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- Nitter, M., et al.
(författare)
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Plasma methionine, choline, betaine, and dimethylglycine in relation to colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2014
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 25:8, s. 1609-1615
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Tidskriftsartikel (refereegranskat)abstract
- Background: Disturbances in one carbon metabolism may contribute to carcinogenesis by affecting methylation and synthesis of DNA. Choline and its oxidation product betaine are involved in this metabolism and can serve as alternative methyl group donors when folate status is low. Patients and methods: We conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), to investigate plasma concentrations of the methyl donors methionine, choline, betaine (trimethylglycine), and dimethylglycine (DMG) in relation to colorectal cancer (CRC) risk. Our study included 1367 incident CRC cases (965 colon and 402 rectum) and 2323 controls matched by gender, age group, and study center. Multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for CRC risk were estimated by conditional logistic regression, comparing the fifth to the first quintile of plasma concentrations. Results: Overall, methionine (OR: 0.79, 95% CI: 0.63-0.99, P-trend = 0.05), choline (OR: 0.77, 95% CI: 0.60-0.99, P-trend = 0.07), and betaine (OR: 0.85, 95% CI: 0.66-1.09, P-trend = 0.06) concentrations were inversely associated with CRC risk of borderline significance. In participants with folate concentration below the median of 11.3 nmol/l, high betaine concentration was associated with reduced CRC risk (OR: 0.71, 95% CI: 0.50-1.00, P-trend = 0.02), which was not observed for those having a higher folate status. Among women, but not men, high choline concentration was associated with decreased CRC risk (OR: 0.62, 95% CI: 0.43-0.88, P-trend = 0.01). Plasma DMG was not associated with CRC risk. Conclusions: Individuals with high plasma concentrations of methionine, choline, and betaine may be at reduced risk of CRC.
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| 2. |
- Vihma, T., et al.
(författare)
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Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system : a review
- 2014
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 14:17, s. 9403-9450
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Forskningsöversikt (refereegranskat)abstract
- The Arctic climate system includes numerous highly interactive small-scale physical processes in the atmosphere, sea ice, and ocean. During and since the International Polar Year 2007-2009, significant advances have been made in understanding these processes. Here, these recent advances are reviewed, synthesized, and discussed. In atmospheric physics, the primary advances have been in cloud physics, radiative transfer, mesoscale cyclones, coastal, and fjordic processes as well as in boundary layer processes and surface fluxes. In sea ice and its snow cover, advances have been made in understanding of the surface albedo and its relationships with snow properties, the internal structure of sea ice, the heat and salt transfer in ice, the formation of superimposed ice and snow ice, and the small-scale dynamics of sea ice. For the ocean, significant advances have been related to exchange processes at the ice-ocean interface, diapycnal mixing, double-diffusive convection, tidal currents and diurnal resonance. Despite this recent progress, some of these small-scale physical processes are still not sufficiently understood: these include wave-turbulence interactions in the atmosphere and ocean, the exchange of heat and salt at the ice-ocean interface, and the mechanical weakening of sea ice. Many other processes are reasonably well understood as stand-alone processes but the challenge is to understand their interactions with and impacts and feedbacks on other processes. Uncertainty in the parameterization of small-scale processes continues to be among the greatest challenges facing climate modelling, particularly in high latitudes. Further improvements in parameterization require new year-round field campaigns on the Arctic sea ice, closely combined with satellite remote sensing studies and numerical model experiments.
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