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2.
RSC Adv ; 12(31): 20074-20079, 2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35919588

RESUMO

Up-conversion nanoparticles have garnered lots of attention due to their ability to transform low energy light (near-infrared) into high-energy (visible) light, enabling their potential use as remote visible light nano-transducers. However, their low efficiency restricts their full potential. To overcome this disadvantage, fluoroindate glasses (InF3) doped at different molar concentrations of Yb3+ and Er3+ were obtained using the melting-quenching technique, reaching the highest green emission at 1.4Yb and 1.75Er (mol%), which corresponds to the 4S3/2 → 4I15/2 (540-552 nm) transition. The particles possess the amorphous nature of the glass and have a high thermostability, as corroborated by thermogravimetric assay. Furthermore, the spectral decay curve analysis showed efficient energy transfer as the rare-earth ions varied. This was corroborated with the absolute quantum yield (QY) obtained (85%) upon excitation at 385 nm with QYEr = 17% and QYYb = 68%. Additionally, InF3-1.4Yb-1.75Er was milled and functionalized using poly(ethylene glycol) to impart biocompatibility, which is essential for biomedical applications. Such functionalization was verified using FTIR, TG/DSC, and XRD.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117893, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31836399

RESUMO

Currently, there is a growing interest in the development of multi-colored materials based on the combination of two or more systems (organic or inorganic) as a strategy to take advantage of their combined physical or chemical properties. These multi-colored materials have found potential applications as sensors, amplifiers, and optical fibers. In this work, the physical characteristics of poly(methyl methacrylate) (PMMA) doped with Terbium(III)-tris-(2,2,6,6-tetramethyl-3,5-heptanedionate) (Tb(tmhd)3) at 1.57-1.58 mmol and Rhodamine B (RhB) at different concentrations were analyzed. The emission obtained from these samples (multichromophoric samples) varied as function of RhB concentration due to an efficient energy transfer process (33-65%). The role of PMMA as inert matrix that assists in the recombination process was confirmed by FTIR and Raman spectra analysis. Moreover, an improvement in thermal resistance of the materials was observed due to the presence of the dopants during the polymerization process.

4.
Rev. otorrinolaringol. cir. cabeza cuello ; 78(1): 36-42, mar. 2018. tab, graf, ilus
Artigo em Espanhol | LILACS | ID: biblio-902812

RESUMO

RESUMEN Introducción: La otomicosis en pacientes inmunosuprimidos esta caracterizada por ser bilateral y ser causada por candida. Pocos estudios comparan las características micológicas encontradas en la microscopía directa y el cultivo. Objetivo: Identificar las características clínicas y micológicas de la otomicosis en pacientes diabéticos. Material y método: Estudio transversal en centro hospitalario de segundo nivel. Criterios de inclusión: pacientes diabéticos con diagnóstico clínico de otomicosis. Intervención: la muestra se examinó directamente bajo el microscopio y se cultivó. Resultados: Se incluyeron 17 pacientes, 10 mujeres y 7 hombres con una edad media de 47,5 años. Los síntomas predominantes fueron hipoacusia en 91,4% (n =16), prurito en 82,4% (n =14), otorrea en 76,5% (n=13)y otalgia en 70,6% (n =12). Afección bilateral se encontró en 47,1% (n =8). Estudio directo al microscopio mostró levaduras en 94,1% (n =16) y 5,9% mostró aspergillus (n =1). Cándida fue el género más comúnmente encontrado en los cultivos y en el examen directo microscópico con 94,1% (n =16) y Candida albicans la especie más común con 88,2% (n =15). Conclusión: Candida albicans es el agente etiológico más común en pacientes diabéticos con otomicosis. Su presentación clínica más frecuente es hipoacusia, prurito y otorrea. El examen directo identificó adecuadamente a los géneros fúngicos.


ABSTRACT Introduction: Otomycosis in immunocompromised patients is characterize by its bilateral course and the predominant etiologic agent is Candida. Few studies compare the mycological features between microscopic direct exam and culture. Aim: To identify the clinical and mycological characteristics of otomycosis in diabetic patients. Material and method: Transversal study. Secondary care center. Inclusion criteria: diabetic patients with clinical diagnosis of otomycosis. Intervention: Direct examination under a microscope of the ear sample and culture. Results: We included 17 patients, 10 women, 7 men with a mean age of 47.5 years. Symptoms were hearing loss 94.1% (n = 16), pruritus 82.4% (n =14) otorrhoea 76.5% (n =13) and otalgia 70.6% (n =12). Bilateral involvement was found in 47.1% (n =8). Direct microscopic study found 94.1% of yeast (n =16) and 5.9% of Aspergillus (n =1). Candida was the most common fungal genus in culture and microscopic exam with 94.1% (n =16) of cases and Candida albicans was the most common species in 88.2% (n =15) cases. Conclusion: Candida albicans is the most common etiologic agent in diabetic patients with otomycosis. Main symptoms were hearing loss, itching and otorrhea. Direct exam correctly identified the fungal genus.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Complicações do Diabetes/microbiologia , Otomicose/microbiologia , Aspergillus fumigatus/isolamento & purificação , Estações do Ano , Fatores de Tempo , Infecções Oportunistas , Candida albicans/isolamento & purificação , Evolução Clínica , Estudos Transversais , Candida glabrata/isolamento & purificação , Complicações do Diabetes/epidemiologia , Otomicose/epidemiologia
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