690 research outputs found

    The polyphenolic and hydroxycinnamate contents of whole coffee fruits from China, India and Mexico

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    Air dried whole coffee fruits, beans and husks from China, India and Mexico were analysed for their chlorogenic acids (CGA), caffeine, and polyphenolic content. Analysis was by HPLC and Orbitrap exact mass spectrometry. Total phenol, total flavonol and antioxidant capacity were measured. The hydroxycinnamate profile consisted of caffeoylquinic acids, feruloyquinic acids, dicaffeoylquinic acids and caffeoyl-feruloylquinic acids. A range of flavan-3-ols as well as flavonol conjugates were detected. The CGA content was similar for both Mexico and India coffee fruits but was much lower in China samples. Highest levels of flavan-3-ols were found in the Indian samples whereas Mexico samples contained the highest flavonols. Amounts of CGAs in the beans were similar to those in the whole fruits, but flavan-3-ols and flavonols were not detected. The husks contained the same range of polyphenols as in the whole fruits. Highest levels of caffeine were found in the Robusta samples

    Systems evaluation of thermal bus concepts

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    Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations

    The effect of the transport property models on the shuttle boundary layer

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    Theoretical solutions for the nonsimilar, laminar boundary-layer were computed for four points along the shuttle entry trajectory. Since the boundary layer is that region of the flow field where the effects of viscosity and of thermal conductivity are most important, numerical solutions for the boundary layer were generated using different models for the transport properties. These solutions indicate that the displacement thickness and the heat-transfer rates are very sensitive to changes in the models for thermal conductivity and for specific heat. Thus, the solutions are sensitive to the assumed transport-property model

    Espresso coffees, caffeine and chlorogenic acid intake: potential health implications

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    HPLC analysis of 20 commercial espresso coffees revealed 6-fold differences in caffeine levels, a 17-fold range of caffeoylquinic acid contents, and 4-fold differences in the caffeoylquinic acid:caffeine ratio. These variations reflect differences in batch-to-batch bean composition, possible blending of arabica with robusta beans, as well as roasting and grinding procedures, but the predominant factor is likely to be the amount of beans used in the coffee-making/barista processes. The most caffeine in a single espresso was 322 mg and a further three contained >200 mg, exceeding the 200 mg day−1 upper limit recommended during pregnancy by the UK Food Standards Agency. This snap-shot of high-street expresso coffees suggests the published assumption that a cup of strong coffee contains 50 mg caffeine may be misleading. Consumers at risk of toxicity, including pregnant women, children and those with liver disease, may unknowingly ingest excessive caffeine from a single cup of espresso coffee. As many coffee houses prepare larger volume coffees, such as Latte and Cappuccino, by dilution of a single or double shot of expresso, further study on these products is warranted. New data are needed to provide informative labelling, with attention to bean variety, preparation, and barista methods

    Developments in convective heat transfer models featuring seamless and selected detail surfaces, employing electroless plating

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    Several model/instrument concepts employing electroless metallic skin were considered for improvement of surface condition, accuracy, and cost of contoured-geometry convective heat transfer models. A plated semi-infinite slab approach was chosen for development and evaluation in a hypersonic wind tunnel. The plated slab model consists of an epoxy casting containing fine constantan wires accurately placed at specified surface locations. An electroless alloy was deposited on the plastic surface that provides a hard, uniformly thick, seamless skin. The chosen alloy forms a high-output thermocouple junction with each exposed constantan wire, providing means of determining heat transfer during tunnel testing of the model. A selective electroless plating procedure was used to deposit scaled heatshield tiles on the lower surface of a 0.0175-scale shuttle orbiter model. Twenty-five percent of the tiles were randomly selected and plated to a height of 0.001-inch. The purpose was to assess the heating effects of surface roughness simulating misalignment of tiles that may occur during manufacture of the spacecraft

    Acute kidney injury prediction in cardiac surgery patients by a urinary peptide pattern: a case-control validation study

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    Background Acute kidney injury (AKI) is a prominent problem in hospitalized patients and associated with increased morbidity and mortality. Clinical medicine is currently hampered by the lack of accurate and early biomarkers for diagnosis of AKI and the evaluation of the severity of the disease. In 2010, we established a multivariate peptide marker pattern consisting of 20 naturally occurring urinary peptides to screen patients for early signs of renal failure. The current study now aims to evaluate if, in a different study population and potentially various AKI causes, AKI can be detected early and accurately by proteome analysis. Methods Urine samples from 60 patients who developed AKI after cardiac surgery were analyzed by capillary electrophoresis-mass spectrometry (CE-MS). The obtained peptide profiles were screened by the AKI peptide marker panel for early signs of AKI. Accuracy of the proteomic model in this patient collective was compared to that based on urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) ELISA levels. Sixty patients who did not develop AKI served as negative controls. Results From the 120 patients, 110 were successfully analyzed by CE-MS (59 with AKI, 51 controls). Application of the AKI panel demonstrated an AUC in receiver operating characteristics (ROC) analysis of 0.81 (95 % confidence interval: 0.72–0.88). Compared to the proteomic model, ROC analysis revealed poorer classification accuracy of NGAL and KIM-1 with the respective AUC values being outside the statistical significant range (0.63 for NGAL and 0.57 for KIM-1)

    Multi-attribute Selection of the Life Insurance Product

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    Cílem bakalářské práce je pomocí metod vícekriteriálního hodnocení variant nalézt nejlepší pojistný produkt životního pojištění pro konkrétní subjekt. Práce je rozdělena do pěti kapitol včetně úvodu a závěru. Druhá kapitola je věnována popisu metod vícekriteriálního rozhodování současně s popisem struktury a prvků rozhodovacího procesu. Obsahem třetí kapitoly je charakteristika životní pojištění a jeho členění. Čtvrtá a poslední kapitola je zaměřena na praktickou část, kde je proveden výběr variant dle výše předepsaného smluvního pojistného a určena kritéria pro výběr nejlepšího produktu. Závěr bakalářské práce uvádí nejlepší variantu rizikového životního pojištění pro konkrétní subjekt.The aim of the bachelor's thesis is to find the best life insurance product for a specific subject using methods of multi-criteria evaluation of variants. The work is divided into five chapters, including an introduction and a conclusion. The second chapter is devoted to the description of multi-criteria decision-making methods, along with the description of the structure and elements of the decision-making process. The content of the third chapter is the characteristics of life insurance and its breakdown. The fourth and last chapter is focused on the practical part, where the selection of variants is carried out according to the above prescribed contractual insurance premium and the criteria for choosing the best product are determined. The conclusion of the bachelor's thesis presents the best variant of risk life insurance for a specific entity.154 - Katedra financívýborn

    Effective activation of antioxidant system by immune-relevant factors reversely correlates with apoptosis of Eisenia andrei coelomocytes

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    Oxidative stress is harmful to the microbes but also to the host, and may result in bystander damage or death. Because of this, respiratory burst triggered in phagocytes by pathogens is counteracted by production of antioxidative factors. The aim of this work was to examine effectiveness of the latter system in earthworms Eisenia andrei by induction of reactive oxygen species, lipofuscin and phenoloxidase by natural (LPS, zymosan, Micrococus luteus) and synthetic (phorbol ester, PMA) stimulants. The compounds impaired numbers, viability (increased apoptosis) and composition of coelomocytes, and triggered the antioxidant activity of catalase and selenium-dependent glutathione peroxidase. The natural pathogenic compounds, unlike PMA, strongly activated antioxidative responses that diminished cell apoptosis. Moreover, repeated exposure to the same or different pathogenic compounds did not induce respiratory burst exhausted phenotype showing that coelomocytes are constantly at bay to withstand numerous infections. The current study reveals importance and efficiency of the oxidative–antioxidative systems in annelids but also confirms its evolutionary conservatism and complexity even in lower taxa of the animal kingdom

    New methods of information distribution on the internet : metadata and their standardization

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