Photocatalytic destruction of Escherichia coli in water over rGO/TiO2 nanocomposites

In the present study, Graphene-TiO2 catalysts are prepared by solvothermal method with varied graphene concentrations (1%, 2.5% and 5%). The prepared nanocomposites were characterized by FTIR, Raman and TEM. The photocatalytic activity towards the destruction of Escherichia coli in water under UV and UV-visible irradiations were studied. Graphene-TiO2 nano composite destructs the bacteria significantly at higher rates than unmodified TiO2 and graphene. The results indicates that, at the beginning, the inactivation of E. coli cells is more due to the generation of reactive oxygen species (ROS) like, OH, H2O2, and O2– . Among all samples, the nano composite containing 2.5 wt.% of graphene exhibits a complete E. coli destruction in a minimum irradiation time of 15 and 20 min under UV–Visible and UV light irradiation respectively. The high photocatalytic activity is achieved with the optimum loading concentration of 2.5 wt. % graphene on titania

Avaliação da ação germicida da luz ultravioleta de cabine de segurança biológica frente às espécies bacterianas / Evaluation of the germicidal action of ultraviolet light in biosafety cabinet concerning bacterial species

RESUMO: Introdução: A cabine de segurança biológica (CBS) é um equipamento de proteção coletiva, utilizado para efe-tuar a contenção de aerossóis produzidos nos procedimentos laboratoriais. A CBS protege tanto os trabalhadores, quanto o material manipulado e o meio ambiente. Dispõe de lâmpadas de luz ultravioleta (UV) que possui ação germicida, alterando os ácidos nucleicos dos micro-organismos. Objetivo: O objetivo do presente estudo foi avaliar a ação germicida da luz UV da CBS classe II, tipo A2, frente à cultura de duas espécies de bactérias com diferentes condições de exposição a luz UV. Material e Métodos: Para o desenvolvimento da pesquisa foram utilizadas as bactérias Staphylococcus aureus ATCC 25923 e Klebsiella pneumoniae ATCC 10031, na concentração de 1,5x108 Unidades Formadoras de Colônias/ml (UFC/ml), que após a semeadura em biplacas de Petri foram expostas à luz UV em diferentes condições e tempos. Resultados: Os resultados obtidos revelaram que as espécies de bactérias apresentaram igual perfil de crescimento ou inibição quando submetidas às diferentes condições de exposição. As biplacas de Petri com as tampas abertas e protegidas ou não com embalagem de esterilização apresentaram, nos tempos 15 e 20 minutos, inibição bacteriana. Nas biplacas protegidas pelo papel alumínio e nas biplacas com a tampa fechada, independentemente do tempo e da condição, os micro-organismos apresentaram crescimento bacteriano. Conclusão: Com os resultados obtidos, sugere-se que a ação germicida da luz UV foi eficaz, garantindo a descontaminação adequada e assegurando a qualidade na biossegurança laboratoria. (AU)

ABSTRACT: Introduction: The biological safety cabinet (BSC) is a collective protective device used to hold aerosols produced in laboratory procedures. The BSC protects workers, material handling, and the environment. It relies on ultraviolet light (UV) lamps that have germicidal action, altering the nucleic acids of microorganisms. Objective: The objective of the present study was to evaluate the germicidal action of BSC class II type A2 UV light against the culture of two bacterial species with different conditions of exposure to UV light. Methods: For the research, the bacteria Sta-phylococcus aureus ATCC 25923 and Klebsiella pneumoniae ATCC 10031 were used, at a concentration of 1.5x108Colony Forming Units/ml (CFU/ml), which were seeded in Petri biplates. Use UV light under different conditions and times. Results: The bacterial species showed the same growth or inhibition profile when subjected to different exposure conditions. Petri dishes with the cover open and protected or not with sterilization packaging showed bacterial inhibition at 15 and 20 minutes. The microorganisms in the biplates protected by the aluminum foil and in the biplates with the cover on, regardless of the time and condition, showed bacterial growth. Conclusion: With the results obtained, it is suggested that the germicidal action of UV light was effective, ensuring adequate decon-tamination and ensuring quality in laboratory biosafety. (AU)

Estudio retrospectivo del carcinoma de células escamosas en bovinos en el departamento de Nariño, Colombia / Retrospective Study of Squamous Cell Carcinoma in Bovines in Nariño Province, Colombia / Estudo retrospectivo do carcinoma de células escamosas em bovinos no departamento de Nariño, Colômbia

Resumen El carcinoma de células escamosas (CCE) es la neoplasia más frecuente en los bovinos. El trabajo determinó la frecuencia del CCE y factores de riesgo asociados desde el año 2007 hasta el 2019, en el departamento de Nariño. Se analizaron 82 casos de la base de datos de la clínica de animales grandes de la Universidad de Nariño, teniendo en cuenta las variables: raza, edad, número de partos, ubicación del tumor, pigmentación de la piel y la altura sobre el nivel del mar de las fincas. Posteriormente, se formaron tres grupos: < 3 años (jóvenes), entre 4 y 7 años (adultos) y > 8 años (seniles). Las 56 fincas están ubicadas a 2973 ± 197.01 metros sobre el nivel del mar (msnm). Las razas estudiadas fueron: Holstein 81.2 %, Normando 7.2%, Montbeliarde 3.4 %, Simhol 3.4 %, Criollas 2.4 %, Jersey 1.2 % y Cebú 1.2 %. La presentación de CCE comprometía en su mayoría, la región ocular y periorbital 85.3 %, seguida de vulva 11.1 % y entre el dorso, ubre y cuerno en un 3.9 %. La despigmentación de la piel se presentó en 31.7 % de los casos. El promedio de edad fue 7.7 ± 1.58 años; dos novillas, 58 adultos y 22 seniles con un promedio de 4.7 ± 1.35 partos. La frecuencia de presentación fue significativamente mayor en animales adultos (p < 0.001). La ubicación del carcinoma fue mayor en el ojo y en el tejido periorbital (p < 0.005), la presentación fue significativa en animales con áreas de piel no pigmentada y en la raza Holstein (p < 0.005 y p < 0.001 respectivamente). Se determinó como factor de riesgo la edad, la despigmentación y la altitud (msnm) de las fincas. El estudio representa el primer reporte de ocurrencia y factores asociados al CCE en bovinos, en el Departamento de Nariño.

Abstract Squamous Cell Carcinoma (SCC) is the most frequent neoplasia in bovines. This work determined the SCC frequency and the associated risk factors from 2007 to 2019 in Nariño Province. Eighty-two cases from the big animal clinic database at the Universidad de Nariño were analyzed. The variables considered herein include: breed, age, parity, tumor location, skin pigmentation and MASL of the farms. Three groups were created: < 3 years old (younger), from 4 to 7 years old (adults), and > 8 years old (elder). The 56 farms are located at 2973 ± 197.01 meters above sea level. The studied breeds include Holstein 81.2%, Normando 7.2%, Montbeliarde 3.4%, Simhol 3.4%, Criollas 2.4%, Jersey 1.2% and Cebú 1.2%. the SCC compromised the eye and periorbital regions in 85.3% of the cases, followed by the vulva 11.1%, and 3.9% in the back, udder and horns. Skin depigmentation was observed in 31.7% of the cases. The average age was 7.7 ± 1.58 years; 2 heifers, 58 adults and 22 elders with a parity of 4.7 ± 1.35 on average. Appearance frequency was significantly higher in adult animals (p<0,001). The location of the carcinoma was greater in the eye and the periorbital tissue (p<0,005). The appearance was significantly higher in animals with non-pigmented skin areas and in the Holstein breed (p<0.005 and p<0.001, respectively). The risk factors found in this research were age, depigmentation and MASL of the farms. This study is the first report of occurrence and factors associated with the SCC in bovines in the Nariño Province.

Resumo O carcinoma de células escamosas (CEC) é a neoplasia mais comum em bovinos. O trabalho determinou a frequência da CCE e os fatores de risco associados de 2007 a 2019, no departamento de Nariño. Foram analisados ​​82 casos a partir do banco de dados da clínica de grandeis animais da Universidade de Nariño, considerando as variáveis: raça, idade, número de partos, localização do tumor, pigmentação da pele e altura acima do nível de mar das fazendas. Três grupos foram formados : <3 anos (jovens), entre 4 e 7 anos (adultos) e> 8 anos (senis). As 56 fazendas estão localizadas a 2973 ± 197,01 metros sobre o nível do mar (msnm). As raças estudadas foram: Holstein 81,2%, Normando 7,2%, Montbeliarde 3,4%, Simhol 3,4%, Crioulo 2,4%, Jersey 1,2% e Cebu 1,2%. A apresentação da CCE comprometeu principalmente a região ocular e periorbital em 85,3%, seguida pela vulva em 11,1% e entre as costas, úbere e corno em 3,9%. A despigmentação da pele ocorreu em 31,7% dos casos. A idade média foi de 7,7 ± 1,58 anos; duas novilhas, 58 adultos e 22 senis, com média de 4,7 ± 1,35 partos. A frequência de apresentação foi significativamente maior em animais adultos (p <0,001). A localização do carcinoma foi maior no olho e no tecido periorbital (p <0,005), a apresentação foi significativa em animais com áreas de pele não pigmentada e na raça Holstein (p <0,005 e p<0,001, respectivamente). A idade, despigmentação e altitude (msnm) das fazendas foram determinadas como fator de risco. O estudo representa o primeiro relato de ocorrência e fatores associados à CCE em bovinos, no Departamento de Nariño.

Intraindividual Comparison of Visual Outcomes between Blue Light-filtering and Ultraviolet Light-filtering Intraocular Lens

PURPOSE: To compare the clinical results of short-term visual acuity and quality of vision after implantation of a yellow-tinted blue light-filtering intraocular lens (IOL) (Acrysof IQ® SN60WF) and an clear ultraviolet (UV) light filtering IOL (enVista™ MX60) in the same patient. METHODS: 44 patients with bilateral cataract received an SN60WF in one eye and an MX60 in the other eye. All eyes were evaluated for refraction power and uncorrected visual acuity (UCVA) at preoperative and 1, 3 months postoperatively. At postoperative 3 months, corrected visual acuity, quality of vision (OQAS II®), contrast sensitivity (CGT 2000®) and visual field (Humphrey Field Analyzer®), and subjective patients' response to the degree of brightness were evaluated. Furthermore, glistening degree, intraocular stability, and posterior capsular opacification were examined. RESULTS: There were no significant differences in average refractive power or UCVA at 1 and 3 months (p > 0.05) between the two groups. At 3 months after cataract surgery, the quality of vision according to OQAS II®, the contrast sensitivity according to CGT 2000® with the glare either on or off, and visual field; showed no difference between the two groups (p > 0.05). Both IOLs had no glistening and posterior capsular opacity. The patients' response to the degree of brightness shows that MX60 (48.3%) has a higher degree of satisfaction. CONCLUSIONS: Yellow-tinted blue light-filtering IOL and clear UV light-filtering IOL had no difference in short-term visual acuity and quality of vision. Subjective brightness perception, however, was better with clear UV light-filtering IOL.

Oxidação de resíduos de triptofano em proteínas: formação de ligação cruzada ditriptofano e implicações patofisiológicas / Oxidation of tryptophan residues in proteins: formation of the ditryptophan cross-link and pathophysiological implications

Apesar de extensa investigação das modificações oxidativas irreversíveis sofridas pelas proteínas in vitro e in vivo, os produtos formados pela oxidação de resíduos de triptofano ainda permanecem apenas parcialmente conhecidos. Recentemente, nosso grupo caracterizou uma ligação cruzada de ditriptofano produzida pela recombinação de radicais hSOD1-triptofanila gerados pelo ataque do radical carbonato produzido durante a atividade peroxidásica da enzima superóxido dismutase humana (hSOD1). Neste trabalho, examinamos se a ligação ditriptofano pode ser formada em outras proteínas, além da hSOD1 e por outros oxidantes, além do radical carbonato. A lisozima da clara do ovo e a beta cristalino bovina foram utilizadas como alvos de oxidação. A lisozima foi utilizada por ser uma enzima pequena (129 aminoácidos) e de estrutura bem conhecida, contendo seis resíduos de Trp. Os resultados mostraram que o radical carbonato, gerado enzimatica ou fotoliticamente, promove a oxidação, dimerização e inativação da lisozima. Os principais produtos de oxidação caracterizados por análise de nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano e N-formilquinurenina juntamente com um dímero de lisozima (lisozima-Trp28-Trp28-lisozima) e um hetero dímero lisozima-hSOD1 (lisozima-Trp28-Trp32-hSOD1), ambos ligados por uma ligação ditriptofano. Também demonstramos que a irradiação da lisozima com luz UVC leva à formação do dímero lisozima-Trp28-Trp28-lisozima. Em consequência, resolvemos tratar a beta cristalino bovina com radical carbonato gerado fotoliticamente ou com luz UVC, e a proteína também sofreu oxidação, dimerização e agregação. Os principais produtos de oxidação caracterizados por nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano, N-formilquinurenina, DOPA e um dímero de beta cristalino (ßB2-Trp151-Trp151-ßB2). A irradiação com luz UVC também levou à formação de um dímero intra-cadeia, caracterizado como ßA2-Trp78-Trp81. Quando a beta cristalino foi irradiada com um simulador de luz solar (UVA e UVB) também foi possível observar um dímero, caracterizado como ßA2-Trp150-Trp150-ßA2. A presença de produtos de oxidação de resíduos de Trp, dentre eles a ligação cruzada ditritpofano, também foi avaliada in vivo, utilizando o cristalino de pacientes que foram submetidos a cirurgia para remoção de catarata. Beta, alfa e gama cristalino foram as principais proteínas identificadas nas frações solúvel e insolúvel do cristalino. A principal modificação pós-traducionais identificada foi deamidação. Um alto conteúdo de resíduos de metionina e triptofano oxidados foram identificados nas proteínas presentes na fração insolúvel. Os principais produtos de oxidação de Trp identificados por nano-ESI-Q-TOF-MS/MS foram quinurenina e N-formilquinurenina. A presença de dímeros covalentes no cristalino com catarata foi confirmada por análises de massas. A completa caracterização desses dímeros (ßB1-Trp127-Trp127-ßB1 e ßB1-Trp193-Trp193-ßB1) confirmou que as cadeias polipeptídicas foram ligadas por uma ligação ditriptofano. Em síntese, nossos dados demonstraram que o radical carbonato e a luz UV podem produzir dímeros de ditriptofano em diferentes proteínas. Também, a presença da ligação cruzada de ditriptofano in vivo (catarata humana) foi pela primeira vez detectada

Despite extensive investigation of irreversible oxidative modifications suffered by proteins in vitro and in vivo, the products formed by oxidation of tryptophan residues remain partially characterized. Our group recently described a ditryptophan cross-link produced by recombination of hSOD1-tryptophanyl radicals generated by attack of the carbonate radical produced during the peroxidase activity of the human superoxide dismutase (hSOD1) enzyme. Here, we examine whether the ditryptophan cross-link can be produced in others proteins besides the hSOD1 and by other oxidants, in addition to the carbonate radical. The egg white lysozyme and bovine beta crystalline were used as targets. Lysozyme was used because it is a small enzyme (129 amino acids) with a well-known structure, containing six Trp residues. The results showed that the carbonate radical, generated enzymatically or photolytically, promotes lysozyme oxidation, inactivation and dimerization. The major oxidation products characterized by nano-ESI-Q-TOF-MS/MS analysis were hydroxy-tryptophan and N-formylkynurenine together with a dimer of lysozyme (lysozyme-Trp28-Trp28-lysozyme) and a hetero dimer hSOD1-lysozyme (lysozyme-Trp28-Trp32-hSOD1), both bound by a ditryptophan cross-link. Also, it was demonstrated that lysozyme irradiation with UVC light leads to the formation of the dimer lysozyme-Trp28-Trp28-lysozyme. In view of these results, we decided to treat beta crystalline bovine with photolytically generated carbonate radical and UVC. Beta crystalline also suffered oxidation, dimerization and aggregation. The major oxidation products characterized were hydroxy-tryptophan, N-formylkynurenine, DOPA and a beta crystalline dimer (ßB2-Trp151-Trp151-ßB2) by nano-ESI-Q-TOF-MS/MS. Irradiation with UVC light also led to the formation of an intra-chain dimer, which was characterized as ßA2-Trp78-Trp81. When beta crystalline was irradiated with a solar simulator (UVA and UVB), it was also possible to observe a dimer which was characterized as ßA2-Trp150-Trp150-ßA2. The presence of oxidized tryptophan products, including the ditryptophan cross-link, was also evaluated in vivo in the lenses of patients submitted to cataract removal. Beta, alpha and gamma crystalline were the main proteins identified in soluble and insoluble fractions of the lenses. The main post translational modification identified was deamidation. A high content of oxidized methionine and tryptophan residues were identified in proteins present in the insoluble fraction. The main tryptophan oxidation products identified by nano-ESI-Q-TOF-MS/MS were kynurenine and N-formylkynurenine. The presence of covalent dimers in the lenses with cataract was demonstrated by mass analysis. Full MS/MS characterization of the dimers ßB1-Trp127-Trp127-ßB1 and ßB1-Trp193-Trp193-ßB1 confirmed that they were linked by a ditryptophan bond. In summary, our data demonstrate that the carbonate radical and UV light can produce ditryptophan dimers in different proteins. Also, the presence of the ditryptophan cross-link was first detected in vivo (human cataract)

Education in Hand Hygiene for Nurses to Visualize Hand Contamination / 医学教育

Background: Hand hygiene is recognized as the leading factor to prevent Healthcare-Associated Infection. This report describes an investigation of education in hand hygiene for nurses to visualize hand contamination.<br>Method: Twenty-nine nurses underwent education using adenosine triphosphate (ATP) measurements and fluorescent cream and black light, and a survey was conducted.<br>Results: A significantly higher number of nurses recognized the importance of hand hygiene after receiving education. Approximately 80% of nurses were able to: ″reflect on their methods for washing their hands″ , ″understand the necessity of keeping their hands clean after removing their gloves″ , and ″check for areas of the hands that had not been cleaned″ .<br>Discussion: This report suggested that education in hand hygiene using adenosine triphosphate (ATP) measurements and fluorescent cream and black light for nurses improves their perception of the importance of hand hygiene.

Current status of accelerated corneal cross-linking.

Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK) ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

Type of light i sand fly captures (diptera: psychodidae) / Tipo de luz en la captura de flebotominos (Diptera: Psychodidae)

The number of visceral leishmaniasis cases has been gradually increasing in Brazil. One of the strategies to reduce the disease transmission is based on vector control. It is therefore of great epidemiological importance to develop more refined methods for monitoring and controlling its vectors, which are the phlebotomine sand flies. The present study evaluates the performance of traps using UV light or conventional incandescent, or white, light in sand flies captures. Traps baited with UV light caught higher numbers of sand flies than traps baited with white light, indicating the potential use of UV light, especially in locations of low sand flies densities.

El número de casos de leishmaniasis visceral en Brasil ha ido en aumento, y una de las estrategias para reducir la transmisión de esta enfermedad tiene como base el control de sus vectores. Por tanto, es de gran importancia epidemiológica desarrollar métodos más refinados para monitorear y controlar sus vectores, que son los flebotominos. El presente estudio compara la atracción ejercida por la luz UV en comparación con luz incandescente convencional, o luz blanca, en la captura de flebotominos. Las trampas adaptadas con luz UV capturaron un mayor número de mosquitos que las trampas adaptadas con luz blanca, lo que indica el uso potencial de la luz ultravioleta, especialmente en las localidades de baja densidad de flebotominos.

E-cadherin and c-Met expression in actinic cheilits and lip squamous cell carcinoma

Objective: The aim of this study was to assess epithelial expression of E-cadherin and c-Met in normal lip, in actinic cheilitis and lip squamous cell carcinoma. Study Design: Biopsies of normal lip vermillion (NL, n=18), actinic cheilitis (AC, n=37), and lip SCC (n=22) were processed for E-cadherin and c-Met immunodetection. Epithelial and tumor cell expression was scored for each sample considering staining intensity and percentage. Results: E-cadherin expression was significantly reduced in AC and lip SCC as compared to normal lip (P<0.05), with a significant reduction in lip SCC as compared to AC (P=0.003). Expression of c-Met was significantly higher in AC and lip SCC as compared to NL (P<0.05), with a significant increase in lip SCC as compared to AC (P<0.0001). Conclusion: The results showed that epithelial E-cadherin expression is reduced and c-Met expression is increased as lip carcinogenesis progresses, suggesting that these proteins may be useful markers of malignant transformation.

Wettability and cellular response of UV light irradiated anodized titanium surface

PURPOSE: The object of this study was to investigate the effect of UV irradiation (by a general commercial UV sterilizer) on anodized titanium surface. Surface characteristics and cellular responses were compared between anodized titanium discs and UV irradiated anodized titanium discs. MATERIALS AND METHODS: Titanium discs were anodized and divided into the following groups: Group 1, anodized (control), and Group 2, anodized and UV irradiated for 24 hours. The surface characteristics including contact angle, roughness, phase of oxide layer, and chemical elemental composition were inspected. The osteoblast-like human osteogenic sarcoma (HOS) cells were cultured on control and test group discs. Initial cellular attachment, MTS-based cell proliferation assay, and ALP synthesis level were compared between the two groups for the evaluation of cellular response. RESULTS: After UV irradiation, the contact angle decreased significantly (P<.001). The surface roughness and phase of oxide layer did not show definite changes, but carbon showed a considerable decrease after UV irradiation. Initial cell attachment was increased in test group (P=.004). Cells cultured on test group samples proliferated more actively (P=.009 at day 2, 5, and 7) and the ALP synthesis also increased in cells cultured on the test group (P=.016 at day 3, P=.009 at day 7 and 14). CONCLUSION: UV irradiation induced enhanced wettability, and increased initial cellular responses of HOS cells on anodized titanium surface.

Immunohistochemical Study on MAPK Expression in Seborrheic Keratosis and Squamous Cell Carcinoma by Sun Exposure / 대한피부과학회지

BACKGROUND: Mitogen-activated protein kinase (MAPK) is a key molecule in intracellular signal transducing pathways that transport extracellular stimuli from cell surface to nuclei. The MAPK family, comprised of extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinases, could be activated by a number of growth factors, cytokines, and other stimuli such as UV light, and has been implicated in the regulation of cell proliferation, tumorigenesis, differentiation, and apoptosis. OBJECTIVE: The purpose of this study was to immunohistochemically analyze the expression of ERK and JNK in epidermal tumors, including seborrheic keratosis (SK) and squamous cell carcinoma (SCC) on sun-exposed skin and unexposed skin. METHOD: SK on sun-exposed skin (5 cases) and unexposed skin (5 cases), and SCC on sun- exposed skin (5 cases) and unexposed skin (5 cases) were immunohistochemically stained with ERK and JNK monoclonal antibodies. RESULTS: ERK was more strongly expressed than JNK in all the cases. In the sun-exposed skin of SK and SCC, ERK was more definitely expressed than in the unexposed area. JNK was not expressed in all tumor cells of SK and SCC. CONCLUSION: This study strongly indicates that ERK expression may be related to sun exposure and responsible for proliferation of tumors. On the other hand, JNK may not be associated with tumor progression, caused by sun exposure.

Photocatalytic Bactericidal Effect of Titanium dioxide(TiO2) Thin Film for Escherichia coli, Aspergillus fumigatus and Mucobabterium tuberculosis / 병원감염관리

BACKGROUND: Titanium dioxide (TiO2) thin film photocatalyst generates strong oxidizing power when illuminated with Ultra Violet (UV) light with wavelengths of less than 385 nm. In this study, we evaluated the bactericidal activity of it against Escherichia coli, Aspergillus fumigatus and Mycobacterium tuberculosis. METHODS: The TiO2 film were prepared from titanium isopropoxide solution and it was coated on either inner(test) or outer(control) side on Petri dish. annealing at 500 degrees C. The test and control suspension of E. coli, A. fumigatus and M. tuberculosis were grown in the chamber coated inner and outer side. respectively with UV light. For the blank, cell suspensions were grown in TiO2 coated Petri dishes without UV light. The bactericidal activities were estimated by survival ratio calculated from the number of viable cells which form the nutrient agar. RESULTS: In the test, the survival ratio for E. coli and M tuberculosis decreased to a negligible level (i.e., essentially complete sterilization) within 1hr and 2 hr, respectively. and that for 11. fumigatus decreased markedly to about 15% within 6 hr. In the control, the survival ratio for E. coli, A. fumigatus and M. tuberculosis decreased to 40% within 150 min. 6 he and 2 hr, respectively. In the blank, the survival ratio for E. coli and M tuberculosis decreased only about 67% within 150 min and 40% within 2hr. In A. fumigatus, TiO2 only caused little Sterilization within 4 hr. CONCLUSIONS: TiO2 photocatalysts under UV light clearly showed bactericidal activity against E. coli, A. fumigarus and M. tuberculosis. This feature render TiO2 photocatalysts to be applicable to eliminate microorganism from indoor air environment combined with ventilation.

Conjunctival autografting for pterygium in younger people from the costal area

The major postoperative problem of pterygium, which may be mostly caused by UV light, is recurrence. So, we studied the postoperative recurrent rate and efficacy of conjunctival autograft for pterygium in younger people exposed to a high UV level. We studied 33 pterygium patients who were operated on by means of conjunctival autograft at Chonnam University Hospital by one operator from Dec. 1994 to Jun. 1995. The study was composed of 10 men (11 eyes) and 23 women (24 eyes); 29 primary (30 eyes) and 4 recurrent pterygia (5 eyes). The follow-up period was 10.7 months and their mean age was 33.9 years-old (19-39 years old). In all cases we used the superotemporal conjuctiva. Anatomic recurrence involving corneal limbus did not occur. But there were 5 cases of persistence or recurrence of preoperative symptoms: epiphora (2 eyes), ocular discomfort (2 eyes), and decreased visul acuity due to induced astigmatism (1 eye). Therefore, we recommended conjunctival autograft as an effective therapeutic technique in that it is able to reduce the recurrent rate and 1mprove subjective symptoms.

Conjunctival autografting for pterygium in younger people from the costal area

The major postoperative problem of pterygium, which may be mostly caused by UV light, is recurrence. So, we studied the postoperative recurrent rate and efficacy of conjunctival autograft for pterygium in younger people exposed to a high UV level. We studied 33 pterygium patients who were operated on by means of conjunctival autograft at Chonnam University Hospital by one operator from Dec. 1994 to Jun. 1995. The study was composed of 10 men (11 eyes) and 23 women (24 eyes); 29 primary (30 eyes) and 4 recurrent pterygia (5 eyes). The follow-up period was 10.7 months and their mean age was 33.9 years-old (19-39 years old). In all cases we used the superotemporal conjuctiva. Anatomic recurrence involving corneal limbus did not occur. But there were 5 cases of persistence or recurrence of preoperative symptoms: epiphora (2 eyes), ocular discomfort (2 eyes), and decreased visul acuity due to induced astigmatism (1 eye). Therefore, we recommended conjunctival autograft as an effective therapeutic technique in that it is able to reduce the recurrent rate and 1mprove subjective symptoms.

A Study on UVI - induced DNA Synthesis in Mouse Skin in Vivo Studied by Autoradiography / 대한피부과학회지

The status of DNA synthesis and the effect of UV radiation on the DNA synthesis were studied in mouse skin by microautoradiography. Mice exposed to 100mJ/cm of UVB were injected intradermally with tritiated thymidine, 5 minutes, 2, 6 and 24 hours after irradiation and biopsies were processed for light microscopic autoradiography, A total of 25 ICR female albino haired mice were used as subjects. We compared heavily labeled cells(>10 grains/nucleus) and sparsely labeled cells (3-10 grains/nucleus) in UVL irradiated skin with nonirradiated control skin. 1. Within 5 minutes after UVL exposure an apparent depression in the number of heavily labeled cells occurred. This reduction was statistically significant and remained so for at least six hours post,irradiation. By 24 hours after UVL exposure, the reduction was recovered to nearly control level. 2. By five minutes after UVL exposure, sparsely labeled cells were observed in basal cell layer and differentiated cell layer. The nurriber of sparsely labeled cells appeared highest at five minutes after UVL exposure and then tended to fall to nearly control level at 24 hours. This aberrant type of TdR H incorporation is thought to represent unscheduled DNA synthesis to repair pyrimidine dimers formed in UVL injured DNA molecules,

Design of Phenylketonuria Fluorescence Detection Optical System / 医疗卫生装备

Objective To design a new type of fluorescence detection optical system for dedicated neonatal PKU screening. Methods The system selects super-luminance UVLED for excitation light source, uses different diameter quartz fiber and Y -type optical fiber which consists of glass fiber bundles, and self focusing optical fiber for collimating light and photomultiplier tubes for testing. Results The system has many features, such as simple structure, small size and high sensitivity. Conclusion The clinic screening requirements are met by the system and a new means of rapid detection is provided for PKU screening in large quantities.

Effects of UV Light on DNA Synthesis Studied by Autoradiography

No abstract available.

Epidermal Changes with Ultraviolet Irradiation and PUVA Treatment in the Black Mouse / 대한피부과학회지

The pretent study was performed to study the epiderrnal changes of ultraviolet irradiation and PUVA treatment in the black mice. The following results were obtained: 1) The histologic changes of the epidermis, number of DOPA positive melanocytes and ultrastructural changes of keratinocytes due to UVB and PUVA were rnore prominent than those of UVA irradiation. 2) The histological changes after 8-MOP photosensitization closely mirnic those of UVR irradiation, and constant, finding was hyperkeratosis. 3) Early histological change after UVL irradiation & IUVA treatment was appearance of dytkeratotic cells. 4) Pro]onged exposure to UVB & PUVA resulted in transient epidermal hyperplasia, and epidermal atrophy occurred 3 weeks after PUVA treatment. 5) Early electron microscopic changes was perinuclear edema, juxtanuclear vacuoles and clumping of tonofilament.

A Study for The Effects of UV exposure and UV Exposure After Being Applied by Sunscreens on Hepatic Microsomal Cytochrome Enzyme System and Vitamin D in Newborn Rats / 대한피부과학회지

We observe changes of activation of hepatic microsomal cytochrome p-450, changes of formation of riug-and N-hydroxylation of 2-acetylaminofluorene, and changes of vitamin D, in the liver which exposed to UV light and expoeed to UV light after being applied by sunscreens. The results of our study are as shown below: 1. The contents of hepatic microsomal cytochrome p-45p of newborn rats were found to be remarkably increase in the group exposed to UV light for 3 weeks (p<0. 001), but such changes were much reduced in the group exposed to UV light for 3 weeks after being applied by sunscreens(p<0.05. p<0.001, ) 2.Cytochrome p-450 induced by UV light was found to be significantly increased ring and N-hydroxylation of 2-acetylarninofluorene known as carcinogenic source for the liver. In the group exposed to UV light for 3 weeks after being applied by sunscreens, both of ring-and N-hydroxylation of 2-acetylaminofluorene were significantly reduced(p<0. 0, p<0. 001). 3, The contents of vitarnin D, in the liver of newborn rats were found to be gradually increased when they were exposed to UV light for 1 week or 3 weeks (p<0. 001), and in the group exposed to UV light after being applied by sunscreens, such changes were reduced remarkably(pg0. (301).