Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 308
Filtrar
Mais filtros

Assunto principal
Tipo de estudo
Idioma
Intervalo de ano de publicação
1.
Front Nutr ; 9: 1006018, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36313106

##### RESUMO

Objective: To investigate the association between ultra-processed food consumption at 23-25 years of age and measurements of body composition-fat mass, fat mass distribution and lean mass at 37-39 years of age in Brazilian adults. Methods: 1978/1979 birth cohort study conducted with healthy adults from Ribeirão Preto, São Paulo, Brazil. A total of 1,021 individuals participated in the fat mass analysis (measured by air displacement plethysmography) and 815 in the lean mass analysis and fat mass distribution (assessed by dual energy X-ray absorptiometry). Food consumption was evaluated by a food frequency questionnaire. Food items were grouped according to the level of processing as per the NOVA classification. Ultra-processed food consumption was expressed as a percentage of total daily intake (g/day). Linear regression models were used to estimate the effect of ultra-processed food consumption (g/day) on body mass index, body fat percentage, fat mass index, android fat, gynoid fat, android-gynoid fat ratio, lean mass percentage, lean mass index and appendicular lean mass index. Marginal plots were produced to visualize interactions. Results: The mean daily ultra-processed food consumption in grams was 35.8% (813.3 g). There was an association between ultra-processed food consumption and increase in body mass index, body fat percentage, fat mass index, android fat and gynoid fat and decrease in lean mass percentage, only in women. Conclusion: A high ultra-processed food consumption is associated with a long-term increase in fat mass and a decrease in lean mass in adult women.

2.
Magn Reson Med ; 2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36161727

##### RESUMO

PURPOSE: To develop and validate a method for B 0 $${B}_0$$ mapping for knee imaging using the quantitative Double-Echo in Steady-State (qDESS) exploiting the phase difference ( Δ Î¸ $$\Delta \theta$$ ) between the two echoes acquired. Contrary to a two-gradient-echo (2-GRE) method, Δ Î¸ $$\Delta \theta$$ depends only on the first echo time. METHODS: Bloch simulations were applied to investigate robustness to noise of the proposed methodology and all imaging studies were validated with phantoms and in vivo simultaneous bilateral knee acquisitions. Two phantoms and five healthy subjects were scanned using qDESS, water saturation shift referencing (WASSR), and multi-GRE sequences. Δ B 0 $$\Delta {B}_0$$ maps were calculated with the qDESS and the 2-GRE methods and compared against those obtained with WASSR. The comparison was quantitatively assessed exploiting pixel-wise difference maps, Bland-Altman (BA) analysis, and Lin's concordance coefficient ( ρ c $${\rho}_c$$ ). For in vivo subjects, the comparison was assessed in cartilage using average values in six subregions. RESULTS: The proposed method for measuring Δ B 0 $$\Delta {B}_0$$ inhomogeneities from a qDESS acquisition provided Δ B 0 $$\Delta {B}_0$$ maps that were in good agreement with those obtained using WASSR. Δ B 0 $$\Delta {B}_0$$ ρ c $${\rho}_c$$ values were ≥ $$\ge$$ 0.98 and 0.90 in phantoms and in vivo, respectively. The agreement between qDESS and WASSR was comparable to that of a 2-GRE method. CONCLUSION: The proposed method may allow B0 correction for qDESS T 2 $${T}_2$$ mapping using an inherently co-registered Δ B 0 $$\Delta {B}_0$$ map without requiring an additional B0 measurement sequence. More generally, the method may help shorten knee imaging protocols that require an auxiliary Δ B 0 $$\Delta {B}_0$$ map by exploiting a qDESS acquisition that also provides T 2 $${T}_2$$ measurements and high-quality morphological imaging.

3.
Rev Bras Epidemiol ; 25: e220024, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36074452

##### RESUMO

OBJECTIVE: To describe the prevalence of physical activity among subjects from birth cohorts of three cities located in different regions of Brazil according to sociodemographic characteristics and sex, comparing the relationships within and between cohorts. METHODS: Cross-sectional study involving 12,724 adolescents and young adults who participated in five birth cohorts: Ribeirão Preto [1978/79 (37/39 years old in 2016) and 1994 (22 years in 2016)]; Pelotas [1982 (30 years in 2012) and 1993 (22 years in 2015)], and São Luís [1997/98 (18/19 years in 2016)]. Leisure-time physical activity was evaluated with questionnaires (insufficiently active: <150 min/week and active: ≥150 min/week) and moderate and vigorous physical activity (MVPA) was objectively measured by accelerometry. Those, in each city, were evaluated accordingly to skin color, socioeconomic classification, and study/work activities. RESULTS: The prevalence of leisure-time physical activity ranged from 29.2% at 30 years old in Pelotas to 54.6% among adolescents from São Luís. The prevalence of leisure-time physical activity was higher among younger people (54.6% in São Luís 1997), while the same was not observed for total physical activity. MVPA (3rd tercile) was higher in the cohorts from Pelotas and São Luís. The prevalence of leisure-time physical activity and MVPA was higher in men. The data showed that the variation in physical activity was associated with sex and sociodemographic conditions in all cohorts. CONCLUSION: Sociodemographic characteristics should be considered when promoting leisure-time physical activity and actions aimed at young people, and adults who are more socioeconomically vulnerable should be encouraged.

##### Assuntos
Coorte de Nascimento , Exercício Físico , Adolescente , Adulto , Brasil/epidemiologia , Cidades , Estudos de Coortes , Estudos Transversais , Humanos , Masculino , Fatores Socioeconômicos , Adulto Jovem
4.
Nutrients ; 14(15)2022 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-35956300

##### RESUMO

Longitudinal studies evaluating the relationship between UPF consumption and the incidence of Metabolic Syndrome (MetS) and its components are still scarce. This study aimed to evaluate the effect of UPF consumption on the incidence of MetS and its components in adults. A prospective study was conducted with 896 participants from the 1978/79 Ribeirão Preto cohort, São Paulo, Brazil. UPF consumption was evaluated in %kcal and %g at ages 23-25 years. Incidence of MetS and its components were estimated at ages 37-39 years, according to the Joint Interim Statement criteria. Poisson regression was used to assess associations, and interactions with sex were investigated. UPF consumption had no association with MetS (%kcal Adjusted PR: 1.00; 95% CI: 0.99-1.01; %g Adjusted PR: 1.00; 95% CI: 0.99-1.01). However, women with higher UPF consumption, in %kcal and %g, had a higher risk of abdominal obesity (%kcal: p = 0.030; %g: p = 0.003); and women with higher UPF consumption, in %g, had a higher risk of low HDL-cholesterol (p = 0.041). For the other components of MetS, no significant associations were observed in either sex. These findings suggest evidence of no association between UPF consumption and MetS; however, consumption of UPF was associated with increased WC and low HDL-c, but only in women.

##### Assuntos
Dieta , Síndrome Metabólica , Adulto , Brasil/epidemiologia , Fast Foods , Feminino , Manipulação de Alimentos , Humanos , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Estudos Prospectivos , Adulto Jovem
5.
Arch Womens Ment Health ; 25(5): 929-941, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35849216

##### RESUMO

Preterm birth (PTB) and postpartum depression (PPD) are important public health issues, and although literature mainly supports the association between them, some reviews have highlighted methodological limitations in the studies in this field, restricting the interpretation of such finding. This study aimed at assessing the association between PTB and PPD, by comparing groups of preterm and full-term mothers in two Brazilian cities with contrasting sociodemographic indicators. This prospective convenience cohort study assessed 1421 women during pregnancy, at childbirth, and in the postpartum period. The Edinburgh Postnatal Depression Scale (EPDS) was administrated to assess PPD within 6 months after delivery and women were considered probably depressed if scores were EDPS ≥ 12. PTB was defined as the delivery before 37 completed weeks of pregnancy. A multivariate Poisson regression was used to estimate relative risk for PPD in mothers of preterm infants, and the final analysis models were adjusted for psychosocial variables, selected according to the directed acyclic graph (DAG) approach. Frequencies of PPD were not significantly different in mothers of preterm and full-term infants, in neither city. In the final adjusted model, PTB was not associated with PPD. The association between PTB and PPD was not confirmed in two large samples from two Brazilian cities with contrasting socioeconomic profile. However, maternal health during pregnancy plays an important role in predicting PPD. Prenatal care should promote maternal mental health as an effort towards decreasing unfavored outcomes for mothers, infants, and families.

##### Assuntos
Depressão Pós-Parto , Nascimento Prematuro , Brasil/epidemiologia , Estudos de Coortes , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/epidemiologia , Depressão Pós-Parto/psicologia , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Gravidez , Nascimento Prematuro/epidemiologia , Estudos Prospectivos
6.
Cien Saude Colet ; 27(7): 2729-2740, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35730842

##### RESUMO

The aim of this study was to investigate the association of sociodemographic factors, lifestyle, maternal reproductive profile and prenatal and childbirth care with neonatal near miss (NNM) morbidity in four birth cohorts. This study involved four population-based birth cohorts: Ribeirão Preto (RP) and São Luís (SL) (2010), Pelotas 2004 (PEL04) and 2015 (PEL15). NNM was defined when one or more of the following conditions were present: birthweight <1,500 g, 5-minute Apgar score <7, gestational age <32 weeks, and report of congenital malformations. The covariates were obtained with questionnaires applied to the puerperal women. Some particularities between cohorts were identified. In the RP and SL cohorts, factors of the more distal levels (sociodemographic, lifestyle, and reproductive profile) were associated with NNM. On the other hand, proximal factors related to healthcare were more significant for the occurrence of NNM in PEL. Only the absence of prenatal care was associated with NNM in all cohorts: RP (OR=4.27, 95%CI 2.16-8.45), SL (OR=2.32, 95%CI 1.09-4.94), PEL04 (OR=4.79, 95%CI 1.59-14.46), and PEL15 (OR=5.10, 95%CI 2.60-9.97).

##### Assuntos
Near Miss , Brasil/epidemiologia , Cidades , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Gravidez , Fatores Socioeconômicos
7.
J Hum Nutr Diet ; 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35722666

##### RESUMO

BACKGROUND: Few studies have assessed dietary patterns (DPs) and the changes in these patterns over time in adults. The present study aimed to investigate whether possible changes in DPs in two assessments are associated with obesity and excess body fat. METHODS: A prospective study was conducted in which data were collected from 1082 adults of a Brazilian birth cohort during two periods 15 years apart (T1: 2002-2004; T2: 2016-2017). Food consumption was assessed in both periods using validated food frequency questionnaires. Three similar DPs were found in the two assessments, and adherence to these patterns was classified as prudent, risk or mixed. Nine DPs changes were defined. At T2, subjects with a body mass index ≥ 30.0 kg m- ² were classified as obese, and men and women with a body fat (BF) percentage ≥ 25.0 and ≥ 35.0, respectively, were classified as having excess BF. A directed acyclic graph was built to adjust the association for confounding variables. RESULTS: At T2, 34.4% of the subjects were obese and 61.4% had excess BF. In the adjusted analysis, the changes associated with obesity and excess BF were prudent-mixed (prevalence ratio [PR] 1.55; 95% confidence interval [CI] = 1.04-2.29 and PR = 1.35; 95% CI = 1.10-1.65), risk-risk (PR = 1.49; 95% CI = 1.03-2.13 and PR = 1.27; 95% CI = 1.04-1.53), risk-mixed (PR = 1.56; 95% CI = 1.05-2.31 and PR = 1.33; 95% CI = 1.07-1.63) and mixed-risk (PR = 1.61; 95% CI = 1.10-2.35 and PR = 1.29; 95% CI = 1.04-1.58). CONCLUSIONS: A decline in food quality over time or stagnation in an unhealthy DP can lead to obesity and excess BF.

8.
Acta Otorhinolaryngol Ital ; 42(3): 265-272, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35396588

##### RESUMO

Objective: To review our 5-year experience with a modified version of glossoepiglottopexy for treatment of obstructive sleep apnoea syndrome (OSA) in two hospitals. Methods: A retrospective analysis was carried out on a cohort of adult patients affected by OSA suffering from primary collapse of the epiglottis who underwent a modified glossoepiglottopexy. All patients underwent drug-induced sleep endoscopy, polysomnographic and swallowing evaluation, and assessment with the Epworth Sleepiness Scale (ESS). Results: Forty-nine patients were retrospectively evaluated. Both the apnoea-hypopnoea index (AHI) (median AHIpost-AHIpre = -22.4 events/h; p < 0.001) and oxygen desaturation index (ODI) showed a significant postoperative decrease (median ODIpost-ODIpre = -18 events/h; p < 0.001), as did hypoxaemia index (median T90% post-T90% pre = -5%; p < 0.001). The ESS questionnaire revealed a significant decrease in postoperative scores (median ESSpost-ESSpre =- 9; p < 0.001). None of the patients developed postoperative dysphagia. Conclusions: Our 5-year experience demonstrates that modified glossoepiglottopexy is a safe and reliable surgical technique for treatment of primary epiglottic collapse in OSA patients.

##### Assuntos
Epiglote , Apneia Obstrutiva do Sono , Adulto , Endoscopia/métodos , Epiglote/cirurgia , Humanos , Hipóxia , Estudos Retrospectivos , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/cirurgia
9.
Cad Saude Publica ; 38(2): e00055621, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35293517

##### RESUMO

Noncommunicable diseases (NCDs) and mental disorders cooccur in adulthood, which is why their determinants and common risk factors should be addressed at an early age. Therefore, we estimated the association of the major risk factors for NCDs with depression and suicide risk by structural equation modeling considering pathways triggered by social vulnerability or mediated by obesity. This population-based study included 2,515 Brazilian adolescents. The following exposures were the major risk factors for NCDs: substance use behaviors (variable deduced from alcohol, tobacco, and drug use), physical inactivity, and components of unhealthy eating markers (added sugar and saturated fat). Obesity was assessed using the fat mass index. The outcomes were depression and suicide risk. Depression was associated with substance use behaviors (SC = 0.304; p < 0.001), added sugar (SC = 0.094; p = 0.005), and females (SC = 0.310; p < 0.001). Suicide risk was also associated with substance use behaviors (SC = 0.356; p < 0.001), added sugar (SC = 0.100; p = 0.012), and females (SC = 0.207; p < 0.001). In adolescents, these associations may help explain the cluster of NCDs and mental disorders in adulthood.

##### Assuntos
Doenças não Transmissíveis , Suicídio , Adolescente , Adulto , Brasil/epidemiologia , Depressão , Feminino , Humanos , Doenças não Transmissíveis/epidemiologia , Fatores de Risco
10.
Medicine (Baltimore) ; 101(6): e28841, 2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35147130

##### RESUMO

ABSTRACT: Determine the most accurate diagnostic criteria of arterial hypertension (AH) for detecting early vascular aging (EVA) defined by pulse wave velocity (PWV) higher than ≥9.2âm/s.Cross-sectional study of a birth cohort started in 1978/79. The following data were collected between April 6, 2016 and August 31, 2017 from 1775 participants: demographic, anthropometric, office blood pressure (BP) measurement, biochemical risk factors, and PWV. A subsample of 454 participants underwent 24-hour ambulatory BP monitoring. The frequencies of AH, and BP phenotypes were calculated according to both guidelines. BP phenotypes (white-coat hypertension, masked hypertension (MHT), sustained hypertension (SH) and normotension) were correlated with risk factors and subclinical target organ damage after adjustment for confounders by multiple linear regression. Receiver operating characteristic curves were constructed to determine the best BP threshold for detecting EVA.A higher frequency of AH (45.1 vs 18.5%), as well as of SH (40.7 vs 14.8%) and MHT (28.9 vs 25.8%) was identified using the 2017âACC/AHA criteria comparing with 2018 ESC/ESH. EVA was associated with the higher-risk BP phenotypes (SH and MHT, Pâ<â.0001) in both criteria. There was a higher accuracy in diagnosing EVA, with the 2017âACC/AHA criteria. Analysis of the receiver operating characteristic curves showed office BP cutoff value (128/83âmm Hg) for EVA closer to the 2017âACC/AHA threshold.The 2017âAHA/ACC guideline for the diagnosis of AH, and corresponding ambulatory BP monitoring values, is more accurate for discriminating young adults with EVA. Clinical application of PWV may help identify patients that could benefit from BP levelsâ<130/80âmm Hg.

##### Assuntos
Envelhecimento/fisiologia , Guias como Assunto , Hipertensão/diagnóstico , Hipertensão Mascarada/diagnóstico , Hipertensão do Jaleco Branco/diagnóstico , Adulto , Pressão Sanguínea , Monitorização Ambulatorial da Pressão Arterial , Estudos Transversais , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Hipertensão Mascarada/epidemiologia , Análise de Onda de Pulso , Sociedades Médicas , Hipertensão do Jaleco Branco/epidemiologia
11.
NMR Biomed ; 35(4): e4670, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35088466

##### RESUMO

Magnetic resonance fingerprinting (MRF) is a rapidly developing approach for fast quantitative MRI. A typical drawback of dictionary-based MRF is an explosion of the dictionary size as a function of the number of reconstructed parameters, according to the "curse of dimensionality", which determines an explosion of resource requirements. Neural networks (NNs) have been proposed as a feasible alternative, but this approach is still in its infancy. In this work, we design a deep learning approach to MRF using a fully connected network (FCN). In the first part we investigate, by means of simulations, how the NN performance scales with the number of parameters to be retrieved in comparison with the standard dictionary approach. Four MRF sequences were considered: IR-FISP, bSSFP, IR-FISP-B1 , and IR-bSSFP-B1 , the latter two designed to be more specific for B 1 + parameter encoding. Estimation accuracy, memory usage, and computational time required to perform the estimation task were considered to compare the scalability capabilities of the dictionary-based and the NN approaches. In the second part we study optimal training procedures by including different data augmentation and preprocessing strategies during training to achieve better accuracy and robustness to noise and undersampling artifacts. The study is conducted using the IR-FISP MRF sequence exploiting both simulations and in vivo acquisitions. Results demonstrate that the NN approach outperforms the dictionary-based approach in terms of scalability capabilities. Results also allow us to heuristically determine the optimal training strategy to make an FCN able to predict T1 , T2 , and M0 maps that are in good agreement with those obtained with the original dictionary approach. k-SVD denoising is proposed and found to be critical as a preprocessing step to handle undersampled data.

##### Assuntos
Aprendizado Profundo , Algoritmos , Encéfalo , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Imagens de Fantasmas
12.
Int J Epidemiol ; 51(1): 27-28g, 2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-34564724
13.
Cad. Saúde Pública (Online) ; 38(2): e00055621, 2022. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1364626

##### RESUMO

Noncommunicable diseases (NCDs) and mental disorders cooccur in adulthood, which is why their determinants and common risk factors should be addressed at an early age. Therefore, we estimated the association of the major risk factors for NCDs with depression and suicide risk by structural equation modeling considering pathways triggered by social vulnerability or mediated by obesity. This population-based study included 2,515 Brazilian adolescents. The following exposures were the major risk factors for NCDs: substance use behaviors (variable deduced from alcohol, tobacco, and drug use), physical inactivity, and components of unhealthy eating markers (added sugar and saturated fat). Obesity was assessed using the fat mass index. The outcomes were depression and suicide risk. Depression was associated with substance use behaviors (SC = 0.304; p < 0.001), added sugar (SC = 0.094; p = 0.005), and females (SC = 0.310; p < 0.001). Suicide risk was also associated with substance use behaviors (SC = 0.356; p < 0.001), added sugar (SC = 0.100; p = 0.012), and females (SC = 0.207; p < 0.001). In adolescents, these associations may help explain the cluster of NCDs and mental disorders in adulthood.

##### Assuntos
Humanos , Feminino , Adolescente , Adulto , Suicídio , Doenças não Transmissíveis/epidemiologia , Brasil/epidemiologia , Fatores de Risco , Depressão
14.
Ciênc. Saúde Colet. (Impr.) ; 27(7): 2729-2740, 2022. tab
Artigo em Inglês | LILACS, MMyP | ID: biblio-1384425

##### RESUMO

Abstract The aim of this study was to investigate the association of sociodemographic factors, lifestyle, maternal reproductive profile and prenatal and childbirth care with neonatal near miss (NNM) morbidity in four birth cohorts. This study involved four population-based birth cohorts: Ribeirão Preto (RP) and São Luís (SL) (2010), Pelotas 2004 (PEL04) and 2015 (PEL15). NNM was defined when one or more of the following conditions were present: birthweight <1,500 g, 5-minute Apgar score <7, gestational age <32 weeks, and report of congenital malformations. The covariates were obtained with questionnaires applied to the puerperal women. Some particularities between cohorts were identified. In the RP and SL cohorts, factors of the more distal levels (sociodemographic, lifestyle, and reproductive profile) were associated with NNM. On the other hand, proximal factors related to healthcare were more significant for the occurrence of NNM in PEL. Only the absence of prenatal care was associated with NNM in all cohorts: RP (OR=4.27, 95%CI 2.16-8.45), SL (OR=2.32, 95%CI 1.09-4.94), PEL04 (OR=4.79, 95%CI 1.59-14.46), and PEL15 (OR=5.10, 95%CI 2.60-9.97).

##### Assuntos
Mortalidade Infantil , Near Miss , Cuidado Pré-Natal , Brasil , Saúde Materno-Infantil , Coorte de Nascimento , Fatores Sociodemográficos , Estilo de Vida
15.
Rev. bras. epidemiol ; 25: e220024, 2022. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1394781

##### RESUMO

ABSTRACT Objective: To describe the prevalence of physical activity among subjects from birth cohorts of three cities located in different regions of Brazil according to sociodemographic characteristics and sex, comparing the relationships within and between cohorts. Methods: Cross-sectional study involving 12,724 adolescents and young adults who participated in five birth cohorts: Ribeirão Preto [1978/79 (37/39 years old in 2016) and 1994 (22 years in 2016)]; Pelotas [1982 (30 years in 2012) and 1993 (22 years in 2015)], and São Luís [1997/98 (18/19 years in 2016)]. Leisure-time physical activity was evaluated with questionnaires (insufficiently active: <150 min/week and active: ≥150 min/week) and moderate and vigorous physical activity (MVPA) was objectively measured by accelerometry. Those, in each city, were evaluated accordingly to skin color, socioeconomic classification, and study/work activities. Results: The prevalence of leisure-time physical activity ranged from 29.2% at 30 years old in Pelotas to 54.6% among adolescents from São Luís. The prevalence of leisure-time physical activity was higher among younger people (54.6% in São Luís 1997), while the same was not observed for total physical activity. MVPA (3rd tercile) was higher in the cohorts from Pelotas and São Luís. The prevalence of leisure-time physical activity and MVPA was higher in men. The data showed that the variation in physical activity was associated with sex and sociodemographic conditions in all cohorts. Conclusion: Sociodemographic characteristics should be considered when promoting leisure-time physical activity and actions aimed at young people, and adults who are more socioeconomically vulnerable should be encouraged.

16.
Phys Med ; 89: 80-92, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34352679

##### RESUMO

MR fingerprinting (MRF) is an innovative approach to quantitative MRI. A typical disadvantage of dictionary-based MRF is the explosive growth of the dictionary as a function of the number of reconstructed parameters, an instance of the curse of dimensionality, which determines an explosion of resource requirements. In this work, we describe a deep learning approach for MRF parameter map reconstruction using a fully connected architecture. Employing simulations, we have investigated how the performance of the Neural Networks (NN) approach scales with the number of parameters to be retrieved, compared to the standard dictionary approach. We have also studied optimal training procedures by comparing different strategies for noise addition and parameter space sampling, to achieve better accuracy and robustness to noise. Four MRF sequences were considered: IR-FISP, bSSFP, IR-FISP-B1, and IR-bSSFP-B1. A comparison between NN and the dictionary approaches in reconstructing parameter maps as a function of the number of parameters to be retrieved was performed using a numerical brain phantom. Results demonstrated that training with random sampling and different levels of noise variance yielded the best performance. NN performance was at least as good as the dictionary-based approach in reconstructing parameter maps using Gaussian noise as a source of artifacts: the difference in performance increased with the number of estimated parameters because the dictionary method suffers from the coarse resolution of the parameter space sampling. The NN proved to be more efficient in memory usage and computational burden, and has great potential for solving large-scale MRF problems.

##### Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador , Algoritmos , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Imagens de Fantasmas
17.
Int J Mol Sci ; 22(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34298936

##### RESUMO

Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the 1H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening. With difficulty accessing clinically suitable exams, the diagnosis of bone diseases, such as osteoporosis, and the associated fracture risk estimation is based on the assessment of bone mineral density (BMD), obtained by the dual-energy X-ray absorptiometry (DXA). However, integrating the information about the structure of the bone with the bone mineral density has been shown to improve fracture risk estimation related to osteoporosis. Portable NMR, based on low-field single-sided NMR devices, is a promising and appealing approach to assess NMR properties of biological tissues with the aim of medical applications. Since these scanners detect the signal from a sensitive volume external to the magnet, they can be used to perform NMR measurement without the need to fit a sample inside a bore of a magnet, allowing, in principle, in vivo application. Techniques based on NMR single-sided devices have the potential to provide a high impact on the clinical routine because of low purchasing and running costs and low maintenance of such scanners. In this review, the development of new methodologies to investigate structural properties of trabecular bone exploiting single-sided NMR devices is reviewed, and current limitations and future perspectives are discussed.

##### Assuntos
Doenças Ósseas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Absorciometria de Fóton/métodos , Animais , Densidade Óssea/fisiologia , Osso Esponjoso/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Humanos , Osteoporose/diagnóstico por imagem
18.
Cad Saude Publica ; 37(6): e00037020, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34190749

##### RESUMO

We analyzed the spatial relation between incomplete vaccine coverage for children and the distance from vaccination services. This was a cross-sectional study of children from 13 to 35 months of age from the cities of São Luís (Maranhão State) and Ribeirão Preto (São Paulo State), Brazil, and from basic health units (UBS, in Portuguese). The sample consisted of 2,744 children from São Luís and 3,325 from Ribeirão Preto. Data about incomplete vaccine coverage for children were obtained from the BRISA birth cohorts. Data about the quality of UBS vaccination services were obtained from the first cycle of the Brazilian National Program for Improvement of Access and Quality of Basic Care (PMAQ-AB, in Portuguese). For the spatial analysis, we determined the distance between the residence of the children (with and without a complete vaccine calendar) and the vaccination services of the UBS (classified according to number of structural items). Incomplete vaccine coverage was more pronounced in São Luís, with greater percentages for human rotavirus and triple viral vaccines, with the latter being the least available. In Ribeirão Preto, incomplete BCG vaccine coverage was more pronounced, with the tetravalent vaccine being the least available. Children from the two cities showed similarities: most of them had adult mothers with 9 to 11 years of schooling and did not reside with siblings in the household. They also showed differences: in São Luís, most mothers belonged to the economic class C, while in Ribeirão Preto they belong to the A and B classes. In the two cities with different socioeconomic conditions, complete vaccine coverage seemed not to depend on the location or quality of the vaccination service. Although São Luís showed a better structure of the services, incomplete vaccine coverage was higher compared to Ribeirão Preto.

##### Assuntos
Vacinação , Vacinas , Adulto , Brasil , Criança , Cidades , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Fatores Socioeconômicos , Análise Espacial
19.
Cad Saude Publica ; 37(4): e00093320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33950086

##### RESUMO

This paper describes the history, objectives and methods used by the nine Brazilian cohorts of the RPS Brazilian Birth Cohorts Consortium (Ribeirão Preto, Pelotas and São Luís) Common thematic axes are identified and the objectives, baseline periods, follow-up stages and representativity of the population studied are presented. The Consortium includes three birth cohorts from Ribeirão Preto, São Paulo State (1978/1979, 1994 and 2010), four from Pelotas, Rio Grande do Sul State (1982, 1993, 2004 and 2015), and two from São Luís, Maranhão State (1997 and 2010). The cohorts cover three regions of Brazil, from three distinct states, with marked socioeconomic, cultural and infrastructure differences. The cohorts were started at birth, except for the most recent one in each municipality, where mothers were recruited during pregnancy. The instruments for data collection have been refined in order to approach different exposures during the early phases of life and their long-term influence on the health-disease process. The investigators of the nine cohorts carried out perinatal studies and later studied human capital, mental health, nutrition and precursor signs of noncommunicable diseases. A total of 17,636 liveborns were recruited in Ribeirão Preto, 19,669 in Pelotas, and 7,659 in São Luís. In the studies starting during pregnancy, 1,400 pregnant women were interviewed in Ribeirão Preto, 3,199 in Pelotas, and 1,447 in São Luís. Different strategies were employed to reduce losses to follow-up. This research network allows the analysis of the incidence of diseases and the establishment of possible causal relations that might explain the health outcomes of these populations in order to contribute to the development of governmental actions and health policies more consistent with reality.

##### Assuntos
Mães , Brasil , Cidades , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Gravidez , Fatores Socioeconômicos
20.
BMC Pulm Med ; 21(1): 178, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34034727

##### RESUMO

BACKGROUND: The excess adiposity, even in the absence of diseases, is responsible for a decline in pulmonary function, which is considered a predictor of mortality and a risk factor for diseases in several epidemiological studies. However, studies on the association between obesity and pulmonary function have found only few associations or inconclusive results. The aim of the study is to evaluate the association between body composition and spirometric parameters, comparing simple obesity measures such as body mass index (BMI) and waist circumference with more precise body composition measurements such as dual-energy X-ray absorptiometry (DXA) and air-displacement plethysmography (BOD POD). METHODS: This is an observational, cross-sectional study that used data from the 1978/79 Ribeirão Preto birth cohort (São Paulo, Brazil). The study included 1746 participants from the 5th follow-up of the cohort. Linear regressions were calculated to evaluate the association between BMI, waist circumference, waist-height ratio (WHtR), BOD POD- and DXA-measured fat mass percentage, and spirometric parameters FEV1, and FVC. RESULTS: For every 1-kg/m2 BMI increase, FVC decreased by 13 ml in males and by 6 ml in females and FEV1 decreased by 11 ml and 5 ml, respectively. Regarding body composition measurements, for a 1% increase in fat mass assessed by BOD POD, FVC decreased by 16 ml in males and by 8 ml in females and FEV1 decreased by 13 ml and 7 ml, respectively. Hence, negative associations between body measurements and FEV1 and FVC were observed in both genders, especially when using the fat mass measurement and were more expressive in men. CONCLUSION: The anthropometric and body composition parameters were negatively associated with the spirometric variables FVC and FEV1. We have also observed that simple measures such as waist-height ratio were sufficient to detect the association of body composition with pulmonary function reduction.

##### Assuntos
Composição Corporal/fisiologia , Pulmão/fisiologia , Absorciometria de Fóton , Adulto , Antropometria , Índice de Massa Corporal , Brasil , Estudos Transversais , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Modelos Lineares , Masculino , Fatores de Risco , Espirometria , Capacidade Vital/fisiologia , Circunferência da Cintura/fisiologia
...