Browsing by Issue Date, starting with "2024-07"
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- Looking beyond the obvious: the ecotoxicological impact of the leachate from fishing nets and cables in the marine mussel Mytilus galloprovincialisPublication . Vilke, Juliano Marcelo; GARCIA DA FONSECA, TAINÁ; Dias de Alkimin, Gilberto; Ribeiro Gonçalves, Joanna Melissa; Edo Cuesta, Carlos; d’ Errico, Giuseppe; Seilitz, Fredric Södergren; Rotander, Anna; Benedetti, Maura; Regoli, Francesco; Lüchmann, Karim H.; Bebianno, MariaOnce in the marine environment, fishing nets and cables undergo weathering, breaking down into micro and nano -size particles and leaching plastic additives, which negatively affect marine biota. This study aims to unravel the ecotoxicological impact of different concentrations of leachate obtained from abandoned or lost fishing nets and cables in the mussel Mytilus galloprovincialis under long-term exposure (28 days). Biochemical biomarkers linked to antioxidant defense system, xenobiotic biotransformation, oxidative damage, genotoxicity, and neurotoxicity were evaluated in different mussel tissues. The chemical nature of the fishing nets and cables and the chemical composition of the leachate were assessed and metals, plasticizers, UV stabilizers, flame retardants, antioxidants, dyes, flavoring agents, preservatives, intermediates and photo initiators were detected. The leachate severely affected the antioxidant and biotransformation systems in mussels' tissues. Following exposure to 1 mg center dot L -1 of leachate, mussels' defense system was enhanced to prevent oxidative damage. In contrast, in mussels exposed to 10 and 100 mg center dot L -1 of leachate, defenses failed to overcome pro -oxidant molecules, resulting in genotoxicity and oxidative damage. Principal component analysis (PCA) and Weight of Evidence (WOE) evaluation confirmed that mussels were significantly affected by the leachate being the hazard of the leachate concentrations of 10 mg center dot L -1 ranked as major, while 1 and 100 mg center dot L -1 was moderate. These results highlighted that the leachate from fishing nets and cables can be a threat to the heath of the mussel M. galloprovincialis .
- Oxyfluorfen: a novel metabolic inhibitor to select microalgal chlorophyll-deficient mutant strains for nutritional applicationsPublication . Trovão dos Santos, Mafalda; Cardoso, Lucas; Schüler, Lisa; Machado, Adriana; Santo, Gonçalo Espírito; Pedroso, Humberto; Reis, Ana; Barros, Ana; Correia, Nádia; Costa, Monya; Ferreira, Sara; Cardoso, Helena; Mateus, Marília; Silva, Joana; Pereira, Hugo; Freitas, Filomena; Varela, JoãoNowadays, there is an increasing demand for novel feedstocks and alternative protein sources to meet global needs. Because of their rich nutritional profiles and high protein contents, microalgae-based food products and supplements are being developed. Nonetheless, these products present organoleptic characteristics such as taste, smell and colour that are often considered unpleasant by human and animal consumers. To address this constraint, strain improvement approaches such as random mutagenesis have been used, which combined with the right selection strategy, lead to more appealing microalgal biomass. In this work, a novel selection strategy using oxyfluorfen, an inhibitor of the chlorophyll synthesis pathway, was applied for the first time to isolate chlorophyll-deficient strains of Scenedesmus rubescens and Chlorella vulgaris upon treatment with ethyl methanesulfonate (EMS). With this approach, one S. rubescens brownish (37Y01) mutant strain, as well as two C. vulgaris mutant strains, one yellow (31Y15) and one white (31W62), were obtained. S. rubescens 37Y01 displayed a reduced protein content of 19.1% dry weight (DW) compared to that of the wildtype, which presented a protein content of 25.0% DW. C. vulgaris wildtype and mutants exhibited higher protein contents, in the 42.844.3% DW range, compared to Scenedesmus rubescens (p < 0.05). The selective pressure of this inhibitor allowed the selection of S. rubescens and C. vulgaris mutants displaying 55% and 95% decrease in chlorophyll content, respectively. The reduced chlorophyll content greatly improves the sensory properties and consumer acceptance of established mutants, increasing the potential of both strains as feedstocks to develop novel food products.
- Effectiveness of sodium alginate and carnauba wax nanoemulsions with lemongrass essential oil on the quality of ‘Hass’ avocado Fruit from early, middle, and late harvest season during prolonged cold storagePublication . Gago, Custódia; Guerreiro, Adriana; Mariana Souza; Martins, Nuno; Fonseca, Daniela; Cabrita, Maria João; Miguel, Maria da Graça; Antunes, Maria DulceAvocado ( Persea Americana Mill.) has gained popularity as a widely produced and consumed fruit worldwide, raising concerns about its storage and transportation. The avocado, being a climacteric fruit sensitive to chilling injury, faces challenges that affect its shelf life and commercial viability. This research delves into the effectiveness of edible sodium alginate 2 % (weight/weight, w/w) (SA) and carnauba wax 1 % (w/w) (CW) coatings, both independently and in combination with lemongrass essential oil, sodium alginate 2 % (w/w) + lemongrass essential oil 1.25 % (SALG) and carnauba wax 1 % + lemongrass essential oil 1.25 % (w/w) CWLG) as postharvest treatments. Uncoated avocados were used as control (CT). The nanocoating-treatments aim to preserve the quality of 'Hass' avocados harvested during the early, middle, and late season. After treating the fruits, some from each treatment group were kept at 21 +/- 1 degrees C for 7 days (shelf life). The rest were stored at 5 degrees C and 90 % RH for 15, 30, and 45 days before being submitted also to shelf life. In each sampling date, quality parameters measured included: firmness, color (L*, ), weight loss, gray pulp symptoms, ethylene production and pulp electrolyte leakage. Also, fatty acids (FA), hydrogen peroxide (HO), malondialdehyde (MDA), alpha-farnesene (Farn) and conjugated trienols (Ctrols) were quantified in avocado pulp. Fruit quality analysis showed that all coatings improve quality and reduction of gray pulp development, especially CW and the incorporation of lemongrass in both matrices. Therefore, these edible coatings can be an alternative to improve preservation of avocado fruit quality through cold storage and subsequent shelf-life, which potentially reduce fruit waste.
- Deep learning models for atypical serotonergic cells recognitionPublication . Corradetti, Daniele; Bernardi, Alessandro; Corradetti, RenatoThe serotonergic system modulates brain processes via functionally distinct subpopulations of neurons with heterogeneous properties, including their electrophysiological activity. In extracellular recordings, serotonergic neurons to be investigated for their functional properties are commonly identified on the basis of "typical"features of their activity, i.e. slow regular firing and relatively long duration of action potentials. Thus, due to the lack of equally robust criteria for discriminating serotonergic neurons with "atypical"features from non-serotonergic cells, the physiological relevance of the diversity of serotonergic neuron activities results largely understudied. New Methods : We propose deep learning models capable of discriminating typical and atypical serotonergic neurons from non-serotonergic cells with high accuracy. The research utilized electrophysiological in vitro recordings from serotonergic neurons identified by the expression of fluorescent proteins specific to the serotonergic system and non-serotonergic cells. These recordings formed the basis of the training, validation, and testing data for the deep learning models. The study employed convolutional neural networks (CNNs), known for their efficiency in pattern recognition, to classify neurons based on the specific characteristics of their action potentials. Results: The models were trained on a dataset comprising 27,108 original action potential samples, alongside an extensive set of 12 million synthetic action potential samples, designed to mitigate the risk of overfitting the background noise in the recordings, a potential source of bias. Results show that the models achieved high accuracy and were further validated on "non-homogeneous"data, i.e., data unknown to the model and collected on different days from those used for the training of the model, to confirm their robustness and reliability in real -world experimental conditions. Comparison with existing methods : Conventional methods for identifying serotonergic neurons allow recognition of serotonergic neurons defined as typical. Our model based on the analysis of the sole action potential reliably recognizes over 94% of serotonergic neurons including those with atypical features of spike and activity. Conclusion: The model is ready for use in experiments conducted with the here described recording parameters. We release the codes and procedures allowing to adapt the model to different acquisition parameters or for identification of other classes of spontaneously active neurons.
- Camptothecin-loaded mesoporous silica nanoparticles functionalized with CpG oligodeoxynucleotide as a new approach for skin cancer treatmentPublication . Qureshi, Munibah; Viegas, Cláudia; Duarte, Sofia O.D.; Girardi, Michael; Shehzad, Adeeb; Fonte, PedroThe therapeutic efficacy of camptothecin (CPT), a potent antitumor alkaloid, is hindered by its hydrophobic nature and instability, limiting its clinical use in treating cutaneous squamous cell carcinoma (SCC). This study introduces a novel nano drug delivery system (NDDS) utilizing functionalized mesoporous silica nanoparticles (FMSNs) for efficient CPT delivery. The FMSNs were loaded with CPT and subsequently coated with chitosan (CS) for enhanced stability and bioadhesion. Importantly, CpG oligodeoxynucleotide (CpG ODN) was attached onto the CS-coated FMSNs to leverage the immunostimulatory properties of CpG ODN, augmenting the chemotherapy's efficacy. The final formulation FMSN-CPT-CS-CpG displayed an average size of 241 nm and PDI of 0.316 with an encapsulation efficiency of 95 %. Comprehensive in vitro and in vivo analyses, including B16F10 cells and DMBA/TPA-induced SCC murine model, demonstrated that the FMSN-CPT-CS-CpG formulation significantly enhanced cytotoxicity against B16F10 cells and induced complete regression in 40 % of the in vivo subjects, surpassing the efficacy of standard CPT and FMSN-CPT treatments. This study highlights the potential of combining chemotherapeutic and immunotherapeutic agents in an NDDS for targeted, efficient skin cancer treatment.
- Ethics and applications of isotope analysis in archaeologyPublication . Stantis, Chris; Schaefer, Benjamin J.; Correia, Maria Ana; Alaica, Aleksa K.; Huffer, Damien; Plomp, Esther; Di Giusto, Marina; Chidimuro, Blessing; Rose, Alice K.; Nayak, Ayushi; Kendall, Ellen J.This synthesis explores specific ethical questions that commonly arise in isotopic analysis. For more than four decades, isotope analysis has been employed in archeological studies to explore past human and animal dietary habits, mobility patterns, and the environment in which a human or animal inhabited during life. These analyses require consideration of ethical issues. While theoretical concepts are discussed, we focus on practical aspects: working with descendant communities and other rights holders, choosing methods, creating and sharing data, and working mindfully within academia. These layers of respect and care should surround our science. This paper is relevant for specialists in isotope analysis as well as those incorporating these methods into larger projects. By covering the whole of the research process, from design to output management, we appeal broadly to archaeology and provide actionable solutions that build on the discussions in the general field.
- Effect of fruit thinning on fruit quality and alternate bearing of ‘Setubalense’ mandarin (Citrus deliciosa)Publication . Guerreiro, T.; Trindade, Ana Rita; Duarte, Amilcar; Matias, PedroCitriculture plays a major role in agriculture worldwide, especially in the Mediterranean region. However, there are limitations in citrus production. Alternate bearing can be a big problem when it is very intense. Trees produce a heavy yield one year (“on” year) and light ones the next (“off” year). During the “on” year, trees produce many small-sized fruits, while in the “off” year, they produce very few, larger fruits. The small size of the fruits is a limitation, as they are less well accepted in the market. The ‘Setubalense’ cultivar, a traditional Portuguese Mediterranean mandarin (Citrus deliciosa), is recognized for its excellent organoleptic characteristics. Despite this, the issues of alternate bearing and small fruit size are leading to the loss of this cultivar. Fruit thinning is a cultural practice involving the removal of some fruits, while leaving others. This practice can be used to manage alternate bearing and to improve fruit size. However, its impact on the plant is not well understood, whether it affects the plant as a whole or at a more localized level, such as within individual branches. To address this, two experiments were installed in August 2019. In the first experiment thinning involved removing 50% of the fruits from the entire tree. In this experiment, the fruit size and fruit quality were higher in the trees where fruit thinning was performed. In the second experiment, thinning was applied to selected branches, also removing 50% of the fruits. In this case, no significant differences were observed, neither in fruit size nor in fruit quality. Furthermore, fruit thinning did not reduce alternate bearing in either experiment.
- Identification of novel DNA methylation prognostic biomarkers for AML with normal cytogeneticsPublication . Cardoso, Cândida; Pestana, Daniel; Gokuladhas, Sreemol; Marreiros, Ana; Justin M. O'Sullivan; Binnie, Alexandra; Teotónio Fernandes, Mónica Alexandra; Castelo-Branco, PedroPURPOSE AML is a hematologic cancer that is clinically heterogeneous, with a wide range of clinical outcomes. DNA methylation changes are a hallmark of AML but are not routinely used as a criterion for risk stratification. The aim of this study was to explore DNA methylation markers that could risk stratify patients with cytogenetically normal AML (CN-AML), currently classified as intermediate-risk.MATERIALS AND METHODSDNA methylation profiles in whole blood samples from 77 patients with CN-AML in The Cancer Genome Atlas (LAML cohort) were analyzed. Individual 5'-cytosine-phosphate-guanine-3' (CpG) sites were assessed for their ability to predict overall survival. The output was validated using DNA methylation profiles from bone marrow samples of 79 patients with CN-AML in a separate data set from the Gene Expression Omnibus.RESULTSIn the training set, using DNA methylation data derived from the 450K array, we identified 2,549 CpG sites that could potentially distinguish patients with CN-AML with an adverse prognosis (intermediate-poor) from those with a more favorable prognosis (intermediate-favorable) independent of age. Of these, 25 CpGs showed consistent prognostic potential across both the 450K and 27K array platforms. In a separate validation data set, nine of these 25 CpGs exhibited statistically significant differences in 2-year survival. These nine validated CpGs formed the basis for a combined prognostic biomarker panel, which includes an 8-CpG Somatic Panel and the methylation status of cg23947872. This panel displayed strong predictive ability for 2-year survival, 2-year progression-free survival, and complete remission in the validation cohort.CONCLUSIONThis study highlights DNA methylation profiling as a promising approach to enhance risk stratification in patients with CN-AML, potentially offering a pathway to more personalized treatment strategies.
- Symbiotic endolithic microbes reduce host vulnerability to an unprecedented heatwavePublication . Zardi, Gerardo; Monsinjon, Jonathan R.; Seuront, Laurent; Spilmont, Nicolas; McQuaid, Christopher D.; Nicastro, KatyHeatwaves are increasingly severe and frequent, posing significant threats to ecosystems and human well-being. Characterised by high thermal variability, intertidal communities are particularly vulnerable to heat stress. Microbial endolithic communities that are found in marine calcifying organisms have been shown to induce shell erosion that alters shell surface colour, lowering body temperatures and increasing survival rates. Here, we investigate how the symbiotic relationship between endolithic microbes and the blue intertidal mussel Mytilus edulis mitigates thermal stress during the unprecedented 2022 atmospheric heatwave in the English Channel. Microbial infestation of the shell significantly enhanced mussel survival, particularly higher on the shore where thermal stress was greater. Using data from biomimetic temperature loggers, we predicted the expected thermal buffer and observed differences up to 3.2 °C between individuals with and without symbionts under the known conditions of the heat wave-induced mortality event. The ecological implications extend beyond individual mussels, affecting the reef-building capacity of mussels, with potential cascading effects for local biodiversity, carbon sequestration, and coastal defence. These findings emphasize the importance of understanding small-scale biotic interactions during extreme climate events and provide insights into the dynamic nature of the endolith-mussel symbiosis along a parasitic-mutualistic continuum influenced by abiotic factors.
- Effectiveness of Sodium Alginate and Carnauba Wax Nanoemulsions with lemongrass essential oil on the quality of ‘Hass’ avocado fruit from early, middle, and late harvest season during prolonged cold storagePublication . Souza, Mariana; Martins, Nuno; Fonseca, Daniela; Cabrita, Maria João; Gago, Custódia; Guerreiro, Adriana; Miguel, Maria da Graça; Antunes, Maria DulceAvocado ( Persea Americana Mill.) has gained popularity as a widely produced and consumed fruit worldwide, raising concerns about its storage and transportation. The avocado, being a climacteric fruit sensitive to chilling injury, faces challenges that affect its shelf life and commercial viability. This research delves into the effectiveness of edible sodium alginate 2 % (weight/weight, w/w) (SA) and carnauba wax 1 % (w/w) (CW) coatings, both independently and in combination with lemongrass essential oil, sodium alginate 2 % (w/w) + lemongrass essential oil 1.25 % (SALG) and carnauba wax 1 % + lemongrass essential oil 1.25 % (w/w) CWLG) as postharvest treatments. Uncoated avocados were used as control (CT). The nanocoating-treatments aim to preserve the quality of 'Hass' avocados harvested during the early, middle, and late season. After treating the fruits, some from each treatment group were kept at 21 +/- 1 degrees C for 7 days (shelf life). The rest were stored at 5 degrees C and 90 % RH for 15, 30, and 45 days before being submitted also to shelf life. In each sampling date, quality parameters measured included: firmness, color (L*, ), weight loss, gray pulp symptoms, ethylene production and pulp electrolyte leakage. Also, fatty acids (FA), hydrogen peroxide (HO), malondialdehyde (MDA), alpha-farnesene (Farn) and conjugated trienols (Ctrols) were quantified in avocado pulp. Fruit quality analysis showed that all coatings improve quality and reduction of gray pulp development, especially CW and the incorporation of lemongrass in both matrices. Therefore, these edible coatings can be an alternative to improve preservation of avocado fruit quality through cold storage and subsequent shelf-life, which potentially reduce fruit waste.