Disinfection Time Research Articles

Inactivation of Replication-Competent Vesicular Stomatitis Virus as SARS-CoV-2 Surrogate on Common Surfaces by Disinfectants.

Surface disinfection is part of a larger mitigation strategy to prevent the spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus causing coronavirus disease-2019 (COVID-19). Research evaluating the time, nature, and extent of surface disinfection of replication-competent viruses is needed. We evaluated the efficacy of two disinfectants against a replication-competent SARS-CoV-2 surrogate on three common public surfaces. Vesicular stomatitis virus expressing green fluorescent protein (VSV-GFP) was our replication-competent SARS-CoV-2 surrogate. Disinfection occurred using Super Sani-Cloth Germicidal Disposable Wipes and Oxivir Tb spray per manufacturer instructions to test the efficacy at reducing the presence, viability, and later replication of VSV-GFP on stainless steel, laminate wood, and porcelain surfaces using standardized methods after recovery and toxicity testing. During the main trials, we placed 100 µL spots of VSV-GFP at viral titers of 108, 107, and 106 PFU/mL on each surface prior to disinfection. Trials were completed in triplicate and post-disinfection measurements on each surface were compared to the measurements of non-disinfected surfaces. Disinfectants were considered efficacious when ≥3-log10 reduction in the number of infectious VSV-GFP virus units was observed on a given surface during all trials. Both disinfectants produced a ≥3.23-log10 reduction in infectious VSV-GFP virus unit numbers, with all trials showing no viable, replication-competent VSV-GFP present on any tested surface. The two disinfectants eliminated the presence, viability, and later replication of VSV-GFP, our SARS-CoV-2 surrogate, on all surfaces. This information suggests that, if following manufacturer instructions, overcleaning surfaces with multiple disinfectant solutions may be unnecessary.

Implementation of a Low-Cost Method to Reduce Bacterial Load in Patient-Room Sink Drains

Background: Sink drains can act as breeding grounds for multidrug-resistant (MDR) bacteria, leading to outbreaks. Drains provide a protected humid environment where nutrient-rich substances are available. Recent and growing installation of water and energy conservation devices have led to increased frequency of drain blockage due to biofilm accumulation. Ineffective drainage may lead to backflow and accumulation of water in the sink during use, increasing the risk of contaminated aerosols formation or direct contamination of surrounding material and equipment. Cleaning and disinfection procedures of sink drains need to be improved to prevent amplification and dispersion of MDR bacteria. The objective of this study was to investigate alternatives to reduce the biofilm and risk of contamination through aerosols. Methods: Sink drains from patient rooms were randomly selected in the neonatal intensive care unit of a 450-bed pediatric hospital. We tested 4 approaches: (1) new drain; (2) self-disinfecting heating-vibration drain; (3) chemical disinfection with 20 ppm chlorine for 30 minutes; and (4) thermal disinfection with > 90°C water for 30 minutes. A special device was used during disinfection to increase the disinfectant contact time with the biofilm. Treatments were conducted weekly, with prior sampling of drain water. Other drains were also sampled weekly, including a control drain with no intervention. Bacterial loads were evaluated using flow cytometry and heterotrophic plate counts. The drains were made of stainless steel, a heat-conductive material. Results: Preliminary results show that chlorine disinfection had a small impact (<1 log) on culturable bacteria at 48 hours after disinfection but not after a week or repeated weekly disinfection. Thermal disinfection using boiling water is promising, showing an important decrease of 4 log in culturable cells after 48 hours and a concentration still 100× lower 1 week after the disinfection. Repeated weekly thermal disinfection maintained lower culturable levels in the drain. No culturable cells were detected in water from the self-disinfecting drain 2 months after installation, whereas the new drain became fully colonized to concentrations similar to those of drains prior to interventions during the same period. Conclusions: Thermal disinfection of drains is a promising alternative to chlorine. This solution is interesting because it is nontoxic and easy to perform, requiring a small volume of hot water. The rapid recolonization of the new drain suggests that replacing contaminated drains is not a sustainable solution and would need to be paired with a thermal disinfection program to maintain low culturable cells.Funding: NoDisclosures: None

Effect of Hygiene Procedures on Lens Case Contamination with Povidone-Iodine or Multipurpose Disinfecting Solutions.

A multipurpose disinfecting solution (MPDS), which contains povidone-iodine (PI) as a disinfectant, has high disinfecting efficacy not only on planktonic bacterium but also on the case biofilms. The addition of case hygiene practice removed more bacteria from cases than MPDS alone. This study compared the ability of two MPDSs, one containing PI and another containing polyaminopropyl biguanide and polyquaternium, to reduce bacterial numbers in solution or adhered to the cases following case hygiene procedures. Bacterial strains (Delftia acidovorans, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis) were exposed to the MPDSs for the recommended disinfection times, and the viable number evaluated according to ISO 14729. Cases were inoculated with bacterial strains and incubated for 24 hours to allow for biofilm formation. Cases were disinfected with both disinfecting solutions for 4 hours and rinsed, followed by recapping or air-drying, or tissue-wiping and air-drying for 18 hours. The number of survivors was counted using standard culture techniques. Both products exceeded the recommended 3-log reduction against planktonic bacteria. Regarding biofilm, after rinsing and recapping wet, the numbers of D. acidovorans (mean difference [95% confidence interval] log10 colony-forming units per case, -2.9 [0.8 to -4.6], P < .01), P. aeruginosa (-2.0 [0.5 to -3.1], P < .01), S. marcescens (-1.7 [0.8 to -3.5], P < .05), and S. epidermidis (-2.1 [0.6 to -3.5], P < .05) in PI cases were significantly lower than in the dual-disinfectant MPDS storage cases. After air-drying, the PI storage cases had significantly lower numbers of S. maltophilia (-2.6 [0.6 to -4.0], P < .01), D. acidovorans (-1.6 [0.7 to -3.3], P < .05), and S. aureus (-1.6 [0.7 to -3.1], P < .05). The addition of tissue-wiping reduced the bacterial numbers in the MPDS storage cases to levels in the PI storage cases. Contact lens users should be recommended to tissue-wipe and air-dry their lens storage cases after disinfection with regular MPDS.

Effects of pressure steam sterilization times on the accuracy of the digital intraoral scanning data

Objective: To provide a scientific basis for the standardized operation of clinical disinfection by comparing and analyzing the influence of disinfection times on the accuracy of digital intraoral scanning. Methods: The author prepared 10 brand-new intraoral scanning heads (Trios, 3Shape, Denmark), scan the same plaster standard dentition model after 1, 20, 40, and 60 times of pressure steam sterilization, and obtained the data of four groups of experimental groups A, B, C, D, and scan the model 5 times repeatedly after each disinfection cycle of each scanning head. A model scanner (D2000, 3Shape, Denmark) was used to scan the standard dentition model, and the scan results were used as the control group data. Vernier calipers and measurement software were used to measure the arch length (the distance between the mesial cheek tips of the first molars on both sides of the maxillary) and the front and back length (the distance from the tongue protrusion of the right incisor to the buccal tip of the first molar on the right of the upper jaw) of the plaster model and the data of the 4 experimental groups. The line distance results of the 4 groups of experimental groups were compared for statistical analysis, and the trueness and precision values of the 4 groups of experimental groups were compared for statistical analysis. Results: The length of the arch across the 4 experimental groups increased with the increase in the number of disinfection (P<0.05), and there were statistical differences compared with the measurement results of the plaster model (P<0.05); the differences in the length of the dental arch were not statistically significant (P>0.05). The treness of the 4 experimental groups is statistically significant (P<0.05), and the trueness was from high to low in order of group A [(114.85±3.75) μm], group B [(124.65±3.85) μm], group C [(131.45±3.04) μm] and group D [(144.64±3.34) μm]; the precision of the 4 experimental groups was not statistically significant (P>0.05). Conclusions: The number of times of pressure steam sterilization can affect the accuracy of the scanning results of the digital intraoral scanner, and with the increase of the number of sterilizations, the error of the scanning results also tends to increase. The number of sterilizations has no effect on the repeatability of the digital scanning results. The increase in the number of times of pressure steam sterilization affects the accross of the arch but has no effect on the length of the dental arch, and the range of change of the length of the arch is within the clinically acceptable range. After 60 times of pressure steam sterilization, the accuracy of digital scan data can still meet clinical needs.

Efecto de la desinfección con hipoclorito de sodio y multiplicación con bencilaminopurina en Musa spp.

Dentro de la familia de las Musaceas, el género Musa ha adquirido importancia en la alimentacion a nivel mundial, ya sea por el consumo directo (fruta) o indirecto (previa cocción) como es en caso de Bolivia, sin embargo por cambio de actividades agroeconómicas este rubro esta siendo afectado, y tambien carecen de un mecanismo de regeneracion de los plantines libre de enfermedades. El presente estudio tuvo como objetivo estandarizar la desinfección de hijuelos de Gran enano (banano) y Harton (plátano) con diferentes concentraciones de hipoclorito de sodio (NaClO) e inducir la multiplicación con la aplicación de bencilaminopurina. Los hijuelos de ambas variedades fueron sometidas a dos tiempos de desinfección, el primero consistió en seleccionar los hijuelos de 10 a 12 cm de longitud y sumergirlas en hipocloriro de sodio al 8 % durante 12 min y posteriormente, se dividio en dos grupos para la segunda desinfeccion de 2 y 4 % con hipoclorito de sodio durante 7 min, luego fueron enjuagadas y sembradas en el medio Murashige y Skoog (MS) con 2 mg L-1 BAP (bencilaminopurina) + 1 mg L-1 ANA (ácido naftalenacético). En la fase de multiplicación los brotes se sembraron en medios de cultivo (MC1 = MS + 2.5 mg L-1 BAP + 1 mg L-1 ANA) y (MC2 = MS + 5 mg L-1 BAP + 1 mg L-1 ANA). Se determinó que la combinacion de una primera y segunda desinfección 8 y 4 % de NaClO desinfectó un 80 % en Gran enano y 40 % en Hartón respectivamente. En la fase de multiplicación se determinó que el medio de cultivo MS suplementado con 5 mg L-1 de BAP favoreció en la formación de 8 brotes en banano en ambas variedades.

Managing the bacterial contamination risk in an axenic mice animal facility.

A gap exists between good laboratory practices with axenic animals and the procedures applied. This work examined the efficacy of sodium dichloroisocyanurate (MB-10) and potassium peroxymonosulfate (Virkon™) disinfectants, as well as the appropriate soaking time for materials used with the ISOcage Biosafety Station™. We also compared the microbial load in cage systems hosting mice over 2 weeks in axenic rooms (ARs) and in typical specific-pathogen-free (SPF) non-axenic rooms (NARs) to identify resistant microorganisms, targeted for longer soaking disinfection, and evaluated the necessary procedures for reducing the microbial load in AR. Staphylococcus was the most frequently isolated genus (in both ARs and NARs). An average of three spore-forming microorganisms per cage were counted from AR. The disinfection time to reach 1 log reduction for Bacillus atrophaeus spores varied from 138 s (100 ppm MB-10) to 290 (Virkon™) to <20 s for S. epidermidis (100 ppm MB-10). AR management protocols lead to a microbial load that is 1000 times lower than that found in NARs. Data comparing the microbial load in SPF and axenic facilities can be used to improve the effectiveness of their microbial control procedures.

The COVID-19 Pandemic, Part 2: Understanding the Efficacy of Oxidized Copper Compounds in Suppressing Infectious Aerosol-Based Virus Transmission

In CORROSION’S June 2020 editorial,1 we explored the COVID-192 pandemic and the antimicrobial function of copper and silver enabled by corrosion Since that editorial was written, we have gone from 2 1 million confirmed infections and over 143,000 related deaths worldwide3 to 114,582,356 cases and 2,541,808 deaths as of March 1, 2021, according to the John Hopkins University COVID-19 Dashboard 3 A cause of this large increase is the high rate of the spread of SARS-CoV-2 (the virus that causes the coronavirus disease COVID-19), which is 40-fold greater than that of SARS-CoV-1 4 Recently, a more highly contagious mutation has been reported which makes this virus (referred to as the COVID-19 virus throughout this editorial) even more transmittable 5 This makes the COVID-19 virus even more difficult to control4 than SARS-CoV-1 Surgical masks are often made of three different fiber layers to prevent the entry of viruses: the outside layer is designed to stop liquids from traveling inwards towards the face, mouth, and nose without encountering an obstacle;an interlayer acts as a barrier against viruses and bacteria;and an inner layer absorbs moisture exhaled by the wearer 7,8 Different materials can be synthesized to act as protective coatings where the fabric can be designed to control pore size relative to airborne aerosol and particulate dimensions,4 as well as function in other ways such as by electrostatic attraction of aerosol particles (a) Possible pathways for transmission of the COVID-19 virus involving human atomization of viruses during the coughing or sneezing of an infected person Elemental copper and silver10 possess intrinsic antimicrobial properties that are enabled by corrosion which releases free metal cations 25,32,34 The free ions are distinct from copper ion sequestering in the oxide layer formed over the surface of the alloy or dissolved but chelated (to form a compound usually with an organic species in the environment, whereupon the organic is bonded to the copper ion) with some molecular species in solution 25,32,34-37 Inactivation time (>99 9% reduction) of Escherichia coli (HCB1) and Legionella pneumophila bacteria in various soluble [Cu2+] concentrations Because the corrosion thermodynamics, kinetics, and the stability of the oxidized products formed can all differ with the molecular identity of the product, inoculum, saliva,40 and perspiration “solution chemistry,”32 these considerations need to be evaluated carefully to fully understand the efficacy of both Cu as a surface disinfectant and Cu compounds as disinfecting agents impregnated in PPE

Nanotechnology in Wastewater Management: A New Paradigm Towards Wastewater Treatment.

Clean and safe water is a fundamental human need for multi-faceted development of society and a thriving economy. Brisk rises in populations, expanding industrialization, urbanization and extensive agriculture practices have resulted in the generation of wastewater which have not only made the water dirty or polluted, but also deadly. Millions of people die every year due to diseases communicated through consumption of water contaminated by deleterious pathogens. Although various methods for wastewater treatment have been explored in the last few decades but their use is restrained by many limitations including use of chemicals, formation of disinfection by-products (DBPs), time consumption and expensiveness. Nanotechnology, manipulation of matter at a molecular or an atomic level to craft new structures, devices and systems having superior electronic, optical, magnetic, conductive and mechanical properties, is emerging as a promising technology, which has demonstrated remarkable feats in various fields including wastewater treatment. Nanomaterials encompass a high surface to volume ratio, a high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization which makes them suitable for application in wastewater treatment. In this article we have reviewed the techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology. Furthermore, this review also highlights the fate of the nanomaterials in wastewater treatment as well as risks associated with their use.

Formation and control of C- and N-DBPs during disinfection of filter backwash and sedimentation sludge water in drinking water treatment

Drinking water treatment plants (DWTPs) produce filter backwash water (FBW) and sedimentation sludge water (SSW) that may be partially recycled to the head of DWTPs. The impacts of key disinfection conditions, water quality parameters (e.g., disinfection times, disinfectant types and doses, and pH values), and bromide concentration on controlling the formation of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloacetamides (HAMs) during disinfection of FBW and SSW were investigated. Concentrations of most disinfection byproducts (DBPs) and associated calculated toxicity increased with extended chlorination for both FBW and SSW. During chlorination of both FBW and SSW, elevated chlorine doses significantly increased THM yields per unit dissolved organic carbon (DOC), but decreased HAN and HAM yields, with minimum effect on HAA yields. Chloramine disinfection effectively inhibited C-DBP formation but promoted N-DBPs yields, which increased with chloramine dose. Calculated toxicities after chloramination increased with chloramine dose, which was opposite to the trend found after free chlorine addition. An examination of pH effects demonstrated that C-DBPs were more readily generated at alkaline pH (pH=8), while acidic conditions (pH=6) favored N-DBP formation. Total DBP concentrations increased at higher pH levels, but calculated DBP toxicity deceased due to lower HAN and HAM concentrations. Addition of bromide markedly increased bromo-THM and bromo-HAN formation, which are more cytotoxic than chlorinated analogues, but had little impact on the formation of HAAs and HAMs. Bromide incorporation factors (BIFs) for THMs and HANs from both water samples all significantly increased as bromide concentrations increased. Overall, high bromide concentrations increased the calculated toxicity values in FBW and SSW after chlorination. Therefore, while currently challenging, technologies capable of removing bromide should be explored as part of a strategy towards controlling cumulative toxicity burden (i.e., hazard) while simultaneously lowering individual DBP concentrations (i.e., exposure) to manage DBP risks in drinking water.

Predictive water virology using regularized regression analyses for projecting virus inactivation efficiency in ozone disinfection

Wastewater reclamation and reuse have been practically applied to water-stressed regions, but waterborne pathogens remaining in insufficiently treated wastewater are of concern. Sanitation Safety Planning adopts the hazard analysis and critical control point (HACCP) approach to manage human health risks upon exposure to reclaimed wastewater. HACCP requires a predetermined reference value (critical limit: CL) at critical control points (CCPs), in which specific parameters are monitored and recorded in real time. A disinfection reactor of a wastewater treatment plant (WWTP) is regarded as a CCP, and one of the CCP parameters is the disinfection intensity (e.g., initial disinfectant concentration and contact time), which is proportional to the log reduction value (LRV) of waterborne pathogens. However, the achievable LRVs are not always stable because the disinfection intensity is affected by water quality parameters, which vary among WWTPs. In this study, we established models for projecting virus LRVs using ozone, in which water quality and operational parameters were used as explanatory variables. For the model construction, we used five machine learning algorithms and found that automatic relevance determination with interaction terms resulted in better prediction performances for norovirus and rotavirus LRVs. Poliovirus and coxsackievirus LRVs were predicted well by a Bayesian ridge with interaction terms and lasso with quadratic terms, respectively. The established models were relatively robust to predict LRV using new datasets that were out of the range of the training data used here, but it is important to collect LRV datasets further to make the models more predictable and flexible for newly obtained datasets. The modeling framework proposed here can help WWTP operators and risk assessors determine the appropriate CL to protect human health in wastewater reclamation and reuse.

In vitro effects of multi-purpose contact lens disinfecting solutions towards survivability of Acanthamoeba genotype T4 in Malaysia.

The incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 105 cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer’s minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 ⁰C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis.

Influence of scarification method on seed germination of the terrestrial orchid Anacamptis laxiflora (Lam.)

Abstract A critical step during in vitro sexual propagation of terrestrial orchids is the treatment of the microscopic seeds with a disinfecting solution that kills bacteria and fungi attached to the seeds. This treatment is necessary to prevent infection of the culture vessels. At the same time, the treatment serves to scarify the seeds, a process that disrupts seed dormancy and initiates germination. The literature is inconclusive with respect to the proper combination of disinfecting solution strength and treatment duration. Both factors should be adapted to each species to guarantee minimal infection rate without damaging the embryo. This research aims to compare three disinfection/scarification methods for seeds of Anacamptis laxiflora (Lam.): (i) soaking in 0.5% NaClO, (ii) soaking in 0.5% NaClO, then centrifugation, and (iii) presoaking the seeds in sucrose solution, then soaking in 0.5% NaClO. The seeds were soaked in the disinfecting solution for 5 to 85 min. Following scarification, the seeds were sown in modified Malmgren nutrient medium. Infected and germinated vessels were counted at 41 and 189 d after sowing. We found that the longer the chemical treatment, the lower the infection rate, and the higher the germination rate. There was no significant difference in germination rate between the NaClO and the NaClO-plus-centrifugation method; in fact, the slight savings in disinfection time effected by centrifugation were more than offset by the added complexity of the method. Moreover, we found that centrifugation significantly delays germination. The sucrose presoak-plus-NaClO method was superior to plain NaClO, as the sucrose stimulates the germination of microbial spores on the surface of the seeds, making them easier to kill. Perhaps seeds with thicker testa as well as whole immature capsules could benefit even more from the pretreatment in sucrose solution.

COV19-CNNet and COV19-ResNet: Diagnostic Inference Engines for Early Detection of COVID-19.

Chest CT is used in the COVID-19 diagnosis process as a significant complement to the reverse transcription polymerase chain reaction (RT–PCR) technique. However, it has several drawbacks, including long disinfection and ventilation times, excessive radiation effects, and high costs. While X-ray radiography is more useful for detecting COVID-19, it is insensitive to the early stages of the disease. We have developed inference engines that will turn X-ray machines into powerful diagnostic tools by using deep learning technology to detect COVID-19. We named these engines COV19-CNNet and COV19-ResNet. The former is based on convolutional neural network architecture; the latter is on residual neural network (ResNet) architecture. This research is a retrospective study. The database consists of 210 COVID-19, 350 viral pneumonia, and 350 normal (healthy) chest X-ray (CXR) images that were created using two different data sources. This study was focused on the problem of multi-class classification (COVID-19, viral pneumonia, and normal), which is a rather difficult task for the diagnosis of COVID-19. The classification accuracy levels for COV19-ResNet and COV19-CNNet were 97.61% and 94.28%, respectively. The inference engines were developed from scratch using new and special deep neural networks without pre-trained models, unlike other studies in the field. These powerful diagnostic engines allow for the early detection of COVID-19 as well as distinguish it from viral pneumonia with similar radiological appearances. Thus, they can help in fast recovery at the early stages, prevent the COVID-19 outbreak from spreading, and contribute to reducing pressure on health-care systems worldwide.

Towards Customizable Robotic Disinfection With Structure-Aware Semantic Mapping

In the current COVID-19 pandemic, people expect to use robots to replace humans to complete the disinfection work in public places. Since different regions in the environment have different risks, in addition to the conventional SLAM capability, the robot also needs to be able to recognize and distinguish different objects in the scene to complete customizable disinfection tasks. In this paper, we propose a LiDAR-based semantic mapping system that can be used for robotic disinfection tasks. By using the prior information about the scene structure, our system can extract different levels of semantic information from the raw point cloud, so as to not only construct an occupancy grid map for navigation, but also construct a hierarchical semantic map that meets the needs of customizable disinfection tasks, including setting the navigation waypoints, disinfection distances and disinfection time. The effectiveness of our proposed system is proved in the real-world metro disinfection applications.

РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ ПО ОЦЕНКЕ ВЛИЯНИЯ ПРЕДПОСЕВНОЙ УФ-ОБРАБОТКИ И РЕЖИМОВ ИСКУССТВЕННОГО ОСВЕЩЕНИЯ ПРИ ПРОРАЩИВАНИИ ЛЮПИНА НА ВИТАМИННЫЙ КОРМ

One of the ways to increase the nutritional value of feed is the use of a biologically active additive based on sprouted grain. The positive use of sprouted grain of wheat and barley has been reliably established. At the same time, the possibilities of using sprouted grain of lupine are considered much less frequently. The authors have described technique and presented the results of experimental studies on assessing the eff ect of pre-sowing UV treatment and artifi cial illumination modes during lupine germination on vitamin feed. The time of UV treatment aimed at disinfection before germination and the time of grain illumination with a phytolamp during germination were chosen as the variable factors, and the length of the shoots was chosen as the response function. The range of seed illumination was from 4 to 10 h, and the UV irradiation time was from 60 to 300 s. The germination period was 5 days. Samples exposed to natural light served as control. According to the experimental data, a regression equation was obtained that describes the eff ect of UV disinfection and illumination time during growth on the length of the shoots, and graphical dependences of the change in the response function in the intervals of variation of the infl uencing factors were constructed. Experimental data have shown that an increase in the time of UV disinfection of seeds has a positive eff ect on the length of the shoots. It was revealed that on the fi fth day of germination, the maximum length of shoots (25 mm at 11 mm in control samples) was obtained with preliminary UV disinfection of germinating seeds for 300 s and 4-hour artifi cial illumination with a phytolamp. The expediency of using this technique when germinating lupine seeds for vitamin feed for animals has been experimentally confi rmed.

Social Density Monitoring Toward Selective Cleaning by Human Support Robot With 3D Based Perception System

Monitoring the safe social distancing then conducting efficient sterilization in potentially crowded public places are necessary but challenging especially during the COVID-19 pandemic. This work presents the 3D human space-based surveillance system enabling selective cleaning framework. To this end, the proposed AI-assisted perception techniques is deployed on Toyota Human Support Robot (HSR) equipped with autonomous navigation, Lidar, and RGBD vision sensor. The human density mapping represented as heatmap was constructed to identify areas with the level being likely the risks for interactions. The surveillance framework adopts the 3D human joints tracking technique and the accumulated asymmetrical Gaussian distribution scheme modeling the human location, size, and direction to quantify human density. The HSR generates the human density map as a grid-based heatmap to perform the safe human distance monitoring task while navigating autonomously inside the pre-built map. Then, the cleaning robot uses the levels of the generated heatmap to sterilize by the selective scheme. The experiment was tested in public places, including food court and wet market. The proposed framework performance analyzed with standard performance metrics in various map sizes spares about 19 % of the disinfection time and 15 % of the disinfection liquid usage, respectively.

Tannic acid-modified silver nanoparticles enhance the anti-Acanthamoeba activity of three multipurpose contact lens solutions without increasing their cytotoxicity

BackgroundFree-living amoebae of the genus Acanthamoeba are cosmopolitan, widely distributed protozoans that cause a severe, vision-threatening corneal infection known as Acanthamoeba keratitis (AK). The majority of the increasing number of AK cases are associated with contact lens use. Appropriate eye hygiene and effective contact lens disinfection are crucial in the prevention of AK because of the lack of effective therapies against it. Currently available multipurpose contact lens disinfection systems are not fully effective against Acanthamoeba trophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent AK infections. Synthesized nanoparticles (NPs) have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that some plant metabolites, including tannins, have anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of tannic acid-modified silver NPs (AgTANPs) conjugated with selected multipurpose contact lens solutions.MethodsThe anti-amoebic activities of pure contact lens care solutions, and NPs conjugated with contact lens care solutions, were examined in vitro by a colorimetric assay based on the oxido-reduction of alamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analysed by ANOVA and Student-Newman-Keuls test using P < 0.05 as the level of statistical significance.ResultsWe show that the NPs enhance the anti-Acanthamoeba activities of the tested contact lens solutions without increasing their cytotoxicity profiles. The activities are enhanced within the minimal disinfection time recommended by the manufacturers.ConclusionsThe conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach for the prevention of AK infections among contact lens users.Graphical

Study on the Dose-effect Relationship of Moxa Burning Fumigation in Air Disinfection in Traditional Chinese Medicine Clinics

Objective — It’s to study the dose-effect relationship of moxa produced by Gansu Baicao Group in the air disinfection in traditional Chinese medicine clinics. Method — Use moxa sticks burning fumigation to disinfect indoor air in the clinics of traditional Chinese medicine experts; use the natural sedimentation method to detect the bacterial content in the air; compare the sterilization effects of 0.5, 1 and 1.5 moxa sticks 0 h, 1 h and 2 h after air disinfection. Results — In the 54m3 TCM clinic, there was no significant difference in the sterilization rate of air bacteria 0h, 1h, and 2h after using 1 moxa stick and 1.5 moxa sticks respectively for fumigation and disinfection (P&gt;0.05). There was a significant difference in the sterilization rate of air bacteria between 1 moxa stick group and 0.5 moxa stick group 0 h after air disinfection (P &lt; 0. 05). There was a significant difference in the sterilization rate of air bacteria between 0 hour and 1 hour after burning fumigation for air disinfection in 0.5 moxa group (P &lt; 0. 05). Conclusion — The best dose of moxa burning fumigation for air disinfection in 54m3 Chinese medicine clinic is 0.5 stick; the best time for air disinfection is 1h after disinfection.

Barriers for Resuming Endoscopy Service in the Context of COVID-19 Pandemic: A Global Survey

Introduction: An outbreak of coronavirus disease 19 (COVID-19) has altered the dynamic of world’s healthcare system, including endoscopic practices. Curious about the situation in different endoscopic units across the globe, the study was designed to evaluate different aspects of practice resumption worldwide.Methods: An online questionnaire was created and distributed by national/regional representatives. Redcap® platform was used as the interface; afterwards, Microsoft Excel 2016 and Prism 5 were utilized for data analysis.Results: A total of 307 responses from 47 countries/regions was collected, from which 290 valid answers were inducted and further analyzed. Almost half (47%) were in post-peak period by August, 2020. Many units were not designated to be COVID-oriented facility. About 15.5% of centers remained unrecovered, mainly in North and South America; those were recovered, training was still withheld significantly. Nevertheless, opened centers kept safety measurement strictly. Though patient load was decreased by 37% in most centers, waiting list was increased 0-25%. Among many surveillance methods, body temperature, PCR and chest CT prevailed the be the most commonly used. 74.8% claimed to have increased post-procedural disinfection time and 68.2% also observed an increased in per-case inspection. PPE usage was implemented highly and shortage of these posed as one of the resumption barriers. Post-procedural patient surveillance was not reinforced.Conclusions: The study reflected closely the global revolution of the pandemic. Shortage in staff and PPE as well as difficulty in training resumption remained barriers worldwide. Incapacity of patient post-procedural surveillance raised concerns in disease control.Funding Statement: None to declare.Declaration of Interests: None to declare.Ethics Approval Statement: The study was approved by the Institutional Review Board of the National Liver Institute, Menoufia University, Egypt (NLI IRB 00003413) in June 2020, protocol number 00203/2020.

UVC disinfection robot.

The aim of the present work is to contribute in the fight against the spread of Covid-19, a novel human coronavirus, in hospitals, public transport, airlines, and any enclosed areas. In this study, we have adopted the physical disinfection method by using UVC light as agent. The UVC devices are studied and classified according their disinfectant units, complementary devices, combined disinfection agents, mobilities, and order types. Our finding shows that a mobile robot is the most efficient device to inactivate microorganisms, so we have developed a robot called i-Robot UVC. The robot is equipped with eight UVC lamps around a central column and two lamps on the top. The column is fixed on a mobile base where several sensors are integrated to measure temperature and humidity on the one hand, and on the other, to detect motion plus position and to avoid obstacles. The robot can estimate automatically the disinfection time while monitored by Wi-Fi connection from a phone or a tablet. I-Robot UVC disinfects rooms and equipment with ultraviolet light, and shuts down when humans are around to keep them safe. The robot can kill 99,999% bacteria and various through UVC lamps led. The innovative robot UVC was patented under the number TN2020/0063.