RESUMO
The inspection and maintenance of transmission systems are necessary for their proper functioning. In this way, among the line's critical points are the insulator chains, which are responsible for providing insulation between conductors and structures. The accumulation of pollutants on the insulator surface can cause failures in the power system, leading to power supply interruptions. Currently, the cleaning of insulator chains is performed manually by operators who climb towers and use cloths, high-pressure washers, or even helicopters. The use of robots and drones is also under study, presenting challenges to be overcome. This paper presents the development of a drone-robot for cleaning insulator chains. The drone-robot was designed to identify insulators by camera and perform cleaning through a robotic module. This module is attached to the drone and carries a battery-powered portable washer, a reservoir for demineralized water, a depth camera, and an electronic control system. This paper includes a literature review on the state of the art related to strategies used for cleaning insulator chains. Based on this review, the justification for the construction of the proposed system is presented. The methodology used in the development of the drone-robot is then described. The system was validated in a controlled environment and in field experimental tests, with the ensuing discussions and conclusions formulated, along with suggestions for future work.
Assuntos
Robótica , Dispositivos Aéreos não Tripulados , Aeronaves , Fontes de Energia Elétrica , EletrônicaRESUMO
Resumo A intoxicação por metanol é um evento considerado raro, principalmente quando feita por via inalatória. Retratou-se neste presente estudo um relato de caso de um paciente que desenvolveu neurite óptica tóxica após exposição ao metanol e ácido acético por via inalatória em seu ambiente de trabalho. Foi descrito sobre as terapias obtidas na literatura, bem como as manifestações clínicas e o manejo a este paciente.
Abstract The methanol toxicity is considered rare event , especially when taken by inhalation . It was portrayed in the present study a case report of a patient who developed toxic optic neuritis after exposure to methanol and acetic acid by inhalation in the workplace . It was described for the therapies from the literature as well as the clinical manifestations and management in this patient.
Assuntos
Humanos , Masculino , Adulto , Neurite Óptica/induzido quimicamente , Exposição por Inalação , Metanol/intoxicação , Oftalmoscopia , Nervo Óptico , Intoxicação/terapia , Escotoma , Complexo Vitamínico B/administração & dosagem , Imageamento por Ressonância Magnética , Angiofluoresceinografia , Acuidade Visual , Neurite Óptica/diagnóstico , Neurite Óptica/terapia , Exposição Ocupacional , Local de Trabalho , Ácido Acético/intoxicação , Testes de Campo Visual , InjeçõesRESUMO
Neonatal priapism is uncommon and its cause is usually unknown, but it can generate anxiety for the parents and the pediatric team. The treatment in most cases is conservative and no sequelae are described.
RESUMO
Neste trabalho promovemos a síntese de sulfóxidos vinílicos ?-substituídos através da reação de acoplamento cruzado de Suzuki-Miyaura. Também foi feita a síntese de sulfóxidos enínicos inéditos, pela adição do nucleófilo no carbono ß-sulfóxido. Esses compostos eram passíveis de serem submetidos a reação de rearranjo de Pummerer aditivo e assim gerarem uma pequena biblioteca de compostos α-tioaldeídos. Um desses aldeídos sintetizados foi empregado na reação de formação de uma imina propargílica, com consequente reação de CuAAC formando iminas triazólicas. Outras iminas arílicas foram sintetizadas, passando por uma etapa de redução, com intuito de se obter a amina livre, para que fosse feita a reação de ciclização com auxílio de um agente eletrofílico. Outra classe de composto organoenxofre foi sintetizada, as N-sulfinil imina, que após a reação de acoplamento cruzado de Sonogashira, com consequente remoção de um grupo protetor e a formação do anel heterocíclico, foram obtidos compostos triazólicos N-sulfinil imínicos.
In this work we promote the synthesis of α-substituted vinylic sulfoxides through the Suzuki-Miyaura cross coupling reaction. Also the synthesis of unpublished enynic sulfoxides was made, by the addition of the nucleophile in the ß-sulfoxide carbon. These compounds were susceptible to additive Pummerer rearragement reaction and thus generated a small library of compounds. One of these aldehydes synthesized was used in the formation reaction of a propargyl imine, with consequent CuAAC reaction, forming triazol imines. Other aryl imines were synthesized, undergoing a reduction step, in order to obtain the free amine, so that the cyclization reaction was carried out with the aid of an electrophilic agent. Another class of organosulfur compound was synthesized, the N-sulfinyl imine, which after the Sonogashira cross-coupling reaction, with consequent removal of a protecting group and formation of the heterocyclic ring, N-sulfinyl imine triazolic compounds were obtained.
Assuntos
Iminas , Sulfetos , Sulfóxidos , Espectroscopia de Ressonância MagnéticaRESUMO
The layer formed by fluoride compounds on tooth surface is important to protect the underlying enamel from erosion. However, there is no investigation into the properties of protective layer formed by NaF and TiF4 varnishes on eroded enamel. This study aimed to evaluate the thickness, topography, nanohardness, and elastic modulus of the protective layer formed by NaF and TiF4 varnishes on enamel after erosion using nanoindentation and atomic force microscopy (AFM). Human enamel specimens were sorted into control, NaF, and TiF4 varnish groups (n = 10). The initial nanohardness and elastic modulus values were obtained and varnishes were applied to the enamel and submitted to erosive challenge (10 cycles: 5 s cola drink/5 s artificial saliva). Thereafter, nanohardness and elastic modulus were measured. Both topography and thickness were evaluated by AFM. The data were subjected to ANOVA, Tukey's test and Student's t test (α = 0.05). After erosion, TiF4 showed a thicker protective layer compared to the NaF group and nanohardness and elastic modulus values were significantly lower than those of the control group. It was not possible to measure nanohardness and elastic modulus in the NaF group due to the thin protective layer formed. AFM showed globular deposits, which completely covered the eroded surface in the TiF4 group. After erosive challenge, the protective layer formed by TiF4 varnish showed significant properties and it was thicker than the layer formed by NaF varnish.
Assuntos
Cariostáticos/química , Esmalte Dentário/efeitos dos fármacos , Fluoretos/química , Fluoreto de Sódio/química , Titânio/química , Erosão Dentária/prevenção & controle , Análise de Variância , Bebidas Gaseificadas , Módulo de Elasticidade , Testes de Dureza , Humanos , Teste de Materiais , Microscopia de Força Atômica , Valores de Referência , Reprodutibilidade dos Testes , Saliva Artificial/química , Estatísticas não Paramétricas , Propriedades de Superfície , Fatores de TempoRESUMO
Abstract The layer formed by fluoride compounds on tooth surface is important to protect the underlying enamel from erosion. However, there is no investigation into the properties of protective layer formed by NaF and TiF4 varnishes on eroded enamel. This study aimed to evaluate the thickness, topography, nanohardness, and elastic modulus of the protective layer formed by NaF and TiF4 varnishes on enamel after erosion using nanoindentation and atomic force microscopy (AFM). Human enamel specimens were sorted into control, NaF, and TiF4 varnish groups (n = 10). The initial nanohardness and elastic modulus values were obtained and varnishes were applied to the enamel and submitted to erosive challenge (10 cycles: 5 s cola drink/5 s artificial saliva). Thereafter, nanohardness and elastic modulus were measured. Both topography and thickness were evaluated by AFM. The data were subjected to ANOVA, Tukey's test and Student's t test (α = 0.05). After erosion, TiF4 showed a thicker protective layer compared to the NaF group and nanohardness and elastic modulus values were significantly lower than those of the control group. It was not possible to measure nanohardness and elastic modulus in the NaF group due to the thin protective layer formed. AFM showed globular deposits, which completely covered the eroded surface in the TiF4 group. After erosive challenge, the protective layer formed by TiF4 varnish showed significant properties and it was thicker than the layer formed by NaF varnish.
Assuntos
Humanos , Fluoreto de Sódio/química , Titânio/química , Erosão Dentária/prevenção & controle , Cariostáticos/química , Esmalte Dentário/efeitos dos fármacos , Fluoretos/química , Valores de Referência , Saliva Artificial/química , Propriedades de Superfície , Fatores de Tempo , Teste de Materiais , Bebidas Gaseificadas , Reprodutibilidade dos Testes , Análise de Variância , Estatísticas não Paramétricas , Microscopia de Força Atômica , Módulo de Elasticidade , Testes de DurezaRESUMO
An efficient methodology for the synthesis of aryl-substituted vinyl sulfoxides through direct substitution of aryl-substituted alkynyl grignard reagents on menthyl-p-toluenesulfinate followed by Suzuki-Miyaura cross-coupling reaction has been developed. It has also been described that the reaction of alkyl-substituted and cycloalkyl-substituted alkynyl grignard reagents with menthyl-p-toluenesulfinate led to two products, i.e., alkynyl sulfoxide derivatives, as a result of substitution, and enyne sulfoxide derivatives, which resulted from substitution followed by Michael type addition. It was possible to selectively synthesize the enyne sulfoxide derivatives by changing the concentration of the grignard reagent. These alkenyl sulfoxides were transformed into the corresponding [Formula: see text]-thio aldehydes in high yields via additive Pummerer rearrangement.
Assuntos
Sulfóxidos/síntese química , Aldeídos/química , Estrutura Molecular , Estereoisomerismo , Sulfóxidos/químicaRESUMO
We have developed an efficient, CuI-catalyzed, microwave-assisted method for the synthesis of bis-1,2,3-triazole derivatives starting from a 3,4,6-tri-O-acetyl-D-glucal-derived mesylate. This mesylate was obtained from 3,4,6-tri-O-acetyl-D-glucal through C-glycosidation, deprotection of acetate groups to alcohols, and selective mesylation of the primary alcohol. This mesylate moiety was then converted to an azide through a microwave-assisted method with good yield. The azide, once synthesized, was then treated with different terminal alkynes in the presence of CuI to synthesize various bis-triazoles in high yields and short reaction times.
Assuntos
Desoxiglucose/análogos & derivados , Triazóis/química , Triazóis/síntese química , Catálise , Técnicas de Química Sintética , Química Click , Cobre/química , Desoxiglucose/química , Glicosilação , Iodetos/químicaRESUMO
The aim of this study was to assess differences between apple juices and fermented apple beverages elaborated with fruits from different varieties and at different ripening stages in the aroma profile by using chemometrics. Ripening influenced the aroma composition of the apple juice and fermented apple. For all varieties, senescent fruits provided more aromatic fermented apple beverages. However, no significant difference was noticed in samples made of senescent or ripe fruits of the Lisgala variety. Regarding the juices, ripe Gala apple had the highest total aroma concentration. Ethanal was the major compound identified in all the samples, with values between 11.83mg/L (unripe Lisgala juice) and 81.05mg/L (ripe Gala juice). 3-Methyl-1-butanol was the major compound identified in the fermented juices. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied and classified the juices and fermented juices based on physicochemical and aroma profile, demonstrating their applicability as tools to monitor the quality of apple-based products.
Assuntos
Bebidas/análise , Frutas/química , Malus/química , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Bebidas/classificação , Fermentação , Manipulação de Alimentos , Frutas/classificação , Frutas/crescimento & desenvolvimento , Malus/classificação , Malus/crescimento & desenvolvimentoRESUMO
Melanoma maligno é uma doença comum e agressiva que frequentemente causa metástase para o intestino delgado. Este estudo ilustra um caso de intussuscepção do intestino delgado causada por uma lesão metastática de melanoma visualizada à 18F-FDG PET/TC em uma paciente de 48 anos idade que realizou exame de reestadiamento.
Malignant melanoma is a common and aggressive disease that frequently causes metastases to the small bowel. This study illustrates a case of small bowel intussusception secondary to metastatic melanoma visualized at 18F-FDG PET/CT in a 48-year-old woman who had this examination for restaging purposes.