Flow Dynamics in Human Aorta with Coexisting Models of Bicuspid Aortic Stenosis and Coarctation of the Aorta

Coarctation of the aorta (COA) is an obstruction of the aorta and is usually associated with bicuspid and tricuspid aortic valve stenosis (AS). The main objective of this work is to understand the hemodynamic of COA from different perspectives. This was performed using a global approach including: numerical simulations, mathematical lumped parameter modeling and experimental measurements. Numerous investigations pointed to a relationship between the genesis and the progression of cardiovascular disease and the locally irregular flow occurring at the diseased zone. Therefore, to examine the relationship between arterial disease and hemodynamics conditions, a joint experimental and numerical investigation was performed to understand physics of fluid flow of COA. When COA coexists with AS, the left ventricle faces a double hemodynamic load: a valvular load plus a vascular load. First, a formulation describing the instantaneous net pressure gradient through COA was introduced and the predictions compared to in vitro results. The model was then used to determine left ventricular work induced by coexisting aortic stenosis and coarctation with different severities. The suggested model can be used to guide the choice of optimal operative procedure (aortic valve replacement and/or coarctation repaired surgery) and to predict the potential outcome for such patients. Early detection and accurate estimation of COA severity is the most important predictor of successful long-term outcome. However, current clinical parameters used for the evaluation of the severity of COA have several limitations. In this study, first, we evaluated the limitations of current existing parameters (Catheter trans-COA pressure gradients and Doppler echocardiographic trans-COA pressure gradients) for the evaluation of the severity of COA. Then, we suggested a new approach based on COA Doppler velocity index and COA effective orifice area capable of predicting more accurately the severity of COA. An original in-vitro study was performed using a mock flow circulation model with different COA severities and various aortic valve conditions under different flow rates. In conclusion, this study investigated the flow dynamics of COA and development of a lumped parameter model, based on non-invasive measurements, capable of accurately investigating the impact of coexisting AS and COA on left ventricular workload. In addition, this study proposed two innovative approaches to evaluate the severity of COA correctly

The Impact of Nature, The Teaching and Learning of Elementary Lessons in Students 9-11 Years Old (Case Study: Shiraz Elementary Schools)

In today’s world some changes have been occurred in human lifestyle, these changes, along with the advantages, have led to a series of disadvantages including their disconnection with the nature. One of the most important areas to re-establish the relationship is the school. The presence of nature at schools, and holding some classes in nature, in addition to meeting the special needs of children causes their separation from those small and boring classes as well as their interest in courses . This study aimed to investigate the role of nature in children’s learning. For this purpose, third, fourth and fifth grade classes of 3 schools were held outside the school environment and in the nature in 5 courses. The study is a combinational research and field, indirect observation and library data collection methods were applied, where in the indirect observation, two types of questionnaires were prepared related to the students and teachers and were randomly distributed among 580 students and 50 elementary school teachers. Test reliability was assessed using Cronbach’s alpha and it was obtained to be 0.890. The results of this study indicate that the physical place as one of the factors in children’s learning has the maximum impact on teaching and learning of children. At the end of the study and by investigating the existing factors in the environment we understood that the expansion of the nature and natural light of it causes the students’ interest in lessons in nature

Comparison of tooth brushing related knowledge, attitude and health behavior as well as dental health status among boy and girl students in elementary schools in district 4 of Tehran in 2015

Background and aims: Assessment of oral health status is considered as one of the main criteria for evaluating the public health. Knowledge and attitude towards oral health behavior, especially brushing and gender differenceare factors influencing oral health. This study was aimed to compare tooth brushing related knowledge, attitude and health behavior as well as …. (DMFT) among girl and boy students in elementary schools in district 4 of Tehran in2015.Method: The present cross-sectional (descriptive and analytical) study was carried out among 408 girl and boy elementary students from six randomly selected schools in district 4 of Tehran, Iran. Two-stage cluster sampling was selected and employed. A valid and reliable researcher-… questionnaire was used for this study. Dental visits wereperformed on the basis of DMFT index and all students were assured of information confidentiality. The data were analyzed using SPSS (version 16) software.Results: In the current study, comparing female students with males showed that the mean scores of brushing knowledge, attitude and health behavior in girls was higher than boys and the difference was statistically significant (p=0.001). However, the observed mean DMFT difference between the girls and boys in this study was not significant (p>0.05). Furthermore, a strong and statistically significant relationship was noticed between frequency of brushing and DMFT in both sexes (p<0.05).Conclusion: Mean scores of knowledge, attitude and behavior in both sexes were fairly good and also better in female students than males. It was further found that boys and girls in our study can be, respectively, classified as low and very low mean DMFT groups based on World Health Organization classification. Therefore, appropriate educational interventions with more focus on the vulnerable group of boys are highly advocated in order to improve their knowledge and attitude. Key Words: Knowledge, Attitude, DMFT, Health behavior brushin

Hemodynamic Changes following Aortic Valve Bypass: A Mathematical Approach

Aortic valve bypass (AVB) has been shown to be a viable solution for patients with severe aortic stenosis (AS). Under this circumstance, the left ventricle (LV) has a double outlet. The objective was to develop a mathematical model capable of evaluating the hemodynamic performance following the AVB surgery. A mathematical model that captures the interaction between LV, AS, arterial system, and AVB was developed. This model uses a limited number of parameters that all can be non-invasively measured using patient data. The model was validated using in vivo data from the literature. The model was used to determine the effect of different AVB and AS configurations on flow proportion and pressure of the aortic valve and the AVB. Results showed that the AVB leads to a significant reduction in transvalvular pressure gradient. The percentage of flow through the AVB can range from 55.47% to 69.43% following AVB with a severe AS. LV stroke work was also significantly reduced following the AVB surgery and reached a value of around 1.2 J for several AS severities. Findings of this study suggest: 1) the AVB leads to a significant reduction in transvalvular pressure gradients; 2) flow distribution between the AS and the AVB is significantly affected by the conduit valve size; 3) the AVB leads to a significant reduction in LV stroke work; and 4) hemodynamic performance variations can be estimated using the model.Fonds quebecois de la recherche sur la nature et les technologies (176048

Cost-effectiveness analysis of topiramate versus phenobarbital in the treatment of children with febrile seizure in Shiraz

Background: Febrile seizure is the most common disorder in childhood, with a prevalence of 2% to 5%. There are many drugs for treatment of this disease; however, the most common prescribed medication in Iran is phenobarbital that is cheap, but it has many side effects. Topiramate is a medication with fewer side effects that is currently prescribed in Iran only for patients with epilepsy; also, it has recently been prescribed and tested for children with febrile seizure. The aim of this study was to compare the cost-effectiveness of topiramate versus phenobarbital in patients with febrile seizure in the south of Iran in 2017.Methods: This econometric cost-effectiveness and cost-utility study was conducted on 91 patients with febrile seizure to assess two strategies of oral drug therapy including phenobarbital and topiramate in 2016-2017. Of all, 51 patients were treated with phenobarbital and 40 patients received topiramate. In order to collect the required data, we followed up the patients for six months, using a randomized and single-blinded approach. In this study, a decision tree model was used. The outcomes of the model included febrile seizure and utility. The study was conducted from the perspective of the community; therefore, direct and indirect costs were included in the study. Excel and TreeAge software (2011) were used to analyze the results.Results: The results showed that topiramate was cheaper and more effective than phenobarbital. In patients in the phenobarbital and topiramate groups, the mean costs were $740 and$674 per ppp, utility scores were 0.72 and 0.82, and febrile seizure without side effects were 0.3 and 0.6, respectively. Moreover, one-way sensitivity analysis confirmed the robustness of the results of the study.Conclusion: According to the results, topiramate in patients with febrile seizure is a fully cost-effective and cost-efficient strategy that can be suggested as a better alternative for children with febrile seizure

Reverse Osmosis and Nano Filtration Membranes Performance's Comparison in Assaluyeh Industrial Wastewater Treatment

Restriction of freshwater resources is one of the major challenges that humanity has always been faced with. The use of treatment membranes in effluent recovery is one of the basic solutions to deal with this global problem. Therefore, in the present study, the performance of nanofiltration and reverse osmosis membranes in Assaluyeh industrial wastewater treatment has been compared and evaluated. The membranes used in this system are of commercial type of spiral woven polyamide. The effect of flow pressure and flow rate on the membrane permeate flux, total dissolved solids, separation efficiency percentage and membrane flux reduction have been evaluated. In both membranes, with increasing pressure from 5 to 7 bar at a constant flow rate of 720 L/h, the flux enhanced and the TDS rate decreased. The separation efficiency percentage of industrial wastewater using NF and RO membranes at optimum pressure of 7 bar was obtained 92% and 98.4%, respectively, which indicates higher RO filtration performance than NF. Increasing the flow rate from 600 to 840 L/h at a constant pressure of 7 bar improved the permeate flux for the samples. The amount of TDS with rising flow rate in NF membrane showed a decreasing and then increasing trend while in RO membrane there were slight changes. Meanwhile, the flow rate had no effect on the separation efficiency percentage of RO membrane, but in NF membrane, first an increasing and then a decreasing trend was observed. The highest separation efficiency percentage with NF and RO membranes at 720 L/h flow rate was 92% and 98.5%, respectively. The study of the effect of increasing pressure and flow rate on the percentage of flux reduction showed that in RO membrane it increases while in NF membrane this parameter depends on the result of the effect of flow rate and pressure

Rice Farmers’Behaviors andAttitudesTowardAgricultural Extension Programs in Healthy Food Production (Case of Lahijan and Amlash Counties, Northern Iran)

This study aimed to explain the behavior and attitudes of farmersin the adoption of Integrated Pest Management (IPM) technologies in rice fields. The main instrument of research was a questionnaire whose validity was confirmed by a panel of professors and executive experts, and its reliability was confirmed by apreliminary test.The sample employed in the research study comprised farmers who were participating in extension programs ofintegrated pest management held in Lahijan and Amlash during 2012-2014. The findingsshowed that the predominant activity of farmers was the use of combined methods (chemical and non-chemical), leaving crop residue on the field, and using biological control, with the rank average of 9.27, 9.25, and 9.12 from the total average of 6.5, respectively. In addition to, private extension cooperatives, rice supervisors, agricultural extension staff, educators, and TV programs with the average of 11.14, 10.87, 10.80, and 10.71 of the total average of 7.49 had the highest role in informing the farmers. Based on such findings, some suggestions were also given, such as concentration on special aspects of integrated pest management, attention to the education of rural women, and employing young and educated members of farmers’ families as arms of agriculture extension in transferring innovation ofintegrated pest management to families

The role of aortic compliance in determination of coarctation severity: Lumped parameter modeling, in vitro study and clinical evaluation

Early detection and accurate estimation of the extent of coarctation of the aorta (COA) is critical to long-term outcome. Peak-to-peak trans-coarctation pressure gradient (PKdP) higher than 20 mmHg is an indication for interventional/surgical repair. Patients with COA have reduced proximal and distal aortic compliances. A comprehensive study investigating the effects of variations of proximal COA and systemic compliances on PKdP, and consequently on the COA severity evaluation has never been done. This study evaluates the effect of aortic compliance on diagnostic accuracy of PKdP. Lumped parameter modeling and in vitro experiments were performed for COA severities of 50%, 75% and 90% by area. Modeling and in vitro results were validated against retrospective clinical data of PKdP, measured in 54 patients with COA. Modeling and in vitro. PKdP increases with reduced proximal COA compliance (+36%, +38% and +53% for COA severities of 50%, 75% and 90%, respectively; p<0.05), but decreases with reduced systemic compliance (−62%, −41% and −36% for COA severities of 50%, 75% and 90%, respectively; p<0.01). Clinical study. PKdP has a modest correlation with COA severity (R=0.29). The main determinants of PKdP are COA severity, stroke volume index and systemic compliance. Systemic compliance was found to be as influential as COA severity in PKdP determination (R=0.30 vs. R =0.34). In conclusion, PKdP is highly influenced by both stroke volume index and arterial compliance. Low values of PKdP cannot be used to exclude the severe COA presence since COA severity may be masked by reduced systemic compliance and/or low flow conditions