767 research outputs found

    Chebyshev spectral solution of nonlinear Volterra-Hammerstein integral equations

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    AbstractIn this paper, the Chebyshev spectral (CS) method for the approximate solution of nonlinear Volterra-Hammerstein integral equations (τ)=F(τ)+∫oτK(τr)G(r,Y(r))dr,τ∈[0,T] is investigated. The method is applied to approximate the solution not to the equation in its original form, but rather to an equivalent equation z(t)=g(t, y(t)), t ∈ [−1, 1]. The function z is approximated by the Nth degree interpolating polynomial zN, with coefficients determined by discretizing g(t, y(t)) at the Chebyshev-Gauss Labatto nodes. We then define the approximation to y to be of the form yN(t)=f(t)+∫-11K(t,s)zN(s)ds,τ∈[-1,1] and establish that, under suitable conditions, limN→∞ yN(t) = y(t) uniformly in t. Finally, a numerical experiment for a nonlinear Volterra-Hammerstein integral equation is presented, which confirms the convergence, demonstrates the applicability and the accuracy of the Chebyshev spectral (CS) method

    Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation

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    The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance

    Metal Chelates of Diacetylacetanilide

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    694-69

    Teleparallel Versions of Friedmann and Lewis-Papapetrou Spacetimes

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    This paper is devoted to investigate the teleparallel versions of the Friedmann models as well as the Lewis-Papapetrou solution. We obtain the tetrad and the torsion fields for both the spacetimes. It is shown that the axial-vector vanishes for the Friedmann models. We discuss the different possibilities of the axial-vector depending on the arbitrary functions ω\omega and ψ\psi in the Lewis-Papapetrou metric. The vector related with spin has also been evaluated.Comment: 13 pages, accepted for publication in GR

    Chicory abrogates oxidative stress, inflammation and caspase-dependent apoptosis in acute hepatic injury model induced by acetaminophen in rats

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    In this study the protective effect of chicory leaves hydroalcoholic extract (CIE) against acute liver injury induced by a single dose of acetaminophen (700 mg/kg, i.p.) was investigated in rats. The CIE and silymarin treatment (standard reference) were given in a dose of (100 mg/kg, p.o.) for 3 days before and at 1 and 12 h following acetaminophen administration. Treatment with CIE signiïŹcantly reduced the levels of serum ALT, AST, alkaline phosphatase, bilirubin, total cholesterol, triglycerides, urea, creatinine, TNF-α and hepatic contents of malondialdehyde (MDA), nitric oxide, caspase-3 and hydroxyproline, with significant increases in serum total protein, albumin, HDL- cholesterol and hepatic activities of reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) as compared with the acetaminophen group. The histopathological alterations mediated by acetaminophen were ameliorated by CIE. It was concluded that CIE protects rat liver against acetaminophen hepatotoxicity, most probably through abrogation of oxidative stress, inflammation and caspase-3 dependent apoptosis

    Alopecia universalis after discontinuation of pegylated interferon and ribavirin combination therapy for hepatitis C: a case report

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    Abstract For the last decade, the combination therapy of pegylated interferon (Peg-IFN) plus ribavirin (RBV) has been considered as the standard of care treatment for chronic hepatitis C virus (HCV) infection. However, it has been associated with an increased incidence of many adverse cutaneous reactions and emergence of autoantibodies or even autoimmune diseases. We report a case of irreversible alopecia universalis (AU) with complete hair loss extended to the whole body, which started after discontinuation of Peg-IFN/RBV combination therapy for chronic HCV infection. In conclusion, this case represents an uncommon presentation of a common disease. Physicians must be aware of the potential adverse reactions of an antiviral therapy containing IFN, which might occur even after the discontinuation, and fully inform the patient at the beginning of his treatment course. We hope that interferon-free regimens will utterly supplant interferon-based therapy for most or all HCV patients avoiding the emergence of autoimmune manifestations

    Effect of different treatments on germination of Romi red grape seeds

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    Germination of seeds required a stratification period either at cold (5 ± 1 °C) or warm (18 ± 1 °C) conditions. Besides, production of normal seedlings (seedlings with plumule) needed stratification of at least 60 d. Cold stratification treatments increased pronouncedly the percentages of seed germination and normal seedlings when seeds were first subjected to warm stratification conditions. Soaking the seeds in IAA, IBA or Ethrel at different concentrations before sowing failed completely to produce normal seedlings. Conversely, the best results with respect to germination i;ercentage and normal seedlings were obtained with GA-, especially at 5000 ppm, followed by thiourea and kinetin. Applying GA3 to seeds immediately before stratification was more effective than adding it after stratification.Der Einfluß verschiedener Behandlungsbedingungen auf die Samenkeimung bei der Rebsorte Romi redDie Samen der Rebsorte Romi red keimten nur nach Stratifikation, entweder unter KĂ€lte- oder unter WĂ€rmebedingungen (5 ± 1 °C bzw. 18 ± 1 °C). Normale SĂ€mlinge, d. h. solche mit Plumula, entwickelten sich nur bei einer Stratifikationsdauer von mindestens 60 d. Durch Kaltstratifikation wurde der Anteil keimender Samen und normaler SĂ€mlinge bedeutend erhöht, wenn die Samen zuvor warmstratifiziert worden waren. Das Einweichen der Samen vor der Aussaat in unterschiedlichen Konzentrationen von IAA, IBA oder Ethrel förderte die Bildung normaler SĂ€mlinge in keiner Weise. Umgekehrt wurden im Hinblick auf die Samenkeimung und die Bildung normaler SĂ€mlinge die besten Ergebnisse mit GA3, vor allem in der Konzentration von 5000 ppm erzielt; auch Thioharnstoff und Kinetin zeigten einen positiven Einfluß. GA3-Behandlung der Samen unmittelbar vor der Stratifikation war wirksamer als danach

    Joint source-channel coding for a quantum multiple access channel

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    Suppose that two senders each obtain one share of the output of a classical, bivariate, correlated information source. They would like to transmit the correlated source to a receiver using a quantum multiple access channel. In prior work, Cover, El Gamal, and Salehi provided a combined source-channel coding strategy for a classical multiple access channel which outperforms the simpler "separation" strategy where separate codebooks are used for the source coding and the channel coding tasks. In the present paper, we prove that a coding strategy similar to the Cover-El Gamal-Salehi strategy and a corresponding quantum simultaneous decoder allow for the reliable transmission of a source over a quantum multiple access channel, as long as a set of information inequalities involving the Holevo quantity hold.Comment: 21 pages, v2: minor changes, accepted into Journal of Physics

    Immunohistochemical Study of Androgen Receptor Expression in Estrogen Receptor-Negative Invasive Breast Carcinoma and its Relation with Clinicopathologic Factors

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    BACKGROUND: Estrogen receptor (ER)-negative breast carcinomas lack the expression of ER and they have no targeted hormone therapies. The androgen receptor (AR) is a newly emerge biomarker. Detecting AR in these tumors may provide a target for future therapies. AIM: The aim of the study is to examine the immunohistochemical expression profiles of AR protein in ER-negative invasive breast carcinomas and to assess the relation between AR expression and the clinicopathologic factors such as age, tumor size, tumor grade, tumor type, immunohistochemical type, lymph node status, and Ki67 expression. METHODS: Sixty paraffin blocks of ER-negative invasive breast carcinoma cases were stained immunohistochemically by AR. Positive expression was defined as ≄1% nuclear staining. RESULTS: AR positivity was detected in 55% of the studied cases. The positive cases were scored by H-score with a median=117, and a range of 3–285 and by Allred score with a median=7, and a range of 3-8. AR is expressed in 60.9% of triple-negative breast carcinoma cases. AR expression was higher in older age, and there were significant positive correlations between the degree of AR expression (AR%, AR intensity, and H-score) and age (p=0.050, 0.007, 0.033, respectively). There was non-significant negative correlation between Ki67% and the degree of AR expression (AR%, AR intensity, H-score, and Allred score). Regarding different histological types, tumor grade, tumor size, lymph node status, and immunohistochemical types, there was no significant difference between AR positive and AR negative cases. CONCLUSION: AR is frequently expressed in ER-negative invasive breast carcinoma; especially in older age, and in a large number of triple-negative subtypes. This may give chance to benefit from future AR target therapy. We recommend further research work on AR expression in the special histologic subtypes of ER-negative breast carcinoma and in the triple negative group
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