Abstract The flotation mechanism of galena with xanthate as the collector is generally explained based on the mixed potential of the pulp, in which an anodic electron transfer reaction from the collector to the mineral is combined with an O2 cathodic reduction. Sodium sulphide, often used as a mineral activator, strongly influences the pulp's mixed potential, and depending on the dosage applied, it can become a galena depressor reagent. In this way, the current study assesses galena flotability in the absence of collector, as well as in the presence of the collector potassium amyl xanthate (PAX) and sodium sulphide. The effect of an extremely cathodic potential was also studied through the addition of hydrogen peroxide. In addition, the effect of different stages in the oxidation of the galena surface on the flotability was investigated. Moreover, the zeta potential was measured and contact angle (wettability) tests were carried out. The contact angle measurements were taken for a distilled water, PAX solution and for a mixture of PAX and sodium sulphide solution on the oxidized and non-oxidized surface of galena. All the results showed that galena could be floated in all the PAX concentrations tested. It was observed that a moderate oxidation in the galena surface may contribute to an improvement of its flotation with PAX. However, extremely anodic and cathodic potentials cause flotability close to zero. The zeta potential results showed that sodium sulphide affected the interaction between PAX and galena. The measurements of the contact angle corroborated the results obtained in the microflotation tests. pulp O reduction activator pulps s applied reagent way (PAX peroxide investigated Moreover wettability (wettability out water nonoxidized non tested However zero

ABSTRACT This article aims to investigate the behavior of exchange rate in the BRICS countries, with an emphasis on exchange rate passthrough and exchange rate determination empirical models. By applying the ARDL Bounds Testing Approach Methodology, from January 2005 to December 2019. Our main results show that: i) there is a long run cointegration among the variables analyzed for all estimated models; ii) there is a very slow speed of adjustment towards the long run equilibrium; iii) there is evidence of exchange rate passthrough to inflation mainly in the long run, but not as strong as before; iv) there is no evidence of exchange rate overshooting; v) international reserve accumulation can be considered a partial explanation for the evidence of no exchange rate overshooting.

RESUMO O artigo tem por objetivo investigar o comportamento da taxa de câmbio nos países do BRICS com ênfase no repasse da taxa de câmbio e em modelos empíricos de determinação da taxa de câmbio. O artigo aplica metodologia ARDL Bounds Testing de Janeiro de 2005 a Dezembro de 2019. Os principais resultados indicam que: i) existe uma relação cointegrante de longo prazo entre as variáveis analisadas para todos os modelos estimados; ii) a velocidade de ajustamento em direção ao equilíbrio de longo prazo é lenta: iii) existe evidência de repasse cambial para a inflação, principalmente no longo prazo, mas o repasse não é tão expressivo como antes; iv) não existe evidência de ultrapassagem da taxa de câmbio; v) a acumulação de reservas pode ser considerada como uma explicação parcial para a evidência de não ultrapassagem da taxa de câmbio.

ABSTRACT BACKGROUND: Down syndrome (DS) is a non-rare genetic condition that affects approximately 1 in every 800 live births worldwide. Further, it is associated with comorbidities, anatomical alterations of the respiratory tract, and immunological dysfunctions that make individuals more susceptible to respiratory infections. OBJECTIVE: To systematize the current scientific knowledge about the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among individuals with DS. DESIGN AND SETTING: This integrative review was conducted at the Universidade Federal de São Carlos, São Paulo, Brazil. METHODS: This review was conducted in the following databases: the Virtual Health Library (Biblioteca Virtual em Saúde, BVS), PubMed, and Web of Science, using MeSH descriptors. The search included English or Portuguese studies published between January 1, 2020, and October 14, 2022. RESULTS: A total of 55 articles from 24 countries were selected, comprising 21 case-control or cohort studies, 23 case reports or series, and 11 narrative reviews or opinion studies. The articles were grouped into five categories: previous comorbidities, coronavirus disease 2019 (COVID-19) clinical features and evolution, cytokine storm and interleukins, living in institutions as a risk factor, and behavioral actions as a protective factor against SARS-CoV-2 infection. CONCLUSION: Individuals with DS are more susceptible to COVID-19 infection due to variables such as previous comorbidities, immunological factors, and their habitable environments. These aspects confer a higher risk of infection and an unfavorable clinical course. The precise pathways involved in the pathophysiology of COVID-19 in individuals with DS are not clear, thus requiring further studies. SYSTEMATIC REVIEW REGISTRATION: The Open Science Framework registered the research protocol (https://osf.io/jyb97/).

Abstract Objective: To analyze the reliability of estimating the percentage of rhinopharyngeal obstruction by the adenoid using nasofibroscopy and its correlation with clinical symptoms. Methods: Cross-sectional observational study was conducted, involving 80 patients between 4 and 14 years old, recruited from Santa Casa of São Paulo general otorhinolaryngology outpatient service during the years of 2020 and 2021. All patients underwent nasal endoscopy examination, and the recorded videos were randomly assigned to four evaluators in two different sessions, with a minimum interval of 1 month. The evaluators estimated the percentage of rhinopharyngeal obstruction caused by the adenoid. Intra- and inter-evaluator correlations were established by comparing the reports from each evaluator. The data were compared to the Pro Image J Software report, that also estimates a percentage of obstruction by computer graphics. To correlate the grading of obstruction with clinical symptoms, all patients completed the OSA (Obstructive Sleep Apnea) 18 questionnaire, a validated tool for assessing sleep apnea in children. The questionnaire data were then compared to the average scores assigned by the evaluators. Results: Satisfactory intra- and inter-rater correlations were observed, and the results were consistent with the Pro Image J Software. However, no correlation was found between the percentage of obstruction and the severity of clinical symptoms. Conclusion: Nasofibroscopy demonstrates good reliability in assessing a percentage of rhinopharyngeal obstruction caused by adenoids. However, there is no correlation between the degree of obstruction of the rhinopharynx and the clinical symptoms. Level of evidence: 4.

ABSTRACT Objective To investigate the prevalence of internet gaming disorder (IGD) symptoms in a sample of Brazilian adults, and its association with personality, psychiatric symptoms and psychosocial measures. Methods We evaluated 219 adults online recruited using questionnaires and psychometric scales. We evaluated the behavior and pattern of internet games using the Game Addiction Scale (GAS). We tested the association of the previous measures with the GAS scores by spearman correlations and multiple regression analysis. Results Of our sample, 74% played games online. We found correlations between IGD symptoms and most symptoms of mental disorders, with small or moderate effect sizes, as well as correlations with the personality traits of agreeableness (r = -0.272; p < 0.001), conscientiousness (r = - 0.314; p < 0.001), and neuroticism (r = 0.299; p < 0.001). Additionally, we found a negative association with psychosocial outcomes such as quality of life (r = -0.339; p < 0.001) and life satisfaction (r = - 0.202; p < 0.003). The multivariate model included the personality traits of conscientiousness and agreeableness and symptoms of dissociation and somatization as predictors. The prevalence of IGD was 9% in those who played online games. Conclusion IGD is correlated with different areas of the individual’s life, such as personality, quality of life, and several common symptoms of mental disorders. The prevalence can be considered high among players (9%). Conscientiousness, agreeability, somatic symptoms, and dissociative symptoms were associated with the symptoms of IGD.

RESUMO Objetivo Investigar a prevalência de sintomas do transtorno do jogo pela internet (TJI) em uma amostra de adultos brasileiros e sua associação com personalidade, sintomas psiquiátricos e medidas psicossociais. Métodos Avaliamos 219 adultos recrutados on-line por meio de questionários e escalas psicométricas. Avaliamos o comportamento e o padrão dos jogos na internet usando a Game Addiction Scale (GAS). Testamos a associação das medidas anteriores com as pontuações na GAS por meio de correlações de Spearman e análise de regressão múltipla. Resultados De nossa amostra, 74% jogavam jogos on-line. Encontramos correlações entre sintomas do TJI e a maioria dos sintomas de transtornos mentais, com tamanhos de efeito pequenos ou moderados, bem como correlações com os traços de personalidade de amabilidade (r = -0,272; p < 0,001), conscienciosidade (r = - 0,314; p < 0,001) e neuroticismo (r = 0,299; p < 0,001). Além disso, encontramos uma associação negativa com resultados psicossociais, como qualidade de vida (r = -0,339; p < 0,001) e satisfação com a vida (r = - 0,202; p < 0,003). O modelo multivariado incluiu os traços de personalidade de conscienciosidade e amabilidade e sintomas de dissociação e somatização como preditores. A prevalência de TJI foi de 9% entre os que jogavam jogos on-line. Conclusão O TJI está correlacionado com diferentes áreas da vida do indivíduo, como personalidade, qualidade de vida e vários sintomas comuns de transtornos mentais. A prevalência pode ser considerada alta entre os jogadores (9%). Conscienciosidade, amabilidade, sintomas somáticos e sintomas dissociativos estavam associados aos sintomas do TJI.

ABSTRACT Introduction: Chronic kidney disease (CKD) has been increasing significantly. There is evidence that a large part of the population does not have enough knowledge on the subject. Objective: To investigate the level of knowledge about CKD in the general population, its risk factors and means of prevention. Methods: We ran a cross-sectional study in the population of Fortaleza, Ceará – Brazil, between 2017 and 2020, with the application of a questionnaire on CKD, risk factors and prevention. Results: we interviewed 735 volunteers, with a mean age of 38 years, of which 55% were female. Only 17.2% correctly responded to the concept of CKD, and 5.8% knew the concept of creatinine. Low water intake was the most cited risk factor by respondents (79.3%). The main risk factors and direct causes of CKD (diabetes and hypertension) were mentioned less frequently (13.2% and 15.1%, respectively). Men were more correct regarding risk factors and ways to prevent CKD. Older respondents answered more correctly the questions about the definition of CKD (n = 22; 28.6%) and creatinine (n = 7; 9.0%). With regards to education there was a statistically significant correlation in all the questions (p < 0.05). Conclusion: There is little knowledge about CKD in the general population. Higher level of education is associated with better knowledge. More health education actions are needed so that the population becomes better acquainted with CKD and, consequently, can adopt more adequate prevention and control measures.

Resumo Introdução: A doença renal crônica (DRC) vem aumentando de forma significativa. Há evidências de que grande parte da população não tem conhecimento suficiente sobre o assunto. Objetivo: Investigar na população geral o nível de conhecimento sobre a DRC, seus fatores de risco e meios de prevenção. Métodos: Foi realizado estudo transversal na população de Fortaleza, Ceará, Brasil, entre 2017 e 2020, com aplicação de um questionário sobre DRC, fatores de risco e prevenção. Resultados: Foram entrevistados 735 voluntários, com média de idade de 38 anos, dos quais 55% eram do sexo feminino. Apenas 17,2% responderam corretamente ao conceito de DRC, e 5,8% sabiam o conceito de creatinina. A baixa ingestão hídrica foi o fator de risco mais citado pelos entrevistados (79,3%). Os principais fatores de risco e as causas diretas de DRC (diabetes e hipertensão) foram mencionados com menor frequência (13,2% e 15,1%, respectivamente). Os homens tiveram maior acerto com relação aos fatores de risco e às formas de prevenção da DRC. Os entrevistados com idade mais avançada responderam mais corretamente às perguntas sobre a definição de DRC (n = 22; 28,6%) e creatinina (n = 7; 9,0%). No que diz respeito à escolaridade, em todas as perguntas houve correlação estatisticamente significativa (p < 0,05). Conclusão: Há um baixo nível de conhecimento sobre a DRC na população geral. Maior nível de escolaridade associa-se a um melhor conhecimento. São necessárias mais ações de educação em saúde para que a população conheça melhor a DRC e consequentemente possa adotar medidas de prevenção e controle mais adequadas.

Abstract Introduction Malignant Hyperthermia (MH) is an inherited hypermetabolic syndrome triggered by exposure to halogenated anesthetics/succinylcholine. The lack of knowledge regarding this condition might be associated with the rare occurrence of MH reaction and symptoms. Methods This observational study evaluated 68 patients from 48 families with confirmed or suspected MH susceptibility due to medical history of MH reaction or idiopathic increase of creatine kinase or MH-related myopathies. Participants were assessed by a standardized questionnaire and submitted to physical/neurological examination to assess the characteristics of patients with MH, their knowledge about the disease, and the impact suspected MH had on their daily lives. Results Suspected MH impacted the daily life of 50% of patients, creating difficulties in performing surgical/clinical/dental treatment and problems related to their family life/working/practicing sports. The questionnaire on MH revealed a correct answer score of 62.1 ± 20.8 (mean ± standard deviation) on a scale 0 to 100. Abnormal physical/neurological examination findings were detected in 92.6% of susceptible patients. Conclusions Suspected MH had impacted the daily lives of most patients, with patients reporting problems even before MH investigation with IVCT. Patients showed a moderate level of knowledge about MH, suggesting the need to implement continuing education programs. MH susceptible patients require regular follow-up by a health team to detect abnormalities during physical and neurological examination.

Abstract Background Malignant Hyperthermia (MH) is a pharmacogenetic disorder triggered by halogenated anesthesia agents/succinylcholine and characterized by hypermetabolism crisis during anesthesia, but also by day-to-day symptoms, such as exercise intolerance, that may alert the health professional. Objective The study aimed to analyze the incidence of fatigue in MH susceptible patients and the variables that can impact perception of fatigue, such as the level of routine physical activity and depression. Methods A cross-sectional observational study was carried out with three groups - 22 patients susceptible to MH (positive in vitro muscle contracture test), 13 non-susceptible to MH (negative in vitro muscle contracture test) and 22 controls (no history of MH). Groups were assessed by a demographic/clinical questionnaire, a fatigue severity scale (intensity, specific situations, psychological consequences, rest/sleep response), and the Beck depression scale. Subgroups were re-assessed with the Baecke habitual physical exercise questionnaire (occupational physical activity, leisure physical exercise, leisure/locomotion physical activity). Results There were no significant differences among the three groups regarding fatigue intensity, fatigue related to specific situations, psychological consequences of fatigue, fatigue response to resting/sleeping, depression, number of active/sedentary participants, and the mean time and characteristics of habitual physical activity. Nevertheless, unlike the control sub-group, the physically active MH-susceptible subgroup had a higher fatigue response to resting/sleeping than the sedentary MH susceptible subgroup (respectively, 5.9 ± 1.9 vs. 3.9 ± 2, t-test unpaired, p< 0.05). Conclusion We did not detect subjective fatigue in MH susceptible patients, although we reported protracted recovery after physical activity, which may alert us to further investigation requirements.

Abstract Introduction Malignant Hyperthermia (MH) is a pharmacogenetic, hereditary and autosomal dominant syndrome triggered by halogenates/succinylcholine. The In Vitro Contracture Test (IVCT) is the gold standard diagnostic test for MH, and it evaluates abnormal skeletal muscle reactions of susceptible individuals (earlier/greater contracture) when exposed to caffeine/halothane. MH susceptibility episodes and IVCT seem to be related to individual features. Objective To assess variables that correlate with IVCT in Brazilian patients referred for MH investigation due to a history of personal/family MH. Methods We examined IVCTs of 80 patients investigated for MH between 2004‒2019. We recorded clinical data (age, sex, presence of muscle weakness or myopathy with muscle biopsy showing cores, genetic evaluation, IVCT result) and IVCT features (initial and final maximum contraction, caffeine/halothane concentration triggering contracture of 0.2g, contracture at caffeine concentration of 2 and 32 mmoL and at 2% halothane, and contraction after 100 Hz stimulation). Results Mean age of the sample was 35±13.3 years, and most of the subjects were female (n=43 or 54%) and MH susceptible (60%). Of the 20 subjects undergoing genetic investigation, 65% showed variants in RYR1/CACNA1S genes. We found no difference between the positive and negative IVCT groups regarding age, sex, number of probands, presence of muscle weakness or myopathy with muscle biopsy showing cores. Regression analysis revealed that the best predictors of positive IVCT were male sex (+12%), absence of muscle weakness (+20%), and personal MH background (+17%). Conclusions Positive IVCT results have been correlated to male probands, in accordance with early publications. Furthermore, normal muscle strength has been confirmed as a significant predictor of positive IVCT while investigating suspected MH cases.

Abstract This work presents the development of a reconfigurable frequency selective surface (RFSS) for application in the 2400-2483.5 MHz band, standard IEEE 802.11b/g/n (Wi-Fi). The proposed RFSS is based on the four-arms star geometry and PIN diodes were used as switching elements. In the initial design, numerical and measured results, especially for y polarization, PIN diode on-state, shown a difference of 15% for the resonant frequency. To overcome this drawback, a scaling factor was adopted and RFSS was redesigned and characterized, achieving the desired frequency response. The RFSS reconfigurability is confirmed, with a variation of at least 15 dB, when switching the states of the PIN diode. Moreover, the signal strength was measured directly on a notebook, confirming the reconfiguration of the RFSS. Finally, for the y polarization, it was found that for this polarization the frequency response remains virtually unchanged, even for angles of incidence up to 45°. In addition to the Wi-Fi signal control, the observed features make the developed RFSS especially attractive for reconfigurable antennas applications.

Abstract Frequency Selective Surfaces (FSS) are increasingly being used in telecommunications systems due to the numerous advantages presented by this sort of structure, among them low cost, ease of fabrication, and low profile stand out. This work reports the design, fabrication, and characterization of a multilayer frequency-selective absorber (FSA) for broadband operation. The proposed structure shows an absorption performance (operating in the frequency range between 2 GHz and 6 GHz) within the transmission band. The absorber consists of cascaded frequency selective surfaces, which are composed of both conductive square loops, which reflect incident signals, and resistive ones, which act as an absorbing layer. To verify the absorbing structure performance, full-wave numerical simulations and measurements are presented. The measured results are in good agreement with the numerical ones and show that the design performs absorption above 80% within the range of 2.48 GHz to 6.13 GHz, which verifies the project properties. Besides that, numerical results show that the proposed absorber has a proper response under oblique incidence up to 30°.

ABSTRACT Objective: To analyze the factors associated with the increase in domestic violence among teachers in the initial period of the pandemic. Methods: Cross-sectional and analytical study, of the websurvey type, carried out with teachers of public basic education in Minas Gerais, Brazil. Data collection took place from August to September 2020, via a digital form. The dependent variable was self-reported domestic violence. Poisson regression was used. Results: 539 teachers participated in the study in situations of domestic violence in the pandemic, of which 6.3% (n = 34) decreased a little and a lot, 58.3% (n = 314) remained the same and 35.4% (n = 191) increased a little and a lot. In the adjusted analysis, a higher prevalence of increased domestic violence was observed among teachers who reported difficulty with teaching work (PR = 1.38; 95%CI 1.01;1.89); with full adherence to social distancing (PR = 1.33; 95%CI 1.01;1.76); worsening of health status (PR = 1.70; 95%CI 1.23;2.36) and in teachers who felt sad or depressed many times or always (PR = 1.57; 95%CI 1.15;2.16). Conclusion: The increase in domestic violence of the pandemic in teachers was associated with work characteristics and mental health conditions.

RESUMO Objetivo: Analisar os fatores associados ao aumento da violência doméstica entre professores no período inicial na pandemia. Métodos: Estudo transversal e analítico, do tipo websurvey , realizado com professores da educação básica pública de Minas Gerais, Brasil. A coleta de dados ocorreu de agosto a setembro de 2020, via formulário digital. A variável dependente foi o autorrelato da violência doméstica. Utilizou-se a Regressão de Poisson. Resultados: Participaram do estudo 539 professores em situação de violência doméstica na pandemia, dos quais 6,3% (n = 34) diminuíram um pouco e muito, 58,3% (n = 314) permaneceram o mesmo e 35,4% (n = 191) aumentaram um pouco e muito. Na análise ajustada, observou-se maior prevalência do aumento da violência doméstica entre os professores que referiram dificuldade com o trabalho docente (RP = 1,38; IC95% 1,01;1,89); com adesão total ao distanciamento social (RP = 1,33; IC95% 1,01;1,76); piora no estado de saúde (RP = 1,70; IC95% 1,23;2,36) e que se sentiram tristes ou deprimidos muitas vezes ou sempre (RP = 1,57; IC95% 1,15;2,16). Conclusão: O aumento da violência doméstica da pandemia em professores foi associado a características laborais e condições de saúde mental.