In vitro assay of nitrate reductase enzyme and effect of nitrate and phosphate availability in colour strains of Hypnea musciformis (Wulfen) J. V. Lamour. (Gigartinales, Rhodophyta)

A enzima nitrato redutase (NR) catalisa a redução do nitrato a nitrito e controla a taxa de assimilação do nitrato. O ensaio in vitro da nitrato redutase foi otimizado para a linhagem selvagem (marrom, MA) e para a linhagem deficiente em ficoeritrina (verde-clara, VC) de Hypnea musciformis. As duas linhagens foram cultivadas em temperatura de 23 ± 2°C, fotoperíodo de 14 horas, irradiância de 60-90µmol fótons m-2s-1, e meio composto por água do mar esterilizada (30ups) enriquecida com a solução de von Stosch na concentração de 50% (VSES/2). As condições ótimas de ensaio para ambas as linhagens foram: 40µM de NADH; 10min de incubação do extrato bruto (EB) e 100µL de EB. A atividade ótima da NR ocorreu em 4 e 2mM de nitrato para a linhagem VC e MA, respectivamente. As linhagens VC e MA apresentaram, respectivamente, constante aparente de Michaelis-Menten (K M) para NADH de 0,2068 e 0,0837 µM, e K M para nitrato de 0,0492 e 0,0294mM. Os resultados indicam que a NR da linhagem MA tem maior afinidade pelo substrato do que a NR da linhagem VC de H. musciformis. Os experimentos para avaliar os efeitos da disponibilidade de nitrato (5 a 105µM) e nitrato e fosfato (0,5 a 25,5µM, com a relação N:P de 4:1) mostraram que a atividade da NR das linhagens VC e MA não aumentou com a adição de nitrato no meio, o que pode estar relacionado com o estado nutricional dessas algas. A atividade da NR foi maior nos tratamentos com adição de fosfato do que naqueles com adição de apenas nitrato, indicando que esse nutriente é importante para os processos metabólicos relacionados a atividade da NR.The enzyme nitrate reductase (NR) catalyzes the reduction of nitrate to nitrite and controls the rate of nitrate assimilation. The in vitro assay of NR was optimized for the wild strain (brown, MA), and the phycoerythrin-deficient strain (light-green, VC) of Hypnea musciformis. Both strains were cultured at temperature of 23 ± 2°C, photoperiod of 14h, irradiance of 60-90 µmol photons m-2s-1, with medium composed by sterilized seawater (salinity 30 psu) with 50% von Stosch's enrichment solution (VSES/2). The optimal conditions for in vitro assay of NR were: 40µM of NADH; 10min of incubation of crude extracts (EB), and 100µL of EB to both strains. Optimal activity of NR occurred at 4 and 2mM of nitrate to the VC and MA strains, respectively. The VC and MA strains showed, respectively, Michaelis-Menten constants (K M) for NADH of 0.2068 and 0.0837µM, and K M for nitrate of 0.0492 and 0.0294mM. The results indicate that the NR of MA strain has higher affinity by the substrate than the NR of VC strain of H. musciformis. Experiments on the effects of availabilities of nitrate (5 to 105µM) and nitrate and phosphate (0.5 to 25.5µM, with a N:P relation of 4:1) showed that NR activity of VC and MA strain did not increase with the addition of nitrate to the medium, what can be related with their nutritional state. The NR activity was higher in treatments with phosphate addition than those with only nitrate addition, indicating that this nutrient is important to metabolic processes related to the NR activity.CNPqFAPES

The role of the anion in imidazolium-based ionic liquids for fuel and terpenes processing

Abstract: The potentialities of methylimidazolium-based ionic liquids (ILs) as solvents were evaluated for some relevant separation problems—terpene fractionation and fuel processing—studying selectivities, capacities, and solvent performance indices. The activity coefficients at infinite dilution of the solute (1) in the IL (3), g¥ 13, of 52 organic solutes were measured by inverse gas chromatography over a temperature range of 333.2–453.2 K. The selected ILs are 1-butyl-3-methylimidazolium hexafluorophosphate, [C4mim][PF6], and the equimolar mixture of [C4mim][PF6] and 1-butyl-3-methylimidazolium chloride, [C4mim]Cl. Generally, low polar solutes follow g¥ 1,[C4mim]Cl > g¥ 1,[C4mim][PF6]+[C4mim]Cl > g¥ 1,[C4mim][PF6] while the opposite behavior is observed for alcohols and water. For citrus essential oil deterpenation, the results suggest that cations with long alkyl chains, such as [C12mim]+, promote capacity, while selectivity depends on the solute polarity. Promising results were obtained for the separation of several model mixtures relevant to fuel industries using the equimolar mixture of [C4mim][PF6] and [C4mim]Cl. This work demonstrates the importance of tailoring the polarity of the solvents, suggesting the use of ILs with mixed anions as alternative solvents for the removal of aliphatic hydrocarbons and contaminants from fuels.This research was funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth—Digital strategies in biological assets to improve well-being and promote green health, Norte-01-0145-FEDER- 000042, to which A. Zambom is thankful for her grant. S. M. Vilas-Boas thanks FCT and the European Social Fund (ESF) for his Ph.D. grant (SFRH/BD/138149/2018 and COVID/BD/152936/2022). L.P.Silva acknowledges FCT for her Ph.D. grant (SFRH/BD/135976/2018).info:eu-repo/semantics/publishedVersio

Comparison of extraction and transesterification methods on the determination of the fatty acid contents of three Brazilian seaweed species

Seaweeds are photosynthetic organisms important to their ecosystem and constitute a source of compounds with several different applications in the pharmaceutical, cosmetic and biotechnology industries, such as triacylglycerols, which can be converted to fatty acid methyl esters that make up biodiesel, an alternative source of fuel applied in economic important areas. This study evaluates the fatty acid profiles and concentrations of three Brazilian seaweed species, Hypnea musciformis (Wulfen) J.V. Lamouroux (Rhodophya), Sargassum cymosum C. Agardh (Heterokontophyta), and Ulva lactuca L. (Chlorophyta), comparing three extraction methods (Bligh & Dyer - B&D; AOAC Official Methods - AOM; and extraction with methanol and ultrasound - EMU) and two transesterification methods (7% BF3 in methanol - BF3; and 5% HCl in methanol - HCl). The fatty acid contents of the three species of seaweeds were significantly different when extracted and transesterified by the different methods. Moreover, the best method for one species was not the same for the other species. The best extraction and transesterification methods for H. musciformis, S. cymosum and U. lactuca were, respectively, AOM-HCl, B&D-BF3 and B&D-BF3/B&D-HCl. These results point to a matrix effect and the method used for the analysis of the fatty acid content of different organisms should be selected carefully

Mecanismos de precificação de carbono no Brasil: custos econômicos e potenciais de abatimento

Este artigo foi um dos vencedores do Prêmio BNDES pelo Clima, realizado por meio de concurso promovido pelo BNDES em 2022.O presente trabalho foi realizado com apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (Capes) - código de financiamento 001.O Brasil é um dos maiores emissores de gases de efeito estufa (GEE) do mundo e, como tal, as políticas nacionais de mitigação de emissões são de grande relevância para o combate ao aquecimento global. A redução do desmatamento tem sido a principal estratégia nacional de mitigação. No entanto, as atuais políticas climáticas brasileiras estão aquém do necessário para atingir as metas acordadas em Paris. Portanto, medidas adicionais podem ser necessárias para o cumprimento da contribuição nacionalmente determinada (NDC). Nesse sentido, o objetivo principal deste artigo foi analisar os impactos econômicos da implementação de mercados de carbono como medida para alcançar a NDC. Para isso, foi desenvolvido um modelo de equilíbrio geral computável (EGC) com estrutura recursiva-dinâmica denominado Brazilian Energy Emissions Trading Schemes Model (BEETS). O BEETS é um modelo nacional que inova ao agregar módulos de especificação energética e ambiental, permitindo agrupar as emissões por agente emissor (combustíveis, indústrias e residências), atividade emissora e mudança de uso da terra. O modelo ainda especifica um conjunto de 11 famílias representativas divididas por classes de rendimento, o que permite comparar mudanças no padrão de consumo entre as diferentes classes devido à implementação do mercado de emissões de carbono. Além disso, os setores de geração de eletricidade foram desagregados para incorporar as mudanças na matriz elétrica, fonte relevante de emissão. Inicialmente, o BEETS foi utilizado para analisar o potencial de redução de emissões de GEE em setores produtivos brasileiros por meio da construção de curvas de custo de abatimento marginal (MAC, do inglês marginal abatement costs), identificando setores produtivos com maiores potenciais de abatimento. Considerando o potencial de abatimento setorial encontrado, três diferentes cenários de controle de emissões foram construídos: (i) mercado de referência (comando e controle sem negociação); (ii) mercado amplo (mercado de carbono com todos os setores produtivos); e (iii) mercado restrito (mercado de carbono com setores selecionados). Os resultados mostraram que os mercados de carbono são eficientes para alcançar a NDC. Os resultados setoriais encontrados nas simulações permitem identificar setores produtivos estratégicos tanto no desenho de mercados de carbono como na alocação de recursos de fundos de financiamento climático. Por um lado, o mercado restrito exige um preço de carbono mais alto e está associado a um nível mais elevado de emissões de mudanças no uso da terra. Por outro lado, a implementação de um mercado amplo gera efeitos distributivos negativos em comparação ao mercado restrito

Macrocalcitonin Is a Novel Pitfall in the Routine of Serum Calcitonin Immunoassay

Context: Calcitonin (CT) is a sensitive marker of medullary thyroid carcinoma (MTC) and is used for primary diagnosis and follow-up after thyroidectomy. However, persistently elevated CT is observed even after complete surgical removal without evidence of a recurrent or persistent tumor. Objective: To investigate the presence of assay interference in the serum CT of MTC patients who are apparently without a structural disease. Patients and Methods: We studied three index MTC cases for CT assay interference and 14 patients with metastatic MTC. The CT level was measured using an immunofluorometric assay. Screening for assay interference was performed by determination of CT levels before and after serum treatment with polyethylene glycol. Additionally, samples were analyzed by chromatography on ultra-performance liquid chromatography and protein A-Sepharose. Results: Patients with biochemical and structural disease showed CT mean recovery of 84.1% after polyethylene glycol treatment, whereas patients suspected of interference showed recovery from 2-7%. The elution profile on UPLC showed that the immunometric CT from these three patients behaved like a high molecular mass aggregate (>300 kDa). Additionally, when these samples were applied to the protein A-Sepharose, CT immunoreactivity was retained on the column and was only released after lowering the pH. Conclusions: For the first time, our results show the presence of a novel pitfall in the CT immunoassay: "macrocalcitonin." Its etiology, frequency, and meaning remain to be defined, but its recognition is of interest and can help clinicians avoid unnecessary diagnostic investigations and treatment during the follow-up of MTC.Sao Paulo State Research Foundation-FAPESPFAPESPFederal Agency of Support and Evaluation of Postgraduate Education (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)National Council for Scientific and Technological DevelopmentUniv Fed Sao Paulo, Escola Paulista Med, Div Endocrinol, Dept Med,Thyroid Dis Ctr, BR-04039032 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Div Endocrinol, Dept Med,Lab Mol & Translat Endocrinol, BR-04039032 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Biochem, Div Mol Biol, BR-04044020 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Div Endocrinol, Dept Med,Thyroid Dis Ctr, BR-04039032 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Div Endocrinol, Dept Med,Lab Mol & Translat Endocrinol, BR-04039032 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Biochem, Div Mol Biol, BR-04044020 Sao Paulo, SP, BrazilFAPESP: 2006/60402-1FAPESP: 2010/51547-1FAPESP: 2010/19478Web of Scienc

Homozygous Inactivating Mutation In Nanos3 In Two Sisters With Primary Ovarian Insufficiency.

Despite the increasing understanding of female reproduction, the molecular diagnosis of primary ovarian insufficiency (POI) is seldom obtained. The RNA-binding protein NANOS3 poses as an interesting candidate gene for POI since members of the Nanos family have an evolutionarily conserved function in germ cell development and maintenance by repressing apoptosis. We performed mutational analysis of NANOS3 in a cohort of 85 Brazilian women with familial or isolated POI, presenting with primary or secondary amenorrhea, and in ethnically-matched control women. A homozygous p.Glu120Lys mutation in NANOS3 was identified in two sisters with primary amenorrhea. The substituted amino acid is located within the second C2HC motif in the conserved zinc finger domain of NANOS3 and in silico molecular modelling suggests destabilization of protein-RNA interaction. In vitro analyses of apoptosis through flow cytometry and confocal microscopy show that NANOS3 capacity to prevent apoptosis was impaired by this mutation. The identification of an inactivating missense mutation in NANOS3 suggests a mechanism for POI involving increased primordial germ cells (PGCs) apoptosis during embryonic cell migration and highlights the importance of NANOS proteins in human ovarian biology.201478746

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors