1,571 research outputs found

    The influence of dietary carbohydrate and fat on kidney calcification and the urinary excretion of N-acetyl-beta-glucosaminidase (EC 3.2.1.30).

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    1. Male Sprague-Dawley rats were fed on diets containing either sucrose or starch as the carbohydrate component. In one experiment, the diets also contained 200 g either butter or polyunsaturated margarine/kg; in a second experiment, the diets contained less fat in the form of 20 g maize oil/kg. 2. Over a period of 11 months assays were made in the urine of several ions and of the activity of the enzyme N-acetyl-β-glucosaminidase (β-2-acetamido-2-deoxy-β-D glucoside acetamidodeoxygluco-hydrolase; EC 3.2.1.30); at 13 months, examination was made of some of the abdominal viscera, especially of the kidneys. 3. In rats fed on the higher amount of fat, dietary sucrose produced a higher activity of the enzyme than did dietary starch, and a greater excretion of inorganic phosphate. 4. With both the higher and lower amounts of dietary fat, sucrose led to an increase in the weight of the liver and of the kidneys, and an increase in the concentration of calcium and of phosphate in kidney tissue. With the higher amount of fat, sucrose also produced an increase in the concentration of magnesium in the kidney. There was no difference in the concentration of any of the ions assayed in the plasma or, apart from inorganic phosphate, in the urine. 5. The kidneys of the sucrose-fed rats showed nephrocalcinosis, mostly in the cortico-medullary region, and basophilic deposits in the tubules. Attention is drawn to this unusual occurrence of nephrocalcinosis in male rats

    Structure and hydration of membranes embedded with voltage-sensing domains.

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    Despite the growing number of atomic-resolution membrane protein structures, direct structural information about proteins in their native membrane environment is scarce. This problem is particularly relevant in the case of the highly charged S1-S4 voltage-sensing domains responsible for nerve impulses, where interactions with the lipid bilayer are critical for the function of voltage-activated ion channels. Here we use neutron diffraction, solid-state nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics simulations to investigate the structure and hydration of bilayer membranes containing S1-S4 voltage-sensing domains. Our results show that voltage sensors adopt transmembrane orientations and cause a modest reshaping of the surrounding lipid bilayer, and that water molecules intimately interact with the protein within the membrane. These structural findings indicate that voltage sensors have evolved to interact with the lipid membrane while keeping energetic and structural perturbations to a minimum, and that water penetrates the membrane, to hydrate charged residues and shape the transmembrane electric field

    Experiment Simulation Configurations Used in DUNE CDR

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    The LBNF/DUNE CDR describes the proposed physics program and experimental design at the conceptual design phase. Volume 2, entitled The Physics Program for DUNE at LBNF, outlines the scientific objectives and describes the physics studies that the DUNE collaboration will perform to address these objectives. The long-baseline physics sensitivity calculations presented in the DUNE CDR rely upon simulation of the neutrino beam line, simulation of neutrino interactions in the far detector, and a parameterized analysis of detector performance and systematic uncertainty. The purpose of this posting is to provide the results of these simulations to the community to facilitate phenomenological studies of long-baseline oscillation at LBNF/DUNE. Additionally, this posting includes GDML of the DUNE single-phase far detector for use in simulations. DUNE welcomes those interested in performing this work as members of the collaboration, but also recognizes the benefit of making these configurations readily available to the wider community.Comment: 9 pages, 4 figures, configurations in ancillary file

    Search for the Rare Decay K_{L}\to\pi^{0}\pi^{0}\gamma

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    The KTeV E799 experiment has conducted a search for the rare decay KLπ0π0γK_{L}\to\pi^{0}\pi^{0}\gamma via the topology KLπ0πD0γK_{L}\to\pi^{0}\pi^{0}_D\gamma (where πD0γe+e\pi^0_D\to\gamma e^+e^-). Due to Bose statistics of the π0\pi^0 pair and the real nature of the photon, the KLπ0π0γK_{L}\to\pi^{0}\pi^{0}\gamma decay is restricted to proceed at lowest order by the CP conserving direct emission (DE) of an E2 electric quadrupole photon. The rate of this decay is interesting theoretically since chiral perturbation theory predicts that this process vanishes at level O(p4)O(p^4). Therefore, this mode probes chiral perturbation theory at O(p6)O(p^6). In this paper we report a determination of an upper limit of 2.43×1072.43\times 10^{-7} (90% CL) for KLπ0π0γK_{L}\to\pi^{0}\pi^{0}\gamma. This is approximately a factor of 20 lower than previous results.Comment: six pages and six figures in the submission. Reformatted for Physics Review
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