7 resultados para 4-23
em Deakin Research Online - Australia
Resumo:
A novel hierarchical MnO2/carbon strip (MnO2/C) microsphere is synthesized via galvanostatic charge-discharge of a MnO@C matrix precursor where the carbon is from a low-cost citric acid. This hierarchical structure is composed of manganese oxides nanoflakes and inlaid carbon strips. The ultrathin nanoflakes assemble to form porous microspheres with a rippled surface superstructure. Due to its improved conductivity and remarkable increased phase contact area, this novel structure exhibits an excellent electrochemical performance with a specific capacitance of 485.6 F g -1 at a current density of 0.5 A g-1 and an area capacitance as high as 4.23 F cm-2 at a mass loading of 8.7 mg cm-2. It also shows an excellent cycling stability with 88.9% capacity retention after 1000 cycles. It is speculated that the present low-cost novel hierarchical porous microspheres can serve as a promising electrode material for pseudocapacitors. © 2014 American Chemical Society.
Resumo:
Six untrained, male subjects (23 ± 1 years old, 84 ± 5 kg, VO2peak= 3.7 ± 0.8 l min–1) exercised for 60 min at 75 ± 1%VO2peak on 7 consecutive days. Muscle samples were obtained before the start of cycle exercise training and 24 h after the first and seventh exercise sessions and analysed for citrate synthase activity, glycogen and glucose transporter 4 (GLUT-4) mRNA and protein expression. Exercise training increased (P < 0.05) citrate synthase by ~20% and muscle glycogen concentration by ~40%. GLUT-4 mRNA levels 24 h after the first and seventh exercise sessions were similar to those measured before the start of exercise training. In contrast, GLUT-4 protein expression was increased after 7 days of exercise training (12.4 ± 1.5 versus 3.4 ± 1.0 arbitray units (a.u.), P < 0.05) and although it tended to be higher 24 h after the first exercise session (6.0 ± 3.0 versus 3.4 ± 1.0 a.u.), this was not significantly different (P= 0.09). These results support the suggestion that the adaptive increase in skeletal muscle GLUT-4 protein expression with short-term exercise training arises from the repeated, transient increases in GLUT-gene transcription following each exercise bout leading to a gradual accumulation of GLUT-4 protein, despite GLUT-4 mRNA returning to basal levels between exercise stimuli.
Resumo:
Previous studies have suggested that tris(4,7-diphenyl-1,10-phenanthrolinedisulfonate)ruthenium(II) (Ru(BPS)34−) has great potential as a chemiluminescence reagent in acidic aqueous solution. We have evaluated four different samples of this reagent (two commercially available and two synthesised in our laboratory) in comparison with tris(2,2′-bipyridine)ruthenium(II) (Ru(bipy)32+) and tris(1,10-phenanthroline)ruthenium(II) (Ru(phen)32+), using a range of structurally diverse analytes. In general, Ru(BPS)34− produced more intense chemiluminescence, but the oxidised Ru(BPS)33− species is less stable in aqueous solution than Ru(bipy)33+ and produced a greater blank signal than Ru(bipy)33+ or Ru(phen)33+, which had a detrimental effect on sensitivity. Although the complex is often depicted with the sulfonate groups of the BPS ligand in the para position on the phenyl rings, NMR characterisation revealed that the commercially available BPS material used in this study was predominantly the meta isomer.
Resumo:
This study investigated rural Lao PDR village women's views and experiences of recent, or impeding, childbirth to better understand barriers to maternity service usage. Lao PDR has the highest maternal mortality rate (MMR) in the South-East Asian region with very low utilization rates for skilled birth assistance and health sector delivery services. The study site, Sekong, a southern Lao province, was lowest in the country on virtually all indicators of reproductive and maternal health, despite several recent maternal health service interventions. The study's aim was to gain a fuller understanding of barriers to maternity services usage to contribute towards maternity services enhancement, and district and national policy-making for progressing towards 2015 MDG 4 & 5 targets.
A descriptive cross-sectional study was used. First, face-to-face questionnaires were used to collect demographic and reproductive health and health care experience data from 166 village woman (120 with a child born in the previous year, and 46 who were currently pregnant). In- epth individual interviews then followed with 23 purposively selected woman, to probe personal experiences and perspectives on why women preferred home birthing.
The majority of women had given birth at home, assisted by untrained birth attendants (relatives or neighbours). While seventy percent had accessed some antenatal services, postpartum follow-up attendance was very low (17 percent). Limited finances, lack of access to transport and prior negative health service experiences were important factors influencing women's decision making. Giving birth at home was seen by many, not just as unavoidable, but, as the preferred option.
Recent top-down maternal health initiatives have had little impact in this region. Improving maternal and child-health strategies requires much greater community participation and use of participatory action methodologies, to increase women's engagement in policy and planning and subsequent usage of health service developments.
