23 results on '"João Pires"'
Search Results
2. Investigating the Impact of Topology and Physical Impairments on the Capacity of an Optical Backbone Network
- Author
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Alexandre Freitas and João Pires
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network capacity ,fiber assignment ,random networks ,optical networks ,optical communications ,Applied optics. Photonics ,TA1501-1820 - Abstract
Optical backbone networks constitute the fundamental infrastructure employed today by network operators to deliver services to users. As network capacity is a key factor influencing optical network performance, it is important to understand how topological and physical properties impact its behavior and to have the capability to estimate its value. In this context, we propose here a method to evaluate the network capacity that relies on the optical reach to account for physical layer aspects in conjunction with constrained routing techniques for traffic routing. As this type of routing can lead to traffic blocking, particularly due to the limitation on the number of wavelengths per fiber, we also propose a fiber assignment algorithm designed to deal with this problem. We apply this method to a set of randomly generated networks using a modified Waxman model, and for a network with 60 nodes, in a scenario without blocking, we obtain capacities of about 2.5 Pbit/s for a symbol rate of 64 Gbaud and about 5 Pbit/s for a symbol rate of 128 Gbaud. Remarkably, this duplication in the total network capacity is achieved by an increase in the total fiber length of only about 51%.
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- 2024
- Full Text
- View/download PDF
3. Novel Carbonaceous Adsorbents Prepared from Glycerin Waste and Dopamine for Gas Separation
- Author
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Mary Batista, Renato Carvalho, Moisés L. Pinto, and João Pires
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glycerin ,dopamine ,activated carbon ,ethane ,ethylene ,adsorption ,Organic chemistry ,QD241-441 - Abstract
Glycerin, a low-valued waste from biodiesel production, and dopamine were used as precursors for adsorbent materials. The study is centered on the preparation and application of microporous activated carbon as adsorbent materials in the separation of ethane/ethylene and of gases that are natural gas or landfill gas components (ethane/methane and carbon dioxide/methane). The activated carbons were produced by the following sequence reactions: facile carbonization of a glycerin/dopamine mixture and chemical activation. Dopamine allowed the introduction of nitrogenated groups that improved the selectivity of the separations. The activating agent was KOH, but its mass ratio was kept lower than one to improve the sustainability of the final materials. The solids were characterized by N2 adsorption/desorption isotherms, SEM, FTIR spectroscopy, elemental analysis, and point of zero charges (pHPZC). The order for adsorption of the different adsorbates (in mmolg−1) on the most well performing material—Gdop0.75—is methane (2.5) < carbon dioxide (5.0) < ethylene (8.6) < ethane (8.9).
- Published
- 2023
- Full Text
- View/download PDF
4. Evaluation of an Imine-Linked Polymer Organic Framework for Storage and Release of H2S and NO
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Sílvia Carvalho, João Pires, Cristina Moiteiro, and Moisés L. Pinto
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porous organic cages ,gas adsorption ,delivery vehicles ,NO/H2S release ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Hydrogen sulfide (H2S) and nitric oxide (NO) are especially known as toxic and polluting gases, yet they are also endogenously produced and play key roles in numerous biological processes. These two opposing aspects of the gases highlight the need for new types of materials to be developed in addition to the most common materials such as activated carbons and zeolites. Herein, a new imine-linked polymer organic framework was obtained using the inexpensive and easy-to-access reagents isophthalaldehyde and 2,4,6-triaminopyrimidine in good yield (64%) through the simple and catalyst-free Schiff-base reaction. The polymeric material has microporosity, an ABET surface area of 51 m2/g, and temperature stability up to 300 °C. The obtained 2,4,6-triaminopyrimidine imine-linked polymer organic material has a higher capacity to adsorb NO (1.6 mmol/g) than H2S (0.97 mmol/g). Release studies in aqueous solution showed that H2S has a faster release (3 h) from the material than NO, for which a steady release was observed for at least 5 h. This result is the first evaluation of the possibility of an imine-linked polymer organic framework being used in the therapeutic release of NO or H2S.
- Published
- 2023
- Full Text
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5. Microporous Volumes from Nitrogen Adsorption at 77 K: When to Use a Different Standard Isotherm?
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João Pires, Rafaela Fernandes, Moisés L. Pinto, and Mary Batista
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nitrogen-adsorption ,standard-isotherm ,microporosity ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
This work reviews the application of various standard isotherms to evaluate the micropore volume in a range of microporous materials. The selected materials have quite different surface chemistry, and are relevant due to their properties for adsorption and catalysis: zeolites, activated carbons, clay-based materials and MOFs. Some cases were analysed before and after being used as supports in the heterogenization of homogeneous catalysts. The discussion is centred, but not limited, to the three standard isotherms that are mostly employed in the literature (t-curve, non-porous carbon and non-porous hydroxylated silica) for the assessment of the micropore volume. For a given material the values of the micropore volumes from the different standard isotherms were compared, particularly against the values from the largely used t-curve. The cases where major discrepancies were found could normally be ascribed to samples that have a broad micropore size distribution.
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- 2021
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6. Chitosan Biocomposites for the Adsorption and Release of H2S
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Mary Batista, Moisés L. Pinto, Fernando Antunes, João Pires, and Silvia Carvalho
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hydrogen sulphide (H2S) ,zeolites ,activated carbon ,glycerin ,chitosan ,adsorption ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
The search for H2S donors has been increasing due to the multiple therapeutic effects of the gas. However, the use of nanoporous materials has not been investigated despite their potential. Zeolites and activated carbons are known as good gas adsorbents and their modification with chitosan may increase the material biocompatibility and simultaneously its release time in aqueous solution, thus making them good H2S donors. Herein, we modified with chitosan a series of A zeolites (3A, 4A and 5A) with different pore sizes and an activated carbon obtained from glycerin. The amount of H2S adsorbed was evaluated by a volumetric method and their release capacity in aqueous solution was measured. These studies aimed to verify which of the materials had appropriate H2S adsorption/release properties to be considered a potential H2S donor. Additionally, cytotoxicity assays using HeLa cells were performed. Considering the obtained results, the chitosan composite with the A zeolite with the larger pore opening was the most promising material to be used as a H2S donor so a further cytotoxicity assay using H2S loaded was conducted and no toxicity was observed.
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- 2021
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7. Understanding the Barrier and Mechanical Behavior of Different Nanofillers in Chitosan Films for Food Packaging
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João Pires, Camila Damásio de Paula, Victor Gomes Lauriano Souza, Ana Luísa Fernando, and Isabel Coelhoso
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biopolymer ,mechanical properties ,bionanocomposites ,food packaging ,oxygen permeability ,water vapor permeability ,Organic chemistry ,QD241-441 - Abstract
The continuous petroleum-based plastics manufacturing generates disposal issues, spreading the problem of plastic pollution and its rise in the environment. Recently, innovative techniques and scientific research promoted biopolymers as the primary alternative for traditional plastics, raising and expanding global bioplastic production. Due to its unmatched biological and functional attributes, chitosan (Ch) has been substantially explored and employed as a biopolymeric matrix. Nevertheless, the hydrophilicity and the weak mechanical properties associated with this biopolymer represent a significant intrinsic restriction to its implementation into some commercial applications, namely, in food packaging industries. Distinct methodologies have been utilized to upgrade the mechanical and barrier properties of Ch, such as using organic or inorganic nanofillers, crosslinkers, or blends with other polymers. This review intends to analyze the most recent works that combine the action of different nanoparticle types with Ch films to reinforce their mechanical and barrier properties.
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- 2021
- Full Text
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8. A Comparison of Different Approaches to Quantify Nitric Oxide Release from NO-Releasing Materials in Relevant Biological Media
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Rosana V. Pinto, Fernando Antunes, João Pires, Ana Silva-Herdade, and Moisés L. Pinto
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nitric oxide ,quantification ,biological media ,porous materials ,oxyhaemoglobin assay ,Griess assay ,Organic chemistry ,QD241-441 - Abstract
The development of solid materials that deliver nitric oxide (NO) are of interest for several therapeutic applications. Nevertheless, due to NO’s reactive nature, rapid diffusion and short half-life, reporting their NO delivery characteristics is rather complex. The full knowledge of this parameter is fundamental to discuss the therapeutic utility of these materials, and thus, the NO quantification strategy must be carefully considered according to the NO-releasing scaffold type, to the expected NO-releasing amounts and to the medium of quantification. In this work, we explore and discuss three different ways of quantifying the release of NO in different biological fluids: haemoglobin assay, Griess assay and NO electrochemical detection. For these measurements, different porous materials, namely zeolites and titanosilicates were used as models for NO-releasing platforms. The oxyhaemoglobin assay offers great sensitivity (nanomolar levels), but it is only possible to monitor the NO release while oxyhaemoglobin is not fully converted. On the other hand, Griess assay has low sensitivity in complex biological media, namely in blood, and interferences with media make NO measurements questionable. Nevertheless, this method can measure micromolar amounts of NO and may be useful for an initial screening for long-term release performance. The electrochemical sensor enabled real-time measurements in a variety of biological settings. However, measured NO is critically low in oxygenated and complex media, giving transient signals, which makes long-term quantification impossible. Despite the disadvantages of each method, the combination of all the results provided a more comprehensive NO release profile for these materials, which will help to determine which formulations are most promising for specific therapeutic applications. This study highlights the importance of using appropriate NO quantification tools to provide accurate reports.
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- 2020
- Full Text
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9. Waste-Glycerol as a Precursor for Carbon Materials: An Overview
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Mary Batista, Silvia Carvalho, Renato Carvalho, Moisés L. Pinto, and João Pires
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Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Abstract
Biodiesel is produced by the transesterification of animal fats and vegetable oils, producing a large amount of glycerol as a by-product. The crude glycerol cannot be used in the food or pharmaceutical industries. It is crucial to transform glycerol into value-added products with applications in different areas to biodiesel be economically viable. One of the possible applications is its use as a precursor for the synthesis of carbon materials. The glycerol-based carbon materials have distinct properties due to the presence of sulfonic acid groups on the material surface, making them efficient catalysts. Additionally, the glycerol-based activated carbon materials show promising results concerning the adsorption of gases and liquid pollutants and recently as capacitors. Despite their potential, currently, little research has been carried out on the synthesis and application of those materials. This review summarized the preparation and application of carbon materials from glycerol, intending to show the potential of these materials.
- Published
- 2022
10. Supplementation of an Anthocyanin-Rich Elderberry (Sambucus nigra L.) Extract in FVB/n Mice: A Healthier Alternative to Synthetic Colorants
- Author
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Tiago Azevedo, Tiago Ferreira, João Ferreira, Filipa Teixeira, Diana Ferreira, Rita Silva-Reis, Maria João Neuparth, Maria João Pires, Maria de Lurdes Pinto, Rui M. Gil da Costa, Margarida M. S. M. Bastos, Rui Medeiros, Luís Félix, Carlos Venâncio, Maria Inês Dias, Isabel Gaivão, Lillian Barros, and Paula A. Oliveira
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Fluid Flow and Transfer Processes ,Process Chemistry and Technology ,General Engineering ,General Materials Science ,Sambucus nigra ,in vivo ,oral administration ,colorant ,Instrumentation ,Computer Science Applications - Abstract
Sambucus nigra L., popularly known as elderberry, is renowned for its amazing therapeutic properties, as well as its uses as a food source, in nutraceuticals, and in traditional medicine. This study’s aim was to investigate the effects of an elderberry extract (EE) on mice for 29 days, as well as the safety of the extract when used as a natural colorant. Twenty-four FVB/n female mice (n = 6) were randomly assigned to one of four groups: control, 12 mg/mL EE (EE12), 24 mg/mL EE (EE24), or 48 mg/mL EE (EE48). The predominant anthocyanins detected were cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside. Food and drink intake were similar between groups, with the exception of EE48, who drank significantly less compared with the Control. Biochemical analysis of the liver showed that the changes observed in histological analysis had no pathological significance. The EE, at doses of 24 and 48 mg/mL, significantly reduced the oxidative DNA damage compared with the non-supplemented group. The S. nigra extract showed a favorable toxicological profile, affording it potential to be used in the food industry.
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- 2022
11. Eco-Friendly ZnO/Chitosan Bionanocomposites Films for Packaging of Fresh Poultry Meat
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Carolina Rodrigues, Marta M. Alves, Victor Gomes Lauriano Souza, Isabel M. Coelhoso, Catarina Pimenta, Catarina Santos, Sara Valente, João Pires, Ana Luisa Fernando, MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos, DCTB - Departamento de Ciências e Tecnologia da Biomassa (ex-GDEH), DQ - Departamento de Química, and LAQV@REQUIMTE
- Subjects
Materials science ,Active packaging ,antioxidant activity ,zinc oxide nanoparticles ,Antimicrobial activity ,Shelf life ,shelf-life extension ,Chitosan ,chemistry.chemical_compound ,Antioxidant activity ,active packaging ,Generally recognized as safe ,Materials Chemistry ,Food science ,Food Preservatives ,antimicrobial activity ,biodegradable material ,Surfaces and Interfaces ,Environmentally friendly ,Surfaces, Coatings and Films ,Food packaging ,Food waste ,chemistry ,lcsh:TA1-2040 ,Shelf-life extension ,Zinc oxide nanoparticles ,Biodegradable material ,lcsh:Engineering (General). Civil engineering (General) - Abstract
UID/EMS/04077/2019 UID/QUI/50006/2019 UID/QUI/00100/2019 Contrato No: IST-ID/154/2018) under Decree-Law No. 57/2016 and 57/2017. The advances on the development of novel materials capable to enhance the shelf life of food products may contribute to reduce the current worldwide food waste problem. Zinc oxide nanoparticles (ZnO NPs) are considered GRAS (Generally Recognized as Safe) by the Food and Drug Administration (FDA) and due to their good antimicrobial properties are suitable to be applied as active compounds in food packaging. ZnO NPs were synthesized to be tested in active bionanocomposites through an eco-friendlier route using apple peel wastes. This work aimed to develop bionanocomposites based on chitosan and incorporated with ZnO NPs to characterize its bioactivity via in vitro and in situ studies, using fresh poultry meat as the food matrix. Overall, bio-based biodegradable films presented good antimicrobial activity, being the intrinsic antimicrobial properties of chitosan enhanced by the ZnO NPs added on the system. When used as primary packaging of the meat, the samples protected with the films presented a decrease on the deterioration speed, which was represented by the preservation of the initial reddish color of the meat and reduction on the oxidation process and microbiological growth. The nanoparticles enhanced especially the antioxidant properties of the films and proved to be potential food preservatives agents to be used in active food packaging. publishersversion published
- Published
- 2020
12. Effect of a Sub-Chronic Oral Exposure of Broccoli (Brassica oleracea L. Var. Italica) By-Products Flour on the Physiological Parameters of FVB/N Mice: A Pilot Study
- Author
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Tânia Martins, Paula Alexandra Oliveira, Maria João Pires, Maria João Neuparth, Germano Lanzarin, Luís Félix, Carlos Venâncio, Maria de Lurdes Pinto, João Ferreira, Isabel Gaivão, Ana Isabel Barros, Eduardo Rosa, and Luís Miguel Antunes
- Subjects
isothiocyanates ,broccoli flour ,by-products ,diet ,FVB/N mice ,glucosinolates ,Health (social science) ,Chemical technology ,TP1-1185 ,Plant Science ,Health Professions (miscellaneous) ,Microbiology ,Article ,Food Science - Abstract
Brassica by-products are a source of natural bioactive molecules such as glucosinolates and isothiocyanates, with potential applications in the nutraceutical and functional food industries. However, the effects of oral sub-chronic exposure to broccoli by-product flour (BF) have not yet been evaluated. The objective of this pilot study was to analyse the effects of BF intake in the physiological parameters of FVB/N mice fed a 6.7% BF-supplemented diet for 21 days. Glucosinolates and their derivatives were also quantified in plasma and urine. BF supplementation significantly decreased (p < 0.05) the accumulation of perirenal adipose tissue. Furthermore, mice supplemented with BF showed significantly lower (p < 0.01) microhematocrit values than control animals, but no impact on the general genotoxicological status nor relevant toxic effects on the liver and kidney were observed. Concerning hepatic and renal antioxidant response, BF supplementation induced a significant increase (p < 0.05) in the liver glutathione S-transferase (GST) levels. In BF-supplemented mice, plasma analysis revealed the presence of the glucosinolates glucobrassicin and glucoerucin, and the isothiocyanates sulforaphane and indole-3-carbinol. Overall, these results show that daily intake of a high dose of BF during three weeks is safe, and enables the bioavailability of beneficial glucosinolates and isothiocyanates. These results allow further testing of the benefits of this BF in animal models of disease, knowing that exposure of up to 6.7% BF does not present relevant toxicity.
- Published
- 2022
13. Anatomy and Imaging of Rat Prostate: Practical Monitoring in Experimental Cancer-Induced Protocols
- Author
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Paula A. Oliveira, Miguel Correia-Cardoso, José M. Gonzalo-Orden, Ana I. Faustino-Rocha, Rita Ferreira, Margarida Fardilha, Maria João Pires, Fernanda Seixas, and Mário Ginja
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magnetic resonance imaging (MRI) ,Magnetic Resonance Imaging (MRI) ,Clinical Biochemistry ,030232 urology & nephrology ,Computed tomography ,Review ,computed tomography (CT) ,Macroscopy ,Imaging modalities ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,macroscopy ,medicine ,Ultrasonography ,Microscopy ,lcsh:R5-920 ,medicine.diagnostic_test ,business.industry ,Computed Tomography (CT) ,Cancer ,Magnetic resonance imaging ,Anatomy ,ultrasonography ,medicine.disease ,Rat Prostate ,Microscopic Anatomy ,030220 oncology & carcinogenesis ,microscopy ,business ,lcsh:Medicine (General) - Abstract
The rat has been frequently used as a model to study several human diseases, including cancer. In many research protocols using cancer models, researchers find it difficult to perform several of the most commonly used techniques and to compare their results. Although the protocols for the study of carcinogenesis are based on the macroscopic and microscopic anatomy of organs, few studies focus on the use of imaging. The use of imaging modalities to monitor the development of cancer avoids the need for intermediate sacrifice to assess the status of induced lesions, thus reducing the number of animals used in experiments. Our work intends to provide a complete and systematic overview of rat prostate anatomy and imaging, facilitating the monitoring of prostate cancer development through different imaging modalities, such as ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI).
- Published
- 2019
14. A Comparison of Different Approaches to Quantify Nitric Oxide Release from NO-Releasing Materials in Relevant Biological Media
- Author
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Ana S. Silva-Herdade, Moisés L. Pinto, Fernando Antunes, Rosana V. Pinto, and João Pires
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electrochemical sensor ,Pharmaceutical Science ,macromolecular substances ,Electrochemical detection ,Solid material ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,lcsh:Organic chemistry ,nitric oxide ,Drug Discovery ,Biological fluids ,Biological media ,Physical and Theoretical Chemistry ,oxyhaemoglobin assay ,Transient signal ,No release ,Titanium ,Griess assay ,Molecular Structure ,Chemistry ,Silicates ,Organic Chemistry ,quantification ,Chemistry (miscellaneous) ,Oxyhemoglobins ,biological media ,Zeolites ,Molecular Medicine ,Biochemical engineering ,Porosity ,porous materials - Abstract
The development of solid materials that deliver nitric oxide (NO) are of interest for several therapeutic applications. Nevertheless, due to NO&rsquo, s reactive nature, rapid diffusion and short half-life, reporting their NO delivery characteristics is rather complex. The full knowledge of this parameter is fundamental to discuss the therapeutic utility of these materials, and thus, the NO quantification strategy must be carefully considered according to the NO-releasing scaffold type, to the expected NO-releasing amounts and to the medium of quantification. In this work, we explore and discuss three different ways of quantifying the release of NO in different biological fluids: haemoglobin assay, Griess assay and NO electrochemical detection. For these measurements, different porous materials, namely zeolites and titanosilicates were used as models for NO-releasing platforms. The oxyhaemoglobin assay offers great sensitivity (nanomolar levels), but it is only possible to monitor the NO release while oxyhaemoglobin is not fully converted. On the other hand, Griess assay has low sensitivity in complex biological media, namely in blood, and interferences with media make NO measurements questionable. Nevertheless, this method can measure micromolar amounts of NO and may be useful for an initial screening for long-term release performance. The electrochemical sensor enabled real-time measurements in a variety of biological settings. However, measured NO is critically low in oxygenated and complex media, giving transient signals, which makes long-term quantification impossible. Despite the disadvantages of each method, the combination of all the results provided a more comprehensive NO release profile for these materials, which will help to determine which formulations are most promising for specific therapeutic applications. This study highlights the importance of using appropriate NO quantification tools to provide accurate reports.
- Published
- 2020
15. Dietary Supplementation with the Red Seaweed Porphyra umbilicalis Protects against DNA Damage and Pre-Malignant Dysplastic Skin Lesions in HPV-Transgenic Mice
- Author
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Margarida Bastos, José M. M. M. de Almeida, Mário Pacheco, Susana Santos, Maria João Pires, Rui Costa, Tiago Ferreira, Sílvia Lemos, Rui Pereira, Aura Colaço, Rui Medeiros, Eduardo Rosa, Maria João Neuparth, Isabel Gaivão, Paula A. Oliveira, and Helena Abreu
- Subjects
Genetically modified mouse ,DNA damage ,genotoxicity assay ,Pharmaceutical Science ,Physiology ,Biology ,medicine.disease_cause ,papillomavirus ,Lesion ,03 medical and health sciences ,0302 clinical medicine ,food ,Functional food ,Drug Discovery ,medicine ,cancer ,K14HPV16 ,lcsh:QH301-705.5 ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) ,030304 developmental biology ,0303 health sciences ,Cancer ,medicine.disease ,food.food ,Porphyra umbilicalis ,lcsh:Biology (General) ,030220 oncology & carcinogenesis ,medicine.symptom ,Micronucleus ,Genotoxicity - Abstract
Some diet profiles are associated with the risk of developing cancer, however, some nutrients show protective effects. Porphyra umbilicalis is widely consumed, having a balanced nutritional profile, however, its potential for cancer chemoprevention still needs comprehensive studies. In this study, we incorporated P. umbilicalis into the diet of mice transgenic for the human papillomavirus type 16 (HPV16), which spontaneously develop pre-malignant and malignant lesions, and determined whether this seaweed was able to block lesion development. Forty-four 20-week-old HPV+/&minus, and HPV&minus, /&minus, mice were fed either a base diet or a diet supplemented with 10% seaweed. At the end of the study, skin samples were examined to classify HPV16-induced lesions. The liver was also screened for potential toxic effects of the seaweed. Blood was used to study toxicological parameters and to perform comet and micronucleus genotoxicity tests. P. umbilicalis significantly reduced the incidence of pre-malignant dysplastic lesions, completely abrogating them in the chest skin. These results suggest that P. umbilicalis dietary supplementation has the potential to block the development of pre-malignant skin lesions and indicate its antigenotoxic activity against HPV-induced DNA damage. Further studies are needed to establish the seaweed as a functional food and clarify the mechanisms whereby this seaweed blocks multistep carcinogenesis induced by HPV.
- Published
- 2019
16. Physical and Morphological Characterization of Chitosan/Montmorillonite Films Incorporated with Ginger Essential Oil
- Author
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João Pires, Maria Paula Amaro de Castilho Duarte, Jorge Caldeira, Francisco Manuel Braz Fernandes, Ana Luisa Fernando, Andreia A. S. Lopes, Carolina Rodrigues, Rui Jorge Cordeiro Silva, Patrícia Freitas Rodrigues, Victor Gomes Lauriano Souza, and Isabel M. Coelhoso
- Subjects
chemistry.chemical_classification ,Materials science ,nanotechnology ,Nanoparticle ,chemistry.chemical_element ,Surfaces and Interfaces ,Polymer ,Exfoliation joint ,Oxygen ,biobased polymers ,Surfaces, Coatings and Films ,Chitosan ,chemistry.chemical_compound ,Montmorillonite ,chemistry ,lcsh:TA1-2040 ,Permeability (electromagnetism) ,Materials Chemistry ,chitosan ,lcsh:Engineering (General). Civil engineering (General) ,Glass transition ,Nuclear chemistry - Abstract
Novel bionanocomposite films of chitosan/montmorillonite (CS/MMT) activated with ginger essential oil (GEO) were produced and characterized in terms of their physical and morphological properties. The homogenization process led to a good interaction between the chitosan and the nanoparticles, however the exfoliation was diminished when GEO was incorporated. Film glass transition temperature did not statistically change with the incorporation of either MMT or GEO, however the value was slightly reduced, representing a relaxation in the polymer chain which corroborated with the mechanical and barrier properties results. Pristine chitosan films showed excellent barrier properties to oxygen with a permeability of 0.184 ×, 10&minus, 16 mol/m·, s·, Pa being reduced to half (0.098 ×, Pa) when MMT was incorporated. Although the incorporation of GEO increased the permeability values to 0.325 ×, Pa when 2% of GEO was integrated, this increment was smaller with both MMT and GEO (0.285 ×, Pa). Bionanocomposites also increased the UV light barrier. Thus, the produced bioplastics demonstrated their ability to retard oxidative processes due to their good barrier properties, corroborating previous results that have shown their potential in the preservation of foods with high unsaturated fat content.
- Published
- 2019
17. Absorption and Excretion of Glucosinolates and Isothiocyanates after Ingestion of Broccoli (Brassica oleracea L. var italica) Leaf Flour in Mice: A Preliminary Study
- Author
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Tânia Martins, Tiago Ferreira, Bruno Colaço, Beatriz Medeiros-Fonseca, Maria de Lurdes Pinto, Ana Novo Barros, Carlos Venâncio, Eduardo Rosa, Luís Miguel Antunes, Paula Alexandra Oliveira, and Maria João Pires
- Subjects
broccoli by-products ,bioavailability ,health ,C57BL/6J mice ,Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
During the harvesting of the broccoli plant, the leaves are discarded, being considered a by-product that may be up to 47% of total broccoli biomass, representing a large amount of wasted material. The use of broccoli leaves is of great interest in the sense that this wasted material is rich in health promoter compounds, such as isothiocyanates. In this study, C57BL/6J mice ingested 790 mg/kg broccoli leaf flour, and the presence of glucosinolates and isothiocyanates in the plasma, liver, kidney, adipose tissue, faeces and urine was analysed at 1, 2, 4, 8, 12 and 24 h post-ingestion. In plasma, only glucoerucin (GE), glucobrassicin (GB), sulforaphane (SFN) and indol-3-carbinol (I3C) were detected, and all four compounds peaked between 4 and 8 h after ingestion. The compounds SFN, SFN-glutathione (SFN-GSH), SFN–cysteine (SFN-CYS) and SFN-N-acetyl-cysteine (SFN-NAC) were excreted in faeces at high levels, while glucoraphanin (GR), the precursor of SFN, was not detected in any biological samples other than urine. In the liver, the compounds GE, SFN-CYS, SFN-NAC and I3C were detected, while in the kidney, only GE, GB and SFN-GSH were present. None of the glucosinolates and isothiocyanates analysed were detected in fat tissue. These results demonstrate that glucosinolates and their derivatives were absorbed into the bloodstream and were bioavailable after ingestion of powdered broccoli leaves.
- Published
- 2023
- Full Text
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18. Effects of Sulforaphane and Chlorophyl a in a Western Diet-Induced Obesity Model
- Author
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Tânia Martins, Ana Filipa Matos, Joana Soares, Rúben Leite, Maria João Pires, Maria de Lurdes Pinto, Maria João Neuparth, Sandra Mariza Monteiro, Ana Rita Sequeira, Luís Félix, Carlos Venâncio, Eduardo Rosa, Paula Alexandra Oliveira, and Luís Miguel Antunes
- Subjects
Chlorophyl a ,C57BL/6J mice ,diet-induced obesity ,sulforaphane ,Food processing and manufacture ,TP368-456 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
The global rise in obesity and its co-morbidities raises worldwide health, social and economic concerns, especially in developed countries. Compounds derived from natural sources are now in the focus of pharmacological therapies. In recent years, sulforaphane (SFN) has been the subject of studies due to its anti-cancer, anti-inflammatory, antioxidant and potential anti-obesity effects. Lately, some studies have also reported the anti-obesogenic potential of chlorophyll. In this study, we evaluated the anti-obesity effects of SFN and chlorophyll a (Chlo.a) in C57BL/6J mice fed with a Western diet, rich in sugar and fat. The study lasted 14 weeks, and for the last 4 weeks SFN (0.25 or 0.5 mg/kg/day) or Chlo.a (0.2 or 0.5 mg/kg/day) was administered orally. The results showed that supplementation with SFN or Chlo.a resulted in an increase in body temperature and a reduction in the size of adipocytes. However, the administration of SFN or Chlo.a for 4 weeks did not decrease the body weight gain or hepatic steatosis, and increased hepatic ROS counterbalancing with an increase in SOD activity. In conclusion, in the animal model used, treatment with SFN or Chlo.a did not show strong anti-obesity effects; however, slight improvements were observed with the supplementation of these compounds.
- Published
- 2023
- Full Text
- View/download PDF
19. The Effect of Lemon Juice (Citrus limon L.) Treated with Melatonin on the Health Status and Treatment of K14HPV16 Mice
- Author
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Fátima Badiche-El Hilali, Beatriz Medeiros-Fonseca, Jéssica Silva, Ana C. Silvestre-Ferreira, Maria João Pires, Rui M. Gil da Costa, Francisco Peixoto, Paula A. Oliveira, and Daniel Valero
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lemon ,melatonin ,valorization ,antioxidant ,HPV16 ,human papillomavirus ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Lemon is a fruit rich in antioxidant properties and has several health benefits, namely the reduction of skin edema and anticarcinogenic properties, which are due to its high content of bioactive compounds. Melatonin can improve and preserve the properties of lemon for longer and also has health benefits. The aim of this study was to evaluate the effects of oral administration of lemon juice after melatonin treatment on murinometric parameters of wild-type (WT) mice and transgenic mice carrying human papillomavirus (HPV). Two trials were performed for oral administration of the lemon extract compound: in drinking water and in diet. First of all, lemons were treated by immersion with melatonin at 10 mM. Then, lemons were squeezed, and the juice obtained was freeze-dried and stored to be subsequently added to drinking water or diet, according to the assay. Thus, mice were divided into eight groups in the drink assay (each with n = 5): group 1 (G1, WT, control), group 2 (G2, WT, 1 mL lemon), group 3 (G3, WT, 1.5 mL lemon), group 4 (G4, WT, 2 mL lemon), group 5 (G5, HPV16, control), group 6 (G6, HPV16, 1 mL lemon) group 7 (G6, HPV16, 1.5 mL lemon) and group 8 (G6, HPV16, 2 mL lemon). The diet assay was divided into four groups: group 1 (G1, WT, control), group 2 (G2, WT, 4 mL lemon), group 3 (G3, HPV16, control) and group 4 (G4, HPV16, 4 mL lemon). In the drink assay, the highest concentration of melatonin (308 ng/100 mL) was for groups 4 and 8, while in the food assay, there was only one concentration of melatonin (9.96 ng/g) for groups 2 and 4. Both trials lasted 30 days. During this time, body weight, food and water were recorded. Afterward, they were sacrificed, and samples were collected for different analyses. At the concentrations used, the lemon juice with melatonin had no adverse effects on the animals’ health and showed a positive outcome in modifying weight gain and enhancing antioxidant activity in mice. Moreover, a reduction in the incidence of histological lesions was observed in treated animals. Further research is needed to better understand the effects of lemon extract on health and treatment outcomes in this animal model.
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- 2024
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20. Effect of Santolina chamaecyparissus on Physiological Parameters: Data from an Animal Model of Mammary Cancer
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Tiago Azevedo, Jessica Silva, Abigaël Valada, Lara Anjos, Ana Cristina Silvestre-Ferreira, Tiane Cristine Finimundy, Lillian Barros, Manuela Matos, Maria João Neuparth, Maria João Pires, and Paula A. Oliveira
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mammary cancer ,natural compounds ,Santolina chamaecyparissus ,Wistar rats ,Medicine - Abstract
Breast cancer is the most common cancer worldwide. Santolina chamaecyparissus L. has successfully inhibited the MCF-7 cancer cell line. This study aims to evaluate the chemopreventive effects of S. chamaecyparissus aqueous extract (SCE) on female rats’ physiological parameters with mammary cancer induced by N-methyl-N-nitrosourea (MNU). The institutional ethics committee approved this study. Twenty-eight four-week-old female Wistar rats were divided into Control, MNU-induced (IND), SCE and SCE+IND. SCE was supplemented with drinking water (120 µg/mL). At 50 days of age, MNU was intraperitoneally administered. Humane endpoints were evaluated weekly. After twenty-one weeks, animals were sacrificed by ketamine/xylazine overdose and blood was collected. A complete blood count was performed using an automated haematology analyser. An autoanalyzer was used to measure serum markers (albumin, cholesterol, glucose and triglycerides). SCE’s chemical characterisation was performed by LC-MS, as it found nineteen phenolic compounds, the main molecules were myricetin-O-glucuronide and 1,3-O-dicaffeoylquinic acid. Regarding haemoglobin concentration, there was a difference (p = 0.050) between SCE and Control (16.38 ± 0.41 g/dL and 15.18 ± 0.29 g/dL, respectively). Mean Platelet Volume differed between SCE+IND (8.29 ± 0.15 fL) and IND (9.03 ± 0.26 fL) (p = 0.014). Platelet Distribution Width differed between 9.06 ± 0.14 fL (SCE + IND) and 10.58 ± 0.42 fL (IND) (p < 0.001), but also between SCE (8.78 ± 0.16 fL) and SCE + IND versus control (9.86 ± 0.17 fL) (p = 0.007 and p = 0.034, respectively). SCE had no effect on the humane endpoints or serum markers. Platelet size appears to have been significantly affected by SCE. SCE supplementation had no effect on liver or kidney function or the well-being of the animals, implying it could be a viable treatment option for breast cancer. Histological analysis will help confirm SCE’s toxicological profile.
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- 2022
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21. An Integrative Approach to Characterize the Early Phases of Dimethylhydrazine-Induced Colorectal Carcinogenesis in the Rat
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Rita Silva-Reis, Catarina Castro-Ribeiro, Mariana Gonçalves, Tiago Ferreira, Maria João Pires, Carlos E. Iglesias-Aguirre, Adrián Cortés-Martín, María V. Selma, Juan Carlos Espín, Elisabete Nascimento-Gonçalves, Alexandra Moreira-Pais, Maria J. Neuparth, Francisco Peixoto, Eduardo Rosa, Adelina Gama, Rita Ferreira, Paula A. Oliveira, and Ana I. Faustino-Rocha
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gut microbiota ,inflammation ,oxidative stress ,Biology (General) ,QH301-705.5 - Abstract
This study aimed to characterize an animal model of colorectal cancer (CRC) in the early stages of disease development. Twenty-nine male Wistar rats were divided into two control groups (CTRL1 and CTRL2), receiving EDTA–saline injections and two induced groups (CRC1 and CRC2), receiving 1,2-dimethylhydrazine (DMH) injections for seven consecutive weeks. CRC1 and CTRL1 were euthanized at the 11th week, while CRC2 and CTRL2 were euthanized at the 17th week. DMH treatment decreased microhematocrit values and IL-6, ghrelin, and myostatin serum levels. Histopathological analysis of intestinal sections showed that DMH-treated rats were characterized by moderate to severe epithelial dysplasia. An adenoma was observed in one animal (CRC2 group), and the presence of inflammatory infiltrate at the intestinal level was primarily observed in DMH-treated animals. DMH also induced Ki-67 immunoexpression. The gut microbiota analysis showed a higher abundance of Firmicutes, Clostridia, Clostridiales, Peptostreptococcaceae, Blautia, Romboutsia, and Clostridium sensu stricto in CRC than CTRL rats, whereas Prevotellaceae, Prevotella, Akkermansia, and Lactobacillus levels were more prevalent in CTRL animals. Our results suggest that this model could be helpful to investigate chemoprevention in the early stages of CRC.
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- 2022
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22. Dietary Supplementation with Chestnut (Castanea sativa) Reduces Abdominal Adiposity in FVB/n Mice: A Preliminary Study
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Pedro Rodrigues, Tiago Ferreira, Elisabete Nascimento-Gonçalves, Fernanda Seixas, Rui Miguel Gil da Costa, Tânia Martins, Maria João Neuparth, Maria João Pires, Germano Lanzarin, Luís Félix, Carlos Venâncio, Isabel C.F.R. Ferreira, Margarida M.S.M. Bastos, Rui Medeiros, Isabel Gaivão, Eduardo Rosa, and Paula A. Oliveira
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in vivo ,cholesterol ,adipose tissue ,oxidative stress ,Biology (General) ,QH301-705.5 - Abstract
The production of chestnut (Castanea sativa Miller) is mostly concentrated in Europe. Chestnut is recognized by its high content of antioxidants and phytosterols. This work aimed to evaluate the effects of dietary chestnut consumption over physiological variables of FVB/n mice. Eighteen FVB/n male 7-month-old mice were randomly divided into three experimental groups (n = 6): 1 (control group) fed a standard diet; 2 fed a diet supplemented with 0.55% (w/w) chestnut; and 3 supplemented with 1.1% (w/w) chestnut. Body weight, water, and food intake were recorded weekly. Following 35 days of supplementation, the mice were sacrificed for the collection of biological samples. Chestnut supplementation at 1.1% reduced abdominal adipose tissue. Lower serum cholesterol was also observed in animals supplemented with chestnut. There were no significant differences concerning the incidence of histological lesions nor in biochemical markers of hepatic damage and oxidative stress. These results suggest that chestnut supplementation may contribute to regulate adipose tissue deposition.
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- 2020
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23. The Cyclooxigenase-2 Inhibitor Parecoxib Prevents Epidermal Dysplasia in HPV16-Transgenic Mice: Efficacy and Safety Observations
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Tiago Ferreira, Sandra Campos, Mónica G. Silva, Rita Ribeiro, Susana Santos, José Almeida, Maria João Pires, Rui Miguel Gil da Costa, Cláudia Córdova, António Nogueira, Maria João Neuparth, Rui Medeiros, Margarida Maria da Silva Monteiro Bastos, Isabel Gaivão, Francisco Peixoto, Maria Manuel Oliveira, and Paula Alexandra Oliveira
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COX-2 ,NSAID ,in vivo ,K14HPV16 ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Carcinogenesis induced by high-risk human papillomavirus (HPV) involves inflammatory phenomena, partially mediated by cyclooxigenase-2. In pre-clinical models of HPV-induced cancer, cyclooxygenase-2 inhibitors have shown significant efficacy, but also considerable toxicity. This study addresses the chemopreventive effect and hepatic toxicity of a specific cyclooxigensase-2 inhibitor, parecoxib, in HPV16-transgenic mice. Forty-three 20 weeks-old female mice were divided into four groups: I (HPV16−/−, n = 10, parecoxib-treated); II (HPV16−/− n = 11, untreated); III (HPV16+/−, n = 11, parecoxib-treated) and IV (HPV16+/−, n = 11, untreated). Parecoxib (5.0 mg/kg once daily) or vehicle was administered intraperitoneally for 22 consecutive days. Skin lesions were classified histologically. Toxicological endpoints included genotoxic parameters, hepatic oxidative stress, transaminases and histology. Parecoxib completely prevented the onset of epidermal dysplasia in HPV16+/− treated animals (0% versus 64% in HPV16+/− untreated, p = 0.027). Parecoxib decreases lipid peroxidation (LPO) and superoxide dismutase (SOD) activity and increases the GSH:GSSG ratio in HPV16+/− treated animals meaning that oxidative stress is lower. Parecoxib increased genotoxic stress parameters in wild-type and HPV16-transgenic mice, but didn’t modify histological or biochemical hepatic parameters. These results indicate that parecoxib has chemopreventive effects against HPV16-induced lesions while maintaining an acceptable toxicological profile in this model.
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- 2019
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