867 resultados para PLASMA-LEVELS


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Maintenance of bridge structures is a major issue for the Queensland Department of Main Roads. In the previous phase of this CRC project an initial approach was made towards the development of a program for lifetime prediction of metallic bridge components. This involved the analysis of five representative bridge structures with respect to salt deposition (a major contributor to metallic corrosion) to determine common elements to be used as “cases” - those defined for buildings are not applicable. The five bridges analysed included the Gladstone Port Access Road Overpass, Stewart Road Overpass, South Johnstone River Bridge, Johnson Creek Bridge and the Ward River Bridge.

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Objectives: The current study was conducted to determine levels of cardiac knowledge and cardiopulmonary resuscitation (CPR) training in older people in Queensland, Australia.---------- Methods: A telephone survey of 4490 Queensland adults examined respondents’ knowledge of coronary heart disease (CHD) risk factors, knowledge of heart attack symptoms, knowledge of the local emergency telephone number, as well as respondents’ rates and recency of training in CPR.---------- Results: Older participants, aged 60 years and over, were approximately one and a half times more likely than the 30–39 year-old reference group to have limited knowledge of heart disease risk factors (OR = 1.53), and low knowledge of heart attack symptoms (OR = 1.60). Knowledge of the local emergency telephone number also decreased with age. Older participants had significantly lower rates of training in CPR, with almost three quarters (71.7%) reporting that they had never been trained. Older people who had completed CPR training were significantly less likely to have done so recently.---------- Conclusions: Cardiac knowledge levels and CPR training rates in older Queensland persons were lower than those found in the younger population.

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Since China’s Economic Reform and its Open Door Policy, China has entered a new era of education (Adamson, 2002; Hu, 2005a). English has gained status as a language for international relations (Graddol, 1997) and international trade (Qu, 2007). Hence, in 2001, China’s Ministry of Education (MOE) required universities to offer 5-10% of their course units in English, particularly in the fields of information technology, biotechnology, finance and law (Jen, 2001; MOE, 2001). However, “the upgrading of national English proficiency, then, is predicted largely on the professional competence of the teaching force” (Hu, 2005b, p. 655). For TEFL academics, one component of this competence is the capacity to conduct research (Day, 1991; Shu, 2002). Indeed, research productivity has become essential for university success, and academics’ employment and promotional prospects. This study aims to investigate 182 Chinese TEFL academics’ research outputs across three Chinese higher education institutions through the research question: What are the research productivity levels of Chinese TEFL academics? A survey instrument was devised to gather TEFL academics’ calculations of research productivity and, in particular, the quality and quantity of research outputs over a five-year period (2004-2008). Descriptive statistics through SPSS were used to analyse data across research output fields (e.g., journal articles, conference papers). Academic status varied (n=182; teaching assistants 23.6%, lecturers 47.3%, associate professors 22.5%, and professors 6.6%) as did years of teaching (1-5 years 27.4%, 6-10 years 24.7%, 11-15 18.1%, 16-20 years 13.7%, > 21 years 15.9%). Results (n=182, male=27%, females=73%) indicated 18% had not produced any research in the five-year period. Indeed, more than 70% had produced no research in all categories except non-core journal articles and provincial projects. An overwhelming majority of TEFL academics had zero productivity in 10 of the 12 categories. Nevertheless, there were highly-productive TEFL academics, who had produced five or more pieces of research across the 12 categories. In addition, there was not much difference between sole and co-authored research outputs, except non-core journal articles where sole authored work was 20% higher than co-authored work. China’s desire for international competitiveness in education will require measures that facilitate higher levels of research productivity. These measures must include professional development, support and mentoring programs, and employment of personnel who can guide these processes. Research performance is an outcome, hence there is a need to understand Chinese TEFL academics’ perceptions about research, and experiences that may hinder and facilitate higher research productivity.

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Homework presents many challenges for refugees from Africa who are arriving in Australian schools with histories of little, no or severely interrupted schooling. This is evident in the emergence of school- and community-based homework help, clubs and tutoring programs for the students. The aim of this article is to describe the homework support options accessed by eight students from Burundi, Rwanda, Eritrea and Sudan who participated in a study of pedagogy for middle school-aged African refugees, and the views on homework of their parents and teachers. The article shows some tensions between family and school expectations and the dilemmas that arise for teachers in a broader context of public concern about and official policy statement on excessive and repetitive homework. It is argued that application of policy guidelines needs to account for disadvantages that potentially accrue to students who cannot design their own independent study programs. Further, it is suggested that integration of skills and meaning-based pedagogy inherent in recent approaches to literacy education has potential for ensuring that students receive the forms of homework they require.

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The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC—a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices—thus, supporting the PCA approach.

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A spectrophotometric method for the simultaneous determination of the important pharmaceuticals, pefloxacin and its structurally similar metabolite, norfloxacin, is described for the first time. The analysis is based on the monitoring of a kinetic spectrophotometric reaction of the two analytes with potassium permanganate as the oxidant. The measurement of the reaction process followed the absorbance decrease of potassium permanganate at 526 nm, and the accompanying increase of the product, potassium manganate, at 608 nm. It was essential to use multivariate calibrations to overcome severe spectral overlaps and similarities in reaction kinetics. Calibration curves for the individual analytes showed linear relationships over the concentration ranges of 1.0–11.5 mg L−1 at 526 and 608 nm for pefloxacin, and 0.15–1.8 mg L−1 at 526 and 608 nm for norfloxacin. Various multivariate calibration models were applied, at the two analytical wavelengths, for the simultaneous prediction of the two analytes including classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), radial basis function-artificial neural network (RBF-ANN) and principal component-radial basis function-artificial neural network (PC-RBF-ANN). PLS and PC-RBF-ANN calibrations with the data collected at 526 nm, were the preferred methods—%RPET not, vert, similar 5, and LODs for pefloxacin and norfloxacin of 0.36 and 0.06 mg L−1, respectively. Then, the proposed method was applied successfully for the simultaneous determination of pefloxacin and norfloxacin present in pharmaceutical and human plasma samples. The results compared well with those from the alternative analysis by HPLC.

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Purpose: The purpose of this paper is to report the resistance of plasma-sprayed titanium dioxide (TiO2) nanostructured coatings in a corrosive environment.----- Design/methodology/approach: Weight loss studies are performed according to ASTM G31 specifications in 3.5?wt% NaCl. Electrochemical polarization resistance measurements are made according to ASTM G59-91 specifications. Corrosion resistance in a humid and corrosive environment is determined by exposing the samples in a salt spray chamber for 100?h. Microstructural studies are carried out using an atomic force microscope and scanning electron microscope.----- Findings: The nanostructured TiO2 coatings offer good resistance to corrosion, as shown by the results of immersion, electrochemical and salt spray studies. The corrosion resistance of the coating is dictated primarily by the geometry of splat lamellae, density of unmelted nanoparticles, magnitude of porosity and surface homogeneity.----- Practical implications: The TiO2 nanostructured coatings show promising potential for use as abrasion, wear-resistant and thermal barrier coatings for service in harsh environments.----- Originality/value: The paper relates the corrosion resistance of nanostructured TiO2 coatings to their structure and surface morphology.

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Although systemic androgen deprivation prolongs life in advanced prostate cancer, remissions are temporary because patients almost uniformly progress to a state of a castration-resistant prostate cancer (CRPC) as indicated by recurring PSA. This complex process of progression does not seem to be stochastic as the timing and phenotype are highly predictable, including the observation that most androgen-regulated genes are reactivated despite castrate levels of serum androgens. Recent evidence indicates that intraprostatic levels of androgens remain moderately high following systemic androgen deprivation therapy, whereas the androgen receptor (AR) remains functional, and silencing the AR expression following castration suppresses tumor growth and blocks the expression of genes known to be regulated by androgens. From these observations, we hypothesized that CRPC progression is not independent of androgen-driven activity and that androgens may be synthesized de novo in CRPC tumors leading to AR activation. Using the LNCaP xenograft model, we showed that tumor androgens increase during CRPC progression in correlation to PSA up-regulation. We show here that all enzymes necessary for androgen synthesis are expressed in prostate cancer tumors and some seem to be up-regulated during CRPC progression. Using an ex vivo radiotracing assays coupled to high-performance liquid chromatography-radiometric/mass spectrometry detection, we show that tumor explants isolated from CRPC progression are capable of de novo conversion of [(14)C]acetic acid to dihydrotestosterone and uptake of [(3)H]progesterone allows detection of the production of six other steroids upstream of dihydrotestosterone. This evidence suggests that de novo androgen synthesis may be a driving mechanism leading to CRPC progression following castration.

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Few frameworks exist for the teaching and assessment of programming subjects that are coherent and logical. Nor are they sufficiently generic and adaptable to be used outside the particular tertiary institutions in which they were developed. This paper presents the Teaching and Assessment of Software Development (TASD) frame-work. We describe its development and implementation at an Australian university and demonstrate, with examples, how it has been used, with supporting data. Extracts of criteria sheets (grading rubrics) for a variety of assessment tasks are included. The numerous advantages of this new framework are discussed with comparisons made to those reported in the published literature.

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This paper presents the possibility of utilizing a current source topology instead of a voltage source as an efficient, flexible and reliable power supply for plasma applications. A buck-boost converter with a current controller has been used to transfer energy from an inductor to a plasma system. A control strategy has also been designed to satisfy all the desired purposes. The main concept behind this topology is to provide high dv/dt regardless of the switching speed of a power switch and to control the current level to properly transfer adequate energy to various plasma applications.

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Background: It has been proposed that adenosine triphosphate (ATP) released from red blood cells (RBCs) may contribute to the tight coupling between blood flow and oxygen demand in contracting skeletal muscle. To determine whether ATP may contribute to the vasodilatory response to exercise in the forearm, we measured arterialised and venous plasma ATP concentration and venous oxygen content in 10 healthy young males at rest, and at 30 and 180 seconds during dynamic handgrip exercise at 45% of maximum voluntary contraction (MVC). Results: Venous plasma ATP concentration was elevated above rest after 30 seconds of exercise (P < 0.05), and remained at this higher level 180 seconds into exercise (P < 0.05 versus rest). The increase in ATP was mirrored by a decrease in venous oxygen content. While there was no significant relationship between ATP concentration and venous oxygen content at 30 seconds of exercise, they were moderately and inversely correlated at 180 seconds of exercise (r = -0.651, P = 0.021). Arterial ATP concentration remained unchanged throughout exercise, resulting in an increase in the venous-arterial ATP difference. Conclusions: Collectively these results indicate that ATP in the plasma originated from the muscle microcirculation, and are consistent with the notion that deoxygenation of the blood perfusing the muscle acts as a stimulus for ATP release. That ATP concentration was elevated just 30 seconds after the onset of exercise also suggests that ATP may be a contributing factor to the blood flow response in the transition from rest to steady state exercise.