22 research outputs found
Dosimetric quality control at the radiotherapy department from Hospital CUF-Descobertas (HCD): the importance of quality control from the physics' sector and results of the auditorship ESTRO-EQUAL
A calibração e o controlo da qualidade de um acelerador linear são passos muito importantes num serviço de Radioterapia, para
garantir a qualidade dos tratamentos prestados. O sector da FĂsica da Unidade de Radioterapia do Hospital Cuf Descobertas
implementou um rigoroso Programa de controlo de qualidade ao equipamento produtor de radiação e aos equipamentos medidores de radiação, de acordo com o Dec-Lei 180/2002 e com os protocolos internacionais. Para tal, foram implementados procedimentos, criadas folhas de cĂĄlculo, instruçÔes de trabalho e impressos. Foram ainda implementados testes aos equipamentos com periodicidade definida: controlo de qualidade diĂĄrio e controlo de qualidade apĂłs intervençÔes (manutençÔes preventivas e correctivas). No decorrer do ano de 2005, o sector da FĂsica colaborou activamente com toda a equipa da Radioterapia na implementação da Norma ISO 9001:2000 no serviço, contribuindo com o seu know how na implementação desta, numa ĂĄrea tĂŁo importante como a da garantia da qualidade dos feixes de radiação e das respectivas calibraçÔes em dose. Numa procura de melhoria contĂnua da qualidade dos serviços prestados aos pacientes, decorre ainda uma auditoria externa da EQUAL-ESTRO*, intercomparação postal com dosĂmetros termoluminescentes. A qualidade dos feixes de energias utilizados
diariamente Ă© analisada, tanto ao nĂvel das calibraçÔes absolutas de cada um dos feixes de fotĂ”es e de electrĂ”es, como ao nĂvel dos
cålculos de dose obtidos com o sistema de planimetria XiO da CMS. Os resultados das duas primeiras fases da intercomparação,
relativa aos dois feixes de fotĂ”es de 6 MV e 15 MV e feixes de electrĂ”es de 4 MeV, 8 MeV e 12 MeV, foram considerados pela EQUAL-ESTRO num nĂvel Ăłptimo (desvio mĂĄximo na dose medida em relação Ă dose de referĂȘncia |d| †3%).ABSTRACT - The calibration and the quality control of a linear accelerator are very important steps in a radiotherapy department, since they both guarantee the quality of patient treatment. In accordance with Dec-Law 180/2002 and with international protocols, the Physicsâ sector of the Radiotherapy unit/department from Hospital Cuf-Descobertas implemented a rigorous program of quality control to the equipment that produces radiation as well as, to the measuring equipment of radiation. For that purpose, worksheets and instructions of work had been created. Still, tests to the equipment with definite regularity had been implemented such as: daily quality control and, quality control after interventions (preventive and corrective maintenances). In the year of 2005, in collaboration with the remainder Radiotherapy department the Norm ISO 9001:2000 was implemented. During this process the Physicsâ sector contributed with its know how, in a so important area as is the one of quality control of radiation beams and, respective dose calibration. For the continuous improvement of the supplied services to the patients, an external auditorship of the EQUAL-ESTRO by postal
intercomparison with thermoluminescents dosimeters, still elapses. The quality of the radiation beams that are daily used, are
analysed in both fronts: absolute calibrations for all energies of photon and electron beams and, dose calculations with the treatment planning system XiO from CMS. The results of the two first phases of this intercomparison, two beams of photons of 6
MV and 15 MV and three beams of electrons of 4MeV, 8MeV and 12MeV, had been considered by the EQUAL-ESTRO in an excellent level (maximum deviation for the measured dose in relation to the dose of reference: |d| †3 %)
Boosting cultural heritage in rural communities through an ICT platform: the Viv@vĂł project
Rural regions concentrate on themselves a very rich set of ancestral traditions. The
perpetuation of such traditions has been achieved through transmission between
generations. Unfortunately, all this knowledge is typically elders-centered and it lacks
effective processes of digitalization, storage and providing-systems for that all this heritage can effectively be perpetuated through future generations that are digital-born. From this base, it was created a project case study limited to the Portuguese Northeast region, named Viv@vĂł â living in the grandma's house. This paper presents the ICT platform that was created in this project and some main achievements during the project development process.
Tourism and mainly experience and cultural heritage tourism are growing in touristâs
interests. Rural regions have an untapped potential for this slice of tourism industry. Rural
regions have an enormous collection of ancestral knowledge that we are responsible to
deliver to future generations as an inheritance to which they are entitled.The present work was developed under the Viv@vĂł Project: "Living in the Grandma's House", with the reference NORTE-01- 0145-FEDER-023637, financed by the Regional Operational Program of the North, Notice 02/SAICT/2016.info:eu-repo/semantics/publishedVersio
Whatâs retinoic acid got to do with it? Retinoic acid regulation of the neural crest in craniofacial and ocular development
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151310/1/dvg23308.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151310/2/dvg23308_am.pd
VUV spectroscopy of water under cellular conditions
The understanding of radiation damage within cells, and thence mutagenesis, depends upon a detailed knowledge of the spectroscopy and dissociation dynamics of water. Results of a new study of the electronic state spectroscopy of water, using synchrotron radiation are reported. In order to gain some insight into how the spectroscopy and dissociation dynamics of water is influenced by its environment we also report photo-absorption spectra of water within thin films of poly(o-methoxyaniline) which have been suggested as a good mimic for biological membranes in the cellular environment. Comparison of these spectra with those of gaseous water and condensed amorphous water ice suggest that water in such films is similar to gaseous water and does not show the blue shift suggested in some cellular models. The lowest energy of OH production from dissociation of water in the cellular environment may therefore be around 6.7 eV (185 nm)
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Acetic acid electronic state spectroscopy by high-resolution vacuum ultraviolet photo-absorption, electron impact, He(I) photoelectron spectroscopy and ab initio calculations
Electronic state spectroscopy of CH3COOH has been investigated using Vacuum UltraViolet (VUV) photo-absorption spectroscopy in the energy range 3.5-10.6 eV. The availability of a high-resolution photon beam (similar to 0.075 nm) has allowed detailed analysis of the vibrational progressions and allowed us to propose, for the first time, new assignments for several Rydberg series. Excited states located in the 10-14 eV region have been studied for the first time. The VUV photo-absorption spectrum is compared with the electron energy loss spectrum (EELS) recorded in dipolar transition mode (100 eV incident energy, similar to 0 degrees scattering angle) in the 5.0-14 eV energy loss range. A He(l) photoelectron spectrum has also been recorded from 10.5 to 13 eV and compared to earlier low resolution works. A new value of (10.657 +/- 0.002) eV for the ground ionic state adiabatic ionisation energy is proposed. All spectra presented in this paper represent the highest resolution data yet reported for acetic acid. New ab initio calculations help in the assignment of the spectral bands. (c) 2005 Elsevier B.V. All rights reserved
Water VUV electronic state spectroscopy by synchrotron radiation
Electronic state spectroscopy of water has been studied using synchrotron radiation. The spectra presented in this Letter represent the highest resolution (similar to 0.075 nm) measurements in the energy range 6.0-11.0 eV and have allowed a detailed analysis of several new vibrational progressions to be observed in the 8.5-10 eV region and enabled us to assign the Rydberg series in the 9.9-10.8 eV energy absorption for the first time. Absolute cross-sections are also reported and compared with the previous data
Comparison between 3D laser scanning and computed tomography on the modelling of head surface
Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação ArtĂstica (IDI&CA) 2016 do Instituto PolitĂ©cnico de Lisboa. CĂłdigo de referĂȘncia IPL/2016/SoftImob_ISELThe measurement of people physical parameters and proportions constitutes an importante field of science, the anthropometry, since it is related to the characterization of the human size and constitution; it allows improving the design and sizing of systems and devices to human use. To enable these measurements, different direct and indirect methodologies may be used depending on the particular aim of a specific study and on the eventual availability of data sources that can be used also for this purpose. Because of this relevance, the present work intends to assess the influence of diferente acquisition and reconstruction methods in the modelling of a 3D head surface. In order to assess the significance of the differences between acquisition and reconstruction methods a set of measurements between several anatomic references of a physical phantom were carried out. Statistical evaluation using the Friedman test for non-parametrical pared samples was considered. We found, so far, no statistically significant differences between the several methods considered for acquisition and reconstruction.info:eu-repo/semantics/publishedVersio
Comparison between 3D laser scanning and computed tomography on the modelling of head surface
The measurement of people physical parameters and proportions constitutes an important field of science, the anthropometry since it is related to the characterization of the human size and constitution; it allows improving the design and sizing of systems and devices to human use. To enable these measurements, different direct and indirect methodologies may be used depending on the particular aim of a specific study and on the eventual availability of data sources that can be used also for this purpose. Because of this relevance, the present work intends to assess the influence of different acquisition and reconstruction methods in the modeling of a 3D head surface. In order to assess the significance of the differences between acquisition and reconstruction methods, a set of measurements between several anatomic references of a physical phantom were carried out. Statistical evaluation using the Friedman test for non-parametrical pared samples was considered. We found, so far, no statistically significant differences between the several methods considered for acquisition and reconstruction.info:eu-repo/semantics/publishedVersio
Using 3D anthropometric data for the modelling of customised head immobilisation masks
Projeto IPL/2016/SoftImob/ISEL; Projeto IPL/2016/CardiaCor_ESTeSL; Projeto LAETA_UID/EMS/50022/2019.Head immobilization thermoplastic masks for radiotherapy purposes involve a distressful modeling procedure for the patient. To assess the possibility of using different acquisition and reconstruction methods to obtain a 3D skin surface model of PIXY-phantom-head and to present a proposal of an alternative head immobilization mask prototype. Phantom head geometry acquisitions using: computed tomography (reconstructed with ImageJ and Osirix); and 3D Laser Scanner (reconstructed with SolidWorks). From these reconstructed surface models, a set of landmarks was measured and subsequently compared with physical measurements obtained with a Rosscraft-Calliper. For statistical evaluation, relative deviations graphics and Friedman-test for non-parametrical paired samples were used, with a significance level of 5%. For a first assessment of the proposed mask performance, a radiotransparent material was considered, the strength and stiffness evaluation is performed using the finite element method. There are small differences between all the acquisitions and reconstructions methods and the physical measurements, statistically significant differences (X2F(6)) = 6.863, p=0.334) were not found. The proposed mask performed well from the strength and stiffness perspectives, leading to the desired immobilization aim. The immobilization mask design proposal may be an effective alternative to the present completely hand-made situation, which presents a high degree of discomfort and stress to the patients.info:eu-repo/semantics/publishedVersio
Age differences in central and peripheral intraocular pressure using a rebound tonometer
AIM: To evaluate the influence of age on the measurements and relationships among central and peripheral intraocular pressure (IOP) readings taken with a rebound tonometer. METHODS: The IOPs were measured using the ICare rebound tonometer on the right eyes of 217 patients (88 men and 129 women) aged 18â85â
years (mean 45.9 (SD 19.8)â
years), at the centre and at 2â
mm from the nasal and temporal limbus along the horizontal meridian. Three age groups were established: young (â©œ30â
years old; nâ=â75), middle aged (31â60â
years old; nâ=â77) and old patients (>60â
years old; nâ=â65). RESULTS: A high correlation was found between the central and peripheral IOP readings, with the central readings being higher than the peripheral ones. Higher IOP values for the central location were found in the younger patients. Older patients had significantly lower temporal IOP readings than those for the remaining two groups (p<0.001), whereas no significant differences were found among groups when IOP was measured at the central and nasal locations. A significant decrease was observed in the nasal and temporal IOP readings as the age increased (pâ=â0.011 and 0.006, respectively). CONCLUSION: Older patients had lower IOP values than the middleâaged and younger patients in the temporal peripheral location. A negative correlation was found between age and IOP by rebound tonometry in the corneal periphery but not in its centre