Congestive heart failure in rats is associated with increased expression and targeting of aquaporin-2 water channel in collecting duct

We tested whether severe congestive heart failure (CHF), a condition associated with excess free-water retention, is accompanied by altered regulation of the vasopressin-regulated water channel, aquaporin-2 (AQP2), in the renal collecting duct. CHF was induced by left coronary artery ligation. Compared with sham-operated animals, rats with CHF had severe heart failure with elevated left ventricular end-diastolic pressures (LVEDP): 26.9 ± 3.4 vs. 4.1 ± 0.3 mmHg, and reduced plasma sodium concentrations (142.2 ± 1.6 vs. 149.1 ± 1.1 mEq/liter). Quantitative immunoblotting of total kidney membrane fractions revealed a significant increase in AQP2 expression in animals with CHF (267 ± 53%, n=12) relative to sham-operated controls (100 ± 13%, n=14). In contrast, immunoblotting demonstrated a lack of an increase in expression of AQP1 and AQP3 water channel expression, indicating that the effect on AQP2 was selective.Furthermore, postinfarction animals without LVEDP elevation or plasma Na reduction showed no increase in AQP2 expression (121 ± 28% of sham levels, n=6). Immunocytochemistry and immunoelectron microscopy demonstrated very abundant labeling of the apical plasma membrane and relatively little labeling of intracellular vesicles in collecting duct cells from rats with severe CHF, consistent with enhanced trafficking of AQP2 to the apical plasma membrane. The selective increase in AQP2 expression and enhanced plasma membrane targeting provide an explanation for the development of water retention and hyponatremia in severe CHF

Effects of rf Current on Spin Transfer Torque Induced Dynamics

The impact of radiofrequency (rf) currents on the direct current (dc) driven switching dynamics in current-perpendicular-to-plane nanoscale spin valves is demonstrated. The rf currents dramatically alter the dc driven free layer magnetization reversal dynamics as well as the dc switching level. This occurs when the frequency of the rf current is tuned to a frequency range around the dc driven magnetization precession frequencies. For these frequencies, interactions between the dc driven precession and the injected rf induce frequency locking and frequency pulling effects that lead to a measurable dependence of the critical switching current on the frequency of the injected rf. Based on macrospin simulations, including dc as well as rf spin torque currents, we explain the origin of the observed effects.Comment: 5 pages, 4 figure

The need for a holistic approach to sustainability in new product development from the designers perspective

There are a growing number of tools available to the Product Designer to assist them in making informed decisions on the implications of the choices they make in specifying materials and manufacturing processes for their designs in terms of carbon impact. Unfortunately some can be misleading, indicating for example that a particular material has a low potential environmental impact, but failing to inform on the reality of the economic viability in its use or how readily available it might be for that use. These tools also have their limits, for example few can cater for the huge variety of company type and address the varied environmental interests of their owners (or lack of it). There is a need for designers to be fully aware of the broader issues relating to the environmental impact of their work beyond those that can be evaluated by a tool; highlighting the need for the complex range of issues associated with reducing environmental impact to be addressed along with and as creatively as all other design parameters. This paper takes as a case study, the design of a digital cordless phone undertaken by the author for a major UK telecoms service provider, where a holistic approach to sustainability from the designer’s perspective was a fundamental project requirement and uses this as an example of how designers can set their own holistic approach to sustainability in New Product Development (NPD), placing ecotools in perspective and hopefully providing an inspirational example for student designers

Interest in the commercial? Using commercial design projects in pedagogy

This paper considers the issues surrounding the use of live commercial design research projects as teaching material for Product Design students. The premise for the paper is based around the Design Unit, a design and research group at De Montfort University in Leicester, staffed by academics who are also involved in lecturing product design students. It highlights an observation that students may not become highly engaged when presented with assignments based on 'real life' design projects that have previously been completed by Design Unit staff. It could be argued that such projects are simply too big, the detail can seem esoteric and feel irrelevant to the fledgling designer. In addition, the commercial constraints of the real world project could, at times, impose inappropriate restrictions on student designers. As a lecturer used to dealing with industry experts and then being expected to present to design students on a project within a new industry sector, it could be quite easy to become complacent with regards to the student's prior knowledge. The aims of this paper are to explore what key areas can be extracted from commercial projects to make the best use of them as educational material. It will aim to suggest tools that could be used to present the material in an effective way and how this could better engage the student to help them understand the validity of the proposed design project or teaching aid

A little knowledge is a dangerous thing? Do BSc product design courses discourage collaboration?

BSc Product Design Courses aim to equip the Product Designer with a better understanding of the needs of professionals such as manufacturing engineers, material specialists, electrical engineers whilst also maintaining a focus on conventional design skills. One could debate that this greater understanding of these engineering disciplines should allow more productive collaboration with their respective practitioners. A key area looked at by this paper is, does this bias towards the technical, affect the designers predisposition towards collaborating with end users or those involved in the user experience in driving a new product design forward? It will also consider the argument that the Product Designer is now in a position to collaborate less with other technical disciplines, with ever simpler tools such as FEA, CFD being part of CAD suites, allowing designers to carry out the kind of validation that would have once been exclusively the preserve of specialists. The paper examines two completed design projects for SME clients, by a design research group based at De Montfort University. One project was undertaken by a BA graduate, the other a BSc graduate. It will look at how each graduate collaborated with end users and technical specialists and the effect this had on the project outcome. One of the projects will then be presented as a hypothetical live project to final year BSc and BA students and their approach to collaboration with end users and technical specialists examined

Electrical Switching Dynamics in Circular and Rectangular Ge2Sb2Te5 Nanopillar Phase Change Memory Devices

We have measured the critical phase change conditions induced by electrical pulses in Ge2Sb2Te5 nanopillar phase change memory devices by constructing a comprehensive resistance map as a function of pulse parameters (width, amplitude and trailing edge). Our measurements reveal that the heating scheme and the details of the contact geometry play the dominant role in determining the final phase composition of the device such that a non-uniform heating scheme promotes partial amorphization/crystallization for a wide range of pulse parameters enabling multiple resistance levels for data storage applications. Furthermore we find that fluctuations in the snap-back voltage and set/reset resistances in repeated switching experiments are related to the details of the current distribution such that a uniform current injection geometry (i.e. circular contact) favors more reproducible switching parameters. This shows that possible geometrical defects in nanoscale phase change memory devices may play an essential role in the performance of the smallest possible devices through modification of the exact current distribution in the active chalcogenide layer. We present a three-dimensional finite element model of the electro-thermal physics to provide insights into the underlying physical mechanisms of the switching dynamics as well as to quantitatively account for the scaling behaviour of the switching currents in both circular and rectangular contact geometries. The calculated temporal evolution of the heat distribution within the pulse duration shows distinct features in rectangular contacts providing evidence for locally hot spots at the sharp corners of the current injection site due to current crowding effects leading to the observed behaviour

challenges and opportunities from a public health perspective

ABSTRACT - Despite improvements in healthcare interventions, the incidence of adverse events and other patient safety problems constitutes a major contributor to the global burden of diseases and a concern for Public Health. In the last years there have been some successful individual and institutional efforts to approach patient safety issues in Portugal, unless such effort has been fragmented or focused on specific small areas. Long-term and global improvement has remained elusive, and most of all the improvement of patient safety in Portugal, must evaluate not only the efficacy of a change but also what was effective for implementing the change. Clearly, patient safety issues result from various combinations of individual, team, organization, system and patient factors. A systemic and integrated approach to promote patient safety must acknowledge and strive to understand the complexity of work systems and processes in health care, including the interactions between people, technology, and the environment. Safety errors cannot be productively attributed to a single human error. Our objective with this paper is to provide a brief overview of the status quo in patient safety in Portugal, highlighting key aspects that should be taken into account in the design of a strategy for improving patient safety. With these key aspects in mind, policy makers and implementers can move forward and make better decisions about which changes should be made and about the way the needed changes to improve patient safety should be implemented. The contribution of colleagues that are international leaders on healthcare quality and patient safety may also contribute to more innovative research methods needed to create the knowledge that promotes less costly successful changes.-------------------------- RESUMO – As questões relacionadas com a Segurança do Doente, e em particular, com a ocorrência de eventos adversos tem constituído, de há uns tempos a esta parte, uma crescente preocupação para as organizações de saúde, para os decisores políticos, para os profissionais de saúde e para os doentes/utentes e suas famílias, sendo por isso considerado um problema de Saúde Pública a que urge dar resposta. Em Portugal, nos últimos anos, têm sido desenvolvidos esforços baseados, maioritariamente, em iniciativas isoladas, para abordar os aspectos da Segurança do Doente. O facto de essas iniciativas não serem integradas numa estratégia explícita e de dimensão regional ou nacional, faz com que os resultados sejam parcelares e tenham visibilidade reduzida. Paralelamente, a melhoria da qualidade dos cuidados de saúde (a longo prazo) resultante dessas iniciativas tem sido esparsa e nem sempre a avaliação tem sido feita tendo em conta critérios de efectividade e de eficiência. A Segurança do Doente resulta da interacção de diversos factores relacionados, por um lado, com o doente e, por outro, com a prestação de cuidados que envolvem elementos de natureza individual (falhas activas) e organizacional/estrutural (falhas latentes). Devido à multifactorialidade que está na base de «problemas/falhas» na Segurança do Doente, qualquer abordagem a considerar deve ser sistémica e integrada. Simultaneamente, tais abordagens devem contemplar a compreensão da complexidade dos sistemas e dos processos de prestação de cuidados de saúde e as suas interdependências (envolvendo aspectos individuais, tecnológicos e ambientais). O presente trabalho tem por objectivo reflectir sobre o «estado da arte» da Segurança do Doente em Portugal, destacando os elementos-chave que se consideram decisivos para uma estratégia de acção nesse domínio. Com esses elementos os responsáveis pela governação da saúde poderão valorizar os aspectos que consideram decisivos para uma política de Segurança do Doente mais eficaz. A contribuição de quatro colegas internacionalmente reconhecidos como líderes na área da Qualidade em Saúde e da Segurança do Doente, constitui, por certo, uma oportunidade ímpar para a identificação e discussão de alguns dos principais desafios, ameaças e oportunidades que se colocarão, no curto prazo em Portugal, na área da Segurança do Doente.publishersversionpublishe