Chain transfer to solvent in the radical polymerization of structurally diverse acrylamide monomers using straight-chain and branched alcohols as solvents

Chain transfer to solvent in conventional radical polymerizations of N-tert-butylacrylamide (TBAM) and N-(2-morpholin-4-ylethyl) acrylamide (MEA) in a range of alcohol solvents is investigated. Mayo analysis of polymerization of TBAM in linear alcohols (C-3-C-9) resulted in an approximately linear increase in chain transfer to solvent constant (C-tr,(S)) with the number of methylene (CH2) units in the solvent. The branched alcohol 3-methyl-3-pentanol gave the smallest C-tr,C-S (using Mayo analysis), and thus allowed attainment of higher molecular weights (MWs) in the nitroxide-mediated polymerizations (NMP) of TBAM. Overall, the data show that MEA is more prone to chain transfer to solvent than TBAM (higher C-tr,C-S), and further analysis of the conventional radical polymerization of MEA in 3-methyl-3-pentanol indicate chain transfer to monomer may also be occurring. The first controlled/ living polymerizations of MEA are detailed with chain transfer having a greater impact on maximum achievable MWs in NMP in comparison to TBAM

A consideration of Artistic Truth

The choice of subject or theme, “A Consideration of Artistic Truth”, for the dissertation and the parallel poetic endeavour is discussed in detail in the “Background” section of the dissertation later. Suffice it to say here that it has come out of my experience and knowledge of poetry and literature and the writers whose work has influenced and inspired me, my personal situation and motivation for writing at that moment, my past experiences - successes and failures – and the reason for the crossroads I felt I was at in terms of the need for change and direction in writing. The thesis begins with a selection of poems all of which were written and workshopped during the postgraduate MA in Creative Writing programme in WIT as part of the structure of the course. Feedback from my supervisors and fellow students in the workshop class, whose invaluable suggestions have no doubt influence the rewriting process, sometimes forms part of the reflection in the dissertation. Though naturally they are not responsible for any mistakes or errors in judgment I might make about my own work. I have written the dissertation in the form of a “reflective journal”. I wrote it between September 2007 and March 2009; keeping a notebook in longhand as a way of developing an awareness and insight into the creative process in my writing. My hope was that this approach to the thesis, that is the creative work combined with a reflection on the creative process, would both bring me to a deeper awareness and exploration of the theme and that it would also be important for me to see and reflect on how, what, and where this seeking for artistic truth would bring to the process of writing a new body of poetic work. I am conscious that I am sharing here some of my raw creative material. To this end, I decided to include some of the poems or early drafts in the text, so as to make them immediately relevant and accessible to the flow and discussion of my thesis, when and if that happened. Obviously, all my writing is not relevant to the main thrust of the thesis, but where major changes or departure points are marked in the discovery process of writing, these are illustrated by the work it produced. Looking back over the work of the past two years and the work on the Reflective Journal in particular, certain observations are better made now. The discipline of keeping a reflective journal did prove challenging from the point of view of controlling the spontaneity and avoiding reworking as much as possible apart from editing. Where a theme such as a discussion of another writer’s work became interesting to me, then the framework for the research and the reflective writing on it tended to take up the same timeframe, as experienced in “real” journal writing. Sometimes, the poetic work came first and the reflection later or vice versa. This allows the reader to see sometimes as much if not more than I see, as I have not drawn conclusions in a way which will make my reflection mean only what I want it to mean. Overall, the Consideration on Artistic Truth consists of subtle insights which came only after I had begun to discover, if only at an intuitive level, how my writing process works. This can be seen possibly in the way in the Journal it brings me back to reflecting on some of my earlier work, and discussing related matters such as giving and attending readings, and the politics of reviewing work. In that way I am repeatedly reconsidering and making new connections with the theme, perhaps in the light of new reading, discussions with fellow writers and classmates, and then coming to a new synthesis which explains the writing process over and over again

Identification of novel toxin inhibitors of apamin-sensitive calcium-activated potassium channels

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN026415 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Interaction of soft condensed materials with living cells: Phenotype/transcriptome correlations for the hydrophobic effect

The assessment of biomaterial compatibility relies heavily on the analysis of macroscopic cellular responses to material interaction. However, new technologies have become available that permit a more profound understanding of the molecular basis of cell–biomaterial interaction. Here, both conventional phenotypic and contemporary transcriptomic (DNA microarray-based) analysis techniques were combined to examine the interaction of cells with a homologous series of copolymer films that subtly vary in terms of surface hydrophobicity. More specifically, we used differing combinations of N-isopropylacrylamide, which is presently used as an adaptive cell culture substrate, and the more hydrophobic, yet structurally similar, monomer N-tert-butylacrylamide. We show here that even discrete modifications with respect to the physiochemistry of soft amorphous materials can lead to significant impacts on the phenotype of interacting cells. Furthermore, we have elucidated putative links between phenotypic responses to cell–biomaterial interaction and global gene expression profile alterations. This case study indicates that high-throughput analysis of gene expression not only can greatly refine our knowledge of cell–biomaterial interaction, but also can yield novel biomarkers for potential use in biocompatibility assessment

Prolonged cytotoxic effect of colchicine released from biodegradable microspheres

One the main problems of cancer chemotherapy is the unwanted damage to normal cells caused by the high toxicities of anticancer drugs. Any system of controlled drug delivery that would reduce the total amount of drug required, and thus reduce the side effects, would potentially help to improve chemotherapy. In this respect, biodegradable gelatin microspheres were prepared by water/oil emulsion polymerization and by crosslinking with glutaraldehyde (GTA) as the drug-carrier system. Microspheres were loaded with colchicine, a model antimitotic drug, which was frequently used as an antimitotic agent in cancer research involving cell cultures. Microsphere sizes, swelling and degradation properties, drug-release kinetics, and cytotoxities were studied. Swelling characteristics of microspheres changed upon changing GTA concentration. A decrease in swelling values was recorded as GTA crosslink density was increased. In vitro drug release in PBS (0.01M, pH 7.4) showed rapid colchicine release up to similar to83% (at t = 92 h) for microspheres with low GTA (0.05% v/v), whereas a slower release profile (only similar to39%) was obtained for microspheres with high GTA (0.50% v/v) content, for the same period. Cytotoxicity tests with MCF-7, HeLa and H-82 cancer cell lines showed that free colchicine was very toxic, showing an similar to100% lethal effect in both HeLa and H-82 cell lines and more than 50% decrease in viability in MCF-7 cells in 4 days. Indeed, entrapped colchicine indicated similar initial high toxic effect on cell viability in MCF-7 cell line and this effect became more dominant as colchicine continued to be released from microspheres in the same period. In conclusion, the control of the release rate of colchicine from gelatin microspheres was achieved under in vitro conditions by gelatin through the alteration of crosslinking conditions. Indeed, the results suggested the potential application of gelatin microspheres crosslinked with GTA as a sustained drug-delivery system for anticancer drugs for local chemotherapy administrations. (C) 2004 Wiley Periodicals, Inc

Coastal taipan (Oxyuranus scutellatus) envenomation of a dog

Case report: An 8-year-old mixed-breed dog was envenomed by a juvenile coastal taipan (Oxyuranus scutellatus). The dog presented initially with coagulopathy and weakness, then developed neuromuscular paralysis and respiratory failure. Progressive myopathy peaked 3 days following admission. Taipan antivenom administration, mechanical ventilation therapy and supportive patient care resulted in complete recovery. Symptoms of neuropathy began to resolve 3 days following envenomation, with the dog discharged 6 days following envenomation.\ud \ud Conclusion: To the author's knowledge, this is the first reported case of coastal taipan envenomation of a dog