Dietary enrichment by almond supplementation: effects on risk factors for cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of death in Europe responsible for more than 4.3 million deaths annually. The World Health Organisation funded the Monica project (1980s-1990s) which monitored ten million subjects aged 22-6Syrs, and demonstrated that coronary heart disease (CHD) mortality declined over 10 years, was due in two thirds of cases to reduced incidence of CHD (reduced risk behaviours e.g. poor diet and smoking) and one third by improved treatments. Epidemiological evidence suggests diets rich in antioxidants decrease incidence of CVD. Regular consumption of nuts, rich in vitamin E and polyphenols reduces atherosclerosis, an important risk for heart disease. Intervention studies to date using alpha tocopherol (an active component of vitamin E) have not consistently proved beneficial. This thesis aims to investigate the effect of almond supplementation on vascular risk factors in healthy young males (18-3Syrs); mature males and female(>SOyrs); and males considered at increased risk of CVD (18-3Syrs) in a cohort of 67 subjects. The effects of almond intake were assessed after 2Sg/d for four weeks followed by SOg/d for four weeks and compared to a control group which did not consume almonds or change their diet. Cardiovascular risk was assessed by plasma lipid profiles, apolipoprotein A1, plasma nitrates/nitrates, vascular flow, BMl, blood pressure, sVCAM-1 and protein oxidation. Systolic and diastolic blood pressures were reduced in almond supplemented volunteers but not in controls. Dietary monounsaturated fatty acids, polyunsaturated fatty acid content and total dietary fats were increased by almond supplementation. Neither sVCAM-1, venous occlusion plethysmography nor plasma nitrite levels were affected by almond intake in any independent group. No significant changes in plasma lipids, and apolipoprotein A1 were observed. In conclusion almonds supplementation caused a reduction in blood pressure that may be due to increased sensitivity of the baroreceptors after increased monounsaturated fatty acid intake.

Remobilisation of uranium and thorium by ore-forming fluids: a mineralogical study. Available in 2 volumes.

Mineralogical investigations have determined the sites of u and Th associated with two radioelement-enriched granites from different geological settings. In the Ririwai ring complex, Nigeria, the u- and Th-bearing accessories have been greatly affected by post-magmatic alteration of the biotite granite. Primary thorite, zircon and monazite were altered to Zr(±Y)-rich thorite, partially metamict zircon (enriched in Th, U, Y, P, Fe, Mn, Ca) and an unidentified LREE-phase respectively, by pervasive fluids which later precipitated Zr-rich coffinite. More intense, localised alteration and albitisation completely remobilised primary accessories and gave rise to a distinctive generation of haematite- and uranothorite-enriched zircon with clear, Hi-enriched rims and xenotime overgrowths. In the Ririwai lode, microclinisation and later greisenisation locally remobilised or altered zircon and deposited Y-ricl1 coffinite and Y(±Zr)-rich thorite which was overgrown by traces of xenotime and LREE-phase(s) of complex and variable composition. Compositions indicating extensive solid-solution among thorite, coffinite, xenotime and altered zircon are probably metastable and formed at low temperatures. The widespread occurrence of REE-rich fluorite suggests that F-complexing aided the mobility of REE, Y, U, Th and Zr during late-magmatic to post-magmatic alteration, while uranyl-carbonate complexing may have occurred during albitisation. The Caledonian, Helmsdale granite in northern Scotland has undergone pervasive and localised hydrothermal alteration associated with U enrichment. Zircon xenocrysts, primary sphene and apatite contain a small.proportion of this U which is largely adsorbed on to secondary iron-oxide, TiOand phyllosilicates.Additional sites for U in the overlying, Lower Devonian Ousdale arkose include coffinite, secondary uranyl phosphates, hydrocarbon and traces of xenotime and unidentified LREE-phases. U may have been leached from the granite and deposited in the arkose, along channelways associated with the Helmsdale fault, by convecting, hydrothermal fluids

Effect of calcium source on structure and properties of sol-gel derived bioactive glasses

The aim was to determine the most effective calcium precursor for synthesis of sol-gel hybrids and for improving homogeneity of sol-gel bioactive glasses. Sol-gel derived bioactive calcium silicate glasses are one of the most promising materials for bone regeneration. Inorganic/organic hybrid materials, which are synthesized by incorporating a polymer into the sol-gel process, have also recently been produced to improve toughness. Calcium nitrate is conventionally used as the calcium source, but it has several disadvantages. Calcium nitrate causes inhomogeneity by forming calcium-rich regions, and it requires high temperature treatment (>400 C) for calcium to be incorporated into the silicate network. Nitrates are also toxic and need to be burnt off. Calcium nitrate therefore cannot be used in the synthesis of hybrids as the highest temperature used in the process is typically 40-60 C. Therefore, a different precursor is needed that can incorporate calcium into the silica network and enhance the homogeneity of the glasses at low (room) temperature. In this work, calcium methoxyethoxide (CME) was used to synthesize sol-gel bioactive glasses with a range of final processing temperatures from 60 to 800 C. Comparison is made between the use of CME and calcium chloride and calcium nitrate. Using advanced probe techniques, the temperature at which Ca is incorporated into the network was identified for 70S30C (70 mol % SiO, 30 mol % CaO) for each of the calcium precursors. When CaCl was used, the Ca did not seem to enter the network at any of the temperatures used. In contrast, Ca from CME entered the silica network at room temperature, as confirmed by X-ray diffraction, Si magic angle spinning nuclear magnetic resonance spectroscopy, and dissolution studies. CME should be used in preference to calcium salts for hybrid synthesis and may improve homogeneity of sol-gel glasses.