1,207 research outputs found
Direct observation of irradiation-induced nanocavity shrinkage in Si
Nanocavities in Si substrates, formed by conventional H implantation and thermal annealing, are shown to evolve in size during subsequent Si irradiation. Both ex situ and in situ analytical techniques were used to demonstrate that the mean nanocavity diameter decreases as a function of Si irradiation dose in both the crystalline and amorphous phases. Potential mechanisms for this irradiation-induced nanocavity evolution are discussed. In the crystalline phase, the observed decrease in diameter is attributed to the gettering of interstitials. When the matrix surrounding the cavities is amorphized, cavity shrinkage may be mediated by one of two processes: nanocavities can supply vacancies into the amorphous phase and/or the amorphous phase may flow plastically into the nanocavities. Both processes yield the necessary decrease in density of the amorphous phase relative to crystalline material
Structural effect of heavy ion irradiation on GdBaCuO ceramics
The influence of twin boundaries as sinks on defects induced by 480 keV Kr ion irradiation in GdBaCuO crystals was observed in situ at 40 and 300 K. The interaction of the dislocations with the twin boundaries followed on a video recording. A crystalline to amorphous transition was observed above a total fluence of ∼ 4 - 5 x 10^12 Kr/cm2. A comparison between orthorhombic (Os) crystals and a monoclinic structure (Ms) (close to Os and whose parameters were calculated) shows that the behaviour of irradiation-induced extended defects does not depend on a small initial deformation of the orthorhombic cell. In both case, an occasional orthorhombic (or monoclinic) to tetragonal phase transition only occurs when the amorphization process has begun
Preferential amorphization and defect annihilation at nanocavities in silicon during ion irradiation
Si containing a band of nanocavities has been irradiated with Si+ ions at elevated temperatures to study interactions of irradiation-induced defects with open volume defects. For irradiation at 100 degreesC, nanocavities are shown to be preferential nucleation sites for amorphization. It is proposed that this behavior occurs to minimize the local free energy, whereby less dense amorphous Si is free to expand into the cavity open volume. Furthermore, for irradiation at 300 degreesC, cavities are very efficient sinks for Si interstitials during irradiation, leaving a region denuded of interstitial-based clusters surrounding each nanocavity. (C) 2000 American Institute of Physics. [S0003-6951(00)01552-7]
Prediagnostic Serum Vitamin D Levels and the Risk of Crohn’s Disease and Ulcerative Colitis in European Populations: A Nested Case-Control Study
Background: A low vitamin D status has been put forward as a potential risk factor for the development of inflammatory bowel disease (IBD). This study investigated the association between prediagnostic circulating vitamin D concentrations and dietary intakes of vitamin D, and the risk of Crohn’s disease (CD) and ulcerative colitis (UC). Methods: Among 359,728 participants of the European Prospective Investigation into Cancer and Nutrition cohort, individuals who developed CD or UC after enrollment were identified. Each case was matched with2 controls by center, gender, age, date of recruitment, and follow-up time. At cohort entry, blood samples were collected and dietary vitamin D intakes were obtained from validated food frequency questionnaires. Serum 25-hydroxyvitamin D levels were measured using liquid chromatography-tandem mass spectrometry. Conditional logistic regression was performed to determine the odds of CD and UC. Results: Seventy-two participants developed CD and 169 participants developed UC after a median follow-up of 4.7 and 4.1 years, respectively. Compared with the lowest quartile, no associations with the 3 higher quartiles of vitamin D concentrations were observed for CD (p trend = 0.34) or UC (p trend = 0.66). Similarly, no associations were detected when serum vitamin D levels were analyzed as a continuous variable. Dietary vitamin D intakes were not associated with CD (p trend = 0.39) or UC (p trend = 0.83). Conclusions: Vitamin D status was not associated with the development of CD or UC. This does not suggest a major role for vitamin D deficiency in the etiology of IBD, although larger studies are needed to confirm these findings
Co-benefits from sustainable dietary shifts for population and environmental health: an assessment from a large European cohort study
Funding European Commission (DG-SANCO) , the International Agency for Research on Cancer (IARC) , MRC Early Career Fellowship (MR/M501669/1) .Background Unhealthy diets, the rise of non-communicable diseases, and the declining health of the planet are highly
intertwined, where food production and consumption are major drivers of increases in greenhouse gas emissions,
substantial land use, and adverse health such as cancer and mortality. To assess the potential co-benefits from shifting
to more sustainable diets, we aimed to investigate the associations of dietary greenhouse gas emissions and land use
with all-cause and cause-specific mortality and cancer incidence rates.
Methods Using data from 443 991 participants in the European Prospective Investigation into Cancer and Nutrition
(EPIC) study, a multicentre prospective cohort, we estimated associations between dietary contributions to greenhouse
gas emissions and land use and all-cause and cause-specific mortality and incident cancers using Cox proportional
hazards regression models. The main exposures were modelled as quartiles. Co-benefits, encompassing the potential
effects of alternative diets on all-cause mortality and cancer and potential reductions in greenhouse gas emissions and
land use, were estimated with counterfactual attributable fraction intervention models, simulating potential effects of
dietary shifts based on the EAT–Lancet reference diet.
Findings In the pooled analysis, there was an association between levels of dietary greenhouse gas emissions and allcause
mortality (adjusted hazard ratio [HR] 1·13 [95% CI 1·10–1·16]) and between land use and all-cause mortality
(1·18 [1·15–1·21]) when comparing the fourth quartile to the first quartile. Similar associations were observed for
cause-specific mortality. Associations were also observed between all-cause cancer incidence rates and greenhouse
gas emissions, when comparing the fourth quartile to the first quartile (adjusted HR 1·11 [95% CI 1·09–1·14]) and
between all-cause cancer incidence rates and land use (1·13 [1·10–1·15]); however, estimates differed by cancer type.
Through counterfactual attributable fraction modelling of shifts in levels of adherence to the EAT–Lancet diet, we
estimated that up to 19–63% of deaths and up to 10–39% of cancers could be prevented, in a 20-year risk period, by
different levels of adherence to the EAT–Lancet reference diet. Additionally, switching from lower adherence to the
EAT–Lancet reference diet to higher adherence could potentially reduce food-associated greenhouse gas emissions
up to 50% and land use up to 62%.
Interpretation Our results indicate that shifts towards universally sustainable diets could lead to co-benefits, such as
minimising diet-related greenhouse gas emissions and land use, reducing the environmental footprint, aiding in
climate change mitigation, and improving population health.European Commission
European Commission Joint Research CentreWorld Health OrganizationUK Research & Innovation (UKRI)
Medical Research Council UK (MRC) MR/M501669/
Nutrient-wide association study of 57 foods/nutrients and epithelial ovarian cancer in the European Prospective Investigation into Cancer and Nutrition study and the Netherlands Cohort Study
Serum endotoxins and flagellin and risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort
Background: Chronic inflammation and oxidative stress are thought to be involved in colorectal cancer development. These processes may contribute to leakage of bacterial products, such as lipopolysaccharide (LPS) and flagellin, across the gut barrier. The objective of this study, nested within a prospective cohort, was to examine associations between circulating LPS and flagellin serum antibody levels and colorectal cancer risk. Methods: A total of 1,065 incident colorectal cancer cases (colon, n = 667; rectal, n = 398) were matched (1:1) to control subjects. Serum flagellin- and LPS-specific IgA and IgG levels were quantitated by ELISA. Multivariable conditional logistic regression models were used to calculate ORs and 95% confidence intervals (CI), adjusting for multiple relevant confouding factors. Results: Overall, elevated anti-LPS and anti-flagellin biomarker levels were not associated with colorectal cancer risk. After testing potential interactions by various factors relevant for colorectal cancer risk and anti-LPS and anti-flagellin, sex was identified as a statistically significant interaction factor (Pinteraction < 0.05 for all the biomarkers). Analyses stratified by sex showed a statistically significant positive colorectal cancer risk association for men (fully-adjusted OR for highest vs. lowest quartile for total anti-LPS + flagellin, 1.66; 95% CI, 1.10–2.51; Ptrend, 0.049), whereas a borderline statistically significant inverse association was observed for women (fully-adjusted OR, 0.70; 95% CI, 0.47–1.02; Ptrend, 0.18). Conclusion: In this prospective study on European populations, we found bacterial exposure levels to be positively associated to colorectal cancer risk among men, whereas in women, a possible inverse association may exist. Impact: Further studies are warranted to better clarify these preliminary observations
Plasma Elaidic Acid Level as Biomarker of Industrial Trans Fatty Acids and Risk of Weight Change: Report from the EPIC Study
Background Few epidemiological studies have examined the association between dietary trans fatty acids and weight gain, and the evidence remains inconsistent. The main objective of the study was to investigate the prospective association between biomarker of industrial trans fatty acids and change in weight within the large study European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Methods Baseline plasma fatty acid concentrations were determined in a representative EPIC sample from the 23 participating EPIC centers. A total of 1,945 individuals were followed for a median of 4.9 years to monitor weight change. The association between elaidic acid level and percent change of weight was investigated using a multinomial logistic regression model, adjusted by length of follow-up, age, energy, alcohol, smoking status, physical activity, and region. Results In women, doubling elaidic acid was associated with a decreased risk of weight loss (odds ratio (OR) = 0.69, 95% confidence interval (CI) = 0.55-0.88, p = 0.002) and a trend was observed with an increased risk of weight gain during the 5-year follow-up (OR = 1.23, 95% CI = 0.97-1.56, p = 0.082) (p-trend<.0001). In men, a trend was observed for doubling elaidic acid level and risk of weight loss (OR = 0.82, 95% CI = 0.66-1.01, p = 0.062) while no significant association was found with risk of weight gain during the 5-year follow-up (OR = 1.08, 95% CI = 0.88-1.33, p = 0.454). No association was found for saturated and cis-monounsaturated fatty acids. Conclusions These data suggest that a high intake of industrial trans fatty acids may decrease the risk of weight loss, particularly in women. Prevention of obesity should consider limiting the consumption of highly processed foods, the main source of industrially-produced trans fatty acids
Measured adiposity in relation to head and neck cancer risk in the European Prospective Investigation into Cancer and Nutrition
BACKGROUND: Emerging evidence from cohort studies indicates that adiposity is associated with greater incidence of head and neck cancer (HNC). However, most studies have used self-reported anthropometry which is prone to error. METHODS: Among 363 094 participants in the European Prospective Investigation into Cancer and Nutrition study (EPIC) with measured anthropometry, there were 837 incident cases of HNC. HNC risk was examined in relation to body mass index (BMI) [lean: 30 kg/m²], waist circumference (WC), hip circumference (HC) and waist to hip ratio (WHR) using Cox proportional hazards models. RESULTS: Among men, a BMI < 22.5 kg/m² was associated with higher HNC risk [hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.23 - 2.12)]; BMI was not associated with HNC among women. WC and WHR were associated with greater risk of HNC among women, (WC per 5 cm: HR 1.08, 95% CI 1.02 - 1.15; WHR per 0.1 unit: HR 1.64, 95% CI 1.38 - 1.93). After stratification by smoking status, the association for WHR was present only among smokers (p interaction 0.004). Among men, WC and WHR were associated with HNC only upon additional adjustment for BMI (WC per 5 cm: HR 1.16, 95% CI 1.07 - 1.26; WHR per 0.1 unit: HR 1.42, 95% CI 1.21 - 1.65). CONCLUSION: Central adiposity, particularly among women, may have a stronger association with HNC risk than previously estimated. IMPACT: Strategies to reduce obesity may beneficially impact HNC incidence.The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l’Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ), Federal Ministry of Education and Research (BMBF), Deutsche Krebshilfe, Deutsches Krebsforschungszentrum and Federal Ministry of Education and Research (Germany); the Hellenic Health Foundation (Greece); Associazione Italiana per la Ricerca sul Cancro-AIRC-Italy and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC- 2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), PI13/00061 to Granada; , PI13/01162 to EPIC-Murcia), Regional Governments of Andalucía, Asturias, Basque Country, Murcia and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Research Council and County Councils of Skåne and Västerbotten (Sweden); Cancer Research UK (14136 to K.T. Khaw, N.J. Wareham; C570/A16491 to R.C. Travis and C8221/A19170 to Tim Key (EPIC-Oxford), Medical Research Council (1000143 to K.T. Khaw, N.J. Wareham, MR/M012190/1 to Tim Key (EPIC-Oxford)) (United Kingdom)
Measured adiposity in relation to head and neck cancer risk in the European Prospective Investigation into Cancer and Nutrition
BACKGROUND: Emerging evidence from cohort studies indicates that adiposity is associated with greater incidence of head and neck cancer (HNC). However, most studies have used self-reported anthropometry which is prone to error. METHODS: Among 363 094 participants in the European Prospective Investigation into Cancer and Nutrition study (EPIC) with measured anthropometry, there were 837 incident cases of HNC. HNC risk was examined in relation to body mass index (BMI) [lean: 30 kg/m²], waist circumference (WC), hip circumference (HC) and waist to hip ratio (WHR) using Cox proportional hazards models. RESULTS: Among men, a BMI < 22.5 kg/m² was associated with higher HNC risk [hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.23 - 2.12)]; BMI was not associated with HNC among women. WC and WHR were associated with greater risk of HNC among women, (WC per 5 cm: HR 1.08, 95% CI 1.02 - 1.15; WHR per 0.1 unit: HR 1.64, 95% CI 1.38 - 1.93). After stratification by smoking status, the association for WHR was present only among smokers (p interaction 0.004). Among men, WC and WHR were associated with HNC only upon additional adjustment for BMI (WC per 5 cm: HR 1.16, 95% CI 1.07 - 1.26; WHR per 0.1 unit: HR 1.42, 95% CI 1.21 - 1.65). CONCLUSION: Central adiposity, particularly among women, may have a stronger association with HNC risk than previously estimated. IMPACT: Strategies to reduce obesity may beneficially impact HNC incidence.The coordination of EPIC is financially supported by the European Commission (DG-SANCO) and the International Agency for Research on Cancer. The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l’Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ), Federal Ministry of Education and Research (BMBF), Deutsche Krebshilfe, Deutsches Krebsforschungszentrum and Federal Ministry of Education and Research (Germany); the Hellenic Health Foundation (Greece); Associazione Italiana per la Ricerca sul Cancro-AIRC-Italy and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); ERC- 2009-AdG 232997 and Nordforsk, Nordic Centre of Excellence programme on Food, Nutrition and Health (Norway); Health Research Fund (FIS), PI13/00061 to Granada; , PI13/01162 to EPIC-Murcia), Regional Governments of Andalucía, Asturias, Basque Country, Murcia and Navarra, ISCIII RETIC (RD06/0020) (Spain); Swedish Cancer Society, Swedish Research Council and County Councils of Skåne and Västerbotten (Sweden); Cancer Research UK (14136 to K.T. Khaw, N.J. Wareham; C570/A16491 to R.C. Travis and C8221/A19170 to Tim Key (EPIC-Oxford), Medical Research Council (1000143 to K.T. Khaw, N.J. Wareham, MR/M012190/1 to Tim Key (EPIC-Oxford)) (United Kingdom)
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