35 resultados para estrôncio


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The sources of betatherapy for clinical use in Brazil are, the vast majority of strontium-90, radioactive element that is not produced in the country, and therefore requires importation of international laboratories accredited by the International Atomic Energy Agency (IAEA).The use of these resources is always limited the crediting of characteristic values supplied by the manufacturer tables that provide the nominal value of activity and dose distribution to determine the irradiation time of the injury. The Institute of Nuclear Energy Research (IPEN / CNEN-SP) has recently researching the emission profile of these types of radiation sources, and some jobs are being developed with ionization chambers extrapolation for the purpose of standardizing a systematic calibration sources betatherapy. Other studies using parallel measures dosimeters (TLD's) and simulations with the Monte Carlo method. Radiological films have also been used in studies of applicators dosimetric analysis of strontium-90. This paper seeks to analyze the different methods for calibration of applicators betatherapy, already consolidated in studies by examining the advantages and disadvantages of each procedure

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose was to evaluate the effectiveness of beta-radiation with strontium-90 as single modality treatment of canine third eyelid squamous cell carcinoma (SCC). Nine dogs diagnosed with third eyelid SCC were treated with strontium-90. Radiation therapy was administered in four fractions of 100cGy per site every four days and at a depth of 0.2cm (Strontium-90 build' up) in each fraction. Radiation with beta therapy was well tolerated in all animals with no occurrence of radiation induced cataracts. In all cases, there were increased signs of conjunctival inflammation around the mass, which subsided with topical anti-inflammatory. Two dogs required surgical treatment for local tumor recurrence at 150 days and 352 days. In the remaining seven cases, disease free interval ranged from 1239 days to 2555 days. Beta therapy using 90Sr may be a valid alternative for the treatment of third eyelid SCC in dogs