926 research outputs found

    Solid State NMR Characterization and Adsorption Properties of Lignocellulose-Clinoptilolite Composites Prepared with Siloxanes Coupling Agents

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    This study reports the preparation of lignocellulose-clinoptilolite composites by means of N-terminated siloxanes as coupling agents, after acid hydrolysis. Reactions were carried out in the presence of dibutyltin dilaurate as catalyst by reacting lignocellulose modified with the coupling agents and clinoptilolite at 140 °C inDMFunder nitrogen atmosphere. The light in weight and fluffy composites obtained were characterized by FT-IR, XRD, TGA, SEM and Solid State NMR. Results depicted possible chemical interactions between the two materials (lignocellulose and clinoptilolite). Used as adsorbents, the composites showed to be good candidates for the removal of used motor oil fromaqueous solution, withupto 92mg g–1 of chemical oxygen demand removed.KEYWORDS Lignocellulose, clinoptilolite, chemical modification, composites, solid state NMR, used motor oil

    Rheology of Ring Polymer Melts: From Linear Contaminants to Ring/Linear Blends

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    Ring polymers remain a major challenge to our current understanding of polymer dynamics. Experimental results are difficult to interpret because of the uncertainty in the purity and dispersity of the sample. Using both equilibrium and non-equilibrium molecular dynamics simulations we have systematically investigated the structure, dynamics and rheology of perfectly controlled ring/linear polymer blends with chains of such length and flexibility that the number of entanglements is up to about 14 per chain, which is comparable to experimental systems examined in the literature. The smallest concentration at which linear contaminants increase the zero-shear viscosity of a ring polymer melt of these chain lengths by 10% is approximately one-fifth of their overlap concentration. When the two architectures are present in equal amounts the viscosity of the blend is approximately twice as large as that of the pure linear melt. At this concentration the diffusion coefficient of the rings is found to decrease dramatically, while the static and dynamic properties of the linear polymers are mostly unaffected. Our results are supported by a primitive path analysis.Comment: 5 pages, 4 figures, accepted by PR

    What does touch tell us about emotions in touchscreen-based gameplay?

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    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ACM. It is posted here by permission of ACM for your personal use. Not for redistribution.Nowadays, more and more people play games on touch-screen mobile phones. This phenomenon raises a very interesting question: does touch behaviour reflect the player’s emotional state? If possible, this would not only be a valuable evaluation indicator for game designers, but also for real-time personalization of the game experience. Psychology studies on acted touch behaviour show the existence of discriminative affective profiles. In this paper, finger-stroke features during gameplay on an iPod were extracted and their discriminative power analysed. Based on touch-behaviour, machine learning algorithms were used to build systems for automatically discriminating between four emotional states (Excited, Relaxed, Frustrated, Bored), two levels of arousal and two levels of valence. The results were very interesting reaching between 69% and 77% of correct discrimination between the four emotional states. Higher results (~89%) were obtained for discriminating between two levels of arousal and two levels of valence

    The effects of tumor treating fields and temozolomide in MGMT expressing and non-expressing patient-derived glioblastoma cells

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    AbstractA recent Phase 3 study of newly diagnosed glioblastoma (GBM) demonstrated the addition of tumor treating fields (TTFields) to temozolomide (TMZ) after combined radiation/TMZ significantly increased survival and progression free survival. Preliminary data suggested benefit with both methylated and unmethylated O-6-methylguanine-DNA methyl-transferase (MGMT) promoter status. To date, however, there have been no studies to address the potential interactions of TTFields and TMZ. Thus, the effects of TTFields and TMZ were studied in vitro using patient-derived GBM stem-like cells (GSCs) including MGMT expressing (TMZ resistant: 12.1 and 22GSC) and non-MGMT expressing (TMZ sensitive: 33 and 114GSC) lines. Dose-response curves were constructed using cell proliferation and sphere-forming assays. Results demonstrated a ⩾10-fold increase in TMZ resistance of MGMT-expressing (12.1GSCs: IC50=160μM; 22GSCs: IC50=44μM) compared to MGMT non-expressing (33GSCs: IC50=1.5μM; 114GSCs: IC50=5.2μM) lines. TTFields inhibited 12.1 GSC proliferation at all tested doses (50–500kHz) with an optimal frequency of 200kHz. At 200kHz, TTFields inhibited proliferation and tumor sphere formation of both MGMT GSC subtypes at comparable levels (12.1GSC: 74±2.9% and 38±3.2%, respectively; 22GSC: 61±11% and 38±2.6%, respectively; 33GSC: 56±9.5% and 60±7.1%, respectively; 114 GSC: 79±3.5% and 41±4.3%, respectively). In combination, TTFields (200kHz) and TMZ showed an additive anti-neoplastic effect with equal efficacy for TTFields in both cell types (i.e., ± MGMT expression) with no effect on TMZ resistance. This is the first demonstration of the effects of TTFields on cancer stem cells. The expansion of such studies may have clinical implications
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