631 research outputs found

    Improving starch and fibre in wheat grain for human health

    Get PDF
    Reducing the prevalence of diet- related diseases, including obesity and type 2 diabetes, is a major challenge for health professionals, food manufacturers and governments in both developed and developing countries. Cereals are key targets in meeting this challenge as they are staple foods throughout the world and major sources of energy (derived principally from starch) and dietary fibre. Wheat is the staple cereal in the UK and Europe, and the UK Biotechnology and Biological Sciences Research Council (BBSRC)- supported Designing Future Wheat programme is focused on manipulating the content and composition of starch and fibre to improve health impacts, including reducing the glycaemic response and improving fermentation in the colon. This work is contributing to the development of improved cultivars by breeders and foods by processors. It is also increasing our understanding of the behaviour of these components in the human gastrointestinal (GI) tract and will contribute to the establishment of targets and recommendations for regulatory authorities

    The flow of anisotropic nanoparticles in solution and in blood

    Full text link
    The alignment of anisotropic nanoparticles in flow has been used for a range of applications such as the preparation of strong fibres and the assembly of in-plane aligned 1D-nanoobjects that are used for electronic devices, sensors, energy and biological application. Important is also the flow behaviour of nanoparticles that were designed for nanomedical applications such as drug delivery. It is widely observed that non-spherical nanoparticles have longer circulation times and a more favourable biodistribution. To be able to understand this behaviour, researchers have turned to analyzing the flow of non-spherical nanoparticles in the blood stream. In this review, an overview of microfluidic techniques that are used to monitor the alignment of anisotropic nanoparticles in solution will be provided, which includes analysis by small angle X-ray scattering (SAXS) and polarized light microscopy. The flow of these nanoparticles in blood is then discussed as the presence of red blood cells causes margination of some nanoparticles. Using fluorescence microscopy, the extent of margination can be identified, which coincides with the ability of nanoparticles to adhere to the cells grown along the wall. While these studies are mainly carried out in vitro using blood, initial investigations in vivo were able to confirm the unusual flow of anisotropic nanoparticles

    Loss of starch synthase IIIa changes starch molecular structure and granule morphology in grains of hexaploid bread wheat.

    Get PDF
    Starch synthase III plays a key role in starch biosynthesis and is highly expressed in developing wheat grains. To understand the contribution of SSIII to starch and grain properties, we developed wheat ssIIIa mutants in the elite cultivar Cadenza using in silico TILLING in a mutagenized population. SSIIIa protein was undetectable by immunoblot analysis in triple ssIIIa mutants carrying mutations in each homoeologous copy of ssIIIa (A, B and D). Loss of SSIIIa in triple mutants led to significant changes in starch phenotype including smaller A-type granules and altered granule morphology. Starch chain-length distributions of double and triple mutants indicated greater levels of amylose than sibling controls (33.8% of starch in triple mutants, and 29.3% in double mutants vs. 25.5% in sibling controls) and fewer long amylopectin chains. Wholemeal flour of triple mutants had more resistant starch (6.0% vs. 2.9% in sibling controls) and greater levels of non-starch polysaccharides; the grains appeared shrunken and weighed ~ 11% less than the sibling control which was partially explained by loss in starch content. Interestingly, our study revealed gene dosage effects which could be useful for fine-tuning starch properties in wheat breeding applications while minimizing impact on grain weight and quality

    Investigating MgII Absorption in Paired Quasar Sight-Lines

    Full text link
    We test whether the Tinker & Chen model of MgII absorption due to the gaseous halo around a galaxy can reproduce absorption in quasar pairs (both lensed and physical) and lensed triples and quads from the literature. These quasars exhibit absorption from a total of 38 MgII systems spanning z=0.043 - 2.066 with mean redshift =1.099 and weighted mean rest-frame equivalent width of 0.87 Ang. Using the Tinker & Chen model to generate simulated sight-lines, we marginalize the unknown parameters of the absorbing galaxies: dark matter halo mass, impact parameter, and azimuthal angle on the sky. We determine the ability of the model to statistically reproduce the observed variation in MgII absorption strength between paired sight-lines for different values of the gas covering fraction f_c and the characteristic length scale ell_c, within which the variation in absorption equivalent widths between sight-lines exponentially decreases. We find a best-fit f_c=0.60 \pm 0.15 and ell_c<8/h_70 kpc (1\sigma confidence limits), with smaller f_c allowed at larger ell_c. At 99.7% confidence, we are able to rule out f_c>0.87 for all values of ell_c and the region where ell_c<1.0/h_70 kpc and f_c<0.3.Comment: 24 pages, 11 figures, 2 tables, accepted for publication in MNRAS, 1 Dec 201

    The effect of fructose feeding on intestinal triacylglycerol production and de novo fatty acid synthesis in humans

    Get PDF
    A high fructose intake exacerbates postprandial plasma triacylglycerol (TAG) concentration, an independent risk factor for cardiovascular disease, although it is unclear whether this is due to increased production or impaired clearance of triacylglycerol (TAG)-rich lipoproteins. We determined the in vivo acute effect of fructose on postprandial intestinal and hepatic lipoprotein TAG kinetics and de novo lipogenesis (DNL). Five overweight men were studied twice, 4 weeks apart. They consumed hourly mixed-nutrient drinks that were high-fructose (30% energy) or low-fructose (<2% energy) for 11 hours. Oral 2H2O was administered to measure fasting and postprandial DNL. Postprandial chylomicron (CM)-TAG and very low-density lipoprotein (VLDL)-TAG kinetics were measured with an intravenous bolus of [2H5]-glycerol. CM and VLDL were separated by their apolipoprotein B content using antibodies. Plasma TAG (P<0.005) and VLDL-TAG (P=0.003) were greater, and CM-TAG production rate (PR, P=0.046) and CM-TAG fractional catabolic rate (FCR, P=0.073) lower when high-fructose was consumed, with no differences in VLDL-TAG kinetics. Insulin was lower (P=0.005) and apoB48 (P=0.039), apoB100 (P=0.013) and NEFA (P=0.013) were higher after high-fructose. Postprandial hepatic fractional DNL was higher than intestinal fractional DNL with high-fructose (P=0.043) and low-fructose (P=0.043). Fructose consumption had no effect on the rate of intestinal or hepatic DNL. We provide the first measurement of the rate of intestinal DNL in humans. Lower CM-TAG PR and CM-TAG FCR with high-fructose consumption suggests lower clearance of CM, rather than elevated production, may contribute to elevated plasma TAG, possibly due to lower insulin-mediated stimulation of lipoprotein lipase
    corecore