Design of a neutron microscope based on Wolter mirrors.

The predominant geometry for a neutron imaging experiment is that of a pinhole camera. This is primarily due to the difficulty in focusing neutrons due to the weak refractive index, which is also strongly chromatic. Proof of concept experiments demonstrated that neutron image forming lenses based on reflective Wolter mirrors can produce quantitative, high spatial resolution neutron images while also increasing the time resolution compared to the conventional pinhole camera geometry. Motivated by these results, we report the design of a neutron microscope where two Wolter mirrors replace condensing and objective lenses, in direct analogy with typical visible light microscopes. Ray tracing results indicate that this system will yield 3 µm spatial resolution images with an acquisition time of order <1 s (104 faster than currently possible at this spatial resolution) with a field of view of about 5 mm in diameter.

Characterization and calibration of a multilayer coated Wolter optic for an imager on the Z-machine at Sandia National Laboratories.

The need for a time-resolved monochromatic x-ray imaging diagnostic at photon energies >15 keV has motivated the development of a Wolter optic to study x-ray sources on the Z-machine at Sandia National Laboratories. The work is performed in both the LLNL's x-ray calibration facility and SNL's micro-focus x-ray lab. Characterizations and calibrations include alignment, measurement of throughput within the field of view (FOV), the point-spread function within the FOV both in and out of focus, and bandpass in the FOV. These results are compared with ray tracing models, showing reasonable agreement.

Design and raytrace simulations of a multilayer-coated Wolter x-ray optic for the Z machine at Sandia National Laboratories.

Recent breakthroughs in the fabrication of small-radii Wolter optics for astrophysics allow high energy density facilities to consider such optics as novel x-ray diagnostics at photon energies of 15-50 keV. Recently, the Lawrence Livermore National Laboratory, Sandia National Laboratories (SNL), the Smithsonian Astrophysical Observatory, and the NASA Marshall Space Flight Center jointly developed and fabricated the first custom Wolter microscope for implementation in SNL's Z machine with optimized sensitivity at 17.5 keV. To achieve spatial resolution of order 100-200 microns over a field of view of 5 × 5 × 5 mm3 with high throughput and narrow energy bandpass, the geometry of the optic and its multilayer required careful design and optimization. While the geometry mainly influences resolution and the field of view of the diagnostic, the mirror coating determines the spectral response and throughput. Here we outline the details of the design and fabrication process for the first multilayer-coated Wolter I optic for SNL's Z machine (Z Wolter), including its W/Si multilayer, and present results of raytrace simulations completed to predict and verify the performance of the optic.

A Wolter imager on the Z machine to diagnose warm x-ray sources.

A new Wolter x-ray imager has been developed for the Z machine to study the emission of warm (>15 keV) x-ray sources. A Wolter optic has been adapted from observational astronomy and medical imaging, which uses curved x-ray mirrors to form a 2D image of a source with 5 × 5 × 5 mm3 field-of-view and measured 60-300-µm resolution on-axis. The mirrors consist of a multilayer that create a narrow bandpass around the Mo Kα lines at 17.5 keV. We provide an overview of the instrument design and measured imaging performance. In addition, we present the first data from the instrument of a Mo wire array z-pinch on the Z machine, demonstrating improvements in spatial resolution and a 350-4100× increase in the signal over previous pinhole imaging techniques.

Measuring the quality of performance of a genitourinary medicine primary care team / Medición de la calidad de los resultados de la medicina genitourinaria del equipo de atención primaria

OBJECTIVES: To measure the quality of the clinical Genitourinary (G-U) Medicine and Sexually Transmitted Infection (GUM/STI) management process at a primary care polyclinic and establish a baseline for future monitoring and evaluation. METHODS: This was a prospective cohort study on 220 data abstracted clinical notes randomly selected and stratified by gender, age and first point of contact from 2131 GU/STI patients of the GUM/STI clinic seen from 2003-5. Data were also obtained by tele-interview of a subset of 27 individuals. Measurements were incidence (95% CI) as proportions of successful level of activity and outcome indicators for diagnosis, treatment and prognosis. RESULTS:Among 220 patients, the incidence (95% CI) of accurate clinical diagnosis and treatment was 40.5% (33%, 46%) before laboratory results boosted it to 96% (93%, 99%). Successful prognosis at 1st, 2nd and 3rd follow-up was 23.2%, 56.6% and 86.2%. The risk at follow-up for 1, 2 and >2 GU/STI episodes was 28.9%, 45.8% and 25.3%. Follow-up of partners was low, 4.7%. Adequate health promotion and preventive services were reported in 86.5% (78%, 88%) of 220 patients' records and by 84.5% (71%, 98%) of 26 who were tele-interviewed. In 88.5% (76%, 100%) of those (27) tele-interviewed, there was satisfaction with the service, but 73.8% (56%, 90%) would have preferred appointments and 29.6% (12%, 47%) preferred extended hours. Per capita ideal cost of medication could have been BB$6.30 (± 1.56) instead of actual BB$13.05 (± 1.84); (BB$2 = US$1). CONCLUSION: GU/STI quality performance improvement in Barbados requires rapid laboratory diag-nosis, standardized data formats with prompt expedited partner notification and treatment appointments and use of recommended algorithm that can half the cost of medication. Genitourinary medicine should be strategized instead of STI to better encapsulate the spectrum diversity of presentations and points of service.

OBJETIVO: Medir la calidad de la medicina genitourinaria clínica y el proceso del tratamiento de las infecciones de transmisión sexual (MGU/ITS) en un policlínico de atención primaria, y establecer una línea de base para el monitoreo y la evaluación futuros. MÉTODOS: Se trató de un estudio de cohorte prospectivo realizados sobre 220 notas clínicas extraídas de datos, seleccionadas aleatoriamente y estratificadas por género, edad y primer punto de contacto, de 2131 pacientes MGU/ITS de la clínica MGU/ITS atendidos en 2003-2005, y por tele-entrevista de un subconjunto de 27 individuos. Las mediciones fueron incidencias (95% IC) como proporciones del nivel de éxito de la actividad e indicadores de los resultados para el diagnóstico, el tratamiento y la prognosis. RESULTADOS: Entre 220 pacientes, la incidencia (95% IC) del diagnóstico clínico exacto y el tratamiento fue 40.5% (33%, 46%) antes de que los resultados de laboratorio la elevaran a 96% (93%, 99%). La prognosis exitosa en el primer, segundo y tercer seguimiento fue 23.2%, 56.6% y 86.2%. El riesgo en el seguimiento para los episodios GU/ITS 1, 2, y > 2 fue 28.9%, 45.8% y 25.3%. El seguimiento de parejas fue bajo, 4.7%. La promoción adecuada de la salud y los servicios de prevención fueron reportados en 86.5% (78%, 88%) de las historias de 220 pacientes y por 84.5% (71%, 98%) de 26 que fueron tele-entrevistados. En 88.5% (76%, 100%) de los (27) tele-entrevistados, hubo satisfacción con el servicio, pero 73.8% (56%, 90%) hubiera preferido citas y 29.6% (12%, 47%) extensión del horario. El costo ideal per capita de la medicación podría haber sido 6.30 BBD (± 1.56) en lugar de 13.05 BBD (± 1.84); (2 BBD = 1 USD). CONCLUSIONES: El mejoramiento en cuanto a resultados de calidad en GU/ITS en Barbados, requiere diagnósticos de laboratorio rápidos, formatos estandarizados de datos con pronta notificación a las parejas, citas para el tratamiento, y uso del algoritmo recomendado que puede reducir a la mitad el costo de la medicación. MUG debe ser estrategizada en lugar del TIS, a fin de encapsular mejor el espectro de la diversidad en las presentaciones y puntos de servicio.

Measuring the quality of performance of a genitourinary medicine primary care team.

OBJECTIVES: To measure the quality of the clinical Genitourinary (G-U) Medicine and Sexually Transmitted Infection (GUM/STI) management process at a primary care polyclinic and establish a baseline for future monitoring and evaluation. METHODS: This was a prospective cohort study on 220 data abstracted clinical notes randomly selected and stratified by gender, age and first point of contact from 2131 GU/STI patients of the GUM/STI clinic seen from 2003-5. Data were also obtained by tele-interview of a subset of 27 individuals. Measurements were incidence (95% CI) as proportions of successful level of activity and outcome indicators for diagnosis, treatment and prognosis. RESULTS: Among 220 patients, the incidence (95% CI) of accurate clinical diagnosis and treatment was 40.5% (33%, 46%) before laboratory results boosted it to 96% (93%, 99%). Successful prognosis at 1st, 2nd and 3rd follow-up was 23.2%, 56.6% and 86.2%. The risk at follow-up for 1, 2 and >2 GU/STI episodes was 28.9%, 45.8% and 25.3%. Follow-up of partners was low, 4.7%. Adequate health promotion and preventive services were reported in 86.5% (78%, 88%) of 220 patients' records and by 84.5% (71%, 98%) of 26 who were tele-interviewed. In 88.5% (76%, 100%) of those (27) tele-interviewed, there was satisfaction with the service, but 73.8% (56%, 90%) would have preferred appointments and 29.6% (12%, 47%) preferred extended hours. Per capita ideal cost of medication could have been BB$6.30 (+/- 1.56) instead of actual BB$13.05 (+/- 1.84); (BB$2 = US$1). CONCLUSIONS: GU/STI quality performance improvement in Barbados requires rapid laboratory diagnosis, standardized data formats with prompt expedited partner notification and treatment appointments and use of recommended algorithm that can half the cost of medication. Genitourinary medicine should be strategized instead of STI to better encapsulate the spectrum diversity of presentations and points of service.

Immunological and virological responses to highly active antiretroviral therapy in a non-clinical trial setting in a developing Caribbean country.

OBJECTIVE: Few data exist on the efficacy of antiretroviral therapy in individuals infected with HIV in the Caribbean. We evaluated the virological and immunological responses of HIV-infected adults starting highly active antiretroviral therapy (HAART). DESIGN: This was a prospective observational cohort study. METHODS: A total of 158 antiretroviral-naive patients who initiated HAART between January 2002 and March 2003, and completed at least 6 months of treatment and follow up, were included in the analysis. The response to therapy was assessed by changes in CD4 cell counts and viral loads from baseline. The mean increase in CD4 cell count, the rate of virological success (a viral load of <50 HIV-1 RNA copies/mL) and the rate of immunological success (an increase in CD4 cell count of > or =50 cells/microL over the baseline value) after commencing HAART were measured. RESULTS: In total, 82% of patients (123 of 150) achieved viral loads of <50 copies/mL after 6 months of therapy. Viral success rate after 6 months of HAART was similar irrespective of gender, pre-HAART CD4 cell count and pre-HAART viral load. However, patients older than 40 years were significantly more likely to achieve virological success than those younger than 40 years. At 6 months after starting HAART, 79.5% of patients were estimated to have achieved immunological success and 17.9% had an increase in CD4 cell count of > or =200 cells/microL over the baseline value. The median increase in CD4 cell count for the 156 patients who had CD4 cell counts at baseline and at 6 months of therapy was 122 cells/microL. CONCLUSION: In this cohort of antiretroviral-naive HIV-infected adults, there was a high rate of virological and immunological success after 6 months of HAART, irrespective of the pre-HAART viral load and CD4 cell count.