identification using the impression formed by the minute ridges seen on the fingertips. Fingerprint has certain individual characteristics that are unique. Latent fingerprints are most generally seen prints from the crime scene. Such prints are obtained when natural oils and perspiration existing between the fingertip ridges are transferred to a surface by any contact. Latent prints are invisible and are much harder to detect and preserve. In this research paper, a new method for the development of Latent fingerprints is used that’s brick powder. The brick powder is used in various Porous and Non-porous surfaces like plastic glass, ordinary mirror, matchbox, painted wall, writable CD, wooden substrate, currency note, door handle, floor surface, book cover, sunglasses, and mobile glass card for development of latent fingerprint impression.

Contact time and disinfectant formulation significantly impact the efficacies of disinfectant towelettes against Candida auris on hard, non-porous surfaces

There has been an increase in Candida auris healthcare-associated infections, which result from cross-contamination from surfaces and equipment. In this study, we tested the efficacies of EPA-registered disinfectant towelettes products that are increasingly used for infection control against C. auris at a range of contact times following modifications to standard EPA protocol MB-33-00. Hydrogen peroxide (HP)-based disinfectant towelettes were more efficacious against C. auris than the quaternary ammonium chloride (QAC)-alcohol-based disinfectant towelettes irrespective of tested contact times. Thirty s contact time was significantly less effective in reducing C. auris compared to 1-, 2-, 3-, and 10-min contact times. However, there were no statistically significant differences in the level of disinfection among 1-min and longer contact times regardless of product chemistry. None of the products achieved a standard six-log10 reduction at any tested contact times. Overall, the HP-based disinfectant towelette was significantly more fungicidal than the QAC-alcohol-based disinfectant towelette. For all product types, 30 s contact time did not achieve the same level of disinfection as 1-min or longer contact times. Overall, disinfectant towelette efficacy is dependent upon product formulation and contact time.