Browsing by Issue Date, starting with "2022-08"
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- Association between neurodegeneration and macular perfusion in the progression of diabetic retinopathy: a 3-year longitudinal studyPublication . Marques, Inês P.; Ferreira, Sónia; Santos, Torcato; Madeira, Maria H.; Santos, Ana Rita; Mendes, Luís; Lobo, Conceição; Cunha-Vaz, JoséThe aim of this study was to explore the relation between retinal neurodegenerative changes and vessel closure (VC) in individuals with nonproliferative diabetic retinopathy (NPDR) in a follow-up period of 3 years. This is a 3-year prospective longitudinal study with four annual visits. This study involved 74 individuals with type 2 diabetes, NPDR, and Early Treatment Diabetic Retinopathy Study grades from 10 to 47, one eye/person. An age-matched healthy control population of 84 eyes was used as control group. Participants were annually examined by color fundus photography, spectral domain-optical coherence tomography (SD-OCT) and OCT-angiography (OCTA). VC was assessed by OCTA vessel density maps. SD-OCT segmentations were performed to access central retinal thickness (CRT) and retinal neurodegeneration considered as thinning of the ganglion cell plus inner plexiform layer (GCL + IPL). Results: Type 2 diabetic individuals presented significantly higher CRT (p = 0.001), GCL + IPL thinning (p = 0.042), and decreased vessel density at the superficial capillary plexus (p < 0.001) and full retina (FR) (p = 0.001). When looking at changes occurring over the 3-year period of follow-up (Table 2), there were statistically significant decreases in GCL + IPL thickness (−0.438 μm/year; p = 0.038), foveal avascular zone circularity (−0.009; p = 0.047), and vessel density in superficial capillary plexus (−0.172 mm−1/year; p < 0.001), deep capillary plexus (DCP) (−0.350 mm−1/year; p < 0.001), and FR (−0.182 mm−1/year; p < 0.001). A statistically significant association was identified between GCL + IPL thinning and decrease in DCP vessel density (β = 0.196 [95% confidence interval: 0.037, 0.355], z = 2.410, p = 0.016), after controlling for age, gender, diabetes duration, hemoglobin A1c level, and CRT. Retinal neurodegenerative changes show a steady progression during a 3-year period of follow-up in eyes with NPDR and appear to be directly associated with progression in decreased vessel density including vascular closure through preferential involvement of the DCP. Our findings provide evidence that retinal neuropathy is linked with microvascular changes occurring in diabetic patients.
- Annual variations in the mineral element content of five fish species from the portuguese coastPublication . Pinto, Filipa R.; Duarte, Ana M.; Silva, Frederica; Barroso, Sónia; Mendes, Susana; Pinto, Edgar; Almeida, Agostinho; Sequeira, Vera; Vieira, Ana Rita; Serrano Gordo, Leonel; Gil, Maria ManuelThe most consumed fish species in Portugal do not correspond to the most caught fish species on the Portuguese coast. From the point of view of ocean sustainability and economics, it is important to study unexploited or underexploited fish species that have the potential to be introduced into the food market. This potential can be reflected by their nutritional value, where mineral elements are often overlooked despite their importance in human health. Therefore, it is important to study the elemental concentration of those fish species, which should also include seasonal variations of essential mineral elements such as Ca, P, Mg, Na, K, Fe, Cu, Mn, Zn, and I, and non-essential elements such as As, Ni, Cd, and Pb. This work is part of a project that studied five fish species with the potential to be brought to the market: three species with low commercial value (Trachurus picturatus, Spondyliosoma cantharus and Trigla lyra) and two species with no commercial value (Serranus cabrilla and Capros aper), caught over a year in the coast of Portugal. Mineral elements were quantified by ICP-OES (ICP-MS for I). The results showed that the studied fish species present significant elemental concentrations, similar to those found in the most caught fish species in Portugal. Trachurus picturatus was found to be a source of Fe, and all species are sources of I. Overall, Spondyliosoma cantharus proved to be the most element-rich species. Sensorially, Cu was related to “metallic odour” and Fe to “metallic flavour”, and I was related to “seaweed odour” and “seawater flavour”. Additionally, toxic elements such as Cd, Pb, Ni and As were not detected. The corresponding Hazard Quotients (HQ) show the safety of the consumption of these fish species concerning the content of potentially toxic elements.
- The simpler the better: Highly sensitive 17α-ethinylestradiol sensor based on an unmodified carbon paper transducerPublication . Torrinha, Álvaro; Carneiro, Pedro; Dias, Diana; Delerue-Matos, Cristina; Morais, SimoneThe remarkable features of a carbon fiber paper sensor (CP) were employed for detection of the estrogenic hormone 17α-ethinylestradiol (EE2), considered a contaminant of emerging concern due to its potential ecotoxicity and widespread in the aquatic ecosystems. In this work, an unpreceded CP pre-treatment study was conducted with the (Il)-hexacyanoferrate(III) ion pair, however a bare sensor without pre-treatment revealed higher efficiency on the oxidation of EE2 compared to a chemical and electrochemical pre-treated CP and a gold nanoparticles modified CP, being thus selected for EE2 determinations. The analytical conditions were thoroughly optimized in terms of electrolyte pH (pH 7), differential pulse voltammetry parameters (modulation time 0.003 s, amplitude 0.09 V, interval time 0.1 s and step potential 0.01 V), and analyte preconcentration potential (0.4 V) and time (180 s). The hormone can be determined by the CP in a wide linear range from 0.1 to 1000 nM, achieving a detection limit of 0.14 ± 0.005 nM and an outstanding sensitivity of 1636 ± 232 μA μM−1 cm−2 in the lowest linear zone (0.1–1 nM). The sensor was validated in river water and fish reaching good recoveries (91.2 ± 4.6 to 109.0 ± 7.1%), reproducibility and repeatability. Moreover, the sensor showed high selectivity to EE2 in the presence of several potential interfering compounds and frequently prescribed drugs, though it could not discriminate the similar hormone, 17β-estradiol, being the total concentration obtained in this case. CP-based sensors emerge as efficient electroanalytical tools, suggesting that modification of the surface may not always be beneficial in terms of sensitivity
- Barriers to volunteering in the field of intellectual disability: a cluster analysisPublication . Cruz, Soraia; Ferreira, Marisa Roriz; Borges, Ana; Casais, BeatrizThis paper aims to characterise the profiles of individuals likely to feel discouraged to volunteer in the field of intellectual disability. The socio-emotional contours of intellectual disability hinder the involvement of volunteers in this field. There is evidence of the particular barriers to volunteering in activities involving intellectually disabled people, but there is a dearth of research on the characteristics of individuals that mention such barriers. A survey applied to 197 individuals allowed, through latent classes, to identify three clusters of individuals—assuming volunteering as having a negative impact; unawareness of the reality of intellectual disability; and no barriers to volunteering; and three groups of barriers to volunteering in the field of intellectual disability—characteristics of intellectually disabled people; awareness; introversion. Based on the characteristics of the clusters identified, the study addresses possible strategies to overcome the constraints, aiming at involving volunteers in activities targeting individuals with intellectual impairments and to better target the recruitment of volunteering actions in this field. The continuous understanding of barriers to donate time can allow institutions to minimise constraints and overcome hurdles by emphasising the value of experiences that meet the motivations of volunteers.
- In vitro cytotoxic activity of african plants: a reviewPublication . Canga, Isabel; Vita, Pedro; Oliveira, Ana Isabel; Castro, María Ángeles; Pinho, CláudiaIn African countries, cancer not only is a growing problem, but also a challenge because available funding and resources are limited. Therefore, African medicinal plants play a significant role in folk medicine and some of them are traditionally used for the treatment of cancer. The high mortality rate and adverse effects associated with cancer treatments have encouraged the search for novel plant-based drugs, thus, some African plants have been studied in recent years as a source of molecules with proven cytotoxicity. This review aims to discuss the cytotoxic activity, in vitro, of African plant crude extracts against cancer cell lines. For the period covered by this review (2017–2021) twenty-three articles were found and analyzed, which included a total of 105 plants, where the main cell lines used were those of breast cancer (MCF-7 and MDA-MBA-231) and colorectal cancer (HCT-116 and Caco-2), which are among the most prevalent cancers in Africa. In these studies, the plant crude extracts were obtained using different solvents, such as ethanol, methanol, or water, with variable results and IC50 values ranging from <20 µg/mL to >200 µg/mL. Water is the preferred solvent for most healers in African countries, however, in some studies, the aqueous extracts were the least potent. Apoptosis and the induction of cell cycle arrest may explain the cytotoxic activity seen in many of the plant extracts studied. Considering that the criteria of cytotoxicity activity for the crude extracts, as established by the American National Cancer Institute (NCI), is an IC50 < 30 μg/mL, we conclude that many extracts from the African flora could be a promising source of cytotoxic agents.
- Barriers to volunteering in the field of intellectual disability: a cluster analysisPublication . Cruz, Soraia; Ferreira, Marisa Roriz; Borges, Ana; Casais, BeatrizThis paper aims to characterise the profiles of individuals likely to feel discouraged to volunteer in the field of intellectual disability. The socio-emotional contours of intellectual disability hinder the involvement of volunteers in this field. There is evidence of the particular barriers to volunteering in activities involving intellectually disabled people, but there is a dearth of research on the characteristics of individuals that mention such barriers. A survey applied to 197 individuals allowed, through latent classes, to identify three clusters of individuals—assuming volunteering as having a negative impact; unawareness of the reality of intellectual disability; and no barriers to volunteering; and three groups of barriers to volunteering in the field of intellectual disability—characteristics of intellectually disabled people; awareness; introversion. Based on the characteristics of the clusters identified, the study addresses possible strategies to overcome the constraints, aiming at involving volunteers in activities targeting individuals with intellectual impairments and to better target the recruitment of volunteering actions in this field. The continuous understanding of barriers to donate time can allow institutions to minimise constraints and overcome hurdles by emphasising the value of experiences that meet the motivations of volunteers.
- Workplace violence in healthcare settings: Work-related predictors of violence behavioursPublication . Barros, Carla; Meneses, Rute F.; Sani, Ana; Baylina, PilarHealthcare workers are exposed to workplace violence such as physical assaults, psychological violence and threats of violence. It is crucial to understand factors associated with workplace violence to prevent and mitigate its consequences. This study aims to identify work-related factors that might influence workplace violence in healthcare settings. A cross-sectional study was developed between March and April of 2022 with healthcare workers. The Aggression and Violence at Work Scale was used to assess workplace violence, and psychosocial risks were assessed through the Health and Work Survey—INSAT. Statistical analysis using bivariate analysis was performed to identify the psychosocial risk factors related to physical violence, psychological violence and vicarious violence. Subsequently, a multiple linear regression was performed to identify the models that better explained the relationship between psychosocial risk factors and the three dimensions of violence. Psychological violence was frequently experienced by the healthcare workers. Significant associations were found between psychosocial risk factors and physical, psychological and vicarious violence, namely working hours, work relationships, employment relations, high demands and work intensity. These findings highlight the importance of taking into consideration work-related factors when designing interventions to prevent and address workplace violence in healthcare settings.
- Boosting cosmeceutical peptides: coupling imidazolium-based ionic liquids to pentapeptide-4 originates new leads with antimicrobial and collagenesis-inducing activitiesPublication . Gomes, Ana; Bessa, Lucinda J.; Fernandes, Iva; Aguiar, Luísa; Ferraz, Ricardo; Monteiro, Cláudia; Martins, M. Cristina L.; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaFollowing our previous reports on dual-action antibacterial and collagenesis-inducing hybrid peptide constructs based on “pentapeptide-4” (PP4, with amino acid sequence KTTKS), whose N-palmitoyl derivative is the well-known cosmeceutical ingredient Matrixyl, herein we disclose novel ionic liquid/PP4 conjugates (IL-KTTKS). These conjugates present potent activity against either antibiotic-susceptible strains or multidrug resistant clinical isolates of both Gram-positive and Gram-negative bacterial species belonging to the so-called “ESKAPE” group of pathogens. Noteworthy, their antibacterial activity is preserved in simulated wound fluid, which anticipates an effective action in the setting of a real wound bed. Moreover, their collagenesis-inducing effects in vitro are comparable to or stronger than those of Matrixyl. Altogether, IL-KTTKS exert a triple antibacterial, antifungal, and collagenesis-inducing action in vitro. These findings provide solid grounds for us to advance IL-KTTKS conjugates as promising leads for future development of topical treatments for complicated skin and soft tissue infections (cSSTI). Further studies are envisaged to incorporate IL-conjugates into suitable nanoformulations, to reduce toxicity and/or improve resistance to proteolytic degradation.
- Broadband spectral verification of optical clearing reversibility in lung tissuePublication . Oliveira, Luís R.; Ferreira, Ricardo M.; Pinheiro, Maria R.; Silva, Hugo F.; Tuchin, Valery V.; Oliveira, LuísThe increase of tissue transparency through sequential optical immersion clearing treatments and treatment reversibility have high interest for clinical applications. To evaluate the clearing reversibility in a broad spectral range and the magnitude of the transparency created by a second treatment, the present study consisted on measuring the spectral collimated transmittance of lung tissues during a sequence of two treatments with electronic cigarette (e-cig) fluid, which was intercalated with an immersion in saline. The saline immersion clearly reverted the clearing effect in the lung tissue in the spectral range between 220 and 1000 nm. By a later application of a second treatment with the e-cig fluid, the magnitude of the optical clearing effect was observed to be about the double as the one observed in the first treatment, showing that the molecules of the optical clearing agent might have converted some bound water into mobile water during the first treatment.
- Schedulability Analysis for 3-Phase Tasks with Partitioned Fixed-Priority SchedulingPublication . Arora, Jatin; Maia, Cláudio; Rashid, Syed Aftab; Nelissen, Geoffrey; Tovar, EduardoMulticore platforms are being increasingly adopted in Cyber-Physical Systems (CPS) due to their advantages over single-core processors, such as raw computing power and energy efficiency. Typically, multicore platforms use a shared memory bus that connects the cores to the off-chip main memory. This sharing of memory bus may cause tasks running on different cores to compete for access to the main memory whenever data/instructions are need to be read/written from/to the main memory. Such competition is problematic, as it may cause variations in the execution time of tasks in a non-deterministic way. To reduce the complexity of analysing this problem, the 3-phase task model was proposed that divides tasks' executions into distinct memory and execution phases. The distinctive memory phases are then scheduled to eliminate/minimize main memory contention between concurrently executing tasks. However, 3-phase tasks running on different cores may still compete to access the shared memory bus/main memory in order to execute memory phases. This paper presents a partitioned scheduling-based approach that allows one to derive memory bus contention-aware worst-case response time of tasks that follow the 3-phase task model. In particular, the bus-contention analysis is derived by considering two memory access models, i.e., (i) dedicated memory access model, where a core having allowed to access the main memory via memory bus is permitted to execute more than one memory phase, and (ii) fair memory access model, that restrict each core to execute only one memory phase in its allocated bus access. Both these models represent different system and application requirements, and the resulting bus contention of tasks may vary depending on the considered model. To evaluate the effectiveness of the proposed bus contention analysis, we compare its performance against an existing analysis in the state-of-the-art by performing (i) case-study experiments, using benchmarks from the Mälardalen Benchmark suite, and (ii) empirical evaluation using synthetic task sets. Results show that our proposed analysis can improve task set schedulability of 3-phase tasks by up to 88 percentage points.