Use Of Ultraviolet Light Research Articles

Modeling and application of array light sources in ultraviolet communication systems

Reliable communication over long distances using ultraviolet (UV) light is challenging due to the strong scattering and atmospheric absorption of UV light. However, with advancements in UV LED technology, the performance of transmitters can be significantly enhanced by employing an array of light sources, which improves the overall quality of communication. Despite these advancements, the impact of various array configurations—such as shape, quantities, and other parameters—on light intensity distribution and UV optical communication remains largely unexplored. In this work, we first modeled the light intensity distribution of arrayed light sources with varying shapes, quantities, and other parameters. We improved the traditional Monte Carlo method to better accommodate these distributions, enabling more accurate simulations. Subsequently, we obtained simulation results for different array configurations. Building on these findings, we developed a UV LED array communication system that achieved a bit error rate (BER) of 10−6 for information transmission over a distance of 500 meters. This research provides valuable insights into the long-distance transmission capabilities of UV light using arrayed light sources.

A Comparison of ChatGPT and Expert Consensus Statements on Surgical Site Infection Prevention in High-Risk Paediatric Spine Surgery.

Artificial intelligence (AI) represents and exciting shift for orthopaedic surgery, where its role is rapidly evolving. ChatGPT is an AI language model which is preeminent among those leading the mass consumer uptake of AI. Artamonov and colleagues compared ChatGPT with orthopaedic surgeons when considering the diagnosis and management of anterior shoulder instability; they found a limited correlation between them. This study aims to further explore how reliable ChatGPT is compared with orthopaedic surgeons. Twenty-three statements were extracted from the article "Building Consensus: Development of a Best Practice Guideline (BPG) for Surgical Site Infection (SSI) Prevention in High-risk Pediatric Spine Surgery" by Vitale and colleagues. These included 14 consensus statements and an additional 9 statements that did not reach consensus. ChatGPT was asked to state the extent to which it agreed with each statement. ChatGPT appeared to demonstrate a fair correlation with most expert responses to the 14 consensus statements. It appeared less emphatic than the experts, often stating that it "agreed" with a statement, where the most frequent response from experts was "strongly agree." It reached the opposite conclusion to the majority of experts on a single consensus statement regarding the use of ultraviolet light in the operating theatre; it may have been that ChatGPT was drawing from more up to date literature that was published subsequent to the consensus statement. This study demonstrated a reasonable correlation between ChatGPT and orthopaedic surgeons when providing simple responses. ChatGPT's function may be limited when asked to provide more complex answers. This study adds to a growing body of discussion and evidence exploring AI and whether its function is reliable enough to enter the high-accountability world of health care. This article is of high clinical relevance to orthopaedic surgery given the rapidly emerging applications of AI. This creates a need to understand the level to which AI can function in the clinical setting and the risks that would entail.

Fabricating porous adsorbent coatings using resin curing method: A comprehensive experimental investigation

This study investigates a novel stereolithography-based technique using ultraviolet (UV) light and photopolymer resin to fabricate porous and robust MIL-101 (Cr) adsorbent layers. A unique acid-base reaction step is integrated to control the void size of the adsorbent layer. To prepare the slurry, ingredients are mixed in specific ratios, comprising photopolymer resin (50–55 %), sodium bicarbonate (20–23 %), and MIL-101 (Cr) (23–30 %). Afterward, the slurry-coated samples are treated with concentrated Hydrochloric acid (HCl, 12 M or 36.5 %) and are cured using UV light after controlled delays, forming a porous adsorbent layer. The adsorbent layers are experimentally characterized as a function of the initial slurry recipe and the time delay between acid treatment and UV curing. Furthermore, scanning electron microscopy (SEM) and energy-dispersive X-ray Spectroscopy (EDS) are used to analyze the coated layers. Water isotherm experiments are performed to test the coated layers performance for both MIL-101 (Cr) powders and coated samples. The void size volume fraction for coated samples is found to vary between 22 % and 42 %, and maximum void size is observed for 27 % adsorbent and 4 seconds time delay. Such a comprehensive characterization provides a rapid and efficient alternative to conventional adsorbent structuring methods for fabricating adsorbent layers.

Induction of Gynogenetic Diploids the Tropical Oyster, Crassostrea belcheri 1873 (Ostreids: Ostreoidea)

The induction of diploid gynogenesis in the Tropical oyster, Crassostrea belcheri 1873, was carried out through two main experiments: 1) the destruction of spermatozoa DNA using ultraviolet (UV) irradiation, and 2) the induction of gynogenetic diploids. UV light source was placed 30 cm over the sperm for various durations, including 0 (control), 30, 60, 90, and 120 seconds. The study revealed that the highest survival rate was observed in trochophore at 90 minutes (42.5 ± 2.50%) compared to the normal control C. belcheri (p>0.05). Based on cytogenetic study, haploid (n=10), diploid (2n=20), and aneuploid were observed in all trials, while only diploid (2n=20) could be seen in the control group. Diploid gynogenesis was induced using 100 µmol 6-DMAP for 10 minutes. The study found that the survival rate and developmental stages in both trochophore and D-shape were gradually decreasing as the duration of UV rays increased. The highest survival rate of trochophore in the control group was 75.20 ± 4.84%, while survival rates in other experimental groups ranged from 52.22 ± 4.82% to 59.33 ± 13.57%. However, regarding the survival rate of D-shape larvae, their survival rates were relatively low across all trials. They displayed abnormal embryo development, distorted shape, unnatural swimming, and were smaller than normal (40-50 µm). Moreover, haploid (n=10), diploid (2n=20), triploid (3n=30), tetraploid (4n=40), and aneuploid were observed in all trials, while only diploid (2n=20) could be discovered in the control group. However, gynogenesis in this tropical oyster is still limited at this time. Therefore, suitable conditions for inducing gynogenesis in oysters should be further developed.

The use of ultraviolet light generated from light-emitting diodes for the disinfection of transvaginal ultrasound probes.

Transvaginal ultrasound probes (TVUS) are used for several gynecological procedures. These need to be disinfected between patient use. In the current study we examine whether UVC delivered using light emitting diodes for 90 seconds can provide sufficient disinfection efficacy. A new UVC device that delivers UVC radiation at 265nm-275nm for 90 seconds was used. TVUS probes were swabbed before and after use in an in vitro fertilization clinic. Microbes on the swabs were cultured and identified. In addition, the ability of the UVC device to provided repeated high-level disinfection was analysed by deliberately contaminating probes with spores of Bacillus subtilis and then performing the UVC disinfection and bacterial culture. 50% of probes were contaminated with bacteria, most commonly Bacillus sp., directly after in vivo use. Whereas 97% were sterile after UVC disinfection for 90 seconds. The UVC treatment resulted in no growth of B. subtilis spores after each of five repeated contaminations with 5-9 x 107 spores on the probes. This study has found that UVC delivered via light emitting diodes for only 90 seconds can produce high level disinfection of transvaginal probes.

Application of ultraviolet light sources in charge management systems for space gravitational wave detection

Gravitational waves are a kind of matter wave, which is caused by the violent motion and changes of matter and energy. Detecting gravitational waves allows people to observe the universe from a new perspective. In the process of gravitational wave detection, high-energy particles and cosmic rays in space can penetrate the exterior of the spacecraft and reach the surface of the inertial sensor's test mass (TM), continuously accumulating charges. Once the charge on the TM exceeds a certain threshold, the electrostatic forces between the TM and surrounding conductors generate significant acceleration noise, which will affect the measurement accuracy of the inertial sensors and, consequently, the success of the gravitational wave detection mission. Therefore, controlling the charge on the TM surface, known as charge management, is essential. The most commonly used charge management method is based on the photoelectric effect, using ultraviolet (UV) light to control the potential between the surface of the TM and the surrounding conductors. In previous charge management systems (CMSs), UV mercury lamps and UV light-emitting diodes (LEDs) were used as light sources, achieving varying levels of success. This paper mainly reviews the research progress of UV light sources in CMS for space gravitational wave detection. Mercury lamps, as the first-generation system light source, can fulfill the mission but have some drawbacks such as slow startup, high power consumption and significant electromagnetic interference. UV LEDs, because of their advantages in size and weight, have gradually become the current light source for CMS. In recent years, with the development of UV micro-LED technology, UV LEDs have achieved higher external quantum efficiency and lower power consumption, demonstrating their potential applications in CMS, and becoming a promising UV light source for future charge management systems.

Quality of Coffea Arabica L. beans that emit fluorescence when subjected to ultraviolet light

The demand for specialty coffees on the world market is growing, and their commercial value is directly linked to their quality. When subjected to ultraviolet (UV) light, some raw coffee beans show a blue fluorescence. Around the world, producers and traders have used UV light as a quality analysis method to detect defects in beans that cannot be seen with the naked eye. Despite being a technique used for a long time, almost no scientific study has been done to confirm and clarify the matter. Therefore, the work aims to evaluate the quality of the beans that emit and do not emit fluorescence from the same batch. For this, a batch of natural specialty coffee was divided into treatments with different fluorescence concentrations and analyzed sensorially and physicochemically. It was observed that the increase in fully fluorescent beans concentration negatively affected the coffee final score and astringency, and the increase in partially fluorescent beans concentration negatively affected the final score, astringency, sweetness, acidity, bitterness, and aftertaste of the coffee. Furthermore, attributes such as fruity notes and sweetness were affected by the presence of fluorescence, thus changing the sensory profile. In the physicochemical analyses, a reduction in the coffee quality was observed for the parameters of potassium leaching, electrical conductivity, fatty acidity, polyphenols, titratable acidity, moisture and weight of 1000 seeds. Therefore, it was possible to observe that the use of UV light to assess the green coffee beans quality can be a viable method.

A novel fast timing detector based on the double micro-mesh gaseous structure with reflective photocathode

Fast timing detectors play an important role in high energy physics, medical imaging and other fields. In view of wider applications and potential in the future, new detector technologies need to be investigated. A novel detection concept of fast timing based on the double micro-mesh gaseous structure with a reflective photocathode (FT-DMM) is introduced in light of its good time resolution and long-term operation. A sufficient number of photoelectrons (PEs) and a time resolution of better than 300 picoseconds (ps) for single photoelectron (SPE) are obtained by simulations, suggesting that an overall time resolution better than 100ps is feasible. The FT-DMM prototype was fabricated and tested using ultraviolet (UV) light. The gas gain can reach up to 106, while the measured time resolution of SPE is consistent with the simulated one. Furthermore, a time resolution of approximately 115ps was achieved at an average number of PEs of 5.9, and better time resolution can be expected as more PEs to be generated. These results confirm the good potential of FT-DMM as a fast timing detector for charged particle and UV light detection.

Updated temperature correction for computing seawater nitrate with in situ ultraviolet spectrophotometer and submersible ultraviolet nitrate analyzer nitrate sensors

AbstractSensors that use ultraviolet (UV) light absorption to measure nitrate in seawater at in situ temperatures require a correction to the calibration coefficients if the calibration and sample temperatures are not identical. This is mostly due to the bromide molecule, which absorbs more UV light as temperature increases. The current correction applied to in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) nitrate sensors generally follows Sakamoto et al. (2009, Limnol. Oceanogr. Methods 7, 132–143). For waters warmer than the calibration temperature, this correction model can lead to a 1–2 μmol kg−1 positive bias in nitrate concentration. Here we present an updated correction model, which reduces this small but noticeable bias by at least 50%. This improved model is based on additional laboratory data and describes the temperature correction as an exponential function of wavelength and temperature difference from the calibration temperature. It is a better fit to the experimental data than the current model and the improvement is validated using two populations of nitrate profiles from Biogeochemical Argo floats navigating through tropical waters. One population is from floats equipped with ISUS sensors while the other arises from floats with SUNA sensors on board. Although this model can be applied to both ISUS and SUNA nitrate sensors, it should not be used for OPUS UV nitrate sensors at this time. This new approach is similar to that used for OPUS sensors (Nehir et al., 2021, Front. Mar. Sci. 8, 663800) with differing model coefficients. This difference suggests that there is an instrumental component to the temperature correction or that there are slight differences in experimental methodologies.

Multisized Photoannealable Microgels Regulate Cell Spreading, Aggregation, and Macrophage Phenotype through Microporous Void Space.

Microgels are an emerging platform for in vitro models and guiding cell fate due to their inherent porosity and tunability. This work describes a light-based technique for rapidly annealing microgels across a range of diameters. Utilizing 8-arm poly(ethylene)glycol-vinyl sulfone, the number of arms available for crosslinking, functionalization, and annealing is stoichiometrically controlled. Small and large microgels are fabricated to explore how microgel diameter impacts void space and the role of porosity on cell spreading, cell aggregation, and macrophage polarization. Mesenchymal stromal cells spread rapidly in both formulations, yet the smaller microgels permit a higher cell density. When seeded with macrophages, the smaller microgels promote an M1 phenotype, while larger microgels promote an M2 phenotype. As another application, the inherent porosity of annealed microgels is leveraged to induce cell aggregation. Finally, the microgels are implanted to examine how different size microgels influence endogenous cell invasion and macrophage polarization. The use of ultraviolet light allows for microgels to be noninvasively injected into a desired mold or wound defect before annealing, and microgels of different properties combined to create a heterogeneous scaffold. This approach is clinically relevant given its tunability and fast annealing time.

Insights into periodate oxidation of antibiotics mediated by visible-light-induced polymeric carbon nitride: Performance and mechanism

Periodate (PI)-based advanced oxidation processes (AOPs) have drawn growing attention in an effort to alleviate pollutants issues in the aqueous environment. Different from previous use of ultraviolet light or metal catalysts, this study proposes a novel system for the visible-light-assisted activation of PI via metal-free polymeric carbon nitride (CN). The best catalytic effect was achieved by CN synthesized from urea (UCN). Effective charge separation predominately caused kinetic increase in photocatalytic degradation, where interfacial electron transfer in UCN/PI/Vis system occurred in the synergistic process. UCN generated photogenerated electrons-hole under visible light irradiation. The organic pollutant acted as an electron donor. PI could effectively act as an electron capture agent and inhibit the complexation of charge carriers. The combination of PI-based AOP and photocatalysis greatly increased the degradation of pollutants through photocatalysis, achieving the effect of 1 + 1 > 2. The tetracycline (TC) effectively underwent nearly 100 % removal within 10 min and the corresponding kobs attained 0.40839 min−1. Besides, outstanding catalytic performance in a broad range of pH (2.99–11.01) was confirmed. Meanwhile, the UCN/PI/Vis system demonstrated favorable immunity to common wastewater components, good stability, and reusability. The prominent active species for TC degradation were singlet oxygen (1O2) and iodate radical (IO3·, IO4·), followed by superoxide radicals (O2−). This study establishes a precedent for visible-light-induced activation of PI by UCN, interfacial electron transfer occurs in a synergistic process, and greatly accelerated photocatalytic oxidation is accomplished with PI acting as an electron scavenger.

Facilitations in the Clinical Diagnosis of Human Scabies through the Use of Ultraviolet Light (UV-Scab Scanning): A Case-Series Study.

To confirm the suspicion of scabies, dermatologists have one pathognomonic sign, "the tunnel" through which Sarcoptes scabiei digs into the epidermis. Light microscopy is considered the most reliable procedure, but it is time-consuming and operator-dependent. Recently, dermoscopy has greatly improved the chances of recognizing mite in situ, but it is still linked to the examiner's experience and to the magnification capability of the device used. This article, based on a case-series study, describes a novel diagnostic path, which uses an ultraviolet LED source at 365 nm and a digital camera for the evaluation of lesions that raise the suspicion of scabies. The gallery emits a naked-eye-visible wavy bluish-white linear luminescence, better than that of any standard lighting. UVA light is also able to identify Sarcoptes scabiei as a white or green point-shaped area. This sign can only be appreciated by enlarging its picture to full frame on a common PC monitor. Ultraviolet light (365 nm) seems to offer help in the diagnosis of scabies because it saves time compared with light microscopy and because it does not require contact with the patient's skin, as in dermoscopy. Although examiner experience remains an important factor, it is easily compensated by procedural simplicity, the cost of the devices and, especially, by the clarity of the results, even in non-specific lesions.

Preliminary study on volumetric 3D printing using visible light

The realm of 3D printing has been a valuable aspect of manufacturing and mechanical engineering to which complex geometries have been made that might be otherwise highly costly or not feasible by other manufacturing methods. This is where volumetric 3D printing has been advantageous by generating complex geometry with no defects on the surface. The problem with the research done so far is that the material used uses photoinitiators that photo-synthesize using ultraviolet (UV) light. The problem with this material is that it is attached to the destructive issues brought on by interacting with UV light, making some additives useless. To solve part of this problem, a solution to the material problem must be shown that a resin can be cured using visible light. This study has investigated the feasibility of a novel manufacturing process termed, the visible light–induced–volumetric 3D printing (VLI-V3DP) process that resulted in successfully finding resin that can be cured using visible light in the 470 and 530 nm range. By curing simple geometry using visible light, one can formulate a resin that can sustain just about any additives that can meet any goal, whether it is organic or not.

Use of Ultraviolet Light for Surface Decontamination of Raw Chicken Carcasses

Aim: Fresh chicken meat is especially susceptible to surface contamination. The researchers are looking into non-thermal and non-chemical preservation techniques for meat. Therefore, the present study was planned to investigate the use of UV-C light for the decontamination of raw chicken carcasses at refrigeration temperature (0-4OC).
 Study Design: The study was undertaken in two phases wherein, the first phase standardization of UV dose and later the comparative effect of selected UV light and sodium hypochlorite exposure on the shelf life of poultry carcasses (0-4OC) was carried out.
 Place and Duration of Study: The experiment was performed in the Department of Veterinary Public Health, Poultry and Goat Processing Unit, College of Veterinary and Animal Sciences, Parbhani (MH) India, from October 2021 to April 2022.
 Methodology: We performed the microbial, physicochemical, and sensory (odour) evaluation of the chicken carcasses during storage up to 72 hrs. Amongst various UV doses with different exposure times and distances tested, UV-C light exposure generated 233.86, 103.93, 207.87, and 415.75 mJ/cm2 energy for various groups.
 Results: A microbial analysis in a standardization study revealed that a significantly (p<0.05) lower total viable count was observed in UV (415.75 mJ/cm2) group. Similarly, counts of Staphylococcus spp. and E. coli were significantly (p<0.05) lower in UV-C light (207.87 mJ/cm2 and 415.75 mJ/cm2) groups. The shelf-life analysis indicated that UV-C light (415.75 mJ/cm2) and sodium hypochlorite (50 ppm) were equally effective in reducing the microflora of carcasses. The pH and TBA values of both treatment groups did not differ significantly but an increasing trend was recorded for peroxide and tyrosine values throughout the storage period.
 Conclusion: The findings of the present study indicate that UV-C light technology may be applied for surface decontamination of raw chicken carcasses.

Degradation of Amido Black Dye Using Ultra-Violet Light Catalyzed by Iron Oxide Nanoparticles: Kinetics and Mechanism of Degradation

In this study, we investigated the degradation of amido black dye in an aqueous solution using ultra-violet (UV) light catalyzed by iron oxide nanoparticles (nano-Fe). The nano-Fe was synthesized by sodium borohydride reduction of ferric chloride solution and was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence spectrophotometry (XRF). The SEM of the nano-Fe showed regular spherical particles, the XRD examination showed a weak and broad peak at Fe (1 1 0), and the XRF study showed that the element with the highest composition was Fe2O3 (60.80%). The degradation experiments showed that the UV light catalyzed by nano-Fe could effectively degrade amido black dye. The nano-Fe/UV system could degrade 5 mg/L of amido black dye up to 93.2% at 254 nm after being irradiated for 60 min. The nano-Fe/UV system could be described by the Langmuir–Hinshelwood kinetic model, and the rate constants (kapp) were 0.0183–0.0323 min−1. Thus, UV light combined with nano-Fe can be applied for the efficient remediation of dye wastewater.

UV-light assisted synthesis of high silica faujasite-type zeolite

Currently, the direct synthesis of faujasite-type (FAU) zeolites with Si/Al ratios greater than 3 depends on organic or inorganic additives. Here, we report the first additive-free synthesis of faujasite with Si/Al ratios greater than 3 using ultraviolet (UV) light assistance. The obtained zeolite shows excellent catalytic performance comparable to the commercial zeolite Y. UV light promotes the incorporation of more framework Si the faujasite framework. • FAU-type zeolite with Si/Al ratio above 3 is synthesized from an additive-free system. • UV illumination during gel aging promotes the incorporation of more Si in the faujasite framework. • As-synthesized faujasite shows higher benzene selectivities than commercial zeolite Y. • Long wavelength UV light holds potential to create OH . radicals in aluminosilicate gel.

Beta-Glucosidase 1 (bgl1) Gene Analysis in Mutant and Wild-type of Penicillium sp. ID10-T065

In the previous study, Penicillium sp. ID10-T065 has been mutated using ultraviolet (UV), ethyl methyl sulfonate (EMS) and the combination of UV-EMS to increase Beta-glucosidase (bgl) activity. There were three mutants selected, UV13 (UV mutant), EM31 (EMS mutant), and UM23 (UV-EMS mutant). This study examined the mutations in the bgl gene encoding (bgl1) as well as sequence differences between mutants and wild-type of Penicillium sp. ID10-T065. The gene analysis was performed by PCR amplification and sequencing of the bgl1 gene. The results of bgl1 gene sequences (600 bp) from mutants were aligned with the wild-type, it was discovered that there were base alterations from position 2025 to 2050. Mutant UV13 showed the highest base alterations (7 bases) which occurred at position 2027 (T→C); 2036 (T→G); 2040 (T→G); 2047 (G→C); and 2048-2050 (TTG→GGA). Mutant EM31 showed alterations in five bases at positions 2034 (G→A), 2036 (T→G), 2037 (G→C), 2044 (G→C), and 2047 (G→T). Mutant UM23 showed two base alterations at position 2025 (T→A) and 2037 (G→C). UV irradiation and EMS mutation resulted in transition and transversion DNA, whereas the combination of UV-EMS mutation resulted in transversion mutations. Base alterations in UV13 and EM31 mutants, causing missense and silent mutation, while in UM23 mutant only silent mutations occur. The bgl1 gene analysis showed that mutation using UV light was more effective than using EMS or a combination of UV-EMS in Penicillium sp. ID10-T065.

Enhancement of vitamin D2 in edible mushroom using ultraviolet irradiation and assessing its storage and cooking stability

Purpose The purpose of this study was to optimize the parameters for enhancing the vitamin D2 formation in three edible mushroom varieties, namely, shiitake mushroom (Lentinula edodes), white button mushroom (Agaricus bisporus) and oyster mushroom (Pleurotus ostreatus) using ultraviolet (UV) irradiation. Design/methodology/approach Freshly harvested mushrooms were irradiated with UV-B and UV-C lamps. Further, mushrooms were treated with UV-B at a distance ranging between 10 and 50 cm from the UV light source, for 15–150 min, to maximize the conversion of ergosterol to vitamin D2. Analysis of vitamin D2 content in mushrooms before and after UV exposure was done by high pressure liquid chromatography (HPLC). Findings HPLC results showed a significant (p < 0.001) increase in vitamin D2 levels of shiitake (17.3 ± 0.35 µg/g), button (24.9 ± 0.71 µg/g) and oyster (19.1 ± 0.35 µg/g) mushrooms, irradiated with UV-B at a distance of 20–30 cm for 120 min. Further, stability studies revealed that vitamin D2 levels in UV-B-irradiated mushrooms gradually increased for 48 and 72 h of storage at room and refrigeration temperatures, respectively. During cooking operations, 62%–93% of vitamin D2 was retained in UV-B-irradiated mushrooms. Originality/value This study describes the most effective parameters such as ideal wavelength, mushrooms size, duration of exposure and distance from UV sources for maximum vitamin D2 formation in edible mushrooms using UV irradiation. Further, assessment of vitamin D2 stability in UV exposed mushrooms during storage period and cooking operations has been carried out. In addition, this study also provides a comparison of the vitamin D2 levels of the three widely cultivated and consumed mushroom varieties treated simultaneously under similar UV exposure conditions.

Use of ultraviolet light in graduate medical education to assess confidence among residents and fellows in handwashing instruction.

Coronavirus disease 2019 (COVID-19) has made it imperative to focus on strategies to improve hand hygiene to minimize threats of viral transmission in hospitals. We investigated the potential of using ultraviolet (UV) light as a visual tool in hand-hygiene education to bring awareness of individual handwashing effectiveness to healthcare workers. In 2020, 117 individuals participated in the simulation and completed surveys on proper handwashing technique. Of these, 114 were first-year residents and fellows. Surveys of confidence in hand hygiene were obtained before and after formal hand-hygiene education utilizing UV light with Glo Germ lotion. The UV light and Glo Germ lotion were used to identify deficiencies in individual handwashing technique. With a total response rate of 97.4%, first-year residents and fellows demonstrated a significant decrease in handwashing confidence in pre- and posteducation surveys. Study participants who had had formal hand-hygiene training in the previous 3 years also indicated confidence in hand hygiene similar to those who had not had previous hand-hygiene training. Conclusions: Overall, resident interns and fellows may have falsely elevated their hand-hygiene confidence levels. However, conclusions regarding the confidence of residents and fellows individually could not be made due to sample size. Many healthcare personnel practice improper handwashing techniques, which may be improved with education and training that includes UV light.

Ultraviolet Light-Emitting Diode (UV-LED) Sterilization of Citrus Bacterial Canker Disease Targeted for Effective Decontamination of Citrus Sudachi Fruit.

A kind of citrus fruit with special flavor, Citrus sudachi harvested in Japan, are exported to various countries. However, the Citrus sudachi needs to be sterilized using aqueous solution of sodium hypochlorite because there is a possibility of the adhesion of citrus bacterial canker (CBC) which is not found in Europe. Due to the sterilization with time-consuming work, a more effective decontamination technique is required. A decontamination method using ultraviolet (UV) light irradiation is thus anticipated. Especially, the use of light emitting diodes (LEDs) wi UV light has many advantages in terms of energy consumption, lifetime, and compactness； although an appropriate method is yet to be established. In this study, we evaluate the fundamental effectiveness of UV-LED decontamination on the basis of the bactericidal ability on CBC in petri dishes, using six kinds of UV-LEDs (265, 280, 285, 300, 310, and 365 nm) . For each irradiation, the resultant bactericidal abilities (BAs) were evaluated precisely taking into account the differences in their optical absorptions. In addition, BAs per unit photon number were also estimated, as a fundamental wavelength-dependence of BA. As a result, the effectiveness of UV-LED irradiation with relatively short wavelengths was demonstrated clearly.