50 research outputs found

    Penerapan Model Pembelajaran Koopeartif Tipe Cooperative, Integrated, Reading And Composition (CIRC) pada Materi Struktur Atom dan Sistem Periodik Unsur Kelas X SMAN 1 Pasangkayu

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    Reaserch was conducted on the atomic structure subject and the periodic table with implementing cooperative learning model type of coopeative, integrated reading and composition (CIRC) in SMAN 1 Pasangkayu is applied to the learning model with the conventional lecture method. This study aims to implement cooperative learning model of CIRC towards the chemical learning outcomes. The population in this study is a class X student of SMAN 1 Pasangkayu academic year 2013/2014 the number of students 300 people, and the study sample X.4 class as experiment class with (n = 30) applying cooperative learning model CIRC and class X.3 as class control the number of students (n = 32) whithout using cooperative learning model CIRC. Testing the hypothesis t-test of the right-hand side. The results of the analysis of data obtained average scores on the experimental class = 76.90 and 60.81 for the control class normaly distibuted both classes and has variance (F test) are homogeneous. Tesing hypothesis obtained tcount t-test = 4.73 > ttabel = 1.67 with a significance level (α) = 0.05. The results showed that the application of cooperative learning model CIRC gives the positive effect on student learning outcomes in the atomic structure subject and the periodic table of elements (H0 rejected H1 is accepted)

    Serbuk dari Limbah Cangkang Telur Ayam Ras sebagai Adsorben terhadap Logam Timbal (Pb)

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    The aim of this study is to determine the optimum time and weight required for eggshell powder when it absorbs Pb, and to determine the adsorption capacity of the eggshell powder at the optimum condition for Pb with the shaking time variation of 10, 20, 30, 40 and 50 minutes. The weight variation of adsorbent is 0.25, 0.50, 0.75, 1 and 1.25 grams. The work steps in this study were production of the eggshell powder as the adsorbent, making of a solution of Pb 60 ppm, and determination the Pb concentration at equilibrium using a spectrophotometer spektrodirect respectively. The results obtained after the adsorption process for the time variation was 30 minutes, this optimum time giving %Pb absorbed was 94.65%. The weight variation of adsorbent is 1 gram, this optimum weight giving %Pb absorbed was 98.91%. Furthermore, the absorption capacity adsorbent of eggshell powder in both optimum conditions was 0.078 mg Pb/mg adsorbent

    Model Pembelajaran Kooperatif Tipe Stad (Student Teams Achievement Division) Dikombinasikan dengan Media Animasi pada Materi Laju Reaksi Kelas XI SMA Negeri 1 Palu

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    Students have difficulties in understanding chemistry subject contained mathematical calculation like on reaction rate topic. Cooperative learning model STAD type can be an alternative for the material contained calculation whereas animation media is for conceptual understanding. The objective of the research was to determine the influence of cooperative learning model STAD type combined with animation media for the eleventh grade students of SMA Negeri 1 Palu in academic year 2012/2013 toward the students' learning outcome on reaction rate material. This research was quasy experimental using posttest-only control group design. The population was the whole eleventh grade students of science program with the sample determination using purposive sampling method. The sample were class of science program 2 as the experimental class which using cooperative learning model STAD type with animation media whereas class of science program 4 as the control one which using convensional learning method. The research results showed that cooperative learning model STAD type combined with animation media at reaction rate material gave students' learning outcome higher than convensional method

    Foam Behaviour of an Aqueous Solution of Piperazine- N-Methyldiethanolamine (MDEA) Blend as a Function of the Type of Impurities and Concentrations

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    This study focuses on the effect of impurities in the natural gas stream on the characteristic of foam behaviour in the blended piperazine and MDEA solution. Hydrocarbon liquids, Iron Sulphide, Sodium Chloride, Acetic Acid, Methanol and Polyethylene Glycol were used as the impurities. The results indicated that the type of impurities determined the foam formation of the amine solution. The concentration of piperazine-MDEA blends also enhanced to the increasing of the foam height of blended piperazine-MDEA. Iron sulfide, hydrocarbon and sodium chloride are the impurities which apparently contributed to the high foaming tendency of the solutions. At the same concentration of the impurities, iron sulfide appeared as the most influential contaminant to the foam formation, which promoted the highest foamability in any concentrations of the blend piperazine-MDE

    Pharmacological levels of withaferin A (Withania somnifera) trigger clinically relevant anticancer effects specific to triple negative breast cancer cells

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    Withaferin A (WA) isolated from Withania somnifera (Ashwagandha) has recently become an attractive phytochemical under investigation in various preclinical studies for treatment of different cancer types. In the present study, a comparative pathway-based transcriptome analysis was applied in epithelial-like MCF-7 and triple negative mesenchymal MDA-MB-231 breast cancer cells exposed to different concentrations of WA which can be detected systemically in in vivo experiments. Whereas WA treatment demonstrated attenuation of multiple cancer hallmarks, the withanolide analogue Withanone (WN) did not exert any of the described effects at comparable concentrations. Pathway enrichment analysis revealed that WA targets specific cancer processes related to cell death, cell cycle and proliferation, which could be functionally validated by flow cytometry and real-time cell proliferation assays. WA also strongly decreased MDA-MB-231 invasion as determined by single-cell collagen invasion assay. This was further supported by decreased gene expression of extracellular matrix-degrading proteases (uPA, PLAT, ADAM8), cell adhesion molecules (integrins, laminins), pro-inflammatory mediators of the metastasis-promoting tumor microenvironment (TNFSF12, IL6, ANGPTL2, CSF1R) and concomitant increased expression of the validated breast cancer metastasis suppressor gene (BRMS1). In line with the transcriptional changes, nanomolar concentrations of WA significantly decreased protein levels and corresponding activity of uPA in MDA-MB-231 cell supernatant, further supporting its anti-metastatic properties. Finally, hierarchical clustering analysis of 84 chromatin writer-reader-eraser enzymes revealed that WA treatment of invasive mesenchymal MDA-MB-231 cells reprogrammed their transcription levels more similarly towards the pattern observed in non-invasive MCF-7 cells. In conclusion, taking into account that sub-cytotoxic concentrations of WA target multiple metastatic effectors in therapy-resistant triple negative breast cancer, WA-based therapeutic strategies targeting the uPA pathway hold promise for further (pre)clinical development to defeat aggressive metastatic breast cancer

    Impact of voluntary exercise and housing conditions on hippocampal glucocorticoid receptor, miR-124 and anxiety

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    Background: Lack of physical activity and increased levels of stress contribute to the development of multiple physical and mental disorders. An increasing number of studies relate voluntary exercise with greater resilience to psychological stress, a process that is highly regulated by the hypothalamic-pituitary-adrenal (HPA) axis. However, the molecular mechanisms underlying the beneficial effects of exercise on stress resilience are still poorly understood. Here we have studied the impact of long term exercise and housing conditions on: a) hippocampal expression of glucocorticoid receptor (Nr3c1), b) epigenetic regulation of Nr3c1 (DNA methylation at the Nr3c1-1F promoter and miR-124 expression), c) anxiety (elevated plus maze, EPM), and d) adrenal gland weight and adrenocorticotropic hormone receptor (Mc2r) expression. Results: Exercise increased Nr3c1 and Nr3c1-1F expression and decreased miR-124 levels in the hippocampus in single-housed mice, suggesting enhanced resilience to stress. The opposite was found for pair-housed animals. Bisulfite sequencing showed virtually no DNA methylation in the Nr3c1-1F promoter region. Single-housing increased the time spent on stretch attend postures. Exercise decreased the time spent at the open arms of the EPM, however, the mobility of the exercise groups was significantly lower. Exercise had opposite effects on the adrenal gland weight of single and pair-housed mice, while it had no effect on adrenal Mc2r expression. Conclusions: These results suggest that exercise exerts a positive impact on stress resilience in single-housed mice that could be mediated by decreasing miR-124 and increasing Nr3c1 expression in the hippocampus. However, pair-housing reverses these effects possibly due to stress from dominance disputes between pairs
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