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1.
Sensors (Basel) ; 20(7)2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32235454

RESUMO

This research offers a method for separating the components of tissue impedance, namely resistance and capacitive reactance. Two objects that have similar impedance or low contrast can be improved through separating the real and imaginary images. This method requires an Electrical Impedance Tomography (EIT) device. EIT can obtain potential data and the phase angle between the current and the potential measured. In the future, the device is very suitable for imaging organs in the thorax and abdomen that have the same impedance but different resistance and capacitive reactance. This device consists of programmable generators, Voltage Controlled Current Source (VCCS), mulptiplexer-demultiplexer potential meters, and phase meters. Data collecting was done by employing neighboring, while reconstruction was used the linear back-projection method from two different data frequencies, namely 10 kHz and 100 kHz. Phantom used in this experiment consists of distillated water and a carrot as an anomaly. Potential and phase data from the device is reconstructed to produce impedance, real, and imaginary images. Image analysis is performed by comparing the three images to the phantom. The experimental results show that the device is reliable.


Assuntos
Impedância Elétrica , Processamento de Imagem Assistida por Computador/métodos , Tórax/diagnóstico por imagem , Tomografia/métodos , Algoritmos , Humanos , Imagens de Fantasmas
2.
Heliyon ; 10(12): e32349, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38975194

RESUMO

A gold-coated Kretschmann setup has been constructed and explored as a surface plasmon resonance (SPR) platform, specifically tailored for the detection of low-concentration sodium chloride (NaCl) solutions. The setup employs a BK7 prism coated with a 50 nm gold layer, serving as a plasmonic layer, to induce resonance. This resonance arises from the interplay between light waves and free electrons propagating at the interface of two media. The experimental findings reveal a notable resonance angle shift of 10° when the NaCl concentration is varied from 0 to 2.5 %. Furthermore, angle interrogation provides insightful details about the sensor's response to changes in the refractive index, showcasing a commendable sensitivity of 2400°/RIU, a high level of linearity at 0.9771, and an impressive resolution of 0.217 %. The demonstrated capabilities of this sensor underscore its potential for widespread applications, particularly in the monitoring of salt concentration across diverse domains such as seawater analysis, food processing, and fermentation processes. The robust performance and precision of this proposed sensor position it as a valuable tool with promising prospects for addressing the needs of various industries dependent on accurate salt concentration measurements.

3.
Microbes Infect ; 25(8): 105187, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37517605

RESUMO

Comprehending the morphological disparities between SARS-CoV-2 and SARS-CoV viruses can shed light on the underlying mechanisms of infection and facilitate the development of effective diagnostic tools and treatments. Hence, this study aimed to conduct a comprehensive analysis and comparative assessment of the morphology of SARS-CoV-2 and SARS-CoV using transmission electron microscopy (TEM) images. The dataset encompassed 519 isolated SARS-CoV-2 images obtained from patients in Italy (INMI) and 248 isolated SARS-CoV images from patients in Germany (Frankfurt). In this paper, we employed TEM images to scrutinize morphological features, and the outcomes were contrasted with those of SARS-CoV viruses. The findings reveal disparities in the characteristics of SARS-CoV-2 and SARS-CoV, such as envelope protein (E) 98.6 and 102.2 nm, length of spike protein (S) 10.11 and 9.50 nm, roundness 0.86 and 0.88, circularity 0.78 and 0.76, and area sizes 25145.54 and 38591.35 pixels, respectively. In conclusion, these results will augment the identification of virus subtypes, aid in the study of antiviral medications, and enhance our understanding of disease progression and the virus life cycle. Moreover, these findings have the potential to assist in the development of more accurate epidemiological prediction models for COVID-19, leading to better outbreak management and saving lives.


Assuntos
COVID-19 , Vírus , Humanos , SARS-CoV-2/metabolismo , Vírus/metabolismo , Antivirais/uso terapêutico , Microscopia Eletrônica de Transmissão
4.
Nanomaterials (Basel) ; 12(10)2022 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-35630976

RESUMO

In the current world situation, population and industrial growth have become major problems for energy and environmental concerns. Extremely noxious pollutants such as heavy metal ions, dyes, antibiotics, phenols, and pesticides in water are the main causes behind deprived water quality leading to inadequate access to clean water. In this connection, graphite carbon nitride (GCN or g-C3N4) a nonmetallic polymeric material has been utilized extensively as a visible-light-responsive photocatalyst for a variety of environmental applications. This review focuses on recent developments in the design and photocatalytic applications of metal-doped GCN-based nanomaterials in CO2 photoreduction, water splitting toward hydrogen production, bacterial disinfection, and organic pollutant degradation. Additionally, this review discusses various methods of using GCN-based materials to optimize dye sensitization, metal deposition, ion doping, and their environmental applications.

5.
Front Optoelectron ; 15(1): 28, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-36637608

RESUMO

A stable mode-locked laser was demonstrated using a newly developed zinc phthalocyanine (ZnPc) thin film as passive saturable absorber (SA) in ytterbium-doped fiber laser (YDFL). The ZnPc thin film was obtained using a casting method and then inserted between the two fiber ferrules of a YDFL ring cavity to generate mode-locked pulses. The resulting pulsed laser operated at a wavelength of 1034.5 nm having a repetition rate of 3.3 MHz. At pump power of 277 mW, the maximum output power and pulse energy are achieved at 4.92 mW and 1.36 nJ, respectively. ZnPc has a high chemical and photochemical stability, and its significance for use as a potential SA in a mode-locked laser is reported in this work.

6.
J Biomed Opt ; 17(7): 071308, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22894469

RESUMO

The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm; 0.775 mV/mm and 0.4 mm; 0.5109 mV/mm and 0.5 mm; and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.


Assuntos
Diagnóstico Bucal/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Aumento da Imagem/instrumentação , Iluminação/instrumentação , Reconhecimento Automatizado de Padrão/métodos , Fotometria/instrumentação , Dente/anatomia & histologia , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Estudos de Viabilidade , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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