UV-C Light Research Articles

Ultraviolet Light-Assisted Decontamination of Chemical Warfare Agent Simulant 2-Chloroethyl Phenyl Sulfide on Metal-Loaded TiO2/Ti Surfaces.

The application of ultraviolet (UV) light for the decontamination of chemical warfare agents (CWAs) has gained recognition as an effective method, especially for treating hard-to-reach areas where wet chemical methods are impractical. In this study, TiO2/Ti was employed as a model catalyst, which was contaminated with 2-chloroethyl phenyl sulfide (CEPS), and subjected to photocatalytic decontamination using both UVB and UVC light. Additionally, photocatalytic decontamination efficiency by introducing Au, Pt, and Cu onto the TiO2/Ti surface was explored. During the photodecomposition process under UVC light, at least eight distinct secondary byproducts were identified. It was observed that the introduction of overlayer metals did not significantly enhance the photodecomposition under UVC light instead overlaid Au exhibited substantially improved activity under UVB light. Whereas, photodecomposition process under UVB light, only five secondary products were detected, including novel compounds with sulfoxide and sulfone functional groups. This novel study offers valuable insights into the generation of secondary products and sheds light on the roles of overlayer metals and photon wavelength in the photodecontamination process of CWA.

Characterization and the Effect of Different Parameters on Photocatalytic Activity of Montmorillonite/TiO2 Nanocomposite under UVC Irradiation

This study aimed to modify montmorillonite (MMT) with titanium dioxide (TiO2) by wet stirring method combined with ultrasonic to form MMT/TiO2 nanocomposite and used as a photocatalyst in the removal of organic dye rhodamine B (RhB). The characteristics of the synthesized samples were analyzed by methods such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). The degradation of RhB was carried out for 210 min under UVC irradiation, and the decolorization efficiency of RhB was evaluated by UV-vis spectroscopy. The results show that the TiO2 anatase nanoparticles are randomly distributed on the surface or the space between the MMT sheets to form a house-of-card structure. After 210 min of exposure under a UVC light source, the decolorization efficiency reached 91.5% for the solution with pH = 6.8, photocatalyst content 0.1 g/L, initial concentration RhB 10 mg/L, and UVC power 15 W. Liquid chromatography–mass spectrometry (LCMS) identified the degradation intermediates that MMT/TiO2 successfully cleaved the chromophore structure and formed more minor broken-ring by-products. The influence of operating parameters on RhB removal efficiency, including solution pH, photocatalyst content, initial dye concentration, inorganic, and organic scavengers, was studied. In addition, the kinetic modeling study shows that the RhB photodegradation reaction is consistent with the Langmuir-Hinshelwood first-order kinetic model.

Photo-Induced Tautomerism of Isocytosine in Aqueous Solution when Irradiated with UVC Light

It was found that the irradiation of aqueous solution of isocytosine with UVC light provokes an oxo-hydroxy phototautomerism of the compound with a rate constant of 5.29× 10-3 min-1. It was observed a backward reaction, after removing the UV light source, with a rate constant of 0.12×10-3 min-1. Two mechanisms of the phototautomerism were investigated at the B3LYP/aug-cc-pVDZ theoretical level in water surroundings (PCM). The first one showed a consecutive dissociation and association of a proton through conical intersections S0/S1 whose structures were located at the same theoretical level in the gas phase. It occurs along the 1πσ* excited-state reaction pathway. The more probable mechanism includes an excited-state H-transfer supported by a water molecule as a catalyst. It occurs along the 1ππ* excited-state reaction pathway which we found over the IRC ground-state energy curve. The water molecule drastically reduces the energy barrier in the ground state as well in the excited state.

RoboCoV Cleaner: An Indoor Autonomous UV-C Disinfection Robot with Advanced Dual-Safety Systems.

In the face of today's ever-evolving global health landscape and ambient assisted living (AAL), marked by the persistent emergence of novel viruses and diseases that impact vulnerable categories and individual safety, the need for innovative disinfection solutions has surged to unprecedented levels. In pursuit of advancing the field of autonomous UV-C disinfection robotics, we conducted two comprehensive state-of-the-art analyses: the first one in the literature and the second one in existing commercial disinfection robots to identify current challenges. Of all of the challenges, we consider the most outstanding ones to be safeguarding humans and animals and understanding the surroundings while operating the disinfection process challenges that we will address in this article. While UV-C lamps have demonstrated their effectiveness in sterilizing air and surfaces, the field of autonomous UV-C disinfection robotics represents a critical domain that requires advancement, particularly in safeguarding the wellbeing of humans and animals during operation. Operating UV-C disinfection robots in close proximity to humans or animals introduces inherent risks, and existing disinfection robots often fall short in incorporating advanced safety systems. In response to these challenges, we propose the RoboCoV Cleaner-an indoor autonomous UV-C disinfection robot equipped with an advanced dual and redundant safety system. This novel approach incorporates multiple passive infrared (PIR) sensors and AI object detection on a 360-degree camera. Under our test, the dual-redundant system reached more than 90% when detecting humans with high accuracy using the AI system 99% up to 30 m away in a university hallway (different light conditions) combined with the PIR system (with lower accuracy). The PIR system was proved to be a redundant system for uninterrupted operation during communication challenges, ensuring continuous sensor information collection with a swift response time of 50 ms (image processing within 200 ms). It empowers the robot to detect and react to human presence, even under challenging conditions, such as when individuals wear masks, in complete darkness, under UV light, or in environments with blurred visual conditions. In our test, the detection system performed outstandingly well with up to 99% detection rate of humans. Beyond safety features, the RoboCoV Cleaner can identify objects in its surroundings. This capability empowers the robot to discern objects affected by UV-C light, enabling it to apply specialized rules for targeted disinfection. The proposed system exhibits a wide range of capabilities beyond its core purpose of disinfection, making it suitable for healthcare facilities, universities, conference venues, and hospitals. Its implementation has the ability to improve significantly human safety and protect people. By showcasing the RoboCoV Cleaner's safety-first approach and adaptability, we aim to set a new benchmark for UV-C disinfection robots, promoting clean and secure environments while protecting vulnerable people, even in challenging scenarios.

Study of the photocatalytic activity of clay supported TiO2 nanoparticles for methylene blue degradation.

The photocatalytic degradation of a methylene blue (MB) solution was studied using a formulation of TiO2 nanoparticles (NPs) suspended in a commercial antibacterial paint, and supported on clay strips. All experiments were carried out in a batch reactor containing a UV-C light source and the MB solution under stirring. Parameters such as catalyst mass loading, MB concentration, as well as catalyst properties were considered for the experimental procedure. The effect of the mass loading on the photocatalytic activity of the TiO2 formulations immobilized on the clay supports was evaluated using 100, 200, and 500 mg of TiO2 on 40 mL of paint, sampling the MB solution under degradation at 0, 2, 5, 10, 20, 50, 100 and 200 min. The aliquots were analyzed by optical spectroscopy in the 400-1000 range to determine the absorbance, calculate the concentration with the Beer-Lambert equation, and obtain the amount of MB degradation. The maximum photocatalytic degradation of MB for the supported photocatalyst was 52%, 55%, and 60%, respectively. For comparison, suspended TiO2 nanoparticles lead to ca. 95% of MB photodegradation in ca. 60 min. The supported photocatalysts were tested in three consecutive cycles of 200 min to study the mechanical and photocatalytic stability. The activity of the photocatalysts with mass loading of 100 and 200 mg TiO2 decreased to ca. 35% after the three cycles, while the formulation with 500 mg TiO2 remained stable for three cycles. The final samples of each cycle were characterized by XRF, discarding erosion of the material from the support.

Synergistic Effect of Nano Strontium Titanate Coating and Ultraviolet C Photofunctionalization on Osteogenic Performance and Soft Tissue Sealing of poly(ether-ether-ketone).

This study aimed to evaluate the bioactivity of poly(ether ether ketone) (PEEK) after surface modification by persistent photoconductive strontium titanate (SrTiO3) magnetron sputtering and ultraviolet (UV) C irradiation. According to the different modifications, the PEEK specimens were randomly divided into five groups (n = 38/group): PEEK, Sr100-PEEK, Sr200-PEEK, UV/PEEK, and UV/Sr200-PEEK. Then, the specimens of Sr100-PEEK and Sr200-PEEK groups were, respectively, coated with 100 and 200 nm thickness photocatalyst SrTiO3 on the PEEK surface by magnetron sputtering. Subsequently, UV-C light photofunctionalized the specimens of PEEK and Sr200-PEEK groups to form UV/PEEK and UV/Sr200-PEEK groups. The specimens were characterized by a step meter, scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), and a water contact angle meter. The release test of the Sr ion was performed by inductively coupled plasma mass spectrometry (ICP-MS). In vitro study, osteogenic activity (MC3T3-E1 osteoblast-like cells) and epithelial and connective tissue attachment (gingival epithelial cells GE1 and fibroblasts NIH3T3) were analyzed in five groups. Surface morphology of the specimens was changed after coating, and the Sr content on the Sr-PEEK surface was increased with increasing coating thickness. In addition, the contact angle was increased significantly after magnetron sputtering. After UV-C photofunctionalization, the content of surface elements changed and the contact angle was decreased. The release of Sr ion was sustained, and the final cumulative release amount did not exceed the safety limit. In vitro experiments showed that SrTiO3 improved the cell activity of MC3T3-E1 and UV-C irradiation further enhanced the osteogenic performance of PEEK. Besides, UV-C irradiation also significantly promoted the cell viability, development, and expression of adhesion proteins of GE1 and NIH3T3 on PEEK. The present investigation demonstrated that nano SrTiO3 coating with UV-C photofunctionalization synergistically enhanced the osteogenic properties and soft tissue sealing function of PEEK in vitro.

A dielectric barrier discharge based low pressure narrow band far UV-C 222 nm excimer lamp and its efficiency analysis

Far UV-C light at wavelength 222 nm is gaining popularity nowadays due to its properties that it cannot penetrate even the outer dead skin of humans and the tear layer of the eyes. This wavelength has been proven to be much safer for human health. In this paper, a dielectric barrier discharge (DBD) based Far UV-C excimer lamp with a very narrow and intense spectrum peaking at a wavelength of 222 nm has been reported. Optimization of high voltage electrodes has been carried out to minimize the lamp heating without using any external cooling. The discharge produced in this configuration is diffused discharge at a low pressure of 140 mbar. Generally, at low pressure, a very wide band of spectra having full-width half maxima (FWHM) of 8–15 nm is obtained. In this case, due to the confined gas gap and bi-polar pulse power arrangements, the spectra obtained are very narrow, having an FWHM of 1.7 nm. Applied voltage, frequency and gas pressure are optimized to get high electrical-to-optical conversion efficiency of the lamp. The measured radiated intensity at the applied input electrical power of 31 W from the optimized lamp is ∼2.5 mW cm−2, which results in the electrical to optical conversion efficiency as high as 12.5%. The bacterial efficiency of the developed lamp is also examined on pathogenic gram-positive (S. aureus) and gram-negative (E. coli) bacteria. Complete inactivation of S. aureus and E. coli has been achieved at a UV dose of 3 mJ/cm2 and 12 mJ cm–2, respectively. Morphological studies of treated bacteria have also been performed to correlate the results.

UV-C Light Treatment to Extend the Shelf-Life of Paneer (Un-ripened Soft Cheese)

Aim: Application of UV-C light to reduce the post-processing surface contamination and to extend the shelf-life of paneer
 Study Design: The study was aimed for 3×4 factorial design and the paneer samples were exposed to UV-C light for 60, 120 and 180 seconds and studied for its surface decontamination bymicrobiological studies and effect on sensory properties using 9-point hedonic scale after 3, 6 and 9, days of storage in a refrigerated conditions.
 Place and Duration of Study: Karnataka Veterinary Animal and Fisheries Sciences University (KVAFSU), Dairy Science College, Mahagaon Cross, Kalaburagi, Karnataka, India
 Methodology: A standard method was followed for the preparation of paneer. The paneer samples were treated with UV-C light in a UV chamber. Further, the samples were analysed for its Total Bacterial Count (TBC), Yeast and Moulds, and Coliform count, and sensory attributes such as flavour, colour and appearance, body and texture, and overall acceptability on a 9-point hedonic scale. The sensory evaluation of the sample was carried out by a panel of minimum 10 semi-trained judges who are well acquainted with the product features.
 Results: The effect of varied exposure time of UV-C light and after storage days for a specific period was studied on the level of destruction of microbial-count and effect on the sensory characteristics. There was a significant (P=0.05) difference between the treated and non-treated samples in their microbial-count., and a log scale reduction in the bacterial and yeast and mould count on the surface by the effect of UV-C light was observed. The overall acceptability score for UV-C treated and non-treated sample was 8.36 and 8.10 at 0th day, and 7.02 and 5.65 after 9 days, respectively. Hence, the result was comparable to that of non-treated paneer.
 Conclusion: The chemical-free and cost-effective UV-C treatment for surface decontamination of microorganisms could be a viable technique to extend the shelf-life of paneer.
 Recommendation: Combination of other non-thermal techniques with UV-C light and with different packaging method could be studied to enhance the keeping quality.

Investigation of antimicrobial activity of Ultraviolet B radiation and its potential to generate fructose-mediated reactive oxygen species in coconut water

We evaluated the potential antimicrobial activity and inactivation kinetics, photo-reactivation potential and ability to generate reactive oxygen species (ROS) and consequent ascorbic acid degradation in fructose enriched coconut water. UV-B caused 4.5 ± 0.19 log inactivation in E. coli K12 at 0.45 J/cm2 and inactivation kinetics followed Weibull model, compared to log-linear 4 ± 0.05 log reduction at 0.2 J/cm2 dose of UV-C. A lower extent of UV-A (360 nm) induced photo-reactivation was observed in UV-B treated samples compared to UV-C. UV-B mediated microbial inactivation was largely caused by DNA damage and impaired metabolic activity of E. coli. UV-B treatment did not cause membrane damage, or thiol oxidation. Compared to UV-C, UV-B produced lower concentration of ROS from fructose. At a dose required for 4 log reduction of E. coli K12 by UV-B, only 8% ascorbic acid degraded. These results show that UV-B is an attractive alternative to UV-C treatment. Industrial relevanceUV-C irradiation is a cost-effective measure to ensure food safety. However, for fructose-rich products fruit juices, UV-C exposure to photo-sensitive compounds like fructose generates reactive oxygen species that can deteriorate the quality of fructose-rich products. In this context, UV-B provides comparable, albeit slower, antimicrobial effect but provokes milder fructose mediated oxidative stress than UV-C. This study highlights the potential for using UV-B as an alternative to UV-C light treatment for liquid foods.

Superior UVC light-mediated catalytic activity of a novel NiFe2O4@ TiO2 magnetic nanocomposite synthesized with green route using Pulicaria Gnaphalodes plant extract for enhanced photocatalytic degradation of an antibiotic in water solution

In this study, the NiFe2O4@TiO2 magnetic nanocomposite was synthesized by the green synthesis method, which is an efficient and economical method. Pulicaria Gnaphalodes plant extract was used for nanocomposite synthesis because this method is suitable for the biosynthesis of nanocomposites on a large scale, and the nanocomposite produced by plants is more stable. The efficiency of the synthesized nanocomposite was investigated for the photocatalytic degradation of Penicillin G (PNG) under UVC light irradiation in aqueous solutions. The structural characteristics of this nanocomposite were determined by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and dynamic light scattering. The effect of different parameters including pH, nanocomposite dose, penicillin G concentration and time were studied to reach optimum conditions. About 71% of PNG in optimal conditions (pH = 9, nanocomposite dose = 0.6 g/L, and penicillin G concentration = 10 mg/L) was decomposed. Generally, the NiFe2O4@TiO2 nanocomposite can be used as an efficient catalyst for the degradation of PNG in aqueous solutions.

Photodegradation of Wastewater Containing Organic Dyes Using Modified G-C3N4-Doped ZrO2 Nanostructures: Towards Safe Water for Human Beings

Historically, the photocatalytic efficacy of graphitic carbon nitride (g-C3N4) has been constrained by a rapid charge recombination rate and restricted sensitivity to visible light. To overcome these limitations and enhance the performance of g-C3N4, the strategic formation of heterojunctions with semiconductor materials is deemed the optimal approach. The present study employed a facile sonication-assisted pyrolysis method to synthesize a g-C3N4@ZrO2 nanocomposite photocatalyst. This hybrid material was characterized extensively using a comprehensive suite of analytical techniques, including XRD, SEM, EDX, FTIR, and UV-Vis DRS. A comparative analysis of photocatalytic applications under identical conditions was conducted for all synthesized materials, wherein they were subjected to UVc light irradiation. The photocatalytic degradation of various dye models, such as MB, EY, and a combination of dyes, was assessed using the prepared nanocomposites. The g-C3N4@ZrO2 photocatalysts showcased superior photocatalytic performance, with a particular variant, g-CNZ6, exhibiting remarkable activity. With a bandgap energy of 2.57 eV, g-CNZ6 achieved impressive degradation efficiencies of 96.5% for MB and 95.6% for EY within 40 min. Following previous studies, the superoxide radical anions (O2−. and h+) were largely accountable for the degradation of MB. Therefore, the observed efficacy of the g-C3N4@ZrO2 nanocomposite photocatalyst can be attributed to the increased generation of these reactive species.

UV-C Light Intervention as a Barrier against Airborne Transmission of SARS-CoV-2.

SARS-CoV-2 continues to impact human health globally, with airborne transmission being a significant mode of transmission. In addition to tools like vaccination and testing, countermeasures that reduce viral spread in indoor settings are critical. This study aims to assess the efficacy of UV-C light, utilizing the Violett sterilization device, as a countermeasure against airborne transmission of SARS-CoV-2 in the highly susceptible Golden Syrian hamster model. Two cohorts of naïve hamsters were subjected to airborne transmission from experimentally infected hamsters; one cohort was exposed to air treated with UV-C sterilization, while the other cohort was exposed to untreated air. Treatment of air with UV-C light prevented the airborne transmission of SARS-CoV-2 from the experimentally exposed hamster to naïve hamsters. Notably, this protection was sustained over a multi-day exposure period during peak viral shedding by hamsters. These findings demonstrate the efficacy of the UV-C light to mitigate against airborne SARS-CoV-2 transmission. As variants continue to emerge, UV-C light holds promise as a tool for reducing infections in diverse indoor settings, ranging from healthcare facilities to households. This study reinforces the urgency of implementing innovative methods to reduce airborne disease transmission and safeguard public health against emerging biological threats.

Design, construction and robust validation of a germicidal device based on UV irradiation: a necessity for hospital disinfection in the COVID-19 era

Pandemic by SARS-CoV-2 has revealed the importance of disinfection methods due to pathogens of medical importance being detectable and infective after several hours on contaminated surfaces, including medical devices. The aim of this work was to design, construction, and validation of a UVC light irradiation system in the short wavelength region (200 to 320 nm). We studied the effective of the system through in vitro disinfection to eliminate pathogens such as SARS-CoV-2, ESKAPE bacteria and fungi in biofilm and planktonic forms. Doses of 0.25 J/cm2 (10 s of exposure to UVC light), 100% death of ESKAPE bacteria and fungi in planktonic form was observed. Through biofilm formation induction assays of these microorganisms showed resistance to treatment with UV light; however, their viability was not detected after 20 s of exposure (via confocal microscopy). For SARS-CoV-2, 100% reduction was reached after 120 s of exposure. This evidence shows the need to employ emerging methods of disinfection of surfaces and medical devices since these are potential vehicles for transmitting pathogens. The advantages of using UV light as an emergent disinfection method in the era of COVID-19 are discussed.

Effects of germicidal ultraviolet-C light on grape mealybug (Pseudococcus maritimus)

Germicidal ultraviolet-C light (UV–C) has been used to effectively suppress grapevine powdery mildew (Erysiphe necator). However, effects on arthropod pests that would be simultaneously exposed to UV-C during applications directed at E. necator, are poorly understood. The grape mealybug (Pseudococcus maritimus) is one such grapevine pest. We exposed mated P. maritimus adult females in a lab study to UV-C light doses of 100, 200, 500 and 1000 J/m2. UV-C was applied during darkness and was followed by an additional 4 h dark period post-treatment to enhance possible suppressive effects of UV-C. Positive (2% horticultural oil) and negative (untreated) controls were included. Adult female P. maritimus oviposition was observed two weeks after treatment, and hatching of eggs was enumerated four weeks after treatment. UV-C treatment of mated adult females, regardless of dose, did not prevent oviposition or reduce ovisac viability. In a separate lab experiment, first instar P. maritimus nymphs were similarly exposed to UV-C doses of 200 and 1000 J/m2 with and without a 4hr dark period. UV-C treatments were compared to the same positive and negative controls. Nymph mortality was assessed at 24 and 48 h after UV-C treatment. Increasing doses of UV-C treatments, followed by a dark period, had a small, but significant impact on nymph mortality relative to the untreated control. Further studies on the potential sublethal effects (e.g., fecundity or longevity) of single or multiple exposures or increased UV-C doses upon juvenile stages of P. maritimus are warranted, as longer-term and multigenerational effects of UV-C have been observed in other arthropod systems.

Photodegradation of the main synthetic musk (HHCB) in water: kinetic study and influencing factors.

Galaxolide (HHCB) is the most common synthetic musk compound detected in numerous daily products. Despite its persistence in the aquatic environment, the photodegradation of HHCB remains poorly understood. In this study, we investigated the direct and indirect photolysis kinetics of HHCB under simulated sunlight and UVC light. Our aim was to determine the role of reactive oxygen species (ROS) responsible for HHCB degradation in the aquatic environment and to identify its transformation products. The influence of environmental factors on indirect photolysis was investigated by testing both synthetic waters (containing humic acid, carbonate (CO32-), and nitrate (NO3-)) and real waters (riverine and effluent). Hydrogen peroxide (H2O2/UVC) was tested to simulate the wastewater treatment process. Quencher experiments were conducted to identify the role of ROS in HHCB photodegradation, including hydroxyl radicals (˙OH), carbonate radicals (CO3˙-), triplet states of dissolved organic matter (3DOM*), and singlet oxygen (1O2). The results clearly indicated that HHCB was efficiently degraded by direct photolysis under both light conditions. The presence of H2O2 led to the most efficient HHCB degradation due to the high production of ˙OH induced under UVC. Indirect photolysis contribution was observed, induced by ˙OH, CO3˙-, 3DOM*, and 1O2 to different extents depending on the light and matrix composition. The experiments led to the detection of transformation products: HHCB lactone, a well-known transformation product, and two other substances with proposed structures. This study provides a comprehensive identification of the processes involved in the direct and indirect photodegradation of HHCB, which could serve as the basis for evaluating and modeling the fate of HHCB in aquatic environments.

Revolutionizing Infection Control: Autonomous UV-C Disinfection Robots in Healthcare Environments

Healthcare-associated Infections (HAIs) continue to present a significant challenge in healthcare settings, particularly within operating rooms and patient rooms where the risk of contamination is high. Despite rigorous cleaning protocols, traditional methods often struggle to fully eradicate microorganisms, contributing to a notable percentage of HAIs, especially among surgical patients. This paper examines the potential of ultraviolet (UV) light technology, specifically within the C band range (200-280nm), as a promising adjunct to conventional cleaning practices. UV-C light has demonstrated remarkable efficacy in deactivating bacteria, viruses, and fungi by disrupting their DNA, rendering them incapable of replication. This technology offers a versatile solution for sterilizing air, water, and surfaces, including hard-to-reach areas inaccessible to manual cleaning. Incorporating UV-C robots into routine cleaning procedures holds promise in augmenting the effectiveness of environmental decontamination efforts. By addressing the limitations of traditional cleaning methods and targeting residual pathogens, the integration of UV-C technology has the potential to significantly reduce the incidence of HAIs. Furthermore, the implementation of UV-C robots in healthcare facilities could lead to improved patient outcomes, reduced healthcare costs associated with treating HAIs, and a safer environment for both patients and healthcare workers. This paper synthesizes current evidence and highlights the implications of adopting UV-C technology as a crucial step toward enhancing infection control measures in healthcare settings.

Photo-polymerization using quantum dots for stable epoxy coatings

Flame-made titania quantum dots can initiate epoxy photo-polymerization when UVC light is applied, while remaining insensitive to UVA light, producing films that are mechanically stable.

Developmental validation of the AGCU YNFS Y Kit: A new 6-dye multiplex system with 44 Y-STRs and 5 Y-InDels for forensic application.

With the widespread use of the Y chromosome in genetics, a lot of commercially available Y chromosome kits were developed, validated, and applied to forensic science practice. The AGCU YNFS Y Kit is a new Y chromosome system containing forty-four preferred Y short tandem repeats (Y-STRs) and five common Y-InDels. In this study, the AGCU YNFS Y system was validated to verify its performance by following the guidelines of the Scientific Working Group on DNA Analysis Methods (SWGDAM). A series of validation experiments included the following parameters: PCR-based studies, sensitivity studies, species specificity studies, stability studies, mixture studies, precision studies, stutter calculation, mutation and statistical analysis, population study, and case samples and degradation studies. The results suggested that appropriately changing PCR amplification conditions did not affect genotyping; the kit had good sensitivity for trace amounts of DNA (0.0625 ng), mixtures of multiple male individuals (minor: major = 1: 9), and three PCR inhibitors (more than 250 μM hematin, 250 ng/μL humic acid and 50 ng/μL tannic acid). The maximum standard deviation of allele size did not exceed 0.1552 reflecting the high accuracy of the system. By this, 87 DNA-confirmed pairs of father-son pairs were also analyzed for mutations. A total of 18 loci were mutated, with mutation rates ranging from 11.5×10-3 to 34.5×10-3 (95% CI 7.2×10-3-97.5×10-3, DYS627 and DYF404S1). In the population study, the haplotype diversity of 87 unrelated individuals was 0.9997, and discrimination capacity was 0.9885. Degradation studies have demonstrated that UV-C light exposure for up to 120 hours has no effect on male blood and semen-vaginal secretion mixtures. However, complete typing could no longer be obtained after 48 hours of UV exposure in single male saliva and in male saliva and female blood mixed samples. Collectively, the AGCU YNFS Y Kit is sensitive and accurate and can play its application value in forensic science practice.

Knowledge, Attitudes, and Perceptions of UV-C Light Technologies for Agricultural Surface Water Decontamination by Produce Growers in Kansas and Missouri

Knowledge, Attitudes, and Perceptions of UV-C Light Technologies for Agricultural Surface Water Decontamination by Produce Growers in Kansas and Missouri

Effects of packaging under active modified atmospheres combined with UV-C light for preserving quality of fresh cut watermelon

Effects of packaging under active modified atmospheres combined with UV-C light for preserving quality of fresh cut watermelon