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  • Eye discomfort at close work in Portuguese university students: A comparative analysis between the pre-COVID and confinement period
    Publication . Nunes, Amélia Fernandes; Leitão, Mara Filipa Antunes; Nunes, António; Monteiro, Pedro
    Background Many individuals experience visual symptoms associated with near work. The level of discomfort appears to increase with the amount of digital screen use. Objective To study the eye discomfort with near tasks in university students in the pre-COVID period and in the period of confinement due to the pandemic. Methods Two independent samples of students, aged between 18 and 35 years, were used to assess symptomatic behaviour with the Convergence Insufficiency Symptom Survey (CISS) questionnaire. In the pre-COVID period the sample had 342 participants, 64.6% females and in the COVID period 322 students participated, 71.4% females. The study of differences was carried out by the Mann-Whitney U test. The interpretation of the statistical inference was performed for a significance level≤0.05. Results There was an increase in the number of symptomatic cases in the COVID period without statistical evidence of differences in the frequency of symptoms reported in the two periods. The dimensions "somatic sensations" and "cognitive performance" were the typology of symptoms that most contributed to visual complaints with near vision. There was a significantly different symptomatic behaviour between genders in the period of confinement (p = 0.001), worsening in females and improving in males. Conclusion These findings suggest that females and males exposed to digital environments, over time, may exhibit different symptomatic behaviour. Our results suggest that boys adapt more quickly than girls. Factors that predispose to these changes, aetiology and potential intervention actions still need further study.
  • The role of ayahuasca in cell viability and oxidative stress in gastric adenocarcinoma cell line
    Publication . Gonçalves, Joana; Cascalheira, José; Valentão, Patrícia; Luís, Ângelo; Gallardo, Eugenia; Duarte, Ana Paula
    Ayahuasca, a psychoactive beverage native to the Amazon, originally derived from Banisteriopsis caapi stem scrapings and Psychotria viridis leaves, exhibits hallucinogenic properties due to N,Ndimethyltryptamine. When combined with β-carbolines, it enters the bloodstream and central nervous system, inhibiting monoamine oxidase-A. Over time, therapeutic effects have been associated to ayahuasca consumption. This study assessed the impact of extracts from three plant decoctions used in ayahuasca preparation on the gastric adenocarcinoma cell line (AGS). MTT reduction assays selected B. caapi, Mimosa hostilis, and Peganum harmala samples as most effective. Lactate dehydrogenase activity evaluated membrane integrity loss, while oxidative stress induction was measured using dihydroethidium and 2′,7′-dichlorodihydrofluorescein diacetate probes. Results revealed apoptosis induction in AGS Ucells, with all three samples significantly reducing oxidative stress.
  • Comparative study of sample preparation procedures to determine the main compounds in ayahuasca beverages by QuEChERS and high‐performance liquid chromatography analysis
    Publication . Gonçalves, Joana; Rosado, Tiago; Barroso, Mário; Restolho, José; Fernández, Nicolás; Luís, Ângelo; Gallardo, Eugenia; Duarte, Ana Paula
    Introduction Ayahuasca is a psychoactive drink originally consumed by indigenous people of the Amazon. The lack of regulation of this drink leads to uncontrolled consumption, and it is often consumed in religious contexts. Objective The aim of this work is to compare three miniaturised extraction techniques for extracting the main ayahuasca compounds from beverages. Methodology Three sample pretreatment techniques were evaluated (dispersive liquid–liquid microextraction [DLLME], microextraction by packed sorbent [MEPS] and QuEChERS [Quick, Easy, Cheap, Effective, Rugged and Safe]) for the simultaneous extraction of N,N-dimethyltryptamine (DMT), tetrahydroharmine (THH), harmine, harmaline, harmol and harmalol from ayahuasca beverage samples. Then, the most promising technique (QuEChERS) was chosen to pre-concentrate the analytes, subsequently detected by high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD). Results The procedure was optimised, with the final conditions being 500 μL of extractor solvent, 85 mg of primary secondary amine (PSA) and 4 s of vortexing. The analytical method was validated, showing to be linear between 0.16 and 10 μg/mL for β-carbolines and between 0.016 and 1 μg/mL for DMT, with coefficients of determination (R2) between 0.9968 and 0.9993. The limit of detection (LOD) and lower limit of quantification (LLOQ) were 0.16 μg/mL for all compounds, except for DMT (0.016 μg/mL) and extraction efficiencies varied between 60.2% and 88.0%. Conclusion The analytical methodology proved to be accurate and precise, with good linearity, LODs and LLOQs. This method has been fully validated and successfully applied to ayahuasca beverage samples.
  • The Role of Ayahuasca in Colorectal Adenocarcinoma Cell Survival, Proliferation and Oxidative Stress
    Publication . Gonçalves, Joana; Feijó, Mariana; Socorro, Sílvia; Luís, Ângelo; Gallardo, Eugenia; Duarte, Ana Paula
    The psychedelic beverage ayahuasca is originally obtained by Banisteriopsis caapi (B. caapi) (BC) and Psychotria viridis (P. viridis) (PV). However, sometimes these plant species are replaced by others that mimic the original effects, such as Mimosa hostilis (M. hostilis) (MH) and Peganum harmala (P. harmala) (PH). Its worldwide consumption and the number of studies on its potential therapeutic effects has increased. This study aimed to evaluate the anticancer properties of ayahuasca in human colorectal adenocarcinoma cells. Thus, the maximum inhibitory concentration (IC50) of decoctions of MH, PH, and a mixture of these (MHPH) was determined. The activities of caspases 3 and 9 were evaluated, and the cell proliferation index was determined through immunocytochemical analysis (Ki-67). Two fluorescent probes were used to evaluate the production of oxidative stress and the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) was also evaluated. It was demonstrated that exposure to the extracts significantly induced apoptosis in Caco-2 cells, while decreasing cell proliferation. MH and MHPH samples significantly reduced oxidative stress and significantly increased glutathione peroxidase activity. No significant differences were found in SOD activity. Overall, it was demonstrated that the decoctions have a potential anticancer activity in Caco-2 cells.
  • Attribution of somatosensory properties to an upper limb prosthesis
    Publication . Fonseca, Gonçalo; Nunes-Pereira, João; Pereira Silva, A
    The nervous system is a complex network composed by cells, tissue, and organs that have the ability of receiving, transmit, regulate, and send information and stimuli, not only within our body but from our surroundings1. This information is produced by a complex system of neurochemical and electrical reactions that produce the perceptions of heat, smell, taste, proprioception, and touch that lead to physical reactions (movement)2. When that transmission of information is lost due to malformations or accident, there are several physiological responses that will either be lost or try to find new pathways to function and make sense out the current situation. Bringing the division of this work into three phases. The first phase, the production of the prosthetic model by 3D printing (Fig. 1a), reducing the time-consuming production of the different parts by changing production characteristics like infill, layer height, surface quality, ironing and type of material used. The second phase, the instrumentalization of the prosthetic (Fig. 1b) focussing on allowing it to function by controlled and regulated force execution, with lowcost servomotors and components, with easy access to replacement. The third phase, the construction of the sensing mimicking, add-on sensory system using piezoresistive sensors attached to the palm side of a glove on specific regions that allowed not only the location and detection of the forces being exerted, but also their quantification (Fig. 1c). The type of instrumentalization planning used on the sensory glove, allow an easier access to the sensors and other components, making it quite to replace or to adapt . Overall, the results produced were very promising, and better than expected, allowing not only the localization and measurement of force, and analog read for each sensor without too much signal interference, but also a better access and cost reduction prototype.
  • First Chemical Profile Analysis of Acacia Pods
    Publication . Pedro, Soraia; Fernandes, Tiago A.; Luís, Ângelo; Antunes, A M M; Gonçalves, J. C.; Gominho, Jorge; Gallardo, Eugenia; Anjos, Ofélia
    This study intended to evaluate the potential industrial applications of various Acacia species (Acacia melanoxylon, Acacia longifolia, Acacia cyclops, Acacia retinodes, Acacia pycnantha, Acacia mearnsii, and Acacia dealbata) by examining their chemical composition, antioxidant, and antimicrobial properties. Using high-resolution mass spectrometry, a comprehensive analysis successfully identified targeted compounds, including flavonoids (flavonols/flavones) and phenolic acids, such as 4-hydroxybenzoic acid, p-coumaric acid, and ellagic acid. Additionally, p-coumaric acid was specifically identified and quantified within the hydroxycinnamic aldehydes. This comprehensive characterization provides valuable insights into the chemical profiles of the studied species. Among the studied species, A. pycnantha exhibited a higher concentration of total phenolic compounds, including catechin, myricetin, quercetin, and coniferaldehyde. Furthermore, A. pycnantha displayed notable antibacterial activity against K. pneumoniae, E. coli, S. Typhimurium, and B. cereus. The identified compounds in Acacia pods and their shown antibacterial activities exhibit promising potential for future applications. Moreover, vibrational spectroscopy was a reliable method for distinguishing between species. These significant findings enhance our understanding of Acacia species and their potential for various industrial applications.
  • 3D Printed Robotic Hand with Piezoresistive Touch Capability
    Publication . Fonseca, Gonçalo; Nunes-Pereira, João; Silva, Abilio
    This work proposes the design of a low-cost sensory glove system that complements the operation of a 3D-printed mechanical hand prosthesis, providing it with the ability to detect touch, locate it and even measure the intensity of associated forces. Firstly, the production of the prosthetic model was performed using 3D printing, which allowed for quick and cheap production of a robotic hand with the implementation of a mechanical system that allows controlled movements with high performance and with the possibility of easily replacing each piece individually. Secondly, we performed the construction and instrumentation of a complementary sensory mimicry add-on system, focusing on the ability to sense touch as the primary target. Using piezoresistive sensors attached to the palm of the glove, a multi-sensor system was developed that was able to locate and quantify forces exerted on the glove. This system showed promising results and could be used as a springboard to develop a more complex and multifunctional system in the future.
  • A Systematic Review on the Therapeutic Effects of Ayahuasca
    Publication . Gonçalves, Joana; Luís, Ângelo; Gallardo, Eugenia; Duarte, Ana Paula
    Traditional therapies, resorting to the use of plants, have acquired a great demand over the years, both for economic reasons and the preference for natural treatments. Some studies suggest that ayahuasca may have beneficial properties in treating some physical and psychological imbalances. Thus, we carried out a systematic review of studies published up to December 2022, where these themes were addressed. The search was carried out in the PubMed database, and only studies written in English and published in peer-reviewed journals were included. Thus, 228 publications were identified, of which 66 were included in the present study. The reviewed studies suggest that ayahuasca may have beneficial effects on various physical and psychological conditions, namely in the treatment of depression, anxiety and various diseases of the neurobiological system, as well as anti-inflammatory and antimicrobial properties, demonstrating its therapeutic potential. The number of studies that address this issue has also been growing, demonstrating interest in the search for alternative treatments. However, to the best of our knowledge, this is the first systematic review where all the findings of therapeutic effects associated with the consumption of ayahuasca are reviewed.
  • Natural Products: Therapeutic Properties and Beyond II
    Publication . Duarte, Ana Paula; Luís, Ângelo; Gallardo, Eugenia
    Historically, natural products have contributed to drug discovery as a source of active molecules due to their great diversity and structural complexity. Thus, they have contributed to the development of drugs for applications in different therapeutic areas. In recent decades, there has been a paradigm shift in drug discovery strategies that has allowed for identifying new natural products that exhibit activities on therapeutic targets. Newman and Cragg studied the origin of 1330 new drugs that had been approved between 1981 and 2010 and found that 64% of them were somewhat related to natural compounds [1]. In a recent review by these same authors, it was noted that, within all of the drugs newly approved by the Food and Drug Administration between January 1981 and September 2019, compounds derived from natural products ranked second [2]. Besides the importance of the discovery of new molecules based on natural compounds, the concern today is focused on the therapeutic potential of secondary metabolites classified as drugs of abuse, such as derivatives of cannabis [3] and psilocybin [4], or even on the use of plants used ancestrally in medicine as well [5,6]. On the other hand, with the development of computational techniques, a decision has been made to study the possibilities of analyzing the pharmacological potential of natural products or their derivatives and converting these molecules into low toxicity active products. However, apart from the use of naturally occurring compounds in the field of health, they have been studied and are increasingly used in solutions, for instance in the agrochemical and food industries. After the success of the Special Issue “Natural Products: Therapeutic Properties and Beyond I”, this second edition aims to categorize the state of the art concerning scientific research on natural products, including their applications as compounds with added value to human health. This issue intends to be used as a text for academia or as a reference tool for researchers, particularly for those working in the fields of medicinal chemistry, toxicology, phytochemistry, and natural product chemistry, and for health and industry professionals.
  • Natural Products: Therapeutic Properties and Beyond II
    Publication . Duarte, Ana Paula; Luís, Ângelo; Gallardo, Eugenia
    Historically, natural products have contributed to drug discovery as a source of active molecules due to their great diversity and structural complexity. Thus, they have contributed to the development of drugs for applications in different therapeutic areas. In recent decades, there has been a paradigm shift in drug discovery strategies that has allowed for identifying new natural products that exhibit activities on therapeutic targets. Newman and Cragg studied the origin of 1330 new drugs that had been approved between 1981 and 2010 and found that 64% of them were somewhat related to natural compounds [1]. In a recent review by these same authors, it was noted that, within all of the drugs newly approved by the Food and Drug Administration between January 1981 and September 2019, compounds derived from natural products ranked second [2]. Besides the importance of the discovery of new molecules based on natural compounds, the concern today is focused on the therapeutic potential of secondary metabolites classified as drugs of abuse, such as derivatives of cannabis [3] and psilocybin [4], or even on the use of plants used ancestrally in medicine as well [5,6]. On the other hand, with the development of computational techniques, a decision has been made to study the possibilities of analyzing the pharmacological potential of natural products or their derivatives and converting these molecules into low toxicity active products. However, apart from the use of naturally occurring compounds in the field of health, they have been studied and are increasingly used in solutions, for instance in the agrochemical and food industries. After the success of the Special Issue “Natural Products: Therapeutic Properties and Beyond I”, this second edition aims to categorize the state of the art concerning scientific research on natural products, including their applications as compounds with added value to human health. This issue intends to be used as a text for academia or as a reference tool for researchers, particularly for those working in the fields of medicinal chemistry, toxicology, phytochemistry, and natural product chemistry, and for health and industry professionals.