172 research outputs found

    Approximate Optimal Control of Volterra-Fredholm Integral Equations Based on Parametrization and Variational Iteration Method

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    This article presents appropriate hybrid methods to solve optimal control problems ruled by Volterra-Fredholm integral equations. The techniques are grounded on variational iteration together with a shooting method like procedure and parametrization methods to resolve optimal control problems ruled by Volterra - Fredholm integral equations. The resulting value shows that the proposed method is trustworthy and is able to provide analytic treatment that clarifies such equations and is usable for a large class of nonlinear optimal control problems governed by integral equations

    An Overview of the Persian EFL learners’ Spelling Difficulties

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    Spelling is considered a difficult skill for foreign and second language learners of English as the ability to spell in English language comes with a lot of effort, particularly when the English spelling system is known to be a complex system, even among native speakers. The difficulties could be linguistic and extra-linguistic. This conceptual paper reviews the differences and similarities between English and Persian spelling system, the sages of spelling difficulties among children, particularly the approach suggested by Tabrizi, Tabrizi, and Tabrizi (2013)in which the stages of learning spelling among Iranian learners are analyzed. The types of morphological, phonological, and orthographical spelling difficulties, factors contributing to the spelling difficulty, as well as a comprehensive literature review of EFL studies conducted on English spelling are provided in this paper. Finally, the mental processing and the role of memory are discussed briefly. It was concluded that examining the differences between the learners’ first language and English language may provide useful insights into the English spelling problems faced by EFL learners

    Accuracy of Endoscopy in Predicting the Depth of Mucosal Injury Following Caustic Ingestion; a Cross-Sectional Study

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    Introduction: Esophagogastroduodenoscopy (EGD) is currently considered as the primary method of determining the degree of mucosal injury following caustic ingestion. The present study aimed to evaluate the screening performance characteristics of EGD in predicting the depth of gastrointestinal mucosal injuries following caustic ingestion.Methods: Adult patients who were referred to emergency department due to ingestion of corrosive materials, over a 7-year period, were enrolled to this diagnostic accuracy study. Sensitivity, specificity, positive and negative predictive values as well as negative and positive likelihood ratios of EGD in predicting the depth of mucosal injury was calculated using pathologic findings as the gold standard.Results: 54 cases with the mean age of 35 ± 11.2 years were enrolled (59.25% male). Primary endoscopic results defined 28 (51.85%) cases as second grade and 26 (48.14%) as third grade of mucosal injury. On the other hand, pathologic findings reported 21 (38.88%) patients as first grade, 14 (25.92%) as second, and 19 patients (35.18%) as third grade. Sensitivity and specificity of endoscopy for determining grade II tissue injury were 50.00 (23.04-76.96) and 47.50 (31.51-63.87), respectively. These measures were 100.00 (82.35-100) and 80.00 (63.06-91.56), respectively for grade III. Accuracy of EGD was 87.03% for grade III and 48.14% for grade II.Conclusion: Based on the findings of the present study, endoscopic grading of caustic related mucosal injury based on the Zargar’s classification has good accuracy in predicting grade III (87%) and fail accuracy in grade II injuries (48%). It seems that we should be cautious in planning treatment for these patients solely based on endoscopic results.

    Epidemiologic Features and Outcomes of Caustic Ingestions; a 10-Year Cross-Sectional Study

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    Introduction: Caustic ingestions are among the most prevalent causes of toxic exposure. The present 10-year survey aimed to evaluate the epidemiologic features and outcomes of caustic ingestion cases presenting to emergency department.Methods: This is a retrospective cross-sectional study on patients who were admitted to a referral toxicology center during 2004 to 2014, following caustic ingestion. Baseline characteristics, presenting chief complaint, severity of mucosal injury, complications, imaging and laboratory findings as well as outcomes (need for ICU admission, need for surgery, mortality) were recorded, reviewing patients’ medical profile, and analyzed using SPSS 22.Results: 348 patients with mean age of 37.76 ± 17.62 years were studied (55.6% male). The mean amount of ingested caustic agent was 106.69 ± 100.24 mL (59.2 % intentional). Intentional ingestions (p < 0.0001), acidic substance (p = 0.054), and higher volume of ingestion (p = 0.021) were significantly associated with higher severity of mucosal damage. 28 (8%) cases had died, 53 (15.2%) were admitted to ICU, and 115 (33%) cases underwent surgery.Conclusion: It seems that, suicidal intention, higher grade of mucosal injury, higher volume of ingestion, lower level of consciousness, lower serum pH, and higher respiratory rate are among the most important predictors of need for ICU admission, need for surgery, and mortality

    Estimating Spray Characteristics of the Air-Blast atomizer of a Typical Jet Engine using Definition of the New Non-dimensional Number K: Numerical and Experimental Study

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    In this paper, by using a numerical solution and experiment investigation, a non-dimensional number is introduced to estimate the characteristics of a real engine airblast atomizer spray. This type of atomizers is usually used in airplain engines. The test is conducted in ambient atmospheric pressure and at 300 K temperature and the effects of pressure on atomizer flow rate and spray con angle are investigated. We used the discrete phase model and real information of the ALF502 engine for simulations and for boundary conditions respectively. Since the main application of this airblast atomizer is in aircraft engines and in the real working conditions, none of the pressure and flow rate parameters is constant, thus, the main aim of this research is to define a nondimensional number K, which considers the effects of working liquid flow rate, air flow rate and pressure on the droplets average diameter and spray con angle simultaneously. The results showed that, in general, with the increase of non-dimensional K number, the average diameter of droplets in primary and secondary break up increases, but spray con angle decreases. Furthermore, numerical solution results are compared with experiment results and 9.98% error was observed

    Investigation of the effects of the essence and extract of Allium jesdianum on the activity of COX-1 and COX-2 enzymes

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    Recent studies on the analgesic effects of Allium jesdianum herb across different types of pain including formalin test biphasic pain, have suggested the probability of effectiveness of the extract of this herb on cyclooxygenase enzymes (COX). In this study we investigated the effects of the essence and extract of A. jesdianum on COX-1 and COX-2 in human fresh blood. For this experimental study, A. jesdianum collected from Sefidkouh region in Khorramabad of Iran. Extract and essence (the leaves of the plant) were prepared at various concentrations 0.5-6 mg/ml and 0-100 mg/ml respectively. The percentage of activity of COX-1 and COX-2 enzyme was measured by percentage of production of TXB2 and PGE2. Solvents Dimethyl sulfoxide (DMSO) and Phosphatebuffered saline (PBS) were used as control for comparing with extract or essence effects. Also indomethacin was used as a positive control. The extract (59 +/- 8.2; P0.05). Further, all doses of A. jesdianum essence inhibited the platelet aggregation (P<0.05). It can be stated that the essence and extract of A. jesdianum herb had inhibitory effects on COX-1 enzyme, where the extract was also able to inhibit platelet aggregation

    Prevalence of Stroke in neonates who admitted with seizures in neonatal intensive care unit

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    How to Cite This Article: Farhadi R, Alaee AR, Alipour Z, Abbaskhanian A, Nakhshab M, Derakhshanfar H. Prevalence of Stroke in NeonatesWho Admitted With Seizures in Neonatal Intensive Care Unit. Iran J Child Neurol. Autumn 2015;9(4):41-47.AbstractObjectivePrevalence of neonatal stroke has been reported 1/2300-1/4000 live births and accounts for 12-20% of the cases of neonatal seizures. Although stroke has been introduced as the second cause of the neonatal seizures in literatures, it may remain unclear in diagnostic evaluations of seizure in neonates. This study was performed to assess the prevalence of stroke in neonates with seizure.Materials &amp; MethodsIn this cross-sectional study, all neonates ≥ 28 weeks of gestation with a diagnosis of seizures admitted to the NICU of Boo-Ali Sina Hospital in Sari, north of Iran, were enrolled. Brain CT scan and a Transcranial Doppler ultrasonography were performed for the all cases. In cases that stroke were reported in one or two above modalities, an MRI was also performed and prevalence of stroke was reported. Putative risk factors of stroke were analyzed with univariate and multivariate statistical methods.ResultsFrom 174 newborn infants, 75.3% of neonates were male. Prevalence of stroke was 8%, 2.3% and 3.4% in Doppler ultrasonography, CT scan and MRI reports respectively. Umbilical venous catheterization was the risk factor of stroke in the univariate and multivariate analysis (P= 0.001; OR, 10.39; 95% CI, 2.72-39.77). The most common form of seizure was focal clonic seizures (78.6%) in neonates with stroke.ConclusionInvestigation of stroke as an etiology of neonatal seizures is essential because seizure may be the only symptom of neonatal cerebral infarction. Doppler ultrasonography can be a valuable diagnostic tool at first in critically ill neonates or in situations that MRI is not available primarily. Further studies with notice to outcome assessment of these infants recommended.

    Educational Costs of Residents in a Teaching Hospital: a case study

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    Background & Objectives: Residents spend much of their time at the hospitals to earn their required educational skills and although they act as a kind of human resource in the hospital, they increase hospital costs. The present study was designed to calculate the share of educational costs of different medical residents in hospitals. Methods: In this descriptive and applied study performed in one of the hospitals affiliated to Iran University of Medical Sciences, the hospital cost items of education of residents in different medical fields during the academic year of 2017-2018 were identified by use of two scenarios. Results: In short, mean educational cost of one resident in the studied academic year was about 5357basedonthefirstscenarioandabout5404 based on the first scenario and about 5404 according to the second scenario. Based on both scenarios, salaries paid to residents accounted for more than 50% of the costs followed by the cost of consumed materials by residents. Forensic Medicine and Anesthesiology residency programs had respectively the lowest and highest share of costs in both scenarios. Conclusion: The cost of training in the hospital is different among residency fields based on the required tests and errors in each field. But, in order to save hospital costs, the culture of optimal use of materials as well as medical equipment should be taught to residents. Key­words: Education Economics, Costing, Direct Costs, Residents, Teaching hospital ­Citation: Aleboyeh MR, Reza pour A, Meshkani Z, Alipour V, Soleimani movahed M. Educational Costs of Residents in a Teaching Hospital: a case study. Journal of Health Based Research 2019; 5(2): 117-30

    Comparison of Face to Face vs. Group Training on Self-pulse Rate taking Ability of Patients

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    Introduction: Determining the rate and regularity of peripheral arterial pulses has a major role in assessing the clinical status of patients with cardiovascular disorders. We compared two training methods on the ability of patients to take their radial pulse rate accurately.Methods: Three-hundred patients were randomly divided into two arms. One arm received individual face-to-face training and the other arm received group training via displaying an animation movie. Immediately after the training and then after 48 hours, the patients were tested by a nurse to find out whether they have learned the correct technique of taking radial pulse rate or not.Results: Immediately after the intervention, 84.9% in face-to-face arm and 81.8% in group training arm were able to correctly count their radial pulse rate (P = 0.536). After 48 hours, 71.7% in face-to-face and 60.8% in group training arm were able to correctly count their radial pulse rate (P = 0.051).Conclusions: Both methods were effective to improve the ability of the patients to count their radial pulse rate correctly though face-to-face method was marginally superior to group training
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