The change in frequencies of D. melanogaster and D. simulans in competition experiments was used to measure the effect of radiation on the fitness of a population. A dose of 250 or 500 rads given to the males of highly inbred lines of D. simulans at the beginning of competition and every three weeks thereafter increased the relative frequency of the irradiated population. If the dose was increa...

Introduction Radiotherapy is regarded as the first treatment of choice for nasopharyngeal carcinoma. Despite the advantages of radiotherapy, patients may suffer from a wide range of side-effects due to the presence of many sensitive normal tissues in these regions. If the absorbed dose exceeds the tolerance level in parotid glands and the spinal cord, myelopathy, Lhermitte's sign and xerostomia...

Background: A new treatment approach for most patients who have undergone early stage non-small-cell lung carcinoma (NSCLC), is wedge resection plus permanent implant brachytherapy. However, the specification of dose to medium at low energies especially in heterogeneous lung is unclear yet.Objective: The present study aims to modify source strength for different configurations of 125I and 103...

introduction: radioiodine therapy is an effective method for treating thyroid cancer carcinoma, but it has some affects on normal tissues, hence dosimetry of vital organs are important to weigh the risks and benefits of this method. the aim of this study is to measure the absorbed doses of important organs by mcnp (monte carlo n particle) simulation and comparing the results of different method...

background: panoramic imaging is one of the most common imaging methods in dentistry. regarding the side-effects of ionizing radiation, it is necessary to survey different aspects and details of panoramic imaging. in this study, we compared the absorbed x-ray dose around two panoramic x-ray units: pm 2002 cc proline (planmeca, helsinki, finland) and cranex tome (soredex, helsinki, finland). mat...

background: most preclinical studies are carried out on mice. for internal dose  assessment of a mouse, specific absorbed fraction (saf) values play an important role.  in most studies, saf values are estimated using older standard human organ compositions  and values for limited source target pairs. objective: saf values for monoenergetic photons of energies 15, 50, 100, 500,  1000 and 4000 ke...

background: therapeutic radiopharmaceuticals are designed to deliver high doses of radiation to selected target organs with an aim of minimizing unwanted radiation to surrounding healthy tissue. due to the potential of targeted radiotherapy to treat a wide range of malignant conditions, [153sm]-samarium maltolate was developed for possible therapeutic applications. materials and methods: the or...

abstract background: accurate methods of radiation therapy dose calculation. there are different monte carlo codesfor simulation of photons, electrons and the coupled transport of electrons and photons. mcnpis a general purpose monte carlo code that can be used for electron, photon and coupledphoton-electron transport.monte carlo simulation of radiation transport is considered to be one of the ...

We consider stochastic diffusion processes absorbed at the boundary of a domain. It is shown that there exist initial distributions which ensure a given decreasing of density of the absorbed process.

For finite-time quantum Otto heat engine with working fluid consisting of either a (i) qubit or (ii) harmonic oscillator, we show that the relative fluctuation output work is always greater than corresponding input absorbed from hot bath. As result, ratio between and receives lower bound in terms square value average efficiency engine. The saturation received quasi-static limit can be shown for...