The Nehari Manifold for p-Laplacian Equation with Dirichlet Boundary Condition

The Nehari manifold for the equation −∆pu(x) = λu(x)|u(x)|p−2 + b(x)|u(x)|γ−2u(x) for x ∈ Ω together with Dirichlet boundary condition is investigated in the case where 0 < γ < p. Exploiting the relationship between the Nehari manifold and fibrering maps (i.e., maps of the form of t → J(tu) where J is the Euler functional associated with the equation), we discuss how the Nehari manifold changes as λ changes, and show how existence results for positive solutions of the equation are linked to the properties of Nehari manifold

Monte Carlo calculation of neutron doses to organs of a female undergoing a pelvic 18 MV irradiation

Applying of high-energy photon beams beside all advantages obstacled by photoneutrons that may cause extra dose to the patient that has not been considered in routine radiotherapy. The purpose of this study is calculation of neutron and gamma doses to a female undergoing a pelvic 18 MV irradiation. A simplified Linac head model as a sphere with 10 cm radius of tungsten and with the total spectrum of an isotropic neutron distribution was located inside a typical bunker. The female anthropomorphic phantom was irradiated with equal weighted four-field pelvic box (18MV). MCNPX (2.4.0) code was used to calculate of absorbed doses. The greatest effective dose, 1.04 mSv Gy-1, was calculated for the AP field while the lowest effective dose, 0.36 mSv Gy-1, was obtained for the RL field. The Percent risk of fatal second malignancy of neutron contamination following a 70 Gy x-ray treatment dose (with equal weights for each field, 17.5 Gy) is 0.152 , including 0.056 for the AP field, 0.033 for the PA field, 0.031 for the RL field and 0.032 for the LL field. If this dose delivered only with the AP field, the risk would be 0.224 , which is 32 higher than that is in case of 4-field irradiation. Our present analysis shows that this simplified model can be used to estimating of photoneutron doses

The effects of backscattered radiation into beam monitor chamber: Study of 6 and 18 MV conventional and removed flattening filter clinical accelerator

In some linear accelerators (Linac), the collected charges in beam monitor chamber (BMC) is partly caused by the backscattered particles from the accelerator components downstream the BMC that influence the Linac output factors. In the intensity modulated radiation therapy technique, the desired dose distribution can be achieved through an unflattened beam. Although removing the flattening filter provides some advantages, the amount of backscatter radiation into BMC can be changed. In this study, contribution of backscattered particles into the BMC response of a Varian 2300 C/D Linac with and without a flattening filter was determined for 6, 18 MV photon beams. The experimental procedure included telescopic method and calculation procedure consisted of Monte Carlo simulation (MCNPX, version 2.4.0), were used to investigate the contribution of backscattered particles into the BMC performance. Our results showed a 2.3 and 3 increase in backscatter for a 0.5 � 0.5 cm2 field compared to a 40 � 40 cm2 field for 6 MV and 18 M V, respectively. The energy deposition from backscattered radiation is mainly caused by backscattered electrons. Removing the flattening filter did not change the BMC performance for a conventional Linac with a flattening filter. However, this result was not valid for small fields (e.g. 0.5 � 0.5 cm2, 18 MV). The corrected backscatter factors is necessary to taking into account the contribution of backscattered radiation in the monitor chamber response for small fields in the case of the free flattening filter Linacs (18 MV)

High-dose-rate 192Ir brachytherapy dose verification: A phantom study

Background: The high-dose-rate (HDR) brachytherapy might be an effective tool for palliation of dysphagia. Because of some concerns about adverse effects due to absorbed radiation dose, it is important to estimate absorbed dose in risky organs during this treatment. Objectives: This study aimed to measure the absorbed dose in the parotid, thyroid, and submandibular gland, eye, trachea, spinal cord, and manubrium of sternum in brachytherapy in an anthropomorphic phantom. Materials and Methods: To measure radiation dose, eye, parotid, thyroid, and submandibular gland, spine, and sternum, an anthropomorphic phantom was considered with applicators to set thermoluminescence dosimeters (TLDs). A specific target volume of about 23 cm3 in the upper thoracic esophagus was considered as target, and phantom planned computed tomography (CT) for HDR brachytherapy, then with a micro-Selectron HDR (192Ir) remote after-loading unit. Results: Absorbed doses were measured with calibrated TLDs and were expressed in centi-Gray (cGy). In regions far from target (� 16 cm) such as submandibular, parotid and thyroid glands, mean measured dose ranged from 1.65 to 5.5 cGy. In closer regions (� 16 cm), the absorbed dose might be as high as 113 cGy. Conclusions: Our study showed similar depth and surface doses; in closer regions, the surface and depth doses differed significantly due to the role of primary radiation that had imposed a high-dose gradient and difference between the plan and measurement, which was more severe because of simplifications in tissue inhomogeneity, considered in TPS relative to phantom. © 2015, Iranian Journal of Cancer Prevention

Evaluation of the Effect of Different Ferrule Designs on Fracture Resistance of Maxillary Incisors Restored with Bonded Posts and Cores

Introduction: In cases of severe hard tissue loss, 2 mm circumferential ferrule is difficult to achieve. So in these cases we should use different ferrule designs.This in vitro study investigated the effect of different ferrule designs on the fractureresistance of teeth restored with bonded post and cores.Materials and Methods: Forty freshly-extracted central incisors were endodontically treated. The teeth were randomly divided into four groups; group 1 were teeth with 2 mm circumferential ferrule above the CEJ, group 2 were teeth with 2 mm ferrule only on the palatal side of the teeth, group 3 consisted of teeth with 2 mm ferrule only on the facial side and group 4 were teeth with 2 mm ferrule on the palatal and facial side of teeth with interproximal concavities.All teeth were restored with fiber posts and composite cores. The specimen was mounted on a universal testing machine and compressive load was applied to the long axis of the specimen until failure occurred.Results: The fracture resistance was 533.79 ± 232.28 in group 1, 634.75± 133.35 in group 2, 828.90 ±118.27 in group 3 and 678.78± 160.20 in group 4. The post hoc analysis showed statistically significant difference between groups 1 and 3 .Conclusions: The results of this in vitro study showed that facial ferrule increases the fracture resistance of endodontically treated teeth restored with bonded post and cores

Hemoglobin Q-Iran detected in family members from Northern Iran: a case report

<p>Abstract</p> <p>Introduction</p> <p>Hemoglobin Q-Iran (α75Asp→His) is an important member of the hemoglobin Q family, molecularly characterized by the replacement of aspartic acid by histidine. The first report of hemoglobin Q-Iran and the nomenclature of this hemoglobinopathy dates back to 1970. Iran is known as a country with a high prevalence of α- and β-thalassemia and different types of hemoglobinopathy. Many of these variants are yet to be identified as the practice of molecular laboratory techniques is limited in this part of the world. Applying such molecular methods, we report the first hemoglobin Q-Iran cases in Northern Iran.</p> <p>Case presentation</p> <p>An unusual band was detected in an isoelectric focusing test and cellulose acetate electrophoresis of a sample from a 22-year-old Iranian man from Mazandaran Province. Capillary zone electrophoresis analysis identified this band as hemoglobin Q. A similar band was also detected in his mother's electrophoresis (38 years, Iranian ethnicity). The cases underwent molecular investigation and the presence of a hemoglobin Q-Iran mutation was confirmed by the amplification refractory mutation system polymerase chain reaction method. Direct conventional sequencing revealed a single guanine to cytosine missense mutation (c.226G > C; <it>G</it>AC ><it>C</it>AC) at codon 75 in the α-globin gene in both cases.</p> <p>Conclusion</p> <p>The wide spectrum and high frequency of nondeletional α-globin mutations in Mazandaran Province is remarkable and seem to differ considerably from what has been found in Mediterranean populations. This short communication reports the first cases of patients with hemoglobin Q found in that region.</p

Increasing the Production of Carotenoids in Chlorella sorokiniana IG-W-96 by Changing the Concentration of Nutrients and Phytohormones

Introduction  Carotenoids have many effects on human health. These compounds are produced by plants and microalgae. The extraction of carotenoids from microalgae such as Chlorella has received much attention, since microalgae grow all year round (regardless of the season) and at a much faster rate than plants in non-arable lands. The aim of this research was to optimize the concentrations of nutrients (nitrogen and phosphorous) in the growth medium of microalgae with the objective of maximizing carotenoids content. At the optimized nutrient conditions, the effect of phytohormones on production of carotenoids using Chlorella sorokiniana IG-W-96 was investigated.   Materials and Methods Chlorella sorokiniana IG-W-96 was cultivated in BG11 growth medium with light intensity of 25000 lux and light: dark cycle of 16: 8 supplied with compressed air flow of 0.5 vvm containing 6% vol carbon dioxide. Under three concentrations of nitrate (0.04, 0.25, 1.5 ) and three concentrations of phophate (0.01, 0.04, 0.16 ) and carotenoid concentration was measured. Full factorial experimnetal design was performed and the resuts of the experiments were analyzed using Minitab (ver. 21.01.1). Finally, the best concentrations of nitrate and phosphate were chosen for pigments production, and at that concentration, naphthalene acetic acid (0, 2.5, 5, 7.5, 10 and 12 ppm) was added to the culture medium to check its effect on pigments production. By measuring the dry weight of C. sorokiniana, its growth rate was determined. After extracting the pigments with solvent, the concentration of the pigments was determined by measuring the amount of light absorption.   Results and Discussion Dry weight The results showed that the highest amount of dry weight was related to the treatment with nitrate amount of 0.25 , and nitrate more and less than this amount caused a decrease in growth. This result was not dependent on the amount of phosphate and was true for all phosphate concentrations. Nitrate reduction from 1.5 to 0.25 increased the growth of microalgae up to 81.8%, so that the dry weight of 0.88  reached 1.6 . However,  reduction of nitrate from 0.25 to 0.04  decreased the dry weight by 65.6%. In order to reach the maximum growth rate, it is necessary to determine the appropriate concentration of each nutrient.   Carotenoids Unlike the dry weight, not only the pigment production did not decrease with the excessive of nitrate concentration, but also the maximum amount of pigment production was related to the treatment with the maximum amount of nitrate concentration. Based on the results obtained, the concentration of carotenoids was higher in the concentration of 1.5  of nitrate and 0.04  of phosphate (6.7 ). When the nitrate concentration was very low (0.04 ), changing the phosphate concentration had no significant effect on the production rate of any of the pigments. Only when the nitrate concentration was high (1.5 ), change in phosphate concentration caused a change in pigments concentration. The increase of phosphate concentration from 0.01 to 0.04 increased the carotenoids concentration to 1.65-fold. Of course, increasing phosphate concentration to 0.16 did not affect the pigments concentration.  Based on the statistical analysis, the P-value<0.05 indicated that the effect of the factors and the model was significant. In this situation, in order to increase the production of carotenoids, naphthalene acetic acid was added to the phytohormone culture medium. At the optimal concentration of 2.5 ppm of naphthalene acetic acid, the concentration of carotenoids increased by 26.71% and reached 8.49 . However, phytohormone had no significant effect on dry weight.   Conclusion Carotenoid production using microalgae could be maximized through optimization of nutrients concentrations (nitrate and phosphate) in the growth medium. Phytohormones could further increase the prodcution of carotenoids at optimum concnetrations

Uterus dysplasia associated with cervico-vaginal agenesis

Müllerian ducts can form upper parts of normal female reproductive system and any failure in ductal fusion may result in to müllerian duct anomalies (MDA). We present a case of MDA and a uterus dysplasia with no evidence of cervical or upper vaginal tissue. This case showes the role of magnetic resonace imaging (MRI) on MDA diagnosis and urges the need for a unified reliable and practical classification more compatible with clinical practice. © 2017, Royan Institute (ACECR). All rights reserved

Uterus dysplasia associated with cervico-vaginal agenesis

Müllerian ducts can form upper parts of normal female reproductive system and any failure in ductal fusion may result in to müllerian duct anomalies (MDA). We present a case of MDA and a uterus dysplasia with no evidence of cervical or upper vaginal tissue. This case showes the role of magnetic resonace imaging (MRI) on MDA diagnosis and urges the need for a unified reliable and practical classification more compatible with clinical practice. © 2017, Royan Institute (ACECR). All rights reserved