Background: The present study aimed to investigate the equivalent dose in vital organs, including heart and lung, due to secondary particles produced during breast proton therapy. Materials and Methods: The numerical ORNL female-phantom was improved and simulated using the Monte Carlo MCNPX code. The depth-dose profile of proton beams with different energies was simulated. The proper energy ran...

One advantage of using protons for signaling and regulation as opposed to posttranslational modifications or cofactors is the potential for extremely rapid temporal responses. Protons can diffuse through water exceptionally quickly (“Grotthuss diffusion,” made possible in part by the quantum mechanical tunneling ability of protons), possibly facilitated by short-range motion in proteins (58). T...

background: the purpose of this paper is to establish an easy and reliable biodosimeter protocol to evaluate the biological effects of proton beams. materials and methods: human peripheral blood lymphocytes were irradiated using proton beams (let: 34.6 kev μm−1), and the chromosome aberrations induced were analyzed using cytokinesis-blocked (cb) micronucleus (mn) assay. to determine the efficie...

Introduction Proton therapy is used to treat malignant tumors such as melanoma inside the eye. Proton particles are adjusted according to various parameters such as tumor size and position and patient’s distance from the proton source. The purpose of this study was to assess absorbed doses in eyes and various tumors found in the area of sclera and choroid and the adjacent tissues in radiotherap...

The optimized geometries, harmonic vibrational frequencies, and energies of the structures of monohydrated alloxan were computed at the DFT/ωB97X-D and B3LYP/6-311++G** level of theory. Results confirm that the monohydrate exists as a dipolar alloxan-water complex which represents a global minimum on the potential energy surface (PES). Trajectory dynamics simulations show that attempt to reorie...

This review focuses on the detailed characterization of proton and metal reactivity on the surface of bacteriogenic iron oxides (BIOS). This substance is composed of a highly porous matrix of ferrihydrite intermixed with intact and fragmented Gallionella ferruguinea cells. Studies concerning proton and metal cation binding to the BIOS were designed to assess their surface chemical heterogeneity...

In this paper, the study of melatonin and 60 meta- and ortho-substituted melatonins is presented. The reaction enthalpies related to the hydrogen atom transfer (HAT), single electron transfer - proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) have been calculated using DFT/B3LYP method in gas-phase and water. Results show that electron-withdrawing substituents incre...

The soil yeast Trichosporon cutaneum, which is distinguished by having a strictly oxidative metabolism, can be induced to utilize phenol as a sole carbon source. The present paper shows that such phenol-induced cells contain a specific, energy-dependent uptake system for phenol. Phenol uptake is not directly linked to its o-hydroxylation inside the cell, the first step of phenol metabolism. The...

An improved M.I.T. bag model with hyper central interaction is used to calculate the charge radius for proton containing u and d quarks. We present a theoretical approach to the internal structure of three-body hyper central interacting quarks in a proton, in which we take proton as a bag. We discuss a few of results obtained using a six-dimension potential, which is attractive for small separa...

The four DNA nucleosides guanosine, adenosine, cytidine and thymidine have been produced in the gas phase by a laser thermal desorption source, and irradiated by a beam of protons with 5 keV kinetic energy. The molecular ions as well as energetic neutrals formed have been analyzed by mass spectrometry in order to shed light on the ionization and fragmentation processes triggered by proton colli...