Development of a jet pump-assisted arterial heat pipe

The development of a jet pump assisted arterial heat pipe is described. The concept utilizes a built-in capillary driven jet pump to remove vapor and gas from the artery and to prime it. The continuous pumping action also prevents depriming during operation of the heat pipe. The concept is applicable to fixed conductance and gas loaded variable conductance heat pipes. A theoretical model for the jet pump assisted arterial heat pipe is presented. The model was used to design a prototype for laboratory demonstration. The 1.2 m long heat pipe was designed to transport 500 watts and to prime at an adverse elevation of up to 1.3 cm. The test results were in good agreement with the theoretical predictions. The heat pipe carried as much as 540 watts and was able to prime up to 1.9 cm. Introduction of a considerable amount of noncondensible gas had no adverse effect on the priming capability

Design, development and testing of a cryogenic temperature heat pipe for the icicle system

An analytical model was formulated for a cryogenic heat pipe, and thermal and transport analyses were developed to predict the performance characteristics of various heat pipe designs. These analyses permitted optimization of various design parameters. A series of four breadboard heat pipes were fabricated and tested to provide inputs such as internal film coefficients, minimum capillary radii, and wick permeabilities which are required for the analyses. The results of instrumentation, charging, and testing of cryogenic heat pipes were applied to the prototype heat pipes. After a thorough design analysis of three potential heat pipe wicks (slab, artery, and axial groove), the first two were chosen for application to two prototype heat pipes. Detailed designs were made of the two heat pipes and the units were fabricated. Tests were conducted which verified the integrity and safety margin of the design to withstand the internal pressure at ambient temperature and fatigue of thermal cycling. During the acceptance testing in the vacuum chamber, no difficulty was experienced in priming the slab-wick heat pipe and it met the performance design requirements. The artery-wick heat pipe would not prime with nitrogen working fluid for any test conditions

Ethnographic methods for process evaluations of complex health behaviour interventions.

This is the final version of the article. Available from BioMed Central via the DOI in this record.This article outlines the contribution that ethnography could make to process evaluations for trials of complex health-behaviour interventions. Process evaluations are increasingly used to examine how health-behaviour interventions operate to produce outcomes and often employ qualitative methods to do this. Ethnography shares commonalities with the qualitative methods currently used in health-behaviour evaluations but has a distinctive approach over and above these methods. It is an overlooked methodology in trials of complex health-behaviour interventions that has much to contribute to the understanding of how interventions work. These benefits are discussed here with respect to three strengths of ethnographic methodology: (1) producing valid data, (2) understanding data within social contexts, and (3) building theory productively. The limitations of ethnography within the context of process evaluations are also discussed

Non-conditioned generation of Schroedinger cat states in a cavity

We investigate the dynamics of a two-level atom in a cavity filled with a nonlinear medium. We show that the atom-field detuning $\delta$ and the nonlinear parameter $\chi^{(3)}$ may be combined to yield a periodic dynamics and allowing the generation of almost exact superpositions of coherent states ({\sl Schr\"odinger} cats). By analysing the atomic inversion and the field purity, we verify that any initial atom-field state is recovered at each revival time, and that a coherent field interacting with an excited atom evolves to a superposition of coherent states at each collapse time. We show that a mixed field state (statistical mixture of two coherent states) evolves towards a pure field state ({\sl Schr\"odinger} cat) as well. We discuss the validity of those results by using the field fidelity and the {\sl Wigner} function.Comment: REVTeX4, 8 pages, 7 figures, link to an external animation fil

Heterogeneity in Kv2 Channel Expression Shapes Action Potential Characteristics and Firing Patterns in CA1 versus CA2 Hippocampal Pyramidal Neurons.

The CA1 region of the hippocampus plays a critical role in spatial and contextual memory, and has well-established circuitry, function and plasticity. In contrast, the properties of the flanking CA2 pyramidal neurons (PNs), important for social memory, and lacking CA1-like plasticity, remain relatively understudied. In particular, little is known regarding the expression of voltage-gated K+ (Kv) channels and the contribution of these channels to the distinct properties of intrinsic excitability, action potential (AP) waveform, firing patterns and neurotransmission between CA1 and CA2 PNs. In the present study, we used multiplex fluorescence immunolabeling of mouse brain sections, and whole-cell recordings in acute mouse brain slices, to define the role of heterogeneous expression of Kv2 family Kv channels in CA1 versus CA2 pyramidal cell excitability. Our results show that the somatodendritic delayed rectifier Kv channel subunits Kv2.1, Kv2.2, and their auxiliary subunit AMIGO-1 have region-specific differences in expression in PNs, with the highest expression levels in CA1, a sharp decrease at the CA1-CA2 boundary, and significantly reduced levels in CA2 neurons. PNs in CA1 exhibit a robust contribution of Guangxitoxin-1E-sensitive Kv2-based delayed rectifier current to AP shape and after-hyperpolarization potential (AHP) relative to that seen in CA2 PNs. Our results indicate that robust Kv2 channel expression confers a distinct pattern of intrinsic excitability to CA1 PNs, potentially contributing to their different roles in hippocampal network function

Navigating the maze: Qualitative research methodologies and their philosophical foundations

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordObjectives: One of the three objectives of the Society and College of Radiographers is the promotion and dissemination of research in radiography and radiotherapy. This article aims to assist in the production of high standard research by explaining how transparency in reporting the underpinning philosophical basis of a qualitative study can be achieved in addition to the more customary descriptions of how data were collected and analysed. Key findings: Unlike their quantitative equivalent, qualitative research methodologies are less well understood and reported in radiography research, in particular the philosophical and epistemological assumptions which underpin the methods used. Conclusion: Demonstrating consistency between the philosophical position taken and the methods used within a study is an important aspect of research quality. Implications for practice: Qualitative research can offer valuable insights into the social, organisational, behavioural and interpersonal aspects of medical imaging practice. These may include wellbeing, attitudes, perceptions and beliefs, leadership, management practices, education, professionalism and a wide range of issues around patients' experiences during medical imaging. Patient care and outcomes can be positively impacted as a result of acquiring these insights

Family preferences for home or hospital care at diagnosis for children with diabetes in the DECIDE study.

This is the final version of the article. Available from Wiley via the DOI in this record.AIMS: A diagnosis of Type 1 diabetes in childhood can be a difficult life event for children and families. For children who are not severely ill, initial home rather than hospital-based care at diagnosis is an option although there is little research on which is preferable. Practice varies widely, with long hospital stays in some countries and predominantly home-based care in others. This article reports on the comparative acceptability and experience of children with Type 1 diabetes and their parents taking part in the DECIDE study evaluating outcomes of home or hospital-based treatment from diagnosis in the UK. METHODS: Semi-structured interviews with 11 (pairs of) parents and seven children were conducted between 15 and 20 months post diagnosis. Interviewees were asked about adaptation to, management and impact of the diabetes diagnosis, and their experience of initial post-diagnosis treatment. RESULTS: There were no differences between trial arms in adaptation to, management of or impact of diabetes. Most interviewees wanted to be randomized to the 'home' arm initially but expressed a retrospective preference for whichever trial arm they had been in, and cited benefits relating to learning about diabetes management. CONCLUSIONS: The setting for early treatment did not appear to have a differential impact on families in the long term. However, the data presented here describe different experiences of early treatment settings from the perspective of children and their families, and factors that influenced how families felt initially about treatment setting. Further research could investigate the short-term benefits of both settings.National Institute for Social Care and Health Research Clinical Research Centr

Benefits and Pitfalls of Secondary Antibodies: Why Choosing the Right Secondary Is of Primary Importance

Simultaneous labeling of multiple targets in a single sample, or multiplexing, is a powerful approach to directly compare the amount, localization and/or molecular properties of different targets in the same sample. Here we highlight the robust reliability of the simultaneous use of multiple mouse monoclonal antibodies (mAbs) of different immunoglobulin G (IgG) subclasses in a wide variety of multiplexing applications employing anti-mouse IgG subclass-specific secondary antibodies (2°Abs). We also describe the unexpected finding that IgG subclass-specific 2°Abs are superior to general anti-mouse IgG 2°Abs in every tested application in which mouse mAbs were used. This was due to a detection bias of general anti-mouse IgG-specific 2°Abs against mAbs of the most common mouse IgG subclass, IgG1, and to a lesser extent IgG2b mAbs. Thus, when using any of numerous mouse mAbs available through commercial and non-profit sources, for cleaner and more robust results each mAb should be detected with its respective IgG subclass-specific 2°Ab and not a general anti-mouse IgG-specific 2°Ab