Inactivation of Poliovirus by Ozone and the Impact of Ozone on the Viral Genome / 生物医学与环境科学（英文）

OBJECTIVE@#To investigate the mechanisms underlying ozone-induced inactivation of poliovirus type 1 (PV1).@*METHODS@#We used cell culture, long-overlapping RT-PCR, and spot hybridization assays to verify and accurately locate the sites of action of ozone that cause PV1 inactivation. We also employed recombinant viral genome RNA infection models to confirm our observations.@*RESULTS@#Our results indicated that ozone inactivated PV1 primarily by disrupting the 5'-non-coding region (5'-NCR) of the PV1 genome. Further study revealed that ozone specifically damaged the 80-124 nucleotide (nt) region in the 5'-NCR. Recombinant viral genome RNA infection models confirmed that PV1 lacking this region was non-infectious.@*CONCLUSION@#In this study, we not only elucidated the mechanisms by which ozone induces PV1 inactivation but also determined that the 80-124 nt region in the 5'-NCR is targeted by ozone to achieve this inactivation.

Ambient ozone pollution is associated with decreased semen quality: longitudinal analysis of 8945 semen samples from 2015 to 2018 and during pollution-control period in Beijing, China / 亚洲男科学杂志(英文版)

Previous studies suggest that air pollution has a negative effect on semen quality. However, most studies are cross-sectional and the results are controversial. This study investigated the associations between air pollutants (PM2.5, PM10, SO2, NO2, CO, and O3) and semen quality among sperm donation candidates, especially when the air pollution was artificially controlled in Beijing, China. We analyzed 8945 semen samples in the human sperm bank of Peking University Third Hospital (Beijing, China) from October 2015 to May 2018. Air pollution data during the entire period (0-90 days prior) and key stages (0-9, 10-14, and 70-90 days prior) of sperm development were collected from the China National Environmental Monitoring Centre. The association between air pollutants and semen parameters (sperm concentration and progressive motility) was analyzed by a mixed model adjusted for age, abstinence duration, month, and average ambient temperature. Only O3during key stages of 0-9 days and 10-14 days and the entire period was negatively associated with sperm concentration between 2015 and 2018 (P < 0.01). During the period of air pollution control from November 2017 to January 2018, except for the increase in O3concentration, other five pollutants' concentrations decreased compared to those in previous years. In this period, the sperm concentration decreased (P < 0.001). During the pollution-control period, O3exposure 10-14 days prior was negatively associated with sperm concentration (95% CI: -0.399--0.111; P < 0.001). No significant association was found between the other five pollutants and semen quality during that period. Our study suggested that only O3exposure was harmful to semen quality. Therefore, O3should not be neglected during pollution control operation.

Evaluating clinical and laboratory effects of ozone in non-surgical periodontal treatment: a randomized controlled trial

Abstract Objective: This study aims to evaluate the clinical and biochemical (oxidative stress and pro-inflammatory mediators) effects of the gaseous ozone use accompanied by scaling and root planning (SRP) in periodontal treatment. Material and Methods: The study population consisted of 40 patients with chronic periodontitis (CP) randomly sorted into two groups of 20. The experimental group received SRP plus 3 watts gaseous ozone in two separate applications five days apart, whereas the control group received SRP plus placebo. Clinical periodontal parameters were assayed and saliva samples were taken before the initial and one month after the second treatment. Periodontal examination assessed plaque index (PI), gingival index (GI), probing depth, and clinical attachment level (CAL). Total antioxidant status (TAS), total oxidant status (TOS), nitric oxide (NO), 8-hydroxy-2'-deoxyguanosine (8-OHdG), myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), and transforming growth factor-beta (TGF-β) levels were evaluated from saliva samples. Results: Changes following treatment in PI, GI, probing depth, and CAL scores were similar for both groups (p>0.05). Of note, TGF-β levels were observed to be higher in the treatment group than in controls (p<0.05). Changes in 8-OHdG, TAS, TOS, NO, MPO, GSH and MDA levels, however, were not significantly different between groups (p>0.05). Conclusion: The findings of this study indicate that SRP plus gaseous ozone versus SRP alone does not correlate to a significant improvement in periodontal recovery.

The effects of ozone on bacterial growth and thiol-disulphide homeostasis in vascular graft infection caused by MRSA in rats

Abstract: Purpose: To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated. Methods: Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles. Results: There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups. Conclusions: We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.

Effect of ozone and methylprednisolone treatment following crush type sciatic nerve injury

ABSTRACT PURPOSE: To assess and compare the histopathological effects of ozone therapy and/or methylprednisolone (MPS) treatment on regeneration after crush type sciatic nerve injury. METHODS: Forty Sprague-Dawley male rats were randomly allocated into four groups. Four groups received the following regimens intraperitoneally every day for 14 days after formation of crush type injury on sciatic nerve: Group I: ozone (20mcg/ml); Group II: methylprednisolone (2mg/kg); Group III: ozone (20 mcg/ml) and methylprednisolone (2mg/kg); Group IV: isotonic saline (0.9%). The histomorphological evaluation was made after biopsies were obtained from the sites of injury. RESULTS: Significant differences were noted between groups in terms of degeneration (p=0.019), nerve sheath cell atrophy (p=0.012), intraneural inflammatory cellular infiltration (p=0.002), perineural granulation tissue formation (p=0.019), perineural vascular proliferation (p=0.004), perineural inflammatory cellular infiltration (p<0.001) and inflammation in peripheral tissue (p=0.006). Degeneration was remarkably low in Group III, while no change in nerve sheath cell was noted in Group II. CONCLUSION: The combined use of methylprednisolone and ozone treatment can have beneficial effects for regeneration after crush type nerve injury.

Medical ozone treatment ameliorates the acute distal colitis in rat

PURPOSE: To investigate the effect of medical ozone treatment on the experimental acute distal colitis in rats. METHODS: Eighteen rats were randomly distributed into three equal groups; control, acute distal colitis (ADC) without and with medical ozone treatment. Rats in the control group were taken saline. ADC was performed by rectal way with 4% acetic acid in groups 2 and 3, and the group 3 was treated with medical ozone for three weeks both rectally and intraperitoneally. At the twenty second day the distal colons samples were obtained for malondialdehyde and myeloperoxidase, blood samples were obtained to measure the levels of TNF-α and IL-1β levels. Histolopatological examination was evaluated with Ki-67, IL-1β and VEGF immunostaining densities. RESULTS: There was significant increase in tissue MDA, MPO activity, TNF-α and IL-1β after ozone administration. There was also a significant difference at immunostaining densities of histopathological examination. CONCLUSIONS: Medical ozone treatment ameliorated the experimental acute distal colitis induced by acetic acid in rats. Its possible effect is by means of decreasing inflammation, edema, and affecting the proliferation and the vascularization.

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

Abstract The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

Emisiones biogénicas de monoterpenos en el parque nacional natural Tayrona, santa marta (Colombia) / Monoterpenes ioggenic emissions in the tayrona natural park, santa marta (Colombia)

Los monoterpenos y otros compuestos orgánicos volátiles emitidos por la vegetación (emisiones biogénicas) juegan un papel significativo en la química troposférica por su participación en la formación de oxidantes fotoquímicos (p.e. ozono troposférico). Es así como la estimación de emisiones biogénicas resulta útil para establecer valores aproximados de la concentración, fundamental en la elaboración de programas de mejoramiento de calidad del aire. El objetivo del trabajo consistió en estimar las emisiones biogénicas de monoterpenos en el Parque Nacional Natural Tayrona, seleccionado por contar con áreas de vegetación autóctona de la región tropical con escasa o nula intervención antropogénica. Se aplicaron sensores remotos para la clasificación de cobertura vegetal, obteniendo la distribución espacial de la vegetación típica e identificando las familias de mayor dominancia. Las emisiones de monoterpenos se calcularon en 3,54 x 10(4) kg d-1, representadas 60% por la familia Leguminosae, 37,4% por la familia Euphorbiaceae, 2,4% por la familia Anacardiaceae y menos de 1% por las familias Rubiaceae y Polygonaceae. Durante las horas de sol en el área del parque (de las 6 a las 18 horas) se registraron las mayores temperaturas diarias y las más altas tasas de emisión de monoterpenos (59,6%); la cuarta parte de las emisiones ocurren entre las 10 y las 15 horas (24,2%), periodo en el que la radiación solar presenta máximos diarios y establece condiciones críticas para la formación de oxidantes fotoquímicos. La influencia de los vientos en la distribución espacio-temporal de las emisiones en el ambiente y la información de la rosa de vientos, evidencia que el 26% de las masas de aire proceden del N y el 15% del NE en el último trimestre del año, situación que podría favorecer la dispersión de monoterpenos a centros urbanos próximos al parque natural, pudiendo alterar la química atmosférica local con la formación de oxidantes fotoquímicos.

Monoterpenes and other volatile organic compounds emitted by vegetation (biogenic emissions) play a significant role in tropospheric chemistry because of their participation in the formation of photochemical oxidants (i.e. troposfheric ozone). This is how the estimation of biogenic emissions is useful for determining approximate values of monoterpenes concentration, which is essential in developing programs to improve air quality. The aim of this work was to estimate biogenic emissions of monoterpenes in the Tayrona National Park, that was selected because of the presence of native vegetation of the tropics with little or no human interference. Remote sensing was applied for classification of vegetation, coverage obtaining the spatial distribution of the typical vegetation and identifying the most dominant families. Monoterpenes emissions were estimated at 3.54 x 104 kg d-1, represented 60% of the Leguminosae family, 37.4% of the Euphorbiaceae family, 2.4% of the Anacardiaceae family and less than 1% of Rubiaceae and Polygonaceae families. During daylight hours in the park area (from 6:00 a.m. to 6:00 p.m.) the highest daily temperatures were registered and the highest emission rates of monoterpenes (59.6%); one fourth of the emissions occur between 10:00 a.m. and 3:00 p.m. (24.2%), period in which solar radiation presents daily maximums and establishes critical conditions for the formation of photochemical oxidants. The influence of winds on the spatial-temporal distribution of emissions shows that 26% of the air mass come from the N and 15% of NE in the last quarter of year, a situation that could favor the spread of monoterpenes to urban centers near the natural park, which could alter the local atmospheric chemistry with the formation of photochemical oxidants.

El ejercicio físico aumenta el daño pulmonar inducido por la exposición aguda e intermitente a 0, 5 ppm de ozono en ratas juveniles / Physical exercise increases pulmonary damage induced by acute and intermittent exposure to 0.5 ppm of ozone in juvenile rats

El ozono (O3) troposférico es el principal oxidante del esmog fotoquímico. Como es un contaminante aéreo, sus efectos están relacionados con la dosis efectiva = [Concentración] x [tiempo de exposición] x [ventilación minuto]. Objetivo: Determinar si el ejercicio físico -que aumenta la ventilación minuto- puede aumentar el daño pulmonar inducido por la exposición a O3 en ratas en reposo. Material y Métodos: Se usó 4 series de ratas Sprague-Dawley juveniles. Dos series fueron expuestas a 0,5 ppm de O3 (4 h diarias por 2 días) en reposo (n = 13) o durante ejercicio (n = 12). Dos series control respiraron aire filtrado (AF) en reposo (n = 13) o durante sesiones de ejercicio (n = 13), en una rueda vertical giratoria (15 min de ejercicio alternados con 15 min de descanso hasta completar 4 h diarias durante 2 días). Las ratas fueron eutanasiadas y se determinó la razón peso húmedo/peso seco (PH/PS) en el pulmón izquierdo. En el lavado broncoalveolar (LBA) del pulmón derecho, se determinó recuento total de células, proteínas totales y actividad de gamma-glutamiltraspeptidasa (GGT). Resultados: la razón PH/PS y el recuento de células y las proteínas del LBA aumentaron en las ratas en reposo expuestas a O3 comparadas con las ratas en reposo que respiraron AF (p < 0,05 ANOVA & Newman-Keuls). La actividad de GGT en el LBA fue mayor en las ratas que en ejercicio respiraron AF en comparación con las ratas que respiraron AF en reposo (p < 0,05). Hubo aumento de GGT, proteínas y recuento de células en el LBA de la serie [ejercicio + O3] comparada con la serie [reposo + O3] (p < 0,05). Conclusión: El ejercicio físico aumenta el daño pulmonar inducido por la exposición aguda e intermitente a 0,5 ppm de O3 en ratas juveniles.

Tropospheric ozone (O3) is the major oxidant of photochemical smog. Being an air pollutant, its effects are related to effective dose = [Concentration] x [exposure time] x [pulmonary ventilation]. Objective: Determine whether physical exercise -that increases pulmonary ventilation- is able to augment the pulmonary damage induced by O3 exposure in resting rats. Material and Methods: Four series of juvenile Sprague-Dawley rats were used. Two series were exposed to 0.5 ppm O3 (4 hours a day for 2 days) at rest (n=13) or during exercise (n=12). Two control series breathed filtered air (FA) at rest (n=13) or during exercise sessions (n=13), in a vertical rotary wheel (15 min exercise alternated with 15 min resting until to completing 4 hours a day for 2 days). Rats were euthanized and wet weight / dry weight ratio (W/D ratio) was determined in left lung. Total cell counting, total protein content and γ-glutamyltraspeptidase (GGT) activity were determined in the right lung bronchoalveolar lavage fluid (BALF). Results: W/D weight ratio as well as total cell counting and protein content increased in BALF from resting rats exposed to O3 as compared with resting rats breathing FA (p < 0.05 ANOVA & Newman-Keuls test). GGT activity in BALF increased in rats under exercise breathing FA as compared with resting rats breathing FA (p<0.05). GGT, proteins and cells counting increased in BALFfrom series [exercise + O3] as compared to series [resting + O3] (p< 0.05). Conclusion: Physical exercise increases lung damage induced by intermittent and acute 0.5 ppm O3 exposure in juvenile rats.

Effect of ozone gas on the shear bond strength to enamel

Ozone is an important disinfecting agent, however its influence on enamel adhesion has not yet been clarified. Objective: Evaluate the influence of ozone pretreatment on the shear strength of an etch-and-rinse and a self-etch system to enamel and analyze the respective failure modes. Material and Methods: Sixty sound bovine incisors were used. Specimens were randomly assigned to four experimental groups (n=15): Group G1 (Excite® with ozone) and group G3 (AdheSE® with ozone) were prepared with ozone gas from the HealOzone unit (Kavo®) for 20 s prior to adhesion, and groups G2 (Excite®) and G4 (AdheSE®) were used as control. Teeth were bisected and polished to simulate a smear layer just before the application of the adhesive systems. The adhesives were applied according to the manufacturer's instructions to a standardized 3 mm diameter surface, and a composite (Synergy D6, Coltene Whaledent) cylinder with 2 mm increments was build. Specimens were stored in 100% humidity for 24 h at 37°C and then subjected to a thermal cycling regimen of 500 cycles. Shear bond tests were performed with a Watanabe device in a universal testing machine at 5 mm/min. The failure mode was analyzed under scanning electron microscope. Means and standard deviation of shear bond strength (SBS) were calculated and difference between the groups was analyzed using ANOVA, Kolmogorov-Smirnov, Levene and Bonferroni. Chi-squared statistical tests were used to evaluate the failure modes. Results: Mean bond strength values and failure modes were as follows: G1- 26.85±6.18 MPa (33.3% of adhesive cohesive failure); G2 - 27.95±5.58 MPa (53.8% of adhesive failures between enamel and adhesive); G3 - 15.0±3.84 MPa (77.8% of adhesive failures between enamel and adhesive) and G4 - 13.1±3.68 MPa (36.4% of adhesive failures between enamel and adhesive). Conclusions: Shear bond strength values of both adhesives tested on enamel were not influenced by the previous application of ozone gas.

Performance effect of rabbit carotid artery treated with decellularization and photo-oxidation / 中南大学学报(医学版)

OBJECTIVE@#To analyze and discuss the feasibility of rabbit carotid artery treated with decellularization and photo-oxidation.@*METHODS@#Sixty vascular slices of rabbit carotid artery were divided into a fresh group, a cryopreservation group, a glutaraldehyde group, and a decellularization plus photo-oxidation group 15 in each group. To evaluate the physical properties of all the rabbit carotid arteries by testing heat-shrinking temperature, tensile stress and the max elongation of each group. Then by buliding subcutaneous embedding model in SD rats we evaluated the biological stability and the anti-calcification function property of the above rabbit carotid arteries, and the detection means included HE stain, atomic absorption spectrometry and Von-Kossa calcium salt stain.@*RESULTS@#The heat-shrinking temperature, tensile stress and the max elongation in the cryopreservation group were lower or shorter than those of the other groups and the difference had statistical significance (P<0.05). Although the heat-shrinking temperature and the tensile stress in the decellularization plus photo-oxidation group were lower or shorter than those in the glutaraldehyde group (P<0.05), the max elongation in the decellularization plus photo-oxidation group was much longer than that in the glutaraldehyde group (P<0.05). The rabbit carotid artery treated with decellularization plus photo-oxidation showed lower immunogenicity and better biological stability and better anti-calcification property compared with the other groups.@*CONCLUSION@#Decellularization associated with photo-oxidation is a suitable and novel protocol for small caliber artery allograft with a diameter of less than 6 mm which is unbreakable to mechanical properties and conducive to biological stability, which has a broad prospect.

The antimicrobial effect of 0.1 ppm ozonated water on 24-hour plaque microorganisms in situ

Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely.

La ozonoterapia en pacientes con enfisema pulmonar / Rectal ozone therapy for patients with pulmonary emphysema

Background: Ozone therapy may stimulate antioxidant systems and protect against free radicals. It has not been used formerly in patients with pulmonary emphysema. Aim: To assess the effects of rectal ozone therapy in patients with pul-monary emphysema. Material and Methods: Sixty four patients with pulmonary emphysema, aged between 40 and 69 years, were randomly assigned to receive rectal ozone in 20 daily sessions, rectal medicinal oxygen or no treatment. Treatments were repeated three months later in the frst two groups. At baseline and at the end of the study, spirometry and a clinical assessment were performed. Results: fifty patients completed the protocol, 20 receiving ozone therapy, 20 receiving rectal oxygen and 10 not receiving any therapy. At baseline, patients on ozone therapy had significantly lower values of forced expiratory volume in the frst second (fEV1) and fEV1/forced vital capacity. At the end of the treatment period, these parameters were similar in the three treatment groups, therefore they only improved significantly in the group on ozone therapy. No differences were observed in other spirometric parameters. Conclusions: Rectal ozone therapy may be useful in patients with pulmonary emphysema.

The use of ozonated water and 0.2% chlorhexidine in the treatment of periodontitis patients: A clinical and microbiologic study.

Background: The development of periodontal disease has been thought to be associated with several restricted members of the oral anaerobic species, such as black-pigmented Porphyromonas species and Actinobacillus actinomycetemcomitans (Aa), in the subgingival environment. Apart from bacteria, certain viruses and fungi that are associated with periodontal disease are also present in the subgingival plaque . Materials and Methods: A randomized, double-blind, crossover split-mouth design was performed. A total of 16 patients suffering from generalized chronic periodontitis were selected for the study. The study period of 18 days was divided into two time-intervals, i.e. baseline (0 days) to 7 th day, with a washout period of 4 days followed by a second time interval of 7 days. The use of ozone and chlorhexidine gluconate (CHX) irrigation was randomized. Both the patient and the clinician evaluating the clinical parameters were blinded regarding the type of irrigation used. Results: The interpretation of clinical and microbial data is from baseline to 7 th day. A higher percentage of plaque index (12%), gingival index (29%) and bleeding index (26%) reduction was observed using ozone irrigation as compared to chlorhexidine. The percentile reduction of Aa (25%) using ozone was appreciable as compared to no change in Aa occurrence using chlorhexidine. By using O 3 and chlorhexidine, there was no antibacterial effect on Porphyromonas gingivalis (Pg) and Tannerella forsythensis. The antifungal effect of ozone from baseline (37%) to 7 th day (12.5%) was pronounced during the study period, unlike CHX, which did not demonstrate any antifungal effect. Conclusion: Ozone may be considered as an alternative management strategy due to its powerful ability to inactivate microorganisms. Also, there is growing evidence that ozone can be employed as a useful therapeutic agent in both dentistry and medicine.

[Comparison of photolysis and sonolysis processes for degradation of reactive red 198]

Carcinogenic and mutagenic potential of some azo dyes as a category of common dyes in different types of industries has been reported. The degradation of one commercially available dyestuff [C.I. Reactive Red 198 [RR 198]] by means of ultraviolet radiation [UV], ultrasonic irradiation [US], UV/H[2]O[2] and US/H[2]O[2] processes was investigated. Photolysis process was accomplished in a laboratory-scale batch photoreactor equipped with a 55W immersed-type low-pressure mercury vapour lamp [UVC] and sonication in a sonoreactor with low frequency [42 kHz] plate type transducer at 170W of acoustic power with emphasis on the effect of various parameters on decolouration and degradation efficiency. Initial results showed that, color removal efficiencies by US and US/H[2]O[2] processes were negligible. Almost complete disappearance of RR 198 [20 mg/L] in UV/H[2]O[2] process was possible to achieve after 10 min of irradiation. It is found that lower pH and lower concentration of dye favor the dye degradation. Hence any increase in initial dye concentration results in decreased decolouration rates. Also, the experimental results indicated that the kinetics of sono-oxidation and photo-oxidation processes fit well by pseudo-first order kinetics and first order reaction kinetics, respectively. It is concluded that UV/H[2]O[2] reaction was more effective than other reactions in bleaching and the reaction rate was sensitive to the operational parameters and increased with increasing H[2]O[2] concentration up to 15 mM

Are environmental pollutants risk factors for low birth weight? / Os poluentes ambientais são fatores de risco para o baixo peso ao nascer?

The aim of this study was to assess the association between prenatal exposure to air pollutants and low birth weight in a medium-sized city. An ecological study was performed, using live birth data from São José dos Campos, São Paulo State, Brazil. The environmental data were obtained from the São Paul State Environmental Agency. The study included full-term newborns whose mothers were 20 to 34 years of age and had at least a complete high school education, seven or more prenatal visits, singleton pregnancy, and vaginal delivery, in order to minimize potential confounding from these variables. Logistic regression was used to estimate the effect of each pollutant. Low birth weight was defined as less than 2,500g. The sample included a total of 2,529 data from 2001 that met the inclusion criteria (25.6 percent of the total). We identified 99 newborns (3.95 percent of the sample) with low birth weight, and the pollutants sulfur dioxide and ozone were associated with low birth weight. The final model was À(x) = -1.79 + 1.30 (SO2) + 1.26 (O3). Thus, sulfur dioxide and ozone were identified as risk factors for low birth weight in a medium-sized city in Southeast Brazil.

O objetivo foi estimar o papel de poluentes no baixo peso ao nascer numa cidade de porte médio. Foi um estudo ecológico com dados obtidos da Declaração de Nascido Vivo relativos a São José dos Campos, São Paulo, Brasil. Os dados ambientais foram fornecidos pela Companhia de Tecnologia de Saneamento Ambiental (CETESB). Foram incluídos no estudo recém-nascidos a termo, com mães entre 20 e 34 anos de idade, segundo grau completo, sete ou mais consultas realizadas no pré-natal, gravidez única e parto normal, para minimizar o efeito de confusão destas variáveis. Utilizou-se regressão logística para estimar o efeito de cada poluente. Baixo peso ao nascer foi considerado aquele inferior a 2.500g. Foram incluídos 2.529 dados de 2001 que atenderam aos critérios de inclusão (25,6 por cento do total). Identificamos 99 recém-nascidos (3,95 por cento dessa amostra) com baixo peso e os poluentes dióxido de enxofre e ozônio como associados ao baixo peso ao nascer. O modelo final foi À(x) = -1,79 + 1,30 (SO2) + 1,26 (O3). Assim, identificou-se o dióxido de enxofre e ozônio como responsáveis pelo baixo peso ao nascer numa cidade de porte médio do Sudeste brasileiro.

Modeling of ozone as a disinfectant of indicators bacteria in the drinking water

Ozone is considered one of the most effective disinfectants that can inactivate resistant pathogenic microorganisms in which conventional disinfectant such as chlorine and chlorine dioxide fail due to its strong biocidal oxidizing properly. The study aimed at modeling of ozone as a disinfectant of indicators bacteria in the drinking water. This work involved a series of batch experiments with raw water, taken from the intake of El-Nozha Water Purification Plant, Alexandria governorate. The ozone doses applied in this study were 1.2, 2.2, 3.4, and 4.3 mg/l. The disinfected effluent was collected at 5, 10, 20 and 30 min. The indicator microorganisms HPC bacteria, total coliforms, faecal coliforms and Streptococcus faecalis were examined before and after the ozonation. The optimum ozone dosage applied in raw water to achieve 90% reduction of the indicator microorganisms was 2.5 mg/l. The optimum contact time to achieve 90% reduction of the indicator microorganisms in raw water was 8 min. By applying of ozone as post disinfection on filtered water the reduction percent of the indicator microorganisms were 100%. This study estimated that the ozones cost was 1.76 piasters/m[3]. Ozone as a primary disinfection must be applied on raw water to reduce the formation of THMs due to pre-chlorination of raw water at present, in addition to effective killing power of ozone onto microorganisms that will improve water quality

Research on short-term biological stability and cytotoxicity of allogenic arteries cross-linked by dye-mediated photooxidation in vivo / 生物医学工程学杂志

This study evaluated the biological stability and cytotoxicity of rabbit thoracic aorta cross-linked by dye-mediated photooxidation in vivo environment of blood flow. Rabbits, whose allogenic thoracic aorta was cross-linked by dye-mediated photooxidation (DMP, n=6) and glutaraldehyde (GA, n=6), were in the DMP group and GA group, respectively; rabbits, whose homogenic abdominal aorta was orthotopic transplanted (OT, n=6), were in the OT group. Then the donor arteries were transplanted into the position of the abdominal arteries of rabbits. After operation, the animals were fed for 1 month, then each of graft arteries was removed for observation. Biological stability was evaluated through histological analysis under optical microscope. Cytotoxicity was evaluated through ratio of coverage of endothelial cell (ES) under scanning-electron microscope. The results showed that no statistically significant difference was noted between DMP group and OT group (P>0.05); however, there was a significant difference between DMP group and GA group (P<0.01). The stability index in DMP group was much higher than that in GA group. There was a statistically significant difference between DMP group and GA group (P<0.01). Ratio was much higher in DMP group than in GA group. In conclusion, the arteries cross-linked by dye-mediated photooxidation treatment appeared to have higher biological stability and lower cytotoxicity in rabbit allogenic transplation model.

Volatile organic compounds emitted from hardwood drying as a function of processing parameters

During the drying of wood, volatile organic compounds are emitted. These emissions contribute, in the presence of nitrogen oxides and sunlight, to the formation of ground level ozone and other harmful photo-oxidants. Emissions of volatile organic compounds from the drying of birch sawdust in a spouted bed were analyzed with a flame ionization detector and with a gas chromatograph-mass pectrometer. A D-optimal model of the emissions showed that the emissions increased exponentially with decreasing sawdust moisture content and that the final sawdust moisture content was influencing emissions about twice as much as the inlet drying medium temperature and the month of logging. At inlet temperatures of 140-170 °C, the emissions increased steeply when the moisture content of the sawdust reached 10%, whereas an inlet temperature of 200 °C caused a surge of thermal degradation products at 15% moisture content. The results of this study should help to reduce the emissions of volatile hydrocarbons during the drying of hardwood sawdust and wood chips

Histomorphologic properties of bovine jugular vein conduit treated withdye-mediated photooxidation following decellularization / 中南大学学报(医学版)

OBJECTIVE@#To determine the histocompatibility and histoconstancy of bovine jugular vein conduit (BJVC) treated by dye-mediated photooxidation following decellularization before and after implantation in Wistar rats.@*METHODS@#Each of 20 fresh bovine jugular veins with a retained native valve procured from a slaughterhouse was cut into 4 trial patches with valves, which were randomly divided into 4 groups. The 4 groups were treated respectively by dye-mediated photooxidation(DMP), glutaraldehyde(GA), decellularization(DC), and dye-mediated photooxidation following decellularization (DC+DMP). One of the trial patches in each group was implanted subcutaneously in the same Wistar rat. Two months later, all trial rats were killed and the specimens were retrieved. Tissue protein extraction was used to estimate the cross-linked degree of BJVC treated by dye-mediated photooxidation following decellularization. To observe the morphologic properties of the specimens, HE staining and electron microscopes were used.@*RESULTS@#Compared with others, the patches in the DC+DMP group were flexible, stretched, and relatively intact; lining endothelium was comparatively smooth; collagen fiber structure was slightly loose intact; and many cells were uniformly infiltrated in all layers.@*CONCLUSION@#BJVC treated by dye-mediated photooxidation following decellularization is superior to others in histocompatibility, and the rate of degradation can be regulated by the degree of dye-mediated photooxidation.