2,228,819 research outputs found

    Complexation between oleanolic and maslinic acids with native and modified cyclodextrins

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    Oleanolic (OA) and maslinic (MA) acids are two natural triterpenoids with a wide range of beneficial effects for human health. However, their low solubility and permeability make their application in the food or industry difficult. The complexation of OA and MA with alpha- beta-, gamma-, HP-alpha-, HP-beta- and HP-gamma-CDs under different pH and temperature conditions has been studied. Neither alpha- nor HP-alpha-CDs formed inclusion complexes, while beta-, HP-beta- and HP-gamma-CDs provided AL type and gamma-CDs BS phase solubility diagrams. Complexation was shown to be more stable in the case of MA but complexation efficiency was greater for OA. Increasing the pH and temperature of the complexation media tended to improve the complexation process with triterpenic acids.Agencia de Ciencia y Tecnología de la Región de Murcia under the project PFEseneca/06/10Ciencias de la Alimentació

    Further developments in exact state reconstruction in deterministic digital control systems

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    A more general version of the ideal state reconstructor for deterministic digital control systems previously developed is presented. In the original version, measurements prefiltered by a multi-input/multi-output moving-average (MA) process were utilized in the state reconstruction process. In this version, the MA-prefiltered measurements can be supplemented by standard instantaneous measurements. The ideal state reconstructor is so named because: if the plant parameters are known exactly, its output will exactly equal the true state of the plant, not just approximate it. Furthermore, it adds no additional states or eigenvalues to the system. Nor does it affect the plant equation for the system in any way; it affects the measurement equation only. An example is presented which illustrates the procedure for choosing the parameters in it

    Form-function relationships in dragonfly mandibles under an evolutionary perspective

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    © 2017 The Author(s). Functional requirements may constrain phenotypic diversification or foster it. For insect mouthparts, the quantification of the relationship between shape and function in an evolutionary framework remained largely unexplored. Here, the question of a functional influence on phenotypic diversification for dragonfly mandibles is assessed with a large-scale biomechanical analysis covering nearly all anisopteran families, using finite element analysis in combination with geometric morphometrics. A constraining effect of phylogeny could be found for shape, the mandibular mechanical advantage (MA), and certain mechanical joint parameters, while stresses and strains, the majority of joint parameters and size are influenced by shared ancestry. Furthermore, joint mechanics are correlated with neither strain nor mandibular MA and size effects have virtually play no role for shape or mechanical variation. The presence of mandibular strengthening ridges shows no phylogenetic signal except for one ridge peculiar to Libelluloidea, and ridge presence is also not correlated with each other. The results suggest that functional traits are more variable at this taxonomic level and that they are not influenced by shared ancestry. At the same time, the results contradict the widespread idea that mandibular morphology mainly reflects functional demands at least at this taxonomic level. The varying functional factors rather lead to the same mandibular performance as expressed by the MA, which suggests a many-to-one mapping of the investigated parameters onto the same narrow mandibular performance space

    Ground states versus low-temperature equilibria in random field Ising chains

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    We discuss with the aid of random walk arguments and exact numerical computations the magnetization properties of one-dimensional random field chains. The ground state structure is explained in terms of absorbing and non-absorbing random walk excursions. At low temperatures, the magnetization profiles follow those of the ground states except at regions where a local random field fluctuation makes thermal excitations feasible. This follows also from the non-absorbing random walks, and implies that the magnetization length scale is a product of these two scales. It is not simply given by the Imry-Ma-like ground state domain size nor by the scale of the thermal excitations.Comment: 7 pages LaTeX, 8 eps-figures include

    Postharvest Losses of NOR Tomato Fruit Line MA 131-6-3 Treated by Ethephon and Calcium Carbide

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    TEthephon dan kalsium karbida adalah senyawa pematangan buatan yang sering digunakan untuk mempercepat pematangan buah selama pascapanen. Kedua senyawa ini diinduksi pada buah tomat galur non-ripening (NOR) MA 131-6-3 karena menghasilkan etilen endogen dan respirasi yang lebih rendah. Penelitian ini bertujuan untuk mengetahui pengaruh ethephon dan kalsium karbida terhadap kerugian pascapanen tomat NOR selama 14 dan 28 hari setelah perlakuan. Aplikasi eksogen dari 1,500 ppm ethephon dan 15 g kg-1 kalsium karbida diberikan pada buah tomat NOR galur MA 131-6-3 dan kondisi lingkungan pada suhu 28.08±1.80 °C dan kelembaban relatif 75.67±2.09%. Penelitian ini dilaksanakan di Desa Sidoarum, Kecamatan Godean, Kabupaten Sleman, Provinsi Daerah Istimewa Yogyakarta, Indonesia, pada ketinggian 125 m di atas permukaan laut. Hasilnya, ethephon dapat meningkatkan pembusukan buah tomat. Selanjutnya, kalsium karbida dapat mempercepat metabolisme yang berdampak pada susut bobot, mengubah warna menjadi kekuningan (b*), meningkatkan warna cerah (chroma), tetapi warna buah tomat tidak dapat menjadi merah.Kata kunci: kematangan buah, kualitas buah, pascapanen, total asam tertitrasi, total padatan terlarutEthephon and calcium carbide are artificial ripening compounds that are often used to faster fruit ripening during postharvest. These two compounds were induced in non-ripening (NOR) tomato fruit line MA 131-6-3 because it produced endogenous ethylene and lower respiration. This study aimed to determine the effect of ethephon and calcium carbide on postharvest losses of NOR tomatoes for 14 and 28 days after treatment. Exogenous application of 1,500 ppm ethephon and 15 g kg-1 was given to NOR tomato fruit of line MA 131-6-3 and ambient conditions at temperature 28.08±1.80 °C and relative humidity 75.67±2.09%. This experiment was carried out in Sidoarum village, Godean district, Sleman regency, Special Region of Yogyakarta province, Indonesia, in 125 m above sea level. As a result, ethephon can increase fruit rotting. Furthermore, calcium carbide can accelerate metabolism which has an impact on physiological loss in weight, changing color to yellowish (b*), increasing vivid color (chroma), but the color of tomato fruit cannot turn red. Keywords: fruit ripening, fruit quality, postharvest, total soluble solids, total titratable acidit

    Interrelation of work function and surface stability: the case of BaAl4

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    The relationship between the work function (Phi) and the surface stability of compounds is, to our knowledge, unknown, but very important for applications such as organic light-emitting diodes. This relation is studied using first-principles calculations on various surfaces of BaAl4. The most stable surface [Ba terminated (001)] has the lowest Phi (1.95 eV), which is lower than that of any elemental metal including Ba. Adding barium to this surface neither increases its stability nor lowers its work function. BaAl4 is also strongly bound. These results run counter to the common perception that stability and a low Phi are incompatible. Furthermore, a large anisotropy and a stable low-work-function surface are predicted for intermetallic compounds with polar surfaces.Comment: 4 pages, 5 figures, to be published in Chem. Ma

    Beef meat promotion of dimethylhydrazine-induced colorectal carcinogenesis biomarkers is suppressed by dietary calcium

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    Red meat consumption is associated with increased risk of colorectal cancer. We have previously shown that haemin, Hb and red meat promote carcinogen-induced preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF) in rats. We have also shown that dietary calcium, antioxidant mix and olive oil inhibit haemin-induced ACF promotion, and normalize faecal lipoperoxides and cytotoxicity. Here we tested if these strategies are effective also against red meat promotion in dimethylhydrazine-induced rats. Three diets with 60% beef meat were supplemented with calcium phosphate (33 g/kg), antioxidant agents (rutin and butylated hydroxyanisole, 0•05% each) and olive oil (5 %). ACF, MDF, faecal water cytotoxicity, thiobarbituric acid reactive substances (TBARS) and urinary 1,4-dihydroxynonane mercapturic acid (DHN-MA) were measured. Beef meat diet increased the number of ACF (þ30 %) and MDF (þ100 %) (P,0•001), which confirms our previous findings. Promotion was associated with increased faecal water TBARs ( £ 4) and cytotoxicity ( £ 2), and urinary DHN-MA excretion ( £ 15). Calcium fully inhibited beef meat-induced ACF and MDF promotion, and normalized faecal TBARS and cytotoxicity, but did not reduce urinary DHN-MA. Unexpectedly, high-calcium control diet-fed rats had more MDF and ACF in the colon than low-calcium control diet-fed rats. Antioxidant mix and olive oil did not normalize beef meat promotion nor biochemical factors. The results confirm that haem causes promotion of colon carcinogenesis by red meat. They suggest that calcium can reduce colorectal cancer risk in meat-eaters. The results support the concept that toxicity associated with the excess of a useful nutrient may be prevented by another nutrient

    A non-standard CP transformation leading to maximal atmospheric neutrino mixing

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    We discuss a neutrino mass matrix Mν\mathcal{M}_\nu originally found by Babu, Ma, and Valle (BMV) and show that this mass matrix can be characterized by a simple algebraic relation. From this relation it follows that atmospheric neutrino mixing is exactly maximal while at the same time an arbitrary mixing angle θ13\theta_{13} of the lepton mixing matrix UU is allowed and--in the usual phase convention--CP violation in mixing is maximal; moreover, neither the neutrino mass spectrum nor the solar mixing angle are restricted. We put forward a simple seesaw extension of the Standard Model where the family lepton numbers are softly broken by the Majorana mass terms of the right-handed neutrino singlets and the BMV mass matrix results from a non-standard CPCP symmetry.Comment: 13 pages, plain LaTeX, no figures; minor modifications, final version for Phys. Lett.
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