1000 resultados para 13077-021


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The Co2+ sorption of two wool powders was investigated using its radioisotope 57Co (T1/2=271.8 days and γ=122.1 and 136.5 keV) as a tracer. The effects of the type of buffer, the pH value, the contact time and the initial concentration of Co2+ on the sorption behaviour of wool powders were studied. The Co2+ releasing ability of wool powders and the re-use of wool powders to sorb Co2+ were also examined. The optimum sorption of Co2+ by the powders occurred at pH 8 in phosphate buffer and pH 10 in ammonium sulphate buffer. Fourier-transform infrared spectroscopy (FTIR) was used to study the changes in chemical structure of the wool after exposure to both buffer solutions. Compared to the untreated wool fibre, the fine wool powders showed rapid sorption rates and high sorption capacities for Co2+. Co2+ ions were recovered after exposing the Co2+ loaded wool to HCl (0.1 M) and buffer at pH 3 (glycine/sodium chloride). After releasing Co2+ ions from wool powders, the efficiency of wool powders re-used to sorb Co2+ was 80% of that of the fresh wool powders. It is concluded from this study that wool powder can be used as an efficient sorbent to remove and release Co2+ from solution.

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PURPOSE: The objective of this study was to assess the reliability of testing skeletal muscle strength and peak aerobic power in a clinical population of patients with chronic heart failure (CHF).

METHODS: Thirty-three patients with CHF (New York Heart Association (NYHA) Functional Class 2.3 ± 0.5; left ventricular ejection fraction 27% ± 7%; age 65 ± 9 years; 28:5 male-female ratio) underwent two identical series of tests (T1 and T2), 1 week apart, for strength and endurance of the muscle groups responsible for knee extension/flexion and elbow extension/flexion. The patients also underwent two graded exercise tests on a bicycle ergometer to measure peak oxygen consumption (VO2peak). Three months later, 18 of the patients underwent a third test (T3) for each of the measures. Means were compared using MANOVA with repeated measures for strength and endurance, and ANOVA with repeated measures for VO2peak.

RESULTS: Combining data for all four movement patterns, the expression of strength increased from T1 to T2 by 12% ± 25% (P < .001; intraclass correlation coefficient [ICC] = 0.89). Correspondingly, endurance increased by 13% ± 23% (P = .004; ICC = 0.87). Peak oxygen consumption was not significantly different (16.2 ± 0.8 and 16.1 ± 0.8 mL·kg-1·min-1 for T1 and T2, respectively;P = .686; ICC = 0.91). There were no significant differences between T2 and T3 for strength (2% ± 17%;P = .736; ICC = 0.92) or muscle endurance (-1% ± 15%;P = .812; ICC = 0.96), but VO2peak decreased from 16.7 ± 1.2 to 14.9 ± 0.9 mL·kg-1·min-1 (-10% ± 18%;P = .021; ICC = 0.89).

CONCLUSIONS: These data suggest that in a population of patients with CHF, a familiarization trial for skeletal muscle strength testing is necessary. Although familiarization is not required for assessing oxygen consumption as a single measurement, VO2peak declined markedly in the 3-month period for which these patients were followed. Internal consistency within patients was high for the second and third strength trials and the first and second tests of VO2peak.

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Background: Streamlining emergency department (ED) care of patients with chronic obstructive pulmonary disease (COPD) may be an important strategy in managing the increasing burden of this disease.

Study objectives: The aim of this study was to identify factors predictive of hospital admission in ED patients with COPD, specifically factors that can be used early in the ED episode of care.

Methods: Using retrospective regression analysis, case data from 321 randomly selected medical records from five Australian EDs were analysed. Patient characteristics, triage and ED system features, physiological status, and ED treatment during the first four hours of ED care were compared between discharged and admitted patients.

Results: Factors available on ED arrival associated with increased likelihood of admission were: age (OR = 1.04, p = 0.008) respiratory symptoms affecting activities of daily living (OR = 1.8, p = 0.043) and signs of respiratory dysfunction (OR = 2.5, p = 0.005). Factors available from the first four hours of ED care associated with increased likelihood of admission were: age (OR = 1.04, p = 0.021), oxygen use at four hours (OR = 3.5, p = 0.002) and IV antibiotic administration (OR = 2.6, p = 0.026). There were conflicting findings regarding the association between ambulance transport and admission.

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Objectives : The association between lower socioeconomic status (SES), obesity, lifestyle choices and adverse health consequences are well documented, however to date the relationship between these variables and area-based SES (equivalised for advantage and disadvantage) has not been examined simultaneously in one population or with more than tertiary divisions of SES. We set out to examine the risk factors for obesity and metabolic disorders in the same population across quintiles of area-based SES.

Methods :
We performed a descriptive cross-sectional study using existing data from a population-based random selection of women aged 20–92 years (n = 1110) recruited from the Barwon Statistical Division, South Eastern Australia.

Results :
All measures of adiposity were inversely associated with SES, and remained significant after adjusting for age. Lifestyle choices associated with adiposity and poorer health, including smoking, larger serving sizes of foods, and reduced physical activity, were significantly associated with individuals from lower SES groups.

Conclusions :
Greater measures of adiposity and less healthy lifestyle choices were observed in individuals from lower SES. Significant differences in body composition were identified between quintiles 1 and 5, whereas subjects in the mid quintiles had relatively similar measures. The inverse relationship between SES, obesity and less healthy lifestyle underscores the possibility that these associations may be causal and should be investigated further.

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Surface alloying via fluidised bed reactor (FBR) chemical vapour deposition (CVD) can be used to produce adherent and highly corrosion resistant surface layers. In this work, 304, 316, and 409 stainless steels and 1020 steel were chromised, producing distinct surface layers tens of micrometres thick. The composition and surface of these layers was characterised using microscopy, GDOES, and XPS. Surfaces were highly enriched in Cr and displayed improved corrosion resistance as determined by electrochemical evaluations. This work demonstrates that it is possible to form continuous, functional and corrosion resistant Cr-rich surface layers via FBR-CVD on a variety of steels.

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Background: Inadequate fruit and vegetable consumption is associated with increased chronic disease risk and represents a considerable global health burden. Despite evidence that dietary habits track from early childhood, there are few published trials of interventions attempting to increase preschoolers’ fruit and vegetable consumption.

Objective: The Healthy Habits trial aimed to assess the efficacy of a telephone-based intervention for parents to increase the fruit and vegetable consumption in their 3–5-y-old children.

Design: A cluster randomized controlled trial was conducted involving 394 parents of children aged 3–5 y recruited through local preschools. Parents allocated to the intervention received printed resources plus four 30-min telephone calls targeting aspects of the home food environment associated with children's fruit and vegetable consumption. Parents allocated to the control group received generic printed nutrition information. Children's fruit and vegetable consumption was assessed by using the Fruit and Vegetable Subscale of the Children's Dietary Questionnaire, which was administered via telephone interview at baseline and 2 and 6 mo later.

Results: Analysis of all available data showed that children's fruit and vegetable scores were significantly higher in the intervention group than in the control group at 2 mo (P < 0.001) and at 6 mo (P = 0.021). Sensitivity analysis using baseline observation carried forward showed an intervention effect at 2 mo (P = 0.008) but not at 6 mo (P = 0.069).

Conclusions: Telephone-delivered parent interventions may be an effective way of increasing children's fruit and vegetable consumption in the short term. Further investigation to determine whether the intervention effect is maintained in the longer term is recommended.

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As mean fibre diameter (MFD) is the primary determinant of mohair price we aimed to quantify the lifetime changes in mohair MFDas Angora goats aged and grew. Measurements were made over 12 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins including South African, Texan and interbred admixtures of these and Australian sources. Records of sire, dam, birthweight, birth parity, liveweight, fleece growth and fleece quality were taken for does and castrated males (wethers) (n = 267 animals). Fleece-free liveweights (FFLwt) were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. A restricted maximum likelihood growth curve model was developed for relating MFD to FFLwt, age and other measurements.Asimple way of describing the results is:MFD= k (FFLwt)b E; where k is a parameter that can vary in a systematic way with shearing(age), breed, weaning weight, sire, dam and individual; b is a parameter that is the same for nearly the whole study; and E are independent errors from a log-normal distribution. The analysis shows that ^b = 0.34, with s.e. (^b) = 0.021. Thus, mohair MFD was allometrically related to the cube root of FFLwt over the lifetime of Angora goats. However, the allometric proportionality constant differed in a systematic way with age at shearing, genetic strain, weaning weight, sire, dam and individual. For Texan-breed goats, MFD decreased as weaning weight increased (P = 0.00016). The findings indicate that management factors that affect liveweight and weaning weight have lifetime effects on mohair fibre diameter and therefore the value of mohair and the profitability of the mohair enterprise.