| 1. |
- Dastani, Zari, et al.
(författare)
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Novel Loci for Adiponectin Levels and Their Influence on Type 2 Diabetes and Metabolic Traits : A Multi-Ethnic Meta-Analysis of 45,891 Individuals
- 2012
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 8:3, s. e1002607-
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Tidskriftsartikel (refereegranskat)abstract
- Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (P=4.5 x 10(-8)-1.2 x 10(-43)). Using a novel method to combine data across ethnicities (N = 4,232 African Americans, N = 1,776 Asians, and N = 29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3 x 10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (p=4.3 x 10(-3), n = 22,044), increased triglycerides (p=2.6 x 10(-14), n = 93,440), increased waist-to-hip ratio (p=1.8 x 10(-5), n = 77,167), increased glucose two hours post oral glucose tolerance testing (p=4.4 x 10(-3), n = 15,234), increased fasting insulin (p = 0.015, n = 48,238), but with lower in HDL-cholesterol concentrations (p=4.5x10(-13), n = 96,748) and decreased BMI (p= 1.4 x 10(-14), n = 121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance.
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| 2. |
- Antti, Britt-Marie, et al.
(författare)
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Pulp chemistry in calcite flotation. : Modelling of oleate adsorption using theoretical equilibrium calculations
- 1989
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Ingår i: Mining engineering. - 0026-5187. ; 2:1, s. 93-109
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers the conditions required for direct flotation of calcite. Flotation experiments have been performed with oleate as the collector reagent and water glass as the dispersant and modifier. To be able to explain what happens in the flotation, solubility and adsorption experiments have been conducted parallel to, and under the same conditions as, the flotation experiments. Theoretical equilibrium calculations have been made with the help of data from the practical experiments for the purpose of modelling the adsorption experiments. With theoretical equilibrium calculations it is possible to predict that silicate ions will form complexes with calcium ions at the mineral surface.
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| 3. |
- Antti, Britt-Marie, et al.
(författare)
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Pulp chemistry in industrial mineral flotation. Studies of surface complex on calcite and apatite surfaces using FTIR spectroscopy
- 1989
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Ingår i: Mining engineering. - : Elsevier BV. - 0026-5187. ; 2:2, s. 217-227
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Tidskriftsartikel (refereegranskat)abstract
- Flotation experiments in a Hallimond tube have been performed on calcite and apatite at pH levels and oleate concentrations judged to be interesting from the point of view of adsorption isotherms. For the calcite system, adsorption isotherms indicate precipitation of calcium oleate after monolayer formation at pH 9, 10 and 11. In the apatite system, a double layer of oleate is formed. This means that apatite, unlike calcite, is sensitive to collector reagent overdosage. With the aid of FTIR techniques it is possible to demonstrate the existence of a surface complex in the apatite system with a calcium-oleate ratio of 1:1 at monolayer coverage of the surface. In conditions corresponding to bulk precipitation of calcium oleate, this compound can be detected by FTIR analysis of unfloated material.
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| 4. |
- Antti, Britt-Marie
(författare)
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Pulpkemi och kalcitflotation
- 1986
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Ingår i: Workshop i mineralteknik. - : MinFo. ; , s. 81-104
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Forssberg, Eric, et al.
(författare)
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Computer-assisted calculations of thermodynamic equilibria in the chalcopyrite-ethyl xanthate system
- 1984
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Ingår i: Reagents in the Minerals Industry. - London : The Institution of Mining and Metallurgy. - 0900488786 ; , s. 251-264
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Calculations show that thermodynamic data can be used to construct pulp chemistry models that satisfactorily describe events in mineral pulps. The usefulness of such models can be enhanced by the insertion of kinetic restrictions derived from analyses of mineral pulps from commercial-scale operations. A number of interesting findings concerning the chalcopyrite-ethyl xanthate system are demonstrated. As it is possible to calculate an operating line for any given flotation system, the calculation results can be compared at all times with practical experience and measurements of flotation processes.
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| 6. |
- Rao, K. Hanumantha, et al.
(författare)
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Flotation of mica minerals and selectivity between muscovite and biotite while using mixed anionic/cationic collectors
- 1990
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Ingår i: Minerals & metallurgical processing. - 0747-9182. ; 7:3, s. 127-132
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Tidskriftsartikel (refereegranskat)abstract
- Selective flotation of muscovite from a material containing muscovite (15.4%), biotite (13%), and siliceous gangue (quartz and feldspar), using a mixed collector system of sodium oleate and dodecylamine acetate has been described. Muscovite is found to float in preference to biotite, when the pulp is initially conditioned with oleate followed by amine at basic pH values. The results indicate that a product containing 63% muscovite with a recovery of 93% can be obtained, while using 75-150 g/t of oleate and 96 g/t of amine. The biotite grade and recovery are found to be around 30% and 20%, respectively. A good selectivity between muscovite and siliceous gangue is obtained. A final product containing 95% muscovite with an overall recovery of 75% is obtained when the flotation concentrate is subjected to magnetic separation. These studies indicate the possibility of separating muscovite from biotite by using a mixture of collectors.
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| 7. |
- Rao, K. Hanumantha, et al.
(författare)
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Flotation of phosphatic material containing carbonatic gangue using sodium oleate as collector and sodium silicate as modifier
- 1989
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Ingår i: International Journal of Mineral Processing. - : Elsevier BV. - 0301-7516 .- 1879-3525. ; 26:1, s. 123-140
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Tidskriftsartikel (refereegranskat)abstract
- The effect of sodium silicate as a depressant for calcite is examined in the flotation of phosphatic material containing calcite and siliceous gangue using sodium oleate as collector. Maximum flotation of apatite occurs at pH 8, whereas the pH at which calcite floats best varies with particle size. At pH 8 and 9, sodium silicate depresses calcite to some extent beyond 1500 g/t (2·10−3 M), and the depression is more pronounced at higher pH but the recovery of apatite is correspondingly low at these pH values. Selective action of silicate on calcite surfaces can be seen from the analysis of pulp liquid. However, for the pH range 7–11 and at any sodium silicate concentration, no significant selectivity between apatite and calcite is achieved.The influence of oleate concentration, pH and the concentration of sodium silicate on the flotation behaviour are discussed in detail.
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| 8. |
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| 9. |
- Rao, K. Hanumantha, et al.
(författare)
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Mechanism of oleate interaction on salt-type minerals part I. Adsorption and electrokinetic studies of calcite in the presence of sodium oleate and sodium metasilicate
- 1988
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Ingår i: Colloids and Surfaces. - 0166-6622 .- 1873-4340. ; 34:3, s. 227-239
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption mechanism of oleate on calcite is investigated through adsorption and electrokinetic studies. The adsorption isotherms at pH 9, 10 and 11 show a plateau value at an oleate adsorption density of 5.7 μmol m-2, which virtually corresponds to the monolayer coverage of the bidimensional condensed state of oleate with a reported molecular coverage area of 33 angstrom2 (liquid-crystal state). A steep increase increase in the slope of the isotherms characterizing calcium oleate precipitation appears after monolayer coverage and the solubility product of calcium oleate is found to be in the range pK 13.65-13.87 from the solution conditions. The zeta potentials correspond to the adsorption of oleate until monolayer coverage, and physical adsorption of precipitated calcium oleate on top of the chemisorbed oleate layer is also confirmed.
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| 10. |
- Rao, K. Hanumantha, et al.
(författare)
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Mechanism of oleate interaction on salt-type minerals, Part II. Adsorption and electrokinetic studies of apatite in the presence of sodium oleate and sodium metasilicate
- 1990
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Ingår i: International Journal of Mineral Processing. - 0301-7516 .- 1879-3525. ; 28:1, s. 59-79
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Tidskriftsartikel (refereegranskat)abstract
- The mechanism of oleate interaction on apatite is investigated through adsorption and electrokinetic studies. The adsorption density at monolayer coverage corresponds to a condensed state of surfactant molecule with a molecular area of 33 Å2. The isotherm at pH 8 showed the monolayer coverage followed by the precipitation step of calcium oleate, whereas at pH values 9, 10 and 11, the isotherms showed bilayered structure of oleate on the surface before the precipitation step of calcium oleate. The vertical step characterizing calcium oleate precipitation after bilayer formation is found to be dependent on the solid/liquid ratio. The zeta-potentials correlate to the adsorption of oleate up to bilayer formation. The presence of sodium silicate has no influence on the adsorption of oleate.
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