Showing: 10 from total: 2591 publications
151. Cellular and Mitochondrial Toxicity of Tolcapone, Entacapone, and New Nitrocatechol Derivatives
Pinto, M ; Silva, TB ; Sardao, VA ; Simoes, R ; Albuquerque, B ; Oliveira, PJ ; Valente, MJ ; Remiao, F ; Soares-da-Silva, P
in ACS PHARMACOLOGY & TRANSLATIONAL SCIENCE, 2024, ISSN: 2575-9108,  Volume: 7, 
Article,  Indexed in: crossref, scopus, unpaywall, wos 
Abstract Nitrocatechols are the standard pharmacophore to develop potent tight-binding inhibitors of catechol O-methyltransferase (COMT), which can be used as coadjuvant drugs to manage Parkinson's disease. Tolcapone is the most potent drug of this class, but it has raised safety concerns due to its potential to induce liver damage. Tolcapone-induced hepatotoxicity has been attributed to the nitrocatechol moiety; however, other nitrocatechol-based COMT inhibitors, such as entacapone, are safe and do not damage the liver. There is a knowledge gap concerning which mechanisms and chemical properties govern the toxicity of nitrocatechol-based COMT inhibitors. Using a vast array of cell-based assays, we found that tolcapone-induced toxicity is caused by direct interference with mitochondria that does not depend on bioactivation by P450. Our findings also suggest that (a) lipophilicity is a key property in the toxic potential of nitrocatechols; (b) the presence of a carbonyl group directly attached to the nitrocatechol ring seems to increase the reactivity of the molecule, and (c) the presence of cyano moiety in double bond stabilizes the reactivity decreasing the cytotoxicity. Altogether, the fine balance between lipophilicity and the chemical nature of the C1 substituents of the nitrocatechol ring may explain the difference in the toxicological behavior observed between tolcapone and entacapone.

152. The relevance of the initial conditions in glassy carbon electrode sensing applications: the ferri/ferrocyanide redox reaction model system in aqueous solution
de Sá, MH ; Pereira, CM
in ELECTROCHIMICA ACTA, 2024, ISSN: 0013-4686,  Volume: 489, 
Article,  Indexed in: scopus, crossref, wos 
Abstract Carbon electrodes, especially the glassy carbon electrodes (GCE) are widely accepted as very versatile sensing platforms. However, correlating the behaviour of the ferri/ferrocyanide redox couple ([Fe(CN) 6 ] 3-/4 ) with the GCE ' s surface modification is challenging. The surface modification can be achieved by applying a preconditioning electrochemical activation procedure. Hence, we report the investigation performed in order to provide further insights into the electrochemical behaviour of the commonly used redox probe in aqueous solutions. To that aim we took advantage of powerful and complementary electrochemical analytical techniques, like cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Thus, this work highlights the critical role of the GCE initial conditions for optimizing the charge transfer processes and therefore to improve the [Fe(CN) 6 ] 3-/4- performance in sensing applications. The best results were obtained in phosphate buffer saline solution with previous electrochemical activation by fast potential cycling between [-0.5 and +1.8] V (vs. Ag| AgCl (KCl sat.)). Finally, one can consider this an eco-friendly and simple procedure to be carried out in the lab, however, its use must be carefully optimized when exploring other systems, as highlighted herein.

153. Proposal for the Collection Systems and Valorization of Biowaste: A Study for the Municipalities Association of Cova da Beira; [Proposta de Sistemas de Recolha e Valorização de Biorresíduos: Um Estudo para a Associação de Municípios da Cova da Beira]
David, F ; Rodrigues, P ; Soares, E ; Monteiro, E ; Melo, N ; Gregório, J ; Rodrigues, R
in Revista Portuguesa de Estudos Regionais, 2024, ISSN: 1645-586X, 
Article,  Indexed in: scopus 
Abstract This research aims to identify the best solutions to implement biowaste collection systems in a group of municipalities in Center of Portugal, Castelo Branco and Guarda districts, either through recycling at the source or selective collection, to valorize and reduce the impacts of this type of waste disposal. The recycling at the source and the selective collection are differentiated by their treatment method: the first, which uses domestic and community composters, and biocomposters, makes citizens responsible for the treatment of their biowaste; and the second consists of the process of collecting waste placed in eco-points, separated by type of material (glass, paper, plastic, biowaste, among others waste) so that they can be recycled by the infrastructures provided by the municipalities. However, both methods are complementary to respond to society’s economic and environmental needs. Methodologically, this research relied on a two-track approach. Initially, a literature review is carried out, based on the legislation that proposes measures to protect the environment and human health by preventing or reducing waste. Subsequently, a descriptive statistical analysis, supported by the information provided by the group of municipalities, shows the economic and financial resources needed to support the investment required over a period of ten years. © (2024), (APEQ - Associacao Portuguesa para o Estudo do Quaternario). All rights reserved.

154. Research on the volatility, phase transitions and thermodynamic stability of five organochlorine compounds
Almeida, RRP ; Pinheiro, DA ; Monte, JS
in Chemosphere, 2024, ISSN: 0045-6535,  Volume: 351, 
Article,  Indexed in: crossref, scopus, unpaywall 
Abstract The present investigation describes the experimental evaluation of relevant physicochemical properties of five organochlorine compounds (OCs), including some that are related to their environmental mobility. The vapor pressures of (2,4′-Dichlorodiphenyl)dichloroethane (2,4′-DDD, CASN:53-19-0), 1,1-Dichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDD, CASN:72-54-8) and 2,2-Bis(4-chlorophenyl)acetic acid (4,4′-DDA, CASN:83-05-6), as well as of the bactericide Nitrapyrin (CASN:1929-82-4) and of the rodenticide Crimidine (CASN:535-89-7) were determined at different temperatures. The Knudsen mass-loss effusion technique was employed to determine the sublimation vapor pressures of the referred compounds, apart from Crimidine. For the latter compound, a static method using a capacitance diaphragm manometer enabled the measurement of vapor pressures of both condensed (crystalline and liquid) phases. This technique was also used to measure the vapor pressures of the crystalline phase of Nitrapyrin over a larger temperature range, as well as its vaporization vapor pressures. The results of the standard molar enthalpies, entropies, and Gibbs energies of sublimation for all five compounds and of vaporization for Crimidine and Nitrapyrin, at reference temperatures, were derived. For these two compounds the phase diagram representations of the (p,T) results, in the vicinity of the triple point, were obtained. DSC analysis enabled the determination of the crystalline heat capacities of the five OCs studied and also of their temperatures and enthalpies of fusion. Gas-phase thermodynamic properties were estimated using quantum chemical calculations. The thermodynamic stability of the compounds studied was evaluated and compared in the crystalline and gaseous phases, at 298.15 K, in consideration with estimated results of the standard Gibbs energies of formation. Combined with other physical and chemical properties, the results derived from this study can be used to predict the mobility, and environmental fate of these pollutants. © 2024 Elsevier Ltd

155. Thermochemical Research on Furfurylamine and 5-Methylfurfurylamine: Experimental and Computational Insights
Amaral, LMPF ; Almeida, ARRP ; da Silva, MAVR
in MOLECULES, 2024, ISSN: 1420-3049,  Volume: 29, 
Article,  Indexed in: crossref, scopus, unpaywall, wos 
Abstract The need to transition from fossil fuels to renewables arises from factors such as depletion, price fluctuations, and environmental considerations. Lignocellulosic biomass, being abundant, and quickly renewable, and not interfering with food supplies, offers a standout alternative for chemical production. This paper explores the energetic characteristics of two derivatives of furfural-a versatile chemical obtained from biomass with great potential for commercial sustainable chemical and fuel production. The standard (p degrees = 0.1 MPa) molar enthalpies of formation of the liquids furfurylamine and 5-methylfurfurylamine were derived from the standard molar energies of combustion, determined in oxygen and at T = 298.15 K, by static bomb combustion calorimetry. Their standard molar enthalpies of vaporization were also determined at the same temperature using high-temperature Calvet microcalorimetry. By combining these data, the gas-phase enthalpies of formation at T = 298.15 K were calculated as -(43.5 +/- 1.4) kJmol-1 for furfurylamine, and -(81.2 +/- 1.7) kJmol-1 for 5-methylfurfurylamine. Furthermore, a theoretical analysis using G3 level calculations was performed, comparing the calculated enthalpies of formation with the experimental values to validate both results. This method has been successfully applied to similar molecules. The discussion looks into substituent effects in terms of stability and compares them with similar compounds.

156. Application of Engineered Nanomaterials as Nanocatalysts in Catalytic Ozonation: A Review
Cardoso, RMF ; da Silva, JCGE ; da Silva, LP
in MATERIALS, 2024, ISSN: 1996-1944,  Volume: 17, 
Review,  Indexed in: crossref, scopus, unpaywall, wos 
Abstract Given the growing scarcity of water and the continuous increase in emerging pollutants detected in water bodies, there is an imperative need to develop new, more effective, and sustainable treatments for wastewater. Advanced oxidation processes (AOPs) are considered a competitive technology for water treatment. Specifically, ozonation has received notable attention as a promising approach for degrading organic pollutants in wastewater. However, different groups of pollutants are hardly degradable via single ozonation. With continuous development, it has been shown that using engineered nanomaterials as nanocatalysts in catalytic ozonation can increase efficiency by turning this process into a low-selective AOP for pollutant degradation. Nanocatalysts promote ozone decomposition and form active free radicals responsible for increasing the degradation and mineralization of pollutants. This work reviews the performances of different nanomaterials as homogeneous and heterogeneous nanocatalysts in catalytic ozonation. This review focuses on applying metal- and carbon-based engineered nanomaterials as nanocatalysts in catalytic ozonation and on identifying the main future directions for using this type of AOP toward wastewater treatment.

157. Phase transition study of bathophenanthroline and bathocuproine: A multitechnique approach
Ferraz, JMS ; Romagnoli, L ; Brunetti, B ; Ciccioli, A ; Ciprioti, SV ; Freitas, VLS ; da Silva, MDMCR
in JOURNAL OF CHEMICAL THERMODYNAMICS, 2024, ISSN: 0021-9614,  Volume: 198, 
Article,  Indexed in: crossref, scopus, wos 
Abstract The thermal behaviour of bathophenanthroline and bathocuproine has been studied using several techniques, namely, differential scanning calorimetry and thermogravimetry. To determine their respective enthalpies of sublimation, vapor pressure measurements were carried out using different methods, such as Knudsen effusion mass loss/mass spectrometry, isothermal thermogravimetry, and a quartz crystal microbalance technique. Furthermore, the enthalpies of sublimation were determined by measuring the heat change of the sublimation process using high-temperature Calvet microcalorimetry. The results obtained in this work allowed the determination of the standard molar enthalpies of sublimation at 298.15 K, for bathophenanthroline and bathocuproine. The values obtained were (183.8 +/- 2.2) kJ & sdot;mol- 1 and (206.2 +/- 2.8) kJ & sdot;mol- 1, respectively. Additionally, the standard molar enthalpies of fusion were determined to be (30.4 +/- 0.4) kJ & sdot;mol- 1 and (26.5 +/- 1.6) kJ & sdot;mol- 1 for bathophenanthroline and bathocuproine, respectively. The analysis of the results allows a deeper understanding of the phase transition behavior for these compounds from the condensed to the gaseous phases, elucidating molecular decomposition and the inherent intermolecular forces governing the species.

158. Concentrations of Potentially Toxic Elements in Topsoils of Urban Agricultural Areas of Rome
Chandramohan, MS ; da Silva, IM ; da Silva, JE
in ENVIRONMENTS, 2024, ISSN: 2076-3298,  Volume: 11, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Urban agricultural soils have important social, environmental, and economic roles in big cities, contributing to their sustainability. However, food production in urban soils may be compromised due to soil pollution that resulted from decades of industrial, non-regulated environmental activity and mobile transport. In this study, 12 soils from the urban agricultural area of Rome (Italy) were analyzed for the potentially toxic elements (PTEs) Be, Ba, Pb, Co, Ni, V, Zn, Hg, Cd, As, Cu, and Cr. All but one of the soils under analysis were characterized by at least one PTE concentration above the threshold limit defined by the D.Lgs 152/06 for agricultural soils. Multivariate analysis showed that the soils could be classified into five clusters: clusters I and II had relatively lower mean PTE concentrations; clusters III, IV, and V had relatively higher mean PTE concentrations with several PTE concentrations above the threshold proposed by ILD. Three factors contributing to the variability of the PTE's concentration in the soils under investigation were identified: a geological factor related to PTE As, Ba, Be, and V; an anthropogenic factor related to Pb and Cu; and a mixed factor related to Co, Cr, Ni, and Zn. High PTE content may limit the utilization of urban soils for food production.

159. Metal Concentrations in Topsoils of Urban Agricultural Areas of Rome
Chandramohan, MS ; Silva, IM ; Marinari, S ; Marabottini, R ; Silva, JEd
2024,
Unpublished,  Indexed in: crossref 
Abstract <jats:p>Urban gardens have important social, environmental and economic roles in big cities, contributing to their sustainability. However, food production in urban gardens may be compromised due to soil pollution that resulted from decades of industrial non-regulated environmental activity and mobile transport. In this study, 12 soils from the urban agricultural area of Rome (Italy) were analyzed for the metals Be, Ba, Pb, Co, Ni, V, Zn, Hg, Cd, As, Cu, and Cr. All but one of the soils under analysis were characterized by at least one metal concentration above the threshold limit defined by the Italian Legislative Decree 152/2006 (ILD) for agricultural soils. Multivariate analysis showed that the soils could be classified into five clusters: clusters I and II had relatively lower mean metal concentrations; clusters III, IV, and V had relatively higher mean metal concentrations with several metal concentrations above the threshold proposed by ILD. Three factors contributing to the variability of the metal’s concentration in the soils under investigation were identified: geological factor, related with metals As, Ba, Be, and V; anthropogenic factor, related with Pb and Cu; and, a mixed factor related with Co, Cr, Ni, and Zn. High metal content may limit the utilization of urban soils as urban gardens for food production.</jats:p>

160. Environmental Stressors of Mozambique Soils Quality
Pereira, MJ ; Esteves da Silva, JC
2024,
Unpublished,  Indexed in: crossref 
Abstract <jats:p>Mozambique is one of the poorest countries of the world. However, it has natural resources and if they are managed under sustainable development principles, Mozambique can overcome the current problems. In the present socio-economic status, soil is one of its most important resources and must be protected from pollution and from degradation. This review focuses on the identification and discussion of the main soil quality stressors, namely: soil fertility; deforestation and its sources: agriculture, timber harvesting, charcoal production and uncontrolled fires; mining activities, manly gold artisanal explorations and industrial open-pit coal mining. The sustainable use of the natural resources is mandatory to allow future generations to continue profiting for this nature-based wealth.</jats:p>