43 research outputs found
Lighting in the third dimension : laser scanning as an architectural survey and representation method
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
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
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
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
Correlation between hyponatremia and high risk clinical and echocardiographic features in patients with acute heat failure
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
Protective effect of N-acetylcysteine against oxygen radical-mediated coronary artery injury
Influence of random shrinkage porosity on equivalent elastic modulus of casting: A statistical and numerical approach
Right ventricle free wall mechanics in metabolic syndrome without type-2 diabetes: effects of a 3-month lifestyle intervention program
Correlation between albuminuria and tissue Doppler-derived left ventricular myocardial performance index in patients with type 2 diabetes
Background: Albuminuria is considered as a significant predictor of cardiovascular morbidity and mortality in patients with diabetes mellitus. The main purpose of this study was to determine the correlation between albuminuria and global left ventricular (LV) function in patients with type 2 diabetes (T2D). Methods: This observational study was conducted on 80 consecutive asymptomatic patients with T2D and an LV ejection fraction �55. The patients were divided into two groups depending on the presence or absence of albuminuria. Echocardiography-derived indices of the LV function were then compared between these groups. Results: The patients with albuminuria were older (mean ± SD: 60.37 ± 9.05 vs 54.52 ± 10.26 years of age, P =.01) and had higher hemoglobin A1c (HbA1c) levels (8.45 ± 1.97 vs 7.25 ± 1.93 mg/dL, P =.012) than those without albuminuria. Among the echocardiographic variables, the patients with albuminuria had higher LV Tei-index (median lower-upper quartile: 0.620 0.455-0.824 vs 0.441 0.336-0.586, P <.001), more prolonged early filling (E)-wave deceleration time (274.87 ± 75.97 vs 239.40 ± 61.35 ms, P =.032), increased interventricular septal wall thickness (1.11 ± 0.31 vs 0.95 ± 0.21 cm, P =.012), and lower mean early diastolic mitral annular velocity (7.57 ± 2.34 vs 8.68 ± 2.46 cm/s, P =.046) than those without albuminuria. Among risk factors, only albuminuria and HbA1c levels were associated with a significant increase in LV Tei-index (Beta = 0.426 and P <.001, Beta = 0.226 and P =.042, respectively). Conclusion: The LV Tei-index was significantly higher in diabetic patients with than without albuminuria. Low HbA1c levels were correlated with a decrease in LV Tei-index. © 2021 Wiley Periodicals LL