52 research outputs found

    A singular structure: Monopost made in composites

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    p. 3002-3012This work presents the design process, the analysis, and the performance of a cylindrical hollow monopost, made entirely in composites. It is about a translucent structure of height 40m, external diameter 1.60m and the average wall-thickness 11mm. The material is a polymer made up of vinylster resin and reinforced by glass fiber (GFRP). The manufactured processing used is filament winding. Moreover, due to geographical emplacement where it is situated, the structure has to support wind velocity value above 180Km/h and its elastic modulus of the material does not exceed 25GPa. Eventually, we was able to achieve an optimum solution and strentgh structure, considering and developing differents types of approaches and analysis, such as linear, non-linear and buckling.Rovira, JA.; Martin, P.; Pons, D.; Almerich Chulia, AI. (2009). A singular structure: Monopost made in composites. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/670

    Effects of Ursolic Acid and its Analogues on Soybean 15-Lipoxygenase Activity and the Proliferation Rate of A human Gastric Tumour Cell Line

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    The authors have previously isolated and purified ursolic acid from heather flowers (Calluna vulgarts). This terpene was found to inhibit HL-60 leukaemic cell proliferation and arachidonic acid oxidative metabolism in various cell species. The effects of ursolic acid and its analogues on soybean 15-lipoxygenase activity and on the proliferation of a human gastric tumour cell line (HGT), have been assessed. These triterpenes inhibited soybean 15-lipoxygenase at its optimal activity (pH 9). The proliferation ofHGT was decreased in a dose-dependent manner. At 20 μM the rank order is: ursolic acid > uvaol > oleanolic acid > methyl ursolate. The carboxylic group at the C28 position of ursolic acid appears to be implicated in the inhibition of both lipoxygenase activity and cell proliferation. Thus methylation of this group decreases these two inhibitory properties. Oleanolic acid, which differs by the position of one methyl group (C20 instead of C19) is less inhibitory than ursolic acid. The lipophilicity of the terpene is also implicated since uvaol appears to be more inhibitory than methyl ursolate

    Ibuprofen-loaded calcium phosphate granules : combination of innovative characterization methods to relate mechanical strength to drug location

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    This paper studies the impact of the location of a drug substance on the physicochemical and mechanical properties of two types of calcium phosphate granules loaded with seven different contents of ibuprofen, ranging from 1.75% to 46%. These implantable agglomerates were produced by either low or high shear granulation. Unloaded Mi-Pro pellets presented higher sphericity and mechanical properties, but were slightly less porous than Kenwood granules (57.7% vs 61.2%). Nevertheless, the whole expected quantity of ibuprofen could be integrated into both types of granules. A combination of surface analysis, using near-infrared (NIR) spectroscopy coupling chemical imaging, and pellet porosity, by mercury intrusion measurements, allowed ibuprofen to be located. It was shown that, from 0% to 22% drug content, ibuprofen deposited simultaneously on the granule surface, as evidenced by the increase in surface NIR signal, and inside the pores, as highlighted by the decrease in pore volume. From 22%, porosity was almost filled, and additional drug substance coated the granule surfaces, leading to a large increase in the surface NIR signal. This coating was more regular for Mi-Pro pellets owing to their higher sphericity and greater surface deposition of drug substance. Unit crush tests using a microindenter revealed that ibuprofen loading enhanced the mechanical strength of granules, especially above 22% drug content, which was favorable to further application of the granules as a bone defect filler

    Up for Count? Central Bank Words and Financial Stress

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    While knowing there is a financial distress when you see it might be true, it is not particularly helpful. Indeed, central banks have an interest in understanding more systematically how their communication affects the markets, not least in order to avoid unnecessary volatility; the markets for their part have an interest in better deciphering the message of central banks, especially of course with regard to the conduct of future monetary policy. In this paper we use a novel approach rooted in textual analysis to begin to address these issues. Building on previous work from textual analysis, we are able to use quantitative methods to help identify and measure financial stress. We apply the techniques to the European Central Bank's Monthly Bulletin and show that the results give a much more complete and nuanced picture of market distress than those based only on market data and may help improve how the Central Bank's communication is designed and understood

    Correspondence: Strongly-driven Re + CO2 redox reaction at high-pressure and high-temperature

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    Santamaría-Perez, D.; Mcguire, C.; Makhluf, A.; Kavner, A.; Chulia-Jordan, R.; Jorda Moret, JL.; Rey Garcia, F.... (2016). Correspondence: Strongly-driven Re + CO2 redox reaction at high-pressure and high-temperature. Nature Communications. 7:1-3. doi:10.1038/ncomms13647S137Yoo, C. S. et al. Crystal structure of carbon dioxide at high pressure: “superhard” polymeric carbon dioxide. Phys. Rev. Lett. 83, 5527–5530 (1999).Santoro, M. et al. Partially collapsed cristobalite structure in the non molecular phase V in CO2 . Proc. Natl Acad. Sci. 109, 5176–5179 (2012).Datchi, F., Mallick, B., Salamat, A. & Ninet, S. Structure of polymeric carbon dioxide CO2-V. Phys. Rev. Lett. 108, 125701 (2012).Santoro, M. et al. Silicon carbonate phase formed from carbon dioxide and silica under pressure. Proc. Natl Acad. Sci. 108, 7689–7692 (2011).Santoro, M. et al. Carbon enters silica forming a cristobalite-type CO2.SiO2 solid solution. Nat. Commun. 5, 3761 (2014).Corma, A., Rey, F., Rius, J., Sabater, M. J. & Valencia, S. Supramolecular self-assembled molecules as organic directing agent for synthesis of zeolites. Nature 431, 287–290 (2004).Guth, J.-L., Kessler, H. & Wey, R. in Studies in Surface Science and Catalysis Vol. 28 (eds Murakami, Y., Iijima, A. & Ward, J. W.) 121 (Kodansha-Elsevier, 1986).Santamaria-Perez, D. et al. Exploring the chemical reactivity between carbon dioxide and three transition metals (Au, Pt, and Re) at high-pressure high-temperature conditions. Inorg. Chem. 55, 10793–10799 (2016).Magneli, A. Studies on rhenium oxides. Acta Chem. Scand. 11, 28–33 (1957)

    Production of benzylisoquinoline alkaloids in Saccharomyces cerevisiae

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    The benzylisoquinoline alkaloids (BIAs) are a diverse class of metabolites that exhibit a broad range of pharmacological activities and are synthesized through plant biosynthetic pathways comprised of complex enzyme activities and regulatory strategies. We have engineered yeast to produce the key intermediate reticuline and downstream BIA metabolites from a commercially available substrate. An enzyme tuning strategy was implemented that identified activity differences between variants from different plants and determined optimal expression levels. By synthesizing both stereoisomer forms of reticuline and integrating enzyme activities from three plant sources and humans, we demonstrated the synthesis of metabolites in the sanguinarine/berberine and morphinan branches. We also demonstrated that a human P450 enzyme exhibits a novel activity in the conversion of (R)-reticuline to the morphinan alkaloid salutaridine. Our engineered microbial hosts offer access to a rich group of BIA molecules and associated activities that will be further expanded through synthetic chemistry and biology approaches

    Re-emergence of enterovirus D68 in Europe after easing the COVID-19 lockdown, September 2021

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    We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.Peer Reviewe

    Discovering and Disentangling Effects of US Macro-Announcements in European Stock Markets

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    In this study, we analyze the effect of US macroeconomic announcements on European stock returns, return volatility and bid-ask spreads using intraday data. We find that certain announcements are generally more important to the European stock market than others, and that the direction of news is important for returns. We provide first evidence that a stock-individual analysis is crucial to disentangle overall market reactions from stock-specific impacts and that effects vary dramatically between stocks. The analysis of quoted spreads reveals that return volatility affects the spread size positively, and that spreads are systematic ally higher directly after news releases. This is followed by structurally lower spreads, indicating quickly decreasing asymmetric information in the market after announcements. Additionally, spreads tend to react to announcements even if the returns or the volatility of the underlying stock is not significantly affected. This points at the importance of the analysis of news events beyond return and volatility analyses.In diesem Beitrag analysieren wir die Effekte von makroökonomischen Ankündigungen auf europäische Aktienrenditen, deren Volatilität und deren Geld-Brief Spannen. Unter Verwendung von ultrahochfrequenten Daten zeigt sich, dass bestimmte Ankündigungen generell wichtiger für den Europäischen Aktienmarkt sind als andere, und dass die Richtung der neuen Informationen in den Ankündigungen für die Reaktion von Aktienrenditen wichtig ist. Positive Neuigkeiten führen zu positiven Reaktionen und vice versa. Des Weiteren zeigen wir, dass eine aktienindividuelle Betrachtung entscheidend ist, um Gesamtmarktreaktionen von unternehmensspezifischen Reaktionen auf Ankündigungen zu unterscheiden. Es zeigt sich, dass sich die unternehmensspezifischen Reaktionen zwischen den einzelnen Unternehmen teilweise drastisch unterscheiden. Die Analyse zeigt außerdem, dass Geld-Brief Spannen positiv von der Volatilität der Renditen abhängen, und dass Geld-Brief Spannen direkt nach den Ankündigungen systematisch höher ausfallen. Systematisch niedrigere Geld-Brief Spannen in den Folgeminuten deuten jedoch auf eine rasche Anpassung an die neue Informationslage und schnell abnehmende asymmetrische Information hin. Des Weiteren zeigen unsere Ergebnisse, dass Geld-Brief Spannen auch von Ankündigungen beeinflusst werden, die keinen signifikanten Einfluss auf die Renditen oder die Volatilität der zugrunde liegenden Aktie haben. Dieses Ergebnis unterstreicht die Wichtigkeit der Analyse von Ankündigungen, selbst wenn diese für Renditen oder Volatilitäten unwichtig erscheinen

    Iridoids and Anthraquinones from the Malaysian Medicinal Plant, Saprosma scortechinii (Rubiaceae)

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    A further investigation of the leaves and stems of Saprosma scortechinii afforded 13 compounds, of which 10 are new compounds. These were elucidated as the bis-iridoid glucosides, saprosmosides G (1) and H (2), the iridoid glucoside, 6-O-epi-acetylscandoside (3), and the anthraquinones, 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-β-primeveroside (5), 1,3-dihydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-β-primeveroside (6), 1,3,6-trihydroxy-2-methoxymethyl-9,10-anthraquinone (7), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (8), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-β-primeveroside (9), and 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (10). Structure assignments for all compounds were established by means of mass and NMR spectroscopies, chemical methods, and comparison with published data. The new anthraquinones were derivatives of munjistin and lucidin
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