Avoiding induced heating in optical trap

Paloma Rodríguez-Sevilla, Yuhai Zhang, Patricia Haro-González, Francisco Sanz-Rodríguez, Francisco Jaque, José García Sole, Xiaogang Liu, Daniel Jaque, "Avoiding induced heating in optical trap", Optical Trapping and Optical Micromanipulation XIV, Proc. SPIE 10347 - 1034716 (25 August 2017); doi: 10.1117/12.2276355. ne print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Proceedings of XIV Optical Trapping and Optical Micromanipulation Conference (San Diego, California, United States)Luminescence of a single upconverting particle (NaYF 4 :Er 3+ ,Yb 3+ ) can be used to determine the optical trap temperature due to the partial absorption of the trapping beam either by the medium (water) or the optically trapped particle itself. This fact is an important drawback can be reduced by shifting the trapping wavelength out of the water absorption band, or by using time-modulated laser trapping beams. Both approaches have been studied and the results have shown that the thermal loading due to the trapping radiation can be minimized.This work was supported by the Spanish Ministerio de Educación y Ciencia (MAT2016-75362-C3-1-R) and by COST Action 1403. P.H.G. thanks the Spanish Ministerio de Economía y Competitividad (MINECO) for the Juan de la Cierva- Incorporación program. P.R.S. thanks MINECO and the Fondo Social Europeo (FSE) for the “Promoción del talento y su Empleabilidad en I+D+i” statal program (BES-2014-069410

The luminescent quantum efficiency of Cr³⁺ ions in co-doped crystals of LiNb0<syb>3</sub> : ZnO determined by simultaneous multiple-wavelength photoacoustic and luminescence experiments

In this paper, the luminescent quantum efficiency of Cr³⁺ ions in co-doped crystals of LiNb03: ZnO: Cr³⁺ is determined by using a method based on simultaneous multiple-wavelength measurement of photoacoustic and luminescence signal after pulsed laser excitation. The quantum efficiency found in this lattice was (10 ±4)% . This result was compared with the value found from the study of the lifetime in terms of the temperature of the luminescent levels involved. In this last case, two non-equivalent crystal sites were found for Cr³⁺ ions, and two fluorescence quantum yields were determined. After the estimation of the concentration of each site by electron paramagnetic resonance experiments, the averaged fluorescence quantum yield value was (9 ± 2)% in agreement with the previous result.Facultad de Ciencias ExactasCentro de Investigaciones Óptica

The luminescent quantum efficiency of Cr³⁺ ions in co-doped crystals of LiNb0<syb>3</sub> : ZnO determined by simultaneous multiple-wavelength photoacoustic and luminescence experiments

In this paper, the luminescent quantum efficiency of Cr³⁺ ions in co-doped crystals of LiNb03: ZnO: Cr³⁺ is determined by using a method based on simultaneous multiple-wavelength measurement of photoacoustic and luminescence signal after pulsed laser excitation. The quantum efficiency found in this lattice was (10 ±4)% . This result was compared with the value found from the study of the lifetime in terms of the temperature of the luminescent levels involved. In this last case, two non-equivalent crystal sites were found for Cr³⁺ ions, and two fluorescence quantum yields were determined. After the estimation of the concentration of each site by electron paramagnetic resonance experiments, the averaged fluorescence quantum yield value was (9 ± 2)% in agreement with the previous result.Facultad de Ciencias ExactasCentro de Investigaciones Óptica

Sistema de Trazabilidad Vitivinícola Basado en IoT

129 p.La globalización ha incrementado el interés de los países en la adquisición de productos de calidad que involucran una cantidad significativa de pasos en los procesos de producción. Dando la posibilidad de que industrias de los países en desarrollo quieran exportar productos de calidad, de manera segura. Para lograr este objetivo, se requiere de un sistema de registro que permita corroborar si un producto cumple con los estándares básicos de calidad. Dentro de Chile y particularmente la región del Maule, la producción de vino es una de la más grande del país. Reconocido en todo el mundo, su elaboración es muy rigurosa y la gran industria del sector vitivinícola es reconocida por el buen tratamiento de las etapas en los procesos productivos. La trazabilidad permite asegurar la calidad del producto a través del registro de los procesos de producción. Comúnmente el proceso de registro se hace a través de personas en plataformas ofimáticas o manualmente por medio de libros de anotación. Para asegurar la integridad de la información nace la necesidad de crear un sistema que abarque una infraestructura de dispositivos IoT que permitan la captura de datos y procesamiento de estos de manera autónoma, por medio de un sistema web que permita el almacenamiento y respaldo de los datos. Con la finalidad de que se consulten los datos por medio de dispositivos móviles a través de una aplicación para dicho dispositivo, visualizando cada uno de los procesos involucrados para la elaboración de una botella de vino. El proyecto es desarrollado bajo la metodología Personal Extremme Programming (PXP) que permite ajustar el desarrollo a un solo programador y se adapta a los cambios de manera progresiva, mientras se desarrolla la aplicación. También se especifican los diseños lógicos, físicos, diagrama de clases y modelo de datos del sistema, de manera que se pueda entender los objetos y artefactos que interactúan. Se explica las etapas de desarrollo del proyecto, con las tareas y actividades asociadas en cada una de las iteraciones planificadas. Dando como resultado, un sistema que está construido bajo tres tecnologías que permite asegurar la trazabilidad en los procesos de producción del vino. Abarcando la captura de información por medio de sensores y dispositivos IoT, creación de trazados entre procesos por medio de un controlador centralizado, el respaldo de información y generación de código QR por medio de una plataforma web. Con la finalización de una aplicación móvil que permite consultar la información de trazabilidad asociada a un código QR en una botella de vino. Concluyendo finalmente con las metodologías de evaluación aplicadas con sus respectivos resultados

Upconverting nanorockers for intracellular viscosity measurements during chemotherapy

Funding: Ministerio de Economía y Competitividad de España (MAT2016-75362-C3-1-R and MAT2017-83111R); Instituto de Salud Carlos III (PI16/ 00812); Comunidad Autónoma de Madrid (B2017/BMD-3867RENIMCM), and co-financed by the European Structural funds and also by COST action CM1403; Comunidad de Madrid predoctorate contracts and from the Spanish national project FIS2017-86007-C3-1-P (R.D-B and R.P.P).Chemicals capable of producing structural and chemical changes on cells are used to treat diseases (e.g., cancer). Further development and optimization of chemotherapies require thorough knowledge of the effect of the chemical on the cellular structure and dynamics. This involves studying, in a noninvasive way, the properties of individual cells after drug administration. Intracellular viscosity is affected by chemical treatments and it can be reliably used to monitor chemotherapies at the cellular level. Here, cancer cell monitoring during chemotherapeutic treatments is demonstrated using intracellular allocated upconverting nanorockers. A simple analysis of the polarized visible emission of a single particle provides a real-time readout of its rocking dynamics that are directly correlated to the cytoplasmic viscosity. Numerical simulations and immunodetection are used to correlate the measured intracellular viscosity alterations to the changes produced in the cytoskeleton of cancer cells by anticancer drugs (colchicine and Taxol). This study evidences the possibility of monitoring cellular properties under an external chemical stimulus for the study and development of new treatments. Moreover, it provides the biomedical community with new tools to study intracellular dynamics and cell functioning.PostprintPeer reviewe

Bismuth selenide nanostructured clusters as optical coherence tomography contrast agents: beyond gold-based particles

Optical coherence tomography (OCT) is an imaging technique currently used in clinical practice to obtain optical biopsies of different biological tissues in a minimally invasive way. Among the contrast agents proposed to increase the efficacy of this imaging method, gold nanoshells (GNSs) are the best performing ones. However, their preparation is generally time-consuming, and they are intrinsically costly to produce. Herein, we propose a more affordable alternative to these contrast agents: Bi2Se3 nanostructured clusters with a desert rose-like morphology prepared via a microwave-assisted method. The structures are prepared in a matter of minutes, feature strong near-infrared extinction properties, and are biocompatible. They also boast a photon-to-heat conversion efficiency of close to 50%, making them good candidates as photothermal therapy agents. In vitro studies evidence the prowess of Bi2Se3 clusters as OCT contrast agents and prove that their performance is comparable to that of GNSsJ.Y. acknowledges the support from the China Scholarship Council (CSC file no. 201704910867). R.M. acknowledges the support of the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant agreement no. 797945 (LANTERNS). This work was supported by the Spanish Ministry of Economy and Competitiveness under projects MAT2017-83111R, MAT2017-85617-R, and PID2019- 106211RB-I00, by the Instituto de Salud Carlos III (PI16/ 00812), by the Comunidad Autonoma de Madrid (B2017/ ́ BMD-3867 RENIM-CM), and cofinanced by the European Structural and Investment Fun

Comparative theoretical analysis between parallel and perpendicular geometries for 2D particle patterning in photovoltaic ferroelectric substrates

This paper describes the dielectrophoretic potential created by the evanescent electric field acting on a particle near a photovoltaic crystal surface depending on the crystal cut. This electric field is obtained from the steady state solution of the Kukhtarev equations for the photovoltaic effect, where the diffusion term has been disregarded. First, the space charge field generated by a small, square, light spot where d < l (being d a side of the square and l the crystal thickness) is studied. The surface charge density generated in both geometries is calculated and compared as their relation determines the different properties of the dielectrophoretic potential for both cuts. The shape of the dielectrophoretic potential is obtained and compared for several distances to the sample. Afterwards other light patterns are studied by the superposition of square spots, and the resulting trapping profiles are analysed. Finally the surface charge densities and trapping profiles for different d/l relations are studied

Plasmonic Copper Sulfide Nanoparticles Enable Dark Contrast in Optical Coherence Tomography

This is the peer reviewed version of the following article: Marin, R., Lifante, J., Besteiro, L. V., Wang, Z., Govorov, A. O., Rivero, F., ... & Jaque, D. (2020). Plasmonic Copper Sulfide Nanoparticles Enable Dark Contrast in Optical Coherence Tomography. Advanced Healthcare Materials 2020 9.5 (2020): 1901627, which has been published in final form at https://onlinelibrary.wiley.com/doi/full/10.1002/adhm.201901627. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsOptical coherence tomography (OCT) is an imaging technique affording noninvasive optical biopsies. Like for other imaging techniques, the use of dedicated contrast agents helps better discerning biological features of interest during the clinical practice. Although bright OCT contrast agents have been developed, no dark counterpart has been proposed yet. Herein, plasmonic copper sulfide nanoparticles as the first OCT dark contrast agents working in the second optical transparency window are reported. These nanoparticles virtually possess no light scattering capabilities at the OCT working wavelength (≈1300 nm); thus, they exclusively absorb the probing light, which in turn results in dark contrast. The small size of the nanoparticles and the absence of apparent cytotoxicity support the amenability of this system to biomedical applications. Importantly, in the pursuit of systems apt to yield OCT dark contrast, a library of copper sulfide nanoparticles featuring plasmonic resonances spanning the three optical transparency windows is prepared, thus highlighting the versatility and potential of these systems in light-controlled biomedical applicationsThis project was partially funded by the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant agreement No. 797945 “LANTERNS”. This work was partially supported by the Ministerio de Economía y Competitividad de España (MAT2016-75362-C3-1-R) and (MAT2017-83111R), by the Instituto de Salud Carlos III (PI16/00812), by the Comunidad Autónoma de Madrid (B2017/BMD-3867RENIMCM), and co-financed by the European Structural and investment fund. Additional funding was provided by the European Commission Horizon 2020 project NanoTBTech. L.V.B was supported by the Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China and China Postdoctoral Science Foundation (2017M622992 and 2019T120820). Z.W. was supported by the National Basic Research Program of China (Project 2013CB933301) and the National Natural Science Foundation of China (Project 51272038). A.G. was funded via the 1000-talent Award of Sichuan and by the Volkswagen Foundation. Prof. Jorge Rubio-Retama is gratefully acknowledged for granting access to the dynamic light scattering instrument and for the fruitful discussio

The value of early and comprehensive diagnoses in a human fetus with hydrocephalus and progressive obliteration of the aqueduct of Sylvius: Case Report

BACKGROUND: Mutant rodent models have highlighted the importance of the ventricular ependymal cells and the subcommissural organ (a brain gland secreting glycoproteins into the cerebrospinal fluid) in the development of fetal onset hydrocephalus. Evidence indicates that communicating and non-communicating hydrocephalus can be two sequential phases of a single pathological phenomenon triggered by ependymal disruption and/or abnormal function of the subcommissural organ. We have hypothesized that a similar phenomenon may occur in human cases with fetal onset hydrocephalus. CASE PRESENTATION: We report here on a case of human fetal communicating hydrocephalus with no central nervous system abnormalities other than stenosis of the aqueduct of Sylvius (SA) that became non-communicating hydrocephalus during the first postnatal week due to obliteration of the cerebral aqueduct. The case was followed closely by a team of basic and clinic investigators allowing an early diagnosis and prediction of the evolving pathophysiology. This information prompted neurosurgeons to perform a third ventriculostomy at postnatal day 14. The fetus was monitored by ultrasound, computerized axial tomography and magnetic resonance imaging (MRI). After birth, the follow up was by MRI, electroencephalography and neurological and neurocognitive assessments. Cerebrospinal fluid (CSF) collected at surgery showed abnormalities in the subcommissural organ proteins and the membrane proteins L1-neural cell adhesion molecule and aquaporin-4. The neurological and neurocognitive assessments at 3 and 6 years of age showed neurological impairments (epilepsy and cognitive deficits). CONCLUSIONS: (1) In a hydrocephalic fetus, a stenosed SA can become obliterated at perinatal stages. (2) In the case reported, a close follow up of a communicating hydrocephalus detected in utero allowed a prompt postnatal surgery aiming to avoid as much brain damage as possible. (3) The clinical and pathological evolution of this patient supports the possibility that the progressive stenosis of the SA initiated during the embryonic period may have resulted from ependymal disruption of the cerebral aqueduct and dysfunction of the subcommissural organ. The analysis of subcommissural organ glycoproteins present in the CSF may be a valuable diagnostic tool for the pathogenesis of congenital hydrocephalus

Calculation of dielectrophoretic potential generated under illumination patterns on x- and z-cut LiNbO3 : application to photovoltaic particle trapping

The dielectrophoretic potential generated near the surface of a z-cut LiNbO3 by photovoltaic charge transport has been calculated for first time. The procedure and results are compared with the ones corresponding to x-cut. Diferences in the position, sharpness and time evolution are reported, and their implication on particle trapping are discussed