فهرست مطالب

  • Volume:7 Issue: 4, 2017
  • تاریخ انتشار: 1396/06/15
  • تعداد عناوین: 12
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  • M. H Bahreyni-Toosi, M. H Zare, A. Ale Davood, M. T Shakeri, S. Soudmand Page 317
    Background And Objective
    Multi-walled Carbon Nano Tubes (MWCNTs) as an important element of nanosciences have a remarkable absorption in the region of NIR window (650-900 nm) which can overcome the limitations of deep treatment in photothermal therapy. To disperse MWCNTs in water, it is proposed to attach carboxylated functional group (-COOH) to MWCNTs in order to increase dispersivity in water.
    Materials And Methods
    A stable suspension of MWCNTs-COOH with different concentrations (from 2.5 to 500 μg/ml) was prepared. Then, they were compared for their ability to increase temperature in the presence of 810 nm laser irradiation and through a wide range of radiation time (from 20 to 600 s) and three laser powers (1.5, 2 and 2.5 w). The temperature rise was recorded real time every 20 seconds by a precise thermometer.
    Results
    Absorption spectrum of MWCNTs-COOH suspension was remarkably higher than water in a wavelength range of 200 to 1100 nm. For example, using the concentrations of 2.5 and 80 μg/ml of MWCNTs-COOH suspension caused a temperature elevation 2.35 and 9.23 times compared to water, respectively, upon 10 min laser irradiation and 2.5 w. Moreover, this predominance can be observed for 1.5 and 2 w radiation powers, too. Our findings show that the maximum of temperature increase was obtained at 80 μg/ml concentration of MWCNT-COOH suspension for three powers and through all periods of exposure time. Our results show that the minimum required parameters for a 5°C temperature increase (a 5°C temperature increase causes cell death) were achieved through 2.5 w, 28 μg/ml concentration and 20 second irradiation time in which both concentration and radiation times were relatively low.
    Conclusion
    Our results showed that MWCNTs-COOH can be considered as a potent photothermal agent in targeted therapies. New strategies must be developed to minimize the concentration, irradiation time and radiation power used in experiments.
    Keywords: Hyperthermia, Multiwalled Carbon Nanotubes, Nanoparticles, Near Infrared, Photothermal Therapy
  • H. Dowlatabadi, A. A Mowlavi, M. Ghorbani, S. Mohammadi Page 333
    Objective
    The aim of the present study is to simulate 6 MV and 18 MV photon beam energies of a Siemens Primus Plus medical linear accelerator (Linac) and to verify the simulation by comparing the results with the measured data.
    Methods
    The main components of the head of Siemens Primus Plus linac were simulated using MCNPX Monte Carlo (MC) code. To verify the results, experimental data of percentage depth dose (PDD) and beam dose profile for 5 × 5 cm2, 10 × 10 cm2 and 20 × 20 cm2 field sizes were measured and compared with simulation results. Moreover, gamma function was used to compare the measurement and simulation data.
    Results
    The results show a good agreement, within 1%, was observed between the data calculated by the simulations and those obtained by measurement for 6 MV photon beam, while it was within 2% for 18 MV photon beam, except in the build-up region for both beams. Gamma index values were less than unity in most data points for all the mentioned energies and fields. To calculate the dose in the phantom, cells were selected in different modes, one of the modes due to the lack of dose gradient and overlapping, produced better results than others produce.
    Conclusion
    There was good settlement between measured and MC simulation values in this research. The simulation programs can be used for photon modes of Siemens Primus Plus linac in conditions in which it is not possible to perform experimental measurements.
    Keywords: Radiotherapy, Siemens Primus plus Linac, MC Simulation, 6, 18 MV Photon Beams, Gamma Function
  • A. H Heidari, A. Shabestani Monfared, H. Mozdarani, A. Mahmoudzadeh, A. Razzaghdoust Page 347
    Background
    We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation.
    Objective
    The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells.
    Methods
    Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed). Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy). 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes.
    Results
    A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE) and decreases in polychromatic erythrocyte/polychromatic erythrocyte normochromatic erythrocyte ratio (PCEs/PCEs㐡) (P
    Conclusion
    The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.
    Keywords: High Natural Background Radiation (HNBR), Sulfur, Gamma Rays, Bone Marrow Micronucleus Assay, Ramsar
  • A. Soleimani, S. H Rasta, T. Banaei, A. Asgharsharghi Bonab Page 355
    Introduction
    The aim of the present study was to determine burn intensity in retinal laser photocoagulation based on laser parameters; wavelength, power, beam size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera, physical eye model and computer simulation in a clinical study.
    Materials And Methods
    Participants were 10 adult patients between 50-80 years with proliferative diabetic retinopathy. A multicolor-photo coagulator with 532 nm green and 672 nm red for retina photocoagulation in diabetic retinopathy was used to investigate the participants. Lesion size was measured for spot sizes 50 and 100 μm, with 100 and 150 mW laser power, and pulse duration 50 and 100 ms by OCT. Artificial eye and Zemax-optical design software were used with the same laser parameters.
    Results
    Appearance of OCT and fundus images showed direct relationship between retina burn size and lesion intensity with exposure time and power and also reverse relationship with laser spot size. Compared to red wavelength, burn size and lesion intensity increased in green wavelength. On the other hand, results from physical eye model were the same as clinical examination shown. Laser spot size in retina with Zemax simulation demonstrated that red wavelength was greater than green one.
    Conclusion
    This study showed shorter pulses provide decrease in duration of laser surgery with significantly reduced pain. Results and calculations described in this article can help clinicians adjusting the required total coagulated area, the number of lesions and pattern density.
    Keywords: Retinal Laser Surgery, Photocoagulation, Diabetic Retinopathy, Lesion Size, Optical Coherence Tomography, Laser Parameters of surgery
  • M. Ghofrani Jahromi, H. Parsaei, A. Zamani, M. Dehbozorgi Page 365
    Background
    Electromyographic (EMG) signal decomposition is the process by which an EMG signal is decomposed into its constituent motor unit potential trains (MUPTs). A major step in EMG decomposition is feature extraction in which each detected motor unit potential (MUP) is represented by a feature vector. As with any other pattern recognition system, feature extraction has a significant impact on the performance of a decomposition system. EMG decomposition has been studied well and several systems were proposed, but feature extraction step has not been investigated in detail.
    Objective
    Several EMG signals were generated using a physiologically-based EMG signal simulation algorithm. For each signal, the firing patterns of motor units (MUs) provided by the simulator were used to extract MUPs of each MU. For feature extraction, different wavelet families including Daubechies (db), Symlets, Coiflets, bi-orthogonal, reverse bi-orthogonal and discrete Meyer were investigated. Moreover, the possibility of reducing the dimensionality of MUP feature vector is explored in this work. The MUPs represented using wavelet-domain features are transformed into a new coordinate system using Principal Component Analysis (PCA). The features were evaluated regarding their capability in discriminating MUPs of individual MUs.
    Results
    Extensive studies on different mother wavelet functions revealed that db2, coif1, sym5, bior2.2, bior4.4, and rbior2.2 are the best ones in differentiating MUPs of different MUs. The best results were achieved at the 4th detail coefficient. Overall, rbior2.2 outperformed all wavelet functions studied; nevertheless for EMG signals composed of more than 12 MUPTs, syms5 wavelet function is the best function. Applying PCA slightly enhanced the results.
    Keywords: Electromyographic signal, EMG decomposition, Decomposability index, Feature extraction, Motor Unit Potential Classification, Wavelet Function, Wavelet Transform
  • R. Zeinali, A. Keshtkar, A. Zamani, N. Gharehaghaji Page 379
    Background
    Volume estimation of brain is important for many neurological applications. It is necessary in measuring brain growth and changes in brain in normal/abnormal patients. Thus, accurate brain volume measurement is very important. Magnetic resonance imaging (MRI) is the method of choice for volume quantification due to excellent levels of image resolution and between-tissue contrast. Stereology method is a good method for estimating volume but it requires to segment enough MRI slices and have a good resolution. In this study, it is desired to enhance stereology method for volume estimation of brain using less MRI slices with less resolution.
    Methods
    In this study, a program for calculating volume using stereology method has been introduced. After morphologic method, dilation was applied and the stereology method enhanced. For the evaluation of this method, we used T1-wighted MR images from digital phantom in BrainWeb which had ground truth.
    Results
    The volume of 20 normal brain extracted from BrainWeb, was calculated. The volumes of white matter, gray matter and cerebrospinal fluid with given dimension were estimated correctly. Volume calculation from Stereology method in different cases was made. In three cases, Root Mean Square Error (RMSE) was measured. Case I with T=5, d=5, Case II with T=10, D=10 and Case III with T=20, d=20 (T=slice thickness, d=resolution as stereology parameters). By comparing these results of two methods, it is obvious that RMSE values for our proposed method are smaller than Stereology method.
    Conclusion
    Using morphological operation, dilation allows to enhance the estimation volume method, Stereology. In the case with less MRI slices and less test points, this method works much better compared to Stereology method.
    Keywords: Brain Volumetry, Stereology Method, Dilation Operation, MRI, Gray Matter, White Matter, Cerebrospinal Fluid, Brainweb Database
  • A. Shanei, Z. Alinasab, A. Kiani, M. A Nematollahi Page 389
    Objective
    It is well-known that all living cells emit ultra-weak photon emission (UPE), which is due to byproducts of chemical reactions in cell metabolisms. It has been shown that Reactive Oxygen Species (ROS) in the cells enhances the UPE intensity. The magnitude of such UPE is extremely weak (i.e. a few to 103 photons/ (sec.cm2)), and the detection of such ultra-weak signals is hardly possible via sensitive instruments like photomultiplier tube (PMT) that can detect single photons.
    Materials And Methods
    H2O2 factor with various concentrations was applied on the HT-29 cells to generate ROS. H2O2 concentrations were so low to be nondestructive to the cells. Then, the effect of ROS generation on UPE intensity was investigated. PMT was used to detect UPE from HT-29 cells.
    Results
    The topical application of H2O2 was significantly different (P 0.01) for integrated UPE in the cell groups in the presence of H2O2.
    Conclusion
    The results show that the recorded UPE from HT-29 cells increased with the topical application of exogenous ROS inducer. As a result, UPE can be used as a non-invasive technique for monitoring ROS in cells.
    Keywords: Ultra-Weak Photon Emission, HT-29, Reactive Oxygen Species, Hydrogen Peroxide, Photomultiplier Tube (PMT)
  • A. Tavakoli Golpaygani, M. M Movahedi, M. Reza Page 397
    Introduction
    Nowadays, more than 10,000 different types of medical devices can be found in hospitals. This way, medical electrical equipment is being employed in a wide variety of fields in medical sciences with different physiological effects and measurements. Hospitals and medical centers must ensure that their critical medical devices are safe, accurate, reliable and operational at the required level of performance. Defibrillators are critical resuscitation devices. The use of reliable defibirillators has led to more effective treatments and improved patient safety through better control and management of complications during Cardiopulmonary Resuscitation (CPR).
    Materials And Methods
    The metrological reliability of twenty frequent use, manual defibrillators in use ten hospitals (4 private and 6 public) in one of the provinces of Iran according to international and national standards was evaluated.
    Results
    Quantitative analysis of control and instrument accuracy showed the amount of the obtained results in many units are critical which had less value over the standard limitations especially in devices with poor battery. For the accuracy of delivered energy analysis, only twelve units delivered acceptable output values and the precision in the output energy measurements especialy in weak battry condition, after activation of discharge alarm, were low.
    Conclusion
    Obtained results indicate a need for new and severe regulations on periodic performance verifications and medical equipment quality control program especially for high risk instruments. It is also necessary to provide training courses on the fundumentals of operation and performane parameters for medical staff in the field of meterology in medicine and how one can get good accuracy results especially in high risk medical devices.
    Keywords: Meterology, Reliability, Defebrillator, Electroshock, Patient Safety, Medical Electrical Equipment
  • A. Garavand, M. Samadbeik, M. Kafashi, Sh Abhari Page 403
    Background
    Mobile health is one of the new technologies for the utilization of health information. For its successful implementation as well as any other system, we must primarily measure the adoption and use of its factors. The purpose of this study was to systematically investigate published articles about the factors affecting the adoption of mobile health and categorizing the factors affecting the adoption of this system.
    Methods
    This study is a comprehensive review done by searching major databases such as Google Scholar, Emerald, Science Direct, Iran Medex, SID, Magiran, Pub med, etc. In addition, we use Mobile, mobile Health adoption, mobile Health TAM, Health TAM keywords in the range of 2004 to 2015.
    Results
    Among the studies that use information technology theories to survey the factors affecting the adoption of mobile health, TAM model was used more than other models. Factors such as perceived ease of use, perceived usefulness and facilitating condition form TUATU are the most effective in the adoption of mobile health.
    Conclusion
    Results showed that by considering factors such as perceived ease of use, perceived usefulness and facilitating condition can increase the adoption of mobile health system. Consequently, these factors are recommended to be considered in planning to run systems.
    Keywords: Mobile Health, Technology Acceptance Models, Perceived Ease of use, perceived Usefulness, Facilitating Condition
  • M. S Golvardi Yazdi, M. Naderizadeh, R. Afzalipour, H. A Abedi, M. Radmehr, R. Golvardi Yazdi, Sh Salari Pashaghi Page 409
    Introduction
    Many items are needed for dressing including sterile dressing set, antiseptic and washing solutions, leucoplast tape, waste bin for infectious garbage, waste bin for noninfectious garbage, safe disposal trash for sharp cutting instruments, bedpan and sometimes drugs. All the items are laid out on a simple wheeled trolley. The multiplicity of items together with problems in placing tools on trolley, forgetting some items, disturbing sterile condition, falling and damaging equipment and the need for at least two people for each procedure, all are the reasons to design and develop Automatic Trolley for Washing and Dressing the Wounds.
    Material and
    Method
    To develop a mobile unit which meets our needs for dressing, the trolley patents registered in America and different companies were evaluated as well as the materials and methods used while dressing were considered.
    Results
    Automatic Trolley for Washing and Dressing the Wounds was designed and developed. It comprises the followings: drawer, waste bin for infectious garbage, waste bin for noninfectious garbage, shelves for serum and betadine solution, serum stand, peristaltic pump, flexible tube for connecting serum, a place for bedpan, foot pedal for serum flow, two eye-sensor chambers for solution betadine and scrub, an auxiliary work surface.
    Conclusion
    Due to the usual requirements for dressing, we have designed an equipped mobile unit which covers all the objectives of dressing and increases the speed of procedure. Moreover, due to the contrived equipment on the trolley, procedures are done quickly and second person is not required to assist. Automatic Trolley for Washing and Dressing the Wounds is made up of stainless steel which could be mass housing and commercializing which would play a deserving role in improving the fundamentals of health care and wound treatment.
    Keywords: Automatic Trolley, Dressing, Wound