Overexpression of S6 Kinase 1 in Brain Tumours Is Associated with Induction of Hypoxia-Responsive Genes and Predicts Patients' Survival

mTOR/S6K pathway is a crucial regulator of cell growth and metabolism. Deregulated signalling via S6K has been linked to various human pathologies, including metabolic disorders and cancer. Many of the molecules signalling upstream of S6K have been shown to be either mutated or overexpressed in tumours, leading to S6K activation. The role of S6K1 in brain tumours is not fully investigated. In this study, we investigated the gene expression profile of S6 kinases in brain and CNS tumours using the publically available Cancer Microarray Database. We found that S6K1 but not S6K2 gene is overexpressed in brain tumours and this upregulation is associated with patients' poor survival. Furthermore, we interrogated Oncomine database for the expression profile of hypoxia-induced genes using a literature-defined concept. This gene list included HIF1A, VEGFA, SOX4, SOX9, MMP2, and NEDD9. We show that those genes are upregulated in all brain tumour studies investigated. Additionally, we analysed the coexpression profile of S6K1 and hypoxia responsive genes. The analysis was done across 4 different brain studies and showed that S6K1 is co-overexpressed with several hypoxia responsive genes. This study highlights the possible role of S6K1 in brain tumour progression and prediction of patients' survival. However, new epidemiological studies should be conducted in order to confirm these associations and to refine the role of S6K1 in brain tumours as a useful marker for patients' survival

The Usefulness Of Accounting Information, Economic Variables, And Corporate Governance Measures To Predict Corporate Failure

This paper has the core aim of investigating the usefulness of employing accounting information, macroeconomic variables and corporate governance measures to predict corporate failure in an Egyptian setting. The empirical study is directed to adapting a corporate failure prediction model applied to a sample of Egyptian companies listed in the Egyptian stock market. A sample of 79 companies drawn from the 100 most actively traded firms listed in the Egyptian stock market has been used for the empirical testing. A pooled sample is formed covering the period 2000-2005 inclusive. The empirical study emphasized improving failure prediction accuracy by introducing two classes of variables besides financial ratios based on accounting information. These classes of variables are economic variables and corporate governance measures. Logistic regression analysis has been used to test the predictive accuracy of four models. Model I included accounting information only. Model II added economic variables to accounting information. Model III included corporate governance measures and accounting information. Finally, model IV employed these three classes of variables together. Analysis of the statistical testing results indicated that employing the three classes of variables together improved the prediction accuracy to reach 84.8% in the classification sample and 78.2% in the validation sample. Furthermore, model IV is used to predict failure up to three years prior to failure and therefore can provide a tool for failure prediction for enhancing auditing, investment and credit decisions in an Egyptian market setting

A fixed point iteration approach for analyzing the pull-in dynamics of beam-type electromechanical actuators

© 2020 Informa UK Limited, trading as Taylor & Francis Group. In this paper, a numerical approach is suggested to find a semi-analytical solution for the common nonlinear boundary value problems (BVPs) of cantilever-type micro-electromechanical system (MEMS) and nano-electromechanical system (NEMS) with a set of model parameters. The nonlinear BVPs that are studied involve the states of the single and double cantilever-shaped beams under the influence of Casimir and Van der Waals force for proper distances of separation. The method is based upon an integral operator that is formed considering Green’s function connected with the execution of Picard’s or Mann’s fixed point schemes. The numerical results for different cases of beam are presented and compared with those obtained by previous works to show the applicability, efficiency, and high accuracy of the suggested method

Reactive Oxygen Species, Lipid Peroxidation and Antioxidative Defense Mechanism

Lipid peroxidation can be defined as the oxidative deterioration of lipids containing any number of carbon-carbon double bonds. Lipid peroxidation is a well-established mechanism of cellular injury in both plants and animals, and is used as an indicator of oxidative stress in cells and tissues. Lipid peroxides are unstable and decompose to form a complex series of compounds including reactive carbonyl compounds. The oxidation of linoleates and cholesterol is discussed in some detail. Analytical methods for studying lipid peroxidation were mentioned. Various kinds of antioxidants with different functions inhibit lipid peroxidation and the deleterious effects caused by the lipid peroxidation products

OBAME: Optimized Bio-inspired Algorithm to Maximize Search Efficiency in P2P Databases

AbstractP2P databases are characterized by high site-failure rates, unpredictable network topology and complex management, due to the complete absence of a centralized controller. These characteristics have introduced novel challenges and research issues to the field. Among the most difficult challenges is the process of locating information among various participants in the network. This paper presents an original contribution by proposing an Optimized Bio-inspired Algorithm to maximize search efficiency in P2P databases (OBAME). Experimental results showed that OBAME outperformed Ant- and Bee- Inspired algorithms in terms of network traffic and query response time

DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING RP-HPLC METHOD FOR THE DETERMINATION OF XIPAMIDE IN PURE AND DOSAGE FORMS

Objective: A simple, selective, precise and stability-indicating RP-HPLC-method was developed and validated for the determination of xipamide (XIP).Methods: Stability tests were done through exposure of the analyte solution to thermal, photolytic, hydrolytic and oxidative stress conditions. The chromatographic separation was carried out in less than five min on a RP stainless-steel C-18 analytical column (150 mm ×4.6 mm ID, 5 µm) with an isocratic elution system of 0.023 M orthophosphoric acid of pH 2.6 and acetonitrile as the mobile phase in the ratio of 60: 40 at 1.5 ml/min flow rate at room temperature. A diode array UV was used at 220 nm for detection.Results: The degradation products were well separated from the pure drug. The elution time of XIP was found to be 4.561±0.024 min. The method was validated in terms of linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ) and robustness. Good linearity was found in the concentration range of 1–100 µg/ml with a correlation coefficient of 0.9999. Intraday and interday precision were within 1.4%. LOD and LOQ were 0.088 μg/ml and 0.267 μg/ml, respectively and percentage recovery of XIP was found to be 99.92±1.02 %. Conclusion: The proposed method was successfully applied to the determination of XIP in pure form and in its pharmaceutical preparation without interference from its degradation products.Keywords: Xipamide, Stability indicating RP-HPLC, Stress degradation, Pure form, Dosage form