Percorrer por data de Publicação, começado por "2025-07-10"
A mostrar 1 - 10 de 32
Resultados por página
Opções de ordenação
- Do clear aligners release toxic chemicals? : a systematic reviewPublication . Ferreira, Mariana de Almeida Baraças; Lopes, Pedro André Ferreira Campos; Gomes, Ana Teresa Peixoto de CamposClear aligners are a modern orthodontic solution designed to address dental malocclusions discreetly and effectively. In terms of clinical side effects, the most reported issues among aligner users are mild irritation of the oral mucosa, localized inflammation, and hypersensitivity. The use of advanced polymer materials in clear aligners, such as polyurethane and PET-G, has gained widespread acceptance due to their mechanical properties, biocompatibility and aesthetic appeal. However, concerns persist regarding their potential to release chemical compounds. The goal of this work is to understand the impact of the toxicity of clear aligners on oral cavity of orthodontic patients. An extensive systematic search was conducted in electronic databases PubMed, Scopus and Cochrane, to identify articles with relevant data. This systematic review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines to answer a question formulated according to the Population, Intervention, Comparison and Outcomes strategy. Four hundred and thirteen articles potentially relevant were identified and after applying PRISMA guidelines and inclusion/exclusion criteria, seven articles were included in this review. The results suggest that clear aligners are generally safe, but concerns remain regarding the chemical leaching of thermoplastic materials, bacterial accumulation due to reduced saliva flow, and mild inflammatory responses. This review emphasizes that although most materials are biocompatible, some exhibit moderate cytotoxicity, with the potential to impact these patients9 oral health, underscoring the need for continued research and improvements in material composition.
- Systemic Gamification Theory (SGT): a holistic model for inclusive gamified digital learningPublication . Coelho, Franz; Abreu, Ana MariaGamification has emerged as a powerful strategy in digital education, enhancing engagement, motivation, and learning outcomes. However, most research lacks theoretical grounding and often applies multiple and uncontextualized game elements, limiting its impact and replicability. To address these gaps, this study introduces a Systemic Gamification Theory (SGT)—a comprehensive, human-centered model for designing and evaluating inclusive and effective gamified educational environments. Sustained in Education, Human–Computer Interaction, and Psychology, SGT is structured around four core principles, emphasizing the importance of integrating game elements (1—Integration) into cohesive systems that generate emergent outcomes (2—Emergence) aligned synergistically (3—Synergy) with contextual needs (4—Context). The theory supports inclusivity by accounting for individual traits, situational dynamics, spatial settings, and cultural diversity. To operationalize SGT, we developed two tools: i. a set of 10 Heuristics to guide and analyze effective and inclusive gamification; and ii. a Framework for designing and evaluating gamified systems, as well as comparing research methods and outcomes across different contexts. These tools demonstrated how SGT enables robust, adaptive, and equitable gamified learning experiences. By advancing theoretical and practical development, SGT fosters a transformative approach to gamification, enriching multimedia learning through thoughtful system design and reflective evaluation practices.
- The EUDC as an international paradigm facing the algorithmic societyPublication . Albuquerque, André Lobianco de; Botelho, Catarina Isabel Tomaz SantosThe thesis turns itself over the increasing influence of the information industry over modern days democracies and society in general, the development and consequences of the Algorithmic Society, and how Digital Constitutionalism has been conceptualised as a legal regulatory response to its arising threats to sovereignty and individual rights. The research uses the European Union Digital Constitutionalism movement as its practical example, revising prominent authors on their work over the subject, such as Czarnocki, Giovanni de Gregorio, and Edoardo Celeste. This research understands that the EUDC does have to focus on its theoretical expansion, but also keep on track the current international political developments. Reaching out and merging with the American point of view for digital regulations would only hurt the original animus of the EUDC, causing more harm than helping on sustaining its ideas. The thesis concludes that there are multiple other relevant international actors for the European Union to grow with, and that this factor should take priority on enhancing the EUDC as the global pioneering protective tool it is supposed to be.
- The art of Italian craftsmanship : Campari to acquire LuxardoPublication . Boi, Leonardo; Assunção, António Borges deThis dissertation analyses the proposed acquisition of Privilegiata Fabbrica Maraschino “Excelsior” Girolamo Luxardo S.p.A. by Davide Campari-Milano N.V on a cash-free, debt-free basis. Luxardo, one of the oldest and still operating family-owned businesses producing liqueurs and distillates, represents a perfect fit for Campari’s Regional Priorities portfolio, which includes brands with limited scale but outstanding potential for expansion in the domestic market and abroad. Furthermore, the acquisition aligns with Campari’s premiumization pathway and its external growth strategy focused particularly on spirits, seeking local and identity specialty brands in markets where it has direct distribution. This study examines the M&A process of the proposed transaction from a holistic perspective, starting with the industry and market analysis, the identification of the ideal target, and the strategic rationale supporting the acquisition. It then includes a preliminary valuation through selected intrinsic and relative methodologies, and the examination of the preferred form of consideration, concluding with the assessment of shareholder value creation. This analysis highlights the potential value creation from the proposed transaction, primarily driven by revenue synergies and Campari’s proven A&P and distribution capabilities. The preliminary purchase price is set at €177.5 million, subject to confirmation following an extensive due diligence, implying a 39.2% premium to Luxardo’s fair value based on intrinsic valuation. The preferred payment structure includes a mix of stock and cash with a floating collar structure, along with a deferred portion of the consideration structured through an earn-out component.
- Flying towards consolidation : an analysis of the potential acquisition of TAP Air Portugal by Lufthansa GroupPublication . Lütkehaus, Benjamin; Assunção, António Borges deThis thesis examines the potential acquisition of TAP Air Portugal by the Lufthansa Group in the light of ongoing consolidation in the European aviation industry. Following TAP's stabilization after COVID and the announced reprivatization, Lufthansa is emerging as a key candidate for the takeover to strengthen its multi-brand and multi-hub strategy. The study starts with a review of theoretical concepts related to mergers and acquisitions (M&A), including motives, success factors, and valuation methods. A comprehensive analysis of the European aviation sector reveals increasing financial pressure, changing consumer preferences, and the strategic need for consolidation. Company-specific analyses of Lufthansa and TAP shed light on their operational performance, strategic positioning, and financial structures. Stand-alone valuations are performed for both companies using the discounted cash flow and relative valuation methods. Finally, a transaction scenario is developed to assess synergy potential, financing aspects, and regulatory risks. The results indicate that TAP's strong presence on transatlantic routes, particularly between Europe and Brazil, and its strategically located hub in Lisbon could represent significant added value for Lufthansa. Operational and financial synergies are identified, particularly in the areas of fleet integration, route optimization, and procurement. Despite identifiable risks, including regulatory controls and political uncertainties, the analysis concludes that the acquisition has the potential to create long-term value for Lufthansa shareholders. This case is another example of the strategic use of M&A to address structural challenges in the European aviation landscape.
- Juniperus pseudosabina extract-mediated green synthesis of zinc oxide artichoke-like structures for antibacterial applicationsPublication . Kurbanova, Zulfira; Pereira, Sofia I. A.; Sousa, Ana S. S.; Piccirillo, Clara; Shaislamov, Ulugbek; Yubuta, Kunio; Teshima, Katsuya; Eitinger, Thomas; Hojamberdiev, MirabbosThe green synthesis of zinc oxide (ZnO) using plant extracts provides an environmentally friendly alternative to conventional chemical and physical methods. This study investigates the green synthesis of ZnO using Juniperus pseudosabina (J. plseudosabina) extract, eliminating the need for thermal treatment and pH adjustment with alkali metal hydroxides. ZnO nanoparticles are synthesized by varying the plant extract volume (0–20 mL) in a 95 mL aqueous solution of Zn(NO3)2·6H2O. The optimal ratio (5 mL extract) yields phase-pure ZnO with an artichoke-like morphology. The possible formation mechanism of these structures is discussed. Additionally, ZnO is modified with silver (Ag) at concentrations of 0–3 at% to improve antibacterial properties. Structural and morphological characterizations confirm the formation of phase-pure ZnO with high crystallinity. Viable plate count assays demonstrate that both non-modified and Ag-modified ZnO exhibited strong antibacterial activity against Staphylococcus aureus and Escherichia coli, achieving 99.999 % bacterial inactivation. These findings suggest that ZnO and Ag-modified ZnO synthesized using J. pseudosabina extract can be a sustainable antibacterial agent, supporting its application in biomedical and environmental fields.
- The impact of the non-financial reporting directive on acquisition performance : a comparative study of EU and US acquiring firmsPublication . Olsen, Oliver Næss; Revelo, JoséThis study examines whether acquiring firms subject to the EU’s Non-financial Reporting Direct ive (NFRD) experience significantly different acquisition performance compared to US acquiring firms not subject to the NFRD. A comparative study was conducted as disclosure of non-financial information remains largely voluntary in the US, while regulations in the EU mandating disclosure continue to evolve. To address the impact of the NFRD on acquisition performance, I examined acquisition performance through an Event study to assess short-term market reactions to announced deals (between 2018 and 2023) and a two-way fixed-effects difference-in-differences (DiD) estima tion coupled with Propensity Score Matching (PSM) to evaluate actual post-acquisition performance (between 2007 and 2023). The findings reveal that markets react more positively to announced deals for acquiring firms subject to the NFRD. They also reveal that stronger ESG performance has a negative effect on market reactions for acquiring firms not subject to the NFRD, while stronger ESG performance has a positive effect for firms subject to the NFRD. Conversely, acquiring firms subject to the NFRD exhibit weaker post-acquisition performance compared to acquirers not sub ject to the NFRD. However, strong ESG performance significantly mitigates this negative effect for acquirers subject to the NFRD in the first-year post-acquisition. These results suggest that while the NFRD reduces information asymmetry and enhances investor confidence, compliance costs may divert resources from effective post-acquisition integration. It also highlights that genuine ESG commitment acts as a value driver in M&A.
- Did ESG provide stock market resilience? : an empirical analysis of European firms during COVID-19Publication . Heipp, Lukas Ruprecht; Revelo, JoséThis study examines whether ESG contributed to stock market resilience in Europe during the COVID-19 crisis. Using a dataset of publicly listed firms across 29 European countries, I applied Ordinary Least Squares regression and Difference-in-Differences analysis to assess ESG’s impact on stock returns. The findings indicate that ESG did not significantly influence stock performance. Instead, larger firms with higher cash reserves and lower debt demonstrated stronger resilience in the short-term. Additionally, momentum effects played a crucial role. Over time, as financial uncertainty diminished, market-based risk measures became the dominant drivers of stock performance. Several factors may explain these results, including ESG rating inconsistencies, reporting differences, and greenwashing concerns. Furthermore, the relevance of ESG varies across industries, reducing the effectiveness of broad ESG metrics in predicting resilience. These findings have important implications for corporate leaders, investors, and regulators. Firms should focus on financial stability and material ESG factors that drive real value. Investors must critically assess ESG ratings, while regulators should enhance disclosure standards for greater transparency and comparability.
- Media synchronicity effects on telecommuters’ working experiencePublication . Kilson, Gabriel Almeida; Tavares, PatríciaThe widespread adoption of work from home has ignited a critical debate surrounding the necessity of in-office attendance and its influence on organizational performance. A central concern is that reduced face-to-face interaction might impede internal communication and overall effectiveness. Drawing on Media Synchronicity Theory, this chapter explores how employees experience media synchronicity in relation to shared understanding, contribution visibility, and performance evaluation. To investigate these experiences, we adopted a phenomenological approach, conducting online interviews with full-time telecommuters across various professional settings. Our findings challenge the conventional view, demonstrating that telecommuting does not inherently hinder complex discussions. Instead, telecommuters strategically select media options based on the communication context, enabling them to achieve high-quality communication. We further highlight the limitations of relying solely on quantitative metrics for assessing performance in highly interactive, non-repetitive roles, advocating for regular, synchronous communication between employees and managers. This chapter concludes with practical, managerial implications for optimizing internal communication and informing telecommuting policies.
- Evaluating the role of local partnerships in the international expansion of German B2B startups : overcoming market entry barriers through strategic alliancesPublication . Demirovic, Benjamin; Almeida, SílviaThis thesis examines how local partnerships enable German B2B startups to enter international markets more quickly. It focuses on the role of partnerships as a tool to compensate for internal gaps and to navigate global expansion under pressure. The study draws on qualitative data from semi-structured interviews with founders, expansion team members, investors, and an incubator mentor involved with German B2B startups. Using the Gioia methodology, the data was coded and analyzed to identify patterns in how partnerships shape internationalization strategies. Research reveals that German B2B startups choose foreign markets because of outside chances rather than their own preparedness. This causes a conflict because limited resources clash with the need for speed. Teaming up with local partners helps solve this problem by giving early market access. These partnerships also build trust with local players and help meet regulatory requirements. Startups use them to adapt quickly in unfamiliar markets. Over-reliance, however, can slow capability development and create strategic risk. Startups introduce trial periods or clear role definitions as safeguards. Partnerships are used as temporary substitutes for internal strength but require active management. The study shows that partnerships are not just a means to enable early internationalization. They are also a response to internal limitations under time pressure. Startups use them to move quickly while being mindful of the dangers of dependency, treating them as short-term tools rather than long-term fixes. This reveals a pattern of calculated reliance, where speed is gained at the cost of delayed capability building.