1,780 research outputs found

    Applications of micro-fluidic platforms integrating packed stationary phases

    Get PDF
    To design and fabricate novel centrifugal micro-fluidic platforms integrating packed stationary phases for solid-phase micro-extraction in a wide range of (bio)analytical applications. To design and fabricate novel micro-fluidic platforms integrating packed stationary phases capable of withstanding significant high pressures

    Scramjets and Shock Tunnels: The Queensland Experience

    Get PDF
    This article reports on the use of a shock tunnel to study the operation of scramjet powered configurations at sub-orbital velocities above 2 km/s. Thrust, as given by a net thrust equation, is used as a figure of merit throughout the study. After a short description of the shock tunnel used and its operating characteristics, experiments on the combustion release of heat in a constant area duct with hydrogen fuel are reviewed. The interaction between heat release in the combustion wake and the walls of the duct produced pressure distributions which followed a binary scaling law, and indicated that the theoretically expected heat release could be realized in practice, albeit with high pressure or long combustion ducts. This heat release, combined with attainable thrust nozzle characteristics and a modest level of configuration drag, indicated that positive thrust levels could be obtained well into the sub-orbital range of velocities. Development of a stress wave force balance for use in shock tunnels allowed the net thrust generated to be measured for integrated scramjet configurations and, although the combination of model size and shock tunnel operating pressure prevented complete combustion of hydrogen, the cruise condition of zero net thrust was achieved at 2.5 km/s with one configuration, while net thrust was produced with another configuration using an ignition promoter in hydrogen fuel. Nevertheless, the combination of boundary layer separation induced inlet choking and limited operating pressure levels prevented realization of the thrust potential of the fuel. This problem may be alleviated by recent increases in the shock tunnel operating pressures, and by promising research involving inlet injection of the fuel. Research on the drag component of the net thrust equation resulted from the development of a fast response skin friction gauge. It was found that existing theories of turbulent boundary skin friction predicted the skin friction when combustion of hydrogen occurred outside the boundary layer, but combustion within the boundary layer dramatically reduced the skin friction. Finally, for the first time in the world, supersonic combustion was produced in a free flight experiment. This experiment validated shock tunnel results at stagnation enthalpies near 3 MJ/k

    Violence toward nurses, the work environment, and patient outcomes

    Get PDF
    Purpose: To relate nurses' self-rated perceptions of violence (emotional abuse, threat, or actual violence) on medical-surgical units to the nursing working environment and to patient outcomes.Design: Cross-sectional collection of data by surveys and primary data collection for 1-week periods on 94 nursing wards in 21 hospitals in two states of Australia.Methods: Nursing Work Index-Revised (NWI-R); Environmental Complexity Scale (ECS) PRN-80 (a measure of patient acuity); and a nursing survey with three questions on workplace violence; combined with primary data collection for staffing, skill mix, and patient outcomes (falls, medication errors).Findings: About one third of nurses participating (N=2,487, 80.3% response rate) perceived emotional abuse during the last five shifts worked. Reports of threats (14%) or actual violence (20%) were lower, but there was great variation among nursing units with some unit rates as high as 65%. Reported violence was associated with increased ward instability (lack of leadership; difficult MD and RN relationships). Violence was associated with unit operations: unanticipated changes in patient mix; proportion of patients awaiting placement; the discrepancy between nursing resources required from acuity measurement and those supplied; more tasks delayed; and increases in medication errors. Higher skill mix (percentage of registered nurses) and percentage of nurses with a bachelor of science in nursing degrees were associated with fewer reported perceptions of violence at the ward level. Intent to leave the present position was associated with perceptions of emotional violence but not with threat or actual assault.Conclusions: Violence is a fact of working life for nurses. Perceptions of violence were related to adverse patient outcomes through unstable or negative qualities of the working environment. Perceptions of violence affect job satisfaction.Clinical Relevance: In order to manage effectively the delivery of nursing care in hospitals, it is essential to understand the complexity of the nursing work environment, including the relationship of violence to patient outcomes. © 2009 Sigma Theta Tau International

    Developing an interactive electronic maternity record

    Full text link
    Women have a strong need to be involved in their own maternity care. Pregnancy hand-held records encourage women's participation in their maternity care; gives them an increased sense of control and improves communication among care providers. They have been successfully used in the UK and New Zealand for almost 20 years. Despite evidence that supports the use of hand-held records, widespread introduction has not occurred in Australia. The need for an electronic version of pregnancy hand-held records has become apparent, especially after the introduction of the Electronic Medical Record in Australia. A personal digital assistant (PDA) was developed as an interactive antenatal electronic maternity record that health-care providers could use in any setting and women could access using the internet. This article will describe the testing of the antenatal electronic maternity record

    Fabrication and characterization of nanotemplated carbon monolithic material

    Get PDF
    A novel hierarchical nanotemplated carbon monolithic rod (NTCM) was prepared using a novel facile nanotemplating approach. The NTCM was obtained using C60-fullerene modified silica gels as hard templates, which were embedded in a phenolic resin containing a metal catalyst for localized graphitization, followed by bulk carbonization, and template and catalyst removal. TEM, SEM, and BET measurements revealed that NTCM possessed an integrated open hierarchical porous structure, with a trimodal pore distribution. This porous material also possessed a high mesopore volume and narrow mesopore size distribution. During the course of carbonization, the C60 conjugated to aminated silica was partly decomposed, leading to the formation of micropores. The Raman signature of NTCM was very similar to that of multiwalled carbon nanotubes as exemplified by three major peaks as commonly observed for other carbon materials, i.e., the sp3 and sp2 carbon phases coexisted in the sample. Surface area measurements were obtained using both nitrogen adsorption/desorption isotherms (BET) and with a methylene blue binding assay, with BET results showing the NTCM material possessed an average specific surface area of 435 m2 g−1, compared to an area of 372 m2 g−1 obtained using the methylene blue assay. Electrochemical studies using NTCM modified glassy carbon or boron doped diamond (BDD) electrodes displayed quasi-reversible oxidation/reduction with ferricyanide. In addition, the BDD electrode modified with NTCM was able to detect hydrogen peroxide with a detection limit of below 300 nM, whereas the pristine BDD electrode was not responsive to this target compound

    Health-seeking beliefs of cardiovascular patients: A qualitative study

    Full text link
    Objectives: The study aims were to (a) describe the experiences of Chinese Australians with heart disease following discharge from hospital for an acute cardiac event; (b) identify patterns and cultural differences of Chinese Australians following discharge from hospital; and (c) illustrate the illness/health seeking behaviors and health beliefs of Chinese Australians. Design: Qualitative study. Methods: Interview data were obtained from the following sources: (a) focus groups of Chinese community participants without heart disease; (b) interviews with patients recently discharged from hospital following an admission for an acute cardiac event; and (c) interviews with Chinese-born health professionals working in Australia. Qualitative thematic analysis was undertaken. Results: Study themes generated from the data were: (1) linking traditional values and beliefs with Western medicine; (2) reverence for health professionals and family; and (3) juxtaposing traditional beliefs and self-management. Conclusions: Considering the influence of cultural values in developing health care plans and clinical decision making is important. © 2011 Elsevier Ltd

    Interplay of Mre11 Nuclease with Dna2 plus Sgs1 in Rad51-Dependent Recombinational Repair

    Get PDF
    The Mre11/Rad50/Xrs2 complex initiates IR repair by binding to the end of a double-strand break, resulting in 5′ to 3′ exonuclease degradation creating a single-stranded 3′ overhang competent for strand invasion into the unbroken chromosome. The nuclease(s) involved are not well understood. Mre11 encodes a nuclease, but it has 3′ to 5′, rather than 5′ to 3′ activity. Furthermore, mutations that inactivate only the nuclease activity of Mre11 but not its other repair functions, mre11-D56N and mre11-H125N, are resistant to IR. This suggests that another nuclease can catalyze 5′ to 3′ degradation. One candidate nuclease that has not been tested to date because it is encoded by an essential gene is the Dna2 helicase/nuclease. We recently reported the ability to suppress the lethality of a dna2Δ with a pif1Δ. The dna2Δ pif1Δ mutant is IR-resistant. We have determined that dna2Δ pif1Δ mre11-D56N and dna2Δ pif1Δ mre11-H125N strains are equally as sensitive to IR as mre11Δ strains, suggesting that in the absence of Dna2, Mre11 nuclease carries out repair. The dna2Δ pif1Δ mre11-D56N triple mutant is complemented by plasmids expressing Mre11, Dna2 or dna2K1080E, a mutant with defective helicase and functional nuclease, demonstrating that the nuclease of Dna2 compensates for the absence of Mre11 nuclease in IR repair, presumably in 5′ to 3′ degradation at DSB ends. We further show that sgs1Δ mre11-H125N, but not sgs1Δ, is very sensitive to IR, implicating the Sgs1 helicase in the Dna2-mediated pathway

    Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis

    Get PDF
    Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands

    Volunteer Involving Organisations: Governance, Funding and Management in Western Australia in 2009 - Companion Report

    Get PDF
    This report analyses the online survey results from three separate but interrelated issues affecting not-for-profit organisations. The first area is governance structures and practices; the second concerns funding activities and entrepreneurial endeavours; and, the third area focuses on practices affecting managers of volunteers. The intention behind this online survey was to do an initial 'mapping' of the key issues in the Western Australian not-for-profit (NFP) sector. There are significant pressures (both external and internal) being exerted in the third sector in relation to notions of transparency, accountability and value-for-money, These research outcomes will now be followed up by more detailed qualitative case study research to investigate these issues fully. These initial findings are, therefore, exploratory in nature
    corecore