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1.
Fiber Bragg grating (FBG)-based acoustic emission (AE) detection and monitoring is considered as a potential and emerging technology for structural health monitoring (SHM) applications. In this paper, an overview of the FBG-based AE monitoring system is presented, and various technologies and methods used for FBG AE interrogation systems are reviewed and discussed. Various commercial FBG AE sensing systems, SHM applications of FBG AE monitoring, and market potential and recent trends are also discussed. 相似文献
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Since pre‐historic times, humans have consumed grains as part of their diet. Being rich in carbohydrates, grains typically form a key part of all food‐based dietary guidelines, with wholegrains recommended as healthy dietary choices. However, grains are also exposed to contaminants from air, soil, water, insects, animals, microbes, humans, storage and shipping containers, and handling and processing equipment and can be one of the main dietary sources of food‐borne contaminants by virtue of their frequent consumption. Recent scientific reports positively highlight wholegrains as foods with inherent health properties, which, because they provide fibre and micronutrients such as B vitamins and zinc, can improve the quality of carbohydrate intake as part of sustainable, healthy diets. This article describes potential health‐protective properties inherent to wholegrains and contends that the presence of contaminants in wholegrains, including mycotoxins, heavy metals and acrylamide, merits continued monitoring but that any such risk does not outweigh the known benefits of wholegrain consumption. 相似文献
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Prebiotics are food components that are selectively used by gut bacteria, conferring a health benefit, most notably stimulating the growth of bifidobacteria. Accepted prebiotics at present are the fibre types galacto‐oligosaccharides, fructo‐oligosaccharides and inulin, some forms of which occur naturally in foods such as pulses, grains, fruit and vegetables. Prebiotics can also be isolated and produced commercially for use as functional ingredients and supplements. The aim of this paper is to provide an overview of the place of prebiotics in a healthy, balanced diet, to explore potential health effects, particularly in relation to gut health, and to consider whether there are implications of consuming a diet low in prebiotics. Dietary fibre is important for health, with high‐fibre diets reducing risk of several chronic diseases, via its effects on bowel function, gut microbiota, and cholesterol and glycaemic levels. The prebiotic effects of some fibre types may contribute to these effects. Evidence from supplementation studies carried out in humans suggests that consumption of prebiotics may confer an array of health benefits such as cholesterol lowering, relief of symptoms of gastrointestinal disorders, increased satiety and immunomodulatory effects, though more studies are needed. Findings from observational and intervention studies indicate that exclusion diets, such as low‐carbohydrate, gluten‐free and the low Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols diet, result in changes to the gut microbiota such as reduced abundance of Bifidobacterium and Lactobacillus species, though whether or not there are any long‐term health implications remains unknown. Studies investigating whether prebiotic supplements may be useful in conjunction with such diets (when these are required for medical reasons) to help restore levels of bacteria that are considered to be beneficial, are warranted. Overall, there is a need to promote high‐fibre foods across the UK population as intakes currently fall well below recommendations. 相似文献
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Aleksandra M. Mech Anna-Leigh Brown Giampietro Schiavo James N. Sleigh 《Journal of anatomy》2020,237(4):603-617
The neuromuscular junction (NMJ) is the highly specialised peripheral synapse formed between lower motor neuron terminals and muscle fibres. Post-synaptic acetylcholine receptors (AChRs), which are found in high density in the muscle membrane, bind to acetylcholine released into the synaptic cleft of the NMJ, thereby enabling the conversion of motor action potentials to muscle contractions. NMJs have been studied for many years as a general model for synapse formation, development and function, and are known to be early sites of pathological changes in many neuromuscular diseases. However, information is limited on the diversity of NMJs in different muscles, how synaptic morphology changes during development, and the relevance of these parameters to neuropathology. Here, this crucial gap was addressed using a robust and standardised semi-automated workflow called NMJ-morph to quantify features of pre- and post-synaptic NMJ architecture in an unbiased manner. Five wholemount muscles from wild-type mice were dissected and compared at immature (post-natal day, P7) and early adult (P31−32) timepoints. The inter-muscular variability was greater in mature post-synaptic AChR morphology than that of the pre-synaptic motor neuron terminal. Moreover, the developing NMJ showed greater differences across muscles than the mature synapse, perhaps due to the observed distinctions in synaptic growth between muscles. Nevertheless, the amount of nerve to muscle contact was consistent, suggesting that pathological denervation can be reliably compared across different muscles in mouse models of neurodegeneration. Additionally, mature post-synaptic endplate diameters correlated with fibre type, independently of muscle fibre diameter. Altogether, this work provides detailed information on healthy pre- and post-synaptic NMJ morphology from five anatomically and functionally distinct mouse muscles, delivering useful reference data for future comparison with neuromuscular disease models. 相似文献
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Damien P. Belobrajdic Shingo Hino Takashi Kondo Stephen A. Jobling Matthew K. Morell David L. Topping 《International journal of food sciences and nutrition》2016,67(6):678-685
Using barley cultivars differing widely in β-glucan content, we aimed to determine their effects on small intestinal macronutrient digestion in 24 ileorectostomised rats. The rats were fed 1 of 4 experimental diets, each containing a different barley variety, for 11 d. The diets had a content of 0, 2.1, 2.6 and 4.3?g of β-glucan/100?g. Feed intake and faecal excretion of fat, protein, starch, and non-starch polysaccharides were determined in the final 5 d of the study and apparent macronutrient digestibility calculated. Higher dietary levels of β-glucan (2.6% and 4.3%) lowered feed intake (by 15 and 19%, respectively) but final body weight was only lowered by the 4.3% β-glucan diet relative to rats fed the 0% β-glucan diet (all ps?0.05). Protein, lipid and starch digestibility was unrelated to the dietary β-glucan content. Higher dietary levels of barley β-glucan lower feed intake of ileorectostomised rats, which is independent of intestinal fermentation and unrelated to macronutrient digestibility. 相似文献
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Peter Agger Thomas Lass Morten Smerup Jesper Frandsen Michael Pedersen 《Journal of anatomy》2015,227(5):695-701
The effects of ex vivo preservation techniques on the quality of diffusion tensor magnetic resonance imaging in hearts are poorly understood, and the optimal handling procedure prior to investigation remains to be determined. Therefore, 24 porcine hearts were examined in six groups treated with different preservation techniques, including chemical fixation and freezing. Diffusion properties of each heart were assessed with diffusion tensor imaging in terms of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da) and radial diffusivity (Dr). Tractography was performed to visualize the course of the cardiomyocytes, assuming greater diffusivity in the longitudinal than the transverse axis of individual cardiomyocytes. Significant differences in MD, Da and Dr were found, as well as in FA between groups (P < 0.001). Freezing of specimens resulted in the lowest mean FA of 0.21 (0.06) and highest Dr of 8.92 (1.5) mm2 s−1. The highest mean FA was found to be 0.43 (0.11) in hearts perfusion-fixed with formalin. Calculated tractographies were indistinguishable among groups except in frozen specimens, where no fibres could be tracked. Perfusion fixation with formalin provided the best tractography, but immersion fixation yielded diffusion data most similar to fresh hearts. These findings suggest that parameters derived from diffusion tensor imaging in ex vivo hearts are sensitive to fixation and storage methods. In particular, freezing of specimens should be avoided prior to diffusion tensor imaging investigation due to significant changes in diffusion parameters and subsequent image deteriorations. 相似文献