ABSTRACT
Early infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 ( RHOBTB2 ) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.
ABSTRACT
The objective of the study was to evaluate the antiparasitic resistance against horse nematodes in the South of Rio Grande do Sul, Brazil. The results concerning the tests of anthelmintic efficacy on horses, stored in the database of the Parasitic Diseases Study Group (GEEP) - Veterinary Faculty, at the Federal University of Pelotas (UFPel), were carried out in the laboratory from 2018 to 2019. Stool samples were received from farms with breeding of adult female and male Criollo horses naturally infected, located in municipalities in the country's southern region. The antiparasitic agents tested were Triclorfon + Fenbendazole, Closantel + Albendazole, Ivermectin + Praziquantel, Fenbendazole, Ivermectin, Doramectin, Mebendazole and Moxidectin. Techniques such as Gordon and Whitlock, Coproculture and Fecal Egg Count Reduction Test were performed. Of all the antiparasitic drugs tested, it was observed that only treatments with Ivermectin 2% showed desired values. The observed results indicate that resistance to macrocyclic lactones is usual in equine parasites in this Brazilian region, despite the results with isolated Ivermectin.(AU)
O objetivo deste estudo é avaliar a resistência antiparasitária contra nematodeos de equinos no sul do Rio Grande do Sul, Brasil. Os resultados referentes aos testes de eficácia anti-helmíntica em cavalos, armazenados no banco de dados do Grupo de Estudos de Doenças Parasitárias (GEEP) - Faculdade de Veterinária, da Universidade Federal de Pelotas (UFPel), foram realizados em laboratório, no período de 2018 a 2019. Amostras de fezes foram recebidas de fazendas com criação de cavalos Crioulos adultos fêmeas e machos naturalmente infectados, localizadas em municípios da região Sul do país. Os agentes antiparasitários testados foram triclorfon + fenbendazol, closantel + ivermectina + praziquantel, fenbendazol, ivermectina, doramectina, mebendazol e moxidectina. Técnicas como Gordon e Whitlock, coprocultura e teste de redução da contagem de ovos fecais foram realizadas. De todos os antiparasitários testados, observou-se que apenas os tratamentos com ivermectina 2% apresentaram os valores desejados. Os resultados indicam que a resistência às lactonas macrocíclicas é comum em parasitas equinos nessa região brasileira, apesar dos resultados com ivermectina isolada.(AU)
Subject(s)
Animals , Drug Resistance, Multiple , Macrolides/analysis , Horses/parasitology , Anthelmintics/analysis , Parasite Egg Count/veterinary , Brazil , Parasitic Sensitivity Tests/veterinary , Antiparasitic Agents/analysisABSTRACT
The aim of this study was to evaluate the effect of ricotta whey (RW), cheese whey (CW), and butter whey (BUW) as replacers of whole milk (WM) at different ratios (0:100, 25:75, 50:50, 75:25, and 100:0) in the physicochemical and sensory qualities of ice cream. All formulations, including a commercial sample used as reference, were analyzed for nutritional composition, energy value, pH, titratable acidity (TA), melting behavior, desorption index, instrumental color properties, instrumental hardness, and consumer sensory testing. Overall, the addition of RW, CW, and BUW increased the moisture content, TA, melting rate, and redness (a*) and yellowness (b*) values but decreased the pH, lightness (L*) value, energy value, levels of ash, protein, lipid, and carbohydrate. As exception, CW did not influence the TA, and BUW resulted in lower lipid reduction and in lower hardness changes, and it did not affect the content of ash, protein, and a* and b* values of ice creams. Any ice cream formulation had dietary fibers and a desorption index. Ricotta whey and CW at all ratios and BUW at 25% did not affect overall liking compared with the commercial sample, whereas purchase intention was only decreased by the addition of BUW from 50 to 100%. Ricotta whey at 75 and 100% decreased melting velocity and creaminess, and BUW at 50, 75, and 100% increased hardness, TA, and cream flavor but decreased creaminess, which contributed negatively to overall liking. Therefore, the evaluated dairy by-products, especially RW and CW, have great potential for replacing milk in ice creams.
Subject(s)
Cheese/analysis , Ice Cream/standards , Milk Substitutes/chemistry , Whey/chemistry , Carbohydrates/analysis , Chemical Phenomena , Consumer Behavior , Dairy Products/analysis , Hydrogen-Ion Concentration , Lipids/analysis , Proteins/analysis , TasteABSTRACT
INTRODUCTION: Global developmental delay (GDD) is an intellectual and adaptive impairment in infants under 5 years of age who fail to meet expected developmental milestones. Intellectual disability is characterized by limitation in intellectual function and adaptive behavior, with onset in childhood. Frequent identifiable causes of GDD and intellectual disability are chromosomal imbalances. The array comparative genomic hybridization (aCGH) has contributed to improve the detection rate of genetic abnormalities and is considered the first-tier genetic test for unexplained intellectual disability. AIM: To analyze the results of a genetic study by aCGH due to GDD or intellectual disability in pediatric patients. PATIENTS AND METHODS: Retrospective analysis of pediatric patients followed in outpatient, which underwent a genetic study by aCGH, from 2012 to 2017. RESULTS: 215 patients were studied by aCGH. Of the total, 64.2% were investigated for intellectual disability and 35.8% for GDD. A 23.3% presented aCGH deletions or duplications, 56% for intellectual disability and 44% for GDD, with chromosomes 16, 22, 2 and 1 being the most implicated. CONCLUSION: Our study demonstrated a higher prevalence in males, according to previously published reports. The rate of detection abnormalities classified as pathogenic was higher than in other studies.
TITLE: Relevancia de los arrays de hibridación genómica comparada en el estudio de los retrasos del desarrollo en pediatría.Introducción. El retraso general del desarrollo (RGD) constituye un trastorno intelectual y del comportamiento adaptativo que aparece en los niños menores de 5 años que no consiguen alcanzar los hitos del desarrollo normal. La discapacidad intelectual se caracteriza por la limitación en el funcionamiento intelectual y en el comportamiento adaptativo, surgida en la infancia. Entre las causas frecuentes y reconocibles del RGD y de la discapacidad intelectual se encuentran los desequilibrios cromosómicos. Los arrays de hibridación genómica comparada (aCGH) han contribuido a mejorar la tasa de detección de las anomalías genéticas y ya se consideran la prueba genética de elección para la discapacidad intelectual de origen desconocido. Objetivo. Analizar los resultados del estudio genético con aCGH motivado por un RGD o una discapacidad intelectual en pacientes pediátricos. Pacientes y métodos. Análisis retrospectivo de pacientes pediátricos sometidos a seguimiento ambulatorio que fueron objeto de un estudio genético con aCGH entre 2012 y 2017. Resultados. El número de pacientes sometidos al estudio con aCGH ascendió a 215. Del total, el 64,2% fueron investigados por discapacidad intelectual, y el 35,8%, por RGD. El 23,3% presentó deleciones o duplicaciones en la aCGH; el 56%, por la discapacidad intelectual; y el 44%, por el RGD, y los cromosomas 16, 22, 2 y 1 fueron los implicados con más frecuencia. Conclusión. El presente estudio demuestra la mayor prevalencia de ambos en el sexo masculino, en consonancia con otras publicaciones precedentes. La tasa de detección de las anomalías clasificadas como patógenas resultó superior a la notificada en otros estudios.
Subject(s)
Comparative Genomic Hybridization , Developmental Disabilities/genetics , Intellectual Disability/genetics , Child , Child, Preschool , Female , Humans , Male , Retrospective StudiesABSTRACT
TITLE: ¿Distrés respiratorio persistente o algo más?
Subject(s)
Muscular Atrophy, Spinal/diagnosis , Respiratory Distress Syndrome, Newborn/diagnosis , DNA-Binding Proteins/deficiency , DNA-Binding Proteins/genetics , Diagnosis, Differential , Exons/genetics , Gastrostomy , Glycogen Storage Disease Type II/diagnosis , Hernias, Diaphragmatic, Congenital/diagnosis , Heterozygote , Humans , Infant, Newborn , Male , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/therapy , Mutation, Missense , Point Mutation , Respiration, Artificial , Respiratory Distress Syndrome, Newborn/genetics , Respiratory Distress Syndrome, Newborn/therapy , Transcription Factors/deficiency , Transcription Factors/geneticsABSTRACT
A criação de equinos brasileira movimenta anualmente cerca de R$ 16,15 bilhões e impulsiona o setor econômico primário do país. O mercado de animais da raça Crioula vem se expandindo devido ao seu alto potencial zootécnico. No Rio Grande do Sul, a criação é tipicamente extensiva, aliada, muitas vezes, à alta densidade animal, o que favorece as constantes infecções por diversos parasitos. O objetivo deste estudo foi analisar retrospectivamente a frequência de parasitos gastrointestinais em cavalos da raça Crioula naturalmente infectados na região sul do Rio Grande do Sul. Foram utilizadas 585 amostras de fezes de equinos da raça Crioula, adultos, de ambos os sexos, recebidas de criatórios e centros reprodutivos localizados na região. Do total de amostras, 89,74% (525/585) foram positivas para algum helminto. Em 57,60% (337/585) das amostras, observaram-se somente ovos da família Strongylidae. Infecções por Parascaris spp. e Strongyloides sp., apresentaram frequências de 2,22% (13/585) e 1,53% (9/585), respectivamente. Assim, pode-se concluir que os parasitos mais frequentes na população equina da região sul do RS pertencem à família Strongylidae.(AU)
Subject(s)
Animals , Strongylida Infections/epidemiology , Strongylida , Gastrointestinal Tract/parasitology , Horses/parasitology , Brazil/epidemiology , HelminthsABSTRACT
OBJECTIVE: Damage to the spinal cord is known to be associated with a posterior shift of the motor cortical upper limb representation, i.e. towards the somatosensory cortex. Due to missing pre-traumatic data, knowledge resulted from comparing findings between patients and healthy subjects. Here, we present a case of transient spinal cord injury resulting in a left-sided hemiparesis for 4 weeks. By chance, this patient had a pre-lesional navigated transcranial magnetic stimulation (nTMS) motor mapping 2 years before. Hence, nTMS mapping was repeated during the acute (after 1 day), sub-acute (after 10 days) and chronic (after 2 years) phase to trace the cortical reorganization following this incident. METHODS: Acute clinical work-up included magnetic resonance imaging and navigated transcranial magnetic stimulation (nTMS). Motor mapping was performed with 110% of the abductor pollicis brevis muscle (APB) resting motor threshold (rMT). Amplitudes and latencies of the motor-evoked potential (MEPs) were recorded and analyzed. In addition, motor function was evaluated by the Medical Research Council (MRC) scale, a standard Purdue Pegboard test and by a reaction time (RT) task. RESULTS: MRI revealed no aberrant findings. nTMS mapping, however, showed a posterior shift of the APB representation from the anatomical hand knob towards the somatosensory cortex in the acute in comparison to the pre-lesional phase. Concomitantly, there was an increase of rMT (6%). Within 10 days, there was an incomplete reversal of the posterior shift in parallel with improvement of the clinical motor function. Long-term follow-up revealed a complete restitution of nTMS cortical mapping and motor function. CONCLUSION: The present case report thoroughly documents a rapid cortical reorganization within a few days after a transient spinal shock. Our data adds further evidence to the literature suggesting a posterior shift of motor cortical representation following spinal cord injury. For the first time, 52 cortical reorganization was shown idiosyncratically in a single patient arising from the fortuitous fact of having a pre - lesional nTMS map.
Subject(s)
Brain Mapping/methods , Motor Cortex/physiopathology , Spinal Cord Injuries/physiopathology , Adult , Cervical Vertebrae , Evoked Potentials, Motor/physiology , Female , Humans , Magnetic Resonance Imaging/methods , Motor Cortex/diagnostic imaging , Paresis/diagnostic imaging , Paresis/physiopathology , Spinal Cord Injuries/diagnostic imaging , Time Factors , Transcranial Magnetic Stimulation/methodsABSTRACT
INTRODUÇÃO: A reabilitação cardíaca é uma das formas de tratamento da insuficiência cardíaca, que além de melhorar a capacidade funcional e qualidade de vida, também contribui para a redução da mortalidade e reinternação. O OBJETIVO do estudo foi identificar o perfil de pacientes submetidos areabilitação precoce em serviço de urgência e emergência. MÉTODOS: Trata-se de um estudo transversal retrospectivo de 30 pacientes com insuficiência cardíaca que foram inclusos no protocolo institucional de reabilitação. O protocolo consiste em estratificação de risco, prescrição do exercício e execução do mesmo. Todos os pacientes foram estratificados em baixo, moderado e alto risco e com base nisso foi feita a prescrição do exercício. O protocolo consiste na realização de exercícios de membros superiores com ciclo ergômetro com ou sem o uso de ventilação não invasiva. RESULTADOS: As principais etiologias da insuficiência cardíaca foram isquêmicas (30%) e cardiomiopatia dilatada (30%). O perfil hemodinâmico que prevaleceu foi o perfil C (53,3%) e a classe funcional III (46,7%). A média de fração de ejeção foi de 28,8% e a estratificação de alto risco esteve presente em 90% dos casos. CONCLUSÃO: Os dados deste estudo demonstram um predomínio de classificação de alto risco dos pacientes, assim como um tempo de internação prolongado. Assim, mais estudos na área são necessários para entendimento dessa população e para a aplicação de reabilitação cardíaca. Descritores: Insuficiência cardíaca; prevalência; exercício; fisioterapia.
Subject(s)
Health Profile , Emergencies , Heart FailureABSTRACT
Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.
Subject(s)
Antifungal Agents/pharmacology , Candida/drug effects , Candidiasis/prevention & control , Probiotics/pharmacology , Animals , Antifungal Agents/therapeutic use , Biofilms/drug effects , Candida/pathogenicity , Disease Models, Animal , Lactobacillus/physiology , Probiotics/therapeutic use , VirulenceABSTRACT
TITLE: Protocolo para la investigación etiológica de la parálisis cerebral.
Subject(s)
Cerebral Palsy/etiology , Cerebral Palsy/diagnosis , Child , Child, Preschool , Clinical Protocols , Humans , InfantABSTRACT
BACKGROUND: Autism spectrum disorders (ASD) affect many children with an estimated prevalence of 1%. Array-comparative genomic hybridization (CGH) offers significant sensitivity for the identification of submicroscopic chromosomal abnormalities and it is one of the most used techniques in daily practice. The main objective of this study was to describe the usefulness of array-CGH in the etiologic diagnosis of ASD. METHODS: Two-hundred fifty-three patients admitted to a neurogenetic outpatient clinic and diagnosed with ASD were selected for array-CGH (4 × 180K microarrays). Public databases were used for classification in accordance with the American College of Medical Genetics Standards and Guidelines. RESULTS: About 3.56% (9/253) of copy number variations (CNVs) were classified as pathogenic. When likely pathogenic CNVs were considered, the rate increased to 11.46% (29/253). Some CNVs apparently not correlated to the ASD were also found. Considering a phenotype-genotype correlation, the patients were divided in two groups. One group according to previous literature includes all the CNVs related to ASDs (23 CNVs present in 22 children) and another with those apparently not related to ASD (10 CNVs present in 7 children). In 18 patients, a next-generation sequencing (NGS) panel were performed. From these, one pathogenic and 16 uncertain significance variants were identified. CONCLUSION: The results of our study are in accordance with the literature, highlighting the relevance of array-CGH in the genetic of diagnosis of ASD population, namely when associated with other features. Our study also reinforces the need for complementarity between array-CGH and NGS panels or whole exome sequencing in the etiological diagnosis of ASD.
Subject(s)
Autism Spectrum Disorder/epidemiology , Autism Spectrum Disorder/genetics , Comparative Genomic Hybridization/methods , DNA Copy Number Variations/genetics , Adolescent , Child , Child, Preschool , Databases, Genetic , Female , Gene Duplication/genetics , Genotype , Humans , Male , Phenotype , Portugal/epidemiology , Retrospective StudiesABSTRACT
TITLE: Distonia temprana poco frecuente (DYT16) en una niña portuguesa.
Subject(s)
Dystonic Disorders/genetics , Mutation, Missense , Point Mutation , RNA-Binding Proteins/genetics , Age of Onset , Brazil/ethnology , Child , Consanguinity , Disease Progression , Exons/genetics , Female , Homozygote , Humans , PortugalABSTRACT
Abstract This study investigated the occurrence, prevalence, mean abundance and mean intensity of monogenoidean parasites in Piaractus mesopotamicus farmed in cages in the reservoir of the Itaipu Hydroelectric Power Station, Paraná River, Brazil. The parasite distribution pattern and the correlation of prevalence and abundance with the total length of hosts were also investigated. Four monogenoidean species were collected: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni and M. viatorum. All the parasites collected in P. mesopotamicus showed the typical aggregated distribution pattern, and the abundance and the prevalence did not shown any correlation with the total length of hosts.
Resumo Neste estudo foi investigada a ocorrência, prevalência, abundância média e intensidade média de Monogenoidea parasitos de Piaractus mesopotamicus, cultivados em tanques-rede no reservatório da Usina Hidrelétrica de Itaipu, rio Paraná, Brasil. Foram investigados ainda o padrão de distribuição parasitária e a correlação entre a prevalência e abundância com o comprimento total dos hospedeiros. Quatro espécies de Monogenoidea foram coletadas: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni e M. viatorum. Todos os parasitos coletados em P. mesopotamicus apresentaram típico padrão de distribuição agregada e não foi observada correlação entre a abundância e a prevalência e o comprimento total dos hospedeiros.
Subject(s)
Animals , Platyhelminths/physiology , Rivers/parasitology , Characidae , Fish Diseases/epidemiology , Helminthiasis, Animal/epidemiology , Brazil/epidemiology , Population Density , Fish Diseases/parasitology , Helminthiasis, Animal/parasitologyABSTRACT
This study investigated the occurrence, prevalence, mean abundance and mean intensity of monogenoidean parasites in Piaractus mesopotamicus farmed in cages in the reservoir of the Itaipu Hydroelectric Power Station, Paraná River, Brazil. The parasite distribution pattern and the correlation of prevalence and abundance with the total length of hosts were also investigated. Four monogenoidean species were collected: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni and M. viatorum. All the parasites collected in P. mesopotamicus showed the typical aggregated distribution pattern, and the abundance and the prevalence did not shown any correlation with the total length of hosts.
Subject(s)
Characidae , Fish Diseases/epidemiology , Helminthiasis, Animal/epidemiology , Platyhelminths/physiology , Rivers/parasitology , Animals , Brazil/epidemiology , Fish Diseases/parasitology , Helminthiasis, Animal/parasitology , Population DensityABSTRACT
A proposta de Skinner intitulada Seleção por Consequências parece garantir uma filiação a umaepistemologia selecionista. Tal noção, entretanto, carece de uma definição consensual na área. O objetivodeste artigo é propor uma conceituação da proposta skinneriana. Para tanto, realizou-se uma análise dosprincipais textos do autor sobre o tema, a fim de delimitar os aspectos que julgamos serem suficientes edefinidores dessa proposta científica. Concluímos que a seleção por consequências pode ser definidacomo um modo causal fundamentado em uma relação de interdependência probabilística entre eventos, aqual explica a origem e a evolução do fenômeno comportamental como produto de três histórias devariação e seleção: filogenética, ontogenética e cultural(AU)
Subject(s)
BehaviorABSTRACT
Skinner em 1 981 propôs um modo causal geral para explicar o comportamento envolvendo doisprocessos básicos e complementares: variação e seleção. Algumas vezes o selecionismo é apresentadocomo um substituto do mecanicismo dentro e fora do âmbito comportamental. Contudo, há um ponto detensão nessa interpretação: o comportamento/condicionamento reflexo. Esse tipo de comportamento e deaprendizagem seria explicado através de leis compatíveis com o mecanicismo, as leis do reflexo, nãoenvolvendo variação e seleção. Em que medida, então, a seleção pelas consequências seria um modoexplicativo geral se nem mesmo seria aplicável a todos os casos de comportamento? Uma interpretaçãoalternativa é oferecida sobre a natureza e o alcance do selecionismo skinneriano(AU)
Subject(s)
ReflexABSTRACT
Skinner em 1 981 propôs um modo causal geral para explicar o comportamento envolvendo dois processos básicos e complementares: variação e seleção. Algumas vezes o selecionismo é apresentado como um substituto do mecanicismo dentro e fora do âmbito comportamental. Contudo, há um ponto de tensão nessa interpretação: o comportamento/condicionamento reflexo. Esse tipo de comportamento e de aprendizagem seria explicado através de leis compatíveis com o mecanicismo, as leis do reflexo, não envolvendo variação e seleção. Em que medida, então, a seleção pelas consequências seria um modo explicativo geral se nem mesmo seria aplicável a todos os casos de comportamento? Uma interpretação alternativa é oferecida sobre a natureza e o alcance do selecionismo skinneriano
Subject(s)
Humans , ReflexABSTRACT
AIMS: The study investigated whether the interaction with Lactobacillus rhamnosus (ATCC7469) interfere with the expression of virulence factors by Candida albicans (ATCC18804). METHODS AND RESULTS: These micro-organisms were grown in biofilms for 24, 48 and 72 h, Candida was isolated and the expression of the major virulence factors were investigated. The production of phospholipase, protease and haemolysin were observed in appropriate media; observation of germ tubes formation in serum; biofilm formation, after growth in microtitre plates and reading in spectrophotometer. Candida was also tested for antifungal sensitivity to amphotericin B, fluconazole and ketoconazole. The results were compared with the cells of Candida grown in the absence of lactobacilli (control group). Candida cells, which interacted with Lact. rhamnosus (test group), showed significantly lower proteinase and haemolysin activity, when compared with control group. The germ tube formation and biofilm formation capacity also decreased in tested groups, which demonstrated alterations in susceptibility to antifungal drugs. CONCLUSIONS: The results suggest that Lact. rhamnosus is able to influence the expression of virulence factors by C. albicans and can alter its antifungal sensitivity profile. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest reduction in the pathogenicity of Candida and improvement in candidiasis therapy and control.
Subject(s)
Candida albicans/drug effects , Candida albicans/pathogenicity , Lacticaseibacillus rhamnosus/physiology , Antifungal Agents/pharmacology , Biofilms/growth & development , Candida albicans/isolation & purification , Candida albicans/physiology , Microbial Interactions , Virulence Factors/metabolismABSTRACT
Several studies have reported the adverse effects of recalcitrant compounds and emerging contaminants present in industrial effluents, which are not degradable by ordinary biological treatment. Many of these compounds are likely to accumulate in living organisms through the lipid layer. At concentrations above the limits of biological tolerance, these compounds can be harmful to the ecosystem and may even reach humans through food chain biomagnification. In this regard, advanced oxidation processes (AOPs) represent an effective alternative for the removal of the pollutants. This study focused on the AOP involving the use of ultraviolet radiation in homogeneous and heterogeneous systems. Based on the literature review, comparisons between natural and artificial light were established, approaching photoreactors constructive and operational characteristics. We concluded that the high availability of solar power in Brazil would make the implementation of the AOP using natural solar radiation for the decontamination of effluents feasible, thereby contributing to clean production and biodiversity conservation. This will serve as an important tool for the enforcement of environmental responsibility among public and private institutions.
Subject(s)
Solar Energy , Water Purification/methods , Brazil , Oxidation-Reduction , Sunlight , Ultraviolet Rays , Wastewater , Water Purification/economicsABSTRACT
The objective of this work was to study the degradation and mineralization of ethylenethiourea (ETU) in water by ozonation at different pH values and in the presence of hydrogen peroxide. Degradation experiments were performed using an initial ETU concentration of 50 ppm for 180 min with a gas flux of 0.25 dm(3) min(-1) and an O3 production rate of 12.1 mg min(-1). Degradation of by-products was monitored by direct injection electrospray ionization mass spectrometry (ESI-MS), ETU concentration was determined by HPLC-UV, and its mineralization was detected by total organic carbon (TOC) analysis. Optimum degradation of ETU in water was observed at pH = 11, whereas at pH = 3, the degradation of ETU was slowest, indicating that the reaction occurred through different mechanisms. The additional effects of hydroxyl radicals formed at the highest pH can be used to explain the results obtained in this study. Peroxone experiments were carried out in the presence of 400 and 800 mg L(-1) H2O2; the degradation of ETU was faster at 400 mg L(-1) H2O2. This was attributed to the scavenging effect of the excess H2O2. ETU treatment by ozonation produced several by-products of degradation such as ethylene urea and 2-imidazoline.