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1. Characteristics, outcomes and treatment patterns in acute myeloid leukemia patients 60 years or older in Colombia: a RENEHOC-PETHEMA study

Author

Sossa-Melo, Claudia, Abello-Polo, Virginia, Salazar, Luis A., Peña, Angela M., Luna-González, María, Cuervo-Lozada, Diana, Quintero-Vega, Guillermo E., Daza, Jorge, Omaña-Orduz, Olga Paola, Mantilla, William, Perdomo, Iván, Galvez, Kenny, Díaz-Correa, Laura María, Guerrero-Burbano, Paola Andrea, Herrera, Juan Manuel, Idrobo, Henry, Gaviria, L M, Correa-Correa, Mario Ernesto, Lobatón, José, Bermúdez, Carlos Daniel, Pedraza-Morales, Julian Eduardo, Serrano-Casas, Juan Carlos, Jaramillo, Francisco, Gómez, Rigoberto, Rosales, Carmen, Solano, María Helena, Varón, Carlos, Rodríguez-Veiga, Rebeca, Martínez-Cuadrón, David, and Montesinos, Pau

Published
2025
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2. Towards a fiber-optic temporally multiplexed single photon source

Author

Magnoni, Agustina G., Knoll, Laura T., Wölcken, Lina, Defant, Julián, Morales, Julián, and Larotonda, Miguel A.

Subjects
Quantum Physics, Physics - Optics
Abstract

We demonstrate the feasibility of implementing a photon source with sub-Poissonian emission statistics through temporal multiplexing of a continuous wave heralded photon source in the optical communications wavelength range. We use the time arrival information of a heralding photon to actively modify the delay of the heralded photon in an all-fiber assembly, in order to synchronize the output with with respect to an external clock. Within this synchronized operating regime we show that the addition of a single temporal correcting stage can improve the figure of merit for single photon emission of a heralded photon source. We obtain a brightness improvement factor of approximately 1.8 and an enhancement of the signal-to-noise ratio, quantified by the coincidence-to-accidental counts ratio. These results, clear the way for integrated optics non-classical photon sources in the optical communication band., Comment: 6 pages, 6 figures

Published
2024

3. Optical transmitter for time-bin encoding Quantum Key Distribution

Author

Morales, Julián, Aparicio, M. Guadalupe, Longo, Carlos F., Arrieta, Cristian L., and Larotonda, Miguel A.

Subjects
Quantum Physics, Physics - Optics
Abstract

We introduce an electro-optical arrangement that is able to produce time-bin encoded symbols with the decoy state method over a standard optical fiber in the C-band telecom window. The device consists of a specifically designed pulse pattern generator for pulse production, a field-programmable gate array that controls timing and synchronization. The electrical pulse output drive a sequence of intensity modulators acting on a continuous laser that deliver bursts of weak optical pulse pairs of discrete intensity values. Such transmitter allows for the generation of all the quantum states needed to implement a discrete variable Quantum Key Distribution protocol over a single-mode fiber channel. Symbols are structured in bursts; the minimum relative delay between pulses is 1.25 ns, and the maximum symbol rate within a burst is 200 MHz. We test the transmitter on simulated optical channels of 7dB and 14dB loss, obtaining maximum extractable secure key rates of 3.0 kb/s and 0.57 kb/s respectively. Time bin state parameters such as symbol rate, pulse separation and intensity ratio between signal and decoy states can be easily accessed and changed, allowing the transmitter to adapt to different experimental conditions and contributing to standardization of QKD implementations., Comment: 8 pages, 4 figures

Published
2023
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5. An automated blood test for glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) to predict the absence of intracranial lesions on head CT in adult patients with mild traumatic brain injury: BRAINI, a multicentre observational study in Europe

Author

Maignan, Maxime, Viglino, Damien, Jacquin, Laurent, Douplat, Marion, Laribi, Said, Pes, Philippe, Ray, Patrick, Guenezan, Jérémy, Sebbane, Mustapha, Belen, Frédéric, Durand, Guillaume, Abric, Cordelia, Gil-Jardiné, Cédric, Mihai, Pudaru, Morales, Julián, Castuera, Ana, Castano-Leon, Ana María, Delgado, Juan, Alen, Jose F., Lagares, Alfonso, de la Cruz, Javier, Terrisse, Hugo, Mejan, Odile, Pavlov, Vladislav, Vermorel, Celine, and Payen, Jean-François

Published
2024
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6. A Stable High-Capacity Lithium-Ion Battery Using a Biomass-Derived Sulfur-Carbon Cathode and Lithiated Silicon Anode

Author

Marangon, Vittorio, Hernández-Renter, Celia, Olivares-Marín, Mara, Gómez-Serrano, Vicente, Caballero, Álvaro, Morales, Julián, and Hassoun, Jusef

Subjects
Physics - Chemical Physics
Abstract

A full lithium-ion-sulfur cell with a remarkable cycle life was achieved by combining an environmentally sustainable biomass-derived sulfur-carbon cathode and a pre-lithiated silicon oxide anode. X-ray diffraction, Raman spectroscopy, energy dispersive spectroscopy, and thermogravimetry of the cathode evidenced the disordered nature of the carbon matrix in which sulfur was uniformly distributed with a weight content as high as 75%, while scanning and transmission electron microscopy revealed the micrometric morphology of the composite. The sulfur-carbon electrode in the lithium half-cell exhibited a maximum capacity higher than 1200 mAhgS-1, reversible electrochemical process, limited electrode/electrolyte interphase resistance, and a rate capability up to C/2. The material showed a capacity decay of about 40% with respect to the steady-state value over 100 cycles, likely due to the reaction with the lithium metal of dissolved polysulfides or impurities including P detected in the carbon precursor. Therefore, the replacement of the lithium metal with a less challenging anode was suggested, and the sulfur-carbon composite was subsequently investigated in the full lithium-ion-sulfur battery employing a Li-alloying silicon oxide anode. The full-cell revealed an initial capacity as high as 1200 mAhgS-1, a retention increased to more than 79% for 100 galvanostatic cycles, and 56% over 500 cycles. The data reported herein well indicated the reliability of energy storage devices with extended cycle life employing high-energy, green, and safe electrode materials.

Published
2021
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7. Acoustofluidic phase microscopy in a tilted segmentation-free configuration

Author

Morales, Julián Mejía, Hammarström, Björn, Lippi, Gian Luca, Vassalli, Massimo, and Glynne-Jones, Peter

Subjects
Physics - Biological Physics
Abstract

A low-cost device for registration-free quantitative phase microscopy (QPM) based on the transport of intensity equation (TIE) of cells in continuous flow is presented. The method uses acoustic focusing to align cells into a single plane where all cells move at a constant speed. The acoustic focusing plane is tilted with respect to the microscope's focal plane in order to obtain cell images at multiple focal positions. As the cells are displaced at constant speed, phase maps can be generated without the need to segment and register individual objects. The proposed inclined geometry allows for the acquisition of a vertical stack without the need for any moving part, and it enables a cost-effective and robust implementation of QPM. The suitability of the solution for biological imaging is tested on blood samples, demonstrating the ability to recover the phase map of single red blood cells flowing through the microchip.

Published
2021
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8. Real World Evidence From 2 Decades of First-Line TKI Therapy in Chronic Myeloid Leukemia (CML): Insights From ACHO's RENEHOC Registry

Author

Abello Polo, Virginia, Sossa, Claudia, Boquimpani, Carla, Salazar, Luis Antonio, Munevar, Isabel, Gómez, Rigoberto, Cuervo, Diana Marcela, Varón Jaimes, Carlos, Reyes, Jheremy, Idrobo, Henry, Omaña, Paola, Daza, Jorge, Pedraza Morales, Julian Eduardo, Agudelo López, Claudia, Quintero-Vega, Guillermo E., Correa Correa, Mario, Herrera, Juan Manuel, Mantilla, William Armando, Serrano, Juan Carlos, Rosales, Carmen, Gálvez Cárdenas, Kenny Mauricio, Bermúdez, Carlos, Saavedra Ramírez, Domingo, Alzate, Mauricio, and Lobatón Ramírez, José Fernando

Published
2024
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16. On the distribution of three exotic geckos of genus Hemidactylus Gray, 1825 (Squamata, Gekkonidae), and an unusual record of the native lizard Gymnophthalmus speciosus (Hallowell, 1861) outside its elevational range in Colombia/Sobre la distribución de tres geckos exoticos del genero Hemidactylus Gray, 1825 (Squamata, Gekkonidae) y un registro inusual del lagarto nativo Gymnophthalmus speciosus (Hallowell, 1861) fuera de su intervalo altitudinal en Colombia

Author

Henao-Osorio, Jose J., Pereira-Ramirez, Ana M., Cardona-Giraldo, Alexandra, Arias-Monsalve, Hector Fabio, Rojas-Morales, Julian A., Caicedo-Portilla, Jose Ranees, and Ramirez-Chaves, Hector E.

Published
2021
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20. Influence of the length of hospitalisation in post-discharge outcomes in patients with acute heart failure: Results of the LOHRCA study

Author

Miró, Òscar, Padrosa, Joan, Takagi, Koji, Gayat, Étienne, Gil, Víctor, Llorens, Pere, Martín-Sánchez, Francisco Javier, Herrero-Puente, Pablo, Jacob, Javier, Montero, María Mir, Tost, Josep, Díez, María Pilar López, Traveria, Lissete, Torres-Gárate, Raquel, Alonso, María Isabel, Agüera, Carmen, Valero, Amparo, Javaloyes, Patricia, Peacock, W. Frank, Bueno, Héctor, Mebazaa, Alexandre, Fuentes, Marta, Gil, Cristina, Alonso, Héctor, Garmila, Pablo, García, Guillermo Llopis, Yáñez-Palma, María Cecilia, López, Sergio Iglesias, Escoda, Rosa, Xipell, Carolina, Sánchez, Carolina, Gaytan, Josep María, Pérez-Durá, María José, Salvo, Eva, Pavón, José, Noval, Antonio, Torres, José Manuel, López-Grima, María Luisa, Juan, Marian Ángeles, Aguirre, Alfons, Morales, Julián Errasti, Masó, Silvia Mínguez, Ruiz, Francisco, Franco, José Miguel, Mecina, Ana Belén, Sánchez, Susana, Carbajosa, Virginia, Piñera, Pascual, Nicolás, José Andrés Sánchez, Garate, Raquel Torres, Alquezar, Aitor, Rizzi, Miguel Alberto, Herrera, Sergio, Roset, Alex, Cabello, Irene, Richard, Fernando, Pérez, José María Álvarez, Diez, María Pilar López, Álvarez, Joaquín Vázquez, García, Belén Prieto, Sánchez González, María García García yMarta, Marquina, Víctor, Jiménez, Inmaculada, Hernández, Néstor, Brouzet, Benjamín, Ramos, Sergio, López, Ana, Andueza, Juan Antonio, Romero, Rodolfo, Ruíz, Martín, Calvache, Roberto, Lorca, María Teresa, Calderón, Luis, Arriaga, Beatriz Amores, Sierra, Beatriz, Mojarro, Enrique Martín, Bécquer, Lisette Travería, Burillo, Guillermo, García, Lluís Llauger, LaSalle, Gerard Corominas, Urbano, Carmen Agüera, Soto, Ana Belén García, Padial, Elisa Delgado, Ferrer, Ester Soy, Garrido, Manuel, Lucas, Francisco Javier, Gaya, Rut, Bibiano, Carlos, Mir, María, Rodríguez, Beatriz, Sánchez, Natalia, Carballo, José Luis, Rodríguez-Adrada, Esther, and Rodríguez, Belén

Published
2019
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21. Effect of Barthel Index on the Risk of Thirty-Day Mortality in Patients With Acute Heart Failure Attending the Emergency Department: A Cohort Study of Nine Thousand Ninety-Eight Patients From the Epidemiology of Acute Heart Failure in Emergency Departments Registry

Author

Fuentes, Marta, Gil, Cristina, Alonso, Héctor, Garmila, Pablo, Rodríguez Adrada, Esther, Llopis García, Guillermo, Yáñez-Palma, M. Cecilia, López, Sergio Iglesias, Escoda, Rosa, Xipell, Carolina, Sánchez, Carolina, Gaytan, Josep M<ce:sup loc='post">a</ce:sup>, Pérez-Durá, María José, Salvo, Eva, Pavón, José, Noval, Antonio, Torres, José M., López-Grima, María Luisa, Valero, Amparo, Juan, Marian Ángeles, Aguirre, Alfons, Morales, Julián Errasti, Mínguez Masó, Silvia, Isabel Alonso, María, Ruiz, Francisco, Miguel Franco, José, Díaz, Elena, Belén Mecina, Ana, Tost, Josep, Sánchez, Susana, Carbajosa, Virginia, Piñera, Pascual, Sánchez Nicolás, José Andrés, Torres Garate, Raquel, Alquezar, Aitor, Alberto Rizzi, Miguel, Herrera, Sergio, Roset, Alex, Cabello, Irene, Richard, Fernando, Álvarez Pérez, José María, Pilar López Diez, María, Vázquez Álvarez, Joaquín, Alonso Morilla, Ana, Irimia, Andrea, Javaloyes, Patricia, Marquina, Víctor, Jiménez, Inmaculada, Hernández, Néstor, Brouzet, Benjamín, Ramos, Sergio, López, Ana, Antonio Andueza, Juan, Antonio Sevillano, José, Romero, Rodolfo, Calvache, Roberto, Lorca, María Teresa, Calderón, Luis, Amores Arriaga, Beatriz, Sierra, Beatriz, Martín Mojarro, Enrique, Travería Bécquer, Lisette, Burillo, Guillermo, Llauger García, Lluís, Corominas LaSalle, Gerard, Agüera Urbano, Carmen, Belén García, Ana, Elisa Delgado Padial, Soto, Soy Ferrer, Ester, Garrido, Manuel, Javier Lucas, Francisco, Gaya, Rut, Rossello, Xavier, Miró, Òscar, Llorens, Pere, Jacob, Javier, Herrero-Puente, Pablo, Gil, Víctor, Rizzi, Miguel A., Pérez-Durá, María J., Espiga, Fernando R., Sevillano, José A., Vidán, María T., Bueno, Héctor, Pocock, Stuart J., and Martín-Sánchez, Francisco J.

Published
2019
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41. Variability in the indication of brain CT scan after mild traumatic brain injury. A transnational survey

Author

Lagares Gómez-Abascal, Alfonso, Castaño León, Ana María, Richard, Marion, Tsitsopoulos, Parmenion Philip, Morales, Julian, Mihai, Podaru, Pavlov, Vladislav, Mejan, Odile, Cruz, Javier de la, Payen, Jean François, Maignan, Maxime, Jacquin, Laurent, Douplat, Marion, Laribi, Said, Pes, Philippe, Ray, Patrick, Guenezan, Jérémy, Sebbane, Mustapha, Balen, Frédéric, Durand, Guillaume, Abric, Cordelia, Lorca, María Teresa, Ponce, Mariana Garcia, Cuesta, Maite, Alén, Jose A. F., Lagares Gómez-Abascal, Alfonso, Castaño León, Ana María, Richard, Marion, Tsitsopoulos, Parmenion Philip, Morales, Julian, Mihai, Podaru, Pavlov, Vladislav, Mejan, Odile, Cruz, Javier de la, Payen, Jean François, Maignan, Maxime, Jacquin, Laurent, Douplat, Marion, Laribi, Said, Pes, Philippe, Ray, Patrick, Guenezan, Jérémy, Sebbane, Mustapha, Balen, Frédéric, Durand, Guillaume, Abric, Cordelia, Lorca, María Teresa, Ponce, Mariana Garcia, Cuesta, Maite, and Alén, Jose A. F.

Abstract

CRUE-CSIC (Acuerdos Transformativos 2022), Purpose: Clinical guidelines have been developed to standardize the management of mild traumatic brain injury (mTBI) in the emergency room, in particular the indication of brain CT scan and the use of blood biomarkers. The objective of this study was to determine the degree of adherence to guidelines in the management of these patients across four countries of Southern Europe. Methods: An electronic survey including structural and general management of mTBI patients and six clinical vignettes was conducted. In-charge physicians from France, Spain, Greece and Portugal were contacted by telephone and email. Diferences among countries were searched using an unconditional approach test on contingency tables. Results: One hundred and eighty eight physicians from 131 Hospitals (78 Spain, 36 France, 12 Greece and 5 Portugal) completed the questionnaire. There were diferences regarding the in-charge specialist across these countries. There was variability in the use of guidelines and their adherence. Spain was the country with the least guideline adherence. There was a global agreement in ordering a brain CT for patients receiving anticoagulation or platelet inhibitors, and for patients with seizures, altered consciousness, neurological defcit, clinical signs of skull fracture or signs of facial fracture. Aging was not an indication for CT in French centres. Loss of consciousness and posttraumatic amnesia were considered as indications for CT more frequently in Spain than in France. These fndings were in line with the data from the 6 clinical vignettes. The estimated use of CT reached around 50% of mTBI cases. The use of S100B is restricted to fve French centres. Conclusions: There were large variations in the guideline adherence, especially in the situations considered to order brain CT after mTBI., Depto. de Cirugía, Fac. de Medicina, TRUE, pub

Published
2022

44. Variability in the indication of brain CT scan after mild traumatic brain injury. A transnational survey.

Author

Lagares, Alfonso, Castaño-Leon, Ana María, Richard, Marion, Tsitsopoulos, Parmenion Philip, Morales, Julian, Mihai, Podaru, Pavlov, Vladislav, Mejan, Odile, de la Cruz, Javier, Payen, Jean François, Maignan, Maxime, Jacquin, Laurent, Douplat, Marion, Laribi, Said, Pes, Philippe, Ray, Patrick, Guenezan, Jérémy, Sebbane, Mustapha, Balen, Frédéric, and Durand, Guillaume

Subjects
BRAIN, TELEPHONES, ANTICOAGULANTS, LOSS of consciousness, MEDICAL protocols, SURVEYS, BRAIN concussion, CASE studies, QUESTIONNAIRES, PLATELET aggregation inhibitors, RESEARCH funding, COMPUTED tomography, PHYSICIANS, SEIZURES (Medicine), CONSCIOUSNESS disorders, SKULL fractures, EMAIL, AMNESIA, SYMPTOMS
Abstract

Purpose: Clinical guidelines have been developed to standardize the management of mild traumatic brain injury (mTBI) in the emergency room, in particular the indication of brain CT scan and the use of blood biomarkers. The objective of this study was to determine the degree of adherence to guidelines in the management of these patients across four countries of Southern Europe. Methods: An electronic survey including structural and general management of mTBI patients and six clinical vignettes was conducted. In-charge physicians from France, Spain, Greece and Portugal were contacted by telephone and email. Differences among countries were searched using an unconditional approach test on contingency tables. Results: One hundred and eighty eight physicians from 131 Hospitals (78 Spain, 36 France, 12 Greece and 5 Portugal) completed the questionnaire. There were differences regarding the in-charge specialist across these countries. There was variability in the use of guidelines and their adherence. Spain was the country with the least guideline adherence. There was a global agreement in ordering a brain CT for patients receiving anticoagulation or platelet inhibitors, and for patients with seizures, altered consciousness, neurological deficit, clinical signs of skull fracture or signs of facial fracture. Aging was not an indication for CT in French centres. Loss of consciousness and posttraumatic amnesia were considered as indications for CT more frequently in Spain than in France. These findings were in line with the data from the 6 clinical vignettes. The estimated use of CT reached around 50% of mTBI cases. The use of S100B is restricted to five French centres. Conclusions: There were large variations in the guideline adherence, especially in the situations considered to order brain CT after mTBI. [ABSTRACT FROM AUTHOR]

Published
2023
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48. Site-specialization of human oral Gemella species.

Author

Torres-Morales, Julian, Mark Welch, Jessica L., Dewhirst, Floyd E., and Borisy, Gary G.

Subjects
*ORAL mucosa, *PAN-genome, *SPECIES, *DENTAL plaque, *HUMAN microbiota, *OPPORTUNISTIC infections
Abstract

Gemella species are core members of the human oral microbiome in healthy subjects and are regarded as commensals, although they can cause opportunistic infections. Our objective was to evaluate the site-specialization of Gemella species among various habitats within the mouth by combining pangenomics and metagenomics. With pangenomics, we identified genome relationships and categorized genes as core and accessory to each species. With metagenomics, we identified the primary oral habitat of individual genomes. Our results establish that the genomes of three species, G. haemolysans, G. sanguinis and G. morbillorum, are abundant and prevalent in human mouths at different oral sites: G. haemolysans on buccal mucosa and keratinized gingiva; G. sanguinis on tongue dorsum, throat, and tonsils; and G. morbillorum in dental plaque. The gene-level basis of site-specificity was investigated by identifying genes that were core to Gemella genomes at a specific oral site but absent from other Gemella genomes. The riboflavin biosynthesis pathway was present in G. haemolysans genomes associated with buccal mucosa but absent from the rest of the genomes. Overall, metapangenomics show that Gemella species have clear ecological preferences in the oral cavity of healthy humans and provides an approach to identifying gene-level drivers of site specificity. [ABSTRACT FROM AUTHOR]

Published
2023
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50. Acoustofluidic interferometric device for optomechanical cytometry

Author

MEJIA MORALES, JULIAN, Institut de Physique de Nice (INPHYNI), Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université Côte d'Azur, Università degli studi (Gênes, Italie), Gian Luca Lippi, and Rodolfo Quarto

Subjects
Cytométrie, cell optome- chanical properties, Microfluidique, Dispositif interférométrique acoustofluidique (DIA), acoustofluidic interferometric device (AID), Fabry-Perot interferometer, acoustic focusing, acoustic manipulation of cells, cell optome- chanical properties, Fabry-Perot fringe pattern perturbation, Thin lens proxy for a cell, microfluidics, cytometry, acoustofluidic interferometric device (AID), Distance focale d’une lentille mince – proxy pour une cellule, microfluidics, acoustic focusing, Fabry-Perot fringe pattern perturbation, cytometry, Interféromètre Fabry-Perot, Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin), [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Propriétés optomécaniques des cellules, acoustic manipulation of cells, Cell optomechanical properties, Fabry-Perot interferometer, Perturbation des franges Fabry-Pérot, Focalisation acoustique, Thin lens proxy for a cell, Manipulation acoustique des cellules
Abstract

In the past years a growing demand for label-free cell analysis has emerged. This demand answers the need for cell analysis in its developing stages and, perhaps more importantly, to study cell physiological state in a simpler way than using fluorescence-based analyses. Mechanical and optical properties of cells are emerging as powerful biomarkers to discriminate cells. The cell deformation induced by acoustic pressure is measured with the Acoustofluidic Interferometric Device, developed in this Thesis, and allows for studying the cells deformability in a way similar to what is done for the analysis of the Young modulus. Deformability is an integral biomarker that summarizes cell gene expression, while the cell refractive index is related to the density of proteins in the cytoskeleton. The Acoustofluidic Interferometric Device, developed for the measurement of optomechanical cell properties on a cytometric basis, is detailed described and characterized in this thesis. The device enables the assessment of size, deformability and refractive index (or a combination of them) of non-adherent cells by means of a low finesse Fabry Perot resonator and acoustic manipulation.When an acoustically focussed cell (or another micro-sized particle) crosses the axis of the Fabry-Perot cavity it will perturb the resonator’s fringe pattern governed by the Airy’s transmission function. Such perturbation can be characterized and analyzed by means of the parameters ρ (radii of the circular interference fringes), Full Width at Half Maximum of the individual fringe and by the distance between fringes (Free Spectral Range). The analysis of the perturbation enables the assessment of the cell’s optomechanical properties. Measurement of the deformability of Algae and Yeast cells has been carried out to test the instrument’s performance and compared to the equivalent perturbation introduced by Microgel beads and Polystyrene spheres as controls. The experiment is based on the cell-induced fringe pattern perturbation images analysis. Images are acquired under two different conditions; 1) acoustic focussing and 2) acoustically induced deformation. 180 independent intensity profiles are retrieved and analyzed for each image, allowing for statistical analysis of the parameters: cell focal length and perturbed resonator Finesse. The results show a change in the optomechanical properties of the Algae, Yeast and Microgel while the Polystyrene sample remains virtually unchanged, as expected since Polystyrene is much stiffer than a cell and cannot be deformed by the pressure field of the instrument. These results show that the acoustofluidic technique presented here is useful to detect and measure different optomechanical properties which, potentially, can be used as label free biomarkers in clinical diagnosis.; Au cours des dernières années, une demande croissante d’analyse cellulaire sans étiquette est apparue. Cette demande répond au besoin d’analyse cellulaire dans ses étapes de développement et, peut-être plus important encore, d’étudier l’état physiologique des cellules d’une manière plus simple que d’utiliser des analyses basées sur la fluorescence. Les propriétés mécaniques et optiques des cellules deviennent de puissants biomarqueurs pour discriminer les cellules. La déformation cellulaire induite par la pressionacoustique est mesurée avec le Dispositif Interférométrique Acoustofluidique, développé dans cette thèse, et permet d’étudier la déformabilité cellulaire d’une manière similaire à ce qui est fait pour l’analyse du module d’Young. La déformabilité est un biomarqueur intégral qui résume l’expression du gène cellulaire, tandis que l’indice de réfraction cellulaire est lié à la densité des protéines dans le cytosquelette. Le dispositif interférométrique acoustofluidique, développé pour la mesure des propriétés optomécaniques des cellules sur une base cytométrique, est décrit et caractérisé en détail dans cette thèse. L’appareil permet d’évaluer la taille, la déformabilité et l’indice de réfraction (ou une combinaison de ceux-ci) de cellules non adhérentes au moyen d’un résonateur Fabry-Perot de faible finesse et d’une manipulation acoustique. Lorsqu’une cellule focalisée par le champ acoustique (ou une autre particule de micro-taille) croise l’axe de la cavité Fabry-Perot, elle perturbe le motif de franges du résonateur, décrites par la fonction de transmission d’Airy. Une telle perturbation peut être caractérisée et analysée au moyen des paramètres ρ (rayons des franges d’interférence circulaires), pleine largeur à mi-maximum de la frange individuelle et distance entre les franges (intervalle spectrale libre). L’analyse de la perturbation permet d’évaluer les propriétés optomécaniques de la cellule. La mesure de la déformabilité des algues et descellules de levure a été réalisée pour tester les performances de l’instrument et comparée à la perturbation équivalente introduite par les billes de microgel et par des sphères de polystyrène comme témoins. L’expérience est basée sur l’analyse des images de perturbation des franges induites par les cellules. Lesimages sont acquises dans deux conditions différentes; 1) focalisation acoustique et 2) déformation induite acoustiquement. 180 profils d’intensité indépendants sont récupérés et analysés pour chaque image, permettant une analyse statistique des paramètres: distance focale cellulaire et Finesse du résonateur perturbé. Les résultats montrent un changement dans les propriétés optomécaniques des algues, de la levure et du microgel tandis que l’échantillon de polystyrène reste pratiquement inchangé, comme prévu, car le polystyrène est beaucoup plus rigide qu’une cellule et ne peut pas être déformé par le champ de pression de l’instrument. Ces résultats montrent que la technique acoustofluidique présentée ici est utile pour détecter et mesurer différentes propriétés optomécaniques qui, potentiellement, peuvent être utilisées comme biomarqueurs sans étiquette dans le diagnostic clinique.

Published
2021

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