RESUMEN
Signal attenuation limits the operating range in wireless communications and location. To solve the reduced range problem, we can use low-frequency signals in combination with magnetic sensing. We propose the use of an optically pumped magnetometer as a sensor and realize a proof-of-principle detection of binary phase shift keying (BPSK) modulated signals. We demonstrate a ranging enhancement by exploiting both the magnetometer's intrinsic sensitivity of below 1 pT/Hz1/2 and its 1 kHz operating bandwidth through the use of BPSK signals.
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According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry.
Asunto(s)
Humanos , Traumatismos por Radiación/diagnóstico , Liberación de Radiactividad Peligrosa/estadística & datos numéricos , Radiometría/métodos , Piel/efectos de la radiación , Brasil/epidemiología , Chile/epidemiología , Espectroscopía de Resonancia por Spin del Electrón , Traumatismos de los Dedos/etiología , Traumatismos de la Mano/etiología , Mediciones Luminiscentes , Dosis de Radiación , Exposición a la Radiación/efectos adversos , Traumatismos por Radiación/epidemiologíaRESUMEN
We present the design and fabrication of a magnetoresistive imaging system capable of scanning 256 channels simultaneously along linear ranges of either 4 or 13 mm. High speed electronics read the channels and transfer the data to a computer that builds and displays the images. The system was successfully used to image magnetic tapes for real-time forensic validation purposes and can also be applied in other noninvasive imaging applications.
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Aumento de la Imagen/instrumentación , Interpretación de Imagen Asistida por Computador/instrumentación , Magnetismo/instrumentación , Procesamiento de Señales Asistido por Computador , Transductores , Grabación en Video/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Grabación en Video/métodosRESUMEN
In this paper we present the development of a magnetic moment reference material for low moment magnetic samples. We first conducted an inter-laboratory comparison to determine the most useful sample dimensions and magnetic properties for common instruments such as vibrating sample magnetometers (VSM), SQUIDs, and alternating gradient field magnetometers. The samples were fabricated and then measured using a vibrating sample magnetometer. Their magnetic moments were calibrated by tracing back to the NIST YIG sphere, SRM 2853.
RESUMEN
In May 2000, an operator of a (60)Co industrial gamma radiography apparatus, during a routine service, was involved in a partial-body radiological accident, which caused serious injuries to his left hand. Dose reconstruction was started aiming to assess the radiation doses, in order to assist the medical staff in the evaluation and prescription of suitable medical procedures for the patient's treatment and follow-up. This work presents the dose reconstruction used for assessment of the distribution of doses on the patient's left hand, which was made using two methods: physical and computational techniques. For the first technique a physical hand simulator was built. The computational method was performed using microcomputer software for external dose calculations, named 'Visual Monte-Carlo-VMC', together with a hand voxel simulator. The values obtained through both methods for the distribution of absorbed doses on the operator's left hand were compared. About half of them were similar within a range of uncertainty of 20%.
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Radioisótopos de Cobalto/efectos adversos , Mano/efectos de la radiación , Exposición Profesional/efectos adversos , Liberación de Radiactividad Peligrosa , Radiometría/métodos , Adulto , Brasil , Humanos , Masculino , Método de Montecarlo , Dosis de RadiaciónRESUMEN
Industrial electron accelerators are used by eight installations in Brazil, with a total of 14 machines generating electron beams. These facilities are classified into categories I or II, according to the International Atomic Energy Agency (IAEA) system. In category I are included the facilities with an integrally shielded unit with interlocks, where human access during operation is not physically possible owing to the configuration of the shielding. In category II are included the facilities with a unit housed in a shielded room that is kept inaccessible during operation by an entry control system. Of the 14 accelerators operational in Brazil, 11 belong to category I and three to category II. In the present work a methodology for the assessment of the radiological safety of these accelerator facilities was developed and applied, mainly on the basis of specific recommendations from the IAEA. The main safety items were evaluated at those eight installations. According to the results obtained here, no inadequacies were observed at the three installations in category II, from the radiological safety and radioprotection points of view. Nevertheless, two out of the five installations in category I showed several deficiencies. Most of these inadequacies have been corrected during this work, and the rest are in the course of being corrected.
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Electrones , Industrias , Aceleradores de Partículas , Monitoreo de Radiación/métodos , Protección Radiológica/métodos , Administración de la Seguridad/métodos , Brasil , Arquitectura y Construcción de Instituciones de Salud , HumanosRESUMEN
We carried out a phylogenetic and population study in Alouatta caraya and Alouatta belzebul based on cytochrome b DNA sequence data. Maximum Parsimony and Median-Joining analyses grouped A. caraya from different localities showing a population structure in accordance with geographic distribution. The relation between A. caraya haplotypes could be explained with respect to the species range in the Cerrado, one of the most ancient morphoclimatic domains of South America, and the Chaco. Conversely, A. belzebul from the Amazonas and Atlantic forests grouped in a paraphyletic arrangement without an evident geographic pattern. Recent geologic events resulting in the separation of A. belzebul might explain why these geographically distant groups shared similar haplotypes and why ancestral polymorphisms might have been maintained in this species. Time of divergence estimates indicated that the splitting of the Alouatta lineage leading to A. caraya occurred some 4.58 MYA while the lineage leading to A. belzebul emerged 4.14 MYA.
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Alouatta/genética , Citocromos b/genética , Genética de Población/métodos , Polimorfismo Genético/genética , Animales , Evolución Molecular , Datos de Secuencia Molecular , Filogenia , Especificidad de la EspecieRESUMEN
The Monte Carlo program 'Visual Monte Carlo-dose calculation' (VMC-dc) uses a voxel phantom to simulate the body organs and tissues, transports photons through this phantom and reports the absorbed dose received by each organ and tissue relevant to the calculation of effective dose as defined in ICRP Publication 60. This paper shows the validation of VMC-dc by comparison with EGSnrc and with a physical phantom containing TLDs. The validation of VMC-dc by comparison with EGSnrc was made for a collimated beam of 0.662 MeV photons irradiating a cube of water. For the validation by comparison with the physical phantom, the case considered was a whole body irradiation with a point 137Cs source placed at a distance of 1 m from the thorax of an Alderson-RANDO phantom. The validation results show good agreement for the doses obtained using VMC-dc and EGSnrc calculations, and from VMC-dc and TLD measurements. The program VMC-dc was then applied to the calculation of doses due to immersion in water containing gamma emitters. The dose conversion coefficients for water immersion are compared with their equivalents in the literature.
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Método de Montecarlo , Fantasmas de Imagen , Radioisótopos/administración & dosificación , Irradiación Corporal Total/normas , Humanos , Masculino , Modelos Anatómicos , Fotones , Dosificación Radioterapéutica/normas , Equivalencia TerapéuticaRESUMEN
A potential low magnetic moment standard reference material (SRM) was studied in an interlaboratory comparison. The mean and the standard deviation of the saturation moment m s, the remanent moment m r, and the intrinsic coercivity H c of nine samples were extracted from hysteresis-loop measurements. Samples were measured by thirteen laboratories using inductive-field loopers, vibrating-sample magnetometers, alternating-gradient force magnetometers, and superconducting quantum-interference-device magnetometers. NiFe films on Si substrates had saturation moment measurements reproduced within 5 % variation among the laboratories. The results show that a good candidate for an SRM must have a highly square hysteresis loop (m r/m s > 90 %), H c ≈ 400 A·m(-1) (5 Oe), and m s ≈ 2 × 10(-7) A·m(2) (2 × 10(-4) emu).
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The epidemiology and natural evolution of benign prostatic hyperplasia (BPH) are important when considering the topic of natural evolution versus medical treatment. The incidence of BPH increases with age; it is thought that about 75% of men over 50 years of age suffer from some symptoms commonly associated with BPH. There are also differences in the incidence of BPH between various racial and ethnic groups. For example, it is considerably less common amongst Japanese men compared with Caucasians. Evidence from prospective studies, retrospective studies and the placebo arms of randomised, controlled studies regarding the natural evolution of BPH suggests that a strategy of 'watchful waiting' may be considered as a treatment option as the majority of patients do not show a worsening of symptoms over time. However, the chance for improvement of symptoms and the degree of symptom improvement has been shown to be higher with alpha 1-blocker therapy than with 'watchful waiting'. As both symptoms and treatment have an impact on the patient's quality of life, there is now a strong case for involving the patient in making quality-of-life decisions based on his own preferences and attitudes.
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Antagonistas Adrenérgicos alfa/uso terapéutico , Hiperplasia Prostática , Adulto , Anciano , Envejecimiento/patología , Pueblo Asiatico , Humanos , Masculino , Persona de Mediana Edad , Prostatectomía , Hiperplasia Prostática/epidemiología , Hiperplasia Prostática/fisiopatología , Hiperplasia Prostática/terapia , Calidad de Vida , Resultado del Tratamiento , Población BlancaRESUMEN
BACKGROUND: Controversy regarding the relative efficacy of treatments for the relief of the symptoms of benign prostatic hyperplasia (BPH). METHODS: This was a 6-month double-blind randomized equivalence study that compared the effects of a plant extract (320 mg Permixon) with those of a 5 alpha-reductase inhibitor (5 mg finasteride) in 1,098 men with moderate BPH using the International Prostate Symptom Score (IPSS) as the primary end-point. RESULTS: Both Permixon and finasteride decreased the IPSS (-37% and -39%, respectively), improved quality of life (by 38 and 41%), and increased peak urinary flow rate (+25% and +30%, P = 0.035), with no statistical difference in the percent of responders with a 3 ml/sec improvement. Finasteride markedly decreased prostate volume (-18%) and serum PSA levels (-41%); Permixon improved symptoms with little effect on volume (-6%) and no change in PSA levels. Permixon fared better than finasteride in a sexual function questionnaire and gave rise to less complaints of decreased libido and impotence. CONCLUSIONS: Both treatments relieve the symptoms of BPH in about two-thirds of patients but, unlike finasteride, Permixon has little effect on so-called androgen-dependent parameters. This suggests that other pathways might also be involved in the symptomatology of BPH.
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Antagonistas de Andrógenos/uso terapéutico , Fitoterapia , Extractos Vegetales/uso terapéutico , Hiperplasia Prostática/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Antagonistas de Andrógenos/efectos adversos , Colestenona 5 alfa-Reductasa , Método Doble Ciego , Inhibidores Enzimáticos/uso terapéutico , Finasterida/uso terapéutico , Humanos , Cooperación Internacional , Masculino , Persona de Mediana Edad , Oxidorreductasas/antagonistas & inhibidores , Extractos Vegetales/efectos adversos , Próstata/efectos de los fármacos , Próstata/patología , Hiperplasia Prostática/patología , Hiperplasia Prostática/fisiopatología , Serenoa , Conducta Sexual/efectos de los fármacos , Resultado del TratamientoAsunto(s)
Carcinoma de Células Transicionales/terapia , Interferón-alfa/uso terapéutico , Neoplasias de la Vejiga Urinaria/terapia , Carcinoma de Células Transicionales/inmunología , Relación Dosis-Respuesta Inmunológica , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Proteínas Recombinantes , Neoplasias de la Vejiga Urinaria/inmunologíaRESUMEN
This study was undertaken to evaluate the quality of life (QoL) of previously untreated patients with M1 prostate cancer before and during androgen-suppressive treatment. Assessment of QoL was included as an optimal component of EORTC protocol 30853, a phase III trial comparing LH-RH (luteinising hormone-releasing hormone) analogue combined with a non-steroidal anti-androgen versus orchiectomy in patients with M1 prostate cancer. At pretreatment and during the follow-up period, patients were asked to complete a questionnaire assessing their physical and psychosocial functioning, and their symptom levels. Physicians rated the patients' performance status, pain, urological symptoms and erectile function. Due to its optional nature, only a minority of the patients in the trial were recruited for the QoL investigation. 63 patients completed a pretreatment questionnaire, of whom 49 completed a second questionnaire at least once during the initial 15 month follow-up period. While statistically significant correlations were observed between patients' and physicians' ratings of physical functioning and pain, these were of only a moderate magnitude (r = 0.43 and 0.30, respectively). No significant association was observed between physicians' and patients' ratings of micturation problems or of erectile function. Before treatment, fatigue, pain and decreased social role and sexual functioning were the problems most frequently reported by patients. With an average of approximately 1 year follow-up, statistically significant improvements were observed in patients' self-reported urological symptoms and metastatic pain. No significant changes were noted for the other QoL domains assessed. The results of this study confirm earlier findings that physicians' ratings may not reflect accurately the functional health and symptom experience of their patients. Patient-based QoL questionnaires offer the most direct means of evaluating the subjective morbidity associated with prostate cancer and its treatment. To increase participation and compliance rates in future studies, it is recommended that QoL assessment be made mandatory in those clinical trials in which QoL is considered to be an important study endpoint.
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Neoplasias de la Próstata/terapia , Calidad de Vida , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Flutamida/administración & dosificación , Estudios de Seguimiento , Goserelina/administración & dosificación , Humanos , Masculino , Cuerpo Médico de Hospitales , Persona de Mediana Edad , Orquiectomía , Cooperación del Paciente , Neoplasias de la Próstata/complicaciones , Neoplasias de la Próstata/psicología , Encuestas y CuestionariosRESUMEN
The purpose of the study was to compare two doses of interferon-alpha 2b (60 and 100 million units, MU) and to define the recurrence rate per year, tumor rate per year and the toxicity for both treatment arms. 127 patients were admitted to the study and randomized between the two treatments: 64 patients in the 60-MU regimen (28 single primary, 8 multiple primary, 28 recurrent), and 63 patients (22 single primary, 10 multiple primary, 31 recurrent) in the 100-MU regimen. Of the 64 patients receiving 60 MU, 26 patients had recurrences (33 recurrences with a follow-up of 2,478 months). Of the 63 patients receiving 100 MU, 21 patients had recurrences (26 recurrences with a follow-up of 2,329 months). The recurrence rate per year for 60 MU is 0.13 and 0.11 for 100 MU and the tumor rate per year is 0.34 and 0.36, respectively. In conclusion the quality of life of the patients is very good with no side effects, and, using Fisher's exact test for statistical comparison, there was no difference in the recurrence rate per year and the tumor rate per year between the 2 groups.
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Interferón-alfa/administración & dosificación , Recurrencia Local de Neoplasia/prevención & control , Neoplasias de la Vejiga Urinaria/terapia , Administración Intravesical , Adulto , Anciano , Humanos , Interferón alfa-2 , Interferón-alfa/efectos adversos , Persona de Mediana Edad , Proteínas Recombinantes , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
Because of the importance of stannous chloride in various fields of human endeavour, the potential genotoxicity of this reducing agent was evaluated by measurement of either the inactivation or the induction of SOS responses in bacteria. Escherichia coli strains used in this work (wild type, uvrA, recA, lexA and uvrA recA) were treated with stannous chloride; the wild type was found to be the most resistant and the double mutant, the most sensitive strain. As these strains present mutations on specific genes for the repair of DNA, stannous chloride would appear to be capable of inducing and/or producing lesions in DNA and, thus, can be considered to be a potential genotoxic agent. This capability was confirmed by the lysogenic induction of E. coli K12 (lambda) (Inductest) and by microscopic observation of E. coli B filamentation.
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Pruebas de Mutagenicidad/métodos , Mutágenos/toxicidad , Compuestos de Estaño/toxicidad , Reparación del ADN/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Lisogenia/efectos de los fármacosRESUMEN
As a first effort to introduce quality-of-life assessment in prostatic cancer clinical trials, the European Organization for Research and Treatment of Cancer Genitourinary Group, in cooperation with European Organization for Research and Treatment Quality of Life Group, initiated protocol 30853, coordinated by Louis Denis. This protocol compared the efficacy of treatment with orchiectomy alone to that with Zoladex (Zeneca Pharmaceuticals, Alderley Macclesfield, Cheshire, UK) plus flutamide in previously untreated patients with metastatic cancer. The use of patient-administered quality-of-life questionnaires was optional, and of 327 patients, only 22% had pretreatment assessments. This trial revealed many clinician's considerable reluctance to perform quality of life research, partly because of feasibility problems and partly because of doctors' doubts about the value of such efforts. Psychologic distress, fatigue, issues of social and family life, and pain were found to be the most important concerns on a subjective basis, and this finding was confirmed by objective parameters. There was a discrepancy between doctors' evaluations and patients' opinions about subjective morbidity, namely sexual status and pain. Quality of life assessment should become a mandatory part of clinical trials in prostate cancer.
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Neoplasias de la Próstata/psicología , Calidad de Vida , Ensayos Clínicos como Asunto/métodos , Humanos , Masculino , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/cirugía , Encuestas y CuestionariosRESUMEN
BACKGROUND: In recent years, there has been a growing recognition of the need to include parameters representing the patients' view of their conditions that, therefore, are more subjective in nature. METHODS: As a first effort to introduce quality-of-life (QOL) assessment in prostatic cancer clinical trials, the European Organization for Research and Treatment of Cancer (EORTC) Genitourinary Group, in cooperation with the EORTC QOL Group, activated Protocol 30853 (orchiectomy versus goserelin acetate and flutamide in previously untreated patients with Stage M+ disease. Study Coordinator: Louis Denis). The use of patient-administered QOL questionnaires was optional, and of 327 patients, only 22% underwent pretreatment assessments. RESULTS: Psychologic distress, fatigue, social and family life, and pain are the most important to the patient on a subjective basis, and these were confirmed in relation to objective parameters. There was a discrepancy between the doctors' evaluations and the patients' opinions about subjective morbidity, namely, in regard to sexual status and pain. CONCLUSIONS: This EORTC trial revealed the reluctance of clinicians to do QOL research, partly related to feasibility problems and partly to the doctors' doubts about the value of such efforts. QOL assessment should become a mandatory part of clinical trials in prostatic cancer.