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1.
Biosensors (Basel) ; 14(5)2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38785695

RESUMEN

Microwave radiometry (MWR) is instrumental in detecting thermal variations in skin tissue before anatomical changes occur, proving particularly beneficial in the early diagnosis of cancer and inflammation. This study concisely traces the evolution of microwave radiometers within the medical sector. By analyzing a plethora of pertinent studies and contrasting their strengths, weaknesses, and performance metrics, this research identifies the primary factors limiting temperature measurement accuracy. The review establishes the critical technologies necessary to overcome these limitations, examines the current state and prospective advancements of each technology, and proposes comprehensive implementation strategies. The discussion elucidates that the precise measurement of human surface and subcutaneous tissue temperatures using an MWR system is a complex challenge, necessitating an integration of antenna directionality for temperature measurement, radiometer error correction, hardware configuration, and the calibration and precision of a multilayer tissue forward and inversion method. This study delves into the pivotal technologies for non-invasive human tissue temperature monitoring in the microwave frequency range, offering an effective approach for the precise assessment of human epidermal and subcutaneous temperatures, and develops a non-contact microwave protocol for gauging subcutaneous tissue temperature distribution. It is anticipated that mass-produced measurement systems will deliver substantial economic and societal benefits.


Asunto(s)
Microondas , Piel , Humanos , Temperatura Cutánea , Radiometría , Temperatura
2.
Sensors (Basel) ; 22(21)2022 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-36365974

RESUMEN

Aiming at the low efficiency of manual measurement of threads and the lack of practicability in machine vision measurement before, online size measurement of threads at the end of sucker rods based on machine vision was studied. A robotic arm is used to carry an optical device to achieve high-quality image acquisition of threads. Based on the prior knowledge of the thread profile angle, the directional edge detection operator is customized to achieve the accurate detection of the left and right edges of the thread. Noise filtering, sorting, and left and right edge-matching algorithms based on connected domains are developed to eliminate the interference effects of electrostatic dust and oil pollution in online measurement, and the dimension of thread profile angles, pitches, major diameters, and minor diameters can be precisely calculated. The experimental results show that the screw thread parameter measurement time is about 0.13 s; the maximum and minimum average errors of the thread angles are 0.011° and 0.632°, respectively; and the total average deviation is less than 0.08°. For the screw thread pitch, major diameter, minor diameter, and pitch diameter parameter measurement, the deviation of the measurement results between the proposed method and the universal tool microscope (UTM) method is less than 10 µm. It fully proves the effectiveness and accuracy of the method in this paper and, at the same time, shows that the method has good real-time performance and high application significance, which lays a good foundation for the subsequent online thread measurement.


Asunto(s)
Tornillos Óseos , Programas Informáticos , Algoritmos
3.
Talanta ; 125: 94-101, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24840420

RESUMEN

Precise measurement for the purity of organic compounds will fundamentally improve the capabilities and measurement services of the organic chemical analysis. Quantitative nuclear magnetic resonance (qNMR) is an important method to assess the purity of organic compounds. We presented a precise measurement method for the purity of small molecule with identification of impurities. In addition, the qNMR was rarely applied to purity of large compounds such as peptide, for which qNMR peaks are too crowded. Other than general idea of qNMR, we removed unwanted exchangeable peaks by proton exchange, as a new approach for qNMR, to make the quantitative protons of peptide isolated, which can ensure precise measurement. Moreover, a suitable internal standard, acesulfame potassium, was applied. The analytes were valine and peptide T5, due to their importance for protein analysis. For valine, the intraday CV was 0.052%, and the interday CV during 8 months was 0.071%. For peptide T5, simpler operation, shorter analytical time (1h vs. 3 days) and smaller CV (0.36% vs. 0.93%) were achieved by qNMR, compared with a traditional method (amino acid based isotope labeled mass spectrometry) via a hydrolysis reaction. This method has greatly increased the quantitative precision of qNMR for small compounds, and extended application scope of qNMR from small compounds to peptides.


Asunto(s)
Aminoácidos/análisis , Espectroscopía de Resonancia Magnética , Péptidos/análisis , Valina/análisis , Calibración , Cromatografía Liquida , Péptidos/química , Potasio/química , Protones , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem
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