Comparison of bone mineral density measured by dual X-ray, axial dual-energy photon X-ray absorptiometry and laser absorptiometry of calcaneus

The objective of this study was to validate the use of bone mineral measurements of the calcaneus bone by dual X-ray and laser (DXL) in a cross-sectional study carried out in an osteoporosis clinic. Measurements of bone mineral density (BMD) at proximal femur and spine were obtained by dual-energy photon X-ray absorptiometry (DEXA). Osteoporosis was defined by a DEXA T-score <-2.5 at the femoral neck or lumbar spine. Sensitivity, specificity and kappa statistics for DXL were calculated, assuming the DEXA measurement as the gold-standard. The study included 475 women with a mean age of 54±11.9 years. 15 had osteoporosis while 39 were osteopenic (-2.5<T-score between<-1) at the femoral neck or spine. A significant correlation (p<0.001) was found between BMD values as measured by DXL at femoral neck and DEXA at the lumbar spine. Assuming the same T-score cut-off value for the diagnosis osteoporosis and a modified cut-off value for the diagnosis of osteopenia (-2.5<T-score<-1.5), yields a sensitivity of 83 and a specificity of 74 to 86 for the DXL device. In conclusion, BMD measured at the calcaneal bone by DXL, has a good correlation with that measured by axial DEXA

BIM-based surface-specific solar simulation of buildings

Photovoltaic (PV) solar energy is rapidly growing as an attractive alternative to fossil fuels. PV panels can harvest the solar power and turn it into a clean source of electricity. Traditionally, PV panels are only used on the rooftops of buildings. However, with the emergence of building-integrated solar panels in recent years, other surfaces on the building façade can be considered for the installation of PV panels. Given that different panels have different cost and performance profiles, it is of a cardinal importance to properly design the PV panels on the building facades to ensure a maximum benefit-cost ratio. Existing simulation and optimization methods do not discriminate between different types of surfaces of the building and treat the building envelope as a set of polygons. This can result in under- or over- design since there is a strong relationship between the type of the surfaces and the type of PV panels that can be attached to them or integrated with them. The advent of Building Information Modeling (BIM) in recent years has provided a rich platform for object-based evaluation and analysis of buildings. Nonetheless, currently, BIM is not used for a detailed and surface-specific simulation of building surfaces. In this research, a BIM-based method is developed for a detailed simulation of a building envelope using its surface properties. A prototype is developed using Dynamo visual programming platform to demonstrate the feasibility of the proposed method, and a case study is presented for a building in Montreal, Canada. In the light of the result of the case study, it can be concluded that the proposed method is promising in terms of providing the input for a comprehensive planning of the solar panel layout

The cut-off point of dual energy X-ray and laser (DXL) of calcaneus osteoporosis diagnosis in postmenopausal women

Background: Dual X-Ray Absorptiometry (DXA) is a method which can extensively be used for bone mineral densitometry (BMD). Another more recent method is DXL, which associate with dual X ray absorptiometry, assisted by laser measure heel thickness. In this study the cut off points for DXL of calcaneus in the diagnosis of osteoporosis in different bone regions in postmenopausal women had been determined. Materials and Methods: In 268 postmenopausal women, BMD of the spinal and femoral regions was measured by DXA, and the value for the calcaneous was measured by DXL. The agreement of the two methods in the diagnosis of osteoporosis and optimal cut-off point for DXL in defining osteoporosis was obtained. What obtained was the agreement of the two methods in the diagnosis of osteoporosis, as well as the optimal cut-off point for DXL in defining osteoporosis. Results: DXA showed osteoporosis in 40.7 of cases with 35.2 in L2-L4, 16.2 in the femoral neck, and 11.7 for the femoral total region. The DXL found osteoporosis, considering -2.5 SD as a threshold, in 26.1 of cases. Agreement of the two methods in the diagnosis of osteoporosis (Kappa score) was 0.443 for the lumbar region, 0.464 for the neck, and, 0.421 for total femur regions (all P values were significant). Using Receiver Operating Characteristic (ROC ) curves, it was found that a T-score of -2.1, -2.6 and -2.4 as the optimal cut-off point of DXL in the diagnosis of osteoporosis in the lumbar spine, the neck and total region of femur, respectively. Conclusion: The results of this study sh owed a moderate agreement between the two methods in the diagnosis of osteoporosis. It seems that the DXL cannot be used as a substitute for the DXA method, but it can be used as a screening method to find (to diagnose) osteoporosis

Fairness of Financial Contribution in Iranian Health System: Trend Analysis of National Household Income and Expenditure, 2003-2010

BACKGROUND: Social systems are dealing with the challenge of achieving fairness in the distribution of financial burden and protecting the risk of financial loss. The purpose of this paper is to present a trend analysis for the indicators related to fairness in healthcare's financial burden in rural and urban population of Iran during the eight years period of 2003 to 2010. METHODS: We used the information gathered by statistical center of Iran through sampling processes for the household income and expenditures. The indicators of fairness in financial contribution of healthcare were calculated based on the WHO recommended methodology. The indices trend analysis of eight-year period for the rural, urban areas and the country level were computed. RESULTS: This study shows that in Iran the fairness of financial contribution index during the eight-year period has been decreased from 0.841 in 2003 to above 0.827 in 2010 and The percentage of people with catastrophic health expenditures has been increased from 2.3 to above 3.1. The ratio of total treatment costs to the household overall capacity to pay has been increased from 0.055 to 0.068 and from 0.072 to 0.0818 in urban and rural areas respectively. CONCLUSION: There is a decline in fairness of financial contribution index during the study period. While, a trend stability of the proportion of households who suffered catastrophic health expenditures was found

Finite element simulations of interactions between multiple hydraulic fractures in a poroelastic rock

A fully coupled three-dimensional finite-element model for hydraulic fracturing in permeable rocks is utilised to investigate the interaction between multiple simultaneous and sequential hydraulic fractures. Fractures are modelled as surface discontinuities within a three-dimensional matrix. This model simultaneously accounts for laminar flow within the fracture, Darcy flow within the rock matrix, poroelastic deformation of the rock, and the propagation of fractures using a linear elastic fracture mechanics framework. The leakoff of fracturing fluid into the surrounding rocks is defined as a function of the pressure gradient at the fracture surface, the fluid viscosity, and the matrix permeability. The coupled equations are solved numerically using the finite element method. Quadratic tetrahedral and triangle elements are used for spatial discretisation of volumes and surfaces, respectively. The model is validated against various analytical solutions for plane-strain and penny-shaped hydraulic fractures. Several cases of simultaneous fracturing of multiple hydraulic fractures are simulated in which the effects of the various parameters (the in situ stresses, the distance between fractures, the permeability of the matrix, the Biot poroelastic coefficient, and the number of the fractures in a group) are investigated. The results show that the stress induced by the opening of the fractures, and the stress induced by the fluid leakoff, each have the effect of locally altering the magnitudes and orientations of the principal stresses, hence altering the propagation direction of the fractures. Opening of a fracture induces excessive compression (also known as the “stress shadow”) that causes adjacent fractures to curve away from each other. This excessive compression competes against the differential in situ stresses, which tend to cause the fracture to grow in the plane normal to the minimum in situ stress. The stress shadow effect is reduced by increasing the distance between fractures, and is increased by increasing the leakoff, which may be due to increased permeability of the rock, or an increase in the Biot coefficient

Association of serum level of 25-hydroxy Vitamin D deficiency and pulmonary function in healthy individuals

Background. Besides the extensive regulatory role in growing number of biologic processes, Vitamin D has been recently considered essential for lungs function as well as protective against exacerbation of chronic obstructive pulmonary diseases. We assessed the correlation between Vitamin D serum levels with pulmonary function in healthy individuals. Methods. In a cross-sectional study, healthy volunteer (n=92) participants underwent the following laboratory procedures: a blood test, a 24-hour urine collection test, and the serum level of 25-hydroxy Vitamin D before undergoing spirometry. Linear correlation coefficient was calculated to detect the association between serum level of 25-hydroxy Vitamin D and pulmonary volumes. Results. The mean age of participants was 39.95±9.98 years. 48 of participants showed different levels of 25-hydroxy Vitamin D deficiency. We recognized a consistent direct positive correlation between serum levels of 25-hydroxy Vitamin D and lung function volumes. The coefficient for forced vital capacity, forced expiratory volume in 1 second, forced expiratory flow 25-75, and forced expiratory volume in 1 second/forced vital capacity ratio were 0.610, 0.509, 0.454, and 0.551, respectively. Conclusions. Our findings suggest correlation between higher serum levels of 25-hydroxy Vitamin D and improved pulmonary function. Accordingly, supplemental Vitamin D might significantly improve treatment response. © 2018 Maryam Moghaddassi et al

Screening for amyloid deposition by subcutaneous fat tissue aspiration technique in rheumatoid arthritic patients and investigating its clinical significance in Iran

Aim: This study examined the frequency of secondary amyloidosis in Iranian patients with rheumatoid arthritis (RA) in order to determine its clinical significance. Methods: A total of 220 RA patients (167 female, 53 male), with minimum disease duration of 5 years, were included in this prospective study over a period of about 2 years. Abdominal subcutaneous fat-pad aspiration (ASFA) method was used in obtaining specimens from all subjects. All of the specimens were examined for apple-green birefringence under polarized light microscope. Amyloid deposits were graded from 1+ to 3+. Clinical, radiological, and laboratory characteristics of the patients were assessed and recorded. Results: Amyloid deposition was detected in 11 (5) of the fat smears stained with Congo red stain. All of the samples had minimal (1+) amyloid deposits. In this study, amyloid-positive cases showed clinically significant symptoms; six of the patients (55) presented with proteinuria, and seven other cases (64) presented with severe constipation. Conclusion: Abdominal fat amyloid deposition was found to be uncommon in adult Iranian RA patients. In up to half of the patients the deposits were subclinical. A longer follow-up and larger multicentric collaborative study is needed to determine the significance of subclinical amyloid deposits. © 2007 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd

Caprock integrity and public perception studies of carbon storage in depleted hydrocarbon reservoirs

Capture and subsurface storage of CO2 is widely viewed as being a necessary component of any strategy to minimise and control the continued increase in average global temperatures. Existing oil and gas reservoirs can be re-used for carbon storage, providing a substantial fraction of the vast amounts of subsurface storage space that will be required for the implementation of carbon storage at an industrial scale. Carbon capture and storage (CCS) in depleted reservoirs aims to ensure subsurface containment, both to satisfy safety considerations, and to provide confidence that the containment will continue over the necessary timescales. Other technical issues that need to be addressed include the risk of unintended subsurface events, such as induced seismicity. Minimisation of these risks is key to building confidence in CCS technology, both in relation to financing/liability, and the development and maintenance of public acceptance. These factors may be of particular importance with regard to CCS projects involving depleted hydrocarbon reservoirs, where the mechanical effects of production activities must also be considered. Given the importance of caprock behaviour in this context, several previously published geomechanical caprock studies of depleted hydrocarbon reservoirs are identified and reviewed, comprising experimental and numerical studies of fourteen CCS pilot sites in depleted hydrocarbon reservoirs, in seven countries (Algeria, Australia, Finland, France, Germany, Netherlands, Norway, UK). Particular emphasis is placed on the amount and types of data collected, the mathematical methods and codes used to conduct geomechanical analysis, and the relationship between geomechanical aspects and public perception. Sound geomechanical assessment, acting to help minimise operational and financial/liability risks, and the careful recognition of the impact of public perception are two key factors that can contribute to the development of a successful CCS project in a depleted hydrocarbon reservoir

Quality evaluation of national cancer registry system in Iran: Study protocol

Background: Cancer registry can be a very important component of health information system in developing countries. Routine collection of data and ongoing monitoring of their quality can have a crucial role in priority setting and evidence-based policy making for controlling cancers and trends follow-up in low and middle-income countries. Evaluation of cancer registered data consists of four important components including: comparability, completeness, validity, and timeliness. Similar frameworks are utilized in different countries all over the world.Methods and Materials: We will use the national annual cancer registry reports in Iran alone or perhaps along with other Iranian published reports about childhood cancer incidence to determine the stability and trend of incidence rates over time and compare above mentioned reports with childhood cancer incidence data reported by other countries through a systematic review as well as in some cases meta-analysis in order to assess data quality. Data will also be collected from other sources such as death certificates to estimate mortality rates and other different methods will also be additionally applied, by use of which death certificates would be utilized to assess the quality of data, too. Conclusion: As the first step for proper measuring incidence rate of all types of cancers all over the country, we will assess and evaluate reported national cancer registry data in Iran in order to estimate the national burden of cancers in 1990-2013