Validation of a spectrophotometric method for quantification of xanthone in biodegradable nanoparticles

Xanthone has been incorporated for the first time in nanoparticles of poly(D,L-lactide-co-glycolide) (PLGA). For this purpose the estimation of xanthone content in the nanoparticles is a crucial tool for guaranteeing the reliability of the results. Thus, a simple spectrophotometric method was validated according to USP25 and ICH guidelines for its specificity, linearity, accuracy and precision. The method was found to be specific for xanthone in the presence of nanoparticle excipients. The calibration curve was linear over the concentration range of 0.5 to 4.0 mug/mL (r > 0.999). Recovery of xanthone from nanoparticles ranged from 86.5 to 95.9%. Repeatability (intra-assay precision) and intermediate precision were found to be acceptable with relative standard deviations values (RSD) ranging from 0.3 to 3.0% and from 1.4 to 3.1%, respectively. The method was found to be suitable for the evaluation of xanthone content in nanoparticles of PLGA

Development and characterization of PLGA nanospheres and nanocapsules containing xanthone and 3-methoxyxanthone

The aim of the present work was to develop and characterize two different nanosystems, nanospheres and nanocapsules, containing either xanthone (XAN) or 3-methoxyxanthone (3-MeOXAN), with the final goal of improving the delivery of these poorly water-soluble compounds. The xanthones-loaded nanospheres (nanomatrix systems) and nanocapsules (nanoreservoir systems), made of poly(DL-lactide-co-glycolide) (PLGA), were prepared by the solvent displacement technique. The following characteristics of nanoparticle formulations were determined: particle size and morphology, zeta potential, incorporation efficiency, thermal behaviour, in vitro release profiles and physical stability at 4 degrees C. The nanospheres had a mean diameter 77%) were higher than those corresponding to nanospheres for both xanthones. The release of 3-MeOXAN from nanocapsules was similar to that observed for the correspondent nanoemulsion, indicating that drug release is mainly governed by its partition between the oil core and the external aqueous medium. In contrast, the release of XAN from nanocapsules was significantly slower than from the nanoemulsion, a behaviour that suggests an interaction of the drug with the polymer. Nanocapsule formulations exhibited good physical stability at 4 degrees C during a 4-month period for XAN and during a 3-month period for 3-MeOXAN

Improvement of the inhibitory effect of xanthones on NO production by encapsulation in PLGA nanocapsules

For the first time the inhibitory effect of xanthone and 3-methoxyxanthone on nitric oxide (NO) production by IFN-gamma/LPS activated J774 macrophage cell line is reported. A remarkable improvement of this effect promoted by encapsulation of these compounds in nanocapsules of Poly (DL-lactide-co-glycolide) (PLGA) is also demonstrated. A weak inhibitory effect of 3.6% on NO production by activated macrophages was observed for xanthone at the highest studied concentration (100 mu M). This effect was slightly higher for 3-methoxyxanthone at the same concentration, producing a reduction of 16.5% on NO production. In contrast, equivalent concentrations of xanthone and 3-methoxyxanthone incorporated in nanocapsules produced a significant decrease on NO production of 91.8 and 80.0%, respectively. Empty nanocapsules also exhibited a slight NO inhibitory activity, which may be due to the presence of soybean lecithin in the composition of the nanosystems. The viability of the macrophages was not affected either by free or nanoencapsulated xanthones. Fluorescence microscopy analysis confirmed that a phagocytic process was involved in the macrophage uptake of xanthone- and 3-methoxyxanthone-loaded PLGA nanocapsules. Phagocytosis might be the main mechanism responsible for the enhancement of the intracellular delivery of both compounds and consequently for the improvement of their biological effect

Body composition comparison between gender in institutionalized elderly

Este estudo teve como objetivo averiguar sobre a existência de diferenças entre sexos, da composição corporal de idosos institucionalizados.The purpose of this Study was to compare the body composition differences between gender in institutionalized elderly.info:eu-repo/semantics/publishedVersio

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

The grain refinement effect and the ageing behaviour of Al–0.5 wt.% Sc, Al–0.7 wt.% Sc, and Al–1 wt.% Sc alloys are studied on the basis of optic microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) observations and hardness measurements. In Al–Sc alloys the higher grain refinement is observed for Sc contents greater than 0.5 wt.% accompanied by a notorious morphology modification, from coarse columnar grains to a fine perfect equiaxed structure. The as cast structures are characterized by a rich supersaturated solid solution in Sc, that promotes a great age hardening response at 250 C and 300 C. The age hardening curves also demonstrate a low overageing kinetics for all the alloys. Although the higher Sc content in solid solution for the alloys with 0.7 and 1 wt.% Sc, the age hardening response of all the Al–Sc alloys remains similar. The direct age hardening response of the as cast Al–0.5 wt.% Sc is shown to be greater than the solutionised and age hardened alloy.Fundação para a Ciência e Tecnologia (FCT

Development and validation of an HPLC method for the quantitation of 1,3-dihydroxy-2-methylxanthone in biodegradable nanoparticles

A rapid and simple high-performance liquid chromatographic method for the analysis of 1,3-dihydroxy-2-methylxanthone (DHMXAN) in biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanosphere and nanocapsule formulations is developed and validated. The method does not require any complex sample extraction procedure. Chromatographic separation is made with a reversed-phase C18 column, using methanol-water (90:10, v/v) containing 1% (v/v) acetic acid as a mobile phase at a flow rate of 1 mL/min. Identification is made by UV detection at 237 nm. The isocratic system operates at ambient temperature and requires 7.5 min of chromatographic time. The developed method is statistically validated according to ICH guidelines and USP 29 for its specificity, linearity, accuracy, and precision. The assay method proposed in this study is specific for DHMXAN in the presence of nanosphere and nanocapsule excipients. Diode-array analyses confirm the purity of DHMXAN peak in stress conditions (> 99.0%). The method is shown to be linear (r 0.999) over the concentration range of 0.25-3.0 g/mL. Recovery ranges from 99.0% to 102.7% (RSD: 1.49%) and from 98.3% to 101.6% (RSD: 1.07%) for nanospheres and nanocapsules, respectively. Repeatability (intraassay precision) and intermediate precision is acceptable with RSD values ranging from 0.6% to 1.9% and from 0.3% to 2.0%, respectively. The method is shown to be suitable for the evaluation of DHMXAN content entrapped in PLGA nanoparticles

Do the strength levels predict the motor coordination in young basketball players?

O objetivo deste estudo foi averiguar sobre a existência de relação entre os níveis de força e a coordenação motora em basquetebolistas pertencentes ao escalão de sub-18.The aim of this study was to analyse the relation between the strength levels and motor coordination in young basketball players.info:eu-repo/semantics/publishedVersio

Do the strength levels predict the motor coordination in young basketball players?

The aim of this study was to analyse the relation between the strength levels and motor coordination in young basketball players. The sample of this study was composed by 12 basketball players with 15.83 (± 0.55) years old from the U-18 category. The players participate in the inter-regional, national championship round and national cup in 2015/2016 season. The upper limbs strength was evaluated with the push-up exercise, counting the number of repetitions in 30 seconds. The lower limbs strength was evaluated in centimetres with the horizontal jump without preparatory sprint. The motor coordination was evaluated with 6 cones separated by 1,5m in the diagonal. The athletes with ball, skirted the cones and ended with layup finalization, this exercise was measured in seconds. Spearman correlation test was accessed with a significance level of 5%. No significant correlation was observed between upper limbs strength and motor coordination (F =-0,259; p =0.208). However, a negative significant correlation was observed between lower limbs strength and coordination was observed (F =-0,539; p =0,035). Thus, basketball coaches should perform specific strength training seasons intending to improve the motor coordination. Improving strength levels may contribute for motor coordination improvement.info:eu-repo/semantics/publishedVersio

The effect of a six months multicomponent training in elderly's body composition and functional fitness - A before-after analysis

The aim of this study was to assess the elderly’s functional fitness and body composition effects between pre and post multicomponent training program with six months of intervention. The sample of this study was composed of 34 volunteered elders with 68 (± 7.55) years old. The body composition was evaluated by a Tanita BC-545, and a functional fitness test assessed the elderly’s functional fitness. The body composition did not present significant changes between the pre- and post-exercise program intervention. The training program increased the upper limbs’ strength levels and upper body flexibility, and aerobic endurance. Different associations between body composition and functional fitness variables were found between pre and post multicomponent training program. In this study, body composition seems not to be affected. However, functional fitness in upper limbs strength, upper body flexibility, and aerobic endurance improved under six months of multicomponent training.Instituto Superior de Ciências Educativas do Douro – Penafiel, Portugal. 2Instituto Politécnico de Bragança – Bragança, Portugal. 3Research Center in Sports Health and Human Development – Covilhã, Portugal. *Correponding author: Rua Vitorino da Costa, 96, CEP: 4560-708 Penafiel, Portugal. E-mail: [email protected] Conflict of interests: Nothing to declare. Funding: This research is supported by the Portuguese Foundation for Science and Technology, I.P. (project UIDB04045/2020), by Research Center in Sports Health and Human Development, Covilhã, Portugal and Instituto Superior de Ciências Educativas do Douroinfo:eu-repo/semantics/publishedVersio

Assessment of the inter-lap stability and relationship between the race time and start, clean swim, turn and finish variables in elite male junior swimmers’ 200 m freestyle

The aims of this study were to: (1) assess the stability (mean and normative) of the lap performance, and a set of clean swim and turn variables of junior male swimmers in the 200 m freestyle, and; (2) verify the relationship between the start, clean swim, turn, and finish phases in the 200 m freestyle. Seventy-six individual races in the 200 m freestyle at the 2019 long-course LEN European Junior Championships were analysed. Start, clean swim, turn, and finish variables were assessed. The lap performance showed a significant variance. The highest variation was verified between the first and third lap (Coefficient of Variation = 7.37%). The clean swim and the total turn also presented a significant variance. Normative stability indicated a moderate to very-high stability for all variables. All phases of the race had significant correlations with the final race time (p < 0.001). The total turn (i.e., the total time spent to perform the turn), specifically turn #3, showed the largest correlation with the total race performance. The significant correlation between all phases of the race and the final race time indicates that coaches and swimmers should customise the swimmers’ preparation and race strategy at major international competitions, based on the individual characteristics of each swimmerTo LEN and Spiideo AB for providing the video clips. This project was supported by the National Funds through FCT - Portuguese Foundation for Science and Technology (UIDB/DTP/04045/2020)info:eu-repo/semantics/publishedVersio