Repositório Institucional da Universidade Estadual da Paraíba
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Funcionalització de microestructures per la producció fototèrmica de γ-valerolactona.
No full textTreballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2024, Tutors: Albert Serrà Ramos, Elvira Gómez ValentínThe transition to cleaner energy sources is fundamental for mitigating the effects of climate change. One promising example is lignocellulosic biomass, a renewable and sustainable energy source that serves as a precursor to various compounds, including γ-valerolactone (GVL). GVL can be utilized as a biofuel or biopolymer.
This project evaluates the potential use of SrFe12O19/Ni-P and graphite/Ni-P as catalysts for the photo-thermocatalytic and cost-effective production of GVL from levulinic acid, using a laser light as a source of energy. The goal is to scale up this process for future industrial applications. The catalysts were functionalized via a Ni-P electroless deposition process. The impact of temperature, reaction time, and electroless deposition coating time on catalyst efficiency was analysed. For the effective catalysts, different coverages thicknesses were tested. Optimal experimental conditions for reactor experiments with a laser dispositive were previously established by conducting autoclave tests in a conventional oven.
Autoclave tests results evidenced that the SrFe12O19/Ni-P material did not exhibit catalytic properties for the production of γ-valerolactone. In contrast, graphite/Ni-P catalysts achieved nearly 100% conversion, with an optimum minimum reaction temperature of 120 ºC. To evaluate the potential of the graphite/Ni-P catalyst as a photo-thermal catalysts for γ-valerolactone production, experiments were conducted using the laser apparatus under the aforementioned conditions. The results showed that the graphite/Ni-P catalyst with a 10-minute deposition time exhibited higher conversion rates at lower reaction times and demonstrated greater durability and stability throughout the reusability cycles. Consequently, the graphite/Ni-P catalyst with a 10-minute deposition time was identifies as a suitable catalyst for GVL production
Caracterização fenotípica de Staphylococcus spp. isolados de profissionais de saúde em unidades de terapia intensiva: impacto na transmissão cruzada aos pacientes
No full textAs culturas de vigilância são estratégias eficazes para detectar precocemente patógenos e monitorar a resistência antimicrobiana hospitalar. O objetivo deste estudo foi comparar a prevalência de Staphylococcus spp., especialmente MRSA (Methicillin-Resistant Staphylococcus aureus) e MRCoNS (Methicillin-Resistant Coagulase-negative Staphylococcus), e analisar o perfil de resistência de cepas isoladas em UTIs (Unidades de Terapia Intensiva) neonatais de dois hospitais públicos de Campina Grande – PB. Foram coletadas amostras de neonatos (Hospital 1) e de profissionais de saúde (Hospitais 1 e 2), processadas no Laboratório de Microbiologia da UEPB, utilizando ágar manitol salgado e teste de coagulase para caracterizar Staphylococcus aureus, seguido de TSA (Teste de Sensibilidade aos Antimicrobianos). Em ambas as instituições, predominou o gênero feminino, sendo 97,7% (n=42) no Hospital 1 e 86,5% (n=19) no Hospital 2, e a enfermagem, com 37,2% (n=16) e 45,4% (n=9) dos participantes, respectivamente. No Hospital 1, foram isolados 66 microrganismos, sendo 40,9% (n=27) Staphylococcus aureus e 59,1% (n=39) CoNS (Coagulase-negative Staphylococcus), com prevalência de 29,6% (n=8) de MRSA e 56,4% (n=22) de MRCoNS. No Hospital 2, foram identificados 41 microrganismos, com 26,8% (n=11) Staphylococcus aureus e 73,2% (n=30) CoNS. Contudo, todos os isolados de Staphylococcus aureus eram MRSA e 86,6% (n=26) dos CoNS eram MRCoNS. No Hospital 1, a colonização por MRSA nos neonatos predominou nas regiões axilar e nasal, com 45,5% (n=5) e 36,4% (n=4), sugerindo transmissão cruzada devido à contaminação simultânea. No Hospital 1, indica-se cloranfenicol e amoxicilina/clavulânico (1ª linha) e tetraciclina (2ª linha). Deve-se evitar amicacina, ciprofloxacino, clindamicina, eritromicina e gentamicina. No Hospital 2, recomenda-se amicacina e cloranfenicol (1ª linha), gentamicina, sulfametoxazol/trimetoprima e amoxicilina/ácido clavulânico (2ª linha), evitando-se a clindamicina. Em ambos, linezolida, teicoplanina e vancomicina devem ser reservadas à terceira linha. Conclui-se que, diante da elevada resistência bacteriana em UTIs, é imprescindível realizar antibiogramas para garantir o sucesso terapêutico
La denigración y la obstaculización como actos de competencia desleal. Análisis del Caso Ryanair
No full textLa aparición de las nuevas tecnologías ha generado una batalla entre las compañías aéreas y las agencias de viajes, que ofrecen sus servicios no sólo en sus establecimientos sino también a través de la red. La mediación de las agencias de viaje a través de internet consiste en la facilitación a los consumidores de una comparativa de precios de vuelos de diferentes compañías, de tal forma que pueden comprar los billetes de vuelo que consideren más convenientes para sus intereses, puesto que el buscador de la agencia on line les dirige a la página web de la compañía aérea que seleccionen los usuarios, pagando una comisión a la agencia de viajes por la gestión de búsqueda realizada. Ante esta situación, resulta de interés poner de relieve la reacción que ha tenido Ryanair Limited que ha consistido en realizar una serie de declaraciones relativas a las agencias on line, así como introducir en su página web una amenaza de cancelación de vuelos cuando los billetes se hubiesen comprado a través de una de esas agencias, con el fin de que los consumidores compren sus billetes directamente a través de su propia página web o de su central de reservas y, por tanto, no acudan a las agencias on line. Ante este comportamiento, diversas agencias on line, en concreto, Lastminute Network, S.L. (en adelante, Last Minute), Red Universal de Marketing y Booking Online, S.A. (en adelante, Rumbo) y Atrápalo, S.L. (en adelante, Atrápalo), han reaccionado demandado a Ryanair por considerar que su conducta constituye diversos actos de competencia desleal, en concreto, un acto de denigración y un acto de obstaculización contrario a la buena fe. En el presente trabajo se analizan las tres sentencias del Tribunal Supremo en las que se han resuelto las demandas planteadas y, podemos avanzar, ha sido condenada Ryanair en atención a los hechos relatados
Syntaxin-1 is necessary for UNC5A-C/Netrin-1-dependent macropinocytosis and chemorepulsion
No full textIntroduction: Brain connectivity requires correct axonal guidance to drive axons to their appropriate targets. This process is orchestrated by guidance cues that exert attraction or repulsion to developing axons. However, the intricacies of the cellular machinery responsible for the correct response of growth cones are just being unveiled. Netrin-1 is a bifunctional molecule involved in axon pathfinding and cell migration that induces repulsion during postnatal cerebellar development. This process is mediated by UNC5 homolog receptors located on external granule layer (EGL) tracts.
Methods: Biochemical, imaging and cell biology techniques, as well as syntaxin-1A/B (Stx1A/B) knock-out mice were used in primary cultures and brain explants.
Results and discussion: Here, we demonstrate that this response is characterized by enhanced membrane internalization through macropinocytosis, but not clathrin-mediated endocytosis. We show that UNC5A, UNC5B, and UNC5C receptors form a protein complex with the t-SNARE syntaxin-1. By combining botulinum neurotoxins, an shRNA knock-down strategy and Stx1 knock-out mice, we demonstrate that this SNARE protein is required for Netrin1-induced macropinocytosis and chemorepulsion, suggesting that Stx1 is crucial in regulating Netrin-1-mediated axonal guidance
Wheat mixtures as an effective option for weed management in organic farming
No full textIn organic cereal cropping systems, crop diversification has emerged as an environmentally friendly strategy for weed management. However, the role of crop mixtures in weed regulation, particularly in Mediterranean conditions, has been largely overlooked.This study evaluates the effects of wheat mixtures on weed suppression and weed species diversity. Over two years, we compared the weed suppression abilities of three wheat monocultures —Florence-Aurora (FA), Forment (FO), and Montcada (MO)— with two wheat mixtures: Florence-Aurora with Forment (FAFO) and Florence-Aurora with Montcada (FAMO) in five commercial fields. We analysed weed cover, weed biomass, and weed species community composition and richness. Additionally, we analysed some agronomic and functional wheat traits —including establishment, cover, height, biomass, and final tiller number— and correlated with final weed biomass to better understand the crops' ability to suppress weeds.Results indicated that wheat establishment, cover, and height were strongly negatively correlated with weed biomass. Wheat crops differed in both trait values and weed suppression abilities. Crop treatments that exhibited greater establishment, height and wheat cover, FAFO mixture and FO sole crop, significantly decreased weed cover and biomass. Nevertheless, FAMO did not outperform monocultures probably due to trait redundancy between the combined plants. Weed species composition was similar across treatments, although FO significantly reduced weed species richness.In conclusion, this study supports the use of wheat mixtures as an effective weed management strategy that also preserves weed species diversity. It further emphasizes the importance of including wheat plants with strong functional traits to maximize the mixture weed suppression performance
The overexposure of children by their digital influencer parents and the violation of the right to image in the brazilian context
No full textThe digital age has transformed the way people share their lives, and the rise of digital influencers has intensified this phenomenon. In Brazil, there has been a growing overexposure of children by their influencer parents, whether through daily posts or as protagonists of advertising campaigns and monetized content. This study aimed to analyze Brazilian legislation regarding the protection of the image rights of children exposed by digital influencer parents on social media, investigating its gaps, effectiveness, and applicability, as well as proposing guidelines to strengthen the safeguarding of children's personality rights in the digital environment. The research was conducted through an analysis of Brazilian legislation, adopting bibliographic and documentary research. The results show that bills are currently under consideration, which demonstrates that the legislative debate already recognizes the need for more direct protective intervention. However, even if approved, such laws will need to be accompanied by public policies and educational campaigns to change the culture of children's digital hypervisibility. Simply providing regulations is not enough to protect minors from the exploitation of their image. Therefore, the creation of a specific legal framework is essential to ensure legal certainty and uniform interpretation, which must be accompanied by public educational policies and digital awareness campaigns.A era digital transformou a forma como as pessoas compartilham suas vidas, e a ascensão dos influenciadores digitais intensificou esse fenômeno. No Brasil, observa-se um crescimento da superexposição de crianças por seus pais influenciadores, seja por meio de postagens cotidianas cou como protagonistas de campanhas publicitárias e conteúdos monetizados. Este estudo teve como objetivo analisar a legislação brasileira quanto à proteção do direito à imagem de crianças expostas por pais influenciadores digitais nas redes sociais, investigando suas lacunas, eficácia e aplicabilidade, bem como propondo diretrizes para fortalecer a salvaguarda dos direitos da personalidade infantil no ambiente digital. A pesquisa foi realizada por meio da análise da legislação brasileira, adotando-se as pesquisas bibliográfica e documental. Os resultados evidenciam que há tramitação de projetos de lei, o que evidencia que o debate legislativo já reconhece a necessidade de uma intervenção protetiva mais direta. Todavia, ainda que aprovadas, tais leis precisarão ser acompanhadas de políticas públicas e de campanhas educativas para alterar a cultura de hipervisibilidade digital infantil. A simples previsão normativa não é suficiente para proteger os menores da instrumentalização de sua imagem. Portanto, a criação de um marco legal específico é indispensável para garantir segurança jurídica e uniformidade interpretativa, o qual deve ser acompanhado por políticas públicas educativas e campanhas de conscientização digital
Insights into type I photoreactivity of cyclometalated iridium(III) and ruthenium(II) photosensitizers
No full textPhotodynamic therapy (PDT) is a light-activated treatment that relies on the generation of cytotoxic reactive oxygen species (ROS). While most clinically approved photosensitizers (PSs) operate through a type II mechanism—based on energy transfer to molecular oxygen—their efficacy is often compromised in hypoxic tumor microenvironments. In this context, type I PSs capable of initiating electron or hydrogen atom transfer reactions have gained increasing attention due to their reduced dependency on oxygen levels. In this Feature Article, we review recent advances in cyclometalated iridium- and ruthenium-based PSs exhibiting type I photoreactivity, highlighting representative examples from both our own work and the literature. Although rational design strategies are still emerging, selected examples demonstrate how subtle modifications in complex architecture, ligand environment, or metal center identity can influence the balance between type I and type II pathways. In particular, we outline conceptual design motifs—such as cyclometalation with thiophenyl-based ligands, conjugation with fluorophores such as coumarin or BODIPY, and multinuclear architectures—that have been explored to enhance electron-transfer reactivity under hypoxic conditions. Beyond photophysical considerations, we discuss common challenges in the experimental identification of type I mechanisms and emphasize the importance of biologically relevant models, such as 3D cell cultures, for evaluating PS performance. Ultimately, we offer a perspective on how molecular design can be tailored to meet the demands of next-generation PDT agents, aiming to improve therapeutic outcomes in low-oxygen tumor microenvironments, which are characteristic of highly aggressive and treatment-resistant tumors
L'acusatiu preposicional en català: d'on venim i cap a on anem?
No full textEn aquest treball analitzem l’acusatiu preposicional del català tant des del punt de vista de l’evolució diacrònica del fenomen com des de la perspectiva de l’abast que presenta en el conjunt dels dialectes catalans avui dia. Primer, a partir d’un exhaustiu estudi de corpus de la llengua antiga hem constatat que el fenomen ja existia en la llengua medieval (amb pronoms personals, noms propis i SN), de manera que, en aquest sentit, pot considerar-se un fenomen genuí. Ara bé, les dades diacròniques indiquen també diàfanament que a partir del segle XVI, quan la influència de l’espanyol esdevé una realitat cada cop més severa, el percentatge d’ús de la preposició a davant de CD augmenta exponencialment. Si bé a inicis del segle XX la publicació de la normativa fabriana significà un abans i un després en l’aparició del fenomen en els textos escrits formals, el fet és que la comunitat catalanòfona no s’ha arribat a desprendre mai d’aquest recurs morfosintàctic, ans al contrari. Així ho confirmem a bastament a partir d’un estudi a gran escala sobre l’abast del fenomen en el conjunt dels dialectes catalans, basat en entrevistes individuals amb vora 400 parlants, que fan tasques tant de producció d’oracions com d’emissió de judicis de gramaticalitat
Differential impact of COVID-19 on poverty and income of immigrants and natives: the case of Chile
No full text[spa] Se analiza la evolución de las condiciones socioeconómicas del conjunto de la población inmigrante y de tres colectivos con mayor representación –venezolanos, peruanos y haitianos– en comparación con la población chilena, en cuanto a ingresos económicos y situación de pobreza entre los años 2015 y 2022 a fin de observar el impacto de la pandemia COVID-19 en cada grupo. Para ello, se realizó un análisis estadístico descriptivo e inferencial utilizando los microdatos de la encuesta CASEN de los años 2015, 2017, 2020 y 2022. Los principales resultados muestran que la población chilena y migrante fueron afectadas socioeconómicamente en forma desigual por la pandemia, y que, en el caso de venezolanos, haitianos y peruanos, ya habían sufrido una disminución de sus condiciones socioeconómicas previas a la pandemia, pero la situación empeoró con la llegada de esta y la implementación de medidas gubernamentales para combatir su expansión.[eng] The impact of the COVID-19 pandemic on the socioeconomic conditions of the immigrant population, and of the three more important groups –Venezuelans, Peruvians and Haitians–, is analyzed and compared with the Chilean population. For this purpose, a descriptive statistical analysis and an inference analysis are carried out using microdata on income and poverty from the 2015, 2017, 2020 and 2022 CASEN survey. The main results show that the Chilean and migrant population were unequally affected, from a socioeconomic point of view, by the pandemic. More specifically, Venezuelans, Haitians and Peruvians had already experienced a decline in their socioeconomic conditions before the pandemic, but the situation worsened due to COVID-19 and the political measures implemented by the Chilean government to hinder their contagion
Hybrid interpretation with generative AI: a pilot study using the A Duo with ChatGPT instrument
No full textGenerative artificial intelligence is reshaping analytical practices and raises questions about how meaning is constructedwhen analysts work in dialogue with a generative system. This article presents A Duo with ChatGPT, a structured instrumentdesigned to make hybrid interpretation empirically traceable during a qualitative analysis task. Our contribution is methodological,focussing on instrument design and feasibility rather than evaluating ChatGPT’s performance. The frameworkprovides an operational definition of hybrid interpretation and specifies four epistemic dimensions (distributed agency,interpretive abduction, epistemic control, and analytic metacognition). The instrument organises the task into successivephases that alternate between human-only interpretation and guided interactions with ChatGPT and asks participants to recordprompts, system outputs, decisions, and brief annotations of significant moments. The instrument was piloted with threeparticipants with education-related backgrounds and different profiles, an undergraduate student in Pedagogy, an in-serviceprimary teacher, and a doctoral researcher. The pilot suggests that the instrument is feasible and generates analysable processrecords that can be read through the four epistemic dimensions in participants’ written accounts. The article discusses howthese traces support a process-based reading of hybrid interpretation and outlines directions for refinement and replication