48 results on '"Portela, Raquel"'
Search Results
2. The dispersion method does not affect the in vitro genotoxicity of multi-walled carbon nanotubes despite inducing surface alterations
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Burgum, Michael J., Alcolea-Rodríguez, Víctor, Saarelainen, Hanna, Portela, Raquel, Reinosa, Julián J., Fernández, José F., Dumit, Verónica I., Catalán, Julia, Simeone, Felice C., Faccani, Lara, Clift, Martin J.D., Evans, Stephen J., Bañares, Miguel A., and Doak, Shareen H.
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- 2025
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3. Sub-micro- and nano-sized polyethylene terephthalate deconstruction with engineered protein nanopores
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Robles-Martín, Ana, Amigot-Sánchez, Rafael, Fernandez-Lopez, Laura, Gonzalez-Alfonso, Jose L., Roda, Sergi, Alcolea-Rodriguez, Víctor, Heras-Márquez, Diego, Almendral, David, Coscolín, Cristina, Plou, Francisco J., Portela, Raquel, Bañares, Miguel A., Martínez-del-Pozo, Álvaro, García-Linares, Sara, Ferrer, Manuel, and Guallar, Víctor
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- 2023
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4. Influence of Support Structure on Catalytic Performance of Supported Liquid-Phase (SLP) Catalysts in Hydroformylation of 1-Butene
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Madani, Mahtab, Schill, Leonhard, Zahrtmann, Nanette, Portela, Raquel, Arsenjuk, Linda, Franke, Robert, Fehrmann, Rasmus, and Riisager, Anders
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- 2023
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5. Effect of alkali addition on a Cu/SmCeO2 @TiO2 catalyst for NO reduction with CO under oxidizing conditions
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López, Naima, Monte, Manuel, Iglesias-Juez, Ana, Portela, Raquel, Xuyun, Guo, Ye, Zhu, Aguila, Gonzalo, Araya, Paulo, and Guerrero, Sichem
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- 2023
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6. Materials characterisation and software tools as key enablers in Industry 5.0 and wider acceptance of new methods and products
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Konstantopoulos, Georgios, Charitidis, Costas A., Bañares, Miguel A., Portela, Raquel, Zangenberg, Nikolaj, Capria, Ennio, Sebastiani, Marco, Goldbeck, Gerhard, Koumoulos, Elias, Boskovic, Bojan, Diplas, Spyros, Konchakova, Natalia, Todorov, Ilian, Dykeman, Donna, Avataneo, Silvia Giovanna, Falzetti, Marco, Diz, Enrique Lozano, Reinosa, Julian J., Burov, Ekaterina, Škrelić, Dejan, Jeliazkova, Nina, Barton, Bastian, Masotti, Giovanni, Tamarozzi, Tommaso, and Alcón, Iván Moya
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- 2023
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7. Photoactive nano-confined Pt in titania nanotubes (Pt-TiNT) via microwave-assisted flow synthesis
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Luo, Yingjian, Serrano-Lotina, Ana, Budihardjo, Felicia Febriana, Taghipour, Shabnam, Ferdousi, Shammi Akter, Li, Liping, Delgado, Juan Jose, López-Buendía, Ángel, Portela, Raquel, Han, Wei, Bañares, Miguel A., and Yeung, King Lun
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- 2023
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8. Microwave-associated chemistry in environmental catalysis for air pollution remediation: A review
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Bao, Chaosheng, Serrano-Lotina, Ana, Niu, Mingshuang, Portela, Raquel, Li, Yuxin, Lim, Khak Ho, Liu, Pingwei, Wang, Wen-jun, Bañares, Miguel A., and Wang, Qingyue
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- 2023
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9. Crosslinked bacterial cellulose hydrogels for biomedical applications
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Almeida, Ana P.C., Saraiva, João N., Cavaco, Gonçalo, Portela, Raquel P., Leal, Catarina R., Sobral, Rita G., and Almeida, Pedro L.
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- 2022
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10. Ultrasensitive In2O3‑Based Nanoflakes for Lung Cancer Diagnosis and the Sensing Mechanism Investigated by Operando Spectroscopy.
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Cheng, Ye, Portela, Raquel, Wang, Pingli, Liu, Pingwei, Mao, Yupeng, Lim, Khak Ho, Zheng, Jieyuan, Yang, Xuan, Zhang, Gensheng, Ding, Liren, Wang, Wen-Jun, Li, Bo-Geng, Bañares, Miguel A., and Wang, Qingyue
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- 2024
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11. Elucidating the structure of the W and Mn sites on the Mn-Na2WO4/SiO2 catalyst for the oxidative coupling of methane (OCM) at real reaction temperatures
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Ortiz-Bravo, Carlos A., Figueroa, Santiago J.A., Portela, Raquel, Chagas, Carlos A., Bañares, Miguel A., and Toniolo, Fabio Souza
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- 2022
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12. Monolithic SiC supports with tailored hierarchical porosity for molecularly selective membranes and supported liquid-phase catalysis
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Portela, Raquel, Marinkovic, Jakob Maximilian, Logemann, Morten, Schörner, Markus, Zahrtman, Nanette, Eray, Esra, Haumann, Marco, García-Suárez, Eduardo J., Wessling, Matthias, Ávila, Pedro, Riisager, Anders, and Fehrmann, Rasmus
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- 2022
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13. PET microplastics affect human gut microbiota communities during simulated gastrointestinal digestion, first evidence of plausible polymer biodegradation during human digestion
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Tamargo, Alba, Molinero, Natalia, Reinosa, Julián J., Alcolea-Rodriguez, Victor, Portela, Raquel, Bañares, Miguel A., Fernández, Jose F., and Moreno-Arribas, M. Victoria
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- 2022
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14. Differentially Induced Autophagy by Engineered Nanomaterial Treatment Has an Impact on Cellular Homeostasis and Cytotoxicity.
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Alcolea-Rodriguez, Victor, Dumit, Verónica I., Ledwith, Rico, Portela, Raquel, Bañares, Miguel A., and Haase, Andrea
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- 2024
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15. Support Screening to Shape Propane Dehydrogenation SnPt-Based Catalysts
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Festa, Giovanni, Serrano-Lotina, Ana, Meloni, Eugenio, Portela, Raquel, Ruocco, Concetta, Martino, Marco, and Palma, Vincenzo
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Propane dehydrogenation reaction (PDH) is an extremely attractive way to produce propylene; however, the catalysts often lead to byproduct formation and suffer from deactivation. This research focuses on the development of efficient Pt/Sn-based shaped catalysts by utilizing Mg-modified mesoporous silica, sepiolite (natural SiMgOxmesoporous clay), and sepiolite/bentonite/alumina as supports with the aim of achieving superior stability and selectivity for industrial propylene production by PDH. The catalysts were prepared by sequential impregnation of the supports with the corresponding solutions of tin chloride and platinum chloride, by obtaining a nominal loading of 0.7 wt % of Sn and 0.5 wt % of Pt. A range of analytical techniques were used to characterize the catalysts, including X-ray diffraction, nitrogen physisorption isotherms, Hg intrusion porosimetry, thermogravimetric analyses, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The basicity of the catalysts was assessed using carbon dioxide temperature-programmed desorption (CO2-TPD). The results confirm that the support material plays a critical role in catalyst performance; in particular, the presence of weak basic sites, due to magnesium addition, improved selectivity to propylene and reduced coke formation. Catalytic pellets of Sn–Pt supported on macroporous sepiolite or sepiolite and bentonite-modified mesoporous alumina performed comparably with propane conversion very close to thermodynamic equilibrium and selectivity to propylene above 95%. The latter support led to improved stability and was regenerated at milder temperatures, making it suitable for industrial applications.
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- 2024
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16. NanoPyx: super-fast bioimage analysis powered by adaptive machine learning
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Henriques, Ricardo, primary, Saraiva, Bruno, additional, Cunha, Inês, additional, Brito, António, additional, Follain, Gautier, additional, Portela, Raquel, additional, Haase, Robert, additional, Pereira, Pedro, additional, and Jacquemet, Guillaume, additional
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- 2023
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17. NanoPyx: super-fast bioimage analysis powered by adaptive machine learning
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Saraiva, Bruno M., primary, Cunha, Inês M., additional, Brito, António D., additional, Follain, Gautier, additional, Portela, Raquel, additional, Haase, Robert, additional, Pereira, Pedro M., additional, Jacquemet, Guillaume, additional, and Henriques, Ricardo, additional
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- 2023
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18. Effect of alkali addition on a Cu/SmCeO2@TiO2 catalyst for NO reduction with CO under oxidizing conditions
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López, Naima, primary, Monte, Manuel, additional, Iglesias-Juez, Ana, additional, Portela, Raquel, additional, Xuyun, Guo, additional, Ye, Zhu, additional, Aguila, Gonzalo, additional, Araya, Paulo, additional, and Guerrero, Sichem, additional
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- 2023
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19. PlasticsFatE Deliverable Report D1.1 Report on selected MP/NP and basic Physico Chem features
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Costa, Anna Luisa, Altman, Korinna, Barbato, Francesco, and Portela, Raquel
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characterisation ,Physicochemical ,microplastics ,cryomilling ,human health ,nanoplastics - Abstract
The deliverable D1.1 addressed some of the specific objectives of Task 1.1, as summarised below: 1. To select a set of relevant MP/NP to maximise the impact ofPlasticsfatecovering as much aspossible the compositional/morphological classes of micro-nano plastics (MP/NP) commonly spreadinto food, drinking and environmental matrices. 2. To generate and store a bank of relevant reference and/or certified, well-characterisedmicro-nano plastics (MP/NP) covering the identified classes for use inPlasticsfateand for future projectsthatwillcharacteriseor develop strategies to mitigate MP/NP pollution. 3. To develop standardized protocol for how to handle,characterize, store and distribute MP/NP. 4. To facilitate particles labelling, traceability and detection by means of fluorescent markers. In response to specific objective 1, it was established at portfolio (1st Tier) ofPlasticsfateMP/NPmaterials, differing for polymer type, source/size, use scenarios, it was agreed the code for theirclassificationand they were distributed to partners for the characterisation. In response to specific objective 2, BAMwas in charge ofthe creation ofPlasticsfatesamplesrepository, including some primary plastics, some commercial samples and some secondary particles,obtained by BAM throughcryomilling/aging treatments. The samples were checked by BAM andISTEC through dynamic imaging and optical or electronic microscope characterisation. The endotoxincontamination was tested by GAIKER (a partner from WP3), confirming that secondary PE, PETparticles and HDPE commercial sample (CeridustfromCariant) were not affected by endotoxincontamination. In response to specific objective 3, BAM developed and tested protocols for plastics milling andweathering; ISTEC-CNR and UNITO carried out an intensedispersabilitystudyin order toidentifydispersion protocols suitable for characterisation in WP1-3. A two-step process was selected, ageneral protocol for the preparation of stock dispersions and specific dispersants for the dilution ofstock dispersions in relevant simulant fluids (work dispersions). In response to specific objective 4, CSICcharacterisedLa-Eu doped PS nanoparticles purchased anddistributed by STAMI. Traceability was investigated by Raman-luminescence mapping. The results from D1.1. were shared/disseminated through the participation atCUSPchannels/events/workshops, where Task 1.1 partners are involved: Anna Costa/MagdaBlosirepresentatives forPlasticsfatein WG1 (Analytical methods and representative materials) andKorinnaAltmann/DanHodoraba, as coordinator of WG3 (Inter-laboratory comparisons).
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- 2023
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20. OPEN-SOURCE FOR RAMAN SPECTROSCOPY HARMONISATION
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Georgiev, Georgi, Lelinger, Dirk, Iliev, Luchesar, Jeliazkov, Vedrin, Banares, Miguel, Portela, Raquel, and Jeliazkova, Nina
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Raman spectroscopy is becoming a key technology used in the research and development for characterization of materials. Ideally, spectra should be comparable and linked to specific material properties. However, in real life, Raman spectra differ between instruments and depend on the spectrometer, optical path, or sample environment, among others, and only a limited number of calibration standards for Raman spectroscopy are available to date 10.1177/00037028221090988. The CHARISMA EU’s Horizon 2020 project (No. 952921) aims to harmonize and standardize characterization by Raman spectroscopy, including hardware, measurement protocols, and in silico methods, enabling end users to share digital spectral data through a FAIR database across domains and across the entire life cycle of diverse products. We present https://github.com/h2020charisma/ramanchada2, an open-source, MIT-licensed, Python package that collects existing and novel state-of-the-art algorithms allowing the users to process Raman spectra, perform energy and efficiency calibrations and generate synthetic spectra based on user specification and/or data from DFT simulations. Installation with pip is available.ramanchada2 is used as a core dependency of a FAIR Raman database, implemented as a Python API with a cloud backend and HDF5 storage for Raman spectra and metadata. The metadata query and spectra search API is compatible with the eNanoMapper database and the NanoSafety Data Interface 10.1038/s41565-021-00911-6. To facilitate Raman spectra analysis by end users, we are also developing oranchada, an user friendly wrapper of all ramanchada2 functionality. It is available as an add-on for the popular data mining software Orange https://github.com/h2020charisma/oranchada. For the harmonisation of Raman spectroscopy terminology, a collaboratively edited knowledge base is established at https://wiki.charisma.ideaconsult.net/. It is implemented with Wikibase, an extension for MediaWiki.
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- 2023
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21. Digestión gastrointestinal y fermentación colónica de microplásticos biodegradables de ácido poliláctico (PLA) y su interacción con la microbiota intestinal
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European Commission, Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, European Commission, Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, and Moreno-Arribas, M. Victoria
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El interés por los microplásticos (MPs) y sus efectos en la salud ha abierto un campo nuevo de estudio con un crecimiento exponencial. Los MPs se han detectado en numerosos alimentos y bebidas de consumo humano, así como en las heces humanas, mientras que desde la investigación se están proponiendo nuevos materiales y nuevas propiedades de bioplásticos para su uso industrial. El ácido poliláctico (PLA) es el bioplástico más utilizado en envases de alimentos y otros productos desechables, dispositivos biomédicos y procedimientos quirúrgicos. Sin embargo, a pesar de su demostrada biodegradabilidad y biocompatibilidad y de su estatus GRAS (Generally Recognised As Safe), estudios recientes en animales acuáticos e insectos han demostrado que las partículas de PLA pueden alterar las poblaciones microbianas intestinales. Comprender el potencial impacto de los MPs en la microbiota humana y su posible biotransformación en el tracto gastrointestinal es fundamental para evaluar sus riesgos potenciales a nivel digestivo y sistémico.En este trabajo se ha evaluado el efecto de la ingestión de una cantidad realista de MPs de PLA de dos tamaños distintos tras el paso por el tracto gastrointestinal humano. Para ello, se simuló el tránsito digestivo mediante la combinación del modelo in vitro estandarizado Infogest y la fermentación colónica en estático utilizando el simulador gastrointestinal simgi®. La fermentación se llevó a cabo en triplicado utilizando muestras fecales de donantes sanos (n=3). Los posibles cambios en la morfología de las partículas se monitorizaron mediante microscopía electrónica de barrido de emisión de campo (FESEM) y espectroscopía Raman. La composición y funcionalidad microbiana se analizó mediante secuenciación del gen ARNr 16S y predicción funcional bioinformática, y la actividad metabólica microbiana mediante el análisis de ácidos grasos de cadena corta y de ácido láctico. El análisis por FESEM mostró pequeñas perforaciones en la superficie de los MPs de
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- 2023
22. Appendix A. Supplementary data for Simulated gastrointestinal digestion of polylactic acid (PLA) biodegradable microplastics and their interaction with the gut microbiota
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Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Reinosa, Julián J., Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Reinosa, Julián J., Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, and Moreno-Arribas, M. Victoria
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- 2023
23. Simulated gastrointestinal digestion of polylactic acid (PLA) biodegradable microplastics and their interaction with the gut microbiota
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Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Consejo Superior de Investigaciones Científicas (España), Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Reinosa, Julián J., Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Consejo Superior de Investigaciones Científicas (España), Jiménez Arroyo, Cristina, Tamargo, Alba, Molinero, Natalia, Reinosa, Julián J., Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, and Moreno-Arribas, M. Victoria
- Abstract
The accumulation of microplastics (MPs) in the environment as well as their presence in foods and humans highlight the urgent need for studies on the effects of these particles on humans. Polylactic acid (PLA) is the most widely used bioplastic in the food industry and medical field. Despite its biodegradability, biocompatibility, and “Generally Recognized As Safe” (GRAS) status, recent animal model studies have shown that PLA MPs can alter the intestinal microbiota; however, to date, no studies have been reported on the possible gut and health consequences of its intake by humans. This work simulates the ingestion of a realistic daily amount of PLA MPs and their pass through the gastrointestinal tract by combining the INFOGEST method and the gastrointestinal simgi® model to evaluate possible effects on the human colonic microbiota composition (16S rRNA gene sequencing analysis) and metabolic functionality (lactic acid and short-chain fatty acids (SCFA) production). Although PLA MPs did not clearly alter the microbial community homeostasis, increased Bifidobacterium levels tended to increase in presence of millimetric PLA particles. Furthermore, shifts detected at the functional level suggest an alteration of microbial metabolism, and a possible biotransformation of PLA by the human microbial colonic community. Raman spectroscopy and field emission scanning electron microscopy (FESEM) characterization revealed morphological changes on the PLA MPs after the gastric phase of the digestion, and the adhesion of organic matter as well as a microbial biofilm, with surface biodegradation, after the intestinal and colonic phases. With this evidence and the emerging use of bioplastics, understanding their impact on humans and potential biodegradation through gastrointestinal digestion and the human microbiota merits critical investigation.
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- 2023
24. Influence of Support Structure on Catalytic Performance of Supported Liquid-Phase (SLP) Catalysts in Hydroformylation of 1-Butene
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European Commission, Madani, M., Schill, L., Zahrtmann, N., Portela, Raquel, Arsenjuk, L., Franke, R., Fehrmann, R., Riisager, A., European Commission, Madani, M., Schill, L., Zahrtmann, N., Portela, Raquel, Arsenjuk, L., Franke, R., Fehrmann, R., and Riisager, A.
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Several supported liquid-phase (SLP) catalysts with immobilized Rh-biphephos complexes on monolithic supports were prepared and applied for continuous gas-phase hydroformylation (HyFo) of 1-butene. The support comprised macroporous monolithic silicon carbide (SiC) with deposited silica nanoparticles (NPs) in order to provide mesopores with enhanced capillary forces to retain the liquid-phase. Variable parameters were examined for the monolithic SiC supports, including size and loading of deposited silica NPs and intermediate calcination between silica deposition steps to obtain the most efficient support configuration for the SLP system. The SLP catalysts with larger deposited silica NPs gave higher catalytic activity (i.e. 1-butene conversion and turnover frequency) compared to the supports with smaller sized silica NPs. However, the selectivity towards the preferred linear aldehyde was higher in the SLP catalysts with supports containing less silica with small silica NPs. Importantly, the prepared SLP catalyst systems showed long-term stability in HyFo with negligible formation of high boiling aldol condensation products. © 2023, The Author(s).
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- 2023
25. Materials characterisation and software tools as key enablers in Industry 5.0 and wider acceptance of new methods and products
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European Commission, Konstantopoulos, G., Charitidis, C.A., Bañares, Miguel A., Portela, Raquel, Zangenberg, N., Capria, E., Sebastiani, M., Goldbeck, G., Koumoulos, E., Boskovic, B., Diplas, S., Konchakova, N., Todorov, I., Dykeman, D., Avataneo, S.G., Falzetti, M., Diz, E.L., Reinosa, Julián J., Burov, E., Škrelić, D., Jeliazkova, N., Barton, B., Masotti, G., Tamarozzi, T., Alcón, I.M., European Commission, Konstantopoulos, G., Charitidis, C.A., Bañares, Miguel A., Portela, Raquel, Zangenberg, N., Capria, E., Sebastiani, M., Goldbeck, G., Koumoulos, E., Boskovic, B., Diplas, S., Konchakova, N., Todorov, I., Dykeman, D., Avataneo, S.G., Falzetti, M., Diz, E.L., Reinosa, Julián J., Burov, E., Škrelić, D., Jeliazkova, N., Barton, B., Masotti, G., Tamarozzi, T., and Alcón, I.M.
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Recently, the NMBP-35 Horizon 2020 projects - NanoMECommons, CHARISMA, and Easi-stress - organised a collaborative workshop to increase awareness of their contributions to the industry “commons” in terms of characterisation and digital transformation. They have established interoperability standards for knowledge management in characterisation and introduced new solutions for materials testing, aided by the standardisation of faster and more accurate assessment methods. The lessons learned from these projects and the discussions during the joint workshop emphasised the impact of recent developments and emerging needs in the field of characterisation. Specifically, the focus was on enhancing data quality through harmonisation and standardisation, as well as making advanced technologies and instruments accessible to a broader community with the goal of fostering increased trust in new products and a more skilled society. Experts also highlighted how characterisation and the corresponding experimental data can drive future innovation agendas towards technological breakthroughs. The focus of the discussion revolved around the characterisation and standardisation processes, along with the collection of modelling and characterisation tools, as well as protocols for data exchange. The broader context of materials characterisation and modelling within the materials community was explored, drawing insights from the Materials 2030 Roadmap and the experiences gained from NMBP-35 projects. This whitepaper has the objective of addressing common challenges encountered by the materials community, illuminating emerging trends and evolving techniques, and presenting the industry's perspective on emerging requirements and past success stories. It accomplishes this by providing specific examples and highlighting how these experiences can create fresh opportunities and strategies for newcomers entering the market. These advancements are anticipated to facilitate a more efficient transi
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- 2023
26. Effect of alkali addition on a Cu/SmCeO2 @TiO2 catalyst for NO reduction with CO under oxidizing conditions
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Agencia Nacional de Investigación y Desarrollo (Chile), López, N., Monte, M., Iglesias Juez, Ana, Portela, Raquel, Xuyun, G., Ye, Z., Aguila, G., Araya, P., Guerrero, S., Agencia Nacional de Investigación y Desarrollo (Chile), López, N., Monte, M., Iglesias Juez, Ana, Portela, Raquel, Xuyun, G., Ye, Z., Aguila, G., Araya, P., and Guerrero, S.
- Abstract
The accumulation of alkali metals generated during biomass combustion onto the catalysts employed for off-gas treatment can have a detrimental effect on their performance. This work investigates the effect of potassium as a model alkali on an efficient copper-based catalyst supported on SmCeO2 @TiO2. The addition of potassium modifies the redox properties of the Cu species or, more specifically, the metal-ceria interface, providing better catalytic activity for NO reduction in oxidizing conditions. SmCeO2 @TiO2 stabilizes highly dispersed copper species, and the presence of potassium introduces surface distortions that modify the lability of oxygen atoms. The results demonstrate the key role of surface defects and labile oxygen species associated with the CeO2 support. It was found that both Cu/SmCeO2 @TiO2 and K/Cu/SmCeO2 @TiO2 catalysts fully oxidized CO below 350 °C and actively reduced NO with CO in the presence of excess oxygen, reaching a maximum NO conversion of 65% at 316 °C and 83% at 330 °C, respectively, while undesired NO2 release was minimized in the alkaline-loaded sample. © 2023 Elsevier B.V.
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- 2023
27. Microwave-associated chemistry in environmental catalysis for air pollution remediation: A review
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Ministerio de Ciencia e Innovación (España), National Natural Science Foundation of China, Zhejiang University, Bao, Chaosheng, Serrano-Lotina, Ana M., Niu, Mingshuang, Portela, Raquel, Li, Yuxin Qingyue Wang, Lim, Khak Ho Lim, Liu, Pingwei, Wang, Wen-jun, Bañares, Miguel A., Wang, Qingyue, Ministerio de Ciencia e Innovación (España), National Natural Science Foundation of China, Zhejiang University, Bao, Chaosheng, Serrano-Lotina, Ana M., Niu, Mingshuang, Portela, Raquel, Li, Yuxin Qingyue Wang, Lim, Khak Ho Lim, Liu, Pingwei, Wang, Wen-jun, Bañares, Miguel A., and Wang, Qingyue
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Microwave-assisted synthesis has attracted wide attention as an efficient and energy-saving synthesis strategy due to its unique heating mechanism. Environmental catalysts prepared via microwave heating process typically exhibit uniform crystal size with desired morphology, porous structure and interfacial properties, which are important for the catalytic remediation of air pollution. This review first summarizes the principles of microwave heating, followed by the characteristics of the obtained catalysts. The research progress of representative materials (e.g., supported metal catalysts, metal oxides, and porous carbon materials) in the treatment of gaseous pollutants are then categorized in detail. Meanwhile, this review compiles the recent research outputs of air pollutants remediation by environmental catalysts from the perspective of features and reaction pathways facilitated by microwave-assisted synthesis. It demonstrates that microwave-assisted heating can not only improve the synthesis efficiency and the catalytic activity but also modify the selectivity by tuning the catalyst properties. Finally, the use of microwave irradiation to activate environmental catalytic reactions is reviewed, as the application of microwaves can lead to significant improvements due to the possibility of delivering energy directly to the catalytic materials. Nevertheless, challenges remain in the development of highly active and efficient catalyst to realize its practical application. These, together with prospects on the development of environmental catalysts using microwave techniques are provided for enlightening the future of this field of research. © 2023 The Author(s)
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- 2023
28. Sub-micro- and nano-sized polyethylene terephthalate deconstruction with engineered protein nanopores
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European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Universidad Complutense de Madrid, Universidad Autónoma de Madrid, Real Colegio Complutense, Robles-Martín, Ana, Amigot-Sánchez, Rafael, Fernández-López, Laura, González-Alfonso, José L., Roda, Sergi, Alcolea-Rodríguez, Víctor, Heras-Márquez, Diego, Almendral, David, Coscolín, Cristina, Plou Gasca, Francisco José, Portela, Raquel, Bañares, Miguel A., Martínez-del-Pozo, Álvaro, García-Linares, Sara, Ferrer, Manuel, Guallar, Victor, European Commission, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Universidad Complutense de Madrid, Universidad Autónoma de Madrid, Real Colegio Complutense, Robles-Martín, Ana, Amigot-Sánchez, Rafael, Fernández-López, Laura, González-Alfonso, José L., Roda, Sergi, Alcolea-Rodríguez, Víctor, Heras-Márquez, Diego, Almendral, David, Coscolín, Cristina, Plou Gasca, Francisco José, Portela, Raquel, Bañares, Miguel A., Martínez-del-Pozo, Álvaro, García-Linares, Sara, Ferrer, Manuel, and Guallar, Victor
- Abstract
The identification or design of biocatalysts to mitigate the accumulation of plastics, including sub-micro- and nano-sized polyethylene terephthalate (nPET), is becoming a global challenge. Here we computationally incorporated two hydrolytic active sites with geometries similar to that of Idionella sakaiensis PET hydrolase, to fragaceatoxin C (FraC), a membrane pore-forming protein. FraCm1/m2 could be assembled into octameric nanopores (7.0 nm high × 1.6–6.0 nm entry), which deconstructed (40 °C, pH 7.0) nPET from GoodFellow, commodities and plastic bottles. FraCm1 and FraCm2 degrade nPET by endo- and exo-type chain scission. While FraCm1 produces bis(2-hydroxyethyl) terephthalate as the main product, FraCm2 yields a high diversity of oligomers and terephthalic acid. Mechanistic and biochemical differences with benchmark PET hydrolases, along with pore and nPET dynamics, suggest that these pore-forming protein catalytic nanoreactors do not deconstruct macro-PET but are promising in nanotechnology for filtering, capturing and breaking down nPET, for example, in wastewater treatment plants. [Figure not available: see fulltext.]. © 2023, The Author(s).
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- 2023
29. Digestión gastrointestinal y fermentación colónica de microplásticos biodegradables de ácido poliláctico (PLA) y su interacción con la microbiota intestinal
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Jiménez Arroyo, Cristina, Tamargo García, Alba, Molinero, Natalia, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, and European Commission
- Abstract
Resumen del póster presentado a la 16ª Reunión de la Red Española de Bacterias Lácticas (RedBAL), celebrada en Madrid los días 11 y 12 de mayo de 2023., El interés por los microplásticos (MPs) y sus efectos en la salud ha abierto un campo nuevo de estudio con un crecimiento exponencial. Los MPs se han detectado en numerosos alimentos y bebidas de consumo humano, así como en las heces humanas, mientras que desde la investigación se están proponiendo nuevos materiales y nuevas propiedades de bioplásticos para su uso industrial. El ácido poliláctico (PLA) es el bioplástico más utilizado en envases de alimentos y otros productos desechables, dispositivos biomédicos y procedimientos quirúrgicos. Sin embargo, a pesar de su demostrada biodegradabilidad y biocompatibilidad y de su estatus GRAS (Generally Recognised As Safe), estudios recientes en animales acuáticos e insectos han demostrado que las partículas de PLA pueden alterar las poblaciones microbianas intestinales. Comprender el potencial impacto de los MPs en la microbiota humana y su posible biotransformación en el tracto gastrointestinal es fundamental para evaluar sus riesgos potenciales a nivel digestivo y sistémico.En este trabajo se ha evaluado el efecto de la ingestión de una cantidad realista de MPs de PLA de dos tamaños distintos tras el paso por el tracto gastrointestinal humano. Para ello, se simuló el tránsito digestivo mediante la combinación del modelo in vitro estandarizado Infogest y la fermentación colónica en estático utilizando el simulador gastrointestinal simgi®. La fermentación se llevó a cabo en triplicado utilizando muestras fecales de donantes sanos (n=3). Los posibles cambios en la morfología de las partículas se monitorizaron mediante microscopía electrónica de barrido de emisión de campo (FESEM) y espectroscopía Raman. La composición y funcionalidad microbiana se analizó mediante secuenciación del gen ARNr 16S y predicción funcional bioinformática, y la actividad metabólica microbiana mediante el análisis de ácidos grasos de cadena corta y de ácido láctico. El análisis por FESEM mostró pequeñas perforaciones en la superficie de los MPs de PLA tras la etapa gástrica, cuyo aspecto dependió del tamaño de la partícula. Además, tras la fase colónica, se observó la adhesión de materia orgánica y la formación de un biofilm microbiano en la superficie de las partículas. Por otro lado, el análisis por espectroscopía Raman mostró degradación en la superficie de los MPs de menor tamaño, especialmente tras las fases intestinal y colónica. El impacto de los MPs de PLA en la microbiota colónica fue diferencial dependiendo del voluntario y del tamaño de partícula. Se detectaron diferencias en los parámetros de biodiversidad alpha y beta entre el control y los distintos tamaños de partícula durante la fase colónica, cuyas tendencias fueron dependientes del voluntario. A nivel taxonómico y a pesar de la variabilidad, se constató un incremento en los niveles de miembros del género Bifidobacterium en los 3 voluntarios en presencia de los MPs de mayor tamaño. Además, el análisis por predicción funcional reveló un incremento, entre otras funciones, en la actividad pululanasa, previamente descrita en el género Bifidobacterium. Los resultados de este estudio sugieren la biotransformación de los MPs PLA durante la digestión, sin que se hayan encontrado alteraciones en las comunidades microbianas de intestino. Son necesarios más estudios para comprobar las tendencias observadas, profundizar en la posible biodegradación del PLA por parte de la microbiota intestinal y los potenciales metabolitos derivados, y poder descifrar el efecto a largo plazo de los MPs de PLA sobre la microbiota humana y la salud., Proyecto H2020 PlasticsFatE, ref. nº 95921
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- 2023
30. Catalytic Clues for Nanotoxicity: Grouping, Dose-Metrics and Hazard Assessment Based on Number, Nature and Reactivity of Nanomaterials’ Surface Sites
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Alcolea, Victor, primary, Portela, Raquel, additional, Calvino-Casilda, Vanesa, additional, and Banares, Miguel A., additional
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- 2023
- Full Text
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31. Simulated Gastrointestinal Digestion of Polylactic Acid (Pla) Biodegradable Microplastics and Their Interaction with Gut Microbiota
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Moreno-Arribas, Victoria, primary, Jimenez-Arroyo, Cristina, additional, Tamargo, Alba, additional, Molinero, Natalia, additional, Reinosa, JUlian J., additional, Alcolea, Victor, additional, Portela, Raquel, additional, Bañares, Miguel A., additional, and Fernández, Jose Francisco, additional
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- 2023
- Full Text
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32. Analysis of a Cell Wall Mutant Highlights Rho-Dependent Genome Amplification Events in Staphylococcus aureus
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Portela, Raquel, primary, A. Faria, Nuno, additional, Mwangi, Michael, additional, Miragaia, Maria, additional, de Lencastre, Hermínia, additional, Tomasz, Alexander, additional, and Gonçalves Sobral, Rita, additional
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- 2022
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33. UM CASO SUSPEITO DE DISFUNÇÃO CARDÍACA
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Torres Marcos, David, Ventura, Ludovic, Portela, Raquel, Esteves, Mário, and Leitão, Laurinda
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Enquadramento: As fibrilhas de amiloide são polímeros de proteínas implicadas em vários processos fisiológicos. Quando existe acumulação de fibrilhas de amiloide defeituosas ocorre uma patologia denominada amiloidose. Esta pode ter vários subtipos. Descrição do caso: Os autores descrevem o caso de um homem de 78 anos, independente na sua vida diária, que procurou a unidade de saúde queixando-se de dispneia agravada nos últimos meses. Este doente é seguido regularmente nesta unidade, apresentando os seguintes antecedentes pessoais: insuficiência cardíaca congestiva classe III da NYHA, hiperuricemia, fibrilhação auricular permanente, hipertensão essencial controlada e derrame pleural espontâneo dois meses antes. No exame físico, suspeitou-se de um derrame pleural à direita, pelo que foi referenciado para o serviço de urgência hospitalar. Em consequência desta referenciação, foi internado num serviço de Medicina Interna para investigação etiológica. No decurso do internamento, foram feitos múltiplos exames complementares de diagnóstico, nomeadamente: estudos analítico e imagiológicos. Após dois meses de internamento, melhoria sintomática e exames complementares de diagnóstico se terem mostrado inconclusivos, o doente teve alta hospitalar. Posteriormente, em consulta de Cardiologia, foi-lhe pedida ressonância magnética cardíaca por suspeita de patologia sistémica. Este exame revelou sinais muito sugestivos de amiloidose cardíaca. Perante este resultado, o doente foi novamente referenciado ao serviço hospitalar que o acompanhou no primeiro internamento para investigação adicional de uma possível amiloidose. Foi realizada biópsia de gordura abdominal, cujo resultado sugeria diagnóstico de amiloidose. Posteriomente, e após estudos adicionais em consulta de Hematologia, excluiu-se amiloidose sistémica e estabeleceu-se o diagnóstico definitivo de amiloidose cardíaca. Discussão: Perante um quadro clínico, a hipótese diagnóstica mais robusta sustenta-se pela lei das probablibilidades. Contudo, existem exceções que contradizem esta lei, constituindo verdadeiros desafios diagnósticos. Nas situações clínicas raras, a abordagem multidisciplinar é imprescindível, sendo a análise holística em Medicina Geral e Familiar o ponto de partida para este processo., Revista Portuguesa de Hipertensão e Risco Cardiovascular, N.º 84 (2021): Julho / Agosto
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- 2022
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34. ANEURISMA DA ARTÉRIA BRAQUIAL – UM CASO RARO
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Portela, Raquel, Marcos, David, and Almeida, Sara
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Introdução: Os aneurismas no membro superior, especialmente os da artéria braquial, são raros quando comparados com outros aneurismas arteriais periféricos. A maioria destes são pseudo-aneurismas causados por traumatismo, incluindo trauma iatrogénico, cirurgia anterior e abuso de drogas. Os aneurismas verdadeiros podem-se dever a anormalidades congénitas do tecido conjuntivo, síndrome de Kawasaki, doença de Buerger e trauma repetitivo, ou serem idiopáticos. Descrição do caso: Utente do sexo masculino, 39 anos. Toxicodependente, em programa de metadona, seguido na equipa de tratamento para a desabituação de estupefacientes. Recorreu ao Serviço de urgência hospitalar por abcesso axilar direito, após se ter injetado para consumo de heroína, tendo sido medicado e com indicação para seguimento no seu médico assistente. Passado cerca de um mês detetou-se uma tumefação pulsátil no local puncionado, que se veio a revelar uma formação aneurismática verdadeira da artéria braquial, tendo sido referenciado para consulta de Cirurgia Vascular e submetido a intervenção cirúrgica. Conclusões: Encontrou-se um aneurisma verdadeiro da artéria braquial, ao contrário do que seria expetável, um pseudo- aneurisma, dado que houve um trauma penetrante, tratando-se, portanto de uma ocorrência ainda mais rara e que levanta a dúvida se haveria por exemplo alguma doença inflamatória vascular ou aterosclerótica subjacente. Este caso vem reforçar também a importância que existe na cooperação entre a unidade de saúde familiar e os outros serviços multidisciplinares, como a equipa de tratamento para a desabituação de estupefacientes e o serviço de Cirurgia Vascular., Revista Portuguesa de Hipertensão e Risco Cardiovascular, N.º 85 (2021): Setembro / Outubro
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- 2022
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35. Chemometrics for Raman Spectroscopy Harmonization
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Barton, Bastian, primary, Thomson, James, additional, Lozano Diz, Enrique, additional, and Portela, Raquel, additional
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- 2022
- Full Text
- View/download PDF
36. Review of Existing Standards, Guides, and Practices for Raman Spectroscopy
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Ntziouni, Afroditi, primary, Thomson, James, additional, Xiarchos, Ioannis, additional, Li, Xiang, additional, Bañares, Miguel A., additional, Charitidis, Costas, additional, Portela, Raquel, additional, and Lozano Diz, Enrique, additional
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- 2022
- Full Text
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37. Review of Existing Standards, Guides, and Practices for Raman Spectroscopy
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European Commission, Ntziouni, Afroditi, Thomson, James, Xiarchos, Ioannis, Li, Xiang, Bañares, Miguel A., Charitidis, Costas, Portela, Raquel, Lozano-Diz, E., European Commission, Ntziouni, Afroditi, Thomson, James, Xiarchos, Ioannis, Li, Xiang, Bañares, Miguel A., Charitidis, Costas, Portela, Raquel, and Lozano-Diz, E.
- Abstract
[EN] Over the past decades Raman spectroscopy has been extensively used both on an industrial and academic level. This has resulted in the development of numerous specialized Raman techniques and Raman active products, which in turn has led to the adoption and development of standards and norms pertaining to Raman unit’s calibration, performance validation, and interoperability. Purpose of the present review is to list, classify, and engage in a comprehensive analysis of the different standards, guides, and practices relating to Raman spectroscopy. Primary aim of the review is to consider the commonalities and conflicts between these standards and norms and to identify any missing aspects. Standardization in the field of Raman spectroscopy is dominated by the work of American institutions, namely, the American Society of Testing Materials (ASTM or ASTM International), with several active standards in place pertaining to terminology, calibration, multivariate analysis, and specific applications, and the National Institute of Standards and Technology (NIST), providing numerous certified reference materials, referred to as standard reference materials. The industrial application of Raman spectroscopy is dominated by the pharmaceutical industry. As such, pharmacopoeias provide not only important information in relation to pharmaceutical-related applications of Raman spectroscopy, but also invaluable insight, into the basic principles of Raman spectroscopy and important aspects that include calibration, validation, measurement, and chemometric analysis processes, usually by referring to ASTM and NIST standards. Given the fact that Raman spectroscopy is a modern and innovative field, the standardization processes are complex and constantly evolving. Despite the seemingly high number of existing standards, the standardization landscape is incomplete and has not been modernized according to the developments in Raman spectroscopy techniques in recent years. This is evident b
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- 2022
38. Microplásticos y microbiota. Impacto de la ingesta de diferentes tipos de microplásticos sobre la microbiota colónica humana
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Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, European Commission, Tamargo, Alba, Molinero, Natalia, Jiménez Arroyo, Cristina, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, European Commission, Tamargo, Alba, Molinero, Natalia, Jiménez Arroyo, Cristina, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, and Moreno-Arribas, M. Victoria
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- 2022
39. PET microplastics affect human gut microbiota communities during simulated gastrointestinal digestion, first evidence of plausible polymer biodegradation during human digestion
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Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, European Commission, Tamargo, Alba, Molinero, Natalia, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, European Commission, Tamargo, Alba, Molinero, Natalia, Jiménez Reinosa, Julián, Alcolea-Rodríguez, Víctor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, and Moreno-Arribas, M. Victoria
- Abstract
Microplastics (MPs) are a widely recognized global problem due to their prevalence in natural environments and the food chain. However, the impact of microplastics on human microbiota and their possible biotransformation in the gastrointestinal tract have not been well reported. To evaluate the potential risks of microplastics at the digestive level, completely passing a single dose of polyethylene terephthalate (PET) through the gastrointestinal tract was simulated by combining a harmonized static model and the dynamic gastrointestinal simgi model, which recreates the different regions of the digestive tract in physiological conditions. PET MPs started several biotransformations in the gastrointestinal tract and, at the colon, appeared to be structurally different from the original particles. We report that the feeding with microplastics alters human microbial colonic community composition and hypothesize that some members of the colonic microbiota could adhere to MPs surface promoting the formation of biofilms. The work presented here indicates that microplastics are indeed capable of digestive-level health effects. Considering this evidence and the increasing exposure to microplastics in consumer foods and beverages, the impact of plastics on the functionality of the gut microbiome and their potential biodegradation through digestion and intestinal bacteria merits critical investigation.
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- 2022
40. Crosslinked Bacterial Cellulose Hydrogels For Biomedical Applications
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Almeida, Ana P. C., primary, Saraiva, João N., additional, Cavaco, Gonçalo, additional, Portela, Raquel P., additional, Leal, Catarina R., additional, Sobral, Rita G., additional, and Almeida, Pedro L., additional
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- 2022
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41. Microplásticos y microbiota. Impacto de la ingesta de diferentes tipos de microplásticos sobre la microbiota colónica humana
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Tamargo García, Alba, Molinero, Natalia, Jiménez Arroyo, Cristina, Jiménez Reinosa, Julián, Alcolea-Rodriguez, Victor, Portela, Raquel, Bañares, Miguel A., Fernández Lozano, José Francisco, Moreno-Arribas, M. Victoria, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, and European Commission
- Abstract
Resumen del trabajo presentado a la 15ª Reunión de la Red Española de Bacterias Lácticas: Bacterias Lácticas en Alimentación y Salud. Valencia, 26 y 27 de mayo de 2022., PlasticsFatE (H2020) y ALIBIRD-CM 2020 P2018/BAA-4343 (Comunidad de Madrid).
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- 2022
42. Supplemental Material - Chemometrics for Raman Spectroscopy Harmonization
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Barton, Bastian, Thomson, James, Lozano Diz, Enrique, and Portela, Raquel
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FOS: Other engineering and technologies ,99999 Engineering not elsewhere classified - Abstract
Supplemental Material for Chemometrics for Raman Spectroscopy Harmonization by Bastian Barton, James Thomson, Enrique Lozano Diz, and Raquel Portela in Applied Spectroscopy
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- 2022
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43. Diabetes mellitus type 2: factors related to adherence to self-care
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Portela, Raquel de Aguiar, primary, Silva, José Rodrigo Santos, additional, Nunes, Flávia Baluz Bezerra de Farias, additional, Lopes, Maria Lúcia Holanda, additional, Batista, Rosângela Fernandes Lucena, additional, and Silva, Andréa Cristina Oliveira, additional
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- 2022
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44. Diabetes mellitus type 2: factors related to adherence to self-care.
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de Aguiar Portela, Raquel, Silva, José Rodrigo Santos, de Farias Nunes, Flávia Baluz Bezerra, Lopes, Maria Lúcia Holanda, Batista, Rosângela Fernandes Lucena, and Silva, Andréa Cristina Oliveira
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- 2022
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45. Spike detection algorithms for Raman spectroscopy: a comparative study
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Bocklitz, Thomas, Georgiev, Georgi, Portela, Raquel, Bañares, Miguel A., and Coca-Lopez, Nicolas
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- 2024
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46. Caracterização da função do sistema scwdABC de Staphylococcus aureus em interações inter-espécie e com o hospedeiro
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Silva, Miguel Ângelo Patinho, Sobral, Rita, and Portela, Raquel
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Internalização em Macrófagos ,Staphylococcus aureus ,Biossíntese de Peptidoglicano ,Engenharia e Tecnologia::Outras Engenharias e Tecnologias [Domínio/Área Científica] ,Bacteriocinas ,Formação de Biofilme - Abstract
Em estudos anteriores sobre o gene murF de Staphylococcus aureus, responsável pela adição do terminal D-alanil-D-alanina do pentapéptido do peptidoglicano, verificou-se que a sua interrupção, no mutante de inserção F9, levava à anormal incorporação de tripéptido na parede, apesar da sua viabili- dade e taxa de crescimento não serem afetadas. A análise transcriptómica deste mutante revelou a exis- tência de um sistema sobreexpresso, constituído por dois genes de função desconhecida, scwdA e scwdB, e um gene que codifica uma proteína transmembranar, scwdC. Resultados preliminares mostra- ram que estas proteínas têm um papel no fitness de S. aureus aquando da presença de danos na parede e sugerem que ScwdA-B se associam a membranas biológicas através de hélices-α anfipáticas. A hipó- tese colocada é que a expressão das proteínas ScwdA-B seja desencadeada pelo dano na parede, sendo secretadas pela ScwdC, e atuem como bacteriocinas contra outras bactérias ou no hospedeiro. Esta tese teve como objetivo caracterizar o papel do sistema scwdABC em interações inter- espécie e com o hospedeiro. As proteínas ScwdA e ScwdB recombinantes foram expressas e purificadas como fusões His- tag, tendo estes processos sido otimizados. Quanto à localização, os resultados mostraram uma possível associação entre as proteínas ScwdA-B e a membrana celular de Escherichia coli, quando estas proteí- nas são sobreexpressas heterologamente por E. coli. A sobreexpressão de ScwdC na presença de tampão fosfato afetou negativamente o crescimento de S. aureus, um efeito que foi acentuado pelo aumento de concentração de fosfato, e foi revertido na presença de ScwdB, revelando um possível papel no fitness da bactéria em condições de stress. As proteínas, isoladamente, bem como o meio de cultura dos mu- tantes de sobreexpressão não apresentaram atividade antimicrobiana contra as espécies bacterianas e estirpes de S. aureus estudadas, não sendo possível concluir quanto à sua atividade como bacteriocinas. Adicionalmente, os resultados não mostraram uma correlação entre os genes scwdA-B e a capacidade de formação de biofilme. No entanto, a sua sobreexpressão resultou num aumento da internalização de S. aureus em macrófagos. revelando um possível papel de ScwdA-B na interação com o hospedeiro. Previous studies on the Staphylococcus aureus murF gene, responsible for the addition of the D- alanyl-D-alanine terminus of the peptidoglycan pentapeptide, showed that its interruption, in the F9 insertion mutant, led to the abnormal incorporation of tripeptide into the cell wall, although its viability and growth rate were not affected. The transcriptomic analysis of this mutant revealed the overexpres- sion of a genetic system, constituted by two genes of unknown function, scwdA-B, and a gene encoding a transmembrane protein, scwdC. Preliminary results showed a role for these proteins in the fitness of S. aureus in the presence of a cell wall damage and a possible association between ScwdA-B and bio- logical membranes through amphipathic α-helices. The hypothesis raised is that the expression of ScwdA-B proteins is triggered by a damage to the wall, being both proteins secreted, possibly by ScwdC, and acting as bacteriocins on other bacteria or on the host. The aim of this thesis was to characterize the role of the scwdABC system in inter-species and host interactions. ScwdA and ScwdB recombinant proteins were expressed and purified as His-tag fusions and these processes were optimized. The results showed a possible association between the ScwdA-B pro- teins and Escherichia coli cell membrane, when the proteins were heterologously expressed by E. coli. The overexpression of ScwdC in the presence of increasing concentrations of phosphate buffer nega- tively affected the growth of S. aureus, and this effect was reversed in the presence of ScwdB, revealing a possible role of ScwdB in the fitness of the bacteria under stress conditions. The proteins alone, as well as the spent medium of the overexpression mutants did not show antimicrobial activity against the studied bacterial species and S. aureus mutant strains, thus it was not possible to conclude on their activity as bacteriocins. Additionally, the results did not show a correlation between scwdA-B genes and the capacity to form biofilm. However, their overexpression was shown to increase the internaliza- tion of S. aureus into macrophages, revealing a possible role of ScwdA-B in host interaction.
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- 2022
47. Ultrasensitive In 2 O 3 -Based Nanoflakes for Lung Cancer Diagnosis and the Sensing Mechanism Investigated by Operando Spectroscopy.
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Cheng Y, Portela R, Wang P, Liu P, Mao Y, Lim KH, Zheng J, Yang X, Zhang G, Ding L, Wang WJ, Li BG, Bañares MA, and Wang Q
- Subjects
- Humans, Hemiterpenes analysis, Indium chemistry, Nanostructures chemistry, Spectrum Analysis, Raman methods, Lung Neoplasms diagnosis, Platinum chemistry, Limit of Detection, Butadienes chemistry
- Abstract
Rapid gas sensing with high sensitivity and selectivity is pivotal in advanced production, in smart living, and increasingly in medical health applications. This study presents a novel Pt@InNiO
x nanoflake isoprene sensor that achieves an exceptionally low limit of detection (LOD) at 2 ppb, the lowest reported for isoprene sensors to date. Notably, it exhibits high selectivity and remarkable antihumidity capacity, thus meeting the stringent requirements for lung cancer screening. To unravel the sensing mechanism, we fabricate an operando DRIFTS-Raman cell coupled to online electrical measurements. It reveals that the ultrasensitive performance of Pt@InNiOx nanoflakes stems from the activated conjugated structure of isoprene by Pt nanoclusters and from the enhanced isoprene adsorption and electron interaction due to the nanoflake morphology. The p-n junction constructed by doping Ni maintains Fermi level equilibrium, shielding it from humidity interference. Practically, we integrate these ultrasensitive Pt@InNiOx nanoflakes into a miniaturized portable electronic device that successfully distinguishes lung cancer patients with expiratory isoprene below 40 ppb, from the healthy population with isoprene above 60 ppb, enabling an accurate diagnosis in clinics. Our work not only provides a breakthrough in low-cost, noninvasive cancer screening through breath analysis but also advances the rational design of cutting-edge gas sensing materials.- Published
- 2024
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48. The dispersion method does not affect the in vitro genotoxicity of multi-walled carbon nanotubes despite inducing surface alterations.
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Burgum MJ, Alcolea-Rodríguez V, Saarelainen H, Portela R, Reinosa JJ, Fernández JF, Dumit VI, Catalán J, Simeone FC, Faccani L, Clift MJD, Evans SJ, Bañares MA, and Doak SH
- Abstract
Multi-walled carbon nanotubes (MWCNTs) are a desirable class of high aspect ratio nanomaterials (HARNs) owing to their extensive applications. Given their demand, the growing occupational and consumer exposure to these materials has warranted an extensive investigation into potential hazards they may pose towards human health. This study utilised both the in vitro mammalian cell gene mutation and the cytokinesis-blocked micronucleus (CBMN) assays to investigate genotoxicity in human lymphoblastoid (TK6) and 16HBE14o
- human lung epithelial cells, following exposure to NM-400 and NM-401 MWCNTs for 24 h. To evaluate the potential for secondary genotoxicity, the CBMN assay was applied on a co-culture of 16HBE14o- with differentiated human monocytic (dTHP-1) cells. In addition, two dispersion methods (NanoGenoTox vs. high shear mixing) were utilised prior to exposures and in acellular experiments to assess the effects on MWCNT oxidative potential, aspect ratio and surface properties. These were characterized in chemico as well as by electron microscopy and Raman spectroscopy. Structural damage of NM-400 was observed following both dispersion approaches; Raman spectra highlighted greater oxidative transformation under probe sonication as opposed to high shear mixing. Despite the changes to the oxidative potential of the MWCNTs, no statistically significant genotoxicity was observed under the conditions applied. There was also no visible signs of cellular internaliation of NM-400 or NM-401 into either cell type under the test conditions, which may support the negative genotoxic response. Whilst these HARNs may have oxidative potential, cells have natural protective mechanisms for repairing transient DNA damage. Therefore, it is crucial to evaluate biological endpoints which measure fixed DNA damage to account for the impact of DNA repair mechanisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2024
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