A kinetic study on carboxylic acids production using bovine slaughterhouse wastewater: a promising substrate for resource recovery in biotechnological processes.

Carboxylic acids (CA) are considered high added-value compounds, and their production from wastes has gained economic and environmental notoriety. However, the CA production and kinetic modeling using some agro-industrial wastewaters, such as bovine slaughterhouse wastewater (SHW), are not well reported in the literature. Therefore, the objective of this work was to evaluate the CA production potential using SHW as a substrate under acidogenic conditions and to apply mathematical models to estimate the kinetic parameters of particulate organic matter hydrolysis, soluble organic matter consumption, and CA production. Tests were carried out in quadruplicate batch reactors with a 250-mL reaction volume, with brewery sludge as inoculum and using chloroform (0.05%, v/v) for methanogenesis inhibition. The obtained yield was 0.55 g acids gCODA-1, corresponding to 0.76 gCOD gCODA-1. The production of caproic acid without the addition of electron donors was achieved. Mathematical models that describe exponential growth, such as the first-order exponential model, cone model, and Fitzhugh model, were the most suitable to describe the production kinetics of CA. Finally, SHW seems to be a promising substrate to be investigated in the carboxylic platform.

Integration of serial self-testing for COVID-19 as part of contact tracing in the Brazilian public health system: A pragmatic trial protocol.

The coronavirus disease (COVID-19) pandemic has led to an unprecedented public health crisis. Insufficient testing continues to limit the effectiveness of the global response to the COVID-19 pandemic. Molecular testing methods such as reverse transcriptase polymerase chain reaction (RT-PCR) continue to be highly centralized and are a sub-optimal option for population surveillance. Rapid antigen tests (Ag-RDTs) offer multiple benefits including low costs, high flexibility to conduct tests in a wide variety of settings, and faster return of results. Self-test Ag-RDTs (STs) have gained approval in several markets and offer the possibility to expand testing, reaching at-risk populations. While STs have the potential to assist the COVID-19 response, test result integrity, reporting, and appropriate linkage to care continue to hinder the widespread implementation of self-testing programs. This protocol presents a mixed-methods pragmatic trial (ISRCTN91602092) to better understand the feasibility of self-testing as part of a contact tracing strategy within the Brazilian public health system. Approximately 604 close contacts of 150 index cases testing positive for COVID-19 will be enrolled. Index cases will be randomized for their close contacts to participate in either serial (daily) self-testing over a 10-day follow-up period or a more traditional approach to contact tracing with a professional Ag-RDT at one time point post-exposure. Usability workshops and focus group discussions will also be conducted. This study protocol presents a comprehensive plan to assess the effectiveness, operational feasibility, and stakeholder preferences of a serial self-testing strategy for contact tracing within the Brazilian public health system. Our results will contribute to better understanding of the feasibility of a self-testing strategy within the public sector. Potential risks and limitations are discussed. Our findings will have important implications as governments continue working to mitigate the impact of COVID-19, particularly in the context of where to direct limited resources for testing and healthcare infrastructure. Registration: This trial is registered at ISCTRN (ISRCTN91602092).

Biochemical potential evaluation and kinetic modeling of methane production from six agro-industrial wastewaters in mixed culture.

Methane (CH4) production from anaerobic digestion of solid and liquid agro-industrial wastes is an attractive strategy to meet the growing need for renewable energy sources and promote environmentally appropriate disposal of organic wastes. This work aimed at determining the CH4 production potential of six agro-industrial wastewaters (AWW), evaluating the most promising for methanization purposes. It also aims to provide kinetic parameters and stoichiometric coefficients of CH4 production and define which kinetic models are most suitable for simulating the CH4 production of the evaluated substrates. The AWW studied were swine wastewater (SW), slaughterhouse wastewater (SHW), dairy wastewater (DW), brewery wastewater (BW), fruit processing wastewater (FPW), and residual glycerol (RG) of biodiesel production. RG was the substrate that showed the highest methanization potential. Exponential kinetic models can be efficiently applied for describing CH4 production of more soluble substrates. On the other hand, logistic models were more suitable to predict the CH4 production of more complex substrates.

Kinetic modeling of anaerobic carboxylic acid production from swine wastewater.

This work aimed to evaluate the potential of anaerobic carboxylic acids (CA) production from swine wastewater (SW), perform modeling studies of the acidogenic process and estimate the kinetic parameters. Tests were carried out in four batch reactors with 250 mL reaction volume, with brewery sludge as inoculum and using chloroform (0.05%, v/v) for methanogenesis inhibition. Hydrolysis was the main limiting step of CA production from SW, once that it took more than twenty days for the particulate COD consumption to stabilize and fourteen days to produce 60% of the acids formed. A yield of 0.33 mg mgCODA-1, corresponding to 0.40 mgCOD mgCODA-1, was obtained. Kinetic models describing logistic growth functions were best suited to simulate CA production.

Caracterização físico-química e determinação de coeficientes cinéticos aeróbios de remoção da matéria orgânica de águas residuárias agroindustriais / Physical-chemical characterization and determination of aerobic kinetic coefficients for the removal of organic matter from agro-industrial wastewater

RESUMO Os objetivos do presente trabalho foram realizar uma caracterização físico-química de diferentes águas residuárias agroindustriais (ARA) e aplicar modelos cinéticos de primeira e de segunda ordem para verificar qual deles descreve melhor a progressão da demanda bioquímica de oxigênio (DBO) e para determinar coeficientes cinéticos aeróbios de remoção da matéria orgânica das ARA. Efetuou-se o ensaio de progressão da DBO pela incubação de ARA em um sistema respirométrico (Oxitop®). Os modelos cinéticos de primeira e de segunda ordem foram avaliados por erro quadrático médio (RMSE), erro quadrático médio normalizado (NRMSE) e critério de informação de Akaike (AIC). A cinética de biodegradação aeróbia das ARA avaliadas ajustou-se melhor ao modelo de primeira ordem em termos de DBO total e solúvel. Na progressão de DBO total, o maior coeficiente de desoxigenação de primeira ordem (k') foi o da água residuária de abatedouro - ARB (0,56 d-1) - e o menor foi o da água residuária de suinocultura - ARS (0,16 d-1). Os coeficientes de desoxigenação determinados no presente trabalho mostraram-se representativos, podendo ser utilizados para a simulação de processos de degradação da matéria orgânica em condições aeróbias.

ABSTRACT The aim of the present work was to perform a physicochemical characterization of different agroindustrial wastewaters (AIW), to apply first and second order kinetic models to verify which one best describes the progression of the biochemical oxygen demand (BOD) and to determine the aerobic kinetics coefficients of organic matter removal from AIW. The BOD progression assay was performed from the incubation of AIW in a respirometric system (Oxitop®). The first and second order kinetic models were evaluated by mean square error (RMSE), normalized mean square error (NRMSE), and Akaike Information Criterion (AIC). The aerobic biodegradation kinetics of the AIW evaluated was better fitted to the first order model in terms of total and soluble BOD. In the total BOD progression, the highest coefficient of first-order deoxygenation (k ') was that of slaughterhouse wastewater (SW; 0.56 d-1) and the lowest was that of swine wastewater (SSW; 0.16 d-1). The deoxygenation coefficients determined in the present work were representative, and can be used for the simulation of degradation processes of organic matter under aerobic conditions.

Associação de indicadores nutricionais com qualidade de vida em pacientes portadores de doença renal crônica em hemodiálise / Association of nutritional markers with quality of life in chronic kidney disease patients on hemodialysis

Introdução: Possíveis associações entre medidas objetivas do estado nutricional e qualidade de vida (QV) podem assegurar estratégias para melhoria dobem-estar em portadores de doença renal crônica (DRC). Objetivo: Verificar a existência de associação de indicadores nutricionais e nível de QV emportadores de DRC submetidos a hemodiálise (HD). Método: Foram estudados 103 pacientes. Os indicadores nutricionais avaliados foram: ingesta calóricapor diário alimentar de 3 dias, consumo protéico estimado pelo Equivalente Protéico do Aparecimento do Nitrogênio (PNA), índice de massa corporal (IMC)e circunferência muscular do braço (CMB). Para a medida do nível de QV foi utilizado o instrumento Medical Outcomes Study Questionaire 36-Item Short Form Health Survey (SF-36). Foram comparadas as pontuações geradas pelo SF-36 em função de IMC e CMB categorizados, e calculada a correlação linear entre pontuações do SF-36 e indicadores nutricionais, em modelo ajustado para variáveis demográficas, laboratoriais e clínicas. Resultados: Pacientes do sexo feminino classificadas como desnutridas quando comparadas com não-desnutridas, de acordo com IMC, apresentaram pontuações menores referentes à dimensão Estado Geral de Saúde (41,5 vs. 62,6; p=0,028). Entre os homens o PNA se correlacionou com a dimensão Dor (r=0,391, p=0,008) e, entre as mulheres, com Dor (r=0,369, p=0,038), Vitalidade (r=0,445, p=0,011), Limitação por Aspectos Emocionais (r=0,408, p=0,021) e aspontuações resumidas em Componentes Físico (r=0,494, p=0,004) e Mental (r=0,365, p=0,040) de QV. Conclusões: Houve associação de desnutrição ePNA com aspectos físico e mental de QV em mulheres em HD regular.

Introduction: Possible associations between objective nutritional measurements and quality of life (QoL) can ensure strategies to improve the well-being in chronic kidney disease (CKD) patients on hemodialysis (HD). Objective: To verify the existence of association of nutritional markers with QoL level in CKD patients on HD. Method: We studied a sample of 103 patients. The evaluated nutritional markers were: energy intake by the 3-day food diary method,protein consumption estimated by the Protein Equivalent of Total Nitrogen Appearance (PNA), body mass index (BMI), and the mid-arm musclecircumference (MAMC). The Medical Outcomes Study Questionnaire 36-Item Short Form Health Survey (SF-36) was used to measure the QoL level. Wecompared SF-36 scores according to BMI and MAMC categories, and calculated linear correlation between SF-36 scores and nutritional markers, using a model adjusted for demographic, clinical and laboratory data. Results: Malnourished women compared to non-malnourished according to BMI presented lower score due to General Health dimension (41.5 vs 62.6; p=0.028). Among men, PNA was correlated with Pain (r=0.391, p=0.008), and, among women,with Pain (r=0.369, p=0.038), Vitality (r=0.445, p=0.011), Role-emotional (r=0.408, p=0.021) and the score summarized into Physical (r=0.494, p=0.004) and Mental (r=0.365, p=0.040) Components of QoL. Conclusions: There was association of malnutrition and PNA with physical and mental aspects of QoL inwomen on regular HD.

Melhoria do atendimento nutricional às crianças matriculadas num Centro Municipal de Saúde do município do Rio de Janeiro / Improvement of the nutritional care for children enrolled at the Health Center, Rio de Janeiro

O presente artigo refere-se ao estudo de 705 crianças com idade compreendida entre 0 e 6 anos incompletos, atendidas num Centro Municipal de Saúde do Rio de Janeiro. O grupo foi avaliado quanto a: relaçäo peso/idade, freqüência de morbidades que motivaram a consulta, número médio de consultas por faixa de idade e tipo de aleitamento. Com o resultado desse trabalho, será possível traçar um perfil da clientela atendida e oferecer dados para um replanejamento do Serviço da Nutriçäo