BackgroundCoronary artery calcification (CAC) is highly prevalent among dialysis patients and is associated with increased cardiovascular and all cause mortality. Magnesium (Mg) inhibits vascular calcification in animal and in-vitro studies but whether the same effect occurs in humans is uncertain.MethodsA single centre cross-sectional study of 80 prevalent peritoneal dialysis (PD) patients; on PD only for a minimum of 3 months. A radiologist blinded to patient status calculated their abdominal aortic calcification (AAC) scores on lateral lumbar spine radiographs, a validated surrogate for CAC.ResultsEighty patients provided informed consent and underwent lumbar spine radiography. The mean serum Mg was 0.8 mmol/L (standard deviation 0.2) and mean AAC score 8.9 (minimum 0, maximum 24). A higher serum Mg level was associated with a lower AAC score (R 2 = 0.06, unstandardized coefficient [B] = −7.81, p = 0.03), and remained after adjustment for age, serum phosphate, serum parathyroid hormone, low-density lipoprotein cholesterol, smoking history, and diabetes (model adjusted R 2 = 0.36, serum Mg and AAC score B = −11.44, p = 0.00). This translates to a 0.1 mmol/L increase in serum Mg being independently associated with a 1.1-point decrease in AAC score.ConclusionsOur findings suggest that Mg may inhibit vascular calcification. If this association is replicated across larger studies with serial Mg and vascular calcification measurements, interventions that increase serum Mg and their effect on vascular calcification warrant further investigation in the PD population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-017-0549-y) contains supplementary material, which is available to authorized users.

The degrees of freedom afforded by nanocomposite materials and additive manufacturing allow for the precise control over the chromatic properties of gradient index (GRIN) optics. The ability to engineer nanocomposite optical materials using blends of three or more constituents makes it possible to independently specify the refractive index gradient and the dispersion of optical materials. The refractive index spectra of the primary nanocomposite feedstock are defined relative to one another using various concentrations of monomers and nanofillers. Inkjet deposition is then used to print-compose specific feedstock to form refractive index gradients with precise control over dispersion. Arrays of 4-mm-diameter spherical GRIN lenses were fabricated using different nanomaterial compositions. The ability to positively and negatively control dispersion and to obtain achromatic performance was demonstrated. Control over partial dispersion is also shown.

The role of anticoagulant and antiplatelet agents for atrial fibrillation and cardiovascular disease in ESRD remains unclear. Well designed randomized controlled trials to determine the role of anticoagulation in ESRD patients with atrial fibrillation, and anticoagulant and antiplatelet medications in the preservation of central venous catheter function are required.

Inkjet-print additive manufactured freeform gradient refractive index representations of an Alvarez-Lohmann lens were developed and optimized for use in vision-correction inserts for respiratory masks. A series of planar 30-mm by 20-mm Alvarez-Lohmann lens pair were printed and characterized. Select lens pairs were mounted with printed mechanical lens mounts and translation guides optimized for vision correction. Metrology showed accurate reproduction of the cubic refractive phase functions. Tests matching simulated performance showed a large diopter adjustment over a large eyebox and a wide gaze angle. The printed optics were environmentally tested and then mounted in a respiratory mask and demonstrated with gloveaccessible control electronics. The performance demonstrates the benefits of using printed three-dimensional freeform gradient index optics for implementing complex refractive optical functions for challenging applications including artificial and virtual reality systems. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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