Analysis of the physical and microbiocidal characteristics of an emerging and innovative UV disinfection technology

2021 ◽  
pp. bmjinnov-2021-000790
Author(s):  
Gabriele Messina ◽  
Davide Amodeo ◽  
Alessio Corazza ◽  
Nicola Nante ◽  
Gabriele Cevenini
Keyword(s):  
Progressive Increase ◽  
Operating Conditions ◽  
Bacterial Strains ◽  
Key Points ◽  
Critical Issues ◽  
Recent Developments ◽  
Ultraviolet C ◽  
Radiant Power ◽  
Voltage Management ◽  
Uv C

IntroductionSurface disinfection is one of the key points to reduce the risk of transmission both in healthcare and other public spaces. A novel UV-chip disinfection technology is presented. Technological, photonic and microbiocidal characteristics are evaluated taking as reference an ultraviolet-C (UV-C) LED source of equivalent radiant power.MethodsThe UV chip has a circular radiating surface with a diameter of 1.3 cm, emitting UV cold light at about 5 mW and driven current of about 80 µA. Four bacterial strains were used to conduct the microbiological tests at 4°C and 60°C to evaluate the bactericidal performance of the two technologies under the same operating conditions.ResultsSpectral differences were found between the UV-C LED and the chip, with an emission curve strictly around 280 nm and a broader band centred around 264 nm, respectively. Between-technology microbiological inactivation levels were comparable, achieving total abatement (99.999%) in 8 min at 7.5 cm.DiscussionThe UV chip exhibits unique properties that make it applicable in some specific contexts, where UV-C LEDs present the most critical issues. Besides, it is portable and exhibits a broad spectrum of UV wavelengths with a peak where the maximum microbiocidal efficacy occurs. Important issues to be addressed to improve this technology are the high voltage management and the too low energy efficiency.ConclusionThis cold emission technology is virtually unaffected by changes in ambient temperature and is particularly useful in short-distance applications. Recent developments in technology are moving towards a progressive increase in the chip’s radiant power.

scholarly journals Evaluation of 2 Ultraviolet-C Light Boxes for Decontamination of N95 Respirators

2021 ◽  
Vol 6 (1) ◽  
pp. 104-115
Author(s):  
Jennifer Cadnum ◽  
Basya Pearlmutter ◽  
Daniel Li ◽  
Annette Jencson ◽  
Jacob Scott ◽  
...  
Keyword(s):  
Limited Information ◽  
Bacterial Strains ◽  
Bacteriophage Ms2 ◽  
Different Types ◽  
Reduction Methods ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Uv C

Background:  Ultraviolet-C (UV-C) light devices are effective in reducing contamination on N95 filtering facepiece respirators.  However, limited information is available on whether UV-C devices meet the Food and Drug Administration’s (FDA) microbiological requirements for Emergency Use Authorization (EUA) for respirator bioburden reduction.  Methods:  We tested the ability of 2 UV-C light boxes to achieve the 3-log10 microorganism reductions required for EUA for reuse by single users.  Whole 3M 1860 or Moldex 1513 respirators were inoculated on the exterior facepiece, interior facepiece, and internal fibers with bacteriophage MS2 and/or 4 strains of bacteria and treated with UV-C cycles of 1 or 20 minutes.  Colorimetric indicators were used to assess penetration of UV-C through the respirators.    Results:  For 1 UV-C box, a 20-minute treatment achieved the required bioburden reduction for Moldex 1513 but not 3M 1860 respirators.  For the second UV-C box, a 1-minute treatment achieved the required bioburden reduction in 4 bacterial strains for the Moldex 1513 respirator.  Colorimetric indicators demonstrated penetration of UV-C through all layers of the Moldex 1513 respirator but not the 3M 1860 respirator.  Conclusions:  Our findings demonstrate that UV-C box technologies can achieve bioburden reductions required by the FDA for EUA for single users but highlight the potential for variable efficacy for different types of respirators. 

scholarly journals Effectiveness of Ultraviolet-C Room Disinfection on Preventing Healthcare-Associated Clostridioides difficile Infection

2020 ◽  
Vol 41 (S1) ◽  
pp. s33-s33
Author(s):  
Michihiko Goto ◽  
Erin Balkenende ◽  
Gosia Clore ◽  
Rajeshwari Nair ◽  
Loretta Simbartl ◽  
...  
Keyword(s):  
Acute Care ◽  
Acute Care Hospitals ◽  
Incidence Rates ◽  
Positive Test ◽  
Negative Binomial Regression Model ◽  
Test Results ◽  
Clostridioides Difficile ◽  
Ultraviolet C ◽  
Healthcare Associated ◽  
Uv C

Background: Enhanced terminal room cleaning with ultraviolet C (UVC) disinfection has become more commonly used as a strategy to reduce the transmission of important nosocomial pathogens, including Clostridioides difficile, but the real-world effectiveness remains unclear. Objectives: We aimed to assess the association of UVC disinfection during terminal cleaning with the incidence of healthcare-associated C. difficile infection and positive test results for C. difficile within the nationwide Veterans Health Administration (VHA) System. Methods: Using a nationwide survey of VHA system acute-care hospitals, information on UV-C system utilization and date of implementation was obtained. Hospital-level incidence rates of clinically confirmed hospital-onset C. difficile infection (HO-CDI) and positive test results with recent healthcare exposures (both hospital-onset [HO-LabID] and community-onset healthcare-associated [CO-HA-LabID]) at acute-care units between January 2010 and December 2018 were obtained through routine surveillance with bed days of care (BDOC) as the denominator. We analyzed the association of UVC disinfection with incidence rates of HO-CDI, HO-Lab-ID, and CO-HA-LabID using a nonrandomized, stepped-wedge design, using negative binomial regression model with hospital-specific random intercept, the presence or absence of UVC disinfection use for each month, with baseline trend and seasonality as explanatory variables. Results: Among 143 VHA acute-care hospitals, 129 hospitals (90.2%) responded to the survey and were included in the analysis. UVC use was reported from 42 hospitals with various implementation start dates (range, June 2010 through June 2017). We identified 23,021 positive C. difficile test results (HO-Lab ID: 5,014) with 16,213 HO-CDI and 24,083,252 BDOC from the 129 hospitals during the study period. There were declining baseline trends nationwide (mean, −0.6% per month) for HO-CDI. The use of UV-C had no statistically significant association with incidence rates of HO-CDI (incidence rate ratio [IRR], 1.032; 95% CI, 0.963–1.106; P = .65) or incidence rates of healthcare-associated positive C. difficile test results (HO-Lab). Conclusions: In this large quasi-experimental analysis within the VHA System, the enhanced terminal room cleaning with UVC disinfection was not associated with the change in incidence rates of clinically confirmed hospital-onset CDI or positive test results with recent healthcare exposure. Further research is needed to understand reasons for lack of effectiveness, such as understanding barriers to utilization.Funding: NoneDisclosures: None

scholarly journals Towards the Hydrogen Economy—A Review of the Parameters That Influence the Efficiency of Alkaline Water Electrolyzers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3193
Author(s):  
Ana L. Santos ◽  
Maria-João Cebola ◽  
Diogo M. F. Santos
Keyword(s):  
Energy Content ◽  
Water Electrolysis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Sources ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
New Energy ◽  
Recent Developments ◽  
Cell Components

Environmental issues make the quest for better and cleaner energy sources a priority. Worldwide, researchers and companies are continuously working on this matter, taking one of two approaches: either finding new energy sources or improving the efficiency of existing ones. Hydrogen is a well-known energy carrier due to its high energy content, but a somewhat elusive one for being a gas with low molecular weight. This review examines the current electrolysis processes for obtaining hydrogen, with an emphasis on alkaline water electrolysis. This process is far from being new, but research shows that there is still plenty of room for improvement. The efficiency of an electrolyzer mainly relates to the overpotential and resistances in the cell. This work shows that the path to better electrolyzer efficiency is through the optimization of the cell components and operating conditions. Following a brief introduction to the thermodynamics and kinetics of water electrolysis, the most recent developments on several parameters (e.g., electrocatalysts, electrolyte composition, separator, interelectrode distance) are highlighted.

scholarly journals Ultraviolet-C as a Viable Reprocessing Method for Disposable Masks and Filtering Facepiece Respirators

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 801
Author(s):  
Talita Nicolau ◽  
Núbio Gomes Filho ◽  
Andrea Zille
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Personal Protective Equipment ◽  
State Of The Art ◽  
Protective Equipment ◽  
Multiple Methods ◽  
Ultraviolet C ◽  
Single Use ◽  
Uv C ◽  
New Strategies

In normal conditions, discarding single-use personal protective equipment after use is the rule for its users due to the possibility of being infected, particularly for masks and filtering facepiece respirators. When the demand for these protective tools is not satisfied by the companies supplying them, a scenario of shortages occurs, and new strategies must arise. One possible approach regards the disinfection of these pieces of equipment, but there are multiple methods. Analyzing these methods, Ultraviolet-C (UV-C) becomes an exciting option, given its germicidal capability. This paper aims to describe the state-of-the-art for UV-C sterilization in masks and filtering facepiece respirators. To achieve this goal, we adopted a systematic literature review in multiple databases added to a snowball method to make our sample as robust as possible and encompass a more significant number of studies. We found that UV-C’s germicidal capability is just as good as other sterilization methods. Combining this characteristic with other advantages makes UV-C sterilization desirable compared to other methods, despite its possible disadvantages.

scholarly journals Inactivation of Candida auris and Candida albicans by Ultraviolet-C

2020 ◽  
Vol 41 (S1) ◽  
pp. s292-s292
Author(s):  
William Rutala ◽  
Hajime Kanamori ◽  
Maria Gergen ◽  
Emily Sickbert-Bennett ◽  
David Jay Weber
Keyword(s):  
Infection Prevention ◽  
Antifungal Drugs ◽  
Candida Auris ◽  
Healthcare Facilities ◽  
Environmental Surfaces ◽  
Route Of Transmission ◽  
Indirect Exposure ◽  
Ultraviolet C ◽  
Severe Infections ◽  
Uv C

Background:Candida auris is an emerging fungal pathogen that is often resistant to major classes of antifungal drugs. It is considered a serious global health threat because it has caused severe infections with frequent mortality in over a dozen countries. C. auris can survive on healthcare environmental surfaces for at least 7 days, and it causes outbreaks in healthcare facilities. C. auris has an environmental route of transmission. Thus, infection prevention strategies, such as surface disinfection and room decontamination technologies (eg, ultraviolet [UV-C] light), will be essential to controlling transmission. Unfortunately, data are limited regarding the activity of UV-C to inactivate this pathogen. In this study, a UV-C device was evaluated for its antimicrobial activity against C. auris and C. albicans. Methods: We tested the antifungal activity of a single UV-C device using the vegetative bacteria cycle, which delivers a reflected dose of 12,000 µW/cm2. This testing was performed using Formica sheets (7.6 × 7.6 cm; 3 × 3 inches). The carriers were inoculated with C. auris or C. albicans and placed horizontal on the surface or vertical (ie, perpendicular) to the vertical UV-C lamp and at a distance from 1. 2 m (~4 ft) to 2.4 m (~8 ft). Results: Direct UV-C, with or without FCS (log10 reduction 4.57 and 4.45, respectively), exhibited a higher log10 reduction than indirect UV-C for C. auris (log10 reduction 2.41 and 1.96, respectively), which was statistically significant (Fig. 1 and Table 1). For C. albicans, although direct UV-C had a higher log10 reduction (log10 reduction with and without FCS, 5.26 and 5.07, respectively) compared to indirect exposure (log10 reduction with and without FCS, 3.96 and 3.56, respectively), this difference was not statistically significant. The vertical UV had statistically higher log10 reductions than horizontal UV against C. auris and C. albicans with FCS and without FCS. For example, for C. auris with FCS the log10 reduction for vertical surfaces was 4.92 (95% CI 3.79, 6.04) and for horizontal surfaces the log10 reduction was 2.87 (95% CI, 2.36–3.38). Conclusions:C. auris can be inactivated on environmental surfaces by UV-C as long as factors that affect inactivation are optimized (eg, exposure time). These data and other published UV-C data should be used in developing cycle parameters that prevent contaminated surfaces from being a source of acquisition by staff or patients of this globally emerging pathogen.Funding: NoneDisclosures: None

scholarly journals Minimal, superficial DNA damage in human skin from filtered far‐ultraviolet‐C (UV‐C)

2021 ◽  
Author(s):  
R.P. Hickerson ◽  
M.J. Conneely ◽  
S.K. Hirata Tsutsumi ◽  
K. Wood ◽  
D.N. Jackson ◽  
...  
Keyword(s):  
Dna Damage ◽  
Human Skin ◽  
Ultraviolet C ◽  
Far Ultraviolet ◽  
Uv C

scholarly journals The Application of Catalytic Processes on the Production of Algae-based Biofuels: A Review

2020 ◽  
Author(s):  
Antonio Zuorro ◽  
Janet B. García-Martínez ◽  
Andrés F. Barajas-Solano
Keyword(s):  
Fossil Fuels ◽  
Operating Conditions ◽  
Thermochemical Conversion ◽  
Chemical Components ◽  
High Carbon ◽  
Microalgal Biomass ◽  
Microalgae Biomass ◽  
End Products ◽  
Recent Developments ◽  
Thermochemical Processes

Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, the biocrudes obtained from direct thermochemical conversion have substantial quantities of heteroatoms (oxygen, nitrogen, and sulfur) due to the complexity of the biomass's content of chemical components (lipids, carbohydrates, and proteins). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.

scholarly journals Mapping of UV-C dose and SARS-CoV-2 viral inactivation across N95 respirators during decontamination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alisha Geldert ◽  
Alison Su ◽  
Allison W. Roberts ◽  
Guillaume Golovkine ◽  
Samantha M. Grist ◽  
...  
Keyword(s):  
Optical Simulation ◽  
Pathogen Inactivation ◽  
Viral Inactivation ◽  
Flexible Form ◽  
Measurement Tools ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Uv C ◽  
Dose Difference

AbstractDuring public health crises like the COVID-19 pandemic, ultraviolet-C (UV-C) decontamination of N95 respirators for emergency reuse has been implemented to mitigate shortages. Pathogen photoinactivation efficacy depends critically on UV-C dose, which is distance- and angle-dependent and thus varies substantially across N95 surfaces within a decontamination system. Due to nonuniform and system-dependent UV-C dose distributions, characterizing UV-C dose and resulting pathogen inactivation with sufficient spatial resolution on-N95 is key to designing and validating UV-C decontamination protocols. However, robust quantification of UV-C dose across N95 facepieces presents challenges, as few UV-C measurement tools have sufficient (1) small, flexible form factor, and (2) angular response. To address this gap, we combine optical modeling and quantitative photochromic indicator (PCI) dosimetry with viral inactivation assays to generate high-resolution maps of “on-N95” UV-C dose and concomitant SARS-CoV-2 viral inactivation across N95 facepieces within a commercial decontamination chamber. Using modeling to rapidly identify on-N95 locations of interest, in-situ measurements report a 17.4 ± 5.0-fold dose difference across N95 facepieces in the chamber, yielding 2.9 ± 0.2-log variation in SARS-CoV-2 inactivation. UV-C dose at several on-N95 locations was lower than the lowest-dose locations on the chamber floor, highlighting the importance of on-N95 dose validation. Overall, we integrate optical simulation with in-situ PCI dosimetry to relate UV-C dose and viral inactivation at specific on-N95 locations, establishing a versatile approach to characterize UV-C photoinactivation of pathogens contaminating complex substrates such as N95s.

scholarly journals Three-dimensional printing for device selection in cardiology: Several key points should not be neglected

2016 ◽  
Author(s):  
Hongxing Luo ◽  
Zhongmin Wang
Keyword(s):  
3D Printing ◽  
Clinical Medicine ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Image Postprocessing ◽  
Key Points ◽  
Study Results ◽  
Recent Developments ◽  
3D Transesophageal Echocardiography ◽  
Dimensional Printing

We comment on the recent developments and problems of three-dimensional printing in cardiology. Since there are currently no standards or consensuses for 3D printing in clinical medicine and the technology is at its infancy in cardiology, it’s very important to detail the procedures to allow more similar studies to further our understandings of this novel technology. Most studies have employed computed tomography to obtain source data for 3D printing, the use of real-time 3D transesophageal echocardiography for data acquisition remains rare, so it would be very valuable and inspiring to detail the image postprocessing steps, or the reliability of the study results will be doubtful.

Sign in / Sign up

Export Citation Format

Share Document