http://espace.library.uq.edu.au/ The University of Queensland en Fez http://blogs.law.harvard.edu/tech/rss http://espace.library.uq.edu.au/view/UQ:274033 Electrospun scaffolds manufactured using conventional electrospinning configurations have an intrinsic thickness limitation, due to a charge build-up at the collector. To overcome this limitation, an electrostatic lens has been developed that, at the same relative rate of deposition, focuses the polymer jet onto a smaller area of the collector, resulting in the fabrication of thick scaffolds within a shorter period of time. We also observed that a longer deposition time (up to 13 h, without the intervention of the operator) could be achieved when the electrostatic lens was utilised, compared to 9-10 h with a conventional processing set-up and also showed that fibre fusion was less likely to occur in the modified method. This had a significant impact on the mechanical properties, as the scaffolds obtained with the conventional process had a higher elastic modulus and ultimate stress and strain at short times. However, as the thickness of the scaffolds produced by the conventional electrospinning process increased, a 3-fold decrease in the mechanical properties was observed. This was in contrast to the modified method, which showed a continual increase in mechanical properties, with the properties of the scaffold finally having similar mechanical properties to the scaffolds obtained via the conventional process at longer times. This "focusing" device thus enabled the fabrication of thicker 3-dimensional electrospun scaffolds (of thicknesses up to 3.5 mm), representing an important step towards the production of scaffolds for tissue engineering large defect sites in a multitude of tissues. 2012-05-14T22:08:58Z Vaquette, Cédryck og Cooper-White, Justin http://espace.library.uq.edu.au/view/UQ:242752 Provenance studies of iron-age pottery specimens originating from the Mngeni river area in South Africa was carried out by applying XRF spectrometry. A total of sixteen major and trace elements were analysed in a batch of 107 potsherds, excavated from four different archaeological sites in the aforementioned area. A multivariate statistical programme Correspondence Analysis was used in this study to obtain the relevant clustering patterns according to the similarity of the elemental distributions. Differences and similarities in the clusters obtained for the majors and trace elements are discussed. 2011-06-22T00:00:00Z Punyadeera, C. og Jacobson, L. http://espace.library.uq.edu.au/view/UQ:35561 Incorporation of 1 wt % of triallyl isocyanurate (TAIC) significantly enhanced the radiation crosslinking of the perfluoroelastomer, poly(tetrafluoroethylene-co-perfluoromethylvinyl ether) (TFE/PMVE). The dose for gelation was lowered by 70% with the presence of TAIC. The additive also improved the tensile properties of TFE/ PMVE both before and after crosslinking by irradiation. Higher radical yields were obtained with the presence of TAIC at 77 K, indicating the crosslinking promoter was acting as a radical trap. ESR studies showed that radiolysis of TAIC and subsequent photobleaching cleaved an allyl branch from the ring structure. Upon thermal annealing, an allyl radical on the TAIC molecule was observed. (C) 1999 John Wiley & Sons, Inc. 2007-08-13T00:00:00Z Forsythe, J. S. og Hill, D. J. T. og Logothetis, A. L. og Pomery, P. J. og Whittaker, A. K. http://espace.library.uq.edu.au/view/UQ:58942 The radiation chemistry of poly(tetrafluoroethylene-co-perfluoropropylene), FEP, with a mole fraction of tetrafluoroethylene, TFE, of 0.90 has been studied under vacuum using Co-60 gamma -radiation over absorbed dose ranges up to 3.0 MGy. The radiolysis temperatures were 300, 363, 423 and 523 K. New structure formation in the copolymers was analyzed by solid-state F-19 NMR. The new structures formed in the copolymers have been identified and the G-values for the formation of new -CF3 groups was 2.2 at the lower temperatures and increased to 2.9 at 523 K. The G-value for the loss of original -CF3 groups was approximate to1.0 at all temperatures. At the lower temperatures there was a net loss of -CF-groups on irradiation, G(CF) of -1.3, -0.9 and -0.5 at 300, 363 and 423 K, respectively, but at 523 K there was a net gain with G(CF) equal to 0.8. (C) 2001 Elsevier Science B.V. All rights reserved. 2007-08-14T00:00:00Z Gleason, K. K. og Hill, D. J. T. og Lau, K. K. S. og Mohajerani, S. og Whittaker, A. K. http://espace.library.uq.edu.au/view/UQ:72477 2007-08-15T00:00:00Z Wackwella Gamage, N. og Hill, D. J. T. og Lukey, C. A. og Pomery, P. http://espace.library.uq.edu.au/view/UQ:163067 We have used a novel hybrid nano-structured sponge to conduct proof of concept studies for the oral delivery of peptides employing insulin as the loaded model drug. The hybrid sponge was synthesized from a modified acid-base neutralization reaction for hydroxyapatitc (HA) incorporating cMtosan (CHT) as the organic counterpart. The trace addition of chitosan during synthesis resulted in a hybrid colloidal suspension which could be dried to from this hybrid sponge. The sponge morphology was unique indicating two levels of structure with assembled nanoparticles combined with nanoporous HA-CHT architecture. These films showed relatively high levels of insulin loading (~700IU/g of carrier) and could be coated with an alginate based gel. Release of insulin in simulated gastric and intestinal fluids (SGF and SIF) indicated that release was predominant in intestinal conditions and that a complex double mode kinetic release profile was inherent in the system. However, we believe at this stage that this characteristic can be rationalized as the combined effect of release from the drug adsorbed onto the nanoparticles and condensed into the nanoporous architecture. Overall the loading and release were promising and further studies are currently underway to incorporate other functional modifications in the sponge and in vitro characterization. 2009-02-05T00:00:00Z Kumar, Rajendra og Prakash, Kithva Hariram og Cheang, Philip og Aik, Khor Khiam http://espace.library.uq.edu.au/view/UQ:58957 The radiation chemistry of two TFE/PMVE copolymers with TFE mole fractions of 0.66 and 0.81 has been studied under vacuum using Co-60 gamma -radiation over absorbed dose ranges up to 4.2 MGy. The radiolysis temperature was 313 K for both TFE/PMVE copolymers. New structure formation in the copolymers was identified by solid-state F-19 NMR and the G-values for new chain ends of 2.1 and 0.5 and for branching sites of 0.9 and 0.2 have been obtained for the TFE/PMVE with TFE mole fractions of 0.66 and 0.81, respectively. The relative yields of-O-CF3 and -CF2-CF3 chain ends were found to be proportional to the copolymer composition, but the yields of the -CF2-CF3 chain ends and -CF- branch points mere not linearly related ia the composition. rather they wets correlated with the radical yields measured at 77 K. (C) 2001 Elsevier Science Ltd. All rights reserved. 2007-08-14T00:00:00Z Forsythe, J. S. og Hill, D. J. T. og Whittaker, A. K. http://espace.library.uq.edu.au/view/UQ:112928 Solid and solution IR and Raman spectra of a stable nitroxide radical, 1,1,3,3-tetramethylisoindolin-2-yloxyl (TMIO), are reported and compared to ab initio density functional theory calculations of the vibrational frequencies to obtain unequivocal band assignments, in particular of the N-O degrees stretching frequency, v(N-O degrees). The band position was found to be at 1431 cm(-1) for the solid, which is well outside the previously published range of 1310-1380 cm(-1) for nitroxide radicals. This apparently anomalous peak position was confirmed by undertaking isotopic substitution studies through the preparation and recording of vibrational spectra of tetrakis(trideuteriomethyl)isoindolin-2-yloxyl ([H-2(12)]-TMIO) and [H-2(12),N-15]-TMIO analogues. Solution spectra of TMIO in methanol and CCl4 are assessed for possible solvent-dependent spin density distribution effects in the N-O degrees bond. (c) 2005 Elsevier B.V. All rights reserved. 2007-09-19T00:00:00Z Rintoul, L. og Micallef, A. S. og Reid, D. A. og Bottle, S. E. http://espace.library.uq.edu.au/view/UQ:35137 The adsorbed film in small cylindrical mesopores is studied by using MCM-41 samples of uniform cylindrical channels as model systems. It is found that at a given relative pressure, the smaller the pore radius, the thicker the adsorbed film is, as postulated by Broekhoff and De Beer. Thermodynamics analysis established that the stability of the adsorbed film is determined by interface curvature and the potential of interaction between adsorbate and adsorbent. A semiempirical equation is proposed to describe the state of stable adsorbed films in cylindrical mesopores. It is also shown to be useful in calculations of pore size distributions of mesoporous solids. 2007-08-13T00:00:00Z Zhu, HY og Lu, GQ og Zhao, XS http://espace.library.uq.edu.au/view/UQ:116186 Polyelectrolyte (PE)-encapsulated catalase microcrystals were assembled onto gold electrodes by their sequential deposition with oppositely charged PEs, utilizing electrostatic interactions to form enzyme thin films for biosensing. The PE coating around the microcrystals provided a regular surface charge, thus facilitating the stepwise film growth, and it effectively prevented catalase leakage from the assembled films. The encapsulated catalase was shown to retain both its biological and its electrochemical activity. Direct electron transfer between catalase molecules and the gold electrode was achieved without the aid of any electron mediator. In pH 5.0 phosphate buffer solution, the apparent formal potential (E-o') of catalase was -0.131 V (vs Ag/AgCl). As a H2O2 biosensor, films consisting of one layer of the encapsulated catalase displayed considerably higher (similar to5-fold) and more stable electrocatalytic responses to the reduction of H2O2 than did corresponding films made of one layer of nonencapsulated catalase or solubilized catalase. An increase in either the number of "precursor" PE layers between the gold electrodes and the catalase microcrystal layers in the film or the number of PE layers encapsulating the catalase microcrystals was found to decrease the electrocatalytic activity of the electrode. At low precursor PE layer numbers (similar to2) and PE encapsulating layers (similar to4), the current response was proportional to the H2O2 concentration in the range 3.0 x 10(-6) to 1.0 X 10(-2) M. The overall electroactivity of the multilayer film increased for the first two layers of encapsulated catalase, after which a plateau was observed. This was attributed to the increasing difficulty of electron transfer and substrate diffusion limitations. The current approach of using immobilized PE-encapsulated enzyme microcrystals for biosensing provides a versatile method to prepare high enzyme content films with high and tailored enzyme activities. 2007-10-17T00:00:00Z Yu, AM og Caruso, F http://espace.library.uq.edu.au/view/UQ:237977 2011-03-22T00:00:00Z Cavalieri, Francesca og Ng, Sher Leen og Mazzuca, Claudia og Jia, Zhongfan og Bulmus, Volga og Davis, Thomas P. og Caruso, Frank http://espace.library.uq.edu.au/view/UQ:283463 2012-10-16T00:00:00Z Vinu, Ajayan og Srinivasu, Pavuluri og Sawant, Dhanashri P. og Mori, Toshiyuki og Ariga, Katsuhiko og Chang, Jong-San og Jhung, Sung-Hwa og Balasubramanian, Veerappan Vaithilingam og Hwang, Young Kyu http://espace.library.uq.edu.au/view/UQ:161516 The aim of this study was to develop and validate a simple and compact bioreactor system for perfusion cell seeding and culture through 3-dimensional porous scaffolds. The developed Tissue Culture Under Perfusion (T-CUP) bioreactor is based on the concept of controlled and confined alternating motion of scaffolds through a cell suspension or culture medium, as opposed to pumping of the fluid through the scaffolds. Via the T-CUP, articular chondrocytes and bone marrow stromal cells could be seeded into porous scaffolds of different compositions and architectures (chronOS™, Hyaff ®-11, and Polyactive™) at high efficiency (greater than 75%), uniformity (cells were well distributed throughout the scaffold pores), and viability (greater than 97%). Culture of articular chondrocytes seeded into 4-mm thick Polyactive™ scaffolds for 2 weeks in the T-CUP resulted in uniform deposition of cartilaginous matrix. Cultivation of freshly isolated human bone marrow nucleated cells seeded into ENGipore ceramic scaffolds for 19 days in the T-CUP resulted in stromal cell-populated constructs capable of inducing ectopic bone formation in nude mice. The T-CUP bioreactor represents an innovative approach to simple, efficient, and reliable 3D cell culture, and could be used either as a model to investigate mechanisms of tissue development or as a graft manufacturing system in the context of regenerative medicine. 2009-01-22T00:00:00Z Timmins, Nicholas E. og Scherberich, Arnaud og Früh, Jennifer-Annika og Heberer, Michael og Martin, Ivan og Jakob, Marcel http://espace.library.uq.edu.au/view/UQ:242728 We have developed a new protein microarray (Immuno-Flow Protein Platform, IFPP) that utilizes a porous nitrocellulose (NC) membrane with printed spots of capture probes. The sample is pumped actively through the NC membrane, to enhance binding efficiency and introduce stringency. Compared to protein microarrays assayed with the conventional incubation-shaking method the rate of binding is enhanced on the IFPP by at least a factor of 10, so that the total assay time can be reduced drastically without compromising sensitivity. Similarly, the sensitivity can be improved.We demonstrate the detection of 1 pM of C-reactive protein (CRP) in 70 μL of plasma within a total assay time of 7 min. The small sample and reagent volumes, combined with the speed of the assay, make our IFPP also well-suited for a point-of-care/near patient setting. The potential clinical application of the IFPP is demonstrated by validating CRP detection both in human plasma and serum samples against standard clinical laboratory methods. 2011-06-22T00:00:00Z Van Lieshout, R. M. L. og van Domburg, T. og Saalmink, M. og Verbeek, R. og Wimberger-Friedl, R. og van Dieijen-Visser, M. P. og Punyadeera, C. http://espace.library.uq.edu.au/view/UQ:287240 2012-12-14T15:53:47Z Saleh, Fatima A. og Frith, Jessica E. og Lee, Jennifer A. og Genever, Paul G. http://espace.library.uq.edu.au/view/UQ:123404 Two kinds of highly ordered mesoporous silica materials (FDU-11, FDU-13) with novel three-dimensional (3-D) tetragonal and orthorhombic structures were synthesized by using tetra-headgroup rigid bolaform quaternary ammonium surfactant [(CH3)(3)NCH2CH2CH2N(CH3)(2)CH2(CH2)(11)OC(6)H(4)C6H(4)O(CH2)(11)CH2N(CH3)(2)CH2CH2CH2N(CH3)(3)-4Br] (C3-12-12-3) as a template under alkaline conditions. High-resolution transmission electron microscopy (HRTEM), small-angle X-ray scattering (SAXS), and X-ray diffraction (XRD) show that mesoporous silica FDU-11 has primitive tetragonal P4/mmm structure with cell parameters a = b = 8.46 nm, c = 5.22 nm, and c/a ratio = 0.617. N-2 sorption isotherms show that calcined FDU-11 has a high BET surface area of ∼ 1490 m(2)/g, a uniform pore size of ∼ 2.72 nm, and a pore volume of ∼ 1.88 cm(3)/g. Mesoporous silica FDU-13 has primitive orthorhombic Pmmm structure. The cell parameters are a = 9.81, b = 5.67, and c = 3.66 nm. N2 sorption isotherms show that calcined FDU-13 has a high BET surface area of 1210 m(2)/g, a uniform mesopore size of ∼ 1.76 nm, and a large pore volume of ∼ 1.83 cm(3)/g. Such low symmetries for 3-D mesostructures (tetragonal and orthorhombic system) have not been observed before even in amphiphilic liquid crystals, which maybe resulted from an oblate aggregation of the bolaform surfactant and its strong electrostatic interaction with inorganic precursor. A probable mechanism has been proposed for the formation of such a 3-D low symmetrical mesostructure. These results will further extend the synthesis of mesoporous materials and may open up new opportunities for their new applications in catalysis, separation, and nanoscience. 2008-01-25T00:00:00Z Shen, SD og Garcia-Bennett, AE og Liu, Z og Lu, QY og Shi, YF og Yan, Y og Yu, CZ og Liu, WC og Cai, Y og Terasaki, O og Zhao, DY http://espace.library.uq.edu.au/view/UQ:252355 2011-09-20T00:00:00Z Yan, Weidong og Li, Haiqing og Shen, Xiaoli http://espace.library.uq.edu.au/view/UQ:283361 2012-10-16T00:00:00Z Chakravarti, R. og Oveisi, H. og Kalita, P. og Pal, R. R. og Halligudi, S. B. og Kantam, M. L. og Vinu, A. http://espace.library.uq.edu.au/view/UQ:283454 2012-10-16T00:00:00Z Srinivasu, Pavuluri og Vinu, Ajayan http://espace.library.uq.edu.au/view/UQ:283474 Here we report for the first time on the preparation of well-ordered titanium substituted KIT-6 at low acid concentration using polymeric surfactant. The characterization results show that the pore diameter and the unit cell constant of TiKIT-6 increase with increasing Ti incorporation. UV-vis results reveal that most of the Ti are in tetrahedral coordination. In addition, the materials showed higher activity in the epoxidation of styrene than TiSBA-15. 2012-10-16T00:00:00Z Vinu, Ajayan og Srinivasu, Pavuluri og Balasubramanian, Veerappan V. og Ariga, Katsuhiko og Mori, Toshiyuki og Nemoto, Yoshihiro http://espace.library.uq.edu.au/view/UQ:283455 2012-10-16T00:00:00Z Vinu, Ajayan og Gokulakrishnan, Narasimhan og Balasubramanian, Veerappan V. og Alam, Sher og Kapoor, Mahendra P. og Ariga, Katsuhiko og Mori, Toshiyuki http://espace.library.uq.edu.au/view/UQ:162027 2009-01-28T00:00:00Z Aljada, M. og Alameh, K. og Al-Begain, K. http://espace.library.uq.edu.au/view/UQ:67124 2007-08-15T00:00:00Z Thomas, A. C. og Campbell, J. H. http://espace.library.uq.edu.au/view/UQ:272774 2012-04-16T12:55:14Z Xing, Jun og Fang, Wen Qi og Li, Zhen og Yang, Hua Gui http://espace.library.uq.edu.au/view/UQ:230366 2011-02-27T00:00:00Z Wang, Xuewen og Liu, Gang og Wang, Lianzhou og Pan, Jian og Lu, Gao Qing (Max) og Cheng, Hui-Ming http://espace.library.uq.edu.au/view/UQ:256524 2011-10-18T00:00:00Z Guo, WeiChao og Wan, JingJing og Qian, K. og Yu, ChengZhong og Kong, JiLie og Yang, PengYuan og Liu, BaoHong http://espace.library.uq.edu.au/view/UQ:234999 2011-03-11T00:00:00Z Wan, Jingjing og Qian, Kun og Qiao, Liang og Wang, Yunhua og Kong, Jilie og Yang, Pengyuan og Liu, Baohong og Yu, Chengzhong http://espace.library.uq.edu.au/view/UQ:75996 2007-08-15T00:00:00Z Hoenig, Michel R. og Campbell, Gordon R. og Rolfe, Barbara E. og Campbell, Julie H. http://espace.library.uq.edu.au/view/UQ:253076 2011-09-23T00:00:00Z Rotmans, J. I. og Campbell, J. H. http://espace.library.uq.edu.au/view/UQ:201448 2010-03-31T16:07:51Z Leung, Andy og Nielsen, Lars K. og Trau, Matt og Timmins, Nicholas E. http://espace.library.uq.edu.au/view/UQ:194284 2010-01-31T00:00:00Z Su, Yonghua og Qiao, Shizhang og Yang, Huagui og Yang, Chen og Jin, Yonggang og Stahr, Frances og Sheng, Jiayu og Cheng, Lina og Ling, Changquan og Lu, Gao Qing http://espace.library.uq.edu.au/view/UQ:223480 2010-12-05T00:00:00Z Sun, Chenghua og Liu, Li-Min og Selloni, Annabella og Lu, Gao Qing (Max) og Smith, Sean C. http://espace.library.uq.edu.au/view/UQ:191978 2010-01-11T00:00:00Z de Meijere, Armin og Kozhushkov, Sergei I. og Savchenko, Andrei I. http://espace.library.uq.edu.au/view/UQ:185854 2009-11-12T12:01:48Z Liu, Gang og Lu, Haofeng og Chen, Zhigang og Li, Feng og Wang, Lianzhou og Watts, Josh og Lu, Gao Qing og Cheng, Hui-Ming http://espace.library.uq.edu.au/view/UQ:269124 2012-03-06T12:04:05Z Gu, Wenyi og Chen, Jeizhong og Yang, Lei og Zhao, Kong-Nan http://espace.library.uq.edu.au/view/UQ:234790 2011-03-10T00:00:00Z Zhu, Shaoli og Fu, Yongqi og Hou, Junzhan http://espace.library.uq.edu.au/view/UQ:195190 2010-02-11T00:00:00Z Chaleat, C. og Halley, P. og Truss, R. http://espace.library.uq.edu.au/view/UQ:101255 2007-08-23T00:00:00Z Altmann, N. og Halley, P. J. http://espace.library.uq.edu.au/view/UQ:162642 Therapeutic drugs can assist some patients, however, other individuals may exhibit no response. Furthermore, a drug that is normally considered to be safe can have toxic effects in a small proportion of the population, occasionally causing death. Many altered drug responses depend on the genetic constitution of the recipient. The analysis of specific DNA markers within the genome of an individual [single nucleotide polymorphism (SNP) genotyping] could potentially identify subjects at risk in clinical trials and may enable clinicians to individualise medical therapy. The development of technology for personalised medicine relies on the ability to accurately and rapidly identify SNPs in genetic material. Some of the biotechnology tools for SNP identification are colloid-based biosensors, which are proving to possess several advantages over the traditional microarray format. Here, we survey the current technologies used for SNP genotyping and review colloid-based biosensors which are emerging as a higher throughput, potentially more accurate, technology. 2009-02-03T10:25:47Z Johnston, Angus P. R. og Lawrie, Gwendolyn A. og Battersby, Bronwyn J. og Corrie, Simon R. og Trau, Matt http://espace.library.uq.edu.au/view/UQ:198389 2010-03-09T00:00:00Z Brumbley, S. M. og Casu, R. E. og Drenth, J. og Godwin, I. D. og Hermann, S. R. og Knight, D. og Manners, J. M. og Mcintyre, C. L og Smith, G. R. og Tao, Y. og Williams, S. B. http://espace.library.uq.edu.au/view/UQ:234031 With the completion of the first draft of the human genome sequence, the next major challenge is assigning function to genes. One approach is genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes of interest and subsequent mapping and identification of the mutated genes in question. We (a consortium made up of GlaxoSmithKline, the MRC Mammalian Genetics Unit and Mouse Genome Centre, Harwell, Imperial College, London, and the Royal London Hospital) have used ENU mutagenesis in the mouse for the rapid generation of novel mutant phenotypes for use as animal models of human disease and for gene function assignment (Nolan et al., 2000). As of 2003, 35,000 mice have been produced to date in a genome-wide screen for dominant mutations and screened using a variety of screening protocols. Nearly 200 mutants have been confirmed as heritable and added to the mouse mutant catalogue and, overall, we can extrapolate that we have recovered over 700 mutants from the screening programme. For further information on the project and details of the data, see http://www.mgu.har.mrc.ac.uk/mutabase. 2011-03-09T00:00:00Z Rastan, S. og Hough, T. og Kierman, A. og Hardisty, R. og Erven, A. og Gray, I. C. og Voeling, S. og Isaacs, A. og Tsai, H. og Strivens, M. og Washbourne, R. og Thornton, C. og Greenaway, S. og Hewitt, M. og McCormick, S. og Selley, R. og Wells, C. og Tymowska-Lalanne, Z. og Roby, P. og Mburu, P. og Rogers, D. og Hagan, J. og Reavill, C. og Davies, K. og Glenister, P. og Fisher, E. M. C. og Martin, J. og Vizor, L. og Bouzyk, M. og Kelsell, D. og Guenet, J. L. og Steel, K. P. og Sheardown, S. og Spurr, N. og Gray, I. og Peters, J. og Nolan, P. M. og Hunter, A. J. og Brown, S. D. M. http://espace.library.uq.edu.au/view/UQ:282833 2012-10-05T00:00:00Z Cunning, Benjamin V. og Searles, Debra J. og Bhatia, Suresh K. http://espace.library.uq.edu.au/view/UQ:211445 2010-08-08T00:00:00Z Dietmair, Stefanie og Timmins, Nicholas E. og Gray, Peter P. og Nielsen, Lars K. og Kromer, Jens O. http://espace.library.uq.edu.au/view/UQ:217344 2010-09-28T00:00:00Z Mendum, Tom A. og Newcombe, Jane og McNeilly, Celia L. og McFadden, Johnjoe http://espace.library.uq.edu.au/view/UQ:219613 We have developed a simple and sensitive on-chip preconcentration, separation, and electrochemical detection (ED) method for trace analysis of DNA. The microchip comprised of three parallel channels: the first two are for the field-amplified sample stacking and subsequent field-amplified sampled injection steps, while the third one is for the microchip gel electrophoresis (MGE) with ED (MGE-ED). To improve preconcentration and separation performances of the method, the stacking and separation buffers containing the hydroxypropyl cellulose (HPC) matrix were modified with gold nanoparticles (AuNPs). The formation of AuNPs and HPC/AuNP-modified buffers were characterized by UV−visible spectroscopy and TEM experiments. The conducting polymer-modified electrode was also modified with AuNPs to enhance detection performances of the electrode. The conducting polymer/AuNP layers act as electrocatalysts for the direct detection of DNA based on their oxidation in a solution phase. The total sensitivity was improved by 25000-fold when compared with a conventional MGE-ED analysis. The calibration plots were linear (r2 = 0.9993) within the range of 0.003−1.0 pg/μL for a 20-bp DNA sample. The sensitivity was 0.20 nA/(fg/μL), with a detection limit of 5.7 amol in a 50-μL sample, based on S/N = 3. The applicability of the method for the analysis of 13 fragments present in a 100-bp DNA ladder was successfully demonstrated. 2010-11-02T00:00:00Z Shiddiky , Muhammad J. A. og Shim, Yoon-Bo http://espace.library.uq.edu.au/view/UQ:164184 The soil bacterium Bacillus subtilis can use sugars or organic acids as sources of carbon and energy. These nutrients are metabolized by glycolysis, the pentose phosphate pathway, and the Krebs citric acid cycle. While the response of B. subtilis to the availability of sugars is well understood, much less is known about the changes in metabolism if organic acids feeding into the Krebs cycle are provided. If B. subtilis is supplied with succinate and glutamate in addition to glucose, the cells readjust their metabolism as determined by transcriptome and metabolic flux analyses. The portion of glucose-6-phosphate that feeds into the pentose phosphate pathway is significantly increased in the presence of organic acids. Similarly, important changes were detected at the level of pyruvate and acetyl coenzyme A (acetyl-CoA). In the presence of organic acids, oxaloacetate formation is strongly reduced, whereas the formation of lactate is significantly increased. The alsSD operon required for acetoin formation is strongly induced in the presence of organic acids; however, no acetoin formation was observed. The recently discovered phosphorylation of acetolactate decarboxylase may provide an additional level of control of metabolism. In the presence of organic acids, both types of analyses suggest that acetyl-CoA was catabolized to acetate rather than used for feeding the Krebs cycle. Our results suggest that future work has to concentrate on the posttranslational mechanisms of metabolic regulation. 2009-02-12T14:55:33Z Schilling, Oliver og Frick, Oliver og Herzberg, Christina og Ehrenreich, Armin og Heinzle, Elmar og Wittmann, Christoph og Stülke, Jörg http://espace.library.uq.edu.au/view/UQ:110161 Yeast cells were induced to proliferate peroxisomes, and microarray transcriptional profiling was used to identify PEX genes encoding peroxins involved in peroxisome assembly and genes involved in peroxisome function. Clustering algorithms identified 224 genes with expression profiles similar to those of genes encoding peroxisomal proteins and genes involved in peroxisome biogenesis. Several previously uncharacterized genes were identified, two of which, YPL112c and YOR084w, encode proteins of the peroxisomal membrane and matrix, respectively. Ypl112p, renamed Pex25p, is a novel peroxin required for the regulation of peroxisome size and maintenance. These studies demonstrate the utility of comparative gene profiling as an alternative to functional assays to identify genes with roles in peroxisome biogenesis. 2007-09-19T00:00:00Z Smith, J. J. og Marelli, M. og Christmas, R. H. og Vizeacoumar, F. J. og Dilworth, D. J. og Ideker, T. og Galitski, T. og Dimitrov, K. og Rachubinski, R. A. og Aitchison, J. D. http://espace.library.uq.edu.au/view/UQ:295203 2013-03-29T03:39:22Z Nguyen, Quan og Palfreyman, Robin W. og Chan, Leslie C. L. og Reid, Steven og Nielsen, Lars K. http://espace.library.uq.edu.au/view/UQ:178111 2009-06-03T00:00:00Z Kendall, M.A.F. http://espace.library.uq.edu.au/view/UQ:294048 2013-03-17T01:33:10Z Anand, Chokkalingam og Priya, Subramaniam Vishnu og Lawrence, Geoffrey og Mane, Gurudas P. og Dhawale, Dattatray S. og Prasad, Kumaresapillai S. og Balasubramanian, Veerappan V. og Wahab, Mohammad A. og Vinu, Ajayan