Avaliação da efetividade da esterilização por luz ultravioleta em aerossóis contaminados por Sars-Cov-2 / Evaluation of the effectiveness of ultraviolet light sterilization in aerosols contaminated by Sars-Cov-2 / Evaluación de la eficacia de la esterilización por luz ultravioleta en aerosoles contaminados por Sars-Cov-2

O contato direto e a disseminação aérea são os principais mecanismos de transmissão do SARS-CoV-2. Uma abordagem direta para limitar as transmissões virais no ar é inativá-las dentro de um curto período de tempo após sua produção é a luz ultravioleta C (UVC). Neste sentido, o objetivo do presente estudo foi de avaliar a efetividade do uso de luz ultravioleta na esterilização de aerossóis contaminados pelo SARS-CoV-2. Para o estudo foram analisados todos os pacientes que estavam internados na enfermaria COVID com resultados dos swabs positivos. O paciente escolhido para o estudo encontrava-se com resultado positivo e com 8 dias de sintomas. As medições de contaminação da deposição de aerossol na mesa de tomografia foram realizadas em triplicatas, utilizando swabs estéreis com meio de transporte viral. O paciente foi mantido sozinho dentro desta sala por 30 minutos produzindo aerossóis para que pudesse ocorrer contaminação do ar. Após, foram realizadas as medições utilizando a exposição à luz ultravioleta C, coletada nos minutos 0, 5, 10, 15, 30, 60, 120 e 180, após o paciente ter deixado a sala de tomografia. Esta sequência de medições foi realizada por 6 dias, sendo o primeiro dia sem a exposição da luz UVC e 5 dias com a exposição da luz UVC. Após a coleta dos dados, foi realizada a análise dos swabs para os resultados através do método RT-PCR. Os resultados encontrados das coletas desde o tempo 0 até 180 minutos foram negativos para os 6 dias de estudo. Os resultados dos swabs do paciente seguiram positivos do primeiro até o último dia de estudo. Sendo assim, conclui-se a efetividade da utilização da luz ultravioleta como uma forma de descontaminação, juntamente com a ação antimicrobiana do desinfetante, pois a ausência do vírus vivo evidencia a importância de cuidados de higienização para evitar a reincidência da contaminação após a limpeza.

Direct contact and aerial dissemination are the main transmission mechanisms of SARS-CoV-2. A direct approach to limiting airborne viral transmissions is to inactivate them within a short period of time after their production is ultraviolet C (UVC) light. In this sense, the objective of the present study was to evaluate the effectiveness of using ultraviolet light in the sterilization of aerosols contaminated by SARS-CoV-2. For the study, all patients who were admitted to the COVID ward with positive swab results were analyzed. The patient chosen for the study had a positive result and had had 8 days of symptoms. Measurements of contamination from aerosol deposition on the CT table were performed in triplicate, using sterile swabs with viral transport medium. The patient was kept alone inside this room for 30 minutes, producing aerosols so that air contamination could occur. Afterwards, measurements were performed using exposure to ultraviolet C light, collected at 0, 5, 10, 15, 30, 60, 120 and 180 minutes, after the patient had left the tomography room. This sequence of measurements was carried out in 6 days, the first day being without exposure to UVC light and 5 days with exposure to UVC light. After data collection, swab analysis was performed for the results using the RT-PCR method. The results found for collections from time 0 to 180 minutes were negative for the 6 days of study. The patient's swab results were positive from the first to the last day of the study. Thus, the effectiveness of using ultraviolet light as a form of decontamination is concluded, along with the antimicrobial action of the disinfectant, as the absence of the live virus highlights the importance of hygiene care to prevent the recurrence of contamination after cleaning.

El contacto directo y el contagio por vía aérea son los principales mecanismos de transmisión del SRAS-CoV-2. Un enfoque directo para limitar las transmisiones virales en el aire es inactivarlas en un corto período de tiempo después de su producción es la luz ultravioleta C (UVC). En este sentido, el objetivo del presente estudio fue evaluar la eficacia del uso de la luz ultravioleta en la esterilización de aerosoles contaminados con el SARS-CoV-2. Se analizaron todos los pacientes ingresados en la sala COVID con resultados positivos de los hisopos. El paciente elegido para el estudio era positivo y llevaba 8 días con síntomas. Las mediciones de la contaminación por deposición de aerosoles en la mesa de TC se realizaron por triplicado utilizando hisopos estériles con medio de transporte viral. El paciente se mantuvo solo dentro de esta habitación durante 30 minutos produciendo aerosoles para que se produjera la contaminación del aire. A continuación, se realizaron mediciones mediante la exposición a la luz ultravioleta C, recogidas a los 0, 5, 10, 15, 30, 60, 120 y 180 minutos después de que el paciente saliera de la sala de tomografía. Esta secuencia de mediciones se realizó durante 6 días, el primer día sin exposición a la luz UVC y 5 días con exposición a la luz UVC. Tras la recogida de datos, se realizó el análisis de los hisopos para obtener los resultados mediante el método RT-PCR. Los resultados encontrados en las recolecciones desde el tiempo 0 hasta los 180 minutos fueron negativos para los 6 días de estudio. Los resultados de los hisopos de los pacientes siguieron siendo positivos desde el primer hasta el último día del estudio. Así, se concluye la eficacia del uso de la luz ultravioleta como forma de descontaminación, junto con la acción antimicrobiana del desinfectante, ya que la ausencia de virus vivos pone de manifiesto la importancia de los cuidados higiénicos para evitar la reaparición de la contaminación tras la limpieza.

Screening for UV-C irradiation-enhanced transcription factors that regulate the metabolism of phenolic compounds in tomato fruit / 生物工程学报

Solanum lycopersicum phenylalanine ammonia-lyase 5 (SlPAL5) gene regulates the metabolism of phenolic compounds. The study of transcription factors that regulate the expression of SlPAL5 gene is of great significance to elucidate the regulatory mechanism underlying the biosynthesis of phenolic compounds in tomato fruit induced by UV-C irradiation. Here, yeast one-hybrid library of tomato fruit was constructed, and the yeast one-hybrid technology was used to screen the transcription factors that regulate the expression of SlPAL5, the key gene related to the synthesis of phenolic compounds in tomato fruit. As a result, a transcription factor, SlERF7, was obtained and sequenced, followed by the blast homology analysis. Further experiments confirmed that SlERF7 interacted with the promoter of SlPAL5 gene. In addition, UV-C irradiation significantly increased the expression level of SlERF7. These results indicate that SlERF7, which is regulated by UV-C irradiation, might be involved in regulating the transcription of SlPAL5, which provided foundations for further studying the regulation mechanism of the biosynthesis of phenolic compounds in tomato fruit induced by UV-C irradiation.

Ultraviolet-C decontamination of a dental clinic setting: required dose and time of UVC light / Utilização de radiação ultravioleta-C para descontaminação de um consultorio odontológico: tempo e dose de UVC necessária

Viruses can spread to the environment, and it can be challenging to clear it. A direct approach to limit airborne transmission of pathogens in dental clinic offices is to inactivate viruses within a short time of their production and block the person-to-person transmission routes in dental clinics. For this, we can use chemical substances on surfaces and germicidal ultraviolet light (UV), typically at 254 nm, for complementary disinfection of surfaces and air contaminated by aerosols produced by high-speed handpiece or ultrasound scaler. Based on the literature review and the similarity of Sars-Cov-2 with other previously studied corovaviruses, COVID-19 is sensitive to UV irradiation that can break the genome of this virus, inactivating it. In our study, we performed the calculation of the time required to decontaminate a dental care room between each patient change. We can conclude that the use of UVC can be incorporated into the dental care routine to reduce cross contamination. (AU)

Os vírus podem se espalhar para o meio ambiente e pode ser um desafio eliminá-lo. Uma abordagem direta para limitar a transmissão aérea de patógenos nos consultórios de clínicas odontológicas é inativar os vírus o mais rápido possivel após sua produção e bloquear as rotas de transmissão de pessoa para pessoa nas clínicas odontológicas. Para isso, podemos usar substâncias químicas para limpar as superfícies e luz ultravioleta (UV) germicida (UV), normalmente a 254 nm, para desinfecção complementar de superfícies e ar contaminado por aerossóis produzidos pelo altarotação ou ultrassom periodontal. Com base na revisão de literatura e na semelhança do SarsCov-2 com outros corovavirus previamente estudados, o COVID-19 é sensível à irradiação UV que podem quebrar o genoma desse vírus, inativando-o. Em nosso estudo, realizamos o cálculo de tempo necessário para descontaminar uma sala de atendimento odontológico entre cada troca de paciente. Podemos concluir que a utilização de UVC pode ser incorporada à rotina de atendimento odontológico para reduzir a contaminação cruzada entre atendimentos. (AU)

Association between ERCC2/XPD Polymorphisms and UVC-induced DNA Damage Using Transfected Cells Model / 中国医科大学学报

Objective To explore the function of ERCC2/XPD polymorphisms in the repair of DNA damage induced by UVC. Methods Plas?mids stably expressing ERCC2/XPD rs13181 AA(Lys751)and ERCC2/XPD rs13181 CC(Gln751)were transfected into Chinese hamster ovary cells,and the stable ERCC2 transfected cell lines were obtained. MTT assay was used to compare the inhibitory rates of the transfected cells treated with UVC at different irradiation intensity. The DNA damage repair ability of the transfected cells treated with UVC for 1,3,6 and 24 h was detected by modified comet assay. Results Compared with UV5ERCC2(CC),UV5ERCC2(CC) was more sensitive to UVC with decreased cell viability. DNA damage level of UV5ERCC2(CC) cells was more serious than UV5ERCC2(CC). Conclusion DNA repair capacity of ERCC2/XPD rs13181A allelic is lower than its wild?type,suggesting that ERCC2/XPDpolymorphisms play a critical role in UVC?induced DNA damage repair.

Efeitos da modificação por ácidos orgânicos e do processo de secagem sobre as propriedades de expansão do amido de mandioca / Effects of modification by organic acids and the drying process on the expansion properties of cassava starch

O amido fermentado de mandioca, polvilho azedo, possui ampla aplicação em produtos de panificação, devido à propriedade de expansão, sem fermento e sem glúten, o que alavancou a comercialização dos amidos substituintes modificados por ácido. O polvilho azedo é fermentado e seco ao sol, com a geração de ácidos: acético, butírico, lático e propiônico, enquanto os amidos modificados por ácido não são fermentados. Neste trabalho foi produzido o polvilho azedo, seco ao sol e em estufa e amidos modificados pelos ácidos prevalentes na fermentação, secos em UVC. Todos os amidos foram comparados, quanto aos ácidos orgânicos, dos amidos secos em diferentes condições e apenas fermentados, sem secagem, bem com quanto às características físico-químicas e reológicas. Ficou comprovado que a secagem solar favorece um produto mais ácido e de maior expansão. O maior volume específico foi observado para a amostra fermentada seca ao sol, seguida das modificadas por ácido lático 0,5 % e ácido acético 0,5 % e ácido lático 1 %. A baixa expansão da amostra fermentada e seca em estufa (E) mostrou que apenas a presença dos ácidos orgânicos não é suficiente para expansão e que a radiação UV (artificial ou solar) influencia diretamente nessa característica.

The fermented cassava starch, polvilho azedo, has wide application in bakery products, due to expansion property without yeast and gluten, which leveraged the marketing of starches modified by acid. The cassava starch is fermented and sun dried, with the generation of acids: acetic, butyric, lactic and propionic, while starches modified by acid are not fermented. In this work was produced cassava starch, dried in the sun and under oven, and modified by the acids of cassava starch fermentation, dried in UVC. All starches were compared, as the organic acids, dry starches in different conditions and only fermented without drying, as well as with the physicochemical and rheological characteristics. It was proven that solar drying favors a more acidic product and expansion property. The higher specific volume was observed for the sample fermented sun dried, followed by modified by 0.5 % lactic acid and 0.5 % acetic acid and lactic acid 1 %. The low expansion of the fermented sample and dried in an oven showed that only organic acids is not sufficient for expansion and that UV radiation (solar or artificial) directly influences this characteristic.

Induction of secondary metabolite production by UV-C radiation in Vitis vinifera L. Öküzgözü callus cultures

BACKGROUND: The aim of the present work was to examine the role of UV-C irradiation on the production of secondary metabolites (total phenolic, total flavanols, total flavonols, catechin, ferulic acid and trans-resveratrol in phenolic compounds and α-, ß-, γ- δ-tocopherols) in callus cultures. Studies on the effects of UV-C treatment on callus culture are seldom and generally focused on UV-B. However UV-C radiation play an important role in accumule secondary metabolites. RESULTS: In this study, callus cultures from Öküzgözü grape cultivar were initiated from leaf petiole explants. Calli formed after 6 weeks on the medium supplemented with 0.5 mg L-1 benzylaminopurine (BA), 0.5 mg L-1 indole acetic acid (IAA) on B5 media. Callus tissues were exposed to UV-C irradiation at 10, 20 and 30 cm distances from the UV source for 5 and 10 minutes and samples were collected at hours 0, 24 and 48. CONCLUSIONS: The greatest total phenolic content (155.14 mg 100 g-1) was detected in calli exposed to UV-C for 5 min from 30 cm distance and sampled after 24 h. 24 h and 48 h incubation times, 30 cm and 5 min were the most appropriate combination of UV-C application in total flavanol content. Maximum total flavonol content (7.12 mg 100 g-1) was obtained on 0 h, 5 min and 20 cm combination. The highest (+)- catechin accumulation (8.89 mg g-1) was found in calli with 10 min UV-C application from 30 cm distance and sampled after 48 h. Ferulic acid content increased 6 fold in Öküzgözü callus cultures (31.37 µg g-1) compared to the control group. The greatest trans-resveratrol content (8.43 µg g-1) was detected in calli exposed to UV-C for 5 min from 30 cm distance and sampled after 24 h. The highest α-tocopherol concentration was found in calli exposed to UV-C for 10 min from 30 cm distance and sampled after 24 h. As a conclusion, it was showed that UV-C radiation had remarkable promoting effects on the accumulation of secondary metabolites in the calli of Öküzgözü grape cultivar.

Comparative Study of In Vitro Inhibitory Effects of UVC, Terbinafine Hydrochloride 1% and Paeonia Natural Extracts on Trichophyton rubrum / 대한의진균학회지

BACKGROUND: Trichophyton(T.) rubrum is most common fungal pathogen that causes tinea pedis and onychomycosis. It recurrently infects human and usually persists for very long time, provoking public health concern. Due to the limitation in current treatment options, alternative therapies are desirable. We investigated the inhibitory effect of UVC, terbinafine hydrochloride 1% and paeonia natural extracts on T. rubrum in vitro. OBJECTIVE AND METHOD: Total 25 T. rubrum strains were cultured for 10 days on Mycosel agar plate; 5 strains of T. rubrum and 5 copies for each strain. They were divided into 5 groups: control, UVC irradiation, terbinafine spray, paeonia natural extracts spray, UVC and paeonia natural extracts sprays. The cultured media were irradiated for 1 hour daily for 3 weeks in the germicidal lamp emitting 253.7 nm (UVC), power of 2.875 mW/cm2 at 10 cm distance. Terbinafine and paeonia extracts was sprayed twice on the surface to fully cover the colony area. The median diameter of each colony were measured every other day for 3 weeks. The change of colony diameter and the growth rate were analyzed. RESULTS: The UVC had virtually no effect on restraining the growth of T. rubrum, similar with the growth of the control group. However, both the terbinafine spray and paeonia extracts slowed down the growth rate remarkably and showed a similar effect. CONCLUSION: We could only figure out the fungistatic effect, and not the fungicidal effect of paeonia extract and terbinafine hydrochloride in vitro. UVC irradiation setting in this study was totally ineffective. More studies are needed on more variable wavelength and the fluence of UVC irradiation. In addition, further verification on the mechanism and the effect of anti-fungal activity by paeonia extracts are needed.

Non-Cytotoxic Property and DNA Protective Activity against H2O2 and UVC of Thai GAC Fruit Extracts in Human TK6 Cells.

Momordica cochinchinensis (Lour.) fruit of Cucurbitaceae family is indigenous vegetable and fruit to Southeast Asia. It has been generally known as “GAC” whereas in Thailand it is called “Fhuck-khow”. Regarding its richness in anti-oxidants particularly lycopene and beta-carotene, GAC is named "fruit from heaven" and believed to promote longevity, health and vitality. In present study, GAC extracts were prepared from pulp (PU), skin (SK) and seed membrane (SM) by 50%, 95% ethanol and water (W). MTT assay was done in TK6 cells to determine their cytotoxicity property. The non-cytotoxic extracts were further evaluated for the DNA protective activity against H2O2 and UVC using high alkaline (pH >13) comet assay. TK6 cells (1x105 cells/ml) were pre-incubated with GAC extracts (25, 50 and 100μg/ml) for 24 h prior to an exposure to 50 μM H2O2 and a 254-nm UVC germicidal lamp for DNA damage induction. We found that H2O2-induced DNA damage was suppressed by 30- 60 % when cells were pre-treated with PU, SK and SM extracts at all concentrations used. Regarding test condition used, UVC clearly induced DNA damage in TK6 cells greater that that by H2O2. The protective effect of GAC extracts against UVC was found by 20-30%. Our present results suggest that GAC possesses DNA protective ability against H2O2 and UVC. The degree of anti-oxidative damage activity in TK6 cells of GAC extracts is SK95>SMW>SK50.

Estudo do reparo das lesões induzidas no DNA de Escherichia coli pela radiação ultravioleta C (UVC) / Study of repair of induced lesions in the DNA of Escherichia coli by ultraviolet C (UVC)

Didaticamente, podemos dividir o espectro da radiação ultravioleta (UV) em três faixas: UVA (400 a 320 nm), UVB (320 a 290 nm) e UVC (290 a 100 nm). Apesar do UVC ou UV-curto ser eficientemente filtrado pela camada de ozônio da Terra e sua atmosfera, este é uma das faixas do espectro de UV mais usadas para explorar as consequências de danos causados ao DNA, já que a letalidade induzida por este agente está relacionada aos danos diretos no genoma celular, como as lesões dímero de pirimidina, que são letais se não reparadas. Contudo, demonstrou-se que a radiação UVC pode gerar espécies reativas de oxigênio (ERO), como o oxigênio singleto (1O2). Embora, o radical hidroxil (•OH) cause modificações oxidativas nas bases de DNA, alguns trabalhos indicam que o 1O2 também está envolvido nos danos oxidativos no DNA. Esta ERO é produzida por vários sistemas biológicos e reações fotossensibilização, quando cromóforos são expostos à luz visível ou são excitados pela luz UV, permitindo que essa energia possa ser transferida para o oxigênio sendo convertido em 1O2, que é conhecido por modificar resíduos de guanina, gerando 8-oxoG, que caso não seja reparada pode gerar uma transversão GC-TA. O objetivo deste trabalho foi o de elucidar a participação de ERO nos efeitos genotóxicos e mutagênicos gerados pela radiação UVC, assim como as enzimas envolvidas no processo de reparação destas lesões em células de Escherichia coli. Nos ensaios as culturas foram irradiadas com o UVC (254 nm; 15W General Electric G15T8 germicidal lamp, USA). Nossos resultados mostram que o uso de quelantes de ferro não alterou a letalidade induzida pelo UVC. A azida sódica, um captador de 1O2, protegeu as cepas contra os danos genotóxicos gerados pelo UVC e também diminuiu a frequência de mutações induzidas no teste com rifampicina. A reversão específica GC-TA foi induzida mais de 2,5 vezes no ensaio de mutagênese. A cepa deficiente na proteína de reparo Fpg, enzima que corrige a lesão 8-oxoG...

Didactically, we can divide the ultraviolet radiation (UV) spectrum into three bands: UVA (400 to 320 nm), UVB (320-290 nm) and UVC (290-100 nm). Despite the UVC or far-UV be efficiently filtered by Earth´s ozone layer and its atmosphere, this is one of bands of UV spectrum used to explore the consequences of DNA damages, since the UVC-induced lethality is related to direct damage in genome cells, such as pyrimidine dimers, which are lethal if not repaired. However, it was shown that UVC radiation can generate reactive oxygen species (ROS) such as singlet oxygen (1O2). Although hydroxyl radical (•OH) cause oxidative modifications in DNA bases, some works suggests that 1O2 is also involved in oxidative DNA damage. This ROS is produced by several biological systems and photosensitivity reactions when chromophores are exposed to visible light or excited by UV light, allowing that energy can be transferred to the oxygen being converted to 1O2, which is known to modify guanine residues, generating 8-oxoG, if not repaired can lead to a GC-TA transversion. The objective of this work was to elucidate the ROS involvement in the genotoxic and mutagenic effects generated by UVC radiation, as well as the enzymes involved in the repair process of these lesions in Escherichia coli cells. In the assays, cultures were irradiated with UVC (254 nm, 15 W General Electric germicidal lamp G15T8, USA). Our results show that the use of iron chelators did not affect the UVC-induced lethality. The sodium azide, a 1O2 quencher, protected strains against the genotoxic damage produced by UVC and also decreased the frequency of mutations induced in rifampicin assay. Reversal specific GC-TA was induced more than 2.5 fold in the mutagenesis assay. The deficient strain in the repair protein Fpg, an enzyme that corrects 8-oxoG lesions, had less DNA breakage than the wild strain in electrophoresis alkaline assay. The UVC-induced lethality was increased in mutants transformed with the pFPG...

Effect of ultraviolet C irradiation on expression of transforming growth factor β in wound / 中国康复理论与实践

@#ObjectiveTo study the effect of ultraviolet C(UVC) irradiation at different doses on expression of transforming growth factor β(TGF-β) of granulation tissues in wound. MethodsAfter dosing 15mJ/cm2 or 60mJ/cm2 UVC on wound of rats, the expression of TGF-β were observed at both the mRNA level and the protein level by the methods of in situ hybridization and immunohistochemistry respectively. Results At the 7th day after UVC irradiation, the expression of TGF-β in the 15mJ/cm2 group were higher than that in 60mJ/cm2 group and controls (P<0.05)at both the mRNA and the protein level. On the 21st day, the level of TGF-β mRNA in the 60mJ/cm2 group was higher than that in the other two groups(P<0.05).Conclusions At the early stage of wound healing,the treatment of 15mJ/cm2 UVC irradiation promots the expression of TGF-β and might be useful for accelerating wound healing. The level of TGF-β mRNA was up-regulated at the later stage at the dose of 60mJ/cm2 UVC irradiation.

UVC induced translocation of protein kinase C (PKC) and expression change of c-myc oncogene in human skin keratinocytes / 대한해부학회지

Recent studies have documented that UVC induced DNA damage leads to activation of protein kinase C (PKC) isoforms, which result in the transient expression of immediate early gene expression, then in phosphorylation of p53, its nuclear accumulation, and the cascade which leads to DNA repair, apoptosis, or carcinogenesis. But long-term activations and translocations of PKC isoforms were found after recovery of expression of one of immediate early gene, c-myc. Three days later after UVC 5 J/m2 irradiation, PKCalpha and beta molecules were shifted to around nuclei from even distribution in cytosol. Multiple irradiation of UVC (5 J/m2 for 5 times) induced more consolidated translocation of PKC alpha, while up-regulation and translocation of PKCbeta expression was responded with single does. PKCgamma molecule was basically accumulated around nuclear membrane. UVC irradiation caused a transient increase of membrane fraction of PKCgamma with single dose. These results suggest that UVC induced long-term activation of PKC after recovery of c-myc gene expression results from the translocation of PKC isoforms of cytosol to nuclear membrane or around nucleus rather than translocation to cell membrane. These intracellular shift of PKC molecules after 3 days might be not associated with c-myc expression.