282 resultados para Current Conveyor, Currrent Mode, Current Feedback Amplifier, Corto Circuito Virtuale, Compensazione
Resumo:
Human saliva harbours proteins of clinical relevance and about 30% of blood proteins are also present in saliva. This highlights that saliva can be used for clinical applications just as urine or blood. However, the translation of salivary biomarker discoveries into clinical settings is hampered by the dynamics and complexity of the salivary proteome. This review focuses on the current status of technological developments and achievements relating to approaches for unravelling the human salivary proteome. We discuss the dynamics of the salivary proteome, as well as the importance of sample preparation and processing techniques and their influence on downstream protein applications; post-translational modifications of salivary proteome and protein: protein interactions. In addition, we describe possible enrichment strategies for discerning post-translational modifications of salivary proteins, the potential utility of selected-reaction-monitoring techniques for biomarker discovery and validation, limitations to proteomics and the biomarker challenge and future perspectives. In summary, we provide recommendations for practical saliva sampling, processing and storage conditions to increase the quality of future studies in an emerging field of saliva clinical proteomics. We propose that the advent of technologies allowing sensitive and high throughput proteome-wide analyses, coupled to well-controlled study design, will allow saliva to enter clinical practice as an alternative to blood-based methods due to its simplistic nature of sampling, non-invasiveness, easy of collection and multiple collections by untrained professionals and cost-effective advantages.
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Flexible graphene-based thin film supercapacitors were made using carbon nanotube (CNT) films as current collectors and graphene films as electrodes. The graphene sheets were produced by simple electrochemical exfoliation, while the graphene films with controlled thickness were prepared by vacuum filtration. The solid-state supercapacitor was made by using two graphene/CNT films on plastic substrates to sandwich a thin layer of gelled electrolyte. We found that the thin graphene film with thickness <1 μm can greatly increase the capacitance. Using only CNT films as electrodes, the device exhibited a capacitance as low as ~0.4 mF cm−2, whereas by adding a 360 nm thick graphene film to the CNT electrodes led to a ~4.3 mF cm−2 capacitance. We experimentally demonstrated that the conductive CNT film is equivalent to gold as a current collector while it provides a stronger binding force to the graphene film. Combining the high capacitance of the thin graphene film and the high conductivity of the CNT film, our devices exhibited high energy density (8–14 Wh kg−1) and power density (250–450 kW kg−1).
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Deoxyribonucleic acid (DNA) extraction has considerably evolved since it was initially performed back in 1869. It is the first step required for many of the available downstream applications used in the field of molecular biology. Whole blood samples are one of the main sources used to obtain DNA, and there are many different protocols available to perform nucleic acid extraction on such samples. These methods vary from very basic manual protocols to more sophisticated methods included in automated DNA extraction protocols. Based on the wide range of available options, it would be ideal to determine the ones that perform best in terms of cost-effectiveness and time efficiency. We have reviewed DNA extraction history and the most commonly used methods for DNA extraction from whole blood samples, highlighting their individual advantages and disadvantages. We also searched current scientific literature to find studies comparing different nucleic acid extraction methods, to determine the best available choice. Based on our research, we have determined that there is not enough scientific evidence to support one particular DNA extraction method from whole blood samples. Choosing a suitable method is still a process that requires consideration of many different factors, and more research is needed to validate choices made at facilities around the world.
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School counselling in Australia is presently in a state of flux and adaptation. Within this period of change and adjustment, three key points are acknowledged. First structural and organisational change is a constant in the field of school counselling in the Australian context. Second, despite this, the nature of the school counselling role tends to remain the same but with new areas of need being added, such as self harm and cyberbullying. Third, each state and territory in Australia has differing role statements and training requirements for its school counsellors. This paper initially reviews the historical context of school counselling in Australia, including changes and developments in qualifications and training programs. A description is then provided of the current status of school counselling including the differences among the state systems. Issues such as work intensification, uncertainty of tenure, supervision, ethical issues and online counselling are discussed. The scant research into the effectiveness of the profession is outlined, followed by future recommendations.
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Electrochemical aptamer-based (E-AB) sensors represent an emerging class of recently developed sensors. However, numerous of these sensors are limited by a low surface density of electrode-bound redox-oligonucleotides which are used as probe. Here we propose to use the concept of electrochemical current rectification (ECR) for the enhancement of the redox signal of E-AB sensors. Commonly, the probe-DNA performs a change in conformation during target binding and enables a nonrecurring charge transfer between redox-tag and electrode. In our system, the redox-tag of the probe-DNA is continuously replenished by solution-phase redox molecules. A unidirectional electron transfer from electrode via surface-linked redox-tag to the solution-phase redox molecules arises that efficiently amplifies the current response. Using this robust and straight-forward strategy, the developed sensor showed a substantial signal amplification and consequently improved sensitivity with a calculated detection limit of 114 nM for ATP, which was improved by one order of magnitude compared with the amplification-free detection and superior to other previous detection results using enzymes or nanomaterials-based signal amplification. To the best of our knowledge, this is the first demonstration of an aptamer-based electrochemical biosensor involving electrochemical rectification, which can be presumably transferred to other biomedical sensor systems.
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Improving symptom management for palliative care patients has obvious benefits for patients and advantages for the clinicians, as workload demands and work-related stress can be reduced when the emergent symptoms of patients are managed in a timely manner. The use of emergency medication kits (EMKs) can provide such timely symptom relief. The purpose of this study was to conduct a survey of a local service to examine views on medication management before and after the implementation of an EMK and to conduct a nationwide prevalence survey examining the use of EMKs in Australia. Most respondents from community palliative care services indicated that EMKs were not being supplied to palliative care patients but believed such an intervention could improve patient care.
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Rodent (mouse and rat) models have been crucial in developing our understanding of human neurogenesis and neural stem cell (NSC) biology. The study of neurogenesis in rodents has allowed us to begin to understand adult human neurogenesis and in particular, protocols established for isolation and in vitro propagation of rodent NSCs have successfully been applied to the expansion of human NSCs. Furthermore, rodent models have played a central role in studying NSC function in vivo and in the development of NSC transplantation strategies for cell therapy applications. Rodents and humans share many similarities in the process of neurogenesis and NSC biology however distinct species differences are important considerations for the development of more efficient human NSC therapeutic applications. Here we review the important contributions rodent studies have had to our understanding of human neurogenesis and to the development of in vitro and in vivo NSC research. Species differences will be discussed to identify key areas in need of further development for human NSC therapy applications.
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Extending Lash and Urry's (1994) notion of new "imagined communities" through information and communication structures, I ask the question: Are emergent teachers happy when they interact in online learning environments? This question is timely in the context of the ubiquity of online media and its pervasiveness in teachers' everyday work and lives. The research is important nationally and internationally, because the current research is contradictory. On the one hand, feelings of isolation and frustration have been cited as common emotions experienced in many online environments (Su, Bonk, Magjuka, Liu, & Lee, 2005). Yet others report that online communities encourage a sense of belonging and support (Mills, 2011). Emotions are inherently social, are central to learning and online interaction (Shen, Wang, & Shen, 2009). The presentations reports the use of e-motion blogs to explore emotional states of emergent primary teachers in an online learning context as they transition into their first field experience in schools. The original research was conducted with a graduate class of 64 secondary science pre-service teachers in Science Education Curriculum Studies in a large Australian university, including males and females from a variety of cultural backgrounds, aged 17-55 years. Online activities involved the participants watching a series of streamed live lectures within a course of 8 weeks duration, providing a varied set of learning experiences, such as viewing live teaching demonstrations. Each week, participants provided feedback on learning by writing and posting an e-motion diary or web log about their emotional response. The blogs answered the question: What emotions you experience during this learning experience? The descriptive data set included 284 online posts, with students contributing multiple entries. The Language of Appraisal framework, following Martin and White (2005), was used to cluster the discrete emotions within six affect groups. The findings demonstrated that the pre-service teachers' emotional responses tended towards happiness and satisfaction within the typology of affect groups - un/happiness, in/security, and dis/satisfaction. Fewer participants reported that online learning mode triggered negative feelings of frustration, and when this occurred, it often pertained expectations of themselves in the forthcoming field experience in schools or as future teachers. The findings primarily contribute new understanding about emotional states in online communities, and recommendations are provided for supporting the happiness and satisfaction of emergent teachers as they interact in online communities. It demonstrates that online environments can play an important role in fulfilling teachers' need for social interaction and inclusion.
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With the variety of PV inverter types and the number of transformerless PV inverters on the Australian market increasing, we revisit some of the issues associated with these topologies. A recent electric shock incident in Queensland (luckily without serious outcome) associated with a transformerless PV system, highlights the need for earthing PV array structures and PV module frames to prevent capacitive leakage currents causing electric shock. The presented test results of the relevant voltages associated with leakage currents of five transformerless PV inverters stress this requirement, which is currently being addressed by both the Clean Energy Council and Standards Australia. DC current injection tests were performed on the same five inverters and were used to develop preliminary recommendations for a more meaningful DC current test procedure for AS4777 Part 2. The test circuit, methodology and results are presented and discussed. A notable temperature dependency of DC current injections with three of the five inverters suggests that DC current injection should be tested at high and low internal inverter temperatures whereas the power dependency noted only for one inverter does not seem to justify recommendations for a (rather involved) standard test procedure at different power levels.
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Aim: The aim of this survey was to assess registered nurse’s perceptions of alarm setting and management in an Australian Regional Critical Care Unit. Background: The setting and management of alarms within the critical care environment is one of the key responsibilities of the nurse in this area. However, with up to 99% of alarms potentially being false-positives it is easy for the nurse to become desensitised or fatigued by incessant alarms; in some cases up to 400 per patient per day. Inadvertently ignoring, silencing or disabling alarms can have deleterious implications for the patient and nurse. Method: A total population sample of 48 nursing staff from a 13 bedded ICU/HDU/CCU within regional Australia were asked to participate. A 10 item open-ended and multiple choice questionnaire was distributed to determine their perceptions and attitudes of alarm setting and management within this clinical area. Results: Two key themes were identified from the open-ended questions: attitudes towards inappropriate alarm settings and annoyance at delayed responses to alarms. A significant number of respondents (93%) agreed that alarm fatigue can result in alarm desensitisation and the disabling of alarms, whilst 81% suggested the key factors are those associated with false-positive alarms and inappropriately set alarms.
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Self-regulation is a coping strategy that allows older drivers to drive safely for longer. Self-regulation depends largely on the ability of drivers to evaluate their own driving. Therefore the success of self-regulation, in terms of driving safety, is influenced by the ability of older drivers to have insight into their declining driving performance. In addition, previous studies suggest that providing feedback to older adults regarding their driving skills may lead them to change their driving behaviour. However, little is currently known about the impact of feedback on older drivers’ self-awareness and their subsequent driving regulatory behaviour. This study explored the process of self-regulation and driving cessation among older drivers using the PAPM as a framework. It also investigated older adults’ perceptions and opinions about receiving feedback in regards to their driving abilities. Qualitative focus groups with 27 participants aged 70 years or more were conducted. Thematic analysis resulted in the development of five main themes; the meaning of driving, changes in driving pattern, feedback, the planning process, and solutions. The analysis also resulted in an initial model of driving self-regulation among older drivers that is informed by the current research and the Precaution Adoption Process Model as the theoretical framework. It identifies a number of social, personal, and environmental factors that can either facilitate or hinder people’s transition between stages of change. The findings from this study suggest that further elaboration of the PAPM is needed to take into account the role of insight and feedback on the process of self-regulation among older drivers.
Resumo:
BACKGROUND Engineering is a problem-based practically oriented discipline, whose practitioners aim to find effective solutions to engineering challenges, technically and economically. Engineering educators operate within a mandate to ensure that graduate engineers understand the practicalities and realities of good engineering practice. While this is a vital goal for the discipline, emerging influences are challenging the focus on ‘hard practicalities’ and requiring recognition of the cultural and social aspects of engineering. Expecting graduate engineers to possess communication skills essential for negotiating satisfactory outcomes in contexts of complex social beliefs about the impact of their work can be an unsettling and challenging prospect for engineering educators. This project identifies and addresses Indigenous engineering practices and principles, and their relevance to future engineering practices. PURPOSE This Office of Learning and Teaching (OLT) project proposes that what is known/discoverable about indigenous engineering knowledge and practices must be integrated into engineering curricula. This is an important aspect of ensuring that engineering as a profession responds competently to increasing demands for socially and environmentally responsible activity across all aspects of engineering activity. DESIGN/METHOD The project addresses i) means for appropriate inclusion of Indigenous students into usual teaching activities ii) assuring engineering educators have access to knowledge of Indigenous practices and skills relevant to particular engineering courses and topics iii) means for preparing all students to negotiate their way through issues of indigenous relationships with the land where engineering projects are planned. The project is undertaking wide-ranging research to collate knowledge about indigenous engineering principles and practices and develop relevant resource materials. RESULTS It is common to hear that such social issues as ‘Indigenous concerns’ are only of concern to environmental engineers. We challenge that perspective, and make the case that Indigenous knowledge is an important issue for all engineering educators in relation to effective integration of indigenous students and preparation of all engineering graduates to engage with indigenous communities. At the time of first contact, a rich and varied, technically literate, Indigenous social framework possessed knowledge of the environment that is not yet fully acknowledged in Australian society. A core outcome of the work will be development of resources relating to Indigenous engineering practices for inclusion in engineering core curricula. CONCLUSIONS A large body of technical knowledge was needed to survive and sustain human society in the complex environment that was Australia before 1788. This project is developing resource materials, and supporting documentation, about that knowledge to enable engineering educators to more easily integrate it into current curricula. The project also aims to demonstrate the importance for graduating engineers to appreciate the existence of diverse perspectives on engineering tasks and learn how to value - and employ - multiple paths to possible solutions.
Resumo:
There is a growing awareness of the high levels of psychological distress being experienced by law students and the practising profession in Australia. In this context, a Threshold Learning Outcome (TLO) on self-management has been included in the six TLOs recently articulated as minimum learning outcomes for all Australian graduates of the Bachelor of Laws degree (LLB). The TLOs were developed during 2010 as part of the Australian Learning and Teaching Council’s (ALTC’s) project funded by the Australian Government to articulate ‘Learning and Teaching Academic Standards’. The TLOs are the result of a comprehensive national consultation process led by the ALTC’s Discipline Scholars: Law, Professors Sally Kift and Mark Israel.1 The TLOs have been endorsed by the Council of Australian Law Deans (CALD) and have received broad support from members of the judiciary and practising profession, representative bodies of the legal profession, law students and recent graduates, Legal Services Commissioners and the Law Admissions Consultative Committee. At the time of writing, TLOs for the Juris Doctor (JD) are also being developed, utilising the TLOs articulated for the LLB as their starting point but restating the JD requirements as the higher order outcomes expected of graduates of a ‘Masters Degree (Extended)’, this being the award level designation for the JD now set out in the new Australian Qualifications Framework.2 As Australian law schools begin embedding the learning, teaching and assessment of the TLOs in their curricula, and seek to assure graduates’ achievement of them, guidance on the implementation of the self-management TLO is salient and timely.
Resumo:
A switching control strategy is proposed for single inductor current-fed push-pull converter with a secondary side active voltage doubler rectifier or a voltage rectifier used in photovoltaic (PV) grid interfacing. The proposed switching control strategy helps to turn-on and turn-off the primary side power switches with zero-voltage and zero-current switching. The operation of the push-pull converter is analyzed for two modes of operation. The feasibility of the proposed switching control strategy is validated using simulation and experimental results.