37 research outputs found

    Oscillation Criteria for Some Higher Order Integrodynamic Equations on Timescales

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    We study the oscillation behavior for some higher order integrodynamic equations on timescales. We establish some new sufficient conditions guaranteeing that all solutions of theses equations are oscillatory. Some numerical examples in the continuous case are given to validate the theoretical results

    Purification of kappa (k)-carrageenase from locally isolated Cellulosimicrobium cellulans

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    Partial purification of the crude kappa (k)-carrageenase present in the culture filtrates of Cellulosimicrobium cellulans was carried out by fractional precipitation, using ammonium sulphate, acetone and ethanol individually. The highest recovered protein (37.08%) combined with enzyme activity was obtained with ammonium sulphate. The fraction precipitated by 90% ammonium sulphate was re-purified by anion exchange chromatography diethylaminoethyl (DEAE) cellulose, A-52 and 79 fractions were obtained. The loaded protein was separated into 4 peaks. The third protein peak was the major one which contained the most recovered enzyme activity (84.95%) from the eluted fractions. The collected fractions of this peak were subjected to further purification by re-chromatography on Sephadex G-100. The k-carrageenase activity was fractionated into 2 peaks. The first peak was the major one containing 95.622% of the total recovered activity. The pooled fractions of the major protein component showed a specific k-carrageenase activity of 46.22 U/mg protein, yielding about 4.6 fold purification of the crude enzyme preparation. Some properties of purified k-carrageenase obtained from cellusimicrobium cellulans cultures were studied. The optimum reaction temperature of the purified k-carrageenase was 30°C and the maximum activity occurred at a reaction pH of 6.Key words: Cellulosimicrobium cellulans, k-carrageenase, purification, sephadex G-100, diethylaminoethyl (DEAE) sephadex A-52

    Non-invasive index of liver fibrosis induced by alcohol, thioacetamide and schistosomal infection in mice

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    <p>Abstract</p> <p>Background</p> <p>Non invasive approaches will likely be increasing utilized to assess liver fibrosis. This work provides a new non invasive index to predict liver fibrosis induced in mice.</p> <p>Methods</p> <p>Fibrosis was generated by thioacetamide (TAA), chronic intake of ethanol, or infection with <it>S. mansoni </it>in 240 mice. Both progression and regression of fibrosis (after treatment with silymarin and/or praziquantel) were monitored. The following methods were employed: (i) The METAVIR system was utilized to grade and stage liver inflammation and fibosis; (ii) Determination of hepatic hydroxyproline and collagen; and (iii) Derivation of a new hepatic fibrosis index from the induced changes, and its prospective validation in a group of 70 mice.</p> <p>Results</p> <p>The index is composed of 4 serum variable including total proteins, γ-GT, bilirubin and reduced glutathione (GSH), measured in diseased, treated and normal mice. These parameters were highly correlated with both the histological stage and the grade. They were combined in a logarithmic formula, which non-invasively scores the severity of liver fibrosis through a range (0 to 2), starting with healthy liver (corresponding to stage 0) to advanced fibrosis (corresponding stage 3).Receiver operating characteristic curves (ROC) for the accuracy of the index to predict the histological stages demonstrated that the areas under the curve (AUC) were 0.954, 0.979 and 0.99 for index values corresponding to histological stages 1, 2 and 3, respectively. Also, the index was correlated with stage and grade, (0.947 and 0.859, respectively). The cut off values that cover the range between stages 0-1, 1-2 and 2-3 are 0.4, 1.12 and 1.79, respectively. The results in the validation group confirmed the accuracy of the test. The AUROC was 0.869 and there was good correlation with the stage of fibrosis and grade of inflammation.</p> <p>Conclusion</p> <p>The index fulfils the basic criteria of non-invasive marker of liver fibrosis since it is liver-specific, easy to implement, reliable, and inexpensive. It proved to be accurate in discriminating precirrhotic stages.</p

    Suppressive efficiency of Kojic acid from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer

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    Purpose: To evaluate the antioxidant and cytotoxic properties of Kojic acid (KOJIC ACID) from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer.Methods: The crude extract of A. tamarii MM11 was dissolved in a mixture of CH2Cl2/MeOH (85:15) and separation was done using silica gel chromatography using gradient size exclusion chromatograph. The non-polar oily fractions were subjected to gas chromatography-mass&nbsp; spectrometric (GC-MS) analysis. Kojic acid structure was identified by x-beam crystallography and spectroscopic methods. Total antioxidant properties of KOJIC ACID were evaluated by using 1,1-diphenyl-2- picrylhydrazyl (DPPH) against ascorbic acid as a reference. The cytotoxic activity of KOJIC ACID from A. tamarii MM11 was investigated on the human cell line of liver cancer (HepG-2) using a sulforhodamine B (SRB) assay based on a cell density determination by the measurement of cellular protein content.Result: Highly bioactive Kojic acid was isolated as the main product. A. tamarii MM11 Kojic acid showed good antioxidant activity with half-maximal inhibitory concentration of IC50 at concentrations of 10.34 compared to 6.79 μg/mL for ascorbic acid. Kojic acid also showed good cytotoxic activity against HepG-2 cell line of human liver cancer with IC50 at 6.20 compared to 3.25 μg/mL of reference drug doxorubicin.Conclusion: Kojic acid produced naturally from A. tamarii MM11 shows good antioxidant and cytotoxic activity against HepG-2 cell line derived from&nbsp; human liver cancer. These findings suggest that Kojic acid can be therapeutically used as an antitumor drug after further in vivo studies. Keywords: Aspergillus tamarii, Secondary metabolites, Kojic acid, Anticancer, Liver cance

    Hormonal and inflammatory modulatory effects of hesperidin in hyperthyroidism-modeled rats

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    The goal of the current study was to investigate the hormonal modulatory efficiency of hesperidin, through its regulatory potential of immunological, inflammatory, and/or antioxidant changes in on hyperthyroidism modeled adult female albino rats. Both normal and hyperthyroidism modeled rats (140-160g) were randomly divided into four groups (10 animals each) as follows: 1) healthy animals were daily ingested with saline for six weeks, and served as control group, 2) healthy animals were intraperitoneally injected with hesperidin (50 mg/kg/day) for a similar period, 3) hyperthyroidism-modeled animals without any treatment acted as positive control, and 4) hyperthyroidism-modeled animals were treated intraperitoneally with hesperidin for a similar period. The findings showed that hesperidin significantly modulated hyperthyroidism deteriorations, this was evidenced by a remarkable decline in serum T4, FT4, T3, FT3, TNF-α, IL1β-, IL4-, IL-6, and IL-10 levels, with a minor increase in TSH and significant raise in CD4+ level. Similarly, valuable improvement was observed in the oxidative status; serum SOD, GPx, CAT, and GSH levels were dramatically enhanced, associated with remarkable drop in MDA and NO levels. Also, hesperidin demonstrated nephro-hepatoprotective and anti-atherogenic potential, this was achieved from the notable reduction in ALAT and ASAT activities as well as urea, creatinine, cholesterol, and triglyceride close to the corresponding values of healthy group. These findings were supported by histological and immunohistochemical ones that showed a notable decrease in the expression of the calcitonin antibody. In conclusion, hesperidin possesses anti-hyperthyroidism, immunoinflammatory regulatory, and antioxidant activities that evidenced from the improvement of physio-architecture of the thyroid gland, reduction of inflammation and restoration of the impaired oxidative stress. This effect might be mechanized through immunological, inflammatory, apoptotic, and/or antioxidant modulatory pathways

    Stochastic 2D Incompressible Navier-Stokes Solver Using the Vorticity-Stream Function Formulation

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    A two-dimensional stochastic solver for the incompressible Navier-Stokes equations is developed. The vorticity-stream function formulation is considered. The polynomial chaos expansion was integrated with an unstructured node-centered finite-volume solver. A second-order upwind scheme is used in the convection term for numerical stability and higher-order discretization. The resulting sparse linear system is solved efficiently by a direct parallel solver. The mean and variance simulations of the cavity flow are done for random variation of the viscosity and the lid velocity. The solver was tested and compared with the Monte-Carlo simulations and with previous research works. The developed solver is proved to be efficient in simulating the stochastic two-dimensional incompressible flows

    Simulation of radiant cooling systems in cleanroom applications

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    Copyright 2019 ASHRAE. Radiant cooling systems rely on chilled-water pipes to distribute cooling throughout a building rather than a conventional system that uses chilled air and ductwork. Radiant cooling systems rely mainly on the direct cooling of occupants by the radiation heat transfer because the pipes, which commonly run through ceilings or walls, maintain surface temperatures of about 18°C (64.4°F). In a radiant cooling system, ventilation and thermal space conditioning tasks are separated. Forced air is used to fulfill ventilation requirements and radiant cooling panels are used to provide most of the cooling
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