Library Publications
Permanent URI for this community
Browse
Browsing Library Publications by Title
Now showing 1 - 20 of 91209
Results Per Page
Sort Options
Item Restricted 048. Glass(Mohrs Siebeck, 2021) O'Hea, M.Item Metadata only 0D (MoS₂)/2D (g-C₃N₄) heterojunctions in Z-scheme for enhancedphotocatalytic and electrochemical hydrogen evolution(Elsevier, 2018) Liu, Y.; Zhang, H.; Ke, J.; Zhang, J.; Tian, W.; Xu, X.; Duan, X.; Sun, H.; O Tade, M.; Wang, S.MoS2 quantum dots (MSQDs) with high and stable dispersion in water were prepared via a facile one-pot hydrothermal process. The MSQDs were then applied to decorate graphitic carbon nitride (g-C3N4, CN) nanosheets to obtain modified g-C3N4 photocatalysts (MSQD-CN). Compared to pristine g-C3N4, the hybrid photocatalysts showed a slight red shift and stronger light absorption with remarkably improved photocatalytic activity in water splitting to generate hydrogen. The hydrogen-evolution rate over 0.2 wt% MSQD-CN increased by 1.3 and 8.1 times as high as that of 0.2 wt% Pt-CN and g-C3N4, respectively. With deposition of 2 wt% Pt as a cocatalyst, 5 wt% MSQD-CN exhibited the highest photocatalytic efficiency with an average hydrogen evolution reaction (HER) rate of 577 μmol h−1 g−1. Photoluminescence spectra (PL) and photoelectrochemical measurements inferred that MSQDs introduction drastically promoted the electron transfer for more efficient separation of charge carriers, which could lower HER overpotential barriers and enhance the electrical conductivity. In addition, the well-matched band potentials of the MSQD-CN hybrid with an intimate contact interface of p-n heterojunction also inhibited the recombination of photo-generated carriers, leading to enhanced photocatalytic HER performance. A direct Z-scheme charge transfer mechanism of the MSQD-CN hybrid was proposed to further elaborate the synergistic effect between MSQDs, Pt and g-C3N4. This work underlines the importance of heterojunction interface and presents a feasible protocol for rational construction of g-C3N4 based photocatalysts for various photocatalytic applications.Item Metadata only 0D/2D heterojunctions of Vanadate quantum dots/graphitic carbon nitride nanosheets for enhanced visible-light-driven photocatalysis(Wiley, 2017) Ye, M.; Zhao, Z.; Hu, Z.; Liu, L.; Ji, H.; Shen, Z.; Ma, T.0D/2D heterojunctions, especially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility. Herein, unprecedent heterojunctions of vanadate (AgVO₃ , BiVO₄ , InVO₄ and CuV₂ O₆ ) QDs/graphitic carbon nitride (g-C₃ N₄ ) NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up-conversion absorption, and nitrogen coordinating sites of g-C₃ N₄ NSs, highly dispersed vanadate nanocrystals, as well as the strong coupling and band alignment between them lead to superior visible-light-driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts. This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto-electronic applications, not limited in photocatalysis.Item Metadata only (0D/3D) MoS₂ on porous graphene as catalysts for enhanced electrochemical hydrogen evolution(Elsevier, 2017) Liu, Y.; Zhu, Y.; Fan, X.; Wang, S.; Li, Y.; Zhang, F.; Zhang, G.; Peng, W.A new composite material consisting of 0D MoS2 nanodots and 3D MoS2 nano-flowers grown on porous reduced graphene oxide (P-rGO) was synthesized via a two-step process. The P-rGO with a surface area of 759 m2 g−1 was obtained by CO2 activation of reduced graphene oxide (rGO) at 800 °C. MoS2 was then grown on the P-rGO under hydrothermal conditions. Compared to the nonactivated rGO, P-rGO has functional pores for deposition of MoS2 nanodots and less charge transfer resistance, which can provide more active sites for hydrogen generation, thus leading to the improved activity of (0D/3D) MoS2/P-rGO in hydrogen evolution reaction (HER). The overpotential of (0D/3D) MoS2/P-rGO was only ∼150 mV vs. RHE, and the corresponding Tafel slope was ∼56 mV Dec−1, which is comparable to most of the present MoS2/Graphene HER catalysts. The (0D/3D) MoS2/P-rGO exhibits as an efficient noble metal free HER catalyst, and has great potential for the electrochemical hydrogen production.Item Metadata only 1,2,3-triazoles in peptidomimetic chemistry(Wiley-V C H Verlag GMBH, 2011) Pedersen, D.; Abell, A.The ability to synthesise small peptidomimetics that mimic the secondary structure of proteins is an ever expanding area of research directed at sourcing new medicinal agents and biological probes. A significant current challenge is to mimic protein epitopes under physiological conditions using small peptidomimetics that are easy to prepare. The copper- and ruthenium-catalysed Huisgen cycloaddition reactions provide such a general synthetic method, with the resulting 1,2,3-triazoles being good peptide bond mimics. The ability to prepare both 1,4- and 1,5-substituted 1,2,3-triazoles under these chemically benign conditions provides both “linear” and “bent” peptidomimetics. Examples of the use of 1,2,3-triazoles to define the geometry and properties of a peptidomimetic abound. This review highlights such successes but also describes a number of failures in order to guide and inspire future efforts of chemists in this area.Item Metadata only 1,2,3-Triazolyl amino acids as AMPA receptor ligands(Pergamon-Elsevier Science Ltd, 2010) Stanley, N.; Pedersen, D.; Nielsen, B.; Kvist, T.; Mathiesen, J.; Brauner-Osborne, H.; Taylor, D.; Abell, A.The central nervous system glutamate receptors are an important target for drug discovery. Herein we report initial investigations into the synthesis and glutamate receptor activity of 1,2,3-triazolyl amino acids. Two compounds were found to be selective AMPA receptor ligands, which warrant further investigation.Item Metadata only 1,2-dioxines as masked cis γ-hydroxy enones and their versatility in the synthesis of highly substituted γ-lactones(Amer Chemical Soc, 2002) Greatrex, B.; Kimber, M.; Taylor, D.; Fallon, G.; Tiekink, E.Addition of highly stabilized ester nucleophiles to 1,2-dioxines affords good to high yields of γ-lactones with high diastereoselectivity. Heterolytic or homolytic cleavage of the 1,2-dioxines under appropriate conditions generates the key reactive cis γ-hydroxy enones, which ultimately afford the observed γ-lactones. Diastereoselectivity is installed as a result of anti 1,4-addition by the ester enolate to the cis enones followed by intramolecular cyclization. The reaction is tolerant of a range of substitution patterns on the 1,2-dioxine while a broad range of esters are also accommodated. In addition to the synthesis of racemic γ-lactones, highly enantioenriched γ-lactones can also be synthesized when chiral cobalt(II) catalysts are employed for the initial homolytic ring-opening of the 1,2-dioxine.Item Metadata only 1,2-dioxines containing tethered hydroxyl functionality as convenient precursors for pyran syntheses(Amer Chemical Soc, 2005) Avery, T.; Caiazza, D.; Culbert, J.; Taylor, D.; Tiekink, E.A new method for the construction of tetrahydropyrans derived from readily available 1,2-dioxines containing a tethered hydroxyl moiety is described. The reaction proceeds via a base-catalyzed rearrangement of the 1,2-dioxines to either the isomeric cis or trans -hydroxy enones followed by intramolecular oxa-Michael addition of the tethered hydroxyl group.Item Metadata only 1,25-Dihydroxyvitamin D₃ and extracellular calcium promote mineral deposition via NPP1 activity in a mature osteoblast cell line MLO-A5(Elsevier Ireland Ltd, 2015) Yang, D.; Turner, A.; Wijenayaka, A.; Anderson, P.; Morris, H.; Atkins, G.Abstract not available.Item Metadata only (1,3)-β-glucan synthases in barley(Dept Plant Science, 2000) Li, J.; Burton, R.; Paech, N.; Koltunow, A.; Langridge, P.; Fincher, G.; 8th International Barley Genetics Symposium (22 Oct 2000 : Adelaide, Australia); Logue, D.Item Metadata only (1,3;1,4)-beta-D-glucans in cell walls of the Poaceae, lower plants, and fungi: A tale of two linkages(Oxford University Press, 2009) Burton, R.; Fincher, G.(1,3;1,4)-β-D-Glucans consist of unbranched and unsubstituted chains of (1,3)- and (1,4)-β-glucosyl residues, in which the ratio of (1,4)-β-D-glucosyl residues to (1,3)-β-D-glucosyl residues appears to influence not only the physicochemical properties of the polysaccharide and therefore its functional properties in cell walls, but also its adoption by different plant species during evolution. The (1,3;1,4)-β-D-glucans are widely distributed as non-cellulosic matrix phase polysaccharides in cell walls of the Poaceae, which evolved relatively recently and consist of the grasses and commercially important cereal species, but they are less commonly found in lower vascular plants, such as the horsetails, in algae and in fungi. The (1,3;1,4)-β-D-glucans have often been considered to be components mainly of primary cell walls, but recent observations indicate that they can also be located in secondary walls of certain tissues. Enzymes involved in the depolymerisation of (1,3;1,4)-β-D-glucans have been well characterized. In contrast, initial difficulties in purifying the enzymes responsible for (1,3;1,4)-β-D-glucan biosynthesis slowed progress in the identification of the genes that encode (1,3;1,4)-β-D-glucan synthases, but emerging comparative genomics and associated techniques have allowed at least some of the genes that contribute to (1,3;1,4)-β-D-glucan synthesis in the Poaceae to be identified. Whether similar genes and enzymes also mediate (1,3;1,4)-β-D-glucan biosynthesis in lower plants and fungi is not yet known. Here, we compare the different fine structures of (1,3;1,4)-β-D-glucans across the plant kingdom, present current information on the genes that have been implicated recently in their biosynthesis, and consider aspects of the cell biology of (1,3;1,4)-β-D-glucan biosynthesis in the Poaceae.Item Metadata only (1,3;1,4)-β-glucan biosynthesis by the CSLF6 enzyme: position and flexibility of catalytic residues influence product fine structure(American Chemical Society, 2016) Dimitroff, G.; Little, A.; Lahnstein, J.; Schwerdt, J.; Srivastava, V.; Bulone, V.; Burton, R.; Fincher, G.Cellulose synthase-like F6 (CslF6) genes encode polysaccharide synthases responsible for (1,3;1,4)-β-glucan biosynthesis in cereal grains. However, it is not clear how both (1,3)- and (1,4)-linkages are incorporated into a single polysaccharide chain and how the frequency and arrangement of the two linkage types that define the fine structure of the polysaccharide are controlled. Through transient expression in Nicotiana benthamiana leaves, two CSLF6 orthologs from different cereal species were shown to mediate the synthesis of (1,3;1,4)-β-glucans with very different fine structures. Chimeric cDNA constructs with interchanged sections of the barley and sorghum CslF6 genes were developed to identify regions of the synthase enzyme responsible for these differences. A single amino acid residue upstream of the TED motif in the catalytic region was shown to dramatically change the fine structure of the polysaccharide produced. The structural basis of this effect can be rationalized by reference to a homology model of the enzyme and appears to be related to the position and flexibility of the TED motif in the active site of the enzyme. The region and amino acid residue identified provide opportunities to manipulate the solubility of (1,3;1,4)-β-glucan in grains and vegetative tissues of the grasses and, in particular, to enhance the solubility of dietary fibers that are beneficial to human health.Item Metadata only 1,4-Di-tert-butyl (2R,3R)-2-({(2E)-3-[4(acetyloxy)phenyl]prop-2-enoyl}oxy)-3hydroxybutanedioate(Blackwell Munksgaard, 2012) Hixson, J.; Taylor, D.; Ng, S.; Tiekink, E.The title compound, C₂₃H3₃₀O₉, has an approximate T-shape with the tert-butyl ester groups lying either side of the benzene ring. The acetyl group is almost perpendicular to the benzene ring to which it is connected [C-C-O-C torsion angle = -106.7 (3)°]. The conformation about the C=C double bond [1.331 (4) Å] is E. Linear supramolecular chains along the a axis mediated by hydroxy-carbonyl O-H...O hydrogen bonds feature in the crystal packing. The same H atom is also involved in an intramolecular O-H...O interaction.Item Metadata only 1,4-Diethynyl-2,5-dimethoxybenzene at ca 150 K(Blackwell Munksgaard, 2004) Bruce, M.; Head, N.; Skelton, B.; White, A.The principal determinants of packing in crystals of the title compound, C12H10O2, which has crystallographically imposed inversion symmetry, are interactions between the alkyne H atoms and the methoxy O atoms [HO = 2.39 (1) Å].Item Metadata only 1-+ exotic on the lattice with FLIC fermions(Few-body problems in physics, World Scientific Publishing Co. Pte. Ltd, 2007) Hedditch, J.; Lasscock, B.; Leinweber, D.; Williams, A.; Kamleh, W.; Zanotti, J.; Asia-Pacific Conference on Few-Body Problems in Physics (3rd : 2005 : Nakhon Ratchasima; Thailand); Yan, Y.; Kobdai, C.; Suebka, P.Item Metadata only 1-MCP is more effective on a floral brassica (Brassica oleracea var. italica L.) than a leafy brassica (Brassica rapa var. chinensis)(Elsevier Science BV, 2002) Able, A.; Wong, L.; Prasad, A.; O'Hare, T.Florets of broccoli (Brassica oleracea var. italica L.) and the youngest fully expanded leaf detached from pak choy (Brassica rapa var. chinensis) were treated with 1-methylcyclopropene (1-MCP) overnight (16 h) and then stored at supermarket retail temperature (10 °C). A concentration of 12 μl l−1 was considered optimal for both pak choy leaves and broccoli florets. 1-MCP increased shelf life of broccoli florets by just greater than 20% but had little effect on pak choy shelf life (increases between 10 and 20%) in the absence of exogenously applied ethylene. Multiple applications had no further impact while 1-MCP needed to be applied as soon as possible after harvest to have maximal effect. If 1-MCP treatment was applied overnight at 20 °C prior to storage at 10 °C, its effect was slightly increased. However, 1-MCP did protect broccoli and pak choy from the effects of exogenously applied ethylene (0.1 or 1 μl l−1) suggesting it may be useful during retail or storage with ethylene-producing commodities. Differences between the efficacies of 1-MCP on florets compared with leaves are discussed.Item Metadata only 1.1 Student selection and the influence of their clinical and academic environment on learning(Blackwell Munksgaard, 2002) Gaengler, P.; de Vries, J.; Akota, I.; Balciuniene, I.; Bertold, P.; Gajewska, M.; Johnsen, D.; Urtâne, I.; Walsh, L.; Zijlstra, A.Student selection and recruitment play a vital role in the successful outcome of dental education. To identify key issues and practices in selection and recruitment, the group assessed current processes, philosophies and practices from a range of different educational systems, although it was not possible to gather data from all countries or continents within the timeframe provided. Furthermore, the group explored the effect of the educational learning environment on the successful outcome of teaching dental students. It is clear that a wide variety of practices and philosophies exist and are used in different parts of the world. Measuring the success of any given process used for student selection remains a challenge. In some parts of the world, certain practices have become an integral part of the tertiary educational system, and have been applied in a similar way by many or all of the dental schools in that country. In other countries, methods vary from one dental school to another, often reflecting differences in the structure and philosophy of the educational system. There was great variation in the combinations of selection criteria used and in student recruitment strategies. However, it was clear that there was much to be gained by learning from the experiences of other dental schools in student selection. Lessons learned, best practices and philosophies used and supporting value systems proved to be very helpful for benchmarking the processes used. In the discussion of student selection, a number of important questions were raised which deserve further thought and reflection both in the ongoing debate and as part of the ever-changing world of dental education. Important new matters that require more debate and research include: a) ethical issues, including the nature of funding from the student perspective, and the concern that in some regions dentistry may become a profession only for the elite or wealthy students. b) Health standards of students entering dental school. c) How realistic is the applicant's sense of dentistry as a profession? d) How accurate is the students' sense of their career opportunities and the employment market upon graduation? Finally, the over-arching question remains, how valid, reliable and predictable are existing selection practices? Will it be practical and meaningful to standardize methods used, or will exchanging ideas as part of this global debate assist the thought process of dental leaders to improve selection practices by learning from the experiences of other schools in different parts of the world? The processes of open debate, sharing ideas and opinions and identifying sound practices across the globe is a powerful catalyst for developing innovative answers to the complex problems posed by student selection and recruitment. A ‘virtual’ global process with wide input from as many dental schools as possible should improve the efficacy of student selection, and allow dental educators to identify the ‘potential’ of prospective students and predict more accurately dental student outcomes. The debate that we have started will certainly contribute to providing a knowledge base which dental educators will be able to draw on when reviewing selection processes in their own schools.Item Metadata only 1.23 Ga mafic dykes in the North China Craton and their implications for the reconstruction of the Columbia supercontinent(Elsevier, 2015) Wang, W.; Liu, S.; Santosh, M.; Zhang, L.; Bai, X.; Zhao, Y.; Zhang, S.; Guo, R.Abstract not availableItem Metadata only 1.8--1.5-Ga links between the North and South Australian Cratons and the Early--Middle Proterozoic configuration of Australia(Elsevier Science BV, 2004) Giles, D.; Betts, P.; Lister, G.Item Metadata only 1/f, g-r and burst noise used as a screening threshold for reliability estimation of optoelectronic coupled devices(Pergamon-Elsevier Science Ltd, 2000) Xu, J.; Abbott, D.; Dai, Y.In this paper the theoretical analysis of noise sources in Optoelectronic Coupled Devices (OCDs) is given and the relation between typical defects and 1/f, g–r and burst noise is described. According to statistical and experimental results, a threshold to screen potential devices with excess noise is derived, which has been proved theoretically that the screening criterion is reasonable. Moreover, the experimental results show that the method is of practical value.