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Medical Value of Mast Tissue from the Supraglottic Larynx of Children With Aerodigestive Condition.
Background Aging often results in thoracic kyphosis and adverse postural changes. This may interfere with physiologic activity of paraspinal muscles. Few styles of spinal orthosis have been already used to reduce thoracic kyphosis. This paper describes the development of a novel orthosis, which is designed based on the anatomy of the back muscles. This novel orthosis may potentiate muscle activity and balance control among older hyper kyphotic subjects. Objectives The object of this study was to design and preliminary testing of a new orthosis to potentiate muscle activity and balance control among older hyper kyphotic subjects. Material and Methods In this quasi-experimental study, a new postural control orthosis with a textile band structure was designed to provide an additional support for spine and muscles of the back. The functional impact of this orthosis was evaluated in six older hyper-kyphotic subjects. According to the results, the paraspinal muscles activity and balance control were significantly improved. Results The RMS sEMG of the lumbar and thoracic erector spinae muscles reduced significantly (p less then 0.05), and a significant improvement (p less then 0.05) was observed in the balance test when patients put on the novel orthosis (p less then 0.05). Conclusion The new orthosis can considerably improve the paraspinal muscles activity at both the upper and lower lumbar levels. It can also recover balance control among elderly subjects. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Recently, ultrasonic neuromodulation research has been an important and interesting issue. Ultrasonic neuromodulation is possible by the use of low-intensity transcranial focused ultrasound (tFUS) to stimulate or inhibit the neural structures. The primary capability of this method is the improvement in the treatment progress of certain neurological and psychiatric disorders noninvasively. tFUS is able to modulate ionic currents and neural depolarization, causing the alteration in electrical properties of neurons. Objective The study aims to investigate the effect of tFUS waves on the electrical behavior of neurons using the simulation method. Material and Methods In the first part of this simulation study, the propagation of tFUS waves throughout the head was simulated to calculate the value of acoustic pressure at the cortex. In the second part, cortical neurons were simulated by a simple model of spiking neurons proposed by Izhikevich for three common dynamics. Then, the capacitance model was proposed to determine the alteration in the electrical behavior of the neurons during tFUS stimulation. Results At the resting state, the electric potential of the neuron's membrane through the tFUS stimulation has an amplitude of about 30 mv with the similar oscillatory behavior of the acoustic waveform; while,the ultimate electrical behavior of the neuron's membrane indicates a decrease in the electric potential when the neurons fire. Conclusion The electrical behavior of the neuron and the range of its membrane voltage modulated during ultrasonic stimulation. The reduction in the amplitude of membrane potential was observed while neuron spikes. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Recently, multileaf collimators (MLC) have become an important part of any LINAC collimation system because they reduce the treatment planning time and improve the conformity. Important factors that affect MLCs collimation performance are leaves material composition and their thickness. Objective In this study, we investigate main dosimetric parameters of a typical MLC including dose in the buildup point, physical penumbra as well as average and end leaf leakages. Effects of the leaves geometry and density on these parameters are evaluated. Materials and Methods In this analytical study, calculations were performed by using phase space data for Varian ix just above MLC and BEAMnrc/DOSXYZnrc for SSD=100cm and in a water phantom. Results Based on the results, a new MLC with improved dosimetric parameters is proposed. The physical penumbra for proposed MLC is 4.7mm was compared to 5.16 mm for Millennium 120 leaf. Average leakage in our design is reduced to 1.16% compared to 1.73% for Millennium 120 leaf, the end leaf leakage suggested design also reduced to 4.86% compared to 7.26% for Millennium 120 leaf. Conclusion The results show that the proposed MLC could improve the dosimetric parameters and conformity of treatment planning. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background During interventional cardiology processes, patients especially women and children receive high radiation doses due to their sensitivity. Objective In this study, we evaluated a pediatric patient dose separately in those undergone intervention cardiac procedure. Material and Methods In this cross sectional study, a public hospital with 252 patients, Entrance Skin Dose (ESD) and Dose-Area Product (DAP) were recorded. Prior to the beginning of fluoroscopic procedure, the chest thickness and Body Mass Index (BMI) of patients were measured. Furthermore, kV, mAs, angle of tube and time of angiography and angioplasty were recorded. Results Children ratio to all patients underwent the cardiovascular imaging was 1.8. The means of patients' ESD, DAP and fluoroscopy time were 178.3±17 mGy, 1123.6±11 μGycm2 and 281.4±181.2 s, respectively for coronary angiography. The females were 96.8 under 30 years and their dose mean was 276±37 mGy, 368±24 μGycm2 for ESD and DAP received, respectively with 376s fluoroscopy time. Mean mAs was 359±34 and kV was 71.23±2.7. Above all, a direct and significant correlation was found between the patients' chest thickness with kV (p=0.037, r = 0.11) and mAs (p less then 0.001, r = 0.28) variations. Conclusion The results demonstrated that the number of children referred to the cardiology department and also the dose rate received by them during this test was higher than the data provided for children in developing countries. Paying attention to the children's perception of high-fluorescence time is necessary in comparison with total angiography time in order to reduce the number of radiation injuries among pediatrics. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Amyloid fibrils are insoluble arranged aggregates of proteins that are fibrillar in structure and related to many diseases (at least 20 types of illnesses) and also create many pathologic conditions. Therefore understanding the circumstance of fibril formation is very important. Objectives This study aims to work on fibrillar structure formation of fibroin (as a model protein). Material and Methods In this experimental study, fibroin was extracted from bombyx mori silk cocoon, and the concentration was obtained by Bradford method. The protein was incubated in a wide range of times (0 min to 7 days) in specific acidity and thermal conditions (pH=1.6, T=70 °C). The assays of UV-vis spectroscopy with congo red, field emission scanning electron microscopy, transmission electron microscopy, atomic force microscopy and circular dichroism spectroscopy were employed to monitor the fibrillation process. Results Fibroin assemblies were formed upon the process of aggregation and fibril formation with a variety of morphology ranging from nanoparticles to elongated fibrils. Conclusion The results showed progressive pathway of fibril formation. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Glucose transporter (Glut), a cellular transmembrane receptor, has a key role in the metabolism of cell glucose and is also associated with various human carcinomas. Objective In this study, we evaluated a magnetic resonance (MR) imaging contrast agent for tumor detection based on paramagnetic gadolinium oxide (Gd2O3) coated polycyclodextrin (PCD) and modified with glucose (Gd2O3@PCD-Glu) for the targeting of overexpressed glucose receptors. Material and Methods In this experimental study, 3T magnetic resonance imaging (MRI) scanner was used to assess the specific interactions between Glut1-overexpressing tumor cells (MDA-MB-231) and Gd2O3@PCD-Glu NPs. Furthermore, the capacity of transporting Gd2O3@PCD-Glu NPs to tumor cells was evaluated. Results It was found that the acquired MRI T1 signal intensity of MDA-MB-231 cells that were treated with the Gd2O3@PCD-Glu NPs increased significantly. Based on the results obtained, Gd2O3@PCD-Glu NPs can be applied in targeting Glut1-overexpressing tumor cells in vivo, as well as an MRI-targeted tumor agent to enhance tumor diagnosis. Conclusion Results have shown that glucose-shell of magnetic nanoparticles has a key role in diagnosing cancer cells of high metabolic activity. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Radiosensitization using nanoparticles is proposed as a novel strategy for treatment of different cancers. Superparamagnetic iron oxide nanoparticles (SPIONs) have been reported to enhance effects of radiotherapy in several researches. Objective The objective of this research is to investigate the radiosensitization properties of polyglycerol coated SPIONs (PG-SPIONs) on U87-MG cancer cells. Material and Methods In this experimental study, polyglycerol coated SPIONs were synthesized by thermal decomposition method and characterized by FTIR, TEM and VSM analysis. Cellular uptake of nanoparticles by cells was examined via AAS. Cytotoxicity and radiosensitization of nanoparticles in combination with radiation were evaluated by MTT and colony assay, respectively. Results Mean size of nanoparticles was 17.9±2.85 nm. FTIR verified SPIONs coating by Polyglycerol and VSM showed that they have superparamagnetic behaviour. Viability significantly (P 0.05). Dose verification results by TLD for doses of 2 and 4 Gy were 2±0.19 and 4±0.12 Gy respectively. The combination index for all situations was less than 1 and the effect is antagonism. Conclusion However, PG-SPIONs combination with 6 MV X-ray reduced survival of U87-MG cells compared to radiation alone but the effect is antagonism. Copyright © 2020 Journal of Biomedical Physics and Engineering.Background Hesperidin is a bioflavonoid glycoside mainly found in citrus fruit and has been shown radio-protective potential in various measurement systems. Objective In this article aims to investigate the radio-protective effect of hesperidin on the liver of Sprague Dawely rats. Material and Methods In this clinical study, 40 male rats were selected randomly and divided into 8 groups. Santacruzamate A Group 1 did not receive radiation and hesperidin (sham control). Group 2 received only 100 mg/kg body weight (b.w) of hesperidin for 7 consecutive days (HES group); group 3 exposed to dose of 2Gy whole body gamma radiation (2Gy group), and group 4 and 5 received 50 and 100 mg/kg b.w of HES for 7 consecutive days before 2 Gy gamma radiation, respectively.Group 6 exposed to dose of 8Gy gamma radiation (8Gy group); group 7 and 8 received 50 and 100 mg/kg b.w of HES for 7 days before 8Gy gamma irradiation, respectively. Histopathological evaluation was perfomred 24 hours after radiation. Results Administration of hesperidin (50 mg/kg b.
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