نتایج جستجو برای: a radiation
تعداد نتایج: 13500630 فیلتر نتایج به سال:
background: although ionizing radiation is widely used to diagnose many diseases, the relevant hazards are known to be as an important limitation of its application. it is believed that the awareness of ionizing radiation dose values is one of the main stages in patient's radiation protection. the purpose of this study has been to investigate the level of physicians' knowledge about r...
patients and methods we evaluated radiation exposure from initial and downstream testing in a prospectively collected, matched cohort evaluated for cp in the emergency department (ed) with either ccta compared with usual care over a median follow-up of 19.6 months. effective radiation dose was calculated using published conversion factors. results prospective, ecg-triggered acquisition using a ...
The effect of UV beam, which has been emitted from a natural or a manmade source on cells has been studied in previous studies for several times. Radiation of this beam can have different effects on DNA of the cell, cytotoxicity, the structure of cellular proteins and their mechanical properties based on radiation period or frequency. The effect of radiation of two types of beams, namely UVB an...
background: radiation-induced lung injury is a refractory side effect in lung cancer radiotherapy, the mechanism still remains unclear, hence an appropriate animal mode may become useful to investigate it. materials and methods: 50 female wistar rats were randomly divided into 5 groups, average 10 rats/cage: a. control group b. 3gy×10f c. 6gy×5f d. 12.5gy×1f e.15.3gy×1f. by different doses of r...
در دنیا مناطقی وجود دارند که ساکنین آنها در معرض پرتوهای طبیعی زمینه بالا هستند. این مناطق به high background radiation areas hbras ، معروف می باشند. از جمله این مناطق می توان به گوارا پاری در برزیل ، کرالا در هند ، نواحی از آمریکا و یانگ جیانگ در چین اشاره کرد. در ایران نیز مناطق با پرتودهی زمینه بالا مشاهده شده است . رامسر یکی از این مناطق است .
the harmful effects of the long-term ocular exposure to cumulative levels of infrared radiation (ir) in glassblowing and foundries have been recognized since the late 19th century. these effects include cataracts, keratitis, and chronic dry eye problems. therefore, infrared radiation measurements are critical and need to be assessed regularly in the industries and workplaces where there are hig...
today, nuclear medicine has rapidly been developed so that in some cases, plays a unique role in diagnosis but unfortunalty in spite of diagnostic and therapeutic advantages, the term “nuclear” can induce worries in patients and society. in this article, base on new documents, we intend to show that this worries has no scientific basis. to produce a realistic view, regarding to radiation protec...
An analytical technique is proposed for estimation of the radiation pattern of inverted-F antenna (IFA) which is mounted on the side wall of a long cylinder. The method can be applied to describe the IFA radiation in a lot of practical cases. It is indicated that this radiation pattern is a combination of radiation patterns of a horizontal and a vertical small radiator, near the cylinder with a...
background: humans beings are continuously exposed to ionizing radiation from natural sources. the main contributors to natural radiation are high-energy cosmic radiation and radioactive nuclides that originates in the earth’s crust. exposure to high levels of radiation can cause serious health effects. in this study an attempt has been made to monitor the levels of environmental background rad...
the currently reactor wreckage in fukushima raised the following important questions: is our knowledge of the possible dangers of ionizing radiation sufficient to warrant special action? what is the role of the medical community in technical radiation accidents from windscale to fukushima? what is the role of the medical community in terrorist radiation attacks? are we prepared for those challe...
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