81 research outputs found
KNOWLEDGE TRANSMISSION AND THE FAMILY IN TRADITIONAL JAVANESE PERFORMING ARTS
Ph.DDOCTOR OF PHILOSOPH
Novel devices for sampling and analysis of volatiles
This thesis is concerned with the preparation, and subsequent application of, hydrogels as devices for analysing axillary malodour in order to test the efficacy of antiperspirant / deodorant products. Using the well documented ability of hydrogels to absorb water and small molecules, the absorption, storage and subsequent extraction of a model sweat was investigated. Ten volatile fatty acids, one unsaturated aldehyde and one thiol were used in an aqueous solution to represent malodorous sweat in order to investigate the plausibility of such a device.
Quantitative analysis of the malodorous compounds was carried out via GC-FID, with unknown compound identification carried out via GC-MS. Qualitative analysis was acquired with the addition of pH indicators such as bromophenol blue and quinine to the hydrogel device.
The physical properties of the hydrogels were also probed by investigating a range of crosslinker concentrations and alternative hydrogel materials. The swelling kinetics in deionised water and the mechanical properties were investigated by dynamic mechanical analysis and Universal tester.
Bacterial studies illustrated the hydrogels’ suitability for in vivo testing which then illustrated that the model protocol could be transferred to natural samples
Enacting agency: exploring how older adults shape their neighbourhoods
Within research on ageing in neighbourhoods, older adults are often positioned as impacted by neighbourhood features; their impact on neighbourhoods is less often considered. Drawing on a study exploring how person and place transact to shape older adults’ social connectedness, inclusion and engagement in neighbourhoods, this paper explores how older adults take action in efforts to create neighbourhoods that meet individual and collective needs and wants. We drew on ethnographic and community-based participatory approaches and employed qualitative and geospatial methods with 14 older adults in two neighbourhoods. Analysis identified three themes that described the ways that older adults enact agency at the neighbourhood level: being present and inviting casual social interaction, helping others and taking community action. The participants appeared to contribute to a collective sense of connectedness and creation of social spaces doing everyday neighbourhood activities and interacting with others. Shared territories in which others were present seemed to support such interactions. Participants also helped others in a variety of ways, often relating to gaps in services and support, becoming neighbourhood-based supports for other seniors. Finally, participants contributed to change at the community level, such as engaging politically, patronising local businesses and making improvements in public places. Study findings suggest the potential benefits of collaborating with older adults to create and maintain liveable neighbourhoods
The sigma Accessibility Special Interest Group: Resources Update
This article contains a short update on the work of the sigma Accessibility Special Interest Group. We announce the release of resources to assist mathematics tutors and coordinators with the support of mature students and those with dyslexia, dyscalculia and dyspraxia. We provide a brief background to the development of these resources and describe their pilot in two institutions, one in England and the other in Ireland. We close with a description of the next stages of work for the special interest group and a call for additional people to get involved
Methacrylic block copolymers by sulfur free RAFT (SF RAFT) free radical emulsion polymerisation
We demonstrate the use of sulfur free reversible addition-fragmentation chain transfer polymerisation (RAFT as a versatile tool for the controlled synthesis of methacrylic block and comb-like copolymers. Sulfur free RAFT (SF-RAFT) utilises vinyl terminated macromonomers obtained via catalytic chain transfer polymerisation (CCTP) of methacrylates as a chain transfer agent (CTA), and thus precluding adverse aspects of the RAFT such as toxicity of dithioesters. We have synthesised a range of narrow dispersity block copolymers (Đ < 1.2) and comb-like macromolecules by employing emulsion polymerisation allowing for the preparation of relatively large quantities (~50 g) of the above mentioned copolymers promptly and straightforwardly. Copolymers were characterised using 1H NMR, size exclusion chromatography (SEC), thermogravimetric analysis (TGA) and matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF-MS) techniques
Pregnant Smokers Receiving Opioid Agonist Therapy Have an Elevated Nicotine Metabolite Ratio: A Replication Study.
INTRODUCTION: Pregnant women exposed chronically to opioids smoked more cigarettes per day (CPD) and had a higher nicotine metabolite ratio (NMR), 3-hydroxycotinine/cotinine, a biomarker of nicotine metabolism and clearance, than those not receiving opioids. We examined CPD and NMR in a group of pregnant smokers, a quarter of whom were receiving opioid agonist therapy (OAT).
AIMS AND METHODS: Pregnant smokers recruited to participate in a placebo-controlled trial of bupropion for smoking cessation provided a blood sample for measurement of NMR.
RESULTS: Half (52.4%) of the 124 women with NMR data were African American. OAT-treated women (n = 34, 27.4%; 27 receiving methadone and 7 buprenorphine) were more likely to be white (79% vs. 30%, p \u3c .001) and to have a lower mean PHQ-9 total score (2.91 [SD = 2.83] vs. 4.83 [SD = 3.82], p = .007). OAT-treated women reported smoking more CPD (9.50 [SD = 5.26] vs. 7.20 [SD = 3.65], p = .005) and had higher NMR (0.78 [SD = 0.36] vs. 0.56 [SD = 0.25], p = .001) than the non-OAT-treated group. In a linear regression analysis adjusting for race, depression severity, and CPD, NMR was greater in the OAT group (p = .025), among whom the daily methadone-equivalent dosage correlated with NMR (Spearman\u27s ρ = 0.49, p = .003).
CONCLUSIONS: Consistent with the findings of Oncken et al. (2019), we found that OAT smokers smoked more and had higher NMR than non-OAT smokers. As higher NMR is associated with a reduced likelihood of smoking cessation, the effects on NMR of both pregnancy and OAT could contribute to a lower smoking cessation rate in pregnant smokers receiving chronic opioid therapy.
IMPLICATIONS: We replicated the finding that the NMR is significantly greater among pregnant smokers receiving OAT than those not receiving this treatment for opioid use disorder. Furthermore, we found that the dosage of the OAT was significantly associated with the NMR level. These findings may contribute to a poorer response to smoking cessation treatment in pregnant women treated with OAT, particularly those receiving high-dose therapy, and raise the question of whether novel approaches are needed to treat smoking in this subgroup of pregnant smokers
Synthesis of Pd/Ru Bimetallic Nanoparticles by Escherichia coli and Potential as a Catalyst for Upgrading 5-Hydroxymethyl Furfural Into Liquid Fuel Precursors
Escherichia coli cells support the nucleation and growth of ruthenium and
ruthenium-palladium nanoparticles (Bio-Ru and Bio-Pd/Ru NPs). We report a method
for the synthesis of these monometallic and bimetallic NPs and their application
in the catalytic upgrading of 5-hydroxymethyl furfural (5-HMF) to 2,5 dimethylfuran
(DMF). Examination using high resolution transmission electron microscopy with energy
dispersive X-ray microanalysis (EDX) and high angle annular dark field (HAADF) showed
Ru NPs located mainly at the cell surface using Ru(III) alone but small intracellular
Ru-NPs (size 1–2 nm) were visible only in cells that had been pre-“seeded”
with Pd(0) (5 wt%) and loaded with equimolar Ru. Pd(0) NPs were distributed
between the cytoplasm and cell surface. Cells bearing 5% Pd/5% Ru showed some
co-localization of Pd and Ru but chance associations were not ruled out. Cells loaded
to 5 wt% Pd/20 wt% Ru showed evidence of core-shell structures (Ru core, Pd
shell). Here,
with MTHF as the reaction solvent the commercial Ru/C catalyst had little activity
(100% conversion, negligible selectivity to DMF) whereas the 5 wt% Pd/5 wt% Rubio-bimetallic gave 100% conversion and 14% selectivity to DMF from material extracted
from hydrolyzates. The results indicate a potential green method for realizing increased
energy potential from biomass wastes as well as showing a bio-based pathway to
manufacturing a scarcely described bimetallic material.The project was funded by NERC grant NE/L014076/1 to LM
(Program: “Resource Recovery from Wastes”). The Science City
Photoemission Facility used in this research was funded through
the Science Cities Advanced Materials Project 1: “Creating and
Characterizing Next Generation of Advanced Materials” with
support from AWM and ERDF funds. The microscopy work
was conducted at “Centro de Instrumentación Cientifica” at the
University of Granada, Spain
Upconversion of Cellulosic Waste Into a Potential “Drop in Fuel” via Novel Catalyst Generated Using Desulfovibrio desulfuricans and a Consortium of Acidophilic Sulfidogens
The authors acknowledge with thanks, use of GC-FID/GC-MS supplied by Dr. Daniel Lester within the Polymer Characterization Research Technology Platform, University of Warwick and the help of Drs. B. Kaulich, T. Araki,and M. Kazemian at beamline IO8, Diamond Light Source, United Kingdom, who funded the synchrotron study (Award No. SP16407: Scanning X-ray Microscopy Study of Biogenic Nanoparticles; Improved Bionanocatalysts by Design) on I08 Scanning X-ray Microscopy beamline (SXM).The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2019.00970/full#supplementary-materialBiogas-energy is marginally profitable against the “parasitic” energy demands of processing biomass. Biogas involves microbial fermentation of feedstock hydrolyzate generated enzymatically or thermochemically. The latter also produces 5-hydroxymethyl furfural (5-HMF) which can be catalytically upgraded to 2, 5-dimethyl furan (DMF), a “drop in fuel.” An integrated process is proposed with side-stream upgrading into DMF to mitigate the “parasitic” energy demand. 5-HMF was upgraded using bacterially-supported Pd/Ru catalysts. Purpose-growth of bacteria adds additional process costs; Pd/Ru catalysts biofabricated using the sulfate-reducing bacterium (SRB) Desulfovibrio desulfuricans were compared to those generated from a waste consortium of acidophilic sulfidogens (CAS). Methyl tetrahydrofuran (MTHF) was used as the extraction-reaction solvent to compare the use of bio-metallic Pd/Ru catalysts to upgrade 5-HMF to DMF from starch and cellulose hydrolyzates. MTHF extracted up to 65% of the 5-HMF, delivering solutions, respectively, containing 8.8 and 2.2 g 5-HMF/L MTHF. Commercial 5% (wt/wt) Ru-carbon catalyst upgraded 5-HMF from pure solution but it was ineffective against the hydrolyzates. Both types of bacterial catalyst (5wt%Pd/3-5wt% Ru) achieved this, bio-Pd/Ru on the CAS delivering the highest conversion yields. The yield of 5-HMF from starch-cellulose thermal treatment to 2,5 DMF was 224 and 127 g DMF/kg extracted 5-HMF, respectively, for CAS and D. desulfuricans catalysts, which would provide additional energy of 2.1 and 1.2 kWh/kg extracted 5-HMF. The CAS comprised a mixed population with three patterns of metallic nanoparticle (NP) deposition. Types I and II showed cell surface-localization of the Pd/Ru while type III localized NPs throughout the cell surface and cytoplasm. No metallic patterning in the NPs was shown via elemental mapping using energy dispersive X-ray microanalysis but co-localization with sulfur was observed. Analysis of the cell surfaces of the bulk populations by X-ray photoelectron spectroscopy confirmed the higher S content of the CAS bacteria as compared to D. desulfuricans and also the presence of Pd-S as well as Ru-S compounds and hence a mixed deposit of PdS, Pd(0), and Ru in the form of various +3, +4, and +6 oxidation states. The results are discussed in the context of recently-reported controlled palladium sulfide ensembles for an improved hydrogenation catalyst.This project was funded by NERC grant NE/L014076/1 to LM (Program: “Resource Recovery from Wastes”). The Science City Photoemission Facility used in this research was funded through the Science Cities Advanced Materials Project 1: “Creating and Characterizing Next Generation of Advanced Materials” with support from AWM and ERDF funds. The microscopy work was conducted at “Centro de Instrumentación Cientifica” at the University of Granada, Spain. This work was partially supported by the Spanish Government Sistema Nacional de Grantia Juvenil grant PEJ-2014-P-00391 (Promocion de Empleo Joven e Implantacion de la Garantia Juvenil 2014, MINECO) with a scholarship to JGB
Multifunctional composite hydrogels for bacterial capture, growth/elimination, and sensing applications
Hydrogels are cross-linked networks of hydrophilic polymer chains with a three-dimensional structure. Owing to their unique features, the application of hydrogels for bacterial/antibacterial studies and bacterial infection management has grown in importance in recent years. This trend is likely to continue due to the rise in bacterial infections and antimicrobial resistance. By exploiting their physicochemical characteristics and inherent nature, hydrogels have been developed to achieve bacterial capture and detection, bacterial growth or elimination, antibiotic delivery, or bacterial sensing. Traditionally, the development of hydrogels for bacterial/antibacterial studies has focused on achieving a single function such as antibiotic delivery, antibacterial activity, bacterial growth, or bacterial detection. However, recent studies demonstrate the fabrication of multifunctional hydrogels, where a single hydrogel is capable of performing more than one bacterial/antibacterial function, or composite hydrogels consisting of a number of single functionalized hydrogels, which exhibit bacterial/antibacterial function synergistically. In this review, we first highlight the hydrogel features critical for bacterial studies and infection management. Then, we specifically address unique hydrogel properties, their surface/network functionalization, and their mode of action for bacterial capture, adhesion/growth, antibacterial activity, and bacterial sensing, respectively. Finally, we provide insights into different strategies for developing multifunctional hydrogels and how such systems can help tackle, manage, and understand bacterial infections and antimicrobial resistance. We also note that the strategies highlighted in this review can be adapted to other cell types and are therefore likely to find applications beyond the field of microbiology
Branched macromonomers from catalytic chain transfer polymerisation (CCTP) as precursors for emulsion-templated porous polymers
Efforts in the synthesis of macroporous polymers have mostly been directed towards the formation of stable high internal phase emulsions (HIPEs) from commercially available monomers, limiting their scope of application. Therefore, the development of simple synthetic approaches to access tailor-made macromonomers that can be used as precursors for the formation of HIPEs, allowing the design of new generations of polyHIPE materials with bespoke chemical and physical properties, is desirable in the search for new applications. In this work, cobalt(II) mediated catalytic chain transfer polymerisation (CCTP) is used to polymerise ethylene glycol dimethacrylate (EGDMA), producing multi vinyl-terminated branched EGDMA polymers with tuneable branching density and degree of unsaturation. These materials are subsequently implemented as macromonomer crosslinking agents for the formulation of HIPEs. The use of acrylate comonomers as propagation promoters is found to be essential and 2-ethylhexyl acrylate (EHA), isobornyl acrylate (IBOA) and 2-methoxyethyl acrylate (MEA) are investigated as comonomers in the formulations to both facilitate the photochemical curing of the HIPEs and to impart material properties to the products. The CCTP derived branched macromonomers are fully charaterised by GPC, 1H-NMR and MALDI–ToF spectroscopy. Scanning electron microscopy (SEM) is used to explore the morphology of the produced materials. Surface wettability experiments are conducted to evaluate the hydrophilicity of the polyHIPE surface. Compression tests are used to investigate the influence of the branching density of the CCTP macromonomers as well as the nature of comonomers on the mechanical properties of the materials
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