Blastocystis Hominis infection among hospitalized children due to diarrhea in Hajar Hospital, Shahre-Kord, Iran

Background: Blastocystis hominisis is an intestinal protozoan, recently known as a potential pathogen, which causes intestinal disorders, especially in children. The parasite has a worldwide distribution, ranged from 2 up to 30 in some regions. Objectives: Given no specific study focused on infection rate of B. hominis in children with diarrhea in Iran, this study was carried out to detect frequency of the parasite in children with diarrhea. Patients and Methods: In a cross-sectional study from September 2009 to July 2010, one hundred and sixty hospitalized children with diarrhea in Hajar Hospital, Shahre-Kord, Iran were enrolled. Stool samples were collected and were examined microscopically in wet direct smear using normal saline and iodine solution (Lugol). Furthermore, permanent trichrome stain was performed and all stools were stained and studied with oil immersion's lens (100 ×). Results: Out of 160 stool samples were examined, in 37 cases (23) including 25 boys and 12 girls, B. hominis was the most frequent protozoa, followed by Giardia lamblia in 19 cases (12). E. histolitica/dispare were detected only in two cases (1). Conclusions: The frequency of B. hominis in the study was more than other reports from Iran. This study revealed that among hospitalized children with diarrhea, B. hominis was the most common protozoon. © 2012, Shahid Beheshti University of Medical Sciencces

Development Application of Composite Indices (CI): An Emerging Method to the Disciplines of Engineering, Economics and Finance

Interdisciplinary or multidisciplinary research involves the use of a combination of principles from various disciplines: engineering, economics, finance, etc. This particular approach makes a lot of sense; otherwise, all the research will become compartmentalized, and researchers from one discipline will not know what researchers from other disciplines are doing and how those principles can be applied to their own disciplines. One way to create a common base connecting all these disciplines is to use the concept of composite indicators (CI), which is an emerging field of study. The use of composite indices, as part of an emerging method, for research problems in various fields allows for greater understanding of research problems and provides a visionary approach to solve such problems. This paper first states the existing methods for calculation of composite indicators in the literature and then suggests a new method

A New Approach for a Forecasting Model in the Estimation of Social Security Benefits

This paper developed a new way in which Social Security benefits are estimated in response to the reforms to Social Security to retain its financial solvency. The present research carefully presented the current methodology to calculate the Social Security benefits and carefully examined changes to the methodology to estimate Social Security benefits. More specifically, the proposed methodology included functional specifications such as a linear spline, a cubic spline, and a cubic smooth function that would be fitted between the index factor and the cumulative number of years a beneficiary receives the benefits. After a functional relationship was derived, the best fit specification was determined based on the data used to estimate future Social Security benefits

Mathematical Analysis of Unemployment Benefits

During the Great Recession, expenditures on unemployment insurance (UI) benefits increased, and the benefits were extended. This research deals with development of a mathematical model to calculate unemployment benefits. At a conceptual level, unemployment benefits can be considered as directly proportional to salary and the employment period of the worker prior to being laid off. It is also inversely proportional to factors such as other governmental benefits received in that period of unemployment. The approach in this paper presents the need to calculate the unemployment benefits to keep up with the capricious wages and changing regulations. This analysis will include state and federal government benefits. Each state should be able to adapt the new formula, so it can assess the proper baseline for calculating the unemployment benefits needed for their specific cost of living requirements

Occurrence and Fate of Amoxicillin and Penicillin G Antibiotics in Hospital Wastewater Treatment Plants: A Case Study – Gonbad Kavous, Iran

Release of antibiotics to the environment as a result of wastewater effluent discharge is a cause for concern worldwide, as they pose a potential threat to  human health and the earth ecosystem. Penicillin and amoxicillin are widely used antibiotics. Despite their rapid hydrolysis in aqueous matrices, their  presence in the environment is widely investigated. The current study reported and analysed the current state of four hospital wastewater treatment  plants (WWTPs) in Gonbad Kavous, Iran, during 2019, from the perspective of amoxicillin and penicillin G removals. WWTPs were sampled at various  stages of the treatment process to determine at which stage the antibiotics are being removed. Concentrations of amoxicillin and penicillin G in raw  wastewater, analysed by HPLC, varied from 0.35 to 1.02 and 0.02–0.31 μgL−1, respectively. These values reduced in the final effluent, corresponding to  overall efficiency in removing the studied antibiotics of 20-60.5%. Anaerobic processes (i.e. septic tank) slightly outperformed aerobic biological processes  for both antibiotics’ removal, and penicillin G was removed more efficiently than amoxicillin. Effects of wastewater physicochemical properties,  including chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) on antibiotics removal, were  also studied. Whereas statistically significant correlations were noticed between COD, amoxicillin and penicillin G removals, their decline showed no  correlation with TSS removal. Our study shows that despite the deployment of treatment plants, a considerable amount of antibiotics is released into  receiving water bodies, resulting in significant amounts of these pharmaceuticals entering the environment. There is abundant room for further progress  in the detection and quantification of pharmaceuticals and other emerging contaminants in hospital wastewaters and their metabolites and  biodegradation products.&nbsp

Non-invasive MRI quantification of cerebrospinal fluid dynamics in amyotrophic lateral sclerosis patients.

BACKGROUND: Developing novel therapeutic agents to treat amyotrophic lateral sclerosis (ALS) has been difficult due to multifactorial pathophysiologic processes at work. Intrathecal drug administration shows promise due to close proximity of cerebrospinal fluid (CSF) to affected tissues. Development of effective intrathecal pharmaceuticals will rely on accurate models of how drugs are dispersed in the CSF. Therefore, a method to quantify these dynamics and a characterization of differences across disease states is needed. METHODS: Complete intrathecal 3D CSF geometry and CSF flow velocities at six axial locations in the spinal canal were collected by T2-weighted and phase-contrast MRI, respectively. Scans were completed for eight people with ALS and ten healthy controls. Manual segmentation of the spinal subarachnoid space was performed and coupled with an interpolated model of CSF flow within the spinal canal. Geometric and hydrodynamic parameters were then generated at 1 mm slice intervals along the entire spine. Temporal analysis of the waveform spectral content and feature points was also completed. RESULTS: Comparison of ALS and control groups revealed a reduction in CSF flow magnitude and increased flow propagation velocities in the ALS cohort. Other differences in spectral harmonic content and geometric comparisons may support an overall decrease in intrathecal compliance in the ALS group. Notably, there was a high degree of variability between cases, with one ALS patient displaying nearly zero CSF flow along the entire spinal canal. CONCLUSION: While our sample size limits statistical confidence about the differences observed in this study, it was possible to measure and quantify inter-individual and cohort variability in a non-invasive manner. Our study also shows the potential for MRI based measurements of CSF geometry and flow to provide information about the hydrodynamic environment of the spinal subarachnoid space. These dynamics may be studied further to understand the behavior of CSF solute transport in healthy and diseased states

Prevalence and Correlates of Hepatitis C Infection among Male Injection Drug Users in Detention, Tehran, Iran

For the benefit of planning for the future care and treatment of people infected with hepatitis C virus (HCV) and to help guide prevention and control programs, data are needed on HCV seroprevalence and associated risk factors. We conducted a cross-sectional sero-behavioral survey of injection drug users (IDU) detained for mandatory rehabilitation during a police sweep of Tehran, Iran, in early 2006. During the study period, a consecutive sample comprising 454 of 499 (91.0%) men arrested and determined to be IDU by urine test and physical examination consented to a face-to-face interview and blood collection for HCV antibody testing. Overall, HCV prevalence was 80.0% (95% confidence interval (CI) 76.2–83.6). Factors independently associated with HCV infection included history of incarceration (adjusted OR 4.35, 95% CI 1.88–10.08), age of first injection ≤25 years (OR 2.72, 95% CI 1.09–6.82), and history of tattooing (OR 2.33, 95% CI 1.05–5.17). HCV prevalence in this population of IDU upon intake to jail was extremely high and possibly approaching saturation. Findings support that incarceration is contributing to the increased spread of HCV infection in Iran and calls for urgent increased availability of HCV treatment, long-term preparation for the care of complications of chronic infection, and rapid scale-up of programs for the primary prevention of parenterally transmitted infections among drug users

MAGNETIC RESONANCE IMAGE-BASED NUMERICAL MODELING OF CEREBROSPINAL FLUID DYNAMICS: APPLICATION TO FILTRATION AND INTRATHECAL DRUG DELIVERY

Cerebrospinal fluid (CSF) plays a vital role in the immunological support, structural protection and metabolic homeostasis of the central nervous system (CNS). The CSF is a promising route with many potentially important roles for CNS therapeutics such as: a) direct delivery of large drug molecules to the CNS tissue that is not possible via blood injection due to the blood brain barrier and b) CSF filtration, termed Neurapheresis therapy, to remove unwanted solutes in CNS diseases such as alzheimer’s disease, meningitis, subarachnoid hemorrhage and leptomeningeal metastasis. While many studies have shown increasing importance of the role of CSF in CNS system homeostasis, there is a need to understand the impact of realistic geometry on CSF flow patterns. An anatomically accurate and validated CFD model will allow testing and optimization of CNS biomedical technologies such as CSF filtration devices. Such a simulator could reduce cost of non-human primate studies and lead to more rapid application of these technologies for clinical use. In this dissertation, CSF dynamics in monkeys and humans was investigated in four stages as following: First, a magnetic resonance imaging (MRI) protocol was developed and applied to quantify subject-specific CSF space geometry and flow and define the CFD domain and boundary conditions in non-human primates. An algorithm was implemented to reproduce the axial distribution of unsteady CSF flow by non-uniform deformation of the dura surface. Results showed that maximum difference between the MRI measurements and CFD simulation of CSF flow rates was <3.6%. CSF flow along the entire spine was laminar with a peak Reynold’s number of ~150 and average Womersley number of ~5.4. Maximum CSF flow rate was present at the C4-C5 vertebral level. Deformation of the dura ranged up to a maximum of 134 μm. Geometric analysis indicated that total spinal CSF space volume was ~8.7 ml. Average hydraulic diameter, wetted perimeter and SAS area was 2.9 mm, 37.3 mm and 27.24 mm2, respectively. CSF pulse wave velocity along the spine was quantified to be 1.2 m/s. Second, a geometric and hydrodynamic characterization of CSF in eight cynomolgus monkeys (Macaca fascicularis) was presented at baseline and two-week follow-up. Results showed that CSF flow along the entire spine was laminar with a Reynolds number ranging up to 80 and average Womersley number ranging from 4.1-7.7. Maximum CSF flow rate occurred ~25 mm caudal to the foramen magnum. Peak CSF flow rate ranged from 0.3-0.6 ml/s at the C3-C4 level. Geometric analysis indicated that average intrathecal CSF volume below the foramen magnum was 7.4 ml. The average surface area of the spinal cord and dura was 44.7 and 66.7 cm2 respectively. Subarachnoid space cross-sectional area and hydraulic diameter ranged from 7-75 mm2 and 2-3.7 mm, respectively. Stroke volume had the greatest value of 0.14 ml at an axial location corresponding to C3-C4. The third objective of this dissertation was to investigate the impact of spinal cord nerve roots (NR) on CSF dynamics. A subject-specific computational fluid dynamics (CFD) model of the complete spinal subarachnoid space (SSS) with and without anatomically realistic NR and non-uniform moving dura wall deformation was constructed. This CFD model allowed detailed investigation of the impact of NR on CSF velocities that is not possible in vivo using MRI or other non-invasive imaging methods. Results showed that NR altered CSF dynamics in terms of velocity field, steady-streaming and vortical structures. Vortices occurred in the cervical spine around NR during CSF flow reversal. The magnitude of steady-streaming CSF flow increased with NR, in particular within the cervical spine. This increase was located axially upstream and downstream of NR due to the interface of adjacent vortices that formed around NR. Average value for steady streaming velocity was 0.11 ± 0.12 and 0.05 ± 0.04 mm/s (mean ± stdev) for the model with versus without NR (120% greater with NR). The region of greatest difference in steady streaming velocity values was the cervical spine that had up to 5X larger value of steady streaming velocity with NR compared to without. In fourth step, we formulated a subject-specific computational fluid dynamics (CFD) model to parametrically investigate the impact of a novel dual-lumen catheter-based CSF filtration system, the Neurapheresis therapy system (Minnetronix Neuro, Inc., St. Paul, MN), on intrathecal CSF dynamics. The operating principle of this system is to remove CSF from one location along the spine (aspiration port), externally filter the CSF routing the retentate to a waste bag, and return permeate (uncontaminated CSF) to another location along the spine (return port). The CFD model allowed parametric simulation of how the Neurapheresis system impacts intrathecal CSF velocities and steady-steady streaming under various Neurapheresis flow settings ranging from 0.5 to 2.0 ml/min and with a constant retentate removal rate of 0.2 ml/min. simulation of the Neurapheresis system were compared to a lumbar drain simulation with a typical CSF removal rate setting of 0.2 ml/min. Results showed that the Neurapheresis system at a maximum flow of 2.0 ml/min increased average steady-streaming CSF velocity 2X in comparison to lumbar drain (0.190 ± 0.133 versus 0.093 ± 0.107 mm/s, respectively). This affect was localized to the region within the Neurapheresis flow-loop. The mean velocities introduced by the flow-loop were relatively small in comparison to normal cardiac-induced CSF velocities. Finally, a subject-specific multiphase CFD model was constructed based on high-resolution anatomic MRI. The dual-lumen Neurapheresis catheter geometry was added to the model within the posterior spinal subarachnoid space (SAS). Neurapheresis flow aspiration and return rate was 2.0 and 1.8 (mL/min), versus 0.2 (mL/min) drainage for lumbar drain. An in vitro CSF model was constructed with an identical fluid domain geometry. A detailed comparison of numerical and in vitro results was performed by the Bland-Altman correlation analysis. Neurapheresis therapy was found to have a larger impact on steady streaming in comparison to lumbar drain. Steady-streaming in the cranial SAS was ~50X smaller than in the spinal SAS for both cases. Results showed that 85% of the spinal SAS was cleared within one hour with the Neurapheresis flow loop in comparison to 50% clearance after 24-hour with lumbar drain. Clearance was maximized between the aspiration and the return ports with the Neurapheresis therapy. However, intracranial clearance for the Neurapheresis therapy was similar to lumbar drain (66% clearance). Quantitative comparison of Neurapheresis therapy results showed that the speed of clearance match with less than 4% error after 24-hour (50% CFD vs 46% in vitro).doctoral, Ph.D., Biological & Agricultural Engineering -- University of Idaho - College of Graduate Studies, 2019-1

Three-dimensional simulation of a novel rotary-piston engine in the motoring mode

In this simulation study, the flow and thermal characteristics of a novel rotary-piston engine, which is a kind of internal combustion engines, were investigated by computational fluid dynamics and the finite volume method. The structure of this engine is different to others, mainly for having 24 cylinders during the motoring mode. As a novel engine, creation of numerical models based on Reynolds average Navier Stokes (RANS) simulation and analysis of various speed engines on the flow and thermal fields during intake and compression strokes are the focus of this work. The results were illustrated in term of the streamline patterns, in-cylinder temperature and pressure profile, swirl ratio (SR), wall heat flux, and turbulent velocity fluctuation. The present study indicates that, the mean pressure, temperature trace, and heat loss from the wall increase when switching to a higher engine speed. The temperature distribution reveals that the maximum temperature is restricted in the center of the combustion chamber near top dead center (TDC). Also, the maximum amount of turbulent velocity and swirl ratio are achieved at the beginning of the intake stroke and near TDC. It is observed that the obtained numerical results are in general agreement with the available experimental data

Improving the microbial quality and sensory properties of pasteurized sweet cream butter during refrigerated storage using chia seed ethanolic extract

Butter is a perishable food, and its microbial deterioration occurs in refrigeration conditions, leading to a reduction in shelf life and a loss of sensory properties. This study aimed to investigate the effect of chia seed extract (CSE) on the microbial and sensory properties of pasteurized sweet cream butter at 2°C. Ethanolic extract of chia seeds was prepared and added to the butter samples in concentrations of 0.05%, 0.1%, 0.25%, and 0.5% (v/w), and its effects on microbiological and sensory quality were evaluated at 15-day intervals during 60-day refrigerated storage. The results indicated that the addition of 0.25% and 0.5% CSE to butter treatments decreased total viable counts by 0.25–0.6 log CFU/g, total psychrotrophic counts by 1–1.5 log CFU/g, and coliform counts by 3–4 log CFU/g compared to the control sample on days 45 and 60 of storage. Moreover, concentrations of 0.1%–0.5% CSE reduced mold and yeast counts by 1.5–2.6 log CFU/g on days 30–60 of storage compared to the control sample. Escherichia coli and Staphylococcus aureus were not detected in any samples during storage. CSE had a significant effect on the sensory properties (except for aroma) of the butter samples during the 60-day storage. The best color, flavor, and overall acceptance scores were assigned to the treatments containing 0.1%–0.5% CSE compared to the control sample. It could be concluded that adding 0.1% and 0.25% CSE to refrigerated and pasteurized butter can retard microbial spoilage and improve its sensory properties at the same time