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The existence of large-scale turbulent structures within a porous medium, generated through the interaction with a turbulent outer flow, is a highly debated topic, albeit most of the analysis is based on computational studies. This study contributes to the ongoing discussion by providing detailed point-measurements of the velocity in both regions by means of Particle Image Velocimetry (PIV). Two porous models of different porosity are investigated at three Reynolds numbers. The design of the experiments is based on theoretical studies to guarantee the presence of an unperturbed viscous layer at the interface (alias permeability Reynolds numbers of order one). Under these conditions and in compliance with theoretical predictions, the PIV data show the rapid dumping of turbulent fluctuations within the first pore cavities and can be used to validate closure models for volume-averaged computational studies. A point-data analysis is applied in the interfacial region by requiring continuity of tangential velocity and shear stress. The presence of the attached viscous layer implies that the coupling condition for momentum transfer must be controlled by shear, leading to the well-known Beavers and Joseph coupling condition. PIV data corroborate this statement and show the close interdependency between the penetration depth of the outer flow in the porous media and the characteristics of the vortical secondary flows induced by the strain rate at the pore scale. Consequently, the Beavers and Joseph-slip coefficient depends only upon the topology of the porous medium, at least as long as no transition to a perturbed mixing layer occurs at the interface. [ABSTRACT FROM AUTHOR]

We characterize and compare blended and bilayered heterojunctions of polymer photovoltaic devices using poly[oxa-1,4-phenylene-1,2-(1-cyano)-ethenylene-2,5-dioctyloxy-1,4-phenylene-1,2-(2-cyano)-ethenylene-1,4-phenylene] (CN-ether-PPV) and poly[2,5-dimethoxy-1,4-phenylene-1,2-ethenylene-2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-1,2-ethenylene] (M3EH-PPV) as electron- and hole-transporting polymers, respectively. We find that both blended and bilayered structures have substantially improved current densities (>3 mA/cm2) and power efficiencies (∼1% under white light) over neat films. Improved exciton dissociation at multiple interfaces and reduced recombination due to energy and charge transfers increases the charge-carrier collection in both types of heterojunction devices, but low electron mobilities in the polymers lead to low fill factors and reduced quantum efficiency (∼20%) that limit the power efficiency. Time-resolved photoluminescence reveals that for blended structures both the hole and electron-transporting polymers undergo efficient quenching with the exciton decay being dominated by the existence of two fast decay channels of 0.12 and 0.78 ns that are assigned to interspecies charge transfer and account for the increased short-circuit current observed. For layers, these components are not as prevalent. This result indicates that greater exciton generation at the dissociating interface and more efficient charge collection in the thin layers is primarily responsible for the improved short-circuit current, a conclusion that is further supported by numerical simulations of the exciton generation rate and charge collection. We also report evidence for an intermediate exciplex state in both types of structures with the greatest yield for blends with 50 wt % of CN-ether-PPV. Overall, the improved performance is due to different processes in the two structures; efficient bulk exciton quenching and charge transfer in blends and enhanced exciton generation and charge collection in layers. The optimization of each photovoltaic heterostructured device relies on this understanding of the mechanisms by which each material architecture achieves high power efficiencies. [ABSTRACT FROM AUTHOR]

Objectives: to compare the sociodemographic and clinical severity indicators of hospitalized people with HIV in relation to clinical outcomes and urgent hospital admission., Methods: a retrospective cohort study was conducted with 102 medical records of HIV-infected individuals hospitalized in a hospital in southern Brazil. In addition to descriptive analysis, Fisher's exact test, Pearson's Chi-square, and logistic regression were used., Results: the data showed a significant direct effect on severity indicators in the following variables: male sex (p=0.013), skin color (p=0.023), level of education (p=0.000), urgent admissions (p=0.000), late diagnosis (p=0.001), diabetes mellitus (p=0.001), hypertension (p=0.004), kidney disease (p=0.002), high viral load (p=0.006), CD4+ count below 200 (p=0.005), fever (p=0.016), weight loss (p=0.013), co-infection with hepatitis C (p=0.004), and mortality (p=0.007)., Conclusions: three sociodemographic and thirteen clinical markers were identified as being associated with the risk of clinical deterioration in hospitalized people with HIV.

Objective: to analyze the frequency and associated risk factors for COVID-19 infection and the availability of Personal Protective Equipment used by primary healthcare workers., Method: a cross-sectional study was conducted over six months in Rio Grande do Sul. Descriptive analysis was performed, with the comparison of independent samples using Pearson's Chi-square test and Fisher's Exact test (p<.05)., Results: the study included 206 (27%) healthcare workers who presented COVID-19 symptoms. There was a statistical association for the following variables: availability of surgical masks (p=.003), seeking information on the correct use of personal protective equipment (p=.045), having attended people with flu-like syndrome (p=.024), and believing that the highest risk of contamination is when attending a patient positive for coronavirus disease (p=.001)., Conclusion: the availability of personal protective equipment is indispensable for COVID-19 prevention, with special emphasis on the use of surgical masks. Furthermore, the study highlighted the importance of providing Personal Protective Equipment in conjunction with guidance on its use., Highlights: (1) Highlighted impacts on the distribution of PPE necessary for worker safety.(2) Emphasized the need for training and education regarding the use of PPE.(3) Found significance regarding the availability of surgical masks.(4) Identified the need for further research on health safety topics.(5) Revealed a high incidence of symptomatic workers and positive cases of COVID-19.

To evaluate the association of standardized phase angle (SPA) with nutritional status, functional parameters, and postoperative outcomes in surgical cancer patients. This prospective study includes 59 cancer patients from Pelotas (Brazil) admitted for elective cancer surgery. We obtained the phase angle through Bioelectrical Impedance Analysis (BIA) and standardized it according to the population's reference values. We estimated the muscle mass using BIA for later calculation of the Skeletal Muscle Index (SMI) and performed handgrip strength (HGS) and gait speed (GS) tests. We used the Patient-Generated Subjective Global Assessment (PG-SGA) to assess the nutritional status. Postoperative complications and duration of hospital stay were evaluated as the outcomes. The prevalence of malnutrition in the sample was 28.8%, according to ASG-PPP. SPA was statistically lower in patients with malnutrition, with lower HGS and reduced GS. For postoperative outcomes, patients with severe complications and those with prolonged hospitalization also had lower SPA values. The greater the number of functional alterations in patients, the lower the SPA value, mainly when associated with reduced muscle mass assessed by BIA, suggesting that muscle mass reduction plays an important role in the association between functional alterations and phase angle in patients with cancer. According to the parameters used in this study, low SPA value was associated with impaired nutritional and functional status and negative outcomes in the analyzed sample., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Nutritional deficiency, especially malnutrition, is frequent in cancer patients and is associated with changes in body composition, such as low muscle mass. Phase angle (PhA) has been used as a prognostic indicator and may be related to nutritional status, functionality, and quality of life in these patients. The objectives of this study were to assess the effect of chemotherapy treatment on PhA values, comparing the PhA variation before and after treatment, and to evaluate the PhA correlation, as a muscle mass surrogate, with the physical domain of quality of life, functionality, and nutritional risk in a sample of patients with cancer., Methods: A longitudinal study was conducted in patients with cancer undergoing chemotherapy for the first time. All patients aged 18 years or older, newly diagnosed, and undergoing chemotherapy for the first time were included. To analyze the difference in the PhA means according to the different classification variables, the t-test - or ANOVA - was used. The variation of the final and initial PhA was evaluated through the linear regression test., Results: A total of 175 patients were analyzed, of which 66.3% were female. The mean PhA of the initial assessment was significantly higher when compared to the final assessment of the patients PhA (p = 0.018). In both the initial and final assessments, PhA was correlated with the physical domain (r = 0.29; p < 0.001 and r = 0.19; p = 0.021) and with the functionality score (r = - 0.32; p < 0.001 and r = - 0.30; p < 0.001) and total PG-SGA (r = - 0.31; p < 0.001 and r = - 0.23; p = 0.006)., Conclusion: PhA can be considered a predictor of physical quality of life and functionality in cancer patients receiving chemotherapy treatment., (Copyright © 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

OBJECTIVE To describe social distancing practices in nine municipalities of the state of Rio Grande do Sul, Brazil, stratified by gender, age, and educational attainment. METHODS Two sequential cross-sectional studies were conducted in the municipalities of Canoas, Caxias do Sul, Ijuí, Passo Fundo, Pelotas, Porto Alegre, Santa Cruz do Sul, Santa Maria, and Uruguaiana to estimate the population prevalence of COVID-19. The study was designed to be representative of the urban population of these municipalities. A questionnaire including three questions about social distancing was also administered to the participants. Here, we present descriptive analyses of social distancing practices by subgroups and use chi-square tests for comparisons. RESULTS In terms of degree of social distancing, 25.8% of the interviewees reported being essentially isolated and 41.1% reported being quite isolated. 20.1% of respondents reported staying at home all the time, while 44.5% left only for essential activities. More than half of households reported receiving no visits from non-residents. Adults aged 20 to 59 reported the least social distancing, while more than 80% of participants aged 60 years or older reported being essentially isolated or quite isolated. Women reported more stringent distancing than men. Groups with higher educational attainment reported going out for daily activities more frequently. CONCLUSIONS The extremes of age are more protected by social distancing, but some groups remain highly exposed. This can be an important limiting factor in controlling progression of the COVID-19 pandemic.

Purpose: We evaluated phase angle, sarcopenia, and handgrip strength as prognostic factors of postoperative morbimortality in patients with cancer., Methodology: We conducted a prospective study with 60 oncology patients admitted for elective surgery between November 2015 and May 2016. We calculated the standardized phase angle (SPA) and the skeletal mass index of the subjects based on their bioelectrical impedance tests. Handgrip strength (HGS) was measured using a hydraulic dynamometer. Diagnosis of sarcopenia followed the criteria of the European Working Group on Sarcopenia in Older People. The nutritional status of each subject was evaluated through the Patient-Generated Subjective Global Assessment. Evaluation of postoperative complications followed the Clavien-Dindo classification. We also evaluated the duration of hospital stay. Outcomes were postoperative complications and duration of hospital stay., Results: The prevalence of malnutrition was 28.3%, and the prevalence of sarcopenia was 18.6%. The SPA was significantly lower among those who had severe postoperative complications or long hospital stays, while HGS and sarcopenia showed no relationship with these outcomes. Malnutrition was also related to postoperative outcomes., Conclusion: SPA can be considered a prognostic factor in postoperative morbimortality for patients with cancer.