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Martínez-Antón JC, Brun A, Vázquez D, Moreno S, Fernández-Balbuena AA, Alda J. Determination of the characteristic inactivation fluence for SARS-CoV-2 under UV-C radiation considering light absorption in culture media. Sci Rep 2021; 11:15293. [PMID: 34315976 PMCID: PMC8316444 DOI: 10.1038/s41598-021-94648-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/14/2021] [Indexed: 01/21/2023] Open
Abstract
The optical absorption coefficient of culture media is critical for the survival analysis of pathogens under optical irradiation. The quality of the results obtained from experiments relies on the optical analysis of the spatial distribution of fluence which also depends on the geometry of the sample. In this contribution, we consider both the geometrical shape and the culture medium's absorption coefficient to evaluate how the spatial distribution of optical radiation affects pathogens/viruses. In this work, we exposed SARS-CoV-2 to UV-C radiation ([Formula: see text] = 254 nm) and we calculated-considering the influence of the optical absorption of the culture medium-a characteristic inactivation fluence of [Formula: see text] = 4.7 J/m2, or an equivalent 10% survival (D90 dose) of 10.8 J/m2. Experimentally, we diluted the virus into sessile drops of Dulbecco's Modified Eagle Medium to evaluate pathogen activity after controlled doses of UV irradiation. To validate the optical absorption mode, we carried out an additional experiment where we varied droplet size. Our model-including optical absorption and geometrical considerations-provides robust results among a variety of experimental situations, and represents our experimental conditions more accurately. These results will help to evaluate the capability of UV disinfecting strategies applied to a variety of everyday situations, including the case of micro-droplets generated by respiratory functions.
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Affiliation(s)
- Juan Carlos Martínez-Antón
- Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, Av. Arcos de Jalón, 118, 28037, Madrid, Spain
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera Algete-El Casar de Talamanca, Km 8.1, 28130, Valdeolmos, Madrid, Spain
| | - Daniel Vázquez
- Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, Av. Arcos de Jalón, 118, 28037, Madrid, Spain
| | - Sandra Moreno
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera Algete-El Casar de Talamanca, Km 8.1, 28130, Valdeolmos, Madrid, Spain
| | - Antonio A Fernández-Balbuena
- Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, Av. Arcos de Jalón, 118, 28037, Madrid, Spain
| | - Javier Alda
- Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, Av. Arcos de Jalón, 118, 28037, Madrid, Spain.
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Briones E, Cuadrado A, Briones J, Díaz de León R, Martínez-Antón JC, McMurtry S, Hehn M, Montaigne F, Alda J, González FJ. Seebeck nanoantennas for the detection and characterization of infrared radiation. Opt Express 2014; 22 Suppl 6:A1538-A1546. [PMID: 25607310 DOI: 10.1364/oe.22.0a1538] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Arrays of metallic thermocouples in the shape of spiral nanoantennas are proposed as infrared detectors, which use the thermoelectric properties of the metallic interfaces to generate electrical DC signals. The responsivity of these types of antennas is evaluated from both theoretical and numerical perspectives pointing out its potential as infrared sensors. Moreover, the same structures can be used to characterize the state of polarization of the optical near fields with a spatial resolution comparable to the wavelength.
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Martínez-Antón JC. Determination of optical parameters in general film-substrate systems: a reformulation based on the concepts of envelope extremes and local magnitudes. Appl Opt 2000; 39:4557-4568. [PMID: 18350044 DOI: 10.1364/ao.39.004557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present a reformulation of the determination of optical parameters in general film-substrate systems. Developed for interferential films in terms of photometric magnitudes (R, T), the formalism introduced allows us to establish how many parameters can be extracted from a set of measurements and from which type of sample model. These parameters are the refractive index and the absorption of both film and substrate (i.e., ñ1 = n1-jk1 and ñ2 = n2-jk2), the thickness of the film (d), the inhomogeneity of the film (Deltan1), and the surface roughness of the interfaces (sigma1, sigma2) delimiting the film. The new formalism leads to some new analytical results and confirms others. Among the new results we have the following: (a) The mathematical condition commonly related with extremes (maxima and minima) in an interference pattern defines in fact a condition for envelope extremes. (b) The refractive index of a film can be obtained without prior knowledge of the thickness or the refractive index of the substrate (provided we have an optical interference film). (c) Absorption can be directly extracted from an interference-free magnitude T/(1-R). (d) Roughness at the inner surface, inhomogeneity in the film, and absorption are correlated in reflection spectral measurements.
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Affiliation(s)
- J C Martínez-Antón
- Departamento de Optica, Facultad de C. C. Físicas, Universidad Complutense de Madrid, C. Universitaria, 28040 Madrid, Spain.
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Martínez-Antón JC, Bernabeu E. Automatic three-dimensional spectrogoniometer for determination of optical properties and surface parameters. Appl Opt 1994; 33:6059-6061. [PMID: 20936020 DOI: 10.1364/ao.33.006059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An automatic three-dimensional spectrogoniometer is presented. The wavelength of ligth and angles of incidence and observation are variable, making it capable of performing different optical characterizations in an integrated way.
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