RESUMEN
In efforts to develop AIDS vaccine components, we generated combinatorial libraries of recombinant human rhinoviruses that display the well-conserved ELDKWA epitope of the membrane-proximal external region of human immunodeficiency virus type 1 (HIV-1) gp41. The broadly neutralizing human monoclonal antibody 2F5 was used to select for viruses whose ELDKWA conformations resemble those of HIV. Immunization of guinea pigs with different chimeras, some boosted with ELDKWA-based peptides, elicited antibodies capable of neutralizing HIV-1 pseudoviruses of diverse subtypes and coreceptor usages. These recombinant immunogens are the first reported that elicit broad, albeit modest, neutralization of HIV-1 using an ELDKWA-based epitope and are among the few reported that elicit broad neutralization directed against any recombinant HIV epitope, providing a critical advance in developing effective AIDS vaccine components.
Asunto(s)
Epítopos/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp41 de Envoltorio del VIH/inmunología , VIH-1/inmunología , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Antígenos Virales/inmunología , Ensayo de Inmunoadsorción Enzimática , Cobayas , Células HeLa , Humanos , Inmunoglobulina G/inmunología , Masculino , Pruebas de Neutralización , Biblioteca de Péptidos , Ingeniería de Proteínas , Rhinovirus/genéticaRESUMEN
Ultrasonic measurements of attenuation versus frequency were made on model systems comprising olive oil, sucrose, and tripalmitin to represent the constituents of chocolate. Corresponding measurements also were made on chocolate flowing in a pipeline at a pilot plant where the temperature, pressure, and temper of the chocolate were precisely controlled and monitored. Experimental results combined with simulation studies indicate that the effect of ultrasonic scattering from tripalmitin crystals in olive oil is modified by the addition of sucrose crystals at a high concentration. It is proposed that the presence of seed crystals in chocolate (temper) cannot be detected ultrasonically in the practical measurement range 1-12 MHz due to a similar process.
Asunto(s)
Algoritmos , Cacao/química , Análisis de los Alimentos/métodos , Pruebas de Dureza/métodos , Ultrasonido , Dureza , Aceite de Oliva , Aceites de Plantas/química , Reproducibilidad de los Resultados , Dispersión de Radiación , Sensibilidad y Especificidad , Sacarosa/química , Triglicéridos/químicaRESUMEN
Ultrasonic imaging of biofilms in water is difficult due to the very low contrast in acoustic impedance between the biofilm and water. In this paper, biofilms exposed to moist air are scanned through the substrate in order to obtain echoes from the biofilm/air interface. A 50 MHz scanning system was used to scan 1 mm x 1 mm areas of biofilms in a 10 microm grid pattern. Two fast Fourier transform (FFT) based methods for enhancement of the film thickness measurement resolution are compared. Using these techniques, the surface topography of biofilms with thickness less than the acoustic wavelength can be imaged.
Asunto(s)
Bacterias/aislamiento & purificación , Biopelículas , Recuento de Colonia Microbiana/métodos , Interpretación de Imagen Asistida por Computador/métodos , Ultrasonografía Doppler de Pulso/métodos , Ultrasonografía/métodos , Aire , AlgoritmosRESUMEN
Ultrasonic compression wave absorption is investigated as a means to monitor the seeded crystallization of copper (II) sulphate pentahydrate from aqueous solution. Simple models are applied to predict crystal yield, crystal size distribution, and the changing nature of the continuous phase. The Allegra-Hawley scattering formulation is used to simulate ultrasonic absorption as crystallization proceeds. Experiments confirm that simulated attenuation is in agreement with measured results.