ISEL - Instituto Superior de Engenharia de Lisboa
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Percorrer ISEL - Instituto Superior de Engenharia de Lisboa por Domínios Científicos e Tecnológicos (FOS) "Engenharia e Tecnologia::Engenharia Química"
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- A 3D MOF with Cu20/Cu6 clusters: self-assembly, CO2 encapsulation, structural features, and magnetic propertiesPublication . Sliwa, Ewelina I.; Nesterov, Dmytro S.; Klak, Julia; Kirillov, Alexander M.; Smolenski, PiotrAbstract Molecular design of multicopper clusters has been of increasing importance in inorganic chemistry, biomedical science, and functional materials. Herein, two new copper compounds were self-assembled from copper(II) monofluoroacetate or trifluoroacetate, elemental copper, and 1,3,5-triaza-7-phosphaadamantane (PTA). The reaction starting from copper(II) monofluoroacetate yielded a tetranuclear cluster, [Cu4II(μ3-OH)2(μ-L)6(PTA=O)2] (1), where L is monofluoroacetate(1−) and PTA=O is the oxide of PTA. Formation of 1 involves the oxidation of PTA and the incorporation of μ3-OH– ligands. In contrast, a similar reaction with copper(II) trifluoroacetate produced a unique three-dimensional metal–organic framework (3D MOF), formulated as [{Cu20II(CO3)(μ3-O)2(μ3-OH)22(μ-L′)12}{Cu6I(μ3-PTA)6(CH3CN)12}]n·6n(L′)·3n(H2O)·2n(CH3CN) (2), where L′ is trifluoroacetate. It comprises Cu20 clusters, with an encapsulated carbonate anion fixed from atmospheric CO2, which are bridged by {Cu6I(PTA)6} units into a 3D MOF. Control experiments confirmed that carbonate originates from ambient CO2 rather than from added carbonate salts. Both 1 and 2 were fully characterized, and their magnetic properties were investigated, revealing dominant antiferromagnetic interactions within the Cu4 and Cu20 clusters, respectively. Density functional theory (DFT) calculations confirmed the antiferromagnetic ground spin state of 1 and disclosed the stability of the Cu20 core in 2. This work highlights the influence of fluorinated carboxylates and atmospheric conditions on the assembly and architecture of multicopper clusters, and extends their family to new examples.
- Adenine tagged Mn-based coordination polymer for conversion of carbon dioxide to cyclic carbonates under atmospheric pressurePublication . Eskemech, Alehegn; Bhakhar, Rubi; Biswas, Pritam; Karmakar, Anirban; Krishnan, Venkata; Koner, Rik RaniAbstract Natural processes collectively balance the global carbon cycle, effectively controlling atmospheric carbon dioxide (CO2) levels. However, excessive CO2 emissions due to industrialization and population growth have disrupted natural processes by increasing the atmospheric CO2 concentration. To address this issue, CO2 capture and conversion have been implemented. Metal–organic frameworks (MOFs)/coordination polymers (CPs) with bioligands, such as amino acids and nucleobases, are receiving much interest. However, bio-MOFs are not much reported due to the lack of control over their coordination with metal ions. In this work, we have developed an adenine-tagged Mn-CP with dominant basic sites, [Mn(IPT2–)(Ade)(DMF)]n (IPT2– = isophthalate; Ade = adenine; DMF = N,N′-dimethylformamide). The analysis of isosteric heat (Qst) of CO2 adsorption supported the presence of strong interactions between CO2 and Mn-CP. Mn-CP demonstrated moderate to outstanding performance in coupling CO2 with smaller and larger epoxides at ambient pressure under neat conditions. The thermodynamic activation parameters indicate that Mn-CP operates through an associative mechanism (ΔS⧧ = −283.4 J mol−1 K−1), with a reduced kinetic barrier characterized by ΔH⧧ of 17.28 kJ mol–1 and Ea of 20.5 kJ mol–1. The catalytic efficiency of Mn-CP was particularly notable in the coupling reaction of epichlorohydrin and CO2, yielding 92% of the corresponding cyclic carbonate under atmospheric pressure.
- Analysis of integrated calcium looping alternatives in a cement plantPublication . Amorim, Ana; Filipe, Rui; Matos, Henrique A.Calcium looping is a promising post-combustion CO2 capturing technology, highly compatible with the cement industry, one of the major industrial sources of CO2 emissions. Limestone, a raw material for clinker, forms lime, a calcium looping adsorbent. Thus, it is possible to maximize the synergies between a cement plant and a calcium looping unit by establishing an integrated configuration. Nevertheless, the integration of calcium looping in cement plants has not yet been thoroughly studied. This study examines different integration alternatives, developing models for the preheater and calciner using Aspen Plus, validated with operational data, alongside an entrained-flow carbonator model considering adsorbent deactivation. By combining these models, six integrated configurations are proposed and compared with the tail-end calcium looping configuration. The integrated configurations show a reduction in fuel consumption and net energy consumption for the same CO2 avoided emissions. The most promising configuration was identified and a comparative techno-economic analysis was conducted.
- Biochemical methane potential assays for organic wastes as an anaerobic digestion feedstockPublication . Cabrita, Tiago Miguel; Santos, Maria TeresaThe anaerobic digestion process is applied worldwide in the treatment of various organic wastes, allowing energy production from biogas and organic recovery from digested sludge. In the evaluation of suitable substrates for anaerobic digestion, Biochemical Methane Potential assays are the most applied, and, despite several efforts to standardize this method, it is observed that there are still several studies that do not apply all the criteria. This current paper’s main goal is to present a review of anaerobic feedstocks, BMP methodologies, experimental conditions, and results of specific methane production from 2008 to 2023. A wide range of anaerobic feedstocks was found, which was divided into five groups: animal manure, sludge, food wastes, energy crops, and other organic wastes. Several parameters were used to characterize the anaerobic feedstocks, like TS, VS, COD, and pH, displaying different value ranges. The number of publications concerning BMP assays increased significantly over the years until 2021, having stabilized in the last two years. This evolution allowed for several attempts to standardize the BMP method with positive developments, but there are still some gaps in the experimental conditions and the determination of specific methane production. All of this makes the comparison of some studies a challenge.
- Blood molecular profile to predict genotoxicity from exposure to antineoplastic drugsPublication . Ladeira, Carina; Araújo, Rúben; Ramalhete, Luís; Teixeira, Hélder; Calado, CecíliaGenotoxicity is an important information that should be included in human biomonitoring programmes. How-ever, the usually applied cytogenetic assays are laborious and time-consuming, reason why it is critical to develop rapid and economic new methods. The aim of this study was to evaluate if the molecular profile of frozen whole blood, acquired by Fourier Transform Infrared (FTIR) spectroscopy, allows to assess genotoxicity in occupational exposure to antineoplastic drugs, as obtained by the cytokinesis-block micronucleus assay. For that purpose, 92 samples of peripheral blood were studied: 46 samples from hospital professionals occupationally exposed to antineoplastic drugs and 46 samples from workers in academia without exposure (controls). It was first evaluated the metabolome from frozen whole blood by methanol precipitation of macromolecules as haemoglobin, followed by centrifugation. The metabolome molecular profile resulted in 3 ratios of spectral bands, significantly different between the exposed and non-exposed group (p < 0.01) and a spectral principal component-linear discriminant analysis (PCA-LDA) model enabling to predict genotoxicity from exposure with 73 % accuracy. After optimization of the dilution degree and solution used, it was possible to obtain a higher number of significant ratios of spectral bands, i.e., 10 ratios significantly different (p < 0.001), highlighting the high sensitivity and specificity of the method. Indeed, the PCA-LDA model, based on the molecular profile of whole blood, enabled to predict genotoxicity from the exposure with an accuracy, sensitivity, and specificity of 92 %, 93 % and 91 %, respectively. All these parameters were achieved based on 1 mu L of frozen whole blood, in a high-throughput mode, i.e., based on the simultaneous analysis of 92 samples, in a simple and economic mode. In summary, it can be conclude that this method presents a very promising potential for high-dimension screening of exposure to genotoxic substances.
- Carbon aerogels and xerogels: next-generation materials for sustainable energy and environmental solutionsPublication . Tomić, David; Radinović, Kristina; Mladenović, Dušan; Milikić, Jadranka; Santos, Diogo; Pombeiro, Armando; Paul, Anup; Sljukic Paunkovic, BiljanaAbstract Carbon aerogels and xerogels, with their 3D porous architectures, ultralow density, high surface area, and excellent conductivity, have emerged as multifunctional materials for energy and environmental applications. This review highlights recent advances in the synthesis of these materials via polymerisation, drying, and carbonisation, as well as the role of novel precursors such as graphene, carbon nanotubes, and biomass. Emphasis is also placed on doped and metal-decorated carbon gels as efficient electrocatalysts for oxygen reduction reactions, enabling four- and two-electron pathways for energy conversion and the production of green H2O2, respectively. Aerogels’ high specific capacitance and stability also position them as promising materials for supercapacitors. The versatility of carbon aerogels and xerogels offers exciting prospects for future innovations in catalysis, energy storage, and sustainable technologies.
- Carvões industriais como catalisadores heterogéneos em fase gasosaPublication . Salema, Catarina Isabel Mestre de Matos; Nunes, Ângela Maria Pereira Martins; Carvalho, Ana Paula Baptista deNo presente trabalho teve-se como objetivos a avaliação das potencialidades de amostras de carvão ativado de diferentes origens para sua utilização como catalisadores bi-funcionais e suportes de catalisadores monofuncionais. Os carvões ativados usados foram quatro amostras industriais fornecidos pela empresa Ingevity, denominados pelas letras A, B, C e D, e um carvão ativado preparado em laboratório a partir de cortiça, carvão S. De forma a modificar a química superficial dos materiais foi realizado um tratamento oxidativo com HNO3 a diferentes concentrações (21 e 65% (m/m)). A imobilização da platina foi realizada por diferentes métodos, nomeadamente, mistura mecânica, impregnação, permuta iónica e mecanoquímica. Numa primeira etapa estudou-se as propriedades texturais por adsorção de N2 a -196ºC e a química superficial das amostras através da determinação do pH no ponto de carga zero (pHpzc) e por espectroscopia de infravermelho com transformada de Fourier (FTIR). Foi ainda estudada a estabilidade térmica por análise termogravimétrica e a dispersão e homogeneidade das partículas de platina no suporte por microscopia eletrónica de transmissão (TEM). Os ensaios catalíticos foram realizados para a reação de hidroisomerização do n-decano às temperaturas de 320 e 350 ºC e a reação de hidrogenação do tolueno à temperatura de 150ºC. Os catalisadores não demonstraram possuir potencialidades catalíticas como catalisadores bifuncionais na reação de hidroisomerização de n-decano, uma vez que para todas as amostras estudadas a conversão catalítica não foi além de 5.7%, e uma seletividade aos produtos mais desejados (isómeros monoramificados) de 12.25%. Com o objetivo de estudar as potencialidades dos carvões ativados como suportes de partículas metálicas, os materiais forma testados na reação de hidrogenação do tolueno, de modo a caracterizar a dispersão das partículas metálicas, tendo-se obtido uma correlação linear entre a conversão catalítica e o tamanho médio de partículas metálicas imobilizadas nos carvões ativados.
- Chitosan nanoparticles for enhanced immune response and delivery of multi-epitope helicobacter pylori vaccines in a BALB/c mouse modelPublication . Amaral, Rita; Concha, Tomás ; Vítor, Jorge; Almeida, António J.; Calado, Cecília; Diogo Gonçalves, Lídia MariaHelicobacter pylori is the leading cause of chronic gastritis, peptic ulcer, gastric adenocarcinoma, and mucosal-associated lymphoma. Due to the emerging problems with antibiotic treatment against H. pylori in clinical practice, H. pylori vaccination has gained more interest. Oral immunization is considered a promising approach for preventing initial colonization of this bacterium in the gastrointestinal tract, establishing a first line of defense at gastric mucosal surfaces. Chitosan nanoparticles can be exploited effectively for oral vaccine delivery due to their stability, simplicity of target accessibility, and beneficial mucoadhesive and immunogenic properties. Methods: In this study, new multi-epitope pDNA- and recombinant protein-based vaccines incorporating multiple H. pylori antigens were produced and encapsulated in chitosan nanoparticles for oral and intramuscular administration. The induced immune response was assessed through the levels of antigen-specific IgGs, secreted mucosal SIgA, and cytokines (IL-2, IL-10, and IFN-γ) in immunized BALB/C mice. Results: Intramuscular administration of both pDNA and recombinant protein-based vaccines efficiently stimulated the production of specific IgG2a and IgG1, which was supported by cytokines levels. Oral immunizations with either pDNA or recombinant protein vaccines revealed high SIgA levels, suggesting effective gastric mucosal immunization, contrasting with intramuscular immunizations, which did not induce SIgA. Conclusions: These findings indicate that both pDNA and recombinant protein vaccines encapsulated into chitosan nanoparticles are promising candidates for eradicating H. pylori and mitigating associated gastric diseases in humans.
- Comparison of the serum whole molecular composition with the serum metabolome to acquire the pathophysiological statePublication . Correia, Inês; Henrique Fonseca, Tiago Alexandre; Pataco, Jéssica; Oliveira, Mafalda; Caldeira, Viviana; Domingues, N.; Von Rekowski, Cristiana; Araújo, Rúben Alexandre Dinis; Bento, Luís; Calado, Cecília; Domingues, Nuno; Tomar, Rajesh Singh; Mahamud, TosapornOmics Sciences serve as an essential tool to advance precision medicine. Since conventional omics sciences rely on laborious, complex and time-consuming analytical processes, this study evaluated whether the serum molecular fingerprint, captured by FTIR spectroscopy, could predict mortality risk in critically ill patients. Both the whole serum and the serum metabolome (i.e., serum after removal of macromolecules) were analyzed. PCA-LDA models demonstrated strong performance in predicting patients’ pathophysiological state. A significantly more accurate model for predicting the patients’ pathophysiological state was achieved using the serum metabolome (94%) compared to the whole serum (81%). This is consistent with metabolomics, which provides a more direct view of the systems’ functionality. These promising results highlight the importance of FTIR spectroscopy analysis of the serum metabolome, offering a rapid, cost-effective, and high-throughput method for assessing patients' pathophysiological state.
- Compostos de coordenação para materiais antibacterianos biopoliméricos para impressão 3DPublication . Machado, Cristiana Rosado; Sousa, Ana Catarina Cardoso de; Fernandes, Tiago AdrianoOs compostos e polímeros de coordenação, são uma classe diversificada de materiais com inúmeras aplicações, que se apresentam, também, como materiais promissores no desenvolvimento de novos compostos com atividade antibacteriana. O presente trabalho teve como objetivo sintetizar novos compostos de coordenação, com potenciais propriedades antimicrobianas, para incorporação em polímeros biocompatíveis e posterior produção de filmes e peças 3D, através de um processo de cura por fotopolimerização. Foram sintetizados três compostos, dois compostos de coordenação (CC1 e CC2), com centros metálicos de Cu(II) e Zn(II), respetivamente, e um polímero de coordenação (CP3), com centro metálico de Ag(I), utilizando o ligando orgânico, ácido 2-furóico. Os compostos CC1, CC2 e CP3 foram obtidos com rendimentos de 46%, 45% e 24%, respetivamente, e as suas caraterizações e fórmulas foram propostas com base nos resultados obtidos por técnicas espetroscópicas e difração de raios X. Estes compostos foram incorporados em matrizes de polietileno glicol/ polietileno glicol diacrilato: PEG/PEGDA, 10:90 (m/m), com o objetivo de produzir filmes e peças 3D de materiais biocompatíveis e com propriedades antibacterianas. As características físico-químicas foram determinadas e, posteriormente, foram avaliados relativamente à sua capacidade antimicrobiana face a duas estirpes de bactérias Gram-positivas (S.aureus e S.epidermidis) e Gram-negativas (E. coli e P.aeruginosa) e potencial citotoxicidade num ensaio em células humanas de fibroblastos da linha celular L929. No geral, foi possível confirmar que a mistura PEG/PEGDA, 10:90 (m/m), proposta, pode ser dopada com compostos bioativos e utilizada para a produção de filmes e peças 3D, através do processo de cura por fotopolimerização. O material com o CP3 mostrou ser o mais eficiente, no que se refere a uma ação antibacteriana mais abrangente. No entanto, os resultados obtidos para o material com CC2 também se revelaram promissores, no que se refere à ação antimicrobiana contra estirpes de bactérias Gram-positivas.