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1.
NPJ Digit Med ; 4(1): 35, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33627748

RESUMO

Analyses of search engine and social media feeds have been attempted for infectious disease outbreaks, but have been found to be susceptible to artefactual distortions from health scares or keyword spamming in social media or the public internet. We describe an approach using real-time aggregation of keywords and phrases of freetext from real-time clinician-generated documentation in electronic health records to produce a customisable real-time viral pneumonia signal providing up to 4 days warning for secondary care capacity planning. This low-cost approach is open-source, is locally customisable, is not dependent on any specific electronic health record system and can provide an ensemble of signals if deployed at multiple organisational scales.

2.
Phys Chem Chem Phys ; 15(8): 2733-40, 2013 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-23321853

RESUMO

We report a robust and versatile membrane protein based system for selective uptake and release of ions from nanoporous particles sealed with ion-tight lipid bilayers of various compositions that is driven by the addition of ATP or a chemical potential gradient. We have successfully incorporated both a passive ion channel-type peptide (gramicidin A) and a more complex primary sodium ion transporter (ATP synthase) into the supported lipid bilayers on solid nanoporous silica particles. Protein-mediated controlled release/uptake of sodium ions across the ion-tight lipid bilayer seal from or into the nanoporous silica carrier was imaged in real time using a confocal laser scanning microscope and the intensity changes were quantified. ATP-driven transport of sodium ions across the supported lipid bilayer against a chemical gradient was demonstrated. The possibility of designing durable carriers with tight lipid membranes, containing membrane proteins for selective ion uptake and release, offers new possibilities for functional studies of single or cascading membrane protein systems and could also be used as biomimetic microreactors for controlled synthesis of inorganic multicomponent materials.


Assuntos
Complexos de ATP Sintetase/metabolismo , Trifosfato de Adenosina/metabolismo , Gramicidina/química , Bicamadas Lipídicas/metabolismo , Nanoporos , Complexos de ATP Sintetase/química , Fluoresceína/química , Iodetos/química , Transporte de Íons , Íons/química , Bicamadas Lipídicas/química , Dióxido de Silício/química , Sódio/metabolismo
3.
PLoS One ; 7(10): e45828, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23049689

RESUMO

The formation of hybrids of nanofibrillated cellulose and titania nanoparticles in aqueous media has been studied. Their transparency and mechanical behavior have been assessed by spectrophotometry and nanoindentation. The results show that limiting the titania nanoparticle concentration below 16 vol% yields homogeneous hybrids with a very high Young's modulus and hardness, of up to 44 GPa and 3.4 GPa, respectively, and an optical transmittance above 80%. Electron microscopy shows that higher nanoparticle contents result in agglomeration and an inhomogeneous hybrid nanostructure with a concomitant reduction of hardness and optical transmittance. Infrared spectroscopy suggests that the nanostructure of the hybrids is controlled by electrostatic adsorption of the titania nanoparticles on the negatively charged nanocellulose surfaces.


Assuntos
Celulose/química , Nanocompostos/química , Nanopartículas/química , Titânio/química , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Espectrofotometria , Eletricidade Estática
4.
Nanoscale ; 3(9): 3563-6, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21850350

RESUMO

Nanocellulose hybrids are promising candidates for biodegradable multifunctional materials. Hybrids of nanocrystalline cellulose (NCC) and amorphous calcium carbonate (ACC) nanoparticles were obtained through a facile chemical approach over a wide range of compositions. Controlling the interactions between NCC and ACC results in hard, transparent structures with tunable composition, homogeneity and anisotropy.


Assuntos
Carbonato de Cálcio/química , Celulose/química , Nanopartículas/química , Cristalização , Nanopartículas/ultraestrutura
5.
Biophys Chem ; 134(3): 168-77, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18342426

RESUMO

An experimental study of phosphocholine membranes made from one lipid, from mixtures of DPPC and DLPC, and also from lipids and small amounts of alamethicin is presented. We used atomic force microscopy to investigate the spatial organization and structure of lipid domains and also of the defects induced by the peptide. Alamethicin was found to alter the state of lipids in the gel state in a way that domains of fluid lipids are formed close to the defects. Differential calorimetry revealed phase characteristics of the lipid mixtures and the effect of small amounts of alamethicin on the phase behavior. It was also shown that the sound velocity profiles of the membranes suspensions can be well calculated from the heat capacity traces of the samples. This result confirms the correlation between the mechanical properties and the specific heat of membrane systems.


Assuntos
Alameticina/química , Lipídeos de Membrana/química , Calorimetria , Temperatura Alta , Lipídeos de Membrana/metabolismo , Microscopia de Força Atômica , Soluções , Titulometria
6.
Biochim Biophys Acta ; 1768(2): 236-45, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17141732

RESUMO

We present an experimental study of the pore formation processes of small amphipathic peptides in model phosphocholine lipid membranes. We used atomic force microscopy to characterize the spatial organization and structure of alamethicin- and melittin-induced defects in lipid bilayer membranes and the influence of the peptide on local membrane properties. Alamethicin induced holes in gel DPPC membranes were directly visualized at different peptide concentrations. We found that the thermodynamic state of lipids in gel membranes can be influenced by the presence of alamethicin such that nanoscopic domains of fluid lipids form close to the peptide pores, and that the elastic constants of the membrane are altered in their vicinity. Melittin-induced holes were visualized in DPPC and DLPC membranes at room temperature in order to study the influence of the membrane state on the peptide induced hole formation. Also differential scanning calorimetry was used to investigate the effect of alamethicin on the lipid membrane phase behaviour.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Membrana Celular , Dimiristoilfosfatidilcolina/química , Bicamadas Lipídicas/química , Microdomínios da Membrana , Alameticina/farmacologia , Varredura Diferencial de Calorimetria , Indicadores e Reagentes/química , Ionóforos/farmacologia , Meliteno/farmacologia , Fluidez de Membrana , Membranas Artificiais , Microscopia de Força Atômica , Termodinâmica
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