15 resultados para Lawrence, C. W.

em Deakin Research Online - Australia


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New plasticized polymer electrolytes were synthesized based on poly ethylene oxide (PEO), Poly (N,N-dimethylamino-ethyl-methacrylate) (PDMAEMA), LiN(CF3SO2)2 (LITFSI) as the salt and tetraethylene glycol dimethyl ether(tetraglyme) and EC + PC as plasticizers. The preparation and characterization of the polymer electrolytes were investigated as a function of temperature and various concentrations of LITFSI. Impedance spectroscopy and differential scanning calorimeter (DSC) were used to characterize the effects of various temperature, lithium salt concentration and two plasticizers on conductivity. The complex of PDMAEMA/PEO/LiTFSI/tetraglyme (S2) exhibits higher conductivity (4.74 × 10−4 S cm−1at 25 °C) than PDMAEMA/PEO/LiTFSI/EC + PC (S1).

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This chapter describes two modifications made to the conventional ring spinning technology, termed Sirospun™ and Solospun™, which were primarily aimed at significantly reducing the production cost of fabrics. Both were invented at CSIRO in Australia, hence the name ‘Siro’ spinning. The properties of Sirospun and Solospun yarns are different from those of conventional ring-spun yarns and this has opened new market opportunities.

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We have measured forces between molecularly smooth solid surfaces separated by thin films of molten polydimethylsiloxane. We show that a long-range repulsion reported in earlier work is not an equilibrium force, but can be attributed to viscous drag effects. Consistent with previous results, the viscosity of the film can be modeled by assuming that a layer of polymer molecules is immobilized or ‘‘pinned’’ at each surface for a time longer than the time scale of the measurements. We propose that this pinning is a result of entanglement-like effects in the vicinity of a wall.

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Significant long term changes in the earth’s climate have occurred in the past but recently there has been more severe climate fluctuation than have occurred in the past few centuries. The effect of this climate change on the foundation conditions of roads and low-rise buildings is costing several hundred billion dollars world-wide. A method which tracks this climate change will be of great value for companies and governments. C.W. Thornthwaite (1948) defined the Thornthwaite Moisture Index (TMI) as the first base for his climate classification system and mapping in the United States. There are 3 important factors to predict ground movement: (a) the degree of moisture index change (b) the depth at which this change occurs and (c) the foundation soil type. The water budget model was used by Thornthwaite (1948) to calculate the moisture index. This paper also discusses two typical examples of the use of this model. Originally TMI’s were mainly used to map soil moisture conditions for agriculture but soon became a method to predict environmental and pavement foundation changes.

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The intracellular trafficking and subsequent incorporation of Gag-Pol into human immunodeficiency virus type 1 (HIV-1) remains poorly defined. Gag-Pol is encoded by the same mRNA as Gag and is generated by ribosomal frameshifting. The multimerization of Gag and Gag-Pol is an essential step in the formation of infectious viral particles. In this study, we examined whether the interaction between Gag and Gag-Pol is initiated during protein translation in order to facilitate the trafficking and subsequent packaging of Gag-Pol into the virion. A conditional cotransfection system was developed in which virion formation required the coexpression of two HIV-1-based plasmids, one that produces both Gag and Gag-Pol and one that only produces Gag-Pol. The Gag-Pol proteins were either immunotagged with a His epitope or functionally tagged with a mutation (K65R) in reverse transcriptase that is associated with drug resistance. Gag-Pol packaging was assessed to determine whether the Gag-Pol incorporated into the virion was preferentially packaged from the plasmid that expressed both Gag and Gag-Pol or whether it could be packaged from either plasmid. Our data show that translation of Gag and Gag-Pol from the same mRNA is not critical for virion packaging of the Gag-Pol polyprotein or for viral function.

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SMARCB1 is deleted in rhabdoid tumor, an aggressive paediatric malignancy affecting the kidney and CNS. We hypothesized that the oncogenic pathway in rhabdoid tumors involved epigenetic silencing of key cell cycle regulators as a consequence of altered chromatin-remodelling, attributable to loss of SMARCB1, and that this hypothesis if proven could provide a biological rationale for testing epigenetic therapies in this disease. We used an inducible expression system to show that the imprinted cell cycle inhibitor CDKN1C is a downstream target for SMARCB1 and is transcriptionally activated by increased histone H3 and H4 acetylation at the promoter. We also show that CDKN1C expression induces cell cycle arrest, CDKN1C knockdown with siRNA is associated with increased proliferation, and is able to compete against the anti-proliferative effect of restored SMARCB1 expression. The histone deacetylase inhibitor (HDACi), Romidepsin, specifically restored CDKN1C expression in rhabdoid tumor cells through promoter histone H3 and H4 acetylation, recapitulating the effect of SMARCB1 on CDKNIC allelic expression, and induced cell cycle arrest in G401 and STM91-01 rhabdoid tumor cell lines. CDKN1C expression was also shown to be generally absent in clinical specimens of rhabdoid tumor, however CDKN1A and CDKN1B expression persisted. Our observations suggest that maintenance of CDKN1C expression plays a critical role in preventing rhabdoid tumor growth. Significantly, we report for the first time, parallels between the molecular pathways of SMARCB1 restoration and Romidepsin treatment, and demonstrate a biological basis for the further exploration of histone deacetylase inhibitors as relevant therapeutic reagents in the treatment of rhabdoid tumor.

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This study aimed to develop and then test the reliability and validity of a new self-report questionnaire method called the building environmental quality questionnaire (BEQQ) designed to assess the perceived environmental quality in residential apartments in Hong Kong. A total of 108 (46 men and 62 women) Chinese-speaking residents, between 16 and 81 years of age, took part and completed the questionnaire study. The subjects were recruited from 12 different buildings of three distinct quality ratings (low, medium and high) assigned by the building assessment tool called the building health and hygiene index (BHHI). The study was evaluated to determine reliability and this was assessed involving 20 of the participants (18% of the total sample size). The BEQQ was found to have good test-retest reliability, with intra-class correlation coefficient (ICC) values typically around 0.70. The validity testing, also using ICCs, generated moderate to high values for all BEQQ sub-categories (the mean value was around 0.80), indicating a good consistency among residents living within the same building. Finally, the summary BEQQ scores were significantly correlated (—0.68) with the BHHI ratings as the criterion standard. It is concluded that this eight-dimension instrument would provide a short and efficient questionnaire method to obtain self-reported information to determine the perceived residential building quality. The method was shown to yield adequate reliability and has been validated for use in empirical research.

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Geographer C. W. Thornthwaite proposed in 1948 a moisture index called Thornthwaite Moisture Index (TMI) as part of a water balance model for a new classification system for climate. The importance of TMI climatic classification has been recognised in many areas of knowledge and practice worldwide over the last 60 years. However, although past climate research was focused on developing adequate methods for climate classification, current research is more concerned with understanding the patterns of climate change. The use of TMI as an indicator for climate change is still an incipient area of research. The contributions of this paper are twofold. First, it is to fully document a methodology based on geostatistics adopted to produce a time series of TMI maps that are accurate and have high spatial resolution. The state of Victoria, in Australia, over the last century, is used as the case study. Second, by analysing these maps, the paper presents a general evaluation of the spatial patterns found in Victoria related to moisture variability across space and over time. Some potential implications of the verified moisture changes are discussed, and a number of ideas for further development are suggested. © 2014 Institute of Australian Geographers.