Heat transfer coefficients from Newtonian and non-Newtonian fluids flowing in laminar regime in a helical coil

This study aimed to carry out experimental work to obtain, for Newtonian and non-Newtonian fluids, heat transfer coefficients, at constant wall temperature as boundary condition, in fully developed laminar flow inside a helical coil. The Newtonian fluids studied were aqueous solutions of glycerol, 25%, 36%, 43%, 59% and 78% (w/w) and the non-Newtonian fluids aqueous solutions of carboxymethylcellulose (CMC), a polymer, with concentrations 0.1%, 0.2%, 0.3%, 0.4% and 0.6% (w/w) and aqueous solutions of xanthan gum (XG), another polymer, with concentrations 0.1% and 0.2% (w/w). According to the rheological study performed, the polymer solutions had shear thinning behavior and different values of elasticity. The helical coil used has internal diameter, curvature ratio, length and pitch, respectively: 0.004575 m, 0.0263, 5.0 m and 11.34 mm. The Nusselt numbers for the CMC solutions are, on average, slightly higher than those for Newtonian fluids, for identical Prandtl and generalized Dean numbers. As outcome, the viscous component of the shear thinning polymer tends to potentiate the mixing effect of the Dean cells. The Nusselt numbers of the XG solutions are significant lower than those of the Newtonian solutions, for identical Prandtl and generalized Dean numbers. Therefore, the elastic component of the polymer tends to diminish the mixing effect of the Dean cells. A global correlation, for Nusselt number as a function of Péclet, generalized Dean and Weissenberg numbers for all Newtonian and non-Newtonian solutions studied, is presented.

Short Assessment of Health Literacy for Portuguese-speaking Adults

OBJECTIVE: To develop and validate a short health literacy assessment tool for Portuguese-speaking adults. METHODS: The Short Assessment of Health Literacy for Portuguese-speaking Adults is an assessment tool which consists of 50 items that assess an individual's ability to correctly pronounce and understand common medical terms. We evaluated the instrument's psychometric properties in a convenience sample of 226 Brazilian older adults. Construct validity was assessed by correlating the tool scores with years of schooling, self-reported literacy, and global cognitive functioning. Discrimination validity was assessed by testing the tool's accuracy in detecting inadequate health literacy, defined as failure to fully understand standard medical prescriptions. RESULTS: Moderate to high correlations were found in the assessment of construct validity (Spearman's coefficients ranging from 0.63 to 0.76). The instrument showed adequate internal consistency (Cronbach's alpha=0.93) and adequate test-retest reliability (intraclass correlation coefficient=0.95). The area under the receiver operating characteristic curve for detection of inadequate health literacy was 0.82. A version consisting of 18 items was tested and showed similar psychometric properties. CONCLUSIONS: The instrument developed showed good validity and reliability in a sample of Brazilian older adults. It can be used in research and clinical settings for screening inadequate health literacy.

Association between tooth loss and obesity in Brazilian adults: a population-based study

OBJECTIVE: To examine the association between tooth loss and general and central obesity among adults. METHODS: Population-based cross-sectional study with 1,720 adults aged 20 to 59 years from Florianópolis, Southern Brazil. Home interviews were performed and anthropometric measures were taken. Information on sociodemographic data, self-reported diabetes, self-reported number of teeth, central obesity (waist circumference [WC] > 88 cm in women and > 102 cm in men) and general obesity (body mass index [BMI] ≥ 30 kg/m²) was collected. We used multivariable Poisson regression models to assess the association between general and central obesity and tooth loss after controlling for confounders. We also performed simple and multiple linear regressions by using BMI and WC as continuous variables. Interaction between age and tooth loss was also assessed. RESULTS: The mean BMI was 25.9 kg/m² (95%CI 25.6;26.2) in men and 25.4 kg/m2 (95%CI 25.0;25.7) in women. The mean WC was 79.3 cm (95%CI 78.4;80.1) in men and 88.4 cm (95%CI 87.6;89.2) in women. A positive association was found between the presence of less than 10 teeth in at least one arch and increased mean BMI and WC after adjusting for education level, self-reported diabetes, gender and monthly per capita income. However, this association was lost when the variable age was included in the model. The prevalence of general obesity was 50% higher in those with less than 10 teeth in at least one arch when compared with those with 10 or more teeth in both arches after adjusting for education level, self-reported diabetes and monthly per capita family income. However, the statistical significance was lost after controlling for age. CONCLUSIONS: Obesity was associated with number of teeth, though it depended on the participants' age groups.

Anti-tumoral effect of the non-nucleoside DNMT inhibitor RG108 in human prostate cancer cells

Background: Current therapeutic strategies for advanced prostate cancer (PCa) are largely ineffective. Because aberrant DNA methylation associated with inappropriate gene-silencing is a common feature of PCa, DNA methylation inhibitors might constitute an alternative therapy. In this study we aimed to evaluate the anti-cancer properties of RG108, a novel non-nucleoside inhibitor of DNA methyltransferases (DNMT), in PCa cell lines. Methods: The anti-tumoral impact of RG108 in LNCaP, 22Rv1, DU145 and PC-3 cell lines was assessed through standard cell viability, apoptosis and cell cycle assays. Likewise, DNMT activity, DNMT1 expression and global levels of DNA methylation were evaluated in the same cell lines. The effectiveness of DNA demethylation was further assessed through the determination of promoter methylation and transcript levels of GSTP1, APC and RAR-β2, by quantitative methylation-specific PCR and RT-PCR, respectively. Results: RG108 led to a significant dose and time dependent growth inhibition and apoptosis induction in LNCaP, 22Rv1 and DU145. LNCaP and 22Rv1 also displayed decreased DNMT activity, DNMT1 expression and global DNA methylation. Interestingly, chronic treatment with RG108 significantly decreased GSTP1, APC and RAR-β2 promoter hypermethylation levels, although mRNA re-expression was only attained GSTP1 and APC. Conclusions: RG108 is an effective tumor growth suppressor in most PCa cell lines tested. This effect is likely mediated by reversion of aberrant DNA methylation affecting cancer related-genes epigenetically silenced in PCa. However, additional mechanism might underlie the anti-tumor effects of RG108. In vivo studies are now mandatory to confirm these promising results and evaluate the potential of this compound for PCa therapy.

Size at birth and blood pressure in young adults: findings from a Brazilian birth cohort study

^len^lpt^aOBJETIVO: Descrever a prevalência de pressão arterial limítrofe (PAL) e hipertensão (HT) entre adultos jovens e avaliar a associação entre tamanho ao nascer e PAL/HT. MÉTODOS: Dados foram coletados do primeiro estudo brasileiro de coorte de nascimentos em Ribeirão Preto (sudeste do Brasil), iniciado em 1978/79. De 6.827 recém-nascidos de parto único hospitalar, 2.060 foram avaliados aos 23/25 anos. Foram realizadas coleta de sangue, avaliação antropométrica e obtidas informações sobre ocupação, escolaridade, hábitos de vida e doenças crônicas. Pressão arterial (PA) foi classificada em: 1) PAL: PA sistólica (PAS) ≥ 130 e < 140 mm Hg e/ou PA diastólica (PAD) ≥ 85 e < 90 mmHg; 2) HT: PAS ≥ 140 e/ou PAD ≥ 90 mm Hg. Foi aplicado modelo de regressão logística politômica. RESULTADOS: A prevalência de PAL foi de 13,5% (homens 23,2%) e a de HT, 9,5% (homens 17,7%). PAL foi independentemente associada com sexo masculino (RR 8,84; IC95%: 6,09;12,82), comprimento ao nascer ≥ 50 cm (RR 1,97; 1,04; 3,73), índice de massa corporal (IMC) ≥ 30 kg/m² (RR 3,23; 2,02; 5,15) e circunferência de cintura alterada (RR 1,61; 1,13;2,29), enquanto HT associou-se com sexo masculino (RR 15,18; 8,92;25,81), IMC ≥ 30 kg/m² (RR 3,68; 2,23;6,06), circunferência de cintura alterada (RR 2,68; 1,77;4,05) e glicemia elevada (RR 2,55; 1,27;5,10), mas não com comprimento ao nascer. CONCLUSÕES: As prevalências de PAL e HT entre os adultos jovens dessa coorte foram maiores em homens que em mulheres. Maior comprimento ao nascer foi associado com PAL, mas não com HT, enquanto peso ao nascer não foi associado com PAL ou HT. Fatores de risco do adulto explicaram a maioria dos aumentos de PAL ou HT.^les^aOBJETIVO: Describir la prevalencia de presión arterial limítrofe (PAL) e hipertensión (HT) entre adultos jóvenes y evaluar la asociación entre tamaño al nacer y PAL/HT. MÉTODOS: : Los datos fueron colectados en el primer estudio de cohorte de nacimientos brasileño en Ribeirao Preto (sureste de Brasil), iniciado en 1978/79. De 6.827 recién nacidos de parto único hospitalario, 2.060 fueron evaluados a los 23/25 años. Se realizaron colecta de sangre, evaluación antropométrica y obtenidas informaciones sobre ocupación, escolaridad, hábitos de vida y enfermedades crónicas. Presión arterial (PA) fue clasificada en: 1) PAL: PA sistólica (PAS) ≥ 130 y < 140 mm Hg y/o PA diastólica (PAD) ≥ 85 y < 90 mm Hg; 2) HT: PAS ≥ 140 y/o PAD ≥ 90 mm Hg. Se aplicó modelo de regresión logística politómica. RESULTADOS: La prevalencia de PAL fue de 13,5% (hombres 23,2%) y la de HT, 9,5% (hombres 17,7%). PAL fue independientemente asociada con sexo masculino (Riesgo Relativo - RR) 8,84; 95%IC: 6,09;12,82), estatura al nacer ≥ 50 cm (RR 1,97; 1,04; 3,73), índice de masa corporal (IMC) ≥ 30 kg/m2 (RR 3,23; 2,02; 5,15) y circunferencia de cintura alterada (RR 1,61; 1,13;2,29), mientras el HT se asoció con sexo masculino (RR 15,18; 8,92;25,81), IMC ≥ 30 kg/m2 (RR 3,68; 2,23;6,06), circunferencia de cintura alterada (RR 2,68; 1,77;4,05) y glicemia elevada (RR 2,55; 1,27;5,10), pero no con estatura al nacer. CONCLUSIONES: Las prevalencias de PAL y HT entre los adultos jóvenes de la cohorte fueron mayores en hombres que en mujeres. Mayor estatura al nacer fue asociado con PAL, pero no con HT, mientras que el peso al nacer no estuvo asociado con PAL o HT. Factores de riesgo de adulto explicaron la mayoría de los aumentos de PAL o HT.

Non pre-emptive scheduling of messages on SMTV token-passing networks

Fieldbus communication networks aim to interconnect sensors, actuators and controllers within distributed computer-controlled systems. Therefore, they constitute the foundation upon which real-time applications are to be implemented. A specific class of fieldbus communication networks is based on a simplified version of token-passing protocols, where each station may transfer, at most, a single message per token visit (SMTV). In this paper, we establish an analogy between non-preemptive task scheduling in single processors and the scheduling of messages on SMTV token-passing networks. Moreover, we clearly show that concepts such as blocking and interference in non-preemptive task scheduling have their counterparts in the scheduling of messages on SMTV token-passing networks. Based on this task/message scheduling analogy, we provide pre-run-time schedulability conditions for supporting real-time messages with SMTV token-passing networks. We provide both utilisation-based and response time tests to perform the pre-run-time schedulability analysis of real-time messages on SMTV token-passing networks, considering RM/DM (rate monotonic/deadline monotonic) and EDF (earliest deadline first) priority assignment schemes

Risk factors of HIV-related oral lesions in adults

OBJECTIVE: To assess the risk factors in the occurrence of oral lesions in HIV-positive adults. METHODS: A retrospective analytical-descriptive survey was conducted using the medical/dental records of 534 patients with oral lesions associated with HIV. The data were collected from five referral centers for managing HIV and associated comorbidities in the city of Porto Alegre, Southern Brazil, between 1996 and 2011. Using a standardized form, socio-demographic and clinical data were recorded. Exclusively and definitively diagnosed oral pathologies were included and classified according to ECC criteria on Oral Problems Related to HIV Infection. For data analysis cross-tabulations, Chi-squared tests and logistic regression models were used where appropriate. RESULTS: CD4+ counts lower than 350 cells/mm³ (p < 0.001), alcohol consumption (p = 0.011) and female gender (p = 0.031) were predisposing factors for oral candidiasis. The occurrence of hairy leukoplakia was independently associated with CD4+ counts below 500 cells/mm³, (p = 0.029) a viral load above 5,000 copies/mm³ (p = 0.003) and smoking (p = 0.005). CONCLUSIONS: Moderate and severe degrees of immunodeficiency and detectable viral loads were risk factors for the onset of oral lesions. Smoking and alcohol consumption also increased susceptibility to the development of opportunistic infections in HIV-positive adults from Porto Alegre, irrespective of the use of antiretroviral therapy.

Preemption delay analysis for floating non-preemptive region scheduling

In real-time systems, there are two distinct trends for scheduling task sets on unicore systems: non-preemptive and preemptive scheduling. Non-preemptive scheduling is obviously not subject to any preemption delay but its schedulability may be quite poor, whereas fully preemptive scheduling is subject to preemption delay, but benefits from a higher flexibility in the scheduling decisions. The time-delay involved by task preemptions is a major source of pessimism in the analysis of the task Worst-Case Execution Time (WCET) in real-time systems. Preemptive scheduling policies including non-preemptive regions are a hybrid solution between non-preemptive and fully preemptive scheduling paradigms, which enables to conjugate both world's benefits. In this paper, we exploit the connection between the progression of a task in its operations, and the knowledge of the preemption delays as a function of its progression. The pessimism in the preemption delay estimation is then reduced in comparison to state of the art methods, due to the increase in information available in the analysis.

An improved preemption delay upper bound for floating non-preemptive region

In embedded systems, the timing behaviour of the control mechanisms are sometimes of critical importance for the operational safety. These high criticality systems require strict compliance with the offline predicted task execution time. The execution of a task when subject to preemption may vary significantly in comparison to its non-preemptive execution. Hence, when preemptive scheduling is required to operate the workload, preemption delay estimation is of paramount importance. In this paper a preemption delay estimation method for floating non-preemptive scheduling policies is presented. This work builds on [1], extending the model and optimising it considerably. The preemption delay function is subject to a major tightness improvement, considering the WCET analysis context. Moreover more information is provided as well in the form of an extrinsic cache misses function, which enables the method to provide a solution in situations where the non-preemptive regions sizes are small. Finally experimental results from the implementation of the proposed solutions in Heptane are provided for real benchmarks which validate the significance of this work.

The utilization bound of non-preemptive rate-monotonic scheduling in controller area networks is 25%

Consider a distributed computer system comprising many computer nodes, each interconnected with a controller area network (CAN) bus. We prove that if priorities to message streams are assigned using rate-monotonic (RM) and if the requested capacity of the CAN bus does not exceed 25% then all deadlines are met.

Non invasive ventilation during exercise in COPD patients: a systematic review with meta-analysis

COPD is a major cause of morbidity and mortality worldwide, representing a major public health problem due to the high health and economic resource consumption. Pulmonary rehabilitation is a standard care recommendation for these patients, in order to control the symptoms and optimize the functional capacity, reducing health care costs associated with exacerbations and activity limitations and participation. However, in patients with severe COPD exercise performance can be difficult, due to extreme dyspnea, decreased muscle strength and fatigue. In addition, hypoxemia and dyspnea during efforts and daily activities may occur, limiting their quality of life. Thus, NIV have been used as adjunct to exercise, in order to improve exercise capacity in these patients. However, there is no consensus for this technique recommendation. Our objective was to verify whether the use of NIV during exercise is effective than exercise without NIV in dyspnea, walked distance, blood gases and health status in COPD patients, through a systematic review and meta-analysis.

Depressive symptoms in institutionalized older adults

OBJECTIVE To estimate the prevalence of depressive symptoms among institutionalized elderly individuals and to analyze factors associated with this condition. METHODS This was a cross-sectional study involving 462 individuals aged 60 or older, residents in long stay institutions in four Brazilian municipalities. The dependent variable was assessed using the 15-item Geriatric Depression Scale. Poisson’s regression was used to evaluate associations with co-variables. We investigated which variables were most relevant in terms of presence of depressive symptoms within the studied context through factor analysis. RESULTS Prevalence of depressive symptoms was 48.7%. The variables associated with depressive symptoms were: regular/bad/very bad self-rated health; comorbidities; hospitalizations; and lack of friends in the institution. Five components accounted for 49.2% of total variance of the sample: functioning, social support, sensory deficiency, institutionalization and health conditions. In the factor analysis, functionality and social support were the components which explained a large part of observed variance. CONCLUSIONS A high prevalence of depressive symptoms, with significant variation in distribution, was observed. Such results emphasize the importance of health conditions and functioning for institutionalized older individuals developing depression. They also point to the importance of providing opportunities for interaction among institutionalized individuals.

Screening for depressive symptoms in older adults in the Family Health Strategy, Porto Alegre, Brazil

OBJECTIVE To analyze the prevalence of depression in older adults and associated factors. METHODS Cross-sectional study using a stratified random sample of 621 individuals aged ≥ 60 from 27 family health teams in Porto Alegre, RS, Southern Brazil, between 2010 and 2012. Community health agents measured depression using the 15-item Geriatric Depression Scale. Scores of ≥ 6 were considered as depression and between 11 and 15 as severe depression. Poisson regression was used to search for independent associations of sociodemographic and self-perceived health with both depression and its severity. RESULTS The prevalence of depression was 30.6% and was significantly higher in women (35.9% women versus 20.9% men, p < 0.001). The variables independently associated with depression were: female gender (PR = 1.4, 95%CI 1.1;1.8); low education, especially illiteracy (PR = 1.8, 95%CI 1.2;2 6); regular self-rated health (OR = 2.2, 95%CI 1.6;3.0); and poor/very poor self-rated health (PR = 4.0, 95%CI 2.9;5.5). Except for education, the strength of association of these factors increases significantly in severe depression. CONCLUSIONS A high prevalence of depression was observed in the evaluations conducted by community health agents, professionals who are not highly specialized. The findings identified using the 15-item Geriatric Depression Scale in this way are similar to those in the literature, with depression more associated with low education, female gender and worse self-rated health. From a primary health care strategic point of view, the findings become still more relevant, indicating that community health agents could play an important role in identifying depression in older adults.

Disability in instrumental activities of daily living among older adults: gender differences

OBJECTIVE To analyze gender differences in the incidence and determinants of disability regarding instrumental activities of daily living among older adults. METHODS The data were extracted from the Saúde, Bem-Estar e Envelhecimento (SABE – Health, Wellbeing and Ageing) study. In 2000, 1,034 older adults without difficulty in regarding instrumental activities of daily living were selected. The following characteristics were evaluated at the baseline: sociodemographic and behavioral variables, health status, falls, fractures, hospitalizations, depressive symptoms, cognition, strength, mobility, balance and perception of vision and hearing. Instrumental activities of daily living such as shopping and managing own money and medication, using transportation and using the telephone were reassessed in 2006, with incident cases of disability considered as the outcome. RESULTS The incidence density of disability in instrumental activities of daily living was 44.7/1,000 person/years for women and 25.2/1,000 person/years for men. The incidence rate ratio between women and men was 1.77 (95%CI 1.75;1.80). After controlling for socioeconomic status and clinical conditions, the incidence rate ratio was 1.81 (95%CI 1.77;1.84), demonstrating that women with chronic disease and greater social vulnerability have a greater incidence density of disability in instrumental activities of daily living. The following were determinants of the incidence of disability: age ≥ 80 and worse perception of hearing in both genders; stroke in men; and being aged 70 to 79 in women. Better cognitive performance was a protective factor in both genders and better balance was a protective factor in women. CONCLUSIONS The higher incidence density of disability in older women remained even after controlling for adverse social and clinical conditions. In addition to age, poorer cognitive performance and conditions that adversely affect communication disable both genders. Acute events, such as a stroke, disables elderly men more, whereas early deficits regarding balance disable women more.

Cut-off point for WHOQOL-bref as a measure of quality of life of older adults

OBJECTIVE To propose a cut-off for the World Health Organization Quality of Life-Bref (WHOQOL-bref) as a predictor of quality of life in older adults. METHODS Cross-sectional study with 391 older adults registered in the Northwest Health District in Belo Horizonte, MG, Southeastern Brazil, between October 8, 2010 and May 23, 2011. The older adults’ quality of life was measured using the WHOQOL-bref. The analysis was rationalized by outlining two extreme and simultaneous groups according to perceived quality of life and satisfaction with health (quality of life good/satisfactory – good or very good self-reported quality of life and being satisfied or very satisfied with health – G5; and poor/very poor quality of life – poor or very poor self-reported quality of life and feeling dissatisfied or very dissatisfied with health – G6). A Receiver-Operating Characteristic curve (ROC) was created to assess the diagnostic ability of different cut-off points of the WHOQOL-bref. RESULTS ROC curve analysis indicated a critical value 60 as the optimal cut-off point for assessing perceived quality of life and satisfaction with health. The area under the curve was 0.758, with a sensitivity of 76.8% and specificity of 63.8% for a cut-off of ≥ 60 for overall quality of life (G5) and sensitivity 95.0% and specificity of 54.4% for a cut-off of < 60 for overall quality of life (G6). CONCLUSIONS Diagnostic interpretation of the ROC curve revealed that cut-off < 60 for overall quality of life obtained excellent sensitivity and negative predictive value for tracking older adults with probable worse quality of life and dissatisfied with health.