Association of dietary fat intakes with risk of esophageal and gastric cancer in the NIH-AARP diet and health study

The aim of our study was to investigate whether intakes of total fat and fat subtypes were associated with esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC), gastric cardia or gastric noncardia adenocarcinoma. From 1995–1996, dietary intake data was reported by 494,978 participants of the NIH-AARP cohort. The 630 EAC, 215 ESCC, 454 gastric cardia and 501 gastric noncardia adenocarcinomas accrued to the cohort. Cox proportional hazards regression was used to examine the association between the dietary fat intakes, whilst adjusting for potential confounders. Although apparent associations were observed in energy-adjusted models, multivariate adjustment attenuated results to null [e.g., EAC energy adjusted hazard ratio (HR) and 95% confidence interval (95% CI) 1.66 (1.27–2.18) p for trend <0.01; EAC multivariate adjusted HR (95% CI) 1.17 (0.84–1.64) p for trend 5 0.58]. Similar patterns were also observed for fat subtypes [e.g., EAC saturated fat, energy adjusted HR (95% CI) 1.79 (1.37–2.33) p for trend <0.01; EAC saturated fat, multivariate adjusted HR (95% CI) 1.27 (0.91–1.78) p for trend 5 0.28]. However, in multivariate models an inverse association for polyunsaturated fat (continuous) was seen for EAC in subjects with a body mass index (BMI) in the normal range (18.5–<25 kg/m2) [HR (95% CI) 0.76 (0.63–0.92)], that was not present in overweight subjects [HR (95% CI) 1.04 (0.96–1.14)], or in unstratified analysis [HR (95% CI) 0.97 (0.90–1.05)]. p for interaction 5 0.02. Overall, we found null associations between the dietary fat intakes with esophageal or gastric cancer risk; although a protective effect of polyunsaturated fat intake was seen for EAC in subjects with a normal BMI.

Study of fibre distribution and orientations in UHPFRC by electrical resistivity and mechanical tests

This paper presents experimental tests carried out on steel fibre reinforced concrete samples, including mechanical tests as well as non-destructive technique (electrical resistivity) and non destructive technique on cores (X-ray). Electrical resistivity measurements are done as a blind test, to characterise the electrical anisotropy and deduce the distribution and the orientation of fibres. These results are compared to X-ray imaging to check the quality of the non destructive evaluation. Then, flexural and compressive strength are measured on specimens to assess the influence of fibre distribution on the concrete properties.

Assessment of fibre orientation in ultra high performance fibre reinforced concrete and its effect on flexural strength

Fibre distribution and orientation in a series of round panel specimens of ultra high performance fibre reinforced concrete (UHPFRC) was investigated using electrical resistivity measurements and confirmed by X-ray CT imaging. By pouring specimens in different ways, the orientation of steel fibres was influenced and the sensitivity of the electrical resistivity technique was investigated. The round panels were tested in flexure and the results are discussed in relation to the observed orientation of fibres in the panels. It was found that the fibres tended to align perpendicular to the direction of flow. As a result, panels poured from the centre were significantly stronger than panels poured by other methods because the alignment of fibres led to more fibres bridging the radial cracks formed during mechanical testing.

Influence of aggregate and curing regime on the mechanical properties of ultra-high performance fibre reinforced concrete (UHPFRC)

A new generation of concrete, Ultra-high performance fibre reinforced concrete (UHPFRC) has been developed for its outstanding mechanical performance and shows a very promising future in construction applications. In this paper, several possibilities are examined for reducing the price of producing UHPFRC and for bringing UHPFRC away from solely precast applications and onto the construction site as an in situ material. Recycled glass cullet and two types of local natural sand were examined as replacement materials for the more expensive silica sand normally used to produce UHPFRC. In addition, curing of UHPFRC cubes and prisms at 20 degrees C and 90 degrees C has been investigated to determine differences in both mechanical and ductility.

Flexural performance of fibre reinforced concrete made with steel and synthetic fibres

The ductility of concrete made with commercially available steel and synthetic fibres has been investigated. Flexural stress–deflection relationships have been used to determine: flexural strength, flexural toughness, equivalent flexural strength, and equivalent flexural strength ratio. The flexural toughness of concrete was found to increase considerably when steel and synthetic fibres were used. However, equal dosages of different fibres did not result in specimens with the same flexural toughness. Flexural toughness differences of almost 35 J existed even at the same fibre dosage. This also resulted in considerable differences in the minimum required ground supported slab thickness.