787 research outputs found

    Estudios detallados de algunos lípidos en aceite de semilla de Silybum marianum L.

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    Eight lipid patterns of Silybum marianum (L.) Gaertn seed oil, not hitherto reported, (20%) have been elucidated in this laboratory using capillary GLC and HPLC as main tools of analysis. The oil is rich in linoleic acid (53.3%) and oleic acid (21.3%). Five major triacylglycerols containing linoleic acyls namely LLL, LLO, LLP, LOO and LOP were detected by HPLC using FID detector, these triacylglycerols are also predominating in both cottonseed and sunflower oils but in different proportions. The total tocopherols content (260 ppm) was determined directly in the oil by HPLC. It was found that the oil contains alpha -tocopherol as a major constituent (84.5%) resembling sunflower oil. The whole sterols pattern, as determined as their trimethylsilyl derivatives by GLC, includes campesterol, 5-stigmasterol, beta-sitosterol, 7-stigmasterol, avenasterol and spinasterol. The four sterols lipid clases of free and acylated sterols and sterylglycosides have been determined as their 9- and 1- anthroylnitrile derivatives by fluorescence and UV- HPLC respectively.La composición de ocho tipos de lípidos en aceite de semillas de Silybum marianum (L.) Gaertn, hasta ahora no reportados, han sido identificados en este laboratorio, usando GLC capilar y HPLC como herramientas principales de análisis. El aceite es rico en ácidos linoleico (53,3%) y oleico (21,3%). El ácido linoleico está contenido principalmente en cinco formas de triacilgliceroles: LLL, LLO, LLP, LOO y LOP, detectadas por HPLC, usando un detector FID, estos triacilgliceroles son también predominantes en los aceites de semillas de algodón o girasol, pero con diferentes proporciones. El contenido total de tocoferoles (260 ppm) fue determinado directamente en el aceite por HPLC. Se encontró que el aceite contenía alfa-tocoferol como principal constituyente (84,5%), recordando al aceite de girasol. El patrón completo de esteroles determinado por GLC como derivados de trimetilsilil incluyó campesterol, 5-estigmasterol, beta-sitosterol, 7-estigmasterol, avenasterol y spinasterol. Las cuatro clases de esteroles lipídicos, de libres y acilados esteroles y esterilglicósidos han sido determinados como sus derivados de 9- y 1- antroilnitrilo respectivamente por fluorescencia y UV- HPLC

    Parameterized lower bound and NP-completeness of some HH-free Edge Deletion problems

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    For a graph HH, the HH-free Edge Deletion problem asks whether there exist at most kk edges whose deletion from the input graph GG results in a graph without any induced copy of HH. We prove that HH-free Edge Deletion is NP-complete if HH is a graph with at least two edges and HH has a component with maximum number of vertices which is a tree or a regular graph. Furthermore, we obtain that these NP-complete problems cannot be solved in parameterized subexponential time, i.e., in time 2o(k)GO(1)2^{o(k)}\cdot |G|^{O(1)}, unless Exponential Time Hypothesis fails.Comment: 15 pages, COCOA 15 accepted pape

    Glucuronidase Gene: A Strong Evidence of a Novel Interaction of Glucuronidase-labeled Gluconacetobacter diazotrophicus with Spinach, Spinacia oleracea L. Seedlings

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    Gluconacetobacter diazotrophicus lives inside plant tissue cells in the form of colonies and excretes about half of the fixed nitrogen, which offers potential power that improves plant growth. The aim of this study is to find the interaction of glucuronidase (GUS)-labeled G. diazotrophicus with spinach seedlings and the detection of GUS genes using X-gluc dye (5-bromo-4-chloro-3-indolyl-β-D- glucuronic acid). The GUS protocol is used to detect GUS-labeled G. diazotrophicus in spinach seedling tissues by chemical detection using X-gluc dye. The results show that the spinach seedlings are successfully infected with GUS-labeled G. diazotrophicus , with the survival of the seedlings throughout their growth period and an improvement in the growth of pollinated seedlings. The outcomes of the microscopic inspection of the root slices reveal the presence of bacterial cells at the root tips and their concentration in the area of the cell walls of the peripheral cells. Furthermore, the findings of microscopic examinations of longitudinal sections for cotyledons show the presence of a number of bacteria within epidermal cell walls. This indicates that the determinants of the interaction between these bacteria and spinach seedlings are suitable for the expression of the gene responsible for the formation of the nitrogenase enzyme

    Evaluación por HPLC de componentes lipídicos minoritarios de subproductos de la refinación de aceites comestibles

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    An analytical evaluation of some by-products resulting from edible oil refining processing steps has been carried out. By-product samples were taken from four different local refineries that apply chemical refining technology. Pretreatment of the representative samples of the by-products were done prior to analysis followed by chromatographic isolation and derivatization of the minor components, namely, free and acylated sterol (FS and AS) as well as free and acylated sterylglycosides (FSG and ASG). However, tocopherols were directly determined in the pretreated samples. HPLC, using different detectors, was carried out for the determination of these minor components. Several authors have focused on the analysis of sterols and sterol esters, as well as tocopherols in the refining byproducts; however sterylglycosides, as biologically important components, have not been dealt with. This study throws light on the by – products enriched with certain minor components to be possibly utilized as sources for such components. Also, the role of the conditions of the refining steps followed in removing these valuable minor components from oils was discussed. It was found that soapstock samples contained various amounts of total tocopherols ranging from 80 to 230ppm; total FS and AS ranged from 240 to 4000 mg/100g while total FSG and ASG ranged from 1120 to 6375 mg/100g. In the case of deodorization distillate samples total tocopherols ranged from 960 to 7360ppm; total FS and AS ranged from 1020 to 4160 mg/100g and total FSG, ASG ranged from 395 to 880 mg/100g.El trabajo realiza una evaluación analítica de algunos subproductos resultantes del la refinación de aceites comestibles. Las muestras procedieron de 4 plantas que aplicaban refinación química. Después de un pretratamiento de las muestras estas se sometieron a un análisis cromatográfico para el aislamiento y derivatización de los siguientes componentes minoritarios: esteroles libres y acilados (FS y AS) y esterilglicosidos libres y acilados (FSG y ASG). Sin embargo, los tocoferoles se determinaron directamente a partir de las muestras pretratadas. Todos los componentes menores se analizaron mediante HPLC, utilizando detectores apropiados. Algunos autores han estudiado los esteroles y los esteres de los esteroles en los subproductos de la refinación pero ninguno lo ha hecho hasta ahora con los glicosidos de los esteroles, que son son de gran importancia biológica. Este estudio aporta información sobre subproductos enriquecidos con ciertos componentes que pueden ser una fuente interesante de los mismos. En el trabajo se discute asimismo el papel de las condiciones de refinación sobre la eliminación de dichos componentes de los aceites tratados. Se ha encontrado que los jabones contienen cantidades variables de tocoferoles que oscilan entre 80 y 230 ppm; la cantidad total de AS y FS osciló entre 240 a 4000 mg/100g mientras que la concentración total de FSG y ASG varió entre 1120 a 6375 mg/100g. En caso de desodorización, los destilados contuvieron entre 960 to 7360ppm de tocoferol, mientras que el total de FS y AS se situó entre 1020 y 4160 mg/100g y el de los totales de FSG y ASG entre 395 y 880 mg/100g

    On the (non-)existence of polynomial kernels for Pl-free edge modification problems

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    Given a graph G = (V,E) and an integer k, an edge modification problem for a graph property P consists in deciding whether there exists a set of edges F of size at most k such that the graph H = (V,E \vartriangle F) satisfies the property P. In the P edge-completion problem, the set F of edges is constrained to be disjoint from E; in the P edge-deletion problem, F is a subset of E; no constraint is imposed on F in the P edge-edition problem. A number of optimization problems can be expressed in terms of graph modification problems which have been extensively studied in the context of parameterized complexity. When parameterized by the size k of the edge set F, it has been proved that if P is an hereditary property characterized by a finite set of forbidden induced subgraphs, then the three P edge-modification problems are FPT. It was then natural to ask whether these problems also admit a polynomial size kernel. Using recent lower bound techniques, Kratsch and Wahlstrom answered this question negatively. However, the problem remains open on many natural graph classes characterized by forbidden induced subgraphs. Kratsch and Wahlstrom asked whether the result holds when the forbidden subgraphs are paths or cycles and pointed out that the problem is already open in the case of P4-free graphs (i.e. cographs). This paper provides positive and negative results in that line of research. We prove that parameterized cograph edge modification problems have cubic vertex kernels whereas polynomial kernels are unlikely to exist for the Pl-free and Cl-free edge-deletion problems for large enough l

    Molecular and all solid DFT studies of the magnetic and chemical bonding properties within KM[Cr(CN)6_6] (M = V, Ni) complexes

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    A study at both the molecular and extended solid level in the framework DFT is carried out for KM[Cr(CN)6_6] (M = V, Ni). From molecular calculations, the exchange parameters J are obtained, pointing to the expected magnetic ground states, i.e., antiferromagnetic for M = V with J = -296.5 cm1^{-1} and ferromagnetic for M = Ni with J = +40.5 cm1^{-1}. From solid state computations the same ground states and J magnitudes are confirmed from energy differences. Furthermore an analysis of the site projected density of states and of the chemical bonding is developed in which the cyanide ion linkage is analyzed addressing some isomerism aspects.Comment: new results, 5 tables, 7 fig

    Selective laser trabeculoplasty reduces mean IOP and IOP variation in normal tension glaucoma patients

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    Mohammed K El Mallah1, Molly M Walsh2, Sandra S Stinnett2, Sanjay G Asrani21Ocala Eye, Ocala, Florida, USA; 2Duke University Eye Center, Durham, North Carolina, USAPurpose: To evaluate the effect of selective laser trabeculoplasty (SLT) in normal tension glaucoma (NTG) patients.Patients and methods: A retrospective review was performed of NTG patients who had undergone SLT at the Duke University Eye Center between 12/2002 and 7/2005. For each eye of each patient at pre-laser and post-laser time points, the IOP measurements were summarized by mean, standard deviation, and range. Then for each of these descriptive statistics, the differences between pre-laser and post-laser values were obtained. Statistical analysis was performed using a random effects model. Main outcome measures: difference in mean IOP, standard deviation of IOP, and range of IOP.Results: Thirty-one eyes of 18 patients were included for analysis. The average of the mean ­pre-operative IOP measurements was 14.3 ± 2.6 mmHg compared to 12.2 ± 1.7 mmHg (P < 0.001) post-operatively. The mean pre-operative standard deviation was 1.9 ± 0.9 mmHg compared to 1.0 ± 0.6 mmHg (P = 0.002) post-operatively while the mean IOP range prior to treatment was 4.5 ± 2.5 mmHg compared to 2.5 ± 1.9 mmHg (P = 0.017) after treatment.Conclusion: In this pilot study, SLT was found to lower mean IOP and intervisit IOP ­variation in NTG patients. Given the importance of IOP variation and its association with glaucoma ­progression, measurement of IOP variation following treatment with SLT may be considered.Keywords: SLT, NTG, laser, glaucom

    LIQUORICE BEVERAGE EFFECT ON THE PHARMACOKINETIC PARAMETERS OF ATORVASTATIN, SIMVASTATIN, AND LOVASTATIN BY LIQUID CHROMATOGRAPHY-MASS SPECTROSCOPY/MASS SPECTROSCOPY

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    ABSTRACTObjective: The objective of this study is to examine the effects of pre-consumption of freshly prepared liquorice beverage (4 ml/kg) on thepharmacokinetic (PK) parameters of (80 mg/kg) oral dose of atorvastatin, simvastatin, and lovastatin in healthy rats plasma.Methods: A simple, rapid, and applicable analytical method was developed for the determination of each statin in rats' plasma. This method usesliquid chromatography-mass spectroscopy/mass spectroscopy. The mobile phase composed of methanol and formic acid in water and glimepiride asan internal standard. 108 rats were used in this study. Liquorice juice was given, and then each of the statins was given to test groups and liquoriceonly to the control groups, and then plasma samples were withdrawn on specific time schedule then PK analysis was performed.Results: The analytical method showed acceptable linearity, recovery, precision, and accuracy. Administration of liquorice resulted in a significantincrease in maximum concentration in plasma (C) of the three statins, also the area under plasma level-time curves (area under curve) was increasedsignificantly. Moreover, the bioavailability of the drugs. On the other hand, the elimination of the three drugs showed no great changes, which suggestsan interaction between liquorice and the transporting system of statins on the gut and biliary wall.maxConclusion: Consumption of liquorice results in increase bioavailability of atorvastatin, simvastatin, and lovastatin.Keywords: Liquorice, Atorvastatin, Liquid chromatography-mass spectroscopy/mass spectroscopy, Simvastatin, Lovastatin, Pharmacokineticparameters
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