Conservação de abacate ‘Hass’ e guacamole por irradiação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade pós-colheita de abacates "hass" mantidos em temperatura ambiente e tratados com diferentes radiações

This study aimed the avocado ‘Hass’ conservation with the use of radiation. We performed two experiments: Experiment I – fruits irradiated with different doses of cobalt-60 gamma irradiation(0,0; 0,2; 0,4; 0,6 e 1,0 kGy); Experiment II – fruit irradiated by electron accelerator in different doses (0,0; 0,48; 0,8; 1,12 e 1,45 MeV), both maintained at room temperature of 21±1 °C and at relative humidity of 79±5 %. Antioxidant capacity, total phenolic compounds, fresh weight loss, and respiration rate evaluation were performed every three days for 12 days. The experimental design was completely randomized with three replicates per treatment. For statistical analysis, the Tukey test at 5% probability was employed. Under the conditions in which the experiments were performed, the results showed that the gamma radiation use retained the fruits for 12 days, regardless the doses applied. The radiation by electron accelerator use also promote the fruits preservation, regardless the doses employed.

Tratamento de quelóides usando radioterapia pós-operatória com elétrons: estudo comparativo de dois esquemas

Pós-graduação em Bases Gerais da Cirurgia - FMB

Radioterapia com elétrons

Radiotherapy is a field of medical physics, which has been going through a scientific and technological advancement, it is extreme important the professionals that work in this area continuous their study to improve the quality of service provided. For it, they should know the physical principles related as well their employment in radiotherapy. The electrons have been using in therapy of superficial tumors, because they show rapid decrease of dose in depth, they don’t expose the deeper tissues to radiation. The electron therapy has replaced the surface therapy with x-ray and mold brachytherapy, and nowadays, it represents 10 to 15% of radiotherapy treatments. This study brings the definition of physical parameters used in the dosimetry of electron beam, describes the tests for quality control of linear accelerator with a electrons beam, as well the activities realized in the Radiotherapy Division, of Hospital de Clinicas, in the Universidade Estadual of Campinas, in the Clinac 2100C machine

Sistema de cálculo computacional da unidade monitora para feixes de elétrons em radioterapia

In radiation theraphy with electron beam, the electrons are produced in linear accelerators, and energy the most used have between 4MeV and 20MeV. Generally, the treatments are done for superficial injuries, because the low penetration of these particles. In this work a system for calculation of monitor units (U.M.) for cases of treatments with electron beam was developed. The Excel program of Microsoft was used and is easily found in the operational system of the personal microcomputers. In the Excel has been inserted the pertinent data of the linear accelerator of Varian, model 2100C, used in the Service of radiation theraphy of the Hospital of the Clinics of the College of Medicine of the UNESP of Botucatu. For some values of the physical parameters, such as: factors field and factors calibration, not supplied in the tests of acceptance of the machine, still proceeded calculations from interpolation and extrapolation. The mathematical formulas for automatic search of these and others factors used in the calculations of the determination of the U.M had been developed in agreement available routines in Excel. For this the functions had been used the function IF (that it imposes search condition) and the PROCH (that looks a value in a column from determined line), beyond the basic functions of addition, multiplication and division. It is intended to optimize the routine of the Services of radiation theraphy that perform through eletrontheraphy procedures, speeding the calculations and minimizing the occurrence of errors and uncertainties deriving of the maken a mistake manipulation of the parameters gotten in tables of data of electron beams

Efeitos na taxa de transporte de elétrons de plantas daninhas após aplicação de amicarbazone

Entre os herbicidas registrados para cana-de-açúcar, o amicarbazone é um dos mais importantes para o controle das plantas daninhas, sendo preciso que o herbicida seja absorvido, translocado e que ele alcance os cloroplastos das células das folhas para atuar em seu sítio de ligação no fotossistema II. O objetivo deste trabalho foi avaliar os efeitos da aplicação do amicarbazone na taxa de transporte de elétrons (ETR) de Ipomoea grandifolia, Brachiaria decumbens e Digitaria horizontalis. Foi verificada a resposta dessas plantas daninhas, em relação à ETR, quando submetidas ao amicarbazone em solução e na sequência à solução sem herbicida, por meio de leituras da ETR, realizadas em folhas novas e adultas com o uso de um fluorômetro portátil. Verificou-se também o consumo de água das plantas daninhas pela pesagem diária dos recipientes contendo a solução e as plantas. Assim, verificou-se por meio do experimento que a redução dos valores da ETR pode ser utilizada para indicar o nível de intoxicação nas plantas daninhas em estudo. As plantas daninhas I. grandifolia, B. decumbens e D. horizontalis apresentaram respostas diferenciadas quando submetidas a solução sem herbicida após solução com amicarbazone. I. grandifolia apresentou-se mais sensível ao amicarbazone devido à maior dificuldade em recuperar os níveis iniciais de ETR, além de apresentar alterações nas folhas novas após o termino de fornecimento do herbicida. O consumo de água pode explicar esse comportamento em I. grandifolia, visto tratar-se da espécie que mais consumiu água e, consequentemente, mais absorveu o amicarbazone. Já para B. decumbens e D. horizontalis ocorreram menores níveis de absorção de água e, por conseguinte, as folhas velhas tiveram melhor recuperação do transporte de elétrons e não houve intoxicação em folhas novas.

Estudo comparativo entre o tratamento radioterápico com elétrons e betaterapia, após cirurgia de queloides

Introduction: The surgery of keloids as an individual therapy with high rates of recurrence needs adjuvant therapies as complement. Recent keloids are rich in fibroblasts, which are highly radiosensitive and what explains the good results of percutaneous radiotherapy after surgery. Objective: To compare the beta-therapy results with electron-beam technique in newly operated keloids. Material and Methods: a prospective, comparative and randomized study was outlined including patients in the immediate postoperative period of surgical excision of keloids. Divided in G1 and G2 groups respectively, they received treatment with Sr90 (beta-therapy)plates or with electrons from the linear accelerator. The monitoring lasted 10 years. The results were performed using the information from patients, photograph parameters, observation and measurement of injuries, according to the criteria: Unchanged, Regular, Good and Excellent. Results: There were 26 patients, 13 in each group. In G1, 54% presented regular and unchanged improvement criteria and 46% had good or excellent criteria. In G2, the results were respectively 23% and 77%. Conclusion: The irradiation with electron-beam is better than beta-teraphy for the treatment of keloids surgery, due to the distribution in the tissue. No radio-induced tumors were observed.

Modelo de Marcus, elementos de matriz de tunelamento, efeitos de solvente e controle nuclear em reações de transferência de elétrons

This paper aims to give an initial presentation to physics students of the area of electron transfer, addressing its major aspects. The subject is then presented in an introductory way, highlighting and discussing the key points. Primarily, the problem is approached in a simplified manner through a two-state system, and aspects of calculating the matrix-element are discussed. Then, the electron transfer problem, influenced by nuclear reaction coordinates, is addressed and treated by the Marcus theory. Time scales and the concepts of adiabatic and nonadiabatic phenomena are discussed in the context of electron transfer. The classical, semi-classical and quantum formalisms of for the nuclear reactions coordinates are presented, and aspects of solvents are also discussed. Finally, we conclude by examining some recent examples of problems discussed in the literature.

Estudo comparativo entre o tratamento radioterápico com elétrons e betaterapia após cirurgia de quelóide

Pós-graduação em Bases Gerais da Cirurgia - FMB

Poços quânticos e transferência de elétrons

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Simulação computacional de materiais com elétrons fortemente interagentes: DMRG aplicado a super-redes Hubbard com modulação de condução entre camadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estruturas shrimp e propriedades dinâmicas no modelo dissipativo do acelerador de Fermi

Pós-graduação em Física - IGCE

Dinâmica de modelos minimalistas de solvente em reações de transferência de elétrons: aplicação à experimentos de única molécula

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Busca por ressonâncias de grávitons em modelos com dimensões extras no LHC

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O grafeno versus gás de elétrons 2d: filtro fano relativístico de spins por meio de pontas de afm e stm

Pós-graduação em Ciência dos Materiais - FEIS