Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Appl Opt ; 61(10): 2850-2855, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35471361

RESUMEN

To detect the internal humidity of the transformer accurately and sensitively and eliminate the interference caused by electromagnetic fields, an interferometric measurement is proposed in this paper for the first time, to the best of our knowledge. The phase value distribution of the interferogram affected by humidity can be extracted quantitatively. The peak-to-peak value (P-P) of the phase image can reflect the humidity, according to theoretical analysis, and the main factors affecting the P-P are current and humidity. It has been tested by currents of 800 A, 1000 A, and 1200 A and different humidities. The paper reveals the relationship between humidity and P-P, proving that it is a reasonable application of real-time measurement of internal humidity in the transformer.

2.
Appl Opt ; 61(2): 422-428, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-35200879

RESUMEN

Transformer oil used in oil-filled electrical power transformers aims at insulating, stopping arcing and corona discharge, and dissipating transformer heat. Transformer running inevitably induces molecule decomposition, thus leading to gases released into transformer oil. The released gases not only reduce the transformer oil's performance but also possibly induce transformer fault. To prevent catastrophic failure, approaches using, e.g., chromatography and spectroscopy, precisely measure dissolved gases to monitor transformer oil quality; however, many of these approaches still suffer from complicated operations, expensive costs, or slow speed. To solve these problems, we provide a new transformer oil quality evaluation method based on quantitative phase microscopy. Using our designed phase real-time microscopic camera (PhaseRMiC), under- and over-focus images of gas bubbles in transformer oil can be simultaneously captured during field of view scanning. Further, oil-to-gas-volume ratio can be computed after phase retrieval via solving the transport of intensity equation to evaluate transformer oil quality. Compared with traditionally and widely used approaches, this newly designed method can successfully distinguish transformer oil quality by only relying on rapid operations and low costs, thus delivering a new solution for transformer prognosis and diagnosis.

3.
Colloids Surf B Biointerfaces ; 210: 112259, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34883340

RESUMEN

A smartphone-based colorimetric platform for facile glucose detection was constructed below. First, glucose oxidase-Cu3(PO4)2·3H2O hybrid microflowers (GOx-HMFs) were facilely synthesized via biomineralization, which can react with glucose and 3,3',5,5'-tetramethylbenzidine to generate colored product. Next, the color information of product was real-time collected and processed via smartphone to realize accurate glucose detection. The as-constructed colorimetric platform based on GOx-HMFs and smartphone had wide linear range, high sensitivity and good selectivity for glucose detection, moreover, the detection process was convenient and efficient, which provided a new idea for glucose detection.


Asunto(s)
Técnicas Biosensibles , Glucosa Oxidasa , Colorimetría , Glucosa , Teléfono Inteligente
4.
J Cosmet Dermatol ; 21(6): 2429-2436, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34535947

RESUMEN

BACKGROUND: The aging face is characterized by skin laxity and volume loss. Attenuation of facial retaining ligaments significantly contributes to skin sagginess and soft tissue volume loss. AIMS: We designed a prospective cohort study to quantitatively assess the efficacy of hyaluronic acid (HA) with adjunct poly-L-lactic acid (PLLA) injections in strengthening the retaining ligaments. PATIENTS/METHODS: A total of 12 Asian women were treated with HA injections to the orbital, zygomatic, buccal-maxillary, and mandibular retaining ligaments with adjunct supraperiosteal and subdermal PLLA injections to the temporal region, midface, and lower face. Cephalometric measurements were done before treatment and 2, 4, 12, and 24 weeks post-procedurally. RESULTS: Eyebrow peak and tail angles increased 20.0° ± 3.8° to 21.0° ± 3.8° (p < 0.05) and -2.9° ± 4.2° to -1.3° ± 3.3° (p < 0.001) at week 12. Eyebrow-to-orbital-rim distance increased 1.9 ± 2.0 mm to 3.9 ± 1.5 mm (p < 0.001) at week 12. Eyebrow-to-upper-eyelid distance increased 11.6 ± 3.0 mm to 12.7 ± 3.2 mm (p < 0.001) at week 24. Eyebrow-peak-to-lateral-limbus distance decreased 6.1 ± 3.1 mm to 5.3 ± 2.4 mm (p < 0.05) at week 4. Tragus-oral-commissure length and lower-facial-contouring length decreased 281 ± 11 mm to 275 ± 10 mm (p < 0.01) and 297 ± 14 to 292 ± 11 mm (p < 0.05) at week 12, respectively. CONCLUSION: Hyaluronic acid injection for strengthening of facial retaining ligaments with adjunct PLLA is viable, safe, and effective in facial rejuvenation as supported by quantitative data.


Asunto(s)
Técnicas Cosméticas , Envejecimiento de la Piel , Femenino , Humanos , Ácido Hialurónico , Inyecciones Subcutáneas , Poliésteres , Estudios Prospectivos , Rejuvenecimiento
6.
Int J Biol Macromol ; 188: 783-789, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34389390

RESUMEN

Two morphologies of laccase-mineral hybrid complexes, i.e., laccase-mineral hybrid nanoflowers (La-HNF) and nanopetals (La-HNP), were synthesized via biomineralization using Cu3 (PO4)2·3H2O as the mineral for Evans Blue (EB) dye biodegradation. XRD patterns and FT-IR spectra results revealed the successful immobilization of laccase via in-situ formed Cu3(PO4)2·3H2O crystals. Compared with free laccase, laccase-mineral hybrid complexes showed higher enzymatic activity due to the activation effect induced by copper ions of Cu3(PO4)2·3H2O, further, the improved kinetic parameters of laccase-mineral hybrid complexes could be ascribed to nanoscale-dispersed laccase molecules within hybrid complexes. For EB dye biodegradation, the reason why the biodegradation efficiency (94.9%) of La-HNF was higher than that (86.8%) of La-HNP could be synergistic effect of immobilized laccase within 3D hierarchical structure of La-HNF. In addition, the optimized biodegradation conditions (pH 4.6 and 40 °C) of La-HNF were obtained, moreover, 93.2% and 48.1% of EB dye were biodegraded by La-HNF after stored for 30 days and reused for 10 cycles, respectively, demonstrating La-HNF have good practicability.


Asunto(s)
Azul de Evans/metabolismo , Lacasa/química , Minerales/química , Biodegradación Ambiental , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Nanopartículas/química , Nanopartículas/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Trametes/enzimología , Difracción de Rayos X
7.
Talanta ; 224: 121840, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33379058

RESUMEN

A novel smartphone-assisted portable biosensor based on laccase-mineral hybrid microflowers (La-HMFs) was applied for real-time, accurate and reliable quantification of epinephrine (EP). La-HMFs with flower-like hierarchical nanostructure was synthesized via biomineralization using Cu3(PO4)2⋅3H2O as the mineral. Characterization results revealed laccase molecules as the framework were immobilized within La-HMFs. Smartphone-assisted colorimetric assays showed wide linear detection range (1-400 µM) and favorable anti-interference ability for EP detection, and the detection limit was 0.6 µM. Further, due to the protective effect of Cu3(PO4)2⋅3H2O, the immobilized laccase exhibited good stability and desirable reusability.


Asunto(s)
Técnicas Biosensibles , Colorimetría , Epinefrina , Lacasa , Minerales , Teléfono Inteligente
8.
Sci Rep ; 10(1): 19047, 2020 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-33149270

RESUMEN

Interferometry-based online partial discharge (PD) monitor presented in this paper can detect the occurrence of PD sensitively, evaluate the peak value of the discharge inception voltage with random waveform and the damage extent relatively cost effectively. The interferograms affected by the PD are collected online. By extracting the phase information of the interference fringes quantitatively, the peak value of the discharge inception voltage with random waveform can be retrieved real-time. Merits of the proposed method as an online quantitative PD monitor are validated via theoretical analysis as well as experimentations by the use of an artificially localized PD source. Furthermore, the proposed method can capture the light signal emitted by the discharge. Quite in contrast to many commonly used sensor-based methods, our approach avoids the need of amplifying the light signal strength making its practical implantation much convenient. The proposed method promises strong potential for field application.

9.
Enzyme Microb Technol ; 140: 109620, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32912680

RESUMEN

A colorimetric platform based on enzyme-inorganic hybrid nanoflowers was used for ultraviolet-visible detection of hydrogen peroxide (H2O2). The hybrid nanoflowers were prepared via incubation at room temperature using horseradish peroxidase (HRP) and copper phosphate (Cu3(PO4)2) as the organic and inorganic components, respectively. HRP/Cu3(PO4)2 hybrid nanoflowers (HRP-HNFs) showed linear H2O2 detection range from 100 nM to 100 µM, moreover, HRP-HNFs exhibited good selectivity for H2O2 detection due to the specificity of HRP. In addition, HRP-HNFs have good reusability, excellent color stability and long-term storage stability, which indicate HRP-HNFs are promising for catalysis and biomedical applications.


Asunto(s)
Cobre/química , Peroxidasa de Rábano Silvestre/química , Peróxido de Hidrógeno/aislamiento & purificación , Nanoestructuras/química , Fosfatos/química , Técnicas Biosensibles , Catálisis , Colorimetría , Estabilidad de Enzimas , Enzimas Inmovilizadas , Peroxidasa de Rábano Silvestre/metabolismo , Peróxido de Hidrógeno/metabolismo
10.
Sensors (Basel) ; 20(3)2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-31973117

RESUMEN

Taking a photo has become a part of our daily life. With the powerfulness and convenience of a smartphone, capturing what we see may have never been easier. However, taking good photos may not be always easy or intuitive for everyone. As numerous studies have shown that photo composition plays a very important role in making a good photo, in this study, we, therefore, propose to develop a photo-taking app to give a real-time suggestion through a scoring mechanism to guide a user to take a good photo. Due to the concern of real-time performance, only eight commonly used composition rules are adopted in our system, and several detailed evaluations have been conducted to prove the effectiveness of our system.

11.
Nanomaterials (Basel) ; 7(5)2017 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-28468325

RESUMEN

Immunoglobulins are important biomarkers to evaluate the immune status or development of infectious diseases. To provide timely clinical treatments, it is important to continuously monitor the level of multiple immunoglobulins. Localized surface plasmon resonance (LSPR)-based nanoplasmonic sensors have been demonstrated for multiplex immunoglobulins detection. However, the sensor fabrication process is usually slow and complicated, so it is not accessible for large-area and batch fabrication. Herein, we report a large-area (2 cm × 2 cm) nanofabrication method using physical vapor deposition followed by a rapid thermal annealing treatment. To optimize the sensor performance, we systematically characterized three fabrication conditions, including (1) the deposition thickness; (2) the maximum annealing temperature, and (3) the annealing time. The corresponding absorbance spectrum profile and surface morphology of the nanostructures were observed by a UV-VIS spectrometer and atomic force microscopy. We then tested the sensitivity of the sensor using a glucose solution at different concentrations. The results showed that the sensor with 10 nm gold deposition thickness under 5-min 900 °C rapid thermal annealing can achieve the highest sensitivity (189 nm RIU-1). Finally, we integrated this nanoplasmonic sensor with a microchannel and a motorized stage to perform a 10-spot immunoglobulin detection in 50 min. Based on its real-time, dynamic and multi-point analyte detection capability, the nanoplasmonic sensor has the potential to be applied in high-throughput or multiplex immunoassay analysis, which would be beneficial for disease diagnosis or biomedical research in a simple and cost-effective platform.

12.
IEEE Comput Graph Appl ; 28(2): 52-61, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18350933

RESUMEN

This new color-conversion method offers users an intuitive, one-click interface for style conversion and a refined histogram-matching method that preserves spatial coherence.


Asunto(s)
Afecto/efectos de la radiación , Color , Aumento de la Imagen/métodos , Técnica de Sustracción , Interfaz Usuario-Computador , Arte , Colorimetría , Bases de Datos como Asunto , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Almacenamiento y Recuperación de la Información , Valores de Referencia , Tecnología/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...