Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
360
result(s) for
"Costa, Cátia"
Sort by:
Catalyst Accessibility and Acidity in the Hydrocracking of HDPE: A Comparative Study of H-USY, H-ZSM-5, and MCM-41 Modified with Ga and Al
2024
Plastic pollution is a critical environmental issue due to the widespread use of plastic materials and their long degradation time. Hydrocracking (HDC) offers a promising solution to manage plastic waste by converting it into valuable products, namely chemicals or fuels. This work aims to investigates the effect of catalyst accessibility and acidity on the HDC reaction of high density polyethylene (HDPE). Therefore, a variety of materials with significant differences in both textural and acidic properties were tested as catalysts. These include H-USY and H-ZSM.5 zeolites with various Si/Al molar ratios (H-USY: Si/Al = 2.9, 15, 30 and 40; H-ZSM-5: Si/Al = 11.5, 40, 500) and mesostructured MCM-41 materials modified with Ga and Al, also with different Si/metal ratios (Si/Al = 16 and 30; Si/Ga = 63 and 82). Thermogravimetric analysis under hydrogen atmosphere was used as a preliminary screening tool to evaluate the potential of the various catalysts for this application in terms of energy requirements. In addition, batch autoclave reactor experiments (T = 300 °C, PH2 = 20 bar, t = 60 min) were conducted to obtain further information on conversion, product yields and product distribution for the most promising systems. The results show that the catalytic performance in HDPE hydrocracking is determined by a balance between the acidity of the catalyst and its structural accessibility. Accordingly, for catalyst series where the structural and textural properties do not vary with the Si/Al ratio, there is a clear correlation of the HDPE degradation temperature and of the HDPE conversion with the Si/metal ratio (which relates to the acidic properties). In contrast, for catalyst series where the structural and textural properties vary with the Si/Al ratio, no consistent trend is observed and the catalytic performance is determined by a balance between the acidic and textural properties. The product distribution was also found to be influenced by the physical and chemical properties of the catalyst. Catalysts with strong acidity and smaller pores were observed to favor the formation of lighter hydrocarbons. In addition to the textural and acidic properties of the catalyst, the role of coke formation should not be neglected to ensure a comprehensive analysis of the catalytic performance.
Journal Article
Modulatory effect of Gracilaria gracilis on European seabass gut microbiota community and its functionality
2022
Seaweeds are an important source of nutrients and bioactive compounds and have a high potential as health boosters in aquaculture. This study evaluated the effect of dietary inclusion of
Gracilaria gracilis
biomass or its extract on the European seabass (
Dicentrarchus labrax
) gut microbial community. Juvenile fish were fed a commercial-like diet with 2.5% or 5% seaweed biomass or 0.35% seaweed extract for 47 days. The gut microbiome was assessed by 16S rRNA amplicon sequencing, and its diversity was not altered by the seaweed supplementation. However, a reduction in Proteobacteria abundance was observed. Random forest analysis highlighted the genera
Photobacterium
,
Staphylococcus
,
Acinetobacter
,
Micrococcus
and
Sphingomonas,
and their abundances were reduced when fish were fed diets with algae. SparCC correlation network analysis suggested several mutualistic and other antagonistic relationships that could be related to the predicted altered functions. These pathways were mainly related to the metabolism and biosynthesis of protective compounds such as ectoine and were upregulated in fish fed diets supplemented with algae. This study shows the beneficial potential of
Gracilaria
as a functional ingredient through the modulation of the complex microbial network towards fish health improvement.
Journal Article
Analyzing HDPE Thermal and Catalytic Degradation in Hydrogen Atmosphere: A Model-Free Approach to the Activation Energy
by
Munoz, Marta
,
Ribeiro, M.
,
Silva, João
in
Activation analysis
,
Activation energy
,
Approximation
2024
Despite the great interest in thermochemical processes for converting plastic waste into chemical feedstocks or fuels, their kinetics are still a less studied topic, especially under reductive conditions. In the present work, non-isothermal thermogravimetric analysis is used to study the thermal and catalytic conversion of HDPE promoted by parent and metal-based H-USY (15) and H-ZSM-5 (11.5) zeolites under a reducing hydrogen atmosphere. Additionally, the respective kinetic parameters (apparent activation energy, Ea, and frequency factor, A) were determined by applying two distinct model-free methods: Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS). The results showed that Ea of the thermal degradation of HDPE has an average value of 227 kJ/mol for both methods. In the presence of H-USY (15) and H-ZSM-5 (11.5) zeolites, Ea is strongly reduced and is highly dependent on conversion. In the case of H-USY (15), Ea varies from 78 to 157 kJ/mol for the KAS method and from 83 to 172 kJ/mol for the FWO method. Slightly lower values are reported for H-ZSM-5, with Ea values in the range of 53–122 kJ/mol for KAS and 61–107 kJ/mol for FWO. The presence and type of the metal source (Ni, Pt, or Pd) also affect the kinetic parameters of the reaction. The mean Ea values follow the order: Ni > Pt ≈ Pd for H-USY (15) or H-ZSM-5 zeolites. Accordingly, both parent and metal-based H-USY (15) and H-ZSM-5 zeolites can significantly reduce energy consumption in HDPE hydrocracking, thus promoting a more sustainable conversion of plastic waste.
Journal Article
Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach
by
Costa, Cátia
,
Fernandes, Raquel
,
Fernandes, Rúben
in
Anti-inflammatory agents
,
B cells
,
Bioactive compounds
2023
Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.
Journal Article
Real-time PCR protocol for detection and quantification of three pathogenic members of the Vibrionaceae family
2022
Vibriosis, an often-fatal disease induced by pathogenic members of the Vibrionaceae family, causes severe economic losses in aquacultures. To mitigate/avoid vibriosis outbursts, it is vital to detect and quantify these pathogens as early as possible. However, standard microbiological methods are time-consuming and often underestimate cell counts, which calls for the development of valid alternatives. In this study, real-time polymerase chain reaction (qPCR) was employed to detect the pathogenic species Vibrio alginolyticus, Listonella anguillara, and Vibrio harveyi using a new primer pair targeting the groEL gene. In addition, the DNA extraction efficiency of three methods, two commercial kits and the boiling method, was compared. The most efficient method was the DNeasy Blood and Tissue kit, with a detection limit ranging between 154 and 600 CFU mL-1 in the case of V. alginolyticus and L. anguillara, and 48 CFU mL-1 for V. harveyi. Thus, this study presents the development and evaluation of a method for the early quantification of all three species in saline suspensions. However, the results obtained by spiking a microalgae sample with V. harveyi emphasize the importance of adjusting the DNA control’s standard curve to the relevant extraction matrices, as it affects the DNA extraction efficiency and may hamper an accurate quantification with qPCR.
Journal Article
Reuse of Treated Wastewater to Address Water Scarcity in Viticulture: A Comprehensive Review
by
Oliveira, Ana Alexandra
,
Carlos, Cristina
,
Costa, Cátia Sofia
in
Agricultural production
,
Agriculture
,
California
2025
Water scarcity has become an increasingly critical global issue, affecting various sectors, including industrial, domestic, and particularly agriculture. Agriculture, as the largest consumer of water due to its substantial water requirements for food production, faces significant challenges, which are expected to intensify with the growth of the global population. As a result, many countries have begun to explore innovative solutions to address this pressing problem, one of which is the reuse of wastewater for irrigation purposes. This approach has gained particular attention in viticulture, where water consumption is high, and the need for sustainable practices is paramount. This paper delves into the issue of water scarcity, focusing specifically on the winemaking sector. It reviews several studies investigating the potential of wastewater reuse for irrigating vineyards, highlighting both the promising benefits and the challenges associated with this practice. The findings suggest that using treated wastewater for irrigation in viticulture offers a viable solution to mitigate water shortages, particularly in regions facing severe droughts or limited freshwater resources. However, the successful implementation of this approach requires careful monitoring and management of several factors, including soil quality, plant health, fruit development, and the final wine product. Ensuring the safety and quality of the wine, as well as safeguarding consumer health, necessitates rigorous oversight to prevent any negative impacts from the use of reclaimed water.
Journal Article
The impact of a designed lactic acid-based crosslinker in the thermochemical properties of unsaturated polyester resins/nanoprecipitated calcium carbonate composites
by
Serra, Arménio C.
,
Costa, Cátia S. M. F.
,
Marques, Teresa M. P.
in
Acquisitions & mergers
,
Calcium carbonate
,
Characterization and Evaluation of Materials
2017
Unsaturated polyester composites (UPCs) were prepared from biobased unsaturated polyester resins (UPRs) and nanoprecipitated calcium carbonate (NPCC). The UPRs were obtained from the crosslinking reaction of an unsaturated polyester (UP) made from renewable monomers and styrene (St) or a mixture of St with a designed lactic acid-based crosslinker (BPPC). The UPCs were obtained by adding the NPCC to the formulations. Aspects of the composition of the UPs and of the BPPC were confirmed by FTIR and
1
H NMR spectroscopies. Different UPCs were prepared and the influences of the addition of NPCC and of the amount of BPPC on their thermomechanical properties were evaluated. The BPPC has a major influence on the properties of the UPCs, namely a significant improvement of mechanical properties and of the thermal stability of UPCs. Both results suggest that the BPPC may be acting as a compatibilizer between the polymer matrix and the filler.
Journal Article
The Interplay between Atmospheric Conditions and Grape Berry Quality Parameters in Portugal
by
Santos, João A.
,
Costa, Cátia
,
Fontes, Natacha
in
Alcohol
,
anthocyanins
,
Atmospheric temperature
2020
The atmospheric conditions are a strong modulator of grape berry composition, but further research is required to better understand this relationship, which is particularly pertinent under the context of climate change. The present study assesses the relationship between interannual variability in atmospheric conditions (mean, maximum and minimum air temperatures and precipitation totals) on grape berry quality attributes in three main Portuguese wine regions—Douro, Dão and Alentejo—and targets two major varieties growing in Portugal (cv. Touriga Nacional and cv. Aragonez/Tempranillo). Berry weight, titratable acidity (TA), pH, potential alcohol (PA), anthocyanins and total phenols index (TPI) data, collected two to three weeks after the end of the veraison until technological maturity, since 1999 in Douro, 2004 in Alentejo and 2008 in Dão, were selected. Meteorological data were obtained from both automatic weather stations and a climatic database defined at a very-high-resolution grid (<1 km) (PTHRES). The influence of daily mean, maximum and minimum air temperatures (November–October) and precipitation totals (April to June and July to September) on the above-mentioned berry quality parameters were first explored to identify the months/periods more influential to grape berry composition. Different statistical approaches were subsequently carried out to explore in greater detail these relationships. At technological maturity, temperature was negatively correlated to berry weight, titratable acidity, anthocyanins and TPI, but was positively correlated to pH and potential alcohol. Moreover, lowest levels of berry weight and TA (and highest levels of pH) were more frequent in warmer regions, while the opposite was seen in the cooler regions. PA, TPI and anthocyanins at maturity did not show a clear trend across regions. In addition, the maturation parameters of each site were grouped into two clusters—years where the maturation parameter is higher (cluster 1) and years where it is lower (cluster 2)—and significant differences in monthly mean temperatures between clusters were found. Overall, temperatures at veraison and maturation periods (June–August) were more influential in determining grape berry composition at harvest. The influence of precipitation was dependent on location and variety. The results also suggested that berry composition in Alentejo is more sensitive to atmospheric variability, while Aragonez seems more resilient than Touriga Nacional. These outcomes are based on a systematized and unprecedentedly large grape berry quality database in Portugal and provided the grounds for the development of grape quality forecast models, either to be used operationally in each vintage or for assessing potential modifications in berry composition in response to changing climates.
Journal Article
Beyond Organisational Borders: The Soft Power of Innovation in the Health Sector Comment on \What Managers Find Important for Implementation of Innovations in the Healthcare Sector – Practice Through Six Management Perspectives\
2022
Health is not just a physiological state, it is also a relational phenomenon. This means health is a collective challenge, often a cross-border one. Diplomacy in the health sector has progressively received more attention from formal actors (national states, international organisations, etc) but after the coronavirus disease 2019 (COVID-19) challenge, this attention became a global emergency mobilising an expansive set of knowledge-seeking players (industry, research networks, civil society, etc). This paper comments on and leverages the contribution by Palm and Feschier on innovation management at the organisational level to address a complementary dimension: the internationalization process, and the need for a particular set of skills and routines to make innovations travel through different markets and regulatory contexts. Our argument is that marketing (knowing about customers) and diplomacy (understanding framing institutions) constitute a set of dynamic capabilities (soft power) that are critical for the effective internationalization of innovation.
Journal Article