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1.
Chronobiol Int ; : 1-12, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745424

RESUMO

The purpose of this study was to investigate the effects of a novel dietary supplement, including melatonin and magnesium, delivered via coffee pods on sleep quality, resting metabolic rate (RMR), and body composition in individuals with poor sleep quality disturbances. Using a double-blinded, randomized, crossover trial, we recruited 35 participants to a 4-week intervention with both supplements (1.9 mg melatonin + 200 mg elemental magnesium before sleep) and placebo conditions, considering a 7d washout period between treatments. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was applied, RMR (kcal) was measured using indirect calorimetry (canopy ventilated open-circuit system) and body composition was assessed using dual-energy X-ray absorptiometry. Decreases in PSQI and anger - hostility scores, as well as in energy intake and fat mass, were observed (p < 0.05) for both conditions, from baseline to the end of each 4-week intervention. Differences between conditions were also observed for these parameters along with energy spent in activity, number of sedentary breaks, sleep efficiency, latency time, time in bed, total sleep time, awakening time, and movement index (p < 0.05) favouring the supplement condition. However, the final PSQI questionnaire scores still indicated poor sleep quality on average (PSQI > 5), in both conditions, with no changes regarding RMR. A melatonin-magnesium supplement, in a coffee pod format, showed improvements in sleep quality in otherwise healthy individuals with sleep disturbances, however PSQI questionnaire scores still indicated poor quality on average (PSQI > 5).

2.
Biofilm ; 7: 100185, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38444517

RESUMO

The ability of bacteria to adhere to and form biofilms on food contact surfaces poses serious challenges, as these may lead to the cross-contamination of food products. Biomimetic topographic surface modifications have been explored to enhance the antifouling performance of materials. In this study, the topography of two plant leaves, Brassica oleracea var. botrytis (cauliflower, CF) and Brassica oleracea capitate (white cabbage, WC), was replicated through wax moulding, and their antibiofilm potential was tested against single- and dual-species biofilms of Escherichia coli and Pseudomonas putida. Biomimetic surfaces exhibited higher roughness values (SaWC = 4.0 ± 1.0 µm and SaCF = 3.3 ± 1.0 µm) than the flat control (SaF = 0.6 ± 0.2 µm), whilst the CF surface demonstrated a lower interfacial free energy (ΔGiwi) than the WC surface (-100.08 mJ m-2 and -71.98 mJ m-2, respectively). The CF and WC surfaces had similar antibiofilm effects against single-species biofilms, achieving cell reductions of approximately 50% and 60% for E. coli and P. putida, respectively, compared to the control. Additionally, the biomimetic surfaces led to reductions of up to 60% in biovolume, 45% in thickness, and 60% in the surface coverage of single-species biofilms. For dual-species biofilms, only the E. coli strain growing on the WC surface exhibited a significant decrease in the cell count. However, confocal microscopy analysis revealed a 60% reduction in the total biovolume and surface coverage of mixed biofilms developed on both biomimetic surfaces. Furthermore, dual-species biofilms were mainly composed of P. putida, which reduced E. coli growth. Altogether, these results demonstrate that the surface properties of CF and WC biomimetic surfaces have the potential for reducing biofilm formation.

3.
Front Sports Act Living ; 6: 1334739, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38318484

RESUMO

Introduction: In the current experiment, we aimed to evaluate whether eliciting pre-exercise non-thermal cooling sensations would alter perceptual measures, and physical and physiological responses in football referees. Methods: Nine highly trained male football referees undertook two 45-minute intermittent exercise protocols in hot and humid conditions (34.2 ± 0.6°C, 62.5 ± 1.0% relative humidity). In a randomized counterbalanced crossover design, 1 of 2 beverages were given before the warm-up: a 0.01% menthol solution or a placebo noncaloric solution. Physical performance was quantified as total distance covered in each of the three 15-minute exercise blocks. Core temperature, heart rate, thermal sensation and thermal comfort were measured at rest and after each exercise block. Results: No changes were observed between trials and over time for distance covered. No main effect of mouth rinse was observed for core temperature and heart rate, but both increased over time in all conditions (P < 0.001). Thermal sensation and thermal comfort were significantly improved with menthol after mouth-rinsing (P < 0.05), but with no differences at any other time-point. Discussion: These results indicate that non-thermal cooling oral stimuli provide immediate behavioral changes but may not influence physiological or physical responses in football referees, during intermittent exercise in hot and humid environments. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT05632692.

4.
Antibiotics (Basel) ; 12(11)2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-37998822

RESUMO

Chemically modified carbon nanotubes are recognized as effective materials for tackling bacterial infections. In this study, pristine multi-walled carbon nanotubes (p-MWCNTs) were functionalized with nitric acid (f-MWCNTs), followed by thermal treatment at 600 °C, and incorporated into a poly(dimethylsiloxane) (PDMS) matrix. The materials' textural properties were evaluated, and the roughness and morphology of MWCNT/PDMS composites were assessed using optical profilometry and scanning electron microscopy, respectively. The antibiofilm activity of MWCNT/PDMS surfaces was determined by quantifying culturable Escherichia coli and Staphylococcus aureus after 24 h of biofilm formation. Additionally, the antibacterial mechanisms of MWCNT materials were identified by flow cytometry, and the cytotoxicity of MWCNT/PDMS composites was tested against human kidney (HK-2) cells. The results revealed that the antimicrobial activity of MWCNTs incorporated into a PDMS matrix can be efficiently tailored through nitric acid functionalization, and it can be increased by up to 49% in the absence of surface carboxylic groups in f-MWCNT samples heated at 600 °C and the presence of redox activity of carbonyl groups. MWCNT materials changed the membrane permeability of both Gram-negative and Gram-positive bacteria, while they only induced the production of ROS in Gram-positive bacteria. Furthermore, the synthesized composites did not impact HK-2 cell viability, confirming the biocompatibility of MWCNT composites.

5.
Biomolecules ; 13(11)2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-38002253

RESUMO

The application of graphene-based materials in medicine has led to significant technological breakthroughs. The remarkable properties of these carbon materials and their potential for functionalization with various molecules and compounds make them highly attractive for numerous medical applications. To enhance their functionality and applicability, extensive research has been conducted on surface modification of graphene (GN) and its derivatives, including modifications with antimicrobials, metals, polymers, and natural compounds. This review aims to discuss recent and relevant studies related to advancements in the formulation of graphene composites, addressing their antimicrobial and/or antibiofilm properties and evaluating their biocompatibility, with a primary focus on their biomedical applications. It was concluded that GN surface modification, particularly with compounds intrinsically active against bacteria (e.g., antimicrobial peptides, silver and copper nanomaterials, and chitosan), has resulted in biomaterials with improved antimicrobial performance. Furthermore, the association of GN materials with non-natural polymers provides composites with increased biocompatibility when interfaced with human tissues, although with slightly lower antimicrobial efficacy. However, it is crucial to highlight that while modified GN materials hold huge potential, their widespread use in the medical field is still undergoing research and development. Comprehensive studies on safety, long-term effects, and stability are essential before their adoption in real-world medical scenarios.


Assuntos
Anti-Infecciosos , Grafite , Humanos , Grafite/farmacologia , Grafite/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Prata/farmacologia , Prata/química , Polímeros/química
6.
Materials (Basel) ; 16(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37834565

RESUMO

The purpose of this work was to investigate the structural, thermal, micromechanical and tribological properties of novel polymer/metal composite materials for bearing applications. Copper (Cu)-filled Acrylonitrile Butadiene Styrene (ABS) composites were mixed in a laboratory scale by an internal mixer with two blade impellers, and then injection-molded. Neat ABS, ABS+5wt% Cu, ABS+10wt% Cu, and ABS+15wt% Cu were the four materials that were tested. The dispersion of Cu particles in the ABS matrix was investigated using Scanning Electron Microscopy (SEM) and a micro-tomography scan. The filler particles have a uniform distribution in the matrix, according to the observations. The incorporation of Cu filler also refined an increase in the glass transition temperature from Differential Scanning Calorimetry (DSC) and less intensity in the amorphous phase by X-ray diffraction (XRD). Nanoindentation tests were carried out to characterize the micro-mechanical behavior of the composites. Friction and wear analysis were also examined using a pin-on-disk tribometer. Compared with neat ABS, all the micro-composites showed much higher indentation hardness, Vickers hardness, and indentation elastic modulus. It was also concluded that the incorporation of Cu filler into ABS simultaneously improved the friction and wear properties of the composites, which contributed to the suitability of the micro-filled composites with hard metallic particles for a wider range of mechanical components for bearing applications.

7.
Nanomaterials (Basel) ; 13(18)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37764632

RESUMO

Graphene has been broadly studied, particularly for the fabrication of biomedical devices, owing to its physicochemical and antimicrobial properties. In this study, the antibiofilm efficacy of graphene nanoplatelet (GNP)-based composites as coatings for urinary catheters (UCs) was investigated. GNPs were functionalized with nitrogen (N-GNP) and incorporated into a polydimethylsiloxane (PDMS) matrix. The resulting materials were characterized, and the N-GNP/PDMS composite was evaluated against single- and multi-species biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Both biofilm cell composition and structure were analyzed. Furthermore, the antibacterial mechanisms of action of N-GNP were explored. The N-GNP/PDMS composite showed increased hydrophobicity and roughness compared to PDMS. In single-species biofilms, this composite significantly reduced the number of S. aureus, P. aeruginosa, and K. pneumoniae cells (by 64, 41, and 29%, respectively), and decreased S. aureus biofilm culturability (by 50%). In tri-species biofilms, a 41% reduction in total cells was observed. These results are aligned with the outcomes of the biofilm structure analysis. Moreover, N-GNP caused changes in membrane permeability and triggered reactive oxygen species (ROS) synthesis in S. aureus, whereas in Gram-negative bacteria, it only induced changes in cell metabolism. Overall, the N-GNP/PDMS composite inhibited biofilm development, showing the potential of these carbon materials as coatings for UCs.

8.
Contemp Clin Trials Commun ; 35: 101202, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37691850

RESUMO

Background: Within professional European competitions, matches can be played in extreme environmental temperatures, ranging from -5 °C to +30 °C in different countries. Furthermore, the World Cups are usually played in the summer months, when temperatures can exceed 35 °C, increasing physiological stress. Practical and cost-effective cooling strategies may be implemented to help players and referees to cope with exercising in the heat. No study has evaluated the effect of non-thermal internal cooling techniques regarding performance responses on elite football referees, so far. This study aims to analyse the effects of a menthol mouth rinse regarding physical, physiological, and perceptual performance in elite male football referees, during a 90-min football protocol in the heat. Methods: At least thirteen male football referees will be recruited to perform two intermittent football protocols, separated by no less than 7 days. After passing the eligibility criteria, the participants will be randomly assigned to 1 of 2 beverages: (1) intervention - menthol solution 0.01% and (2) placebo - noncaloric berry-flavored solution, both at room temperature. The beverages will be given before warm-up (pre-cooling) and at the half-time (per-cooling). The trials will follow a randomized counterbalanced crossover design, single blinded, and will take place in indoor facilities, with Wet Bulb Globe Temperature (WBGT) > 30 °C, at the same time of the day to control for circadian variations. Impact of the project: The results of this study are expected to determine whether mouth rinsing a menthol solution before and during a football exercise protocol performed in the heat will alter perceptual measures and help ease physiological strain and attenuate performance decrements in elite male football referees, comparing to a non-cooling strategy. Thus, we can be closer to defining nutritional strategies of internal cooling that may be an advantage for the performance of the football referees in the heat. Trial registration: www.ClinicalTrials.gov NCT05632692 registered on 20 November 2022.

9.
Sci Data ; 10(1): 569, 2023 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-37634018

RESUMO

This study describes a dataset containing urban fire events that took place in mainland Portugal between 2013 and 2022. The Regulation n.º3317-A/2018, established by the Portuguese National Emergency and Civil Protection Authority (Autoridade Nacional de Emergência e Proteção Civil, ANEPC), defines the Operations Management System (Sistema de Gestão de Operações, SGO). Among other attributions, this system allows to manage the lyfe-cycle of the urban fire events, from ignition to extinction, through the Operations Decision Support System (Sistema de Apoio à Decisão Operacional, SADO). This system supports the systematic collection of a minimum set of data on each event. All instances included in the dataset were retrieved from SADO. To make the data suitable for analytic purposes, several pre-processing actions were taken, including the steps of data transformation and cleaning. The dataset was further validated by a set of technical procedures aiming to verify both data correctness and utility. The final dataset provides the most recent multi-year record of Portuguese urban fires including 27 variables on 72641 events.

10.
JAC Antimicrob Resist ; 5(3): dlad073, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37313351

RESUMO

Introduction: Antimicrobial resistance (AMR) is a major global health threat, particularity in lower-middle-income countries (LMICs) where antibiotics are readily available, leading to antibiotic misuse. Educational interventions are lacking in Zambia. Our study assessed antimicrobial use and resistance knowledge, attitude and perceived quality of education relating to AMR in Zambian medical schools. Methods: A cross-sectional anonymous survey of students at six accredited medical schools in Zambia using a self-administered questionnaire was administered, using Qualtrics. Chi-squared, Fisher exact test, Pearson correlation test and Student's t-tests were performed for descriptive analyses. Multivariable logistic regression was used to examine associations between knowledge and antibiotic use, beliefs and behaviours. Analysis was performed in SAS version 9.4. Results: One hundred and eighty responses from six medical schools were included in the final analysis. Fifty-six percent of students rated their overall education on antibiotic use as useful or very useful. Ninety-one percent thought that antibiotics are overused, and 88% thought resistance was a problem in Zambia. Only 47% felt adequately trained on antibiotic prescribing, and 43% felt confident in choosing the correct antibiotic for specific infections. Only 2% felt prepared interpreting antibiograms, 3% were trained to de-escalate to narrow-spectrum antibiotics, 6% knew how to transition from IV antibiotics to oral antibiotics, 12% knew of dosing and duration, and 14% understood the spectrum of activity of antibiotics. Forty-seven percent of respondents think hand hygiene is unimportant. Conclusions: Medical students in Zambia expressed a good level of knowledge, but low levels of training and confidence regarding antimicrobial prescribing practices and resistance. Our study highlights training gaps and possible areas of intervention in the medical school curriculum.

11.
Antibiotics (Basel) ; 12(4)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37107116

RESUMO

Microorganisms tend to adhere to food contact surfaces and form biofilms, which serve as reservoirs for bacteria that can contaminate food. As part of a biofilm, bacteria are protected from the stressful conditions found during food processing and become tolerant to antimicrobials, including traditional chemical sanitisers and disinfectants. Several studies in the food industry have shown that probiotics can prevent attachment and the consequent biofilm formation by spoilage and pathogenic microorganisms. This review discusses the most recent and relevant studies on the effects of probiotics and their metabolites on pre-established biofilms in the food industry. It shows that the use of probiotics is a promising approach to disrupt biofilms formed by a large spectrum of foodborne microorganisms, with Lactiplantibacillus and Lacticaseibacillus being the most tested genera, both in the form of probiotic cells and as sources of cell-free supernatant. The standardisation of anti-biofilm assays for evaluating the potential of probiotics in biofilm control is of extreme importance, enabling more reliable, comparable, and predictable results, thus promoting significant advances in this field.

12.
Nanomaterials (Basel) ; 13(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36985952

RESUMO

Atmospheric plasma spray (APS) remains the only certified industrial process to produce hydroxyapatite (Hap) coatings on orthopaedic and dental implants intended for commercialization. Despite the established clinical success of Hap-coated implants, such as hip and knee arthroplasties, a concern is being raised regarding the failure and revision rates in younger patients, which are increasing rapidly worldwide. The lifetime risk of replacement for patients in the 50-60 age interval is about 35%, which is significantly higher than 5% for patients aged 70 or older. Improved implants targeted at younger patients are a necessity that experts have been alerted to. One approach is to enhance their bioactivity. For this purpose, the method with the most outstanding biological results is the electrical polarization of Hap, which remarkably accelerates implant osteointegration. There is, however, the technical challenge of charging the coatings. Although this is straightforward on bulk samples with planar faces, it is not easy on coatings, and there are several problems regarding the application of electrodes. To the best of our knowledge, this study demonstrates, for the first time, the electrical charging of APS Hap coatings using a non-contact, electrode-free method: corona charging. Bioactivity enhancement is observed, establishing the promising potential of corona charging in orthopedics and dental implantology. It is found that the coatings can store charge at the surface and bulk levels up to high surface potentials (>1000 V). The biological in vitro results show higher Ca2+ and P5+ intakes in charged coatings compared to non-charged coatings. Moreover, a higher osteoblastic cellular proliferation is promoted in the charged coatings, indicating the promising potential of corona-charged coatings when applied in orthopedics and dental implantology.

13.
Nanomaterials (Basel) ; 13(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36770342

RESUMO

Due to its several economic and ecological consequences, biofouling is a widely recognized concern in the marine sector. The search for non-biocide-release antifouling coatings has been on the rise, with carbon-nanocoated surfaces showing promising activity. This work aimed to study the impact of pristine graphene nanoplatelets (GNP) on biofilm development through the representative marine bacteria Cobetia marina and to investigate the antibacterial mechanisms of action of this material. For this purpose, a flow cytometric analysis was performed and a GNP/polydimethylsiloxane (PDMS) surface containing 5 wt% GNP (G5/PDMS) was produced, characterized, and assessed regarding its biofilm mitigation potential over 42 days in controlled hydrodynamic conditions that mimic marine environments. Flow cytometry revealed membrane damage, greater metabolic activity, and endogenous reactive oxygen species (ROS) production by C. marina when exposed to GNP 5% (w/v) for 24 h. In addition, C. marina biofilms formed on G5/PDMS showed consistently lower cell count and thickness (up to 43% reductions) than PDMS. Biofilm architecture analysis indicated that mature biofilms developed on the graphene-based surface had fewer empty spaces (34% reduction) and reduced biovolume (25% reduction) compared to PDMS. Overall, the GNP-based surface inhibited C. marina biofilm development, showing promising potential as a marine antifouling coating.

14.
Molecules ; 28(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36770658

RESUMO

The demand for bio-based and safer composite materials is increasing due to the growth of the industry, human population, and environmental concerns. In this framework, sustainable and safer cork-polymer composites (CPC), based on green low-density polyethylene (LDPE) were developed using melt-based technologies. Chitosan and polyethylene-graft-maleic anhydride (PE-g-MA) were employed to enhance the CPC's properties. The morphology, wettability, mechanical, thermal, and antibacterial properties of the CPC against Pseudomonas putida (P. putida) and Staphylococcus aureus (S. aureus) were examined. The CPC showed improved stiffness when compared with that of the LDPE matrix, preferably when combined with chitosan and PE-g-MA (5 wt. %), reinforcing the stiffness (58.8%) and the strength (66.7%). Chitosan also increased the composite stiffness and strength, as well as reduced the surface hydrophilicity. The CPCs' antibacterial activity revealed that cork significantly reduces the biofilm on the polymer matrix. The highest biofilm reduction was found with CPC containing cork and 5 wt. % chitosan for both P. putida (54% reduction) and S. aureus (36% reduction), confirming their potential to extend the lifespan of products for packaging and healthcare, among other applications. This work leads to the understanding of the factors that influence biofilm formation in cork composites and provides a strategy to reinforce their behavior using chitosan.


Assuntos
Incrustação Biológica , Quitosana , Humanos , Quitosana/farmacologia , Polietileno , Incrustação Biológica/prevenção & controle , Staphylococcus aureus , Antibacterianos/farmacologia , Polímeros
15.
Nutrients ; 15(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36678150

RESUMO

Bioelectrical impedance analysis (BIA) and anthropometry are considered alternatives to well-established reference techniques for assessing body composition. In team sports, the percentage of fat mass (FM%) is one of the most informative parameters, and a wide range of predictive equations allow for its estimation through both BIA and anthropometry. Although it is not clear which of these two techniques is more accurate for estimating FM%, the choice of the predictive equation could be a determining factor. The present study aimed to examine the validity of BIA and anthropometry in estimating FM% with different predictive equations, using dual X-ray absorptiometry (DXA) as a reference, in a group of futsal players. A total of 67 high-level male futsal players (age 23.7 ± 5.4 years) underwent BIA, anthropometric measurements, and DXA scanning. Four generalized, four athletic, and two sport-specific predictive equations were used for estimating FM% from raw bioelectric and anthropometric parameters. DXA-derived FM% was used as a reference. BIA-based generalized equations overestimated FM% (ranging from 1.13 to 2.69%, p < 0.05), whereas anthropometry-based generalized equations underestimated FM% in the futsal players (ranging from −1.72 to −2.04%, p < 0.05). Compared to DXA, no mean bias (p > 0.05) was observed using the athletic and sport-specific equations. Sport-specific equations allowed for more accurate and precise FM% estimations than did athletic predictive equations, with no trend (ranging from r = −0.217 to 0.235, p > 0.05). Regardless of the instrument, the choice of the equation determines the validity in FM% prediction. In conclusion, BIA and anthropometry can be used interchangeably, allowing for valid FM% estimations, provided that athletic and sport-specific equations are applied.


Assuntos
Composição Corporal , Esportes , Masculino , Humanos , Adolescente , Adulto Jovem , Adulto , Impedância Elétrica , Antropometria/métodos , Absorciometria de Fóton/métodos
16.
FEMS Microbiol Ecol ; 99(3)2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36633537

RESUMO

Cyanobacteria are new sources of value-added compounds but also ubiquitous and harmful microfoulers on marine biofouling. In this work, the isolation and identification of two cyanobacterial strains isolated from Cape Verde and Morocco, as well as their biofilm-forming ability on glass and Perspex under controlled hydrodynamic conditions, were performed. Phylogenetic analysis revealed that cyanobacterial strains isolated belong to Leptothoe and Jaaginema genera (Leptothoe sp. LEGE 181153 and Jaaginema sp. LEGE 191154). From quantitative and qualitative data of wet weight, chlorophyll a content and biofilm thickness obtained by optical coherence tomography, no significant differences were found in biofilms developed by the same cyanobacterial strain on different surfaces (glass and Perspex). However, the biofilm-forming potential of Leptothoe sp. LEGE 181153 proved to be higher compared with Jaaginema sp. LEGE 191154, particularly at the maturation stage of biofilm development. Three-dimensional biofilm images obtained from confocal laser scanning microscopy showed different patterns between both cyanobacterial strains and also among the two surfaces. Because standard methodologies to evaluate cyanobacterial biofilm formation, as well as two different optical imaging techniques, were used, this work also highlights the possibility of integrating different techniques to evaluate a complex phenomenon like cyanobacterial biofilm development.


Assuntos
Incrustação Biológica , Cianobactérias , Clorofila A , Cabo Verde , Marrocos , Filogenia , Polimetil Metacrilato , Cianobactérias/genética , Biofilmes
17.
Int J Parasitol ; 53(3): 133-155, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36706804

RESUMO

Gastrointestinal nematode (GIN) infections are ubiquitous and often cause morbidity and reduced performance in livestock. Emerging anthelmintic resistance and increasing change in climate patterns require evaluation of alternatives to traditional treatment and management practices. Mathematical models of parasite transmission between hosts and the environment have contributed towards the design of appropriate control strategies in ruminants, but have yet to account for relationships between climate, infection pressure, immunity, resources, and growth. Here, we develop a new epidemiological model of GIN transmission in a herd of grazing cattle, including host tolerance (body weight and feed intake), parasite burden and acquisition of immunity, together with weather-dependent development of parasite free-living stages, and the influence of grass availability on parasite transmission. Dynamic host, parasite and environmental factors drive a variable rate of transmission. Using literature sources, the model was parametrised for Ostertagia ostertagi, the prevailing pathogenic GIN in grazing cattle populations in temperate climates. Model outputs were validated on published empirical studies from first season grazing cattle in northern Europe. These results show satisfactory qualitative and quantitative performance of the model; they also indicate the model may approximate the dynamics of grazing systems under co-infection by O. ostertagi and Cooperia oncophora, a second GIN species common in cattle. In addition, model behaviour was explored under illustrative anthelmintic treatment strategies, considering impacts on parasitological and performance variables. The model has potential for extension to explore altered infection dynamics as a result of management and climate change, and to optimise treatment strategies accordingly. As the first known mechanistic model to combine parasitic and free-living stages of GIN with host feed-intake and growth, it is well suited to predict complex system responses under non-stationary conditions. We discuss the implications, limitations and extensions of the model, and its potential to assist in the development of sustainable parasite control strategies.


Assuntos
Anti-Helmínticos , Doenças dos Bovinos , Doenças Transmissíveis , Gastroenteropatias , Nematoides , Infecções por Nematoides , Parasitos , Animais , Bovinos , Modelos Epidemiológicos , Poaceae , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Infecções por Nematoides/tratamento farmacológico , Gastroenteropatias/epidemiologia , Gastroenteropatias/veterinária , Gastroenteropatias/tratamento farmacológico , Anti-Helmínticos/uso terapêutico , Ruminantes , Ostertagia , Contagem de Ovos de Parasitas/veterinária , Fezes/parasitologia
18.
Nutrition ; 107: 111931, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36584663

RESUMO

OBJECTIVES: The present study aimed to develop and cross-validate a futsal-specific bioelectrical equation for estimating fat-free mass (FFM) in male players. METHODS: A total of 66 futsal players (age 23.3 ± 5.4 years) from the Major Portuguese Futsal League "LIGA PLACARD" and from the 2nd and 3rd National Futsal Leagues were included in this cross-sectional, observational study. The participants underwent a foot-to-hand bioelectrical impedance analysis (BIA) at 50 kHz and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. The sport-specific model was developed by stepwise multiple regression using bioelectrical raw parameters [resistance (R) and reactance (Xc)] as independent variables. Validation was performed using the PRESS approach, least squares regression, concordance correlation coefficient (CCC) and Bland-Altman analyses. RESULTS: A BIA-based model was developed for FFM [FFM (kg) = -8.865 + 0.437 * Body Mass (kg) + 0.186 * Xc + 0.415 * stature (cm)2/R (R2 = 0.89, standard error of estimation = 2.38 kg)]. Results showed a substantial strength of agreement (CCC = 0.953), an r2 of 0.88 with a standard error of estimation equal to 2.31 kg, no mean bias (0.04 kg, p>0.05), low limits of agreement (ranged from -4.5 to 4.6 kg), and no trend (r = -0.170, p = 0.172). CONCLUSIONS: The present equation is the first to allow for a valid, accurate, and sport-specific assessment of FFM in male futsal players.


Assuntos
Composição Corporal , Esportes , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Impedância Elétrica , Estudos Transversais , Reprodutibilidade dos Testes , Absorciometria de Fóton , Índice de Massa Corporal
19.
Int J Mol Sci ; 23(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36498973

RESUMO

Marine biofouling is a natural process often associated with biofilm formation on submerged surfaces, creating a massive economic and ecological burden. Although several antifouling paints have been used to prevent biofouling, growing ecological concerns emphasize the need to develop new and environmentally friendly antifouling approaches such as bio-based coatings. Chitosan (CS) is a natural polymer that has been widely used due to its outstanding biological properties, including non-toxicity and antimicrobial activity. This work aims to produce and characterize poly (lactic acid) (PLA)-CS surfaces with CS of different molecular weight (Mw) at different concentrations for application in marine paints. Loligo opalescens pens, a waste from the fishery industry, were used as a CS source. The antimicrobial activity of the CS and CS-functionalized surfaces was assessed against Cobetia marina, a model proteobacterium for marine biofouling. Results demonstrate that CS targets the bacterial cell membrane, and PLA-CS surfaces were able to reduce the number of culturable cells up to 68% compared to control, with this activity dependent on CS Mw. The antifouling performance was corroborated by Optical Coherence Tomography since PLA-CS surfaces reduced the biofilm thickness by up to 36%, as well as the percentage and size of biofilm empty spaces. Overall, CS coatings showed to be a promising approach to reducing biofouling in marine environments mimicked in this work, contributing to the valorization of fishing waste and encouraging further research on this topic.


Assuntos
Anti-Infecciosos , Incrustação Biológica , Quitosana , Quitosana/farmacologia , Incrustação Biológica/prevenção & controle , Biofilmes , Pintura
20.
Front Nutr ; 9: 959516, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36337635

RESUMO

Exercise in a hot and humid environment may endanger athlete's health and affect physical performance. This systematic review aimed to examine whether internal administration of ice, cold beverages or menthol solutions may be beneficial for physical performance when exercising in different environmental conditions and sports backgrounds. A systematic search was performed in PubMed, Web of Science, Scopus and SPORTDiscus databases, from inception to April 2022, to identify studies meeting the following inclusion criteria: healthy male and female physically active individuals or athletes (aged ≥18 years); an intervention consisting in the internal administration (i.e., ingestion or mouth rinse) of ice slush, ice slurry or crushed ice and/or cold beverages and/or menthol solutions before and/or during exercise; a randomized crossover design with a control or placebo condition; the report of at least one physical performance outcome; and to be written in English. Our search retrieved 2,714 articles in total; after selection, 43 studies were considered, including 472 participants, 408 men and 64 women, aged 18-42 years, with a VO2max ranging from 46.2 to 67.2 mL⋅kg-1⋅min-1. Average ambient temperature and relative humidity during the exercise tasks were 32.4 ± 3.5°C (ranging from 22°C to 38°C) and 50.8 ± 13.4% (varying from 20.0% to 80.0%), respectively. Across the 43 studies, 7 exclusively included a menthol solution mouth rinse, 30 exclusively involved ice slurry/ice slush/crushed ice/cold beverages intake, and 6 examined both the effect of thermal and non-thermal internal techniques in the same protocol. Rinsing a menthol solution (0.01%) improved physical performance during continuous endurance exercise in the heat. Conversely, the ingestion of ice or cold beverages did not seem to consistently increase performance, being more likely to improve performance in continuous endurance trials, especially when consumed during exercises. Co-administration of menthol with or within ice beverages seems to exert a synergistic effect by improving physical performance. Even in environmental conditions that are not extreme, internal cooling strategies may have an ergogenic effect. Further studies exploring both intermittent and outdoor exercise protocols, involving elite male and female athletes and performed under not extreme environmental conditions are warranted. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021268197], identifier [CRD42021268197].

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