In-situ synthesis of CaO and SiO2 nanoparticles onto jute fabrics: exploring the multifunctionality

Fibrous based materials with exceptional functionalities have become a target of interest for researchers worldwide. One promising strategy for the development of active fibrous structures with improved functions is their functionalization with nanoparticles (NPs). In this work, jute fabrics were functionalized with calcium oxide (CaO) and silica (SiO2) NPs in order to obtain fibrous structures with several properties including, hydrophobicity, UV protection, antibacterial activity and the degradation of dyes ability. CaO and SiO2 NPs were synthesized via a simple in situ method, using sodium hydroxide (NaOH) as the reducing agent and water as solvent. Parallelly, the in situ synthesis of the CaO NPs was also tested. The final systems were fully characterized using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy, Ground-State Diffuse Reflectance and Field Emission Scanning Electron Microscopy and Energy Dispersive Spectroscopy. All these techniques confirmed the successful synthesis of the NPs as well as their well distributed presence onto the fabrics. The samples exhibited very good contact angle values, reaching 143.7\textdegree for the fabrics functionalized with CaO and SiO2 NPs and great values of ultraviolet (UV) protection factors (UPF), reaching 50+ for the functionalized fabrics. The developed systems also exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli and photocatalytic activity for the degradation of methylene blue. The wash durability of the nanocoating was also evaluated, confirming that the SiO2 improved the NPs' anchorage onto the fabrics. Overall, this work presents for the first time, the development of jute fabrics with CaO--SiO2 NPs with several functionalities.The authors are thankful to project UID/CTM/00264/2019 of 2C2T—Centro de Ciêcia e Tecnologia Têxtil, funded by National Founds through FCT/MCTESFundação para a Ciência e a Tecnologia, TSSiPRO project, operation code NORTE 01-0145-FEDER-000015, supported by the ‘‘Programa Operacional Regional do Norte’’ number NORTE-45-2015-02 and to the FCT PhD Scholarship (SFRH/BD/147812/2019) of Joana Araújo. Diana Ferreira is thankful to CEECIND/02803/2017. Pilar Teixeira is also thankful to FCT, under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Anticipated adaptation difficulties to higher education: a study with first-year students

A qualidade da adaptação e sucesso no Ensino Superior está relacionada com características prévias dos estudantes, sendo que a literatura sugere diferenças de género, de tipos de estudos e de background familiar nos resultados dos estudantes. Além de variáveis socioculturais nesta determinação, variáveis mais sociocognitivas como as expetativas de resultado e a autoeficácia parecem influenciar as experiências adaptativas dos estudantes. Este estudo caracteriza as dificuldades antecipadas de adaptação de um grupo de 931 estudantes de uma universidade pública portuguesa, que acedem ao primeiro ano do Ensino Superior, uma semana antes do início das suas aulas. A análise das dificuldades antecipadas, avaliadas em três domínios – adaptação académica, integração social e autonomia -, é feita em função da área do curso frequentado, do sexo e do agrupamento em estudantes de primeira geração (pais sem frequência do Ensino Superior) ou estudantes de famílias com formação superior. Os resultados sugerem o impacto destas variáveis, sobretudo em termos da antecipação de dificuldades de integração social e autonomia, apontando para maiores dificuldades antecipadas nas mulheres, estudantes de primeira geração e estudantes de cursos de ciências sociais e humanas. Discutem-se implicações para a investigação e intervenção e contexto de Ensino Superior.The quality of adaptation and success in Higher Education is related to students’ entry characteristics, as literature suggests the impact of gender, the field of studies, and family background on students’ results. In addition to sociocultural factors, social-cognitive variables such as outcome expectations and self-efficacy also influence students’ adaptation experiences. This study characterizes the anticipated difficulties presented by a group of 931 first-year students matriculating at a Portuguese public university, one week before the beginning of classes. The analysis of anticipated difficulties, assessed in three major domains – academic adjustment, social integration, and autonomy -, is conducted concerning the field of studies, sex, and grouping in firstgeneration (students’ whose parents do not have a college education) or students from families with higher education backgrounds. Findings suggest the impact of these variables, namely regarding anticipated social integration and autonomy difficulties, suggesting higher anticipated difficulties by women, first-generation students, and students in social sciences and humanities courses. The results are discussed regarding implications for research and intervention in Higher Education

Controlling ETEC colonization on cultures of an intestinal pig cell line with a T4-like phage

Enterotoxigenic Escherichia coli (ETEC) colonizes the intestine of young pigs causing severe diarrhoea and consequently bringing high producing costs. The rise of antibiotic selective pressure together with on-going limitation on their use demands news strategies to tackle this pathology. The pertinence of using phages to tackle this problematic is being explored, and in this work, the efficacy of a T4-like phage vB_EcoM_FJ1 (FJ1) in reducing the load of ETEC O9:H9 (Sta, F5/F41) was assessed. FJ1 has a 170,053 bp genome, and of the 270 coding sequences none corresponds to identified undesirable proteins, such as integrases or transposases. Envisaging the oral application to piglets, FJ1 was previously encapsulated on CaCO3/alginate. Assays were performed on 15-day cultures of the intestinal pig cell line IPEC-1 seeded in transwell inserts. Phage treatment occurred 2 hours after ETEC infection, when, in average, 5x105 CFU.cm-2 were adhered to cultured cells. Encapsulated phage provided reductions of, approximately, 2.3 Log CFU.cm-2 and 2.8 Log CFU.cm-2 on adhered bacteria, respectively 3 and 6 hours after administration. The repeated exposure of the host to FJ1 led to the emergence of phage-insensitive mutants, phenotype that brought fitness costs to the host strain: they were 70% more vulnerable to the pig complement system and less efficient in adhering to cultured cells (in about 90%). Overall, FJ1 is presented here as promising to fight against ETEC infections through oral administration to piglets.info:eu-repo/semantics/publishedVersio

Aggregation and phase equilibria of fluorinated ionic liquids

Grant SFRH/BD/100563/2014. IF/00190/2014 . IF/00210/2014. PTDC/EQU-EQU/29737/2017. PTDC/QEQ-FTT/3289/2014. IF/00210/2014/CP1244/CT0003. UID/QUI/50006/2019. POCI-01-0145-FEDER - 007265.In this work a specific family of ionic liquids, denominated fluorinated ionic liquids, with fluorine tags equal or longer than four carbon atoms, are fully characterized in order to understand their solubility and self-aggregation in aqueous solutions. The numerous combinations between cations and anions make these compounds a feasible option for the replacement of traditional and toxic surfactants used in the industrial and biomedical field. In this work, the increment of both hydrogenated and fluorinated side chain lengths, the influence of the cation headgroup (imidazolium and cholinium)as well as the difference between perfluorobutanesulfonate and perfluoropentanoate anions were studied. The liquid-liquid phase equilibria of fluorinated ionic liquids based on the perfluorobutanesulfonate anion with water were carried out. The self-aggregation behaviour of the different fluorinated ionic liquids in aqueous solutions was also determined using conductimetric titration, surface tension measurements and transmission electron microscopy. Several thermodynamic and surface parameters were obtained and used to discuss the aggregation process. These novel characterized fluorinated ionic liquids demonstrate an improved surface activity and aggregation behaviour, driven essentially by the increment of both hydrogenated and fluorinated chain lengths.authorsversionpublishe

Amentadione from the Alga Cystoseira usneoides as a Novel Osteoarthritis Protective Agent in an Ex Vivo Co-Culture OA Model

Osteoarthritis (OA) remains a prevalent chronic disease without effective prevention and treatment. Amentadione (YP), a meroditerpenoid purified from the alga Cystoseira usneoides, has demonstrated anti-inflammatory activity. Here, we investigated the YP anti-osteoarthritic potential, by using a novel OA preclinical drug development pipeline designed to evaluate the anti-inflammatory and anti-mineralizing activities of potential OA-protective compounds. The workflow was based on in vitro primary cell cultures followed by human cartilage explants assays and a new OA co-culture model, combining cartilage explants with synoviocytes under interleukin-1 beta (IL-1 beta) or hydroxyapatite (HAP) stimulation. A combination of gene expression analysis and measurement of inflammatory mediators showed that the proposed model mimicked early disease stages, while YP counteracted inflammatory responses by downregulation of COX-2 and IL-6, improved cartilage homeostasis by downregulation of MMP3 and the chondrocytes hypertrophic differentiation factors Col10 and Runx2. Importantly, YP downregulated NF-kappa B gene expression and decreased phosphorylated IkB alpha/total IkB alpha ratio in chondrocytes. These results indicate the co-culture as a relevant pre-clinical OA model, and strongly suggest YP as a cartilage protective factor by inhibiting inflammatory, mineralizing, catabolic and differentiation processes during OA development, through inhibition of NF-kappa B signaling pathways, with high therapeutic potential

Design and photo-Fenton performance of Graphene/CuS/Fe3O4 tertiary nanocomposites for Rhodamine B degradation

This study describes nanocomposites of graphene flakes (GF) combined with CuS, Fe3O4 and CuS−Fe3O4 nanoparticles prepared by wet chemical methods. The Fe3O4 and/or CuS nanoparticles were directly anchored onto GF without requiring additional chemical treatment. The composition, structure and morphology of the nanocomposites, as well as of the pristine GF and metal oxide/sulfide nanoparticles were characterised by X − ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), powder X − ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results confirmed the successful attachment of CuS nanophases (size range: 23.7–50.1 nm) and/or Fe3O4 nanoparticles (size range: 10.6–15.8 nm). The adsorption and photocatalytic properties of the GF−based nanocomposites were evaluated at room temperature using Rhodamine B (RhB) as a model contaminant. Theoretical models were fitted to the adsorption kinetic results using the pseudo-first-order, pseudo-second-order and Elovich equations, while the adsorption mechanism was determined using the intraparticle diffusion, Bangham and Boyd models. The RhB adsorption efficiency was 6.5% for GF@CuS−Fe3O4 after 180 min contact time, whereas for the other materials was significantly higher: 97.6%, 60.9% and 31.9% for GF, GF@CuS and GF@Fe3O4, respectively. The adsorption capacity of GF and composites fitted the pseudo−second−order kinetic and Elovich models. The influence of the nanostructures composition on the corresponding photocatalytic activity in the degradation of RhB under a 150 W halogen lamp was also evaluated. The GF@CuS−Fe3O4 nanocomposite totally eliminated the dissolved RhB after 60 min irradiation, whereas the GF@CuS, GF@Fe3O4 and pristine Fe3O4 removed 75.6%, 80.9% and 30.8%, respectively, after 180 min irradiation. It was found that the photocatalytic behaviour of the composites was best described by the first−order kinetic model. The rate constant of the photocatalytic RhB removal for GF@CuS−Fe3O4 (k = 7.05 ×10−2 min−1) was 2.1, 5.1 and 15.0 times higher than those obtained for GF@CuS, GF@Fe3O4 and pristine Fe3O4, respectively, after 60 min of visible light irradiation.publishe

Petrosamine isolated from marine sponge Petrosia sp. demonstrates protection against neurotoxicity in vitro and in vivo

According to The World Alzheimer Report 2023 by Alzheimer’s Disease International (ADI) estimates that 33 to 38.5 million people worldwide suffer from Alzheimer’s Disease (AD). A crucial hallmark associated with this disease is associated with the deficiency of the brain neurotransmitter acetylcholine, due to an affected acetylcholinesterase (AChE) activity. Marine organisms synthesize several classes of compounds, some of which exhibit significant AChE inhibition, such as petrosamine, a coloured pyridoacridine alkaloid. The aim of this work was to characterize the activity of petrosamine isolated for the first time from a Brazilian marine sponge, using two neurotoxicity models with aluminium chloride, as exposure to aluminium is associated with the development of neurodegenerative diseases. The in vitro model was based in a neuroblastoma cell line and the in vivo model exploited the potential of zebrafish (Danio rerio) embryos in mimicking hallmarks of AD. To our knowledge, this is the first report on petrosamine’s activity over these parameters, either in vitro or in vivo, in order to characterize its full potential for tackling neurotoxicity

Investigating Early/Middle Bronze Age Copper and Bronze Axes by Micro X-Ray Fluorescence Spectrometry and Neutron Imaging Techniques

Micro X-ray fluorescence (micro-XRF) analysis and neutron imaging techniques, namely 2D radiography and 3D tomography, have been applied for the study of four metal axes from the Early/Middle Bronze Age in Western Iberia, a period characterized by a metallurgical change in the use of copper to bronze. Micro-XRF analysis has shown that one of the axes was produced in copper with some arsenic while the other three were produced in a copper-tin alloy (bronze) with variable tin contents and some arsenic and lead. Neutron radiography and tomographywere applied to study internal heterogeneities of the axes in a non-invasiveway since the specificities of neutron interaction with matter allow a suitable penetration of these relatively thick copper-based objects when compared to the use of a conventional X-ray radiography. Neutron imaging allowed the visualization of internal fissures and pores and the evaluation of their distribution, size and shape. Relevant information for the reconstruction of ancient manufacturing techniques was gathered, revealing that one ax was produced with the mold in an angle of ≈25°, probably to facilitate gas escape during metal pouring. Also, information regarding physical weaknesses of the axes was collected, providing relevant data for their conservation. Novelty statement: The present paper combines the use of micro-XRF and neutron imaging techniques, namely (2D) radiography and (3D) tomography for the study of prehistoric metal axes. The XRF spectra allowed identifying major and minor elements present in the alloys, inferring on the absence of elements that could become radioactive for a long period of time after irradiation with neutrons. The specificities of neutron interaction with matter allowed a suitable penetration of these relatively thick copper-based objects when compared to the use of a conventional X-ray radiography. The combination of these non-destructive techniques allowed the evaluation of the metal composition and the internal structure of the axes. Micro-XRF allowed the distinction among copper and bronze axes, and provided data about the composition of early bronzes for which data is scarce. The neutron imaging study allowed for the first timethe visualization of internal heterogeneities in early bronze axes, namely pores and large voids, providing relevant information for the reconstruction of ancient manufacturing techniques and raising pertinent information regarding physical weaknesses of these types of objects.info:eu-repo/semantics/publishedVersio

Metal alloys, matrix inclusions and manufacturing techniques of Moinhos de Golas collection (North Portugal): a study by micro-EDXRF, SEM–EDS, optical microscopy and X-ray radiography

"Article:820"A collection of 35 metallic artefacts comprising various typologies, some of which can be attributed to the Bronze Age and others to later periods, were studied to provide detailed information on elemental composition, manufacturing techniques and preservation state. Elemental analysis by micro-EDXRF and SEM–EDS was performed to investigate the use of different alloys and to study the presence of microstructural heterogeneities, as inclusions. X-ray radiography, optical microscopy and SEM–EDS were used to investigate manufacturing techniques and degradation features. Results showed that most of the artefacts were produced in a binary bronze alloy (Cu–Sn) with 10–15 wt% Sn and a low concentration of impurities. Other artefacts were produced in copper or in brass, the latest with varying contents of Zn, Sn and Pb. A variety of inclusions in the metal matrices were also found, some related to specific types of alloys, as (Cu–Ni)S2 in coppers, or ZnS in brasses. Microstructural observations revealed that the majority of the artefacts were subjected to cycles of thermomechanical processing after casting, being evident that among some artefacts different parts were subjected to distinct treatments. The radiographic images revealed structural heterogeneities related to local corrosion processes and fissures that seem to have developed in wear-tension zones, as in the handle of some daggers. Radiographic images were also useful to detect the use of different materials in one particular brass artefact, revealing the presence of a possible Cu–Sn solder.This work was funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT— Fundação para a Ciência e a Tecnologia under the project UID/CTM/ 50025/2013 to CENIMAT/I3N. C2 TN/IST authors gratefully acknowledge the FCT support through the UID/Multi/04349/2013 project. EF acknowledges FCT for the grant SFRH/BPD/97360/2013. JF acknowledge FCT for the grant SFRH/BD/65143/2009. Part of this project has been done in the framework of the FCT project ENARDAS (PTDC/HISARQ/112983/2009).info:eu-repo/semantics/publishedVersio