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Sample records for da radiacao laser

  1. Effects of the low-intensity red laser radiation on the fluoride uptake in enamel. A clinical trial; Avaliacao dos efeitos da radiacao laser de emissao vermelha em baixa intensidade na incorporacao de fluor no esmalte. Estudo clinico

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    Nakasone, Regina Keiko

    2004-07-01

    Fluoride has been the most important preventive method on development of the caries. This in vivo study evaluated the effects of low-intensity red laser radiation on the fluoride uptake in enamel. Ten healthy participants were recruited for this study. The two maxillary central incisors of each volunteer to be biopsied were used and divided into 4 groups: group G{sub C} (control, which was untreated; group G{sub F} (fluoride), which received topical acidulated phosphate fluoride (APF) 1,23% treatment for 4 minutes; group G{sub LF} (laser + fluoride), which was irradiated with a low-intensity diode laser ({lambda}= 660 nm and dose= 6 J/cm{sup 2}) with APF application after irradiation and group G{sub FL} (fluoride + laser), which received APF before irradiation using the same parameters as G{sub LF}. The determination of fluoride was performed using a fluoride ion electrode after an acid-etch enamel biopsy. The results show a significant increase of the fluoride uptake in enamel for groups G{sub F}, G{sub LF} and G{sub FL} when compared to control group. Although a percentage increase of 57% was observed for G{sub LF} with respect to G{sub F}, there were no statistical differences among treated groups. These findings suggest that low-intensity laser radiation used before APF could be employed in the clinical practice to prevent dental caries. (author)

  2. Effects of the low-intensity laser therapy on the prevention of dental caries induced in rats; Efeitos da radiacao laser em baixa intensidade na prevencao de carie dental induzida em ratos

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    Mueller, Karin Praia

    2004-07-01

    The purpose of this study was to investigate the effects of low intensity laser therapy, associated or not to an acidulated phosphate fluoride, on the prevention of dental caries induced in rats. It was used 40 wistar rats, female, weaned with 18 days, fed with a cariogenic diet during 48 days and inoculated orally with Streptococcus mutans by three consecutive days starting from the second day of the diet. On the fifth day of experiment the animals were divided into five groups: G{sub c} (control) the animas were no submitted to any treatment; G{sub L} (laser) irradiation with low power laser (GaAlAs, {lambda}=660 nm, P=30 mW, {delta}t=5 sec, 5 J/cm{sup 2}); G{sub F} (fluoride) topical application of acidulated phosphate fluoride (APF 1,23%) for four minutes; G{sub LF} (laser + fluoride) irradiation with low power laser followed by topical application of acidulated phosphate fluoride; G{sub FL} (fluoride + laser) topical application of acidulated phosphate fluoride followed by low power laser. The animals were sacrificed after 48 days; the molars were extracted and prepared to determine the dental caries lesions area by optical microscopy, enamel microhardness and analysis of the calcium and phosphorus ratio (Ca/P) by energy dispersive spectroscopy. The results were statistically analyzed by ANOVA (plaser radiation associated with acidulated phosphate fluoride reduces the caries area and could be an alternative in the prevention of the dental caries. (author)

  3. Effects of low intensity laser radiation on osteointegration mechanism of implants: study 'in vivo'; Efeitos da radiacao laser em baixa intensidade no mecanismo de osseointegracao de implantes: estudo 'in vivo'

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    Blay, Alberto

    2001-07-01

    The purpose of this study is to determine whether the process of bone integration of implants placed in rabbit tibia is changed in any way if the region is radiated with laser, as compared to the time required for the bone integration process without radiation. Thirty adult male white New Zealand rabbits were submitted to implant surgery, for subsequent evaluation of the removal torque and resonance frequency. Each animal received two implants of pure titanium, one in each proximal metaphysics of the tibia, which were inserted with a 40 Ncm torque, and their initial stability was also monitored by means of a resonance frequency analyzer. The rabbits were then divided into 3 groups: one control group and two laser groups. The groups were evaluated in regard to removal torque and resonance frequency of the implants, after 3 and 6 weeks. One of the laser groups was radiated with a laser beam of a wavelength in the infrared range (830 nm) and the other group was radiated with a laser beam emitted in the visible range (680 nm). Ten radiation sessions were performed, 48 hours apart, the first of them during the immediate post-operation period. Radiation energy density was 4 J/cm{sup 2} per point, and there were two points at each side of the tibia. Results of the statistical analysis of the resonance frequency indicated that for both laser groups there was a significant difference between frequency values at the time of implant and the values obtained after 3 and 6 weeks. Furthermore, the results obtained for the removal torque of the three groups showed a statistically significant difference after a period of 6 weeks; removal torque values for the laser groups were, in the average, much greater than those of the control group. From these results it is possible to conclude that implants in rabbit tibia, that were exposed to laser radiation with wavelengths of 680 nm and 830 nm, had a better degree of bone integration than the control group.(author)

  4. Evaluation of the effect of low intensity laser radiation on the osseointegration of titanium implants inserted in rabbits' tibia; Avaliacao biomecanica da acao da radiacao laser em baixa intensidade no processo de osseointegracao de implantes de titanio inseridos em tibia de coelhos

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    Castilho Filho, Thyrso

    2003-07-01

    The purpose of this study was to evaluate the influence of low intensity laser irradiation on bone repair process after titanium implant surgeries performed in rabbits' tibia. Thirty three Norfolk rabbits were divided into three different groups according to the implant removal period (14, 21 and 42 days). Two titanium-pure implants were inserted one in each tibia and one side was randomly chosen to be irradiated. Irradiations were performed employing a GaAlAs laser ({lambda}=780 nm) during 10 seconds, with an energy density of 7.5 J/cm{sup 2} on 4 spots: above, bellow, on the right and on the left side of the implants with an interval between irradiations of 48 hours during 14 days. Animals were sacrificed according to the observation times, tibias were removed and the strength removal values recorded. Results showed that, for the 21 and 42 days sacrifices periods, the irradiated side presented a statistically higher implant strength removal values when compared to the non-irradiated side. (author)

  5. Evaluation of the effect of low intensity laser radiation on the osseointegration of titanium implants inserted in rabbits' tibia; Avaliacao biomecanica da acao da radiacao laser em baixa intensidade no processo de osseointegracao de implantes de titanio inseridos em tibia de coelhos

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    Castilho Filho, Thyrso

    2003-07-01

    The purpose of this study was to evaluate the influence of low intensity laser irradiation on bone repair process after titanium implant surgeries performed in rabbits' tibia. Thirty three Norfolk rabbits were divided into three different groups according to the implant removal period (14, 21 and 42 days). Two titanium-pure implants were inserted one in each tibia and one side was randomly chosen to be irradiated. Irradiations were performed employing a GaAlAs laser ({lambda}=780 nm) during 10 seconds, with an energy density of 7.5 J/cm{sup 2} on 4 spots: above, bellow, on the right and on the left side of the implants with an interval between irradiations of 48 hours during 14 days. Animals were sacrificed according to the observation times, tibias were removed and the strength removal values recorded. Results showed that, for the 21 and 42 days sacrifices periods, the irradiated side presented a statistically higher implant strength removal values when compared to the non-irradiated side. (author)

  6. A comparative study of the effect of low laser radiation on mast cells in inflammatory fibrous hyperplasia colored and not colored by the toluidine blue; Estudo comparativo do efeito da radiacao laser em baixa intensidade sobre mastocitos de hiperplasias fibrosas inflamatorias coradas e nao coradas por azul de toluidina

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    Sawazaki, Iris

    2001-07-01

    THIS STUDY SHOWS A COMPARATIVE ANALYSIS OF THE EFFECTS OF THE LASER RADIATION IN LOW INTENSITY ON THE MAST CELL DEGRANULATION IN INFLAMMATORY FIBROUS HYPERPLASIA WHEN THEY ARE COLORED OR NOT BY THE TOLUIDINE BLUE. THE DYE WAS USED IN ORDER TO INCREASE THE ABSORPTION OF THE LASER LIGHT BY THE TISSUE. THE INJURE WAS DIVIDED IN THREE EQUAL PARTS, AND EACH PART RECEIVED A DIFFERENT KIND OF TREATMENT. ONE OF THEM WAS REMOVED TO BE THE CONTROL, THE SECOND PART WAS LASER TREATED AND THEN IMMEDIATELY REMOVED AND THE LAST ONE, AFTER BEING SUPERFICIALLY COLORED, WAS LASER TREATED AND THEN IMMEDIATELY REMOVED . THE ORDER OF THE STAGES WAS RANDOMLY CHANGED , THEN THE TIME BETWEEN THE STAGES WOULD NOT INTERFERE IN THE STATISTICAL ANALYSIS OF THE MAST CELL DEGRANULATION RATES. IT WAS FOUND THAT THE MAST CELL DEGRANULATION RATES WERE 49% FOR THE CONTROL GROUP, 87% FOR THE LASER GROUP AND 88% FOR THE COLORED/LASER GROUP. THERE WAS NO SIGNIFICANT STATISTICAL DIFFERENCES BETWEEN THE GROUP LASER TREATED AND THE ONE COLORED/LASER TREATED. HOWEVER, THERE WAS A SIGNIFICANT DIFFERENCE BETWEEN THE CONTROL AND THE TREATED GROUP (PS {<=} 0,01). (AUTHOR)

  7. Effects of low-intensity GaAlAs laser radiation ({lambda}=660 nm) on dentine-pulp interface after class I cavity preparation; Efeitos da radiacao laser GaAlAs ({lambda}=660 nm) em baixa intensidade na interface dentina-polpa pos-preparo cavitario classe 1

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    Godoy, Bruno Miranda

    2003-07-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, {lambda}=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm{sup 2}, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  8. Mast cells behavior analysis: non mineralized wall of suprabony periodontal pockets submitted to low intensity laser radiation. (An in anima nobile study); Verificacao do comportamento de mastocitos na parede nao mineralizada da bolsa periodontal supra-ossea submetida a radiacao laser de baixa intensidade. (Estudo in anima nobile)

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    Silveira, Livio de Barros

    2001-07-01

    For this study 20 patients with periodontal disease were selected. The treatment required for all of then was the gingivectomy, a ressective periodontal surgery. This technique consists of removing the whole excess of gingival tissue with the intent of reestablishing the anatomy and the correct function. The gingival area was submitted to 2 different wavelengths and then histologically analysed to search for alterations, mainly concerning mast cells behavior, a blood cell responsible, among other things, for blood vases enlargement. During the surgical procedure each gingival area was submitted to infrared low intensity laser ({lambda} = 785 nm) or to red laser ({lambda} = 688 nm), both with 50 mW of power and fluence of 8 J/cm{sup 2}. A third area was analysed, the control area, in which no laser treatment was employed. The samples were fixated in formol, cut and stained by hematoxyline eosine and toluidine blue. Based on the result we can conclude: the 2 wavelengths used in this study led to the reduction in the number of mast cells present in the tissue as well as to the increase on the degranulation of the remaining mast cells, considered statistically significant taken the degranulation index and; there was no significant difference caused by the action of the two laser wavelengths {lambda}=785 nm and {lambda}=688 nm -50 mW of power and fluence of 8 J/cm{sup 2}-, over the degranulation of the mast cells; the length and width of the randomly chosen blood vases were not statistically different among the analysed groups. (author)

  9. Interaction of low-intensity linearly polarized laser radiation with living tissues: effects on tissular acceleration of skin wound healing; Interacao da radiacao laser linearmente polarizada de baixa intensidade com tecidos vivos: efeitos na acelaracao de cicatrizacao tissular em lesoes de pele

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    Ribeiro, Martha Simoes

    2000-07-01

    According to the Maxwell's equations to optical properties of surfaces, the energy deposition efficiency in a microroughness interface depends on the electrical field polarization component. Considering a linearly polarized beam, this efficiency will depend on the roughness parameters to p-polarized light and it will not depend on such parameters to s-polarized light. In this work it was investigated the effects of low-intensity, linearly polarized He-Ne laser beam on skin wounds healing, considering two orthogonal directions of polarization. We have considered a preferential axis as the animals' spinal column and we aligned the linear laser polarization first parallel, then perpendicular to this direction. Burns about 6 mm in diameter were created with liquid N{sub 2} on the back of the animals and the lesions were irradiated on days 3, 7, 10 and 14 post-wounding, D= 1,0 J/cm{sup 2}. Control lesions were not irradiated. The theoretical model consisted in describing linearly polarized light propagation in biological tissues using transport theory. The degree of polarization was measured in normal and pathological skin samples. It was verified that linearly polarized light can survive in the superficial layers of skin and it can be more preserved in skin under pathological condition when compared with health skin. The analysis of skin wound healing process has demonstrated that the relative direction of the laser polarization plays an important role on the wound healing process by light microscopy, transmission electron microscopy and radioautography. (author)

  10. Effects of the copper vapour laser radiation in the root canal wall dentine: in vitro experiment using scanning electron microscopy and stereoscopy; Efeitos da radiacao laser de vapor de cobre na parede de dentina de canais radiculares: estudo in vitro por meio de microscopia eletronica de varredura e microscopio estereoscopico

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    Silveira, Maria Claudia Garcia da

    2001-07-01

    Ten human uniradicular teeth had their crown removed along the cement-enamel junction and right away a proper chemical-surgical preparation of the radicular canals was done; the roots were longitudinally sectioned in order to allow the irradiation of the surfaces of the root canals wall dentine. The hemi-roots were separated in two groups: group I (control), with four hemi-roots, not irradiated; and group II, with 16 hemi-roots, subdivided in four sub-groups submitted to the following exposition time: 0,02 s; 0,05 s; 0,1 s and 0,5 s. A copper vapour laser was used with a 510,6 nm wavelength, total average power of 11 W in green and yellow emissions; average power of 6,5 W in green emission; pulse repetition rate of 16.000 Hz and pulse duration of 30 ns. The pulse energy (green line) is 0,4 mJ and the peak power 13,5 W. The laser cavity is unstable type (R{sub 1}=3.900 mm and R{sub 2}-250 mm). The focusing have focal length lens f{sub 1}=250 mm and f{sub 2}=150 mm. The beam quality is of the M{sup 2}=5. The results obtained by scanning electron microscopy analysis showed the appearance of a cavity in the region of the laser beam incidence in the edges of this cavity, dentin was melt and resolidified presenting also cracks due to heat diffusion. Based on these results, we concluded that the size of the cavity formed in the dentin is directly proportional to the rate of exposure and, the more laser emission in the same area, more damage in the root canals wall dentin occurs. More studies need to be done with different exposition's time in order to obtain a safety protocol that does not cause injury in dental and support tissue. (author)

  11. IL RILIEVO LASER 3D DA PIATTAFORMA AEREA IN ARCHEOLOGIA

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    Alessandro Sebastiani

    2012-04-01

    Full Text Available

    Partendo da un'analisi prettamente archeologica del sito dei templi dello Scoglietto, nella quale si delinea il contesto sul quale si è deciso di operare con metodo LiDAR-FW, si illustrerà questa tecnologia fornendo le linee della strategia di elaborazione della point-cloud di punti laser che sarà utilizzata nella fase di estrazione ed elaborazione del DTM del sito.

     

    LiDAR - Full Waveform

    The LiDAR-FullWaveform was applied to the archaeological site of the temples of Scoglietto (GR. Starting from a purely archaeologi-cal analysis, we decided to work with this technology and we will explain the methodology applied technology.

  12. Low power laser effects in cancer cells and fibroblasts submitted the ionizing radiation; Efeitos do laser de baixa potencia em celulas de linhagem tumoral e fibroblastos submetidos a radiacao ionizante

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    Silva, Camila Ramos

    2015-07-01

    Cancer is considered a public health problem worldwide. According to Brazil's the National Cancer Institute (INCA), 576,000 new cases of cancer were estimated for 2015 in Brazil, representing the second leading cause of death. Radiotherapy may be a treatment to several of types of cancer, frequently using ionizing radiation to eradicate or prevent the proliferation of tumor cells. This treatment, however, can lead to death of non-tumor cells around in irradiated tissue. Given this, adjuvant therapies that can minimize the side effects of ionizing radiation are of extremely importance. In this context, low power laser (LPL) may be an alternative to modulate the response of healthy cells to ionizing radiation. In this study, cells of human gingival fibroblasts (FMM1) and breast cancer (MDAMB- 231) were exposed to gamma radiation at doses of 2.5 and 10 Gy. After twenty-four hours, cell were irradiated with LPL ( λ= 660 nm, 40 mW and total area of 0.04 cm²) with energy densities of 30, 60, 90, 120 and 150 J/cm². The cell viability was measured during four days, using the trypan blue technique. The influence of LPL on the cell cycle and on expression of the nuclear antigen of cellular proliferation (PCNA) was evaluated by flow cytometry. The expression of β-Galactosidase was the chosen method to assess cell senescence. Considering our adopted parameters, and focusing on the non-tumor cells, we have observed an increase in: 1) cell viability; 2) cell population in phases S and G{sub 2}/M cell cycle; 3) PCNA expression with decrease in senescence. No alterations were observed in the cell viability, with greater population in phases S and G{sub 2}/M cell cycle, while the number of senescent cells and the expression of PCNA were decreased. Therefore, we have concluded that the LPL promoted effects on both cell lineages, with increased cell viability on FMM1 cells, whether cancer cells maintained a decreased proliferation. (author)

  13. Analgesia preemptiva com dipirona versus ibuprofeno na fotocoagulação a laser da retina

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    Artur Macaferri Del Santo

    2016-02-01

    Full Text Available RESUMO Objetivo: Comparar a efetividade da dipirona versus o ibuprofeno para a redução da dor na fotocoagulação da retina (FR. Método: Foi realizado um estudo controlado, duplo cego e randomizado englobando trinta e quatro pacientes com retinopatia diabética separados em dois grupos. Grupo A recebeu 1000mg de dipirona e o grupo B recebeu 600mg de ibuprofeno. A dor foi avaliada pela escala visual analógica. Resultado: A média do escore da dor nos grupos A e B foi de 5,2 ± 2.6 e 4,5 ± 1,4, respectivamente. Não houve diferença estatística entre os grupos (p=0,34. O mesmo foi observado quanto à analise entre dor leve, moderada e grave (p=0,09. Os grupos foram semelhantes quanto à idade e sexo. Conclusão: Os medicamentos foram equivalentes ou equipotentes em reduzir a dor ocular durante a fotocoagulação a laser da retina.

  14. EFICÁCIA CLÍNICA DO LASER ACUPUNTURAL NO TRATAMENTO DA DESORDEM TEMPOROMANDIBULAR

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    Diego Rodrigues Pessoa

    2016-12-01

    Full Text Available A disfunção temporomandibular (DTM é a condição mais frequente de dor orofacial crônica. A DTM é caracterizada pela a presença de sinais e sintomas na região orofacial. A acupuntura e Terapia a laser de baixa intensidade (TLBI vêm sendo empregadas no tratamento da DTM. A acupuntura consiste na inserção de agulhas em acupontos específicos do corpo para promover efeitos terapêuticos. A TLBI é uma modalidade de tratamento não invasiva, que vem sendo utilizada com frequência na prática clínica para o tratamento das DTM. Diante do exposto, o objetivo deste estudo foi realizar revisão de literatura, acerca da eficácia clinica do laser acupuntural em pacientes com a DTM. O emprego do laseracupuntural no tratamento das DTM favorece o controle antálgico, miorrelaxante e anti-inflamatório, no entanto, são necessárias novas pesquisas acerca do tema para determinar a eficácia do laser acupuntural em longo prazo para o tratamento de desordens temporomandibulares.

  15. Vaporização a laser do cervix para tratamento da neoplasia intraepitelial cervical

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    Euridice Maria de Almeida Figueiredo

    Full Text Available O câncer cérvico-uterino é muito comum em vários países da América Latina. As estatísticas de mortalidade e as taxas de incidência demonstram a sua real importância. O cânver cérvico-uterino freqüentemente é uma doença progressiva iniciada com mudanças intra-epiteliais, que podem se transformar em um processo invasivo, sendo o nosso objetivo tratar precocemente estas lesões quando ainda é possível a cura de 100%. Em nosso estudo prospectivo foram selecionadas 21 pacientes com neoplasia cervical intra-epitelial reatreadas pela citplogia e diagnosticadas pela histopatologia após biópsia dirigida pela colposcopia. O método terapêutico empregado foi a vaporização a laser com o CO2. Tiveram como pré-requisito os seguintes critérios: informação segura pela colposcopia da zona de transformação e afastar a presença de câncer invasivo; a neoplasia epitelial cervical deve ocupar a ectocervix sem nenhuma extensão para o canal cervical e correlação positiva entre a citologia, colposcopia e histologia. O uso de laser CO2 com microscópio permitiu precisão na aplicação e com vantagens de ser um procedimento ambulatorial diminuindo estresse cirúrgico das pacientes. Foi realizado sem anestesia e com duração média de 15 minutos. A cicatrização completou-se em torno de três semanas e com cuidados operatórios mínimos. Somente dois casos tiveram sangramento vaginal discreto no quinto e décimo dia de pós-operatório, resolvido com tamponamento vaginal por 24 horas. A colposcopia, cirurgia e o seguimento foram feitos pelo autor, tendo uma paciente sido submetida a uma segunda vaporização no quinto mês de controle. Somente uma paciente teve recidiva no 26° mês de seguimento e complementará o tratamento. As vinte outras restantes estão em controle sem recidiva de doença. Em vista dos resultados obtivemos um percentual de cura de 95%, que coincide com a literatura. O uso de laser CO2 no tratamento das neoplasias

  16. O EMPREGO DA TERAPIA LASER DE BAIXA INTENSIDADE NO TRATAMENTO DA HERPES-ZÓSTER E NEURALGIA PÓS-HERPÉTICA COM ACOMETIMENTO OROFACIAL

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    Davidson Ribeiro Costa

    2016-12-01

    Full Text Available O herpes-zóster facial é definido como uma doença infecciosa, que durante seu desenvolvimento apresenta lesões dolorosas na região orofacial. A Neuralgia pós-herpética é uma complicação da HZ facial que é caracteriza pela sintomatologia  dolorosa. A terapia com laser  de baixa intensidade (TLBI tem sido amplamente divulgada nos meios científicos, devido o seu efeito positivo  na redução da dor em uma série de condições. Nesse contexto, o presente estudo objetivou analisar os principais efeitos da TLBI, com base na literatura, de forma a apresentar uma terapia alternativa, que pode ser empregada no tratamento da HZ facial e NPHT, salientando as doses e os possíveis locais para a irradiação em cada fase. A TLBI é uma terapia não invasiva, que não apresenta efeitos adversos, quando empregada de maneira correta. Essa terapia apresenta efeitos anti-álgico, anti-inflamatório, de reparo tecidual e neuronal, o que justifica a sua utilização no tratamento da HZ facial e NPHT.

  17. Efficacy and safety of green laser photocoagulation for threshold retinopathy of prematurity Eficácia e segurança da fotocoagulação com laser verde na retinopatia da prematuridade limiar

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    Rodrigo Pessoa Cavalcanti Lira

    2008-02-01

    Full Text Available PURPOSE: To report the efficacy and safety of green laser photocoagulation for threshold retinopathy of prematurity (ROP. METHODS: We reviewed the clinical records of the neonates who had undergone green laser photocoagulation for threshold ROP at the Federal University of Pernambuco in Brazil between January 2004 and January 2006. All procedures were conducted with local anesthetic drops. The neonates were monitored throughout the procedure by a neonatologist. A frequency-doubled solid state laser, diode-pumped, with 532 nm wavelength was used. The presence of tunica vasculosa lentis or cataract were excluded before laser treatment. The following preoperative data were obtained for each patient: age, birth weight and the grade of ROP. Postoperative data included complications associated with the laser treatment, grade of ROP and evaluation whether further surgery was necessary due to failure of laser photocoagulation. RESULTS: Twenty-two neonates underwent photocoagulation with green laser for threshold ROP. A total of 31 eyes were included in the study. The mean gestational age was 30 ± 3 weeks and the mean birth weight was 1120 ± 490 g. Regression of the disease after laser therapy was observed in 30 eyes (96.7%. Despite treatment one eye presented stage 4A. Only 7 eyes required repetitive laser therapy. No adverse effects such as burning anterior segment tissues or bleeding in the anterior chamber occurred. No posterior segment side-effects were observed. Cataract formation was not observed at the last follow-up examination. CONCLUSIONS: Green laser photocoagulation remains an effective and safe alternative to red laser photocoagulation and to cryotherapy in the treatment of threshold ROP.OBJETIVOS: Avaliar a eficácia e segurança da fotocoagulação com laser verde na retinopatia da prematuridade (ROP limiar. MÉTODOS: Foram revisados prontuários dos neonatos submetidos à fotocoagulação com laser verde para ROP limiar, na

  18. EFEITOS DA TERAPIA LASER DE BAIXA INTENSIDADE EM MODELO EXPERIMENTAL DE TENDINOPATIA EM RATOS: REVISÃO DE LITERATURA

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    Diego Rodrigues Pessoa

    2017-12-01

    Full Text Available Tendinopatia é o termo utilizado para descrever lesões que afetam os tendões (tendinites e tendinoses, caracterizada pela presença de inflamação e degeneração tecidual, associada à sobrecarga mecânica e a movimentos repetitivos. Diversas modalidades terapêuticas têm sido estudadas no tratamento das tendinopatias, entre elas, destaca-se a terapia a laser de baixa intensidade (TLBI que visa acelerar o processo regenerativo, diminuir a inflamação e reduzir a dor.  Diante do exposto, este trabalho teve como objetivo realizar revisão de literatura, de artigos científicos com foco nos efeitos da terapia a laser de baixa intensidade (TLBI, em modelo experimental de tendinopatia em ratos. O estudo baseou-se na investigação de publicações entre janeiro de 2011 a outubro de 2016, em bases de dados eletrônicas com o emprego dos descritores “tendinopatia”, “laserterapia”, “ratos”, “tendão” e “terapia a laser de baixa intensidade”, combinados aos descritores booleanos. Foram selecionados sete artigos que apontam que a TLBI possibilitou a redução de importantes marcadores pró-inflamatórios, tais como IL-6 e TNF-α, bem como a proliferação aumentada de tenócitos, independentemente da dosagem aplicada. Os estudos científicos selecionados nesta revisão sistemática sinalizaram efeitos positivos da TLBI, principalmente na modulação da resposta inflamatória aguda ou crônica após a indução da tendinopatia.

  19. O emprego do laser de CO2 no controle da cárie dentária = The use of CO2 laser on dental on dental caries control

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    Rodrigues, Lidiany Karla Azevedo

    2007-01-01

    Full Text Available O laser de dióxido de carbono atua na inibição da desmineralização do esmalte, reduzindo sua solubilidade aos ácidos e, este efeito pode ser potencializado quando associado a agentes fluoretados. Assim, o objetivo deste trabalho foi descrever as características do laser de CO2, discutir os mecanismos de ação do laser na inibição da desmineralização do esmalte e ainda, revisar a literatura a respeito de seus efeitos quando combinado ao íon flúor

  20. Evaluation of the ocular protection for low intensity therapeutic lasers; Avaliacao da protecao ocular para lasers terapeuticos em baixa intensidade

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    Cordon, Rosely

    2003-07-01

    The low intensity laser therapy (LILT) has been extensively used in medicine and dentistry presenting positive effects. However, the laser radiation can also cause adverse effects. Due to the ocular focalization property, in the wavelength from 400 to 1400 nm, the retina is more susceptible to damage by radiation than any other part of the human body. Then, the ocular protection is frequently emphasized. This protection must attenuate the radiation to a safe level. The International Electrotechnical Commission (IEC) standard IEC 60825-1 suggests safety requirements for medical laser equipment, including the ocular protection, based on maximum permissible exposure levels. The Brazilian legislation adopts a corresponding IEC standard, the NBR IEC 601.2.22, for safety requirements. The aim of this study was to analyze the adequacy of the ocular protectors furnished by four laser equipment manufacturers, commercially available in Brazil, commonly used for LILT. For this purpose, the laser equipment and the respective ocular protectors were characterized. The adequacy was verified according to the IEC standards. It was found, among other results, ocular protectors attenuating to safe levels the radiation emitted by the respective laser equipment, however, presenting inadequate visual transmission. Inefficient protection and protection indicated in cases where they were not necessary were also observed. (author)

  1. Biomecânica da córnea após laser de femtossegundo na cirurgia de catarata

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    Bruno Freitas Valbon

    2015-10-01

    Full Text Available RESUMO Objetivo: Avaliar as alterações da biomecânica da córnea após laser de femtosegundo na cirurgia de catarata e comparar os parâmetros biomecânicos derivados do Corvis ST (Oculus Corvis ST, Scheimpflug Technology; Wetzlar, Germany entre as técnicas do laser de femtossegundo e a facoemulsificação convencional após a cirurgia de catarata. Métodos: Estudo observacional, prospectivo envolvendo 151 olhos de 127 pacientes com diagnóstico de catarata nuclear. Setenta olhos de 65 pacientes foram submetidos à técnica do laser de femtossegundo (Alcon LenSx, Aliso Viejo,USA e 76 olhos de 62 pacientes por meio da facoemulsificação convencional (Alcon Infinit, Fort Worth, USA. O sistema de tonometria de não contato integrado com a câmera ultrarrápida de Scheimpflug (Oculus Corvis ST, Scheimpflug Technology; Wetzlar, Germany foi utilizado para avaliação da biomecânica da córnea antes e após a cirurgia de catarata pelas técnicas do laser de femtossegundo e a facoemulsificação convencional. Os parâmetros biomecânicos utilizados foram: deformidade de amplitude (DA, pressão intraocular, 1st A time, tempo de concavidade máxima, 2nd A time, 1st A Length, 2nd A Length, raio de curvatura de maior alcance, raio de curvatura normal, velocidade de entrada (Vin e de saída (Vout. A densitometria do cristalino (scattering através do PNS (Pentacam Nucleus Staging foi realizado pela tomografia de córnea e segmento anterior (Pentacam® – Oculus, Wetzlar, Germany em todos os pacientes para diagnóstico objetivo da opacidade do cristalino. Os critérios de exclusão foram: doença corneana, doenças da retina e/ou nervo óptico e cirurgia ocular prévia. O teste de Kolmogorov-Smirnov foi utilizado para avaliar a distribuição normal. O teste de Wilcoxon e o test-T foram utilizados para avaliação entre o pré-operatório e o primeiro dia de pós-operatório (D1 nos grupos do laser de femtossegundo (LFS e do faco convencional (FC

  2. Retinopatia da prematuridade: achados refrativos pós-tratamento com crioterapia ou laser Retinopathy of prematurity: refractive errors in patients treated with cryotherapy or laser

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    Sara Pozzi

    2000-10-01

    Full Text Available Objetivos: Determinar e comparar as características refrativas de uma população composta de crianças pré-termo com retinopatia da prematuridade que necessitaram de tratamento com crioterapia ou laserterapia. Método: Análise dos resultados da refração estática de 14 pacientes (de um total de 761 fichas de crianças que nasceram no Hospital São Paulo da Universidade Federal de São Paulo - Escola Paulista de Medicina, entre janeiro de 1988 e abril de 1998, que completaram um ano de idade e que apresentaram Retinopatia da Prematuridade grau 3 com características de "doença limiar" sendo tratadas com crioterapia ou laserterapia. Foram utilizados os testes estatísticos de Wilcoxon e Mann-Whitney para a avaliação dos resultados. Resultados: 64,3% dos pacientes apresentaram miopia. No grupo de pacientes que receberam tratamento com crioterapia, 80% mostrou miopia, que em todos os casos foi alta; 20% hipermetropia leve, com uma média para o equivalente esférico de --3,10 D no olho direito e --3,25 D no olho esquerdo (diferença entre ambos os olhos estatísticamente não significante. No grupo de laserterapia, 55,6% mostrou miopia, sendo 20 % dos casos miopia alta e 80% miopia leve; 11,1% apresentou-se sem ametropia e 33,3 % com hipermetropia leve. O valor da média para o equivalente esférico foi --0,58 D no olho direito e --0,83D no olho esquerdo (diferença entre ambos os olhos estatisticamente significante. A comparação dos resultados refracionais dos dois grupos mostrou uma maior incidência para miopia alta no grupo de pacientes que receberam tratamento com crioterapia (PPurpose: To examine the spherical equivalent of refractive errors in preterm children with threshold retinopathy of prematurity treated with cryotherapy or laser. Patients and Method: A group of 14 one-year-old children (selected from 761 preterm children born at the Hospital São Paulo of the Universidade Federal de São Paulo between 1988 and 1998 with stage

  3. Evaluation of the morphological alteration of the root surface radiated with a diode laser; Avaliacao da alteracao morfologica da superficie cimentaria irradiada com laser de diodo

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    Gulin, Mauricio

    2003-07-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of the

  4. Evaluation of the morphological alteration of the root surface radiated with a diode laser; Avaliacao da alteracao morfologica da superficie cimentaria irradiada com laser de diodo

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, Mauricio

    2003-07-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of

  5. Activity evaluation from different native or irradiated with {sup 60} Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis; Avaliacao da atividade de diferentes venenos de serpentes, nativos ou irradiados, com radiacao gama de {sup 60} Co, quanto ao poder inibitorio do crescimento de Leishmania (Leishmania) amazonensis

    Energy Technology Data Exchange (ETDEWEB)

    Lourenco, Cecilia de Oliveira

    2000-07-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK{sub 2} mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of {sup 60}Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  6. Análise quantitativa da camada de fibras nervosas da retina de cães normais e glaucomatosos através da polarimetria a laser

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    Ana Lucia Braga Martins

    2003-01-01

    Full Text Available As lesões glaucomatosas são progressivas e irreversíveis. Estudos sobre o aparecimento e comportamento desta enfermidade vêm sendo discutidos na oftalmologia em geral. O diagnóstico precoce é de extrema importância para o tratamento e estabilização da mesma. A análise da espessura da camada de fibras nervosas retinianas ''in vivo'' foi proposta na oftalmologia humana, para estabelecer as alterações produzidas pelo glaucoma, e tem demonstrado que tais alterações podem ser detectadas até seis anos antes de alterações de campo visual e aumento de pressão intraocular. Entretanto, na Medicina Veterinária, estes dados carecem de estudo e discussão. Neste experimento foram utilizados dois grupos de cães, com olhos normais e olhos glaucomatosos, que foram submetidos à análise das fibras nervosas retinianas através do Analisador de Fibras Nervosas GDx. Os resultados estatísticos demonstraram que a camada de fibras nervosas dos olhos dos cães glaucomatosos estava mais delgada (p < 0,05 quando comparados aos olhos de cães normais, confirmando a perda de axônios das células ganglionares em olhos de cães com glaucoma.

  7. Evaluation of the permeability of the furcation area of deciduous molars conditioned with Er:YAG laser and cyanoacrylate Avaliação da permeabilidade da região da furca de molares decíduos condicionada com laser de Er:YAG e cianoacrilatos

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    Adriene Mara Souza Lopes-Silva

    2003-09-01

    Full Text Available The purpose of this study was to evaluate in vitro the dentin permeability of the deciduous pulp chamber floor after employing 2-octyl cyanoacrylate and Er:YAG laser. Twenty four deciduous molars were used, divided into four groups. After chemical-surgical preparation each group received a different treatment: Group 1 - control, without treatment; Group 2 - the floor of the pulp chamber was covered with a fine layer of 2-octyl cyanoacrylate; Group 3 - the floor of the pulp chamber was irradiated with Er:YAG laser (250 mJ, 10 Hz for 30 seconds, 80 J of energy and 320 pulses, and covered with a fine layer of 2-octyl cyanoacrylate; and Group 4 - the floor of the pulp chamber was irradiated with Er:YAG laser set at the parameters already described. After that the specimens received application of 0.5% methylene blue, for 15 minutes. The teeth were cut, photographed, and the digitalized images were analyzed using the ImageLab program. The results obtained were submitted to statistical analysis. Group 4 (Er:YAG presented the largest averages in percentage of dye penetration area (19.5%, followed by Group 1 (11.1%, Group 3 (1.4% and Group 2 (0.2%. The experimental model allowed to conclude that the specimens conditioned with 2-octyl cyanoacrylate (Group 2 and Er:YAG laser associated to 2-octyl cyanoacrylate (Group 3 presented a decrease in permeability, and the specimens treated with Er:YAG laser (Group 4 presented an increase in permeability of the analyzed area.A proposta do presente experimento foi avaliar in vitro a permeabilidade da dentina no assoalho da câmara pulpar de dentes decíduos com o emprego do 2-octil cianoacrilato e laser de Er:YAG. Foram empregados 24 molares decíduos, divididos em quatro grupos. Após preparo químico-cirúrgico, cada grupo recebeu um tratamento diferente: Grupo 1 - controle, sem tratamento; Grupo 2 - o assoalho da câmara pulpar foi coberto com uma fina camada de 2-octil cianoacrilato; Grupo 3 - o assoalho da c

  8. Influência da redução medicamentosa da pressão intra-ocular na medida da espessura da camada de fibras nervosas da retina de olhos hipertensos e glaucomatosos pela polarimetria de varredura a laser The influence of intraocular pressure reduction with medication on retinal nerve fiber layer thickness measurements obtained with scanning laser polarimetry in glaucomatous and hypertensive eyes

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    Rodrigo Rezende Gomes Avelino

    2006-10-01

    Full Text Available OBJETIVO: Avaliar o efeito da redução da pressão intra-ocular (PIO obtido com o uso de terapia medicamentosa na espessura da camada de fibras nervosas da retina medida pela polarimetria de varredura a laser (PVL em pacientes glaucomatosos ou hipertensos oculares. MÉTODOS: Trinta e sete olhos de 37 pacientes foram prospectivamente incluídos no estudo e avaliados com a PVL sem uso de medicação ocular hipotensora e num período entre 15 e 30 dias após a instituição de medicação ocular hipotensora, que resultou em redução da PIO de pelo menos 25%. Os parâmetros medidos pela PVL antes e após a redução da PIO foram comparados com o teste t de Student pareado. RESULTADOS: A PIO média dos 37 pacientes diminuiu significativamente de 26,57±4,23 mmHg para 16,54±2,92 mmHg (p0,05. CONCLUSÃO: A redução da PIO com o uso de medicação ocular hipotensora não altera a medida da espessura da camada de fibras nervosas da retina pela PVL em pacientes com glaucoma ou hipertensão ocular.PURPOSE: To evaluate changes in retinal nerve fiber layer thickness as measured by scanning laser polarimetry (SLP after the use of medication to reduce intraocular pressure (IOP in glaucomatous or ocular hypertensive patients. METHODS: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student's t Test. RESULTS: The mean IOP was significantly reduced from 26.57±4.23 mmHg to 16.54 ±2.92 mmHg after the use of medication (p0.05. CONCLUSION: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension.

  9. Laser for the treatment of twin to twin transfusion syndrome Laser na terapia da síndrome de transfusão feto-fetal

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    Denise Araújo Lapa Pedreira

    2005-12-01

    Full Text Available PURPOSE: To report the initial experience in our country with a new technique for twin to twin transfusion syndrome (TTTS treatment, using laser to coagulate the placental vessels responsible for the twin transfusion during gestation. METHODS: Prospective study of eight cases diagnosed with TTTS evaluated in our service from january 2001 to june 2005. Through percutaneous introduction of a 2,0mm diameter fetoscope in the uterine cavity, placental surface vessels where directly visualized. Those identified as responsible for the transfusion were laser coagulated. The procedure combines ultrasonography and fetoscopy, in a so-called sonoendoscopic technique (FETENDO. RESULTS: Among the eight pregnancies evaluated, five cases were submitted to the procedure (10 fetuses. All fetuses survived for at least five weeks after surgery. A total of eight fetuses were born alive and five survived the neonatal period. In a 18 months follow-up after birth, all five are still alive and well and their mean age is now 10,6 months. The total survival rate was 50% and in three pregnancies, at least one fetus survived. CONCLUSIONS: Laser fetoscopy is actually the "gold-standard" treatment of TTTS. Nevertheless is a sophisticated technique that epends of proper training. Our service is the first in our country to offer this therapeutic technique. Our success rate is comparable with the international literature.OBJETIVO: Nosso objetivo é relatar a experiência inicial no país com uma nova técnica de tratamento para a síndrome de transfusão feto-fetal (STT, onde se utiliza o raio laser para coagulação dos vasos placentários responsáveis pela transfusão entre gêmeos durante a gravidez. MÉTODOS: Estudo prospectivo de 8 casos com diagnóstico de STT avaliados pelo nosso serviço de janeiro de 2001 a junho de 2005. Introduzindo-se um fetoscópio de 2,0 mm de diâmetro na cavidade uterina, por via percutânea, foram diretamente visualizados os vasos da superf

  10. Influence of the incidence angle on the morphology of enamel and dentin under Er:YAG laser irradiation; Estudo da influencia da angulacao do feixe laser na morfologia de esmalte e dentina irradiados com laser de Er:YAG

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    Junqueira Junior, Duilio Naves

    2002-07-01

    The purpose of this study is to make an in vitro evaluation, using scanning electron microscopy, of the influence of the laser beam irradiation angle on the enamel and dentin morphology. These tissues were both irradiated by Er:YAG Laser, with the same energy parameter. Twenty-four incisive bovine teeth were used, separated in eight groups, four of enamel, and four of dentin, with three specimens in each group. Each specimen was submitted to three laser applications, varying the incidence angle, between the laser and the tooth surface, at 90, 50 and 20 degrees. The applied frequency was 2 Hz, with 20 pulses in each application. The KaVo Key Laser 3 was employed, wavelength at 2940 nm, adjustable energy from 40 to 600 mJ and repetition rate from 1 to 25 Hz. The groups were distributed according to the energy parameter as follows - enamel: 250 mJ; 300 mJ; 350 mJ and 400 mJ; dentin: 200 mJ; 250 mJ; 300 mJ and 350 mJ. The results evidenced the Laser incidence angle importance; it is an essential parameter in the protocol of utilization and it should not be disregarded. The observations of this study allow to conclude that the Laser incidence angle has direct influence on the morphological aspect of the alterations produced in enamel and dentin. (author)

  11. Estudo experimental da aplicação retiniana do laser infravermelho via transescleral sob condições de baixa visibilidade Transscleral infrared laser retinal photocoagulation experimental study under low visibility conditions

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    Dario Grechi Goulart

    2008-06-01

    Full Text Available OBJETIVOS: Pesquisa experimental, com laser de diodo infravermelho, para estimar a segurança, a reprodutibilidade e a permeabilidade da parede ocular à sua atuação clínica, quando aplicado via transescleral, em condições de baixa visibilidade. MÉTODOS: Submetemos olhos de coelhos pigmentados da raça Nova Zelândia à fotocoagulação retiniana por laser de diodo infravermelho. No olho direito, realizamos fotocoagulação via transescleral sob parâmetros de potência e tempo pré-determinados clinicamente. No olho esquerdo, foram repetidos os mesmos valores da potência e tempo usados no olho direito, desta vez, via transpupilar. Imediatamente e após 2 meses, estudos clínicos baseados na retinografia e histopatológicos foram realizados. RESULTADOS: A permeabilidade da parede ocular, quando da aplicação do laser de diodo infravermelho via transescleral, variou entre 58,95 e 63,87%. A média da permeabilidade da parede ocular a 300 mW (63,14% mostrou-se significativamente superior àquela da permeabilidade da parede ocular encontrada a 500 mW (59,11%, (PPURPOSE: Retinal photocoagulation under poor visualization condition is often required. Transscleral infrared laser can be used as an alternative to regular transpupillary treatment. Based upon retinographic measurements, we proposed to estimate the reproducibility as well as ocular wall permeability rate for this treatment. Our primary goal was to evaluate whether this technique can deliver adequate photocoagulation at predetermined parameters without direct retinal visualization. METHODS: In New Zealand pigmented rabbits, optimal transscleral infrared diode laser settings were administered to the right eye. With the same parameters, transpupillary photocoagulation was repeated in the left eye. Retinographic and clinical examinations were performed immediately and two months later. RESULTS: Ocular wall permeability rate varied between 58.95 and 63.87%. Average permeability using a

  12. Regulation of use of radiation for quarantine purposes; Regulamentacao do uso da radiacao para fins quarentenarios

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    Itepan, Natanael Marcio, E-mail: natanael.itepan@unianhanguera.edu.b [Faculdade Anhanguera, Piracicaba, SP (Brazil); Costa, Neivaldo; Furlan, Gilberto Ribeiro; Walder, Julio Marcos Melges, E-mail: neivaldo@cena.usp.b, E-mail: gilfurlan@cena.usp.b, E-mail: jmwalder@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2011-07-01

    The main aspects of Instruction No. 9 are: a) the nuclear plant that use ionizing radiation as a phyto sanitary treatment for quarantine purposes, must be accredited by the agency of the Agriculture, Livestock and Supply Ministry (MAPA) and the licensing by the Nuclear Energy National Commission (CNEN) and other regulatory bodies, b) control of the applied dose will follow a standard operating procedure should be performed by independent organization, authorized by the Brazilian ONPF (Phyto sanitary Protection National Organization), c) the unit of radiation treatment should ensure traceability and must maintain records of phyto sanitary treatments, d) there should be bilateral work plan between the ONPF of Brazil and other countries for the established radiation treatment protocol. The ONPF of Brazil is the Sanitary Vegetarian Department. Ionizing radiation (cold pasteurization) is shown in an alternative technology to phyto sanitary control for quarantine purposes. (author)

  13. Structural aspects of crotoxin modified by ionizing radiation; Aspectos estruturais da crotoxina modificada pela radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Karina Corleto de; Albero, Felipe Guimaraes; Zezell, Denise Maria; Spencer, Patrick Jack; Nascimento, Nanci do, E-mail: kcorleto@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-03-15

    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 2.0 kGy ({sup 60}Co source). 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. (author)

  14. Gamma radiation effects on polycarbonate-Durolon; A interacao da radiacao gama com o policarbonato Durolon

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Adelina

    1996-12-31

    In this work, the commercial polycarbonate-Durolon, was characterized through measurements of its mechanical, optical viscosimetric and thermal properties, after being irradiated with a {sup 60} Co gamma-source at IPEN-CNEN/SP. These irradiations were carried out different doses and dose rates in air and in vacuum. From the results obtained it was shown that irradiation causes degradation in PC mainly by chain scission, leading to the formation of phenoxy and phenyl radicals which are associated with the yellowness of the material. Both, the concentration of radicals and yellowness of PC increase with the irradiation doses and dose rates. The irradiated PC-Durolon shown a good mechanical stability up to the doses analyzed, but on the other hand, its optical properties do not have the same performance. The viscosity and glass transition temperature of the Durolon decreases with the increase of dose and dose rates. This behavior indicates that main chain scission is the predominant process during irradiation. Furthermore in PC this degradation is higher when the material is irradiated in air, which shows that oxygen also plays an important role in this degradation process. (author). 37 refs., 30 figs., 4 tabs.

  15. Models in the estimate of the diffuse solar radiation; Modelos de estimativa da radiacao solar difusa

    Energy Technology Data Exchange (ETDEWEB)

    Recieri, Reinaldo Prandini; Ferruzzi, Yuri; Silva, Suedemio de Lima [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Mestrado em Engenharia Agricola; Quallio, Silvana [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Biologia; Batista, Vitor Roberto Lourenco [Universidade Estadual do Oeste do Parana (UNIOESTE/FAG), Cascavel, PR (Brazil). Curso de Graduacao em Engenharia Eletrica

    2004-07-01

    In this work we evaluate, by means of polynomial regression analysis, several models that relate the diffuse fraction of the global radiation (K{sub d}) with the clearness index (K{sub t}). The experiment was conducted in the Solar Radiometry Station of Cascavel/PR from the first of January to the 31st of December, in the year of 2001. The solar radiation components were monitored by the following manufactured instruments: pyranometer (KIPP and ZONEN CM3) and pirheliometer (EPPLEY NIP) connected in a sun tracker (ST-1 model). A datalogger CR10X from the CAMPBELL SCIENTIFIC was used in the data acquisition. This datalogger was programmed in the frequency of 1 Hz storing an average of 5 minutes of collected data. Among the equations the best values of RMSE an MBE were find in the fourth and third degrees, respectively. We also find that the fourth degree polynomial equation (K{sub d}=1,172-1,001K{sub t}+3,992K{sub t}{sup 2}-11,742K{sub t}{sup 3}+7,698K{sub t}{sup 4}) generalizes the utilization of equations for diffuse solar radiation estimation. This means that this equation probably can be applied for any place and climatic conditions. (author)

  16. Influence of ionizing radiation on Trypanosoma cruzi; Influencia da radiacao ionizante sobre o Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Szarota, Rosa Maria

    2006-07-01

    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. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system. (author)

  17. Influence of ionizing radiation on Trypanosoma cruzi; Influencia da radiacao ionizante sobre o Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Szarota, Rosa Maria

    2006-07-01

    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. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system. (author)

  18. Análise da dose do laser de baixa potência em equipamentos nacionais Analysis of low-level laser therapy doses in Brazilian equipment

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    TY Fukuda

    2008-02-01

    Full Text Available CONTEXTUALIZAÇÃO: A laserterapia de baixa potência vem sendo cada vez mais utilizada, e o crescente interesse por seus efeitos relaciona-se com a grande quantidade de publicações científicas. Muitos terapeutas e pesquisadores têm-se baseado na definição da dose do laser pela densidade energética (deltaE; porém, a grande variedade de equipamentos de laser pode levar a diferença nos resultados terapêuticos encontrados, por fornecerem parâmetros que variam de acordo com o fabricante. OBJETIVO: Analisar a energia final transmitida ao tecido ao aplicar-se a mesma deltaE em equipamentos de diferentes marcas nacionais. MATERIAIS E MÉTODOS: Foram avaliados sete equipamentos nacionais, com potência média (Pm diferentes, e foram realizadas simulações aplicando deltaE de 1J/cm² em cada aparelho, para avaliar possíveis diferenças na energia final. RESULTADOS: A mesmadeltaE aplicada em diferentes aparelhos nacionais forneceu energia final que variou entre 10 e 90mJ. Esta variação na energia deveu-se principalmente a diferenças na Pm, sendo encontrados valores entre 5,4 e 75mW. CONCLUSÃO: Esta variabilidade na energia final, que é transmitida ao tecido, indica que a deltaE parece não ser o parâmetro que melhor descreve a dose a ser utilizada. É preciso mencionar não só a deltaE, mas também a energia final, para que se possa estabelecer a dose para obtenção do melhor resultado terapêutico.INTRODUCTION: Low-level laser therapy is becoming more popular and there is a growing interest in its effects, as reflected in the increased number of articles published about the subject. Many therapists and researchers have used a laser dose definition based on energy density (deltaE. However, the variety of laser equipments may lead to differences in the therapeutic results found, since the parameters supplied by these equipments vary according to the manufacturer. OBJECTIVE: To analyze the final energy transmitted to the tissue when

  19. Efeito da Convecção no Humor Vítreo Sobre o Dano Térmico de um Melonoma de Coroide Durante Teremoterapia Transpupilar a Laser

    OpenAIRE

    Garcia, Olga Pinheira

    2015-01-01

    O estudo da distribuição de temperaturas no olho humano é capaz de fornecer subsídios para tratamentos hipertérmicos e para o cálculo dos danos causados pela exposição à radiação de uma fonte de laser. Um exemplo é a termoterapia transpupilar a laser (TTT), aplicada no tratamento de um melanoma de coroide. Neste trabalho, foi desenvolvido, através do software comercial SolidWorks®, um modelo tridimensional do olho humano portador de um melanoma de coroide, utilizado para simula...

  20. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  1. Conhecimento das propriedades físicas e da interação do laser com os tecidos biológicos na odontologia Knowledge of the physical properties and interaction of laser with biological tissue in dentistry

    Directory of Open Access Journals (Sweden)

    Thiago Maciel Cavalcanti

    2011-10-01

    Full Text Available A tendência da odontologia é a incorporação de métodos menos invasivos com a finalidade de minimizar a dor e o desconforto durante e após as intervenções odontológicas. Por isso, acredita-se que a laserterapia seja uma excelente opção de tratamento, já que apresenta efeitos benéficos para os tecidos irradiados, como ativação da microcirculação, produção de novos capilares, efeitos anti-inflamatórios e analgésicos, além de estímulo ao crescimento e à regeneração celular. O entendimento da interação entre os lasers e os tecidos baseia-se principalmente no entendimento das reações que podem ser induzidas nesses tecidos pela luz laser. Este trabalho se propõe a mostrar a relevância do conhecimento das propriedades físicas do laser, bem como sua interação com os tecidos biológicos, considerando que os efeitos e os mecanismos de ação da luz laser são complexos e alvos de inúmeras pesquisas com vistas a um melhor delineamento de suas formas de aplicação e indicações.The trend in dentistry is to incorporate less invasive methods to minimize pain and discomfort during and after dental intervention. Therefore, it is believed that laser therapy is an excellent treatment option, since it has beneficial effects for the irradiated tissues, such as activation of microcirculation, production of new capillaries, inflammatory and analgesic effects, in addition to stimulation of growth and cell regeneration. The comprehension of the interaction between lasers and tissue is based mainly on understanding the reactions that can be induced in those tissues by laser. This work intends to show how important it is to know the physical properties of laser as well as its interactions with biological tissues, since its effects and mechanisms of action are complex and are the object of various studies to better understand its forms of application and indications.

  2. Efetividade da fluorescência a laser no diagnóstico de lesões de cárie. Estudos in vitro e in vivo

    OpenAIRE

    Diniz, Michele Baffi [UNESP

    2006-01-01

    O objetivo do presente estudo foi avaliar a efetividade da fluorescência a laser (KaVo DIAGNOdent) para a determinação da severidade de lesões de cárie oclusal em dentes permanentes in vivo e para determinação da remineralização in vitro de lesões de cárie induzidas artificialmente em esmalte de dentes bovinos. No estudo in vitro, 78 blocos de esmalte com lesões de cárie artificial (mancha branca) com valores de dureza Vickers de 38,48 l 0,85 foram submetidos ao tratamento com dentifrício flu...

  3. Reprodutibilidade do exame de medida da camada de fibras nervosas da retina por meio da polarimetria de varredura a laser Reproducibility of retinal nerve fiber layer measurement by scanning laser polarimetry

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    Fernanda Bon Duarte

    1999-10-01

    Full Text Available Objetivo: Analisar a reprodutibilidade das medidas da espessura da camada de fibras nervosas da retina intra e inter-observador. Material e Métodos: As medidas da camada de fibras nervosas foram realizadas em 26 olhos normais por três examinadores diferentes, os quais tomaram três imagens de cada olho. Com base nestas imagens foi executada a média das imagens pelo programa do aparelho. A cada examinador foi solicitado que escolhesse a melhor imagem para cada exame. Foram analisados os resultados obtidos com a melhor imagem, bem como os da média das imagens. Foi calculada a média da espessura da camada de fibras nervosas nas regiões superior, nasal, temporal e inferior e suas relações. Determinou-se a reprodutibilidade nestas circunstâncias tanto inter como intra-observador por meio de teste de análise de variância por postos de Friedman. Resultados: Na análise intra-observador houve ótima reprodutibilidade do exame. Para o examinador G (glaucomatólogo os valores de p foram os seguintes: região superior = 0,48; inferior = 0,89; temporal = 0,30 e nasal = 0,89. Para o examinador R (residente os valores de p foram os seguintes: região superior = 0,89; inferior = 0,24; temporal = 0,89 e nasal = 0,30 e para o examinador T (tecnóloga os valores de p foram os seguintes: região superior = 0,76; inferior = 0,70; temporal = 0,22 e nasal = 0,63. Na análise inter-observador, não foi observada diferença estatisticamente significante das variáveis isoladas considerando-se a média das imagens (p superior = 0,52; inferior = 0,37; temporal = 0,43 e nasal = 0,52. Considerando-se as relações entre as regiões temos que apenas a relação S/I mostrou diferença estatisticamente significante. As demais relações: S/T, S/N, I/T, I/N e T/N não mostraram diferença estatisticamente significante. Para a melhor imagem observou-se diferença estatisticamente significante entre os três examinadores para as variáveis superior/temporal (p = 0

  4. Efeitos da aplicação do L.A.S.E.R. HeNe e do ultravioleta B no vitiligo

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    Ana Carolina Brandt de Macedo

    Full Text Available INTRODUÇÃO: O vitiligo é uma doença crônica despigmentante da pele, ocasionada pela perda funcional dos melanócitos da epiderme. Este estudo teve como objetivo comparar os efeitos da aplicação do L.A.S.E.R. HeNe e do ultravioleta B em pacientes com vitiligo. MÉTODO: Foram selecionados 22 pacientes (11 mulheres e 11 homens, com idade entre 12 e 60 anos (31,68 ± 16,29. Os pacientes foram distribuídos aleatoriamente, de acordo com a ordem de comparecimento no serviço e foram divididos randomicamente em dois grupos: o grupo A (n = 12, submetido à aplicação do L.A.S.E.R. HeNe, para o qual a técnica utilizada foi a pontual com aproximadamente 3 cm de distância entre cada ponto, perpendicularmente à pele, e o grupo B (n = 10, exposto ao Ultravioleta B, aplicado de forma perpendicular com 10 cm de afastamento da pele do paciente. Para mensuração da área tratada, utilizou-se o programa AUTOCAD 2002, no qual foi delimitada a borda da mácula em fotos tiradas no início e no fim do tratamento. RESULTADOS: Inicialmente, no grupo A, a área era de 4,87 cm² ± 3,70 e, após a aplicação, foi de 4,15 cm² ± 2,89, com diferença média de 0,72 cm² (1,89. No grupo B, verificou-se que antes da aplicação a média era de 5,36 cm² ± 6,36 e, a após a aplicação, foi de 4,43 cm² ± 5,17, com diferença média de 0,92 cm² ± 1,29. CONCLUSÃO: Ambos os aparelhos obtiveram resultados significativos na redução da mácula, com maior redução no grupo da ultravioleta.

  5. Clinical evaluation of the immediate effectiveness of GaAIAs laser on the therapy of dentin hypersensitivity Avaliação clínica da eficácia imediata do laser de GaAIAs na terapia da sensibilidade dentinária

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    Márcia Sepúlveda Noya

    2004-12-01

    Full Text Available The aim of the present study was to determine the effectiveness of GaAlAs laser therapy with lambda670nm laser on the treatment of dentin hypersensitivity. Thirty-two intact human teeth were evaluated, the sensitivity of which to thermal (cold water, mechanical (probe and evaporative (air stimuli was recorded before and immediately after irradiation. Whenever desensitization was not observed after the first application, the patient was scheduled for a maximum of three further applications at 4-day intervals. The results demonstrated that laser therapy yielded a statistically significant reduction (pO objetivo deste trabalho foi realizar um estudo clinico para avaliar a eficácia da laserterapia com laser de lambda670nm no tratamento da sensibilidade dentinária. Foram avaliados 32 dentes íntegros cuja sensibilidade a estímulo térmico, tátil e evaporativo foi registrada antes e após irradiação. Quando não era evidenciada dessensibilização após a primeira sessão de irradiação, o paciente era agendado para novas aplicações, máximo de três sessões, sempre com intervalos de quatro dias. De acordo com os resultados a laserterapia promoveu uma redução estatisticamente significante (p< 0,05 da sensibilidade dentinária para os três estímulos analisados. De acordo com os resultados obtidos com a utilização do laser de GaAlAs foi necessária apenas uma sessão terapêutica para os estímulos sonda e térmico, embora tenham sido necessárias duas sessões para conseguir-se redução da sensibilidade ao estímulo evaporativo.

  6. Padronização e caracterização da tecnologia laser em borracha EPDM para o design de joias contemporâneas

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    Mariana Kuhl Cidade

    2016-12-01

    Full Text Available Esta pesquisa trata da geração de referência de padronização na utilização da tecnologia de corte a laser CO2 em borracha EPDM, através do desenvolvimento de joias contemporâneas. Foram conduzidos diversos testes de aplicação de velocidades e número de passadas de feixe laser a fim de determinar a configuração ideal para utilização deste processo no material. Imagens analisadas via MEV auxiliaram a compreensão dos efeitos do feixe laser no elastômero, como a zona de abrangência térmica e a efetividade do corte. Com a melhor definição de corte para um traço uniforme, essa caracterização objetiva auxiliar estudantes, profissionais e indústrias na execução de seus projetos.

  7. Uso combinado da laserterapia de baixa potência e da inibição da ciclooxigenase-2 na reepitelização de ferida incisional em pele de camundongos: um estudo pré-clínico Combined use of low level laser therapy and cyclooxygenase-2 selective inhibition on skin incisional wound reepithelialization in mice: a preclinical study

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    Cíntia Helena Santuzzi

    2011-04-01

    Full Text Available FUNDAMENTOS: A laserterapia de baixa potência e os inibidores seletivos da ciclooxigenase-2 (ICOX2 vem sendo muito utilizados para modular a resposta inflamatória, entretanto, os seus efeitos na reepitelização de feridas não são bem compreendidos. OBJETIVO: Avaliar os efeitos isolados e combinados da laserterapia de baixa potência e da ICOX2 na reepitelização de ferida incisional na pele de camundongos. MÉTODO: Foi induzida uma ferida de 1 cm no dorso de cada camundongo, que foram divididos em quatro grupos (N=20: Controle, Laserterapia, Tratados com celecoxib e Terapia conjugada. Os animais dos grupos celecoxib e Terapia conjugada foram tratados com celecoxib por 10 dias antes da incisão cutânea. As feridas experimentais foram irradiadas com laserterapia de baixa potência He-Ne (632nm, dose: 4J/cm2 em varredura, por 12 segundos durante três dias consecutivos nos grupos Laserterapia e Terapia conjugada. Os animais foram sacrificados no 3º dia de pós-operatório. Amostras das feridas foram coletadas e coradas (Tricromio de Masson para análise histomorfométrica. RESULTADOS: Tanto o grupo Laserterapia, quanto o grupo celecoxib, mostrou aumento da reepitelização cutânea em relação ao grupo Controle, entretanto, o grupo Terapia conjugada não apresentou diferenças. Quanto à queratinização o grupo Laserterapia e Terapia conjugada apresentaram redução dos queratinócitos, comparados com o grupo Controle. CONCLUSÕES: Os resultados mostram que o uso da laserterapia de baixa potência e da ICOX2 isoladamente aumentam as células epiteliais, mas somente a laserterapia de baixa potência reduziu os queratinócitos cutâneos. O tratamento conjugado restabelece a reepitelização inata e dimunui a queratinização, embora ocorra uma acelerada contração da ferida com melhora na organização da ferida na pele de camundongos.BACKGROUND: Low level laser therapy and cyclooxygenase-2 (ICOX2 selective inhibitors have been widely used

  8. Influência da texturização laser na vida de ferramentas de torneamento revestidas por CVD e PVD

    OpenAIRE

    Davi Neves

    2010-01-01

    Resumo: Uma característica dos revestimentos aplicados nas ferramentas de corte é a adesão. A adesão deficiente libera particulados duros e abrasivos resultantes da fragmentação prematura do revestimento, acelerando o desgaste das superfícies em contato. Na texturização, um laser de pulsos curtos e de alta frequência provoca, na interação com a superfície, uma mudança das propriedades advinda da fusão e ablação de material. Neste processo podem ocorrer a limpeza e a texturização simultâneas d...

  9. Análise da eficácia do laser de baixa potência no tratamento da dor tendínea em ratos imunossuprimidos Analysis of low-level laser therapy efficacy on tendon pain treatment in immunosuppressed rats

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    Fernanda de Oliveira Busarello

    2011-12-01

    Full Text Available O comprometimento do sistema imune, que pode ser apresentado por indivíduos com doenças crônicas, leva à baixa resposta imunológica. Um dos tratamentos utilizados para lesões agudas em tendões é o laser de baixa potência, contudo há uma lacuna em relação ao seu uso em imunodepressão. O objetivo do presente estudo foi analisar se o laser de baixa potência é eficaz para o tratamento da dor em ratos imunodeprimidos submetidos a trauma tendíneo. Foram utilizados 23 ratos, machos, da linhagem Wistar, divididos aleatoriamente em três grupos: grupo controle, placebo e laser. Os animais foram imunodeprimidos (por administração de Ciclosporina A e submetidos à lesão no tendão calcâneo direito, com impacto de cerca de 0,40 J. Para o tratamento, utilizou-se laser de baixa potência, 670 nm, 30 mW e dose de 2 J/cm², durante 3 dias. A avaliação da dor foi realizada pelo teste de incapacidade funcional e por filamento de Von Frey digital. Os resultados apresentaram valores significativos para o grupo laser, com diminuição de dor funcional e da dor à pressão na superfície plantar e no local lesionado (tendão calcâneo direito. Portanto, concluiu-se que o laser de baixa potência é eficaz para reduzir a dor em ratos imunodeprimidos submetidos a trauma tendíneo.The commitment of immune system, which may be presented by individuals with chronic diseases, leading to a low immune response. One of the treatments used for acute injuries in tendons is the low-power laser, however there is a gap in relation to its use in immunosuppression. The objective of this study was to analyze if low-level laser therapy is effective for the treatment of pain in immunosuppressed rats subjected to trauma tendon. We used 23 male rats of Wistar strain, divided randomly in three groups: control group, placebo and laser. The animals were immunosuppressed (by administration of Cyclosporin A and underwent right Achilles tendon injury, with impact of about

  10. Laser diagnostic and therapy of dental caries: the clinic point of view; Laser diagnostico e tratamento da carie dental: uma visao clinica

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Priscila Faria

    2001-07-01

    Dental caries's diagnosis is a major dentistry problem from the clinic point of view. The laser beam on the region of 655 nm induces the fluorescence of the compounds present in the hard tissue, quantifying differences between sound and carious enamel and dentine. Diagnodent (Kavo, Germany), showed to be effective regarding dental caries's diagnosis in the present research sampling. The Er:YAG laser (Kavo Key Laser 2, Germany) performed efficient cavity preparations in caries lesions of I and V class type, using up energies that ranged from 300 mJ to 350 mJ with 4 Hz repetition rate for the enamel; and from 250 mJ to 300 mJ with 4 Hz repetition rate for the dentine, and with 80 mJ with 6 Hz of repetition rate for laser conditioning. In the Er:YAG laser preparations no patient was anesthetized even when there were deeper cavities, and the maximum degree of pain ( which ranged from 0 to 10) was 4. In the control group with conventional high-speed drill two patients were anesthetized and the maximum degree of pain was 7. Restorations performed by conventional method of composite were equally satisfying both in caries groups of I and V class type and in the control group. The laser application in the operative dentistry office as a new method of diagnosis and dental preparations should be a good alternative to the use of the conventional dental drill. Nevertheless, dentistry practice has a lot to improve from technology progress, as well as new researches on laser dentistry are necessary in a long term. New types of lasers will come about and will increasingly improve the dental practice assistance and procedures quality. (author)

  11. Laser diagnostic and therapy of dental caries: the clinic point of view; Laser diagnostico e tratamento da carie dental: uma visao clinica

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Priscila Faria

    2001-07-01

    Dental caries's diagnosis is a major dentistry problem from the clinic point of view. The laser beam on the region of 655 nm induces the fluorescence of the compounds present in the hard tissue, quantifying differences between sound and carious enamel and dentine. Diagnodent (Kavo, Germany), showed to be effective regarding dental caries's diagnosis in the present research sampling. The Er:YAG laser (Kavo Key Laser 2, Germany) performed efficient cavity preparations in caries lesions of I and V class type, using up energies that ranged from 300 mJ to 350 mJ with 4 Hz repetition rate for the enamel; and from 250 mJ to 300 mJ with 4 Hz repetition rate for the dentine, and with 80 mJ with 6 Hz of repetition rate for laser conditioning. In the Er:YAG laser preparations no patient was anesthetized even when there were deeper cavities, and the maximum degree of pain ( which ranged from 0 to 10) was 4. In the control group with conventional high-speed drill two patients were anesthetized and the maximum degree of pain was 7. Restorations performed by conventional method of composite were equally satisfying both in caries groups of I and V class type and in the control group. The laser application in the operative dentistry office as a new method of diagnosis and dental preparations should be a good alternative to the use of the conventional dental drill. Nevertheless, dentistry practice has a lot to improve from technology progress, as well as new researches on laser dentistry are necessary in a long term. New types of lasers will come about and will increasingly improve the dental practice assistance and procedures quality. (author)

  12. Effect of diode laser irradiation on the apical sealing of MTA retrofillings Efeito da irradiação de laser de diodo no selamento apical em retrobturações com MTA

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    Eliana Barbosa de Souza

    2006-09-01

    Full Text Available Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05. The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.O selamento apical é fundamental para o sucesso da cirurgia parendodôntica. Assim, procedimentos que melhorem o selamento do remanescente apical devem ser utilizados. O objetivo deste estudo foi verificar se a irradiação de laser de diodo poderia aumentar o selamento apical em cavidades retrógradas obturadas com MTA. Foram utilizadas 20 raízes de dentes humanos extraídos que, após preparo com lima tipo K, tiveram seus canais obturados com guta-percha. Os ápices foram cortados e sofreram preparo de cavidades retr

  13. Bartholin's gland cysts: management with carbon-dioxide laser vaporization Cistos da glândula de Bartholin: tratamento com vaporização laser com CO2

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    Ana Cristina Neves Figueiredo

    2012-12-01

    Full Text Available PURPOSE: To evaluate the effectiveness, recurrence rate, and complications of carbon-dioxide laser vaporization in the treatment of Bartholin's gland cysts. METHODS: A retrospective study including 127 patients with symptomatic Bartholin' gland cysts submitted to carbon-dioxide laser vaporization at our institution from January 2005 to June 2011. Patients with Bartholin's gland abscesses and those suspected of having neoplasia were excluded. All procedures were performed in an outpatient setting under local anaesthesia. Clinical records were reviewed for demographic characteristics, anatomic parameters, intraoperative and postoperative complications, and follow-up data. Data were stored and analyzed in Microsoft Excel® 2007 software. A descriptive statistical analysis was performed, and its results were expressed as frequency (percentage or mean±standard deviation. Complication, recurrence, and cure rates were calculated. RESULTS: The mean age of the patients was 37.3±9.5 years-old (range from 18 to 61 years-old. Seventy percent (n=85 of them were multiparous. The most common symptom was pain and 47.2% (n=60 of patients had a history of previous medical and/or surgical treatment for Bartholin's gland abscesses. Mean cyst size was 2.7±0.9 cm. There were three (2.4% cases of minor intraoperative bleeding. Overall, there were 17 (13.4% recurrences within a mean of 14.6 months (range from 1 to 56 months: ten Bartholin's gland abscesses and seven recurrent cysts requiring reintervention. The cure rate after single laser treatment was 86.6%. Among the five patients with recurrent disease that had a second laser procedure, the cure rate was 100%. CONCLUSIONS: At this institution, carbon-dioxide laser vaporization seems to be a safe and effective procedure for the treatment of Bartholin's gland cysts.OBJETIVO: Avaliar a eficácia, a taxa de recorrência e as complicações da vaporização laser com CO2 no tratamento dos cistos da glândula de

  14. Efeitos da radiação laser de dióxido de carbono em tecido ósseo: estudo macroscópico em ratos Effect of carbon dioxide laser radiation on osseous tissue: macroscopic study in rats

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    Walter NICCOLI-FILHO

    2001-06-01

    Full Text Available O laser de dióxido de carbono (CO2, pelas suas propriedades intrínsecas, tem se tornado um instrumento cirúrgico importante; entre estas podemos citar: hemostasia, redução do edema e da dor pós-operatória e esterilização do campo cirúrgico. Seu uso em tecido ósseo para realização de osteotomias ainda é questionável, principalmente devido à possibilidade de iatrogenias causadas pelo aumento da temperatura tecidual, bem como destes efeitos na área paraincisional. O propósito deste estudo foi proporcionar a confecção de um plano piloto visando analisar macroscopicamente os efeitos da radiação laser de CO2 em tíbia de rato a fim de estabelecerem-se parâmetros de segurança quanto a potência. Foram utilizados 12 ratos. Após anestesia, os ossos foram submetidos a radiação com potência de 1, 3 e 5 watts. Os animais foram sacrificados nos tempos imediatamente após, 3, 7 e 14 dias após a irradiação, visando à remoção do osso tratado. Os espécimes obtidos foram observados através de lupa estereoscópica com aumentos de 14, 25 e 40 vezes e fotografados para posterior análise. Os resultados permitiram concluir que a potência de 1 watt proporciona uma melhor qualidade de resposta à reparação e que as potências de 3 e 5 watts provocaram o atraso na cronologia de reparo.The use of CO2 laser in osseous tissue to execute osteotomies is still questionable, mainly due to the increase of temperature in the site of irradiation. The purpose of this research was to carry out a pilot study in order to analyze macroscopically the effect of CO2 laser irradiation on rat tibia and to establish security parameters regarding power. Twelve rats were submitted to irradiation with 1, 3 and 5 watts of power and were examined immediately, 3, 7 and 14 days after irradiation. The results showed better healing when irradiation was carried out with the power of 1 watt; the 3- and 5-watt powers caused delay in the chronology of healing.

  15. In vitro study of temperature changes in root during Er:YAG laser application; Estudo in vitro da alteracao da temperatura durante a aplicacao do Er:YAG laser intracanal

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Redson Vilela

    2001-07-01

    The temperature increase in root dentine irradiated by Er:YAG laser beam was analyzed, for different dentine thickness and different energy and frequency conditions, aiming the evaluation of Er:YAG laser in endodontic therapy, without causing any damages to close tissues. Twenty four human teeth were separated in four groups with six teeth each, and longitudinally sectioned in thickness of 0.5 mm (first group), 1,0 mm (second group), 1,5 mm (third group) and 2,0 mm (fourth group). Those samples were irradiated with the Er:YAG laser, emitting at the wavelength of 2.94{mu}m, by using a sapphire optic fiber with diameter of 0.375 mm, and forming an angle of 5 deg with the irradiated dentine surface. Three different laser energies were used in this study, 180 mJ, 160 mJ and 140 mJ, with frequencies of 10 Hz and 15 Hz. The temperature data were collected in a digital-analog system and sent to a computer for analysis. It was verified that the time for temperature increases of 5 deg in the external root walls varies according to the laser energy, repetition rate and dentine root thickness. Thus, in this work we could obtain laser parameters to avoid thermal damages in periodontal tissues. (author)

  16. Influência da irradiação do laser na regeneração nervosa em diferentes locais de tratamento Influence of laser radiation in nerve regeneration in different treatment sites

    Directory of Open Access Journals (Sweden)

    Fausto Fernandes de Almeida Sousa

    2009-01-01

    Full Text Available OBJETIVO: Verificar a influência do laser de baixa intensidade de AsGaAl na lesão por esmagamento do nervo peroneiro de ratos através da avaliação funcional da marcha nos diferentes locais de irradiação. MÉTODOS: Foram utilizados 53 ratos, divididos em seis grupos: normal, lesado não tratado, lesado e tratado placebo, lesado e tratado na medula, lesado e tratado no nervo, lesado e tratado em ambos (nervo e medula. O esmagamento do nervo peroneiro foi realizado por meio de uma pinça e subsequente tratado com laser por 28 dias consecutivos. Na avaliação funcional foram analisadas as impressões das pegadas, registradas pela câmera de vídeo em uma passarela de acrílico, no pré-operatório e aos 14º, 21º e 28º dias de pós-operatório, e avaliadas na fórmula PFI por meio do software. RESULTADOS: Na avaliação funcional da marcha foram encontradas diferenças significantes somente no 14º dia de pós-operatório. CONCLUSÃO: A irradiação do laser AsGaAl de baixa intensidade foi capaz de acelerar e potencializar o processo de regeneração nervosa periférica de ratos no 14º dia de pós-operatório, de acordo com a avaliação funcional da marcha, tanto para o grupo tratado na medula quanto para o grupo tratado no nervo.OBJECTIVE: This study seeks to determine, through functional gait assessment in different irradiation sites, the influence of a low-intensity GaAsAl laser beam on an injury caused by crushing the peroneal nerve in rats. METHODS: 53 rats were used, which were divided into six groups: normal, injured and untreated, injured and treated using placebo, injured and treated in the bone marrow, injured and treated in the nerve, and injured and treated in both (nerve and bone marrow. The peroneal nerve was crushed using a pair of tweezers, and subsequently treated with laser for 28 consecutive days. The functional gait evaluation analyzed the footprints, which were recorded with a video camera on an acrylic bridge in the

  17. Equivalente esférico e valores da espessura da camada de fibras nervosas obtidas com o GDX TM Scanning Laser System® Spherical equivalent and nerve fiber layer thickness assessed with GDX TM Scanning Laser System®

    Directory of Open Access Journals (Sweden)

    Lênio Souza Alvarenga

    1999-12-01

    Full Text Available Objetivo: Estudar a influência do equivalente esférico nos valores obtidos pelo GDX TM Scanning Laser System®. Métodos: Foram avaliados 41 olhos de 41 voluntários sem doenças oculares e com campo visual sem alterações. Foi realizada a polarimetria de varredura a laser com o GDX TM Scanning Laser System® de acordo com as instruções contidas no manual do aparelho. Foram comparados os valores obtidos nesse exame em um grupo de pacientes com equivalente esférico positivo e em um outro com este valor nulo ou negativo, pelo teste de Mann-Whitney. Resultados: Não se verificou diferença estatística entre os valores obtidos nos olhos de pacientes do grupo I e os do grupo II. Não foi encontrada correlação entre o equivalente esférico e os valores obtidos com o GDX TM Scanning Laser System®. Conclusões: Na amostra estudada não houve diferença estatística entre os valores obtidos em um grupo de olhos com equivalente esférico positivo e outro com este valor negativo ou nulo, usando-se o GDX TM Scanning Laser System®.Purpose: To evaluate the effect of spherical equivalent on the acquisition of nerve fiber layer (NFL thickness with GDX TM Scanning Laser System®. Methods: Forty-one eyes of 41 volunteers were enrolled in this study. All of them presented with no ocular disease and no visual field defect. The NFL thickness was measured with GDX TM Scanning Laser System® as described in its manual. The values obtained in a group of volunteers with negative spherical equivalent (group I were compared to those from a group with a positive spherical equivalent (group II by the Mann-Whitney test. Results: There was no statistical difference between mea-surements in eyes of group I and those in group II. The NFL thickness measurements were not correlated with the sphe-rical equivalent. Conclusions: In the studied group there was no statistical difference in the GDX TM Scanning Laser System® parameters related to spherical equivalent.

  18. Eficiência do laser diodo 980 nm em comparação à da glicose a 75% na oclusão de veias da orelha de coelhos The efficiency of the diode laser 980 nm compared to glucose 75% in occlusion of the veins in rabbit ears

    Directory of Open Access Journals (Sweden)

    Paulo Roberto da Silva Lima

    2011-06-01

    Full Text Available CONTEXTO: Por ser o laser um método novo no tratamento das varizes, há muitos mitos e dúvidas com relação à sua eficácia; assim, surgiu a necessidade de compará-lo a substância esclerosante mais utilizada em nosso meio (glicose hipertônica. OBJETIVO: Comparar a eficiência do laser diodo 980 nm à glicose 75% na oclusão de veias em orelha de coelho. MÉTODOS: Ensaio aleatório em animais de laboratório por 21 dias. A amostra consistiu de orelhas de coelhos machos adultos. Grupo L (laser: 15 orelhas tratadas com laser; grupo G (glicose 75%: 15 orelhas tratadas com glicose a 75%. Variáveis primárias: veias esclerosadas e/ou ocluídas. Variáveis complementares: volume da substância administrada, complicações e peso. O tamanho da amostra foi estimado em 30 orelhas. Foi realizado o teste exato de Fisher associado ao Risco Relativo (RR, calculando-se o intervalo de confiança (IC de 95% para as variáveis acima. RESULTADOS: A incidência de esclerose ou oclusão venosa no grupo G foi de 53% (8/15; IC95%: 27-79 e no grupo L, 20% (3/15; IC95%: 4-49. O p bicaudal foi de 0,1281, o RR usando a aproximação de Katz foi de 2,66; IC95%: 0,87-8,15. CONCLUSÃO: A eficiência do laser diodo 980 nm em comparação à da glicose 75% na oclusão de veias para o modelo experimental estudado foi equivalente.BACKGROUND: The laser is a new treatment to varicose veins and there is several myths and doubts in relation to its efficacy; then, there is the need to compare it with the most commonly sclerosing solution (hypertonic glucose used in our specialty. OBJECTIVE: To compare the efficiency of the diode laser 980nm to the glucose 75% in the occlusion of veins from the ear of rabbits. METHODS: Aleatory trial in laboratory animals during 21 days. The sample consisted of ears from male adult rabbits. Group L (laser: 15 ears treated with laser; group G (glucose 75%: 15 ears treated with glucose 75%. Primary variables: sclerotic and/or occluded veins

  19. Estudo da microcirculação na hanseníase virchowiana com o uso da microscopia de luz ortogonal polarizada e com laser-doppler fluxometria

    OpenAIRE

    Curt Mafra Treu

    2010-01-01

    A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomia microcirculatória, citando como exemplo as alterações no reflexo vasomotor. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase virchowiana, tanto em sua morfol...

  20. Forest structure and stem volume assessment based on airborne laser scanning / Avaliação da estrutura florestal e do volume de madeira a partir de laser aerotransportado

    Directory of Open Access Journals (Sweden)

    Markus Hollaus

    2012-10-01

    Full Text Available This paper presents a methodology for the derivation of structural parameters and stem volume in forests based on Airborne Laser Scanning (ALS data. We describe three different measures of horizontal and vertical canopy structure: (1 tree crown segmentation, (2 compactness of vegetation patches, and (3 vertical layering of vegetation patches and canopy cover. An empirical regression model for the derivation of stem volume from the ALS and forest inventory sample plot data is described and its results are validated with extensive reference data. Different study areas in Austria were used to illustrate the workflows. The presented study demonstrates the applicability of the proposed methods on study sites and ALS data of differing characteristics, as well as it points out the suitability of ALS as a tool for reliable wide area assessment of structural parameters and stem volume for forested areas.ResumoEsse artigo apresenta uma metodologia para derivação de parâmetros estruturais e de volume de madeira em florestas baseado em dados de Laser Scanner Aerotransportado (ALS. Nós descrevemos três diferentes medidas da estrutura horizontal e vertical da copa: (1 segmentação da copa da árvore, (2 compacidade das manchas de vegetação, (3 estratificação vertical das manchas de vegetação e cobertura do dossel. Um modelo empírico de regressão para derivar o volume de madeira fazendo uso de dados ALS e dados amostrais obtidos em inventário florestal é descrito e seus resultados são validados com extensivos dados de referência. Diferentes áreas na Áustria foram utilizadas para ilustrar o fluxo de trabalho. O estudo apresentado demonstra a aplicabilidade dos métodos propostos nas áreas de estudo e dos dados ALS de diferentes características, bem como aponta a adequação do ALS como ferramenta confiável para avaliação de parâmetros de estrutura e de volume de madeira de amplas áreas florestais.

  1. Avaliação da eficácia do laser de baixa intensidade no tratamento das disfunções têmporo-mandibular: estudo clínico randomizado

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    Maria Helena Chaves de Vasconcelos Catão

    2013-12-01

    Full Text Available OBEJTIVO: avaliar a eficácia do laser de baixa intensidade no tratamento da dor em pacientes com desordens temporomandibulares. MÉTODO:consistiu de um ensaio clínico randomizado divididos em dois grupos: Grupo 1: laser AsGaAl, Grupo 2: laser InGaAlP, do qual participaram 20 pacientes entre 19 e 35 anos de idade, com diagnóstico de sinais e sintomas de DTM. Os pacientes tinham a amplitude de movimento para abertura máxima da boca e lateralidade registados no início e no final do tratamento a laser. O Laser foi aplicado em quatro pontos pré-auriculares, totalizando 12 sessões três vezes por semana, durante um mês. Dor dos pacientes foi registrado com base na utilização da escala analógica visual (EAV e também por exame físico dos pontos álgicos. RESULTADOS: observou-se redução significante (p<0,028 do nível de dor em ambos os grupos, porém no G1 a significância foi maior. A evolução do limiar de sensibilidade muscular evidenciou diferença estatisticamente significante (p<0,05 para G1 e G2. A laserterapia no Grupo 1 melhorou a abertura bucal em média de 4,643 mm, enquanto no Grupo 2, a média foi de 3,71 mm por paciente. CONCLUSÃO: houve eficácia em ambos os lasers no controle da dor e abertura bucal dos pacientes.

  2. Evaluation in vitro of effects of Er:YAG and Nd:YAG lasers irradiation on root canal wall, by stereoscopy, scanning electron micrography and thermographic camera; Avaliacao in vitro dos efeitos da irradiacao laser de Er:YAG e Nd:YAG na parede dentinaria do canal radicular, sob observacao do estereoscopio, da micrografia eletronica e da camera termografica

    Energy Technology Data Exchange (ETDEWEB)

    Goya, Claudia

    2001-07-01

    This study was carried out to evaluate in vitro the effects of Nd:YAG laser and Er:YAG laser irradiation in the root canal wall by SEM, evaluating the apical leakage and the temperature changes during the laser irradiation. Seventy four extracted human teeth were used, they were instrumented and divided into seven groups of 10 teeth each. The teeth were evaluated through stereoscopy, by SEM, and with the thermographic camera. The Nd:YAG laser irradiation parameters were 100 mJ/p, 15 Hz, and Er:YAG laser were 160 mJ/p and 10 Hz, the irradiation was 4 times at 2 mm/sec speed, with 20 sec interval. The apical leakage was not observed in the teeth irradiated by Nd:YAG laser alone or in association with Er:YAG laser. However in the teeth irradiated only by the Er:YAG laser we observed a little leakage. By SEM observation the Nd:YAG laser irradiation showed melting and recrystallization in the dentin surface closing dentinal tubules, and in the samples irradiated by Er:Y AG laser a clean surface, opened dentinal tubules, and the combination by two lasers, showed melting covering some dentinal tubules The thermographic study found the temperature increase was not more than 6 deg C. This study showed the safety parameters applications of Er:YAG laser in association with Nd:YAG laser in root canal treatment, in order to not cause thermal damages to the periodontal tissues. (author)

  3. Characterization of ionizing radiation effects on human skin allografts; Caracterizacao dos efeitos da radiacao ionizante em pele humana para aloenxerto

    Energy Technology Data Exchange (ETDEWEB)

    Bourroul, Selma Cecilia

    2004-07-01

    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. After donor screening and preservation in glycerol (above 85%), the skin can be stored in the Skin Banks. 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. Skin samples were submitted to doses of 25 kGy and 50 kGy in an irradiator of {sup 60}Co and in an electron beam accelerator. 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. (author)

  4. Effects of the ionizing radiation in natural food colours; Efeitos da radiacao ionizante em corantes naturais de uso alimenticio

    Energy Technology Data Exchange (ETDEWEB)

    Cosentino, Helio Morrone

    2005-07-01

    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. (author)

  5. Effect of gamma radiation in the ripening period of prato cheese; Efeito da radiacao gama na maturacao do queijo prato

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Erika Maria Roel

    2001-07-01

    The Prato (cheese washed dough) is one of the must popular cheese of Brazil and must be ripening for 45 to 60 days for to reach characteristics of flavors and texture. The present work studied the effect of gamma radiation in the ripening period of Prato cheese. Two periods of irradiation was studied, in first day and 15{sup th} day of ripening. The cheese was irradiated with doses of 0 (non-irradiated), 1, 2, 3 and 4 kGy at a rate of 0,9696 kGy/h from a cobalto-60 source in the period referred and stored at 10-12 deg C and +- 85% RH for 60 days. The physical-chemical and microbiological characteristics and organoleptic properties were analysed every each 15 days of ripening. Through of the results observed that with the increase of the dose of radiation, decreased the total microbial count and that the irradiation retarded the ripening according to increase of the dose, this probability of the destruction of bacterial lactic. The greatest difference found was in the colour according the increasing of the dose, the cheese was more colorless, less yellow and red. Which the organoleptic properties verified that with the increase of the dose of radiation, there was a lost about the color. The cheese increase the firmness, became dryer and less creamy and tasted flavors less intense, a little more bitter and smoking compared with a control. Even though about these differences there was no refuse of Prato cheese, among the sensorial group for irradiated cheese until 2 kGy. (author)

  6. Effect of gamma-radiation on sugar cane spirit; Efeito da radiacao gama sobre a aguardente de cana de acucar

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Maria Djiliah Camargo Alvarenga de

    2000-07-01

    Irradiation has appeared as an alternative technique in food preservation. Besides cold decontamination irradiation can increase the quality of the food through the improvement of technological properties. For alcoholic beverages ionizing radiation has been applied to wines, whiskeys and beers in countries such as Thailand and China. In those cases, the purpose of the technique was to accelerate aging, to improve the sensory characteristics and as sterilization treatment. The aim of this work was to study the effect of gamma radiation on the quality of sugar cane spirit by gas chromatography analysis of volatile compounds and sensory analysis. The sugar cane spirit newly distilled samples and commercial samples from different states (SP, CE and RJ) were irradiated either in glass or oak cask (Quercus alba sp) in a {sup 60}Co Gammacell 220 at dose rate of 7.7 kGy/h and total doses of 0; 0.1; 2; 5 and 10 kGy. The analytical determination of esters, acetaldehyde and higher alcohols were performed in a gas chromatograph with flame ionization detector employing a Megabore CG-745 column. The alcoholic graduation was measured in a Gay-Lussac alcohometer and the pH was determined using an Analyser 300 pHmeter. The color change was measured by the absorbance at 420 nm in a Shimadzu UV 1601 spectrophotometer. The acceptance tests related to odor, taste, global impression and color were analyzed using Tukey average tests (p {<=}0,05), ANOVA and histograms of panelists' scores frequency. A correlation between acetaldeyde, esters, higher alcohols levels and radiation dose was found in the sugar cane spirit newly distilled samples irradiated in oak cask and commercial samples. An increase in methanol concentration was verified, although remaining enough below the permissible limit accepted by the Brazilian Legislation. A decrease in the alcoholic graduation and pH in the irradiated samples was observed. A slight discoloration in the irradiated samples was verified. According to ANOVA statistics for the sensory analysis, no significant difference between samples, related to odor, taste, global impression was verified. However, a significant difference related to color was observed. (author)

  7. Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy Avaliação da regeneração muscular em animais idosos após tratamento com laser de baixa intensidade

    Directory of Open Access Journals (Sweden)

    Adriana Pertille

    2012-12-01

    Full Text Available BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT without treatment; injury group (IN with muscle contusion and without treatment and laser group (LA with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.CONTEXTUALIZAÇÃO: O processo de envelhecimento e suas consequentes alterações morfofisiológicas desencadeiam redução da habilidade regenerativa das células satélites, redução da vascularização tecidual e aumento da produção de fibroblastos, desenvolvendo-se um ambiente celular desfavor

  8. Ineficácia da laserterapia aplicada no trajeto do nervo e nas raízes medulares correspondentes Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots

    Directory of Open Access Journals (Sweden)

    Fausto Fernandes de Almeida Sousa

    2013-04-01

    Full Text Available OBJETIVO: Verificar a influência da irradiação do laser de baixa intensidade na regeneração do nervo fibular comum de ratos após lesão por esmagamento. MÉTODOS: Foram utilizados 25 ratos, divididos em três grupos: 1 nervo intacto, e não tratados; 2 nervo lesado, e não tratado; 3 nervo lesado, e laser irradiado sobre a região medular correspondente às raízes do nervo ciático e subsequentemente no trajeto do nervo lesado. A irradiação foi realizada por 14 dias consecutivos. RESULTADOS: Foram avaliados por meio da análise funcional da marcha, através do índice funcional do peroneiro, e por análise morfométrica através do número total de fibras nervosas mielinizadas e sua densidade, número total de células de Schwann, número total de vasos sanguíneos e sua área, diâmetro mínimo da fibra e razão-G. CONCLUSÃO: De acordo com a análise estatística, não houve diferença significativa entre os grupos, e os autores concluem que a irradiação do laser de baixa intensidade possui pouca ou nenhuma influência na regeneração nervosa e recuperação funcional. Trabalho experimental.OBJECTIVE: to investigate the influence of low intensity laser irradiation on the regeneration of the fibular nerve of rats after crush injury. METHODS: twenty-five rats were used, divided into three groups: 1 intact nerve, no treatment; 2 crushed nerve, no treatment; 3 crush injury, laser irradiation applied on the medullary region corresponding to the roots of the sciatic nerve and subsequently on the course of the damaged nerve. laser irradiation was carried out for 14 consecutive days. RESULTS: animals were evaluated by functional gait analysis with the peroneal functional index and by histomorphometric analysis using the total number of myelinated nerve fibers and their density, total number of schwann cells, total number of blood vessels and the occupied area, minimum diameter of the fiber diameter and g-quotient. CONCLUSION: according to

  9. Laser ablation - inductive coupled plasma - mass spectrometer (LA-ICP-MS) geochemistry characterization of albitites associated to uranium in Lagoa da Rabicha deposit, Lagoa Real, BA (Brazil)

    International Nuclear Information System (INIS)

    Oliveira, Lucilia A. Ramos de; Rios, Francisco Javier; Amorim, Lucas Eustaquio Dias; Souza, Aurelio da Silva; Prates, Sonia Pinto; Yardley, Bruce; Matos, Evando Carele

    2009-01-01

    The LA-ICP-MS technique is a good tool for mineral geochemical characterization. The technique has high spatial resolution, elevated sensibility, low detection limits and multi-elementary analysis possibility. Almost all chemistry elements can be analyzed by this methodology. Briefly, this methodology consists in vaporize the sample by Laser Ablation, which is dragged by argon into the Plasma where are created and accelerated the ions. They are separated by their mass/charge ratio into the Mass Spectrometer, being conveyed to a detector that convert the signals in specters. In this work LA-ICP-MS analyses were performed in two albitites thin sections, a mineralized and a non mineralized sample. Both samples are from the Lagoa da Rabicha Deposit, Uranium Lagoa Real Province, BA. From these analysis it was possible to chemically characterize the minerals present in the samples and better understand the trace elements on them. The results for plagioclase in both samples show that it is albite (NaAlSi 3 O 8 ). The albite from sample 200907-20 shows traces of strontium, lanthanum, cerium, neodymium, samarium and thorium in one crystal. The albite from sample 200907-23 has strontium with uranium, yttrium and lead in smaller quantities. The results obtained in this work are very important and contribute to a better understanding of the uranium origin in Lagoa Real deposits. (author)

  10. Aplicações do laser de baixa intensidade no tratamento da síndrome do túnel do carpo - doi: 10.5102/ucs.v7i2.996

    Directory of Open Access Journals (Sweden)

    João Paulo Caldas Cardozo

    2010-06-01

    Full Text Available O objetivo deste trabalho foi analisar, por meio de revisão bibliográfica, a eficiência da aplicação do Laser de baixa intensidade (LBI no tratamento da Síndrome do Túnel do Carpo (STC. Para isso foi realizada uma pesquisa de artigos nas bases de dados PUBMED e BIREME, publicados entre 1985 e 2009, nos idiomas espanhol, inglês e português. Grande parte dos artigos consultados revelou que a LBI é eficaz no tratamento de pacientes diagnosticados com Síndrome do Túnel do Carpo. Concluiu-se que, quando associada ao uso de órtese para o punho, a laserterapia é um método eficiente no tratamento da síndrome do túnel do carpo.

  11. Low intensity laser therapy and functional orthopedics contribution in pain and temporo mandibular dysfunction treatment; Contribuicao do laser em baixa intensidade e da ortopedia funcional dos maxilares no tratamento da dor e disfuncao tempora-mandibular

    Energy Technology Data Exchange (ETDEWEB)

    Lollato, Renata Fronzaglia

    2003-07-01

    Temporo Mandibular Dysfunction (TMD) is a term used to describe disorders which involve temporomandibular joint (TMJ), masticatory muscles, and associated structures, isolatedly or not, whose most frequent symptoms pain. Its etiology involve controversies, and among risk factors is Class 11 malocclusion. A lot of techniques are used for TMD treatment, and the most recent are Low Intensity Laser Therapy (LILT) and Functional Orthopedics (FO). The aim of this study was to evaluate pain and buccal mobility in subjects with Class II malocclusion and TMD symptoms, treated with LILT and FO associated or not. Eighteen subjects were selected and divided in three groups. Group 1 was treated with LILT, {lambda} = 780 nm, 70 mW, 15 J/cm{sup 2} per point, in six sessions during two weeks. The application was in three points around the TMJ and in masticatory muscles: masseter, temporalis, sternomastoid and trapezius, on both sides when there was pain. Palpation was made before and five minutes after application and subjects answered a questionnaire with a score for pain evaluation. Group 2 received functional orthopedics aparatology Planas Indirect Composed Plates, and was evaluated once a week during two weeks, after palpation and following the same score as group 1. Group 3 received both therapies at the same time, and the first application coincided with the aparatology installation. The evaluation followed the parameters of group 1. The results were statically analyzed , and in general form did not show significant differences. There was remission of pain symptoms in ali of the groups, and group 3 showed more rapidly results. This fact leaded us to a conclusion that the association of the LILT with FO was the best treatment for the pain symptoms remission in TMD. (author)

  12. Ionizing radiation effects on volatiles formation in Camellia sinensis (L) teas; Efeito da radiacao ionizante na formacao de volateis em chas da planta Camellia sinensis (L)

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo Bernardes

    2009-07-01

    The aim of this study was to evaluate the effects of radiation on volatile formation in white, green, oolong and black teas. Samples were irradiated in room temperature at {sup 60}Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20 kGy. The volatiles organic compound was extracted by hydro distillation and the extract was separated and identified by gas chromatography mass spectrometry (GCMS) analysis. The results show that the volatiles formations are directly proportional to the increase of radiation dose. The white tea showed less influence of ionizing radiation, as 37.86% of the compounds were stable at all doses of radiation and formed 47.53% of new compounds after irradiation. The green tea was the tea that has the greatest influence of radiation effects, increasing 66.12% of volatiles identified in relation to the control sample and only 21.77% of volatiles found naturally were resistant to all doses of radiation. The oolong tea, despite suffering a partial enzymatic treatment, was the second tea that has least interference of radiation in increasing the formation of new volatile. >From this tea, was able to detect 49.59% of new compounds after irradiation and 30.08% of the compounds found naturally were also found after irradiation. The black tea has the second greatest influence of radiation on formation of new volatile (60.94%) and only 17.97% of all identified compounds were not degraded after radiation. (author)

  13. Effect of ionizing radiation on the morphology, physiology and growth of Leishmania ssp; Acao da radiacao ionizante sobre a morfologia, fisiologia e crescimento da Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Bonetti, Franco C.; Spencer, Patrick J.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Junior A, Heitor F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Instituto de Medicina Tropical

    2000-07-01

    The Leishmania spp is a pathogenic protozoan, which cause different diseases in man. The human diseases, in America, caused by this group of protozoa are divided in cutaneous or tegumentar and visceral, known as kala-azar. In this work, our principal study object was the specie that causes tegumentar leishmaniasis, in Brazil. Metabolic studies of cellular respiration and proteins and nucleic acids synthesis were accomplished using radiation as a form of sterilizing the parasites without however affecting their immunogenic capacity The promastigotes forms of irradiated Leishmania spp were totally sterilized with the dose of 1500 Gy, with their reproductive and nucleic acids, as well as protein synthesis capacity blocked. (author)

  14. Evaluation of X ray attenuation by means of radiographic images; Avaliacao da atenuacao da radiacao X por meio de imagens radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Frieda Saicla, E-mail: saicla@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Paredes, Ramon S.C., E-mail: ramon@ufpr.b [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Godoi, Walmor C., E-mail: walmor.godoi@gmail.co [Faculdade de Tecnologia Camoes (FATEC), Curitiba, PR (Brazil); Souza, Gabriel Pinto de [Universidade Estadual Paulista (UNESP), SP (Brazil)

    2011-07-01

    This paper's main goal is to adopt a qualitative methodology to evaluate the attenuation of x-radiation through X-ray images in polymeric materials plus residual lead. To determinate the images it was initially used an experimental setup at the Laboratory for Materials Diagnostics LACTEC. These results correspond to a more qualitative analysis, even with quantitative answers. Through analysis of radiographic images we can measure the intensity of radiation that goes through the plate, making possible to establish a relationship between the attenuation coefficient and the thickness of the material. (author)

  15. Gamma radiation in some microbiological and biochemical parameters of ethanolic fermentation.; Efeito da radiacao gama em alguns parametros microbiologicos e bioquimicos da fermentacao alcoolica

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Andre Ricardo

    2000-07-01

    The objective of this work was to evaluate the effect of gamma radiation in reducing the bacterial population of the sugar cane must and verify its influence in the ethanolic fermentation. For this purpose, some microbiological and biochemical parameters of the ethanolic fermentation were analyzed, such as bacterial count; viability, replication and living replicates of the yeast; p H, acidity (total and volatile), glycerol and production of organic acids (acetic, lactic and succinic) during the fermentation; and fermentative yield. Bacteria of the genera Bacillus and Lactobacillus are the most common contaminants of the ethanolic fermentation and they might cause a decrease in the fermentative yield. The ionizing radiations may affect the microorganisms altering the DNA of the cells, which lose the ability to reproduce themselves and die. The experimental design was in randomized blocks (three) with one replicate in each block. The must was sugar-cane juice with approximately 5% of total reducing sugar. Bacteria of the following species were tested: Bacillus subtilis, Bacillus coagulans, Lactobacillus plantarum and Lactobacillus fermentum. The experiments were the inoculation of each bacteria separately in the must, the inoculation of the mixture of the four bacteria in the must and the use of natural sugar-cane juice with its own contaminating microorganisms. The contaminated must was irradiated with the doses of 0.0 (control), 2.0,4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation (60-Cobalt) at an average rate of 2.0 kGy/h. After the irradiation, the fermentation of the must was carried out using the yeast Saccharomyces cerevisiae (Fleischmann). It was also accomplished an experiment with the inoculation of the mixture of the four bacteria in the must and, instead of using gamma radiation to decontaminate the must, it was used the antimicrobial Kamoran ID in the concentration of 3 ppm. The effects of the irradiation of the must were: reduction of the bacterial population that contaminated the must decrease of the total acidity, the volatile acidity, the p H drop and the production of the organic acids (acetic, lactic and succinic) during the fermentation; increased of the viability, the replication and the percentage of living replicates of the yeast after fermentation; and increased of the fermentative yield. The treatment of the sugar-cane must with gamma radiation reduced its bacterial population, with consequent improved of the microbiological and biochemical parameters of the ethanolic fermentation, including the fermentative yield. The irradiation of the must was a better treatment than the use of the antimicrobial Kamoran ID in the fermentation because the yeast in the experiment with the antimicrobial presented smaller viability, replication and percentage of living replicates than in the experiment with the irradiated must. (author)

  16. Effects of the gamma radiation in the refrigerated bovine meat conservation.; Efeitos da radiacao gama na conservacao da carne bovina refrigerada

    Energy Technology Data Exchange (ETDEWEB)

    Mariano, Carlos Otavio

    2004-07-01

    The meat is one of our largest alimentary source of proteins, however it is bad distributed and bad taken advantage by the population in general. Some segments of the society with excess of foods and other with lack, it generated in these last ones the drama of the hunger. Today there are about 800 million people (13% of the world population) malnourished, that they live in more than 30 countries, almost in totality concentrated in Africa and Asia. But that drama also reaches our own country. Make it arrive to this segment of the less favored population, that is usually in difficult access areas, a food with nutritional quality for the consumption is the great challenge of our society. the objective is increase the shelf life of the food, maintaining their nutritional and sensorial characteristics preserved. By this way, it becomes also a challenge to protect the meat of pathogenic microorganisms and eliminate those might have been installed in the animal still alive or during the manipulation in the meat industry before arriving for the consumption. The use of the gamma radiation allowed to guarantee the product quality in the total absence of the studied pathogenic microorganisms in this project, maintaining the initials organoleptics characteristics (sensorial and physiochemical) for a large period that the one specified by the legislation, increasing this way it shelf life. The sensorial analysis indicated that until the dose of 6,0 kGy there is no alteration in the flavor and with the dose of 8,0 kGy the meat acquired a light smoked flavor, but in the appearance, aroma and texture attributes no confirmed any alterations. The color of the irradiated meat in the used doses didn't present color change compared to the no irradiated meat. The microbiological analysis pretended to verify the elimination of the pathogenic microorganisms: Salmonella ssp, Staphylococcus aureus, Bacillus cereus, Escherichia coli and Clostridium sulphite reducers, as specified in the Resolution RDC no. 12, ANVISA 02/01/2001. The necessary dose for the elimination of the Salmonella ssp and the Bacillus cereus was of 4,0 kGy and for the other microorganisms the dose of 2,0 kGy was enough. The storage test involved a maintenance period of the product for 0, 7, 14,21 and 28 days to the temperature of 7 deg C, as specify the Portaria number 304, DIPOA 22/04/1996, being verified the physicochemical characteristics in meat irradiated with the dose of 8,0 kGy in comparison with the fresh no irradiated meat. The alterations were observed in the Acidity that increased in the period in 5,5% and 12% in comparison with the no irradiated meat; Peroxyde were only detected in the irradiated meat and they stayed constant during the period; the Lipids increased significantly in the beginning of the period arriving to 113% above the no irradiated meat, it decreased during the period and at the end it presented an index of 51% below the no irradiated meat. Finally, Creatinine increases significantly in the irradiated meat, but it stayed constant during the period. The sensorial analysis in the storage test of meat samples irradiated with 4,0 kGy and 8,0 kGy was not verified alterations between the stored and the recently irradiated samples. (author)

  17. Analise da adaptação marginal de proteses fixas implanto-suportadas em liga de titanio, fundidas em monobloco ou submetidas a soldagem laser e eletroerosão atraves do assentamento passivo

    OpenAIRE

    Tatiana Bernardon Peixoto Silva

    2001-01-01

    Resumo: A proposta deste trabalho foi avaliar o desadaptação marginal de infra-estruturas de próteses fixas implanto-suportadas fundidas em monobloco e submetidas à soldagem laser, antes e após a eletroerosão através da análise do assentaIÍlento passivo. Vinte infta-estruturas foram confeccionadas a partir de um modelo mestre metálico com cinco implantes fixados na região inter-forâmes paralelos entre si, e fundidas em titânio comercialmente puro - Ti c. p. (Rematitan - Dentaurum - Pforzhein ...

  18. Influência da energia de soldagem em uniões de lâminas finas através de laser pulsado de Nd:YAG Effect of the heat input on pulsed Nd:YAG laser welding of thin foil

    Directory of Open Access Journals (Sweden)

    Vicente A. Ventrella

    2010-12-01

    Full Text Available A soldagem laser vem sendo utilizada como um importante processo de manufatura. Ela pode ser utilizada tanto no modo contínuo quanto no modo pulsado. No processo onde se utiliza laser pulsado é possível realizar soldas de costura em lâminas finas, através da sobreposição dos pulsos. Nesse caso a velocidade de soldagem é definida pela taxa de sobreposição, taxa de repetição e diâmetro do pulso. A soldagem de sobreposição de lâminas finas apresenta problemas típicos como distorção excessiva da junta soldada, falta de contato entre as lâminas a serem soldadas (presença de um gap de ar, perfuração da junta e presença de altos níveis de tensões residuais. O processo de laser pulsado é preferido em relação ao processo por laser contínuo, pois ele possibilita um melhor controle da energia de soldagem. O presente trabalho estudou a influência da energia do pulso, no caso processo de soldagem laser Nd:YAG, na soldagem de lâminas finas ( 100µm de aço inoxidável austenítico AISI 316L, utilizado no revestimento de sensores (que trabalham em ambiente corrosivo da indústria sucroalcooleira. Utilizou-se energia de pulso de 1,0 a 2,25 Joules, com incremento de 0,25 Joules e largura temporal de 4 ms. As soldas foram realizadas com proteção gasosa de argônio. Foram realizadas análises macrográficas das juntas soldadas, através de secções transversais das mesmas e, ensaios de microdureza Vickers e ensaios de tração. Os resultados obtidos mostraram que o controle da energia do pulso, em processo de soldagem por laser de lâminas finas é de fundamental importância para a geração de juntas soldadas com boas propriedades mecânicas e livres de descontinuidades. O limite de resistência da junta soldada aumentou no início e depois sofreu um pequeno decréscimo em função do aumento da energia do pulso. O processo mostrou-se muito sensível à presença de gap entre as lâminas.Laser beam welding has been used widely

  19. Avaliação da precisão de duas técnicas de união de estruturas metálicas - brasagem e soldagem a laser - em uma prótese clássica de Brånemark pelo método da microscopia eletrônica de varredura (MEV)

    OpenAIRE

    Lucio Hirokuni Kanashiro

    2005-01-01

    Este estudo avaliou a precisão de duas técnicas de união, a brasagem e a soldagem a laser, em estruturas metálicas de uma prótese clássica de Brånemark. Dez estruturas fundidas em NiCr foram segmentadas em 4 partes e analisadas no MEV em pontos pré-estabelecidos, vestibular e proximal, totalizando 8 pontos de análise para cada estrutura. Na primeira fase, foi mensurada a fenda marginal existente entre o análogo do implante e o abutment UCLA antes da união destes segmentos através da brasagem ...

  20. Use of laser fluorescence (DIAGNOdentTM for in vivo diagnosis of occlusal caries: a systematic review O uso da fluorescência a laser (DIAGNOdentTM no diagnóstico de cáries oclusais in vivo: revisão sistemática

    Directory of Open Access Journals (Sweden)

    Isauremi Vieira de Assunção Pinheiro

    2004-09-01

    Full Text Available This systematic review was conducted to assess the accuracy of laser fluorescence (DIAGNOdentTM for diagnosis of occlusal caries in permanent teeth, using any sort of gold standard. The MEDLINE, LILACS, BBO and Cochrane library databases accessed by BIREME were searched for English, Spanish and Portuguese-language papers published between 1982 and 2003. Four works in English were selected. DIAGNOdentTM was found to be an accurate method for diagnosis of occlusal caries, mainly if employed simultaneously with visual inspection.Esta revisão sistemática foi realizada para avaliar a precisão da fluorescência a laser (DIAGNOdentTM para o diagnóstico da cárie oclusal em dentes permanentes, utilizando qualquer tipo de gold standard. As bases de dados MEDLINE, LILACS, BBO e Cochrane Library, acessadas via BIREME, foram utilizadas para a busca de artigos em idioma inglês, espanhol e português, publicados de 1982 a 2003. Foram selecionados quatro trabalhos em inglês. Foi observado que o DIAGNOdentTM é um método preciso para o diagnóstico da cárie oclusal, principalmente se associado à inspeção visual.

  1. GERAÇÃO DE MODELO DIGITAL DE TERRENO POR MEIO DA FILTRAGEM DE DADOS OBTIDOS POR VARREDURA A LASER UTILIZANDO UM MÉTODO BASEADO NO PRINCÍPIO DA DECLIVIDADE

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    Wallace Felipe Francisco Cardoso

    2014-06-01

    Full Text Available Due the advances in the technology of laser scanning systems, research in several countries have been initiated with the aim of exploring the recently technological resources developed. The result obtained by laser scanning systems provided the details of regions features and update many of the national territories models. The data generated by laser scanning match the altimetry data set named as Digital Elevation Model. This model derivation, when containing only terrain features, is called Digital Terrain Model. However, the Digital Terrain Models cannot be easily generated by laser scanning. In general, the Digital Terrain Models are derived from Digital Elevation Models applying filtering methods. This work objective is to adapt a Digital Elevation Model filtering method and discuss the results obtained.

  2. Inibição da expressão de ciclooxigenase 2 em feridas cutâneas de camundongos NOD submetidos à terapia a laser de baixa intensidade Inhibition of cyclooxygenase 2 expression in NOD mice cutaneous wound by low-level laser therapy

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    Carolina de Lourdes Julião Vieira Rocha

    2012-09-01

    Full Text Available CONTEXTO: A terapia a laser de baixa intensidade (LLLT tem sido relatada como importante moduladora da cicatrização de feridas cutâneas aumentando a proliferação fibroblástica associada ao aumento da expressão da citocina fator transformador de crescimento- β2 (TGF-βB2. OBJETIVO: No presente estudo foram avaliados os efeitos da LLLT sobre a expressão da enzima ciclooxigenase 2 (COX2 no sítio do reparo tecidual utilizando o modelo experimental com camundongos diabéticos não obesos (NOD para estudar a cicatrização de feridas cutâneas. MÉTODOS: Foram utilizados 30 camundongos NOD, destes 14 ficaram diabéticos e foram divididos em dois grupos: o grupo I (n=7 foi submetido a um procedimento cirúrgico de feridas cutâneas e o grupo II (n=7 foi submetido a um procedimento cirúrgico de feridas cutâneas e tratados com LLLT. O grupo II foi submetido à LLLT nos seguintes parâmetros: 15 mW de potência, dose de 3,8 J/cm² e tempo de aplicação de 20 segundos. Após sete dias do ato cirúrgico e após aplicação do laser, os animais foram eutanasiados com sobredose de anestesia e amostras das feridas foram colhidas para posterior análise histopatológica, histomorfométrica e imuno-histoquímica. RESULTADOS: A LLLT promoveu a inibição da expressão da COX2 em feridas cutâneas de camundongos diabéticos. CONCLUSÃO: Em conjunto, os resultados sugeriram que a LLLT é capaz de modular negativamente a expressão da enzima COX2 contribuindo para o controle da resposta inflamatória em feridas cutâneas de camundongos NOD.BACKGROUND: Low-level laser therapy (LLLT has been reported to modulate the healing of wounds by inducing an increase in fibroblast number associated with increased expression of the cytokine transforming growth factor-β2 (TGF-β2. OBJECTIVE: In the present study, the effect of LLLT on expression of COX2 at the site of tissue repair was evaluated, using an experimental model with non obese diabetic mice (NOD to study

  3. Clinical evaluation of dentin hypersensitivity treatment with the low intensity Gallium-Aluminum-Arsenide laser - AsGaAl Avaliação clínica do tratamento da hiperestesia dentinária com laser de baixa potência de Arseniato de Gálio-Alumínio - AsGaAl

    Directory of Open Access Journals (Sweden)

    Luciana Chucre Gentile

    2004-12-01

    TODOS: Foram selecionados 32 pacientes, 22 do sexo feminino e 10 do sexo masculino, com idades entre 20-52 anos. Os 32 pacientes foram distribuídos de maneira aleatória em dois grupos, um tratado e outro controle, um total de 68 dentes compôs a amostra, sendo que 35 compuseram o grupo tratado, e 33 o grupo controle. O grupo tratado foi submetido a seis sessões sucessivas de irradiações em intervalos de 48 a 72 horas, o grupo controle recebeu como placebo aplicações de luz do fotopolimerizador. RESULTADOS: observou-se redução significativa na sensação dolorosa entre a fase inicial e após as seis sessões de tratamento com laser, porém tal redução, também pode ser observada para o grupo controle, submetido ao placebo. CONCLUSÃO: a terapia com laser de baixa potência de AsGaAl induz redução estatisticamente significante da sensação dolorosa, após cada uma das aplicações, e entre o início e o final do tratamento, embora não tenha havido, diferença estaticamente significante, ao final do tratamento e após a avaliação mediata dos resultados (após 6 semanas entre o grupo tratado (laser e o grupo controle (placebo; dificultando a mensuração real da efetividade do laser e do efeito placebo.

  4. Efeitos da laserterapia de baixa potência na reposta oxidativa epidérmica induzida pela cicatrização de feridas Effects of low-level laser therapy on epidermal oxidative response induced by wound healing

    Directory of Open Access Journals (Sweden)

    PCL Silveira

    2009-08-01

    Full Text Available INTRODUÇÃO: O uso terapêutico do laser de baixa potência na fisioterapia tem aumentado significativamente. OBJETIVO: Avaliar os efeitos da laserterapia de baixa potência nos parâmetros oxidativos na cicatrização de feridas em ratos. MÉTODOS: Dezoito ratos Wistar foram divididos randomicamente em 3 grupos (controle 5 dias, n=6; 5 dias/2 J/cm², n=6; 5 dias/4 J/cm², n=6. Uma única ferida circular medindo 8 X 8 mm foi cirurgicamente realizada no dorso do rato. Trinta minutos após a última irradiação, os ratos foram submetidos à eutanásia, e o tecido irradiado foi removido cirurgicamente e armazenado a -70ºC. Foi determinada a atividade das enzimas da cadeia respiratória: DCIP oxirredutase (complexo II e succinato desidrogenase solúvel (SDH, atividade do citocromo c oxidase (complexo IV, produção de ânion superóxido, atividade da superóxido dismutase (SOD e catalase (CAT. A lipoperoxidação foi avaliada pela técnica de TBARS. RESULTADOS: Os resultados mostram uma diminuição na atividade do complexo II nos grupos irradiados por 5 dias com 2 e 4 J/cm², enquanto a produção de ânion superóxido mostrou uma diminuição significativa no grupo irradiado por 5 dias com 4 J/cm² em relação ao grupo controle. Além disso, um aumento significativo na atividade da catalase foi observado no grupo irradiado por 5 dias com 2 J/cm², como também uma diminuição da peroxidação lipídica nos dois grupos irradiados. CONCLUSÕES: Os resultados do presente estudo indicam que o laser estimula a atividade antioxidante e protege a célula contra danos oxidativos durante o processo de cicatrização de feridas cutâneas em ratos.BACKGROUND: Therapeutic use of low-level laser in physical therapy has increased significantly. OBJECTIVE: To assess the effects of low-level laser therapy on the oxidative parameters of wound healing in rats. METHODS: Eighteen Wistar rats were randomly divided into three groups (control, 5 days, n=6; 2 J

  5. O impacto da cirurgia de ceratectomia fotorrefrativa (PRK e ceratomileuse assistida por excimer laser in situ (LASIK na qualidade visual e de vida em pacientes com ametropias The impact of photorefractive excimer laser keratectomy (PRK and laser in situ keratomileusis (LASIK on visual quality and life in patients with ametropias

    Directory of Open Access Journals (Sweden)

    Ricardo Belfort

    2008-02-01

    Full Text Available OBJETIVO: Avaliar a qualidade de vida e de visão e o estresse de pacientes portadores de ametropias submetidos a procedimentos cirúrgicos. MÉTODOS: Estudo longitudinal observacional em que foram estudados 100 pacientes; 54 usuários de óculos, 21 usuários de lentes de contato interessados no procedimento cirúrgico e 25 controles usuários de óculos ou lentes de contato, mas que não desejavam ser operados no período de um ano. Os questionários aplicados foram o National Eye Institute Visual Function Questionnaire (NEI-VFQ-25 de qualidade de vida e o Self Reporting Questionnaire - SRQ-20 para avaliação da saúde mental. Os pacientes que se submeteram à cirurgia responderam aos questionários aplicados por uma observadora antes da mesma, três, seis e doze meses após a intervenção. O grupo controle respondeu de forma auto-aplicada no início do estudo, seis e doze meses após a primeira avaliação. RESULTADOS: No grupo da cirugia dos 54 pacientes que usavam óculos 39 fizeram cirurgia de ceratectomia fotorrefrativa por excimer laser(PRK e 15 fizeram ceratomileuse assistida por excimer laserin situ (LASIK e dos 21 que usavam lentes de contato 12 fizeram cirurgia de ceratectomia fotorrefrativa e nove fizeram ceratomileuse assistida por excimer laser in situ (LASIK. O grupo controle esteve estável durante os 12 meses em relação aos instrumentos aplicados. Três meses após a cirurgia o grupo da cirurgia apresentou melhora significante da qualidade de vida e de visão em relação ao pré-operatório independentemente do tipo de cirurgia realizada. Um ano após a cirurgia os índices de qualidade de vida e de saúde mental, foram semelhantes aos do grupo controle. O Self Reporting Questionnaire - SRQ 20 mostrou diminuição significante do índice de sintomas a partir dos três meses de pós-operatório. CONCLUSÃO: A qualidade de visão e de vida dos pacientes submetidos à cirurgia de correção de ametropia mudou

  6. Evaluation of the permeability and morphological alteration of the dental surface after apicoectomy, treatment and preparation with Er:YAG and Nd:YAG lasers; Avaliacao da permeabilidade e da alteracao morfologica da superficie dentinaria apos apicectomia, tratamento e retropreparo com os lasers de Er:YAG e Nd:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Rodrigo Guerra de

    2001-07-01

    One of the objectives of endodontic treatment is to resolve pathological periapical processes caused by microbial contamination of the dental pulp. Correct execution of the necessary chemical preparation prior to surgery generally results in positive outcomes. However, a percentage of cases do not respond favorably and therefore require retreatment, a conservative therapeutic option. There are meanwhile a number of treatment failures which do not respond to these conservative measures and must therefore be subjected to paraendodontic surgical procedures. One of the principal problems of this therapeutic conduct is linked to the surface permeability of the dentin after apicoectomy and the lack of adequate marginal adaptation between the retrofilling material and the cavity walls. This permits the percolation of microorganisms and their metabolic by products from the system of root canals to the periapical region, thereby compromising the necessary tissue repair. The present work proposes the evaluation of the surface and marginal permeability of cut dentin after apicoectomy and treatment with Er:YAG and Nd:YAG lasers with fiber optics and then retrofilled with intermediate restorative material (IRM). A total of 24 single rooted teeth whose canals were endodontically treated were divided into 3 experimental groups: group I, whose apices were sectioned with an Er:YAG laser and the resulting cavity and the cut dental surface were irradiated with this laser via a 50/10 type fiber; in group II the apicoectomy was conducted with an Er:YAG laser and the resulting cavity and the cut surface were irradiated with a Nd:YAG laser; in group III, the samples were apicoectomized and the cavities were treated with a high speed bur (control group). Analysis of the infiltration of the dye methylene blue throughout the cut dental surface and the reconstruction demonstrated that the samples in the irradiated groups presented lower indices of infiltration than the control group. The

  7. Cicatrização da membrana timpânica na timpanocentese com laser de argônio comparado à técnica com microlanceta: estudo experimental em ratos Tympanic membrane healing in myringotomies performed with argon laser or microknife: an experimental study in rats

    Directory of Open Access Journals (Sweden)

    Lucio Almeida Castagno

    2006-12-01

    Full Text Available Otite média secretora (OMS e otite média aguda recorrente (OMAR podem necessitar tratamento cirúrgico para adequada ventilação da orelha média. A abertura clássica do tímpano (timpanocentese requer incisão por microlanceta sob controle de microscópio cirúrgico e mantém-se patente por alguns dias. Estudos recentes sugerem que a timpanocentese feita por diferentes lasers pode permanecer permeável por maior tempo, o que possibilitaria a normalização da otite média. MATERIAL E MÉTODOS: Neste estudo experimental 34 ratos linhagem Wistar, albinos, machos adultos pesando cerca de 300g, foram anestesiados com cetamina 27 mg/kg e xilazina 2,7 mg/kg. A seguir, foram submetidos à timpanocentese incisional com microlanceta no ouvido direito (ML-OD, e à timpanocentese mediada por laser de argônio no ouvido esquerdo (LA-OE. RESULTADOS: Não houve diferença significativa no tempo de cicatrização das timpanocenteses feitas com laser de argônio ou microlanceta. Todas as timpanocenteses cicatrizaram em 10 dias. CONCLUSÃO: A timpanocentese com laser de argônio apresentou patência e cicatrização semelhantes à técnica clássica com microlanceta realizada em ratos Wistar sem enfermidades de orelha média.Secretory otitis media (SOM and recurrent acute otitis media (RAOM may require surgical treatment to proper ventilate the middle ear. Incisional myringotomy is usually done under microscopy with a micro-knife , but it remains patent for just a few days. Recent research indicates that laser assisted myringotomies remain open much longer, allowing middle ear ventilation and healing. MATERIAL AND METHODS: In this experimental study 34 white, male, adult, Wistar rats, without middle ear disease were submited to anesthesia with ketamine 27 mg/kg and xylazine 2,7 mg/kg. Incisional myringotomy was done on the right ear, while laser myringotomy was done on the left. Myringotomies were evaluated periodically until healing. RESULTS: The healing

  8. Análise clínica do efeito da fotobiomodulação laser (GaAs - 904 nm sobre a disfunção temporomandibular Clinical analysis of the effect of laser photobiomodulation (GaAs - 904 nm on temporomandibular joint dysfunction

    Directory of Open Access Journals (Sweden)

    JC Frare

    2008-02-01

    Full Text Available INTRODUÇÃO: Nos últimos anos, tem sido notado grande interesse no estudo de novas modalidades para o tratamento das disfunções temporomandibulares (DTM. A dor descrita como dor facial, cefaléia ou dor de ouvido, comumente exacerbada pela função da mandíbula, é, em geral, a principal queixa do paciente. A fotobiomodulação laser vem sendo utilizada no tratamento da dor em DTM. OBJETIVO: O objetivo deste estudo foi verificar o nível de dor de pacientes com DTM tratados com fotobiomodulação laser. MATERIAIS E MÉTODOS: Foram estudados 18 pacientes do sexo feminino, com idade média de 27 anos (± 7, com diagnóstico de DTM, os quais foram separados aleatoriamente em dois grupos: Placebo (Controle e Tratado. O Grupo Tratado (n= 10 recebeu atendimento duas vezes por semana, por quatro semanas consecutivas (totalizando oito aplicações. Utilizou-se o laser de GaAs (904 nm, 6 J/cm², 0,38 mW/cm², área do feixe de 0,039 cm², com modo de emissão contínua. Realizou-se a aplicação do laser em quatro pontos pré-auriculares e um em meato acústico externo. O Grupo Placebo (n= 8 foi manipulado como o tratado, porém com o laser desligado. Para análise do nível de dor dos pacientes, empregou-se a Escala Visual Analógica (EVA de dor, antes e após a terapia. Para a análise dos dados, empregou-se o teste t de Student, com nível de significância de 5% (pINTRODUCTION: Over the last few years, there has been great interest in studying new methods for treating temporomandibular joint dysfunction (TMD. Pain, described as facial pain, headache or earache, usually exacerbated by jaw use, is generally the patients' main complaint. Laser photobiomodulation has been used for treating pain in cases of TMD. OBJECTIVE: The aim of this study was to investigate the pain levels in TMD patients treated with laser photobiomodulation. MATERIAL AND METHODS: Eighteen female patients of mean age was 27 years (± 7, with a diagnosis of TMD, were studied

  9. Avaliação imediata da dor e edema em lesão muscular induzida por formalina e tratada com laser 808 nm Immediate pain and edema assessment in muscular injury induced by formalin and treated with low-level laser (808nm

    Directory of Open Access Journals (Sweden)

    Emerson Borato

    2008-10-01

    Full Text Available O laser de baixa potência induz a bioestimulação celular, podendo acelerar a cicatrização de feridas, promover a regeneração do músculo esquelético, diminuir a resposta inflamatória, estimular a neoformação de vasos sanguíneos e diminuir a dor. O objetivo deste estudo foi analisar os efeitos de três doses de laser de baixa intensidade (808nm, na dor e edema imediatos, em ratos submetidos a lesão experimental do músculo gastrocnêmio lateral. Foram utilizados 24 ratos Wistar, distribuídos aleatoriamente em quatro grupos, sendo: GC - animais lesionados e tratados com aparelho desligado (simulacro; G20 - animais lesionados e irradiados com dose de 20J/cm²; G50 - animais lesionados e irradiados com 50J/cm; e G100 - animais lesionados e irradiados com 100J/cm². Para a produção da lesão experimental, introduziu-se 0,1mL de formalina a 5% no ventre do músculo gastrocnêmio lateral direito. A avaliação da dor ocorreu através do tempo de elevação da pata (TEP e o edema foi avaliado com auxílio de paquímetro metálico; ambas as avaliações ocorreram pré-lesão, pós-lesão, pós-tratamento, duas, oito e 24 horas pós-lesão. Os resultados mostraram aumento significativo do TEP e da avaliação com paquímetro, após a indução da lesão. Conclui-se que laser nos parâmetros utilizados não produziu diminuição na dor e edema, em animais submetidos a lesão muscular com injeção de formalina a 5%.Low-level laser therapy induces to cellular bioestimulation and can accelerate wound healing, promote skeletal muscle regeneration, decrease inflammatory response, stimulate neovascularization and decrease pain. The aim of this study was to analyze the effects of three doses of low-level laser therapy (808 nm, in the immediate pain and edema, in rats submitted to experimental injury of the lateral gastrocnemius muscle. Twenty four Wistar rats, randomly distributed in the following four groups were used: CG - injured and treated

  10. Marginal microleakage in vitro study of occlusal fissures sealing prepared and etched or not with Er: YAG laser; Avaliacao in vitro da microinfiltracao marginal em selamentos oclusais preparados e condicionados ou nao pelo laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Fernanda de Almeida

    2004-07-01

    The aim of this in vitro study was to evaluate the degree of marginal microleakage in occlusal sealing by invasive techniques, after preparation with Er:YAG laser followed or not by Er:YAG laser etching and compared to the conventional technique. Thirty human premolars were divided into three groups: A (control group) - cavities were prepared with high speed and etched with 37% orthophosphoric acid; group B - cavities were prepared with Er:YAG (350 mJ, 4 Hz and 112 J /cm{sup 2}) and etched with 37% orthophosphoric acid; group C - cavities were prepared with Er:YAG laser (350 mJ, 4 Hz and 112 J/cm{sup 2}), and etched with Er:YAG laser (80 mJ, 4 Hz and 25 m/cm{sup 2}). All cavities were treated with the same adhesive system and restored with flow composite according to manufacturer instructions. Teeth were submitted to thermal cycling procedures and immersed in 50% Silver Nitrate Solutions for 8 hours in total darkness. Teeth were sectioned longitudinally in the bucco-lingual direction, in slices of 1 mm thick. Each slice was immersed into photo developing solution under 16 hours of fluorescent light. Slices were photographed and microleakage was scored from 0 to 7 J by three standard examiners. Results showed statistically significant differences for group C (Er:YAG laser preparation and etching). We concluded that Er:YAG laser can be used for cavity preparation of occlusal sealing, like the conventional high speed method. However, this laser, used as enamel etching agent, could not promote an adequate surface for adhesive procedures. (author)

  11. Lasers '89

    International Nuclear Information System (INIS)

    Harris, D.G.; Shay, T.M.

    1990-01-01

    This book covers the following topics: XUV, X-Ray and Gamma-Ray Lasers, excimer lasers, chemical lasers, nuclear pumped lasers, high power gas lasers, solid state lasers, laser spectroscopy. The paper presented include: Development of KrF lasers for fusion and Nuclear driven solid-state lasers

  12. Root planing with Er:YAG laser X Gracey curette, a study in vitro in scanning electron microscopic study; Avaliacao em microscopia eletronica de varredura da superficie radicular, raspada e alisada com Er: YAG laser

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    Mello, Fabiano Augusto Sfier de

    2000-07-01

    The Er:YAG laser has been studied as a periodontal therapies, used to remove subgingival calculus and its bactericidal effects. The proposal of this study is to evaluate the effectiveness of the Er:YAG laser in root planing in comparison to the traditional method, not surgical. Six recently extracted due to the disease periodontal, were cut longitudinally, tends like this two half of the root. These half were separate in four groups. The first group is the natural tooth (group controls negative), the second group (group controls) was accomplished to root planing with Gracey curette. And in the third to Er:YAG laser with a contact tip, using a 45 deg angle in relation to the root; in the fourth group was scraped and planned with Er:YAG laser and complemented root planing with Gracey curette. The used energy was of 100 mJ (out put) and the frequency of 10 Hz accomplished with irrigation. The obtained results were similar in the groups 2 and 3 in comparison to the amount of smear-layer. In group 4 however, better result was obtained, because the image (SEM) was much more regular and with less amount of smear-layer. The conclusion of the work is that with the association of the laser technique and Gracey curette the results are superior to the conventional treatment. (author)

  13. In vitro study of hydroxy apatite and enamel powder fused in human enamel by Nd:YAG laser; Estudo in vitro da fusao de hidroxiapatita e esmalte em superficies de esmalte humano pelo laser de Nd:YAg

    Energy Technology Data Exchange (ETDEWEB)

    Ferrreira, Marcus Vinicius Lucas

    2000-07-01

    The aim of this study was to evaluate the effects of pulsed Nd:YAG (1064 nm) laser irradiation on hydroxyapatite and enamel powder fusion. This laser beam is not well absorbed by this two compounds for this reason they were mixed with vegetal coal to increase the absorption of the laser beam. Fifteen enamel flat surfaces and six occlusal enamel surfaces were prepared with three different substances: hydroxyapatite mixed with vegetal coal (3:1 in weigh); enamel powder mixed with vegetal coal (3:1 in weigh); vegetal coal. The occlusal surfaces were utilized to determine if the compounds could seal pits and fissures. Flat surfaces were utilized to determine fusion of hydroxyapatite and enamel powder. All samples were irradiated with Nd:YAG laser with the parameters: 80 mJ, 15 Hz, 1,2 W, 100 {mu}s pulse-width, 131,1 J/cm{sup 2}. Laser beam was delivered to the samples with a 300 {mu}m diameter fiber optic. Morphology of the irradiated surfaces were examined by scanning electron microscopy (SEM). The compounds with hydroxyapatite and enamel powder were fused to enamel surfaces. Only partial pits and fissures sealing could be observed. (author)

  14. 'In vitro' study of the efficacy of diode laser and LED irradiation during dental bleaching; Estudo 'in vitro' da acao do LED e laser de diodo no clareamento dental

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Marcia Cristina da Silva

    2003-07-01

    This in vitro study evaluated the efficacy of LED and laser diode irradiation during the dental bleaching procedure, using two bleaching agents (Opalescence X-tra and HP Whiteness). The diode laser and the LED were operated in the continuous mode, with wavelength of 808 nm and 470 nm, respectively. The results of the irradiations were characterized with the CIELAB system calculating the L{sup *}a{sup *}b{sup *} values for the darkened and the bleached teeth (60 bovine incisors). This is to our knowledge the first time that light sources laser and LED are compared with respect to their whitening capability when applied to different agents. Significant differences in the chroma value are obtained for the two whitening agents and for the different light sources, too. Also, in terms of luminance, the combination of laser/ Whiteness HP showed significantly better results than when the same agent was used alone or in combination with LED. Best overall results are obtained with the combination of Whiteness HP and laser. (author)

  15. Estudo da topografia e da osseointegração de implante de titânio sob ação do LASER, com ou sem deposição de hidroxiapatita, em coelhos

    OpenAIRE

    Sisti, Karin Ellen

    2011-01-01

    Objetivo: Estudar a topografia a osseointegração de implantes de titânio sob ação do LASER de alta intensidade com e sem deposição química de hidroxiapatita, em coelhos. Método: Foram utilizados 30 coelhos albinos que receberam em suas tíbias 3 tipos de superfície de implantes: grupo controle(GI) implantes usinados, grupo(GII) irradiado LASER(Yb), e grupo irradiado e depositado hidroxiapatita pelo método biomimético(GIII). Após os períodos de avaliações (30 e 60 dias) os implantes foram subme...

  16. Nd:YAG laser in caries prevention: a clinical study; Avaliacao clinica da eficiencia do laser de Nd:YAG associado ao fluor fosfato acidulado na prevencao de caries de sulcos e fissuras de criancas e adolescentes

    Energy Technology Data Exchange (ETDEWEB)

    Boari, Heloisa Gomes Dimiranda

    2000-07-01

    The caries prevention by using laser irradiation has been investigated during the last 30 years. The Nd: YAG laser associated with acidulated phosphate fluoride has been shown as a very promising technique for enamel caries prevention. The aim of this work was to clinically evaluate the efficiency of Nd: YAG laser associated with acidulated phosphate fluoride in pit and fissure caries prevention of children and adolescents. In this work it was determined the dye that enhance the effect of Nd: YAG laser in enamel. It was selected 242 pre-molar and molar teeth from 33 children and adolescents, aged from 7 to 15 years old. The selected teeth were free from caries or decalcification marks (active white marks) to the clinical and radiographic exams. The teeth were divided into two groups: the first group was laser irradiated and their homologous remained as a control. The right side teeth were dye-assisted Nd:YAG laser irradiated. The dye solution was a moisture of dust coal and equal parts of water and alcohol. The irradiation conditions were 60 mJ/10 Hz, optical fiber in contact mode, with diameter of 300 {mu}m, resulting in an energy density of 84,9 J/cm{sup 2}. The oclusal surface of the teeth was completely irradiated, specially on the slopes and in the deepest part of the pits and fissures. This procedure was repeated three times. In the sequence it was applied the acidulated phosphate fluoride for 4 minutes. On the left side teeth - control group- only acidulated phosphate fluoride was applied for the same time. The final examination considered the presence of caries and active white marks after a period of one year. There were statistical significant differences (p < 0.01) between the lased + fluoride group and the non irradiated group. The present study concluded that the technique used in this work can be an alternative clinical method for caries prevention. (author)

  17. Morphological change study on root surfaces treated with curettes, sonic instruments or Er:YAG laser; Estudo in vitro da alteracao morfologica em superficie radicular tratada com curetas, aparelho ultrasonico ou com laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes Filho, Arlindo Lopes

    2004-07-01

    Periodontal disease is caused by dental plaque and dental calculus on roots surfaces, specially on cervical areas. As dental plaque is the main cause and dental calculus a secondary one, it is practically impossible to separate one factor to the other one. In order to get periodontal tissue health it is necessary to eliminate dental plaque and calculus from root surfaces. In this sense, Er:YAG laser comes in as an excellent way to control periodontal disease, not only, by removing calculus and dental plaque but also for its bacteria reduction. The aim of this study is to compare, by S.E.M., root surfaces changing when they are treated with curettes and ultrasonic scaling or Er:YAG laser irradiation with two different energy levels of 60 mJ/pulse and 100 mJ/pulse and repetition tax of 10 Hz (in the display). It is also objective of this study to check a possible thermic damage to pulp tissue when the roots surfaces are irradiated with Er:YAG laser. We used for this study, five human dental roots, each one of them were cut into four samples, giving us a total of twenty samples, which were divided in five groups of four samples each one. The control group, we did not indicated any kind of treatment. The first group, the roots samples were scaled and planned with Gracey curettes 5/6 and 7/8. The second group, the roots samples were treated with ultrasonic instruments. The third group was irradiated with Er:YAG laser using 60 mJ/pulse , 10 Hz and energy density of 4 J/cm{sup 2} (approximated). The fourth group was irradiated with Er:YAG laser using 100 mJ/pulse, 10 Hz and energy density of 7 J/cm{sup 2} (approximated). The results analysis showed that roots scaling either with Gracey curettes or with ultrasonic instruments created smear layer covering roots surfaces; roots surfaces irradiated with Er:YAG laser showed few roughness in the third group; roots surfaces irradiated with Er:YAG laser showed no smear layer and the Er:YAG laser irradiation did not bring any

  18. Efeitos da terapia fotodinâmica e de uma única aplicação de laser de baixa potência em bactérias in vitro Effects of photodynamic therapy and of a sole low-power laser irradiation on bacteria in vitro

    Directory of Open Access Journals (Sweden)

    Rogério Gubert Benvindo

    2008-01-01

    Full Text Available O laser de baixa potência vem sendo usado para acelerar a cicatrização em úlceras de pressão devido a seus efeitos cicatrizante, antiinflamatório, antiedematoso e analgésico. No entanto, não há consenso quanto a seu efeito em úlceras infectadas. O objetivo deste estudo foi verificar o efeito bactericida da laserterapia e da terapia fotodinâmica (TFD com laser de baixa potência, InGaP, 670 nm, em doses de 2, 4 e 6 J/cm², em bactérias gram-positivas e gram-negativas in vitro. Foram preparadas 32 placas de Petri com bactérias, 16 com Pseudomonas aeruginosa e 16 com Staphilococcus aureus. Aleatoriamente dividiu-se cada grupo em oito subgrupos (duas placas cada: três subgrupos tratados só com laserterapia, em doses de 2 J/cm², 4 J/cm² e 6 J/cm²; três subgrupos tratados com TFD, em doses de 2 J/cm², 4 J/cm² e 6 J/cm²; um tratado apenas com fotossensibilizante (azul de metileno a 0,1 µg/ml; e um subgrupo não tratado (controle. Os subgrupos laser e TFD foram irradiados uma única vez e incubados por 24 horas. Os outros dois subgrupos não receberam irradiação. As culturas foram analisadas visualmente para verificação ou não do halo de inibição. Em todos os subgrupos, de ambas as bactérias, não foi observado qualquer halo de inibição nem de crescimento. Conclui-se que a terapia a laser e a fotodinâmica de baixa potência (InGaP, 670 nm não produziram efeitos bactericidas e/ou bacteriostáticos, tampouco tendo havido efeito bioestimulante sobre as bactérias.Low-level laser therapy has been used to speed up healing process of pressure ulcers due to its antiinflammatory, analgesic, anti-edematous, and scarring effects. However there is no consensus on its effect on infected ulcers. The aim of this study was to verify the bactericidal effect of low-level laser therapy (InGaP, 670 nm and photodynamic therapy (PDT at 2, 4 and 6 J/cm² doses, onto gram-negative and gram-positive bacteria in vitro. Thirty two Petri plates

  19. The influence of low-level laser therapy on biomodulation of collagen and elastic fibers A influência da terapia a laser de baixa densidade de energia na biomodulação das fibras colágenas e elásticas

    Directory of Open Access Journals (Sweden)

    Lívia Souza Pugliese

    2003-12-01

    Full Text Available The study of low-level laser therapy upon extracellular matrix elements is important to understand the wound healing process under this agent. However, little is known about the interference of laser light in relation to collagen and elastic fibers. Cutaneous wounds were performed on the back of 72 Wistar rats and a Ga-Al-As low-level laser was punctually applied with different energy densities. The animals were killed after 24, 48, 72 hours and 5, 7 and 14 days. Tissues were stained with hematoxilin-eosin, sirius red fast green and orcein and then analyzed. It was observed that the treated group exhibited larger reduction of edema and inflammatory infiltrate. The treated animals presented a larger expression of collagen and elastic fibers, although without statistical significance (p > 0.05. Treatment with a dosage of 4 J/cm² exhibited more expressive results than that with 8 J/cm². In this study, the authors concluded that low-level laser therapy contributed to a larger expression of collagen and elastic fibers during the early phases of the wound healing process.O estudo da terapia a laser de baixa densidade de energia sobre os diversos constituintes da matriz extracelular é crucial para o entendimento do processo cicatricial sob esse agente. Todavia, pouco se sabe sobre a interferência do laser em relação às fibras colágenas e elásticas. Realizaram-se ferimentos cutâneos padronizados no dorso de setenta e dois ratos Wistar e, em seguida, aplicação pontual do raio laser de baixa potência do tipo Arseneto de Gálio-Alumínio (Ga-Al-As com diferentes densidades de energia. Os animais foram sacrificados com 24, 48 e 72 horas e aos 5, 7 e 14 dias. Procedeu-se à análise das secções teciduais coradas por hematoxilina-eosina, sírius vermelho e orceína. Observou-se, que nos grupos submetidos à terapia a laser, houve maior redução do edema e infiltrado inflamatório. Os animais tratados apresentaram uma maior expressão de fibras

  20. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0-3) by

  1. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0

  2. Clinical and morphologic evaluation of Er:YAG laser action at the front of cervical dentinal hypersensitivity; Avaliacao clinica e morfologica da acao do laser de Er:YAG frente a hipersensibilidade dentinaria cervical

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Dalva Maria

    2001-07-01

    This work was achieved in vivo and in vitro to evaluate the efficiency of Er:YAG laser in the cervical dentinal hypersensitivity treatment (HSDC). The Clinical study was achieved in patients with HSDC. The treatment was realized in five sessions: the first for selection, the second for exams (clinic and X-Ray) and trying to remove the etiologic factors that could cause the HSDC. The third and fourth sessions were subjected to the radiation with that protocol: 60 mJ energy ,2 Hz frequency, 6 mm out of focus, under air cooling, 20 seconds each application which the same was repeated four times with one minute breaks, which scanning movements and without using anaesthetics. The fifth was evaluation. The patients were evaluated and registered in a subject scale of pain 0 to 3, in the beginning and end of each session of irradiation, and one month after the last session. The results showed that for the irradiated group occurs significant differences in the beginning of each session and between. For the control group did not occur significant differences in the beginning and after each session, but did show a difference between the sessions. As the control group as the irradiated group, had reduction of sensibility between the session. For the morphologic study nine teeth were selected, 7 molars and 2 pre-molars from operative dentistry discipline. Half of the surface was irradiated with Er:YAG laser, the same protocol used in vivo, and the other half was used as a control without receiving any laser irradiation. Subsequently, specimens were prepared for SEM examinations. The results showed that laser treated surfaces showed a reduction of dentine tubular diameter with partial or total closure of the dentine tubules. For the control group, it was observed bigger amounts smear layer and open dentine tubular. The results obtained indicated that the Er:YAG laser can contribute to the HSDC treatment. (author)

  3. Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application Estudo comparado da cicatrização da prega vocal de suínos após exérese de fragmento com laser de CO2 e aplicação tópica pós-operatória de mitomicina e 5-fluorouracil

    Directory of Open Access Journals (Sweden)

    Eduardo Baptistella

    2009-02-01

    Full Text Available PURPOSE: To evaluate the deposition of collagen fibers at pig's vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS: There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragment's exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS: In control group, the mean rate of right vocal fold's collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION: Mitomycin and 5-fluorouracil had promoted beneficial change in vocal fold's cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.OBJETIVO: Avaliar a deposição das fibras de colágeno total em pregas vocais suínas após o uso tópico de mitomicina ou 5-fluorouracil nas exéreses parciais de mucosa com laser de CO2. MÉTODOS: Foram utilizados 18 porcos da raça Larger white anestesiados e submetidos à exérese de fragmento de mucosa de borda livre da prega vocal direita e prega vocal esquerda. Os animais foram divididos em 3 grupos com 6 animais cada: grupo controle, sem aplicação de medicação tópica; grupo mitomicina, com uso tópico dessa substância; grupo 5-fluorouracil, uso tópico. Após 30 dias do experimento os animais foram submetidos à eutanásia, coletadas amostras das pregas vocais e coradas pela técnica do picrosirius red com polarização para a

  4. \\"Avaliação da desinfecção da dentina radicular em profundidade provocada pela irradiação do laser de diodo de alta potência\\"

    OpenAIRE

    Eliana Barbosa de Souza

    2007-01-01

    A presença de microrganismos no interior do sistema de canais radiculares é a principal causa do fracasso na terapia endodôntica. A importância da sanificação durante o preparo do canal fica clara, portanto. Dentre os microrganismos isolados nos casos de insucesso o Enterococcus faecalis é comumente encontrado. O E. faecalis é um microrganismo resistente à terapia endodôntica, à medicação intracanal de hidróxido de cálcio e sua presença contribui para o insucesso em Endodontia. A radiação las...

  5. A efetividade do laser de HeNe 632,8 nm no reestabelecimento da integridade dos tecidos cutâneos em animais experimentais: revisão sistemática Effectiveness of HeNe 632.8 nm laser on skin tissue integrity repair in experimental animals: a systematic review

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    Clarissa Tôrres Leal

    2012-09-01

    Full Text Available O objetivo desta revisão sistemática foi analisar o efeito do laser de HeNe na cicatrização de feridas em ratos. Foram selecionados estudos experimentais que adotaram o laser HeNe para o tratamento de feridas agudas em ratos adultos saudáveis, com lesões induzidas por bisturi, nas bases de dados PubMed/MEDLINE, LILACS e SciELO. Foram utilizados os seguintes descritores: cicatrização de feridas e colágeno, de acordo com o MeSH e o DeCS, além dos unitermos laser HeNe e reparação da pele e seus equivalentes em inglês e espanhol. Três estudos foram incluídos na revisão sistemática, não sendo possível a realização de metanálise, devido à impossibilidade de comparação entre as metodologias dos estudos selecionados. Todos os estudos realizaram análise por meio de cortes histológicos das cicatrizes. A presença de falhas metodológicas nos três artigos dificultou a interpretação fidedigna dos dados encontrados. Os estudos destacaram uma redução na intensidade da resposta inflamatória e uma melhor organização das fibras colágenas no grupo irradiado. A terapia com laser HeNe mostrou boa resposta no reparo tecidual. No entanto, tais resultados devem ser analisados de modo criterioso, uma vez que há presença de heterogeneidade, principalmente em relação aos parâmetros adotados.The aim of this systematic review was to analyze the effect of HeNe laser on wound healing in rats. Experimental studies that adopted HeNe laser as a treatment of acute lesions in healthy adult rats were selected, with scalpel-induced lesions, at PubMed/MEDLINE, LILACS, and SciELO databases. The following keywords were used: wound healing and collagen, according to MeSH and DeCS, besides the terms HeNe laser and skin repair, and their equivalent in Portuguese and Spanish. Three studies were included in this systematic review, but it was not possible to perform a metanalysis, due to impossibility to compare methods of the selected studies. All

  6. Avaliação da camada de fibras nervosas na retinopatia diabética tratada por panfotocoagulação com laser de argônio Examination of the retinal nerve fiber layer in diabetic retinopathy treated by argon laser panphotocoagulation

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    Otacílio de Oliveira Maia Júnior

    2008-04-01

    Full Text Available OBJETIVO: Avaliar alterações na camada de fibras nervosas da retina na retinopatia diabética tratada por panfotocoagulação com laser de argônio. MÉTODOS: Estudo prospectivo de portadores de retinopatia diabética submetidos a panfotocoagulação retiniana. Inicialmente, foram realizados exame oftalmológico completo e tomografia de coerência óptica. Todos pacientes foram submetidos a panfotocoagulação em um dos olhos. A camada de fibras nervosas foi avaliada por meio da tomografia de coerência óptica na 1ª semana, no primeiro, terceiro e sexto meses do tratamento. RESULTADOS: A amostra foi composta por 27 pacientes (27 olhos portadores de diabetes mellitus tipo 2. A idade variou entre 41 e 64 anos (média de 53,7 ± 6,2 anos, sendo 10 (37% pacientes do sexo masculino e 17 (63% do feminino. Quanto ao tipo de retinopatia, 22,2% apresentavam RD proliferativa e 77,8%, RD não proliferativa muito grave. Houve aumento significante nas medidas da espessura da camada de fibras nervosas, permanecendo nos setores temporal, 3 e 4 horas após seis meses de seguimento. Não foi observada qualquer redução na espessura em todos parâmetros analisados. CONCLUSÃO: Não foi evidenciada, a curto e médio prazo, redução na espessura da camada de fibras nervosas em portadores de retinopatia diabética tratada por panfotocoagulação que possa ser identificável por meio da tomografia de coerência óptica. Por outro lado, alguns setores mostraram aumento na espessura durante o seguimento.PURPOSE: To evaluate the alterations in the retinal nerve fiber layer in diabetic retinopathy treated by argon laser panphotocoagulation. METHODS: Prospective study of patients with diabetic retinopathy submitted to retinal panphotocoagulation. Initially, complete ophthalmologic examination and optical coherence tomography were performed. All patients were submitted to panphotocoagulation with argon laser in one of the eyes. The retinal fiber layer was evaluated

  7. Estudo morfométrico e morfológico da cicatrização após uso do laser erbium: YAG em tecidos cutâneos de ratos Morphometrical and morphological study of cicatricial effects caused by application of laser erbium: YAG on the skin of rats

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    Lúcia de Noronha

    2004-02-01

    Full Text Available Este trabalho analisa o efeito da reparação cutânea do laser erbium:yttrium aluminunn garnet (YAG (Er:YAG em pele de ratos através de estudo histológico e morfométrico. Tatuaram-se duas figuras no dorso de cada animal (n = 35, denominadas controle e experimento. Na figura experimento, aplicaram-se três passadas de laser Er:YAG com parâmetros padronizados. Cinco animais foram eutanasiados nos dias 0, 7, 14, 28, 56, 84 e 112 de pós-operatório. O estudo histológico demonstrou no dia 0 dano de ablação médio de 215,24 micrômetros (mm, sendo homogêneo com vaporização da epiderme e porções superficiais da derme. O dano térmico residual foi pequeno (média de 41,45mm, observando-se áreas onde estava praticamente ausente. A fibroplasia cicatricial já estava presente no dia 7 (média de 55,58mm, aumentando rapidamente até o dia 28 (média de 209,49mm, quando atingiu um platô e se manteve até o dia 112. Não houve sinais de processo inflamatório agudo no dia 7 e a reepitelização já estava completa. Concluiu-se que a aplicação de laser na pele de ratos induz reparação cutânea ao longo de 112 dias nas condições do experimento.This study analyses the skin contracture effect of the erbium:YAG (Er:YAG laser on the skin of rats by light microscopic histological and morphometrical evaluations. Two squares of back skin were precision tattooed on each of the animals (n = 35, that were termed control and experimental skin. The experimental skin was treated with three passes of the Er:YAG laser with standardized parameters. Five animals were killed and skin specimens were analyzed at 00, 07, 14, 28, 56, 84 and 112 days. Histologic examination demonstrated a mean of 215.24 micrometers ablative damage that was homogeneous with complete vaporization of the epidermis and superficial dermis. The residual thermal damage was small (mean of 41.45 micrometers observing areas where it was absent. The cicatritial fibroplasy was present at

  8. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser; Avaliacao da reducao bacteriana em conduto radicular infectado e irradiado com laser de diodo. Estudo in vitro

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    Radaelli, Claudia Amaral Rabello de Mello

    2002-07-01

    High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10{sup 8} CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 {mu}m optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm{sup 2}. The temperature was monitored with a K-pipe thermocouple placed at

  9. Histopathological study of the effects of low-intensity laser irradiation ({lambda}=650 nm) on dental pulp tissue after cavity preparation; Estudo histopatologico dos efeitos da irradiacao laser em baixa intensidade ({lambda}=650nm) em tecido pulpar apos preparo cavitario

    Energy Technology Data Exchange (ETDEWEB)

    Bertella, Claudio

    2001-07-01

    The purpose of this study was to evaluate (in vivo) the effects of low-intensity Arsenide Gallium Aluminium laser application post-cavity preparation class 1. Six patients with bilateral pre-molars and molars indicated to extraction for orthodontics aim were selected. Four samples of these teeth underwent cavity preparation with deep from medium to high and two samples underwent cavity preparation from high to pulp expositions. The samples were constituted of two teeth of the same patient and received different treatments. One of the teeth underwent laser exposition and the other one was maintained as control, before restorative procedure with polycarboxylate cement. A diode laser ({lambda}=650 nm), output power 30 mW and fluencies of 1,8 J/cm{sup 2} and 2,7 J/cm{sup 2} in pre-molars and molars, respectively, was used for irradiation with repetition rate of 18 Hz in interrupted continuous wave mode. After seven days, the teeth were extracted and processed histologically with HE to verify morphological changes in the pulpy tissue. The four samples, which cavity preparation and restorative material were not in contact with the pulp, did not show histological differences between irradiated and non-irradiated teeth. Both of them presented the same characteristics of normality. The two samples with exposed pulpy tissue showed different results. The irradiated teeth presented no or slight inflammatory signs when compared to the control samples, which showed abscess in the coronary pulp interior and intense inflammatory infiltrated. These results suggest that the laser irradiation can be used as a therapeutic modality in clinical trials, in the conditions employed in this study. (author)

  10. Evaluation of the temperature rise in pulp chamber during class V preparation with Er:YAG laser; Avaliacao da temperatura na camara pulpar durante preparo classe V com laser de Erbio:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Picinini, Leonardo Santos

    2001-07-01

    One of the major concerns regarding laser irradiation in the dentistry field is the overheating in dental tissue, specially pulpal tissue. A temperature raise over 5.5 deg C is considered to be harmful to its vitality. The current study evaluated the temperature increase in the pulp chamber, during class V preparation, performed with the laser Er:YAG in 36 bovine incisive extracted teeth. The samples were eroded on the outer side of the vestibular wall to obtain the dentinal thickness of 2.0 mm (group I), 1.0 mm (group II) and 0.5 mm (group III). Thermocouples were fixed to the inner part of the vestibular wall using thermal paste, through the palatine opening of the samples. Class V cavities were prepared in the vestibular side only in 1 mm{sup 2} thick dentins. Irradiation parameters used were: 500 mJ/10 Hz, 850 mJ/10 Hz and 1 000 mJ/10 Hz for all the groups. The results were processed by a microcomputer. This study showed that the temperature increased into the pulpal cavity reached around 3 deg C for the groups I (2,0 mm thick dentine) and II (1.0 mm thick dentine). In the group III (0.5 mm thick) temperature was around 5.5 deg C. Thus, the parameters used for cavity preparation, using Er:YAG laser, were safe in relation to the temperature raise for dentinal thickness of 1,0 and 2,0 mm; in 0.5 mm thick dentins, temperature increase reached 5.5 deg C and an appropriate correction in the laser parameters was necessary. (author)

  11. Evaluation in vitro of pulpal chamber temperature of deciduous teeth during Er:YAG laser application; Avaliacao in vitro da temperatura na camara pulpar de dentes deciduos durante aplicacao do laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Sznajder, Alexandre Joseph

    2001-07-01

    The Er:YAG laser technology has been thoroughly studied, since its invention, and has been increasingly recommended in Dentistry. However, its use in deciduous teeth has not been deserving the equivalent attention to its counterpart in permanent teeth, despite of the deciduous teething occur in a phase of life in which it has a far more importance than its substitutes. For that reason, this study aims to identify the suitable parameters to the clinic procedures in deciduous teeth, using the already established protocols in permanent teeth. The study was lead in a way to resemble the most the conditions of the clinical use of the laser. Five groups were analyzed using different energy densities and repetition rates. Each group was composed of 10 first superior right deciduous molars randomly selected. The energy densities and repetition rates used for each group were: 60 mJ 15 Hz, 250 mJ 2 Hz, 250 mJ 15 Hz, 400 mJ 6 Hz and 500 mJ 2 Hz. The results obtained allowed us to conclude that the use of the Er:YAG laser in Odontopediatrics is effective, safe and secure and the main reason for its recommendation is the low transfer of heat to the adjacent tissues of the applied surfaces. (author)

  12. Análise de Fourier para detecção de defeitos localizados na camada de fibras nervosas da retina com a polarimetria a laser Fourier analysis for the detection of localized nerve fiber layer defects using scanning laser polarimetry

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    Felipe Andrade Medeiros

    2003-12-01

    Full Text Available OBJETIVO: Avaliar a utilidade da análise de Fourier como método para detecção de defeitos localizados na camada de fibras nervosas da retina (CFN, utilizando as medidas obtidas com a polarimetria de varredura a laser. MÉTODOS: O estudo incluiu 40 olhos de 40 pacientes com glaucoma apresentando defeitos localizados na CFN detectados à oftalmoscopia e/ou em fotografias da camada de fibras nervosas. O grupo controle foi constituído por 43 olhos de 43 pacientes normais, sem antecedente de pressão intra-ocular elevada ou glaucoma, e com exame normal da CFN e disco óptico. Todos os pacientes foram submetidos a exame da CFN utilizando o aparelho GDx® - Nerve Fiber Analyzer. Para comparação entre os grupos, foram utilizados os parâmetros fornecidos pelo software do aparelho e medidas provenientes dos coeficientes obtidos pela análise de Fourier da curva de distribuição dos valores de espessura da CFN. As várias medidas dos coeficientes de Fourier foram combinadas numa função linear discriminante de maneira a encontrar a combinação que resultasse na melhor separação entre pacientes glaucomatosos com defeitos localizados e os sujeitos normais. Curvas ROC foram construídas para cada medida e valores de sensibilidade para especificidades fixas foram calculados. RESULTADOS: Os parâmetros fornecidos pelo software do GDx mostraram baixo poder de diferenciação entre os pacientes normais e com defeitos localizados na CFN, com sensibilidades variando de 15 a 48% (com especificidade a 91%. Para a mesma especificidade de 91%, a combinação dos coeficientes de Fourier teve sensibilidade de 80%. A área sob a curva ROC para a combinação dos coeficientes de Fourier (0,90 foi significativamente superior à obtida para o parâmetro The Number (0,76. CONCLUSÃO: A análise de Fourier resultou em melhora na capacidade do GDx de detectar defeitos localizados na CFN em relação aos parâmetros fornecidos pelo software do aparelho.PURPOSE: In

  13. Nd:YAG laser associated with metal salts solutions in the treatment of dentinal hypersensitivity; O laser de Nd:YAG associado a solucoes de sais metalicos no tratamento da hipersensibilidade dentinaria

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    Glauche, Carlos Eugenio Correia

    2001-07-01

    The objective of this study was to observe the ultrastructural changes caused by the radiation of Nd:YAG laser on the tooth tissue and determine qualitatively the presence of Sn{sup ++}, Sr{sup ++} and F{sup -}, inside the dentin, being it irradiated or not. Ten molar teeth recently extracted were cut into 2 mm discs. The samples were soaked in a EDTA solution at 17% for 2 minutes and divided into five groups. Group I: the samples were irradiated with Nd:YAG laser (1,5 W, 100 mJ, 15 Hz, 150 {mu}s and 125 J/cm{sup 2}) and after that, a treatment with an SnF{sub 2} aqueous solution at 10% for 30 minutes. Group II: the samples got laser irradiation with the same parameters and then a treatment with an SrCl{sub 2} solution at 10% as a toothpaste (Sensodyne{sup TM}) for 30 minutes. Group III: the samples just got a treatment with a SnF{sub 2} aqueous solution at 10% for 30 minutes. Group IV: the samples just got a treatment with a SrCl{sub 2} toothpaste (Sensodyne{sup TM}) for 30 minutes. Group V: samples that just got laser irradiation in the parameters above mentioned. Then, all samples were prepared for scanning electronic microscopy (SEM) and the samples of groups I, II, III and IV for energy dispersive X-ray microanalysis (EDX). The ultrastructure aspect of the dentin showed the surface totally altered by the irradiation. Pits and whitish globules were found amidst an heterogenous and rough structure, due to the melting and resolidification of the dental structure. Craters were also observed. Carbonization areas were absent. Ions Sn{sup ++} were found at a depth of 250 {mu}m in the samples of group I (Nd:YAG + SnF{sub 2}), whereas in the samples of group III, Sn{sup ++} were not found deeper than 100 {mu}m. Sr{sup ++} could be detected at least at 500 {mu}m in the inner dentin in the samples of group II (Nd:YAG + SrCl{sub 2}). However, Sn{sup ++} were not found at 50 {mu}m in group IV samples. Ions F{sup -} were just found in the irradiated samples of group I

  14. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser; Avaliacao da microinfiltracao marginal em cavidades classe V de dentes deciduos preparados com laser Er:YAG e alta rotacao

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    Pulga, Neusa Vieira Galvao

    2001-07-01

    The evaluation of marginal microleakage in class V restorations of deciduous teeth prepared using Er:laser and comparison to the ones observed when conventionally prepared, using two photopolimerizable materials, composite resin and glass ionomer cement, was the subject of this study. Twenty eight complete deciduous teeth were divided into four groups Group 1 (G1) prepared with high speed drill + composite resin; Group 2 (G2) prepared with high speed drill + glass ionomer cement; Group 3 (G3) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm{sup 2} + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm{sup 2} + glass ionomer cement. After the preparation and restoration the specimens where stored at 37 deg C for 24 hours, thermally stressed, immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in the dark. The specimens were rinsed in water, soaked in photodeveloping solution and exposed to fluorescent light for 6 hours. After this process the samples were sectioned and observed by stereomicroscopy. For comparison the groups were divided into occlusive and cervical microleakage. The results were analysed under the Kruskal-Wallis test. For the occlusive microleakage the statistical significance was 5% among the groups and the average comparison showed higher microleakage for G1 (M=35.1) than for G2 (M=24.0) as well as compared to G3 (M=22.3). The other groups did not present statistical differences among them. For the cervical microleakage the Kruskal-Wallis test did not present any statistical difference. Comparing the occlusive and cervical microleakage data, for every group, using the Wilcoxon test, no statistical differences were observed. Concluding, this study showed the Er:YAG laser to be effective for class V restorations and to result in a smaller microleakage degree using the composite resin. These results indicate

  15. Gamma radiation effect on allergen protein of laying hen eggs;Efeito da radiacao gama em proteina alergenica de ovos de galinhas poedeiras

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    Harder, Marcia Nalesso Costa

    2009-07-01

    The egg is the most complete natural food; it has all the necessary nutrients such as vitamins, aminoacids and essential minerals to maintain a life. However, although, has several proteins that promote allergies in considerable part of the world population. To determine allergenic food proteins, one of the most used tests is the immunoassays such as ELISA (enzyme linked immunosorbent assay), where the antibody recognizes the antigen and this connection is showed by an enzymatic system, in other words, optical density. The aim of this study was to determine the polyclonal antibody efficiency, produced in laboratory, to identify the presence the ovo mucoid antigen in treated eggs by gamma irradiation for its inactivation. To evaluate the treatments, polyclonal antibody was produced in four New Zealand female rabbits, at 45 days old, immunized with bio conjugated ovo mucoid. Was used Freund Complete Adjuvant at first immunization and PBS Buffer at four subsequently immunizations every fifteen days, plus a booster 48 hours before the blood retreated. The blood serum was tittered by PTA ELISA (Plate trapped antigen). All procedures were approved by Institute of Animal Science and Pastures (IZ)'s Committee of Ethical and Animal Experimentation and preceded according to European Norms for ethical and animal welfare. It was used, in nature, commercial laying eggs, from the Genetic Department of Agricultural University Luiz de Queiroz ESALQ/USP. So the samples were submitted to the gamma radiation coming from a source of {sup 60}Co, type Multipurpose at the Energetically Researches and Nuclear Institute (IPEN), under a dose rate of 19.4 and 31.8Gy/hour, in the doses: 0 (control); 10KGy; 20KGy and 30KGy, in all rates. By the ELISA s test we can find the egg allergen ovo mucoid and the radiation treatment do not showed considerable changes. So we can concluded that the antibody produced is capable of identify the ovo mucoid allergenic protein and the gamma irradiation in such rates does not shows changes in that protein, therefore showed some changes in the color and visual viscosity of the egg samples. (author)

  16. Stability of phenolic compounds of the propolis processed by ionizing radiation; Estabilidade de compostos fenolicos da propolis processada por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Andrea H.; Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: amatsuda@net.ipen.br; nelida@usp.br

    2002-07-01

    Propolis is the generic term of a resin of different colors and consistency collected by bees, Apis mellifera, from diverse parts of plants, buds and resinous exudates. It possesses antibacterial , antifungal and antiviral properties and many other biological activities such as antiinflammatory, antiulcer, local anaesthetic, antitumor, etc. The aim of this work is to study the effect of {sup 60} Co ionizing radiation on the stability of phenolic compounds of propolis. (author)

  17. Morpho-functional study of ionizing radiation effects on the rabbits` femoral vein; Avaliacao morfofuncional do efeito da radiacao ionizante sobre a veia femoral. Estudo experimental em coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Sakiyama, Mauro Yoshimitsu

    1996-12-31

    In this study we evaluate the effects of the ionizing radiation on the rabbits femoral vein. The samples of femoral vein were obtained from 56 New Zealand rabbits, male with ageing from 90 to 120 days, that were divided into 4 groups of 14 animals: one control group non-irradiated and three animal groups sacrificed 2 days, 14 days and 90 days after irradiation. In the three irradiated rabbits groups, each animal received the total dose 4000 cGy (rads) divided in 10 sessions of 400 cGy, a dose equivalent that utilized on clinical therapeutic. A morpho functional study of vein samples was carried out with: light microscopy: stained by hematoxin - eosin, Masson`s tricromic, and Verhoeff. Immunohistochemical: reactions of immunoperoxidase with monoclonal mouse anti-human endothelial cell factor CD-31 and anti-human Von Willebrand factor (factor VIII), to study the vein endothelium. Histomorphometry of elastic fiber system stained by Weigert`s resorcin-fuchsin with and without prior oxidation with oxone; for the study of mature, elaunin or pre-mature and oxytalan or young elastic fibers. Electronic microscopy: transmission and scanning. With the methodology utilized we observe changes in the femoral vein of the animals submitted to irradiation in relation to the control group, thus described: there is formation of vacuoles between the endothelium and the basal membrane, called sub endothelial vacuoles, in focal areas. The factor VIII and CD-31 endothelial antigens are preserved with no changes in their functions. Focal alterations are present in the endothelial surface with disorder in the setting and orientation of the endothelial cells. there is degeneration of the elastic fibers with significant decrease in their quantity in the stage, 2 days and 14 days after irradiation. There is increase in the quantity of elastic fibers in the late stage, 90 days after irradiation, tending to normality. In this present study, the changes described are not accompanied by venous thrombosis. (author) 101 refs., 22 figs., 2 tabs.

  18. Morpho-functional study of ionizing radiation effects on the rabbits` femoral vein; Avaliacao morfofuncional do efeito da radiacao ionizante sobre a veia femoral. Estudo experimental em coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Sakiyama, Mauro Yoshimitsu

    1995-12-31

    In this study we evaluate the effects of the ionizing radiation on the rabbits femoral vein. The samples of femoral vein were obtained from 56 New Zealand rabbits, male with ageing from 90 to 120 days, that were divided into 4 groups of 14 animals: one control group non-irradiated and three animal groups sacrificed 2 days, 14 days and 90 days after irradiation. In the three irradiated rabbits groups, each animal received the total dose 4000 cGy (rads) divided in 10 sessions of 400 cGy, a dose equivalent that utilized on clinical therapeutic. A morpho functional study of vein samples was carried out with: light microscopy: stained by hematoxin - eosin, Masson`s tricromic, and Verhoeff. Immunohistochemical: reactions of immunoperoxidase with monoclonal mouse anti-human endothelial cell factor CD-31 and anti-human Von Willebrand factor (factor VIII), to study the vein endothelium. Histomorphometry of elastic fiber system stained by Weigert`s resorcin-fuchsin with and without prior oxidation with oxone; for the study of mature, elaunin or pre-mature and oxytalan or young elastic fibers. Electronic microscopy: transmission and scanning. With the methodology utilized we observe changes in the femoral vein of the animals submitted to irradiation in relation to the control group, thus described: there is formation of vacuoles between the endothelium and the basal membrane, called sub endothelial vacuoles, in focal areas. The factor VIII and CD-31 endothelial antigens are preserved with no changes in their functions. Focal alterations are present in the endothelial surface with disorder in the setting and orientation of the endothelial cells. there is degeneration of the elastic fibers with significant decrease in their quantity in the stage, 2 days and 14 days after irradiation. There is increase in the quantity of elastic fibers in the late stage, 90 days after irradiation, tending to normality. In this present study, the changes described are not accompanied by venous thrombosis. (author) 101 refs., 22 figs., 2 tabs.

  19. Effects of gamma radiation from Cobalt-60 on pequi fruits (Caryocar brasiliense Camb.);Efeitos da radiacao gama do Cobalto-60 em frutos de pequi (Caryocar brasiliense Camb.)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcio Ramatiz Lima dos

    2008-07-01

    The aim of this work was to evaluate gamma radiation effects from Cobalt-60 on post harvest characteristics of pequi fruits (Caryocar brasiliense Camb.). Brazilian savannah is the second biome of American Continent and concentrate a lot of plants and animal species. Many plants and their fruits are still unknown of Brazilian population. Just now, they are gained attention of researchers due their nutritional properties, between then is the pequi fruits. Fruits come from Goias State was classified, washed and processed to separate the endocarp (edible part) from pericarp. The endocarps were packing in polyethylene bags with 150 g, labeled and submitted to radiation process (0.0, 0.4, 0.6 and 1.0 kGy doses) on multipurpose irradiator located in IPEN/USP. The samples were analyzed to chemical (pH, trititable acidity, Deg Brix, ratio TSS/TTA, lipids, ash, humidity, protein, soluble and insoluble fiber, total carotenoids and antioxidant activity) and physical properties (loss weight, texture and color). The loss humidity was proportional to radiation applied doses, the highest loss was observed on fruits to 1.0 kGy doses. Soluble fiber and protein showed no significant differences between treatments. Ash, insoluble fiber, dry matter and lipids showed little significant differences. Significant decrease of the pH values was observed for the irradiated samples in relation to control. Irradiated samples texture showed significant increase compared to control, but showed no significant differences between applied doses. The higher value for texture was (39.89 Newton g-1) for 0.6 kGy dose. Total soluble solids (TSS) showed a significant decrease compared to control, but was not significant between applied treatments. Titratable acidity showed a significant decrease for irradiated samples compared to control for all doses, but it was not significant between treatments. The ratio TSS/TTA showed no significant differences compared to control, only for irradiated fruits at 0.6 kGy doses presented differences compared to other treatments with the lowest value (24.12). Significant increases were observed between treatments and control, indicating an effective action of experimental doses on the parameter color a, both for the applied dose as to the pequi storage time. The parameter 'L' showed a decrease in brightness in relation to the storage time for all treatments, and the luminosity presented increase in relation to the radiation applied doses. There was a significant decrease in the parameter b* values for all applied doses compared to control. The storage time was not significantly influence for this parameter. The lowest values of parameter b* were observed for irradiated fruits at 10.0 kGy dose followed by 3.0 kGy, with reductions of more than 50%. There was a significant decrease in the ascorbic acid levels on irradiated pequi fruits, proportional to the applied dose. The losses were to around 49.85% for irradiated samples with 0.4 kGy dose, 82.28% for 0.6 kGy dose and 85.25% for the 1.0 kGy dose, compared to control. There was a decrease in total carotenoids levels of irradiated pequi samples compared to non irradiated (control). The losses were to 45.56% for irradiated fruits at 1.0 kGy dose compared to control. The control presented the highest total carotenoids value found (16.70 mg 100 g-1). The radiation processing presented a significant reducing effect on antioxidant activity of pequi fruits for all applied doses. Antioxidant capacity reductions were 2.92% for the 0.4 kGy dose, 5.26% to 0.6 kGy dose and 11.52% for the 1.0 kGy dose. The irradiation process using gamma rays from {sup 60}Co is efficiency to protect pequi fruits in post harvest period. (author)

  20. Effects of gamma radiation on country made polycarbonate Durolon FN2200; Efeito da radiacao gama no policarbonato nacional Durolon FN2200

    Energy Technology Data Exchange (ETDEWEB)

    Terence, Mauro Cesar

    1996-07-01

    Type II polycarbonate, PC II, manufactured with high purity reagents as used on medical fabrication was gamma irradiated by {sup 60} Co source with doses from 0 to 300 kGy. Dose effects on the tensile strength at break (TSb) and at yield (TSy), on the molecular weight by viscosity, on optical properties by yellowness index (YI) and transmittance (T), molecular structure by transmission spectroscopy on infrared region (IR). Radical formation and decay at 100 kGy was studied too by electronic paramagnetic resonance (EPR) and nuclear magnetic resonance of proton (NMR {sup 1}H). T S alteration was not observed up to 100 kGy, but molecular weight already suffers alteration at low doses, as well optical properties suffer significant alteration at sterilization doses (25 kGy) by yellowness index of 90% that is not desirable by medical application point of view. Molecular scission degree was calculated from viscosity measurements which value found is 1 and the crosslinking was not observed at sterilization doses. The formation of three different radicals was observed phenoxy, phenyl and isopropyl when irradiated on vacuum and after being put in air contact, scission occurs on PC II on two sites of the polymeric chain, while on PC I scission occurs only in one site. The PC II can be used in sterilized medical devices by gamma radiation from R T point of view, but looking to optical properties in a incorporation of additives will be necessary to cover up this coloration, as an optical whitener. It is interesting to note although PC II has G{sub scission} = 1 and yellowness index of 17% and P C I has G{sub scission} = 16,7 and yellowness index of 27% this difference can be attributed to the large quantity of optical whitener added to PC I. At sterilization doses PC II has an excellent radiolytic stability considering the point of view TS but it is necessary to avoid the yellowness on the fabrication of medical devices that can be radio sterilized. (author)

  1. The combined effect of gamma radiation and stress cracking in polycarbonate;Efeito combinado da radiacao gama e stress cracking no policarbonato

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Raphaela N. de; Rabello, Marcelo S., E-mail: marcelo@dema.ufcg.edu.b [Universidade Federal de Campina Grande (DEMa/UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Silva, Leonardo G.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    In this work the combined effect of gamma irradiation and stress cracking was studied in polycarbonate (PC). Tensile test bars were produced by injection moulding and then exposed to different doses of gamma radiation. After that they were submitted to the contact with isopropanol, the stress cracking agent used in this work. The specimens were tested for mechanical properties, viscosity molecular weight and fractography. The results indicated that the previous radiation intensified the stress cracking effects, as evidenced by the reduction in tensile properties and surface damage caused to the samples. (author)

  2. Ionizing radiation effect on different types of flours used in bakery technology; Efeito da radiacao ionizante em diferentes tipos de farinhas utilizadas em tecnologia de panificacao

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Christian Alexandre Heinz Melsheimer

    2011-07-01

    In this work, an evaluation of the changes caused by ionizing radiation in different types and quantities of products rich in starch (wheat flour, cassava, rye, whole wheat, green banana pulp and maize) on rheological, technological, physical and texture characteristics was studied. The samples were irradiated in a {sup 60}Co source with doses up to 10kGy, and dose rate about 2kGy/h. It was studied the force and the extensibility of strong and weak wheat flours and the rheological behavior was observed for one, five and thirty days after irradiation. The technological characteristic studied for up to 1 month after irradiation, was the enzymatic activity of the irradiated, weak and strong flours. The physical characteristics: height, weight and moisture loss and texture of loaves made with a partial replacement (30%) of wheat flour by different irradiated flours was established. The results showed that with the increase of radiation dose there was an increase of enzymatic activity, especially for higher doses (9kGy). These results corroborate for the understanding that there would be no need of addition of enzymatic improvers for the bread confection. The height, weight, and loss of moisture from the products developed with different substitutions of flours used in the formulations, showed different behaviors. With an increasing of the radiation dose applied, there was an increase in the height of the loaves, as well as a reduced loss of moisture on the products developed with substitution of 30% of the wheat flour with irradiated wheat flour and pulp of green banana flour. From a technological standpoint, the enzymatic activity was not adversely affected by radiation. Considering the characteristics studied, the dose of 9kGy would be recommended seeking the production of loaves. Although the irradiation process is generally applied in the preservation of hygienic quality of food products, its use on different kinds of flours used in bread production may induce some beneficial technological characteristics. (author)

  3. Study of crosslinking induced by gamma radiation in mixtures of polyacrylamide anionic and water; Estudo da reticulacao induzida por radiacao gama de misturas de poliacrilamida anionica e agua

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara, M.T.S.; Brant, A.J.C.; Naime, N.; Guadagnin, H.C.; Ponce, P.; Lugao, A.B., E-mail: ablugao@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Superabsorbent hydrogels are composed of three-dimensional polymeric networks that can absorb and retain body of water hundreds of times the weight of its dry weight. The hydrogels can be crosslinked by chemical or physical. In general, chemical crosslinking is performed in the presence of reactive substances of high toxicity at elevated temperatures, may cause harmful secondary reactions to final product quality. However, ionizing radiation provides the crosslinking in the absence of chemical initiators or crosslinkers, therefore without contamination or toxicity. It also allows the realization of the reaction at low temperatures. These materials find use in several application fields, such as sanitary pads, diapers, controlled release of nutrients to the soil, separation processes, water purification systems and controlled release of drugs. The purpose of this study was to assess the influence of gamma radiation in doses of 15 and 25 kGy, in reticulation system of polyacrylamide (PAAm) and water, which were characterized by swelling and Fourier Transform Infrared Spectroscopy (FTIR). The results show the importance of the amount of water in the reticulation. It was concluded that gamma radiation has excellent potential for the synthesis of hiperabsorbent hydrogels. (author)

  4. Evaluation of effects of ionizing radiation on materials used in dental restorations;Avaliacao dos efeitos da radiacao ionizante em materiais utilizados em restauracoes dentarias

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Mireia Florencio

    2009-07-01

    This work consisted of quantitative studies of the effects caused by ionizing radiation on materials used in dental restorations (Titanium, Amalgam, Resin Composite and Glass Ionomer) aiming the deleterious effects of radiotherapy when patients with tumors in head and neck, arising when the teeth are restored within in the field of radiation. Samples were submitted to X-ray beams of 6 MV from a linear accelerator, VARIAN 2100C model. The samples were analyzed by X-ray fluorescence techniques to compare the chemical composition before and after the irradiation. The sample were submitted to Geiger-Mueller detectors and the ionization chambers in order to verify any residual radiation in the samples. The samples were also analyzed by gamma spectrometry by a Germanium detector. These tests were performed to determine small changes in the composition in the samples due to the radiation interaction. The results of this study may encourage the development of new research for alternative materials in dental restorations that can contribute to improve the quality of life of those patients with tumors of the mouth. (author)

  5. Some effects of gamma radiation in Callosobruchus maculatus (Fabr., 1792) (Coleoptera, Bruchidae); Alguns efeitos da radiacao gama em Callosobruchus maculatus (Fabr., 1792) (Coleoptera, Bruchidae)

    Energy Technology Data Exchange (ETDEWEB)

    Walder, J M.M.

    1975-12-31

    The effect of gamma irradiation from a Cobalt-60 source on Callosobruchus maculatus (Fabr.) was studied in this work. Experiments showed that at a dose-rate of 9820 {+-} 300 rad/hour the LD sub(100) of egg embryos was 2,2 krad, of larvae 3 krad and of pupae 22,8 krad. Total sterilization of adults irradiated of the pupal stage was 5 krad. The sterilizing dose of irradiated adults was 8 krad at a calculated dose-rate of 57.630 {+-} 5000 rad/hour, whereas the LD sub(100) was 330 krad at a dose-rate of 63650 {+-} 1500 rad/hour. It was further verified that the number of eggs laid decreased with the irradiation dose. Longevity tended by increase in the females and diminish in the males as a result of irradiation. (author).

  6. Gamma radiation effects in Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae); Efeitos da radiacao gama em Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae)

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J M

    1974-12-31

    Lethal effects were studied for the egg, larval and pupal stages as well as sterilization of adults of Sitophilus oryzae (L.) by the application of gamma radiation. Irradiation of pupae with an estimated dosis of 7887 {+-} 158 rad inhibits adult emergency. Hypotheses have been suggested that the apparent density and (or) nutrient value of food substrates decisively influence the sterilizing dosis for this insect. Thus, in rice and maize which are apparently denser and (or) of higher nutrient value than maccaroni, insects are sterilized by a dosis of 7 krad, while in maccaroni the sterilizing dosis decreases to 5 krad. (author).

  7. Gamma radiation effects on the structure and properties of polystyrene; Efeitos da radiacao gama na estrutura e nas propriedades do poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Ivania Soares de

    1996-12-31

    Polystyrene is a linear thermoplastic with a molecular weight ranging from 130,000 to 300,000 g/mole. This polymer has wide industrial applications. In medicine it is used to manufacture medical supplies which can be sterilized by ionizing radiation. The sterilization of medical instruments by ionizing radiation was introduced in the 60`s as an alternative method to the conventional treatment with ethylene oxide gas. Radiosterilization is now worldwide standard procedure, as it is cheaper and cleaner. Some polymers, however, may show some changes in their physical properties following irradiation. These changes are due to the prevailing crosslinking and main chain scission induced by the irradiation of the polymeric system. In the present work, Brazilian-made polystyrene Lustrex was irrigated with {gamma} rays in the presence of air at room temperature. Under these conditions, the analysis of viscosimetric essays showed the prevalence of crosslinking effects at doses up to 25 kGy and of main scission effects at does from 25 to 200 kGy. Observed G values (number of events per 100 eV of absorbed energy) pointed to low degrees of both crosslinking (Gx {approx} 0.15) and main chain scission (Gs {approx} 0.09). Therefore, the minor changes in Lustrex`s molecular structure induced by irradiation have not influenced significantly its mechanical, thermal, and optical properties. As a result, Lustrex can be used in applications involving radiation without the need to introduce radioprotective to the polymeric system. (author) 43 refs., 25 figs., 8 tabs.

  8. Development of capacity for measuring ionizing radiation in aircraft crew; Desenvolvimento da capacitacao para efetuar medicoes de radiacao ionizante em tripulacoes de aeronaves

    Energy Technology Data Exchange (ETDEWEB)

    Federico, C.A.; Goncalez, O.L., E-mail: claudiofederico@ieav.cta.b, E-mail: odairl@ieav.cta.b [Centro Tecnico Aeroespacial (CTA/ITA), Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica; Caldas, L.V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper describes the activities performed in a research program of the Institute of Advanced Studies, Brazil, belonging to the Brazilian Air Force, joining to researches from Brazilian Nuclear Energy Commission, in order to bring to Brazil the capacity and acknowledge necessary to the evaluation of dose from ionizing radiation originated in the cosmic radiation and its by products which fall on aircraft crews

  9. Effect of ionizing radiation exposure in the morphology of modified HDPE with amphiphilic particles; Efeito da exposicao a radiacao ionizante na morfologia de PEAD modificado com particulas anfifilicas

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, Ana Luiza M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Vivas, Viviane; Zylberberg, Marcel P.; Silva, Tamara I.; Cardoso, Andre Luis V.; Pereira, Iaci M., E-mail: iacipere@gmail.com [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (Brazil); Patricio, Patricia S.O. [Centro Federal de Educacao Tecnologica de Minas Gerias (CEFET), Belo Horizonte, MG (Brazil)

    2015-07-01

    One of the techniques used to improve the properties of high performance polymers is the addition of hybrid particles in the polymer. In this context, amphiphilic particles were synthesized in order to provide surface characteristics that enhance the interaction of the interface with the polymeric matrix of high density polyethylene (HDPE). The amphiphilic particles were added to matrix of HDPE and the modified polymer composites were exposed to ionizing radiation (x-rays) for different times. The changes caused by exposure to ionizing radiation in the composite morphology was observed through the small angle x-ray technique. The results suggest that the addition of amphiphilic particles increased the stability of the composite to degradation by radiation. (author)

  10. Effect of the ionizing radiation in the sensorial characteristics of the pineapple; Efeitos da radiacao ionizante nas caracteristicas sensoriais do abacaxi

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josenilda Maria da, E-mail: jmnilda@yahoo.com.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Spoto, Marta Helena Fillet; Silva, Juliana Pizarro [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil)

    2007-10-15

    The post-harvest quality of the pineapple cultivar Smooth Cayenne was evaluated after the fruit was irradiated with doses of 100 and 150 Gy and stored for 10, 20 and 30 days at 12 deg C ( +-1) and relative humidity of 85% (+- 5). The controls were untreated fruits. Sensorial analyses were made for each storage period to obtain information about the effects of ionizing radiation on the quality of the fruit. The ionizing radiation dosage had little effect on the sensorial characteristics of the pineapple, although the best results were obtained with fruit irradiated with 100 Gy. The 20-day storage period resulted in the highest consumer acceptability, while the 30-day storage period impaired the fruit's external and internal appearance. (author)

  11. Study of the sensitivity of the radiation transport problem in a scattering medium; Estudo da sensibilidade do problema de transporte de radiacao em meio espalhador

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Rogerio Chaffin

    2002-03-15

    In this work, the system of differential equations obtained by the angular approach of the two-dimensional transport equation by the discrete ordinates method is solved through the formulation of finite elements with the objective of investigating the sensitivity of the outgoing flux of radiation with the incoming flux and the properties of absorption and scattering of the medium. The variational formulation for the system of differential equations of second order with the generalized boundary conditions of Neumann (third type) allows an easy implementation of the method of the finite elements with triangular mesh and approximation space of first order. The geometry chosen for the simulations is a circle with a non homogeneous circular form in its interior. The mapping of Dirichlet-Neumann is studied through various simulations involving the incoming flux, the outgoing flux and the properties of the medium. (author)

  12. Food safety through the training of 2-alcilciclobutanonas in processed foods by ionizing radiation; Seguranca alimentar atraves da formacao de 2-alcilciclobutanonas em alimentos processados por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Rodrigo Mendes

    2016-11-01

    Food irradiation is a means of preserving food which uses a processing technique that exposes the foods at a controlled high energy ionizing radiation. The treatment with the use of ionizing radiation in foods has many applications technologically and technically feasible, including the ability to improve the microbiological safety and reducing levels of pathogenic bacteria, inhibiting the germination of tubers plant application, preserving stored foods or the stability of storage and is also used to increase the shelf life of certain products due to the reduction of contamination by microorganisms. Due to the increase of international trade in food and the growing regulatory requirements of consumer markets increasingly importing and exporting countries have shown interest in food irradiation and conducted research in the practical application of this technology and detection methods of treatment. Numerous surveys were conducted worldwide, resulting in efficient protocols to identify which foods were irradiated or not. Until then, the 'myth' that irradiated food could not be detected and they were not formed any single radiation products has been replaced by the knowledge that many changes can occur in irradiated foods and these changes could be used as tools to identify this technology. The radiation processing resulting in characteristic patterns formations of saturated hydrocarbons, aldehydes, methyl and ethyl esters and 2-alcilciclobutanonas, depending on the fatty acid composition of the lipid that composes the food. Thus the purpose of this study was to collect data to compare the effects of different doses of gamma radiation and electron in foods that have fat to determine possible changes resulting from the use of irradiation, as the presence of 2-Alcilciclobutanonas and also show main equipment used for food irradiation and its categories, with the aim of informing the general public. (author)

  13. Case study on the effect of cosmic radiation in embedded systems in aircraft; Estudo de caso sobre o efeito da radiacao cosmica em sistemas embarcados em aeronaves

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Adriane C.M.; Pereira, Marlon A., E-mail: adriane.acm@hotmail.com, E-mail: marlon@ieav.cta.br [Instituto Tecnologico de Aeronautica (ITA/DCTA), Sao Jose dos Campos, SP (Brazil); Federico, Claudio A.; Goncalez, Odair L., E-mail: claudiofederico@ieav.cta.br, E-mail: odairl@ieav.cta.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil)

    2014-07-01

    High-energy neutrons generated from the interaction of cosmic radiation with atoms of the atmosphere, can cause adverse effects on avionics devices. These effects are referred to as 'Single Event Effects' (SEE) and may occur especially in aircraft onboard computers, from change the logic state of memory cells or functional interruptions, which could compromise flight safety. The effects of the SEE must first be evaluated and entered into the safety analysis process in order to determine the susceptibility to failures by SEE devices. SEE rate can be evaluated separately for thermal neutrons and fast neutrons with energy above 10 MeV. This paper presents an exploratory study of susceptibility to radiation to a specific type of SRAM memory, during periods of maximum and minimum solar, in situations of equatorial and polar flight in the typical flight altitude of existing aircraft and, at higher altitudes, near the maximum of Pfotzer. This study was conducted using estimates of particle flows employing the EXPACS QARM codes and evaluating the expected rate of SEE due to thermal neutrons and fast neutrons separately. The distribution in energy and the flow of neutrons inside the airplane are influenced by the total mass of the aircraft and this influence are also discussed.

  14. Utilization of ultraviolet radiation in effluent disinfestation of domestic waste treatment systems; Utilizacao da radiacao ultravioleta na desinfeccao de efluentes de sistemas de tratamento de esgotos domesticos

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, P.R.R. [Companhia de Tecnologia de Saneamento Ambiental, Sao Paulo, SP (Brazil); Andrade e Silva, L.G. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1995-12-31

    Ultraviolet radiation disinfection of Upflow Anaerobic Sludge Biodigestor (UASB) and UASB with aerated lagoon pos-treatment effluents is possible to be reached utilizing a single low pressure mercury lamp arc (15 W nominal power) in a shell tube flow through reactor (1.2 L useful volume). Fecal coliforms, total coliforms and colifages were used as microbiological parameters. For fecal coliforms, about 3 logarithmic units (log. un.) was removed from UASB with aerated lagoon pos-treatment effluent and 4 log. un. from UASB effluent with 7 and 30 seconds of hydraulic retention time, respectively. Good empirical correlations were obtained between microbiological parameters and hydraulic retention times. (author). 4 refs, 1 fig, 3 tabs.

  15. Bacteriological evaluation of fresh chicken sausage submitted to gamma radiation; Avaliacao bacteriologica da linguica de frango Frescal submetida a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandre

    2002-07-01

    Many developed countries have established a goal of self-sufficiency in food production, while many other obtain their principal foreign exchange through food exports. For these reasons, it is essential to eliminate losses in food products. It is no less important to prevent or combat food-transmitted diseases, principally across poultry and poultry derivatives, which play a major role in certain infections and is the focus of national public health goals in order to increase the international commerce. In tropical countries, perishable products represent the largest markets. The population lives in a constant battle against the deterioration of these foods. Such loss is enormous where the climate favors the proliferation of agents of decomposition and acceleration of putrification. Increasing the useful life of these perishable products will provide producers the option of commercializing them in low harvest season, thus achieving higher prices, and providing sensible growth to the agro-industrial market. Treatment of perishables with gamma radiation presently constitutes one of the most modern, safe, and efficient methods for increasing food preservation. The irradiation of foods can offer various special advantages such as: kill or sterilize pathogenic organisms in food, improving their quality and duration, reducing the level of toxics, slow or stop the aging of roots and tubers, disinfect products of animal and vegetable origin thus slowing their decomposition, increasing their shelf-life, and prolonging their conservation refrigeration. The practice of irradiating foods for the treatment of microorganisms has begun to gain momentum in Brazil, where roughly 25% of all food produced annually is lost to disease and insects activity, increased by lack of adequate storage treatments. Various countries have already adopted the method that, when practiced properly by qualified professionals, does not cause side effects other than the extension of useful life. In light of the lack of present data on the irradiation of fresh chicken sausage, the objective of this study is to evaluate determine the efficiency of this method as a process for reducing the microbial load via measurement of the bacteriology of the product before and after gamma radiation. 45 sample of chicken sausage(acquired directly from the poultry industry) were prepared divided in 3 treatments: the first is a control, the second and third using application of 1,5 and 3,0 kGy, respectively. The chicken sausages irradiated with a dose of 1,5 kGy did not have, statistically significant results apparent in the bacteriological measures. Samples irradiated with 3,0 kGy did experience statistically significant reductions. It is concluded that the irradiating the product with a dose of 3,0 kGy is more effective for the reduction of bacterial population, with the data in these trials indicating a 95,3% reduction in total coliforms, 100% removal of fecal coliforms, and 84,0% reduction of mesophiles, relative to the control samples. (author)

  16. Application of electron beam radiation for peat sterilization and suppression of microbe contaminants; Aplicacao da radiacao por feixe de eletrons como agente esterilizante de microorganismos em substrato turfoso

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, David

    2006-07-01

    Inoculation of root nodule bacteria into legume seeds such as soybean [Glycine max. (L.)], common bean (Phaseolus vulgaris L.) and forage pasture has been effective and convenient as this simple procedure may introduce effective strains of Bradyrhizobium/Rhizobium into agricultural soils without a past history of successful cropping systems with the legume hosts. Peat-based substrates previously sterilized have been used for decades as bacteria carrier, protecting them from the prevailing harsh conditions in tropical soils and ensuring their survival with nutrient and protection against the soil antagonists. The Brazilian Government requires that all peat-based substrates must be gamma-sterilized from a cobalt-60 ({sup 60}Co) source, prior the introduction of the root nodule bacteria into the package. The recommendation is for a dose up to 50 kGy for an effective suppression of pathogens and saprophytes, in order to avoid competition among the substrate microbiota. Recently, the use of the electron beam (EB) accelerator has shown to be a new alternative for peat pre-sterilization, as this technique may promote reactive free-radicals which are efficient to suppress microbial contaminants. This fast technology is considered more environment and ecology friendly-sound than gamma radiation ({gamma}). The disadvantage of not reaching higher depth than gamma rays from {sup 60}Co must be considered, and attempts of optimizing the technique are crucial. This study compared both methods by using increasing rates of radiation by {sup 60}Co by the EB method - O, 10, 20, 30, 40 e 50 kGy in a commercial peat used for inoculants. Experimental data from days 7, 14, 21 and 28 days (growth period) and 150, 180 and 210 days (storage period) indicated high numbers of the strain Rhizobium tropici CM-01, labelled with gusA{sup +} (Study 1) and celB{sup +} (Study 2) from both eat-sterilizing techniques, reaching values above the minimum of 1x10{sup 8} cells g{sup -1} peat. At high rates, above 40 kGy, and after long incubation periods (ex. after 150 days), EB method was more efficient to suppress actinobacteria, one serious antagonist for rhizobia. Strain CM-01 celB{sup +}, data for the period of bacterial growth confirmed the efficiency of the method even at rates as low as 10 kGy. (author)

  17. Laser Technology.

    Science.gov (United States)

    Gauger, Robert

    1993-01-01

    Describes lasers and indicates that learning about laser technology and creating laser technology activities are among the teacher enhancement processes needed to strengthen technology education. (JOW)

  18. Evaluation of low intensity laser effects in the thyroid glands region of male mice; Avaliacao dos efeitos do laser em baixa intensidade na regiao da glandula tireoide de camundongos

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Luciane Hiramatsu

    2002-07-01

    Recent studies have demonstrated that the infra-red laser can cause alterations in thyroid glands. Their normal activity must be preserved, as they produce the thyroidal hormones triiodothyronine (T{sub 3}) and thyroxine (T{sub 4}), that stimulate the oxidative metabolism, essential to maintain a healthy organism. The increase or diminution of these hormones results in alteration of the mitochondria's activity, that determines the secondary effects in the metabolism. The purpose of this study was to evaluate if there was any alteration of the thyroidal hormones plasma levels under irradiation from infra-red laser, with energy density of 4J/cm{sup 2}, in the region of thyroid glands of male mice. It was concluded that there was an hormonal level alteration statistically significant between the first day of irradiation and seven days after the last application. Histological studies showed that there was no morphological changes in histological sections of thyroid glands. The optical absorption spectroscopy of mice's serum presented a peak at approximately 280 nm, attributed to tyrosine (this is the amino acid compounding these hormones). (author)

  19. Irradiation effects of GaAlAs ({lambda}=830 nm) laser on oral traumatic ulceration; Avaliacao dos efeitos da irradiacao de ulceras traumaticas na cavidade bucal com o laser de GaAlAs ({lambda}=830 nm)

    Energy Technology Data Exchange (ETDEWEB)

    Senna, Andre Machado de

    2003-07-01

    Low intensity GaAlAs ({lambda}=830 nm) laser irradiation effects on oral traumatic ulceration were evaluated. For this purpose, twenty patients presenting orthodontic appliance - induced oral traumatic ulceration were randomly distributed in two groups. Patients in group 1 were submitted to the irradiation procedure and group 2 was the control one. The irradiation parameters employed were the following: wavelength 830 nm, one single application of 4 J/cm{sup 2}, punctual in the contact mode and 30 mW power. The control group received the conventional treatment, consisting on topical application of Triancinolon based ointment four times a day. For both groups the agent responsible for the trauma was removed or covered with utility wax whenever removal was impossible. The results were evaluated concerning the wounds size reduction and pain relief. The time of laser irradiation was considered the starting time (time zero) and analysis were done 24 hours, 48 hours and seven days after that. The statistical analysis showed an acceleration in the healing process as well accentuated pain reduction for the irradiated group compared to the control one. These evidences allows us to indicate this protocol of one single application of 4 J/cm{sup 2} as therapy when patients with oral traumatic ulceration can not attend several sessions for a multiple application procedure. (author)

  20. In vitro evaluation of marginal microleakage in class V restorations with composite resin in bovine teeth. Laser irradiation influences and the adhesive system in the dentin pre-treatment; Avaliacao in vitro da microinfiltracao marginal em restauracoes de classe V com resina composta em dentes bovinos. Influencia da irradiacao laser e sistema adesivo no pre-tratamento dentinario

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Wendell Lima de

    2003-07-01

    Microleakage is one of the most important reasons to restorations failure, it is the responsible for marginal colors changing, new caries, hipersensibility and pulpar diseases. Several techniques and materials have been studied to eliminate or, at least, to decrease microleakage. The cavities preparation with Er:YAG laser and autoconditioning adhesive are some of these techniques and materials. This research has the objective to compare, in vitro, microleakage in class V cavities, prepared with high rotation (conventional treatment), Er:YAG laser (Enamel-400 mj/2 Hz/128,38 J/Cm{sup 2}, Dentin 250 mJ/ 2 Hz/ 80,24 J/Cm{sup 2}) and the treatment made at dentin with autoconditioning adhesive (Clerafil SE Bond) using Er:YAG laser (with water or not water) or not using Er:YAG laser. It was used 48 bovines teeth with cavities prepared in vestibular face and gingival wall on cement enamel junction and oclusal wall on enamel. The materials used were autoconditioning adhesive (Clerafil SE Bond) and composite resin Z250. Teeth were divided into four groups of twelve samples each one, according to dentin treatment. Group 1 - Conventional cavity and autoconditioning adhesive. Group 2- Cavity prepared with Er: YAG laser and autoconditioning adhesive. Group 3 - Cavity prepared with Er:YAG laser and dentin conditioning with Er:YAG laser associated to water and autoconditioning adhesive. Group 4 - Cavity prepared with Er:YAG laser and dentin conditioning with Er: YAG laser without water and associated to autoconditioning adhesive. Teeth were restored and stocked at 37 deg C, thermocycled and placed into a 50% silver nitrate solution. Right after, teeth were sliced and evaluated on a stereo microscopic magnifying glass in order to see microleakage degree trying to follow a score from 0 to 3. The findings were submitted to Fisher, Anderson-Darling tests and to the not parametric Sen and Puri test. The results indicated that in gingival edge, the Group 2 showed less microleakage than

  1. Impurity-related point defects and gamma-radiation response of massive quartz from the Borborema pegmatite province, in Brazil; Estudo da suscetibilidade ao escurecimento por radiacao gama de quartzo roseo-leitoso da provincia pegmatitica da Borborema

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    Miranda, Milena Ribas de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos-Graduacao em Engenharia Mineral; Gonzaga, Raysa Sthefany Gomes; Guzzo, Pedro Luiz [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia de Minas; Barreto, Sandra de Brito [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Geologia; Melgarejo, Joan Carles, E-mail: milaribas@hotmail.com, E-mail: raysagonzaga@hotmail.com, E-mail: pguzzo@ufpe.br, E-mail: sandrabrito@smart.net.br, E-mail: joan.carles.melgarejo.draper@ub.edu [Universidade de Barcelona, Barcelona (Spain). Dept. de Cristalografia, Mineralogia e Depositos Minerais

    2012-06-15

    This work has investigated the changes induced by {gamma}-radiation on impurity-related point defects in massive rose quartz from one deposit located at The Borborema Pegmatite Province (Northeast Region, in Brazil). Samples extracted from rose and colorless (milky) quartz blocks were irradiated with doses of {sup 60}Co, from 0.5 to 96 kGy. Point defects related to Al, Ge, Li and OH were measured by optical, infrared, and electron paramagnetic resonance spectroscopy, prior and after irradiation. The contents of Al, Li, Ge, Fe, Ti and other impurities were measured by inductively-coupled plasma mass spectrometry in quartz fragments exhibiting rose, pale-rose, and milky colorations. It was found that [AlO{sub 4}]{sup 0}, [AlO{sub 4}/H]{sup 0} and [GeO{sub 4}/Li]{sup 0} were generated by the dissociation of [AlO{sub 4}/Li]{sup 0} and [Li-OH] centers with doses as lower as 0.5 kGy. Above 8 kGy, the electron paramagnetic resonance signal related to [GeO{sub 4}/Li]{sup 0} decreases due to the intense mobility of Li species throughout the quartz lattice, giving rise to E'{sub 1} centers perturbed by Ge. The increase in [AlO{sub 4}]{sup 0} content with {gamma} doses and the consequent rise in the intensity of smoky color were similar for both rose and colorless quartz. Scanning electron microscopy carried out in insoluble residues obtained after chemical dissolution of each type of quartz revealed the presence of nanometric fibers only in rose specimens. These results suggested that the cause of rose color in massive quartz from Borborema Pegmatite Province is probably related to the presence of dumortierite inclusions. (author)

  2. Laserterapia de baixa intensidade no pós-operatório da síndrome do túnel do carpo Low-level laser therapy after carpal tunnel release

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    Marcelo de Pinho Teixeira Alves

    2011-01-01

    Full Text Available OBJETIVO: Avaliar o tratamento pós-operatório da síndrome do túnel do carpo (STC, utilizando-se a laserterapia de baixa intensidade (LBI. MÉTODO: Foram avaliados prospectivamente 58 pacientes portadores de STC, divididos aleatoriamente em dois grupos: tratamento com LBI (grupo 1 e placebo (grupo 2. Foi utilizado laser de 830nm, de gálio-alumínio-arsênico, e potência de 30mW. RESULTADOS: Houve predominância do sexo feminino, em ambos os grupos. A média de idade dos pacientes do grupo 1 foi de 44,3 anos e do grupo 2, de 51,9 anos. A média do tempo de evolução da doença foi aproximadamente dois anos em ambos os grupos. A média do tempo decorrido para alta do tratamento foi de 3,6 meses, em ambos os grupos, com menor número de pacientes queixosos no pós-operatório do grupo 1 do que do grupo 2. Ao fim do tratamento, no grupo 1, 29,41% dos pacientes apresentavam eletroneuromiografia alterada, enquanto que, no grupo 2, foram 63,64% dos pacientes após seis meses. CONCLUSÕES: Trata-se de estudo inicial sobre a terapêutica adjuvante utilizando LBI no pós-operatório da STC. A metodologia apresentada foi suficiente para a avaliação pós-operatória dos pacientes do estudo. Os pacientes submetidos à LBI após a cirurgia para STC foram beneficiados e obtiveram melhores resultados funcionais quando comparados ao grupo controle. A técnica foi eficaz e sem efeitos adversos nos pacientes estudados.OBJECTIVE: Evaluate the post-operative treatment of CTS, using the LLLT. METHOD: We prospectively evaluated 58 patients with CTS, randomly divided into two groups: treatment with LLLT (Group 1 and placebo (Group 2. A 830 nm gallium-aluminum-arsenic laser was used, with a power of 30 mW. RESULTS: There was female predominance in both groups. The mean age of the patients in Group 1 was 44.3 years and in Group 2, 51.9 years. The average duration of disease progression was around two years in both groups. The average time elapsed since discharge

  3. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser; Estudo in vitro da resistencia a desmineralizacao e da retencao de fluor em esmalte dental irradiado com laser de Er, Cr: YSGG

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    Ana, Patricia Aparecida da. E-mail: patriciadaana@yahoo.com.br

    2007-07-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser ({lambda} of 2.79 {mu}m) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm{sup 2}, 5,6 J/cm{sup 2} e 8,5 J/cm{sup 2} were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F{sup -}) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm{sup 2} and 8.5 J/cm{sup 2} promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm{sup 2} was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste

  4. Histological analysis of low-intensity laser therapy effects in peripheral nerve regeneration in Wistar rats Avaliação histológica dos efeitos da laserterapia de baixa potência sobre os processos de regeneração nervosa periférica em ratos Wistar

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    Cibele Nazaré da Silva Câmara

    2011-02-01

    Full Text Available Purpose: Analyze the influence of low-intensity laser therapy in the sciatic nerve regeneration of rats submitted to controlled crush through histological analysis. Methods: Were used 20 Wistar rats, to analyze the influence of low-intensity laser therapy in the sciatic nerve regeneration, where the injury of the type axonotmesis was induced by a haemostatic clamp Crile (2nd level of the rack. The animals were randomly distributed in 2 groups. Control group (CG n = 10 and Laser group (LG n = 10. These were subdivided in 2 subgroups each, according to the euthanasia period: (CG14 _ n = 5 and CG21 _ n = 5 and (LG14 _ n = 5 and LG21 _ n = 5. At the end of treatment, the samples were removed and prepared for histological analysis, where were analyzed and quantified the following findings: Schwann cells, myelinic axons with large diameter and neurons. Results: In the groups submitted to low-intensity laser therapy, were observed an increase in the number of all analyzed aspects with significance level. Conclusion: The irradiation with low intensity laser (904nm influenced positively the regeneration of the sciatic nerve in Wistar rats after being injured by crush (axonotmesis, becoming the nerve recovery more rapid and efficient.Objetivo: Verificar a influência da terapia com laser de baixa potência na regeneração histológica do nervo ciático de ratos submetidos à neuropraxia controlada. Métodos: Foi utilizada a amostra de 20 ratos da linhagem Wistar, para verificar a influência da terapia com laser de baixa intensidade na regeneração nervosa periférica, onde a lesão do tipo axoniotmese foi induzida por meio de preensão com pinça hemostática de Crile. Os animais foram distribuídos randomicamente dois grupos. Grupo controle (CG n = 10, e Grupo laser (LG n = 10. Cada um destes grupos foi subdividido em dois subgrupos dependendo do período da eutanásia: (CG14 - n = 5 e CG21 - n = 5 e (LG14 - n = 5 e LG21 - n = 5. Ao final do

  5. Evaluation of temperature variation in pulp chamber after high power diode laser irradiation ({lambda}=830 nm) on dental enamel: 'in vitro' study; Avaliacao da variacao da temperatura na camara pulpar apos a irradiacao de diodo laser de alta potencia de 830 nanometros em esmalte dental: estudo 'in vitro'

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    Macri, Rodrigo Teixeira

    2001-07-01

    The aim of this study was to observe the variation of temperature in the pulp chamber caused by irradiation of a commercial diode laser operating in continuous wave with wavelength 830 nm over the dental enamel. In the first part of this study, two types of tooth models were tested: 3,5 mm slice and whole tooth. In the second part, we irradiated the buccal si de of the enamel in 2 primary lower incisors from cattle with Opus 10 diode laser for 10 s with power levels of 1 W and 2 W, always using an absorber. Two thermocouples were used. The first one was inserted in the dentin wall closest to the irradiation site, while the second was inserted in the middle of the pulp chamber. It was observed that the thermocouples registered different temperatures. Always, the dentin thermocouple registered higher temperatures. Considering the dentin records, the irradiation of 1 W for 10 s can be safe for the pulp. Further studies must be developed related to the correct positioning of the thermocouples inside the pulp chamber. This was a first step of using diode laser in enamel, and in this study, we concluded that the Opus 10 diode laser shown to be safe for this use, with 1 W power for 10 S. (author)

  6. In vitro comparative study of share bond of light cured composite resins with halogen light and argon laser, using stainless steel brackets on human premolars; Estudo comparativo in vitro da capacidade adesiva da resina fotoativada pela luz halogena e por laser de argonio, utilizando-se brackets metalicos em pre-molares humanos

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    Carillo, Vitoria Eugenia Bismarck

    2004-07-01

    The aim of this study in vitro was to compare the share bond strength of the light-cured composite resins Transbond XT (Unitek), with halogen light and argon laser. The Adhesive Remmant Index (ARI) was also investigated. The brackets Dyna lock (3M-UNITEK) were bonded to 75 human premolars, divided into 5 groups (15 each) according to time and the polymerization: Group H20, 15 brackets bonded with halogen light for 20s (10s both sides); Group H40, 15 brackets bonded with halogen light for 40s (20s both sides); Group A40, 15 brackets bonded with argon laser for 40s (20s both sides); Group A20, 15 brackets bonded with argon laser for 20s (10s both sides); Group A10, 15 brackets bonded with argon laser for 10s (5s both sides). The pulpal temperature changes were determined during a polymerization, not exceeding 3,5 deg C. After bonding, the teeth were submitted to a thermo cycled of 700 cycles between 5 deg C and 55 deg C, to simulate the consuming that the light cured composite resin would have in a short space of time. The specimens were then placed in PVC ring and embedded in acrylic resin (Aero-Jet). The tensile bond strength test was performed on an Universal Machine set at a crosshead speed of 1,5 mm/min, and for each rupture we registered a graphic and the best load required in Newtons, was converted to MPa and kgf. The share bond strength showed bigger values for the exposure time of 20 seconds, for the Group bonded for halogen light (H20), 7,45 kgf (7,64 MPa) and for argon laser 7,50 kgf (7,69 MPa); lesser values for the exposure time of 40s for the Group with halogen light (H40), 6,15 kgf (6,30 MPa) and argon laser Group (A40), 6,20 kgf (6,35 MPa) 0; and A10, 4,85 kgf (4,97 MPa). In the ARI Index, only A40 Group showed the 1 Index, with statistical results. In this Group, less than half of the remainder adhesive stayed on the surface of the enamel, conferring specimens failed at the enamel-adhesive interface. The results of the in vitro study demonstrate that

  7. Intrapulpal temperature during preparation with the Er:YAG laser: an in vitro study; Avaliacao da temperatura intrapulpar de incisivos bovinos irradiados com o laser de Er:YAG

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    Geraldo-Martins, Vinicius Rangel

    2003-07-01

    This study evaluated the variation of the pulp chamber temperature when dentine, with 2,0 mm of thickness, adjacent to the pulp, was irradiated by the Er:YAG laser. Seventy two bovine incisors were used, that had the enamel and dentine of the buccal surface weared until to reach the thickness used in this study. The teeth were divided in 3 groups, according with the repetition rate used ( Group I = 2 Hz; Group II = 4 Hz and Group III = 6 Hz), and irradiated, with or without water cooling, using 250, 300 and 350 mJ of energy per pulse. Thermocouples were introduced inside the pulp chamber through the palatine opening of the samples and fixed to the vestibular wall of the pulp chamber using a thermal paste. After the statistical analysis, it was verified that there was a decrease of the intrapulpal temperature for all of the parameters in the group I irradiated with water cooling. In the same group, but without cooling, occurred increases of the intrapulpal temperature, however they were less than 2 deg C. In the group 11, only the para meter 350 mJ/4 Hz/ with water cooling presented decrease of the temperature (-0,08 deg C). The other irradiations presented increase of the intrapulpal temperature, varying from 1,5 to 1,9 deg C for irradiations without cooling and of 0,03 the 0,58 deg C for the samples irradiated under water cooling. In the group III, all of the samples presented increase of the intrapulpal temperature, however, they were smaller than to 2,5 deg C. The conditions of this study allow to conclude that the use of the laser of Er:YAG promoted acceptable temperature increases inside the pulp chamber, not reaching the critical level of 5,5 deg C. However, in spite of the temperature variations inside the pulp chamber have not reached critical levels, this procedure should not be recommended because macroscopic observations of the dentine irradiated without water cooling showed dark lesions, suggesting carbonization of this tissue. (author)

  8. In vitro evaluation of the morphologic changes on the root dentine irradiated by CO{sub 2} laser associated or not to calcium hydroxide application; Avaliacao in vitro das alteracoes morfologicas da superficie da dentina radicular irradiada pelo laser de CO{sub 2} associado ou nao a aplicacao de hidroxido de calcio

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    Romano, Ana Cristina Cury Camargo

    2003-07-01

    This in vitro study has evaluated the structural changes on the root dentine irradiated by a CO{sub 2} laser associated or not to calcium hydroxide application, from the irradiated surface analysis by means of Scanning Electronic Microscopy (SEM). The purpose of this evaluation has been the study of an alternative method for the treatment of dentine hypersensitivity. Fourteen human teeth were utilized, third molars, divided into 7 groups. Group I (control group) to which no treatment was applied; Groups II, III and IV were given an application of Ca (OH){sub 2} paste followed by C0{sub 2} laser irradiation, lasting 5 seconds each with intervals of 10 seconds between each application, with continuous emission, power of 0.5 W (Group II), 1.0 W (Group III), and 1.5 W (Group IV); Groups V, VI, and VII were given laser irradiations without the Ca (OH){sub 2} paste following the same parameters applied to groups II, III, and IV respectively. Morphologic changes suggesting to fusion and re-solidification have been observed, as well as the presence of material obstructing the whole analyzed surface on groups II, III, and IV (laser + Ca (OH){sub 2}). As for groups V, VI, and VII, it has been observed fusion, re-solidification, and cracks, and these results being statistically significant when compared the '(Ca (OH){sub 2})' groups to the laser groups. No statistically significant differences were observed regarding the different powers applied in the groups that used the same treatment. Despite this result, it can be stated that powers above 1.0 W (DP = 125,38 W/cm{sup 2}) are unfavorable due to the undesirable morphologic alterations and aesthetic compromising. (author)

  9. In vitro evaluation of the morphologic changes on the root dentine irradiated by CO{sub 2} laser associated or not to calcium hydroxide application; Avaliacao in vitro das alteracoes morfologicas da superficie da dentina radicular irradiada pelo laser de CO{sub 2} associado ou nao a aplicacao de hidroxido de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Ana Cristina Cury Camargo

    2003-07-01

    This in vitro study has evaluated the structural changes on the root dentine irradiated by a CO{sub 2} laser associated or not to calcium hydroxide application, from the irradiated surface analysis by means of Scanning Electronic Microscopy (SEM). The purpose of this evaluation has been the study of an alternative method for the treatment of dentine hypersensitivity. Fourteen human teeth were utilized, third molars, divided into 7 groups. Group I (control group) to which no treatment was applied; Groups II, III and IV were given an application of Ca (OH){sub 2} paste followed by C0{sub 2} laser irradiation, lasting 5 seconds each with intervals of 10 seconds between each application, with continuous emission, power of 0.5 W (Group II), 1.0 W (Group III), and 1.5 W (Group IV); Groups V, VI, and VII were given laser irradiations without the Ca (OH){sub 2} paste following the same parameters applied to groups II, III, and IV respectively. Morphologic changes suggesting to fusion and re-solidification have been observed, as well as the presence of material obstructing the whole analyzed surface on groups II, III, and IV (laser + Ca (OH){sub 2}). As for groups V, VI, and VII, it has been observed fusion, re-solidification, and cracks, and these results being statistically significant when compared the '(Ca (OH){sub 2})' groups to the laser groups. No statistically significant differences were observed regarding the different powers applied in the groups that used the same treatment. Despite this result, it can be stated that powers above 1.0 W (DP = 125,38 W/cm{sup 2}) are unfavorable due to the undesirable morphologic alterations and aesthetic compromising. (author)

  10. Apical microinfiltration evaluation of radicular channels irradiated with Er:YAG laser in vitro; Avaliacao da microinfiltracao apical de condutos radiculares irradiados in vitro com laser de Er:YAG

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    Sebrao, Catia Cilene Nass

    2003-07-01

    It was evaluated, in vitro, the adaptation of the filling material (Sealer 2S{sup R}) to the root channels dentine walls treated using the endodontic technique and prepared with the Er:YAG laser, by the technique of infiltration of methylene blue dye. Using scanning electronic microscopy, the morphologic alteration of the root channel dentine was observed for one sample per studied group. Also, an evaluation of the temperature increase in the external surface of the root during the irradiations was performed for two samples per group. For each group of samples, with eleven roots each, two sub-groups had been considered: the dry, irradiated after completely dry with absorbent cones of paper, and the humid, where a cone of absorbent paper was applied for two seconds in the root canal, leaving them lightly humidified. Considering the used energies for the irradiations, the groups are: G1, control (without irradiation), G2-dry (100 mJ-10 Hz), G2-humid (100 mJ-10 Hz), G3-dry (140 mJ-6 Hz), G3-humid (140 mJ-6 Hz), G4-dry (180 mJ-6 Hz), and G4-humid (180 mJ-6 Hz). The results had shown that apical microinfiltration did not exhibit significant difference among groups. The highest increase in temperature was observed for the dry groups, with the maximum variation of temperature of 6.5 deg C. Under the scanning electronic microscopy analysis, the humid groups had presented cleaner surfaces than the dry groups. The G4-humid group presented extensive regions of fusion and resolidification of the dentine. (author)

  11. Clinical evaluation of the low intensity laser antialgic action of GaAlAs ({lambda}=785 nm) in the treatment of the temporomandibular disorders; Avaliacao clinica da acao antialgica do laser em baixa intensidade de arseneto de galio e aluminio ({lambda}=785 nm) no tratamento das disfuncoes da articulacao temporo-mandibular

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    Sanseverino, Nelly Tichauer Maluf

    2001-07-01

    The therapy with laser emitting low intensity has been currently used in the most diverse fields of medicine as therapeutic conduct for pain. It is a non invasive, painless, non-thermal and aseptic type therapy, without any collateral effects, having a good cost/benefit relationship. However, for the therapy with low-intensity laser to result in positive effects, a correct diagnosis is fundamental, as well as a protocol of adequate application. n odontology, the majority of patients diagnosed with temporomandibular disorders (TMD), present pain and limitations in the movements of the jaw. In this work, a GaAlAs laser emitting low intensity, was used, {lambda}=785 nm, in patients having a dysfunction of the temporomandibular joint with a complaint of pain. Twenty patients were divided into two groups. The group treated received laser therapy in the temporomandibular articulations and in the muscles affected. The dose applied was 45 J/cm{sup 2}, while the ten patients in the control group received 0 J/cm{sup 2}, in a total of nine applications, carried out three times a week, during three weeks. he evaluation of the patients was made through clinical examinations of manual palpation of the masseter, temporal, cervical, posterior neck and sternocleidomastoid muscles, and measurements of opening and laterality of the mouth. The results obtained showed a diminishing of the pain and an increase of the mandibular mobility in the patients treated, when compared to the control group. These results point to this therapy as being an important tool in the treatment of pain in patients with a dysfunction in the TMJ, indicating this therapeutic modality as a co-adjuvant in these treatments. (author)

  12. The influence of screw type, alloy and cylinder position on the marginal fit of implant frameworks before and after laser welding Influência do tipo de parafuso, liga e da posição do cilindro na adaptação marginal das infra-estruturas sob implantes antes e após a soldagem a laser

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    Daniela Castilio

    2006-04-01

    Full Text Available Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. OBJECTIVES: To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. METHODS: After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5mm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (alpha=0.05. RESULTS: Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13µm than the hexagonal screws (27.93 µm. Besides, no statistically significant differences were found after laser welding. CONCLUSIONS: 1 The use of different metal alloys do exert influence on the marginal fit, 2 The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3 cylinder position did not affect marginal fit values.A desadaptação na interface abutment-cilindro protético pode causar perda da pré-carga, levando ao afrouxamento ou fratura dos parafusos de ouro e tit

  13. In vitro study of the effects of cooling water temperature during the use of Er:YAG laser on dentin; Estudo in vitro dos efeitos da temperatura da agua de refrigeracao no uso de laser de Er:YAG em dentina

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    Pinto, Ismael Lucas

    2004-07-01

    This study measured the pulp chamber and the target surface with 2 thermocouples, in order to determine whether cooling with water spray, with Er:YAG laser (Kavo Key 2), was overcooling the tooth, much beyond the necessary, during laser irradiation, within variation limits of 2.2 deg C of body temperature. The parameters used were: E{sub p}=250 mJ per pulse, with frequency ranging between 2 to 4 Hz, for a total DE of 80.20 J/cm{sup 2}, at an angle of incidence of approximately 90 deg, during an exposure period of 1 minute, totaling 120 to 240 pulses. In the first 40 seconds, the spray cooled the tooth rapidly, from 36.5 deg C to below 30 deg C. It was impossible to control the spray output temperature with a simple increase in reservoir temperature, for when water at temperatures ranging between 90 and 100 deg C is placed in the reservoir, the heat dissipates completely during the trajectory. The water jet does not present the same characteristics as a spray, which makes it impossible to conduct a perfect comparative analysis between them. The increase and maintenance of the spray output temperature, by reducing the temperature differential between that of the body and that of the spray of the Er:YAG laser, proved to be extremely promising. The pulp chamber temperature followed that of the spray or water jet, so that when a temperature that is lower than body temperature is used, the temperature of the pulp chamber is decreases, and when body temperature is surpassed, the temperature of the pulp chamber increases. (author)

  14. Comparative study of the action of two different types of bleaching agents activated by two different types of irradiation fonts: xenon plasma arc lamp and 960 nm diode laser; Avaliacao da cor e estudo comparativo da acao de dois tipos diferentes de agentes clareadores ativados pelo laser de diodo e lampada xenonio plasmatica, na superficie do esmalte

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    Walverde, Debora Ayala

    2001-07-01

    This in vitro study compares two different types of tooth bleaching agents stimulated with two different irradiation fonts. These fonts accelerate the action of the bleaching agents upon the enamel surface by heating up the materials. We used the xenon plasma arc lamp and a 960 nm fiber-coupled diode laser to irradiate the two materials containing 35% of hydrogen peroxide (Opus White and Opalescence extra). The color of the teeth was measured with a spectrophotometer using the CIELAB color system that gives the numeric values of L{sup *}a{sup *}b{sup *}. (author)

  15. Comparative study of analgesic effect of the infrared low-intensity laser and 33% sodium fluoride paste in the treatment of dentinal hypersensitivity; Estudo comparativo do efeito analgesico do laser em baixa intensidade de emissao infravermelha e da pasta de fluoreto de sodio a 33% no tratamento da hipersensibilidade dentinaria

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    Oliveira, Glen Anderson Maia de

    2003-07-01

    Different desensitizing agents have been used in the treatment of dentinal hypersensitivity, however, some presented treatments are still frustrating. The purpose of this study was to evaluate the analgesic effect of the low-intensity GaAlAs laser ({lambda}= 830 nm) in the treatment of dentinal hypersensitivity after mechanical and thermal stimuli, and compared it with the 33% sodium fluoride paste. Thirty two teeth with dentinal hypersensitivity were selected and randomly divided into two groups. For the laser group, each tooth was irradiated by a dose of 6 J/cm{sup 2} during two minutes and half on the buccal side. The paste group was treated with a NaF/kaolin/glycerin (33:33:33) paste by burnishing the sensitive surface during four minutes. The sensitivity degree was measured before the beginning of the experiment, 24 h, 48 h, 72 h, 120 h, 15 days and 30 days after the first application. The results indicate that the dentinal hypersensitivity significantly diminished for the paste group after dental explorer. Regarding to air-blast, no significant differences were observed between the groups. Both of them were effective in reducing pain of the dentine hypersensitive after 120 h. (author)

  16. Perioperative effects of oral midazolam premedication in children undergoing skin laser treatment: a double-blinded randomized placebo-controlled trial Efeitos peroperatórios da premedicação oral de midazolam em crianças submetidas a tratamento de pele por laser: estudo duplo-cego randomizado e controlado

    Directory of Open Access Journals (Sweden)

    Mehrdad Shoroghi

    2011-08-01

    tratamento de pele por laser foram distribuídas aleatóriamente em três grupos de 30 cada: o grupo placebo recebeu 0.1mg/kg de suco de laranja, grupos dois e três receberam 0.5 e 1mg/kg de midazolam injetável misturado em igual volume de suco de laranja respectivamente. Os principais registros incluíam a aceitação da máscara, escalas de comportamento e eventos pós-operatórios. RESULTADOS:Não houve diferenças significantes cardíacas, respiratórias e pressão sanguinea sistólica nos três grupos. Contudo, o nível de saturação de oxigênio foi reduzido significantemente nos que receberam 1mg.kg-1 de midazolam. Os níveis médios de ansiedade, separação dos pais, preparo intravenoso, aceitação da máscara de oxigênio, boa sedação, redução do choro e nível de consciência, foram melhores no grupo midazolam. Agitação pós-operatória e retorno do chora foi mais freqüente nos que receberam placebo. Observou-se que o grupo que recebeu 1mg.kg-1 foi melhor comparado ao que recebeu 0.5mg.kg-1. CONCLUSÃO:Como medicação pré-anestésica na dose de 1mg.kg-1 de midazolam, fornecida em igual volume de suco de laranja, é satisfatória no comportamento de crianças durante tratamento de pele por laser, proporcionando satisfação dos pais.

  17. Morphologic analysis, by means of scanning electron microscopy, of the effect of Er: YAG laser on root surfaces submitted to scaling and root planing Análise morfológica, através de microscopia eletrônica de varredura, da ação do laser de Er: YAG em superfícies radiculares submetidas à raspagem e aplainamento radicular

    Directory of Open Access Journals (Sweden)

    Letícia Helena Theodoro

    2002-12-01

    Full Text Available The purpose of this study was to morphologically evaluate, by means of scanning electron microscopy, the effects of Er:YAG laser on the treatment of root surfaces submitted to scaling and root planing with conventional periodontal instruments. Eighteen root surfaces (n = 18, which had been previously scaled and planed, were assigned to 3 groups (n = 6. The control Group (G1 received no further treatment; Group 2 (G2 was irradiated with Er:YAG laser (2.94 mum, with 47 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 0.57 J/cm² of fluency per pulse; Group 3 (G 3 was irradiated with Er:YAG laser (2.94 mum, with 83 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 1.03 J/cm² of fluency per pulse. We concluded that the parameters adopted for Group 3 removed the smear layer from the root surface, exposing the dentinal tubules. Although no fissures, cracks or carbonized areas were observed, an irregular surface was produced by Er:YAG laser irradiation. Thus, the biocompatibility of the irradiated root surface, within the periodontal healing process, must be assessed.O objetivo do presente estudo foi analisar morfologicamente, através de microscopia eletrônica de varredura, os efeitos do laser de Er:YAG no tratamento de superfícies radiculares submetidas à raspagem e aplainamento radicular com instrumentos manuais. Foram utilizados 18 espécimes (n = 18 de superfícies radiculares que após ser submetidos à raspagem e aplainamento radicular foram divididos em 3 grupos (n = 6. O grupo controle (G1 não sofreu nenhum tratamento; Grupo 2 (G2 foi irradiado com laser de Er:YAG (2,94 mim 47 mJ/10 Hz, focalizado,com refrigeração à água durante 15 s e fluência de pulso de 0,57 J/cm²; Grupo 3 (G3 foi irradiado com laser de Er:YAG (2,94 mim, 83 mJ/10 Hz, focalizado, com refrigeração à agua durante 15 s e fluência de pulso de 1,03 J/cm². Através da análise dos resultados podemos concluir que o laser de

  18. Potential of sub-ablative pulsed CO{sub 2} laser irradiation on inhibition of artificial caries-like lesion progress in bovine dental enamel; Potencial de inibicao da progressao da carie artificial por irradiacao sub-ablativa com laser de CO{sub 2} pulsado em esmalte dental bovino

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcella Esteves

    2005-07-01

    The aim of this study was to investigate whether sub-ablative pulsed C0{sub 2} laser (1 0,6 {mu}m) irradiation is capable of reducing the susceptibility of the dental enamel to demineralization, and thus achieving a potential caries-protective effect. The crowns of 51 bovine front teeth, embedded in acrylic resin and polished until exposure of flat enamel surface, were used. The samples were cut in cubes of 10x10 mm, and totally coated with acid-resistant nail varnish, except for an enamel exposed window of 16 mm square. Three groups (n=17) were obtained: control group (CG) not irradiated; group laser A (LA) and group laser B (LB) where the samples were irradiated. The conditions were 60 mJ, 100 Hz, 0,3 J/cm{sup 2} for LA and 135 mJ, 10 Hz, 0,7 J/cm{sup 2} for LB. Two samples of each group were submitted to SEM analysis and fifteen to demineralization in 3 ml acetate buffer solution (0,1 mol/L) with pH 4,5 for 24h at 37 deg C, with regular agitation. After the specimens were removed from the solution, the calcium and phosphorous content were measured with an inductively coupled plasma optical emission spectrometer and 2 more samples of each were submitted to SEM analysis. The obtained Ca and P means in {mu}g/ml and the calculated Ca/P molar ratio were: CG (367,88 {+-} 33,47; 168,91 {+-} 14,55; 1,70 {+-} 0,07) ; LA (372,70 {+-} 41,70; 161,46 {+-} 15,26; 1,79 {+-} 0,07) and LB (328,87 {+-} 24,91; 145,02 {+-} 11,04; 1,77 {+-} 0,05). The ANOVA statistical test revealed statistically significant difference for [Ca], [P] e Ca/P content between the groups (p<0,05). The Tukey test results showed that LB had significantly lower means of Ca and P content in demineralization solution than the other groups (p<0,01), and between LA and control there was not statistically significant difference. For the Ca/P molar ratio LA and LB means were significantly higher than the control (p<0,01) and there was not statistical difference between the two irradiated groups. SEM observations

  19. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  20. Inhibition of carrageenan-induced expression of tissue and plasma prekallikreins mRNA by low level laser therapy in a rat paw edema model Inibição da expressão de RNA mensageiro de pré-calicreínas tecidual e plasmática pela laserterapia em modelo de edema de pata induzido pela carragenina em ratos

    Directory of Open Access Journals (Sweden)

    Moisés P. Silva

    2011-02-01

    Full Text Available BACKGROND: Low level laser therapy (LLLT has been used clinically in order to treat inflammation, where tissue and plasma prekallikrein have crucial importance. Plasma prekallikrein (PPK is synthesized by the hepatocytes and secreted into the bloodstream, where it participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. Tissue prekallikrein is associated with important disease states (including cancer, inflammation, and neurodegeneration and has been utilized or proposed as clinically important biomarker or therapeutic target of interest. OBJECTIVE: To evaluate if LLLT modulates tissue and plasma prekallikreins mRNA expression in the carrageenan-induced rat paw edema. METHODS: Experimental groups were assigned as followed: A1 (Control-saline, A2 (Carrageenan-only, A3 (laser 660nm only and A4 (Carrageenan + laser 660nm. Edema was measured by a plethysmometer. Subplantar tissue was collected for the quantification of prekallikreins mRNA by Real time-Polymerase Chain Reaction. RESULTS: A significantly decrease in the edema was observed after laser irradiation. Expression of prekallikreins increased after carrageenan injection. Tissue and plasma prekallikrein mRNA expression significantly decreased after LLLT's 660nm wavelength. CONCLUSION: These results suggest that expression of tissue and plasma prekallikreins is modulated by LLLT, which can be used in clinical practice due to its anti-inflammatory effects.CONTEXTUALIZAÇÃO: A laserterapia de baixa potência tem sido usada para o tratamento de processos inflamatórios diversos em que a calicreína tecidual e a plasmática possuem participação ativa. A pré-calicreína plasmática (PPK é sintetizada pelos hepatócitos e secretada na corrente sanguínea, onde participa da ativação da coagulação, fibrinólise, geração de cininas e inflamação. A pré-calicreína tecidual está associada com importantes doenças (incluindo c

  1. Influência da naloxona e metisergida sobre o efeito analgésico do laser em baixa intensidade em modelo experimental de dor Influencia de la naloxona y la metisergida sobre el efecto analgésico del láser en baja intensidad en modelo experimental de dolor Influence of naloxone and methysergide on the analgesic effects of low-level laser in an experimental pain model

    Directory of Open Access Journals (Sweden)

    André Peres e Serra

    2010-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A fototerapia com laser (LPT é um método analgésico promissor, embora seu mecanismo de ação não seja totalmente conhecido. O objetivo deste estudo foi avaliar se a ação da LPT é dependente da ativação de receptores opioides ou serotoninérgicos periféricos. MÉTODO: Foram utilizados ratos Wistar machos. A dor produzida foi de caráter inflamatório, através da injeção de carragenina na pata posterior esquerda dos ratos. O laser utilizado foi o Photon Lase III em meio ativo InGaAIP (660 nm, fluência de 2,5 J.cm-2. Analisou-se a hiperalgesia mecânica utilizando filamentos de von Frey. Os animais foram separados em cinco grupos: Carragenina; Laser (LPT; Luz não coerente; LPT + Naloxona e LPT + Metisergida. RESULTADOS: A fototerapia com laser em baixa intensidade mostrou-se um método analgésico eficaz, enquanto o emprego de fonte de luz não coerente não mostrou ter efeito analgésico. O uso de naloxona bloqueou o efeito analgésico do LPT; já o uso de metisergida não afetou a analgesia do LPT. CONCLUSÕES: A LPT nos parâmetros utilizados apresentou efeito analgésico. A analgesia da LPT é mediada por receptores opioides periféricos. A LPT parece não interagir com receptores serotoninérgicos periféricos.JUSTIFICATIVA Y OBJETIVOS: La fototerapia con láser (LPT es un método analgésico promisorio, aunque su mecanismo de acción no se conozca en su totalidad. El objetivo de este estudio fue evaluar si la acción de la LPT es dependiente de la activación de receptores opioides o serotoninérgicos periféricos. MÉTODO: Se usaron ratones Wistar machos. El dolor generado fue de carácter inflamatorio, a través de la inyección de carragenina en la pata posterior izquierda de los ratones. El láser utilizado fue el GaIAsAl (660 nm, fluencia de 2,5 J.cm-2. Se analizó la hiperalgesia mecánica utilizando filamentos de von Frey. Los animales se dividieron en cinco grupos: Carragenina; Láser (LPT

  2. Evaluation of the effects of gamma radiation in minimally processed vegetables of Brassica oleracea species; Avaliacao dos efeitos da radiacao gama em vegetais da especie Brassica oleracea minimamente processados

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Thaise Cristine Fernandes

    2009-07-01

    The consumption of collard greens (Brassica oleracea cv. acephala) and broccoli (Brassica oleracea L. var. italica) has been inversely associated with morbidity and mortality caused by degenerative diseases. These species are highly consumed in Brazil, which enables its use as minimally processed (MP). The growing worldwide concern with the storage, nutritional quality and microbiological safety of food has led to many studies aimed at microbiological analysis, vitamin and shelf life. To improve the quality of these products, radiation processing can be effective in maintaining the quality of the product, rather compromising their nutritional values and sensory. The aim of this study was to evaluate the effectiveness of gamma radiation from {sup 60}Co at doses of 0, 1.0 and 1.5 kGy on the reduction of microbiota in these plants, and analyze their nutritional and sensory characteristics. The methodology used in this study was microbiological analysis, colorimetric analysis, analysis of phenolic compounds, antioxidant analysis and sensory analysis. The microbiological analysis showed a decrease in the development of populations of aerobic microorganisms, psychotropic and yeast and mold with increasing doses of radiation. The sensory analysis showed no significant difference between different times of cooking analyzed. The analysis of phenolic compounds, significant differences between the samples, suggesting that with increasing dose of irradiation was an increase in the amount of phenolic compounds found in broccoli and collard greens MP. It can be observed that the sample of control collard greens showed high antioxidant activity and for the samples treated by irradiation was a decrease of percentage. In contrast the samples of broccoli show an increase in the rate of scavenging DPPH with increase of the dose of radiation. The colorimetric analysis revealed that for samples of MP collard greens and broccoli foil of no significant differences, but for samples of stems of broccoli significant difference on the yellowing during storage. It is concluded that the processing of collard greens and broccoli butter by gamma radiation may be a viable alternative to the industry, since there was a reduction of the population of microorganisms, without changes in the sensory qualities and with minimum changes in the characteristics that confer antioxidant power. (author)

  3. Capture and utilization of solar radiation by the soybean and common bean crops and by weeds; Captacao e aproveitamento da radiacao solar pelas culturas da soja e do feijao e por plantas daninhas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Barbosa dos; Procopio, Sergio de Oliveira; Silva, Antonio Alberto da [Universidade Federal de Vicosa (UFV), MG (Brazil). FItotecnia; Costa, Luiz Claudio [Universidade Federal de Vicosa (UFV), 36571-000, MG (Brazil). Dept. de Engenharia Agricola

    2003-07-01

    Aiming to develop techniques for the establishment of a Weed Integrated Management Program, the performance of common bean (Phaseolus vulgaris L.) and soybean (Glycine max (L.) Merrill) and of weeds Bidens pilosa L., Euphorbia heterophylla L. (two biotypes), sensitive and resistant to ALS inhibitor - herbicides and [ Desmodium tortuosum (SW.) DC.], was evaluated in relation to their efficiency in capturing and utilizing solar radiation.The following indices were calculated: total dry biomass production rate (Ct), leaf dry biomass production rate (Cf), radiation efficient use (x), net assimilation rate (EA), specific leaf area (SA), leaf area index (L), leaf matter ratio (FW) and leaf area ratio (FA). No difference was observed for all characteristics evaluated among E. heterophylla biotypes. Soybean showed the highest rate of total dry biomass production along its cycle and also the highest leaf area index, indicating its greater capacity in capturing light and providing shade to competitive plants. Especially after flowering, common bean was the most efficient in draining its photoassimilates for leaf formation. Soybean showed greater efficiency in converting radiation intercepted in the biomass. (author)

  4. Ionizing radiation effect on teas of Camellia sinensis plant irradiated with different water activities; Efeito da radiacao ionizante em chas da planta Camellia sinensis irradiados com diferentes atividades de agua

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo Bernardes

    2013-07-01

    Tea is the most consumed beverage in the world. Teas from Camellia sinensis plant have high levels of antioxidants, which mean that they may have several beneficial effects on health preservation. For centuries, mankind looks for ways to conserve better and for a longer time the food that they eat. The food irradiation process is a largely technique used worldwide, and is recommended by many health agencies and authorities of several countries. The radiation interacts with the material causing two kinds of effects, the direct and the indirect effect. In the direct effect the radiation interacts with the DNA molecule, breaking it, and then inactivates the cell. In the indirect effect, which represents 70% of the interaction, the radiation breaks the water molecule in a process denominated radiolysis, creating a number of free radicals that will interact with the cellular components, leading to the cell death. Therefore, the aim of this work is to study the effects of gamma radiation on two kinds of tea from Camellia sinensis plant irradiated with different water activities. The green tea and black tea samples had their Aw adjusted to three values (high Aw, medium Aw, and low Aw). The samples were irradiated in {sup 60}Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The analyses used were: microbiology by plate count, total phenolic compounds quantification, antioxidant activity by ORAC assay, and identification and quantification of main antioxidants in these beverages. It was noted that the greater the quantity of free water present in the medium, the lower was the dose to achieve microbiological control. The green tea showed to be a little more susceptible to irradiation by high Aw once there was more variation in the amount of flavonoids and phenolics than the black tea, decreasing the amount of these compounds in some doses, but increasing the amount in other ones. However in both teas, these changes can be considered insignificant, since there was no difference in antioxidant activity at doses up to 10 kGy. The dose of 5.0 kGy was the minimum dose that secured the microbiological control and had no changes on the parameters analyzed. (author)

  5. Evaluation gamma radiation in composite sisal fiber- polyurethane derived of castor oil by bending test; Avaliacao da influencia da radiacao gama em compositos de fibra de sisal - poliuretano derivado de oleo de mamona atraves de ensaios de flexao

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Felipe H. de; Geraldo, Ricardo R.; Vasco, Marina C.; Azevedo, Elaine, E-mail: helunica@yahoo.com.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Claro Neto, Salvador [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Quimica

    2015-07-01

    Materials used for making furniture and accessories or positioning in X -ray examination rooms should not exhale volatile organic compounds and are resistant to ionizing radiation. One solution is the use of vegetable fiber and polyurethane composites of vegetable origin, since they are biodegradable, derived from renewable raw materials and have no volatile organic compounds. The main difficulty in developing this material is fiber adhesion with the polymer. The objective of this study is to evaluate the mechanical properties of composite sisal fiber composite, without further treatment, and polyurethane derived from castor oil, with a dose of 25 kGy gamma radiation, subjected to 3 points bending tests. (author)

  6. Evaluation exposure to the ionizing radiation of workers during the operation of first Brazilian uranium mine; Avaliacao da exposicao de trabalhadores a radiacao ionizante durante a operacao da primeira mina de uranio do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S.; Oliveira, Sergio Q. de; Py Junior, Delcy de A.; Dantas, Marcelino V.A.; Silva, Ana Claudia A.; Garcia Filho, Oswaldo, E-mail: wspereira@inb.gov.b, E-mail: sergioquinet@inb.gov.b, E-mail: delcy@inb.gov.b, E-mail: marcelino@inb.gov.b, E-mail: anasilva@inb.gov.b, E-mail: ogarcia@inb.gov.b [Industrias Nucleares do Brasil (UTM/INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerios. Servico de Radioprotecao

    2011-10-26

    The production of uranium in Brazil initiated, in industrial scale, in the year of 1982, in the Miner-Industrial Complex at Pocos de Caldas, Minas Gerais, Brazil. This paper analysed the data of 13410 individual historic of dose, registered along the years of work, bay the radioprotection service of installation. Descriptive statistics and frequency histograms based on dose historic, and the annual distribution doses and the accumulated doses were evaluated during the functioning period of the CIPC, and his adequacy to the in force legislation at the time of it operation

  7. Synthesis of a gamma irradiation grafted polytetrafluoroethylene (PTFE) based olefinic copolymer; Estudo da sintese de copolimero olefinico a base de politetrafluoroetileno (PTFE) por meio da enxertia induzida por radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Ferreto, Helio Fernando Rodrigues

    2006-07-01

    The extrusion of linear low density polyethylene (LLDPE) is limited by a process related defect known as 'melt fracture' or 'sharkskin', which is a surface defect of the extruded polymer. This defect results in a product with a rough surface that lacks luster and in alterations of specific surface properties. The aim of this study was to obtain a recycled polytetrafluoroethylene polymer with an olefin that could improve the extrudability of the LLDPE. The copolymer was obtained by irradiating recycled PTFE in an inert atmosphere followed by the addition of an olefinic monomer to graft the latter in the polymeric matrix (PTFE). After a certain time of contact, the copolymer was heat treated to permit recombination and elimination of the radicals, both in a reactive and/or inert atmosphere. Three olefinic monomers were used, namely; acetylene, ethylene and 1,3-butadiene. The 1,3-butadiene monomer was found to be more effective with respect to grafting. The specimens were studied using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential thermogravimetry (DTG). 0.2-2.0 wt% of the copolymer that was obtained was mixed with LLDPE. The rheological properties of the mixture were determined with a torque rheometer. The results indicated that the process used rendered a copolymer which when added to LLDPE, improved the extrusion process and eliminated the defect 'melt fracture'. (author)

  8. Calibration method for a in vivo measurement system using mathematical simulation of the radiation source and the detector; Metodo de calibracao de um sistema de medida in vivo atraves da simulacao matematica da fonte de radiacao e do detector

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, John

    1998-12-31

    A Monte Carlo program which uses a voxel phantom has been developed to simulate in vivo measurement systems for calibration purposes. The calibration method presented here employs a mathematical phantom, produced in the form of volume elements (voxels), obtained through Magnetic Resonance Images of the human body. The calibration method uses the Monte Carlo technique to simulate the tissue contamination, the transport of the photons through the tissues and the detection of the radiation. The program simulates the transport and detection of photons between 0.035 and 2 MeV and uses, for the body representation, a voxel phantom with a format of 871 slices each of 277 x 148 picture elements. The Monte Carlo code was applied to the calibration of in vivo systems and to estimate differences in counting efficiencies between homogeneous and non-homogeneous radionuclide distributions in the lung. Calculations show a factor of 20 between deposition of {sup 241} Am at the back compared with the front of the lung. The program was also used to estimate the {sup 137} Cs body burden of an internally contaminated individual, counted with an 8 x 4 Nal (TI) detector and an {sup 241} Am body burden of an internally contaminated individual, who was counted using a planar germanium detector. (author) 24 refs., 38 figs., 23 tabs.

  9. Effect of chitosan addition and gamma radiation on polymeric blends of PVP and PVAL; Efeito da adicao de quitosana e da radiacao gama em blendas polimericas de PVP e PVAL

    Energy Technology Data Exchange (ETDEWEB)

    Terence, M.C.; Castro, P.J.; Miranda, L.F.; Faldini, S.B., E-mail: mauroterence@yahoo.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo. SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    The objective of this project is the study of the effect of chitosan addition and the radiation with gamma rays. The polymeric blend usage is a recent development that expanded the applications of the polymers, due to the improvement of the properties of a single polymer. The PVP and PVAL were chosen because they present the main required characteristics to the formation of a hydrogel, such as water absorption and crosslinking, and the chitosan to improve the interaction between the hydrogel and the organism. The flexibility of the PVP was added with the mechanical resistance of the PVAL and the chitosan biocompatibility. With a defined concentration of PVP and PVAL, films of this blend was irradiated and also solutions with different concentrations of chitosan was prepared to obtain new films of this blend. After obtaining the films, some assays were realized to evaluate the mechanical properties. (author)

  10. Influence of gamma radiation on molluscicidal and antimicrobial action of leaf and stem bark of Ziziphus joazeiro; Influencia da radiacao gama sobre a acao moluscicida e antimicrobiana da folha e casca do caule de Ziziphus joazeiro

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Fabricio O.; Siqueira, Williams N.; Lima, Maira V.; Melo, Larissa S.A.; Luna Filho, Ricardo L.C.; Morais, Vinicius H.T.; Oliveira, Maria L.M.; Melo, Ana M.M.A.; Silva, Edvane B., E-mail: fabriciomendesbio@gmail.com, E-mail: williams.wns@gmail.com, E-mail: mairavasconceloslima@gmail.com, E-mail: larissamelo.pe@gmail.com, E-mail: ricardolclf@hotmail.com, E-mail: viniciushtmorais@hotmail.com, E-mail: mluizamarinho@gmail.com, E-mail: amdemelo@hotmail.com, E-mail: s, E-mail: fabriciomendesbio@gmail.com, E-mail: williams.wns@gmail.com, E-mail: edvborges@yahoo.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2017-11-01

    Ionizing radiation is a physical agent used in several areas of knowledge: in medicine for the diagnosis and treatment of diseases, in the industry, it is apply in the generation of energy, sterilization of equipment and food, for example. Studies show that radiation can modify the molecular structure of substances of natural origin, potentiating or inactivating their function. The compounds derived from plants have received special attention because they constitute a form of medicinal therapy that has been growing notably in recent years. In addition, products of natural origin may also aid in the control of microbiological or animal vectors of parasites. Of the various species of plants being studied, Ziziphus joazeiro, popularly known as jua, native to the Caatinga, is commercially exploited for the manufacture of cosmetics and as anti-inflammatory, antimicrobial, anti influenza, fever and gastritis, bruises and has molluscicidal activity. Therefore, the objective of this work was to evaluate the influence of cobalt-60 gamma radiation on leaf and bark extracts of Z. joazeiro stem, evaluating possible changes in molluscicidal and antimicrobial action. For the experiments, the Z joazeiro extracts were irradiated with doses of 5, 7.5 and 10 kGy (Gammacell-Cobalt-60, dose rate 7.222 kGy/h). Adult mollusks (n = 60) and embryos (n = 1800) of Biomphalaria glabrata were distributed in the following groups: negative control 1 (water only); negative control 2 (extract only); positive control (CuCO{sub 3}); and three groups submitted to irradiated extracts. The antibacterial assay was performed with Gram-positive microorganisms (Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Enterococcus faecalis) belonging to the collection of the Departamento de Antibioticos of the UFPE by disc diffusion method. Statistical analysis was perform by Student's t-test and chi-square test, with a confidence interval of 95%. The results showed that the ionizing radiation was not able to potentiate the molluscicidal action of the extracts studied; however, antimicrobial activity was verify independently of the irradiation. (author)

  11. Dosimetric evaluation of spectrophotometric response of alanine gel solution for gamma, photons, electrons and thermal neutrons radiations; Avaliacao dosimetrica da resposta espectrofotometrica da solucao gel de alanina para radiacao gama, de fotons, de eletrons e de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo

    2009-07-01

    Alanine Gel Dosimeter is a new gel material developed at IPEN that presents significant improvement on Alanine system developed by Costa. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. This work aims to analyse the main dosimetric characteristics this new gel material for future application to measure dose distribution. The performance of Alanine gel solution was evaluated to gamma, photons, electrons and thermal neutrons radiations using the spectrophotometry technique. According to the obtained results for the different studied radiation types, the reproducibility intra-batches and inter-batches is better than 4% and 5%, respectively. The dose response presents a linear behavior in the studied dose range. The response dependence as a function of dose rate and incident energy is better 2% and 3%, respectively. The lower detectable dose is 0.1 Gy. The obtained results indicate that the Alanine gel dosimeter presents good performance and can be useful as an alternative dosimeter in the radiotherapy area, using MRI technique for tridimensional dose distribution evaluation. (author)

  12. Anther development stage and gamma radiation effects on tomato anther-derived callus formation; Efeitos do estadio de desenvolvimento da antera e da radiacao gama na formacao de calos derivados de anteras de tomate

    Energy Technology Data Exchange (ETDEWEB)

    Brasileiro, Ana Christina R.; Willadino, Lilia [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Lab. de Cultura de Tecidos Vegetais. E-mail: lilia@truenet.com.br; Guerra, Marcelo [Pernambuco Univ., Recife, PE (Brazil). Dept. de Botanica. Lab. de Citogenetica Vegetal; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear. Lab. de Radioagronomia; Meunier, Isabelle [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Engenharia Florestal; Camara, Terezinha R. [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Quimica. Lab. de Cultura de Tecidos Vegetais

    1999-12-01

    Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4-F{sub 1}) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mono nucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seed and floral buds of tomato hybrids IPA 5 x Rotam 4 (F{sub 2}), IPA 6 x Rotam 4 (F{sub 2}) and IPA 8 x 217.1 (F{sub 2}) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff and Doy (1972) supplemented with 2.0 mg L{sup -1} NAA + 5.0 mg L{sup -1} KIN and 2.0 mg L{sup -1} NAA + 1.0 mg L{sup -1} KIN. No significant differences for genotype and dosage testes were found for calli formation. (author)

  13. Study of the effect of ionizing radiation on properties of polyamide 6 with fibreglass reinforcement; Estudo do efeito da radiacao ionizante sobre as propriedades da poliamida 6 com reforco de fibra de vidro

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Clovis

    2007-07-01

    It is each time more common the use of polymers reinforced with fibreglass in the domestic market. Between them it is used polyamide 6 that it presents good tension resistance, to the impact and the humidity absorption compared with non-reinforced, being also at the present time used in the automobile industry in parts underneath the hood, especially in the radiator frames. The aim of this work is to study the effect of ionizing radiation on properties of polyamide 6 with fibreglass reinforcement, undergone to different radiation doses. Samples were prepared and irradiated on JOB 188 accelerator with an electron beam energy of 1.5 MeV in air with different doses (100 to 600 kGy) and a dose rate of 22.61 kGy/h. Afterward the irradiation, the properties of the samples of irradiated polyamide 6 with fibreglass reinforcement were evaluated and compared with the samples non-irradiated. It evidenced that the mechanical properties flexural resistance and tension resistance increased and the resistance to the impact decreased. Regarding the thermal properties of the temperature of fusing decreased of 224,4 deg C for 212,5 deg C but the loss of mass ahead of the constant increase of the temperature also decreased. In the property of resistance to the glow wire the polyamide 6 with fibreglass reinforcement had a good performance. The images caught for Scanning Electronic Microscopy show that the irradiation provoked a good integration enters the fibreglass and polymer what was responsible for the good performance in the property of resistance to the glow wire. (author)

  14. Utilization of rice husk ash as filler for polyamide 6 and ionizing radiation effect studies on this composite;Utilizacao da cinza da casca de arroz como carga em matriz de poliamida 6 submetida a radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, Waldir Pedro

    2009-07-01

    In order to improve the dimensional stability, as well as, electrical, mechanical and thermal properties of polymers, new filler to this purpose has been developed. The mos applied filler to propitiate the features previously mentioned are the glass and carbon fibers, the mineral filler as the calcium carbonate, the talc and the micro glass sphere. The main aim of this work was to study the rice husk ash as filler for polyamide 6 and ionizing radiation effect studies on this composite, irradiated by electron beam at different doses, since it is constituted of at least 90% of silicon dioxide, and compared with the talc which is the most applied mineral filler. This comparison was made from a compound made through the refined rice husk ash and the polyamide 6 (PA 6), which is one of the main engineering plastic with applications in several productive areas. The samples were injected and irradiated in a electron accelerator. Afterwards, their mechanical and thermal properties were measured. It was also inject automotive parts to verify the processing of the PA 6 with CCA. The results showed that the use of the rice husk ash as filler for polyamide 6 composite is technically and economically viable. The irradiation of the studied composite (PA 6 with 30% of rice husk ash) did not provide any improvement for the mechanical and thermal properties previously appraised. (author)

  15. Effect of gamma radiation in the conservation of minimally processed cassava-parsley (Arracacia xanthorrhiza Bancroft) packed under vacuous;Efeito da radiacao gama na conservacao da mandioquinha-salsa (Arracacia xanthorrhiza Bancroft) minimamente processada e embalada a vacuo

    Energy Technology Data Exchange (ETDEWEB)

    Iemma, Juliana

    2001-07-01

    In the third millennium, when the main words are globalization, world net of computers, genetic code and efficiency, deep transformations have been incorporated to human behavior. Among such transformations it may be pointed out, matching with the objectives of this study, the modem consumer's profile. The consumers have quickly become more and more conscious and demanding regarding to the quality of the available products in the market. In that sense, the consumer's concern about the natural and healthy appearance, as well as the preservation of the nutritious content of the foods, have been a constant sign of alert for producers and suppliers. Besides, the timeless for domestic preparation of foods have imposed the use of minimally processed as an incontestable reality. A barrier for the production of minimally processed foods is imposed by the degree of perishability of certain products, such as the cassava-parsley. This vegetable is a source of energy, calcium, phosphorus and niacin, and important in the alimentary diet of children, seniors and convalescents. Post harvest treatments try to turn foods less perishable and also conserve as much as possible their original appearance. Among these post harvest treatments for food conservation it may be stood out the irradiation, which is the focus of this study. The objective of this study was to examine the viability of including the cassava parsley in the list of the minimally processed foods. Fresh cassavas were minimally processed and packed under vacuous. Samples were divided for three treatments: control and irradiation with the doses 2.0 and 4.0 kGy. After irradiation the samples were stored under refrigeration temperature (8 deg C) during 28 days. Physical-chemical and microbiological analyzes were carried out at each 7 days of the period of storage, and sensorial analysis were carried out in the 1st, 7th and 14th days of storage. The experimental design was in factorial scheme with two factors: dose of irradiation and period of storage, with 3 replications for the physical-chemical and microbiological analyzes and with 30 replications for the sensorial analysis. The results showed that gamma radiation may be considered an interesting post harvest treatment for conservation of cassava-parsley because the doses of 2.0 and 4.0 kGy did not bring out undesirable alterations in the physical-chemical and sensorial characteristics of the cassava-parsley and showed efficiency in reducing its microbial population. (author)

  16. Synergic effect of gamma radiation with thermal treatment for conserving natural apple juice from Gala variety; Efeito sinergistico da radiacao gama com tratamento termico na conservacao de suco natural de maca da variedade Gala

    Energy Technology Data Exchange (ETDEWEB)

    Blumer, L.; Domarco, R.E.; Spoto, M.H.F.; Walder, J.M.M.; Matraia, C. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1995-12-31

    This paper aims at the feasibility of a new method for conserving natural apple juice using no chemicals. The apple juice was extract from Gala apple variety and was bottled in sterile 100 ml amber vials. The samples were treated by: heat at 60{sup 0} C for 20 minutes; heat at 80{sup 0} C for 20 minutes; radiation; radiation plus heat (60{sup 0}); radiation plus heat 80{sup 0} C. The radiation doses were 0,2,4 and 6 kGy at the dose rate of 1.6 kGy/h. The juice quality control was carried out by chemical analysis (total soluble solids, pH, acidity, ascorbic acid) following the AOAC methodology. The samples were stored under refrigeration conditions 5{+-}3{sup 0} C up to 180 days. It was observed an alteration of the total soluble solids and the pH during the storage period for all treatments. The pH was also affected by the combined treatments (radiation plus heat). The acidity was affected by the interaction of storage period and heat temperature. The ascorbic acid was affected by the synergic effect of heat and radiation and by the interaction radiation and storage period. (author). 8 refs, 6 figs.

  17. Laser Therapy

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Laser Resurfacing Uses for Laser Resurfacing Learn more ...

  18. Lasers technology

    International Nuclear Information System (INIS)

    2014-01-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners

  19. YCOB lasers

    International Nuclear Information System (INIS)

    Richardson, Martin; Hammons, Dennis; Eichenholz, Jason; Chai, Bruce; Ye, Qing; Jang, Won; Shah, Lawrence

    1999-01-01

    We review new developments with a new laser host material, YCa 4 O(BO 3 ) 3 or YCOB. Lasers based on this host material will open new opportunities for the development of compact, high-power, frequency-agile visible and near IR laser sources, as well as sources for ultrashort pulses. Efficient diode-pumped laser action with both Nd-doped and Yb-doped YCOB has already been demonstrated. Moreover, since these materials are biaxial, and have high nonlinear optical coefficients, they have become the first laser materials available as efficient self-frequency-doubled lasers, capable of providing tunable laser emission in several regions of the visible spectrum. Self-frequency doubling eliminates the need for inclusion of a nonlinear optical element within or external to the laser resonator. These laser materials possess excellent thermal and optical properties, have high laser-damage thresholds, and can be grown to large sizes. In addition they are non-hygroscopic. They therefore possess all the characteristics necessary for laser materials required in rugged, compact systems. Here we summarize the rapid progress made in the development of this new class of lasers, and review their potential for a number of applications. (author)

  20. Laser sampling

    International Nuclear Information System (INIS)

    Gorbatenko, A A; Revina, E I

    2015-01-01

    The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

  1. HF laser

    International Nuclear Information System (INIS)

    Suzuki, Kazuya; Iwasaki, Matae

    1977-01-01

    A review is made of the research and development of HF chemical laser and its related work. Many gaseous compounds are used as laser media successfully; reaction kinetics and technological problems are described. The hybrid chemical laser of HF-CO 2 system and the topics related to the isotope separation are also included. (auth.)

  2. Efeito da terapia com laser de arsenieto de gálio e alumínio (660Nm sobre a recuperação do nervo ciático de ratos após lesão por neurotmese seguida de anastomose epineural: análise funcional Effect of gallium-aluminum-arsenide laser therapy (660Nm on recovery of the sciatic nerve in rats following neurotmesis lesion and epineural anastomosis: functional analysis

    Directory of Open Access Journals (Sweden)

    FA Reis

    2008-06-01

    Full Text Available CONTEXTUALIZAÇÃO: As lesões nervosas periféricas podem comprometer atividades diárias de um indivíduo e resultam em perda da sensibilidade e motricidade do território inervado. OBJETIVO: Com o intuito de acelerar os processos regenerativos, objetivou-se analisar a influência da aplicação do laser de arsenieto de gálio e alumínio (AsGaAl, 660Nm sobre a recuperação funcional do nervo ciático de ratos. MATERIAIS E MÉTODOS: O nervo ciático de 12 ratos Wistar foi submetido à lesão por neurotmese e anastomose epineural e divididos em dois grupos: controle e laserterapia. Após a lesão, utilizou-se o laser de GaAlAs, 660Nm, 4J/cm², 26,3mW, feixe de 0,63cm², em três pontos eqüidistantes sobre a lesão, por 20 dias. As impressões das pegadas dos animais foram obtidas antes e após (sete, 14 e 21 dias pós-operatórios o procedimento cirúrgico e calculou-se o índice funcional do ciático (IFC. RESULTADOS: A comparação do IFC não resultou em diferença significante (p>0,05 entre os grupos. CONCLUSÕES: Conclui-se que os parâmetros e métodos empregados na laserterapia demonstram resultados nulos sobre o IFC no período avaliado.CONTEXT: Peripheral nerve injuries result in sensory and motor losses in the innervated area and can hinder individuals’ daily activities. Objective: The objective was to analyze the influence of applying gallium-aluminum-arsenide (GaAlAs laser (660Nm on the functional recovery of the sciatic nerve in rats. METHODS: The sciatic nerve of 12 Wistar rats was subjected to injury consisting of neurotmesis and epineural anastomosis. The rats were divided into two groups: control and laser therapy. After the injury, a GaAlAs laser was used (660Nm, 4J/cm², 26.3mW and 0.63cm² beam at three equidistant points on the injury, for 20 days. Footprint impressions were obtained from the animals before and seven, 14 and 21 days after the surgical procedure and the sciatic functional index (SFI was calculated

  3. Laser welding of tailored blanks

    Directory of Open Access Journals (Sweden)

    Peças, P.

    1998-04-01

    Full Text Available Laser welding has an incrising role in the automotive industry, namely on the sub-assemblies manufacturing. Several sheet-shape parts are laser welded, on a dissimilar combination of thicknesses and materials, and are afterwards formed (stamped being transformed in a vehicle body component. In this paper low carbon CO2 laser welding, on the thicknesses of 1,25 and 0,75 mm, formability investigation is described. There will be a description of how the laser welded blanks behave in different forming tests, and the influence of misalignment and undercut on the formibility. The quality is evaluated by measuring the limit strain and limit effective strain for the laser welded sheets and the base material, which will be presented in a forming limit diagram.

    A soldadura laser assume um papel cada vez mais importante na indústria automóvel, principalmente para a fabricação de sub-conjuntos constituídos por varias partes de chapa de diferentes espessuras (e diferentes materiais, que depois de estampados constituem um componente para integrar num veículo. Descreve-se neste artigo o trabalho de investigação de enformabilidade de chapa de ac.o de baixo carbono soldada por laser de CO2, nas espessuras de 1,25 e 0,75 mm. Apresenta-se uma descrição do comportamento das chapas soldadas por laser em diferentes testes de enformação, e a influência dos defeitos das soldaduras (desalinhamento e queda do banho-undercut no comportamento à enformação. A qualidade é avaliada pela medição da extensão limite e da extensão limite efectiva no material base e no material soldado, que serão representadas num diagrama de limite de enformabilidade.

  4. Study in vitro of dental enamel irradiated with a high power diode laser operating at 960 nm: morphological analysis of post-irradiation dental surface and thermal effect analysis in pulp chamber due to laser application; Estudo in vitro do esmalte dental irradiado com laser de diodo de alta potencia em 960 nm: analise morfologica da superficie dental pos-irradiada e analise do comportamento termico na camara pulpar devido a aplicacao laser

    Energy Technology Data Exchange (ETDEWEB)

    Quinto Junior, Jose

    2001-07-01

    Objectives: This study examines the structural and thermal modifications induced in dental enamel under dye assisted diode laser irradiation. The aim of this study is to verify if this laser-assisted treatment is capable to modify the enamel surface by causing fusion of the enamel surface layer. At the same time, the pulpal temperature rise must be kept low enough in order not to cause pulpar necrosis. To achieve this target, it is necessary to determine suitable laser parameters. As is known, fusion of the enamel surface followed by re-solidification produce a more acid resistant layer. This surface treatment is being researched as a new method for caries prevention. Method and Materials: A series of fourteen identically prepared enamel samples of human teeth were irradiated with a high power diode laser operating at 960 nm and using fiber delivery. Prior to irradiation, a fine layer of cromophorous ink was applied to the enamel surface. In the first part of the experiment the best parameter for pulse duration was determined. In the second part of the experimental phase the same energy density was used but with different repetition rates. During irradiation we monitored the temperature rise in the pulpal cavity. The morphology of the treated samples was analysed under SEM. Results: The morphology of the treated samples showed a homogeneously re-solidified enamel layer. The results of the temperature analysis showed a decrease of the pulpal temperature rise with decreasing repetition rate. Conclusion: With the diode laser it is possible to cause morphological alterations of the enamel surface, which is known to increase the enamel resistance against acid attack, and still maintain the temperature rise in the pulpar chamber below damage threshold. (author)

  5. Caracterização microestrutural e textural, por difração de elétrons retro-espalhados (EBSD), da liga de alumínio 5052 soldada a LASER.

    OpenAIRE

    Moreira, Thiago Augusto de Sousa

    2014-01-01

    Programa de Pós-Graduação em Engenharia de Materiais. Rede Temática em Engenharia de Materiais, Pró-Reitoria de Pesquisa e Pós-Graduação, Universidade Federal de Ouro Preto. Atualmente, existe na indústria da mobilidade uma busca constante pelo aumento da produtividade, eficiência, desempenho e redução de peso, custos e emissão de poluentes, o que resulta na busca constante por novas tecnologias. Neste contexto, materiais tradicionais como os aços estão sendo substituídos por outros, como ...

  6. Laser fusion

    International Nuclear Information System (INIS)

    Eliezer, S.

    1982-02-01

    In this paper, the physics of laser fusion is described on an elementary level. The irradiated matter consists of a dense inner core surrounded by a less dense plasma corona. The laser radiation is mainly absorbed in the outer periphery of the plasma. The absorbed energy is transported inward to the ablation surface where plasma flow is created. Due to this plasma flow, a sequence of inward going shock waves and heat waves are created, resulting in the compression and heating of the core to high density and temperature. The interaction physics between laser and matter leading to thermonuclear burn is summarized by the following sequence of events: Laser absorption → Energy transport → Compression → Nuclear Fusion. This scenario is shown in particular for a Nd:laser with a wavelength of 1 μm. The wavelength scaling of the physical processes is also discussed. In addition to the laser-plasma physics, the Nd high power pulsed laser is described. We give a very brief description of the oscillator, the amplifiers, the spatial filters, the isolators and the diagnostics involved. Last, but not least, the concept of reactors for laser fusion and the necessary laser system are discussed. (author)

  7. Biocavity Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  8. Natural radiation; A radiacao natural

    Energy Technology Data Exchange (ETDEWEB)

    Feliciano, Vanusa Maria Delage

    2016-07-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

  9. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  10. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization; Estudo in vitro dos efeitos promovidos pelo laser de diodo em 960 nm no esmalte dental humano: analise de temperatura, analise morfologica e avaliacao da resistencia a desmineralizacao

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Ilka Tiemy

    2004-07-01

    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm{sup 2}, 3.7 J/cm{sup 2}, 5.6 J/cm{sup 2}, 7.4 J/cm{sup 2} and 9.3 J/cm{sup 2}) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  11. Laser Dyes

    Indian Academy of Sciences (India)

    amplification or generation of coherent light waves in the UV,. VIS, and near IR region. .... ciency in most flashlamp pumped dye lasers. It is used as reference dye .... have led to superior laser dyes with increased photostabilities. For instance ...

  12. Clinical comparative study between the use of lasers and conventional methods of diagnosis and treatment in deciduous teeth with presence of carious lesion; Estudo clinico comparativo entre o uso de lasers e metodos convencionais de diagnostico e tratamento em dentes deciduos da presenca de lesao cariosa

    Energy Technology Data Exchange (ETDEWEB)

    Pulga, Fabiane Galvao

    2001-07-01

    The aim of this work was to evaluate the efficiency of deciduous tooth cavity preparation by the Er:YAG laser in comparison with the conventional burr rotary instrument. Besides, we have used the laser fluorescence technique (DIAGNOdent equipment) for diagnosis and compared it to the usual tactile and visual examination as well as X-ray diagnosis. For this purpose, 20 chronic occlusal carious deciduous molar teeth from children with the ages between 5 to 10 years old were selected. Selection was ma de according to visual inspection, X-ray periapical image and measures of the DIAGNOdent. For treatment the teeth were divided in two groups, 10 to be treated by the Er:YAG laser and 10 with conventional burr. For enamel, the laser energy used was in the interval from 200 to 300 mJ; for the dentine the range was from 100 mJ to 200 mJ. In both cases, the laser frequency was in the range from 2 to 4 Hz. The results have shown that the laser treatment was more accepted by the children than the conventional burro Clinical evaluation of the cavity preparation indicates that the Er:YAG laser treatment is recommend. The DIAGNOdent evaluation method was very effective for diagnosis of carious tissue for initial detection. After successful removal of the carious tissue, confirmed by visual inspection, the DIAGNOdent evaluation method was only effective for the treatment with conventional burro For evaluation of the tooth after cavity preparation with the Er:YAG laser, the measurements oscillate covering the full range of the equipment. Therefore, the use of the DIAGNOdent equipment is indicated only for initial caries diagnosis. (author)

  13. Influência da terapia com laser de baixa potência e hialuronato de sódio de alto peso molecular na ATM de ratos, com artrite, após indução por CFA

    OpenAIRE

    George Azevêdo Lemos

    2015-01-01

    Resumo: A Disfunção temporomandibular (DTM) é uma expressão coletiva que engloba vários sinais e sintomas clínicos relacionados aos músculos da mastigação, articulações temporomandibulares (ATMs) e estruturas associadas. As principais queixas relatadas são ruídos e dor na região da ATM, com maior prevalência em adultos jovens, especialmente mulheres. A inflamação intra-articular é considerada uma das mais importantes fontes de dor nesta disfunção. O processo inflamatório pode se localizar na ...

  14. A study in vitro on radiation effects by Er:YAG laser combined with the fluorine therapy in the acid resistance of the dental enamel submitted to orthodontical brackets; Um estudo in vitro sobre os efeitos da irradiacao pelo laser de Er:YAG combinado com a terapia com fluor na resistencia acida do esmalte de dentes submetidos a aparelho ortodontico fixo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiyasu, Roseli Y A

    2001-07-01

    Several researches have been demonstrating an increase in the resistance acid of the enamel surface when irradiated by some lasers types as Nd:YAG, C0{sub 2}, Er:YAG, and others, mainly when combined with the fluoride therapy after the irradiation of the laser. This study in vitro used the laser of Er:YAG which density of energy of 8.1 J/cm{sup 2} on the enamel about of orthodontical brackets of teeth extracted pre-molars. These teeth were then submitted to a rich way in S. mutans for twenty one days. The cases were analyzed: (1) enamel surface without any treatment, (2) enamel surface without any irradiation laser, but with therapy with acidulated phosphate fluoride, (3) enamel surface irradiated with laser of Er:YAG and (4) enamel surface irradiated by laser of Er:YAG and with application of acidulated phosphate fluoride. The results were analyzed through optical microscopy and scanning electron microscopy. The morphologic changes observed to the scanning electron microscopy suggest increase in the acid resistance of the enamel surface. However, to the optical microscopy, it was still possible to visualize undesirable white stains in the surface of the enamel. (author)

  15. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  16. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  17. Morphological evaluation of cavity preparation surface after duraphat and Er:YAG laser treatment by scanning electronic microscopy; Avaliacao das alteracoes morfologicas da superficie do preparo cavitario apos condicionamento com verniz fluoretado a 2,26 % e laser de Er:YAG atraves de microscopia eletronica de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Luciane Borelli

    2002-07-01

    The treatment of dental surface using different lasers to prevent dental caries has been studied for several on last years. The purpose of this in vitro study was to evaluate the morphological changes on dentin surface from pulpal wall of cavity preparations performed by high-speed drill, treated with 2,26% fluoride varnish (Duraphat) and Er:YAG laser, and then submitted after receiving or not to EDTA 15% treatment. Twenty Class V cavities were performed on ten humans molars. The specimens were randomly divided in to 4 groups: group 1- treatment with Duraphat followed by Er:YAG laser irradiation (120 mJ/ 4 Hz); group 2: Er:YAG laser irradiation, same parameters, followed by Duraphat treatment; group 3- same group 1 followed by immersion in EDTA (5 min); group 4 - same as group 2 followed by immersion in EDTA (5 min). The specimens were processed for SEM analysis. The micrographs showed that Duraphat treatment promoted morphological changes on dentin, closing dentinal tubules; the specimens treated by Duraphat and Er:YAG laser and immersed in EDTA (group 3) showed homogeneous surface, closed and protected dentinal tubules, maintenance of the fluoride varnish on the dentin surface and around the dentinal tubules, showing feasible and efficiency of these therapies the feasibility.(author)

  18. Analysis of the collagen birefringence and the relative attenuation coefficient of health and burned skin irradiated with linearly polarized He-Ne laser; Analise da birrefringencia do colageno e do coeficiente de atenuacao de amostras de pele sadia e queimada irradiadas pelo laser de He-Ne linearmente polarizado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Daniela de Fatima Teixeira da

    2002-07-01

    Low-intensity laser therapy is characterized by its ability to induce athermic effects and nondestructive photobiological processes. Although it has been in use for more than 40 years, this phototherapy is still not an established therapeutic modality. The objectives of this study were: to quantify the collagen fibers organization by polarized light microscopy in normal and burned skin samples at day 17 post-injury considering preferential axis as the animal's spinal column and aligning the linear laser polarization in two directions of polarization, parallel or perpendicular to this axis; to determine the relative attenuation coefficient for the intensity light by the technique of imaging the light distribution in normal and burned skin during wound healing process taking only parallel direction of polarization. To reach the objectives, burns about 6 mm in diameter were created with liquid N{sub 2} on the back of the rats and the lesions were irradiated on days 3, 7, 10 and 14 post-wounding, D= 1 J/cm{sup 2}, to investigate the effects of low-intensity linearly polarized He-Ne laser beam on skin wounds healing. Control lesions were not irradiated. The results have demonstrated that: the skin samples irradiated with linearly parallel polarized He-Ne laser beam showed collagen fibers more organized; burned skin samples presents a higher attenuation coefficient than normal skin samples. These results are important to optimize low intensity laser therapy dosimetry on acceleration wound healing. (author)

  19. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser; Avaliacao da resistencia a tracao de um sistema adesivo self-etching em dentina irradiada com Er:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Andrea Malluf Dabul de

    2000-07-01

    Since Buonocore (1955), several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning , because this promotes the removal of the 'smear layer and exhibition of dentinal structure, for a best penetration and micro- retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces , which were treated with three sandpapers of different granulations (120,400,600), to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 deg C for 24 hours. Soon after, they were submitted to the tensile strength test .After analyzing the results, we can concluded that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self-etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser. (author)

  20. Filosofia da análise da estabilidade da liquidez

    Directory of Open Access Journals (Sweden)

    Rodrigo Antônio Chaves da Silva

    2005-07-01

    Full Text Available A informação foi considerada finalidade de nosso conhecimento, até o período em os pensadores e pesquisadores da contabilidade passaram a raciocinar sobre o conteúdo e o significado dos informes. Nesta busca da razão sobre os estados patrimoniais, surgiu a análise contábil que procura por meio de relações e identidades, o significado da dinâmica expressa da estaticamente na informação. O primeiro aspecto que surgiu no objeto de análise foi o estudo da liquidez, que é um dos principais exercícios do patrimônio. A estabilidade também é outro exercício básico e imprescindível, pois este é que promove o equilíbrio do organismo administrativo. A ciência contábil após a sua dignidade científica passou a trilhar caminhos esplendorosos, amparados em doutrina que permite alcançar os píncaros filosóficos. Os estudos concernentes aos aspectos de interação da estabilidade na liquidez são, complexos e somente com os recursos filosóficos da contabilidade se pode estudá-los com o panorama holístico e sublime. A filosofia da contabilidade não é alheia às suas práticas tecnológicas, podendo buscar pontos sublimes de panoramas abrangentes, para o estudo analítico da liquidez e estabilidade, observando todas as dimensionalidades e essencialidades de acontecimentos, na comprovação e orientação dos estados de ineficácia e eficácia patrimonial.

  1. Il laser

    CERN Document Server

    Smith, William V

    1974-01-01

    Verso il 1960, il laser era ancora "una soluzione alla ricerca di un problema", ma fin dagli anni immediatamente successivi si è rivelato uno strumento insostituibile per le applicazioni più svariate.

  2. Laser Refractography

    CERN Document Server

    Rinkevichyus, B.S; Raskovskaya, I.L

    2010-01-01

    This book describes the basic principles of laser refractography, a flexible new diagnostic tool for measuring optically inhomogeneous media and flows. Laser refractography is based on digital imaging and computer processing of structured laser beam refraction (SLR) in inhomogeneous transparent media. Laser refractograms provide both qualitative and quantitative measurements and can be used for the study of fast and transient processes. In this book, the theoretical basis of refractography is explored in some detail, and experimental setups are described for measurement of transparent media using either 2D (passed radiation) or 3D (scattered radiation) refractograms. Specific examples and applications are discussed, including visualization of the boundary layer near a hot or cold metallic ball in water, and observation of edge effects and microlayers in liquids and gases. As the first book to describe this new and exciting technique, this monograph has broad cross-disciplinary appeal and will be of interest t...

  3. Laser fusion

    International Nuclear Information System (INIS)

    Ashby, D.E.T.F.

    1976-01-01

    A short survey is given on laser fusion its basic concepts and problems and the present theoretical and experimental methods. The future research program of the USA in this field is outlined. (WBU) [de

  4. Laser spectroscopy

    International Nuclear Information System (INIS)

    Letokhov, V.S.

    1981-01-01

    This article describes recent progress in the application of laser atomic spectroscopy to study parameters of nuclei available in very small quantities; radioactive nuclei, rare isotopes, nuclear isomers, etc, for which study by conventional spectroscopic methods is difficult. (author)

  5. Laser fusion

    International Nuclear Information System (INIS)

    Key, M.H.; Oxford Univ.

    1990-04-01

    The use of lasers to drive implosions for the purpose of inertially confined fusion is an area of intense activity where progress compares favourably with that made in magnetic fusion and there are significant prospects for future development. In this brief review the basic concept is summarised and the current status is outlined both in the area of laser technology and in the most recent results from implosion experiments. Prospects for the future are also considered. (author)

  6. Laser Resurfacing

    OpenAIRE

    Janik, Joseph P.; Markus, Jodi L.; Al-Dujaili, Zeena; Markus, Ramsey F.

    2007-01-01

    In a society desiring images of beauty and youthfulness, the world of cutaneous surgery offers the gifts of facial rejuvenation for those determined to combat the signs of aging. With the development of novel laser and plasma technology, pigmentary changes, scarring, and wrinkles can be conquered providing smoother, healthier, younger-looking skin. This review highlights five of the most popular resurfacing technologies in practice today including the carbon dioxide (CO2) laser, the erbium:yt...

  7. Green lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin

    2010-01-01

    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  8. Laser de érbio 2940nm fracionado no tratamento do fotoenvelhecimento cutâneo da face - avaliação após 15 meses

    Directory of Open Access Journals (Sweden)

    Ane Beatriz Mautari Niwa

    2010-03-01

    Full Text Available Introdução: Os procedimentos fracionados ablativos oferecem resultados consistentes, com menor tempo de recuperação e menor risco de efeitos adversos do que os ablativos não fracionados. Objetivo: Avaliar os efeitos de uma nova tecnologia fracionada ablativa com laser de érbio (2.940nm no fotoenvelhecimento facial.Métodos: Pacientes femininas com fotodano moderado na face foram submetidas ao tratamento com laser de érbio 2,940 nm fracionado (Palomar Inc., Burlington MA. Os parâmetrosvariaram de 5 a 9 mJ/µb com duração de pulso de 250 microssegundos a 5 milissegundos. Foram realizadas duas a seis passadas com 50% de sobreposição. As avaliações clínicasocorreram 3 dias, 1,4,8 e 12 semanas, e 15 meses após o procedimento. Três dermatologistas não envolvidos no estudo avaliaram a melhora global do fotodano antes e após 3 meses, através de fotografias digitais e de acordo com a seguinteescala: grau 1=melhora menor que 25%; grau 2=melhora de 26-50%; grau 3=melhora de 51-75% e grau 4=melhora de 76 a 100%.Resultados: Doze pacientes (n=12 femininas, com idade variando de 48 a 78 anos foram incluídas.A avaliação após 3 meses, demonstrou que 23% das pacientes obtiveramgrau 3, 55% grau 2 e 22% grau 1. Melhora significativa (grau > 2 foi observada em 78% e 63% das rugas periorbitárias e periorais respectivamente. Dois pacientes desenvolveramhiperpigmentação pós-inflamatória transitória. Conclusão: O laser com érbio fracionado mostrou-se eficaz e seguro no tratamento do fotoenvelhecimento moderado.Use of 2940 Erbium fractional laser in the treatment of photodamaged skin: clinical evaluation and follow up.

  9. In vitro assessment of the bactericidal effect of low-power arsenium-gallium (AsGa laser treatment Avaliação in vitro da ação bactericida do laser de baixa potência (AsGa

    Directory of Open Access Journals (Sweden)

    Adilvania Ferreira da Costa

    2012-08-01

    Full Text Available The objective of the present study was to perform an in vitro evaluation of the bactericidal action of a low-power arsenium-gallium (AsGa laser at a wavelength of 904nm and energy density of 6 J/cm². Ten petri dishes were seeded with Pseudomonas aeruginosa and another ten with Staphylococcus aureus. The dishes were then randomly divided into four groups with five plates in each group. Two groups were treated with AsGa laser once a day for 5 days, while the other two groups received no treatment. No halo of growth inhibition was found in any of the groups. It was therefore concluded that laser treatment (AsGa, 904nm, 6J/cm² had no bactericidal effect.Verificar, in vitro, o efeito bactericida do laser de baixa potência, AsGa, 904nm, na dose 6 J/cm2. Foram semeadas 10 placas de Petri com a bactéria Pseudomonas aeruginosa e 10 placas de Petri com Staphylococcus aureus. Aleatoriamente, foram divididas em quatro grupos (5 placas cada: dois grupos foram tratados com o laser AsGa a cada 24 horas, durante cinco dias, e dois grupos não receberam tratamento. Em todos os grupos, não foi observado qualquer halo de inibição do crescimento. Assim, concluiuse que a terapia a laser (AsGa, 904nm, 6 J/cm² não produziu efeito bactericida.

  10. LASER hemorrhoidal dearterialization

    Directory of Open Access Journals (Sweden)

    Paulo Boarini

    2017-01-01

    Full Text Available Introduction: Hemorrhoidal disease is associated with the theory of arterial blood hyperflow causing swellings in hemorrhoids and, consequently, hyperplasia and venous congestion. The technique helps to promote the obliteration of the terminals of the superior rectal artery branches without the need for anesthesia by electrofulguration with diode fiber LASER. The objective of this study is to describe the results of 55 patients with hemorrhoidal disease treated by the Hemorrhoidal LASER Procedure technique. Method: Without the need of anesthesia, terminal arterioles of the upper rectal artery are identified by a Doppler transducer (20 MHz probe 3 mm placed on a specially designed proctoscope. After identification, it promotes arteriolar electrofulguration at 980 nm fiber laser diode, causing interruption of hemorrhoidal flow. This procedure is repeated circumferentially, following the clockwise positions. Results: Between 2011 and 2014, 55 patients underwent the Hemorrhoidal LASER Procedure technique for hemorrhoidal disease grades I, II and III. There was no need for anesthesia and only two patients required sedation for the procedure. The overall satisfaction rate was 89%, with symptom resolution in 84% and a decrease of at least one grade in hemorrhoidal disease in 80% of cases. Conclusion: Hemorrhoidal LASER Procedure is a painless outpatient technique that does not require anesthesia, in addition to being safe and easy to perform. It is effective in reducing symptoms and complications of the hemorrhoidal disease grades I and II, with high satisfaction rates. Resumo: Introdução: A doença hemorroidária está associada a teoria vascular de hiperfluxo arterial causando dilatações nos plexos hemorroidários e, consequentemente, hiperplasia e congestão venosa. A técnica HeLP promove a obliteração dos ramos terminais da artéria retal superior, sem a necessidade de anestesia, através da eletrofulguração com fibra de diiodo LASER

  11. Influência de diferentes comprimentos de onda da laserterapia de baixa intensidade na regeneração tendínea do rato após tenotomia Influence of different low-intensity laser therapy wavelengths for rat tendon regeneration following tenotomy

    Directory of Open Access Journals (Sweden)

    ERB Arruda

    2007-08-01

    Full Text Available OBJETIVO: Comparar a influência da terapia laser baixa intensidade (TLBI na organização das fibras de colágeno, na dose de 3J/cm² em dois comprimentos de onda (lambda (670nm e 904nm e na associação de ambos, durante o reparo do tendão calcâneo de ratos. MÉTODO Foram utilizadas 37 ratas da raça Wistar divididas em 5 grupos, submetidas a tenotomia total por meio de cisalhamento transversal do tendão na porção média entre a inserção calcânea e a junção miotendínea, com exceção do grupo GP (n= 6 que não houve lesão. O grupo GA (n= 8 foi submetido à irradiação laser lambda= 904nm, diodo de GaAs, emissão pulsada, duração do pulso de 180ns, freqüência de pulso de 2000Hz e potência de pico de 15W e dose de 3J/cm². O grupo GB (n= 8 foi submetido à irradiação laser lambda= 670nm, diodo de AlGaInP, emissão contínua, potência 30mW e dose de 3J/cm². O grupo GAB (n= 8 recebeu irradiação de ambos os lasers 670nm e 904nm associados. O grupo GCL (n= 7 foi submetido a um tratamento placebo, assim como um grupo padrão. Após um total de 12 sessões de laserterapia, os animais foram submetidos à eutanásia no 14º dia pós-operatório. Após processamento histológico padrão, foi realizada a quantificação do retardo óptico pela birrefringência. RESULTADOS: A análise estatística mostra que todos os grupos irradiados apresentaram valores de retardo óptico maiores quando comparados ao grupo placebo (p= 0,00001, o que indica que apresentaram melhor organização das fibras colágenas ao longo do eixo longitudinal do tendão, evidenciando melhor qualidade no reparo. O grupo GAB foi o que apresentou melhores resultados (p= 0,00001 quando comparado aos demais grupos, excetuando-se o GP, que é o referencial de retardo óptico para esta faixa etária.OBJECTIVE: The aim of this study was to compare the effect of the low level laser therapy in the organization of the collagen fibers with 3 J/cm² of dose in two

  12. Laser material processing

    CERN Document Server

    Steen, William

    2010-01-01

    This text moves from the basics of laser physics to detailed treatments of all major materials processing techniques for which lasers are now essential. New chapters cover laser physics, drilling, micro- and nanomanufacturing and biomedical laser processing.

  13. Laser therapy for cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000905.htm Laser therapy for cancer To use the sharing features ... Lasers are also used on the skin. How Laser Therapy is Used Laser therapy can be used ...

  14. Lasers in Cancer Treatment

    Science.gov (United States)

    ... the advantages of laser therapy? What are the disadvantages of laser therapy? What does the future hold ... therapy is appropriate for them. What are the disadvantages of laser therapy? Laser therapy also has several ...

  15. Practical laser safety

    International Nuclear Information System (INIS)

    Winburn, D.C.

    1985-01-01

    This book includes discussions of the following topics: characteristics of lasers; eye components; skin damage thresholds; classification of lasers by ANSI Z136.1; selecting laser-protective eyewear; hazards associated with lasers; and, an index

  16. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  17. Laser acceleration

    International Nuclear Information System (INIS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-01-01

    The fundamental idea of LaserWakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wake fields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ∼ c and ultra fastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nano materials is also emerging.

  18. Estudo da microcirculação na hanseníase usando videomicroscopia (Microscan) e laser-Doppler associado à iontoforese: um modelo de disautonomia vascular por denervação

    OpenAIRE

    Livia Cristina de Melo Pino Machado

    2013-01-01

    A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomiamicrocirculatória. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase tuberculóide. Utilizamos a videomicroscopia de campo escuro (Microscan), a análise de Four...

  19. Ablation of burned skin with ultra-short pulses laser to promote healing: evaluation by optical coherence tomography, histology, {mu}ATR-FTIR and Nonlinear Microscopy; Ablacao de pele queimada com laser de pulsos ultra-curtos para promocao da cicatrizacao: avaliacao por tomografia por coerencia optica, histologia, {mu}ATR-FTIR e microscopia nao-linear

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Moises Oliveira dos

    2012-07-01

    Burns cause changes in the anatomical structure of the skin associated with trauma. The severity of the burn injury is divided into first, second and third-degree burns. The third-degree burns have been a major focus of research in search of more conservative treatments and faster results in repair for a functional and cosmetically acceptable. The conventional treatment is the use of topical natural or synthetic skin graft. An alternative therapy is the laser ablation process for burned tissue necrosis removal due to the no mechanical contact, fast application and access to difficult areas. The purpose of this study is to evaluate the feasibility of using high intensity femtosecond lasers as an adjunct treatment of burned patients. For this study, 65 Wistar rats were divided into groups of five animals: healthy skin, burned skin, two types of treatment (surgical debridement or femtosecond laser ablation) and four different times in the healing process monitoring. Three regions of the back of the animals were exposed to steam source causing third-degree burn. On the third day after the burn, one of the regions was ablated with high intensity ultrashort laser pulses ({lambda} = 785 nm, 90 fs, 2 kHz and 10 {mu}J/ pulse), the other received surgical debridement, and the last was considered the burn control. The regions were analyzed by optical coherence tomography (OCT), histology, attenuated total reflectance infrared spectroscopy using Fourier transform ({mu}-ATR-FTIR), two-photon excitation fluorescence microscopy (TPEFM) and second harmonic generation technique (SHG) on days 3, 5, 7 and 14 pos-treatments. The results showed that with the laser irradiation conditions used it was possible to remove debris from third degree burn. The techniques used to characterize the tissue allowed to verify that all treatments promoted wound healing. On the fourteenth day, the regeneration curve showed that the attenuation coefficient of laser ablated tissue converges to the values

  20. Laser Heterodyning

    CERN Document Server

    Protopopov, Vladimir V

    2009-01-01

    Laser heterodyning is now a widespread optical technique, based on interference of two waves with slightly different frequencies within the sensitive area of a photo-detector. Its unique feature – preserving phase information about optical wave in the electrical signal of the photo-detector – finds numerous applications in various domains of applied optics and optoelectronics: in spectroscopy, polarimetry, radiometry, laser radars and Lidars, microscopy and other areas. The reader may be surprised by a variety of disciplines that this book covers and satisfied by detailed explanation of the phenomena. Very well illustrated, this book will be helpful for researches, postgraduates and students, working in applied optics.

  1. Study of the effect of gamma radiation on the molecule of tetracycline concerning its behavior as complexing and extracting agent; Estudo do efeito da radiacao gama sobre a molecula de tetraciclina relativamente ao seu comportamento como agente complexante e extrator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade e Silva, Leonardo Gondim de

    1982-07-01

    Both solvent extraction and spectrophotometric techniques were used to show the alterations that gamma radiation causes in the behavior of tetracycline molecule as far as its extracting and complexing power are concerned. The effect of gamma radiation on the solid tetracycline molecule, benzyl alcohol and on the solution of both was examined in solvent extraction systems whose aqueous phases were made up by {sup 152} Eu-{sup 154}Eu radioactive tracer solutions and whose organic phases were constituted by tetracycline-benzyl alcohol solutions. Experiments were performed in order to determine whether or not the water used for the pre-saturation of benzyl alcohol would influence the radiolysis of tetracycline. Solvent extraction and spectrophotometry were the techniques used to obtain the necessary data. Absorption spectra of irradiated tetracycline benzyl alcohol solutions submitted to several gamma radiation doses were examined and the alterations shown by these spectra were examined. The effect of gamma radiation on the tetracycline molecule was also studied when tetracycline-benzyl alcohol solutions were irradiated under several gaseous atmospheres, namely: O{sub 2}, N{sub 2}, SF{sub 6} and N{sub 2}O. The variation on the concentration of the tetracycline-benzyl alcohol solution caused by several doses of gamma radiation was determined by using the spectrophotometric technique. (author)

  2. Change of the natural radiation exposure due to agriculture and industrial activities in a high natural radioactivity area from Brazil; Modificacao da exposicao a radiacao natural devido a atividades agricolas e industriais numa area de radioatividade natural elevada no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Silva Amaral, E.C. da

    1993-12-31

    The Pocos de Caldas Plateau, Minas Gerais State one of the biggest alkaline intrusions in the world. This study has shown the expected value for the mean annual radiation exposure due to the agricultural activities ranges from 6 up to 14 mSv/a depending on the age and living habits of the population group. The inhalation exposure of radon, thoron and their progenies represents the largest radiological health hazard (70-90%); this is followed by the external gamma irradiation from soil (10-25%). Ingestion of natural radionuclides with local food is only of minor radiological consequence. It was found that the lethal cancer risk might increase by 4% for a person born at the plateau, living and working there for the rest of her life. For the remote population the consumption the consumption of food products exported from the plateau leads to an expected value for the collective dose of 19 man Sv/a. This corresponding nominally to the small calculated number of 1 additional case of cancer per year. Therefore the main radiation impact of the agricultural activities are not the increased concentrations of natural radionuclides in food products but the fact that they are produced there with human labor and thus increasing the radiation exposure to a large number of farm workers and their families that move for occupational reasons to that region. The radiation exposure due to the mining and milling activities is, in spite of the significant increase of radionuclide activity concentrations in river waters, only of the order of 0.3 mSv/a. However as a recognized industrial source the ICRP dose limitation system has to be applied. Under this aspect the exposure calculated here, 0.3 mSv/a, should be considered as acceptable. (author). 93 refs, 16 figs, 58 tabs.

  3. Gamma radiation applied to extend the shelf-life of lamb meat vacuum packed and stored under refrigeration; Radiacao gama aplicada para estender a vida util da carne de cordeiro embalada a vacuo e armazenada sob refrigeracao

    Energy Technology Data Exchange (ETDEWEB)

    Fregonesi, Raul Pereira

    2013-07-01

    The State of Sao Paulo has experienced in recent years a significant increase in production, supply and consumption of lamb meat. With the current trend of demand for products of greater convenience, with speed and ease preparation, there is the need to invest in the market supply of refrigerated lamb cuts. Accordingly, irradiation with ionizing energy could be a viable alternative for the marketing of refrigerated cuts of lamb meat. The aim of this work was to study the application of different doses of gamma radiation in order to extend the stability of lamb meat vacuum packed and stored under refrigeration. For this, first a preliminary experiment was conducted aiming to determine parameters such as irradiation dose and storage time. The lamb loins (Longissimus dorsi) were vacuum packed, irradiated with doses of 1,0, 3,0 and 5,0 kGy and stored under refrigeration in cooling chamber at 1 °C. According to the results, a dose of 3,0 kGy may be indicated as the maximum dose of irradiation. After establishing these parameters, the final experiment began, and for that, the lamb loin samples were vacuum packaged and irradiated with doses zero (control), 1,5 kGy and 3,0 kGy and stored under refrigeration at 1 °C. In predetermined periods (zero, 14, 28, 42 and 56 days) microbiological and physical chemical analysis were carried out. Also, a sensory acceptance test was conducted, with 63 consumers, which evaluated aroma, texture, juiciness, flavor and overall quality attributes. All data were statistically evaluated using contrasts between means, with a significance level of 5%. The results obtained for microbiological testing of all samples were absence of Salmonella sp. and sporadic counts of coliforms at 45 °C and Staphylococcus aureus (<10 (est) CFU/g). For other microbiological analysis there were significant effects (p <0,05) of treatment, and time. However, for the physicochemical characteristics, there were only differences (p <0,05) of time from zero to 28 days for pH and color b * (yellow), which declined and increased, respectively, over this period. In the sensory acceptance test, the samples did not differ (p> 0,05) in any of the evaluated attributes. Thus, it was concluded that gamma irradiation in the lamb loins was effective in decreasing the proliferation of microorganisms without damaging its physical and chemical characteristics. At the end of the experiment, it was possible to say that the 3.0 kGy dose was indicated because could extend the shelf life of 14 to 56 days of loin of lamb irradiated and stored at 1 °C . (author)

  4. Evaluation of gamma irradiation effects on carotenoids, ascorbic acid and sugar contents of buriti fruit (Mauritia flexuosa L.); Avaliacao dos efeitos da radiacao gama nos teores de carotenoides, acido ascorbico e acucares do fruto Buriti do Brejo (Mauritia flexuosa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Antonio Luis dos Santos [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Quimica, Quimica Organica e de Produtos Naturais], e-mail: santoslima@ime.eb.br; Lima, Keila dos Santos Cople; Silva, Jaqueline Michele [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear. Irradiacao de Alimentos], e-mail: keila@ime.eb.br, e-mail: jaquelinefisica@bol.com.br; Coelho, Maysa Joppert [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear. Engenharia Ambiental], e-mail: maysa@ime.eb.br; Godoy, Ronoel Luiz de Oliveira [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil). Lab. de Cromatografia Liquida, Quimica Organica e de Produtos Naturais], e-mail: ronoel@ctaa.embrapa.br; Pacheco, Sidney [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil). Lab. de Cromatografia Liquida, Ciencia e Tecnologia de Alimentos], e-mail: sidney@ctaa.embrapa.br

    2009-07-01

    Buriti (Mauritia flexuosa L.), a typical fruit from the Northeast and Center-West Amazon of Brazil, is used in many regional dishes. It is considered an excellent source of carotenoids that are A vitamin precursors, showing a majority of beta-carotene. It also presents ascorbic acid and sugar contents. Many studies have indicated that the lack of A vitamin is the main cause of night blindness and xerophthalmia. Also, ascorbic acid deficiency may cause scorbutic disease. The use of food irradiation is growing and represents an economic benefit to agriculture through the reduction of post-harvesting losses while maintaining food nutritional quality. In this study, buriti in natura was treated with gamma irradiation with doses of 0.5 kGy and 1.0 kGy. The objective was to evaluate the irradiation effects on total carotenoids, ascorbic acid and sugars concentrations of buriti. The fruit was evaluated through the total carotenoids analysis, by spectrophotometry, and the carotenoids (alpha and beta-carotene and lutein), ascorbic acid and sugars were determined by high performance liquid chromatography (HPLC). The results showed that buriti is an excellent source of total carotenoids (44600 {mu}g/100 g). The irradiation of buriti with the dose of 0.5 kGy did not significantly change carotenoids and sugars contents. However, there was a reduction of ascorbic acid concentration with an increase of the dose, which may have been caused by irradiation or by intrinsic and extrinsic factors that alter ascorbic acid stability in food, converting ascorbic to dehydroascorbic acid, while keeping the C vitamin active form. (author)

  5. Effect of gamma radiation from {sup 60}C in conservation and quality of pepper fresh and pulp; Efeito da radiacao gama do {sup 60}Co na conservacao e qualidade de pimenta in natura e em polpa

    Energy Technology Data Exchange (ETDEWEB)

    Milagres, Regina Celia Rodrigues de Miranda

    2014-07-01

    Capsicum peppers are among the most used and most valued seasoning spices in the world. They are highly susceptible to post harvest decay, therefore the use of irradiation may contribute to conservation of this fruit which has significant nutritional, economic and social value. Were evaluated the effects of gamma radiation of {sup 60}Co in increasing the shelf-life and preservation of quality of pepper 'Dedo-de-moca' (Capsicum baccatum var. Pendulum) fresh and pulp associated or not with another conservation methods. Gamma radiation doses were investigated of 0,25; 0,50; 0,75; 1,00; 1,25; 1,50; 2,00 e 3,00 kGy in fresh fruit and 1,50; 2,00; 3,00; 4,50 e 6,00 kGy in pepper pulp. The use of laboratory pasteurization (85°C/3min), the addition of citric acid (5%) and 5% NaCl were also investigated in the pepper pulp. The samples were stored at 5 °C and or 25 °C. Were performed analysis: visual (disease incidence, turgidity and color); bioactive compounds (carotenoids, capsaicinoids, antioxidant capacity and phenolic compounds); physicochemical (Weight loss, firmness, soluble solids (SS), pH, titratable acidity (TA), ratio, color and moisture); respiratory rate and ethylene production; proximate composition (moisture, soluble and insoluble fiber, ash, protein, ether extract, total and available carbohydrate); microbiological contamination (mesophilic aerobic microorganisms, coliforms at 45 °C, Salmonella spp. and yeasts and molds) and sensory (acceptance test, difference test and paired preference). Radiation doses between 0.25 and 3.00 kGy were not effective to increase shelf-life and maintain fresh pepper quality during storage. There was increased intensity of red color, of incidence of disease, decreased turgidity and changes in physical, chemical and nutritional parameters. In pulp, the doses of gamma radiation of 4.50 and 6.00 kGy and the addition of 5% NaCl no changing sensory attributes, physical-chemical and bioactive compounds. Only the antioxidant activity and the color were influenced by irradiation during storage. Coliforms at 45 °C and Salmonella not were detected in irradiated and non-irradiated samples during storage. In the dose of 6.00 kGy there was reduction of the initial count of yeasts and molds of the 5 logarithmic cycles, while other doses decreased by 2 and 3 logarithmic cycles. However, 21 days after the irradiation, the contamination by yeasts and molds increased in all treatments. In pepper Dedo-de-moca fresh, the irradiation doses studied not contributed to preserving the fruit during storage. In the pulp pepper, doses of 4.50 and 6.00 kGy, associated with 5% NaCl proved promising to increase shelf-life without affecting the bioactive compounds, physicochemical characteristics and sensory attributes during storage at 25 °C. (author)

  6. Study of radiation in fresh tomatoes (lycopersicon esculentum Mill) and in the levels of sauce lycopene; Estudo da radiacao ionizante em tomates in natura (lycopersicum esculentum Mill) e no teor de licopeno do molho

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, Adriana Diaz Toni

    2009-07-01

    The purpose of the present study was to determine the effects of ionizing radiation in tomatoes (Lycopersicon esculentum Mill) and at the same time to evaluate the influence of irradiation on the content of lycopene in a sauce made with these fruits irradiated. For this reason tomatoes were subjected to five treatments: control, T1 (0.25 kGy), T2 (0.5 kGy), T3 (1.0 kGy) and T4 (2.0 kGy) and evaluated at 3, 6, 9, 12, 15 and 20 days after irradiation, for the following analysis: maturity, texture, color, soluble solids, pH, acidity and total mass. Measurements were made of lycopene in fresh tomatoes and sauce by open column chromatography according to the ripening of them. The results showed that only the mass was not significantly different (p> 0.05). Treatments 1 and 2 proved to be effective in delaying the maturation and in the maintenance of firm texture (p <0.05). While T4 caused chemical reactions in the structure of tomato, compelling it to mature earlier because of pectin degradation. The completion of a sauce made from tomatoes irradiated to 0.25 kGy, didn't show a significant difference (p> 0.05) when compared to control. However, it didn't indicate lycopene degradation, as the doses of 1.0 and 2.0 kGy. Thus we can conclude that low doses are effective for maintaining pH, firmness, delayed senescence, mass and, in addition to not degrading the major bioactive compound of tomato, lycopene, suggest a higher bioavailability of this one, depending on the radiation application. (author)

  7. Effect of {sup 60} Co gamma radiation on trehalose level of Saccharomyces boulardii cells; Efeito da radiacao gama {sup 60} Co nos niveis de trealose de celulas de Saccharomyces boulardii

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Raquel Gouvea dos; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Nucleo de Radiobiologia; Duarte, Rinaldo; Nicoli, Jacques R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Microbiologia

    1996-07-01

    The medicine Floratil used for diarrhea treatment is composed by lyophilized yeast cells of Saccharomyces boulardii. The action mechanism of this product is unknown. The efficacy of S. boulardii depends on its viability. The increase in the trehalose level in S. cerevisiae cells submitted to a previous sub-lethal level heat shock results in resistance to a lethal shock. The aim of this work was to study weather the cell trehalose level is involved also in the resistance of gamma irradiation. It was noted that the yeast cells surviving to gamma irradiation had more trehalose level than control cells. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S.boulardii cells. (author)

  8. Use of ionizing radiation in the recycling of unserviceable tires of automotive and its adequate environmental disposal; Utilizacao da radiacao ionizante na reciclagem de pneus inserviveis de automovel e sua destinacao ambiental adequada

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Clecia de Moura

    2013-07-01

    The aim of this study was to use ionizing radiation in the recycling of scrap tires of automotive. Samples of rubber unserviceable tires were irradiated with radiation doses 200, 400 and 600kGy in an electron accelerator. Subsequently, they were characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), tensile strength mechanical test, spectrophotometry Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). By thermogravimetry was possible to observe the effects of radiation in the mass loss of material. In the DSC curves were observed exothermic decomposition peaks and associated values of enthalpy variation (ΔH). The mechanical properties of the elastomeric matrix with unserviceable tires powder were studied and its behavior to ionizing radiation was analyzed. FTIR spectra were obtained in the 4000 - 650cm-1 region. It was observed that there was no change in the peaks due irradiation. For SEM the micrographs were enlarged from 32 times up to 1000 times and observed in sizes from 1mm up to 20μm. It was observed at doses of 200 and 400kGy, roughness corresponding to breaks or ruptures possibly caused by radiation. In 600kGy radiation dose was observed cavities caused by radiation. It was observed that at all doses occurred degradation. For samples without powder and with 10, 30 and 50% of unserviceable tires powder it was obtained micrographs of 100μm and 200μm amplification. Also it was possible to observe the incorporation of unserviceable tires powder of automotive in the elastomeric matrix of non-irradiated and irradiated samples. (author)

  9. Study on the energy dependence of gamma radiation detectors for {sup 137}Cs and {sup 60}Co; Estudo da dependencia energetica de detectores de radiacao gama para {sup 137}Cs e {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: rediniz@ipen.b, E-mail: vcsouza@ipen.b, E-mail: vivolo@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ({sup 137}Cs and {sup 60}Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  10. Ionizing radiation effect on central venous catheters (CVC) of polyurethane coatings with silver nanoparticles; Efeito da radiacao ionizante nos revestimentos de cateteres venosos centrais (CVC) de poliuretano com nanoparticulas de prata

    Energy Technology Data Exchange (ETDEWEB)

    Heilman, Sonia; Silva, Leonardo G.A., E-mail: sheilman@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Hewer, Thiago L.R.; Souza, Michele L. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Quimica

    2015-07-01

    The present work aimed to study the use of ionizing radiation for coating of silver nanoparticles on central polyurethane catheters, providing reduction of infections associated with contamination of catheters introduced into the bloodstream. Silver nanoparticles have physical, chemical and biological properties only when compared to metal on a macroscopic scale, and have been used in the medical field because of its remarkable antimicrobial activity. Titanium dioxide nanoparticles obtained by the sol gel method were used as the coating catheters for subsequent impregnation of silver nanoparticles with ionizing radiation at doses of 25 and 50 kGy. A Raman spectrometry was used to identify the polymorph of titanium oxide, rutile. In trials with (ICP OES) were evaluated amounts of titanium and silver coated catheters in titanium oxide and silver.(author)

  11. Study of gamma radiation from {sup 60}Co effects on Apis mellifera venom: biochemical, pharmacological and immunological aspects; Estudo dos efeitos da radiacao gama de {sup 60}Co na peconha de Apis mellifera: aspectos bioquimicos, farmacologicos e imunologicos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Helena

    2001-07-01

    Africanized honeybees are very common insects in Brazil and frequently cause accidents followed by important immunological reactions and even deaths. Their venoms are composed of a complex mixture of substances of general biological actions. Ionizing radiation is able to modify molecular structures affecting the biological properties of proteins. It decreases toxic and enzymatic activities and so, it appears promising as a venom detoxification tool. The main objective of this work was to study the effects of gamma radiation on bee venom, regarding biochemical, pharmacological and immunological aspects. Africanized Apis mellifera whole venom (2 mg/ml) in 0.15 M NaCl solution was irradiated with 2 kGy in a {sup 60}Co source. Native and irradiated bee venoms were submitted to high performance size exclusion chromatography (Tosohaas G2000SW column), high performance reversed phase chromatography in a C-18 column under water/acetonitrile gradient, SDS-PAGE. For both venoms studies have been carried out in UV absorption spectrum, protein concentration, hemolytic activity, and PLA{sub 2} activity analysis, lethality assay (LD{sub 50}). Biodistribution studies was carried out after labelling native and irradiated bee venom with {sup 99m}Tc. The results showed that gamma radiation did not change the protein concentration nor its immunogenicity, although it could be observed that irradiated bee venom UV spectrum and SDS-PAGE profile presented differences when compared to native bee venom. This suggests that some structural alterations in bee venom components could have occurred after irradiation. HPLC-RP profiles showed that gamma radiation could have caused conformational changes, such as unfolding of molecule chains, changing their hydrophobic groups exposuring. The hemolytic and the PLA{sub 2} activities of irradiated bee venom were smaller than the native ones. The gamma radiation diminished the toxicity of bee venom, but did not abolish its bioactivity, like hemolysis. Biodistribution studies showed that native and irradiated bee venom have been rapidly absorbed and suggested that they have hepatic metabolism and renal elimination. The irradiated bee venom seems to be eliminated faster than the native one, which could explain its reduced toxicity. (author)

  12. Dose rate range extension of the calibration of dosemeters at LNMRI, Rio de Janeiro, Brazil; Expansao da faixa de taxas de dose para a calibracao de instrumentos de medir radiacao no LNMRI, Rio de Janeiro, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, T.S.; Carlos, M.T.; Ramos, M.M.O., E-mail: tschirn@ird.gov.b, E-mail: marcia@ird.gov.b, E-mail: mmoramos@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The present work has an objective the implantation of a experimental arrange for application of essays of instrument calibration for measurement of low dose rate, which measure rate less than 10 {mu}Sv/h

  13. Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation;Propriedades mecanicas e termicas de poliuretanas derivadas do oleo de mamona usadas como cimento osseo depois da irradiacao com radiacao gamma

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, E.C. [Universidade Tecnologica Federal do Parana (DF/UTFPR), Curitiba, PR (Brazil). Dept. de Fisica; Soboll, D.S. [Universidade Tecnologica Federal Parana (CPGEI/UTFPR), Curitiba, PR (Brazil); Chierice, G.O.; Claro Neto, S. [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Lepiesnki, C.M. [Universidade Federal do Parana (DF/UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Nascimento, E.M. [Universidade Tecnologica Federal do Parana (DM/UTFPR), Curitiba (Brazil). Dept. de Mecanica

    2009-07-01

    Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

  14. Study of poly(ethylene terephthalate) - PET post consumption and its properties, when it is undergone ionizing radiation; Estudo da reciclagem do poli(tereftalato de etileno) (PET) pos-consumo e de suas propriedades, quando submetido a radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Claudio dos

    2008-07-01

    The plastic materials have an important role in the life style changing, in the lives of the people and it is more and more utilized in the production and consumption by the world population. By the plastic utilization, it became possible the growth phenomenon of disposable products. As a consequence of this conjecture, the recycling of these materials becomes an obliging option of the modern society. The economy provided by the reutilization of the recycling materials is advantageous not only in consideration to the reutilization of the natural resources involved in these products, but specially for its benefit provided in which concern to the preservation of the environmental matters. Within the big universe of the plastics and plastic packaging materials, available in the current market, it was carried out, during this work, the mechanical recycling of the packagings post consumption, produced from PET polymer and more specifically, the bottles used in packagings for beverages as a whole; such as carbonated beverages, mineral water, isotonic, and so on. Thus, the aim of this work was to recycle the PET post-consumption and evaluate the effects provoked by the action of different ionizing radiation doses, in the properties of this recycled polymer, based on virgin PET. Based on the conclusive results, it was taken for granted that the effects provoked by the action of the ionizing radiation from the electron beam by electron accelerators and gamma rays emitted by {sup 60}Co source in the virgin and recycled PET polymer promoted the predominance of the scission reactions at random of the main chain, with consequent decrease of the polymer molecular weight. Such fact was corroborated by the flow index essay and intrinsic viscosity. It was also carried out, thermal analysis by Differential Scanning Calorimetry (DSC) proving the decreasing of molecular weight in the irradiated PET samples. (author)

  15. Evaluation of the effects of gamma radiation on physicochemical characteristics of kiwi (Actinidia deliciosa) cv. Hayward minimally processed; Avaliacao dos efeitos da radiacao gama nas caracteristicas fisico-quimicas de kiwi (Actinidia deliciosa) cv. Hayward minimamente processado

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana Claudia Sampaio

    2011-07-01

    The search for a healthy life has led consumers to rethink their eating habits, consuming fruits and vegetables in place of manufactured products, therefore, the demand for minimally processed products has evolved rapidly. The kiwi fruit (Actinidia deliciosa) has high nutritional value, being rich in C vitamin especially, which has wide acceptance in consumer markets. Thus, along with papaya, passion fruit and pineapple, kiwi can be considered as an additional feature of C vitamin in the diet, or as a substitute for traditional citrus. The aim of this study was to assess the effects of gamma radiation on physical and chemical characteristics of kiwis minimally processed and stored under refrigeration, since this technology increases the shelf life of fruits and vegetables. The Kiwis was stripped, processed and cut into slices, stored in polyethylene bags of 10 cm squared and irradiated at doses of 0 (control), 1 and 2 kGy. A source of {sup 60}Co Gammacell 220, dose rate of 0.429 kGy/hour, in which each treatment had 5 replicates with 15 slices of kiwifruit per replicate. After irradiation the samples were stored in a climatic chamber at 6 degree C (near the temperature of commercial refrigerators). The following criteria were physical chemical analysis: pH, color, chlorophyll content, loss of weight, moisture, acidity and Brix. The analysis were done on 1{sup st}, 7{sup th} and 14{sup th} days after irradiation. The results indicated that gamma radiation did not induce deleterious changes in the physicochemical properties of the kiwi may be used for preservation of minimally processed kiwifruit. (author)

  16. Conservation studies of peruvian carrot (Arracacia xanthorrhiza Bancroft.): effects of packaging, gamma radiation and storage temperature;Estudos de conservacao de mandioquinha-salsa (Arracacia xanthorrhiza Bancroft.): efeitos da embalagem, radiacao gama e temperatura de armazenamento

    Energy Technology Data Exchange (ETDEWEB)

    Chiebao, Helena Pontes

    2008-07-01

    Peruvian carrot (Arracacia xanthorrhiza Bancroft.) is a tuber root that presents a short post-harvest period of conservation, 3 to 5 days, due to a phyto pathology known as soft rot or {sup m}ela{sup ,} caused by bacteria of the genus Erwinia. This bacteria release enzymes that decay the cellular wall, causing the lost of the characteristic rigidity. At present, many conservation methods have been studied in the attempt of prolonging the post harvest conservation, but the combination of processes seems to be the best alternative. The aim of this work was to study the interaction between the conservation processes (refrigeration, vacuum packaging and irradiation) to extend the post-harvest period of the roots. It was studied the combination of two temperatures (25 deg C e 4 deg C), with two packages (boxes and vacuum) and three gamma irradiation doses (1, 2 e 3kGy), obtaining a total of 16 sample groups. The samples were daily analyzed, for a 30 day period, using texture parameters (penetration energy), microbiology and pectinolitic enzymes activities (pectate lyase, polygalactunoronase and pectin methyl esterase). The samples irradiated in doses of 2 and 3kGy, vacuum packed and conserved at 4 deg C extend the post-harvest period of 5 to 28 days, with a decrease of the microbiologic population, but with decreased in the rigidity of the roots (p<0.05). The treatments affected the pectinolitic enzymes profile, however the amplitude of the results and the low number of analysed samples per day, besides the complexity of factors affecting the enzyme activity and the multiple possible sources(endogenous, bacterial or fungous), limits the carefully discussion of the results. (author)

  17. Gamma radiation effects at color, antioxidant capacity and fatty acid profile in peanut (Arachis hypogaea L.); Efeitos da radiacao gama na cor, capacidade antioxidante e perfil de acidos graxos em amendoim (Arachis hypogaea L.)

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Adriano Costa de; Canniatti-Brazaca, Solange Guidolin; Mansi, Debora Niero; Domingues, Maria Antonia Calori [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao; Arthur, Valter, E-mail: arthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2011-01-15

    Irradiation is efficient at extinction fungi contamination in peanuts. Peanuts have high biologic value protein, minerals, vitamin E, complex B, and high concentration of lipids. The objective of this research is to evaluate the gamma irradiation effect on color, total phenolic, antioxidant activity, and fatty acid profile in peanuts (Arachis hypogaea L.). Cultivars IAC-Tatu ST and IAC-Runner 886 were submitted to gamma radiation with doses of 5.0; 7.5; 10.0, and 15.0 kGy and storage at room temperature. There was no significant difference in the color of IAC-Tatu ST. However, significant difference was found in the luminosity and Chroma in IAC-Runner 886. Total fenolics differed from the control with 33.27 mg.g{sup -1} and treatment dose of 10.0 kGy with 58.60 mg.g{sup -1} in IAC-Tatu ST. This parameter not had significant difference in IAC-Runner 886 and the control with 51.59 mg.g{sup -1}. The antioxidant activity did not present significant difference with a dose of 10.0 kGy, recommended for the elimination of fungi in peanuts. The dose of 10.0 kGy showed a decrease in saturated fatty acids, increase in unsaturated fatty acids, and an increase in linolleic acid. The oleic/linoleic relation decreased justifying further research correlating storage and oxidative stability. (author)

  18. Study of the effect of ionizing radiation on composites based on PCL/PLLA and coconut fiber; Avaliacao dos efeitos da radiacao ionizante em compositos de PCL/PLLA com fibra de coco

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, Yasko

    2011-07-01

    Plastic solid waste has become a serious problem recently concerning environmental impact. In this scenario, preparation of polymers and composites based on coconut husk fiber would lead to a reduction on the cost of the final product. Additionally, it will reduce the amount of agribusiness waste disposal in the environment. In Brazil, coconut production is around 1.5 billion fruits by year in a cultivated area of 2.7 million hectares, but the coconut husk fiber has not been used much for industrial applications. Moreover, biodegradable polymers have attracted the attention of the most part of population, due to the environmental issues arising from the increasing use of polymeric materials of low degradability discharged as waste residue. Besides, when considering an application in the medical field, it is necessary that the products are sterilized and, ionizing radiation is widely used to sterilize medical and surgical devices. In this work, it was studied blends and composites based on two commercial polymers: poly (e-caprolactone), PCL, and poly (lactic acid), PLLA, and coconut fiber. Those polymers are biodegradable as well as biocompatible, so it is important to know the effect of ionizing radiation in these materials. Samples were irradiated with gamma rays from {sup 60}Co source and electron beam with radiation doses ranging from 10 kGy up to 1 MGy. The non-irradiated and irradiated samples were studied using several analytical techniques and characterization assays that allowed understanding their properties in order to enable their application as precursors for medical and surgical devices. Thermal stability of non irradiated and irradiated composites up to 100 kGy radiation dose is not affected significantly by the coconut fiber incorporation to the polymeric matrix. Acetylation of fibers was not effective in order to induce any interaction between fibers and polymeric matrix, as expected. That was verified by the slight reduction of stress strength observed in the composites specimens. Besides that, this reduction did not affect negatively mechanical properties of blends compared to the composites. Ionizing radiation neither promoted detectable interaction between polymeric matrix and fibers. Cytotoxicity tests indicated that lixiviation products from homopolymers, blend and composites did not release sufficient amount of substances to induce significant cellular death. Thermal processing used to obtain composites and previous acetylation by chemical treatment contributed to the bioburden reduce. Furthermore, reducing initial bioburden it was possible to diminish radiation doses needed to perform sterilization. Enzymatic and soil degradation were not negatively affected by radiation processing. Even though fiber incorporation to the polymer blend slightly reduced degradation process, composites continued degrading through time. Artifacts produced by means of the materials studied here can be radiation processed with doses up to 100 kGy without prejudice of their biodegradability. (author)

  19. Influence of gamma radiation on the levels of polyphenols and lethality of ethanol extracts of Anacardium occidentale Linn., against Biomphalaria glabrata; Influencia da radiacao gama na acao moluscicida de extratos de cajueiro em Biomphalaria glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.H.F.; Silva, E.B., E-mail: santosghf@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Radioprotecao e Radioecologia; Melo, A.M.M.A.; Lima, C.S.A [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica; Amorim, E.L.C.; Peixoto Sobrinho, T.J.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Farmacia

    2013-08-15

    Plant materials rich in phenolic compounds, such as Anacardium occidentale Linn., Have been used as alternatives to synthetic pesticides in Biomphalaria glabrata control programs, intermediate host of Schistosoma mansoni. Studies show that ionizing radiation can influence the content of phenolic compounds and thus their biological actions. The aim of this study was to evaluate the influence of gamma radiation of {sup 60}Co in polyphenol composition of hydroalcoholic extracts of bark and leaves of A. occidentale and evaluate the toxicity of these extracts to embryos and adults of B. glabrata. To achieve this goal this, the extracts were irradiated at 10 kGy, the controls being maintained from 0 kGy and positive (CaCO{sub 3}) and negative (H{sub 2}O). We quantified the total phenols by the Folin-Ciocalteau and tannins by precipitation of casein. Extracts were used at a concentration of 100 mg/L. The results showed that the radiation caused the changes to the leaves, the percentage of polyphenols and tannins, and the percentage of lethality in embryos and adults Biomphalaria glabrata, these percentages being: 13 ± 5 (0 kGy) and 27 ± 2.5 (10 kGy), and 36.67 ± 5.77 (0 kGy), and 56.67 ± 5.77 (10 kGy), respectively. Gamma radiation caused significant changes in the levels of polyphenols in the extracts of leaves of Anacardium ocidentale Linn., translated by the increased toxicity of this extract against embryos and adults of Biomphalaria glabrata. This indicates that gamma radiation can be used as an agent potentiating the toxicity of plant extracts on the alternate use of these materials as molluscicides. (author)

  20. Ionizing radiation dose control for workers in a nuclear plant working with unsealed sources; Controle da dose de radiacao ionizante para trabalhadores em uma instalacao radiativa com fontes nao seladas

    Energy Technology Data Exchange (ETDEWEB)

    Gerulis, Eduardo

    2006-07-01

    With the liberation of the use of the nuclear energy for peaceful applications, International Commission Radiological Protection, ICRP, founded in 1928, created a system of protection of the undesirable doses of ionizing radiation in 1958. This has been received by workers, members of the public and environment and hence it became possible for the introduction of these applications. This protection system is adopted by the International Agency of Energy Atomic, IAEA, that publishes recommendations in safety series, 88 and by the Comissao Nacional de Energia Nuclear, CNEN, which publishes these regulations. The international recommendations and national regulations were adapted and they need to be applied in this way. The present paper uses recommendations of the publication 75 from ICRP, of the publication 115 from 88 and regulations of the regulation NN 3.01 from CNEN to present, through radiological protection measures, the ionizing radiation dose control for workers in a nuclear plant that works in the research, production, division and packing of unsealed sources to be used in clinical applications. In that way it is possible to prevent appropriately the undesirable doses and to confirm the received doses. (author)

  1. Radiation doses in mammography as planning parameters for premature breast cancer tracking programs; Doses de radiacao em mamografias como parametros de planejamento para programas de rastreamento do cancer precoce da mama

    Energy Technology Data Exchange (ETDEWEB)

    Souza Ferreira, Rubemar de

    1994-12-31

    Radiation doses are the main parameters applied to the evaluation of mammographic radiological impact. This study, for a sample of 407 women, were analyzed, through the thermoluminescent dosimetry, radiation doses in the surface of skin and glandular absorbed doses for cranio-caudal view. The results show the presence of a large dose range to the same mammographic procedure, which, analyzed enclosed with 585 facilities, suggest be necessary the standardization of the mammographic technique. From that results, with the additive model, the excess of breast cancer (radioinduced) and lifetime loss risk, for age groups between 30 and 70 years were estimated. Is demonstrated that the benefits from dedicated mammography, overcome the relationship among the epidemiological aspects of breast cancer and ionizing radiation as an harmful agent, which may show an important correlation for large exposed populations, point out the importance of the continuous risk and benefit evaluation to the new technologies introduced. (author). 86 refs., 40 figs., 14 tabs.

  2. Change of the natural radiation exposure due to agriculture and industrial activities in a high natural radioactivity area from Brazil; Modificacao da exposicao a radiacao natural devido a atividades agricolas e industriais numa area de radioatividade natural elevada no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Silva Amaral, E.C. da

    1992-12-31

    The Pocos de Caldas Plateau, Minas Gerais State one of the biggest alkaline intrusions in the world. This study has shown the expected value for the mean annual radiation exposure due to the agricultural activities ranges from 6 up to 14 mSv/a depending on the age and living habits of the population group. The inhalation exposure of radon, thoron and their progenies represents the largest radiological health hazard (70-90%); this is followed by the external gamma irradiation from soil (10-25%). Ingestion of natural radionuclides with local food is only of minor radiological consequence. It was found that the lethal cancer risk might increase by 4% for a person born at the plateau, living and working there for the rest of her life. For the remote population the consumption the consumption of food products exported from the plateau leads to an expected value for the collective dose of 19 man Sv/a. This corresponding nominally to the small calculated number of 1 additional case of cancer per year. Therefore the main radiation impact of the agricultural activities are not the increased concentrations of natural radionuclides in food products but the fact that they are produced there with human labor and thus increasing the radiation exposure to a large number of farm workers and their families that move for occupational reasons to that region. The radiation exposure due to the mining and milling activities is, in spite of the significant increase of radionuclide activity concentrations in river waters, only of the order of 0.3 mSv/a. However as a recognized industrial source the ICRP dose limitation system has to be applied. Under this aspect the exposure calculated here, 0.3 mSv/a, should be considered as acceptable. (author). 93 refs, 16 figs, 58 tabs.

  3. Effects of ionizing radiation over the structure, metabolism and infectivity of a pathogenic protozoan, Toxoplasma gondii; Efeitos da radiacao ionizante sobre a estrutura, metabolismo e infectividade de um protozoario patogenico, Toxoplasma gondii (Nicole and Manceau, 1908)

    Energy Technology Data Exchange (ETDEWEB)

    Hiramoto, Roberto Mitsuyoshi

    1998-07-01

    The intracellular parasite Toxoplasma gondii (Apicomplexa), has as definitive host domestic and wild felines and as intermediate hosts most species of mammals and birds, Including man. The infection in man is usually asymptomatic, but can become a severe and lethal illness in some special groups like the fetus of primoinfected pregnant woman, or in AIDS and transplanted patients. The transmission is due to ingestion of food or water contaminated with oocysts from cat feces as well as raw or rare cooked cyst containing meet. There is no available vaccine against toxoplasmosis, with some reports of the use ionizing radiation in order to attenuate or suppress the parasite. These studies are promising, but more research is needed to optimize the radiation process and to clarify those alterations caused on T gondii.Using a increasing doses of {sup 60} Co irradiation on T.gondii tachyzoites, we studied many parameters such as morphology, both at optical and electron microscopy level, detection of DNA fragmentation, metabolism alterations (cellular oxidative burst, protein, nucleic acids and DNA synthesis), determination of the parasite survival both in in vivo and in vitro models, antigenicity and immunogenicity after the process, cellular invasion and irradiated tachyzoite induced protection. After definition of 200 Gy of {sup 60} Co irradiation as the lower radiation dose that suppress parasite growth in vitro and in vivo, we found no detectable changes in parasite viability, its cell invasion capacity or in its structural proteins. DNA fragmentation like apoptosis or alterations of the parasite metabolism were similarly not affected by radiation. Mice infection with irradiated parasites induce partial protection when these animals were re-inoculated with non irradiated virulent parasites, inducing greater specific IgG levels as well as a longer survival. Irradiated T.gondii maintains its the ability of invasion, even under radiation effects. Based on our results we conclude that ionizing radiation can be considered as a possible tool in vaccine production due to similar viability, invasivity and metabolism and absence of reproductive capacity, of irradiated tachyzoites. (author)

  4. Application of gamma irradiation for incorporation of rubber powder in the formulations EPDM and NBR rubber; Aplicacao da radiacao gama para incorporacao do po de borracha em formulacoes de borracha EPDM e nitrilica

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila de Ysasa Pozzo

    2014-07-01

    The natural decomposition of rubber is a very slow process due to its three-dimensional network formed by vulcanized crosslinked structures becoming extremely difficult to reprocess this material. The present work aims to study the application of gamma irradiation as devulcanization process for material reuse/recycling. The interactions of elastomers with ionizing radiation of a gamma source were investigated and the changes in physicochemical properties of the materials were evaluated. Formulations of NBR (acrylonitrile - butadiene) and EPDM (ethylene - propylene - diene terpolymer) from the rubber industry were crosslinked by conventional sulfur-based mixing. Master - batch was processed with rubber powder (industrial waste) and virgin rubber. The raw material (master batch) was irradiated in {sup 60}Co source at doses of 50, 100, 150 kGy and dose rate of 5 kGy h{sup -1} at room temperature. The irradiated material was incorporated in classical sulfur-based formulations. The formulations were characterized by: infrared spectroscopy (FTIR), thermal analysis (TG and DTG), tensile strength, elongation at break, hardness, abrasion resistance, rheometry and swelling. The results showed a predominance of chain scission at a dose of 50 kGy for EPDM rubber. For nitrile predominance of chain scission was observed at a dose of 100 kGy. These results show the possibility of the use of gamma radiation for the reuse/recycling of EPDM and nitrile rubbers. (author)

  5. Application of gamma radiation on disinfestation feed grain based food for domestic animals; Aplicacao da radiacao gama na desinfestacao de racoes a base de graos para alimentacao de animais domesticos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Amanda Cristina Oliveira

    2009-07-01

    This study aimed to realize a survey to identify the associated insects to feed the city Sao Paulo / SP and also to assess the effect of gamma radiation on food ration for domestic animals infested by pests. Samples of 20 stores, 'Pet Shop' in different regions in Sao Paulo / SP were subjected to trials of 1 and 45 days for collection of insects with the aid of plastic tray and screens of different sizes. The species Sitophilus zeamais, Cryptolestes ferrugineus, Lasioderma serricorne and Oryzaephilus sp. showed a higher frequency. In assessing the effects of gamma radiation we used samples of maize, sunflower seeds and mix for rodents infested with adults of the species Sitophilus zeamais, Lasioderma serricorne and Plodia interpunctella, after the period of 7 to 10 days the insects were removed and samples subjected to increasing doses of gamma radiation. The species Sitophilus zeamais and Lasioderma serricorne subjected doses from 0,25 to 1,50 kGy and species Plodia interpunctella doses from 0,10 to 2,0 kGy. After 40 days of irradiation was evaluated the number of insects emerged. The results of bioassays with Sitophilus zeamais and with Lasioderma serricorne demonstrated that doses starting at 0,5 kGy was sufficient to cause mortality of eggs and newly emerged larvae. The results with Plodia interpunctella from the 1,5 kGy, hasn't emerged adult insects, concluding that these doses were sufficient to cause mortality of eggs and larvae. (author)

  6. Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films; Estudo do efeito da radiacao por feixe de eletrons nas propriedades de filmes de copoliester alifatico aromatico

    Energy Technology Data Exchange (ETDEWEB)

    Poveda, Patricia Negrini Siqueira

    2008-07-01

    Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex{sup R} and Ecobras{sup R}) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural changes of the samples (crosslinking or degradation) by SEM were not observed. The FT-IR identified the characteristic peaks of each involved functional group (copolyester and corn starch). However, it was not found bands of oxidation of the samples. In the DSC, changes in the melting temperature of the irradiated Ecoflex{sup R} and Ecobras{sup R} samples, was not identified when compared with the samples of reference. However, it was verified a reduction in the melting enthalpy of the Ecobras{sup R} samples after irradiation. The Ecobras{sup R} material presented crosslinking, when submitted to doses of 10 kGy and 40 kGy. The Ecoflex{sup R} material did not present crosslinking when submitted to these doses. The biodegradability of the materials was evaluated by two methods of test: soil simulated and enzymatic. In both methods, the irradiated samples presented faster biodegradation than the references not irradiated. (author)

  7. Effects of gamma radiation on fungal microbiota and mycotoxins in broiler chicken feed; Efeitos da radiacao gama sobre microbiota fungica e micotoxinas encontradas em racao de frangos de corte

    Energy Technology Data Exchange (ETDEWEB)

    Simas, Monica Mattos dos Santos

    2010-07-01

    The purpose of this work was to study the control of toxigenic fungi and mycotoxins in broiler feed by gamma radiation. Feed samples were treated with gamma radiation (0, 5 and 10 kGy) and contaminated with aflatoxins or fumonisins. Performance, hematological and biochemical results indicated that a 5 kGy dose was effective on the control of the deleterious effects caused by mycotoxins on broilers. No significant alterations were observed on the feed chemical composition. Irradiated samples presented lower fungal contamination than those not irradiated. We did not detect alterations on aflatoxin or fumonisin content of feed samples after irradiation. AFLP results demonstrated that Aspergillus flavus and Fusarium verticillioides did not present any correlation between groups, toxin production and irradiation dose. We can conclude that the dose of 5 kGy is indicated for treatment of broiler feed. Despite the fact that it does not change the mycotoxin levels found in the samples, this dose significantly reduces the fungal microbiota and modifies the feed digestibility, increasing the final weight of broiler chickens. (author)

  8. Use of gamma-rays sensitivity for discrimination of upland cultivars of groups Indican and Japonica; Uso da sensitividade a radiacao gama na discriminacao de variedades de arroz-de-sequeiro dos grupos Indica e Japonica

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Luis Roberto Franco [UNESP, Botucatu, SP (Brazil). Dept. de Genetica; Ando, Akihiko [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    2003-07-01

    Sixty-five upland rice cultivars (Oryza sativa L.) were evaluated in relation to gamma-ray sensitivity. Seeds were subjected to seven doses of gamma-radiation and sown in wooden boxes in randomised complete block design with three replications. The experiment was conducted in greenhouse during the year of 1992. Physiological effects caused by radiation in the M{sub 1} generation, were evaluated. The results showed that the sensitivity to the radiation at doses 300 and 360 Gy was useful for distinguishing Indican and Japonica groups. (author)

  9. Effects of ionizing radiation on glycerolated amniotic membranes as a substract for cultured human epithelium; Efeitos da radiacao ionizante em membranas amnioticas gliceroladas empregadas como substrato ao cultivo de epitelio humano

    Energy Technology Data Exchange (ETDEWEB)

    Paggiaro, Andre Oliveira

    2011-07-01

    The amniotic membrane (AM) is a biomaterial with biological properties that are beneficial to tissue repair. It has been used as a temporary coverage to threat burns and chronic wounds. Recently, it has been served as a substrate for keratinocytes culture to construct a living skin equivalent. However, MA is a biological material, and its transplantation could cause infectious disease for receptors. So, it must be preserved and sterilized before clinical use. The aim of this study was to evaluate the radiation effects on glycerol-preserved MA, considering its compatibility to support human keratinocytes culture. Four MA were stored in high concentrations of glycerol (> 85%) and half of them were radio sterilized with a dose of 25 kGy. Then, we established two groups: nonirradiated MA (MA-ni) and irradiated MA (MA-i). Both groups was deepithelialized by a standardized protocol and was investigated morphologically, immunohistochemical and ultrastructural. Subsequently human keratinocytes were cultivated immersed and in air-liquid interface on denuded surface of MA-i and MA-ni. The results were compared at 14 and 21 days of culture by light and electron microscopy. After epithelial denudation, analyses demonstrated the continuity of the basement membrane in MA-ni group, whereas in the irradiated group, there was no indication of the basement membrane’s presence on the surface of MA. The cell cultures showed that in the non-irradiated group, there was growth of a multi-layered and differentiated epithelium, with a stratum corneum’s formation in air-liquid interface. In the irradiated group, the epithelium had only two or three layer, little cell differentiation, with the same results immersed or air-liquid interface system. Glycerol-preserved MA was biocompatible with the growth of a cultivated epithelium, showing its potential as a skin substitute. Irradiation at 25 kGy cause structural damage to the tissue, making changes in basement membrane, that facilitates its loss when exposed to the de-epithelialized protocol. The basement membrane’s loss may explain the difference between the keratinocytes cultivation on MA-I and MA-ni. (author)

  10. Evaluation of the ionizing radiation effects in microbiology, physical and chemical and sensory aspects of ice cream; Avaliacao dos efeitos da radiacao ionizante nos aspectos microbiologicos, fisico-quimicos e sensoriais de sorvetes

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, Vladimir Dias

    2015-06-01

    The ice cream is defined as an emulsion of fats and proteins or a mixture of water and sugar, other ingredients may be added provided since they do not affect the product. It is considered a food of high nutritional value, providing lipids, carbohydrates, protein, calcium, phosphorus, and other minerals and vitamins (A, B1, B2, B6, C, D, E and K), and it is considered one of the most important products and higher interest to the dairy industry due to great demand by the consumers. The diseases related to food consumption are considered one of the most significant problems. Several outbreaks related to microbiological contamination of ice cream have been reported in recent decades in Asia, Europe and America. It is believed that the ice cream, as a frozen food, presents no risk to the population health. However, it is considered an excellent environment for the growth of microorganisms due to its composition, pH close to neutrality and long storage period. The aim of this study was to evaluate the microbiological, sensory and physicochemical aspects of ice cream. The ice cream samples were irradiated with gamma rays (60Co) with the doses of LOkGy, 2.0kGy, 3.0kGy and 4.0kGy. The samples intended for the inoculation of Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 11229) and Salmonella abaetetuba (ATCC 35640) have been irradiated with doses of 1.0, 2.0 and 3.0kGy. It can be concluded that the dose of 3.0kGy was adequate to reduce most of the studied microorganisms to undetected levels. The use of gamma radiation affected the texture and the parameters of the colorimetric analyses of the ice cream. The results of the sensorial analyses showed that the better accepted dose was 3.0kGy. (author)

  11. Gamma radiation physical-chemical effects on vitamin C contents in white and red guavas; Efeitos fisico-quimicos da radiacao gama nos teores de vitamina C em goiabas brancas e vermelhas

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, Jose Daniel V.; Mansur Netto, Elias [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia

    1995-12-31

    Guava (Psidium guajava L.) is valuable tropical fruit because its high C vitamin content. Red an white are the most common species of guava found in tropical areas. The ionizing radiation is normally used as a ripen ring retardant for longer storage periods. This work studies gamma radiation effects on the C vitamin concentration in white and red guava. Samples of juices were irradiated using a source of Cobalt-60, with doses of 1,0 2,5 and 5,0 kGy and storing periods of 0,15 and 30 days. The white guava juice showed a 49% loss in the C vitamin concentration with 5 kGy radiation dose, while the red guava juice showed 33% under the same condition. This shows that the juice of white guava is more sensitive to gamma radiations than the red guava. This results suggests a protection mechanism by colour pigments we believe is associated to the aromatic structures in the red specie. (author). 4 refs., 2 tabs.

  12. Application gamma radiation of cobalt-60 in disinfestation of some types of rations for feeding small animals; Emprego da radiacao gama do cobalto-60 na desinfestacao de alguns tipos de racoes para alimentacao de animais de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Paula Bergamin

    2012-07-01

    The pests as beetles, mites, moths and mushrooms among other, usually infest products stored as: grains, crumbs, flours, coffee, tobacco, dried fruits, animal rations, spices, dehydrated plants, causing the visual depreciation and promoting to deterioration of the products. The present research had as objective the use of the gamma radiation in the disinfestation of some types of rations used for feeding animals of small size. In the first experiment packing of free samples were used measuring 10 cm x 20 cm with capacity of 70 grams of substrate (ration) with 4 types of existent marks in the trade: (1), (2), e (3), and (4). Each treatment consisted of 10 repetitions, that were irradiated with doses of: 0 (control) 0,5; 1,0 and 2,0 kGy, to do the disinfestation of the samples. After the irradiation (disinfestation) of the all irradiated packing and more the control was conditioned in plastic boxes of 80 cm x 50 cm with cover, where the insects were liberated Lasioderma serricorne, Plodia interpuctella, Sitophilus zeamais and Sitophilus oryzae, in a total of 400 for each box and maintained at room acclimatized with 27 {+-} 2 Deg C and relative humidity of 70 {+-} 5%. In the second experiment packing were used made with the materials of packing of the first experiment. Each packing was made of 10 cm x 15 cm, with capacity of 30 grams of substrate (ration). In each repetition was inoculated 10 insects of each species, in a total of 400 insects for experiment per box. The packing with substrate and insect, were stamped in commercial machine and irradiated with doses of: 0 (control) 0,5; 1,0 and 2,0 kGy. The irradiated packing and the control were maintained at room acclimatized same the mentioned in the first experiment. The counting of the number of insects and holes in the packing were made after 60 days. Concluded that only the packing of the ration type number 4 was susceptive to attack of all species of insects. The dose of 0,5 kGy was sufficient to induce the sterilization and consequently the disinfestation of all studied rations. (author)

  13. Effect of gamma radiation and storage on cholesterol oxidative stability of raw and processed eggs;Efeito da radiacao ionizante e do armazenamento sobre a estabilidade oxidativa do colesterol em ovos crus e processados

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Marliz Klaumann Julca

    2005-07-01

    The egg have being studied due its nutritional wealth, for show industrial interest as a raw material, e due its higher cholesterol content. At the same time, due its susceptibility to contamination mainly with salmonella, it is being proposed the ionizing radiation as a hygienic measure. Cholesterol is subject to oxidation, that it is facilitated by several factors, among them ionizing radiation. Formed cholesterol oxides, by its turn, show harmful biological properties to human health, as atherogenicity, cytotoxicity, carcinogenicity and mutagenicity, among others. The objectives of this work were evaluate the effect of ionizing radiation over pH, viscosity and color, besides the oxidative stability of cholesterol, in stored and processed crude eggs. With the increase of used doses (1, 2 and 3 KGy), there was an reduction in the viscosity of the egg white and in the color yolk egg, besides the increase in lipidic oxidation, measured through tiobarbituric acid-reactive substances (TBARS). Specifications as humidity, total lipids and egg yolk cholesterol were not influenced. In the subject of humidity and of cholesterol, there was an meaningful alteration due storage (30 days in 4 deg C). The sum of the analyzed oxides didn't variate with the irradiation, only individually, although it did vary with storage. The thermal processing caused an meaningful increase of TBARS, but despite this, the oxides sum didn't differed between treatments. (author)

  14. Evaluation of the toxicity of the methanolic extract of Caesalpinia Pyramidalis, subjected to gamma radiation, compared to saline artemias; Avaliacao da toxicidade do extrato metanolico de Caesalpinia Pyramidalis, submetido a radiacao gama, frente a artemias salinas

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Juanna G.; Santos, Mariana L.O.; Costa, Michelle C.A.; Siqueira, Williams N.; Silva, Luanna R.S.; Cabral, Daniela L.V.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: marianasantos_ufpe@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    The present study aimed to investigate the possible effect of irradiation of 60 Co in methanol extract of Caesalpinia pyramidalis (catingueira) with function of reducing the toxicity of the extract at concentrations of 1000, 500, 250 and 125 ppm irradiating them with doses of 5 kGy 7 kGy and 10 kGy, using lethality tests with saline Artemias.

  15. Gamma radiation effects on the viscosity of carrageenan, agarans and alginates to be used as food additives; Efeito da radiacao gama na viscosidade de carragenanas, agaranas e alginatos utilizados na industria alimenticia

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, Antonio Joao

    1999-07-01

    Carrageenan, agarans and alginates are phycocolloids, which change the consistence of the foodstuff and prevent undesirable changes such as moisture migration or textural profile changes. These phycocolloids are additives used in large scale for all kind of food products. They are not absorbed for the human organism and do not introduce extra calories in the diet. The process of irradiation, is an alternative method of great potential, because do not increase the temperature and it is highly in the decontamination of food ingredients. In this work, agar alginates and carrageenan were irradiated as powder with different doses (0-10kGy) of Co-60 and the rheological functional performance of water solutions of the irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. The viscosity of these hydrocolloids shows a decrease when submitted to an irradiation with doses until 10 kGy. (author)

  16. Effects of ionizing radiation on nutritional properties of table grapes Benitaka and dark raisins; Efeitos da radiacao ionizante nas propriedades nutricionais das uvas de mesa Benitaka e uvas passas escuras

    Energy Technology Data Exchange (ETDEWEB)

    Santillo, Amanda Galassi

    2011-07-01

    Brazil is a major producer of fruits, but its tropical climate with high humidity and temperature, eventually creates unfavorable conditions for the preservation of food and especially the fruit. Ionizing radiation has the potential to solve problems affecting the food supply in many countries. Using the right dose, this technology can be used to extend shelf life and safety of many fresh fruits in addition to controlling their rates of maturation. There are thousands of grape varieties around the world, most of them belonging Vitis vinifera. This fruit can be dried to obtain raisins in order to maintain the natural characteristics of the product and hinder the growth of microorganisms that can promote the deterioration of fresh fruit. One of the major sources of phenolic compounds are found in grapes, compared to other fruits and vegetables. One of the phenolic compounds represented by resveratrol is that stands out when it comes to fighting various diseases such as cardiovascular diseases, cancer and neurological diseases. The irradiations were performed in {sup 60}Co irradiator Multipurpose Center installed on Radiation Technology (CTR-IPEN-CNEN/SP) with different doses: control, 0.5, 1, 1.5 and 2 kGy for the analysis of color, texture, sensory and microbiological shelf life. For analysis of phenolic compounds and resveratrol were radiated only at doses: control, 1.5 and 3 kGy. With the results it was found that doses of 0.5, 1.5 kGy grape variety Benitaka have been accepted well both in sensory and shelf life tests. Samples of raisins had no variation in this analysis. No microbial growth was found and after treatment with radiation it was possible to prove the presence of resveratrol in all samples. (author)

  17. Assessment of ionizing radiation as a risk factor for breast cancer incidence in Goiania; Avaliacao da radiacao ionizante como fator de risco para a incidencia de cancer de mama em Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Lage, Leonardo Bastos

    2016-11-01

    This research aims to evaluate whether exposure to ionizing radiation to which women are subjected can be associated with the incidence of breast cancer in Goiania. The defined study area is the central region of Goiania, or the Sanitary Districts of Campinas-Centro and Sul, in which are the seven major accident sources of contamination with Cesium 137, and also, as shown by previous study, the majority of new cases of breast cancer (60,43 %). We used the geographical division of the city in census tracts and health districts. The data collection was divided in two stages: the first, for the survey of radiometric measurements, and the second, for identifying the addresses of women diagnosed with breast cancer. The radiometric survey occurred between 2010 and 2014, in which was used an environmental gamma radiation mobile measuring system. This system was composed by a high-sensitivity detector coupled to a Global Positioning System (GPS) and a microcomputer. The assembly was installed on a motor vehicle so that the height of the detector is found at one meter from the ground, and programmed to obtain a measurement of the doses absorbed in the air rate each second. The data collected were: doses absorbed in the air rate, geographical coordinates, altitude, date and time of acquisition. From Mobisys software, files were generated and from ArcGIS 10.0 platform, geospatial assessment survey through the elaboration of thematic maps and geospatial analysis statistics. The annual averages of effective doses and collective effective doses were estimated from the rate of doses absorbed in air collected by the system and the resident population in the census tracts. The second stage begun from the data collection at the Registry of Goiania's Population Based Cancer (RCBPGO), in which were identified addresses of women diagnosed with breast cancer between 2001 and 2010. Part of the data was geographically referenced and using census data were estimated and compared the annual averages of crude rates of incidence. The spatial correlation of groups (clusters) of new cases has been verified, through the Moran index, and from geographically referenced radiometric measurements obtained in the previous step, the correlation between the incidence of breast cancer and ionizing radiation levels was assessed by unconditional linear regression. The results were presented in two papers. In the first, radiometric surveys were conducted in 1.405 of the 1.636 (85,9%) census tracts sectors that make up the seven Sanitary Districts in the city of Goiania. In total 197.811 geographically referenced measures of the absorbed dose rate in the air were made, with a average of 29,85 ± 7,47 and amplitude from 9,17 to 629,88 nGy/h. From these values were estimated the average of annual effective dose and collective effective dose for outdoor environments, with values of 0,036 ± 0,003 mSv/year and 28,51 ± 11,68 man.mSv/year, respectively. The levels of exposure to external gamma radiation, found in the city of Goiania 28 years after the radiological accident with Cesium-137, are compatible with the values estimated by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation). And the value of the annual average of effective dose in Goiania, is lower than in other places in Brazil, which have only 'background' of natural radiation outdoors. The results obtained in this study indicate that the dosimetric situation in Goiania does not present undue risk to people and the environment. In the second article, were identified 4.105 new cases of breast cancer, 2.233 in the study area and 1.286 (57,59%) of these geographically referenced. The annual average values of crude rates of incidence, considering the total numbers of cases and geographically referenced presented in the study area are, respectively, 102,91 and 71,86 new cases per 100.000 women. The crude rate of incidence in Goiania was 66,59 cases per 100.000, while in the study area was 102,91 cases per 100.000 and, outside the area, 46,86 ca ses per 100.000. These value s are within the range of average values presented by other Brazilian capitals, which is 130,99 cases per 100.000 in Porto Alegre-RS, and 20,04 cases in Macapa/AP, and the national average in the capital of 79,37 cases per 100.000 women. The cluster analysis showed a slight spatial correlation of crude rates of breast cancer incidence in three small sets of census tracts, far from the accident sources of contamination with Cesium-137. The scatter plot points and the R{sup 2} value did not indicate any association between the crude rates of incidence and radiometric measurements. This study supports the hypothesis that ionizing radiation levels to which women living in Goiania are exposed, are not associated with the emergence of new cases of breast cancer. (author)

  18. Biodegradability and aging study of rubber films obtained by gamma radiation vulcanization processes of latex; Estudo da biodegradabilidade e envelhecimento de filmes de borracha obtidos por processos de vulcanizacao do latex por radiacao induzida de fonte gama

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Carlos Felipe Pinto

    2005-07-01

    The natural rubber latex (NRL) is industrially crosslinked by the conventional process of vulcanization, which uses sulphur and heat. Otherwise, the network can also be done by the alternative process with ionizing radiation. In this work the crosslinking of NRL was studied by the comparison of the conventional vulcanization system and the ionizing radiation process of {sup 60}C source. The products obtained, the irradiated latex, the irradiated latex with approximately 1% of soy lecithin and the sulphur vulcanized latex were tested by accelerated aging with ultraviolet (UV) and outdoor aging with compostage, tensile strength at break, swelling and gel fraction, fungi micro biota, scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry analysis (TG and DSC). The results showed that the aging with microorganisms have a great influence in the physical properties of the samples. The thermal stability order observed showed that the sulphur vulcanized latex is more resistant, what is probably associated to a network more stable under the aging conditions. On the other hand, the irradiated latex showed intense biodegradation aspects, particularly with the presence of the soy lecithin. (author)

  19. Application of gamma irradiation for incorporation of rubber powder in the formulations of EPDM and natural rubber; Aplicacao da radiacao gama para incorporacao do po de borracha em formulacoes de borracha natural e EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP/CQMA), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente

    2013-07-01

    The objective of this work was to study the behavior of the recycling of rubber burrs in form of powder, of the rubber industry from EPDM rubber powder and natural rubber with SBR. The rubber powder was irradiated and reused in rubber artifacts formulations for classical vulcanization. The processed material was irradiated using a {sup 60}Co source in doses of 50, 100, 150 and 200 kGy and a dose rate of 5 kGy s-1 at room temperature. The radiation created devulcanization active sites for subsequent integration of the material (rubber powder) in formulations of commercial use. The processes were compared and their products characterized by analytical methods of the physical properties such as strength and elongation. Satisfactory results were found, noting a major spin-off of EPDM chain demonstrated by increased elongation.

  20. Gamma radiation effects on the frequency of toxigenic fungus on sene (Cassia angustifolia) and green tea (Camelia sinensis) samples; Efeito da radiacao gama na frequencia de fungos toxigenicos em amostras de sene (Cassia angustifolia) e cha verde (Camellia sinensis)

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, S.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes]. E-mail: siaq06@hotmail.com; Reis, T.A.; Zorzete, P.; Correa, B. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia; Goncalez, E.; Rossi, M.H. [Instituto Biologico, Sao Paulo, SP (Brazil)

    2006-11-15

    The levels of contamination and gamma radiation effects were analyzed in the reduction of toxigenic filamentous fungus in two types of medicinal plants. Aspergillus and Penicillium were the predominant genders and 73,80% of the samples showed high levels of fungus contamination.

  1. Implantation of radiation qualities for mammography in accordance with the IEC 61627 and TRS 457 criteria; Implantacao das qualidades de radiacao para mamografia, segundo os criterios da IEC 61627 e do TRS 457

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Evandro J.; David, Mariano G.; Almeida, Carlos Eduardo de, E-mail: pires@lcr.uerj.b [Universidade do Estado do Rio de Janeiro (LCR/UERJ), RJ (Brazil). Lab de Ciencias Radiologicas; Peixoto, J. Guilherme, E-mail: guilhem@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In this work it is discussed the technical conditions of the implantation of radiation qualities adequate for dosemeter applied to mammography at the Radiological Science Laboratory (RSL) of the University of State of Rio de Janeiro, Brazil. It performed tests for evaluation the homogeneity of the radiation field, the scattering, the half-layers and the system stability. The test results point for adequacy of the laboratory installed at the LCR for calibration of the mentioned dosemeters in seven qualities of radiation and the expanded uncertainty with better capacity of measurement at those qualities was of {+-}1.8% (k = 2)

  2. Influence of gamma radiation on carbohydrates metabolism of ripening papaya (Carica papaya L. cv. Solo); Metabolismo de carboidratos durante o amadurecimento do mamao (Carica papaya L. Cv. Solo): influencia da radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, M.L.P.A. [Universidade de Sao Paulo (FCF/USP), SP (Brazil). Fac. de Ciencias Farmaceuticas; Lajolo, F.M.; Cordenunsi, B.R. [Universidade de Sao Paulo (FCF/USP), SP (Brazil). Fac. de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental

    1999-05-15

    Food irradiation is one of the most promising treatments that can be utilized for fruits disinfestation and extension of shelf life. The authors studied the influence of 0,5 kGy of Gamma irradiation on the soluble carbohydrates composition of papaya (Carica papaya L. cv. Solo) fruit, and on sucrose metabolizing enzymes: sucrose synthase (SS), sucrose-phosphate synthase, acid and neutral invertases activities, during ripening. The results demonstrated that ethylene production, total soluble sugars, sucrose content, and sucrose-phosphate synthase and invertases activities were affected by irradiation, but not respiration, glucose and fructose content, and SS activity. (author)

  3. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation; Estudo da sensibilidade in vitro de diferentes cepas de Vibio cholerae 01 a radiacao gama de 60Co

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ivany Rodrigues de [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Servicos de Saude; Gelli, Dilma Scala; Jakabi, Miyoko [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Microbiologia; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@net.ipen.br

    1998-07-01

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of {sup 60} Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  4. Determination of gamma radiation dose for destruction of Salmonella spp. in chicken flesh.; Determinacao da dose de radiacao gama para a destruicao de Salmonella spp. em carne de frango

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    Santos, Andreia Ferreira dos

    1997-07-01

    The aim of this study was to determinate: 1) the radio sensibility of Salmonella typhimurium ATCC 14028 in soy trypticase broth; 2) the radio sensibility of Salmonella typhimurium ATCC 14028 in chicken thigh and; 3) to recommend a radiation dose which can be non hazardous for human consumption

  5. Effect of ionizing radiation on the oxidation of cholesterol in frozen chicken and beef hamburgers;Efeito da radiacao ionizante sobre a oxidacao do colesterol em hamburgueres de frango e bovino congelados

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Andrea Figueiredo Procopio de

    2004-07-01

    Several technologies have been developed to assure food quality. Among these technological processes, ionizing radiation has been described as a feasible alternative for food conservation, mainly for meat products, since it keeps their natural properties. In hamburgers, the use of irradiation has been studied due to the frequent implication of such products in outbreaks of food-borne diseases. Some of the outbreaks, which even killed consumers, were caused by E. coli O157:H7. But the use of ionizing radiation in hamburgers may form free radicals able to trigger lipid oxidation in the muscle tissue. As a component of the cell membrane lipids, cholesterol may also undergo oxidation and form biologically active compounds, with atherogenic, mutagenic, cytotoxic and cancerous properties. The aim of this work was to evaluate the occurrence of cholesterol oxidation products in chicken hamburgers and beef hamburgers submitted to irradiation and stored frozen, aerobically and under vacuum. The results showed that irradiation caused an increase of around 11% in the concentration of cholesterol oxides in frozen hamburgers. In chicken hamburgers, an increase in the levels of cholesterol oxides was observed ali over the storage period, while in beef hamburgers it was observed only in the final part of the storage period. Packaging itself did not have a significant effect on the concentrations of cholesterol oxides in either of the types of hamburgers studied. However, it showed a significant interaction with irradiation, that is, vacuum packaging prevented the formation of cholesterol oxides in irradiated beef hamburgers. (author)

  6. Study on ionizing radiation effects in diesel and crude oil: organic compounds, hydrocarbon, sulfur and nitrogen; Estudo do efeito da radiacao ionizante em compostos organicos do diesel e do petroleo: hidrocarbonetos, sulfurados e nitrogenados

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Luana dos Santos

    2014-07-01

    Petroleum is the most important energy and pollution source in the world, nowadays. New technologies in petrochemical industry aim to minimize energy spending at the process and to reduce pollution products. Sulfur and nitrogen compounds generate environmental problems; the most relevant is air pollution that affects the population health directly. The nuclear technology has been used in environmental protection through pollutants removal by free radicals produced at action of the radiation in water molecule. The objective of this study is to evaluate the radiation effects on oil and diesel, mainly in the hydrocarbons, organic sulfur, and nitrogen compounds. It was studied a molecule model of sulfur, named benzothiophene, diesel and crude oil samples. The samples were irradiated using a Co-60 source, Gammacell type. The total sulfur concentration in the samples was determined by X-ray fluorescence spectrometry, and organic compounds were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The study of molecular model showed that 95% was degraded at 20 kGy dose rate. Irradiation at 15 kGy of absorbed dose showed some cracking in petrol hydrocarbons, however with higher doses it was observed polymerization and low efficiency of cracking. It was observed that the sulfur compounds from diesel and petroleum was efficiently reduced. The applied doses of 15 kGy and 30 kGy were the most efficient on desulfurization of petroleum, and for diesel the highest variation was observed with 30 kGy and 50 kGy of absorbed dose. The distillation and chromatographic separation using an open column with palladium chloride as stationary phase showed a preferential separation of organic sulfur compounds in petroleum. (author)

  7. Gamma radiation effects of {sup 60} Co on Bombyx mori (Lep., Bombycidae) modifying the silk fiber production; Influencia da radiacao gama ({sup 60} Co) na producao de fios de seda em Bombyx mori(Lep.,Bombycidae)

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro Junior, Francisco [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil); Bendassolli, Jose A. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1997-12-01

    The present work aimed to verify the biological effects of the application of different doses of gamma radiation during the fifth instar of the silkworm catepillar. Sevently eight silkworm caterpillars (Bombyx mori) were irradiated with {gamma}{sup 60} Co radiation at the initial period of the fifth instar. The caterpillars were divided and classified in six batches of thirteen individuals each. Treatments 1 through 5 received 20, 40, 60, 80 and 100 Gy, respectively, and the control, also consisted of thirteen caterpillars, was not irradiated. The results showed a general increase in the silk fiber content in the irradiated batches compared to the control. The weight of the silk cocoons was higher with increasing doses of irradiation, from 20 to 80 Gy, respectively, followed by a decrease in weight in the treatment irradiated with 100 Gy. the results obtained in this experiment enable the conclusion that the radiation applied to the caterpillars significantly influenced the production of silk fiber in this species. (author). 4 refs., 2 figs., 3 tabs.

  8. Study of ionizing radiation effects in human costal cartilage by thermogravimetry and optical coherence tomography; Estudo dos efeitos da radiacao ionizante em cartilagem costal humana por meio de termogravimetria e tomografia por coerencia optica

    Energy Technology Data Exchange (ETDEWEB)

    Martinho Junior, Antonio Carlos

    2012-07-01

    Tissue Banks around the world have stored human cartilages obtained from post mortem 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. In this work, we evaluated the possibility of use Optical Coherence Tomography (OCT) and Thermogravimetric Analysis (TGA) to identify possible structural modifications caused by both preservation methods of cartilage and gamma irradiation doses. Cartilages were obtained from cadaveric donors and were frozen at -70 deg C or preserved in glycerol. Irradiation was performed by {sup 60}Co source with doses of 15, 25 and 50 kGy. Our TGA results showed that glycerolized cartilages irradiated with different doses of radiation does not presented statistical differences when compared to the control group for the dehydration rate. However, the same was not observed for deep-frozen cartilages irradiated with 15 kGy. The results of OCT associated to total optical attenuation coefficient showed that doses of 15 kGy promote cross-link between collagen fibrils, corroborating the results obtained from TGA. Moreover, total optical attenuation coefficient values are proportional to stress at break of cartilages, what will be very useful in a near future to predict the quality of the allografts, without unnecessary loss of biological tissue, once OCT is a nondestructive technique. By PS-OCT images, we found that high doses of ionizing radiation does not promote sufficient impairments to promote complete loss of tissue birefringence. Thus, TGA and OCT are techniques that can be used for tissue banks to verify tissue quality before its transplant. (author)

  9. Study of the combined action of gamma radiation and static electric fields in human cells; Estudo da acao combinada de radiacao gama e campo eletrico estatico em celulas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Moron, Michelle Mendes

    2008-07-01

    The basic principle of radiotherapy is the one of maximizing damage to the tumor, while minimizing it in neighboring health tissues. Several strategies have been worked out aiming at increasing cellular radiosensitivity, and among them is the use of exogenous fields. Our goal in this work is the study in human cells of the effect resulting from the association of irradiation with exposure to exogenous static electric fields. The T47D cell line of breast cancer cells was irradiated with gammas in the 0 - 8 Gy doses range. The corresponding survival curve provided information on the radiosensitivity of this cell line. The rate of cell deaths per Gray in the 0 - 8 Gy range exhibited a maximum at 2 Gy, which corresponds to the most efficient irradiation dose. The viability of this T47D cells exposed to both gamma radiation and 1.250 V/cm static electric field (SEF) was about 12% lower than when only irradiated. The sole exposure of the cells to SEF by 24 and 72 hours didn't induce toxicity. Immunofluorescence runs carried out in irradiated normal MRC5 cell line of human lung fibroblast, without and with exposition to a SEF, have quantified the expression of the y- H2AX histone. The amount of phosphorylated histones was approximately 40% higher after irradiation with 2 Gy plus exposure to a SEF by 1 hour, showing that the electric field negatively interfered in the repairing process of the DNA double strand breaks. The flow cytometry analysis with FACS allowed the investigation of a possible interference of radiation and SEF in the cell distributions among the cellular cycle phases. It was found that in T47D cells treated with 1 and 2 Gy by 24 hours the SEF also negatively interfered in the DNA repairing process, as evidenced by the higher accumulation of cells in the S phase. Therefore, it would be possible to conclude that static and exogenous electric fields are able of negatively interfering in the cellular repair and, presumably, in DNA repair. (author)

  10. Effects of gamma radiation and packaging on conservation of toyonoka strawberries stored under refrigeration.; Efeito da radiacao gama e embalagem na conservacao de morangos 'toyonoka' armazenados sob refrigeracao

    Energy Technology Data Exchange (ETDEWEB)

    Domingues, Danielle Marinelli

    2000-07-01

    Strawberries have short post harvest life due to the rapid spoilage caused by fungal infections, even when stored under refrigeration. The effects of gamma radiation (0.0, 1.5, 2.0 and 2.5 kGy) and two kinds of packages (plastic boxes with or without PVC film wrapping) were evaluated using Toyonoka strawberries kept under refrigeration (3 to 6 deg C and relative humidity of 55%) for 1, 8, 15 and 22 days after irradiation, applied 1 day after harvesting. Deterioration progression and loss of weight occurred in the course of storage and although the content of ascorbic acid had also increased, total titratable acidity, p H and ratio remained constant during all the experimental period, independent of the samples treatments. The use of PVC film packing inhibited dehydration of the strawberries along the storage and also caused reduction in soluble solid content of the fruits stored for more than 8 days. The treatments with 2.0 and 2.5 kGy had caused significant losses of ascorbic acid the higher dose also significantly reduced the texture of the fruits. Sensorial analysis has been performed with 30 untrained judges to evaluate the acceptability of strawberries packed without the PVC wrapping and irradiated with doses of 0.0, 1.5 or 2.0 kGy. No irradiation effects were observed and the samples were acceptable with no significant difference between samples stored for 1 or 8 days after irradiation. PVC film packaging and irradiation were not efficient in delaying post harvest decay of Toyonoka strawberries in the conditions used in these experiments. (author)

  11. Effects of gamma radiation and electron beam on samples of the Brazil nuts artificially inoculated with Aspergillus flavus; Efeitos da radiacao gama e feixe de eletrons sobre amostras de castanhas-do-Brasil inoculadas artificialmente com Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Ednei Assuncao Antunes

    2012-07-01

    The high level of contamination by aflatoxin produced by fungi in lots of Brazil nuts and the strict control by importing countries in relation to the levels of toxins in food, European Union countries decided in 2003 by the return of these lots products from Brazil. Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded that although sensory analysis have demonstrated some loss of organoleptic characteristics, both processes of radiation were effective in reducing the count of A. flavus and aflatoxin contamination. (author)

  12. Influence of gamma radiation on the antioxidant action extracts from leaves of gross Anacardium occidentale Linn; Influencia da radiacao gama na acao antioxidante de extratos brutos de folhas de Anacardium occidentale Linn.

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo Henrique Farias dos; Silva, Edvane Borges da; Amaral, Ademir de Jesus [Universidade Federal de Pernambuco (GERAR/DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia; Lima, Claudia Sampaio de Andrade [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia

    2014-07-01

    Anacardium occidentale Linn. is popularly known as cashew plant, found in Northeastern Brazil, is of great scientific interest because it contains high levels of bioactive compounds, such as polyphenols, flavonoids and tannins, which characterize their applications as natural antioxidants, which can contribute to protect against oxidative processes in the human body. This study aimed to evaluate the effects of {sup 60}Co gamma irradiation in the antioxidant action of the extracts of leaves of A. occidentale. The extracts of A. occidentale were extracted with 70% ethanol, evaporated under reduced pressure and divided into samples control and irradiation at 10 kGy. Subsequently analyzing the kidnapping of radical DPPH (concentrations of 6.25; 12.5; 25; 50; 100 and 200 ppm) and reducing power (concentrations of 25; 50; 100; 200; 400; 600; 800 and 1000 ppm). The results showed increased antioxidant actions dependent on the concentration and dose of 10 kGy in both assays. However, the kidnapping of DPPH activity showed variations from 50% to 92% for control, and 75% and 100% for irradiated. It is observed that the irradiated samples showed maximum activity (100%) in a 4-fold lower concentration (50 ppm) than the control samples. Featuring EC{sub 50} of standards BHT (235.8%) and vitamin C (63.5%) was very low compared with control extracts (8.1%) and irradiated (0.48). However the results obtained in this study indicate that extracts of leaves of A. occidentale irradiated at a dose of 10 kGy exhibit strong antioxidant activity against DPPH and power reducer, this paves its use as a natural source of antioxidants.

  13. Study of stability of humic acids from soil and peat irradiated by gamma rays; Estudo da estabilidade de acidos humicos extraidos de solo e turfa, frente a radiacao ionizante gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Wilson Tadeu Lopes da

    1995-07-01

    Humic acids samples (one deriving from a sedimentary soil and other from a peat), in aqueous media, were irradiated with gamma rays, in doses of 10, 50 and 100 kGy, in order to understand their chemical behavior after the irradiation. The material, before and after irradiation, was analyzed by Elemental Analysis, Functional Groups (carboxylic acids and phenols), UV/Vis Spectroscopy (E{sub 4}/E{sub 6} ratio), IR spectroscopy, CO{sub 2} content and Gel permeation Chromatography (GPC) ). The Elemental Analysis showed the humic acid derived from a peat had a most percentage quantity of Carbon and Hydrogen than the material from a sedimentary soil. From the UV/Vis Spectroscopy, it was observed a decrease of E{sub 4}/E{sub 6} ratio with an increase of the applied dose. The data from GPC are in agreement with this. The results showed that the molecular weight of the material increased by exposing it to a larger radiolitical dose. The peat material was less affected by the gamma radiation than the soil material. The carboxylic groups were responsible by radiochemical behavior of the material. (author)

  14. Effect of gamma irradiation in the viscosity of gelatin and pectin solutions used in food industry; Efeito da radiacao gama sobre a viscosidade de solucoes de gelatina e pectina utilizadas na industria de alimentos

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Yoko

    2008-07-01

    Pectin is a polysaccharide substance of plant origin that may be used as gelling agent, stabilizer in jams, in yogurt drinks and lactic acid beverages. Gelatin, a protein from bovine origin, in this case, is mainly used as gelling agent due to hydrogel formation during cooling. The {sup 60} Co-irradiation process may cause various modifications in macromolecules, some with industrial application, as reticulation. The dynamic response of viscoelastic materials can be used in order to give information about the structural aspect of a system at molecular level. In the present work samples of pectin with different degree of methoxylation, gelatin and the mixture of both were employed to study the radiation sensitivity by means of viscosity measurements. Solutions prepared with citric pectin with high methoxylation content (ATM) 1 por cent, pectin with low content (BTM) 1 por cent, gelatin 0.5 por cent, 1 por cent and 2 por cent, and the mixture 1 por cent and 2 por cent were irradiated with gamma rays at different doses, up to 15 kGy with dose rate about 2 kGy/h. After irradiation the viscosity was measured within a period of 48 h. The viscosity of ATM and BTM pectin solutions decreased sharply with the radiation dose. However, the gelatin sample presented a great radiation resistance. When pectin and gelatin solutions were mixed a predominance of pectin behavior was found. (author)

  15. Gamma radiation effect on tocopherol content in natural and industrialized products and sensory evaluation; Efeito da radiacao gama sobre o conteudo de tocoferois em produtos naturais e industrializados e avaliacao sensorial

    Energy Technology Data Exchange (ETDEWEB)

    Taipina, Magda Sinigallia

    2009-07-01

    Vitamin E content, the percentage of activity retention and the sensory characteristics were analyzed in samples of vitamin E rich foods: pecan nuts, whole grain cookies and a fortified powder formula irradiated with 1 and 3 kGy of {sup 60}Co gamma radiation. For the vitamin E determination (as -tocopherol equivalents) three different samples lots were employed using the colorimetric method standardized by the Instituto Adolfo Lutz of Sao Paulo. For sensory analysis, the Multiple Comparison or Control Difference Test was used for all products, comparing the irradiated samples to the non-irradiated controls and measuring the difference rate in total terms, concerning appearance, odor, texture and flavor, in a category scale of 9 points, ranging from 1 = no difference to 9 = extreme difference to the control. The experimental outline employed was that of randomized complete blocks design, in two consecutive sessions. The obtained data were submitted to variance analysis, ANOVA, and means comparison by Dunnett test, at 5% significance. The results show that there was no E vitamin loss in the pecan nuts, whole grain cookies and powder food samples, irradiated with 1 and 3 kGy doses. With regard to the sensory analysis, the 3 kGy gamma irradiation produced significant changes in the sensory properties of pecan nuts for the attributes: appearance, odor, texture and flavor. The 1 kGy dose did not cause a significant difference for these attributes. Concerning the sensory analysis of whole grain cookies and fortified powder food, significant differences were observed in all the irradiated products, although the difference grades were significantly low, compared to those of the non-irradiated samples, especially when 1 kGy dose was applied. (author)

  16. Shelf-life increase of fresh mushrooms Pleurotus sajor-caju using gamma radiation;Aumento da vida util de cogumelos Pleurotus sajor-caju in natura com aplicacao de radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Moda, Evelise Moncaio

    2008-07-01

    The production and consumption of edible mushrooms has been increasing in the last years due to its nutritional composition and sensory quality. The irradiation of mushrooms has been used with the purpose of maintaining the fresh product characteristics during shelf-life. The present study evaluated the effect of different radiation doses on the conservation of mushrooms Pleurotus sajor-caju, through by chemical, physical, microbiological and sensorial parameters. The packaging consisted on polystyrene trays with 250 g of sample, wrapped in polyvinyl chloride (PVC). The mushrooms were irradiated with doses of 125, 250, 500 and 750 Gy in a Gamma cell 220 type irradiator, and stored at 4 +- 1 deg C and 90% UR for 10 days. The proximate composition (moisture, crude fibre, total protein, total fat and ash), total soluble solids, pH, texture, color (L, a, b, Chroma and ho), enzymatic activity (polyphenoloxidase and peroxidase), microbiological (total coliform, Escherichia coli and total psychotropic bacteria) and sensory evaluation (color, taste and appearance) were determined in the 1st, 5th and 10th storage days. For the respiratory rate analysis, 30 g of sample were placed in jars and stored at 4 +- 1 deg C and 90% UR for 8 days. CO{sub 2} was analyzed every day using a gaseous chromatograph. The results were submitted to variance analysis and average test using the SAS statistical package. The total protein and total fat values did not differ significantly between treatments or storage periods, while the moisture, crude fibre and ash values differ between treatments and periods. The dose of 750 Gy darkness the mushroom in the last evaluation, and texture was better in control during the storage period. The color (L, a), texture and proximate composition values did not differ significantly between treatments or storage periods. A significant increase was observed for soluble solids, b{sup *} and enzymatic activity values in all treatments at the end of the storage period. Values of polyphenoloxidase and peroxidase activities increased in the last day of evaluation in samples irradiated with 250 Gy. This fact may be a result of the water radiolysis process, since mushrooms have high water content. The dose of 125 Gy increased the respiratory rate of the samples until the 5th storage day in comparison to the other treatments, causing reduction in the product shelf-life. The samples irradiated with 250, 500 and 750 Gy had a reduction on the respiratory rate if compared with the control, so contributing to the maintenance of the post harvest quality during the storage. The samples which received 750 Gy obtained the best results in the microbiological analyses, with reduction of total coliform and psychotropic bacteria during the storage period. Sensory analyses showed that the control had higher scores for color, aroma and appearance attributes; they were above the acceptability limit until the last storage day. In general, the irradiated samples were accepted for the evaluated attributes until the 5th storage day; thus, establishing the shelf-life for irradiated mushrooms (author)

  17. Evaluation of occupational radiation dose in nuclear medicine: radiopharmaceutical administration to scintiscanning exams of myocardial perfusion; Avaliacao da dose de radiacao ocupacional em medicina nuclear: administracao de radiofarmacos em exames de cintilografria de perfusao miocardica

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Cassio V., E-mail: cassiok@yahoo.com [Medicina Nuclear do Triangulo (MNT), Uberlandia, MG (Brazil); Michelin, Charlie A.; Jakubiak, Rosangela R., E-mail: charlie@utfpr.edu.br, E-mail: requi@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Lemes, Alyne O.; Silva, Juliana L.M., E-mail: alyne275@gmail.com, E-mail: jujumontesdocinho@gmail.com [Faculdade do Trabalho (FATRA), Uberlandia, MG (Brazil)

    2013-11-01

    In nuclear medicine, workers directly involved in exams are constantly exposed to ionizing radiation. The procedure for administration of the radiopharmaceutical to the patient is one of the most critical times of exposure. In tests of myocardial perfusion scintigraphy (MPS) administration of radiopharmaceutical repeats the steps of rest and cardiac stress. In this study, we used a Geiger -Mueller detector for measuring occupational radiation doses for during the administration of technetium- {sup 99m}- sestamibi in MPS tests. In the evaluation, discriminated the stages of examination and related professional experience time to doses measures at home. It were followed 110 procedures at home (55 conducted by professionals with over 5 years experience and 55 conducted by professionals with less than 1 year of experience) and 55 effort procedures. The results showed that the rest of the procedure time and dose are related to the experience of the worker. More experienced workers were faster (mean: 43 {+-} 16 vs 67 {+-} 25 seconds / procedure), and therefore received lower doses (mean 0.57 {+-} 0.16 versus 0.80 {+-} 0.24 {mu}Sv / procedure), both with statistical significance (p <0.001). In step effort, there were procedures lasting longer (mean: 19 {+-} 2 minutes / procedure), which resulted in higher doses (mean 3.0 {+-} 0.6 {mu}Sv / procedure)

  18. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages; Avaliacao do mecanismo de captacao e endocitose de crotoxina submetida a acao da radiacao, por macrofagos peritoneais de camundongos

    Energy Technology Data Exchange (ETDEWEB)

    Cardi, Bruno Andrade

    1999-07-01

    The purpose was to investigate the uptake and endocytosis of 2000 Gy {sup 60}Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy {sup 60} Co {gamma}-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays ({sup 60} Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  19. Study of radiation detectors response in standard X, gamma and beta radiation standard beams; Estudo da resposta de monitores de radioprotecao em feixes padronizados de radiacao X, gama e beta

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda Beatrice Conceicao

    2010-07-01

    The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ({sup 37}Cs and {sup 60}Co), and some of them were tested in beta radiation ({sup 90}Sr+{sup 9'}0Y e {sup 204}Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author)

  20. Toxoplasma gondii vs ionizing radiation: intestinal immunity induced in C57bl/6j mice by irradiated tachyzoites; Toxoplasma gondii vs radiacao ionizante: estudo da imunidade intestinal em camundongos C57Bl/6j experimentalmente vacinados com taquizoitos irradiados

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    Galisteo Junior, Andres Jimenez. E-mail: galisteo@usp.br

    2004-07-01

    We study the oral route for the development of a vaccine for toxoplasmosis, using parasites irradiated with 60 Cobalt, as an alternative for vaccine development to this worldwide parasitic infection. We evaluated the development of immunity at serum or mucosal levels, and their efficiency in protect the mice against challenge with oral cysts of the Me-49 strain. C57Bl/6j isogenic mice were immunized by oral route with 107 255 Gy irradiated tachyzoites from RH strain, at several protocols using milk as anti-peptic adjuvant and alum hydroxide as antacid. The preparations of irradiated tachyzoites induced production of serum IgG and IgA in immunized mice, as determined by ELISA, with IgG2a as the dominant subclass, similar to chronic infection. Their use with adjuvant allowed the excretion of significant amounts of IgA in stools also IgG, despite a lesser extent. There are suggestion of tolerance induction at mucosal level, with lower antigen induced proliferation and lower in vitro antibody production by spleen and gut lymphocytes, with the latter doses, specially when milk was used as adjuvant. All oral preparations induced some quantitative protection against challenge, which was similar to the parenteral route only isolated alum hydroxide was used as adjuvant. All these data support the possibility of the development of an oral vaccine against toxoplasmosis, using irradiated tachyzoites, which would be possible tool in near future for use in field baits, for immunizing either domestic or wild felines. (author)

  1. Study on the stability of the Maytenus aquifolium Martius chemical components submitted to ionizing radiation (X-ray and {gamma}); Estudo da estabilidade dos componentes quimicos de Maytenus aquifolium Martius frente a radiacao ionizante (X e {gamma})

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Patricia

    1995-07-01

    The interest for medicinal plants has raised again in the last decades, after overcoming a declination period caused by the advances in the researches and development of the synthetic drugs industries. This growing interest has been stimulated mainly by searching cheap and accessible alternative therapies. However, in order to have natural products based treatment in an efficient and safety way, it is necessary to guarantee the plant authenticity, finding adulterations and to assure a low level of microbiological contaminations to avoid damages to consumer's health. The decontamination method should be chosen for eliminating or reduce the microorganisms level without loss of the plant active constituents that would destroy its therapeutic action. At the present work, the possibility of using {gamma} and X electromagnetic radiations to sterilize a Brazilian medicinal plant (Maytenus aquifolium Martius, Celastraceae), which shows anti-ulcer activity, was studied by accomplishing its actives constituent behavior, the triterpenes friedeline and friedelan-3-ol and the phenolic compounds by spectrophotometric techniques (UV-Vis.), high resolution gas chromatography (HRGC) and high resolution gas chromatography coupled to mass spectrometry (HRGC-MS). (author)

  2. Measures and modelling of PAR (photosynthetically-active radiation) for the Northeast of Brazil; Medidas e modelagem da radiacao PAR (photosynthetically-active radiation) para o nordeste do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Tiba, Chigueru; Leal, Sergio da S.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], e-mail: tiba@rce.neoline.com.br

    2004-07-01

    Photosynthetically active solar radiation, known by its acronym in the English language as PAR, is the principal driving force of innumerable biological and physical processes related to biomass production, such as, the evolution of vegetal covering, agricultural productivity, and countless environment aspects, among others. Unfortunately in Brazil and particularly in the Northeast of Brazil, the PAR radiation measures are not a routine part of meteorological station measures, and therefore are still rarer than solar irradiation measures. In this context, a station was installed in Recife, Pernambuco in 2003, to carry out simultaneous measures of daily solar irradiation and PAR irradiation, which permits the modelling and valuation of the relationship between these two parameters and thus makes the estimation of PAR radiation possible, where there used to be only information on solar irradiation. Three others stations are being installed, one on Fernando de Noronha-PE, another in Pesqueira-PE, and the other in Xingo-SE, which complete a group of 4 between Latitudes 8 deg and 10 deg South and Longitudes 34 deg to 38 deg West, each having differentiated Equatorial Climates: island maritime, continental maritime, sylvan (Agreste) and semi-arid. (author)

  3. Effect synergistic of the radiation and of the refrigeration in the conservation of the white shrimp (Litopenaeus vannamei);Efeito sinergistico da radiacao gama e de refrigeracao na conservacao do camarao-branco-do-pacifico (Litopenaeus vannamei)

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes-Lopes, Tatiana Giselle

    2006-07-01

    Taking into account shrimp susceptibility to autolise and bacterial decomposition, this study aimed to evaluate the different gamma irradiation doses influence over meat quality related to microbiological, physical-chemical, nutritional and sensorial aspects, during cold storage of the white shrimp (Litopenaeus vannamei). Samples were taken from fresh shrimps without cephalothoraxes, settled into polystyrene trays, packed with flexible plastic film and submitted to different doses of gamma irradiation (1.0 and 3.5 kGy). Samples were kept under refrigeration (5 deg C) and analyzed at the 1st, 7th, 14th and 21st day of storage. Microbiological analyzes were realized (Coagulase-positive Staphylococcus, Salmonella ssp, coliforms, psychotropic and mesophilic population), and physical-chemical and tests (Total volatile bases (TVNB), pH, non proteic nitrogen (NNP), TBARS analysis - reactive substances to thiobarbituric acid (TBA), trimetil amine (TMA) cholesterol tenor and proximate composition). Instrumental color test were realized and hedonic test was taken to determine cooked products sensorial quality during storing period. It was noticed that the irradiation process reduced bacterial population and during storage all the irradiated samples were under the patterns established by the Brazilian legislation (Brazil, 2005a). Non-irradiated samples were inappropriate for consumption after one week of storage, since they were over Staphylococcus established limits. The pH values ranged from 6.05 to 6.39; 19.47 to 80.84 mg.100g-1 for TVNB; 2.61 to 12.85 mg.100g-1 for TMA-N; 0.22 a 1.20 mg of malonaldeide.1000g{sup -1} for TBA and 53.09 to 134.81 mg.100g-1 for cholesterol concentrations. Irradiated samples kept more stability during storage period when compared to non-irradiated samples, regarding to pH, TVNB and TMA levels. Samples irradiation resulted into cholesterol and TBA values reduction at different evaluated moments. No significant differences (p <= 0.05) were found in terms of instrumental color during the first day of storing when compared to the non-irradiated samples and to the 3.5 kGy irradiated ones. Statistical differences were not found (p <= 0.05) between non-irradiated and irradiated samples within the first day of sensorial analysis. Non-irradiated samples were rejected on the sensorial test after the 7th day of storage, while the 1kGy irradiated samples were accepted until the 14th day. Samples irradiated with 3.5 kGy kept viability in terms off flavour and aspect until the end of the experiment. When compared to conventional refrigerated product, the gamma-irradiation technique, (especially the 3.5 kGy doses) provided a higher stability related to physical chemical properties and microbiological safety during storage. No differences on the sensorial shrimp quality were found. Through gamma irradiation, we obtained a product with minimal procedure modifications, with enhanced shelf life under refrigeration. (author)

  4. The benefits of prone SPECT myocardial perfusion imaging in reducing both artifact defects and patient radiation exposure; Beneficio da aquisicao de imagem na posicao Prona em perfusao miocardica com SPECT para reducao de artefatos e exposicao do paciente a radiacao

    Energy Technology Data Exchange (ETDEWEB)

    Stathaki, Maria; Koukouraki, Sophia; Papadaki, Emmanouela; Tsaroucha, Angeliki; Karkavitsas, Nikolaos, E-mail: mariast_cha@yahoo.gr [Department of Nuclear Medicine, University Hospital of Heraklion, Crete (Greece)

    2015-10-15

    Background: Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation. Objectives: To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure. Methods: We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the 'gold standard' for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings. Results: Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects. Conclusion: Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed. (author)

  5. Quantification of micronuclei in blood lymphocytes of patients exposed to gamma radiation for dose absorbed assessment; Quantificacao de micronucleos em linfocitos de pacientes expostas a radiacao gama para a avaliacao da dose absorvida

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Isvania Maria Serafim da Silva

    2003-02-15

    Dose assessment in an important step to evaluate biological effects as a result of individual exposure to ionizing radiation. The use of cytogenetic dosimetry based on the quantification of micronuclei in lymphocytes is very important to complement physical dosimetry, since the measurement of absorbed dose cannot be always performed. In this research, the quantification of micronuclei was carried out in order to evaluate absorbed dose as a result of radiotherapy with {sup 60}Co, using peripheral blood samples from 5 patients with cervical uterine cancer. For this purpose, an aliquot of whole blood from the individual patients was added in culture medium RPMI 1640 supplemented with fetal calf serum and phytohaemagglutinin. The culture was incubated for 44 hours. Henceforth, cytochalasin B was added to block the dividing lymphocytes in cytokinesis. The culture was returned to the incubator for further of 28 hours. Thus, cells were harvested, processed and analyzed. Values obtained considering micronuclei frequency after pelvis irradiation with absorption of 0,08 Gy and 1,8 Gy were, respectively, 0,0021 and 0,052. These results are in agreement with some recent researches that provided some standard values related to micronuclei frequency induced by gamma radiation exposure in different exposed areas for the human body. The results presented in this report emphasizes biological dosimetry as an important tool for dose assessment of either total or partial-body exposure to ionizing radiation, mainly in retrospective dose investigation. (author)

  6. Radiation effects evaluation for electrons sheaf in packages resistance in a Lasioderma serricorne, Plodia interpunctella and Sitophilus zeamais; Avaliacao dos efeitos da radiacao por feixe de eletrons na resistencia de embalagens a Lasioderma serricorne, Plodia interpunctella e Sitophilus zeamais

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Juliana Nazare

    2011-07-01

    The plagues of stored products consist of a man problem, depreciating products and causing economical damages. Among these curses we have Lasioderma serricorne (F. 1792), Sitophilus zeamais (M. 1855) and Plodia interpunctella (H. 1813) known by infesting stored products as: grains, brans, flours, coffee, tobacco, dried fruits and spices. These curses perforate and penetrate the packages, ovipositing over the substratum. In this context the package plays a fundamental part, preventing the contact and curses' proliferation in the packed product. So, to protect the packed product and to prolong its shelf life, the package should have good mechanical resistance to tension and perforation, good sealing, good barrier properties and should not transfer odors nor strange flavors to the packed product. The ionizing radiation can cause structural changes in polymer packages, these changes are caused by the scission processes and reticulation of the polymers chains. These are concurrent processes and the predominance of one over the other depends on the chemical structure of the polymer, the irradiation conditions and specific factors of the material that will absorb the energy. This work had the objective to evaluate the changes in mechanical properties of package structures used to store granola, cereal bar and pasta, as well as its resistance to perforation by L. serricorne, P. interpunctella and S. zeamais, when submitted to electrons sheaf radiation. In this methodology were used five structures of commercially utilized packages to store granola, cereal bar and pasta composed by (Polypropylene bi-oriented metallic/Polypropylene bi-oriented coextruded - BOPPmet/BOPP 50 {mu}m), (Polypropylene bi-oriented/Polypropylene - BOPP/PP 50 {mu}m), Poli (ethylene terephthalate) metallic/Polypropylene bi-oriented coextruded - PETmet/BOPP 32 {mu}m), Poli (ethylene terephthalate) /Polypropylene - PET/PP1 72 {mu}m), Poli (ethylene terephthalate)/Polypropylene - PET/PP2 32 {mu}m). The structures of packaging were submitted to radiation doses between 0, 10, 20 and 60 kGy, in one electron accelerator of 1,5 M and V, 25 mA and 37,5 kW, dose tax of 11,22 kGy / s, room temperature and air presence . Eight days, Two and Six months after irradiations, mechanical resistance experiment were accomplished to tension and elongating in rupture, sealing resistance and perforation resistance, all based in respective ASTM norms. The perforation experiment by insects were realized in an acclimatized room, where irradiated samples in doses of 0, 10, 20 and 60 kGy were sealed containing 40 g of granola, 40 g of pasta and cereal bar in number of nine by experiment, and equally divided in three plastic screened boxes by studied dose. In each box 20 adults of each insect were added in for 60 days, when the packages were evaluated to verify possible perforations. The differences between the sample results were statistically evaluated by ANOVA (p<0.05). The results showed that concerning the perforation resistance by L. serricorne, P. interpunctella and S. zeamais the polymeric structures evaluated showed low resistance by insects perforation before and after the treatment. BOPPmet/BOPP (50 {mu}m), PETmet/BOPP (32 {mu}m), PET/PP1 (72 {mu}m) and PET/PP2 (32 {mu}m) structures showed significant losses in mechanical properties studied. The BOPP/PP (50 {mu}m) showed the best set of answers in mechanical properties to the radiation treatment with electrons sheaf up to 10 kGy doses. Among the mechanical properties evaluated, sealing was the most affected by ionizing radiation, has shown, in general, increasing losses with radiation dose. (author)

  7. Radiation exposure evaluation of the professional working interventionist procedures in a hemodynamics service; Avaliacao da exposicao a radiacao dos profissionais que executam procedimentos intervencionistas em um servico de hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Leonardo Peres

    2004-07-01

    An evaluation of the dose distribution received by all the workers involved on coronary angioplasty, arteriography, coronary angiography and mitral valvuloplasty procedures has been made in this work. For the measurements, LiF:Mg, Ti TLD(TLD 100) was used, located in seven different points on the worker's body: hands, knees, neck, forehead and thorax, inside and outside lead apron.) The measurements have been done for each hemo dynamical procedure, and the TLD calibrated in personal dose equivalent (H{sub p}(d)) operational quantity for 0,07 mm, 3 mm and 10 mm depth. Nurses and auxiliary doctors did not receive expressive dose values, indicating that the adopted radioprotection procedures seem to be appropriate and sufficient for them. However, the same is not true for the doctors direct in charge of the procedure. The results show the importance of the use of thyroid protections in these cases. This work discusses the main factors that cause occupational dose increase. From all interventionist hemo dynamical procedures analyzed, the dose values received by the doctors on coronary angioplasty procedures and coronary angiography were higher than the ones found on arteriography and mitral valvuloplasty. The higher dose values has been found for coronary angiography procedures in X-ray tools, that work with fluoroscopy on continuous mode and have been executed with brachial way, even in the eyes, hands, knees and thyroid, with or without shield. Multiplying these high dose values, measured in one procedure by the mean number of annual procedures made at the studied hospital by each doctor, the individual dose annual limits can be surpassed. Based on these estimations, some optimizations suggestions have been made and one discussion about the need of additional monitoring points is presented. Different algorithms have been used in order to estimate the effective dose, including a new proposal. The obtained results using the actual Radiodiagnostic Brazilian regulation underestimate the dose, in the major part of the measured cases. The proposed algorithm seem sto offer a better estimation for the occupational effective dose for Interventional Radiology. (author)

  8. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon; Neutrons, radiacao e arqueologia: estudo de caso multianalitico de ceramicas da tradicao borda incisa na Amazonia Central

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz-Marks, Roberto

    2014-07-01

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups. (author)

  9. Analysis of the gamma radiation effects in the composite of polyurethane derived from castor oil and natural fibers; Analise dos efeitos da radiacao gama no composito de poliuretano derivado de mamona com serragem

    Energy Technology Data Exchange (ETDEWEB)

    Kienen, Victor D.; Todt, Matheus L.; Capellari, Giovanni S.; Azevedo, Elaine C. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Neto, Salvador C. [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil)

    2015-07-01

    Composite of Polyurethane derived from castor oil and natural fibers are obtained from renewable raw material, low cost, and for not assaulting nature. This paper analyzes the effects of gamma radiation on composite polyurethane derived from castor with sawdust irradiated with gamma radiation of 25 kGy . It was held from 3 tips bending tests and micrograph by scanning electron microscopy. The results indicate that gamma radiation decreases the breakdown voltage and the micrograph of the fracture indicates brittle fracture occurred. (author)

  10. Radiation exposure evaluation of the professional working interventionist procedures in a hemodynamics service; Avaliacao da exposicao a radiacao dos profissionais que executam procedimentos intervencionistas em um servico de hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Leonardo Peres

    2004-07-01

    An evaluation of the dose distribution received by all the workers involved on coronary angioplasty, arteriography, coronary angiography and mitral valvuloplasty procedures has been made in this work. For the measurements, LiF:Mg, Ti TLD(TLD 100) was used, located in seven different points on the worker's body: hands, knees, neck, forehead and thorax, inside and outside lead apron.) The measurements have been done for each hemo dynamical procedure, and the TLD calibrated in personal dose equivalent (H{sub p}(d)) operational quantity for 0,07 mm, 3 mm and 10 mm depth. Nurses and auxiliary doctors did not receive expressive dose values, indicating that the adopted radioprotection procedures seem to be appropriate and sufficient for them. However, the same is not true for the doctors direct in charge of the procedure. The results show the importance of the use of thyroid protections in these cases. This work discusses the main factors that cause occupational dose increase. From all interventionist hemo dynamical procedures analyzed, the dose values received by the doctors on coronary angioplasty procedures and coronary angiography were higher than the ones found on arteriography and mitral valvuloplasty. The higher dose values has been found for coronary angiography procedures in X-ray tools, that work with fluoroscopy on continuous mode and have been executed with brachial way, even in the eyes, hands, knees and thyroid, with or without shield. Multiplying these high dose values, measured in one procedure by the mean number of annual procedures made at the studied hospital by each doctor, the individual dose annual limits can be surpassed. Based on these estimations, some optimizations suggestions have been made and one discussion about the need of additional monitoring points is presented. Different algorithms have been used in order to estimate the effective dose, including a new proposal. The obtained results using the actual Radiodiagnostic Brazilian regulation underestimate the dose, in the major part of the measured cases. The proposed algorithm seem sto offer a better estimation for the occupational effective dose for Interventional Radiology. (author)

  11. Statistical analysis of natural radiation levels inside the UNICAMP campus through the use of Geiger-Muller counter; Analise estatistica dos niveis de radiacao natural dentro da UNICAMP atraves do uso de contador Geiger-Muller

    Energy Technology Data Exchange (ETDEWEB)

    Fontolan, Juliana A.; Biral, Antonio Renato P., E-mail: fontolanjuliana@gmail.com.br, E-mail: biral@ceb.unicamp.br [Hospital das Clinicas (CEB/UNICAMP), Campinas, SP (Brazil). Centro de Engenharia Biomedica

    2013-07-01

    It is known that the distribution at time intervals of random and unrelated events leads to the Poisson distribution . This work aims to study the distribution in time intervals of events resulting from radioactive decay of atoms present in the UNICAMP where activities involving the use of ionizing radiation are performed environments . The proposal is that the distribution surveys at intervals of these events in different locations of the university are carried out through the use of a Geiger-Mueller tube . In a next step , the evaluation of distributions obtained by using non- parametric statistics (Chi- square and Kolmogorov Smirnoff) will be taken . For analyzes involving correlations we intend to use the ANOVA (Analysis of Variance) statistical tool . Measured in six different places within the Campinas , with the use of Geiger- Muller its count mode and a time window of 20 seconds was performed . Through statistical tools chi- square and Kolmogorov Smirnoff tests, using the EXCEL program , it was observed that the distributions actually refer to a Poisson distribution. Finally, the next step is to perform analyzes involving correlations using the statistical tool ANOVA.

  12. Characterization of an extrapolation chamber and radiochromic films for verifying the metrological coherence among beta radiation fields; Caracterizacao de uma camara de extrapolacao e filmes radiocromicos para verificacao da coerencia metrologica entre campos padroes de radiacao beta

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, Jhonny Antonio Benavente

    2011-07-01

    The metrological coherence among standard systems is a requirement for assuring the reliability of dosimetric quantities measurements in ionizing radiation field. Scientific and technologic improvements happened in beta radiation metrology with the installment of the new beta secondary standard BSS2 in Brazil and with the adoption of the internationally recommended beta reference radiations. The Dosimeter Calibration Laboratory of the Development Center for Nuclear Technology (LCD/CDTN), in Belo Horizonte, implemented the BSS2 and methodologies are investigated for characterizing the beta radiation fields by determining the field homogeneity, the accuracy and uncertainties in the absorbed dose in air measurements. In this work, a methodology to be used for verifying the metrological coherence among beta radiation fields in standard systems was investigated; an extrapolation chamber and radiochromic films were used and measurements were done in terms of absorbed dose in air. The reliability of both the extrapolation chamber and the radiochromic film was confirmed and their calibrations were done in the LCD/CDTN in {sup 90}Sr/{sup 90}Y, {sup 85}Kr and {sup 147}Pm beta radiation fields. The angular coefficients of the extrapolation curves were determined with the chamber; the field mapping and homogeneity were obtained from dose profiles and isodose with the radiochromic films. A preliminary comparison between the LCD/CDTN and the Instrument Calibration Laboratory of the Nuclear and Energy Research Institute / Sao Paulo (LCI/IPEN) was carried out. Results with the extrapolation chamber measurements showed in terms of absorbed dose in air rates showed differences between both laboratories up to de -I % e 3%, for {sup 90}Sr/{sup 90}Y, {sup 85}Kr and {sup 147}Pm beta radiation fields, respectively. Results with the EBT radiochromic films for 0.1, 0.3 and 0.15 Gy absorbed dose in air, for the same beta radiation fields, showed differences up to 3%, -9% and -53%. The beta radiation field mappings with radiochromic films in both BSS2 showed that some of them were not geometrically aligned. (author)

  13. Study of radiation detectors response in standard X, gamma and beta radiation standard beams; Estudo da resposta de monitores de radioprotecao em feixes padronizados de radiacao X, gama e beta

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda Beatrice Conceicao

    2010-07-01

    The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ({sup 37}Cs and {sup 60}Co), and some of them were tested in beta radiation ({sup 90}Sr+{sup 9'}0Y e {sup 204}Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author)

  14. Radiation effects on vitamin A and {beta}-carotene contents in bovine liver and swine pate de foie; Efeito da radiacao gama sobre a vitamina A e o {beta}-caroteno de figado bovino e suino

    Energy Technology Data Exchange (ETDEWEB)

    Taipina, Magda Sinigalia

    2001-07-01

    In this study, vitamin A and {beta}-carotene contents and the percent of activity retention were analyzed in 3 kGy and 30 kGy {sup 60}Co {gamma}-irradiated samples of bovine liver and swine liver pate. Six different lots of liver samples weighing 100 g obtained at the meat market were employed. Irradiation was performed with liver samples initially frozen (-15 deg C). Similarly, six different lots of swine liver pate samples weighing about 100 - 125 g , at temperature of 7 deg C were irradiated. Pre-treatments and analysis methods were those described in Instituto Adolfo Lutz Norms for food analyses. Two and five- gram samples in duplicates for bovine liver and five gram-samples for swine liver pate were used. The results showed that there were no losses of either vitamin A or provitamin A activities in the samples of bovine liver and swine liver pate irradiated with a dose of 3 kGy (retention about 100%). On the other hand, for swine liver pate samples of vitamin A were maintained after irradiation with 30 kGy. (author)

  15. Effects of gamma radiation of Cobalt-60 on arabica and conillon seeds coffea: physic-chemistry evaluation; Efeitos da radiacao gama do Cobalto-60 em sementes de cafe arabica e conillon: avaliacao fisico-quimica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcus Henriques da

    2012-07-01

    Brazil is the largest producer and exporter of coffee in the world. The coffee bean is one of the main products of the Brazilian trade balance. Two species of coffee are the most economically important: the Coffea arabica L. and Coffea canephora Pierre is the largest representative of the Coffea canephora Pierre is the coffea conillon. Food irradiation is an area of research that aims to increase the shelf life of foods and controlling pests. This study aimed to verify the physicochemical variables of Arabica coffee and conillon were affected when exposed to doses of gamma radiation from cobalt-60. The samples were provided by Polo in Coffee Quality Technology, Federal University of Lavras - UFLA. The coffee samples were subjected to irradiation doses: 0 (control), 5 kGy and 10 kGy, a multipurpose irradiator of IPEN - Research Institute of Nuclear Energy and the University of São Paulo, at a rate of 7.5 kGy / hour. For irradiation the samples were vacuum-packed in appropriate packaging aluminised. After the process of irradiation the samples were stored at a temperature of 15 ± 1 deg C and relative humidity of 17 ± 1%. The following analyzes were performed: levels of total sugars, glucose, sucrose, caffeine, humidity, pH, total acidity, electrical conductivity and fibers. Analyses were performed 1, 30, 60 and 90 days after irradiation, and the results were submitted to analysis of variance and means were compared by Tukey test at 5%. It was observed that the analysis results of the samples irradiated with 5 kGy and 10 kGy showed values similar to the control. It was concluded that irradiation did not induce deleterious effects on arabica coffee seeds and conillon irradiated with 5 kGy and 10 kGy to 90 days after irradiation. (author)

  16. Saccharose action on chrysanthemum cut inflorescences, Dendranthema grandiflorum Kitamura, after exposition to gamma radiation; Acao da sacarose na manutencao de inflorescencias cortadas de crisantemo, Dendranthema grandiflorum Kitamura, apos exposicao a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Olivia Kimiko

    1998-07-01

    During the last years the Brazilian floriculture expanded and it is expected to achieve a prominent role in near future. The national territory has many favorable regions, with adequate climate for the development of commercially important cultures. Flower exportation is not expressive yet, but the country has conditions to become a great exotic tropical plants exporter. On the other hand, developed countries, as USA and Japan, have a rigorous phyto sanitary inspection to prevent the introduction of new plagues and diseases through fresh products. Ionizing radiation is considered a reliable disinfestation method to control numerous fruit and flower plagues. The aim of of this work was to verify the tolerance of some Compositae family flowers to ionizing radiation and the effects to sucrose action in protecting the flowers against the gamma-radiation induced damages. This was done by measuring biochemical and physiological parameters as a function of time after irradiation. The chrysanthemum flowers were sensitive to gamma radiation, but when the inflorescences were supplied after irradiation with preservative solution containing 2% sucrose, protection against the damaging effects of radiation was achieved. The dose of 750 Gy, considered appropriate for disinfestation purpose, did not modify the protein and lipid levels, nor plasma, tonoplast and mitochondria membrane ATPase or mitochondria cytochrome-c oxidase activities. The ethylene and carbonic gas rate production increased soon after the irradiation, but decreased one day later. The decrease of the microsomal membrane fluidity and the increase of the chrysanthemum were the most sensitive parameters to measure the irradiation treatment changes. The sucrose supply was able to maintain the irradiated flowers membrane fluidity level close to the unirradiated control. Rhodante manglesii Lindl and Helichrysum bracteatum Andr. were tolerant up to 1 KGy, thus being adequate to be disinfected by gamma radiation. (author)

  17. Gamma radiation and thermal treatment effects on the conservation of natural apple (Malus domestica) juice, cv. gala; Efeito da radiacao gama e do tratamento termico na conservacao do suco natural de maca (Malus domestica), cv. gala

    Energy Technology Data Exchange (ETDEWEB)

    Blumer, Lucimara

    1995-12-01

    This work studies the apple juice preservation without chemicals. The samples were exposed to the following treatments: heating (control, 60{sup 0} C/20 min and 80{sup 0} C/20 min); irradiation (control; 2, 4 and 6 kGy); heating plus irradiation. The quality control was carried out by physical and chemical analyses (soluble solids; titratable acidity, pH, ascorbic acid and color), microbiological and sensorial analyses. The samples were stored at refrigeration temperature (5 {+-} 3{sup 0} C) for 180 days. The results showed few variations in the soluble solids, acidity, pH and ascorbic acid for all treatments. However, the 6 kGy dose kept the chemical characteristics of the juice, providing a clear juice, with better appearance and microorganisms free. (author). 24 refs., 11 figs., 12 tabs.

  18. Evaluation of area monitor response for neutrons in radiation field generated by a 15 MV clinic accelerator; Avaliacao da resposta dos monitores de area para neutrons em campo de radiacao gerado por um acelerador clinico de 15 MV

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Ana Paula

    2011-07-01

    The clinical importance and usage of linear accelerators in cancer treatment increased significantly in the last years. Coupled with this growth came the concern about the use of accelerators with energies over to 10 MeV which produce therapeutic beam contaminated with neutrons generated when high-energy photons interact with high-atomic-number materials such as tungsten and lead present in the accelerator itself. At these facilities, measurements of the ambient dose equivalent for neutrons present difficulties owing to the existence of a mixed radiation field and possible electromagnetic interference near the accelerator. The Neutron Laboratory of the IRD - Brazilian Institute for Radioprotection and Dosimetry, aiming to evaluate the survey meters performance at these facilities, initiated studies of instrumentation response in the presence of different neutron spectra. Neutrons sources with average energies ranging from 0.55 to 4.2 MeV, four different survey meters and one ionization chamber to obtain the ratio between the dose due to neutrons and gamma radiation were used in this work. The evaluation of these measurements, performed in a 15 MV linear accelerator room is presented. This work presents results that demonstrate the complexity and care needed to make neutrons measurements in radiotherapy treatment rooms containing high energy clinical accelerators. (author)

  19. In vitro evaluation of ionizing radiation effects in bone tissue by FTIR spectroscopy and dynamic mechanical analysis; Avaliacao in vitro dos efeitos da radiacao ionizante em tecido osseo bovino por espectroscoia ATR-FTIR e analise dinamica-mecanica

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo Noronha

    2013-07-01

    Ionizing radiation from gamma radiation sources or X-ray generators is frequently used in Medical Science, such as radiodiagnostic exams, radiotherapy, and sterilization of haloenxerts. Ionizing radiation is capable of breaking polypeptidic chains and causing the release of free radicals by radiolysis.of water. It interacts also with organic material at the molecular level, and it may change its mechanical properties. In the specific case of bone tissue, studies report that ionizing radiation induces changes in collagen molecules and reduces the density of intermolecular crosslinks. The aim of this study was to verify the changes promoted by different doses of ionizing radiation in bone tissue using Fourier Transform Infrared Spectroscopy (FTIR) and dynamic mechanical analysis (DMA). Samples of bovine bone were irradiated using Cobalt-60 with five different doses: 0.01 kGy, 0.1 kGy, 1 kGy, 15 kGy and 75 kGy. To study the effects of ionizing irradiation on the chemical structure of the bone, the sub-bands of amide I, the crystallinity index and relation of organic and inorganic materials, were studied. The mechanical changes were evaluated using the elastic modulus and the damping value. To verify whether the chemical changes and the mechanical characteristics of the bone were correlated, the relation between the analysis made with spectroscopic data and the mechanical analysis data was studied. It was possible to evaluate the effects of different doses of ionizing radiation in bone tissue. With ATR-FTIR spectroscopy, it was possible to observe changes in the organic components and in the hydroxyapatite crystals organization. Changes were also observed in the elastic modulus and in the damping value. High correlation with statistical significance was observed among (amide III + collagen)/{sub v1,v3}, PO{sub 4}{sup 3-} and the delta tangent, and among 1/FHWM and the elastic modulus. (author)

  20. Energy efficiency of photovoltaic modules mono and polycrystalline in function of global solar radiation; Eficiencia energetica de modulos fotovoltaicos mono e poli-cristalinos em funcao da radiacao solar global

    Energy Technology Data Exchange (ETDEWEB)

    Seraphim, Odivaldo Jose [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], e-mail: seraphim@fca.unesp.br; Siqueira, Jair Antonio Cruz [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas], e-mail: jairsiqueira@fca.unesp.br; Silva, Carliane Diniz e [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil); Fiorentino, Jair de Jesus [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Engenharia Eletrica], e-mail: jairfiorentino@terra.com.br; Araujo, Joao Alberto Borges de [Faculdade de Tecnologia de Botucatu (FATEC), SP (Brazil). Dept. de Engenharia de Producao

    2004-07-01

    This research proposes a methodology to evaluate the acting of the solar energy conversion in electric energy, generated by photovoltaic modules installed under field conditions, constituted monocrystalline and polycrystalline silicon cells. The modules were appraised with relationship to energy efficiency for different marks and potency levels, in function of the readiness of solar radiation, being used loads sized for the nominal potency level of each module. The energy efficiency values calculated with the data obtained in field, didn't agree with the technical information presented by the makers of the modules monocrystalline, as being more efficient than the polycrystalline. Was ended, therefore, that the modules of the appraised marks presented inferior medium efficiency at 50% of the values supplied by the makers (author)

  1. Effects of ionizing radiation in the physico-chemical characteristics of red wine Cabernet Sauvignon; Efeitos da radiacao ionizante nas caracteristicas fisico-quimicas do vinho tinto Cabernet Sauvignon

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fellipe Souza da; Leiras, Anderson; Wagner, Walsan, E-mail: fellipe.souzadasilva@gmail.com [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The oenology in the current days is increasingly aimed obtain improvements on wine quality produced without there the deterioration of characteristics of the same, using new technologies for such order. The objective of present work will be the application of the radiation ionizing in wines Cabernet Sauvignon, with the interest of analyzing its effects on physic-chemical characteristics of this wines, such as quality, aging and etc. Were analyzed the following strands: degree alcoholic; dry extract; density and absorbance with spectrometer (420, 520 and 620 nm). (author)

  2. Effect of gamma radiation on the growth of Aspergillus Flavus aflatoxins producer and on the use of polymerase chain reaction technique (PCR) in samples of maize grains artificially inoculated; Efeitos da radiacao gama no crescimento de Aspergillus flavus produtor de aflatoxinas e no emprego da tecnica da Reacao em Cadeia da Polimerase (RCP) em amostras de graos de milho inoculadas artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Simone

    2003-07-01

    The aim of this present study was to verify the effects of gamma radiation on the growth of Aspergillus flavus Link aflatoxins producer; to demonstrate the application of Polymerase Chain Reaction (PCR) technique in the diagnostic of A. Flavus, as well to verify the effect of radiation in the profile of DNA bands. Twenty samples of grains maize with 200 g each were individually irradiated with 20 kGy, to eliminate the microbial contamination. In following, the samples were inoculated with an toxigenic A. flavus (1x10{sup 6} spores/ml), incubated for 15 days at 25 deg C with a relative humidity of around 97,5% and irradiated with 0, 2; 5 and 10 kGy. The samples, 5 to each dose of irradiation, were individually analyzed for the number of fungal cells, water activity, viability test (fluorescein diacetate and ethidium bromide), PCR and aflatoxins (AFB) detection. The results showed that the doses used were effective in reducing the number of Colony Forming Units (CFU/g) mainly the doses of 5 and 10 kGy. In addition, the viability test showed a decrease of viable cells with increase of irradiation doses. The reduction of AFB{sub 1} and AFB-2, was more efficient with the use of 2 kGy in comparison with the dose of 5 kGy, while the dose of 10 kGy, degraded the aflatoxins. Thereby, it was observed that AFB2 showed to be more radiosensitive. The use of PCR technique showed the presence of DNA bands, in all samples. (author)

  3. Effects of low-energy laser irradiation on the distalization velocity during experimental canine tooth movement in humans: 'comparative clinical study'; Efeitos da irradiacao com laser em baixa intensidade na velocidade de distalizacao de caninos durante a movimentacao ortodontica: 'estudo clinico comparativo'

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Delma Rebelo

    2003-07-01

    This research investigated the effects of low level laser therapy (LLLT) upon the velocity of canine tooth movement and consequently bone remodeling. A total of eleven patients were treated with a 780 nm diode laser. One side of the upper arcade was considered control group and was not irradiated but received mechanical activation every thirty days. The opposite side received the same mechanical activation but was also irradiated at days 0, 3, 7 and 14 of each month. Data of the biometrical progress were taken on both sides on days 3,7,14,21 and 30 of each month. The results indicate that all patients showed significant acceleration of the distalization velocity on the side treated with LLLT when compared to the control. (author)

  4. A Sintaxe da Janela

    Directory of Open Access Journals (Sweden)

    Luís Antônio Jorge

    1993-12-01

    Full Text Available A preocupação fundamenta! do trabalho é de caráter ontológico: esboçar o problema das significações apriorísticas e autônomas dos elementos que compõem a sintaxe arquitetônica. O trabalho elege um desses elementos: a janela. Este artigo parte da aproximação histórica entre a janela e a secção da pirâmide visual, construção imaginária da teoria da perspectiva renascentista. A consideração da janela na linguagem arquitetônica implica reconhecer uma ambigüidade essencial: a janela deve inserir-se ordenadamente no plano da parede - raciocínio típico da modenatura - mas também relacionar-se com a imagem vista através dela, que extrapola o plano, ressaltando a tridimensionalidade - herança da perspectiva renascentista, fundamentada no espaço euclidiano. Ver janela ou ver através da janela são alternativas que se colocam tanto ao observador interno ao edifício, quanto ao externo. Texto de duplaface, a sintaxe da janela versa sobre o relacionamento desses dois lados

  5. Laser polarimetry

    International Nuclear Information System (INIS)

    Goldstein, D.H.

    1989-01-01

    Polarimetry, or transmission ellipsometry, is an important experimental technique for the determination of polarization properties of bulk materials. In this technique, source radiation of known polarization is passed through bulk samples to determine, for example, natural or induced birefringence and dichroism. The laser is a particularly appropriate source for this technique because of its monochromaticity, collimation, and radiant intensity. Lasers of many different wavelengths in different spectral regions are now available. Laser polarimetry can be done in any of these wavelength regions where polarizing elements are available. In this paper, polarimetry is reviewed with respect to applications, sources used, and polarization state generator and analyzer configurations. Scattering ellipsometry is also discussed insofar as the forward scattering measurement is related to polarimetry. The authors then describe an infrared laser polarimeter which we have designed and constructed. This instrument can operate over large wavelength regions with only a change in source. Polarization elements of the polarimeter are in a dual rotating retarder configuration. Computer controlled rotary stages and computer monitored detectors automate the data collection. The Mueller formulation is used to process the polarization information. Issues and recent progress with this instrument are discussed

  6. excimer laser

    Indian Academy of Sciences (India)

    2014-01-07

    Jan 7, 2014 ... is necessary to deposit one order higher input electric power into gas medium than ... cross-sectional view of the laser system is shown in figure 2A. The system mainly consists ... Considering the simplicity and reliability of the.

  7. Laser device

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides a light source for light circuits on a silicon platform. A vertical laser cavity is formed by a gain region arranged between a first mirror structure and a second mirror structure, both acting as mirrors, by forming a grating region including an active material...

  8. Nanowire Lasers

    Directory of Open Access Journals (Sweden)

    Couteau C.

    2015-05-01

    Full Text Available We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs, solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D nature, flexibility in material choice and combination, and intrinsic optoelectronic properties. First, we provide an overview on using quasi-1D nanowire systems to realize subwavelength lasers with efficient, directional, and low-threshold emission. We then describe the state of the art for nanowire lasers in terms of materials, geometry, andwavelength tunability.Next,we present the basics of lasing in semiconductor nanowires, define the key parameters for stimulated emission, and introduce the properties of nanowires. We then review advanced nanowire laser designs from the literature. Finally, we present interesting perspectives for low-threshold nanoscale light sources and optical interconnects. We intend to illustrate the potential of nanolasers inmany applications, such as nanophotonic devices that integrate electronics and photonics for next-generation optoelectronic devices. For instance, these building blocks for nanoscale photonics can be used for data storage and biomedical applications when coupled to on-chip characterization tools. These nanoscale monochromatic laser light sources promise breakthroughs in nanophotonics, as they can operate at room temperature, can potentially be electrically driven, and can yield a better understanding of intrinsic nanomaterial properties and surface-state effects in lowdimensional semiconductor systems.

  9. Excimer Laser Technology

    CERN Document Server

    Basting, Dirk

    2005-01-01

    This comprehensive survey on Excimer Lasers investigates the current range of the technology, applications and devices of this commonly used laser source, as well as the future of new technologies, such as F2 laser technology. Additional chapters on optics, devices and laser systems complete this compact handbook. A must read for laser technology students, process application researchers, engineers or anyone interested in excimer laser technology. An effective and understandable introduction to the current and future status of excimer laser technology.

  10. Laser ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Bykovskij, Yu

    1979-02-01

    The characteristics a laser source of multiply-ionized ions are described with regard to the interaction of laser radiation and matter, ion energy spectrum, angular ion distribution. The amount of multiple-ionization ions is evaluated. Out of laser source applications a laser injector of multiple-ionization ions and nuclei, laser mass spectrometry, laser X-ray microradiography, and a laser neutron generators are described.

  11. Complicações na dacriocistorrinostomia transcanalicular com laser diodo: complications Transcanalicular dacryocystorhinostomy with diode laser

    Directory of Open Access Journals (Sweden)

    Eduardo Alonso Garcia

    2009-08-01

    Full Text Available OBJETIVO: Analisar as complicações da aplicação do laser de diodo para o tratamento da obstrução nasolacrimal adquirida. MÉTODOS: Foram realizados 44 procedimentos (dacriocistorrinostomia transcanalicular com laser de diodo com intubação bicanalicular de silicone sob anestesia local entre fevereiro de 2002 a novembro de 2007 em 41 pacientes (3 bilateralmente, sendo 32 mulheres e 9 homens. RESULTADOS: As complicações mais frequentes no intraoperatório foram: dificuldade de passar a sonda de Crawford (13,6% e passagem da fibra óptica dificultada (11,3%. No pós-operatório, a epífora foi a ocorrência mais frequente (15,9%, seguida pela retirada acidental do silastic (11,3%. CONCLUSÃO: Os índices de complicações intra e pós-operatórias se equivalem aos artigos publicados com a mesma técnica cirúrgica (e mesmo tipo de laser.PURPOSE: To evaluate the complications of the use of diode laser in the treatment of acquired nasolacrimal obstruction. METHODS: Forty four procedures (transcanalicular dacryocystorhinostomy with diode laser with bicanalicular silicone tube intubation and local anesthesia where performed from February 2002 to November 2007 in 41 patients (3 bilaterally, 32 women and 9 men. RESULTS: The most common intraoperative complications were disability to pass the Crawford probe (13.6% and the laser probe (11.3%. Regarding postoperative complications, epiphora was the event of higher frequency (15.9% followed by the non-intentional silastic extrusion by the patient (11.3%. CONCLUSION: Intraoperative and postoperative complications rate were similar of others articles that demonstrated the same surgical technique (with same laser.

  12. Dermatological laser treatment

    International Nuclear Information System (INIS)

    Moerk, N.J.; Austad, J.; Helland, S.; Thune, P.; Volden, G.; Falk, E.

    1991-01-01

    The article reviews the different lasers used in dermatology. Special emphasis is placed on the treatment of naevus flammeus (''portwine stain'') where lasers are the treatment of choice. Argon laser and pulsed dye laser are the main lasers used in vascular skin diseases, and the article focuses on these two types. Copper-vapour laser, neodymium-YAG laser and CO 2 laser are also presented. Information is provided about the availability of laser technology in the different health regions in Norway. 5 refs., 2 figs

  13. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  14. Project LASER

    Science.gov (United States)

    1990-01-01

    NASA formally launched Project LASER (Learning About Science, Engineering and Research) in March 1990, a program designed to help teachers improve science and mathematics education and to provide 'hands on' experiences. It featured the first LASER Mobile Teacher Resource Center (MTRC), is designed to reach educators all over the nation. NASA hopes to operate several MTRCs with funds provided by private industry. The mobile unit is a 22-ton tractor-trailer stocked with NASA educational publications and outfitted with six work stations. Each work station, which can accommodate two teachers at a time, has a computer providing access to NASA Spacelink. Each also has video recorders and photocopy/photographic equipment for the teacher's use. MTRC is only one of the five major elements within LASER. The others are: a Space Technology Course, to promote integration of space science studies with traditional courses; the Volunteer Databank, in which NASA employees are encouraged to volunteer as tutors, instructors, etc; Mobile Discovery Laboratories that will carry simple laboratory equipment and computers to provide hands-on activities for students and demonstrations of classroom activities for teachers; and the Public Library Science Program which will present library based science and math programs.

  15. Tópicos da teoria da relatividade

    OpenAIRE

    Fragata, Paulo Renato Ferreira

    2013-01-01

    Dissertação de Mestrado, Matemática para Professores, 25 de Outubro 2013, Universidade dos Açores. Qualquer descrição física da natureza tem por base a especificação da posição e do instante em que decorre determinado acontecimento. Para tal, é necessário recorrer a um sistema de coordenadas, escolhido por cada observador, do modo que ele achar mais pertinente. Dada a generalidade na escolha do sistema de coordenadas, é útil conhecer as regras que nos permitem comparar cálculos feitos em d...

  16. Laser and caries diagnosis: the state of the art and evaluation in vitro of the differences of the fluorescence between sound, carious and demineralized enamel; Laser e diagnostico de caries: estado da arte e avaliacao in vitro das diferencas de fluorescencia entre esmalte sadio, cariado e desmineralizado

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Maria Angelica Lopes Chaves

    2001-07-01

    The aim of this study was to evaluate the methods for establishing dental caries diagnosis that make use of Laser light as source of illumination, establishing the 'state of the art'. Experimental observation of the differences among fluorescence of sound, demineralized and carious enamel by visible luminescent spectroscopy was also done. Six human teeth, extracted for clinical reasons were studied, and the results showed that the spectrum of carious enamel is different from the sound and demineralized ones. The differences are more evident relative to sond enamel and carious enamel, the same occurring between demineralized and carious enamel. The review of the literature aimed to make comparative considerations between QLF, LF and DELF; their effectiveness relative to traditional methods such as visual, visual with probe, radiography. It was verified that DELF was more sensitive, but could not discriminate between different degrees of mineral loss. QLF, compared to DIAGNOdent has the same sensitivity, but it is better for scientific purposes. The experimental part of the present study used on argon ion Laser to illuminated the teeth and signs of emission of fluorescence were captured by a PMT and then analyzed by a computer system with EG and G software. The results showed that the spectrum of carious enamel is different from the sound and demineralized. The differences are more evident in relation to sound and carious enamel, the same occurs between demineralized and carious enamel. (author)

  17. Evaluation of effects of laser irradiation therapy ({lambda}=830 nm) on oral ulceration induced by fixed orthodontic appliances; Efeito terapeutico da irradiacao com laser de arseneto de galio aluminio ({lambda}=830 nm) em lesoes provocadas pelo aparelho ortodontico fixo na cavidade oral

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Maria Teresa Jabur

    2001-07-01

    Twenty patients presenting fixed orthodontic appliance - induced oral ulceration were randomly chosen for this study. These patients were then divided into two groups. In Group ,1 the ulceration was submitted to low intensity infrared laser ({lambda}=830 nm), at 30 mW fluency per point 1,3 J/cm{sup 2} at an exposure time ranging from 3s to 33s, depending on ulceration size. Ulceration was irradiated on the first day, the process being repeated 24 and then 48 hours later. Evaluations were made seven days after the first irradiation. Group 2 comprised of patients who were exposed to conventional treatment where wax was used to cover the afflicted area. These patients also took triancinolona. Evaluation was made on the same day. In both groups the cause of irritation was eliminated whenever was possible. Clinical results pointed out that the healing process was slightly faster in cases of LILT treated oral ulceration. The latter also presented significant decrease in symptoms of pain. Comparative statistical evaluation results between both groups has shown that in the case of Group 1 patients (those submitted to low-intensity infrared laser beam): 1) Healing process was faster with reduction of sore areas; 2) immediate relief of pain following first irradiation, as stated by patients. Taking into consideration the vast amount of patients who are bearers of fixed orthodontic appliances and whose most usual and frequent complaint is pain and irritation, the use of LILT is highly recommended due to its simplicity and efficacy. (author)

  18. Comparative analysis of the effect of the GaAlAs laser irradiation in 780 nm and 660 nm in the hypersensitive dentin; Analise comparativa do efeito da irradiacao do laser de GaAlAs em 780 nm e 660 nm na hipersensibilidade dentinaria

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Sun Chien

    2003-07-01

    This study was to evaluate and compare the effects of the low intensity in laser radiation among GaAlAs 780 nm and GaAlAs 660 nm. The main proposal is to verify if there is any difference of the effects or results in low intensity laser application treatment of hypersensitive dentin, keeping the same parameters, only differing in wavelength. The samples were distributed in two groups. Group A 90 cases, treated with GaAlAs 780 nm and group B irradiated with GaAlAs 660 nm with a total of 76 cases analyzed. The results of application with GaAlAs 660 nm and GaAlAs 780 nm do not differ statistically. Which means using any one of the irradiation gives the same results. However can be noted that the response of reduction of hypersensitivity is faster with the radiation of GaAlAs 780 nm, but the results after three applications is the same for both types of radiation. (author)

  19. Laser and caries diagnosis: the state of the art and evaluation in vitro of the differences of the fluorescence between sound, carious and demineralized enamel; Laser e diagnostico de caries: estado da arte e avaliacao in vitro das diferencas de fluorescencia entre esmalte sadio, cariado e desmineralizado

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Maria Angelica Lopes Chaves

    2001-07-01

    The aim of this study was to evaluate the methods for establishing dental caries diagnosis that make use of Laser light as source of illumination, establishing the 'state of the art'. Experimental observation of the differences among fluorescence of sound, demineralized and carious enamel by visible luminescent spectroscopy was also done. Six human teeth, extracted for clinical reasons were studied, and the results showed that the spectrum of carious enamel is different from the sound and demineralized ones. The differences are more evident relative to sond enamel and carious enamel, the same occurring between demineralized and carious enamel. The review of the literature aimed to make comparative considerations between QLF, LF and DELF; their effectiveness relative to traditional methods such as visual, visual with probe, radiography. It was verified that DELF was more sensitive, but could not discriminate between different degrees of mineral loss. QLF, compared to DIAGNOdent has the same sensitivity, but it is better for scientific purposes. The experimental part of the present study used on argon ion Laser to illuminated the teeth and signs of emission of fluorescence were captured by a PMT and then analyzed by a computer system with EG and G software. The results showed that the spectrum of carious enamel is different from the sound and demineralized. The differences are more evident in relation to sound and carious enamel, the same occurs between demineralized and carious enamel. (author)

  20. Laser Research Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Research lab is thecenter for the development of new laser sources, nonlinear optical materials, frequency conversion processes and laser-based sensors for...

  1. Laser therapy (image)

    Science.gov (United States)

    A laser is used for many medical purposes. Because the laser beam is so small and precise, it enables ... without injuring surrounding tissue. Some uses of the laser are retinal surgery, excision of lesions, and cauterization ...

  2. Laser fusion: an overview

    International Nuclear Information System (INIS)

    Boyer, K.

    1975-01-01

    The laser fusion concept is described along with developments in neodymium and carbon dioxide lasers. Fuel design and fabrication are reviewed. Some spin-offs of the laser fusion program are discussed. (U.S.)

  3. Laser power supply

    International Nuclear Information System (INIS)

    Bernstein, D.

    1975-01-01

    The laser power supply includes a regulator which has a high voltage control loop based on a linear approximation of a laser tube negative resistance characteristic. The regulator has independent control loops for laser current and power supply high voltage

  4. Comparative study of smear layer removal by different etching modalities and Er:YAG laser irradiation on the root surface: a scanning electron microscopy study; Estudo comparativo, atraves de microscopia eletronica de varredura, da acao de diferentes substancias quimicas e do laser de Er:YAG, na remocao de smear layer, em superficies radiculares submetidas a raspagem e aplainamento

    Energy Technology Data Exchange (ETDEWEB)

    Theodoro, Leticia Helena

    2001-07-01

    The aim of this study was to compare the effects of citric acid, EDTA, citric acid with tetracycline, and Er:YAG laser to smear layer removal on the root surface after scaling with manual instruments by SEM. Thirty specimens (n=30) of root surface before scaling were divided into 6 groups (n=5). The Control Group (G1) was not treated; Group 2 (G2) was conditioned with citric acid gel 24%, pH1, during 2 minutes; Group 3 (G3) was conditioned with EDTA gel 24%, pH 7, during 2 minutes; Group 4 (G4) was conditioned with citric acid and tetracycline gel 50%, pH1 during 2 minutes; Group 5 (G5) was irradiated with Er:YAG laser (2.94 {mu}m), 47 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 0.58 J/cm{sup 2}; Group 6 (G6) was irradiated with Er:YAG laser (2.94{mu}m), 83 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 1.03 J/cm{sup 2}. The micrographic were analyzed by scores and following the statistical analysis with Kruskal Wallis (p<0.05) H=20,31. The G1 was significantly different of all groups (28.0); the G2 (13.4), G3 (11.7), and G4 (13.6) showed no difference in relation to G5 (20.3) and G6 (6.0), but the G6 was significantly different from G5. From the results, it can be conclude that: 1) there was intensity smear layer after scaling and root planing; 2) all treatments were effective to smear layer remove with significantly difference to G2, G3, G4, G5 and G6; G2, G3 and G4 were not statistically different from G5 and G6; 3) G6 was more effective in the smear layer remotion in relation to G5 and both presented irregular root surface. (author)

  5. Bleaching Dengan Teknologi Laser

    OpenAIRE

    Eliwaty

    2008-01-01

    Penulisan tentang bleaching dengan laser dimaksudkan untuk menambah wawasan serta pengetahuan dari pembaca di bidang kedokteran gigi. Macam-macam laser yang dipergunakan dalam bleaching yaitu argon, CO2 serta dioda laser. Contoh merek produk laser yaitu Blulaze, Dentcure untuk argonlaser, Novapulse untuk C02 serta Opus 5 untuk dioda laser. Laser bleaching hasilnya dapat dicapai dalam satu kunjungan saja, cepat, efisien namun biayanya relatif mahal, dapat menimbulkan burn, sensitivitas se...

  6. Laser safety at high profile laser facilities

    International Nuclear Information System (INIS)

    Barat, K.

    2010-01-01

    Complete text of publication follows. Laser safety has been an active concern of laser users since the invention of the laser. Formal standards were developed in the early 1970's and still continue to be developed and refined. The goal of these standards is to give users guidance on the use of laser and consistent safety guidance and requirements for laser manufacturers. Laser safety in the typical research setting (government laboratory or university) is the greatest challenge to the laser user and laser safety officer. This is due to two factors. First, the very nature of research can put the user at risk; consider active manipulation of laser optics and beam paths, and user work with energized systems. Second, a laser safety culture that seems to accept laser injuries as part of the graduate student educational process. The fact is, laser safety at research settings, laboratories and universities still has long way to go. Major laser facilities have taken a more rigid and serious view of laser safety, its controls and procedures. Part of the rationale for this is that these facilities draw users from all around the world presenting the facility with a work force of users coming from a wide mix of laser safety cultures. Another factor is funding sources do not like bad publicity which can come from laser accidents and a poor safety record. The fact is that injuries, equipment damage and lost staff time slow down progress. Hence high profile/large laser projects need to adapt a higher safety regimen both from an engineering and administrative point of view. This presentation will discuss all these points and present examples. Acknowledgement. This work has been supported by the University of California, Director, Office of Science.

  7. Semiconductor Laser Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  8. Laser Protection TIL

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Protection TIL conducts research and analysis of laser protection materials along with integration schemes. The lab's objectives are to limit energy coming...

  9. MACIEZ DA CARNE BOVINA

    Directory of Open Access Journals (Sweden)

    Antonio Bento Mancio

    2006-10-01

    Full Text Available Dentre as características de qualidade da carne bovina, a maciez assume posição de destaque, sendo considerada a característica organoléptica de maior influência na aceitação da carne por parte dos consumidores. A dureza da carne pode ser dividida em dureza residual, causada pelo tecido conjuntivo e outras proteínas do estroma, e dureza de actomiosina, causada pelas proteínas miofibrilares. Dentre os fatores que influenciam a maciez da carne, podem ser destacados a genética, a raça, a idade ao abate, o sexo, a alimentação, o uso de agentes hormonais (?-adrenérgicos e os tratamentos post-mortem. A qualidade final da carne é resultante de tudo o que aconteceu com o animal durante toda a cadeia produtiva. Devem-se assegurar procedimentos adequados de transporte, armazenamento, manipulação, exposição e preparo da carne, a fim de se obter um produto de melhor qualidade. PALAVRAS-CHAVE: Calpaínas, calpastatina, qualidade da carne, rigor mortis, tecido muscular.

  10. Laser Photochemistry.

    Science.gov (United States)

    1981-07-01

    inverted by the first, i.e., at the moment of time t = T, such that i = (2n+)lT, where 0 is the Rabi frequency (Oraevski et al., 1976). . classical... anisotropic molecule present. CW HeNe, Ar+ and Kr+ lasers are used, and the filter method is necessary because of time-scales lo8 - 10ll Hz. Some general...e.g., truncated harmonic oscillator, square well, spherically symmetric Morse or Lennard-Jones, anisotropic (angle-dependent) Morse or Lennard-Jones

  11. GERONTOLOGIA: ESTADO DA ARTE

    Directory of Open Access Journals (Sweden)

    Vera M.A.Tordino Brandão

    2010-02-01

    Full Text Available O Programa de Gerontologia da PUC desenvolve pesquisas focando o ser na perspectiva do envelhecimento. As atividades são interdisciplinares e reúnem docentes, alunos e ex-alunos. Nesta mesa redonda apresentamos um panorama sobre estes estudos. Na área da educação e comunicação o foco está centrado na longevidade e na preparação e representação social da velhice. São ressaltadas como temáticas: a formação continuada de profissionais e pesquisadores; o significado da religiosidade/espiritualidade ao longo da trajetória, e sua repercussão na qualidade de vida do idoso; os programas sócio-educacionais para idosos e concepções sobre educação; o monitoramento da mídia na cobertura da crescente longevidade e seus impactos. Em identidade e modos de morar reflete-se sobre soluções planejadas e sua adequação para a inclusão do envelhecimento populacional como questão fundamental, que implica a elaboração de novas políticas, investigações e, especialmente, apresenta-se como questão a ser analisada, refletida e vivenciada pela sociedade em geral. Quanto à saúde, o Programa desenvolve várias pesquisas numa abordagem interdisciplinar tendo como objetos de estudo: a terapia assistida com animais direcionada a idosos com diagnóstico de Alzheimer; o acompanhamento terapêutico e o atendimento psicoterapêutico em grupo, a aplicação da técnica de Calatonia em idosos moradores de ILPI, além da investigação sobre impasses clínicos no idoso frágil. Palavras-chave: gerontologia, longevidade, envelhecimento

  12. Conjecturas da Epistemológia Jurídica e Aspectos da Teoria da Linguagem

    OpenAIRE

    Oliveira, Rita de Cássia Cartelli de; Cesumar; Motta, Ivan Dias; Cesumar

    2008-01-01

    Apresentar-se-ão reflexões em torno da epistemologia jurídica e alguns aspectos da teoria da linguagem; a necessidade de acompanhamento e aprimoramento da linguagem jurídica, para que o direito não se distancie da realidade, mantendo-se apenas como um sistema do status quo; uma breve análise de algumas teorias da ciência do direito e da linguagem; as especificidades dos termos lingüísticos para a análise da ciência do direito, pautada na contemporaneidade sob a perspectiva humanista, buscando...

  13. Post harvest changes gamma-irradiated banana Prata; Modificações pós-colheita de banana 'prata' y-irradiada

    Energy Technology Data Exchange (ETDEWEB)

    Vilas Boas, E.V. de; Chitarra, A. B.; Chitarra, M. I.F.

    1996-09-15

    The effect of the gamma-irradiation was evaluated at 0.25 and 0.50 kGy, on the development of peel coloration, CO{sub 2} and ethylene evolution, conversion of starch to sugars, pulp-to-peel ratio, pectic solubilization and activities of enzymes of the cell wall, pectin methylesterase (PME), and polygalacturonase (PG), during maturation of 'Prata' bananas. The gamma-irradiation did not affect the normal colour development of the fruits. An increase in the ethylene peak and a decrease in the CO{sub 2} peak was observed. The gamma-irradiation did not affect the degradation of starch, while a delay in soluble sugar accumulation was noted on the 6 and 7 colour grades. The fruits subjected to 0.25 kGy had the highest increase in the pulp-to-peel relation, beginning with colour grade 5, due to a possible stress effect of that dose. An increase of pectin solubilization was observed. Higher PME activities were exhibited by irradiated fruits, although the gamma-irradiation suppressed the PG activity throughout the maturation period. The gamma-irradiation did not extend the post-harvest life of 'Prata' bananas. (author) [Portuguese] Avaliou-se o efeito da radiacao y a 0,25 e 0,50 kGy sobre o desenvolvimento da coloracao da casca da banana, a evolucao de etileno e CO{sub 2} a conversao de amido em acucares, a relacao polpa/casca, a solubilizacao pectica e as atividades das enzimas relacionadas a degradacao da parede celular, a pectinametilesterase (PMF) e poligalacturonase (PG), na polpa da banana 'prata' durante sua maturacao. A radiacao y nao afetou o desenvolvimento normal da coloracao da casca; entretanto, incrementou o pico de etileno e reduziu o pico de CO{sub 2}. A radiacao y nao afetou a degradacao do amido, mas determinou um efeito retardador sobre o acumulo de acucares soluveis totais na polpa, nos graus 6 e 7 de coloracao da casca. A dose 0,25 kGy determinou o maior incremento na relacao polpa/casca, a partir do grau 5 de coloracao, resultado de um possivel efeito

  14. CONDICIONANTES DA COMPETITIVIDADE EMPRESARIAL

    Directory of Open Access Journals (Sweden)

    José Luiz Contador

    2010-03-01

    Full Text Available Este trabalho examina teoricamente os fatores determinantes da competitividade do produto e do negócio, imprescindíveis à elaboração de estratégias competitivas que visam à obtenção e sustentação de vantagens competitivas. Esse tema é objeto tanto da área de marketing estratégico quanto da de estratégia empresarial. Nas duas áreas, há um ponto de consenso que afirma que a empresa deve diferenciar sua oferta para conquistar e manter vantagem competitiva. Mas, os estudos conduzidos por meio do modelo de Campos e Armas da Competição revelaram que a empresa pode diferenciar seu produto e/ou serviço de modo mais amplo, levando em consideração, na formulação da sua estratégia competitiva, também o campo da competição, quer do produto, quer dela própria. Assim, o objetivo deste artigo é evidenciar que, para a empresa ser competitiva, além de diferenciar seu produto e/ou seu serviço no sentido tradicional, ela precisa: 1 diferenciar seu produto incluindo a definição em quais campos vai competir em cada segmento; e 2 escolher as armas da competição que irá utilizar e definir a intensidade de cada arma. Para atingir tal objetivo, foram necessários vários conceitos do modelo de Campos e Armas da Competição: campo da competição, arma da competição, tese do modelo, configuração dos campos da competição, campo coadjuvante, produto coadjuvante e par produto-mercado. Como uma proposta inovadora sempre desperta dúvida, é mostrado o processo de validação do modelo de Campos e Armas da Competição e são discutidas sua universalidade, consistência e completude.

  15. Laser Propulsion - Quo Vadis

    International Nuclear Information System (INIS)

    Bohn, Willy L.

    2008-01-01

    First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community

  16. Efeito da eutonia no tratamento da fibromialgia

    OpenAIRE

    Maeda,Cecília; Martinez,José Eduardo; Neder,Matilde

    2006-01-01

    OBJETIVO: avaliar a eutonia como método terapêutico auxiliar no tratamento da fibromialgia (FM). MÉTODOS: estudou-se um grupo de 20 mulheres, segundo os critérios do American College of Rheumatology (ACR), com duração mínima de seis meses, sem alterações no tratamento medicamentoso ou prescrição de exercícios nesse período. As pacientes foram avaliadas através do questionário de dados sociodemográficos; Escala Visual Analógica (EVA) para dor e questionário genérico de avaliação da qualidade d...

  17. Het Italiaanse voorzetsel da

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In een voorzetselstudie in het kader van Jackendoffs semantische theorie wordt het sterk polyseme Italiaanse voorzetsel da geanalyseerd als een verzameling deelbetekenissen waarbij de meeste door een of meer semantische regels afgeleid kunnen worden van de basisbetekenis ruimtelijke

  18. ESPECTROS INFRAVERMELHOS DA CREATINA

    Directory of Open Access Journals (Sweden)

    Kumiko K. Sakane

    2011-08-01

    Full Text Available São apresentados espectros infravermelhos da creatina, na faixa de 4000 a 400 cm−1. Os resultados são comparados com espectros observados e calculados, publicados na literatura.

  19. Significados Ocultos da Enfermagem

    Directory of Open Access Journals (Sweden)

    Wiliam César alves Machado

    2011-04-01

    Full Text Available Sabe-se que as ações de cuidar em enfermagem foram sendo moldadas através da história da humanidade e deram-se, majoritariamente, na esfera do subjetivo que permeia as interações existenciais do ser humano que cuida e daquele que recebe cuidados. Campo fecundo para intercâmbios eletromagnéticos. Suas origens remontam ao cuidado prestado por mães, pais, avós, irmãos e demais familiares incumbidos da responsabilidade de ajudar entes recém-natos, crianças, doentes e idosos em suas necessidades de cuidados para preservação da vida.

  20. Evaluation of microleakage occurred in class V restoration prepared with Er:YAG laser and also with high speed, restored using composite; Avaliacao da microinfiltracao em cavidades classe V preparada com laser de Er:YAG ou alta rotacao, jateadas ou nao com bicarbonato de sodio e restauradas com resina composta

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Angelo Maercio Finochio

    2002-07-01

    The microleakage is one of the great problems found in restoring dentistry. In spite of adhesive system evolution, several materials have been studied intending to minimize or to eliminate the microleakage occurred between the tooth and restorative material. The objective of this in vitro study was to evaluate and compare the marginal microleakage in class V cavities prepared by Er:YAG laser or high speed and restored with composite resin. One of the groups received the sodium bicarbonate jet while the other group have not received. Twenty teeth third extracted molars were sectioned in the sense medial-distal being obtained forty samples that were divided in four groups: Group I (G1): prepared with Er:YAG laser (2940 nm), E= 350 mJ/p, F=2 Hz, fluency of 112,5 J/cm{sup 2}. Preparing occlusion margin slice with 250 mJ/p, F=2 Hz, fluency of 80,3 J/cm{sup 2}. The prepared total area was irradiated with E=80 mJ/p, F=2 Hz and fluency of 25,75 J/cm{sup 2}. Every prepared area was finally submitted to sodium bicarbonate jet. Group 2 (G2): it was employed the same parameters used on group 1, except the sodium carbonate jet application. Group 3 (G3): the cavities' prepare were executed with high speed rotation using diamond cylindrical point. The slice confection has been made with the same point with 45 degrees inclined, utilizing also the sodium carbonate jet in all prepared area. Group 4 (G4): it was executed similarly prepared to group 3, without the sodium bicarbonate jet. In all the groups the cavities were washed with water spray and drought with air jet. Dentin and enamel surfaces have been conditioned with phosphoric acid at 35%. All the samples of all groups were restored using the single bond system adhesive and composite resin Z250, kept at 37 deg C in stove during 24 hours, thermally stressed, immersed in silver nitrate solution at 50% for 24 hours while kept in darkness. The specimens were soaked in photo developing solution and exposed to fluorescent light for

  1. Evaluation of microleakage occurred in class V restoration prepared with Er:YAG laser and also with high speed, restored using composite; Avaliacao da microinfiltracao em cavidades classe V preparada com laser de Er:YAG ou alta rotacao, jateadas ou nao com bicarbonato de sodio e restauradas com resina composta

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Angelo Maercio Finochio

    2002-07-01

    The microleakage is one of the great problems found in restoring dentistry. In spite of adhesive system evolution, several materials have been studied intending to minimize or to eliminate the microleakage occurred between the tooth and restorative material. The objective of this in vitro study was to evaluate and compare the marginal microleakage in class V cavities prepared by Er:YAG laser or high speed and restored with composite resin. One of the groups received the sodium bicarbonate jet while the other group have not received. Twenty teeth third extracted molars were sectioned in the sense medial-distal being obtained forty samples that were divided in four groups: Group I (G1): prepared with Er:YAG laser (2940 nm), E= 350 mJ/p, F=2 Hz, fluency of 112,5 J/cm{sup 2}. Preparing occlusion margin slice with 250 mJ/p, F=2 Hz, fluency of 80,3 J/cm{sup 2}. The prepared total area was irradiated with E=80 mJ/p, F=2 Hz and fluency of 25,75 J/cm{sup 2}. Every prepared area was finally submitted to sodium bicarbonate jet. Group 2 (G2): it was employed the same parameters used on group 1, except the sodium carbonate jet application. Group 3 (G3): the cavities' prepare were executed with high speed rotation using diamond cylindrical point. The slice confection has been made with the same point with 45 degrees inclined, utilizing also the sodium carbonate jet in all prepared area. Group 4 (G4): it was executed similarly prepared to group 3, without the sodium bicarbonate jet. In all the groups the cavities were washed with water spray and drought with air jet. Dentin and enamel surfaces have been conditioned with phosphoric acid at 35%. All the samples of all groups were restored using the single bond system adhesive and composite resin Z250, kept at 37 deg C in stove during 24 hours, thermally stressed, immersed in silver nitrate solution at 50% for 24 hours while kept in darkness. The specimens were soaked in photo developing solution and exposed to fluorescent

  2. ORIGEM DA ANGTIA MODERNA

    Directory of Open Access Journals (Sweden)

    Edvino Rabuske

    1971-01-01

    Full Text Available O tema que me foi proposto "origem da angtia moderna". Por certo, um tema extremamente complexo. Trata-se de surpreender as modalidades modernas de um fenomeno, antigo como o prrio homem. Visando contribuir numa semana de reflexo sobre a esperan crist em, que esta abordada a partir, de diversos gulos, parece indicado que esta exposio n se atenha a um ico aspeto da angtia.

  3. Laser safety and practice

    International Nuclear Information System (INIS)

    Low, K.S.

    1995-01-01

    Lasers are finding increasing routine applications in many areas of science, medicine and industry. Though laser radiation is non-ionizing in nature, the usage of high power lasers requires specific safety procedures. This paper briefly outlines the properties of laser beams and various safety procedures necessary in their handling and usage. (author)

  4. Diode lasers and arrays

    International Nuclear Information System (INIS)

    Streifer, W.

    1988-01-01

    This paper discusses the principles of operation of III-V semiconductor diode lasers, the use of distributed feedback, and high power laser arrays. The semiconductor laser is a robust, miniature, versatile device, which directly converts electricity to light with very high efficiency. Applications to pumping solid-state lasers and to fiber optic and point-to-point communications are reviewed

  5. Laser cladding with powder

    NARCIS (Netherlands)

    Schneider, M.F.; Schneider, Marcel Fredrik

    1998-01-01

    This thesis is directed to laser cladding with powder and a CO2 laser as heat source. The laser beam intensity profile turned out to be an important pa6 Summary rameter in laser cladding. A numerical model was developed that allows the prediction of the surface temperature distribution that is

  6. Semiconductor laser shearing interferometer

    International Nuclear Information System (INIS)

    Ming Hai; Li Ming; Chen Nong; Xie Jiaping

    1988-03-01

    The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

  7. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  8. Laser Microdissection.

    Science.gov (United States)

    Frost, Andra R; Eltoum, Isam-Eldin; Siegal, Gene P; Emmert-Buck, Michael R; Tangrea, Michael A

    2015-10-01

    Laser microdissection (LM) offers a relatively rapid and precise method of isolating and removing specified cells from complex tissues for subsequent analysis of their RNA, DNA, protein or metabolite content, thereby allowing assessment of the role of different cell types in the normal physiological or disease processes being studied. In this unit, protocols for the preparation of mammalian frozen tissues, fixed tissues, and cytologic specimens for LM, including tissue freezing, tissue processing and paraffin embedding, histologic sectioning, cell processing, hematoxylin and eosin staining, immunohistochemistry, and image-guided cell targeting are presented. Also provided are recipes for generating lysis buffers for the recovery of nucleic acids and proteins. The Commentary section addresses the types of specimens that can be utilized for LM and approaches to staining of specimens for cell visualization. Emphasis is placed on the preparation of tissue or cytologic specimens as this is critical to effective LM. Copyright © 2015 John Wiley & Sons, Inc.

  9. Laser EXAFS

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.; Schwenzel, R.E.; Campbell, B.E.

    1983-01-01

    Apparatus for obtaining EXAFS data of a material, comprising means for directing radiant energy from a laser onto a target in such manner as to produce X-rays at the target of a selected spectrum and intensity, suitable for obtaining the EXAFS spectrum of the material, means for directing X-rays from the target onto spectral dispersive means so located as to direct the spectrally resolved X-rays therefrom onto recording means, and means for positioning a sample of material in the optical path of the X-rays, the recording means providing a reference spectrum of X-rays not affected by the sample and absorption spectrum of X-rays modified by transmission through the sample

  10. Multibeam Fibre Laser Cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre......-laser cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  11. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  12. Use of the gamma radiation, in a dose of 0,4 kGy, on the storage temperature reduction of the banana nanica;Utilizacao da radiacao gama, na dose de 0,4kGy, na reducao da temperatura de armazenamento da banana nanica

    Energy Technology Data Exchange (ETDEWEB)

    Manoel, Luciana, E-mail: luciana_manoel@yahoo.com.b [Universidade Estadual Paulisa (UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Programa de Pos-graduacao em Energia na Agricultura; Vieites, Rogerio Lopes, E-mail: vieites@fca.unesp.b [Universidade Estadual Paulisa (UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Gestao e Tecnologia Agroindustrial

    2009-07-01

    The aim was to evaluate the use of gamma radiation, in a dose of 0,4 kGy, on the storage temperature reduction of the banana 'Nanica'. The bananas 'Nanica' were harvested in the Arm Taperao, Brotas (SP) town, and sent to CBE (Companhia Brasileira de Esterilizacao-Cotia-SP) for irradiation and constitution of the following treatments: T1 (fruits irradiated at 0,4 kGy and stored at 16 +-1 deg C); T2 (fruits irradiated at 0,4 kGy and stored at 14 +-1 deg C); T3 (fruit irradiated ata 0,4 kGy and stored at 12+-1 deg C); T4 (fruits non-irradiated and stored at 16+-1 deg C); T5 (fruits non-irradiated and stored at 14+-1 deg C) and T6 (fruits non-irradiated and stored at 12+-1 deg C). The fruits were stored in B.O.Ds. of the Agroindustrial Management and Technology Department, with a relative humidity of 80+-5%. The experiment was divided in two groups: control group (post harvest conservation and disease incidence) and parcel group (soluble solids and pulp/peel). The analyses were performed in intervals of five days during a period of 25 days. The experimental design employed was completely randomized (DIC) by applying a factor of 2 x 3 x 6 (irradiation x temperature x time). The Tukey test with 5% of probability was used for comparison between means. The storage temperature of the bananas 'Nanica' was not reduce by irradiation. (author)

  13. Study of seasonal variation of the gamma radiation at Praia da Areia Preta, Guarapari, Espirito Santo, Brazil: radiometry and risk analysis; Estudo da variacao sazonal dos niveis de radiacao gama na Praia da Areia Preta, Guarapari, Espirito Santo, Brasil: radiometria e analise de risco ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Jorge Costa de

    2003-07-01

    The objective of this work is the study of the natural gamma radiation at the Areia Preta Beach (APB) in Guarapari, state of Espirito Santo, Brazil. The level of this radiation is dependent on the concentration of the radioactive mineral monazite in the sand. Probable risks of the exposure to gamma radiation at the APB were evaluated by the preliminary environmental risk analysis technique. For this purpose were conducted two annual sets monitoring gamma radiation in the APB every two months and so, acquired the seasonal variation of the radioactive levels. Additional/y was investigated the granulometry of the heavy mineral fraction and also carried out electronic microscopic scanning and radiometric age dating of the monazites of the APB, the mineral separation by magnetic susceptibility, and the mineralogic determination of the sediment. In order to gain a more complete picture of the seasonal variation, and, consequently, of the risk of exposure to ionizing radiation at the APB, the radiometric variation was also studied at some other beaches in the same region. The results indicate that the highest radiometric values are measured in summer and the lowest in winter. The radiometric dating of the monazites from the APB revealed the ages of 475 and 530 Ma. The Preliminary Hazard Analysis indicates a minimum risk of excessive radioactive exposition. It would take a period of approximately 870 years of a beach fully crowded to result in one case of bad consequences due to exposure to gamma radiation. (author)

  14. Evaluation of seawater contamination with benzene, toluene and xylene in the Ubatuba north coast, SP region, and study of their removal by ionizing radiation; Avaliacao da contaminacao da agua do mar por benzeno, tolueno e xileno na regiao de Ubatuba, litoral norte (SP) e estudo da degradacao destes compostos por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Kelly Cristina Santana de

    2006-07-01

    A major concern with leaking petroleum is the environmental contamination by the toxic and low water-soluble components such as benzene, toluene, and xylenes (BTX). These hydrocarbons have relatively high pollution potential because of their significant toxicity. The objective of this study was to evaluate the contamination of seawater by the main pollutants of the output and transport of petroleum, such as benzene, toluene, and xylene, and their removal by the exposure to the ionizing radiation. The studied region was Ubatuba region, SP, between 23 deg 26'S and 23 deg 46'S of latitude and 45 deg 02'W and 45 deg 11'W of longitude, area of carry and output of petroleum, and samples were collected from November, 2003 to July, 2005. For BTX in seawater analysis, the Purge and Trap concentrator with FIDGC detector showed significantly higher sensibility than Head Space concentrator with MSGC detector. The minimal detected limits (MDL) obtained at FIDGC were of 0.50 {mu}g/L for benzene, 0.70 {mu}g/L for toluene, and 1.54 {mu}g/L for xylene, and the obtained experimental variability was 15%. While the concentrator type Headspace system with MS detector showed higher MLD, about of 9.30 mg/L for benzene, 8.50 mg/L for toluene, and 9.80 mg/L for xylene, and 10% of experimental variability. In the studied area the benzene concentration varied from 1.0 {mu}g/L to 2.0 {mu}g/L, the concentration of toluene varied from < 0.70 {mu}g/L to 3.24 {mu}g/L and the maximum value of xylene observed was of 2.92 {mu}g/L. The seawater samples contaminated with BTX standard and exposed to ionizing radiation using a source of {sup 60}Co, presented a removal from 10% to 40% of benzene at 20 kGy absorbed doses and concentration of 35.1 mg/L and 70.2 mg/L, respectively; from 20% to 60% of toluene removal with 15 kGy absorbed dose and from 20% to 80% of xylene with 15 kGy absorbed dose in similar concentrations. (author)

  15. Study of the rice husk ash utilization as filler polypropylene matrix and ionization radiation effect on this composite; Estudos da utilizacao da cinza de casca de arroz como carga em matriz de polipropileno e do efeito da radiacao ionizante sobre este composito

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro, Eduardo de Faria

    2010-07-01

    In the first step of this work, it was evaluated the possibility of using rice husk ash as a filler in polypropylene (PP) making a comparison with talc which is the most used mineral filler in polymers. This comparison was made by using polypropylene with 20% rice husk ash as well as polypropylene with 20% talc measuring their properties. Despite the properties of the PP with 20% rice husk ash decreased compared with the composite of polypropylene with 20% talc it can be said that the rice husk ash can be used as filler for or other utilization less noble of PP . This way it is being given a destination for this residue that it is disposable in the environment contributing to its preservation, moreover reducing the product cost. This work had also as an aim to study the ionizing radiation effect in the properties of these composites. It was used the coupling agent, maleic anhydride , to verify a best sample homogenization. According to the results it can be said that PP is a semicrystalline polymer, and so it has its morphology modified when exposed to the irradiation process. This fact is due to the scission mechanisms of the polymeric chains which it is in compliance to the literature. (author)

  16. Evaluation of seawater contamination with benzene, toluene and xylene in the Ubatuba north coast, SP region, and study of their removal by ionizing radiation; Avaliacao da contaminacao da agua do mar por benzeno, tolueno e xileno na regiao de Ubatuba, litoral norte (SP) e estudo da degradacao destes compostos por radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Kelly Cristina Santana de

    2006-07-01

    A major concern with leaking petroleum is the environmental contamination by the toxic and low water-soluble components such as benzene, toluene, and xylenes (BTX). These hydrocarbons have relatively high pollution potential because of their significant toxicity. The objective of this study was to evaluate the contamination of seawater by the main pollutants of the output and transport of petroleum, such as benzene, toluene, and xylene, and their removal by the exposure to the ionizing radiation. The studied region was Ubatuba region, SP, between 23 deg 26'S and 23 deg 46'S of latitude and 45 deg 02'W and 45 deg 11'W of longitude, area of carry and output of petroleum, and samples were collected from November, 2003 to July, 2005. For BTX in seawater analysis, the Purge and Trap concentrator with FIDGC detector showed significantly higher sensibility than Head Space concentrator with MSGC detector. The minimal detected limits (MDL) obtained at FIDGC were of 0.50 {mu}g/L for benzene, 0.70 {mu}g/L for toluene, and 1.54 {mu}g/L for xylene, and the obtained experimental variability was 15%. While the concentrator type Headspace system with MS detector showed higher MLD, about of 9.30 mg/L for benzene, 8.50 mg/L for toluene, and 9.80 mg/L for xylene, and 10% of experimental variability. In the studied area the benzene concentration varied from 1.0 {mu}g/L to 2.0 {mu}g/L, the concentration of toluene varied from < 0.70 {mu}g/L to 3.24 {mu}g/L and the maximum value of xylene observed was of 2.92 {mu}g/L. The seawater samples contaminated with BTX standard and exposed to ionizing radiation using a source of {sup 60}Co, presented a removal from 10% to 40% of benzene at 20 kGy absorbed doses and concentration of 35.1 mg/L and 70.2 mg/L, respectively; from 20% to 60% of toluene removal with 15 kGy absorbed dose and from 20% to 80% of xylene with 15 kGy absorbed dose in similar concentrations. (author)

  17. History and principle of lasers

    International Nuclear Information System (INIS)

    Townes, Ch.H.; Schwob, C.; Julien, J.; Forget, S.; Robert-Philip, I.; Balcou, Ph.

    2010-01-01

    In the first article C.H. Townes, the inventor of the maser, describes the work and ideas that led to the invention of the laser. The second article explains how a laser operate and the third article reviews the main different types of laser: solid lasers, gas lasers, diode lasers and dye lasers

  18. Technological laser application

    International Nuclear Information System (INIS)

    Shia, D.O.; Kollen, R.; Rods, U.

    1980-01-01

    Problems of the technological applications of lasers are stated in the popular form. Main requirements to a technological laser as well as problems arising in designing any system using lasers have been considered. Areas of the laser applications are described generally: laser treatment of materials, thermal treatment, welding, broach and drilling of holes, scribing, microtreatment and adjustment of resistors, material cutting, investigations into controlled thermonuclear fussion

  19. Laser ablation principles and applications

    CERN Document Server

    1994-01-01

    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  20. As dobras da imagem

    Directory of Open Access Journals (Sweden)

    Profª. Drª. Fátima Antunes da Silva (Yaska Antunes

    2009-05-01

    Full Text Available O presente trabalho tem por objetivo tentar compreender a produção da imagem visual no teatro. Para isso se vale da apropriação livre do conceito de “dobra? de Gilles Deleuze para se referir à multiplicidade de imagens criadas pelas diversas modalidades artísticas. Como no teatro há o entrelaçamento de imagens verbais – palavras enunciadas pelo texto dramático ou teatral – com imagens visuais – a visualidade advinda da composição cênica concreta que organiza no espaço ator e objeto –, a ênfase só podia recair sobre estas duas formas imagéticas. No caso do teatro, surge ainda a percepção de que para além da materialidade da cena, outras imagens emergem do confronto entre palco e platéia. Nesse sentido, imagem teatral seria então aquilo que surge da interação entre ator e espectador. A contribuição desse trabalho pode estar no fato de atualizar certos conceitos sobre a criação da imagem poética na poesia e no cinema para aplicá-los ao teatro. Ao recuperar o pensa-mento de Otávio Paz, Alfredo Bosi, Sergei Eisenstein, entre outros, bus-ca-se promover uma reflexão mais aprofundada sobre a construção visual no teatro.

  1. New power lasers

    International Nuclear Information System (INIS)

    Yamanaka, Masanobu; Daido, Hiroyuki; Imasaki, Kazuo.

    1989-01-01

    As the new power lasers which are expected to exert large extending effect to the fields of advanced science and technology including precision engineering as well as laser nuclear fusion, LD-excited solid laser, X-ray laser and free electron laser are taken up and outlined. Recently, the solid laser using high power output, high efficiency semiconductor laser as the exciting beam source has been developed. This is called laser diode (LD)-excited solid laser, and the heightening of power output and efficiency and the extension of life are planned. Its present status and application to medical use, laser machining, laser soldering and so on are described. In 1960, the laser in visible region appeared, however in 1985, the result of observing induced emission beam by electron collision exciting method was reported in USA. In the wavelength range of 200 A, holography and contact X-ray microscope applications were verified. The various types of soft X-ray laser and the perspective hereafter are shown. The principle of free electron laser is explained. In the free electron laser, wavelength can be changed by varying electron beam energy, the period of wiggler magnetic field and the intensity of magnetic field. Further, high efficiency and large power output are possible. Its present status, application and the perspective hereafter are reported. (K.I.)

  2. Laser applications in materials processing

    International Nuclear Information System (INIS)

    Ready, J.F.

    1980-01-01

    The seminar focused on laser annealing of semiconductors, laser processing of semiconductor devices and formation of coatings and powders, surface modification with lasers, and specialized laser processing methods. Papers were presented on the theoretical analysis of thermal and mass transport during laser annealing, applications of scanning continuous-wave and pulsed lasers in silicon technology, laser techniques in photovoltaic applications, and the synthesis of ceramic powders from laser-heated gas-phase reactants. Other papers included: reflectance changes of metals during laser irradiation, surface-alloying using high-power continuous lasers, laser growth of silicon ribbon, and commercial laser-shock processes

  3. Trauma da Veia Porta

    Directory of Open Access Journals (Sweden)

    Gustavo Pereira Fraga

    Full Text Available OBJETIVO: O trauma da veia porta é raro e freqüentemente fatal por causa de exsanguinação e alta incidência de lesões de estruturas adjacentes. Devido às pecualiaridades desta lesão e diferentes condutas propostas na literatura, o objetivo dos autores é relatar a experiência neste tipo de lesão. MÉTODO: Estudo retrospectivo, de janeiro de 1994 e dezembro de 2001, de 1370 pacientes submetidos à laparotomia devido trauma abdominal. Entre esses, 15 pacientes apresentavam lesão da veia porta. As lesões foram classificadas conforme a sua extensão e localização. RESULTADOS: O mecanismo de trauma predominante foi o penetrante. O diagnóstico da lesão foi realizado no intraoperatório. Os procedimentos executados foram: sutura, anastomose término-terminal e ligadura da veia porta. A mortalidade foi de 53,3%. CONCLUSÃO: A lesão da veia porta possui alta taxa de mortalidade e o atendimento adequado está diretamente relacionado à sobrevida.

  4. Raman fiber lasers

    CERN Document Server

    2017-01-01

    This book serves as a comprehensive, up-to-date reference about this cutting-edge laser technology and its many new and interesting developments. Various aspects and trends of Raman fiber lasers are described in detail by experts in their fields. Raman fiber lasers have progressed quickly in the past decade, and have emerged as a versatile laser technology for generating high power light sources covering a spectral range from visible to mid-infrared. The technology is already being applied in the fields of telecommunication, astronomy, cold atom physics, laser spectroscopy, environmental sensing, and laser medicine. This book covers various topics relating to Raman fiber laser research, including power scaling, cladding and diode pumping, cascade Raman shifting, single frequency operation and power amplification, mid-infrared laser generation, specialty optical fibers, and random distributed feedback Raman fiber lasers. The book will appeal to scientists, students, and technicians seeking to understand the re...

  5. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  6. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture

  7. Ceramic Laser Materials

    Science.gov (United States)

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  8. Spectroscopic and imaging diagnostics of pulsed laser deposition laser plasmas

    International Nuclear Information System (INIS)

    Thareja, Raj K.

    2002-01-01

    An overview of laser spectroscopic techniques used in the diagnostics of laser ablated plumes used for thin film deposition is given. An emerging laser spectroscopic imaging technique for the laser ablation material processing is discussed. (author)

  9. Da Vinci Linjen

    DEFF Research Database (Denmark)

    Nissen, Poul

    Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin.......Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin....

  10. Thin-sheet zinc-coated and carbon steels laser welding

    Directory of Open Access Journals (Sweden)

    Peças, P.

    1998-04-01

    Full Text Available This paper describes the results of a research on CO2 laser welding of thin-sheet carbon steels (zinccoated and uncoated, at several thicknesses combinations. Laser welding has an high potential to be applied on sub-assemblies welding before forming to the automotive industry-tailored blanks. The welding process is studied through the analysis of parameters optimization, metallurgical quality and induced distortions by the welding process. The clamping system and the gas protection system developed are fully described. These systems allow the minimization of common thin-sheet laser welding defects like misalignement, and zinc-coated laser welding defects like porous and zinc volatilization. The laser welding quality is accessed by DIN 8563 standard, and by tensile, microhardness and corrosion tests.

    Este artigo descreve os resultados da investigação da soldadura laser de CO2 de chapa fina de acó carbono (simples e galvanizado, em diferentes combinações de espessura. A soldadura laser é um processo de elevado potencial no fabrico de tailored-blanks (sub-conjuntos para posterior enformação, constituidos por varias partes de diferentes materiais e espessuras para a indústria automóvel. São analisados os aspectos de optimização paramétrica, de qualidade metalúrgica da junta soldada e das deformações resultantes da soldadura. São descritos os mecanismos desenvolvidos de fixação das chapas e protecção gasosa, por forma a minimizar os defeitos típicos na soldadura laser de chapa fina como o desalinhamento e da soldadura laser de chapa galvanizada como os poros e a volatilização do zinco. Por fim apresentam-se resultados da avaliação da qualidade da soldadura do ponto de vista qualitativo através da norma DIN 8563, e do pontos de vista quantitativo através de ensaios de tracção, dureza e corrosão.

  11. Lasers in periodontics.

    Science.gov (United States)

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-08-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  12. Excimer laser applications

    International Nuclear Information System (INIS)

    Fantoni, R.

    1988-01-01

    This lecture deals with laser induced material photoprocessing, especially concerning those processes which are initiated by u.v. lasers (mostly excimer laser). Advantages of using the u.v. radiation emitted by excimer lasers, both in photophysical and photochemical processes of different materials, are discussed in detail. Applications concerning microelectronics are stressed with respect to other applications in different fields (organic chemistry, medicine). As further applications of excimer lasers, main spectroscopic techniques for ''on line'' diagnostics which employ excimer pumped dye lasers, emitting tunable radiation in the visible and near u.v. are reviewed

  13. Lasers in chemical processing

    International Nuclear Information System (INIS)

    Davis, J.I.

    1982-01-01

    The high cost of laser energy is the crucial issue in any potential laser-processing application. It is expensive relative to other forms of energy and to most bulk chemicals. We show those factors that have previously frustrated attempts to find commercially viable laser-induced processes for the production of materials. Having identified the general criteria to be satisfied by an economically successful laser process and shown how these imply the laser-system requirements, we present a status report on the uranium laser isotope separation (LIS) program at the Lawrence Livermore National Laboratory

  14. Laser in urology. Laser i urologien

    Energy Technology Data Exchange (ETDEWEB)

    Breisland, H.O. (Aker Sykehus, Oslo (Norway))

    1991-09-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs.

  15. Laser materials processing with diode lasers

    OpenAIRE

    Li, Lin; Lawrence, Jonathan; Spencer, Julian T.

    1996-01-01

    Laser materials processing is currently dominated by CO2, Nd-YAG and Excimer lasers. Continuous advances in semiconductor laser technology over the last decade have increased the average power output of the devices annualy by two fold, resulting in the commercial availability of the diode lasers today with delivery output powers in excess of 60W in CW mode and 5kW in qasi-CW mode. The advantages of compactness, high reliability, high efficiency and potential low cost, due to the mass producti...

  16. 1982 laser program annual report

    International Nuclear Information System (INIS)

    Hendricks, C.D.; Grow, G.R.

    1983-08-01

    This annual report covers the following eight sections: (1) laser program review, (2) laser systems and operation, (3) target design, (4) target fabrication, (5) fusion experiments program, (6) Zeus laser project, (7) laser research and development, and (8) energy applications

  17. The impact of treatment density and molecular weight for fractional laser-assisted drug delivery

    DEFF Research Database (Denmark)

    Haak, Christina S; Bhayana, Brijesh; Farinelli, William A

    2012-01-01

    Ablative fractional lasers (AFXL) facilitate uptake of topically applied drugs by creating narrow open micro-channels into the skin, but there is limited information on optimal laser settings for delivery of specific molecules. The objective of this study was to investigate the impact of laser...... treatment density (% of skin occupied by channels) and molecular weight (MW) for fractional CO(2) laser-assisted drug delivery. AFXL substantially increased intra- and transcutaneous delivery of polyethylene glycols (PEGs) in a MW range from 240 to 4300 Da (Nuclear Magnetic Resonance, p...

  18. Profilaxia da peste

    Directory of Open Access Journals (Sweden)

    Renato dos Santos Araújo

    1967-12-01

    Full Text Available O autor parte da premissa de que a profilaxia da doença infecciosa decorre do encadeamento epidemiológico: fonte de infecção-veículo transmissor - receptivel, para explicar a da peste, baseada no mesmo princípio. Depois de citar os 4 principais complexos epidemiológicos da peste e afirmar que tôda a profilaxia da doença consiste em atingir os dois primeiros elos dessas cadeias e proteger o último, passa a classificar os vários métodos profiláticos empregados em 2 grandes grupos: o das medidas destrutivas ou provisórias e o das medidas supressivas ou definitivas. Entre as primeiras arrola a desratização e a despulização, às quais acrescenta o tratamento e isolamento do doente e do portaãor, e entre as segundas inclui a anti-ratização e a imunização. A seguir, passa a explicar em que consistem essas várias medidas profiláticas e quais os agentes de que se tem lançado mão para executá-las, expendendo ao curso dessa exposição o conceito que formula a respeito de cada uma delas, à guisa de apreciação do seu valor relativo. Enaltece sobretudo as medidas supressivas ou definitivas, às quais empresta a maior significação na luta antipestosa, chamando a atenção, em especial, para a necessidade de estudos imunológicos para aperfeiçoamento do poder imunitário das vacinas de germes vivos avirulentos, que considera um grande recurso para a profilaxia da doença, sobretudo para a proteção do rurícola, cujo labor e modo de vida o expõem inevitavelmente a se infectar, por ocasião da ocorrência de epizootias de origem silvestre. Concluída essa primeira parte, passa a fazer o histórico de como se desenvolveu a campanha contra a peste, no Brasil, desde a época da sua invasão em 1899 pelo pôrto de Santos até os nossos dias. Nesse histórico, detem-se um pouco para expôr a atuação do extinto Serviço Nacional de Peste, o qual, criado em 1941, após a reorganização do Departamento Nacional de Saúde, passou

  19. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  20. Laser in operative dentistry

    Directory of Open Access Journals (Sweden)

    E. Yasini

    1994-06-01

    Full Text Available Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry, etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.

  1. Laser for fusion energy

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1995-01-01

    Solid state lasers have proven to be very versatile tools for the study and demonstration of inertial confinement fusion principles. When lasers were first contemplated to be used for the compression of fusion fuel in the late 1950s, the laser output energy levels were nominally one joule and the power levels were 10 3 watts (pulse duration's of 10 -3 sec). During the last 25 years, lasers optimized for fusion research have been increased in power to typically 100,000 joules with power levels approaching 10 14 watts. As a result of experiments with such lasers at many locations, DT target performance has been shown to be consistent with high gain target output. However, the demonstration of ignition and gain requires laser energies of several megajoules. Laser technology improvements demonstrated over the past decade appear to make possible the construction of such multimegajoule lasers at affordable costs. (author)

  2. Radiological protection against lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ballereau, P

    1974-04-01

    A brief description of the biological effects of laser beams is followed by a review of the factors involved in eye and skin damage (factors linked with the nature of lasers and those linked with the organ affected) and a discussion of the problems involved in the determination of threshold exposure levels. Preventive measures are recommended, according to the type of laser (high-energy pulse laser, continuous laser, gas laser). No legislation on the subject exists in France or in Europe. Types of lasers marketed, threshold exposure levels for eye and skin, variations of admissible exposure levels according to wavelength, etc. are presented in tabular form. Nomogram for determination of safe distance for direct vision of a laser is included.

  3. Advances in Fiber Lasers

    National Research Council Canada - National Science Library

    Morse, T

    1999-01-01

    Most of the time of this contract has been devoted toward improvements in optical fiber lasers and toward gathering experience to improve our program in high power, cladding pumped optical fiber lasers...

  4. Laser Processing and Chemistry

    CERN Document Server

    Bäuerle, Dieter

    2011-01-01

    This book gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of lasers in “standard” laser machining and laser chemical processing (LCP), including the patterning, coating, and modification of material surfaces. This fourth edition has been enlarged to cover the rapid advances in the understanding of the dynamics of materials under the action of ultrashort laser pulses, and to include a number of new topics, in particular the increasing importance of lasers in various different fields of surface functionalizations and nanotechnology. In two additional chapters, recent developments in biotechnology, medicine, art conservation and restoration are summarized. Graduate students, physicists, chemists, engineers, a...

  5. Fiber Laser Array

    National Research Council Canada - National Science Library

    Simpson, Thomas

    2002-01-01

    ...., field-dependent, loss within the coupled laser array. During this program, Jaycor focused on the construction and use of an experimental apparatus that can be used to investigate the coherent combination of an array of fiber lasers...

  6. ISTEF Laser Radar Program

    National Research Council Canada - National Science Library

    Stryjewski, John

    1998-01-01

    The BMDO Innovative Science and Technology Experimentation Facility (BMDO/ISTEF) laser radar program is engaged in an ongoing program to develop and demonstrate advanced laser radar concepts for Ballistic Missile Defense (BMD...

  7. Wavelength sweepable laser source

    DEFF Research Database (Denmark)

    2014-01-01

    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  8. Laser surgery - skin

    Science.gov (United States)

    ... Bleeding Problem not going away Infection Pain Scarring Skin color changes Some laser surgery is done when you are asleep and ... TG, Elston DM, eds. Andrews' Diseases of the Skin: Clinical ... lasers, lights, and tissue interactions. In: Hruza GJ, Avram ...

  9. Laser in operative dentistry

    OpenAIRE

    E. Yasini; Gh. Rahbari; A. Matorian

    1994-01-01

    Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy) and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry), etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks...

  10. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  11. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  12. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  13. Laser technologies for laser accelerators. Annual report

    International Nuclear Information System (INIS)

    1985-01-01

    The primary result of the work reported is the determination of laser system architectures that satsify the requirements of high luminosity, high energy (about 1 TeV), electron accelerators. It has been found that high laser efficiency is a very hard driver for these accelerators as the total average laser output optical power is likely to fall above 10 MW. The luminosity requires rep rates in the kHz range, and individual pulse lengths in the 1-10 psec range are required to satisfy acceleration gradient goals. CO 2 and KrF lasers were chosen for study because of their potential to simultaneously satisfy the given requirements. Accelerator luminosity is reviewed, and requirements on laser system average power and rep rate are determined as a function of electron beam bunch parameters. Laser technologies are reviewed, including CO 2 , excimers, solid state, and free electron lasers. The proposed accelerator mechanisms are summarized briefly. Work on optical transport geometries for near and far field accelerators are presented. Possible exploitation of the CO 2 and DrF laser technology to generate the required pulse lengths, rep rates, and projected efficiencies is illustrated and needed development work is suggested. Initial efforts at developing a 50 GeV benchmark conceptual design and a 100 MeV demonstration experiment conceptual design are presented

  14. Laser induced pyrolysis techniques

    International Nuclear Information System (INIS)

    Vanderborgh, N.E.

    1976-01-01

    The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

  15. Solar pumped laser

    Science.gov (United States)

    Lee, J. H.; Hohl, F.; Weaver, W. R. (Inventor)

    1984-01-01

    A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

  16. Introducing the Yellow Laser

    Science.gov (United States)

    Lincoln, James

    2018-01-01

    The author has acquired a yellow laser with the specific wavelength of 589 nm. Because this is the first time such a laser has been discussed in this journal, I feel it is appropriate to provide a discussion of its function and capabilities. Normal laser safety should be employed, such as not pointing it into eyes or at people, and using eye…

  17. Coatings for laser fusion

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1981-01-01

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors

  18. uv dye lasers

    International Nuclear Information System (INIS)

    Abakumov, G.A.; Fadeev, V.V.; Khokhlov, R.V.; Simonov, A.P.

    1975-01-01

    The most important property of visible dye lasers, that is, continuous wavelength tuning, stimulated the search for dyes capable to lase in uv. They were found in 1968. Now the need for tunable uv lasers for applications in spectroscopy, photochemistry, isotope separation, remote air and sea probing, etc. is clearly seen. A review of some recent advances in uv dye lasers is reviewed

  19. LaserFest Celebration

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25

    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  20. Laser beam cutting method. Laser ko ni yoru kaitai koho

    Energy Technology Data Exchange (ETDEWEB)

    Kutsumizu, A. (Obayashi Corp., Osaka (Japan))

    1991-07-01

    In this special issue paper concerning the demolition of concrete structures, was introduced a demolition of concrete structures using laser, of which practical application is expected due to the remarkable progress of generating power and efficiency of laser radiator. The characteristics of laser beam which can give a temperature of one million centigrade at the irradiated spot, the laser radiator consisting of laser medium, laser resonator and pumping apparatus, and the laser kinds for working, such as CO{sub 2} laser, YAG laser and CO laser, were described. The basic constitution of laser cutting equipment consisting of large generating power radiator, beam transmitter, beam condenser, and nozzle for working was also illustrated. Furthermore, strong and weak points in the laser cutting for concrete and reinforcement were enumerated. Applications of laser to cutting of reinforced and unreinforced concrete constructions were shown, and the concept and safety measure for application of laser to practical demolition was discussed. 5 refs., 8 figs.

  1. da Zehirlenmeleri

    Directory of Open Access Journals (Sweden)

    Necati Akbulut

    2015-02-01

    Full Text Available Gıda Teknolojisinin gelişmesi ile, gıda maddesinin tüketici için daha alımlı olmasını sağlamak, kısa zamanda bozulmasını engellemek ve pazara yeni çeşitler sunmak için bazı kimyasal maddeler kullanılmaya başlanılmıştır. Bunun yanında tarımda kullanılan kimyasal maddeler artmış, ambalaj sanayi gelişmiş, bu dada maddelerine bulaşan maddelerin türlerini arttırmıştır. Ayrıca gıda maddelerine belirli amacı olmadan katılan maddelerde vardır. Diğer taraftan tüketiciyi aldatmak, hile yapmak, çok kar sağlamak veya kötü kaliteyi gizlemek amacı ile de kullanılan maddeler bulunmaktadır. İster teknik zorunluk, ister hile amacıyla olsun bu tür yabancı maddeler öncelikle insan sağlığını ilgilendirmektedir. Bazı maddelerin vücuda alınması sakıncasız olduğu halde, bazıları sakıncalıdır. Sakıncasız olanlarında belirli bir sınırın üzerinde uzun süre alınmaları zararlı olabilmektedir. Bu toplum sağlığı sorunu birçok ülkeyi gıda sanayiinde kullanılan kimyasal maddelerin hoşgörü sınırlarının hesaplanması noktasına götürmüştür.

  2. Introduction to laser technology

    CERN Document Server

    Hitz, C Breck; Hecht, Jeff; Hitz, C Breck; John Wiley & Sons

    2001-01-01

    Electrical Engineering Introduction to Laser Technology , Third Edition. Would you like to know how a laser works, and how it can be modified for your own specific tasks? This intuitive third edition-previously published as Understanding Laser Technology , First and Second Editions-introduces engineers, scientists, technicians, and novices alike to the world of modern lasers, without delving into the mathematical details of quantum electronics. It is the only introductory text on the market today that explains the underlying physics and engineering applicable to all lasers. A unique combinatio.

  3. Quantum well lasers

    CERN Document Server

    Zory, Jr, Peter S; Kelley, Paul

    1993-01-01

    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  4. Coherent laser beam combining

    CERN Document Server

    Brignon, Arnaud

    2013-01-01

    Recently, the improvement of diode pumping in solid state lasers and the development of double clad fiber lasers have allowed to maintain excellent laser beam quality with single mode fibers. However, the fiber output power if often limited below a power damage threshold. Coherent laser beam combining (CLBC) brings a solution to these limitations by identifying the most efficient architectures and allowing for excellent spectral and spatial quality. This knowledge will become critical for the design of the next generation high-power lasers and is of major interest to many industrial, environme

  5. The laser thermonuclear fusion

    International Nuclear Information System (INIS)

    Coutant, J.; Dautray, R.; Decroisette, M.; Watteau, J.P.

    1987-01-01

    Principle of the thermonuclear fusion by inertial confinement: required characteristics of the deuterium-tritium plasma and of the high power lasers to be used Development of high power lasers: active media used; amplifiers; frequency conversion; beam quality; pulse conditioning; existing large systems. The laser-matter interaction: collision and collective interaction of the laser radiation with matter; transport of the absorbed energy; heating and compression of deuterium-tritium; diagnoses and their comparison with the numerical simulation of the experiment; performances. Conclusions: difficulties to overcome; megajoule lasers; other energy source: particles beams [fr

  6. Laser Cutting, Development Trends

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    1999-01-01

    In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type....

  7. Lasers in space.

    CSIR Research Space (South Africa)

    Michaelis, MM

    2008-04-01

    Full Text Available cube, laser beam reflectors, placed on the Moon half a century ago. These early achievements will soon be followed by a plethora of experiments involving lasers in low earth orbit (LEO) or at Lagrange points. And not much later, laser communications... will stretch out as far as Mars and beyond. One important low Earth orbit (LEO) application is the removal of space debris by Earth based or LEO relayed lasers as promoted by Phipps et al.3. Another is military communication. The prominent L1 laser space...

  8. Tunable laser applications

    CERN Document Server

    Duarte, FJ

    2008-01-01

    Introduction F. J. Duarte Spectroscopic Applications of Tunable Optical Parametric Oscillators B. J. Orr, R. T. White, and Y. He Solid-State Dye Lasers Costela, I. García-Moreno, and R. Sastre Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating Homogeneous Distributions of Functional Nanoparticles F. J. Duarte and R. O. James Broadly Tunable External-Cavity Semiconductor Lasers F. J. Duarte Tunable Fiber Lasers T. M. Shay and F. J. Duarte Fiber Laser Overview and Medical Applications

  9. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    Ueda, Kenichi

    2006-01-01

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti 3+ :Al 2 O 3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10 -2 to 67 x 10 3 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti 3+ :Al 2 O 3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  10. Advanced lasers for fusion

    International Nuclear Information System (INIS)

    Krupke, W.F.; George, E.V.; Haas, R.A.

    1979-01-01

    Laser drive systems' performance requirements for fusion reactors are developed following a review of the principles of inertial confinement fusion and of the technical status of fusion research lasers (Nd:glass; CO 2 , iodine). These requirements are analyzed in the context of energy-storing laser media with respect to laser systems design issues: optical damage and breakdown, medium excitation, parasitics and superfluorescence depumping, energy extraction physics, medium optical quality, and gas flow. Three types of energy-storing laser media of potential utility are identified and singled out for detailed review: (1) Group VI atomic lasers, (2) rare earth solid state hybrid lasers, and (3) rare earth molecular vapor lasers. The use of highly-radiative laser media, particularly the rare-gas monohalide excimers, are discussed in the context of short pulse fusion applications. The concept of backward wave Raman pulse compression is considered as an attractive technique for this purpose. The basic physics and device parameters of these four laser systems are reviewed and conceptual designs for high energy laser systems are presented. Preliminary estimates for systems efficiencies are given. (Auth.)

  11. A REFORMA DA IGREJA

    Directory of Open Access Journals (Sweden)

    Vítor Galdino Feller

    2014-01-01

    Full Text Available O pontificado do papa Francisco trouxe à tona o tema da reforma da Igreja. Retoma-se essa causa que acompanha a história da Igreja desde os seus primórdios e que interessa a todos os membros do povo santo de Deus. O texto divide-se em quatro partes. Primeiro, faz-se um apanhado histórico dos anseios de reforma da Igreja, mostrando que, muitas vezes em instâncias subterrâneas, sempre houve o desejo e também ações concretas de renovação. Em seguida, apresenta-se como razão para a reforma da Igreja o anúncio e a realização do Reino de Deus, pelo qual é preciso que a Igreja se volte à concretude humana e histórica de Jesus de Nazaré, pela superação do apego ao poder e às estruturas religiosas. Num terceiro momento, trata-se do critério pelo qual se mede a realização e a veracidade da reforma da Igreja: a santidade de cada fiel e do povo cristão no meio do mundo. Por fim, conclui-se que o caminho para a reforma da Igreja está na escuta dos clamores do Espírito Santo, que fala na própria Igreja e no mundo através do sensus fidei dos fiéis, das Igrejas particulares, dos pobres, das mulheres e das realidades terrestres. ABSTRACT: The pontificate of Pope Francis brought to the surface the theme of reform of the Church. This essay takes up this cause that accompanies the history of the Church from its beginnings and concerns all the members of the holy people of God. The text is divided into four parts. First, it gives a historical summary of the yearnings for reform of the Church, showing that, in many instances subterranean, there has always been the desire and also the concrete actions of renewal. Following from this, the essay presents as the reason for the reform of the Church the proclamation and the realization of the Kingdom of God, whereby it is necessary that the Church return to the concrete human and historical Jesus of Nazareth, in order to overcome the addiction to power and to religious structures. In the

  12. A cultura da internet

    OpenAIRE

    Cádima, Francisco Rui

    2017-01-01

    O novo ambiente digital é cada vez mais perturbante na sua dimensão ‘visível’ e está, em boa parte, incontrolável nessa área ainda algo desconhecida da Internet negra, conhecida por deep web ou dark net, convoca-nos para uma reflexão profunda de largo espectro, que não se pode vincular apenas às questões de mercado, tecnológicas e de redes, mas que nos vem alertar sobretudo para a ordem do político e da cidadania, do ‘desconhecido’ e do conhecimento e, enfim, do acesso à rede, quer no que is...

  13. Micromachining with copper lasers

    Science.gov (United States)

    Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

    1997-04-01

    In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

  14. Laser Applications in Orthodontics

    Science.gov (United States)

    Heidari, Somayeh; Torkan, Sepideh

    2013-01-01

    A laser is a collimated single wavelength of light which delivers a concentrated source of energy. Soon after different types of lasers were invented, investigators began to examine the effects of different wavelengths of laser energy on oral tissues, routine dental procedures and experimental applications. Orthodontists, along with other specialist in different fields of dentistry, can now benefit from several different advantages that lasers provide during the treatment process, from the beginning of the treatment, when separators are placed, to the time of resin residues removal from the tooth surface at the end of orthodontic treatment. This article outlines some of the most common usages of laser beam in orthodontics and also provides a comparison between laser and other conventional method that were the standard of care prior to the advent of laser in this field. PMID:25606324

  15. ORION laser target diagnostics

    International Nuclear Information System (INIS)

    Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K.

    2012-01-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  16. ORION laser target diagnostics.

    Science.gov (United States)

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

    2012-10-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  17. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  18. Laser safety in dentistry

    Science.gov (United States)

    Wigdor, Harvey A.

    1997-05-01

    One of the major causes of anxiety in the dental clinic is the dental handpiece. Because dentists wish to provide a method which can replace the drill there has often been a premature use of the laser in dentistry. Various lasers have been introduced into the clinic before research has shown the laser used is of clinical benefit. Any new treatment method must not compromise the health of the patient being treated. Thus a method of evaluating the clinical abilities of dentists and their understanding the limitations of the laser used must be developed. Dentist must be trained in the basic interaction of the laser on oral tissues. The training has to concentrate on the variation of the laser wavelength absorption in the different tissues of the oral cavity. Because of the differences in the optical properties of these tissues great care must be exercised by practitioners using lasers on patients.

  19. Lasers in materials science

    CERN Document Server

    Ossi, Paolo; Zhigilei, Leonid

    2014-01-01

    This book covers various aspects of lasers in materials science, including a comprehensive overview on basic principles of laser-materials interactions and applications enabled by pulsed laser systems.  The material is organized in a coherent way, providing the reader with a harmonic architecture. While systematically covering the major current and emerging areas of lasers processing applications, the Volume provides examples of targeted modification of material properties achieved through careful control of the processing conditions and laser irradiation parameters. Special emphasis is placed on specific strategies aimed at nanoscale control of material structure and properties to match the stringent requirements of modern applications.  Laser fabrication of novel nanomaterials, which expands to the domains of photonics, photovoltaics, sensing, and biomedical applications, is also discussed in the Volume. This book assembles chapters based on lectures delivered at the Venice International School on Lasers...

  20. Alternate laser fusion drivers

    International Nuclear Information System (INIS)

    Pleasance, L.D.

    1979-11-01

    One objective of research on inertial confinement fusion is the development of a power generating system based on this concept. Realization of this goal will depend on the availability of a suitable laser or other system to drive the power plant. The primary laser systems used for laser fusion research, Nd 3+ : Glass and CO 2 , have characteristics which may preclude their use for this application. Glass lasers are presently perceived to be incapable of sufficiently high average power operation and the CO 2 laser may be limited by and issues associated with target coupling. These general perceptions have encouraged a search for alternatives to the present systems. The search for new lasers has been directed generally towards shorter wavelengths; most of the new lasers discovered in the past few years have been in the visible and ultraviolet region of the spectrum. Virtually all of them have been advocated as the most promising candidate for a fusion driver at one time or another

  1. Flexible Laser Metal Cutting

    DEFF Research Database (Denmark)

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

    2014-01-01

    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  2. [da Vinci surgical system].

    Science.gov (United States)

    Watanabe, Gou; Ishikawa, Norihiro

    2014-07-01

    The da Vinci surgical system was developed by Intuitive Surgical Inc. in the United States as an endoscopic surgical device to assist remote control surgeries. In 1998, the Da Vinci system was first used for cardiothoracic procedures. Currently a combination of robot-assisted internal thoracic artery harvest together with coronary artery bypass grafting (CABG) through a mini-incision (ThoraCAB) or totally endoscopic procedures including anastomoses under robotic assistance (TECAB) are being conducted for the treatment of coronary artery diseases. With the recent advances in catheter interventions, hybrid procedures combining catheter intervention with ThoraCAB or TECAB are anticipated in the future.On the other hand, with the decrease in number of coronary artery bypass surgeries, the share of valvular surgeries is expected to increase in the future. Among them, mitral valvuloplasty for mitral regurgitation is anticipated to be conducted mainly by low-invasive procedures, represented by minimally invasive cardiac surgery( MICS) and robot-assisted surgery. Apart from the intrinsic good surgical view, robotic-assisted systems offer additional advantages of the availability of an amplified view and the easy to observe the mitral valve in the physiological position. Thus, robotic surgical surgeries that make complicated procedures easier are expected to accomplish further developments in the future. Furthermore, while the number of surgeries for atrial septal defects has decreased dramatically following the widespread use of Amplatzer septal occluder, robotic surgery may become a good indication for cases in which the Amplatzer device is not indicated. In Japan, clinical trial of the da Vinci robotic system for heart surgeries has been completed. Statutory approval of the da Vinci system for mitral regurgitation and atrial septal defects is anticipated in the next few years.

  3. Lasers: principles, applications and energetic measures

    International Nuclear Information System (INIS)

    Subran, C.; Sagaut, J.; Lapointe, S.

    2009-01-01

    After having recalled the principles of a laser and the properties of the laser beam, the authors describe the following different types of lasers: solid state lasers, fiber lasers, semiconductor lasers, dye lasers and gas lasers. Then, their applications are given. Very high energy lasers can reproduce the phenomenon of nuclear fusion of hydrogen atoms. (O.M.)

  4. A utilização da teoria da aprendizagem significativa no ensino da Enfermagem

    OpenAIRE

    Alana Tamar Oliveira de Sousa; Nilton Soares Formiga; Simone Helena dos Santos Oliveira; Marta Miriam Lopes Costa; Maria Júlia Guimarães Oliveira Soares

    2015-01-01

    RESUMO Objetivo: sintetizar a produção científica acerca da Teoria da Aprendizagem Significativa no processo de ensino-aprendizagem em Enfermagem. Método: revisão integrativa realizada nas bases de dados MEDLINE, LILACS, SciELO, BDENF e CINAHL, com artigos que abordaram a temática ou aspectos da teoria da aprendizagem significativa de David Ausubel. Fizeram parte da amostra dez artigos, sendo seis escritos no idioma português e quatro no inglês, publicados de 1998 a 2013. Resultados: cinco...

  5. Os (descaminhos da identidade

    Directory of Open Access Journals (Sweden)

    Oliveira Roberto Cardoso de

    2000-01-01

    Full Text Available A conferência procurou apresentar uma interpretação das vicissitudes da identidade étnica e/ou nacional quando observada em situações de ambigüidade. É quando o processo identitário expressa crises reais ou virtuais, como as que têm lugar entre imigrantes latino-americanos nos Estados Unidos, entre povos de diferentes regiões da Espanha emigrados para Barcelona, entre catalães espanhóis, franceses e andorranos residentes em Andorra, e entre povos indígenas em regiões de fronteira do Brasil com países vizinhos. O exame do processo identitário que tem lugar em diferentes latitudes, nas Américas e na Europa, sugere que os fenômenos socioculturais de etnicidade e de nacionalidade possuem em comum características tais como a busca de reconhecimento da pessoa moral, o respeito à diferença e, como corolário ético, a elevação do que se pode definir como "taxa de consideração".

  6. Hepatotoxicidade da cianotoxina microcistina

    Directory of Open Access Journals (Sweden)

    Andréa de Castro Leal

    2004-01-01

    Full Text Available Constitui interesse emergente em saúde pública avaliar a possibilidade de intoxicação humana por biotoxinas de algas cianofíceas, principalmente as hepatotoxinas do grupo das microcistinas. A microcistina, um heptapeptídeo monocíclico, é produzida principalmente pela cianobactéria Microcistis aeruginosa. São caracterizadas por alguns aminoácidos variáveis, dois deles com uma estrutura não usual que possuem importante papel na hepatotoxidade da microcistina. Apesar do acometimento humano atribuído as microcistinas incluírem gastroenterite, reações alérgicas ou irritativas, neurotoxicidade, o principal alvo da toxina é o fígado. Nos hepatócitos as microcistinas são carreadas pelo sistema transportador do ácido biliar, inibindo a atividade da proteína fosfatase no citoplasma. A inibição leva a mudanças morfológicas na membrana plasmática pela hiperfosforilação de citoqueratinas, e à atividade de promoção tumoral pelas proteínas hiperfosforiladas. Os métodos de detecção e quantificação de microcistinas no ambiente incluem a cromatografia líquida, o bioensaio em camundongos e os testes imunoenzimáticos. O último vem ganhando destaque pela praticidade e alta sensibilidade.

  7. Lasers in space

    Science.gov (United States)

    Michaelis, M. M.; Forbes, A.; Bingham, R.; Kellett, B. J.; Mathye, A.

    2008-05-01

    A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging. Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping. SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It would be equally useful as a power source for the transmission of information over light year distances. We briefly mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the Big Bang lase?"

  8. Topoplastia de Cvintal assistida por laser de femtossegundo

    Directory of Open Access Journals (Sweden)

    Alexandre Takayoshi Ishizaki

    2013-06-01

    Full Text Available Apresentamos um relato de astigmatismo tardio progressivo pós-transplante de córnea para ceratocone, associado à afinamento periférico na junção doador-receptor, o que presumidamente pode ser considerado como recorrência da ectasia. O caso foi tratado por meio de Topoplastia de Cvintal assistida por laser de femtossegundo para a confecção da incisão com geometria "top hat", seguido de sutura com ajuste per-operatório guiado por ceratoscopia.

  9. Ação da laserterapia no processo de proliferação e diferenciação celular: revisão da literatura

    Directory of Open Access Journals (Sweden)

    Águida Cristina Gomes Henriques

    Full Text Available O uso da luz laser de baixa intensidade vem sendo utilizado como terapia coadjuvante ou de forma terapêutica isolada em várias especialidades odontológicas. Suas principais indicações incluem ação anti-inflamatória, analgésica e indutora da reparação tecidual. O poder cicatrizante do laser de baixa potência é discutido neste trabalho assim como os mecanismos de biomodulação e estimulação da mitose. Estas propriedades, já estudadas em células benignas, quando aplicadas em células neoplásicas malignas, abrem espaço para discussões. O objetivo do presente trabalho foi realizar uma revisão da literatura sobre os aspectos indutivos do laser no processo de proliferação celular principalmente no que se refere a estes mecanismos em células neoplásicas malignas.

  10. Complicações primárias da interface do 'flap' de LASIK

    Directory of Open Access Journals (Sweden)

    Renata Loures Bueno de Moraes

    2016-02-01

    Full Text Available RESUMO Laser in situ Keratomileusis (LASIK é uma das técnicas mais aceitas na cirurgia refrativa atualmente. Sua previsibilidade, reprodutibilidade, segurança e baixos índices de efeitos colaterais justificam a ampla difusão dessa técnica. Trata-se de um procedimento cirúrgico a laser cujo objetivo consiste na modificação da estrutura corneana, permitindo uma mudança do ponto focal do olho. Dessa forma, é possível corrigir ametropias tais como a miopia, astigmatismo e pequenos graus de hipermetropia. A técnica do LASIK consiste na criação de um flap corneano por meio da utilização de um microcerátomo ou do laser de femtossegundo. Em seguida, é realizada a aplicação do excimer laser sobre o leito estromal com posterior reposicionamento do flap, criando-se uma interface entre as lamelas anterior e posterior da córnea. Apesar das inúmeras vantagens, existem patologias que resultam de complicações primárias da interface do flap, que podem causar confusão no momento do diagnóstico, por possuírem semelhanças quanto à sua apresentação clínica. O objetivo desse trabalho é definir, caracterizar e comparar tais entidades com intuito de facilitar o diagnóstico diferencial dessas patologias evitando a adoção de um tratamento equivocado. Como resultado do estudo, são apresentadas recomendações quanto à conduta nos casos de cada patologia de interface, com investigação por meio da anamnese e exame clínico, a fim de permitir diagnóstico diferencial entre as principais entidades primárias da interface do procedimento LASIK.

  11. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  12. Emission spectrum of an electric-discharge ClF laser

    International Nuclear Information System (INIS)

    Deryugin, A A; Razhev, A M; Kochetov, Igor' V

    1998-01-01

    Experiments revealed a complex structure of the emission spectrum of an electric-discharge ClF laser, corresponding to the D'-A' transitions with a maximum near 285 nm. The vibrational bands in the emission spectrum overlapped at the base in the range 282-286 nm because of a high pressure in the gaseous active medium. Theoretical calculations were made and an interpretation was provided of the vibrational structure of the emission spectrum of the ClF molecules. The emission spectrum of the electric-discharge ClF laser was shown to consist of the 0-4, 0-5, 0-6, 1-6, 1-7, and 2-8 bands of the D'-A' transition. A total efficiency of 0.1% was achieved for the first time for the ClF laser and lasing was observed in a gaseous He - F 2 -BCl 3 active medium. (lasers, active media)

  13. Designing of Raman laser

    International Nuclear Information System (INIS)

    Zidan, M. D.; Al-Awad, F.; Alsous, M. B.

    2005-01-01

    In this work, we describe the design of the Raman laser pumped by Frequency doubled Nd-YAG laser (λ=532 nm) to generate new laser wavelengths by shifting the frequency of the Nd-YAG laser to Stokes region (λ 1 =683 nm, λ 2 =953.6 nm, λ 3 =1579.5 nm) and Antistokes region (λ ' 1 =435 nm, λ ' 2 =369.9 nm, λ ' 3=319.8 nm). Laser resonator has been designed to increase the laser gain. It consists of two mirrors, the back mirror transmits the pump laser beam (λ=532 nm) through the Raman tube and reflects all other generated Raman laser lines. Four special front mirrors were made to be used for the four laser lines λ 1 =683 nm, λ 2 =953.6 nm and λ ' 1 = 435 nm, λ ' 2 =369.9 nm. The output energy for the lines υ 1 s, υ 2 s, υ 1 as,υ 2 as was measured. The output energy of the Raman laser was characterized for different H 2 pressure inside the tube. (Author)

  14. Laser program overview

    International Nuclear Information System (INIS)

    Storm, E.; Coleman, L.W.

    1985-01-01

    The objectives of the Lawrence Livermore National Laboratory Laser Fusion program are to understand and develop the science and technology of inertial confinement fusion (ICF), and to utilize ICF in short- and long-term military applications, and, in the long-term, as a candidate for central-station civilian power generation. In 1984, using the Novette laser system, the authors completed experiments showing the very favorable scaling of laser-plama interactions with short-wavelength laser light. Their Novette experiments have unequivocally shown that short laser wavelength, i.e., less than 1 μm, is required to provide the drive necessary for efficient compression, ignition, and burn of DT fusion fuel. In other experiments with Novette, the authors made the first unambiguous observation of amplified spontaneous emission in the soft x-ray regime. The authors also conducted military applications and weapons physics experiments, which they discuss in detail in the classified volume of our Laser Program Annual Report. In the second thrust, advanced laser studies, they develop and test the concepts, components, and materials for present and future laser systems. Over the years, this has meant providing the technology base and scientific advances necessary to construct and operate a succession of six evermore-powerful laser systems. The latest of these, Nova, a 100-TW/100-kJ-class laser system, was completed in 1984. The Nd:glass laser continues to be the most effective and versatile tool for ICF and weapons physics because of its scalability in energy, the ability to efficiently convert its 1=μm output to shorter wavelengths, its ability to provide flexible, controlled pulse shaping, and its capability to adapt to a variety of irradiation and focusing geometries. For these reasons, many of our advanced laser studies are in areas appropriate to solid state laser technologies

  15. Laser pumped lasers for isotope separation

    International Nuclear Information System (INIS)

    Fry, S.M.

    1976-01-01

    A study of the isotope separation laser requirements reveals that high pressure polyatomic molecular gas laser pumped lasers can attain the necessary characteristics including tunability, energy output, pulse width, and repetition rate. The results of a search, made for molecules meeting the appropriate requirements for one of several pump schemes utilizing a CO 2 laser and with output in the 12 μm or 16μm wavelength range, are presented. Several methods of pumping are reviewed and two novel pump schemes are presented. A laser pumped laser device design is given, and operation of this device and associated diagnostic equipment is confirmed by repeating experiments in OCS and NH 3 . The results of OCS laser experiments show that an improvement in pump rate and output per unit length is obtained with the device, using a wedged transverse pumping scheme. A new multi-line laser system in NH 3 pumped by a TEA CO 2 laser is reported. More than forty transitions spanning the wavelength range of 9.2 to 13.8 μm are observed and identified. A strong output at 12.08 μm is one of the closest lines yet found to the required laser isotope separation wavelength. Far infrared emission near 65 μm is observed and is responsible for populating levels which lase in pure ammonia near 12.3 μm. Buffer gas (e.g., N 2 or He) pressures of approximately 40--800 torr cause energy transfer by collision-induced rotationaltransitions from the pumped antisymmetric to the lasing symmetric levels in the nu 2 = 1 band of ammonia. Most of the observed lines are aP(J,K) transitions which originate from the nu 2 /sup s/ band. Measurements of the pressure dependence of the laser output shows that some lines lase at pressures greater than one atmosphere. Transient behavior of the 12.08 μm line is calculated from a simplified analytic model and these calculations are compared to the experimental results

  16. Pattern Laser Annealing by a Pulsed Laser

    Science.gov (United States)

    Komiya, Yoshio; Hoh, Koichiro; Murakami, Koichi; Takahashi, Tetsuo; Tarui, Yasuo

    1981-10-01

    Preliminary experiments with contact-type pattern laser annealing were made for local polycrystallization of a-Si, local evaporation of a-Si and local formation of Ni-Si alloy. These experiments showed that the mask patterns can be replicated as annealed regions with a resolution of a few microns on substrates. To overcome shortcomings due to the contact type pattern annealing, a projection type reduction pattern laser annealing system is proposed for resistless low temperature pattern forming processes.

  17. High energy HF pulsed lasers

    International Nuclear Information System (INIS)

    Patterson, E.L.; Gerber, R.A.

    1976-01-01

    Recent experiments show that pulsed HF lasers are capable of producing high energy with good efficiency. Preliminary experiments show that the laser radiation from the high-gain medium can be controlled with a low-power probe laser beam or with low-level feedback. These results indicate that the HF laser may have potential for second-generation laser fusion experiments

  18. Low-level laser therapy and Calendula officinalis in repairing diabetic foot ulcers.

    Science.gov (United States)

    Carvalho, Ana Flávia Machado de; Feitosa, Maura Cristina Porto; Coelho, Nayana Pinheiro Machado de Freitas; Rebêlo, Veruska Cronemberger Nogueira; Castro, Juçara Gonçalves de; Sousa, Patrícia Regina Gomes de; Feitosa, Valrian Campos; Arisawa, Emilia Angela Lo Schiavo

    2016-01-01

    To evaluate the effects of low-level laser therapy isolated and associated with Calendula officinalis oil in treating diabetic foot ulcers. An experimental, randomized, controlled, prospective, interventional clinical case study using a quantitative approach. The sample consisted of 32 diabetic patients of both genders. Participants were randomly divided into four groups. Doppler Ultrasound evaluation of the Ankle-Brachial Index, brief pain inventory and analog pain scale were performed at baseline and after 30 days. Reduced pain was observed in the Low-level laser therapy and Low-level laser therapy associated with Essential Fatty Acids groups (pgrupos. Ultrassom Doppler, avaliação do Índice Tornozelo-Braquial, Inventário breve de dor e escala de dor analógica foram realizados no início e após 30 dias. Houve redução da dor nos grupos Terapia a Laser de Baixa Intensidade e Terapia a Laser de Baixa intensidade associada aos Ácidos Graxos Essenciais, com pgrupos mantiveram-se estáveis. Na análise da redução de área da lesão, o grupo Terapia a Laser de Baixa Intensidade associada aos Ácidos Graxos Essenciais apresentou uma significância p=0,0032, e o grupo Terapia a Laser de Baixa Intensidade, p=0,0428. A Terapia a Laser de Baixa Intensidade, realizada tanto isoladamente quanto associada ao óleo de Calendula officinalis, foi eficaz no alívio da dor e na aceleração do processo de reparo tecidual de pé diabético.

  19. Laser Safety Inspection Criteria

    International Nuclear Information System (INIS)

    Barat, K

    2005-01-01

    A responsibility of the Laser Safety Officer (LSO) is to perform laser safety audits. The American National Standard Z136.1 Safe use of Lasers references this requirement in several sections: (1) Section 1.3.2 LSO Specific Responsibilities states under Hazard Evaluation, ''The LSO shall be responsible for hazards evaluation of laser work areas''; (2) Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''; and (3) Appendix D, under Survey and Inspections, it states, ''the LSO will survey by inspection, as considered necessary, all areas where laser equipment is used''. Therefore, for facilities using Class 3B and or Class 4 lasers, audits for laser safety compliance are expected to be conducted. The composition, frequency and rigueur of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms. In many institutions, a sole Laser Safety Officer (LSO) or a number of Deputy LSO's perform these audits. For that matter, there are institutions that request users to perform a self-assessment audit. Many items on the common audit list and the associated findings are subjective because they are based on the experience and interest of the LSO or auditor in particular items on the checklist. Beam block usage is an example; to one set of eyes a particular arrangement might be completely adequate, while to another the installation may be inadequate. In order to provide more consistency, the National Ignition Facility Directorate at Lawrence Livermore National Laboratory (NIF-LLNL) has established criteria for a number of items found on the typical laser safety audit form. These criteria are distributed to laser users, and they serve two broad purposes: first, it gives the user an expectation of what will be reviewed by an auditor, and second, it is an

  20. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  1. Nuclear-pumped lasers

    CERN Document Server

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  2. Power Laser Ablation Symposia

    CERN Document Server

    Phipps, Claude

    2007-01-01

    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  3. Laser induced nuclear reactions

    International Nuclear Information System (INIS)

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin

    1998-01-01

    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10 19 W/cm 2 . In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that μCi of 62 Cu can be generated via the (γ,n) reaction by a laser with an intensity of about 10 19 Wcm -2

  4. Lasers for isotope separation

    International Nuclear Information System (INIS)

    O'Hair, E.A.; Piltch, M.S.

    1976-01-01

    The Los Alamos Scientific Laboratory is conducting research on uranium enrichment. All processes being studied employ uranium molecules and use lasers to provide isotopic selectivity and enrichment. There are four well-defined infrared frequencies and two ultraviolet frequency bands of interest. The infrared frequencies are outside the range of the available lasers and an extensive research and development activity is currently underway. Lasers are available in the uv bands, however, much development work remains. The specification for the commercial uranium enrichment plant lasers will depend upon the results of the current enrichment experiments, the laser capital cost, reliability, and maintenance cost. For the processes under investigation there are specific photon requirements but latitude in how these requirements can be met. The final laser selections for the pilot plant need not be made until the mid-1980's. Between now and that time as extensive as possible a research and development effort will be maintained

  5. Inertial fusion by laser

    International Nuclear Information System (INIS)

    Dautray, R.; Watteau, J.-P.

    1980-01-01

    Following a brief historical survey of research into the effects of interaction of laser with matter, the principles of fusion by inertial confinement are described and the main parameters and possible levels given. The development of power lasers is then discussed with details of performances of the main lasers used in various laboratories, and with an assessment of the respective merits of neodymium glass, carbon dioxide or iodine lasers. The phenomena of laser radiation and its interaction with matter is then described, with emphasis on the results of experiments concerned with target implosion with the object of compressing and heating the mixture of heavy hydrogen and tritium to be ignited. Finally, a review is made of future possibilities opened up by the use of large power lasers which have recently become operational or are being constructed, and the ground still to be covered before a reactor can be produced [fr

  6. Principles of Lasers

    CERN Document Server

    Svelto, Orazio

    2010-01-01

    This new Fifth Edition of Principles of Lasers incorporates corrections to the previous edition. The text’s essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions: "Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field … Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics) "Already well established as a self-contained introduction to the physics and technology of lasers … Professor Svelto’s book, in this lucid translation by David Hanna, can be strongly recommended for...

  7. Atomic iodine laser

    International Nuclear Information System (INIS)

    Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

    1978-05-01

    The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

  8. Strong field laser physics

    CERN Document Server

    2008-01-01

    Since the invention of the laser in the 1960s, people have strived to reach higher intensities and shorter pulse durations. High intensities and ultrashort pulse durations are intimately related. Recent developments have shown that high intensity lasers also open the way to realize pulses with the shortest durations to date, giving birth to the field of attosecond science (1 asec = 10-18s). This book is about high-intensity lasers and their applications. The goal is to give an up to date introduction to the technology behind these laser systems and to the broad range of intense laser applications. These applications include AMO (atomic molecular and optical) physics, x-ray science, attosecond science, plasma physics and particle acceleration, condensed matter science and laser micromachining, and finally even high-energy physics.

  9. Hepatotoxicidade da cianotoxina microcistina

    OpenAIRE

    Leal,Andréa de Castro; Soares,Manoel do Carmo Pereira

    2004-01-01

    Constitui interesse emergente em saúde pública avaliar a possibilidade de intoxicação humana por biotoxinas de algas cianofíceas, principalmente as hepatotoxinas do grupo das microcistinas. A microcistina, um heptapeptídeo monocíclico, é produzida principalmente pela cianobactéria Microcistis aeruginosa. São caracterizadas por alguns aminoácidos variáveis, dois deles com uma estrutura não usual que possuem importante papel na hepatotoxidade da microcistina. Apesar do acometimento humano atrib...

  10. Arduino based laser control

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  11. Shiva laser system performance

    International Nuclear Information System (INIS)

    Glaze, J.; Godwin, R.O.; Holzrichter, J.F.

    1978-01-01

    On November 18, 1977, after four years of experimentation, innovation, and construction, the Shiva High Energy Laser facility produced 10.2 kJ of focusable laser energy delivered in a 0.95 ns pulse. The Shiva laser, with its computer control system and delta amplifiers, demonstrated its versatility on May 18, 1978, when the first 20-beam target shot with delta amplifiers focused 26 TW on a target and produced a yield of 7.5 x 10 9 neutrons

  12. Lasers in Ophthalmology

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    In recent years,lasers have entered every fieldof medicine and especially so in ophthalmol-ogy.The scientific basis of lasers in ophthal-mology is based on three mechanisms:1.Photothermal effectLasers:argon,krypton,dye and diodeA thermal effect is generated when laserenergy is absorbed by pigment leading to in-creased vibration and therefore heat content.A

  13. Laser Journal (Selected Articles),

    Science.gov (United States)

    1982-09-10

    laser is described. The apparatus structure and some experimental results are reported. MATERIAL AND ELEMENT MAGNETO -OPTIC PROPERTIES OF Pr dYb),(1oAI...with a magneto -optical modulator. The measuring system is simple and sensitive, with reading accuracy of ±0.0050 and error 45%. STUDY ON EXPERIMENTAL...laser radiation therapy . He Fang de East Chiia Hospital APPLICATION OF N4d,:Y q LASER TO TREAT INTERNAL HEMERRHOID Zhuo Ruilin Zu Songlin (Shanghai

  14. Laser precision microfabrication

    CERN Document Server

    Sugioka, Koji; Pique, Alberto

    2010-01-01

    Miniaturization and high precision are rapidly becoming a requirement for many industrial processes and products. As a result, there is greater interest in the use of laser microfabrication technology to achieve these goals. This book composed of 16 chapters covers all the topics of laser precision processing from fundamental aspects to industrial applications to both inorganic and biological materials. It reviews the sate of the art of research and technological development in the area of laser processing.

  15. Aspectos moleculares da anemia falciforme

    Directory of Open Access Journals (Sweden)

    Galiza Neto Gentil Claudino de

    2003-01-01

    Full Text Available No presente artigo abordaram-se vários aspectos relacionados à natureza molecular da anemia falciforme, desordem hematológica de caráter hereditário que acomete expressivo número de indivíduos em várias regiões do mundo. As pesquisas realizadas em torno desta patologia da hemácia, ao longo de quase um século, a partir de 1910, cooperaram para a criação de um novo e importante segmento da ciência, denominado biologia molecular. A descoberta dos polimorfismos da mutação (GAT->GTG no gene que codifica a cadeia beta da hemoglobina, originando diferentes haplótipos da doença, permitiu um melhor e mais amplo conhecimento em torno da heterogeneidade clínica nos pacientes falcêmicos. Analisando a hemoglobina na sua estrutura normal e mutante, sua produção e evolução, pode-se ter um entendimento mais completo da fisiopatologia desta doença e da sua complexidade clínica.

  16. Lasers for the SILVA laser isotope separation process

    International Nuclear Information System (INIS)

    Lapierre, Y.

    1997-01-01

    The main principles of the laser isotope separation process for the production of enriched uranium at lower cost, are reviewed and the corresponding optimal laser characteristics are described. The development of the SILVA laser isotope separation process involved researches in the various domains of pump lasers, dye lasers, laser and optics systems and two test facilities for the feasibility studies which are expected for 1997

  17. High power lasers

    CERN Document Server

    Niku-Lari, A

    1989-01-01

    The use of lasers for the working and treatment of materials is becoming increasingly common in industry. However, certain laser applications, for example, in welding, cutting and drilling, are more widely exploited than others. Whilst the potential of lasers for the surface treatment of metals is well recognised, in practice, this particular application is a relative newcomer. The 24 papers in this volume present the latest research and engineering developments in the use of lasers for processes such as surface melting, surface alloying and cladding, and machining, as well as discussing th

  18. Degenerate band edge laser

    Science.gov (United States)

    Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

    2018-05-01

    We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

  19. Gigashot Optical Laser Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Deri, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-13

    The Gigashot Optical Laser Demonstrator (GOLD) project has demonstrated a novel optical amplifier for high energy pulsed lasers operating at high repetition rates. The amplifier stores enough pump energy to support >10 J of laser output, and employs conduction cooling for thermal management to avoid the need for expensive and bulky high-pressure helium subsystems. A prototype amplifier was fabricated, pumped with diode light at 885 nm, and characterized. Experimental results show that the amplifier provides sufficient small-signal gain and sufficiently low wavefront and birefringence impairments to prove useful in laser systems, at repetition rates up to 60 Hz.

  20. Notes on Laser Acceleration

    International Nuclear Information System (INIS)

    Tajima, T.

    2008-01-01

    This note intends to motivate our effort toward the advent of new methods of particle acceleration, utilizing the fast rising laser technology. By illustrating the underlying principles in an intuitive manner and thus less jargon-clad fashion, we seek a direction in which we shall be able to properly control and harness the promise of laser acceleration. First we review the idea behind the laser wakefield. We then go on to examine ion acceleration by laser. We examine the sheath acceleration in particular and look for the future direction that allows orderly acceleration of ions in high energies

  1. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  2. Lasers in materials processing

    International Nuclear Information System (INIS)

    Davis, J.I.; Rockower, E.B.

    1981-01-01

    A status report on the uranium Laser Isotope Separation (LIS) Program at the Lawrence Livermore National Laboratory is presented. Prior to this status report, process economic analysis is presented so as to understand how the unique properties of laser photons can be best utilized in the production of materials and components despite the high cost of laser energy. The characteristics of potential applications that are necessary for success are identified, and those factors that have up to now frustrated attempts to find commercially viable laser induced chemical and physical process for the production of new or existing materials are pointed out

  3. Mid-Infrared Lasers

    Data.gov (United States)

    National Aeronautics and Space Administration — Mid infrared solid state lasers for Differential Absorption Lidar (DIAL) systems required for understanding atmospheric chemistry are not available. This program...

  4. Laser fusion program overview

    International Nuclear Information System (INIS)

    Emmett, J.L.

    1977-01-01

    This program is structured to proceed through a series of well defined fusion milestones to proof of the scientific feasibility, of laser fusion with the Shiva Nova system. Concurrently, those key technical areas, such as advanced lasers, which are required to progress beyond proof of feasibility, are being studied. We have identified and quantified the opportunities and key technical issues in military applications, such as weapons effects simulations, and in civilian applications, such as central-station electric power production. We summarize the current status and future plans for the laser fusion program at LLL, emphasizing the civilian applications of laser fusion

  5. Physics of semiconductor lasers

    CERN Document Server

    Mroziewicz, B; Nakwaski, W

    2013-01-01

    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  6. Principles of laser dynamics

    CERN Document Server

    Khanin, YI

    1995-01-01

    This monograph summarizes major achievements in laser dynamics over the past three decades. The book begins with two introductory Chapters. Chapter 1 offers general considerations on quantum oscillators, formulates the requirements for the laser key elements and shows how these requirements are met in different laser systems. The second Chapter proposes the mathematical models used in semiclassical laser theory, discusses the approximations and simplifications in particular cases, and specifies the range of applicability of these models. In Chapters 3-5 attention is given primarily to the stea

  7. Laser transmitter system

    International Nuclear Information System (INIS)

    Dye, R.A.

    1975-01-01

    A laser transmitter system is disclosed which utilizes mechanical energy for generating an output pulse. The laser system includes a current developing device such as a piezoelectric crystal which charges a storage device such as a capacitor in response to a mechanical input signal. The capacitor is coupled to a switching device, such as a silicon controlled rectifier (SCR). The switching device is coupled to a laser transmitter such as a GaAs laser diode, which provides an output signal in response to the capacitor being discharged

  8. Laser in urology

    International Nuclear Information System (INIS)

    Breisland, H.O.

    1991-01-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs

  9. Tunable Microfluidic Dye Laser

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter

    2003-01-01

    We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye conce