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1.
Indian J Dent Res ; 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39282787

RESUMEN

INTRODUCTION: The gummy smile (GS) or excessive gum visibility (EGV) is an aesthetic concern that affects an individual's attractiveness and personality. TREATMENT PLANNING: Lip Repositioning surgery (LRP) is a less invasive surgery that can be attributed to treating EGV due to hypermobile lip muscles or mild-to-moderate vertical maxillary excess (VME). Three patients went through LRP surgery by stripping overlying mucosa from the buccal vestibule, followed by suturing the lip mucosa to the mucogingival junction (MGJ), creating shallow vestibule and restricted muscle pull and reducing gingival visibility (GV) during a smile. FOLLOWUP: Three months of follow-up showed a satisfactory result with 3.67 ± 0.58 mm mean reduction in GV.

2.
Int J Biol Macromol ; 265(Pt 2): 130867, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38508557

RESUMEN

This study focuses on the fabrication of a novel sensing platform on a screen-printed carbon electrode, modified by a combination of hydrothermally synthesized iron dioxide (ε-Fe2O3) nanoparticles and Chitosan (CS) biopolymer. This unique organic-inorganic hybrid material was developed for Electrochemical Impedance Spectroscopy (EIS) sensing, specifically targeting heavy metal ions that include Hg2+, Cd2+, as well as Pb2+. The investigation encompassed a comprehensive analysis of various aspects of the prepared Fe2O3 and CS/ε-Fe2O3 nanocomposites, including phase identification, determination of crystallite size, assessment of surface morphology, etc. CS/ε-Fe2O3 was drop-casted and deposited on the Screen-Printed Electrode (SPE). The resulting sensor exhibited excellent performance in the precise and selective quantification of Hg2+, Cd2+, and Pb2+ ions, with minimal interference from other substances. The fabricated sensor exhibits excellent performance as the detection range for Hg2+, Cd2+, and Pb2+ ions linearity is 2-20 µM, sensitivity, and LOD are 243 Ω/ µM cm2 and 0.191 µM, 191 Ω/µM cm2, and 0.167 µM, 879 Ω/ µM cm2, and 0.177 µM respectively. The stability of the CS/ε-Fe2O3/SPE electrode is demonstrated by checking its conductivity for up to 60 days for Hg2+, Cd2+, and Pb2+ ions. The reusability of the fabricated electrode is 14 scans, 13 scans, and 12 scans for Hg2+, Cd2+, and Pb2+ ions respectively. The findings indicate the successful development of an innovative CS/ε-Fe2O3 electrode for the EIS sensing platform. This platform demonstrates notable potential for addressing the critical need for efficient and sensitive EIS sensors capable of detecting a range of hazardous heavy metal ions, including Hg2+, Cd2+, and Pb2+.


Asunto(s)
Quitosano , Mercurio , Metales Pesados , Nanopartículas , Cadmio/química , Plomo , Carbono , Metales Pesados/análisis , Mercurio/química , Electrodos , Agua/química , Iones
3.
ACS Appl Bio Mater ; 6(12): 5842-5853, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-38054277

RESUMEN

A propitious biosensor for adrenaline (AD) detection in bovine serum albumin (BSA) real samples, which can be used for diagnosis and treatment of neurodegenerative disorders, is reported here. The biosensor consists of a La/ZF/rGO/ITO bioelectrode, which is fabricated by electrophoretic deposition of zinc ferrite/reduced graphene oxide (ZF/rGO) nanohybrid followed by drop casting of laccase (La) enzymes. The material characterization and electrochemical studies revealed that the ZF/rGO nanohybrid enhanced the electroactive surface and facilitated direct electron transfer between the electrode and electrolyte interface, resulting in enhanced electrocatalytic performance. The cyclic voltammetry and electrochemical impedance spectroscopy results asserted that the ZF/rGO nanohybrid decreased the charge-transfer resistance (Rct) and increased the surface adsorption, leading to a high diffusion coefficient (D) of 0.192 cm2/s. The biosensor exhibited a high sensitivity of 0.71 Ω/µM cm2, a good linear range (0.1 to 140 µM with R2 = 0.98), and a low limit of detection (LOD) is 12.5 µM, demonstrating the synergic effect of ZF and rGO in the La/ZF/rGO/ITO bioelectrode with AD. The biosensor also exhibited high selectivity and stability (55 days) in the presence of interfering substances and in BSA samples, with a recovery percentage close to 100 ± 5% RSD, indicating its potential biosensing applications for real-world applications in disease diagnostics, monitoring, and treatment.


Asunto(s)
Técnicas Biosensibles , Enfermedades Neurodegenerativas , Humanos , Lacasa , Técnicas Electroquímicas/métodos , Epinefrina , Impedancia Eléctrica , Técnicas Biosensibles/métodos , Electrodos
4.
HardwareX ; 10: e00228, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35607666

RESUMEN

We report a sensitive, fixed-wavelength, lock-in-based optical detector built from a light-emitting diode, two colour filters, a photodetector, a small number of discrete analogue components, and a low-cost microcontroller development board. We describe the construction, operating principle, use and performance of the optical detector, which may be used for both absorption and fluorescence measurements in either a 10-mm pathlength cuvette or a low-volume (<100 µl) flow-cell. For illustrative purposes the detector is applied here to a cholesterol assay based on the enzyme-mediated conversion of (non-emissive) Amplex Red into the fluorescent dye resorufin, providing a detection limit of ~ 200 nM - some four orders of magnitude lower than the typical concentration of cholesterol in human serum. (The resorufin molecule itself is detectable down to concentrations of ~ 20 nM). The system may be readily adapted to other biomolecules through a simple change of enzyme.

5.
Small ; 16(47): e2004891, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33125820

RESUMEN

Metal halide perovskites (MHPs) have excellent optoelectronic and photovoltaic applications because of their cost-effectiveness, tunable emission, high photoluminescence quantum yields, and excellent charge carrier properties. However, the potential applications of the entire MHP family are facing a major challenge arising from its weak resistance to moisture, polar solvents, temperature, and light exposure. A viable strategy to enhance the stability of MHPs could lie in their incorporation into a porous template. Metal-organic frameworks (MOFs) have outstanding properties, with a unique network of ordered/functional pores, which render them promising for functioning as such a template, accommodating a wide range of MHPs to the nanosized region, alongside minimizing particle aggregation and enhancing the stability of the entrapped species. This review highlights recent advances in design strategies, synthesis, characterization, and properties of various hybrids of MOFs with MHPs. Particular attention is paid to a critical review of the emergence of MHP@MOF for comprehensive studies of next-generation materials for various technological applications including sensors, photocatalysis, encryption/decryption, light-emitting diodes, and solar cells. Finally, by summarizing the state-of-the-art, some promising future applications of reported hybrids are proposed. Considering the inherent correlation and synergic functionalities of MHPs and MOFs, further advancement; new functional materials; and applications can be achieved through designing MHP@MOF hybrids.

6.
Phys Chem Chem Phys ; 19(33): 22546-22554, 2017 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-28809967

RESUMEN

In the last few decades, dye-sensitized solar cell (DSC) technology has been demonstrated to be a promising candidate for low cost energy production due to cost-effective materials and fabrication processes. Arguably, DSC stability is the biggest challenge for making this technology appealing for industrial exploitation. This work provides further insight into the stability of DSCs by considering specific dye-electrolyte systems characterized by Raman and impedance spectroscopy analysis. In particular, two ruthenium-based dyes, Z907 and Ru505, and two commercially available electrolytes, namely, the high stability electrolyte (HSE) and solvent-free Livion 12 (L-12), were tested. After 4700 h of thermal stress at 85 °C, the least stable device composed of Z907/HSE showed an efficiency degradation rate of ∼14%/1000 h, while the Ru505/L-12 system retained 96% of its initial efficiency by losing ∼1% each 1000 h. The present results show a viable route to stabilize the DSC technology under prolonged annealing conditions complying with the IEC standard requirements.

7.
Biosens Bioelectron ; 62: 47-51, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24976150

RESUMEN

An electrochemical biosensor based on manganese oxide (Mn3O4) and chitosan (Cn) nanocomposite has been fabricated for fish freshness detection. The electrophoretic deposition of Mn3O4 nanoparticles (15-20 nm) with Cn has changed their morphological arrangement leading to pearl shaped of Mn3O4-Cn nanocomposite on indium tin oxide substrate. Size and morphology of nanocomposite have been confirmed by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results of electrochemical response reveal that this improved sensor has widest detection range of xanthine concentration from 1 to 500 µM and excellent sensitivity of 1.46 µA µM(-1) cm(-2). The fabricated XOx/Mn3O4-Cn/ITO biosensor can detect as low as 1.31 µM of xanthine and lower Km value of 0.018 µM confirming its superior affinity towards the nanocomposite film.


Asunto(s)
Quitosano/química , Compuestos de Manganeso/química , Nanocompuestos/química , Óxidos/química , Xantina/análisis , Técnicas Biosensibles/instrumentación , Electroquímica/instrumentación , Electrodos , Diseño de Equipo , Límite de Detección , Nanocompuestos/ultraestructura , Difracción de Rayos X
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