Disinfection Capability Research Articles

Far-UVC light (222 nm) efficiently inactivates clinically significant antibiotic-resistant bacteria on diverse material surfaces.

This study is crucial, providing compelling evidence on Far-ultraviolet radiation C (Far-UVC) light's efficacy against clinically significant antibiotic-resistant bacteria-a pressing issue in microbiology and infection control. Our research employs antibiotic-resistant strains from clinically isolated bacteria, emphasizing real-world relevance. Simultaneously, we assess Far-UVC light (222 nm) across diverse material surfaces commonly found in clinical settings. This dual approach ensures practical applicability and broad relevance. Our comprehensive setup and rigorous methodologies unequivocally demonstrate Far-UVC light's potency in combating antibiotic-resistant bacteria. Since 222 nm far-UVC has a disinfection capability and is harmless to mammalian cells, this dual effectiveness positions Far-UVC as a secure tool for infection control, with potential applications in healthcare settings, mitigating antibiotic-resistant bacteria spread, and reducing healthcare-associated infections.

Enhanced electrochemical disinfection for decentralized sewage treatment through nickel foam cathode modified with CoFe2O4-spinel ferrite and multi-way carbon nanotubes

Electrochemical disinfection is characterized by its simple operation and maintenance, along with effective sterilization capabilities, making it ideal for decentralized wastewater treatment in rural areas. As a bimetallic oxide, spinel ferrite exhibits excellent catalytic activity for the oxygen reduction reaction (ORR). Herein, a novel cathode was fabricated from nickel foam modified with spinel ferrite and multi-way carbon nanotubes (CoFe2O4-MWCNTs@NF). The modification successfully strengthens the electrochemical cathode reaction to generate strong oxidants such as hydrogen peroxide and Hydroxyl radical, enabling the disinfection of water bodies with low chloride concentrations. Compared to other influencing factors (including current density, aeration rate, and electrode spacing), the impact of conductivity on hydrogen peroxide generation is relatively minor. Modified electrodes still exhibited effective disinfection capabilities in water with low conductivity. At a current density of 2 mA/cm², the CoFe2O4-MWCNTs@NF electrode achieved 4.00 log removal of E.coli in real treated sewage within 15 minutes, with an energy consumption of 1.038 kWh/m³. Electrochemical disinfection also had a certain degradation ability for sulfonamides and quinolones antibiotics in water. The disinfection and antibiotic removal effects of the modified electrode demonstrated its potential for practical applications.

Design strategies based on UV-C LED characterization to enhance Escherichia coli inactivation

This research is focused on the development of a UV-C LED lamp designed for effective water disinfection, tackling as a primary issue the low quantum efficiency and significant self-heating due to elevated operating currents which reduce the LED performance. By conducting thorough characterization and employing strategies including aluminum heat sinks and varied electrical biasing methods such as constant current, PWM, and high-current short-time pulses. The study assesses the disinfection potential against pathogenic bacteria such as Escherichia coli and Salmonella. Results indicate successful E. coli inactivation within agar mediums and notable growth suppression in Mueller-Hinton culture mediums, as confirmed through optical density measurements. Therefore, this investigation underlines the importance of optimized operational strategies to enhance UV-C LED lamps' disinfection capabilities.

Enhanced inactivation of Staphylococcus aureus and Escherichia coli using conjugated polyindole polymer nanoparticles under visible light irradiation

AbstractThe areas of environmental cleanup and bacteria inactivation are particularly interesting in polymer‐based nanomaterials because of their unique physicochemical properties. Conjugated polymer nanoparticles (CP NPs) have potential uses in the biological and environmental, but little is known about them. This study aimed to examine the efficacy of CP nanoparticles in the photocatalytic inactivation of S. aureus and E. coli under visible irradiation (λ ≤ 420 nm), with minor enhancements observed. The simple and one‐step chemical oxidation technique was used to prepare CP nanoparticles. X‐ray powder diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), Scanning electron microscope (SEM), Energy‐dispersive X‐ray (EDS), and Transmission electron microscopy (TEM) analyses were utilized to characterize the physicochemical properties of CP nanoparticles for comprehensive structural analysis. The synthesized CP nanoparticles exhibited outstanding photocatalytic disinfection capabilities, achieving a degradation of 98.6%. This research not only provides insights into the physical characteristics of CP nanoparticles but also illustrates their antibacterial efficacy against two different bacterial pathogens, namely S. aureus and E. coli. Therefore, this research highlights an eco‐friendly and inexpensive preparation of conjugated polymer nanoparticles for a wide range of applications.

Identification and Measurement of Biomarkers at Single Microorganism Level for In Situ Monitoring Deep Ultraviolet Disinfection Process.

Since the COVID-19 disease has been further aggravated, the prevention of pathogen transmission becomes a vital issue to restrain casualties. Recent research outcomes have shown the possibilities of the viruses existing on inanimate surfaces up to few days, which carry the risk of touch propagation of the disease. Deep ultraviolet germicide irradiation (UVGI) with the wavelength of 255-280nm has been verified to efficiently disinfect various types of bacteria and virus, which could prevent the aggravation of pandemic spread. Even though considerable experiments and approaches have been applied to evaluate the disinfection effects, there are only few reports about how the individual bio-organism behaves after ultraviolet C (UVC) irradiation, especially in the aspect of mechanical changes. Furthermore, since the standard pathway of virus transmission and reproduction requires the host cell to assemble and transport newly generated virus, the dynamic response of infectious cell is always the vital aspect of virology study. In this work, high power LEDs array has been established with 270nm UVC irradiation to evaluate disinfection capability on various types of bio-organism, and incubator embedded atomic force microscopy (AFM) is used to investigate the single bacterium and virus under UVGI. The real-time tracking of the living Vero cells infected with adenovirus has also been presented in this study. The results show that after sufficient UVGI, the outer shell of bacteria and viruses remain intact in structure, however the bio-organisms lost the capability of reproduction and normal metabolism. The experiment results also indicate that once the host cell is infected with adenovirus, the rapid production of newborn virus capsid will gradually destroy the cellular normal metabolism and lose mechanical integrity.

Reviewing the evidence of antimicrobial activity of glycols.

In the 1940s and 1950s, researchers seeking safe and novel ways to eliminate airborne pathogens from enclosed spaces, investigated glycol vapours as a method of disinfection. More recently, the COVID-19 pandemic highlighted the need for a non-toxic aerial disinfectant that can be used in the presence of people. This scoping review is intended to analyse the early and more recent literature on glycol disinfection, scrutinizing the methodologies used, and to determine if the use of glycols as modern-day disinfectants is justified PRISMA-ScR guidelines were used to assess the 749 articles retrieved from the Web of Science platform, with 46 articles retained after the search strategy was applied. Early studies generally demonstrated good disinfection capabilities against airborne bacteria and viruses, particularly with propylene glycol (PG) vapour. Vapour pressure, relative humidity, and glycol concentration were found to be important factors affecting the efficacy of glycol vapours. Contact times depended mainly on the glycol application method (i.e. aerosolization or liquid formulation), although information on how glycol efficacy is impacted by contact time is limited. Triethylene glycol (TEG) is deemed to have low toxicity, carcinogenicity, and mutagenicity and is registered for use in air sanitization and deodorization by the US Environmental Protection Agency. Glycols are also used in liquid formulations for their antimicrobial activity against a wide range of microorganisms, although when used as a non-active excipient in products, their contribution to antimicrobial efficacy is rarely assessed. The appropriate use of liquid glycol-containing formulations was found to positively impact the antimicrobial capabilities of disinfectants when used at temperatures <0, food preservatives, and dental medicaments. Providing modern delivery technology can accurately control environmental conditions, the use of aerosolized glycol formulations should lead to successful disinfection, aiding infection prevention, and control regimens.

Exploring hospital resilience protective or risk factors: lessons for future disaster response efforts.

Hospital resilience is essential in responding to disasters, but current research focuses mainly on frameworks and models rather than the protection of resilience and analysis of risk factors during public health emergencies. This study aims to examine the development of resilience in Chinese frontline hospitals during the initial COVID-19 outbreak in 2020, providing insights for future disaster response efforts. We conducted interviews with 26 hospital staff members who were involved in the initial response to the COVID-19 outbreak in China. We used a semi-structured interview approach and employed purposive sampling and snowball sampling techniques. The interview outline was guided by the 'Action Framework' proposed by the World Health Organization (WHO) for responding to infectious disease emergencies. This framework includes dimensions such as command, surveillance, risk communication, medical response, and public health response. We analyzed the collected data using Colaizzi's seven-step data analysis method and the template analysis method. WHO's 'action framework' effectively highlights the factors that contribute to hospital resilience. While medical response, including the availability of materials and facilities, the use of information technology, and the capacity for infectious disease diagnosis and treatment, remains crucial, other important aspects include awareness and beliefs about infections, treatment experience, interdisciplinary collaboration, and more. Additionally, it is essential to establish an intelligent command system, foster trusting partnerships between teams, improve monitoring capabilities for infectious disease agents, enhance risk communication through information synchronization and transparency, strengthen infection control planning, and improve environmental disinfection capabilities for effective public health emergency response. These contradictions significantly impact the enhancement of hospital resilience in dealing with major infectious disease outbreaks. In responding to sudden major infectious diseases, hospitals play a vital role within the healthcare system. Enhancing hospital resilience involves more than just improving treatment capabilities. It also requires effective command coordination at the hospital level, infection control planning, and the deployment of intelligent equipment. Additionally, planning for effective communication and coordination between hospitals, communities, and the national healthcare system can further enhance hospital resilience.

Harnessing the photocatalytic potential of bismuth ferrite-activated carbon nanocomposite (BFO-AC) for Staphylococcus aureus decontamination under visible light.

In response to the escalating global issue of microbial contamination, this study introduces a breakthrough photocatalyst: bismuth ferrite-activated carbon (BFO-AC) for visible light-driven disinfection, specifically targeting the Gram-positive bacterium Staphylococcus aureus (S. aureus). Employing an ultrasonication method, we synthesized various BFO-AC ratios and subjected them to comprehensive characterization. Remarkably, the bismuth ferrite-activated carbon 1:1.5 ratio (BA 1:1.5) nanocomposite exhibited the narrowest band gap of 1.86 eV. Notably, BA (1:1.5) demonstrated an exceptional BET surface area of 862.99 m2/g, a remarkable improvement compared to pristine BFO with only 27.61 m2/g. Further investigation through FE-SEM unveiled the presence of BFO nanoparticles on the activated carbon surface. Crucially, the photocatalytic efficacy of BA (1:1.5) towards S. aureus reached its zenith, achieving complete inactivation in just 60 min. TEM analysis revealed severe damage and rupture of bacterial cells, affirming the potent disinfection capabilities of BA (1:1.5). This exceptional disinfection efficiency underscores the promising potential of BA (1:1.5) for the treatment of contaminated water sources. Importantly, our results underscore the enhanced photocatalytic performance with an increased content of activated carbon, suggesting a promising avenue for more effective microorganism inactivation.

Quantifying drought-driven temperature impacts on ozone disinfection credit and bromate control

Climate change and drought can lead to unprecedented changes in surface water temperature requiring utilities to examine their ozone system's disinfection capability while minimizing bromate production.

Highly efficient aramid fiber supported polypropylene membranes modified with reduced graphene oxide based metallic nanocomposites: antimicrobial and antiviral capabilities.

Polypropylene hybrid polymeric membranes with aramid support have been fabricated using Thermally Induced Phase Separation (TIPS). Different modifying materials, such as metallic nanoparticles and reduced graphene oxide (rGO), improve the properties of these membranes. The nanomaterials and the fabricated membranes have been characterized with FTIR spectrometer, SEM and UV-Vis Spectrophotometer. Following that, the disinfection capabilities of the fabricated hybrid membranes were investigated. The antibacterial capability of the membranes is established through the testing of the membranes against bacterial strains S. aureus and E. coli, whereas the antiviral evaluation of the membranes was made against H9N2 and IBV strains. This research aims to develop advanced hybrid membranes that effectively disinfect water by incorporating novel nanomaterials and optimizing fabrication techniques.

The attract-kill inhibition mechanism in Ag/chitosan hydrogel for long-acting control of Ralstonia solanacearum.

In this study, we developed an innovative eco-friendly antiseptic nanocomposite, specifically a silver nanoparticle (Ag NP)-immobilized chitosan hydrogel (Ag@Cs/Csh gel), synthesized through a cross-linking reaction involving polyvinylpyrrolidone (PVP) and tetraethyl orthosilicate (TEOS). This nanocomposite was designed to combat Ralstonia solanacearum (R. solanacearum) infections, particularly in Solanaceae plants. Chitosan of varying molecular weights (50-190 kDa for Cs and 300-375 kDa for Csh) was used to control the swelling efficacy and regulate the release of Ag NPs. The gels were loaded with either 0.1 or 0.25 mg of Ag NPs and assessed for their antibacterial efficacy against R. solanacearum at various concentrations using the turbidity method. At 5 × 104 CFU mL-1, all gel samples, except for controls, exhibited notable antibacterial activity lasting up to 18.5 days. At higher concentrations of 5 × 106 and 5 × 108 CFU mL-1, the 0.25-Ag@Cs/Csh gel achieved nearly 100% eradication over 18.5 days. Notably, parallel experiments with various concentrations of Ag NPs alone showed limited antibacterial effectiveness against R. solanacearum. Therefore, we propose an "attract and kill" antibacterial mechanism to elucidate the enhanced disinfection capability of the Ag@Cs/Csh gel. Initially, the positively charged chitosan hydrogel attracts negatively charged bacteria, followed by steady Ag+ ion release to eradicate them, providing potent and prolonged antibacterial efficacy.

A Volume-Adjustable Artificial Womb for Extremely Preterm Infants.

More than 13 million children are born preterm annually. Prematurity-related mortality accounts for 0.9 million deaths worldwide. The majority of those affected are Extremely Preterm Infants (gestational age less than 28weeks). Immaturity causes organ failure and specific morbidities like germinal matrix hemorrhage, bronchopulmonary dysplasia, and necrotizing enterocolitis. Artificial womb and placenta technologies address these issues. As a bridge-to-life technology, they provide a liquid environment to allow organ maturation under more physiological conditions. The proposed artificial womb can adapt to fetal growth. Volume adjustment is achieved by removing fluid from the interspace between an inner and outer chamber. Results of the in vitro tests showed a temperature constancy of 36.8°C ± 0.3°C without pressure loss over 7days. The volume of the inner sac was variable between 3.6 and 7.0L. We designed a filtration and disinfection system for this particular purpose. This system has proven strong disinfection capabilities, effective filtering of metabolic waste, and the ability to avoid phospholipid washout. The presented artificial womb has sufficient volume variability to adapt to the physiologic growth of an extremely preterm neonate over a 4-week period. We regard this as an important step in the development of this bridge-to-life technology.

Supramolecular porphyrin/ZnFe layered double hydroxide heterojunction as multifunctional photocatalytic surface for effective sterilization and degradation: Performance and enhanced mechanism insight

In this work, supramolecular tetrakis(4-carboxyphenyl)porphyrin/ZnFe layered double hydroxide (S-TCPP/ZnFe-LDH) heterojunction was developed and applied as photocatalytic surface bonding on flexible substrate (cotton fabric, CF) to fabricate an effective photocatalytic platform (S-TCPP/ZnFe-LDH@CF) for antibiotic degradation and bacterial inactivation. In which, S-TCPP/ZnFe-LDH heterojunction was synthesized using an in-situ self-assembly method, and the supramolecular porphyrin nanocrystals can interact with ZnFe-LDH nanosheets via covalently combining. The host catalyst ZnFe-LDH in this photocatalytic platform has limited photocatalytic activity. The introduction of photosensitive S-TCPP can effectively improve the activity of the photocatalytic surface. The photocatalytic degradation rate of antibiotic ciprofloxacin over S-TCPP/ZnFe-LDH@CF was 2.87 times higher than ZnFe-LDH@CF. The easy-recovered S-TCPP/ZnFe-LDH@CF also can completely inactivate typical Gram bacteria (106 CFU/mL) within 60 min of visible light irradiation. Moreover, S-TCPP/ZnFe-LDH@CF retained considerable stability and durability without obvious metal ions leakage after the reaction. The results of free radical quenching experiments, ESR tests, photoelectrochemical studies and band structures analyses indicate that the combination of S-TCPP and ZnFe-LDH was closely related to a type II photocatalysis heterojunction with the matched band positions. And S-TCPP/ZnFe-LDH heterojunction demonstrated the ability to effectively activate molecular oxygen via both electron transfer and energy transfer approaches to produce multiple reactive oxygen species. The grafting of S-TCPP on ZnFe-LDH broadened the light response range and intensity, as well as enhanced electron transfer and charge separation, showing significantly improved water purification and disinfection capabilities. This work provides a new advanced photocatalytic surface based on photoactive LDH combined with photosensitive supramolecular materials for the efficient treatment of wastewater containing organic pollutants and biohazards.

Hydrothermal integration of MoO2–MoS2@rGO nanoframe networks: A promising approach for efficient bacterial disinfection in wastewater

The efficient disinfection of bacterial contaminants in wastewater is a critical challenge in the field of environmental remediation. Herein, we present a novel approach for efficient bacterial disinfection using hydrothermally integrated MoO2–MoS2@rGO nanoframe networks. The developed nanoframe networks exhibit a unique architecture comprising of molybdenum dioxide (MoO2) and molybdenum disulfide (MoS2) impregnated on algae biomass reduced graphene oxide (rGO). The as-synthesized nanoframe networks demonstrate exceptional antibacterial activity against Escherichia coli bacteria. The disinfection efficiency was evaluated by measuring the bacterial viability and observing the morphological changes using scanning electron microscopy. The MoO2–MoS2@rGO nanoframe networks exhibited a remarkable antibacterial effect, achieving a high disinfection rate of 95.8% within a short contact time of 10 min. The efficient bacterial disinfection capability of the nanoframe networks can be attributed to the synergistic effects of MoO2, MoS2, and rGO components. The MoO2 nanoparticles generate reactive oxygen species (ROS), persuading oxidative stress and leading to bacterial inactivation. The MoS2 nanoparticles possess inherent antibacterial properties through the release of Mo and S ions. The rGO nanosheets provide a conductive and stable platform, facilitating the charge transfer during the antibacterial process. Furthermore, the hydrothermal integration method enables easy scalability and cost-effectiveness of the MoO2–MoS2@rGO nanoframe networks. The nanoframe networks can be easily recovered and reused, reducing waste generation and promoting sustainability. Overall, this study presents a promising approach for efficient bacterial disinfection in wastewater using hydrothermally integrated MoO2–MoS2@rGO nanoframe networks. The remarkable antibacterial performance, along with the advantages of scalability and reusability, makes these nanoframe networks a potential candidate for practical applications in environmental remediation and water treatment processes.

Assessment of the air disinfection effect of low-concentration ozone in a closed environment

Ozone, a prevalent pollutant in enclosed spaces, can pose health risks even at low levels. Despite its widespread use for disinfection, the efficacy in neutralizing airborne pathogens in confined settings remains uncertain. A study was conducted to investigate the disinfection capabilities of low-concentration ozone (several dozen parts per billion, ppb), within an isolation ward. Serratia marcescens and phi-X174 were used as tracer bioaerosols. The study examined two scenarios of applying low-concentration ozone in closed environments: direct introduction of low-concentration ozone into the ward and comparison of air disinfection effects of ozone-producing and non-ozone-producing UVC lamps. The UVC lamps chosen for this study were of 185 nm and 254 nm, which cannot coexist with humans when turned on. The results revealed that ozone concentrations below 60 ppb did not significantly impact air disinfection regarding Serratia marcescens and there was no noteworthy difference in effectiveness between the two types of UVC lamps for both Serratia marcescens and phi-X174. However, using UVC lamp resulted in a significantly higher air disinfection effect compared to the absence of a UVC lamp. For Serratia marcescens, the inclusion of ozone-producing and non-ozone producing UVC lamps (k = 49.8 ± 9.2 h−1, 52.9 ± 8.6 h−1, mean ± SD) significantly enhanced the decay rate by 29.6 h−1 and 32.7 h−1 respectively, compared with the absence of UVC lamps (k = 20.2 ± 2.3 h−1, mean ± SD). These findings highlight the limited potential of low-concentration ozone for air disinfection and emphasize the need for cautious utilization in enclosed environments.

Activation of peroxodisulfate by Ag3PO4/N, S-doped graphene for efficient organic degradation and bacterial disinfection

Advanced peroxodisulfate (PDS)-based oxidation processes have a promising potential for water purification. In this study, Ag3PO4 coupled with nitrogen and sulfur co-doped graphene (NSG) was synthesized and, owing to its excellent visible-light utilization efficiency, Ag3PO4-NSG catalyst was used for photoactivation of PDS. Under optimal reaction conditions of 20 mg·L-1 amoxicillin (AMX), 0.2 g·L-1 Ag3PO4-NSG, and 1.25 mM PDS, the Ag3PO4-NSG/PDS/visible-light system achieved 100 % removal efficiency of AMX in 10 min; the kinetic reaction constant of this system (0.48 min−1) was 28.38 and 5.14 times higher than that of Ag3PO4-NSG/PDS and Ag3PO4-NSG/visible-light systems, respectively. This enhancement is attributed to the presence of NSG, which provides additional active sites and effectively facilitates charge transfer. Additionally, the effects of the amount of photocatalyst, initial contaminant concentration, and initial PDS concentration were investigated. Possible intermediates and degradation pathways were also investigated. The proposed system exhibited excellent degradation ability in water bodies with different water quality characteristics and in complex real water. Moreover, this system showed excellent water disinfection capability, achieving complete inactivation of Escherichia coli within 20 min, with an improvement of 3.0-log inactivation of E. coli than that by the Ag3PO4-NSG system. Based on the appropriate energy band level of Ag3PO4-NSG, the carrier separation rate was improved, and sulfate (SO4·-), hydroxyl (·OH), and superoxide (·O2–) radicals were produced for the effective degradation of AMX and inactivation of E. coli. This study contributes to the application of Ag3PO4-based photocatalyst for water purification and provides new opportunities for PDS photoactivation.

A systematic simulation of disinfection for the flow-through UV reactors with staggered ring baffles under the Eulerian framework

An integrated UV disinfection model is presented to simulate the disinfection in the flow through UV reactors. The concentration of microorganisms, the mean residence time, and the mean dose are solved under the Eulerian framework. An unbaffled reactor and three baffled reactors with staggered baffles are simulated. The accuracy of the computation is validated against Sozzi's measurement and simulation in the unbaffled reactor. The staggered baffles improve the flow field and enhance the mixing. The mean residence time is significantly changed by baffles. The cumulative frequency distributions of the mean residence time in the outlet plane may become narrow and wide depending on the size of baffles. The radiation intensity is nearly the same for all reactors. The mean dose is significantly affected by the baffles. The area-averaged mean doses at the outlet are nearly the same for all reactors whereas the range of the mean dose in the outlet plane is narrowed by baffles. Better disinfection levels are obtained in the baffled reactors than the unbaffled reactor, which is determined by the narrower distribution of the mean dose in the outlet plane. The increasing flow rate decreases the disinfection level for all reactors. The reduction equivalent dose is proportional to the minimum mean dose Dmin in the outlet plane and the slope decreases as the inactivation constant increases, meaning a decreasing effect of Dmin on the reduction equivalent dose. Dmin in the outlet plane can be used to characterize the disinfection capability of the flow-through UV reactors.

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review.

The utilization of lasers has been regarded as a novel technique for the purposes of clinical use in the dental field. Recently, numerous studies have been conducted on the potential applications of laser therapy in endodontics. Moreover, due to their ablation, penetrability, and disinfection capabilities, lasers have performed well with respect to endodontic treatments, including root canal treatment, vital pulp therapy (pulp capping and pulpotomy), dentinal hypersensitivity treatment, and management of dental pain related to pulp and periradicular disease. In particular, the superiorities of laser-aided pulp therapy are emphasized through condensed clinical controlled trials, and histological studies, in this review. Moreover, the ingenious use of laser applications with respect to aiding in the acceleration of root development and the extraction of foreign matters (i.e., broken files and fiber posts) in canals has quickly become the cutting-edge trend of current research. This review offers a summary and discussion of the current literature on all the aforementioned laser applications. Moreover, the characteristics of laser devices, including erbium lasers, neodymium-doped lasers, CO2 lasers, and diode lasers, are detailed and discussed here, providing useful references for laser application in endodontics. We also focus on the different wavelengths with respect to the lasers that are applied in endodontics. High-power lasers perform well as operative instruments; in addition, low-level lasers lead to the regulation of pulp inflammation, and the promotion of pulp healing. This narrative review provides a summary of the advanced applications of lasers in conjunction with various devices in the practice of endodontics, and aims to inspire innovative perspectives on lasers in the context of the treatment of dental diseases, especially pulp diseases, in the future.

Surface Environment and Energy Density Effects on the Detection and Disinfection of Microorganisms Using a Portable Instrument.

Real-time detection and disinfection of foodborne pathogens are important for preventing foodborne outbreaks and for maintaining a safe environment for consumers. There are numerous methods for the disinfection of hazardous organisms, including heat treatment, chemical reaction, filtration, and irradiation. This report evaluated a portable instrument to validate its simultaneous detection and disinfection capability in typical laboratory situations. In this challenging study, three gram-negative and two gram-positive microorganisms were used. For the detection of contamination, inoculations of various concentrations were dispensed on three different surface types to estimate the performance for minimum-detectable cell concentration. Inoculations higher than 103~104 CFU/mm2 and 0.15 mm of detectable contaminant size were estimated to generate a sufficient level of fluorescence signal. The evaluation of disinfection efficacy was conducted on three distinct types of surfaces, with the energy density of UVC light (275-nm) ranging from 4.5 to 22.5 mJ/cm2 and the exposure time varying from 1 to 5 s. The study determined the optimal energy dose for each of the microorganisms species. In addition, surface characteristics may also be an important factor that results in different inactivation efficacy. These results demonstrate that the proposed portable device could serve as an in-field detection and disinfection unit in various environments, and provide a more efficient and user-friendly way of performing disinfection on large surface areas.

A multidisciplinary approach to the comparison of three contrasting treatments on both lampenflora community and underlying rock surface

Removing lampenflora, phototrophic organisms developing on rock surfaces in tourist cavities due to the artificial lighting, is a challenge for sustainable and appropriate long-term management of caves. Photosynthetic-based biofilms usually cause rock biodeterioration and an ecological imbalance in cave ecosystems. In this work, a detailed investigation of the effects of the 3 most commonly used lampenflora cleaning operations (NaClO, H2O2 and UVC) was carried out in Pertosa-Auletta Cave (Italy). The application of NaClO showed good disinfection capability over extended periods of time without causing any appreciable rock deterioration. The H2O2 treatment showed to be corrosive for the rock surfaces covered with vermiculation deposits. The chemical alteration of organic and inorganic compounds by H2O2 did not remove biomass, favoring biofilm recovery after three months of treatment. Both NaClO and H2O2 treatments were effective at removing photoautotrophs, although the bacterial phyla Proteobacteria and Bacteroidetes as well as Apicomplexa and Cercozoa among the Eukaryotes, were found to be resistant to these treatments. The UVC treatments did not show any noticeable effect on the biofilms.