38 research outputs found

    Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer

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    INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-κB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS – 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma

    Consequences of Covid-19 on the Social Isolation of the Chinese Economy: Accounting for the Role of Reduction in Carbon Emissions

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    The main contribution of the present study to the energy literature is linked to the interaction between economic growth and pollution emission amidst globalization. Unlike other studies, this research explores the effect of economic and social isolation as a dimension of globalization. This allows underpinning the effects on the Chinese economic development of the isolation phenomenon as a consequence of coronavirus (COVID-19). To this end, annual time frequency data is used to achieve the hypothesized claims. The study resolutions include (i) The existence of a long-run equilibrium bond between the outlined variables (ii) The long-run estimates suggest that the Chinese economy over the investigated period, is inelastic to pollutant–driven economic growth as reported by the dynamic ordinary least squares, fully modified ordinary least squares and canonical regressions with a magnitude of 0.09%. (iii) The Chinese isolation is less responsive to its economic growth while the country political willpower is elastic as demonstrated by current government commitment to dampen the effect of the COVID-19 pandemic. This is marked by the aggressive response on the government officials resolute by flattening the exponential impact of the pandemic. Based on these robust results some far-reaching policy implication(s) are underlined in the concluding remark section

    A molecular tectonics-crystal engineering approach for building organic-inorganic composites. Potential application to the growth control of hydroxyapatite crystals

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    The effect of bisamidinium type dications as tectons on the crystal formation of hydroxyapatite was investigated. Evidence of the structural interactions between three tectons with different numbers and locations of H-bond donor sites and hydroxyapatite crystals has been shown. Some correlations between the molecular structure of the organic tectons and the morphology of hydroxyapatite crystals were observed. These results may be of interest in the control of hydroxyapatite morphogenesis as well as its surface properties

    Progressive Failure Studies of Stiffened Panels Subjected to Shear Loading

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    Experimental and analytical results are presented for progressive failure of stiffened composite panels with and without a notch and subjected to in plane shear loading well into their postbuckling regime. Initial geometric imperfections are included in the finite element models. Ply damage modes such as matrix cracking, fiber-matrix shear, and fiber failure are modeled by degrading the material properties. Experimental results from the test include strain field data from video image correlation in three dimensions in addition to other strain and displacement measurements. Results from nonlinear finite element analyses are compared with experimental data. Good agreement between experimental data and numerical results are observed for the stitched stiffened composite panels studied
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