Percorrer por autor "Silva, Paula"
A mostrar 1 - 6 de 6
Resultados por página
Opções de ordenação
- Burnout among Portuguese healthcare workers during the COVID-19 pandemicPublication . Duarte, Ivone; Teixeira, Andreia; Castro, Luísa; Marina, Sílvia; Ribeiro, Carla; Jácome, Cristina; Martins, Vera; Ribeiro-Vaz, Inês; Pinheiro, Hugo Celso; Silva, Andreia Rodrigues; Ricou, Miguel; Sousa, Bruno; Alves, Cristiana; Oliveira, Andreia; Silva, Paula; Nunes, Rui; Serrão, CarlaDuring COVID-19 pandemic, healthcare workers (HCWs) have had high workload and have been exposed to multiple psychosocial stressors. The aim of this study was to evaluate HCWs in terms of the relative contributions of socio-demographic and mental health variables on three burnout dimensions: personal, work- related, and client-related burnout.
- Enantiomeric biodistribution and toxicity of 3-chloromethcathinone (3-CMC) in Wistar rats after acute exposure – preliminary dataPublication . Langa, Ivan; Rocha-Pereira, Carolina; Milhazes, Nuno; Silva, Diana Dias da; Domingues, Susana; Silva, Paula; Barbosa, Joana; Faria, Juliana; Tiritan, Maria Elizabeth; Ribeiro, Cláudia; Dias da Silva, Diana CristinaThere has been a surge in global attention to New Psychoactive Substances (NPS) [1]. Synthetic cathinones stand out as a widely consumed NPS class. Notably, 3-chloromethcathinone (3-CMC) accounted for over 34% of NPS seizures in 2021 [2], which underscores concerns regarding its consumption and health effects. Of note, 3-CMC is chiral and mostly sold as a racemate. As human me-tabolism and pharmacological effects can be enantioselective [3], determination of the impact of enanti-oselectivity in toxicokinetics/toxicodynamics is essential for the assessment of 3-CMC effects. This work aimed to evaluate in vivothe enantioselective biodistribution and toxicity of racemic 3-CMC, after an acute exposure to 3-CMC. Ten-week-old male Wistar rats were administered intraperitoneally with saline or 3-CMC (10 or 20 mg/kg; n=6). Twenty-four hours after, animals were deeply anesthetized and nine organs (brain, liver, kidneys, lungs, heart, spleen, gut, muscle, adipose tis-sue), blood and urine were collected. For evaluation of the enantiomeric biodistribution, a previous in houseestablished indirect method by gas chromatography [3], was adapted and validated. Some biochem-ical analysis was performed using an analyser, whereas TBARS, ATP, glutathione and total protein were determined by spectrophotometry. Organs were also processed for histological analysis. After 24 h, 3-CMC was not found in most organs. Both enantiomers were detected in urine with one dominant enantiomer, suggesting enantioselectivity in metabolism. The histopathological results showed possible central chromatolysis in the brain (20 mg/kg), liver inflammation, renal lesions, lungs’ haemoptysis, and alveolar haemorrhage, in most 3-CMC-exposed animals. No differences were observed inthe heart. Our findings show rapid 3-CMC renal elimination, with enantio selectivity in metabolism. Alt-hough biochemical evaluations are ongoing, the results are expected to give further insights on the 3-CMC toxicity and histological abnormalities found in the brain, kidneys, liver and lungs.
- Enantiomeric biodistribution, metabolic profile, and toxicity of 3-chloromethcathinone in Wistar rats following acute exposurePublication . Langa, Ivan; Rocha-Pereira, Carolina; Silva, Paula; Milhazes, Nuno; Silva, Diana Dias da; Domingues, Susana; Resende, Albina Dolores; Barbosa, Joana; Faria, Juliana; Tiritan, Maria Elizabeth; Ribeiro, Cláudiaynthetic cathinones are a class of new psychoactive substances (NPS) with 3-chloromethcathinone (3-CMC) accounting for over 46% of NPS-related seizures in 2023. Sold as a racemate, 3-CMC exhibits enantioselective metabolism and pharmacological effects, making enantioselectivity a critical factor in evaluating its toxicokinetics and toxicodynamics. This study aimed to evaluate the enantiomeric biodistribution, metabolic profile, and toxicity of 3-CMC racemate in Wistar rats following acute exposure. For this purpose, a gas chromatography–mass spectrometry (GC–MS) method was validated for quantifying 3-CMC in biological matrices and for characterizing its biodistribution in vivo. Rats were intraperitoneally administered with saline (control) or 3-CMC (10 or 20 mg kg−1, b.w.). Animals were sacrificed 24 h after administration, and plasma, urine, and tissues were collected for biodistribution, biochemical, and histopathological analyses. 3-CMC was exclusively detected in the urine, along with three additional pairs of enantiomeric metabolites. Both 3-CMC and its metabolites exhibit enantiomeric fractions (EF) different from 0.5, indicating enantiomeric enrichment. Administration of 3-CMC significantly decreased plasma levels of creatine kinase-MB, alkaline phosphatase, and aspartate aminotransferase, along with increased levels of glucose and urea. In the urine, decreased levels of albumin were observed. Oxidative stress and energy biomarkers were altered in the brain, lungs, and kidneys. Histopathological analysis revealed morphological alterations in the brain, liver, and lungs at both doses, and in the kidneys at the highest dose. However, no significant alterations were observed in the other tissues. Taken together, our findings suggest enantioselective metabolism and indicate that, although rapidly eliminated by the kidneys, 3-CMC still causes significant toxicity in target organs, such as the brain, liver, lungs, and kidneys. This highlights the high toxicity of the drug or its metabolites, even over short-term exposure.
- Muscle Energy Technique versus PNF: effectiveness on hamstring muscle stretchingPublication . Silva, Paula; Santos, Rubim; Macedo, RuiAlthough PNF´s Contract-Relax with Antagonist Contraction (CRAC) and Muscle Energy Techniques (MET) increase muscle flexibility and Range of Motion (ROM), few studies compared their effectiveness. They share several features but one major difference, the intensity of muscle contraction prior to stretch, perceived maximum in CRAC, and a percentage of the perceived maximum in the MET. Confirm if CRAC and MET are effective in stretching the hamstring muscle in the short term, if both are determine the most effective.
- Perceptions of music students about the effects of loud music and protective practicesPublication . Rodrigues, Matilde; Silva, Mariana; Silva, Paula; Gomes, Rui; Prior, Ana; Ignacio, OctavioAs with professional musicians, also students can be exposed to dangerous sound pressure levels in the course of their academic activity, which can result in hearing damages. However, there are very few studies focused on the problem of music students’ exposure to loud music, particularly about the students’ perceptions and behaviours. In view of this, this study attempts to analyse the perceptions of the students about loud music risks, as well as to characterize their preventive behaviours and health effects. To analyse this issue, a questionnaire was developed and applied to music students of a secondary school. 123 students participated in the study. The results showed that most of students perceive ensemble classes and group study as noisy. However, several students assessed the sound levels in the different classes and in the additional study as low or moderate. Brass and percussion were identified as the noisiest instruments and strings were perceived as producing low and moderate sound pressure levels. The results also showed that only a part of the students were concerned with the health effects related to the exposure to high sound levels and the majority reported do not use hearing protection, since they never tried to use it or they seen it as non-necessary. The findings of this study showed that music students are not entirely aware of the risks associated with the exposure to high noise levels in the course of their practice and a strategy to improve protective behaviours need to be implemented in the music schools.
- Re-utilization of sewage sludges as a precursor for activated carbon productionPublication . Gutiérrez, Maria S. C.; Rocha, Maria J.; Mendes, Sandra S.; Freitas, Maria Madalena; Silva, Paula; Beleza, VitorinoThe possibility of re-utilization of sewage sludges from wastewater treatment plants as raw-material for activated carbon production was investigated. Activated carbons were prepared from secondary sludges by physical activation with carbon dioxide. Pyrolysis was carried out in nitrogen atmosphere at 873 K during 3 h. Physical activation was performed in pure CO2 flow, for 1h, at temperatures between 1123 and 1223 K. Global yields of the process range from 30 to 4o wt %. Activated carbons have surface areas from 60 to 100 m?/g and micropore volumes up to 0,020 cm3/g. Porous structure presents about 50% microporosity. A chemically activated sample (H.SO,, 973 K, 15 min, N, flow) was also prepared for comparative purposes. Results show that activated carbons produced have potential to be used as pollutant adsorbent, but further optimization studies will be needed in order to improve its porous structure.