The electrical behavior of neurons can be more complex in the presence of autapse. In the presence of an autaptic connection, the Izhikevich neuron model can show a variety of dynamic behaviors, such as chaotic behavior. This paper presents a novel, high speed and robust pseudo random number generator based on the autaptic Izhikevich neuron oscillator and its FPGA implementation. The autaptic Izhikevich neuron model is simulated and dynamically analyzed. Then, the proposed pseudo-random number generator is modeled and simulated using the Xilinx system generator platform, synthesized using Xilinx Synthesis Tool, and implemented on the XILINX SPARTAN-6 XC6SLX9 FPGA evaluation board. As a post processing operation, the XOR function is used to increase the randomness of the output bit sequences. The FPGA implementation results show that the implementation cost of the proposed pseudo-random number generator is lower than similar works, and the proposed generator achieves a maximum frequency of 63.2 MHz. The NIST test suite is used for testing the quality of the generated bit sequences. The NIST test results indicates the high quality of the generated random bit sequence.

Background: The Background: To assess the radiation protection and radiation monitoring practices among medical radiation workers (MRWs) in Malaysian hospitals, and to identify demographic and occupational factors influencing the consistent use of radioprotective garments and dosimeters. Materials and Methods: A link to an online survey was distributed to MRWs with the help of research coordinators at participating hospitals. A total of 387 respondents answered the online survey between April and June 2019. They reported the consistency with which they used radioprotective garments, dosimeters and other protective measures, together with the reasons for inconsistency. We then compared consistent and inconsistent groups by demographic and occupational data. Results: The respondents exhibited excellent adherence to radiation protection but showed poor adherence to radiation monitoring. The main reasons for non-use of radioprotective garments were inadequate items and the need to prioritize others. Forgetfulness and fear of losing dosimeters were the common reasons for the non-consistent use of monitoring devices. Radiologists were the most consistent group using radioprotective garments compared to other job positions (p<. 050). Middle-aged respondents were more consistent in using radioprotective aprons than younger respondents (p<. 005). Work schedule, institution and gender also influenced the consistency of using radioprotective garments and dosimeters. Conclusion: There is an urgent need to improve the personal dosimeter adherence rate in this country and any shortage of radioprotective garments should be tackled immediately. Ultimately, it is crucial to understand the workers’,tasks and their safety measures to avoid underestimating occupational radiation exposure and risk.

Background: In this study, a comparison between various types of radiotherapy treatment for parotid gland cancer was performed to achieve the optimal treatment technique.Methods: Treatment planning and countering performed with TiGRT software for 15 patents with parotid gland cancer. Six techniques were performed and compared. Finally, by comparing the dose volume histograms (DVH), average dose received by each organ was determined and the best method was introduced. Techniques were as: 1. an ipsilateral wedge pair technique using 6 MV photons; 2. a 3-field anteroposterior (AP) (wedged) posteroanterior (PA) (wedged) and lateral portal technique using 6 MV photons; 3. a mixed beam technique using 6 MV photons and 12 MeV electrons (1: 4 weighting); 4. a mixed beam technique using 6 MV photons and 15 MeV electrons (1: 4 weighting); 5: four 6 MV photon beams with different gantry angles; and 6. similar to fifth technique with an additional small ring around the tumor tissue. Findings: Intensity-modulated arc therapy (IMRT) techniques five and six delivered maximum dose to the target and minimum dose to organ at risks (OAR). Among 3-D conformal radiotherapy techniques (CRT), technique number two delivered more amount of dose to the target than techniques number three and four. The dose delivered to the contrary parotid gland was negligible for intensity-modulated arc therapy techniques.Conclusion: Intensity-modulated arc therapy techniques are most appropriate methods for treating cancer of the parotid gland and the sixth technique delivered better dose distribution in the tumor and healthy tissues. Second D conformal radiotherapy technique delivered higher average dose to the target.

Introduction: Conventional fractionation (CF) and hypofractionation (HF) are two radiotherapy methods against cancer, which are applied in medicine. Understanding the efficacy and molecular mechanism of the two methods implies more investigations. In the present study, proteomic findings about the mentioned methods relative to the controls were analyzed via network analysis. Methods: The significant differentially expressed proteins (DEPs) of prostate cancer (PCa) cell line DU145 in response to CF and HF radiation therapy versus controls were extracted from the literature. The protein-protein interaction (PPI) networks were constructed via the STRING database via Cytoscape software. The networks were analyzed by “, NetworkAnalyzer”,to determine hub DEPs. Results: 126 and 63 significant DEPs were identified for treated DU145 with CF and HF radiation respectively. The PPI networks were constructed by the queried DEPs plus 100 first neighbors. ALB, CD44, THBS1, EPCAM, F2, KRT19, and MCAM were highlighted as common hubs. VTM, OCLN, HSPB1, FLNA, AHSG, and SERPINC1 appeared as the discriminator hub between the studied cells. Conclusion: 70% of the hubs were common between CF and HF conditions, and they induced radio-resistance activity in the survived cells. Six central proteins which discriminate the function of the two groups of the irradiated cells were introduced. On the basis of these findings, it seems that DU145-CF cells, relative to the DU145-UF cells, are more radio-resistant.

Introduction & Background: Today, radiotherapy alone or in combination with other therapeutic methods for treatment of various cancers is very effective and has a special place in medicine. This treatment modality is used in two ways, in combination with radiopharmaceuticals and in the vicinity of tumors, or by irradiation of tumor bed from an external source. One of the unwanted effects of this type of treatment is its effect on the musculoskeletal sys-tem. Considering the better long term survival of cancer patients and the appearance of late-onset side effects of those malignancies, knowledge about the effects of radiotherapy on the musculoskeletal system and the methods of differentiating them from secondary involvement by malignant diseases, has gained significant importance.

radiation, as a means of food preservation, was first discussed in 1905. In this method, food is exposed to a certain doze of ionizing ray with the purpose of destroying or deactivating microorganisms and insects, delaying the procedure of ripening of fruits and vegetables, preventing glandular and root vegetables from new shooting, and in general, increasing the period of preservation under certain conditions.

Background: Intensity-Modulated radiation Therapy (IMRT) is one of the best methods in the treatment of optic nerve sheath meningioma (ONSM) with tumor growth control and visual stabilization. In this study, various IMRT techniques were evaluated from the point of view of dose fall-off beyond the target boundaries to achieve the optimal technique. Methods: The optimization of 3 IMRT techniques was performed using 3, 5, and 7 fields with 6 MV photons in 15 patients with ONSM using Prowess Panther treatment planning system. To evaluate treatment plans, in addition to data extracted from dose-volume histogram (DVH) and evaluation of target coverage indices, differential and cumulative dose gradient indices (DGIs) were calculated and compared between the three techniques. Findings: The maximum and the mean dose received by the tumor increased with increasing number of IMRT fields. The uniformity (UI) and homogeneity (HI) indices were significantly different between the 3-field and 7-field techniques; and the conformity index (CI) was close to ideal value (0. 99) in 7-field technique. Difference of differential dose gradient index (dDGI) was negligible between the three techniques, and only at the 45% isodose level, there was a significant difference between the 5-and 7-field techniques. Cumulative dose gradient index (cDGI) showed smaller values in 7-field technique than the other two techniques. Conclusion: The three IMRT techniques have no considerable statistical difference in dose fall-off rate beyond tumor boundaries; and their choice in the treatment of ONSM depends on the physician's discretion based on the whole patient's conditions.

Background: Thyroid cancer is one of the most common secondary malignancies as a result of receiving therapeutic doses to the head and neck. In this study, the probability of secondary thyroid cancer risk due to neutron contamination of 15 MV Siemens Linear Accelerator (LINAC) in brain tumor 3D-Conformal radiation Therapy (3D-CRT) was calculated. Methods: Neutron fluence and neutron dose were measured at different points at the treatment table using an energy-independent neutron detector consisting of a sphere moderator and a Boron Trifluoride (BF3) counter, and the neutron dose equivalent to the thyroid was determined to calculate the probability of secondary cancer risk. Findings: The neutron dose equivalent was obtained at the central axis (0. 304 mSv/Gy) and at 4 cm (0. 285 mSv/Gy), 15 cm (0. 229 mSv/Gy), 45 cm (0. 125 mSv/Gy), and 150 cm (0. 02 mSv/Gy) inferior. The neutron dose equivalent reaching the thyroid for the total prescribed dose was 12. 366 mSv. According to that, the probability of secondary thyroid cancer risk was obtained as 0. 001%. Conclusion: The thyroid dose in high-energy radiation therapy of brain tumor cannot cause significant biological damage. Therefore, the risk of secondary thyroid cancer due to neutron contamination is relatively low.