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One of the most used methods to measure antioxidant capacity in food is the ferric reducing antioxidant power (FRAP) test, which is simple, sensitive, and economical, nevertheless has long analysis times, causing measurement errors due to the instability of the FRAP reagent due to its precipitation sequential injection analysis (SIA) is a flow technique that can correct these disadvantages because it is more quickly. So, a novel FRAP-SIA method was developed to evaluate the antioxidant capacity. The system was optimized using a central composite design for hydrodynamic and chemical factors, resulting in a flow rate of 35 µL s-1, and aspirate volumes of 33 µL-38 µL-33 µL for the sequence (FRAP-Antioxidant-FRAP). FRAP reagent was prepared with an HCl solution at 0.005 mol L-1, improving its stability 24 times, concerning when it is in acetate buffer at pH 3.6. The method showed excellent accuracy (RSD <3%) with a LOD of 1.0 µmol L-1 of Trolox for a linear range of 5-120 µmol L-1. The reaction time was diminished by 96% concerning the FRAP-microplate assay (from 30 min to 1.2 min). The method was applied in beverages and extracts, obtaining recovery values ranging from 91.24 to 114.22%.

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INTRODUCTION: Haemophilia B (HB) is an X-linked hereditary bleeding disorder characterized by coagulation factor IX (FIX) deficiency. To improve the quality of life of patients and adherence to treatment, recombinant factor concentrates modified to extend their half-life have been developed, called extended half-life factors (EHL: extended half-life). Nonacog beta pegol (N9-GP) is a glycopegylated recombinant human FIX molecule that has a half-life of 93 h with a single dose and has shown a higher recovery percentage than other molecules. To diagnose and monitor the treatment of haemophiliac patients, FIX activity is determined with the one-stage clotting assay (OSA) and/or the chromogenic assay. The objective of this work, carried out in three centres, was to measure the recovery of N9-PG with 10 different activated partial thromboplastin time (APTT) reagents on three platforms, in samples spiked in vitro with N9-GP, at four different concentration levels. METHODS: It was measured the recovery of N9-GP with 10 different APTT reagents (polyphenol, ellagic acid, silice dioxide, colloidal silica as APTT activator on three platforms, in sample spiked in vitro with N9-GP. RESULTS: The results show heterogeneity in the activity of N9-GP measured by OSA with the different APTT reagents when the calibrations were performed with the specific calibrator of each coagulometer. A recovery percentage between 87% and 108% was obtained only with polyphenol and ellagic acid as activator in the three platforms evaluated. The other reagents studied overestimate or underestimate, with no clear profile. When a calibration curve was performed with a calibrator prepared from the N9-GP vial, all APTT reagents met the established recovery requirement. CONCLUSION: APTT reagents with polyphenol or ellagic acid as activator would be the only ones appropriate when using the commercially available OSA with specific calibrator to monitor patients treated with N9-GP.

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Los fenotipos de obesidad se presentan en individuos con igual índice de masa corporal que tienen diferentes perfiles metabólicos y pronósticos de salud. Su presencia desde etapas tempranas de la vida hace que incremente la probabilidad de que una mujer arribe al embarazo con estas características, por lo que es necesario promover un posicionamiento conceptual para su identificación. En gestantes normopeso, se sugiere identificar el fenotipo normopeso obeso cuando presenta valor igual o superior al 30 por ciento de la grasa corporal o al 90 percentil de la suma de pliegues cutáneos tricipital y subescapular. De ellas, las que tengan valores iguales o superiores al 75 percentil del índice de adiposidad visceral y del producto de acumulación de los lípidos, se consideran normopeso metabólicamente obesas. En las obesas se propone el uso de los criterios que definen al síndrome metabólico en mujeres, con valores ajustados para gestantes, para identificar la salud metabólica. Los argumentos expuestos demuestran lo idóneo de estratificar el riesgo metabólico al inicio de la gestación al clasificarlas en fenotipos de obesidad, mediante indicadores antropométricos, bioquímicos y clínicos que identifican al síndrome metabólico(AU)

The obesity phenotypes settle down in individuals with equal body mass index that present different metabolic profiles and health prognosis. Its presence from early stages of life increases the probability that women get pregnant with this characteristic, so it is considered necessary to promote a conceptual position for its identification at the beginning of pregnancy. In normal-weight pregnant woman, we propose to use the value of 30 percent or the 90th percentile of the sum of the triceps and subescapularis skinfold to define obese normal-weight phenotype. Of these, those with values equal to or greater than the 75th percentile of visceral adiposity index and the lipids accumulation product would be considered obese metabolically normal-weight. In obese pregnant woman the use of the criteria that define metabolic syndrome in women, is proposed to identify the metabolic health. The exposed theoretical foundations demonstrate the suitability of stratifying metabolic risk at the beginning of pregnancy by classifying it into obesity phenotypes, through anthropometric, biochemical, and clinical indicators(AU)

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This study searched for the best synthesis route for producing an adsorbent from the alkaline fusion of volcanic rock powder waste. The samples synthesized under different conditions of temperature and alkalizing ratio/precursor material, nine in total (NP.F, NP.F1, NP.F2, ...NP.F8 ), were used in the adsorption of acid green 16 (AG 16) and acid red 97 (AR 97) dyes and Ag+, Co2+, and Cu2+ ions. Subsequently, the 22 central composite rotational design (CCRD) was applied, and the effects of the alkalizing ratio (NaOH)/volcanic rock (VR) and temperature (T) on the synthesis process were analyzed in terms of their influence on the physical properties of the materials and in the process of adsorption of contaminants. From the experimental design, it can be seen that the independent variables alkalizing ratio/volcanic rock and temperature greatly influence the characteristic and synthesis of adsorbent materials by alkaline fusion, which in turn reflects on the results achieved in the adsorption of contaminants. Therefore, the temperature of 550 °C and NaOH/VR ratio equal to 1 was the most satisfactory synthesis route to obtain high values of adsorption capacity (q, mg g-1) and removal (R, %) for all studied contaminants, as well as the optimization of the physical characteristics of the material. For example, the adsorption capacity of dye AG 16 was 49.1 mg g-1, and for Ag+ was 66.2 mg g-1, while the removal percentages were 97.6% and 93.4%, respectively. This approach made it possible to transform volcanic rock powder wastes into an efficient adsorbent to treat contaminated waters with dyes and metals.

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BACKGROUND: Marbofloxacin (MAR) is a veterinary antimicrobial, marketed in injectable solution, oral suspension, and tablets. MAR has no monograph for tablet evaluation in official compendiums. High Performance Liquid Chromatography (HPLC) methods present in the literature for evaluating MAR in tablets do not follow the principles of green and sustainable analytical chemistry. OBJECTIVE: A green, clean, and sustainable method by HPLC was developed and validated to evaluate the content and stability of MAR in tablets, in addition to comparing it with other methods available in the literature. METHOD: A C8, 5 µm, 4.6 × 150 mm (ACE®) column, purified water with 0.2% formic acid-ethanol (70:30, v/v) as the mobile phase, and a flow rate of 0.7 mL/min at 296 nm were used. RESULTS: The method was linear over a concentration range of 1-10 µg/mL, selective for tablet matrix and forced degradation, precise with relative standard deviations (RDS) less than 5%, accurate with recovery of 99.99%, and robust to changes in the mobile phase, flow rate, wavelength, equipment, and column brand. The retention time for MAR was approximately 3.1 min. CONCLUSIONS: The method can be used in routine analysis of MAR in tablets in chemical-pharmaceutical laboratories. Furthermore, it can be used to verify the stability of MAR-based products and proved to be interchangeable with spectrophotometric method in the UV region and turbidimetric microbiological method. HIGHLIGHTS: A green method for evaluation of marbofloxacin tablets by HPLC was developed and validated. Additionally, it has been shown to be interchangeable with UV and turbidimetric methods.

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Tannins, which are water-soluble polyhydroxyphenols found in plant structures, offer a sustainable alternative to inorganic products for treating effluents. To overcome their solubility in water, new methods have been developed to immobilize tannin on materials such as nanocellulose, resulting in tannin-based adsorbents. This study investigates the production of different types of tannin-based adsorbents immobilized on nanocellulose nanofibrils using glutaraldehyde as a crosslinking agent. The adsorbents were characterized for their morphology, chemical composition, tannin leaching, thermal stability, and copper adsorption capacity. The main results showed that tannin leaching from the adsorbents in water was greatly reduced with glutaraldehyde. Scanning electron microscopy images showed tannin coating on the surface of nanocellulose nanofibrils due to immobilization. The lyophilized adsorbent was effective in adsorbing Cu (II) within 1 min, with the adsorbed amount increasing gradually until stabilization after 45 min. Overall, this study suggests that tannin immobilized on nanofibrillated cellulose has the potential to offer a sustainable and renewable alternative for effluent treatment.

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Antigen tests have been crucial for managing the COVID-19 pandemic by identifying individuals infected with SARS-CoV-2. This remains true even after immunity has been widely attained through natural infection and vaccination, since it only provides moderate protection against transmission and is highly permeable to the emergence of new virus variants. For this reason, the widespread availability of diagnostic methods is essential for health systems to manage outbreaks effectively. In this work, we generated nanobodies to the virus nucleocapsid protein (NP) and after an affinity-guided selection identified a nanobody pair that allowed the detection of NP at sub-ng/mL levels in a colorimetric two-site ELISA, demonstrating high diagnostic value with clinical samples. We further modified the assay by using a nanobody-NanoLuc luciferase chimeric tracer, resulting in increased sensitivity (detection limit = 61 pg/mL) and remarkable improvement in diagnostic performance. The luminescent assay was finally evaluated using 115 nasopharyngeal swab samples. Receiver Operating Characteristic (ROC) curve analysis revealed a sensitivity of 78.7% (95% confidence interval: 64.3%-89.3%) and specificity of 100.0% (95% confidence interval: 94.7%-100.0%). The test allows the parallel analysis of a large number of untreated samples, and fulfills our goal of producing a recombinant reagent-based test that can be reproduced at low cost by other laboratories with recombinant expression capabilities, aiding to build diagnostic capacity.

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AIMS: The aim was to develop an electrochemical/optical set-up and correlate it (as validation) with other chemical and physical methods to obtain a simple and cost-effective system to study biofilm formation. METHODS AND RESULTS: A simple microfluidic cell and methods allowed continuous monitoring of the first, critical steps of microbial attachment. We monitored sulfate-reducing bacteria (SRB) at the early stages of biofilm formation. Herein, we studied the formation and adherence of SRB consortium biofilms over an indium tin oxide (ITO) conducting surface using microbiological and chemical methods, microscopic observations [scanning electron microscopy (SEM) and optical], and electrochemical impedance spectroscopy (EIS) measurements. The SRB biofilm formation was evaluated for 30 d by SEM and EIS. Charge transfer resistance decreased when the microbial population colonized the electrode. The monitoring of early-stage biofilm formation was performed using EIS at a single frequency of 1 Hz during the first 36 h. CONCLUSIONS: The simultaneous use of optical, analytical, and microbiological methods allowed us to connect the kinetics of the growth of the microbial consortium to the values obtained via the electrochemical technique. The simple setup we present here can help laboratories with limited resources to study biofilm attachment and facilitates the development of various strategies to control biofilm development in order to avoid damage to metallic structures (microbiologically influenced corrosion, MIC) or the colonization of other industrial structures and medical devices.

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The growing appearance of antibiotic-resistant strains of microorganisms originated from the widespread use and ubiquitous presence of such drugs is a major concern in the world. The development of methodologies able to detect such substances at low concentration in real water samples is mandatory to overcome this problem. Europium(III) is known to form complexes with tetracycline (TC) with photoluminescent characteristics useful for TC determination. In the present work, we synthesized for the first time carbon nanoparticles (CN) showing delayed photoluminescence using a Europium(III) doping synthesis. The new material (PCNEu) was characterized both morphologically and spectroscopically, showing an analytical photoluminescent signal in presence of TC, arising from the 5D0→7F2 transition of europium, one hundred times higher than that of the europium salt alone in presence of the antibiotic. This enhancement is a consequence of the amplifying effect exerted by nanoparticle structure itself, leading to an efficient synergistic "antenna effect" in the system PCNEu - TC. The analytical signal is affected both by pH and the nature of the buffer used, and it allows the detection of tetracycline in waters with a limit of detection of 2.18 nM and recoveries between 90 and 110%. The analytical performance of the developed methodology enables having lower limits of detection than other luminescent and chemiluminescent reported methodologies.

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Introdução: A detecção da microalbuminúria tem sido amplamente estudada como um indicador precoce de lesão endotelial em pacientes com diabetes tipo 2. A microalbuminúria é caracterizada pela presença de níveis aumentados de albumina na urina, refletindo disfunção endotelial e comprometimento da barreira glomerular. A lesão endotelial é um importante fator de risco para o desenvolvimento de complicações vasculares, como doença arterial coronariana, acidente vascular cerebral e insuficiência renal. Objetivos: Investigar a detecção da microalbuminúria através do teste rápido de urina de fita, como um preditor de lesão endotelial em pacientes diabéticos tipo 2. Métodos: Estudo observacional, analítico e transversal, realizado no Ambulatório de Geriatria do Hospital do Servidor Público Municipal de São Paulo. A amostra foi composta por 36 pacientes diabéticos tipo 2, avaliados entre dezembro de 2022 e abril de 2023. Todos os pacientes consentiram e assinaram o Termo de Consentimento Livre e Esclarecido. Resultados: Perfil composto principalmente por mulheres, com idade média de 76,9 anos e tempo médio de diagnóstico de 12,5 anos. A maioria dos pacientes não apresentava complicações macro ou microvasculares. Entre aqueles com complicações macrovasculares(19,4%), a doença arterial coronariana foi a mais comum. Apenas 8,3% dos pacientes possuíam clearence de creatinina abaixo de 30ml/min e os níveis de albuminuria avaliados pelo teste rápido estavam alterados em 52,8% dos participantes. Conclusão: Embora a microalbuminúria possa ser um indicador importante de lesão endotelial em pacientes diabéticos tipo 2 em trabalhos prévios, nossa pesquisa não conseguiu demonstrar associação com relevância estatística entre presença de complicação macro e microvascular e microalbuminúria, provavelmente devido ao número reduzido de pacientes analisados. Ainda assim, a detecção da microalbuminúria deve ser considerada na avaliação e monitoramento desses pacientes, visando uma intervenção precoce e o controle adequado das complicações vasculares. Palavras-chave: Diabetes Mellitus. Microalbuminúria. Angiopatias Diabéticas. Controle glicêmico. Testes de Função Renal.

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