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1.
Food Res Int ; 169: 112932, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37254358

RESUMO

The increasing exposure of the population to Cannabis sativa has revealed allergies to different parts of the plant, among which hemp seed. Nonetheless, the major hemp seed allergens remain to be identified. Several known families of allergens are present in hemp seed, including notably seed storage proteins. We therefore aimed to investigate the potential allergenicity of the hemp seed storage proteins and their potential cross-reactivity to different seeds and nuts. For this, we extracted hemp seed proteins sequentially using buffers with increasing levels of salinity (H2O, T2 and T3) to yield extracts differentially enriched in storage proteins. We used these extracts to perform immunoblots and ELISAs using sera of patients either sensitized to hemp seeds or sensitized/allergic to other seeds and nuts. Immunoblots and proteomics analyses identified vicilins and edestins as potential hemp seed allergens. Moreover, ELISA analyses revealed a correlation between sensitization to hazelnut and the hemp seed T3 extract (enriched in storage proteins). The possible cross-reactivity between hazelnut and hemp seed proteins was further strengthened by the results from inhibition ELISAs: the incubation of sera from hazelnut-sensitized individuals with increasing concentrations of the T3 extract inhibited serum IgE binding to the hazelnut extract by about 25-30%. Our study thus identifies vicilins and edestins as potential hemp seed allergens and highlights a possible cross-reactivity with hazelnut. The clinical relevance of this cross-reactivity between hemp seed and hazelnut needs to be further investigated in hazelnut-allergic individuals.


Assuntos
Cannabis , Corylus , Hipersensibilidade a Noz , Humanos , Alérgenos , Antígenos de Plantas , Imunoglobulina E , Proteínas de Armazenamento de Sementes , Sementes , Extratos Vegetais
2.
Sci Rep ; 9(1): 19206, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31844081

RESUMO

The microbial reduction of nitrate, via nitrite into gaseous di-nitrogen (denitrification) plays a major role in nitrogen removal from aquatic ecosystems. Natural abundance stable isotope measurements can reveal insights into the dynamics of production and consumption of nitrite during denitrification. In this study, batch experiments with environmental bacterial communities were used to investigate variations of concentrations and isotope compositions of both nitrite and nitrate under anoxic conditions. To this end, denitrification experiments were carried out with nitrite or nitrate as sole electron acceptors at two substrate levels respectively. For experiments with nitrate as substrate, where the intermediate compound nitrite is both substrate and product of denitrification, calculations of the extent of isotope fractionation were conducted using a non-steady state model capable of tracing chemical and isotope kinetics during denitrification. This study showed that nitrogen isotope fractionation was lower during the use of nitrite as substrate (ε = -4.2 and -4.5‰ for both treatments) as compared to experiments where nitrite was produced as an intermediate during nitrate reduction (ε = -10 and -15‰ for both treatments). This discrepancy might be due to isotopic fractionation within the membrane of denitrifiers. Moreover, our results confirmed previously observed rapid biotic oxygen isotope exchange between nitrite and water.

3.
Philos Trans A Math Phys Eng Sci ; 374(2072)2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27298429

RESUMO

Cellulose nanocrystals (CNCs) are negatively charged colloidal particles well known to form highly stable surfactant-free Pickering emulsions. These particles can vary in surface charge density depending on their preparation by acid hydrolysis or applying post-treatments. CNCs with three different surface charge densities were prepared corresponding to 0.08, 0.16 and 0.64 e nm(-2), respectively. Post-treatment might also increase the surface charge density. The well-known TEMPO-mediated oxidation substitutes C6-hydroxyl groups by C6-carboxyl groups on the surface. We report that these different modified CNCs lead to stable oil-in-water emulsions. TEMPO-oxidized CNC might be the basis of further modifications. It is shown that they can, for example, lead to hydrophobic CNCs with a simple method using quaternary ammonium salts that allow producing inverse water-in-oil emulsions. Different from CNC modification before emulsification, modification can be carried out on the droplets after emulsification. This way allows preparing functional capsules according to the layer-by-layer process. As a result, it is demonstrated here the large range of use of these biobased rod-like nanoparticles, extending therefore their potential use to highly sophisticated formulations.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'.


Assuntos
Celulose/química , Emulsões/química , Nanopartículas/química , Nanotecnologia , Propriedades de Superfície
4.
J Appl Physiol (1985) ; 118(6): 716-22, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25593289

RESUMO

"Objective" methods to monitor physical activity and sedentary patterns in free-living conditions are necessary to further our understanding of their impacts on health. In recent years, many software solutions capable of automatically identifying activity types from portable accelerometry data have been developed, with promising results in controlled conditions, but virtually no reports on field tests. An automatic classification algorithm initially developed using laboratory-acquired data (59 subjects engaging in a set of 24 standardized activities) to discriminate between 8 activity classes (lying, slouching, sitting, standing, walking, running, and cycling) was applied to data collected in the field. Twenty volunteers equipped with a hip-worn triaxial accelerometer performed at their own pace an activity set that included, among others, activities such as walking the streets, running, cycling, and taking the bus. Performances of the laboratory-calibrated classification algorithm were compared with those of an alternative version of the same model including field-collected data in the learning set. Despite good results in laboratory conditions, the performances of the laboratory-calibrated algorithm (assessed by confusion matrices) decreased for several activities when applied to free-living data. Recalibrating the algorithm with data closer to real-life conditions and from an independent group of subjects proved useful, especially for the detection of sedentary behaviors while in transports, thereby improving the detection of overall sitting (sensitivity: laboratory model = 24.9%; recalibrated model = 95.7%). Automatic identification methods should be developed using data acquired in free-living conditions rather than data from standardized laboratory activity sets only, and their limits carefully tested before they are used in field studies.


Assuntos
Atividade Motora/fisiologia , Postura/fisiologia , Acelerometria/métodos , Adulto , Algoritmos , Calibragem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Comportamento Sedentário , Software , Adulto Jovem
5.
Biomacromolecules ; 15(10): 3766-71, 2014 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-25180643

RESUMO

Chitin is a natural polymer of glucosamine bearing N-acetyl groups. Chitin nanocrystals (ChiNCs), resulting from the acid hydrolysis of amorphous regions of chitin, are crystalline positively charged rod-like particles. ChiNCs show some interfacial properties and very efficiently stabilize oil/water interfaces, leading to the so-called Pickering emulsions. In accordance with the irreversible adsorption of particles, these Pickering emulsions proved stable over time, with constant emulsion volume for several months, even though natural creaming may occur. The emulsions produced are not clearly susceptible to ionic strength or pH in terms of average droplet diameter. However, when mixed with a large amount of oil, high internal phase emulsions (HIPE) containing up to 96% of internal phase are formed as a gel with a texture that can be modulated from soft to solid gel by adjusting concentration, pH, and ionic strength.


Assuntos
Quitina/química , Emulsões/química , Nanopartículas/química , Adsorção/fisiologia , Concentração de Íons de Hidrogênio , Hidrólise , Óleos/química , Concentração Osmolar , Tamanho da Partícula , Polímeros/química , Água/química
6.
Artigo em Inglês | MEDLINE | ID: mdl-24110766

RESUMO

Physical activity (PA) and the energy expenditure it generates (PAEE) are increasingly shown to have impacts on everybody's health (e.g. development of chronic diseases) and to be key factors in maintaining the physical autonomy of elderlies. The SVELTE project objective was to develop an autonomous actimeter, easily wearable and with several days of autonomy, which could record a subject's physical activity during his/her daily life and estimate the associated energy expenditure. A few prototypes and dedicated algorithms were developed based on laboratory experiments. The identification of physical activity patterns algorithm shows good performances (79% of correct identification), based on a trial in semi-free-living conditions. The assessment of the PAEE computation algorithm is under validation based on a clinical trial.


Assuntos
Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Atividade Motora , Atividades Cotidianas , Algoritmos , Metabolismo Energético , Feminino , Humanos , Masculino , Processamento de Sinais Assistido por Computador
7.
Int J Cardiol ; 161(3): 143-50, 2012 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-21982700

RESUMO

BACKGROUND: Meta-analyses have suggested that remote telemedical management (RTM) positively affects clinical outcomes in chronic HF patients. The results of two recent randomised RTM trials do not corroborate these results. We aim to report prospectively defined and exploratory subgroup analyses for the TIM-HF trial and to identify a patient profile that could potentially benefit from RTM for further investigation in randomised clinical trials. METHODS: In TIM-HF, 710 stable chronic HF patients, in NYHA class II or III with a history of HF decompensation within 2 years previously or a LVEF ≤ 25% were randomly assigned (1:1) to RTM or usual care. The primary outcome was total death and secondary outcomes included days lost due to death or HF hospitalisation and a composite of cardiovascular death and HF hospitalisation. Twelve subgroups were prospectively defined and patient profiling was investigated for the subgroup with a prior history of HF decompensation, an LVEF ≥ 25% and a PHQ-9 score<10. RESULTS: The subgroup treatment effects were significant for total mortality for the PHQ-9 subgroup only (p for interaction<0.027). For the outcome 'number of days lost due to hospitalisation for HF or death', the subgroup treatment effects were significant (p for interaction<0.05) for patients with a prior HF decompensation or an ICD implant or a PHQ score of <10 and for the patient-profiling subgroup. CONCLUSIONS: Telemedicine management may not be appropriate for all HF patients. Future research needs to investigate which HF population may benefit from this intervention.


Assuntos
Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Telemedicina/métodos , Idoso , Feminino , Seguimentos , Inquéritos Epidemiológicos/métodos , Insuficiência Cardíaca/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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