57 research outputs found

    A Novel Structural Assessment Technique to Prevent Damaged FRP-Wrapped Concrete Bridge Piers from Collapse

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    Repairing deteriorated concrete bridge piers using externally wrapped fiber reinforced polymer (FRP) composites have been proven as an effective approach. This technique has also been applied to low-rise building structures. Failures in FRP-wrapped concrete structures may occur by flexural failures of critical sections or by debonding of FRP plate from the concrete substrate. Debonding in the FRP/adhesive/concrete interface region may cause a significant decrease in member capacity leading to a premature failure of the system. In this chapter, a novel structural assessment technique aiming at inspecting the near-surface FRP debonding and concrete cracking of damaged FRP-wrapped concrete bridge piers to prevent the structures from collapse is presented. In the first part of this chapter, failure mechanisms of FRP-wrapped concrete systems are briefly discussed. The second part of this chapter introduces a novel structural assessment technique in which far-field airborne radar is applied. In this development, emphasis is placed on inspection of debonding in glass FRP (GFRP)-wrapped concrete cylinders, while the technique is also applicable to beams and slabs with bonded GFRP composites. Physical radar measurements on laboratory specimens with structural damages were conducted and used for validating the technique. Processed experimental measurements have shown promising results for the future application of the technique. Finally, research findings and issues are summarized.National Science Foundation (U.S.) (Grant CMS-0324607)Lincoln Laborator

    Targeting cancer metabolism: a therapeutic window opens

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    Genetic events in cancer activate signalling pathways that alter cell metabolism. Clinical evidence has linked cell metabolism with cancer outcomes. Together, these observations have raised interest in targeting metabolic enzymes for cancer therapy, but they have also raised concerns that these therapies would have unacceptable effects on normal cells. However, some of the first cancer therapies that were developed target the specific metabolic needs of cancer cells and remain effective agents in the clinic today. Research into how changes in cell metabolism promote tumour growth has accelerated in recent years. This has refocused efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy.Burroughs Wellcome FundSmith Family FoundationStarr Cancer ConsortiumDamon Runyon Cancer Research FoundationNational Institutes of Health (U.S.

    Dietary intake and plasma phospholipid concentrations of saturated, monounsaturated and trans fatty acids and colorectal cancer risk in the EPIC cohort

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    Epidemiologic studies examining the association between specific fatty acids and colorectal cancer (CRC) risk are inconclusive. We investigated the association between dietary estimates and plasma levels of individual and total saturated (SFA), monounsaturated (MUFA), industrial‐processed trans (iTFA), and ruminant‐sourced trans (rTFA) fatty acids, and CRC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). Baseline fatty acid intakes were estimated in 450,112 participants (6,162 developed CRC, median follow‐up=15 years). In a nested case‐control study, plasma phospholipid fatty acids were determined by gas chromatography in 433 colon cancer cases and 433 matched controls. Multivariable‐adjusted hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were computed using Cox and conditional logistic regression, respectively. Dietary total SFA (highest vs. lowest quintile, HRQ5vs.Q1=0.80; 95%CI:0.69‐0.92), myristic acid (HRQ5vs.Q1=0.83, 95%CI:0.74‐0.93) and palmitic acid (HRQ5vs.Q1=0.81, 95%CI:0.70‐0.93) were inversely associated with CRC risk. Plasma myristic acid was also inversely associated with colon cancer risk (highest vs. lowest quartile, ORQ4vs.Q1=0.51; 95%CI:0.32‐0.83), whereas a borderline positive association was found for plasma stearic acid (ORQ4vs.Q1=1.63; 95%CI:1.00‐2.64). Dietary total MUFA was inversely associated with colon cancer (per one‐standard deviation increment, HR1‐SD=0.92, 95%CI: 0.85‐0.98), but not rectal cancer (HR1‐SD=1.04, 95%CI:0.95‐1.15, Pheterogeneity=0.027). Dietary iTFA, and particularly elaidic acid, was positively associated with rectal cancer (HR1‐SD =1.07, 95%CI:1.02‐1.13). Our results suggest that total and individual saturated fatty acids and fatty acids of industrial origin may be relevant to the aetiology of CRC. Both dietary and plasma myristic acid levels were inversely associated with colon cancer risk, which warrants further investigation

    Biomarkers for nutrient intake with focus on alternative sampling techniques

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    Association between serum phospholipid fatty acid levels and adiposity among Lebanese adults: a cross-sectional study

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    There have been increases in the incidence of obesity in Lebanon over the past few decades. Fatty acid intake and metabolism have been postulated to influence obesity, but few epidemiological studies have been conducted. The aim of this study was to investigate the correlation between serum fatty acid levels and indicators of obesity in a cross-sectional study nested within a cohort of 501 Lebanese adults residing in Greater Beirut. A total of 395 available serum samples (129 men, 266 women) were profiled for phospholipid fatty acid composition. Spearman correlation coefficients adjusted for relevant confounders and corrected for multiple testing were calculated between serum fatty acids, desaturation indices, and indicators of adiposity (body mass index (BMI) and waist). BMI was significantly positively correlated with saturated fatty acids in men (r = 0.40, p < 0.0001, q < 0.0001) and women (r = 0.33, p < 0.0001, q < 0.0001). BMI was significantly positively correlated with monounsaturated fatty acid palmitoleic acid in women (r = 0.15, p = 0.01, q = 0.03). This study suggests that high blood levels of some saturated fatty acids and the monounsaturated fatty acid palmitoleic acid, likely derived from both dietary intakes of saturated fatty acids and endogenous lipogenesis, may have been associated with adiposity in the Lebanese population. The causality of these associations needs to be explored in experimental settings
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