| 1. |
- Coduri, Mauro, et al.
(författare)
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Local structure and magnetism of Fe2O3 maghemite nanocrystals : The role of crystal dimension
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Here we report on the impact of reducing the crystalline size on the structural and magnetic properties of γ-Fe2O3 maghemite nanoparticles. A set of polycrystalline specimens with crystallite size ranging from ~2 to ~50 nm was obtained combining microwave plasma synthesis and commercial samples. Crystallite size was derived by electron microscopy and synchrotron powder diffraction, which was used also to investigate the crystallographic structure. The local atomic structure was inquired combining pair distribution function (PDF) and X-ray absorption spectroscopy (XAS). PDF revealed that reducing the crystal dimension induces the depletion of the amount of Fe tetrahedral sites. XAS confirmed significant bond distance expansion and a loose Fe-Fe connectivity between octahedral and tetrahedral sites. Molecular dynamics revealed important surface effects, whose implementation in PDF reproduces the first shells of experimental curves. The structural disorder affects the magnetic properties more and more with decreasing the nanoparticle size. In particular, the saturation magnetization reduces, revealing a spin canting effect. Moreover, a large effective magnetic anisotropy is measured at low temperature together with an exchange bias effect, a behavior that we related to the existence of a highly disordered glassy magnetic phase.
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| 2. |
- Linseisen, Jakob, et al.
(författare)
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Red blood cell fatty acids and risk of colorectal cancer in the European Prospective investigation into cancer and nutrition (EPIC)
- 2021
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research (AACR). - 1055-9965 .- 1538-7755. ; 30:5, s. 874-885
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Tidskriftsartikel (refereegranskat)abstract
- Background: A growing body of evidence suggests that alterations of dietary fatty acid (FA) profiles are associated with colorectal cancer risk. However, data from large-scale epidemiologic studies using circulating FA measurements to objectively assess individual FA and FA categories are scarce.Methods: We investigate the association between red blood cell (RBC) membrane FAs and risk of colorectal cancer in a case–control study nested within a large prospective cohort. After a median follow-up of 6.4 years, 1,069 incident colorectal cancer cases were identified and matched to 1,069 controls among participants of the European Prospective Investigation into Cancer and Nutrition (EPIC). The FA composition of RBC phospholipids (in mol%) was analyzed by gas chromatography, and their association with risk of colorectal cancer was estimated by multivariable adjusted conditional logistic regression models.Results: After correction for multiple testing, subjects with higher concentrations of RBC stearic acid were at higher risk for colorectal cancer (OR ¼ 1.23; 95% CI ¼ 1.07–1.42, per 1 mol%). Conversely, colorectal cancer incidence decreased with increasing proportions of RBC n-3 PUFA, particularly eicosapentaenoic acid (0.75; 0.62–0.92, per 1 mol%). The findings for the n-6 PUFA arachidonic acid were inconsistent.Conclusions: The positive association between prediagnostic RBC stearic acid and colorectal cancer reflects putative differences in FA intake and metabolism between cancer cases and matched controls, which deserve further investigation. The inverse relationship between EPA and colorectal cancer is in line with the repeatedly reported protective effect of fish consumption on colorectal cancer risk.Impact: These findings add to the evidence on colorectal cancer prevention.
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| 3. |
- Matta, Michèle, et al.
(författare)
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Dietary intake of trans fatty acids and breast cancer risk in 9 European countries
- 2021
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Ingår i: BMC Medicine. - : Springer Science and Business Media LLC. - 1741-7015. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Trans fatty acids (TFAs) have been hypothesised to influence breast cancer risk. However, relatively few prospective studies have examined this relationship, and well-powered analyses according to hormone receptor-defined molecular subtypes, menopausal status, and body size have rarely been conducted. Methods: In the European Prospective Investigation into Cancer and Nutrition (EPIC), we investigated the associations between dietary intakes of TFAs (industrial trans fatty acids [ITFAs] and ruminant trans fatty acids [RTFAs]) and breast cancer risk among 318,607 women. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusted for other breast cancer risk factors. Results: After a median follow-up of 8.1 years, 13,241 breast cancer cases occurred. In the multivariable-adjusted model, higher total ITFA intake was associated with elevated breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06–1.23; P trend = 0.001). A similar positive association was found between intake of elaidic acid, the predominant ITFA, and breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06–1.23; P trend = 0.001). Intake of total RTFAs was also associated with higher breast cancer risk (HR for highest vs lowest quintile, 1.09, 95% CI 1.01–1.17; P trend = 0.015). For individual RTFAs, we found positive associations with breast cancer risk for dietary intakes of two strongly correlated fatty acids (Spearman correlation r = 0.77), conjugated linoleic acid (HR for highest vs lowest quintile, 1.11, 95% CI 1.03–1.20; P trend = 0.001) and palmitelaidic acid (HR for highest vs lowest quintile, 1.08, 95% CI 1.01–1.16; P trend = 0.028). Similar associations were found for total ITFAs and RTFAs with breast cancer risk according to menopausal status, body mass index, and breast cancer subtypes. Conclusions: These results support the hypothesis that higher dietary intakes of ITFAs, in particular elaidic acid, are associated with elevated breast cancer risk. Due to the high correlation between conjugated linoleic acid and palmitelaidic acid, we were unable to disentangle the positive associations found for these fatty acids with breast cancer risk. Further mechanistic studies are needed to identify biological pathways that may underlie these associations.
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| 4. |
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| 5. |
- Papadimitriou, Nikos, et al.
(författare)
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A Prospective Diet-Wide Association Study for Risk of Colorectal Cancer in EPIC
- 2022
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Ingår i: Clinical Gastroenterology and Hepatology. - : Saunders Elsevier. - 1542-3565 .- 1542-7714. ; 20:4, s. 864-873.e13
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Evidence regarding the association of dietary exposures with colorectal cancer (CRC) risk is not consistent with a few exceptions. Therefore, we conducted a diet-wide association study (DWAS) in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate the associations between several dietary exposures with CRC risk.Methods: The association of 92 food and nutrient intakes with CRC risk was assessed in 386,792 participants, 5069 of whom developed incident CRC. Correction for multiple comparisons was performed using the false discovery rate, and emerging associations were examined in the Netherlands Cohort Study (NLCS). Multiplicative gene-nutrient interactions were also tested in EPIC based on known CRC-associated loci.Results: In EPIC, alcohol, liquor/spirits, wine, beer/cider, soft drinks, and pork were positively associated with CRC, whereas milk, cheese, calcium, phosphorus, magnesium, potassium, riboflavin, vitamin B6, beta carotene, fruit, fiber, nonwhite bread, banana, and total protein intakes were inversely associated. Of these 20 associations, 13 were replicated in the NLCS, for which a meta-analysis was performed, namely alcohol (summary hazard ratio [HR] per 1-SD increment in intake: 1.07; 95% confidence interval [CI], 1.04–1.09), liquor/spirits (HR per 1-SD increment in intake, 1.04; 95% CI, 1.02–1.06), wine (HR per 1-SD increment in intake, 1.04; 95% CI, 1.02–1.07), beer/cider (HR per 1-SD increment in intake, 1.06; 95% CI, 1.04–1.08), milk (HR per 1-SD increment in intake, 0.95; 95% CI, 0.93–0.98), cheese (HR per 1-SD increment in intake, 0.96; 95% CI, 0.94–0.99), calcium (HR per 1-SD increment in intake, 0.93; 95% CI, 0.90–0.95), phosphorus (HR per 1-SD increment in intake, 0.92; 95% CI, 0.90–0.95), magnesium (HR per 1-SD increment in intake, 0.95; 95% CI, 0.92–0.98), potassium (HR per 1-SD increment in intake, 0.96; 95% CI, 0.94–0.99), riboflavin (HR per 1-SD increment in intake, 0.94; 95% CI, 0.92–0.97), beta carotene (HR per 1-SD increment in intake, 0.96; 95% CI, 0.93–0.98), and total protein (HR per 1-SD increment in intake, 0.94; 95% CI, 0.92–0.97). None of the gene-nutrient interactions were significant after adjustment for multiple comparisons.Conclusions: Our findings confirm a positive association for alcohol and an inverse association for dairy products and calcium with CRC risk, and also suggest a lower risk at higher dietary intakes of phosphorus, magnesium, potassium, riboflavin, beta carotene, and total protein.
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| 6. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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