1,108 research outputs found
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
Optimising the management of vaginal discharge syndrome in Bulgaria: cost effectiveness of four clinical algorithms with risk assessment
OBJECTIVES: To evaluate the performance and cost effectiveness of the WHO recommendations of incorporating risk-assessment scores and population prevalence of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) into vaginal discharge syndrome (VDS) algorithms. METHODS: Non-pregnant women presenting with VDS were recruited at a non-governmental sexual health clinic in Sofia, Bulgaria. NG and CT were diagnosed by PCR and vaginal infections by microscopy. Risk factors for NG/CT were identified in multivariable analysis. Four algorithms based on different combinations of behavioural factors, clinical findings and vaginal microscopy were developed. Performance of each algorithm was evaluated for detecting vaginal and cervical infections separately. Cost effectiveness was based on cost per patient treated and cost per case correctly treated. Sensitivity analysis explored the influence of NG/CT prevalence on cost effectiveness. RESULTS: 60% (252/420) of women had genital infections, with 9.5% (40/423) having NG/CT. Factors associated with NG/CT included new and multiple sexual partners in the past 3 months, symptomatic partner, childlessness and >or=10 polymorphonuclear cells per field on vaginal microscopy. For NG/CT detection, the algorithm that relied solely on behavioural risk factors was less sensitive but more specific than those that included speculum examination or microscopy but had higher correct-treatment rate and lower over-treatment rates. The cost per true case treated using a combination of risk factors, speculum examination and microscopy was euro 24.08. A halving and tripling of NG/CT prevalence would have approximately the inverse impact on the cost-effectiveness estimates. CONCLUSIONS: Management of NG/CT in Bulgaria was improved by the use of a syndromic approach that included risk scores. Approaches that did not rely on microscopy lost sensitivity but were more cost effective
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Practice patterns and outcomes of equivocal bone scans for patients with castration-resistant prostate cancer: Results from SEARCH.
ObjectiveTo review follow-up imaging after equivocal bone scans in men with castration resistant prostate cancer (CRPC) and examine the characteristics of equivocal bone scans that are associated with positive follow-up imaging.MethodsWe identified 639 men from five Veterans Affairs Hospitals with a technetium-99m bone scan after CRPC diagnosis, of whom 99 (15%) had equivocal scans. Men with equivocal scans were segregated into "high-risk" and "low-risk" subcategories based upon wording in the bone scan report. All follow-up imaging (bone scans, computed tomography [CT], magnetic resonance imaging [MRI], and X-rays) in the 3 months after the equivocal scan were reviewed. Variables were compared between patients with a positive vs. negative follow-up imaging after an equivocal bone scan.ResultsOf 99 men with an equivocal bone scan, 43 (43%) received at least one follow-up imaging test, including 32/82 (39%) with low-risk scans and 11/17 (65%) with high-risk scans (p = 0.052). Of follow-up tests, 67% were negative, 14% were equivocal, and 19% were positive. Among those who underwent follow-up imaging, 3/32 (9%) low-risk men had metastases vs. 5/11 (45%) high-risk men (p = 0.015).ConclusionWhile 19% of all men who received follow-up imaging had positive follow-up imaging, only 9% of those with a low-risk equivocal bone scan had metastases versus 45% of those with high-risk. These preliminary findings, if confirmed in larger studies, suggest follow-up imaging tests for low-risk equivocal scans can be delayed while high-risk equivocal scans should receive follow-up imaging
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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
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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
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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
Interview with Bruce J. Terris
For transcript, click the Download button above. For video index, click the link below.
Bruce J. Terris was an assistant in the US Solicitor General\u27s office from 1958 to 1965, where he argued sixteen cases before the Supreme Court. In 1970 he went into private practice. He was counsel in many landmark environmental law cases and was active in numerous District of Columbia-area nonprofits. In 1977 he was named a Penn Law honorary fellow. He died in 2017
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