Characterization of non-tuberculosis mycobacteria by neutron radiography.

The genus Mycobacterium shares many characteristics with Corynebacterium and Actinomyces genera, among which the genomic guanine plus cytosine content and the production of long branched-chain fatty acids, known as mycolic acids are enhanced. Growth rate and optimal temperature of mycobacteria are variable. The genus comprises more than 140 known species; however Mycobacterium fortuitum, a fast growing nontuberculous mycobacterium, is clinically significant, because it has been associated to several lesions following surgery procedures such as liposuction, silicone breast and pacemaker implants, exposure to prosthetic materials besides sporadic lesions in the skin, soft tissues and rarely lungs.

Dose assessment for releases from medical installations in the city of Rio de Janeiro.

The values of effluent releases to urban sewage system in Brazilian regulation were investigated and compared with the current International Atomic Energy Agency recommended criteria, using the city of Rio de Janeiro as a case study. Deterministic and probabilistic assessments were performed for two conservative scenarios, considering the exposure of the population in general and the exposure of workers in sewage treatment plants. The results from the deterministic assessment were found to be more restrictive than those from the probabilistic assessment.

Spectrally average conversion coefficients for air kerma to ambient dose equivalent for clinical linear accelerator.

This work aims to calculate the conversion coefficients from air kerma to ambient dose equivalent, H*(10)/K(air) for photon beams produced by linear accelerators, such as the Clinac-4, Clinac-6, Clinac-18 and Clinac-2500, after transmission through primary barriers of radiotherapy treatment rooms. Concrete walls of thickness 1.0, 1.

Use of a bioindicator system in the study of the mutagenetical effects in the neighborhoods of deposits of radioactive waste.

The purpose of the research described in this paper was to analyze the biological mutational effects caused by low doses of ionizing radiation on biological samples placed nearby and around deposits of radioactive waste, as a way of monitoring the environment close to them. In order to do this, the plant Tradescantia pallida was chosen, and through micronuclei tests the sensitivity of the dose/response to bio-monitoring could be observed. The plants were exposed for a period of 24h in previously chosen sites around Brazil, within the proximity of nuclear waste deposits.

Calculation of dose components in head phantom for boron neutron capture therapy.

Application of neutrons to cancer treatment has been a subject of considerable clinical and research interest since the discovery of the neutron by Chadwick in 1932 (3). Boron neutron capture therapy (BNCT) is a technique of radiation oncology which is used in treating brain cancer (glioblastoma multiform) or melanoma and that consists of preferentially loading a compound containing 10B into the tumor location, followed by the irradiation of the patient with a beam of neutron. Dose distribution for BNCT is mainly based on Monte Carlo simulations.

The use of neutron radiography in agriculture to improve the food quality.

The report presented in the 7th ONU's Conference (USA, 2001) about climatic changes that took place at the end of 2001 informs that, in less than 50 years, more than 45% of the world population will be suffering from lack of water. This fact occurs by the absence of management on water resources, mainly, in agriculture. As the excess as the lack of humidity in soil can change the harvest quality, causing physiologic anomalies in food and promoting soil diseases incidence caused by bacteria and fungus.