2,462 research outputs found

    The development of a mapping tool for the evaluation of building systems for future climate scenarios on European scale

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    The paper presents a tool for the mapping of the performance of building systems on European scale for different (future) time periods. The tool is to use for users and be applicable for different building systems. Users should also be able to use a broad range of climate parameters to assess the influence of climate change on these climatic parameters. Also should the calculation time be reasonable short. The mapping tool is developed in MATLAB, which can be used by other users for their own studies.Comment: 21 pages, 24 figures, pre-conferenc

    Contrast-enhanced micro-CT imaging in murine carotid arteries : a new protocol for computing wall shear stress

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    Background: Wall shear stress (WSS) is involved in the pathophysiology of atherosclerosis. The correlation between WSS and atherosclerosis can be investigated over time using a WSS-manipulated atherosclerotic mouse model. To determine WSS in vivo, detailed 3D geometry of the vessel network is required. However, a protocol to reconstruct 3D murine vasculature using this animal model is lacking. In this project, we evaluated the adequacy of eXIA 160, a small animal contrast agent, for assessing murine vascular network on micro-CT. Also, a protocol was established for vessel geometry segmentation and WSS analysis. Methods: A tapering cast was placed around the right common carotid artery (RCCA) of ApoE(-/-) mice (n = 8). Contrast-enhanced micro-CT was performed using eXIA 160. An innovative local threshold-based segmentation procedure was implemented to reconstruct 3D geometry of the RCCA. The reconstructed RCCA was compared to the vessel geometry using a global threshold-based segmentation method. Computational fluid dynamics was applied to compute the velocity field and WSS distribution along the RCCA. Results: eXIA 160-enhanced micro-CT allowed clear visualization and assessment of the RCCA in all eight animals. No adverse biological effects were observed from the use of eXIA 160. Segmentation using local threshold values generated more accurate RCCA geometry than the global threshold-based approach. Mouse-specific velocity data and the RCCA geometry generated 3D WSS maps with high resolution, enabling quantitative analysis of WSS. In all animals, we observed low WSS upstream of the cast. Downstream of the cast, asymmetric WSS patterns were revealed with variation in size and location between animals. Conclusions: eXIA 160 provided good contrast to reconstruct 3D vessel geometry and determine WSS patterns in the RCCA of the atherosclerotic mouse model. We established a novel local threshold-based segmentation protocol for RCCA reconstruction and WSS computation. The observed differences between animals indicate the necessity to use mouse-specific data for WSS analysis. For our future work, our protocol makes it possible to study in vivo WSS longitudinally over a growing plaque

    Een routekaart voor raadsakkoorden: varianten, ervaringen en lessen

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    The Legitimacy and Effectiveness of Law & Governance in a World of Multilevel Jurisdiction

    Intravascular Palpography for Vulnerable Plaque Assessment

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    Palpography assesses the local mechanical properties of tissue using the deformation caused by the intraluminal pressure. The technique was validated in vitro using diseased human coronary and femoral arteries. Especially between fibrous and fatty tissue, a highly significant difference in strain (p = 0.0012) was found. Additionally, the predictive value to identify the vulnerable plaque was investigated. A high-strain region at the lumen vessel wall boundary has 88% sensitivity and 89% specificity for identifying these plaques. In vivo, the technique is validated in an atherosclerotic Yucatan minipig animal model. This study also revealed higher strain values in fatty than in fibrous plaques (p < 0.001). The presence of a high-strain region at the lumen-plaque interface has a high predictive value to identify macrophages. Patient studies revealed high strain values (1% to 2%) in noncalcified plaques. Calcified material showed low strain values (0% to 0.2%). With the development of three-dimensional palpography, identification of weak spots over the full length of a coronary artery becomes available. Patients with myocardial infarction or unstable angina have more high-strain spots in their coronary arteries than patients with stable angina. In conclusion, intravascular palpography is a unique tool to assess lesion composition and vulnerability. Three-dimensional palpography provides a technique that may develop into a clinically available tool for decision making to treat hemodynamically nonsignificant lesions by identifying vulnerable plaques. The clinical utility of this technique is yet to be determined, and more investigation is needed

    Caregivers' understanding of dementia predicts patients' comfort at death: a prospective observational study

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    Background: Patients with dementia frequently do not receive adequate palliative care which may relate to poor understanding of the natural course of dementia. We hypothesized that understanding that dementia is a progressive and terminal disease is fundamental to a focus on comfort in dementia, and examined how family and professional caregivers' understanding of the nature of the disease was associated with patients' comfort during the dying process. Methods: We enrolled 372 nursing home patients from 28 facilities in The Netherlands in a prospective observational study (2007 to 2010). We studied both the families and the physicians (73) of 161 patients. Understanding referred to families' comprehension of complications, prognosis, having been counseled on these, and perception of dementia as "a disease you can die from" (5-point agreement scale) at baseline. Physicians reported on this perception, prognosis and having counseled on this. Staff-assessed comfort with the End-of-Life in Dementia - Comfort Assessment in Dying (EOLD-CAD) scale. Associations between understanding and comfort were assessed with generalized estimating equations, structural equation modeling, and mediator analyses. Results: A family's perception of dementia as "a disease you can die from" predicted higher patient comfort during the dying process (adjusted coefficient -0.8, 95% confidence interval (CI): -1.5; -0.06 point increment disagreement). Family and physician combined perceptions (-0.9, CI: -1.5; -0.2; 9-point scale) were also predictive, including in less advanced dementia. Forty-three percent of the families perceived dementia as a disease you can die from (agreed completely, partly); 94% of physicians did. The association between combined perception and higher comfort was mediated by the families' reporting of a good relationship with the patient and physicians' perception that good care was provided in the last week. Conclusions: Awareness of the terminal nature of dementia may improve patient comfort at the end of life. Educating families on the nature of dementia may be an important part of advance care planning

    Минералогические исследования в пещерной системе Снежная-Меженного-Иллюзия (Западный Кавказ, Бзыбский хребет): предварительные результаты и направления дальнейших работ

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    В статье приводятся сведения о минеральном составе водных хемогенных и водных механических отложений в пещерной системе Снежная-Меженного-Иллюзия. В состав водных хемогенных отложений входят Mg- и Sr-содержащий кальцит, арагонит, гипс, гидромагнезит, целестин, стронцианит, доломит, гетит, рутил и циркон. Водные механические отложения сложены преимущественно доломитом, кварцем и кальцитом. В схожих по морфологии и микроклимату частях пещерной системы наблюдаются одинаковые вторичные минералы.У статті наводяться відомості про мінеральний склад водних хемогенних і водних механічних відкладень в печерній системі Сніжна-Меженого-Ілюзія. До складу водних хемогенних відкладень входять кальцит, який містить Mg і Sr, арагоніт, гіпс, гідромагнезіт, целестин, стронціаніт, доломіт, гетит, рутил і циркон. Водні механічні відкладення складені переважно доломітом, кварцом і кальцитом. У схожих за морфологєю та мікрокліматом частинах печерної системи спостерігаються однакові вторинні мінерали.The article presents the preliminary characteristic of the mineral composition of chemogenic formations and clastic deposits of Snezhnaya-Mezhennogo-Illusia cave system. Chemogenic formations are composed by Mg- and Sr-calcite, aragonite, gypsum and hydromagnesite, celestite, strontianite, dolomite, goethite, rutile and zircon. Clastic sediments are composed mainly by dolomite, quartz and calcite. Same secondary minerals are observed in those parts of the cave system that have similar morphology and microclimate
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