Elevated ammonium concentrations in pump‐and‐treat effluent from a volatile organic compounds–contaminated municipal aquifer originate from two industrial sources: infiltration of drainage from the blending operations of a fertilizer company (FC) located in the recharge area ( of 500 to 700 parts per million [ppm] N and of 150 to 300 ppm N) and leakage from waste water treatment ponds maintained by an adjacent chemical company (CC) ( of 50 to 70 ppm N, with no ). Geochemical and isotope data are used to trace the mechanisms for the strong attenuation observed between the source areas and the municipal ground water treatment wells ( < 10 ppm N). Conservative mixing calculations demonstrate a loss of and along the flowpath relative to K+ and Cl−. Reactive loss of in these anoxic ground water is attributed to anaerobic oxidation by anammox bacteria. Lines of evidence leading to this conclusion include (1) loss of both and under anoxic conditions along the flowpath; (2) a progressive enrichment of and , indicating reactive loss of ammonium and nitrate; (3) values greater than coexisting , which precludes loss by nitrification to ; and (4) significant N2 overpressuring with increasing values. Anaerobic ammonium oxidation by anammox bacteria uses nitrate as the electron donor: . The recently discovered anammox reaction is more energetically favorable than denitrification and is now considered to play a major role in the global nitrogen cycle. It has been observed in waste water bioreactors and sea water but not previously in ground water.

AimsThe chemokine receptor CCR5 and its inflammatory ligands have been linked to atherosclerosis, an accelerated form of which occurs in saphenous vein graft disease. We investigated the function of vascular smooth muscle CCR5 in human coronary artery and saphenous vein, vascular tissues susceptible to atherosclerosis, and vasospasm.Methods and resultsCCR5 ligands were vasoconstrictors in saphenous vein and coronary artery. In vein, constrictor responses to CCL4 were completely blocked by CCR5 antagonists, including maraviroc. CCR5 antagonists prevented the development of a neointima after 14 days in cultured saphenous vein. CCR5 and its ligands were expressed in normal and diseased coronary artery and saphenous vein and localized to medial and intimal smooth muscle, endothelial, and inflammatory cells. [125I]-CCL4 bound to venous smooth muscle with KD = 1.15 ± 0.26 nmol/L and density of 22 ± 9 fmol mg−1 protein.ConclusionsOur data support a potential role for CCR5 in vasoconstriction and neointimal formation in vitro and imply that CCR5 chemokines may contribute to vascular remodelling and augmented vascular tone in human coronary artery and vein graft disease. The repurposing of maraviroc for the treatment of cardiovascular disease warrants further investigation.

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Graphite is a key material in the design and operation of a wide range of nuclear reactors because of its attractive combination of thermal, mechanical, and neutron interaction properties. In all its applications, the microstructural evolution of nuclear graphite under operating conditions will strongly influence reactor lifetime and performance. However, measuring the 3D microstructural characteristics of nuclear graphite has traditionally faced many challenges. X-ray tomographic techniques face limitations in achievable resolution on bulk (mm-sized) specimens while serial sectioning techniques like FIB-SEM struggle to achieve adequate milling rates for tomographic imaging over representative volumes. To address these shortcomings, we present here a multiscale, targeted, correlative microstructural characterization workflow for nuclear graphite employing micro-scale and nano-scale x-ray microscopy with a connected laser milling step in between the two modalities. We present details of the microstructure, including porosity analysis, spanning orders of magnitude in feature size for nuclear graphite samples including IG-110.

Research to support nuclear energy development faces many challenges. Understanding material microstructures is not only essential to predicting and understanding the in-service performance of materials used in nuclear energy production, but also in understanding aging and corrosion of these materials as they interact with their environment. However, microstructural characterization of nuclear materials poses unique obstacles. Unique materials and material combinations push traditional microstructural evaluation techniques to their limits. Radioactive samples make normally routine microstructural characterization tasks much more complex. Precious samples force rigorous, multi-scale analysis workflows. And, materials that face and must endure uniquely harsh operational environments increase the demands for deep microstructural understandings. In this context, multiscale characterization workflows and the technology that supports them play an integral role in advancing materials development for nuclear energy production.