80 research outputs found

    Lighting in the third dimension : laser scanning as an architectural survey and representation method

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    This paper proposes tridimensional (3D) laser scanning to architects and lighting designers as a lighting enquiry and visualization method for existing built environments. The method constitutes a complement to existing lighting methods by responding to limitations of photometric measurements, computer simulation and HDR imagery in surveying and visualizing light in actual buildings. The research explores advantages and limitations of 3D laser scanning in a case study addressing a vast, geometrically complex and fragmented naturally and artificially lit space. Lighting patterns and geometry of the case study are captured with a 3D laser scanner through a series of four scans. A single 3D model of the entire space is produced from the aligned and fused scans. Lighting distribution patterns are showcased in relation to the materiality, geometry and position of windows, walls, lighting fixtures and day lighting sources. Results and presented through images similar to architectural presentation drawings. More specifically, the lighting distribution patterns are illustrated in a floor plan, a reflected ceiling plan, an axonometry and a cross-section. The point cloud model of the case study is also generated into a video format representing the entire building as well as different viewpoints. The study shows that the proposed method provides powerful visualization results due to the unlimited number of images that can be generated from a point cloud and facilitates understanding of existing lighting conditions in spaces

    A photobiological approach to biophilic design in extreme climates

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    This paper proposes the biophilic design approach as a plausible hypothesis for the challenging conditions related to living and working in extreme cold climates. Biophilic design has recently been developed to overcome the adverse effects of the built environment and to improve human well-being by redefining the human-nature relationship. Yet, biophilic design should be adapted to extreme cold climates in order to meet the biological needs of people in northern territories. This issue becomes more important when considering the availability of natural light due to the strong seasonal photoperiod and its effects on human well-being in such regions. The present paper critically reviews biophilic design patterns and identifies their main shortcomings. These shortcomings include the lack of (1) recommendations applicable to extreme cold climates (2) adaptation to the local photoperiods, and (3) a systemic framework integrated into the design process. The paper draws attention to the image-forming and non-image-forming effects of light as a basis of the human-nature design approach. In this regard, photobiological outcomes have been reviewed. Then, the paper discusses the existing lighting standards and guidelines in North America and how they have mainly been developed to fulfil the image-forming demands for light. Further efforts are needed to revise these standards with respect to the non-image-forming effects of light and the biophilic design requirements. Finally, adaptive building envelopes are presented as a hypothetical solution to optimize the biophilic qualities of buildings and address the biological needs of people living and working in extreme cold climates in northern territories

    Speckle tracking echocardiography in hypokinetic non-dilated cardiomyopathy: comparison with dilated cardiomyopathy

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    Aims: Hypokinetic non-dilated cardiomyopathy (HNDC), which is determined by impaired left ventricular (LV) systolic function despite normal LV size, has been categorized as a subgroup of dilated cardiomyopathy (DCM) spectrum. Lack of data regarding advanced echocardiographic data in this population motivated us to design the present study in order to assess LV myocardial deformation properties of HNDC patients against the ones with dilated left ventricle. Methods and results: Thirty-one HNDC patients and 23 DCM patients were enrolled in the study consecutively. Myocardial deformation parameters including global longitudinal strain, global circumferential strain, LV basal and apical rotation, LV twist, and LV mechanical dispersion were obtained with the use of two-dimensional speckle tracking-based methods in all patients. Left cardiac chamber volume was also measured using three-dimensional HeartModel application. Patients with enlarged left ventricle tend to have lower LV ejection fraction. Comparing with HNDC group, DCM patients showed worse global circumferential strain (coefficient ± standard error 3.59 ± 0.94, P < 0.001) and LV mechanical dispersion (coefficient ± standard error 16.46 ± 7.09, P = 0.02) after regression analysis, while neither the global longitudinal strain nor the LV twist was not significantly different between two study population. Conclusions: Left ventricular enlargement has a substantial effect on the circumferential strain and mechanical dispersion more than other deformation parameters that may play a role in the assumed poor prognosis of heart failure patients with dilated left ventricle. © 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiolog

    Biophilic, photobiological and energy-efficient design framework of adaptive building façades for Northern Canada

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    This paper develops an integrated design framework of adaptive building façades (ABFs) to respond to photobiological and thermal needs of occupants, biophilic factors, energy requirements and climatic features in Northern Canada, i.e. near and above 50°N. The paper discusses the importance of biophilic and photobiological factors and ABFs to improve occupants’ health and human-nature relations and deal with the extreme climate in Northern Canada where non-adapted buildings that could negatively affect occupants’ wellbeing. The paper shows that existing ABFs must be further developed for northern applications in terms of (i) the physical structure and configuration of components (ii) the design of solar shading/louver panels to address photobiological and biophilic requirements (iii) the development of lighting adaptation scenarios to respond to biophilic and photobiological needs, local photoperiods and energy issues, and (iv) the overall biophilic quality for accessibility to natural patterns. The ABFs’ framework was developed in three phases including (1) process environmental data (2) produce adaptation scenarios, and (3) operate adaptation scenarios. The research discussed major issues of all phases that must be further studied, especially the development of hourly/daily/seasonally lighting adaptation scenarios. The paper develops a holistic parametric methodology to integrate and optimize major design variables of ABF’s components

    Comparison of transthoracic echocardiography and right heart catheterization for assessing pulmonary arterial pressure in patients with congenital or valvular heart defects

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    Background- Although right heart catheterization (RHC) has acceptable accuracy for the measurement of pulmonary arterial pressure (PAP), significant risks and cost issues are worrisome. Thus, a non-invasive technique such as echocardiography for assessing PAP would clearly be of great clinical value. We aimed to compare estimated systolic PAP (SPAP) by echocardiogram with the actual RHC measurements in the two groups of congenital and valvular heart diseases (CHD and VHD, respectively), in whom pulmonary hypertension (PHT) was clinically suspected. Methods- A total of 103 consecutive patients with confirmed CHD or VHD referred to our center between January and December 2009 were studied. Participants underwent transthoracic echocardiography and RHC within 4 hours of each other. Results- The mean SPAP in the CHD group was no different measured by RHC or echo (46.49 ± 29.04 vs. 46.45 ± 23 mmHg, p = 0.541). The mean SPAP in the VHD group measured by RHC was significantly higher than that measured by echo (48.70 ± 14.50 vs. 44.90 ± 11.0 mmHg, p = 0.041). Fifty-one (49.5) patients were found to have PHT at RHC. Echocardiography correctly identified 48 of these patients (sensitivity= 94.1). Nineteen of the 52 patients without PHT on RHC were correctly identified by echocardiography (specificity= 36.5). The positive and negative predictive values for echocardiography in assessing the presence or absence of PHT were 59.3 and 86.4, respectively. Conclusion- Integration of hemodynamic data with the echo examination can appropriately provide comprehensive assessment of PHT with high sensitivity in individual patients with congenital or valvular heart defects

    Correlation between hyponatremia and high risk clinical and echocardiographic features in patients with acute heat failure

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    Background and purpose: Heart failure (HF) is characterized by decreased ability of the heart to provide sufficient blood flow or fill with the blood. Hyponatremia is the most commonly seen electrolyte abnormality in patients with heart failure that is associated with increased morbidity and mortality. The aim of this study was to assess the correlation between hyponatremia and high risk clinical and echocardiographic features in patients with acute HF. Materials and methods: This cross-sectional analytic study was performed in 271 patients with acute systolic heart failure admitted to Sari Fatemeh Zahra hospital, 2018-2019. Patients were divided into two groups: hyponatremic and normonatremic groups. Vital signs, echocardiographic variables, body mass index (BMI), and common cardiovascular risk factors were compared between the two groups using SPSS V18. Results: This study included 130 males (48) and 141 females (52) and the patients� mean age was 69.90±14.02 years. Patients with hyponatremia had lower BMI and systolic and diastolic blood pressure levels and higher platelet counts compared to other group (P =0.01, 0.002, 0.005, and 0.047, respectively). Also, these patients, were found with higher frequency of moderate to severe functional mitral regurgitation (P= 0.076). Linear regression analysis showed hyponatremia as an independent predictor of hypotension and hemodynamic instability in patients with hyponatremia. Conclusion: This study showed that patients with acute HF and hyponatremia are at higher risk of developing hypotension, cachexia, and increased platelet counts which put them at greater risk for cardiovascular morbidity and mortality. © 2020, Mazandaran University of Medical Sciences. All rights reserved

    Two-channel dansyl/tryptophan emitters with a cholic acid bridge as reporters for local hydrophobicity within supramolecular systems based on bile salts

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    The aim of the present work is to develop two-channel emitters to probe local hydrophobicity by means of fluorescence quenching within different biomimetic supramolecular environments. To achieve this goal, the dansyl (Dns) and tryptophan (Trp) fluorophores have been covalently attached to cholic acid (CA) in order to ensure simultaneous incorporation of the two emitting units into the same compartment. In principle, the two fluorophores of the synthesized Dns-CA-Trp probes could either exhibit an orthogonal behavior or display excited state interactions. The fluorescence spectra of 3 beta-Dns-CA-Trp showed a residual Trp emission band at ca. 350 nm and an enhanced Dns maximum in the 500-550 nm region. This reveals a partial intramolecular energy transfer, which is consistent with the Dns and Trp singlet energies. Thus, the two photoactive units are not orthogonal; nevertheless, 3 beta-Dns-CA-Trp seems appropriate as a two-channel reporter for the supramolecular systems of interest. Fluorescence quenching of 3 beta-Dns-CA-Trp by iodide (which remains essentially in bulk water) was examined within sodium cholate, sodium taurocholate, sodium deoxycholate and mixed micelles. Interestingly, a decrease in the emission intensity of the two bands was observed with increasing iodide concentrations. The most remarkable effect was observed for mixed micelles, where the quenching rate constants were one order of magnitude lower than in solution. As anticipated, the quenching efficiency by iodide decreased with increasing hydrophobicity of the microenvironment, a trend that can be correlated with the relative accessibility of the probe to the ionic quencher.Financial support from the Spanish Government (CTQ2012-38754-C03-03), Predoctoral FPU fellowship (AP2008-03295), and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Gómez Mendoza, M.; Marín García, ML.; Miranda Alonso, MÁ. (2014). Two-channel dansyl/tryptophan emitters with a cholic acid bridge as reporters for local hydrophobicity within supramolecular systems based on bile salts. Organic and Biomolecular Chemistry. 12(42):8499-8504. https://doi.org/10.1039/c4ob01394hS849985041242Vayá, I., Lhiaubet-Vallet, V., Jiménez, M. C., & Miranda, M. A. (2014). Photoactive assemblies of organic compounds and biomolecules: drug–protein supramolecular systems. Chem. Soc. Rev., 43(12), 4102-4122. doi:10.1039/c3cs60413fGomez-Mendoza, M., Marin, M. 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    Imagery datasets for photobiological lighting analysis of architectural models with shading panels (No. 2)

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    This repository include imagery datasets captured inside architectural models to explore impacts of colored shading panels on photobiological lighting parameters. The dataset is compiled as part of a doctoral dissertation in architecture, authored by Mojtaba Parsaee, supervised by Claude MH Demers, Marc Hébert, Jean-François Lalonde, at Laval University. The description of the datasets and experimental conditions and procedures are fully dissipated in a companion paper submitted with the same title to Data In Brief.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
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