Experimental Design to Optimize High-Volume Ash Grout in the Presence of Welan Gum and Superplasticizer

Applications such as soil, rock and oil-well grouting all require enormous amounts of cement and are good examples of areas where a high volume of fly ash could partially replace cement to produce low-cost, environmentally safe and durable concrete. There is an increasing need to identify the rheological properties of cement grout using a simple test to determine the fluidity, and other properties of underwater grouts such as washout resistance and compressive strength. This paper presents statistical models developed using a fractorial design which was carried out to model the influence of key parameters on properties affecting the performance of underwater grout. Such responses of fluidity included mini-slump and flow time measured by Marsh cone, washout resistance, unit weight and compressive strength. The models are valid for mixes with 0.40 to 0.60 water-to-cementitious materials ratio, 0.02 to 0.08% of anti-washout admixture, by mass of binder, and 0.6 to 1.8% of superplasticizer, by mass of cementitious materials. The grout was made with 50% of pulverized-fuel ash replacement, by mass ofcementitious materials. Also presented are the derived models that enable the identification of underlying primary factors and their interactions that influence the modelled responses of underwater cement grout. Such parameters can be useful to reduce the test protocol needed for proportioning of underwater cement grout. This paper highlighted the influence of W/CM and dosage of antiwashout admixture and superplasticizer on fluidity, washout resistance and compressive strength and attempted also to demonstrate the usefulness of the models to improve understanding of trade-offs between parameters.

A politics of what: the enactment of peritoneal dialysis in indigenous Australians

This paper explores, on the one hand, the requirements of the technologies and practices that have been developed for a particular type of renal patient and health network in Australia. On the other, we examine the cultural and practical specificities entailed in the performance of these technologies and practices in the Indigenous Australian context. The praxiographic orientation of the actor-network approach – which has been called 'the politics of what' (Mol 2002) – enabled us to understand the difficulties involved in translating renal healthcare networks across cultural contexts in Australia; to understand the dynamic and contested nature of these networks; and to suggest possible strategies that make use of the tensions between these two disparate networks in ways that might ensure better healthcare for Indigenous renal patients.

Effect of timing of dialysis commencement on clincial outcomes of patients with planned initiation of peritoneal dialysis in the ideal trial

Background: Since the mid-1990s, early dialysis initiation has dramatically increased in many countries. The Initiating Dialysis Early and Late (IDEAL) study demonstrated that, compared with late initiation, planned early initiation of dialysis was associated with comparable clinical outcomes and increased health care costs. Because residual renal function is a key determinant of outcome and is better preserved with peritoneal dialysis (PD), the present pre-specified subgroup analysis of the IDEAL trial examined the effects of early-compared with late-start dialysis on clinical outcomes in patients whose planned therapy at the time of randomization was PD.

Methods: Adults with an estimated glomerular filtration rate (eGFR) of 10 - 15 mL/min/1.73 m2 who planned to be treated with PD were randomly allocated to commence dialysis at an eGFR of 10 - 14 mL/min/1.73 m2 (early start) or 5 - 7 mL/min/1.73 m2 (late start). The primary outcome was all-cause mortality.

Results: Of the 828 IDEAL trial participants, 466 (56%) planned to commence PD and were randomized to early start (n = 233) or late start (n = 233). The median times from randomization to dialysis initiation were, respectively, 2.03 months [interquartile range (IQR):1.67 - 2.30 months] and 7.83 months (IQR: 5.83 - 8.83 months). Death occurred in 102 early-start patients and 96 late-start patients [hazard ratio: 1.04; 95% confidence interval (CI): 0.79 - 1.37]. No differences in composite cardiovascular events, composite infectious deaths, or dialysis-associated complications were observed between the groups. Peritonitis rates were 0.73 episodes (95% CI: 0.65 - 0.82 episodes) per patient-year in the early-start group and 0.69 episodes (95% CI: 0.61 - 0.78 episodes) per patient-year in the late-start group (incidence rate ratio: 1.19; 95% CI: 0.86 - 1.65; p = 0.29). The proportion of patients planning to commence PD who actually initiated dialysis with PD was higher in the early-start group (80% vs 70%, p = 0.01).

Conclusion: Early initiation of dialysis in patients with stage 5 chronic kidney disease who planned to be treated with PD was associated with clinical outcomes comparable to those seen with late dialysis initiation. Compared with early-start patients, late-start patients who had chosen PD as their planned dialysis modality were less likely to commence on PD.

High volume versus low volume balance training on postural sway in adults with previous ankle inversion injury

Balance training is commonly used in the rehabilitation process of ankle injuries; however, the exercise prescription guidelines for prescribing balance training are poorly understood. The aim of the present study was to determine if high or low volume balance training is more effective in improving postural sway after an 8 week balance training program utilising the same exercises. Seventeen subjects (14 male, 3 female) with a mean age of 24.06 ± 5.6 years were randomly allocated into a control group (CG), low volume training (LVT) or high volume training (HVT). All subjects had sustained at least two inversion ankle injuries within the last 18 months. Subjects completed 8 weeks of balance training of up to 30 mins duration, 3 times per week. LVT consisted of 40 repetitions for week 1, progressing to 90 repetitions by week 8. HVT consisted of 60 repetitions for week 1, progressing to 130 repetitions by week 8. The maximum centre of pressure (COP) excursion was obtained from the porce plate in the medial-lateral (ML) direction and subsequently used for pre-test and post-test analysis. After the 8 week training intervention, there was a significant (P<0.001) difference in postural sway between pre and post testing for both the LVT (pre = 88.69mm ± 25.08mm, post = 72.17mm ± 27.53mm) and HVT (pre = 77.47mm ±10.57mm, post = 58.54mm ± 7.01mm) groups. There was no significant (P>0.01) difference detected for improvements between the LVT and HVT, however reported effect sizes (ES) showed large effect size chances in the high volume training (ES = 1.7) whereas low volume training showed medium effect sizes changes (ES = 0.6). This preliminary study demonstrates the importance of training volume in the rehabilitation of ankle injuries, with the HVT being superior to LVT.

Patients' experiences of peritoneal dialysis at home: a phenomenological approach

O objetivo deste estudo foi compreender a experiência da diálise peritoneal domiciliar, a partir da narrativa dos pacientes. A abordagem do estudo inspirou-se na fenomenologia hermenêutica de Paul Ricoeur. Foram entrevistados 19 pacientes na unidade de hemodiálise de um hospital público brasileiro, de março a setembro de 2009. As entrevistas foram orientadas pela questão: descreva sua experiência na diálise peritoneal. Os resultados desvelaram a percepção dos participantes sobre o significado da doença em suas vidas e as drásticas transformações pessoais sofridas nesse processo. Sentimentos de angústia e dor física foram acompanhados por importantes limitações pessoais e sociais, impostas pelo tratamento. Eles esperam por um futuro incerto, reconhecendo sua dependência da ajuda dos familiares e dos profissionais da saúde. Os resultados desvelam as dificuldades e a falta de perspectivas vividas pelos pacientes em diálise, demonstrando o papel crucial que cabe aos profissionais que os acompanham. Ajudá-los a desenvolver o autocuidado e maximizar sua qualidade de vida é prioridade na assistência a esses pacientes.