1
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Cooper D, Licitra C, Boussadi Y, Ben-Bakir B, Masenelli B. Mapping of the Electrostatic Potentials in a Fully Processed Led Device with nm-Scale Resolution by In Situ off-Axis Electron Holography. Small Methods 2023; 7:e2300537. [PMID: 37199144 DOI: 10.1002/smtd.202300537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Indexed: 05/19/2023]
Abstract
The optoelectronic properties of a fully processed red emitting AlGaInP micro-diode device is measured using standard I-V and luminescence measurements. A thin specimen is then prepared for in situ transmission electron microscopy analysis by focused ion beam milling, then the changes of electrostatic potential as a function of applied forward bias voltage are mapped by off-axis electron holography. We demonstrate that the quantum wells in the diode sit on a potential gradient until the threshold forward bias voltage for light emission is reached; at which point the quantum wells are aligned at the same potential. From simulations, a similar effect for the band structure can be demonstrated, where the quantum wells are aligned at the same energy level, and contain electrons and holes that are available for radiative recombination at this threshold voltage. We demonstrate that off-axis electron holography can be used to directly measure the potential distribution in optoelectronic devices, and is a powerful tool to help better understand their performance and to improve simulations.
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Affiliation(s)
| | | | | | | | - Bruno Masenelli
- Univ. Lyon, INSA Lyon, CNRS, Ecole Centrale de Lyon, Université Claude Bernard Lyon 1, INL, UMR5270, 69621, Villeurbanne, France
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2
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Devos A, Chevreux F, Licitra C, Chargui A, Chapelon LL. Elastic and thermo-elastic characterizations of thin resin films using colored picosecond acoustics and spectroscopic ellipsometry. Photoacoustics 2023; 31:100498. [PMID: 37152401 PMCID: PMC10160771 DOI: 10.1016/j.pacs.2023.100498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023]
Abstract
Colored Picosecond Acoustics (CPA) and Spectroscopic Ellipsometry (SE) are combined to measure elastic and thermoelastic properties of polymer thin-film resins deposited on 300 mm wafers. Film thickness and refractive index are measured using SE. Sound velocity and thickness are measured using CPA from the refractive index. Comparing the two thicknesses allows checking consistency between both approaches. The same combination is then applied at various temperatures from 19° to 180°C. As the sample is heated, both thickness and sound velocity change. By monitoring these contributions separately, the Temperature Coefficient on sound Velocity (TCV) and the Coefficient on Thermal Expansion are deduced. The protocol is applied to five industrial samples made of different thin-film resins currently used by microelectronic industry. Young's modulus varies from resin to resin by up to 20%. TCV is large on each resin and varies from one resin to another up to 57%.
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Affiliation(s)
- A. Devos
- IEMN – UMR8250 CNRS, Avenue Poincaré BP 69, 59652 Villeneuve d′Ascq, France
- Corresponding author.
| | | | - C. Licitra
- Univ. Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - A. Chargui
- IEMN – UMR8250 CNRS, Avenue Poincaré BP 69, 59652 Villeneuve d′Ascq, France
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3
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Mollard L, Riu J, Royo S, Dieppedale C, Hamelin A, Koumela A, Verdot T, Frey L, Le Rhun G, Castellan G, Licitra C. Biaxial Piezoelectric MEMS Mirrors with Low Absorption Coating for 1550 nm Long-Range LIDAR. Micromachines (Basel) 2023; 14:mi14051019. [PMID: 37241642 DOI: 10.3390/mi14051019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023]
Abstract
This paper presents the fabrication and characterization of a biaxial MEMS (MicroElectroMechanical System) scanner based on PZT (Lead Zirconate Titanate) which incorporates a low-absorption dielectric multilayer coating, i.e., a Bragg reflector. These 2 mm square MEMS mirrors, developed on 8-inch silicon wafers using VLSI (Very Large Scale Integration) technology are intended for long-range (>100 m) LIDAR (LIght Detection And Ranging) applications using a 2 W (average power) pulsed laser at 1550 nm. For this laser power, the use of a standard metal reflector leads to damaging overheating. To solve this problem, we have developed and optimised a physical sputtering (PVD) Bragg reflector deposition process compatible with our sol-gel piezoelectric motor. Experimental absorption measurements, performed at 1550 nm and show up to 24 times lower incident power absorption than the best metallic reflective coating (Au). Furthermore, we validated that the characteristics of the PZT, as well as the performance of the Bragg mirrors in terms of optical scanning angles, were identical to those of the Au reflector. These results open up the possibility of increasing the laser power beyond 2W for LIDAR applications or other applications requiring high optical power. Finally, a packaged 2D scanner was integrated into a LIDAR system and three-dimensional point cloud images were obtained, demonstrating the scanning stability and operability of these 2D MEMS mirrors.
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Affiliation(s)
- L Mollard
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - J Riu
- Beamagine, Bellesguard, E08755 Castellbisbal, Spain
| | - S Royo
- Beamagine, Bellesguard, E08755 Castellbisbal, Spain
- Centre for the Development of Sensors, Instrumentation, and Systems, Universitat Politècnica de Catalunya (UPC-CD6) Rambla Sant Nebridi 10, E08222 Terrassa, Spain
| | - C Dieppedale
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - A Hamelin
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - A Koumela
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - T Verdot
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - L Frey
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - G Le Rhun
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - G Castellan
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
| | - C Licitra
- University Grenoble Alpes, CEA, Leti, F-38000 Grenoble, France
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4
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Sefkow-Werner J, Le Pennec J, Machillot P, Ndayishimiye B, Castro-Ramirez E, Lopes J, Licitra C, Wang I, Delon A, Picart C, Migliorini E. Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors. ACS Appl Mater Interfaces 2022; 14:10.1021/acsami.2c08272. [PMID: 35849638 PMCID: PMC7614070 DOI: 10.1021/acsami.2c08272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The automation of liquid-handling routines offers great potential for fast, reproducible, and labor-reduced biomaterial fabrication but also requires the development of special protocols. Competitive systems demand for a high degree in miniaturization and parallelization while maintaining flexibility regarding the experimental design. Today, there are only a few possibilities for automated fabrication of biomaterials inside multiwell plates. We have previously demonstrated that streptavidin-based biomimetic platforms can be employed to study cellular behaviors on biomimetic surfaces. So far, these self-assembled materials were made by stepwise assembly of the components using manual pipetting. In this work, we introduce for the first time a fully automated and adaptable workflow to functionalize glass-bottom multiwell plates with customized biomimetic platforms deposited in single wells using a liquid-handling robot. We then characterize the cell response using automated image acquisition and subsequent analysis. Furthermore, the molecular surface density of the biomimetic platforms was characterized in situ using fluorescence-based image correlation spectroscopy. These measurements were in agreement with standard ex situ spectroscopic ellipsometry measurements. Due to automation, we could do a proof of concept to study the effect of heparan sulfate on the bioactivity of bone morphogenetic proteins on myoblast cells, using four different bone morphogenetic proteins (BMPs) (2, 4, 6, and 7) in parallel, at five increasing concentrations. Using such an automated self-assembly of biomimetic materials, it may be envisioned to further investigate the role of a large variety of extracellular matrix (ECM) components and growth factors on cell signaling.
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Affiliation(s)
- Julius Sefkow-Werner
- Univ. Grenoble Alpes, CNRS, Grenoble INP**, LMGP, 38000 Grenoble, France
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Jean Le Pennec
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Paul Machillot
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Bertin Ndayishimiye
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Elaine Castro-Ramirez
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Joao Lopes
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | | | - Irene Wang
- Univ. Grenoble Alpes, CNRS, LiPhy, Grenoble, France
| | | | - Catherine Picart
- Univ. Grenoble Alpes, CNRS, Grenoble INP**, LMGP, 38000 Grenoble, France
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
| | - Elisa Migliorini
- Univ. Grenoble Alpes, CNRS, Grenoble INP**, LMGP, 38000 Grenoble, France
- Univ. Grenoble Alpes, CEA, INSERM, U1292 Biosanté, CNRS EMR 5000 BRM, 3800, Grenoble, France
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5
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Quinchard G, Poletti T, Zakhama R, Pereira J, Larrue A, Badano G, Licitra C, de Lamaestre RE, Reverchon JL, Delga A. Revisiting the Fabry-Perot reflectivity method for mid-infrared optical index measurement: case study of InGaAs, AlInAs, and InP. Appl Opt 2022; 61:4079-4086. [PMID: 36256083 DOI: 10.1364/ao.456827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 04/19/2022] [Indexed: 06/16/2023]
Abstract
We revisit the Fabry-Perot (FP) reflectivity method to measure optical indices in the mid-infrared spectrum. This simple approach can be readily implemented using a standard Fourier transform infrared spectrometer. Measuring samples with multiple heights allows for enhanced precision of the measurement, making the FP method consistent in values and uncertainties with more advanced ellipsometric measurements. An extensive discussion about experimental errors is carried out. Results between 4 and 12 µm for AlInAs, n-doped InGaAs, and InP, which are the most standard materials for quantum cascade lasers, are given.
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6
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Ben Hadj Mabrouk A, Licitra C, Chateauminois A, Veillerot M. Effect of the molecular weight on the depth profiling of PMMA thin films using low‐energy Cs
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sputtering. SURF INTERFACE ANAL 2021. [DOI: 10.1002/sia.6991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | | | - Antoine Chateauminois
- Soft Matter Science and Engineering Laboratory (SIMM) PSL Research University, UPMC Univ. Paris 06, Sorbonne Universités, ESPCI Paris, CNRS 75231 Paris Cedex 05 France
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7
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Van-Straaten M, Ben Hadj Mabrouk A, Veillerot M, Licitra C, D'Agosto F, Jousseaume V. Filling of Nanometric Pores with Polymer by Initiated Chemical Vapor Deposition. Macromol Rapid Commun 2020; 41:e2000200. [PMID: 32519398 DOI: 10.1002/marc.202000200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/14/2020] [Indexed: 11/10/2022]
Abstract
The integration of porous thin films using microelectronic compatible processes sometimes requires the protection of the interior of the pores during the critical integration steps. In this paper, the polymerization of neo-pentyl methacrylate (npMA) is performed via initiated chemical vapor deposition (iCVD) on a porous organosilicate (SiOCH) and on a dense SiOCH. The characterizations by Fourier-transform infrared spectroscopy, spectroscopic ellipsometry, and time-of-flight secondary ion mass spectrometry of the different stacks show that iCVD is a powerful technique to polymerize npMA in the nanometric pores and thus totally fill them with a polymer. The study of the pore filling for very short iCVD durations shows that the polymerization in the pores is complete in less than ten seconds and is uniform in depth. Then, the poly(npMA) film growth continues on top of the filled SiOCH layer. These characteristics make iCVD a straightforward and very promising alternative to other infiltration techniques in order to fill the porosity of microporous thin films.
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Affiliation(s)
- Manon Van-Straaten
- Université Grenoble Alpes, CEA, LETI, Grenoble, F-38000, France.,Université de Lyon, Univ Lyon 1, CPE Lyon, CNRS, UMR 5265, C2P2 (Chemistry, Catalysis, Polymers, and Processes), Team LCPP Bat 308F, 43 Bd du 11 Novembre 1918, Villeurbanne, F-69616, France
| | | | - Marc Veillerot
- Université Grenoble Alpes, CEA, LETI, Grenoble, F-38000, France
| | | | - Franck D'Agosto
- Université de Lyon, Univ Lyon 1, CPE Lyon, CNRS, UMR 5265, C2P2 (Chemistry, Catalysis, Polymers, and Processes), Team LCPP Bat 308F, 43 Bd du 11 Novembre 1918, Villeurbanne, F-69616, France
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8
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Vergnaud C, Dau MT, Grévin B, Licitra C, Marty A, Okuno H, Jamet M. New approach for the molecular beam epitaxy growth of scalable WSe 2 monolayers. Nanotechnology 2020; 31:255602. [PMID: 32187582 DOI: 10.1088/1361-6528/ab80fe] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The search for high-quality transition metal dichalcogenides mono- and multi-layers grown on large areas is still a very active field of investigation. Here, we use molecular beam epitaxy to grow WSe2 on 15 × 15 mm large mica in the van der Waals regime. By screening one-step growth conditions, we find that very high temperature (>900 °C) and very low deposition rate (<0.15 Å min-1) are necessary to obtain high quality WSe2 films. The domain size can be as large as 1 µm and the in-plane rotational misorientation of 1.25°. The WSe2 monolayer is also robust against air exposure, can be easily transferred over 1 cm2 on SiN/SiO2 and exhibits strong photoluminescence signal. Moreover, by combining grazing incidence x-ray diffraction and transmission electron microscopy, we could detect the presence of few misoriented grains. A two-dimensional model based on atomic coincidences between the WSe2 and mica crystals allows us to explain the formation of these misoriented grains and gives insight to achieve highly crystalline WSe2.
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Affiliation(s)
- Céline Vergnaud
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-Spintec, 38000 Grenoble, France
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9
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Buchter A, Hoffmann J, Delvallée A, Brinciotti E, Hapiuk D, Licitra C, Louarn K, Arnoult A, Almuneau G, Piquemal F, Zeier M, Kienberger F. Scanning microwave microscopy applied to semiconducting GaAs structures. Rev Sci Instrum 2018; 89:023704. [PMID: 29495818 DOI: 10.1063/1.5015966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A calibration algorithm based on one-port vector network analyzer (VNA) calibration for scanning microwave microscopes (SMMs) is presented and used to extract quantitative carrier densities from a semiconducting n-doped GaAs multilayer sample. This robust and versatile algorithm is instrument and frequency independent, as we demonstrate by analyzing experimental data from two different, cantilever- and tuning fork-based, microscope setups operating in a wide frequency range up to 27.5 GHz. To benchmark the SMM results, comparison with secondary ion mass spectrometry is undertaken. Furthermore, we show SMM data on a GaAs p-n junction distinguishing p- and n-doped layers.
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Affiliation(s)
- Arne Buchter
- Federal Institute of Metrology METAS, Lindenweg 50, 3003 Bern-Wabern, Switzerland
| | - Johannes Hoffmann
- Federal Institute of Metrology METAS, Lindenweg 50, 3003 Bern-Wabern, Switzerland
| | | | - Enrico Brinciotti
- Keysight Laboratories, Keysight Technologies, Inc., Gruberstrasse 40, 4020 Linz, Austria
| | | | | | - Kevin Louarn
- LNE, 29 Avenue Roger Hennequin, F-78197 Trappes, France
| | | | | | | | - Markus Zeier
- Federal Institute of Metrology METAS, Lindenweg 50, 3003 Bern-Wabern, Switzerland
| | - Ferry Kienberger
- Keysight Laboratories, Keysight Technologies, Inc., Gruberstrasse 40, 4020 Linz, Austria
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10
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Picardi G, Królikowska A, Yasukuni R, Chaigneau M, Escude M, Mourier V, Licitra C, Ossikovski R. Exchange of Methyl- and Azobenzene-Terminated Alkanethiols on Polycrystalline Gold Studied by Tip-Enhanced Raman Mapping. Chemphyschem 2014; 15:276-82. [DOI: 10.1002/cphc.201300918] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Indexed: 11/07/2022]
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11
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Capodanno D, Giacoppo D, Dipasqua F, Micciche E, Licitra C, Tamburino C. Usefulness of the logistic Clinical SYNTAX score for predicting 1-year mortality in patients undergoing percutaneous coronary intervention of the left main coronary artery. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p1238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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12
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Avadhani J, Sasidharan S, Carton C, Lowen M, Klapproth T, Licitra C. Dosimetric Analysis of Small Field 6 MeV Electrons to Replace Superficial X-Rays for Superficial Cancers. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.2255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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13
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Avadhani J, Sasidharan S, Carton C, Lowen M, Klapproth T, Licitra C. SU-E-T-231: Comparison of Beam Characteristics of Small Field 6 MeV Electrons as Replacement for Superficial X Ray Beam. Med Phys 2012; 39:3756. [DOI: 10.1118/1.4735294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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14
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Rochat N, Klymko N, Licitra C, Gambacorti N. Evidence of light depolarization in grazing incidence germanium attenuated total reflection prisms. Appl Spectrosc 2011; 65:1046-1050. [PMID: 21929859 DOI: 10.1366/11-06275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Attenuated total reflection (ATR) infrared absorption spectroscopy is a well-known vibrational spectroscopy technique for many different applications. In recent years this technique has been used to detect thin layer(s) lying on a solid substrate. Such a sample needs high pressure to ensure good optical contact between sample and prism and a p-polarization to enhance the signal to be detected. Such conditions have not been detailed in the literature regarding the effect of high pressure on the ATR measurement. This study shows the detrimental effect of high pressure on the ATR spectra. This effect is related to light depolarization induced by the germanium prism under high pressure. Moreover, the importance of polarizer position in the optical bench is highlighted. Indeed, due to the pressure-induced depolarization of the prism, the polarizer has to be placed before the prism to limit undesirable effects on the ATR spectrum baseline.
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Affiliation(s)
- Névine Rochat
- CEA-Leti, MINATEC Campus, 17 rue des martyrs-38054 Grenoble cedex 9, France.
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15
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Foldyna M, De Martino A, Licitra C, Foucher J, Ben Hatit S. Profile characterization of diffraction gratings using angle-resolved polarimetric measurements. EPJ Web of Conferences 2010. [DOI: 10.1051/epjconf/20100502003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Avadhani. J, Sasidharan S, Carton C, Lowen M, Klapproth T, Licitra C. SU-FF-J-31: Quantitative Analysis of Prostate Motion Using Implanted Fiducial Markers Based On Port Film Image Guidance. Med Phys 2009. [DOI: 10.1118/1.3181323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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17
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Hajjeh R, McDonnell S, Reef S, Licitra C, Hankins M, Toth B, Padhye A, Kaufman L, Pasarell L, Cooper C, Hutwagner L, Hopkins R, McNeil M. Outbreak of sporotrichosis among tree nursery workers. J Infect Dis 1997; 176:499-504. [PMID: 9237718 DOI: 10.1086/514070] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In spring 1994, an outbreak of sporotrichosis occurred at a tree nursery in Florida; 9 (14%) of 65 workers involved in production of sphagnum moss topiaries developed lymphocutaneous sporotrichosis. A cohort study of all 65 employees was conducted to identify risk factors for sporotrichosis, and an environmental investigation was done. The risk of sporotrichosis increased significantly with the duration of working with sphagnum moss (P < .05), in particular with filling topiaries (P < .05), and with having less gardening experience (P < .05). Wearing gloves was protective (P < .005). Sporothrix schenckii was cultured from patients and sphagnum moss used in topiary production. Use of restriction fragment length polymorphism revealed an identical pattern for patient isolates that was different from the patterns of environmental isolates. Physicians should be aware of sporotrichosis in patients with ulcerative skin lesions who have a history of occupational or recreational exposure to sphagnum moss.
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Affiliation(s)
- R Hajjeh
- Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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Abstract
Total cases of fatal asthma in the occupational setting reported in the literature are reviewed and the case of a 39-year-old foundry worker who died at work is described. A diagnosis of occupational asthma induced by diphenylmethane diisocyanate (MDI) had been assessed 5 years in advance through a 0.005-ppm exposure inhalation challenge. Postmortem microscopic examination of the lung showed epithelial desquamation, eosinophilic/neutrophilic infiltration of the mucosa, dilatation of bronchial vessels, edema, hypertrophy and disarray of smooth muscle. Fatal asthma attack in a MDI-sensitized individual, to our knowledge, has not been previously described.
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Affiliation(s)
- M Carino
- Division of Occupational Medicine, Clinica del Lavoro-Pavia Foundation, Cassano Medical Center, Italy
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19
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Blumberg HM, Stephens DS, Licitra C, Pigott N, Facklam R, Swaminathan B, Wachsmuth IK. Molecular epidemiology of group B streptococcal infections: use of restriction endonuclease analysis of chromosomal DNA and DNA restriction fragment length polymorphisms of ribosomal RNA genes (ribotyping). J Infect Dis 1992; 166:574-9. [PMID: 1380050 DOI: 10.1093/infdis/166.3.574] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epidemiologic investigation of group B streptococcal (GBS) infections has been limited by the lack of a discriminatory typing system. Therefore, the use of restriction endonuclease analysis of chromosomal DNA (REAC) and DNA restriction fragment length polymorphisms of rRNA genes (ribotyping) to subtype molecularly GBS isolates associated with human invasive disease was investigated. Chromosomal DNA of selected GBS isolates was initially digested with 24 different restriction enzymes. HhaI gave the best discrimination of hybridization banding patterns (ribotypes) and was used with all study isolates. Ribotyping and REAC differentiated among isolates of the same and different serotypes. Nine ribotype patterns were noted among the 76 isolates studied, including 4 among serotype Ia/c and 4 additional ribotypes among serotype III isolates. Epidemiologically related isolates (e.g., mother-infant or twin-twin pairs) had identical REAC and ribotype patterns. Epidemiologically unrelated isolates with the same ribotype usually had different REAC patterns, suggesting that REAC may be a more sensitive technique for strain differentiation. REAC and ribotyping were reproducible and proved to be successful molecular epidemiologic methods for subtyping GBS.
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Affiliation(s)
- H M Blumberg
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30303
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