Disinfection Process Research Articles

Plasma disinfection procedures for surfaces in emergency service vehicles: a field trial at the German Red Cross

The demand for thorough disinfection within ambulances is essential, given the in-vehicle medical procedures and the potential high risk of infections due to patients' open wounds. One solution that can address this hygiene challenge involves the application of reactive products generated from atmospheric (air) oxygen and water vapor, activated through the use of cold plasma. Cold plasma's charged particles perforate the cell membranes of microorganisms. This process does not work in human cells, as proteins in the form of enzymes within the body break down the cold plasma and protect the cells. The study was done on an ambulance that was contaminated in eight places. Samples were taken from each site, and two surfaces measuring approximately 8 × 8 cm were carefully sealed and marked. These surfaces were deliberately contaminated by applying an Enterococcus faecium suspension of 8.5 × 107 CFU/mL using a sterile cotton swab. It was followed by the disinfection procedure, that was initiated with the PLASMOCAR device. It was positioned on the front workspace and operated for a duration of 30 min, utilizing the vehicle's onboard voltage. Throughout the operation, all doors and windows were closed and the vehicle's air conditioning system remained active. After the completion of the disinfection process, samples were collected from the surfaces for bacterial counts. A reduction of 3.73 log levels in initial bacteria was accomplished within the rescue vehicle for Enterococcus faecium, equivalent to a 10–fourfold reduction in bacteria, eliminating up to 99.99% of the initial microorganisms. This success makes the process well-suited and convenient as an ongoing "background" procedure to enhance the established disinfection procedures. The established disinfection procedures outlined in the hygiene plan must be promptly implemented whenever mechanical surface cleaning is required. The use of PLASMOCAR offers an extra layer of protection and security, significantly decreasing the risk of microorganism transmission through cross-contamination and aerosols. This is a significant benefit for the well-being of both staff and patients.

Microbiological Load on the Various Surfaces

Microorganisms are ubiquitous, including within habitats, and they have a negative impact on human health, sanitation, and living situations. Surface microbial load is affected by various factors such as location, usage, cleaning, and environment. Kitchen countertops, toilet fittings, doorknobs, electrical appliances, and fabrics can harbor bacteria, viruses, fungi, and archaea. These pathogens may originate from persons, air or external sources. It is known that high microbial loads on surfaces cause health hazards. Pathogenic bacteria can live for extended durations on surfaces, causing infections by contact or aerosolization. Surface microbial load can be decreased through cleaning and disinfection processes. Reducing microbiological contamination requires the use of appropriate cleaning products, and procedures. In antimicrobial coatings, silver ions and other disinfectants can inhibit surface bacterium adhesion and growth. To mitigate health risks, it is necessary to comprehend microbial colonization and survival on various surfaces. This article examines common surface bacteria, microbial load factors, transmission pathways, and their impact on human health.

Sustainable Water Management with Design and Economic Evaluation of Recycling Greywater at Abu Dhabi University—A Case Study on Decentralization

Wastewater can be segregated as greywater and blackwater separately. The greywater generated in malls, restaurants, and university buildings is generally dilute, while it will later become concentrated when it is merged into the main sewage collection line. It would be more economical and environmentally friendly if the greywater is treated locally using a modular wastewater treatment facility that produces treated water amenable for other uses such as irrigation or horticulture. The objective of this article is to study the economic feasibility and design a decentralized plant that produces fresh water from greywater generated at the Abu Dhabi university campus located in the United Arab Emirates. The proposed unit will consist of a compact design of filtration, chemical treatment and disinfection processes that would generate treated wastewater that can be used for horticulture in and around the local campus or can be stored and supplied for irrigation purposes. Several parameters such as total suspended solids, biological oxygen demand, and chemical oxygen demand are measured and monitored throughout the entire process and are regulated by appropriate operations performed for each unit. This study shows that decentralization of greywater treatment is not only economical but also essential for the management of fresh water, which in turn assures environmental sustainability. By using coagulation, flocculation and chlorination with a 30 mg/L alum dosage, 0.6 mg/L of polyacrylamide and 0.12 mg/L of sodium hypochlorite, respectively, greywater is treated to meet the water specification for reusing it for horticulture. Further, a modular plant with an investment of USD 8 M is proved to process 90,000 tons of greywater with a 34% discounted rate of return.

Abatement of Nitrophenol in Aqueous Solution by HOCl and UV/HOCl Processes: Kinetics, Mechanisms, and Formation of Chlorinated Nitrogenous Byproducts

HOCl and UV activated HOCl (UV/HOCl) have been applied for water disinfection and abatement of organic contaminants. However, the production of toxic byproducts in the HOCl and UV/HOCl treatment should be scrutinized. This contribution comparatively investigated the elimination of 4-nitrophenol and the generation of chlorinated byproducts in HOCl and UV/HOCl treatment processes. 61.4% of 4-nitrophenol was removed by UV/HOCl in 5 min with HOCl dose of 60 μM, significantly higher than that by UV (3.3%) or HOCl alone (32.0%). Radical quenching test showed that HO• and Cl• played important roles in UV/HOCl process. 2-Chloro-4-nitrophenol and 2,6-dichloro-4-nitrophenol were generated consecutively in HOCl process; but their formation was less in the UV/HOCl process. Trichloronitromethane (TCNM) was only found in the UV/HOCl process, and its production increased with increasing HOCl dosage. Besides chlorinated products hydroxylated and dinitrated products were also identified in the UV/HOCl process. Transformation pathways involving electrophilic substitution, hydroxylation, and nitration were proposed for 4-nitrophenol transformation in the UV/HOCl process. Wastewater matrix could significantly promote the transformation of 4-nitrophenol to 2-chloro-4-nitrophenol in UV/HOCl process. Results of this study are helpful to advance the understanding of the transformation of nitrophenolic compounds and assess the formation potential of chlorinated byproducts in HOCl and UV/HOCl disinfection processes.

African Swine Fever: Transmission, Spread, and Control through Biosecurity and Disinfection, Including Polish Trends.

African swine fever is a contagious disease, affecting pigs and wild boars, which poses a major threat to the pig industry worldwide and, therefore, to the agricultural economies of many countries. Despite intensive studies, an effective vaccine against the disease has not yet been developed. Since 2007, ASFV has been circulating in Eastern and Central Europe, covering an increasingly large area. As of 2018, the disease is additionally spreading at an unprecedented scale in Southeast Asia, nearly ruining China's pig-producing sector and generating economic losses of approximately USD 111.2 billion in 2019. ASFV's high resistance to environmental conditions, together with the lack of an approved vaccine, plays a key role in the spread of the disease. Therefore, the biosecurity and disinfection of pig farms are the only effective tools through which to prevent ASFV from entering the farms. The selection of a disinfectant, with research-proven efficacy and proper use, taking into account environmental conditions, exposure time, pH range, and temperature, plays a crucial role in the disinfection process. Despite the significant importance of ASF epizootics, little information is available on the effectiveness of different disinfectants against ASFV. In this review, we have compiled the current knowledge on the transmission, spread, and control of ASF using the principles of biosecurity, with particular attention to disinfection, including a perspective based on Polish experience with ASF control.

A pilot study on the antimicrobial efficacy of a novel UV-LED system against drainage stack bioaerosol emissions during flushing episodes

Inactivation of airborne microorganisms by ultraviolet (UV) light has been considered one of the most effective procedures among disinfection methods. Ultraviolet light-emitting diodes (UV-LEDs) have a unique place as an emerging technology in air disinfection processes because of their rapid effectiveness and lack of material deterioration. In this study, the efficacy of high-power 285 nm UV-LEDs was explored for Escherichia coli (E. coli) (ATCC15597) inactivation in drainage stack airflow under continuous- and pulsed-UV irradiation conditions. Most relevant photoelectric properties influencing the device operation and performance, including duty cycles and input voltage, were thoroughly investigated. Antimicrobial efficiency varied from 29.0% to 88.0%. The antimicrobial efficiency of pulsed UV irradiation at different duty cycles but the same UV dose was similar. Antimicrobial efficiency was positively correlated with input voltage but negatively correlated with airflow velocity. Moreover, antimicrobial efficiency increased almost linearly with input power per airflow volume (P/Qa). The estimated Z-values of E. coli ranged from 0.0027 to 0.0341 cm2/µJ, and about 29–370 μJ/cm2 of UV dose can be used to obtain one-log inactivation of E. coli, depending on the experimental conditions. The results of this investigation indicate that UVB units can inactivate gastrointestinal drainage stack bioaerosols effectively. This study provides critical information and guidelines for disinfecting drainage stacks with UV, which may aid pathogen infection control in public environments during outbreaks.

A passive continuous flow pasteurisation process designed for solar application. Part I: Indoor experiments for thermal characterization and bacteria inactivation

Within the framework of the WHO's universal sanitation policy, water disinfection processes with low manufacturing and maintenance costs must be developed. This is the case with solar pasteurisation, the effectiveness of which, at 50–70 °C, has been already demonstrated in the literature. To be fully acceptable, the process must be appropriately energy efficient and be able to adapt to natural fluctuations in solar radiation. An experimental indoor test platform under controlled conditions, with thermal powers supplied similar to those of a future solar application with a standard thermal panel, was designed. Experimental results highlighted the specific thermal energy consumption (SECtherm), which is highly dependent on the effectiveness of a deliberately oversized heat recovery exchanger. The operation under both stationary and dynamic regimes underscored the role of the thermostatic valve which autonomously calibrated the flow of the fluid according to the injected available power. For the temperature range sufficient to inactivate microorganisms [50–70 °C], the specific thermal energy consumption reached values between 3.5 and 6 kWhtherm.m−3. The bacterial indicators, Escherichia coli and Enteroccocus, currently present in surface waters in the south of France, were no longer detected (<10 MPN.100 mL−1) after one-minute of pasteurisation at 55 °C and 60 °C, respectively.

Gravity driven ceramic membrane loaded birnessite functional layer for manganese removal from groundwater: The significance of disinfection on biofilm

Gravity-Driven Ceramic Membrane (GDCM) technology has gained popularity and recognition in water purification on account of its low energy consumption and convenient operation. This study aimed to comprehensively assess the effects of different disinfectants, including hydrogen peroxide (H2O2) and sodium hypochlorite (NaClO), on GDCM performance. It focused on the change in manganese removal and structure of the powdered activated carbon (PAC) - manganese oxides (MnOx) pre-deposited at the membrane interface and as well membrane fouling mitigation. The results showed that after the first two disinfection cycles, the flux recovery was 15 LMH for H2O2, while using NaClO only achieved an average recovery of 2 LMH and increased the effluent manganese, exceeding 0.1 mg/L within a short period of time. During the disinfection process, H2O2 exhibited better performance in mitigating membrane fouling compared to NaClO in the GDCM system. Additionally, by observing the recovery time of Mn2+ after disinfection, it can be deduced that the initial manganese removal mainly resulted from biological action of manganese-oxidizing bacteria (MnOB), while the later stage relied primarily on the catalytic oxidation action of birnessite. Fluorescence excitation–emission matrix analysis (EEM) indicated that most organic compounds dissolved in the disinfectant solution after disinfection, with some permeating through the membrane, while the remaining portion continued to accumulate in the filter cake layer. This accumulation was further confirmed by the enhanced absorbance peaks of functional groups (–NH and –OH) in the Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscope - energy dispersive x-ray spectroscopy (SEM-EDS) mapping analysis revealed that MnOx formed more lamellar structures between nano-flower balls after disinfection. This increased the number of active sites and opened up water flow channels, contributing to improved flux. X-ray photoelectron spectroscopy (XPS) analysis demonstrated that Mn3+ as the dominant valence in MnOx exhibited excellent catalytic oxidation ability. Raman analysis and X-ray diffraction (XRD) indicated that MnOx showed consistent Raman spectra with birnessite before and after disinfection, and the oxidative effect of disinfection did not alter the crystal structure of MnOx. This result demonstrates the importance of applying effective disinfection in the GDCMs.

Seaweed-based alginate/hydroxyapatite composite for the effective removal of bacteria, cyanobacteria, algae, and crystal violet from water.

A novel cost-effective and multifunctional nanocomposite was developed based on sustainable macroalgae biomass. The brown seaweed Sargassum latifolium was utilized for alginate extraction and the calcareous red seaweed Tricleocarpa fragilis was utilized as CaCO3 source for nanohydroxyapatite synthesis. The developed Zn2+-crosslinked alginate/nanohydroxyapatite (ZA/nHA) beads were characterized by FT-IR, XRD, and TEM. The antimicrobial potential of ZA/nHA to disinfect synthetic Escherichia coli-contaminated water was evaluated at different bacterial load and composite concentrations. The developed ZA/nHA effectively inactivated bacteria at initial concentration ≤ 105 CFU mL-1 and 0.5-1% (w/v) of ZA/nHA within 300-360 min. The kinetics of bacterial disinfection exhibited better fitting to Weibull model than Log-liner model, which confirmed the disinfection process. Furthermore, treatment of the cyanobacterium (Chroococcus sp.) and the microalga (Chlorella sp.) with ZA/nHA showed promising antialgal properties as indicated by reductions in chlorophyll a. The treatment indicated 100% and 90% removal of Chroococcus sp. and Chlorella sp. within 2 and 4 days, respectively. The developed ZA/nHA also exhibited a promising application as a biosorbent for crystal violet (CV). The adsorption process was very fast (0.171 mg CV g-1 adsorbent was removed within 7 min at pH 6.0). The adsorption kinetics exhibited better fitting to the pseudo-second order and Elovich models than the pseudo-first order equation. Besides, Sips model better represented the isotherm data of CV adsorption. The thermodynamic analysis indicated exothermic adsorption, which became more favorable at low temperature and high CV concentration. The developed nanocomposite is eco-friendly and suitable for multiple environmental applications.

Enhancing Disinfection Efficiency of Wastewater Treatment Plant Effluent: The Role of ZnO Nanoparticles in Ultrasonic and UV-C Processes

Ultrasonic (US) and UV-C disinfection technologies have been successfully used in wastewater treatment plants (WWTPs) for disinfection purposes. The US technology is typically used as a pre-treatment step to break down larger particles and make them more susceptible to disinfection. The UV-C technology is commonly used as a final disinfection step in many WWTPs. The study aimed to assess the potential of using Zinc Oxide (ZnO) Nanoparticles (NPs) to improve the effectiveness of UV-C and US disinfection methods in treating wastewater effluent, offering a more comprehensive solution to wastewater treatment. In this experimental study, a Laboratory US Bath (40[Formula: see text]kHz) and a UV-C lamp (16[Formula: see text]W) were used. In order to investigate the effectiveness of ZnO NPs in the reduction of microbial load, 5[Formula: see text]mg/L of ZnO NPs was added to the effluent samples. Then, samples were examined for Total Coliform (TC) and Fecal Coliform (FC) reduction by the standard MPN/100[Formula: see text]mL test. The Chick‘s law was used to calculate the efficiency of microbial load. The relationship between variables was determined by regression analysis using Excel and SPSS-ver 21 software. In this study, the samples were examined in three groups: Samples that were only exposed to sonication or received UV-C radiation with Turbidity of 18 NTU (Group A) and Turbidity of 5 NTU (Group B), and Samples that received 5 mg/L of ZnO NPs (Group C). By increasing the time from 0.5 min to 10 min in the presence of UV-C, the amount of microbial population decreased, and 2 min was considered the optimal time. The maximum removal efficiencies by US for TC were 74.07,77.7, 85.1% (40∘C) and 92.5,100, and 100% (60∘C) in group A (in 30 min sonication), 85.7, 85.7, 100% (40∘C), respectively, and were 100% in other groups (B and C), respectively. The maximum removal efficiencies by US for FC were 76.4%, 88.2%, and 100% (40∘C) and 88.2%, 100%, and 100% (60∘C) in group A (in 30 min sonication), respectively, and were 100% in other groups (B and C). In this study, an important increase in the disinfection ability of ZnO NPs has been observed in the presence of US and UV-C. So, the ZnO NPs/UV-C and ZnO NPs/US processes are valuable alternatives to conventional disinfection processes by over 90% improvement of disinfection efficiency.

Effect of peeling, cutting, or shredding of lettuce, carrot, or potato on the efficacy of chlorine disinfection.

Minimally processed vegetables are washed and subsequently disinfected by immersion in water solutions with antimicrobials which reduce the initial pathogenic or spoilage microbial load. Chlorine remains one of the most widely used disinfectants for vegetables and hence the importance of studying its properties. The aim of this study was to evaluate the effect of peeling, cutting, and shredding on the effectiveness of chlorine (200 ppm) as a disinfectant in lettuce, carrot, and potato. Three independent repetitions of each experiment were completed, and data was statistically analyzed. Results showed that the maintenance of the chlorine concentration in the disinfectant solution, over time, depended on the vegetables' preliminary processing technique (whole, peeled, cut, or shredded) (p < 0.05). In general, the disinfection treatments studied reduced Escherichia coli by 1-8 logs. The addition of chlorine in the disinfectant solution allowed greater reduction in E. coli than using water immersions (p < 0.05) and disinfection times longer than 5 min did not improve these microbiological reductions (p>0.05). The vegetables' subdivision (whole, peeled, cut, or shredded) can affect both E coli's reduction and the vegetables' residual chlorine concentration. No trend was observed in terms of sensory differences and their relationship to the vegetables' processing and disinfection. These results suggest that each facility must validate its disinfection processes, according to the conditions established on site and reduction goals related to initial microbial counts, vegetables' quality, processing operations, and other important aspects.

Direct generation of DBPs from city dust during chlorine-based disinfection

Chlorine-based disinfectants, such as sodium hypochlorite, are extensively used in our daily lives. In particular, during the recent Covid-19 pandemic and post-pandemic period, excessive amounts of chlorine-based disinfectants were used both indoors and outdoors to interrupt virus transmission. However, the interaction between disinfectants and city dust during the disinfection process has not been sufficiently evaluated. In this study, we conducted a comprehensive investigation into the intrinsic characteristics (e.g. morphology, size, elemental composition, and organic content, etc.) of dust collected from various indoor and outdoor areas. The results showed that the organic carbon content of indoor dust reached 6.14 %, with a corresponding measured dissolved organic carbon value of 4.17 ± 0.23 mg/g (normalized to the dust weight). Concentrations of regulated DBPs, resulting from the interaction between dust and NaClO, ranged from 57.78 ± 2.72 to 102.80 ± 22.63 µg/g for THMs and from 119.18 ± 6.50 to 285.14 ± 36.95 µg/g for HAAs (normalized to the dust weight). More significantly, using non-target analysis through gas chromatography quadrupole time-of-flight mass spectrometry (GC-qTOF-MS), we identified a total of 68, 89, and 87 types of halogenated DBPs from three typical indoor and outdoor sites (R-QH, C-JS, and W-BR, respectively). These unknown DBPs included compounds with higher toxicity compared to regulated DBPs. These findings highlight that city dust is a significant source of DBP generation during chlorine-based disinfection, posing potential harm to both the ecological environment and human health.

Educational Intervention on Cleaning and Sanitation of Surfaces in a Pediatric Hospitalization Unit

Introduction: Environmental surfaces may serve as a reservoir for various microorganisms and consequently, they represent a potential risk for the spread of healthcare-associated infections. Objective: This study aimed to assess the cleaning and sanitation of surfaces (CSS) before and after implementing a Standardization Program for Cleaning and Sanitation of Surfaces (SPCSS). Methods: An analytical, comparative, and intervention study was conducted from 2020 to 2021 in a pediatric hospitalization unit in Midwest Brazil. Four frequently touched surfaces were monitored before and after the cleaning and sanitation process using the following methods: Adenosine Triphosphate (ATP) quantification, Colony-Forming Unit (CFU) count, and visual inspection. The study consisted of three stages: stage I (situational diagnosis of the CSS process), stage II (implementation of the SPCSS), and stage III (assessment 60 days after implementing the program). A total of 576 assessments were performed in all three study stages. Results: The CSS process was effective in all three study stages by using the ATP and CFU methods. In stage I, statistically significant results were obtained for four surfaces using the ATP method, and two by the CFU count. In stages II and III, all surfaces presented lower ATP and CFU results (p&lt;0.05). In the visual inspection, only the bathroom door handle (stage I: p=0.041; stage III: p=0.007) and toilet flush handle (stage I: p=0.026; stage III: p=0.007) passed the test. Implications for Nursing: This study presents subsidies to evaluate the cleaning and disinfection process carried out by the nursing and hygiene team. Conclusion: The SPCSS exerted a positive impact on the CSS process.

Comparison of chlorination resistance of biodegradable microplastics and conventional microplastics during the disinfection process in water treatments

Nowadays, microplastics (MPs) widely exist in the environment, and water treatment plants are important sources of MPs. Chlorine is widely used in the disinfection process in water treatment plants and has strong oxidation, however, the chemical and physical properties changes of MPs during chlorination were unclear. Thus, in this study, based on the actual used chlorine concentrations, different chlorination conditions were simulated to study the variation of MPs after chlorination. Meanwhile, the produced disinfection by-products were monitored. The results showed that under high chlorination concentration conditions, functional groups of polyethylene (PE), polystyrene (PS), and polylactic acid (PLA) changed, while no peak shift or change of poly (butyleneadipate-co-terephthalate) (PBAT) could be detected. Moreover, after chlorination, partial yellowing and cracks appeared on PS, PLA, and PBAT, while PE remained white and showed little morphological changes. Besides, chlorination led to the narrowing of the cold crystallization peak and melting peak of PLA, while chlorination had little influence on the crystal structure of PE and PBAT. Furthermore, the reaction between PLA and chlorine mostly produced more trichloromethane than other types of MPs. Consequently, when chlorine concentrations were in the range of 2.5 to 5000 mg/L, the chlorination resistance was PBAT/PE > PLA > PS. Specifically, PBAT had the strongest chlorination resistance in terms of chemical properties, while PE had the strongest chlorination resistance in terms of physical properties. Therefore, the degradability of biodegradable MPs is not higher than that of conventional MPs in all cases. Moreover, it should be noted that most changes occurred only in high chlorine concentrations. Thus, neither conventional MPs nor biodegradable MPs can be completely degraded during the chlorination process in water treatments.

Determination, Method Development and Validation of Six Nitrosamine Impurities in Purified water by using LC-MS/MS

N-nitroso dimethylamine (NDMA) and some other N-nitrosamines has been detected as potent mutagenic and carcinogenic arising in purified water due to the use of potable water required for production of purified water. The dominating precursors of N-nitrosamines formation during the purified water disinfection process are secondary and tertiary amines. NDMA is a disinfection of product found by the ozonation and chlorination of purified water. A high-performance liquid chromatography tandem mass spectrometry was developed to study the appearance of N-nitrosamines in purified water. The compounds were detected by Atmospheric Pressure Chemical Ionization (APCI) or Electrospray Ionization (ESI) which are the ionization modes with multiple reaction monitoring mode. Chromatographic separation was performed on a Phenomenex kinetex F5 column having the size 250 × 4.6mm, 5µ. This study proves that NMBA, NDMA, NDEA, NEIPA, NDIPA and NDBA detected in the purified water. Finally, the developed analytical method was strongly applied to the analysis of N-nitrosamines in purified water.

Portable IoT-Based Disinfection Box

The COVID-19 pandemic is an ongoing global health event that began in 2019. It is caused by a novel strain of coronavirus known as SARS-CoV-2. Bacteria and viruses can cause illness in human. Therefore, a Portable IoT-based Disinfection Box is developed in this work to disinfect small electronic devices such as smartphone, smartwatch or even a 13-inch tablet, that may come into contact with bacteria and viruses. There are three special features of this Disinfection Box which are the timer itself, Web Interface Monitoring, portable and spacious with dimensions of 29 × 18 × 14 cm3. The ESP32 Wi-Fi module with NodeMCU-32S Base module as a microcontroller is used in this work and it controls the 2-channel Relay in order to turn ON and OFF the UV-C LED light strip. Besides that, it is also connected to the LCD display with I2C module to display the real-time of disinfection process. The Dashboard of Arduino IoT Cloud allows the user to control and monitor the operation of disinfection process. When a small electronic device is placed inside the Disinfection Box, UV-C LED light strip is turned on to begin the disinfection process. The effectiveness of the UV-C LED light strip is investigated by using the Petri dish with agar. It is shown from the experimental procedures that 10-minute disinfection time provided by the Disinfection Box is sufficient to disinfect small electronic devices such as smartphone and smartwatch. This is based on the great reduction of bacteria colonies on the agar in Petri dish after being kept in a dark place with room temperature for 4 days.

Is ultraviolet light disinfection fit to be the future standard for the disinfection of flexible endoscopes without a working channel?

To investigate colony-forming unit (CFU) reduction on contaminated flexible endoscopes (FEs) without a working channel after UV-C light disinfection, compared to the current disinfection method with the endoscope washer disinfector (EWD). After pharyngolaryngoscopy, a manual pre-cleaning with tap water was performed. A culture was then collected by rolling the distal 8-10 cm of the FE over an Agar plate. The FE was disinfected using the D60 (60-s disinfection process with UV-C light) or the EWD (gold standard reprocessing process with water and chemicals). Another culture was then taken. After incubation, a CFU count was performed. A total of 200 FEs without a working channel were divided equally between the two disinfection groups. After clinical use and manual pre-cleaning, 84 of the 100 (84.0%) (UV-C light group) and 79 of the 100 (79.0%) (EWD) FEs were contaminated with at least 1 CFU. FEs that showed no contamination after use were excluded from further analysis. After disinfection with UV-C light, 72 (85.7%) FEs showed no contamination (i.e., 0 CFUs) versus 66 (83.5%) FEs after reprocessing with the EWD. There is no difference in CFUs reduction on contaminated FEs without a working channel between UV-C light disinfection and the current gold standard, the EWD.

New diamond coatings for a safer electrolytic disinfection.

In this work, a new coating of boron-doped diamond ultra-nanocrystalline (U-NBDD), tailored to prevent massive formation of perchlorates during disinfection, is evaluated as electrode for the reclaiming of treated secondary wastewater by the electrochemically assisted disinfection process. Results obtained are compared to those obtained by using a standardelectrode(STD) that was evaluated as a standard in previous research showing outstanding performance for this application. First tests were carried out to evaluate the chlorine speciation obtained after the electrolysis of synthetic chloride solutions at two different ranges of current densities. Concentrations of hypochlorite obtained using the U-NBDD anode at 25mAcm-2 were 1.5-fold higher, outperforming STD anode; however, at 300mAcm-2, an overturn on the behavior of anodes occurs where the amount of hypochlorite produced on STD anode was 1.5-fold higher. Importantly, at low current density the formation of chlorates and perchlorates is null using U-NBDD. Then, the disinfection of the real effluent of the secondary clarifier of a municipal wastewater treatment facility is assessed, where inactivation of Escherichia coli is achieved at low charge applied per volume electrolyzed (0.08 A h L-1) at 25mAcm-2 using the U-NBDD. These findings demonstrate the appropriateness of the strategy followed in this work to obtain safer electro-disinfection technologies for the reclaiming of treated wastewater.

Anti-infective Efficacy of Mechanical Debridement with Adjunctive Modalities on Clinical and Cytokine Parameters in Treatment of Chronic Periodontitis: Randomized Controlled Clinical Trial.

Periodontal debridement involves conventional scaling and root planing (SRP) along with variant forms of adjunctive therapies. In the present clinical trial, we investigated if the adjunctive use of HybenX gel or diode laser along with SRP could provide a favorable outcome for the treatment of chronic periodontitis. The present study involved 60 subjects diagnosed with chronic periodontitis who were randomly assigned as test groups (laser or HybenX) or control group (SRP alone). The primary outcomes of the clinical trial were pocket probing depth (PPD) and clinical attachment level (CAL), which was evaluated at baseline and at third-month time interval. Additionally, secondary outcomes included estimation of reduction in inflammatory mediators interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) in gingival crevicular fluid using enzyme-linked immunosorbent assay at baseline and third-month intervals. Normality determination was checked using Shapiro-Wilk test. Since the data was not normally distributed, nonparametric tests were applied. The comparison of clinical parameters between the groups was analyzed with Kruskal-Wallis test. Wilcoxon sign rank test was used to compare the pairwise comparison of clinical parameters among the groups from baseline to third-month follow-up. The inflammatory mediators at various time points were compared using a One-way analysis of variance test, and the inflammatory mediators in each study group were compared using a paired t-test. Both the test groups demonstrated a decrease in PPD and CAL. However, the HybenX group exhibited statistically significant reduction at the end of the third-month study interval compared to the laser group and SRP alone. Further, the secondary outcome IL-1β and TNF-α analysis exhibited statistically significant reduction in all the groups posttherapy. The adjunctive application of HybenX gel yielded an advantage compared to laser and SRP for the treatment of chronic periodontitis. Adjunctive use of the oral tissue desiccant (HybenX gel) combined with SRP improved the periodontal pocket disinfection process and enhanced tissue healing devoid of adverse effects.

Expert consensus on the clinical application of single-use (disposable) flexible bronchoscopes

Single-use (disposable) flexible bronchoscope is widely used clinically both in China and abroad and has become an important tool for diagnostic and therapeutic procedures in respiratory diseases. The lightweight, portability, and non-reusability of the single-use flexible bronchoscope makes its use not only similar to that of conventional flexible bronchoscope, but with additional applications and indications. Currently, single-use flexible bronchoscopes are used in pulmonology, critical care medicine, infectious diseases, anesthesia, emergency departments and other clinical settings. Chinese Respiratory Endoscopy Experts have developed a consensus on the clinical application of disposable bronchoscopy in China after extensive online and offline consultation, questionnaire surveys and extensive solicitation of opinions. This consensus was developed using clinical experiences gained and lessons learned during clinical practices over the past ten years to standardize and rationalize use of single-use flexible bronchoscope. The consensus addressed nine key issues concerning single-use flexible bronchoscope: definition, construction, benefits, application scenarios, preoperative preparation, sedation, anesthesia requirements, disinfection processes and training requirement ans management. Finally, twelve recommendations were developed. The consensus used the modified GRADE methodology to grade the evidence evaluation and recommendations. This is the current state of consensus on single-use flexible bronchoscope in China, and we hope to improve the standardized application of single-use flexible bronchoscope in China in the future. Summary of consensus opinions: 1. Definition and structure of single-use flexible bronchoscope.A single-use flexible bronchoscope, also known as a disposable flexible bronchoscope, includes two parts: a portable touch screen display and different types of bronchoscopes.2. The advantages of single-use flexible bronchoscope.[Consensus Opinion 1]: Single-use flexible bronchoscope is sterile (strongly recommended 86.7%).[Consensus Opinion 2]: The cost of single-use flexible bronchoscope is relatively low (strongly recommended at 53.3%).[Consensus Opinion 3]: Single-use flexible bronchoscope is portable and easy to use (strongly recommended at 80%).[Consensus Opinion 4]: Single-use flexible bronchoscope can be used as a complementary tool for teaching and scientific research (strongly recommended at 80%).3. The value of single-use flexible bronchoscope in the diagnosis and treatment of pulmonary infection.[Consensus Opinion 5]: For infectious diseases, unexplained pneumonia, and multi-drug resistant organisms (MDRO), the use of disposable bronchoscopy is recommended(strongly recommended at 90%).4. Application of single-use flexible bronchoscope in the diagnosis and treatment of critically ill patients.[Consensus Opinion 6]: Single-use flexible bronchoscope can be used immediately to manage patients with difficult airways in emergency situations (strongly recommended 53.3%).[Consensus Opinion 7]: Single-use flexible bronchoscope can be used immediately for the management of airway foreign bodies and hemoptysis in emergency situations (strongly recommended 80%).5. Application of single-use flexible bronchoscope in the diagnosis and treatment with complex bronchoscopic procedures.[Consensus Opinion 8]: For complex bronchoscopic procedures, when multiple endoscopic surgeries are required in addition to current endoscopic procedures, given the vulnerability of reusable bronchoscope to damage during the procedures, the use of a single-use flexible bronchoscope combined with a reusable bronchoscope for "dual endoscopic surgery" is recommended (strongly recommended 26.7%).6. Application of single-use flexible bronchoscope in preoperative preparation.[Consensus Opinion 9]: When managing critically ill patients or patients requiring emergency airway management, preoperative preparation can be temporarily delayed (strongly recommended 93.7%).7. Application of single-use flexible bronchoscope in sedation and anesthesia.[Consensus Opinion 10]: Use of single-use flexible bronchoscope for topical anesthesia. For complex procedures, choose topical anesthesia with tracheal intubation or supraglottic airways in general anesthesia (66.7% is strongly recommended).8. Does single-use flexible bronchoscope require standardized training?[Consensus Opinion 11]: The use of disposable bronchoscope requires standardized and systematic training (strongly recommended 93.3%).9. Cleaning and disinfection requirements for single-use flexible bronchoscope.[Consensus Opinion 12]: Single-use flexible bronchoscope is disposable and does not require disinfection (strongly recommended 93.3%).