Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal. Molina P, D. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC standard were carried out.
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Structural aspects of crotoxin modified by ionizing radiation; Aspectos estruturais da crotoxina modificada pela radiacao ionizante. Ionizing radiation has proven to be an excellent tool for reducing the toxicity of venoms and isolated toxins, resulting in better immunogens for serum production, the only effective treatment in case of snake bites, and contributing to the welfare of serum-producing animals. Since the action of gamma radiation of venoms and toxins has not been yet fully clarified from the structural point of view, we proposed in this paper, to characterize the crotoxin, a venom protein of the species Crotalus durissus terrificus by Circular Dichroism CD and Infrared Spectroscopy FTIR techniques.
After chromatographic techniques, crotoxin was irradiated with 2. The CD spectra obtained of native and irradiated crotoxin solutions showed changes between the samples in characteristic regions of -sheet and-helix. The Infrared analyse showed expressive changes in the spectra of the native and irradiated crotoxin amide I band region.
These tests showed that crotoxin when subjected to gamma radiation, showed changes in their structural conformation compared with the samples in the native state. Such changes probably occur in the secondary structure and may explain its neurotoxic activity loss. Biofunctional polymers prepared by ionizing radiation; Polimeros biofuncionais preparados pela radiacao ionizante. Martellini, Flavia; Rodas, Andrea C. Polymeric systems with biomedical and biochemical properties can be obtained by radiation induced polymerization.
Those systems exhibit a pharmaceutical or biocatalytic activity if drugs or enzymes are immobilized in the polymer matrices.
This work deals with the synthesis by gamma radiation of acrylic monomers and paracetamol, a drug with analgesic and anti thermic action, which can be used as medication in drug delivery systems. Besides, polyethylene and polypropylene radiation grafted with a hydrogel containing carboxylic groups acrylic acid , showed to be a suitable substrate for the enzyme coupling, such as urease and glucose oxidase. The grafted matrices allow the immobilization of any biocomponent with protein structure.
Drug delivery system prepared by ionizing radiation of the N,N-dimethyl acrylamide with acryloyloxy-acetanilide copolymerization; Sistema de liberacao de droga obtido via radiacao ionizante pela copolimerizacao do N,N-dimetilacrilamida com 4-acriloiloxiacetanilida.
Martellini, Flavia; Higa, Olga Z. Radiation induced polymerization has been used in biomaterials used in systems which such as drug delivery DDS. This work describes the copolymerization of the monomers by gamma rays N,N-dimethyl acrylamide DMAA and acryloyloxy-acetanilide AOA for the immobilization of paracetamol, an analgesic and anti thermic drug.
The samples were irradiated in the dose range of Gy. The hydrolysis was studied considering the formation of sodium salts of 4-hydroxy acetanilide at different times of treatment using colorimetric assay. Study of physical, chemical and structural effects caused by ionizing radiation and preservation on human costal cartilage; Estudo dos efeitos fisicos, quimicos e estruturais ocasionados pela radiacao ionizante e preservacao em cartilagem costal humana.
Tissue Banks around the world have stored human cartilages obtained from cadaver donors for use in several kinds of reconstructive surgeries. To ensure that such tissues are not contaminated, they have been sterilized with ionizing radiation. However, high doses of gamma radiation may cause undesirable changes in the tissues, decreasing the mechanical properties of the grafts.
Samples of human costal cartilage were obtained from 20 cadaver donors ranging between 18 and 55 years old. Thermogravimetry TG , Optical Coherence Tomography OCT and mechanical tension and compression tests were carried out to evaluate the changes in the cartilage.
Regarding the thermogravimetric results, the obtained data has shown that the TG curves have the same pattern independently of the sample irradiated or not. On the other hand, non-irradiated samples showed great variability of thermogravimetric curves among different donors and for the same donor.
Samples deep-frozen, when irradiated with 25 and 50 kGy, presented a decrease of their mechanical behavior smaller than those preserved in high concentrations of glycerol and irradiated with the same dose.
Therefore, deep-frozen cartilages can be sterilized with doses until 50 kGy and cartilages preserved in high concentrations of glycerol can be sterilized with doses until 25 kGy without significant changes in their bio-mechanical properties.
The environmental pollution is one of the biggest problems nowadays. It was also studied the different ionizing radiation doses effects 25, 50, 75, , , , , e kGy on the blend properties using an electron beam accelerator. The mechanical tensile strength, impact and hardness , thermal Vicat softening temperature, differential scanning calorimetry and termogravimetric and microscopic light microscopy and scanning electron microscopy properties of the blend were studied.
The analysis of the results showed to be a not mixing and compatible blend, with mechanical and thermal properties which appeared to be similar to the properties of the component material used in the blend in separate satisfactory, resulting in a resistant material and of low cost, being able to be used in the production of parts that do not demand specifications techniques. The use of the ionizing radiation improved some of the mechanical and thermal properties of the blend these modifications had been random and irregular, depending directly on the dose of applied radiation and the type of property making possible more specific applications for this material.
Obtention of gelatin biopolymers by ionizing radiation; Obtencao de biopolimeros de gelatina por radiacao ionizante.
The gelatin Gel is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions.
As a hydrophilic polymer, the Gel has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels.
Two-dimension multiwire detector for ionizing radiation; Detector multifilar bidimensional para radiacao ionizante. The cathode strips are connected to the taps of delay-lines chips. The position of the incidence of radiation is extracted by measuring the time difference of the pulse arriving at the extremities of the delay-line chain for each coordinate.
The performance of the detector has been tested using 5. An integral non linearity better than 0. Influence of ionizing radiation on Trypanosoma cruzi; Influencia da radiacao ionizante sobre o Trypanosoma cruzi. Chagas's disease is one of the major public health problems in South America, promoting high prejudice to the local population.
Despite the massive efforts to control it, this disease has no cure and presents puzzling unsolved questions. Considering that many researchers have used ionizing radiation to modify protozoans or biomolecules, we investigated the immunological response aspects of susceptible and resistant mice using irradiated parasites.
Low radiation doses preserved the reproductive and invasive capacities of the parasite. Both susceptible and resistant animals, after immunization with irradiated parasites produced specific antibodies. After a challenge, the animals presented low parasitaemia, excepting those immunized with the antigen irradiated with higher doses. Using low radiation doses, we were able to selectively isolate trypomastigotes, leading to an improvement in the quality of the immune response, as previously reported when performing complement system assays.
These data highlight the importance of selecting trypomastigote forms for immunization against T. Las radiaciones ionizantes : una realidad cotidiana. Directory of Open Access Journals Sweden. Characterization of ionizing radiation effects on human skin allografts; Caracterizacao dos efeitos da radiacao ionizante em pele humana para aloenxerto.
The skin has a fundamental role in the viability of the human body. In the cases of extensive wounds, allograft skin provides an alternative to cover temporarily the damaged areas. The glycerol at this concentration has a bacteriostatic effect after certain time of preservation. On the other hand, skin sterilization by ionizing radiation may reduces the quarantine period for transplantation in patients and its safety is considered excellent. The objectives of this work were to establish procedures using two sources of ionizing radiation for sterilization of human skin allograft, and to evaluate the skin after gamma and electron beam irradiation.
The analysis of stress-strain intended to verify possible effects of the radiation on the structure of preserved grafts. Morphology and ultra-structure studies were also accomplished. The samples irradiated with a dose of 25 kGy seemed to maintain the bio mechanic characteristics.
The gamma irradiated samples with a dose of 50 kGy and submitted to an electron beam at doses of 25 kGy and 50 kGy presented significant differences in the values of the elasticity modulus, in relation to the control. The analysis of the ultramicrographies revealed modifications in the structure and alterations in the pattern of collagen fibrils periodicity of the irradiated samples. Ionizing radiation, nuclear energy and radiation protection for school; Radiacao ionizante , energia nuclear e protecao radiologica para a escola.
Lucena, E. Since the discovery of X-rays in , ionizing radiation has been applied in many sectors of society, such as medicine, industry, safety, construction, engineering and research. However, population is unaware of both the applications of ionizing radiation and their risks and benefits. It can be seen that most people associate the terms 'radiation' and 'nuclear energy' with the atomic bomb or cancer, most likely because of warlike applications and the stealthy way radioactivity had been treated in the past.
Thus, it is necessary to clarify the population about the main aspects related to the applications, risks and associated benefits. These knowledge can be disseminated in schools. Brazilian legislation for basic education provides for topics such as nuclear energy and radioactivity to high school students. However, some factors hamper such an educational practice, namely, few hours of class, textbooks do not address the subject, previous concepts obtained in the media, difficulty in dealing with the subject in the classroom, phobia, etc.
One solution would be the approximation between schools and institutions that employ technologies involving radioactivity, which would allow students to know the practices, associated radiological protection, as well as the risks and benefits to society. Currently, with the increasing application of ionizing radiation, especially in medicine, it is necessary to demystify the use of radioactivity. Effects of the ionizing radiation in natural food colours; Efeitos da radiacao ionizante em corantes naturais de uso alimenticio.
The world's fast growing population and its consequent increase in demand for food has driven mankind into improving technologies which ensure a safer supply of such commodities.
Both food radiation processing and its constituents are highlighted as a feasible alternative technique capable of meeting food safety standards. Natural dyes are extensively employed in the food industry thanks to their colour enhancing properties on food products. This paper has aimed at studying the effects of ionizing radiation on three natural dyes: carminic acid and its derivatives cochineal dyes , bixine and its salts annatto dyes and curcumin turmeric dyes , used in the food and cosmetic industries within dilutions and doses those goods might eventually be processed in.
It also envisages clarifying the compatibility of the irradiation technique with the keeping of such relevant sensorial attribute which is the product colour. Spectrophotometry and capillary electrophoresis were the analytic methods employed. All in all, a colour decrease proportional to the increase on the applied gamma radiation 1 to 32 kGy has been observed.
The annatto dyes have proven moderately stable whereas turmeric has shown to be highly sensitive to radiation. Those results shall be taken into account as far as the need to alter the formulae additive amount in the product is concerned whenever undergoing radiation processing.
Ionizing radiation sources used in medical applications in Brazil; Fontes de radiacao ionizante utilizadas em medicina no Brasil. Araujo, A M. This programme has two main aims: First: to contribute for research in the field of ionizing radiation effects and risks including information about equipment quality control and procedures adopted by professionals working in Radiation Medicine.
Second: to investigate the radiation protection status in Brazil, in order to give assistance to Brazilian health authorities for planning regional radiation programmes and training programmes for medical staffs. Evaluation of peach palm Bactris gasipaes Kunth processed by radiation; Avaliacao do palmito pupunha Bactris gasipaes Kunth processado por radiacao ionizante. The peach palm can be obtained from several species of palms, but the peach palm has attracted great interest by producers, as has characteristics of precocity, rusticity and tillering, producing a palm-quality differentiating it from other palmettos for their sweet flavor and yellowish.
The food irradiation has been used as a treatment to ensure microbiological food safety of products to avoid infection. Its use combined with minimal processing could increase the safety and quality of minimally processed vegetables. We aimed at evaluating the effect of gamma radiation and electron beams to control bacteria; assess the physical characteristics through analysis of color and texture in peach palm in natura minimally processed and subjected to ionizing radiation stored at 8 deg C as well as evaluating the sensory characteristics.
The results in the microbiological analysis showed that ionizing radiation promotes reduction of microbial load in both treatments.
DENSITOMETRO HELIO PDF
Measurements conducted in the graphite pit of the Argonne Thermal Source Reactor have confirmed its ability to detect high-energy prompt fission gamma rays while discriminating against a significant flux of low-energy gamma rays from the decay of fission products. A normalisation for the four — detector system for gamma — gamma angular correlation studies. A procedure is proposed which excludes the. Therefore the difference between the intensity of X-ray transmitted through soft tissue and that of X-ray through soft tissue plus bone indicates amount of bone mineral deensitometro under the constant water thickness densiitometro. Development of multiphase meter using gamma densitometer concept.