Showing: 10 from total: 2477 publications
141. Synchrotron-based FTIR evaluation of biochemical changes in cancer and noncancer cells induced by brominated marine coelenteramine
Magalhaes, CM ; Ducic, T ; Pereira, RB ; Gonzalez-Berdullas, P ; Rodriguez-Borges, JE ; Pereira, DM ; da Silva, JCGE ; Algarra, M ; da Silva, LP
in ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 2023, ISSN: 0003-9861,  Volume: 743, 
Article,  Indexed in: crossref, scopus, unpaywall, wos 
Abstract The mode of action toward gastric cancer cells of brominated Coelenteramine, an analogue of a metabolic product of a marine bioluminescent reaction, was investigated by synchrotron radiation-based Fourier Transform Infrared spectrocopy (FTIR). This method revealed that the anticancer activity of brominated Coelenteramine is closely connected with cellular lipids, by affecting their organization and composition. More specifically, there is an increasing extent of oxidative stress, which results in changes in membrane polarity, lipid chain packing and lipid composition. However, this effect was not observed in a noncancer cell line, helping to explain its selectivity profile. Thus, synchrotron radiation-based FTIR helped to identify the potential of this Coelenteramine analogue in targeting membrane lipids, while proving to be a powerful technique to probe the mechanism of anticancer drugs.

142. Can ChatGPT Enhance Chemistry Laboratory Teaching? Using Prompt Engineering to Enable AI in Generating Laboratory Activities
Araújo, JL ; Saúde, I
in Journal of Chemical Education, 2023, ISSN: 0021-9584,  Volume: 101, 
Article,  Indexed in: crossref, scopus 
Abstract The rapid evolution of Artificial Intelligence (AI) is profoundly shaping our society. Among various AI tools, ChatGPT stands out for its user-friendly nature and wide accessibility to the public. However, despite their countless potential benefits, these tools also face significant challenges, especially in sensitive areas like Education. In this publication, we conduct a prompt engineering essay with ChatGPT to understand the potential and challenges of this tool in designing new, high-quality chemistry laboratory activities. We aimed to assess its performance in proposing scientifically and pedagogically suitable protocols for chemistry laboratory activities based on the 11th-grade Portuguese curriculum. The initial exploratory essay was conducted to fine-tune the prompt, followed by the analysis of proposals for the five mandatory laboratory activities in this subject. ChatGPT demonstrates the ability to interpret and reproduce the specialized symbolic language of chemistry, effectively conceptualizing problems and laboratory activities in a clear and understandable manner for a broader audience (i.e., chemistry students). However, it is crucial to highlight the scientific-pedagogical limitations concerning the accuracy and appropriateness of the proposed laboratory activities, particularly in terms of safety and sustainability. Therefore, the use of AI in education should be approached critically and reflectively. While AI holds immense potential to transform the dynamics of teaching and learning, the role and expertise of the Chemistry teacher remain of the utmost importance to ensure the scientific and pedagogical quality of Chemistry classes. © 2024 American Chemical Society and Division of Chemical Education, Inc.

143. Drivers of FDI in small states
Forte, R ; Neves, C
in JOURNAL OF THE ASIA PACIFIC ECONOMY, 2023, ISSN: 1354-7860,  Volume: 28, 
Article,  Indexed in: crossref, scopus, wos 
Abstract This paper examines the determinants of FDI in small states, as only a small number of studies have analyzed the determinants of FDI in these countries. Small states have particular features that justify the need for a deeper analysis. Based on a panel data for 42 small states between 2005 and 2019, results clearly indicate the importance of the quality of human capital and the availability of infrastructures as the strongest drivers of FDI in small states. The country's level of openness, the availability of natural resources, the level of corporate tax and control of corruption also seems to play a relevant role therein. Moreover, the results suggest that the determinants differ depending on the region to which the country belongs and differ between island and non-island countries. These results can help small countries in defining policies that help them to attract FDI, which is crucial for their sustainable development.

144. Assessment of Surface Water Quality Using the Water Quality Index (IWQ), Multivariate Statistical Analysis (MSA) and Geographic Information System (GIS) in Oued Laou Mediterranean Watershed, Morocco
Azhari, HE ; Cherif, E ; Sarti, O ; Azzirgue, E ; Dakak, H ; Yachou, H ; da Silva, JCGE ; Salmoun, F
in WATER, 2023, ISSN: 2073-4441,  Volume: 15, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities' impact on surface water quality in the Oued Laou watershed, Northern Morocco. Thirteen surface water samples were characterized for 26 physicochemical and biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), water quality indices (WQI), irrigation water quality (IWQI), and Geographic Information System (GIS) were employed to identify the sources of surface water pollution, their suitability for consumption, and the distribution of surface water quality. The results showed that the major ion concentrations were reported in the following order: Ca2+, Na+, Mg2+, and K+; and HCO3- > CO32- > Cl- > SO42- > NO3- > F- > PO43- > NO2-. It was also demonstrated that almost all parameters had concentrations lower than World Health Organization (WHO) limits, except for bicarbonate ions (HCO3-) and the biochemical oxygen demand for five days (BOD5), which exceeded the WHO limits at 120 mg/L and 3 mg/L, respectively. Furthermore, the types of Ca2+-HCO3- (Calcium-Bicarbonate) and Ca2+-Mg2+-HCO3- (Calcium-Magnesium-Bicarbonate) predominated in surface water. The Principal Component Analysis (PCA) indicates that the Oued Laou river was exposed to two forms of contamination, the first being attributed to anthropogenic activities such as agriculture, while the second reflects the water-sediment interaction. The Hierarchical Cluster Analysis (HCA), reflecting the mineralization in the study area, has classified the samples into four clusters. The Inverse Distance Weighting (IDW) of the WQI indicates that 7.69% and 38.46% of the surface water represent, respectively, excellent and good quality for drinking. At the same time, the IWQI revealed that 92.30% of the water surface is good for irrigation. As a result, the combination of WQIs, PCA, IWQI, and GIS techniques is effective in providing clear information for assessing the suitability of surface water for drinking and its controlling factors and can also support decision-making in susceptible locations such as the Oued Laou river in northern Morocco.

145. Phytochemical Compounds and Anticancer Activity of Cladanthus mixtus Extracts from Northern Morocco
El Mihyaoui, A ; Charfi, S ; Erbiai, E ; Pereira, M ; Duarte, D ; Vale, N ; Castillo, MEC ; Badoc, A ; Lamarti, A ; da Silva, JCGE ; Arnao, MB
in CANCERS, 2023, ISSN: 2072-6694,  Volume: 15, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Simple Summary Cancer is a dramatic illness that ranks among the most pressing health concerns facing humanity and necessitates a proactive approach to treatment. Phytochemicals are regarded as interesting molecules for the development of anticancer drugs due to their pleiotropic effects on broad targets. The actions of phytochemicals are focused on tumor cells alone, with no negative effects on normal cells. The intricate process of carcinogenesis involves numerous signaling cascades. This study examined the effects of four organ extracts from a Mediterranean endemic plant, Cladanthus mixtus, on human tumor cells. To the best of our knowledge, this is the first study on this plant from northern Morocco showing relevant antiproliferative activity against two cancer cell lines and one non-tumoral cell line. Many of the chemotherapeutic drugs for the treatment of cancer are molecules identified and isolated from plants or their synthetic derivatives. This work aimed to identify the bioactive compounds using LC-MS and GC-MS and to evaluate the anticancer activity of the methanolic extracts of roots, stems, leaves, and flowers from Cladanthus mixtus. The anticancer activity was evaluated in vitro against two cancer cell lines: human breast carcinoma (MCF-7) and human prostate carcinoma (PC-3), using the MTT assay and microscopic observation. A human normal lung fibroblast (MRC-5) was included to determine the extract's safety for non-tumoral cells. The chemical composition results by LC-MS analysis revealed the presence of 24 phenolic compounds. Furthermore, GC-MS analysis allowed the identification of many biomolecules belonging to terpenoids, esters, alcohols, alkanes, fatty acids, organic acids, benzenes, phenols, ketones, carbonyls, amines, sterols, and other groups. The findings suggest that the majority of C. mixtus extracts have antiproliferative activity against two cancer cell lines, MCF-7 and PC-3, and one non-tumoral cell line, MRC-5. The activity was dose-dependent, and the highest effect was obtained with leaf extract in the two cancer cell lines. Moreover, these extracts demonstrated an acceptable toxicological profile against normal cells. Overall, C. mixtus extracts revealed promising antitumor properties provided by their phytochemical composition.

146. The mitochondria-targeted antioxidant AntiOxCIN4 protects against cardiac oxidative/nitrosative stress in the amyotrophic lateral sclerosis SOD1G93A mouse
Mena, D ; Cagide, F ; Benfeito, S ; Soares, P ; Grilo, L ; Pinheiro, P ; Teixeira, J ; Borges, F ; Oliveira, PJ ; Duarte, AI
in EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, 2023, ISSN: 0014-2972,  Volume: 53, 
Abstract,  Indexed in: wos 

147. The mitochondria-targeted antioxidant AntiOxCIN4 attenuates brain and skeletal muscle oxidative/nitrosative stress in the amyotrophic lateral sclerosis SOD1G93A mouse
Mena, D ; Soares, P ; Cagide, F ; Benfeito, S ; Grilo, L ; Silva, DF ; Pinheiro, P ; Ferreiro, E ; Teixeira, J ; Silva, F ; Borges, F ; Oliveira, PJ ; Duarte, AI
in EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, 2023, ISSN: 0014-2972,  Volume: 53, 
Abstract,  Indexed in: wos 

148. Annealing-assisted optimization for persistency of afterglow of SrAl2O4:Eu2+/Dy3+ microparticles for forensic detection
Kumar, A ; Crista, DMA ; Núñez-Montenegro, A ; da Silva, JCGE ; Verma, SK
in RSC ADVANCES, 2023, ISSN: 2046-2069,  Volume: 13, 
Article,  Indexed in: crossref, scopus, wos 
Abstract In the present work, Eu2+/Dy3+ ions doped/co-doped into persistent SrAl2O4 microparticles have been developed through solid-state synthesis followed by homogenization and particle size reduction in a ball milling device. These particles have shown a broad and long-persistent afterglow around the 528 nm wavelength of electromagnetic radiation through a broad excitation at around 400 nm. The luminescence intensity was optimized through the selection of different annealing temperatures in the range of 1100 C-degrees to 1500 C-degrees, with intervals of 100 C-degrees. Several structural and optical characterization techniques, such as XRD, SEM, FTIR, thermogravimetric analysis, and photoluminescence, were utilized to judge the preparation and ability of these particles in possible applications in latent fingermark detection on various difficult surfaces. The persistency and stability of these particles were calculated using a digital lux meter.

149. 2H-chromene and 7H-furo-chromene derivatives selectively inhibit tumour associated human carbonic anhydrase IX and XII isoforms
Sequeira, L ; Distinto, S ; Meleddu, R ; Gaspari, M ; Angeli, A ; Cottiglia, F ; Secci, D ; Onali, A ; Sanna, E ; Borges, F ; Uriarte, E ; Alcaro, S ; Supuran, CT ; Maccioni, E
in JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY, 2023, ISSN: 1475-6366,  Volume: 38, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Tumour associated carbonic anhydrases (CAs) IX and XII have been recognised as potential targets for the treatment of hypoxic tumours. Therefore, considering the high pharmacological potential of the chromene scaffold as selective ligand of the IX and XII isoforms, two libraries of compounds, namely 2H-chromene and 7H-furo-chromene derivatives, with diverse substitution patterns were designed and synthesised. The structure of the newly synthesised compounds was characterised and their inhibitory potency and selectivity towards human CA off target isoforms I, II and cancer-associated CA isoforms IX and XII were evaluated. Most of the compounds inhibit CA isoforms IX and XII with no activity against the I and II isozymes. Thus, while the potency was influenced by the substitution pattern along the chromene scaffold, the selectivity was conserved along the series, confirming the high potential of both 2H-chromene and 7H-furo-chromene scaffolds for the design of isozyme selective inhibitors. [GRAPHICS]

150. Early Activation of Antioxidant Responses in Ni-Stressed Tomato Cultivars Determines Their Resilience Under Co-exposure to Drought
Spormann, S ; Soares, C ; Martins, V ; Azenha, M ; Gerós, H ; Fidalgo, F
in JOURNAL OF PLANT GROWTH REGULATION, 2023, ISSN: 0721-7595,  Volume: 42, 
Article,  Indexed in: crossref, scopus, wos 
Abstract Throughout their life cycle, plants are subjected to a variety of environmental constraints, including abiotic stresses. The present study aimed at characterizing the responses of the two tomato cultivars Gold Nugget (GN) and Purple Calabash (PC) exposed to a combination of nickel (Ni) and drought. The following hypotheses were pursued: (i) the activation of responses to one stressor eases further adjustments to a second stressor; and (ii) the two tomato cultivars are differentially susceptible to drought and heavy metal-stress. Besides biometrical evaluations, the distribution of Ni in tissues and the redox homeostasis in both cultivars were compared in response to Ni-stress, polyethylene glycol (PEG)-induced drought, and to their combination. Regarding single stresses, Ni caused more harmful effects to plants than PEG-induced drought, in terms of growth inhibition and production of reactive oxygen species. Ni was mostly accumulated in the roots. The GN cultivar promptly activated antioxidant defenses under Ni-stress, while, in PC, such antioxidants were more strongly induced under combined stress. Stress co-exposure led to a drastic proline accumulation, resembling a signal of stress sensitivity. Overall, the GN cultivar seemed to be less susceptible to the combined stress than PC, as it could activate stronger antioxidant defenses under single Ni toxicity, possibly easing further adjustments demanded by the later co-exposure to drought. This study showed that the two cultivars of the same species had different levels of perception and responsiveness to Ni-induced stress, which translated into different susceptibilities to the combined exposure to PEG-induced drought. [GRAPHICS] .