821 research outputs found

    Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

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    Conjugated porous polymers for heterogeneous visible light photocatalysis

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    Rapid protium-deuterium exchange of 4-aminopyridines in neutral D2O under microwave irradiation

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    4-Aminopyridines undergo surprisingly rapid and highly-selective H/D exchange at C-2 and C-6 in neutral D2O upon microwave irradiation at only 190 °C for 2 h in a sealed vessel. This method contrasts and complements acid-mediated H/D exchange, requires no catalyst and is appropriate for the synthesis of deuterium isotop-ologues of N- and C-substituted 4-aminopyridines and a ben-zofused (quinoline) analogue

    Microwave-assisted Bohlmann–Rahtz synthesis of highly-substituted 2-aminonicotinates

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    Microwave irradiation of 2-carbethoxyacetamidine and an ethynyl ketone under acidic or basic conditions in ethanol at 150 °C for 1.5 h facilitated Bohlmann-Rahtz pyridine synthesis to give highly-substituted ethyl 2 aminonicotinates with total regiocontrol and in reasonable to excellent yield, following purification by immobiliza tion upon an acidic resin

    Multi-Estimator Full Left Ventricle Quantification through Ensemble Learning

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    Cardiovascular disease accounts for 1 in every 4 deaths in United States. Accurate estimation of structural and functional cardiac parameters is crucial for both diagnosis and disease management. In this work, we develop an ensemble learning framework for more accurate and robust left ventricle (LV) quantification. The framework combines two 1st-level modules: direct estimation module and a segmentation module. The direct estimation module utilizes Convolutional Neural Network (CNN) to achieve end-to-end quantification. The CNN is trained by taking 2D cardiac images as input and cardiac parameters as output. The segmentation module utilizes a U-Net architecture for obtaining pixel-wise prediction of the epicardium and endocardium of LV from the background. The binary U-Net output is then analyzed by a separate CNN for estimating the cardiac parameters. We then employ linear regression between the 1st-level predictor and ground truth to learn a 2nd-level predictor that ensembles the results from 1st-level modules for the final estimation. Preliminary results by testing the proposed framework on the LVQuan18 dataset show superior performance of the ensemble learning model over the two base modules.Comment: Jiasha Liu, Xiang Li and Hui Ren contribute equally to this wor

    Genetic variation of durum wheat landraces using morphological and protein markers

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    Genetic variations of cultivars are very interesting in reducing genetic vulnerability and lead to stable control of production. The aim of this research was to study genetic diversity among six durum wheat cultivars. For the first assay we evaluated seven morphological traits which are: spikelet per spike, spike length, spike width, beard length, plant height, width of truncation and barb length. The tested genotypes were classified in three groups according to the linkage distance analysis. The genetic variability was also evaluated for seed storage-proteins by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE). Electrophoregram allowed the estimation of the durum wheat genetic similarity (GS). This GS analysis based on Unweighted Pair Group Method with Arithmetic averages (UPGMA), permits to obtain the same genotypic clustering. No significant correlation was observed among the two methods tested. It is concluded that seed storage protein profiles could be useful markers in the studies of genetic diversity and genotypes classification, which can be used to improve the efficiency of wheat breeding programs.Key words: Wheat genotypes, SDS-PAGE, genetic diversity, cluster analysis

    Effect of temperature, oxygen and light on the degradation of β-carotene, lutein and α-tocopherol in spray-dried spinach juice powder during storage

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    © 2019 The aim of this study was to evaluate the interaction between packaging parameters (transmission of light and oxygen) and storage temperatures (4, 20, 40 °C) on nutrient retention of Spinach (Spinacia oleracea) juice, spray-dried in the absence of an added encapsulant. β-Carotene was more susceptible to degradation compared with lutein and α-tocopherol. Under our experimental conditions, it was observed that excluding low fluorescent light intensity and air by vacuum packaging at 20 °C did not seem to improve nutrient retention loss over time (p > 0.05). The rate of β-carotene, lutein and α-tocopherol loss displayed first order reaction kinetic with low activation energy of 0.665, 2.650 and 13.893 kJ/mol for vacuum, and 1.089, 4.923 and 14.142 kJ/mol for non-vacuum, respectively. The reaction kinetics and half-life for β-carotene, lutein and α-tocopherol at 4 °C and non-vacuumed were 2.2 × 10 −2 , 1.2 × 10 −2 , and 0.8 × 10 −2 day −1 , and 32.08, 58.25 and 85.37 day, respectively

    Policy, toxicology and physicochemical considerations on the inhalation of high concentrations of food flavour

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    Food flavour ingredients are required by law to obtain prior approval from regulatory bodies, such as the U.S. Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA) in terms of toxicological data and intended use levels. However, there are no regulations for labelling the type and concentration of flavour additives on the product, primarily due to their low concentration in food and generally recognised as safe (GRAS) status determined by the flavour and extract manufacturers’ association (FEMA). Their status for use in e-cigarettes and other vaping products challenges these fundamental assumptions, because their concentration can be over ten-thousand times higher than in food, and the method of administration is through inhalation, which is currently not evaluated by the FEMA expert panel. This work provides a review of some common flavour ingredients used in food and vaping products, their product concentrations, inhalation toxicity and aroma interactions reported with different biological substrates. We have identified several studies, which suggest that the high concentrations of flavour through inhalation may pose a serious health threat, especially in terms of their cytotoxicity. As a result of the wide range of possible protein-aroma interactions reported in our diet and metabolism, including links to several non-communicable diseases, we suggest that it is instrumental to update current flavour- labelling regulations, and support new strategies of understanding the effects of flavour uptake on the digestive and respiratory systems, in order to prevent the onset of future non-communicable diseases. © 2020, The Author(s)

    The ART of performance: engaging young people with assisted reproductive technologies

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    More children than ever before are conceived with the use of assisted reproductive technologies and many are raised in families that are structurally different from most. Research on the experiences of children growing up in diverse families has shown that children may face disapproval, a lack of understanding, and in some cases, bullying by those outside of their home environment, including from their peers at school This study evaluated the use of theatrical performance and post-performance discussions as a method of informing young people about different families. Findings indicated that performance was an effective and engaging learning tool, as it presented first-hand experiences of family diversity. Post-performance discussions were important in enabling young people to improve their understanding of different methods of Assisted Reproductive Technologies and diverse family forms. Young people were found to value engagement activities that are unbiased, interactive, and do not make them feel awkward or uncomfortable
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