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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: Prostate cancer,Linac,Treatment plan,Integral dose,Cobalt-60
- چکیده:
- چکیده انگلیسی: Introduction: This study was designed to evaluate dosimetric parameters such as rectal dose, bladder dose, integral dose (ID), homogeneity index (HI) and conformity index (CI) in various treatment plans for prostate cancer.
Materials and Methods: Pelvic computed tomography (CT) scans of 27 patients were acquired and transferred to the RTDosePLAN treatment planning system. For each patient, 8 conventional plans (3, 4, 5 and 6 fields) were planned for the cobalt-60 photon energy. Subsequently, the same plans were performed for 6 MV and 18 MV photon energies.
Results: By increasing the energy of the beam relative to the cobalt-60 energy, the Dmean values for rectum and bladder were reduced from 3% to 4% and 4% to 6%, respectively, the dose received by the whole of the bladder volume decreased by 26% for 6 MV and by 58% for 18 MV. Increasing the photon beam energy decreased CI to 7% and 10%, ID was decreased by10% and 20% and Dmax was decreased by 3% and 4%, respectively.
Discussion and Conclusion: A six-field treatment plan in comparison to the other plans offers the minimum dose to critical organs and sufficient dose to the prostate. Increasing the photon energy improves the treatment parameters of the bladder and the PTV.- انتشار مقاله: 26-08-1387
- نویسندگان: Seyed Ali Vaezzadeh,Mahmood Allahverdi,Hasan Nedaie,Mahdi Aghili,Mahbod Esfehani,Ehsan Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Mathematical Finance and Application
- نوع مقاله: Journal Article
- کلمات کلیدی: tax,Tax Gap,Corporate Governance Effectiveness,future earnings changes
- چکیده:
- چکیده انگلیسی: The Iranian economy in recent years is due to the development of economic sanctions, a sharp decline in the price of oil and the deficit resulting from revenue - dependent on oil revenues and the trend towards tax revenues. While comparing the volume of the Iranian economy with the amount of tax income indicates the existence of a relatively significant tax gap. The tax gap is the difference between the collected taxes and the tax required by the law. The purpose of this study is to answer the question whether corporate governance is effective and strong on the relation between tax gap and future earnings changes? The statistical population of the research in Tehran Stock Exchange (TSE) firms and statistical sample consists of 120 companies in the period of 2007-2017. In order to test the hypotheses, multivariate regression using mixed data - data approach has been used. The results indicate that there is a significant inverse relationship between the tax gap and future earnings changes. It can be argued that increasing the difference between earnings accounting earnings can be associated with decreasing interest in the next year and less stability. On the other hand, significant positive relation between corporate governance is efficient and strong with future earnings changes. because corporate governance will ultimately lead to more sustainable future gains due to the decline of discretionary accruals in discretionary accruals. It is also reinforced by the effect of the tax gap on future earnings changes in firms that have efficient corporate governance, and this effect is only seen for a year later. And is not effective for the second and third years.
- انتشار مقاله: 02-06-1399
- نویسندگان: Rasoul Karami,Seyed Ali Vaez,Ghasem Rekabdar
- مشاهده