ABSTRACT
Extracellular soluble algal organic matter (AOM) significantly interferes with microalgae flocculation. This study investigated the effects of various AOM fractions on Chlorella sp. flocculation using ferric chloride (FeCl3), sodium hydroxide (NaOH), and chitosan. All flocculants achieved high separation efficiency (87-99 %), but higher dosages were required in the presence of AOM. High molecular weight (>50 kDa) AOM fraction was identified as the primary inhibitor of flocculation across different pH levels, whereas low/medium molecular weight (<3 and <50 kDa) AOM had minimal impact. Compositional analysis revealed that the inhibitory AOM fraction is a glycoprotein rich in carbohydrates, including neutral, amino, and acidic sugars. The significance of this study is in identifying carboxyl groups (-COOH) from acidic monomers in >50 kDa AOM that inhibit flocculation. Understanding AOM composition and the interaction dynamics between AOM, cells, and flocculants is crucial for enhancing the techno-economics and sustainability of flocculation-based microalgae harvesting.
Subject(s)
Chlorella , Flocculation , Solubility , Chlorella/metabolism , Flocculation/drug effects , Hydrogen-Ion Concentration , Organic Chemicals/pharmacology , Microalgae/metabolism , Extracellular Space/chemistry , Molecular Weight , Chitosan/chemistry , Chitosan/pharmacologyABSTRACT
BACKGROUND: Atrial fibrillation (AF) affects about 2% to 4% of the world population, and in patients hospitalized in intensive care units, this incidence can reach up to 23% in those with septic shock. The impact of AF in patients with sepsis is reflected in worse clinical outcomes, and the identification of the triggering factors can be a target for future prevention and treatment strategies. OBJECTIVES: To verify the relationship between the development of AF and mortality in patients over 80 years of age included in the sepsis protocol and to identify the risk factors that contribute to the development of AF in this population. METHODS: Retrospective observational study, with a review of electronic medical records and inclusion of 895 patients aged 80 years or older, included in the sepsis protocol of a high-complexity private hospital in São Paulo, SP, from January 2018 to December 2020. All tests were performed with a significance level of 5%. RESULTS: The incidence of AF in the sample was 13%. After multivariate analysis, using multiple logistic regression, it was possible to demonstrate an association of mortality, in the studied population, with the SOFA score (odds ratio [OR] 1.21 [1.09 - 1.35]), higher values of C-reactive protein (OR 1.04 [1.01 - 1.06]), need for vasoactive drugs (OR 2.4 [1.38 - 4.18]), use of mechanical ventilation (OR 3.49 [1.82 - 6.71]), and mainly AF (OR 3.7 [2.16 - 6.31]). CONCLUSION: In very elderly patients (80 years of age and older) with sepsis, the development of AF was shown to be an independent risk factor for in-hospital mortality.
FUNDAMENTO: A fibrilação atrial (FA) acomete cerca de 2% a 4% da população mundial. Nos pacientes internados em unidades de terapia intensiva, esta incidência pode chegar em até 23% naqueles com choque séptico. O impacto da FA nos pacientes sépticos se reflete em piores desfechos clínicos e o reconhecimento dos fatores desencadeantes pode ser alvo para estratégias de tratamento e prevenção futuras. OBJETIVOS: Verificar a relação entre desenvolvimento de FA e mortalidade nos pacientes acima de 80 anos incluídos no protocolo sepse e identificar fatores de risco que contribuam para o desenvolvimento de FA nesta população. MÉTODOS: Estudo observacional retrospectivo, com revisão de prontuários eletrônicos e inclusão de 895 pacientes com 80 anos ou mais, incluídos no protocolo sepse de um hospital privado de alta complexidade em São Paulo/SP, no período de janeiro de 2018 a dezembro de 2020. Todos os testes foram realizados com nível de significância de 5%. RESULTADOS: A incidência de FA na amostra foi de 13%. Após análise multivariada por regressão logística múltipla, foi possível demonstrar associação de mortalidade na população estudada, com o escore SOFA ( odds ratio [OR] 1,21 [1,09 1,35]), valores mais altos de proteína C-reativa (OR 1,04 [1,01 1,06]), necessidade de droga vasoativa (OR 2,4 [1,38 4,18]), uso de ventilação mecânica (OR 3,49 [1,82 6,71]) e principalmente FA (OR 3,7 [2,16 6,31). CONCLUSÕES: No paciente grande idoso (80 anos ou mais) com sepse, o desenvolvimento de FA se mostrou como fator de risco independente para mortalidade intra-hospitalar.
Subject(s)
Atrial Fibrillation , Sepsis , Aged , Humans , Aged, 80 and over , Atrial Fibrillation/etiology , Hospital Mortality , Brazil/epidemiology , Sepsis/complications , Sepsis/therapy , Retrospective Studies , Risk Factors , Intensive Care Units , Observational Studies as TopicABSTRACT
Resumo Fundamento A fibrilação atrial (FA) acomete cerca de 2% a 4% da população mundial. Nos pacientes internados em unidades de terapia intensiva, esta incidência pode chegar em até 23% naqueles com choque séptico. O impacto da FA nos pacientes sépticos se reflete em piores desfechos clínicos e o reconhecimento dos fatores desencadeantes pode ser alvo para estratégias de tratamento e prevenção futuras. Objetivos Verificar a relação entre desenvolvimento de FA e mortalidade nos pacientes acima de 80 anos incluídos no protocolo sepse e identificar fatores de risco que contribuam para o desenvolvimento de FA nesta população. Métodos Estudo observacional retrospectivo, com revisão de prontuários eletrônicos e inclusão de 895 pacientes com 80 anos ou mais, incluídos no protocolo sepse de um hospital privado de alta complexidade em São Paulo/SP, no período de janeiro de 2018 a dezembro de 2020. Todos os testes foram realizados com nível de significância de 5%. Resultados A incidência de FA na amostra foi de 13%. Após análise multivariada por regressão logística múltipla, foi possível demonstrar associação de mortalidade na população estudada, com o escore SOFA ( odds ratio [OR] 1,21 [1,09 - 1,35]), valores mais altos de proteína C-reativa (OR 1,04 [1,01 - 1,06]), necessidade de droga vasoativa (OR 2,4 [1,38 - 4,18]), uso de ventilação mecânica (OR 3,49 [1,82 - 6,71]) e principalmente FA (OR 3,7 [2,16 - 6,31). Conclusões No paciente grande idoso (80 anos ou mais) com sepse, o desenvolvimento de FA se mostrou como fator de risco independente para mortalidade intra-hospitalar.
Abstract Background Atrial fibrillation (AF) affects about 2% to 4% of the world population, and in patients hospitalized in intensive care units, this incidence can reach up to 23% in those with septic shock. The impact of AF in patients with sepsis is reflected in worse clinical outcomes, and the identification of the triggering factors can be a target for future prevention and treatment strategies. Objectives To verify the relationship between the development of AF and mortality in patients over 80 years of age included in the sepsis protocol and to identify the risk factors that contribute to the development of AF in this population. Methods Retrospective observational study, with a review of electronic medical records and inclusion of 895 patients aged 80 years or older, included in the sepsis protocol of a high-complexity private hospital in São Paulo, SP, from January 2018 to December 2020. All tests were performed with a significance level of 5%. Results The incidence of AF in the sample was 13%. After multivariate analysis, using multiple logistic regression, it was possible to demonstrate an association of mortality, in the studied population, with the SOFA score (odds ratio [OR] 1.21 [1.09 - 1.35]), higher values of C-reactive protein (OR 1.04 [1.01 - 1.06]), need for vasoactive drugs (OR 2.4 [1.38 - 4.18]), use of mechanical ventilation (OR 3.49 [1.82 - 6.71]), and mainly AF (OR 3.7 [2.16 - 6.31]) Conclusion In very elderly patients (80 years of age and older) with sepsis, the development of AF was shown to be an independent risk factor for in-hospital mortality.