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1.
BMJ Open Sport Exerc Med ; 7(1): e000924, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33768961

RESUMO

Objectives: To establish pupil fitness levels, and the relationship to global norms and physical education (PE) enjoyment. To measure and describe physical activity (PA) levels during secondary school PE lessons, in the context of recommended levels, and how levels vary with activity and lesson type. Methods: A cross-sectional design; 10 697 pupils aged 12.5 (SD 0.30) years; pupils who completed a multistage fitness test and wore accelerometers to measure PA during PE lessons. Multilevel models estimated fitness and PE activity levels, accounting for school and class-level clustering. Results: Cardiorespiratory fitness was higher in boys than girls (ß=-0.48; 95% CI -0.56 to -0.39, p<0.001), within absolute terms 51% of boys and 54% of girls above the 50th percentile of global norms. On average, pupils spent 23.8% of PE lessons in moderate-to-vigorous PA (MVPA), and 7.1% in vigorous PA (VPA). Fitness-focused lessons recorded most VPA in co-educational (ß=1.09; 95% CI 0.43 to 1.74) and boys-only lessons (ß=0.32; 95% CI -0.21 to 0.85). In girls-only lessons, track athletics recorded most VPA (ß=0.13; 95% CI -0.50 to 0.75) and net/wall/racket games (ß=0.97; 95% CI 0.12 to 1.82) the most MVPA. For all lesson types, field athletics was least active (ß=-0.85; 95% CI -1.33 to -0.36). There was a relationship of enjoyment of PE to fitness (ß=1.03; 95% CI 0.83 to 1.23), and this relationship did not vary with sex (ß=-0.14 to 0.23; 95% CI -0.16 to 0.60). Conclusions: PE lessons were inactive compared with current guidelines. We propose that if we are to continue to develop a range of sporting skills in schools at the same time as increasing levels of fitness and PA, there is a need to introduce additional sessions of PE activity focused on increasing physical activity. Trial registration number: NCT03286725.

3.
Support Care Cancer ; 29(1): 145-154, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32323003

RESUMO

PURPOSE: Existing research indicates that physical activity (PA) is beneficial to men with prostate cancer (PCa). We examined the potential of a single-contact peer-support-based behavioural intervention to promote PA engagement in men treated for PCa. METHODS: A mixed methods design was employed, comprising a two-arm pragmatic trial and semi-structured interviews. The intervention was a 10-min PA-based presentation by a former patient, delivered in group seminars that are provided for patients as standard care. Seminars were alternately allocated to (a) cancer exercise specialist talk + patient speaker talk or (b) cancer exercise specialist talk only. Self-reported PA, exercise motivation, quality of life, fatigue and clinical and demographic characteristics were obtained from n = 148 (intervention: n = 69; control: n = 79) patients immediately prior to the seminar, and at follow-up ≈ 100 days later. Data were analysed using ANCOVA models and χ2 tests. Fourteen semi-structured interviews with intervention participants, which explored how the intervention was experienced, were analysed using a grounded theory-style approach. RESULTS: The intervention had no significant effect on quantitatively self-reported PA (p = 0.4). However, the intervention was statistically and clinically beneficial for fatigue (p = 0.04) and quality of life (p = 0.01). Qualitative analysis showed that the intervention was beneficial to psychological wellbeing and some participants had increased intention to engage in PA as a result of the intervention. CONCLUSIONS: A brief one-off PA-based presentation for men with PCa, delivered by a former patient alongside cancer exercise specialist advice, may result in clinically significant benefits to quality of life and may influence PA intention in certain individuals.


Assuntos
Exercício Físico/psicologia , Prostatectomia/psicologia , Neoplasias da Próstata/cirurgia , Qualidade de Vida/psicologia , Apoio Social , Terapia Comportamental , Aconselhamento , Fadiga/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Grupo Associado , Projetos Piloto , Autorrelato
4.
Nanoscale ; 7(34): 14505-14, 2015 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-26260123

RESUMO

The spontaneous wrapping of nanoparticles by membranes is of increasing interest as nanoparticles become more prevalent in consumer products and hence more likely to enter the human body. We introduce a simulations-based tool that can be used to visualize the molecular level interaction between nanoparticles and bilayer membranes. By combining LIME, an intermediate resolution, implicit solvent model for phospholipids, with discontinuous molecular dynamics (DMD), we are able to simulate the wrapping or embedding of nanoparticles by 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayer membranes. Simulations of hydrophilic nanoparticles with diameters from 10 Å to 250 Å show that hydrophilic nanoparticles with diameters greater than 20 Å become wrapped while the nanoparticle with a diameter of 10 Å does not. Instead this smaller particle became embedded in the bilayer surface where it can interact with the hydrophilic head groups of the lipid molecules. We also investigate the interaction between a DPPC bilayer and hydrophobic nanoparticles with diameters 10 Å to 40 Å. These nanoparticles do not undergo the wrapping process; instead they directly penetrate the membrane and embed themselves within the inner hydrophobic core of the bilayers.


Assuntos
Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Nanopartículas/química , 1,2-Dipalmitoilfosfatidilcolina/química , Interações Hidrofóbicas e Hidrofílicas
5.
Langmuir ; 31(3): 1086-94, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25549801

RESUMO

We extend LIME, an intermediate resolution, implicit solvent model for phospholipids previously used in discontinuous molecular dynamics simulations of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayer formation at 325 K, to the description of the geometry and energetics of 1,2-distearoyl-sn-glycero-3-phospho-L-serine (DSPS) and 1,2-dihenarachidoyl-sn-glycero-3-phosphocholine (21PC) and mixtures thereof at both neutral and low pH at 310 K. A multiscale modeling approach is used to calculate the LIME parameters from atomistic simulation data on a mixed DPPC/DSPS system at different pH values. In the model, 17 coarse-grained sites represent DSPS and 18 coarse-grained sites represent 21PC. Each of these coarse-grained sites is classified as 1 of 9 types. LIME/DMD simulations of equimolar bilayers show the following: (1) 21PC/DSPS bilayers with and without surface area restrictions separate faster at low pH than at neutral pH, (2) 21PC/DSPS systems separate at approximately the same rate regardless of whether they are subjected to surface area restrictions, and (3) bilayers with a molar ratio of 9:1 (21PC:DSPS) phase separate to form heterogeneous domains faster at low pH than at neutral pH. Our results are consistent with experimental findings of Sofou and co-workers (Bandekar et al. Mol. Pharmaceutics, 2013, 10, 152-160; Karve et al. Biomaterials, 2010, 31, 4409-4416) that more doxorubicin is released from 21PC/DSPS liposomes at low pH than at neutral pH, presumably because greater phase separation is achieved at low pH than at neutral pH. These are the first molecular-level simulations of the phase separation in mixed lipid bilayers induced by a change in pH.


Assuntos
Bicamadas Lipídicas/química , Fosfatidilcolinas/química , Fosfosserina/química , Concentração de Íons de Hidrogênio , Cinética , Simulação de Dinâmica Molecular , Temperatura , Termodinâmica
6.
Adv Colloid Interface Sci ; 208: 214-24, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24703299

RESUMO

How nanoparticles interact with biomembranes is central for understanding their bioactivity. Biomembranes wrap around nanoparticles if the adhesive interaction between the nanoparticles and membranes is sufficiently strong to compensate for the cost of membrane bending. In this article, we review recent results from theory and simulations that provide new insights on the interplay of bending and adhesion energies during the wrapping of nanoparticles by membranes. These results indicate that the interplay of bending and adhesion during wrapping is strongly affected by the interaction range of the particle-membrane adhesion potential, by the shape of the nanoparticles, and by shape changes of membrane vesicles during wrapping. The interaction range of the particle-membrane adhesion potential is crucial both for the wrapping process of single nanoparticles and the cooperative wrapping of nanoparticles by membrane tubules.


Assuntos
Biofísica/métodos , Membrana Celular/química , Modelos Biológicos , Nanopartículas/química , Adesividade , Algoritmos , Animais , Fenômenos Biofísicos , Biofísica/tendências , Elasticidade , Transferência de Energia , Humanos , Bicamadas Lipídicas/química , Propriedades de Superfície
7.
J Phys Chem B ; 117(17): 5019-30, 2013 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-23521567

RESUMO

A new intermediate resolution model for phospholipids, LIME, designed for use with discontinuous molecular dynamics (DMD) simulations is presented. The implicit-solvent model was developed using a multiscale modeling approach in which the geometric and energetic parameters are obtained by collecting data from atomistic simulations of a system composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) molecules and explicit water. In the model, 14 coarse-grained sites that are classified as 1 of 6 types represent DPPC. DMD simulations performed on a random solution of DPPC resulted in the formation of a defect-free bilayer in less than 4 h. The bilayer formed quantitatively reproduces the main structural properties (e.g., area per lipid, bilayer thickness, bond order parameters) that are observed experimentally. In addition, the bilayer transitions from a liquid-crystalline phase to a tilted gel phase when the temperature is reduced. Transbilayer movement of a lipid from the bottom leaflet to the top leaflet is observed when the temperature is increased.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Método de Monte Carlo , Temperatura , Termodinâmica , Água/química
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