RESUMO
Spotted fever group (SFG) rickettsiae are obligatory intracellular bacteria that cause disease in humans and other animals. Ixodid ticks are the principal vectors of SFG rickettsiae. The present study aimed to determine the prevalence and species identity of SFG rickettsiae in ticks and horses from urban and rural areas of western Cuba using PCR assays. Tick samples, collected from 79 horses, consisted of 14 Amblyomma mixtum adults, 111 Dermacentor nitens adults and 19 pools of D. nitens nymphs (2-5 individuals/pool). The PCR results revealed the presence of Rickettsia spp. in 64% of the A. mixtum adults, 16% of the D. nitens adults, and 11% of the pooled samples of D. nitens nymphs. In contrast, Rickettsia spp. was not detected in any of the 200 horse blood samples included in this study. DNA sequence data of the rickettsial 17 kDa antigen gene showed that Rickettsia amblyommatis was present in A. mixtum; and Rickettsia felis in D. nitens. This is the first report of R. felis in D. nitens in Cuba. The present study extends our knowledge of the potential vector spectrum and distribution of SFG rickettsiae pathogens in western Cuba.
Assuntos
Cavalos , Ixodidae/microbiologia , Rickettsia , Rickettsiose do Grupo da Febre Maculosa/veterinária , Amblyomma/microbiologia , Animais , Vetores Aracnídeos/microbiologia , Cuba/epidemiologia , DNA Bacteriano/genética , Dermacentor/microbiologia , Doenças dos Cavalos/microbiologia , Cavalos/microbiologia , Cavalos/parasitologia , Ninfa/microbiologia , Patologia Molecular , Reação em Cadeia da Polimerase/veterinária , Rickettsia/genética , Rickettsia/isolamento & purificação , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Rickettsiose do Grupo da Febre Maculosa/microbiologia , Infestações por Carrapato/veterináriaRESUMO
In this investigation, the behavior of the mechanical properties of composites of high-density polyethylene/hydroxyapatite (HDPE/HA) with and without ethylene-acrylic acid copolymer (EAA) as possible compatibilizer, was studied. Different mathematical models were used to predict their Young's modulus, tensile strength and elongation at break. A comparison with the experimental results shows that the theoretical models of Guth and Kerner modified can be used to predict the Young's modulus. On the other hand, the values obtained by the Verbeek model do not show a good agreement with the experimental data, since different factors that influence the mechanical properties are considered in this model such as: aspect ratio of the reinforcement, interfacial adhesion, porosity and binder content. TEM analysis confirms the discrepancies obtained between the experimental Young's modulus values and those predicted by the Verbeek model. The values of "P", "a" and "σ(A)" suggest that an interaction among the carboxylic groups of the copolymer and the hydroxyl groups of hydroxyapatite might be present. In composites with 20 and 30 wt% of filler, this interaction does not improve the Young's modulus values, since the deviations of the Verbeek model are significant.
Assuntos
Resinas Acrílicas/química , Durapatita/química , Fenômenos Mecânicos , Polietileno/química , Polietilenos/química , Módulo de Elasticidade , Resistência à Tração , Termodinâmica , Temperatura de TransiçãoRESUMO
In the present work, the effectiveness of styrene/ethylene-butylene/styrene rubbers grafted with maleic anhydride (MA) and a metallocene polyethylene (mPE) as toughening materials in binary and ternary blends with polypropylene and its nanocomposite as continuous phases was evaluated in terms of transmission electron microscopy (TEM), scanning electron microscopy (SEM), oscillatory shear flow and dynamic mechanical thermal analysis (DMA). The flexural modulus and heat distortion temperature values were determined as well. A metallocene polyethylene and a polyamide-6 were used as dispersed phases in these binary and ternary blends produced via melt blending in a corotating twin-screw extruder. Results showed that the compatibilized blends prepared without clay are tougher than those prepared with the nanocomposite of PP as the matrix phase and no significant changes in shear viscosity, melt elasticity, flexural or storage moduli and heat distortion temperature values were observed between them. However, the binary blend with a nanocomposite of PP as matrix and metallocene polyethylene phase exhibited better toughness, lower shear viscosity, flexural modulus, and heat distortion temperature values than that prepared with polyamide-6 as dispersed phase. These results are related to the degree of clay dispersion in the PP and to the type of morphology developed in the different blends.
Assuntos
Cristalização/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Polipropilenos/química , Elasticidade , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Reologia/métodos , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , ViscosidadeAssuntos
Negro ou Afro-Americano , Comparação Transcultural , Etnicidade , Hospitalização , Esquizofrenia/etnologia , Psicologia do Esquizofrênico , Atividades Cotidianas/psicologia , Adulto , Ásia/etnologia , População Negra , Crime , Inglaterra , Feminino , Seguimentos , Humanos , Masculino , Cooperação do Paciente/psicologia , Esquizofrenia/diagnóstico , Esquizofrenia/reabilitação , Ajustamento Social , Meio Social , Índias Ocidentais/etnologiaRESUMO
Se efectuó un estudio abierto no comparativo para determinar la dosis mínima del fluconazol en el tratamiento de 20 pacientes con Tinea pedis y Tinea corporis/cruris. Se seleccionaron 20 pacientes, 10 con Tinea pedis y 10 con Tinea corporis/cruris, siendo 15 del sexo masculino y 5 del sexo femenino con edad promedio de 31.8 años (rango 18-65 años). Los pacientes recibieron una dosis única semanal de fluconazol 150 mg, con evaluaciones clínicas y micológicas a los 7-10 días después de cada dosis y luego una evaluación final a los 28-30 días. Se anotaron todos los hallazgos clínicos y microbiológicos en la fórmula respectiva de cada paciente. Los resultados finales indicaron que 8 (80 por ciento) de 10 pacientes con Tinea pedis alcanzaron curación y que ocho (80 por ciento) de los 10 casos con Tinea corporis/cruris también fueron curados. La mayoría de los casos de Tinea corporis/cruris requirieron solo dos dosis de tratamiento, en tanto que la mitad de los casos de Tineas pedis requirieron de las 4 dosis/semanas de tratamiento. No se presentaron efectos adversos severos debido al tratamiento. Finalmente, el autor concluye que el fluconazol en dosis semanales de 150 mg, es un recurso terapéutico de gran eficacia y buena tolerancia en el tratamiento de las dermatofitosis.