Introduction: In radiotherapy, the bolus is often used while treating the tumor under the uneven surfaces of the patients for correcting the anatomical irregularities and increasing skin dose. Wet cotton and wet gauze are still used in developing countries, since the use of wet cotton and wet gauze has certain disadvantages, there is a need for transparent bolus which ...

Background: The accuracy and the reproducibility of radiotherapy can be provided by using immobilization devices such as thermoplastic masks. In head and neck cancer radiotherapy, the patients are mostly immobilized by using thermoplastic masks. In this study, the effect of the thermoplastic mask to the surface and buildup region doses was investigated by using Markus parallel plate ion chamber...

conclusions the automatic bolus-tracking method, results in higher contrast enhancement of the aorta and spleen at the portal phase, but has no effect on liver enhancement. however, bolus tracking is associated with reduced variability for liver enhancement among different patients. results forty-eight patients (23 male, 25 female, mean age=56.4±13.5 years) were included. the contrast enhanceme...

Abstract Measurements of ultrahigh-fidelity absorption spectra can help validate quantum theory, engineer ultracold chemistry, and remotely sense atmospheres. Recent achievements in cavity-enhanced spectroscopy using either frequency-based dispersion or time-based approaches have set new records for accuracy with uncertainties at the sub-per-mil level. However, laser scanning susceptibility to ...

human body consists of some tissues among which bone is one of the important living and growing tissue . in this research, energy absorption buildup factor (eabf) values of 27 types of bone have been computed for photon energy 0.03 to 1.5 mev up to 40 mean free path (40mfp) penetration depths. the inner bone tissue, spongiosa and male sternum had the largest values of eabf in low photon energie...

Neutron dose-equivalent buildup factors were calculated for point isotropic neutron sources irradiating infinite slablike shields of lead, iron and water using the MCNP code. The factors are presented for some source neutron energies in the range from 0.025 eV to 14 MeV, and for shield thicknesses from 0.5 to 10 mfp. Since the MCNP code considers all kinds of neutron interactions with matter, a...

Stream segregation is the process by which the auditory system disentangles the mixture of sound inputs into discrete sources that cohere across time. The length of time required for this to occur is termed the "buildup" period. In the current study, we used the buildup period as an index of how quickly sounds are segregated into constituent parts. Specifically, we tested the hypothesis that st...

Currently, type curve analysis methods are being commonly used in conjunction with the conventional methods to obtain better interpretation of well test data. Although the majority of published type curves are based on pressure drawdown solutions, they are often applied indiscriminately to analyze both pressure drawdown and buildup data. Moreover, the limitations of drawdown type curves, to ana...

purpose: to compare the morphology and function of corneal enthothelial cell in early postoperative period after phacoemulsification with infusion or bolus intracameral adrenaline. methods: in this prospective randomized study, 71 eyes of 71 patients scheduled for phacoemulsification were randomly assigned to two groups: one group (31 eyes) received bolus intraocular adrenaline at 1/10,000 conc...