13 research outputs found
Repetibilidad y reproducibilidad de las medidas de tejidos in vivo efectuadas con ultrasonidos en ovejas adultas y sus correlaciones con la condición corporal
La evaluación de la condición corporal permite conocer el estado de
reservas de los animales (Santucci et al., 1991; Delfa el al., 1995; Teixeira et al.,
1995), siendo el espesor de los tejidos en la región esternal el punto de elección en
caprinos tal como mostró Morand-Fehr et al. (1989). Este conocimiento permite
adecuar la alimentación de los animales, no obstante esta metodología es muy
susceptible a errores entre operadores (Evans, 1978). Así la substitución de esta
técnica por otras más objetivas presenta interés práctico. Las medidas de
ultrasonidos que permiten determinar las medidas de espesor de los tejidos, con
elevada repetible edad y reproducibilidad, podrán ser una alternativa interesante
EMG signal processing for the study of localized muscle fatigue—pilot study to explore the applicability of a novel method
This pilot study aimed to explore a method for characterization of the electromyogram
frequency spectrum during a sustained exertion task, performed by the upper limb. Methods: Nine
participants underwent an isometric localized muscle fatigue protocol on an isokinetic
dynamometer until exhaustion, while monitored with surface electromyography (sEMG) of the
shoulder’s external rotators. Firstly, three methods of signal energy analysis based on primer
frequency contributors were compared to the energy of the entire spectrum. Secondly, the chosen
method of analysis was used to characterize the signal energy at beginning (T1), in the middle (T2)
and at the end (T3) of the fatigue protocol and compared to the torque output and the shift in the
median frequencies during the trial. Results: There were statistically significant differences between
T1 and T3 for signal energy (p < 0.007) and for central frequency of the interval (p = 0.003). Moreover,
the isometric peak torque was also different between T1 and T3 (p < 0.001). Overall, there were no
differences between the signal energy enclosed in the 40 primer frequency contributors and the
analysis of the full spectrum energy; consequently, it was the method of choice. The reported fatigue
and the decrease in the produced muscle torque was consistent with fatigue-induced alterations in
the electromyogram frequency spectrum. In conclusion, the developed protocol has potential to be
considered as an easy-to-use method for EMG-based analysis of isometric muscle exertion until
fatigue. Thus, the novelty of the proposed method is to explore, in muscle fatigue, the use of only
the main contributors in the frequency domain of the EMG spectrum, avoiding surplus information,
that may not represent muscle functioning. However, further studies are needed to investigate the
stability of the present findings in a more comprehensive sample.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020
and UIDP/05757/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
Optimized ultrasound-assisted extraction of phenolic compounds from Thymus comosus Heuff. ex Griseb. et Schenk (wild thyme) and their bioactive potential
An optimized ultrasound-assisted extractive method was developed to obtain a polyphenol-enriched extract from
the aerial parts of Thymus comosus Heuff. ex Griseb. et Schenk. Optimization process was conducted based on
Design of Experiment (DoE) principles, determining the influence of three independent variables (time, ultrasound
amplitude, ethanol concentration) on the total phenolic content of the extract (dependent variable).
Additionally, the phenolic composition of the extract was characterized through UHPLC-HRMS, revealing beside
the most abundant flavonoid-type compounds the presence of salvianolic acids C, D and L in high amounts.
Phytochemical profile of the extract was correlated with its antioxidant activity (tested through five complementary
assays) and enzyme-inhibitory potential, showing important antiglucosidase and anticholinesterase
effects. Overall, it was concluded that the developed method is suitable for obtaining a good recovery of both
phenolic and non-phenolic compounds from Thymus comosus aerial parts, and their presence in the optimized
extract is responsible for its pharmacological potential.This work was supported by a grant of the Romanian Ministry of
Education and Research, CNCS – UEFISCDI, project number PN-III-P1-
1.1-PD-2019-1245, within PNCDI III”. The authors are grateful to the
Foundation for Science and Technology (FCT, Portugal) for financial
support through national funds FCT/MCTES to CIMO (UIDB/00690/2020), and for the contracts of J. Pinela (CEECIND/01011/2018) and L.
Barros (institutional scientific employment program-contract).info:eu-repo/semantics/publishedVersio
Development of an optimized drying process for the recovery of bioactive compounds from the Autumn Fruits of Berberis vulgaris L. and Crataegus monogyna Jacq
Hot air drying has proven to be an efficient method to preserve specific edible plant materials
with medicinal properties. This is a process involving chemical, physical, and biological
changes in plant matrices. Understanding these processes will lead to an improvement in the yields
of bioactive compounds. This study aims to optimize the drying process of two species’ fruits used
in folk medicine, Berberis vulgaris and Crataegus monogyna. The optimized extracts’ antioxidant capacity
was assessed using various assays, with the barberry extract showing very good activity
(50.85, 30.98, and 302.45 mg TE/g dw for DPPH, TEAC, and FRAP assays, respectively). Both species
exerted good fungal α-glucosidase inhibitory activity (IC50 = 0.34 and 0.56 mg/mL, respectively) but
no activity on mammalian α-glucosidase. Additionally, this study identified and quantified the
main bioactive compounds. The results presented herein are a breakthrough in industrializing this
drying process. Additional studies are necessary to mechanistically understand the drying process
involved in these plant materials.This work was supported by a grant of the Romanian Ministry of Education and Research,
CNCS–UEFISCDI, project number PN-III-P2-2.1-PED-2019-5360.The authors are grateful to the Foundation for Science and Technology (FCT; Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020), the national funding for F.C.T. and P.I. and through the institutional scientific employment program contract for M.I.D., and L.B. The authors are grateful to FEDER—Interreg España—Portugal programme
for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P.info:eu-repo/semantics/publishedVersio
Biological profiles of Q. cerris, Q. dalechampii, and Q. robur bark extracts: A characterization study
The main objective of the present study was to characterize the extracts obtained from the bark of three oak species in order to assess their use in potential cosmetic products
Valorization of Corn Silk as an Agricultural By-Product through the Optimization of Ultrasound-Assisted Extraction
Corn silk, derived from the stigmas of corn (Zea mays, Poaceae) flowers, possesses valuable bioactive compounds that can be harnessed for therapeutical, nutritional, and industrial purposes. This research aimed to optimize the extraction of bioactive compounds from corn silk, specifically flavonoids and total antioxidant capacity, by comparing it with classical extraction (infusion and maceration). The study identified significant factors influencing total flavonoid content (TFC) and antioxidant activity (assessed through an ABTS assay), including ethanol concentration, ultrasonic amplitude, and their quadratic interactions. This optimized combination of independent variables (37.89% ethanolic concentration, 48.58% ultrasound amplitude, and an extraction time of 38.72 min) yielded a balanced extraction, maximizing both TFC and antioxidant activity. Further analyses revealed significant total phenolic content, total flavonoid content (50.69 ± 0.36 mg GAE, 23.54 ± 0.01 mg QE, and 78.33 ± 0.94 mg TE/g extract, respectively), and potent in vitro antioxidant activity, affirming the efficacy of the optimized extraction. The study also explored the inhibitory effects on α-glucosidase (IC50 = 411.67 ± 25.39 µg/mL), acetylcholinesterase (IC50 = 1166.4 ± 399.38 µg/mL), and pancreatic lipase (IC50 = 1519.67 ± 209.04 µg/mL), showcasing potential antidiabetic and neuroprotective properties. While tyrosinase inhibition activity was not observed, the research emphasizes the nutraceutical potential of corn silk, offering valuable insights for its utilization and further exploration in the pharmaceutical and functional food industries
Contextos da adesão e do abandono do tratamento por portadores de HIV em países de baixa renda
Não podemos esquecer que o diagnóstico da seropositividade causa um grande
impacto no indivíduo, despoletando sentimentos e emoções negativas. Assim sendo, é
preciso que ele conheça a doença e o tratamento, para perceber que a adaptação a um
novo estilo de vida é necessária, mas não é limitadora da vida (Camargo, 2013). Dessa
forma poderá encarar a cronicidade do VIH/SIDA e o processo de adesão a um regime
de tratamento completo e prolongado, evitando falhas que aumentam o risco de incompleta
supressão viral e ainda de desenvolvimento de cepas virais resistentes aos medicamentos
disponíveis (Feitosa, Lima, Caetano, Andrade, & Beserra, 2008). A adesão
à terapia antirretroviral (TARV) está fortemente associada à supressão viral máxima e
duradoura, reduzidas taxas de resistência e aumento da sobrevida e qualidade de vida
dos pacientes. Constitui um desafio para o paciente e equipa multidisciplinar, pois trata-
se de uma doença crónica que exige acompanhamento ambulatorial e laboratorial
frequentes, além de uma rigorosa toma de medicação prescrita (Menezes et al., 2019).
A adesão ao tratamento também reflete a forma como o paciente percepciona a
relação da necessidade do uso de medicamentos com a doença.info:eu-repo/semantics/publishedVersio
Exploring Polyphenols Extraction from Thuja occidentalis L. Bark: Optimization, Phytochemical Profiling, and Biological Evaluation
Polyphenols were extracted from Thuja occidentalis L. bark and characterized in terms of phytochemical composition and biological activity. The optimization process investigated the impacts of extraction duration, ultrasound amplitude, and ethanol concentration on the total phenolic content in the extract. The antioxidant capacity was examined using DPPH and ABTS assays, and anti-enzyme activity against alpha-glucosidase, alpha-amylase, lipase, acetylcholinesterase, and tyrosinase was determined. The experimental model revealed optimal extraction parameters: a hydroethanolic solvent with 44% v:v ethanol, a 15-minute extraction time, and a 40% ultrasound amplitude. These parameters were validated and confirmed by reaching the target Total Phenolic Content (TPC) predicted by MODDE software. The resulting lyophilized extract exhibited a high polyphenolic content (161.84 ± 23.48 mg GAE/g dry extract) and demonstrated strong antioxidant properties. Notably, it showed significant inhibition of alpha-glucosidase and alpha-amylase, suggesting potential antidiabetic effects, though its inhibition of tyrosinase activity was relatively weak. These findings provide a foundation for further investigations to confirm the qualitative and quantitative presence of specific polyphenolic metabolites in the extract and elucidate the mechanisms underlying its bioactive properties
Comparative Study on the Chemical Composition and Biological Activity of Polyphenolic Extracts Obtained from Maclura pomifera (Raf.) C.K. Schneid Bark and Periderm
Literature is limited regarding the potential use of the bark of Maclura pomifera as a source of bioactive compounds. The influence of different extraction methods was assessed for the chemical and biological properties of extracts obtained from the bark and periderm of M. pomifera. The extraction process was completed using three methods: microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and sonicator-assisted extraction (SAE). The extracts were characterized by total polyphenol content. The antioxidant capacity was evaluated using DPPH and ABTS methods, the antimicrobial effect was tested against Gram-positive and Gram-negative bacterial strains, and the inhibition of enzyme activity was conducted using α-glucosidase, lipase, and α-amylase assays. The extracts obtained from the periderm exhibited a lower total polyphenolic content compared to those obtained from the bark. The highest antioxidant activity using the DPPH method was observed in the MAE bark extracts and when using the ABTS method, and the highest activity was observed in the UAE bark extracts. Enzymatic activity was most strongly inhibited by the SAE bark extract. The most pronounced antibacterial potential was observed in the MAE and UAE bark extracts, with minimum inhibitory concentration values obtained below 1 mg/mL
Untargeted phytochemical profiling and biological activity of small yellow onion (Allium flavum L.) from different regions of Romania
This study examined the phytochemical profiles (mainly phenolics, carotenoids, and organosulfur compounds) and biological effects of hydroalcoholic extracts of Allium flavum (AF), a species of the Allium genus commonly known as small yellow onion. Unsupervised and supervised statistical approaches revealed clear differences between extracts prepared with samples collected from different areas of Romania. Overall, the AFFF (AF flowers collected from Făget) extract was the best source of polyphenols, also showing the highest antioxidant capacity evaluated through both in vitro DPPH, FRAP, and TEAC anti-radical scavenging assays and cell-based OxHLIA and TBARS assays. All the tested extracts exhibited α-glucosidase inhibition potential, while only the AFFF extract exhibited anti-lipase inhibitory activity. The phenolic subclasses annotated were positively correlated with the assessed antioxidant and enzyme inhibitory activities. Our findings suggested that A. flavum has bioactive properties worth exploring further, being a potential edible flower with health-promoting implications