Browsing by Issue Date, starting with "2022-12-19"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Synthesis and biological evaluation of Amphotericin B formulations based on organic salts and ionic liquids against Leishmania infantumPublication . Ferraz, Ricardo; Santarém, Nuno; Santos, Andreia F. M.; Jacinto, Manuel L.; Cordeiro-da-Silva, Anabela; Prudêncio, Cristina; Noronha, João Paulo; Branco, Luis C.; Petrovski, ŽeljkoNowadays, organic salts and ionic liquids (OSILs) containing active pharmaceutical ingredients (APIs) are being explored as drug delivery systems in modern therapies (OSILs-API). In that sense, this work is focused on the development of novel OSILs-API based on amphotericin B through an innovative procedure and the evaluation of the respective biological activity against Leishmania infantum. Several ammonium, methylimidazolium, pyridinium and phosphonium organic cations combined with amphotericin B as anion were synthesized in moderate to high yields and high purities by the water-reduced buffer neutralization method. All prepared compounds were characterized to confirm the desired chemical structure and the specific optical rotation ([α]D25) was also determined. The biological assays performed on L. infantum promastigotes showed increased activity against this parasitic disease when compared with the starting chloride forms and amphotericin B alone, highlighting [P6,6,6,14][AmB] as the most promising formulation. Possible synergism in the antiprotozoal activity was also evaluated for [P6,6,6,14][AmB], since it was proven to be the compound with the highest toxicity. This work reported a simple synthetic method, which can be applied to prepare other organic salts based on molecules containing fragile chemical groups, demonstrating the potential of these OSILs-AmB as possible agents against leishmaniasis.
- Modelling of Determinants of Logistics 4.0 Adoption: Insights from Developing CountriesPublication . Khan, Shahbaz; Singh, Rubee; Sá, José Carlos; Santos, Gilberto; Pinto Ferreira, LuísWith the emergence of industry 4.0, several elements of the supply chain are transforming through the adoption of smart technologies such as blockchain, the internet of things and cyber physical systems. Logistics is considered one of the important elements of supply chain management and its digital transformation is crucial to the success of industry 4.0. In this circumstance, the existing logistics system needs to be upgraded with industry 4.0 technologies and emerge as logistics 4.0. However, the adoption/transformation of logistics 4.0 is dependent on several determinants that need to be explored. Therefore, this study has the prime objective of investigating the determinants of logistics 4.0 adoption in the context of a developing country, specifically, India. Initially, ten determinants of logistics 4.0 are established after a survey of the relevant literature and the input of industry experts. Further, a four-level structural model is developed among these determinants using the Interpretive Structural Modelling (ISM) approach. In addition, a fuzzy Matrix of Cross-Impact Multiplications Applied to Classification (MICMAC) analysis is also conducted for the categorization of these determinants as per their driving and dependence power. The findings show that top management supports, information technology infrastructure and financial investment are the most significant determinants towards logistics 4.0 adoption. This study facilitates the supply chain partners to focus on these high-level determinants for the effective adoption of logistics 4.0. Moreover, the findings lead to a more in-depth insight into the determinants that influence logistics 4.0 and their significance in logistics 4.0 adoption in emerging economies
- User Reputation on E-Commerce: Blockchain-Based ApproachesPublication . Maria José Angélico Gonçalves; Rui Humberto Pereira; Marta Alexandra Guerra Magalhães Coelho; Angélico Gonçalves, Maria José; Pereira, Rui HumbertoUser trust is a fundamental issue in e-commerce. To address this problem, recommendation systems have been widely used in different application domains including social media healthcare, e-commerce, and others. In this paper, we present a systematic review of the literature in the area of blockchain-based reputation models and we discuss the obtained results, answering the initial research questions. These findings lead us to conclude that the existing systems are based on a trusted third party (TTP) to collect and store reputation data, which does not provide transparency on users’ reputation scores. In the recent literature, on the one hand, blockchain-based reputation systems have been highlighted as possible solutions to effectively provide the necessary transparency, as well as effective identity management. On the other hand, new challenges are posed in terms of user privacy and performance, due to the specific characteristics of the blockchain. According to the literature, two major approaches have been proposed based on public and permissioned blockchains. Each approach applies adjusted models for calculating reputation scores. Despite the undoubted advantages added by a blockchain, the problem is only partially solved since there is no effective way to prevent blockchain oracles from feeding the chain with false, unfair, or biased data. In our future work, we intend to explore the two approaches discussed in the literature in order to propose a new blockchain-based model for deriving user reputation scores.