Developing an in situ LED irradiation system for small-angle X-ray scattering at B21, Diamond Light Source.

Beamline B21 at the Diamond Light Source synchrotron in the UK is a small-angle X-ray scattering (SAXS) beamline that specializes in high-throughput measurements via automated sample delivery systems. A system has been developed whereby a sample can be illuminated by a focused beam of light coincident with the X-ray beam. The system is compatible with the highly automated sample delivery system at the beamline and allows a beamline user to select a light source from a broad range of wavelengths across the UV and visible spectrum and to control the timing and duration of the light pulse with respect to the X-ray exposure of the SAXS measurement. The intensity of the light source has been characterized across the wavelength range enabling experiments where a quantitative measure of dose is important. Finally, the utility of the system is demonstrated via measurement of several light-responsive samples.

Beamline B21: high-throughput small-angle X-ray scattering at Diamond Light Source.

B21 is a small-angle X-ray scattering (SAXS) beamline with a bending magnet source in the 3 GeV storage ring at the Diamond Light Source Ltd synchrotron in the UK. The beamline utilizes a double multi-layer monochromator and a toroidal focusing optic to deliver 2 × 1012 photons per second to a 34 × 40 µm (FWHM) focal spot at the in-vacuum Eiger 4M (Dectris) detector. A high-performance liquid chromatography system and a liquid-handling robot make it possible to load solution samples into a temperature-controlled in-vacuum sample cell with a high level of automation. Alternatively, a range of viscous or solid materials may be loaded manually using a range of custom sample cells. A default scattering vector range from 0.0026 to 0.34 Å-1 and low instrument background make B21 convenient for measuring a wide range of biological macromolecules. The beamline has run a full user programme since 2013.

Electrical impedance myography in Duchenne muscular dystrophy and healthy controls: A multicenter study of reliability and validity.

INTRODUCTION: Electrical impedance myography (EIM) is a non-invasive, painless, objective technique to quantify muscle pathology. METHODS: We measured EIM in 8 arm and leg muscles in 61 boys with Duchenne muscular dystrophy (DMD) and 31 healthy boys, ages 3-12 years, at 5 centers. We determined the reliability of EIM and compared results in boys with DMD to controls and to 6-minute walk distance (6MWD), North Star Ambulatory Assessment (NSAA), timed functional tests (TFTs), and strength (hand-held dynamometry). RESULTS: EIM was well tolerated and had good inter- and intrarater reliability (intraclass correlation coefficient 0.81-0.96). The averaged EIM phase value from all muscles was higher (P < 0.001) in controls (10.45 ± 2.29) than boys with DMD (7.31 ± 2.23), and correlated (P ≤ 0.001) with 6MWD (r = 0.55), NSAA (r = 0.66), TFTs (r = -0.56), and strength (r = 0.44). CONCLUSION: EIM is a reliable and valid measure of disease severity in DMD. Longitudinal studies comparing EIM with other assessments over time in DMD are warranted.

African-American clergy's perceptions of the leading health problems in their communities and their role in supporting parishioners' health.

This article is a report on a survey of Southern California pastors to learn of their perceptions of the leading health problems in their congregations. Participants (N=41) identified stress, overweight, and obesity as the top three health indicators that effect the health of their congregations. Tobacco use and substance abuse were listed among the top five. From a list of health problems, pastors felt that from the pulpit they could impact parishioners responsible sexual behavior most. Pastors expressed their opinions about the reasons for certain maladies and addictions. The findings indicate room for improvement in building clergy's understanding of the nature of illness and addiction and in empowering them in their role of supporting healthy behaviors in the African-American community.