EFFECT OF DIFFERENT SOLVENTS ON THE OPTICALLY STIMULATED LUMINESCENCE SIGNAL FROM MGB4O7:CE,LI-LOADED POLYMER FILMS.

The detailed dose analysis at the extremities remains a challenge, without affecting operators' mobility and their tactile sense. Using films loaded with optically stimulated luminescence (OSL) crystals have been studied in order to overcome some of these challenges in 2D dosimetry. In this work, we investigated flexible polymeric films loaded with MgB4O7:Ce,Li to acquire a better understanding of the dependence of the dosimetric signal characteristics on the production process and the influence of using different powder grain sizes. In film production, five different solvents were used: acetone-benzene, dichloromethane, chloroform, tetrahydrofuran and formic acid. Our results indicate that acetone-benzene is the solvent mixture that less influences the signal emitted by treated crystals, in comparison with the signal emitted by the pristine crystal powder. Conversely, by using formic acid, the crystalline structure of the sample was most severely modified, leading to a drastic reduction of the emitted OSL signal. We found that the extent of the grain surface in contact with the solvent in the process is important and should be taken into consideration when choosing the proper grain size to be used. Highlights  Polymeric films loaded with MgB4O7:Ce,Li crystals were produced using different solvents.Different effect on the OSL signal was found depending on the used solvent.Among the evaluated solvents, acetone-benzene was the one that less affected the OSL signal.

Spirometry for the diagnosis of airway obstruction in patients with risk factors for COPD: the GOLD and lower limit of normal criteria.

OBJECTIVE: The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. METHODS: This was an observational study of individuals ≥ 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD-, respectively) and according to the LLN criterion (LLN+ and LLN-, respectively). We also evaluated the level of agreement between the two criteria. RESULTS: A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (k = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals ≥ 70 years of age (k = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN- category (p = 0.03), as was the median DLCO (p = 0.04). CONCLUSIONS: The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

Computational dose evaluation on children exposed to natural radioactivity from granitic rocks used as architectural materials.

Considering the higher radiosensitivity of children in comparison to adults, studies related to children's exposure to ionising radiation have been long considered of relevance. For this study, the MCNPX2.7.0 Monte Carlo code and four paediatric voxel computational anthropomorphic phantoms, of both genders and aged 5 and 10 years, were used to simulate scenarios, where children are exposed to natural radiation emitted by sources in the ground by radionuclides of40K and of232Th and238U radioactive series. These elements are part of the composition of ten different types of ornamental rocks obtained from three regions of Brazil, and used as architectural material for flooring of houses. The virtual paediatric anthropomorphic phantoms were positioned in a room with dimensions of (4.0 × 5.0 × 2.8) m3filled with atmospheric air and a 3 cm thick granitic floor acting as a uniformly distributed planar gamma radiation source. The walls of the room were composed of 20 cm thick concrete. Gonads, bone marrow, bladder, colon, and skin were found to be the organs which receive the highest doses. The mean values of effective dose per air kerma at 1 m above the ground summed for all three radionuclides, were 0.96 and 0.68 Sv Gy-1for the 5 and 10 year old phantoms, respectively. The obtained results showed that the granitic rocks considered implicate annual effective doses which are 69%-78% lower than the annual limits, recommended by ICRP Publication 103.

Mobile shielding evaluation on the fetal dose during a breast radiotherapy using Monte Carlo simulation.

PURPOSE: Evaluation of the out-of-field dose is an important aspect in radiotherapy. Due to the fetus radiosensitivity, this evaluation becomes even more conclusive when the patient is pregnant. In this work, a linear accelerator Varian Clinac 2100c operating at 6 MV, a pregnant anthropomorphic phantom (Maria), and different shields added above the abdominal region of the phantom were used for the analysis based on MCNPX. METHODS: The simulations were performed for the medial and lateral projections, using either an open field collimation (10×16cm2) or a multileaf collimator. The added shields (M1 and M2) were designed based on models proposed by Stovall et al. [1], intending to reduce the deposited dose on the fetus and related structures. RESULTS: The presence of the shields showed to be effective in reducing the doses on the fetus, amniotic sac, and placenta, for example. A reduction of about 43% was found in the dose on the fetus when M2 was added, using the open field collimation, in comparison with the situation with no shield, being the lateral projection the main responsible for the dose. The use of MLC significatively reduced the doses in different structures, including on the fetus and amniotic sac, for example, in comparison to the open field situation. A slight increment on the dose in organs such as the eyes, thyroid and brain was found in both collimation systems, due to the presence of the shields. The contribution of the leakage radiation from the tube head of the linear accelerator was found to be in the order of µGy, being reduced by the presence of the M2 shield. CONCLUSION: Using the shields showed to be an essential feature in order to reduce the dose not only on the fetus, but also in important structures responsible to its development.

Spirometry for the diagnosis of airway obstruction in patients with risk factors for COPD: the GOLD and lower limit of normal criteria / Espirometria para o diagnóstico de obstrução das vias aéreas em pacientes com fatores de risco para DPOC: os critérios GOLD e limite inferior da normalidade

ABSTRACT Objective: The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. Methods: This was an observational study of individuals ≥ 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD−, respectively) and according to the LLN criterion (LLN+ and LLN−, respectively). We also evaluated the level of agreement between the two criteria. Results: A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (k = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals ≥ 70 years of age (k = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN− category (p = 0.03), as was the median DLCO (p = 0.04). Conclusions: The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

RESUMO Objetivo: A identificação de obstrução persistente das vias aéreas é fundamental para o diagnóstico de DPOC. As diretrizes da GOLD sugerem um critério fixo - relação VEF1/CVF pós-broncodilatador < 70% - para definir obstrução, embora outras diretrizes sugiram que a relação VEF1/CVF pós-broncodilatador < o limite inferior da normalidade (LIN) é o critério mais preciso. Métodos: Estudo observacional com indivíduos ≥ 40 anos de idade com fatores de risco para DPOC encaminhados ao nosso laboratório de função pulmonar para espirometria. Também foram registrados sintomas respiratórios. Calculamos a prevalência de obstrução e de ausência de obstrução das vias aéreas segundo o critério GOLD (GOLD+ e GOLD−, respectivamente) e segundo o critério LIN (LIN+ e LIN−, respectivamente). Avaliamos também o grau de concordância entre os dois critérios. Resultados: Foram incluídos 241 indivíduos. Obstrução das vias aéreas foi identificada segundo o critério GOLD em 42 indivíduos (17,4%) e segundo o critério LIN em 23 (9,5%). A concordância global entre os dois critérios foi boa (k = 0,67; IC95%: 0,52-0,81), embora tenha sido menor entre os indivíduos ≥ 70 anos de idade (k = 0,42; IC95%: 0,12-0,72). A proporção de obesos foi menor na categoria GOLD+/LIN+ do que na categoria GOLD+/LIN− (p = 0,03), assim como a mediana de DLCO (p = 0,04). Conclusões: A utilização do critério GOLD parece estar associada a uma maior prevalência de DPOC. A concordância entre os critérios GOLD e LIN também parece ser boa, embora seja mais fraca em indivíduos mais velhos. A utilização de diferentes critérios para definir obstrução das vias aéreas parece identificar indivíduos com diferentes características. É essencial compreender o significado clínico da discordância entre esses critérios. Até que mais dados estejam disponíveis, recomendamos uma abordagem holística e individualizada e também um acompanhamento cuidadoso dos pacientes com resultados discordantes para obstrução das vias aéreas.

The Importance of Sleep Fragmentation on the Hemodynamic Dipping in Obstructive Sleep Apnea Patients.

INTRODUCTION: Obstructive sleep apnea (OSA) has been associated with non-dipping blood pressure (BP). The precise mechanism is still under investigation, but repetitive oxygen desaturation and arousal induced sleep fragmentation are considered the main contributors. METHODS: We analyzed beat-to-beat measurements of hemodynamic parameters (HPs) during a 25-min period of wake-sleep transition. Differences in the mean HP values for heart rate (HR), systolic BP (SBP), and stroke volume (SV) during wake and sleep and their standard deviations (SDs) were compared between 34 controls (C) and 22 OSA patients. The Student's t-test for independent samples and the effect size by Cohen's d (d) were calculated. HP evolution was investigated by plotting the measured HP values against each consecutive pulse wave. After a simple regression analysis, the calculated coefficient beta (SCB) was used to indicate the HP evolution. We furthermore explored by a hierarchical block regression which variables increased the prediction for the SCB: model 1 BMI and age, model 2 + apnea/hypopnea index (AHI), and model 3 + arousal index (AI). RESULTS: Between the two groups, the SBP increased in OSA and decreased in C resulting in a significant difference (p = 0.001; d = 0.92). The SV demonstrated a similar development (p = 0.047; d = 0.56). The wake/sleep variation of the HP measured by the SD was higher in the OSA group-HR: p < 0.001; d = 1.2; SBP: p = 0.001; d = 0.94; and SV: p = 0.005; d = 0.82. The hierarchical regression analysis of the SCB demonstrated in SBP that the addition of AI to AHI resulted in ΔR 2: +0.163 and ΔF + 13.257 (p = 0.001) and for SV ΔR 2: +0.07 and ΔF 4.83 (p = 0.003). The AI but not the AHI remained statistically significant in the regression analysis model 3-SBP: ß = 0.717, p = 0.001; SV: ß = 0.469, p = 0.033. CONCLUSION: In this study, we demonstrated that in OSA, the physiological dipping in SBP and SV decreased, and the variation of all investigated parameters increased. Hierarchical regression analysis indicates that the addition of the AI to BMI, age, and AHI increases the prediction of the HP evolution following sleep onset for both SBP and SV and may be the most important variable.

[Primary tuberculosis of the breast: a case report]. / Tuberculose primária da mama: A propósito de um caso clinico.

Tuberculosis of the breast is an uncommon disease. The authors present a case of an asymptomatic 64 year-old patient whose mammography showed a right breast nodule which needed aetiological investigation. Complementary diagnostic exams did not lead to a differential diagnosis between granulomatous lesion and breast carcinoma; nodule aspiration results suggested tuberculosis of the breast but were unclear and so tuberculosis antibiotics were initiated. No other tuberculosis infectious focus was found at clinical- laboratory evaluation. Imagiology progress was favourable, so patient continued treatment. The authors highlight the low rate of primary tuberculosis of the breast and make a brief reference to the pathology, which has a low rate of microbiological and pathological- anatomical identification.