24 research outputs found

    Centrifugally Spun PHBV Micro and Nanofibres

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    This paper reports the first study on centrifugal spinning of PHBV fibres. Fibres were spun from solution using a range of polymer concentrations, spin speeds and spinneret to collector distances. A PHBV polymer concentration of 25% w/v spun at 9000 r min⁻Âč produced the highest quality fibres, with fibre diameters predominantly in the 0.5-3 ÎŒm range. The rate at which fibre could be produced at the 9000 r min‟Âč spin speed and with a spinneret to collector distance of 39.2 cm was equivalent to 11 km of fibre per minute per needle. Average fibre strengths of 3 MPa were achieved, together with average moduli of 100 MPa, indicating that the fibres had higher strength but lower stiffness than electrospun PHBV. The productivity and mechanical properties achieved, together with the excellent biocompatibility of PHBV, means that these fibres have potential for application in a range of biomedical applications

    Collection of Epithelial Cells from Rodent Mammary Gland Via Laser Capture Microdissection Yielding High-Quality RNA Suitable for Microarray Analysis

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    Laser capture microdissection (LCM) enables collection of cell populations highly enriched for specific cell types that have the potential of yielding critical information about physiological and pathophysiological processes. One use of cells collected by LCM is for gene expression profiling. Samples intended for transcript analyses should be of the highest quality possible. RNA degradation is an ever-present concern in molecular biological assays, and LCM is no exception. This paper identifies issues related to preparation, collection, and processing in a lipid-rich tissue, rodent mammary gland, in which the epithelial to stromal cell ratio is low and the stromal component is primarily adipocytes, a situation that presents numerous technical challenges for high-quality RNA isolation. Our goal was to improve the procedure so that a greater probe set present call rate would be obtained when isolated RNA was evaluated using Affymetrix microarrays. The results showed that the quality of RNA isolated from epithelial cells of both mammary gland and mammary adenocarcinomas was high with a probe set present call rate of 65% and a high signal-to-noise ratio

    Simultaneous Impact of the Presence of Foreign MNEs on Indigenous Firms’ Exports and Domestic Sales

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    YesIncorporating the global production network approach and competitor analysis, this paper establishes an analytical framework with two hypotheses for the role of foreign multinational enterprises (FMNEs) in indigenous firms’ exports and domestic sales. First, the presence of FMNEs as a whole is likely to have a negative impact on indigenous firms’ domestic sales but a simultaneous positive impact on their exports in an emerging economy like China. Second, the presence of MNEs from Hong Kong, Macau and Taiwan (HMT MNEs) is more likely to generate this pattern of impact than MNEs from other countries (Other FMNEs). The FDI-led export strategy contributed to the dominance of the scenario described by the first hypothesis in China, while a higher degree of market commonality and resource similarity of HMT MNEs with that of indigenous Chinese firms than Other FMNEs leads to the second hypothesis. These novel hypotheses are tested and supported by a very large and recent firm-level panel dataset from Chinese manufacturing

    Medical imaging and facial soft tissue thickness studies for forensic craniofacial approximation: a pilot study on modern Cretans

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    Forensic cases may require craniofacial approximations for unidentifiable victims. The accuracy of these approximations is improved by using population-specific average soft tissue depths. This study used CT scans from 64 Cretan adults (32 male and 32 female) to produce three-dimensional models of each individual’s cranium and skin surface. Using the models, the soft tissue depths were measured at 36 craniofacial landmarks; the means and standard deviations were calculated for the general Cretan population, and for male and female Cretans separately. Cretan facial soft tissue depths were then compared to those of French, Slovak, and Korean adults. 16 of the 36 landmarks exhibited sex differences among Cretans, with males having consistently thicker depths than females. The facial soft tissue depths of Cretan adults also presented significant differences when compared to other populations. Overall, the average soft tissue depths obtained represent the first database for the craniofacial approximation of Cretan (Greek) adults
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