141 research outputs found

    Promoting EFL learning towards peaceful global citizenship

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    This paper addresses SDG target 4.7 through the lens of Nancy Fraser’s (2008) conceptualisation of parity-of-participation. Her three-pillar conceptualisation includes the equitable distribution of material wealth, egalitarian status among all people, and equal access to representation. This paper attempts to apply her three pillars of participation to the primary classroom which has rarely been attempted before and never in the context of a middle income country. Drawing on interviews, surveys and drawingswith nearly 400 primary-school children in Egypt, we explore how they perceive participation within their classrooms and how participation may influence learning and future life. We conclude by noting that there is an irony in some children’s responses, whereby they display a strong ambition to speak English well, yet believe that they will learn to speak by being passive and silent in the classroom. Other children, however, critique the status quo and suggest more participatory approaches to learning English that will both improve their English mastery and model parity-of-participation in ways that may support their development into adults who strive to live peacefully together as global citizens

    ‘The teacher who helps children learn best’: affect and authority in the traditional primary classroom

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    This paper draws on the views of nearly 400 Year 5 pupils across nine classes in three government primary schools in Alexandria, Egypt. It explores how they perceived the role of affect in their classroom; and their teachers’ authority. By presenting pupils with sentences to complete, our research explored how the prevailing traditional approach to teaching influenced pupils in their English classroom. We also collected data by interviewing 38 pupils individually and carrying out Group Interviews with the pupils’ teachers. We concluded that pupils were acutely aware of how their feelings and their relationship to the teacher influenced their capacity to learn cognitively. Many of them said that they did not respect those teachers who refused to exercise an ethic of care in the classroom. In these cases, they did not see their teachers as authoritative; and pupils’ learning was impeded

    Metabolic profling of cytotoxic metabolites from five Tabebuia species supported by molecular correlation analysis

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    Tabebuia is the largest genus among the family Bignoniaceae. Tabebuia species are known for their high ornamental and curative value. Here, the cytotoxic potential of extracts from the leaves and stems of fve Tabebuia species was analyzed. The highest activity was observed for T. rosea (Bertol.) DC. stem extract against HepG2 cell line (IC50 4.7 ”g/mL), T. pallida L. stem extract against MCF-7 cell line (IC50 6.3 ”g/mL), and T. pulcherrima stem extract against CACO2 cell line (IC50 2.6 ”g/mL). Metabolic profiling of the ten extracts using liquid chromatography–high-resolution mass spectrometry for dereplication purposes led to annotation of forty compounds belonging to diferent chemical classes. Among the annotated compounds, irridoids represent the major class. Principle component analysis (PCA) was applied to test the similarity and variability among the tested species and the score plot showed similar chemical profling between the leaves and stems of both T. pulcherrima and T. pallida L. and unique chemical profling among T. rosea (Bertol.) DC., T. argentea Britton, and T. guayacan (Seem.) Hemsl. leaf extracts and the stem extract of T. rosea (Bertol.) DC. Additionally, a molecular correlation analysis was used to annotate the bioactive cytotoxic metabolites in the extracts and correlate between their chemical and biological profles

    Cytotoxic Activity and Metabolic Profiling of Fifteen Euphorbia Species

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    Euphorbia is a large genus of flowering plants with a great diversity in metabolic pattern. Testing the cytotoxic potential of fifteen Euphorbia species revealed highest activity of E. officinarum L. against CACO2 cell line (IC50 7.2 ”M) and of E. lactea Haw. against HepG2 and MCF-7 cell lines (IC50 5.2 and 5.1 ”M, respectively). Additionally, metabolic profiling of the fifteen tested species, using LC-HRMS, for dereplication purposes, led to the annotation of 44 natural compounds. Among the annotated compounds, diterpenoids represent the major class. Dereplication approach and multivariate data analysis are adopted in order to annotate the compounds responsible for the detected cytotoxic activity. Results of PCA come in a great accordance with results of biological testing, which emphasized the cytotoxic properties of E. lactea Haw. A similarity correlation network showed that the two compounds with the molecular formula C16H18O8 and C20H30O10, are responsible for cytotoxic activity against MCF-7 and HepG2 cell lines. Similarly, the compound with molecular formula C18H35NO correlates with cytotoxic activity against CACO2

    Discovery of two brominated oxindole alkaloids as staphylococcal DNA gyrase and pyruvate kinase inhibitors via inverse virtual screening

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    In the present study, a small marine-derived natural products library was assessed for antibacterial potential. Among 36 isolated compounds, a number of bis-indole derivatives exhibited growth-inhibitory activity towards Gram-positive strains (Bacillus subtilis and multidrug-resistant Staphylococcus aureus). 5- and 6-trisindoline (5-Tris and 6-Tris) were the most active derivatives (minimum inhibitory concentration, MIC, 4–8 µM) that were subsequently selected for anti-biofilm activity evaluation. Only 5-Tris was able to inhibit the staphylococcal biofilm formation starting at a 5 µM concentration. In order to investigate their possible molecular targets, both natural products were subjected to in silico inverse virtual screening. Among 20 target proteins, DNA gyrase and pyruvate kinase were the most likely to be involved in the observed antibacterial and anti-biofilm activities of both selected natural products. The in vitro validation and in silico binding mode studies revealed that 5-Tris could act as a dual enzyme inhibitor (IC50 11.4 ± 0.03 and 6.6 ± 0.05 µM, respectively), while 6-Tris was a low micromolar gyrase-B inhibitor (IC50 2.1 ± 0.08 µM), indicating that the bromine position plays a crucial role in the determination of the antibacterial lead compound inhibitory activity

    Epigenetic modifiers induce bioactive phenolic metabolites in the marine-derived fungus penicillium brevicompactum

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    Fungi usually contain gene clusters that are silent or cryptic under normal laboratory culture conditions. These cryptic genes could be expressed for a wide variety of bioactive compounds. One of the recent approaches to induce production of such cryptic fungal metabolites is to use histone deacetylases (HDACs) inhibitors. In the present study, the cultures of the marine-derived fungus Penicillium brevicompactum treated with nicotinamide and sodium butyrate were found to produce a lot of phenolic compounds. Nicotinamide treatment resulted in the isolation and identification of nine compounds 1–9. Sodium butyrate also enhanced the productivity of anthranilic acid (10) and ergosterol peroxide (11). The antioxidant as well as the antiproliferative activities of each metabolite were determined. Syringic acid (4), sinapic acid (5), and acetosyringone (6) exhibited potent in vitro free radical scavenging, (IC50 20 to 30 µg/mL) and antiproliferative activities (IC50 1.14 to 1.71 µM) against HepG2 cancer cell line. Furthermore, a pharmacophore model of the active compounds was generated to build up a structure-activity relationship

    Bioactive brominated oxindole alkaloids from the Red Sea sponge Callyspongia siphonella

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    In the present study, LC-HRESIMS-assisted dereplication along with bioactivity-guided isolation led to targeting two brominated oxindole alkaloids (compounds 1 and 2) which probably play a key role in the previously reported antibacterial, antibiofilm, and cytotoxicity of Callyspongia siphonella crude extracts. Both metabolites showed potent antibacterial activity against Gram-positive bacteria, Staphylococcus aureus (minimum inhibitory concentration (MIC) = 8 and 4 ”g/mL) and Bacillus subtilis (MIC = 16 and 4 ”g/mL), respectively. Furthermore, they displayed moderate biofilm inhibitory activity in Pseudomonas aeruginosa (49.32% and 41.76% inhibition, respectively), and moderate in vitro antitrypanosomal activity (13.47 and 10.27 ”M, respectively). In addition, they revealed a strong cytotoxic effect toward different human cancer cell lines, supposedly through induction of necrosis. This study sheds light on the possible role of these metabolites (compounds 1 and 2) in keeping fouling organisms away from the sponge outer surface, and the possible applications of these defensive molecules in the development of new anti-infective agents

    Collagen extract obtained from Nile tilapia (Oreochromis niloticus L.) skin accelerates wound healing in rat model via up regulating VEGF, bFGF, and α-SMA genes expression

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    Background Collagen is the most abundant structural protein in the mammalian connective tissue and represents approximately 30% of animal protein. The current study evaluated the potential capacity of collagen extract derived from Nile tilapia skin in improving the cutaneous wound healing in rats and investigated the underlying possible mechanisms. A rat model was used, and the experimental design included a control group (CG) and the tilapia collagen treated group (TCG). Full-thickness wounds were conducted on the back of all the rats under general anesthesia, then the tilapia collagen extract was applied topically on the wound area of TCG. Wound areas of the two experimental groups were measured on days 0, 3, 6, 9, 12, and 15 post-wounding. The stages of the wound granulation tissues were detected by histopathologic examination and the expression of vascular endothelial growth factor (VEGF), and transforming growth factor (TGF-ß1) were investigated using immunohistochemistry. Moreover, relative gene expression analysis of transforming growth factor-beta (TGF-ß1), basic fibroblast growth factor (bFGF), and alpha-smooth muscle actin (α-SMA) were quantified by real-time qPCR. Results The histopathological assessment showed noticeable signs of skin healing in TCG compared to CG. Immunohistochemistry results revealed remarkable enhancement in the expression levels of VEGF and TGF-ÎČ1 in TCG. Furthermore, TCG exhibited marked upregulation in the VEGF, bFGF, and α-SMA genes expression. These findings suggested that the topical application of Nile tilapia collagen extract can promote the cutaneous wound healing process in rats, which could be attributed to its stimulating effect on recruiting and activating macrophages to produce chemotactic growth factors, fibroblast proliferation, and angiogenesis. Conclusions The collagen extract could, therefore, be a potential biomaterial for cutaneous wound healing therapeutics. Backgroun

    New Pim-1 Kinase Inhibitor From the Co-culture of Two Sponge-Associated Actinomycetes

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    Saccharomonospora sp. UR22 and Dietzia sp. UR66, two actinomycetes derived from the Red Sea sponge Callyspongia siphonella, were co-cultured and the induced metabolites were monitored by HPLC-DAD and TLC. Saccharomonosporine A (1), a novel brominated oxo-indole alkaloid, convolutamydine F (2) along with other three known induced metabolites (3-5) were isolated from the EtOAc extract of Saccharomonospora sp. UR22 and Dietzia sp. UR66 co-culture. Additionally, axenic culture of Saccharomonospora sp. UR22 led to isolation of six known microbial metabolites (6-11). A kinase inhibition assay results showed that compounds 1 and 3 were potent Pim-1 kinase inhibitors with an IC50 value of 0.3 ± 0.02 and 0.95 ± 0.01 ΌM, respectively. Docking studies revealed the binding mode of compounds 1 and 3 in the ATP pocket of Pim-1 kinase. Testing of compounds 1 and 3 displayed significant antiproliferative activity against the human colon adenocarcinoma HT-29, (IC50 3.6 and 3.7 ΌM, respectively) and the human promyelocytic leukemia HL-60, (IC50 2.8 and 4.2 ΌM, respectively). These results suggested that compounds 1 and 3 act as potential Pim-1 kinase inhibitors that mediate the tumor cell growth inhibitory effect. This study highlighted the co-cultivation approach as an effective strategy to increase the chemical diversity of the secondary metabolites hidden in the genomes of the marine actinomycetes
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