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1.
BMJ Open ; 12(12): e066871, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36521903

RESUMO

OBJECTIVES: The COVID-19 pandemic has led to the prioritisation of teleconsultation instead of face-to-face encounters. However, teleconsultation revealed some shortcomings and undesirable effects that may counterbalance benefits. This study aims to explore the perspective of patients with chronic diseases on teleconsultation in primary care. This article also proposes recommendations to provide patient-oriented and appropriate teleconsultations. DESIGN: We conducted a qualitative descriptive study that explored the patients' perception regarding teleconsultation services and the following themes: access, perceived benefits and disadvantages, interprofessional collaboration, patient-centred approach, specific competencies of professionals, and patient's global needs and preferences. SETTING: Six primary care clinics in three regions of Quebec. PARTICIPANTS: 39 patients were interviewed by telephone through semistructured qualitative interviews. RESULTS: Patients want to maintain teleconsultation for the postpandemic period as long as their recommendations are followed: be able to choose to come to the clinic if they wish to, feel that their individual and environmental characteristics are considered, feel involved in the choice of the modality of each consultation, feel that interprofessional collaboration and patient-centred approach are promoted, and to maintain the professionalism, which must not be lessened despite the remote context. CONCLUSION: Patients mainly expressed high satisfaction with teleconsultation. However, several issues must be addressed. Patients do and should contribute to the implementation of teleconsultation in primary care. They wish to be frequently consulted about their preferred consultation modality, which may change over time. The patient perspective must, therefore, be part of the balanced implementation of optimal teleconsultation that is currently taking place.


Assuntos
COVID-19 , Consulta Remota , Humanos , COVID-19/epidemiologia , Pandemias , Doença Crônica , Atenção Primária à Saúde , Percepção
2.
Nanomaterials (Basel) ; 12(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36296776

RESUMO

Plant-derived natural bioactive molecules are of great therapeutic potential but, so far, their application in nanomedicine has scarcely been studied. This work aimed at comparing two methodologies, i.e., adsorption and in situ incorporation, to prepare hybrid polyphenol/hydroxyapatite nanoparticles. Two flavonoids, baicalin and its aglycone derivative baicalein, and two phenolic acids derived from caffeic acid, rosmarinic and chlorogenic acids, were studied. Adsorption of these polyphenols on pre-formed hydroxyapatite nanoparticles did not modify particle size or shape and loading was less than 10% (w/w). In contrast, presence of polyphenols during the synthesis of nanoparticles significantly impacted and sometimes fully inhibited hydroxyapatite formation but recovered particles could exhibit higher loadings. For most hybrid particles, release profiles consisted of a 24 h burst effect followed by a slow release over 2 weeks. Antioxidant properties of the polyphenols were preserved after adsorption but not when incorporated in situ. These results provide fruitful clues for the valorization of natural bioactive molecules in nanomedicine.

3.
BMC Prim Care ; 23(1): 84, 2022 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-35436845

RESUMO

BACKGROUND: The implementation of evidence-based innovations is incentivized as part of primary care reform in Canada. In the Province of Québec, it generated the creation of interprofessional care models involving registered nurses and social workers as members of primary care clinics. However, the scope of practice for these professionals remains variable and suboptimal. In 2019, expert committees co-designed and published two evidence-based practice guides, but no clear strategy has been identified to support their assimilation. This project's goal is to support the implementation and deployment of practice guides for both social workers and registered nurses using a train-the-trainer educational intervention. METHODS/DESIGN: This three-phase project is a developmental evaluation using a multiple case study design across 17 primary care clinics. It will involve trainers in healthcare centers, patients, registered nurses and social workers. The development and implementation of an expanded train-the-trainer strategy will be informed by a patient-oriented research approach, the Kirkpatrick learning model, and evidence-based practice guides. For each case and phase, the qualitative and quantitative data will be analyzed using a convergent design method and will be integrated through assimilation. DISCUSSION: This educational intervention model will allow us to better understand the complex context of primary care clinics, involving different settings and services offered. This study protocol, based on reflective practice, patient-centered research and focused on the needs of the community in collaboration with partners and patients, may serve as an evidence based educational intervention model for further study in primary care.


Assuntos
Enfermeiras e Enfermeiros , Assistentes Sociais , Prática Clínica Baseada em Evidências , Humanos , Atenção Primária à Saúde , Quebeque
4.
Front Zool ; 18(1): 58, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34749755

RESUMO

BACKGROUND: A basal spicule of the hexactinellid sponge Monorhaphis chuni may reach up to 3 m in length and 10 mm in diameter, an extreme case of large spicule size. Generally, sponge spicules are of scales from micrometers to centimeters. Due to its large size many researchers have described its structure and properties and have proposed it as a model of hexactinellid spicule development. Thorough examination of new material of this basal spicule has revealed numerous inconsistencies between our observations and earlier descriptions. In this work, we present the results of detailed examinations with transmitted light and epifluorescence microscopy, SEM, solid state NMR analysis, FTIR and X-ray analysis and staining of Monorhaphis chuni basal spicules of different sizes, collected from a number of deep sea locations, to better understand its structure and function. RESULTS: Three morphologically/structurally different silica layers i.e. plain glassy layer (PG), tuberculate layer (TL) and annular layer (AL), and an axial cylinder (AC) characterize adult spicules. Young, immature spicules display only plain glassy silica layers which dominate the spicule volume. All three layers i.e. PG, TL and AL can substitute for each other along the surface of the spicule, but equally they are superimposed in older parts of the spicules, with AL being the most external and occurring only in the lower part of the spicules and TL being intermediate between AL and PG. The TL, which is composed of several thinner layers, is formed by a progressive folding of its surface but its microstructure is the same as in the PG layer (glassy silica). The AL differs significantly from the PG and TL in being granular and porous in structure. The TL was found to display positive structures (tubercles), not depressions, as earlier suggested. The apparent perforated and non-perforated bands of the AL are an optical artefact. The new layer type that we called the Ripple Mark Layer (RML) was noted, as well as narrow spikes on the AL ridges, both structures not reported earlier. The interface of the TL and AL, where tubercles fit into depressions of the lower surface of the AL, represent tenon and mortise or dovetail joints, making the spicules more stiff/strong and thus less prone to breaking in the lower part. Early stages of the spicule growth are bidirectional, later growth is unidirectional toward the spicule apex. Growth in thickness proceeds by adding new layers. The spicules are composed of well condensed silica, but the outermost AL is characterized by slightly more condensed silica with less water than the rest. Organics permeating the silica are homogeneous and proteinaceous. The external organic net (most probably collagen) enveloping the basal spicule is a structural element that bounds the sponge body together with the spicule, rather than controlling tubercle formation. Growth of various layers may proceed simultaneously in different locations along the spicule and it is sclerosyncytium that controls formation of silica layers. The growth in spicule length is controlled by extension of the top of the axial filament that is not enclosed by silica and is not involved in further silica deposition. No structures that can be related to sclerocytes (as known in Demospongiae) in Monorhaphis were discovered during this study. CONCLUSIONS: Our studies resulted in a new insight into the structure and growth of the basal Monorhaphis spicules that contradicts earlier results, and permitted us to propose a new model of this spicule's formation. Due to its unique structure, associated with its function, the basal spicule of Monorhaphis chuni cannot serve as a general model of growth for all hexactinellid spicules.

5.
Mater Sci Eng C Mater Biol Appl ; 118: 111537, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33255090

RESUMO

Aseptic loosening and bacterial infections are the two main causes of failure for metallic implants used for joint replacement. A coating that is both bioactive and possesses antimicrobial properties may address such shortcomings and improve the performance of the implant. We have sought to study the properties of combining hydroxyapatite-based nanoparticles or coatings with baicalein, a plant-extracted molecule with both antibacterial and antioxidant properties. (B-type) carbonated hydroxyapatite nanoparticles prepared by a chemical wet method could subsequently adsorbed by soaking in a baicalein solution. The amount of adsorbed baicalein was determined to be 63 mg.g-1 by thermogravimetric measurements. In a second approach, baicalein was adsorbed on a biomimetic calcium-deficient hydroxyapatite planar coating (12 µm thick) deposited on Ti6Al4V alloy from an aqueous solution of calcium, phosphate, sodium and magnesium salts. Soaking of the hydroxyapatite coated on titanium alloy in a baicalein solution induced partial dissolution/remodeling of the upper surface of the coating. However, the observed remodeling of the surface was much more pronounced in the presence of a baicalein solution, compared to pure water. The presence of adsorbed baicalein on the HAp layer, although it could not be precisely quantified, was assessed by XPS and fluorescence analysis. Planar coatings exhibited significant antibacterial properties against Staphylococcus epidermidis. Baicalein-modified nanoparticles exhibited significant antioxidant properties. These results illustrate the potential of hydroxyapatite used as a carrier for natural biologically-active molecules and also discuss the challenges associated with their applications as antibacterial agents.


Assuntos
Durapatita , Nanopartículas , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Flavanonas , Propriedades de Superfície , Titânio
6.
Anal Bioanal Chem ; 410(4): 1205-1216, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28573323

RESUMO

Optical biosensors for the detection of toxic species in aqueous media were developed via the encapsulation of microalgae in sol-gel matrices. In a first step, the effect of cadmium(II), lead(II), and anthracene on the chlorophyll a fluorescence intensity of Anabaena flos-aquae, Chlorella vulgaris, and Euglena gracilis microalgae in suspension was studied. Complementary ATP-metry measurements demonstrated a direct relationship between optical response and pollutant toxicity, in a cell- and dose-dependent manner. In a second step, microalgae were successfully encapsulated in silicate-colloidal silica nanocomposite matrices. However, a complete loss of cell response to pollutant addition was observed, despite the preservation of cell viability. Introduction of a low amount (5 mol%) of amine- or ethyl-bearing silanes in the matrix formulation allowed the recovery of the sensing capacity of the immobilized microalgae, without impacting on the response time (30 s). Porosimetry and 29Si solid-state NMR spectroscopy showed that the organic moieties are fully integrated into the inorganic network, tuning the ability of the target pollutant to diffuse and reach the encapsulated algae. This versatile strategy could be useful for the easy and fast assessment of contamination levels in polluted waters. Graphical Abstract Microalgal biosensors for aqueous contaminants using organically doped silica as cellular hosts.


Assuntos
Técnicas Biossensoriais , Microalgas/metabolismo , Dióxido de Silício/metabolismo , Poluentes da Água/metabolismo
7.
Environ Sci Pollut Res Int ; 24(33): 25977-25985, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28940003

RESUMO

The interaction of oil shale, as a widespread sedimentary rock, with common antibiotics ofloxacine, oxytetracycline, and ciprofloxacine was studied. The selected Moroccan deposit and its thermally treated forms were fully characterized from a chemical and structural point of view, indicating the prevalence of quartz as a mineral component together with aluminum- and iron-rich phase that are converted into Al-doped iron oxide phases upon heating. The presence of 4 wt% organics was also detected, which was removed at 550 °C without significant loss of specific surface area. The pseudo-second-order kinetic model and Langmuir equation were found the most adequate to reproduce the kinetics and isothermal sorption experiments. These analyses enlighten the contribution of the organic matter on antibiotic retention as well as the key role of hydrophobic interactions on the molecule-mineral surface interactions. Our results emphasize the possible contribution of raw oil shale in the accumulation of antibiotics in soils and suggest that thermally treated oil shell powders can constitute cheap mineral sorbents for environmental cleaning.


Assuntos
Antibacterianos/química , Recuperação e Remediação Ambiental/métodos , Minerais/química , Poluentes do Solo/química , Adsorção , Antibacterianos/análise , Ciprofloxacina/análise , Ciprofloxacina/química , Interações Hidrofóbicas e Hidrofílicas , Minerais/análise , Marrocos , Ofloxacino/análise , Ofloxacino/química , Oxitetraciclina/análise , Oxitetraciclina/química , Pós/análise , Pós/química , Poluentes do Solo/análise
8.
Langmuir ; 31(40): 11078-85, 2015 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-26387475

RESUMO

The conjugation of polyethylenimine (PEI) to silica nanoparticles has emerged as a useful strategy in gene delivery. Here we investigate the influence of the PEI conjugation mode on the transfection ability of plain silica nanoparticles. Surface functionalization with sulfonate- and chloride-bearing silanes modulates the amount and conformation of PEI and therefore the particles' affinity for the plasmid, without impacting on cytotoxicity. However, transfection efficiency in both immortalized and primary cells is more directly correlated to the nature and strength of the particle-PEI interactions. It suggests that PEI detachment from the particle surface at the stage of endosomal escape is a key event in the plasmid delivery process. These data should provide fruitful guidelines for the fine tuning of colloidal surfaces intended for intracellular delivery of bioactive molecules.


Assuntos
Vetores Genéticos , Polietilenoimina/química , Dióxido de Silício/química , Transfecção , Células 3T3 , Animais , Células Cultivadas , Eletroforese em Gel de Ágar , Humanos , Camundongos , Microscopia de Fluorescência
9.
J Colloid Interface Sci ; 417: 1-8, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24407653

RESUMO

HYPOTHESIS: Hydroxyapatite and magnetite are two environmentally-friendly mineral phases that have fruitful properties for remediation process. The formation of magnetic core@sorbent shell nanostructures should provide efficient materials for toxic metal removal from aqueous media. However the nanoscale confinement of hydroxyapatite may influence its reactivity. EXPERIMENTS: Fe3O4@Hydroxyapatite nanocomposites were prepared by surface-controlled precipitation of hydroxyapatite layers from 10 nm to 150 nm in thickness on iron oxide spheres. The surface reactivity of the core-shell particles toward selected inorganic ions of environmental relevance (Pb(II), Y(III), Eu(III), Sb(III)) was studied by batch sorption experiments, X-ray diffraction and electron microscopy. FINDINGS: The reactivity of the hydroxyapatite coating varied from partial cation exchange to dissolution/transformation of the shell. The nature and extent of the reactions depended significantly on the hydroxyapatite layer structure but was not significantly influenced by the magnetic core. These novel nanocomposites should be useful for environmental applications.

10.
Chem Commun (Camb) ; 49(33): 3410-2, 2013 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-23507842

RESUMO

Incorporation of disulfide bridges in the core structure of silica nanoparticles modifies their intracellular fate within dermal fibroblasts, especially influencing their degradation pathway.


Assuntos
Dissulfetos/química , Nanopartículas/química , Dióxido de Silício/química , Linhagem Celular , Fluoresceína-5-Isotiocianato/química , Humanos , Microscopia de Fluorescência , Silanos/química
11.
J Solid State Chem ; 185: 95-100, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22287800

RESUMO

Organofunctionalized apatite nanoparticles were prepared using a one step process involving dissolution/precipitation of natural phosphate rock and covalent grafting of nitrilotris(methylene)triphosphonate (NTP). The synthesized materials were characterized by Brunauer-Emmett-Teller (BET) surface measurement, thermogravimetry, inductively coupled plasma emission spectroscopy (ICP-ES), elemental analysis, multinuclear solid state cross-polarization/magic angle spinning (CP/MAS) and single-pulse NMR spectroscopy, transmission electron microscopy (TEM) and energy dispersive x-ray analysis (EDXA). After grafting BET measurements yielded particle specific surface areas ranging from 88 to 193 m(2) g(-1) depending on the grafted phosphonate. The results show that the surfaces of the nanoapatite particles can be covered with functional groups bound through a variable number of R-P-O-Ca bonds to render them organoapatites.

12.
Langmuir ; 27(24): 15176-84, 2011 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-22053732

RESUMO

Zirconia-hydroxyapatite nanocomposites were prepared by sol-gel deposition of zirconium oxide from a zirconium alkoxide in the presence of apatite colloidal suspension under ultrasonication. The material porosity evolves from mainly microporous zirconia to mesoporous hydroxyapatite, with decreasing surface area and increasing pore volume. XRD studies indicate that the apatite phase is well-preserved within the composite materials. The homogeneous dispersion of apatite colloids within the zirconia network was supported by TEM observations and nitrogen sorption measurements. (31)P solid-state NMR studies suggest that partial dissolution of apatite may have occurred during the preparation, leading to the adsorption of phosphate species on zirconia particles. This is confirmed by XRD studies of nanocomposites after thermal treatment that demonstrate the preferred formation of tetragonal over monoclinic ZrO(2) in the presence of hydroxyapatite. In order to investigate the surface properties of these novel materials, the adsorption of Pb(2+), Cr(3+), and Cr(2)O(7)(2-) was evaluated. Metal cations were preferentially adsorbed on apatite-rich composites, whereas Cr(2)O(7)(2-) shows a good affinity for the zirconia-rich phases. Zirconia-apatite materials showed the most promising performance in terms of recyclability. These nanocomposites that combine microporosity, mesoporosity and dual sorption properties for these species appear as interesting materials for metal ion remediation and may also find applications as biomaterials.


Assuntos
Cromo/química , Materiais Revestidos Biocompatíveis/síntese química , Coloides/síntese química , Durapatita/química , Nanocompostos/química , Zircônio/química , Adsorção , Cromo/metabolismo , Materiais Revestidos Biocompatíveis/análise , Materiais Revestidos Biocompatíveis/metabolismo , Coloides/análise , Coloides/metabolismo , Durapatita/metabolismo , Íons , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Nanocompostos/análise , Nanocompostos/ultraestrutura , Nitrogênio/química , Fosfatos/química , Porosidade , Espalhamento a Baixo Ângulo , Propriedades de Superfície , Ultrassom , Difração de Raios X , Zircônio/metabolismo
13.
Dalton Trans ; 39(44): 10644-51, 2010 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-20886132

RESUMO

Organically-modified hydroxyapatite materials were synthesized through the addition of oxalic, succinic, adipic and citric acids to a calcium hydroxide solution before neutralization by ammonium dihydrogenphosphate. All carboxylic acids have a significant influence on apatite crystallinity and nanoparticle size, as indicated by XRD and TEM. Chemical and thermogravimetric analyses as well as FTIR and {(1)H}-(13)C CP MAS NMR spectroscopies indicate that the additives are present in the final material. (1)H, {(1)H}-(31)P HPDec MAS, CP MAS and 2D {(1)H}-(31)P CP-HETCOR MAS NMR experiments suggest that carboxylic acids are localized on the apatite nanocrystallite surface, resulting in the formation of a disordered outer layer. Nitrogen sorption measurements indicate minor modifications of the specific surface area of the resulting mesoporous materials upon carboxylic acid addition but more significant variations in the average dimensions of the pores as well as in the chemical nature of the pore surface. Although these evolutions are mainly in good agreement with the ligand affinity for calcium ions in solution, an unexpected difference was observed between succinic and adipic acid, that may be attributed to steric constraints resulting from the interfacial nature of the calcium-ligand interactions. These data should provide useful guidelines to identify novel efficient additives to control apatite growth.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Ácidos Carboxílicos/química , Quelantes/química , Durapatita/química , Durapatita/síntese química , Cálcio/química , Hidróxido de Cálcio/química , Cátions Bivalentes/química , Ligantes , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Nitrogênio/química , Tamanho da Partícula , Fosfatos/química , Porosidade , Soluções/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
14.
Phys Chem Chem Phys ; 11(43): 10204-10, 2009 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-19865778

RESUMO

The interactions of cyclic polyamines with tetraethoxysilane in the conditions of the Stöber synthesis of silica nanoparticles were studied and compared to the behavior of a linear polyamine. Granular core-plain shell hybrid particles were obtained whose morphology and size vary with the nature and amount of added ligand. The influence of polyamines on silica condensation could be understood on the basis of a SN(2) reaction involving a pentacoordinated Si complex and depends on the accessibility and nucleophilicity of the ligand. In this case, the polyamine conformation is the key factor determining its ability to activate silica formation. The final size of the hybrid particles was determined by the aggregation of resulting primary nanoparticles that is controlled by electrostatic interactions, and thus depends on the ligand positive charge. These results were compared to biological and biomimetic processes of silica formation where acid-base/electrostatic interactions of silica precursors with linear polyamines have been described.


Assuntos
Nanopartículas/química , Poliaminas/química , Silanos/química , Dióxido de Silício/química , Ciclamos , Compostos Heterocíclicos/química , Microscopia Eletrônica de Transmissão , Conformação Molecular , Nanopartículas/ultraestrutura , Tamanho da Partícula , Trientina/química
15.
Langmuir ; 24(8): 4026-31, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18303930

RESUMO

In the view of designing functional nanoparticles, the encapsulation of 1,4,7,10-tetraazacyclododecane (cyclen) within silica nanoparticles using the Stöber process was studied. In the presence of cyclen and tetraethoxysilane (TEOS), silica particles exhibiting an unusual core-shell structure were obtained. On then basis of TEM, DLS, and NMR data, we suggest that the particle core is constituted of hybrid primary nanoparticles resulting from cyclen-silica interactions, whereas the shell formation results from further condensation of unreacted silica precursors. Control experiments performed with the zinc-cyclen complex and ammonia addition suggest that cyclen-TEOS interactions arise from the activation of the silicon alkoxide hydrolysis with the polyazamacrocycle amine groups. These data are discussed in the context of silica biomineralization mechanisms, where polyamine/silica interactions have been shown to play a major role. Moreover, the possibility to control the size and the structure of these nanoparticles makes them promising materials for pharmaceutical applications.


Assuntos
Compostos Aza/química , Compostos Macrocíclicos/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Dióxido de Silício/química , Ligantes , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Estrutura Molecular , Tamanho da Partícula
16.
Anal Bioanal Chem ; 390(7): 1889-98, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18278484

RESUMO

A major issue in the study of biosilicification processes is the harsh chemical conditions required for silica dissolution, which often lead to denaturation of the associated bio-organic matter. In order to demonstrate the potential of solid state NMR for investigating silicified materials of natural origin, this technique was applied to isotopically enriched Thalassiosira pseudonana diatom cells. (29)Si, (1)H,(31)P, (13)C and (15)N solid state NMR studies were performed on whole cells, SDS-extracted and H(2)O(2)-cleaned silica shells. Cross-polarization techniques were useful for identifying the presence of mobile and rigid molecules, allowing loosely bound and silica-entrapped species to be discriminated. Successive cleaning procedures efficiently eliminated weakly associated organic matter. The H(2)O(2)-cleaned silica shell still contained carbohydrates (mainly chitin) and proteins as well as lipids. This suggests that the role of lipids in diatom shell formation may have been underestimated so far, demonstrating the potential of solid state NMR for studying composite biomaterials.


Assuntos
Parede Celular/química , Diatomáceas/química , Ressonância Magnética Nuclear Biomolecular/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dióxido de Silício/química
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