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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: Intensity Modulated Radiation Therapy,Quality Control,Film Dosimetry
- چکیده:
- چکیده انگلیسی: Introduction
Intensity Modulated Radiation Therapy (IMRT) has made a significant progress in radiation therapy centers in recent years. In this method, each radiation beam is divided into many subfields that create a field with a modulated intensity. Considering the complexity of this method, the quality control for IMRT is a topic of interest for researchers. This article is about the various steps of planning and quality control of Siemens linear accelerators for IMRT, using film dosimetry. This article in addition to review of the techniques, discusses the details of experiments and possible sources of errors which are not mentioned in the protocols and other references.
Materials and Methods
This project was carried out in Isfahan Milad hospital which has two Siemens ONCOR linear accelerators. Both accelerators are equipped with Multi-Leaf Collimators (MLC) which enables us to perform IMRT delivery in the step-and-shoot method. The quality control consists of various experiments related to the sections of radiation therapy. In these experiments, the accuracy of some components such as treatment planning system, imaging device (CT), MLC, control system of accelerator, and stability of the output are evaluated. The dose verification is performed using film dosimetry method. The films were KODAK-EDR2, which were calibrated before the experiments. One of the important steps is the comparison of the calculated dose with planning system and the measured dose in experiments.
Results
The results of the experiments in various steps have been acceptable according to the standard protocols. The calibration of MLC and evaluation of the leakage through the leaves of MLC was performed by using the film dosimetry and visual check. In comparison with calculated and measured dose, more that 80% of the points have to be in agreement within 3% of the value. In our experiments, between 85 and 90% of the points had such an agreement with IMRT delivery.
Conclusion
The EDR2 films are suitable for quality control of IMRT. According to complexity of the quality control for IMRT, the physicists of each center have to develop specific guidelines according to their equipments and limitations. An accurate treatment planning system with capability of inverse planning is an essential need for IMRT. The result of the planning system has to be compared with experiments in various situations.- انتشار مقاله: 21-07-1390
- نویسندگان: Keyvan Jabbari,Alireza Amouheidari,Shadi Babazadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mechanical Engineering Transactions of the ISME
- نوع مقاله: Journal Article
- کلمات کلیدی: Support,Force Transmissibility,Jeffcott Rotor,Rotor designs,Optimal Damping
- چکیده:
- چکیده انگلیسی: Rotating machinery support design with the aim of reducing the force transmitted to the foundation has significant importance regarding the various applications of these machineries. In this paper presents a rapid approximate method for calculating the optimum support flexibility and damping of flexible rotors to minimize force transmissibility in the vicinity of the rotor first critical speed. First, the governing equations for the Jeffcott rotor model mounted on flexible supports are derived and the optimal parameters for the supports have been analytically achieved. Next with consideration of the complexity and tedious of the analytic equations, a numerical algorithm for determination of the optimal support design parameters is introduced which may be applied to any rotor model regardless of the model complexity and number of degrees of freedom. The simulation results show the effect of optimal parameters on the considerable reduction of the force transmitted to the foundation. The method has the advantage of being quickly and easily applied and can reduce analysis time by eliminating a time consuming search for the approximate optimum damping using more exact methods.
- انتشار مقاله: 09-06-1397
- نویسندگان: Hamidreza Heidari,Pedram Safarpour
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Genetics and Plant Breeding
- نوع مقاله: Journal Article
- کلمات کلیدی: Grape,Expression analysis,Thioredoxin h,Semiquantitative RT-PCR
- چکیده: تیوردوکسین ها، دی سولفید ردوکتازهای کوچک و فراوانی هستند که در واکنش های تبادلی دی تیول- دی سولفید شرکت می کنند. در مقایسه با جانوران و پروکاریوت ها که تنها حاوی یک یا تعداد کمی از ژن های کدکننده تیوردوکسین ها می باشند، گیاهان عالی دارای هشت نوع تیوردوکسین متفاوت از قبیل: f، m، x، y، z، o، s و h هستند. تیوردوکسین h با اشکال متعدد در فرآیندهای مختلفی همچون جوانه زنی بذر، محافظت سلولی در برابر تنش اکسیداتیو، خودناسازگاری و غیره شرکت می نماید. بررسی بیان سه ژن تیوردوکسین h، به نام های VvTrx h1، VvTrx h2 و VvCxxS2 در بافت های مختلف سه رقم انگور (عسکری، بیدانه قرمز و بیدانه سفید) در مراحل رشدی مختلف بوسیله تکنیک RT-PCR نیمه کمی مورد مطالعه قرار گرفت. ژن های تیوردوکسین h انگور در بافت های حبه، برگ، دمبرگ، خوشه، ساقه، ریشه و بذر در مراحل رشدی مختلف بیان شده و در مقایسه با بافت ریشه، بالاترین سطح بیان آیزوفرم ها در بافت حبه مشاهده گردید. در بافت حبه، بیان آیزوفرم های VvTrx h1، VvTrx h2 و VvCxxS2 در شش مرحله رشدی شامل 14، 28، 42، 56، 82 و 110 روز پس از گلدهی (dpa) مورد بررسی قرار گرفت و مشاهده شد که بالاترین سطح بیان آیزوفرم ها به مرحله ترش- شیرین (Veraison, 56 dpa) تعلق دارد. بیان ژن های تیوردوکسین h انگور در بافت های برگ، دمبرگ و خوشه در سه مرحله رشدی جوانی، بلوغ و پیری نیز مورد مطالعه قرار گرفته و در مقایسه با بافت حبه، الگوی مشخصی از بیان را نشان ندادند. در مقایسه با آیزوفرم های VvTrx h1 و VvCxxS2، آیزوفرم VvTrx h2 بالاترین سطح بیان را در بافت های مختلف نشان داد که حاکی از ایفای نقش مهم این آیزوفرم در گیاه انگور می باشد.
- چکیده انگلیسی: Thioredoxins (Trxs) are small ubiquitous disulfide reductases that participate in dithiol-disulfide exchange reactions. In contrast to animals and prokaryotes that typically possess one or a few genes encoding Trxs, higher plants contain eight different Trx types: f, m, x, y, z, o, s, and h. Trx h with multiple forms is involved in different processes such as seed germination, cellular protection against oxidative stress, self-incompatibility etc. The expression analysis of the three h-type Trx genes, called VvTrx h1, VvTrx h2 and VvCxxS2 was studied in different tissues of three grape cultivars (Askari, Red Seedless and White Seedless) at various develpmental stages by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). The grape Trx h genes were expressed in berry, leaf, petiole, cluster, stem, root, and seed tissues at different developmental stages. The higher expression of the isoforms was observed in berry tissues as compared to those of the roots. In berry tissues, the expression of VvTrx h1, VvTrx h2 and VvCxxS2 isoforms were analyzed at six growth stages, including 14, 28, 42, 56, 82, and 110 days post anthesis (dpa). The highest level of expression was observed at veraison stage (56 dpa). The expression of grape Trx h genes was also analyzed in leaf, petiole and cluster tissues at three developmental stages including young, mid and old stages with a imprecise pattern of expression in comparison to the berry tissues. In contrast to VvTrx h1 and VvCxxS2 isoforms, VvTrx h2 showed the highest level of expression in different tissues, suggesting a major role for this isoform in grape.
- انتشار مقاله: 16-12-1388
- نویسندگان: Raheem Haddad,Reza Heidari-Japelaghi,Ghasemali Garoosi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: oxidative stress,Kidney,Nitric oxide,Reperfusion injury,Remote ischemic per-conditioning
- چکیده:
- چکیده انگلیسی: Objective(s): We investigated the role of nitric oxide (NO) in the protective effects of remote ischemic per-conditioning (rIPerC) on renal ischemia/reperfusion (I/R) injury in male rats.
Materials and Methods: I/R treatment consisted of 45 min bilateral renal artery ischemia and 24 hr reperfusion interval. rIPerC was performed using four cycles of 2 min occlusions of the left femoral artery and 3 min reperfusion at the beginning of renal ischemia. The animals were given normal saline (vehicle), NG-nitro-L-arginine methyl ester (L-NAME) or L-arginine. Following the reperfusion period, renal functional- and oxidative stress- parameters, as well as histopathological changes were assessed.
Results: In comparison with the sham group, I/R resulted in renal dysfunction, as indicated by significantly lower creatinine clearance and higher fractional excretion of sodium. This went along with decreased glutathione peroxidase (GPX) and catalase (CAT) activity in the I/R group, increased malondialdehyde (MDA) contents and histological damages. In comparison with the I/R group, the rIPerC group displayed improved renal function, increased activity of GPX and CAT enzymes, and decreased MDA level. However, these effects were abrogated by L-NAME injection and augmented by L-arginine treatment.
Conclusion: According to the results, the functional and structural consequences of rIPerC against I/R-induced kidney dysfunction, which is associated with reduction of lipid peroxidation and intensification of anti-oxidant systems, is partially dependent on NO production.- انتشار مقاله: 31-05-1396
- نویسندگان: Firouzeh Gholampour,Leila Khangah,Jafar Vatanparast,Hamid Reza Karbalaei-Heidari,Seyed Molammad Owji,Aminollah Bahaoddini
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Crocus sativus,Safranal,Harmaline,Essential tremor
- چکیده:
- چکیده انگلیسی: Objective(s): Due to unsatisfactory response or intolerable side effects of current drugs, treatment of essential tremor remains inadequate. Thus, we aimed to investigate the protective and therapeutic effects of aqueous and ethanolic extracts of Crocus sativus (saffron), and its active consistent, safranal, on the harmaline-induced tremor in mice.
Materials and Methods: To induce tremor, harmaline (30 mg/kg) was injected intraperitoneally. Test groups were also given the aqueous and ethanolic extracts of saffron (40, 80, and 160 mg/kg) as well as safranal (0.1, 0.3, and 0.5 ml/kg), intraperitoneally, 10 min before harmaline administration (prophylactic study) or 10 min after the onset of tremors (curative study). The latency of onset, duration, and intensity of tremor were recorded.
Results: The extracts (80 and160 mg/kg) dose dependently attenuated duration of harmaline-induced tremors as did reference drug, propranolol (2 and 5 mg/kg). Only the highest dose of extracts (160 mg/kg) attenuated intensity of harmaline-induced tremors throughout the study. Safranal at the doses of (0.1 and 0.3 ml/kg) but not 0.5 ml/kg attenuated duration and intensity of tremor. Onset of tremor increased with the extracts (80 and 160 mg/kg) in prophylactic study, as the effect observed with propranolol at the dose of 5 mg/kg. Safranal did not affect the latency of tremor.
Conclusion: Both aqueous and ethanolic extracts of saffron and with a less effect, low doses of safranal, have relatively protective and suppressive effects on the harmaline-induced tremor and different constituents of extracts seem to participate in the protective effects against harmaline induced tremor.- انتشار مقاله: 10-03-1394
- نویسندگان: Bahareh Amin,Mahshad Malekzadeh,Mahmoud Reza Heidari,Hossein Hosseinzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Rat,oxidative stress,hepatotoxicity,CCl4,Anise seed,HepG2 cells
- چکیده:
- چکیده انگلیسی: Objective(s): Protective effects of different extracts and essential oil from Pimpinella anisum L. seeds were examined against carbon tetrachloride (CCl4)-induced toxicity. The parameters such as serum transaminases, lactate dehydrogenase activity, hepatic glutathione content, liver lipid peroxidation and histopathological changes of liver were assessed as toxicity markers. In the in vitro model of this study, markers such as cell viability, cellular reduced and oxidized glutathione and lipid peroxidation in HepG2 cells were evaluated.
Materials and Methods:Human liver cancer cell line HepG2 and male Sprague-Dawley rats were treated with extracts and essential oil, and markers of hepatotoxicity were investigated.
Results: The data revealed that the n-hexane extract, effectively attenuated CCl4‑induced toxicity in both in vitro and in vivo models in current investigation.
Conclusion: As the oxidative stress markers were ameliorated, it might be concluded that anise seed possesses protective effects probably due to its antioxidant constituents.- انتشار مقاله: 06-12-1393
- نویسندگان: Akram Jamshidzadeh,Reza Heidari,Mojtaba Razmjou,Forouzan Karimi,Mahmood Reza Moein,Omid Farshad,Amin Reza Akbarizadeh,Mohammad Reza Houshangi Shayesteh
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Pain,Melatonin,oxidative stress,diabetes,Vitamin E,Peripheral neuropathy
- چکیده:
- چکیده انگلیسی: Objective(s) Previous studies have indicated that diabetes mellitus might be accompanied by neuropathic pain. Oxidative stress is implicated as a final common pathway in development of diabetic neuropathy. Pharmacological interventions targeted at inhibiting free radical production have shown beneficial effects in diabetic neuropathy. The aim of this study was to investigate and compare the possible analgesic effects of melatonin and vitamin E in diabetic rats. Materials and Methods This study was performed on 32 male Wistar rats divided into 4 groups: control, diabetic, melatonin-treated diabetic and vitamin E-treated diabetic. Experimental diabetes was induced by intraperitoneal streptozotocin (50 mg/kg) injection. Melatonin (10 mg/kg, i.p.) and vitamin E (100 mg/kg, i.p.) were injected for 2 weeks after 21st day of diabetes induction. At the end of administration period, pain-related behavior was assessed using 0.5% formalin test according to two spontaneous flinching and licking responses. The levels of lipid peroxidation as well as glutathione-peroxidase and catalase activities were evaluated in lumbosacral dorsal root ganglia. Results Formalin-evoked flinching and total time of licking were increased in both acute and chronic phases of pain in diabetic rats as compared to control rats, whereas treatment with melatonin or vitamin E significantly reduced the pain indices. Furthermore, lipid peroxidation levels increased and glutathione-peroxidase and catalase activities decreased in diabetic rats. Both antioxidants reversed the biochemical parameters toward their control values. Conclusion These results suggest that oxidative stress may contribute to induction of pain in diabetes and further suggest that antioxidants, melatonin and vitamin E, can reduce peripheral neuropathic pain in streptozotocin-induced diabetic rats.
- انتشار مقاله: 06-07-1394
- نویسندگان: Farrin Babaei-Balderlou,Samad Zare,Reza Heidari,Farah Farrokhi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Catalysis
- نوع مقاله: Journal Article
- کلمات کلیدی: tetracycline,Catalytic activity,NiO,Ammonia precipitation,Ponceau 4R
- چکیده:
- چکیده انگلیسی: Nickel oxide (NiO) nano-size powder is synthesized using nickel (II) acetate tetrahydrate, sodium lauryl sulfate (SLS) and ammonia as precursors. Applied surfactant is anionic surfactant. The sample was characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM). The results obtained confirm the presence of nickel oxide nano-powders produced during chemical precipitation. Evaluation of the catalytic activity of developed nano-NiO particles were carried out using ultraviolet visible spectra. The uv-vis spectra obtained after ultraviolet irradiation in the presence of nickel oxide can indicate the degradation of tetracycline (TC) and dye Acid red -18 (ponceau 4R). The prepared NiO exhibits that 75% of Acid red -18 has been eliminated after 10 min.The results indicate that optimum concentration of NiO catalyst and the best pH for the degradation of AR were 0.5 g L-1 and pH 7, respectively. The best TC degradation results were obtained with 2 g L−1of the photocatalyst at pH 11.
- انتشار مقاله: 30-01-1396
- نویسندگان: Alireza Heidarineko,Azar Bagheri Ghomi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Behavioral Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: test anxiety,Keywords: Mindfulness,Educational Well-being
- چکیده:
- چکیده انگلیسی: Abstract
Introduction: The present study was aimed to assess the effectiveness of mindfulness on test anxiety and educational well-being in secondary school female students.
Method: The study has been conducted based on a semi-experimental design of pretest-posttest type with a control group and a follow up stage. Forty students were selected based on a purposive sampling method and were assigned to two groups: (control and experimental groups, Each containing 20 individuals) based on a simple randomized method One of the experimental group received mindfulness training for a period of 10 sessions, each lasting for 45 minutes (twice a week). Data analysis was conducted using Multivariate Covariance Analysis (MANCOVA) and ANCOVA’s single-variable analysis method using SPSS software.
Results: The results of MANCOVA showed a positive and significant effect of mindfulness training on test anxiety and academic well-being (p <0.01). Also, the results of treatment in the follow-up test were stable after one and a half months (p <0.01).
Conclusion: According to the findings of this study it can be stated that mindfulness training can help reduce test anxiety and improve academic well-being.- انتشار مقاله: 23-08-1398
- نویسندگان: Sara Jahani,Saeed Bakhtiyar-Pour,Behnam Makvandi,Alireza Heidarie,Parvin Ehteshamzadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Behavioral Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: empowerment,Organizational Culture,Job satisfaction,Keywords: Organizational Intelligence,Workplace-life Skills
- چکیده:
- چکیده انگلیسی: Abstract Introduction: The present study aimed to determine the effectiveness of organizational intelligence, workplace-life skills, and employee empowerment training on job satisfaction and organizational culture of employees with job stress in the Persian Gulf Star Oil Company (PGSOC). Method: The research method was quasi-experimental with a pretest-posttest design and a control group. The research sample consisted of 80 employees with job stress (20 employees in the experimental group 1 (organizational intelligence training), 20 in the experimental group 2 (workplace-life skills training), 20 in the experimental group 3 (employee empowerment training) and 20 in the control group). these employees were selected by a simple random sampling method. The research tools included Minnesota Job Satisfaction Questionnaire, Denison Organizational Culture Survey, and Rice Job Stress Questionnaire. Multivariate analysis of covariance (MANCOVA) and ANCOVA were used to analyze the data. Results: The results indicated that organizational intelligence, workplace-life skills, and employee empowerment training increased job satisfaction and organizational culture in employees with job stress in experimental groups 1, 2 and 3 in comparison to the control group. Conclusion: Organizational intelligence, workplace-life skills and empowerment training for employees could be effective in increasing job satisfaction and organizational culture.
- انتشار مقاله: 26-12-1398
- نویسندگان: Amin Zamiri,Alireza Heidari,Parviz Asgari,Behnam Makvandi
- مشاهده