RESUMEN
Three-dimensional X-ray diffraction (3DXRD) is shown to be feasible at the I12 Joint Engineering, Environmental and Processing (JEEP) beamline of Diamond Light Source. As a demonstration, a microstructually simple low-carbon ferritic steel was studied in a highly textured and annealed state. A processing pipeline suited to this beamline was created, using software already established in the 3DXRD user community, enabling grain centre-of-mass positions, orientations and strain tensor elements to be determined. Orientations, with texture measurements independently validated from electron backscatter diffraction (EBSD) data, possessed a â¼0.1° uncertainty, comparable with other 3DXRD instruments. The spatial resolution was limited by the far-field detector pixel size; the average of the grain centre of mass position errors was determined as ±â¼80â µm. An average per-grain error of â¼1â ×â 10-3 for the elastic strains was also measured; this could be reduced in future experiments by improving sample preparation, geometry calibration, data collection and analysis techniques. Application of 3DXRD onto I12 shows great potential, where its implementation is highly desirable due to the flexible, open architecture of the beamline. User-owned or designed sample environments can be used, thus 3DXRD could be applied to previously unexplored scientific areas.
RESUMEN
BACKGROUND: This study aims to explore the views of women concerning their choice of long-acting method of contraception. METHOD: Two-hundred and eighty-six women who had either been sterilised or fitted with an etonorgestrel (ETN) implant or the levonorgestrel intrauterine system (LNG IUS) were invited to take part. A response rate of 54% was achieved. Women from all three groups reported positive and negative experiences with their chosen method. RESULTS: Women frequently choose sterilisation specifically because it is irreversible, does not involve hormonal treatment, and they do not wish to retain choice of future fertility. Women incorrectly regard sterilisation as more reliable than any reversible method. Regret after sterilisation was common, even if this was preceded by full counselling. Even among patients of practices with a special interest in family planning, long-acting methods, although available, were not widely known about. CONCLUSION: This study suggests that women chose sterilisation for one of three main reasons: to avoid the possible side-effects of hormones; to avoid continually having to make decisions regarding child-bearing; and/or a lack of information regarding reversible methods. Sterilisation is often chosen by women specifically because of its irreversibility. This may explain why long-acting reversible methods have remained relatively unpopular.
Asunto(s)
Conducta de Elección , Conducta Anticonceptiva/psicología , Anticoncepción/métodos , Anticoncepción/psicología , Adulto , Desogestrel , Implantes de Medicamentos , Emociones , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Entrevistas como Asunto , Dispositivos Intrauterinos , Persona de Mediana Edad , Embarazo no Planeado , Estudios Retrospectivos , Adulto JovenRESUMEN
Neutrophils are abundant, short-lived leukocytes, and their death by apoptosis is central to hemostasis and the resolution of inflammation, yet the trigger for their entry into apoptosis is unknown. We show here that death receptor signaling, including CD95 death-inducing signaling complex (DISC) formation and caspase 8 activation, occurred early in neutrophil apoptosis. However, death receptor ligation was not required for apoptosis, suggesting a novel mechanism for caspase 8 activation. We detected ceramide generation and clustering of CD95 in lipid rafts early in neutrophil apoptosis, and neutrophil apoptosis and ceramide generation were both significantly inhibited in acid sphingomyelinase knockout (ASM(-/-)) mice compared to wild-type littermates. Further studies revealed that ceramide generation, CD95 clustering, and neutrophil apoptosis were dependent on reactive oxygen species (ROSs) and were preceded by a fall in reduced glutathione levels. We propose that accumulation of ROSs, as a consequence of altered redox status, initiates ligand-independent death receptor signaling via activation of ASM and clustering of preformed DISC components in lipid rafts and is therefore a primary factor limiting neutrophil life span.