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Utadiya S, Trivedi V, Srivastava A, Cabrera H, Crespo ML, Sheoran G, Anand A. Optical thickness measurement of occluded samples by lens-less Fourier transform digital holography, thermal loading, and machine learning. Appl Opt 2024; 63:B16-B23. [PMID: 38437251 DOI: 10.1364/ao.503589] [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: 08/21/2023] [Accepted: 10/31/2023] [Indexed: 03/06/2024]
Abstract
Thickness measurements of objects, especially transparent and semi-transparent objects, are essential for their characterization and identification. However, in the case of occluded objects, the optical thickness determination becomes difficult, and an indirect way must be devised. Thermal loading of the objects changes their opto-thermal properties, which will be reflected as a change in their optical thickness. The key to quantifying such occluded objects lies in collecting these opto-thermal signatures. This could be achieved by imaging the changes occurring to a probe wavefront passing through the object while it is being thermally loaded. Digital holographic interferometry is an ideal tool for observing phase changes, as it can be used to compare wavefronts recorded at different instances of time. Lens-less Fourier transform digital holographic imaging provides the phase information from a single Fourier transform of the recorded hologram and can be used to quantify occluded phase objects. Here we describe a technique for the measurement of change in optical thickness of thermally loaded occluded phase samples using lens-less Fourier transform digital holography and machine learning. The advantage of the proposed technique is that it is a single shot, lens-less imaging modality for quasi-real-time quantification of phase samples behind thin occlusions.
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2
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Rodriguez LG, Niemela J, Cabrera H. Measuring the linear optical absorption coefficient by interferometry and the thermal lensing effect: a numerical analysis. Appl Opt 2023; 62:9002-9008. [PMID: 38108735 DOI: 10.1364/ao.500989] [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: 07/18/2023] [Accepted: 10/20/2023] [Indexed: 12/19/2023]
Abstract
We report on a pump-probe thermal lensing method for measuring the linear absorption coefficient of liquids by using interferometry and numerical analysis. The method is based on interferograms generated when a localized photothermal effect is induced in the sample. The photothermal effect itself is induced by a pump beam impinging on a sample located on-axis of the probe beam, which is one of the paths of a Mach-Zehnder interferometer. A digital camera is employed as the acquisition device allowing the capture and storage of the experimental data. During the experiment, a total of three photographs are taken and stored on a personal computer, and by using an algorithm, the numerical analysis is done. Numerical analysis is subsequently used to calculate the photothermal phase difference and the normalized spatial distribution of the pump beam irradiance. Plotting the phase difference as a function of the spatial distribution of the pump beam produces a linear dependence from which the linear absorption coefficient is obtained. The sensitivity of the method (λ/1500) is validated using ethanol, methanol, and carbon disulfide.
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Rahman A, Niemela J, Cabrera H. Z-scan model for Laguerre-Gaussian excitation in mode-mismatched thermal lens spectrometry. Appl Opt 2023; 62:8286-8291. [PMID: 38037931 DOI: 10.1364/ao.502075] [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: 08/03/2023] [Accepted: 10/05/2023] [Indexed: 12/02/2023]
Abstract
In this work, we have introduced a Z-scan thermal lens (TL) model based on Laguerre-Gaussian (LG) L G10 laser induced excitation in a mode-mismatched dual-beam configuration. The analytical expression of the TL signal and its dependence on sample to detector distance as well as the Z-scan have been derived. The theoretical analysis shows that the phase shift and TL signal are higher than the values obtained using an excitation with the T E M 00 Gaussian profile. The experimental demonstration of the theoretical approach has been performed using the L G10 and T E M 00 Gaussian beams, respectively. Experimental proofs of the model are presented and found to be in agreement, demonstrating that Laguerre-Gaussian induced excitation is more sensitive than the Gaussian one.
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Rodriguez LG, Niemela J, Cabrera H. Thermal lensing approach based on parabolic approximation and Mach-Zehnder interferometer. Heliyon 2023; 9:e20492. [PMID: 37790966 PMCID: PMC10543229 DOI: 10.1016/j.heliyon.2023.e20492] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/05/2023] Open
Abstract
A thermal lensing approach based on parabolic approximation and Mach-Zehnder interferometer for measuring optical absorption and thermal diffusivity coefficients in pure solvents is described in this work. The approach combines the sensitivity of both thermal lensing methods and interferometry techniques. The photothermal effect is induced by a pump laser beam generating localized changes in the refractive index of the sample, which are observed as a shift in phase of the interference pattern. Each interference pattern is recorded by means of a digital camera and stored as digital images as a function of time. The images are then numerically processed to calculate the phase shifting map for a specific time. From each phase shifting map, the experimental phase difference as a function of time is calculated giving a phase-time transient, which is fitted to a mathematical model to estimate the optical absorption and thermal diffusivity of the sample. The experimental results show that the sensitivity is approximately λ/4800 for the minimum phase difference measured.
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Affiliation(s)
- Luis G. Rodriguez
- Universidad Técnica de Manabí, Facultad de Ciencias Básicas, Departamento de Física, Avenida Urbina, Portoviejo, 130105, Ecuador
| | - Joseph Niemela
- MLAB, STI Unit, The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
| | - Humberto Cabrera
- MLAB, STI Unit, The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
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Mikaeeli A, Korte D, Cabrera H, Chomicki D, Dziczek D, Kharchenko O, Song P, Liu J, Wieck AD, Pawlak M. Measuring Thermal Diffusivity of Azoheteroarene Thin Layers by Photothermal Beam Deflection and Photothermal Lens Methods. Materials (Basel) 2023; 16:6312. [PMID: 37763590 PMCID: PMC10532707 DOI: 10.3390/ma16186312] [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: 07/24/2023] [Revised: 08/18/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023]
Abstract
Measurement of thermal properties of thin films is challenging. In particular, thermal characterization is very difficult in semi-transparent samples. Here, we use two photothermal methods to obtain information about the thermal diffusivity as well as thermal conductivity of azoheteroarene functionalized polymer thin layers. The photothermal beam deflection (PBD) method is employed to gather data directly on thermal conductivity and thermal diffusivity, while the thermal lens (TL) method is employed to measure the effective thermal diffusivity. Consequently, the thermal diffusivity of the layers is indirectly estimated from the effective thermal diffusivity using a well-established theoretical relationship. Despite the utilization of distinct methods, our study reveals a remarkable consistency in the highly accurate results obtained from both approaches. This remarkable agreement reaffirms the reliability and mutual compatibility of the employed methods, highlighting their shared ability to provide accurate and congruent outcomes.
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Affiliation(s)
- Ameneh Mikaeeli
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland; (D.C.); (D.D.); (M.P.)
- Chair of Applied Solid-State Physics, Faculty of Physics and Astronomy, Ruhr-University Bochum, Universitaetsstrasse 150, D-44780 Bochum, Germany;
| | - Dorota Korte
- Laboratory of Enviromental Research, University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia;
| | - Humberto Cabrera
- MLab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy;
| | - Dariusz Chomicki
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland; (D.C.); (D.D.); (M.P.)
| | - Dariusz Dziczek
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland; (D.C.); (D.D.); (M.P.)
| | - Oksana Kharchenko
- Faculty of Chemistry, Taras Shevchenko National University of Kyiv, 64/13 Volodymyrska St., 01601 Kyiv, Ukraine;
- MiNt Laboratory, University of Angers, 4 Rue Larrey, 49100 Angers, France
| | - Peng Song
- School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (P.S.); (J.L.)
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China
| | - Junyan Liu
- School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; (P.S.); (J.L.)
- State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China
| | - Andreas D. Wieck
- Chair of Applied Solid-State Physics, Faculty of Physics and Astronomy, Ruhr-University Bochum, Universitaetsstrasse 150, D-44780 Bochum, Germany;
| | - Michal Pawlak
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland; (D.C.); (D.D.); (M.P.)
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Nourzadeh H, Lotfi M, Cabrera H, Crespo ML, Dashtdar M. The phase range extension and accuracy improvement in Fresnel biprism-based digital holography microscopy. Rev Sci Instrum 2023; 94:2888616. [PMID: 37144944 DOI: 10.1063/5.0145654] [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] [Received: 02/07/2023] [Accepted: 04/19/2023] [Indexed: 05/06/2023]
Abstract
We report a highly stable and affordable dual-wavelength digital holographic microscopy system based on common-path geometry. A Fresnel biprism is used to create an off-axis geometry, and two diode laser sources with different wavelengths λ1 = 532 nm and λ2 = 650 nm generate the dual-wavelength compound hologram. In order to extend the measurement range, the phase distribution is obtained using a synthetic wavelength Λ1 = 2930.5 nm. Furthermore, to improve the system's temporal stability and reduce speckle noise, a shorter wavelength (Λ2 = 292.5 nm) is used. The feasibility of the proposed configuration is validated by the experimental results obtained with Molybdenum trioxide, Paramecium, and red blood cell specimens.
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Affiliation(s)
- Hasti Nourzadeh
- Department of Physics, Shahid Beheshti University, Evin, Tehran 19839-69411, Iran
| | - Maryam Lotfi
- Department of Physics, Shahid Beheshti University, Evin, Tehran 19839-69411, Iran
| | - Humberto Cabrera
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
| | - Maria Liz Crespo
- Multidisciplinary Laboratory (MLAB), STI Unit, The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
| | - Masoomeh Dashtdar
- Department of Physics, Shahid Beheshti University, Evin, Tehran 19839-69411, Iran
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
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Alsadig A, Abbasgholi-NA B, Vondracek H, Medagli B, Fortuna S, Posocco P, Parisse P, Cabrera H, Casalis L. DNA-Directed Protein Anchoring on Oligo/Alkanethiol-Coated Gold Nanoparticles: A Versatile Platform for Biosensing Applications. Nanomaterials (Basel) 2022; 13:nano13010078. [PMID: 36615988 PMCID: PMC9823620 DOI: 10.3390/nano13010078] [Citation(s) in RCA: 1] [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] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 05/27/2023]
Abstract
Herein, we report on a smart biosensing platform that exploits gold nanoparticles (AuNPs) functionalized through ssDNA self-assembled monolayers (SAM) and the DNA-directed immobilization (DDI) of DNA-protein conjugates; a novel, high-sensitivity optical characterization technique based on a miniaturized gel electrophoresis chip integrated with online thermal lens spectrometry (MGEC-TLS), for the high-sensitivity detection of antigen binding events. Specifically, we characterized the physicochemical properties of 20 nm AuNPs covered with mixed SAMs of thiolated single-stranded DNA and bio-repellent molecules, referred to as top-terminated oligo-ethylene glycol (TOEG6), demonstrating high colloidal stability, optimal binder surface density, and proper hybridization capacity. Further, to explore the design in the frame of cancer-associated antigen detection, complementary ssDNA fragments conjugated with a nanobody, called C8, were loaded on the particles and employed to detect the presence of the HER2-ECD antigen in liquid. At variance with conventional surface plasmon resonance detection, MGEC-TLS characterization confirmed the capability of the assay to titrate the HER2-ECD antigen down to concentrations of 440 ng/mL. The high versatility of the directed protein-DNA conjugates immobilization through DNA hybridization on plasmonic scaffolds and coupled with the high sensitivity of the MGEC-TLS detection qualifies the proposed assay as a potential, easily operated biosensing strategy for the fast and label-free detection of disease-relevant antigens.
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Affiliation(s)
- Ahmed Alsadig
- Department of Physics, University of Trieste, 34127 Trieste, Italy
- NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
| | - Behnaz Abbasgholi-NA
- NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy
| | - Hendrik Vondracek
- NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
| | - Barbara Medagli
- Department of Medicine, Surgery and Health Sciences at the University of Trieste, 34149 Trieste, Italy
| | - Sara Fortuna
- Italian Institute of Technology (IIT), Via Melen–83, B Block, 16152 Genova, Italy
| | - Paola Posocco
- Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy
| | - Pietro Parisse
- NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
- Institute of Materials (IOM-CNR), Area Science Park, 34149 Trieste, Italy
| | - Humberto Cabrera
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy
| | - Loredana Casalis
- NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Trieste, Italy
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Stegarescu A, Cabrera H, Budasheva H, Soran ML, Lung I, Limosani F, Korte D, Amati M, Borodi G, Kacso I, Opriş O, Dan M, Bellucci S. Synthesis and Characterization of MWCNT-COOH/Fe 3O 4 and CNT-COOH/Fe 3O 4/NiO Nanocomposites: Assessment of Adsorption and Photocatalytic Performance. Nanomaterials (Basel) 2022; 12:3008. [PMID: 36080044 PMCID: PMC9457809 DOI: 10.3390/nano12173008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
In this study the adsorption and photodegradation capabilities of modified multi-walled carbon nanotubes (MWCNTs), using tartrazine as a model pollutant, is demonstrated. MWCNT-COOH/Fe3O4 and MWCNT-COOH/Fe3O4/NiO nanocomposites were prepared by precipitation of metal oxides in the presence of MWCNTs. Their properties were examined by X-ray diffraction in powder (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based Scanning PhotoElectron Microscopy (SPEM), and Brunauer-Emmett-Teller (BET) analysis. It was found that the optimal adsorption conditions were pH 4 for MWCNT-COOH/Fe3O4 and pH 3 for MWCNT-COOH/Fe3O4/NiO, temperature 25 °C, adsorbent dose 1 g L-1, initial concentration of tartrazine 5 mg L-1 for MWCNT-COOH/Fe3O4 and 10 mg L-1 for MWCNT-COOH/Fe3O4/NiO and contact time 5 min for MWCNT-COOH/Fe3O4/NiO and 15 min for MWCNT-COOH/Fe3O4. Moreover, the predominant degradation process was elucidated simultaneously, with and without simulated sunlight irradiation, using thermal lens spectrometry (TLS) and UV-Vis absorption spectrophotometry. The results indicated the prevalence of the photodegradation mechanism over adsorption from the beginning of the degradation process.
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Affiliation(s)
- Adina Stegarescu
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Humberto Cabrera
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, Costiera 11, 34151 Trieste, Italy
| | - Hanna Budasheva
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia
| | - Maria-Loredana Soran
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Ildiko Lung
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Francesca Limosani
- INFN-National Laboratories of Frascati, Via Enrico Fermi 54, 00044 Frascati, Italy
- Department of Information Engineering, Polytechnic University of Marche, Via Brecce Bianche, 1, 60131 Ancona, Italy
| | - Dorota Korte
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica, Slovenia
| | - Matteo Amati
- Spectroscopy, Photoemission and Dynamics, Elettra—Sincrotrone Trieste S.C.p.A. S.S. 14, km 163.5 in Area Science Park, Basovizza, 34149 Trieste, Italy
| | - Gheorghe Borodi
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Irina Kacso
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Ocsana Opriş
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Monica Dan
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| | - Stefano Bellucci
- INFN-National Laboratories of Frascati, Via Enrico Fermi 54, 00044 Frascati, Italy
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Abbasgholi-NA B, Nokhbeh SR, Aldaghri OA, Ibnaouf KH, Madkhali N, Cabrera H. Thermal Diffusivity and Conductivity of Polyolefins by Thermal Lens Technique. Polymers (Basel) 2022; 14:polym14132707. [PMID: 35808756 PMCID: PMC9269369 DOI: 10.3390/polym14132707] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
A mode-mismatched thermal lens spectrometry (TLS) technique, in a pump–probe two-laser-beam configuration, was employed for the experimental determination of the thermal properties of four selected well-characterized polyolefin homopolymer films. We investigated the thermal diffusivity (D) and thermal conductivity (κ) of high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and polypropylene. We also measured the structural properties (i.e., average molecular weight, polydispersity index, branching number), along with the rheological and thermal properties (i.e., melting point, specific heat capacity Cp, degree of crystallinity) of samples by high-temperature gel permeation chromatography (HT-GPC), rheometric mechanical spectrometry (RMS), differential scanning calorimetry (DSC), and densitometry. The relationship between microstructural properties such as degree of crystallinity, D, and κ was investigated. The results show that there is good correlation between the degree of crystallinity and D. The TL technique enables measurement of D in semitransparent thin films within an uncertainty of 4%.
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Affiliation(s)
- Behnaz Abbasgholi-NA
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy;
- NanoInnovation Laboratory, Elettra-Sincrotrone Trieste S.C.p.A., 34151 Trieste, Italy
| | - Seyed Reza Nokhbeh
- Department of Chemistry, Ferdowsi University of Mashhad, Mashhad 9177948974, Iran;
| | - Osamah A. Aldaghri
- Physics Department, College of Sciences, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13318, Saudi Arabia; (O.A.A.); (K.H.I.)
| | - Khalid Hassan Ibnaouf
- Physics Department, College of Sciences, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13318, Saudi Arabia; (O.A.A.); (K.H.I.)
| | - Nawal Madkhali
- Physics Department, College of Sciences, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13318, Saudi Arabia; (O.A.A.); (K.H.I.)
- Correspondence: (N.M.); (H.C.)
| | - Humberto Cabrera
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy;
- Correspondence: (N.M.); (H.C.)
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Abbasgholi N Asbaghi B, Alsadig A, Cabrera H. Online electrophoretic nanoanalysis using miniaturized gel electrophoresis and thermal lens microscopy detection. J Chromatogr A 2021; 1657:462596. [PMID: 34689905 DOI: 10.1016/j.chroma.2021.462596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/13/2021] [Revised: 09/13/2021] [Accepted: 09/28/2021] [Indexed: 10/20/2022]
Abstract
Online thermal lens microscopy (TLM) coupled with gel electrophoresis (GE) can represent a powerful tool for separating and detecting a wide range of biomaterials. Unlike slab gel electrophoresis (SGE), the proposed method does not require prolonged procedure between separation and detection. In this work, we developed an online monitoring GE system to separate and detect nanosized materials. The design is based on a homemade and cost-effective miniaturized GE chip (MGEC) integrated with real-time TLM detection through microcontroller-based digitization board platform. To validate the feasibility and practicability of the proposed approach, we evaluated its separation capability via employing synthesized Fe3O4-Au core-shell nanoparticles (NPs) which served remarkably for the proof-of-concept. The optimum conditions for the separation process were achieved through optimization of the excitation power as 30 mW, detection position at 24 mm, the concentration of agarose gel 0.5 % w/v, and 37.5 V/cm as the effective electric field strength. The findings showed that two populations of Fe3O4-Au, core-shell, and uncapped Fe3O4 NPs, were effectively separated in less than eleven minutes, demonstrating rapid assessment of the nanomaterial production quality. Moreover, other characterization techniques such as HRTEM and EDX were employed to confirm the presence of the two dissimilar kinds of NPs separated using MGEC-TLM. The sensitivity of the method was demonstrated by determining the limit of detection (23 pM) for 10 nm AuNPs. It is envisaged that our presented system enables rapid, economical, low volume of reagents consumption and high potential analysis for quality test in various bioanalytical and nanotechnological applications.
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Affiliation(s)
| | - Ahmed Alsadig
- PhD School in Nanotechnology, University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy; NanoInnovation Lab, Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste, Italy
| | - Humberto Cabrera
- Optics Lab, STI Unit, The Abdus Salam International Centre for Theoretical Physics, Trieste 34151, Italy.
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Bertolini G, Gürlü O, Pröbsting R, Westholm D, Wei J, Ramsperger U, Zanin DA, Cabrera H, Pescia D, Xanthakis JP, Schnedler M, Dunin-Borkowski RE. Non-topographic current contrast in scanning field emission microscopy. R Soc Open Sci 2021; 8:210511. [PMID: 34295530 PMCID: PMC8278050 DOI: 10.1098/rsos.210511] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
In scanning field emission microscopy (SFEM), a tip (the source) is approached to few (or a few tens of) nanometres distance from a surface (the collector) and biased to field-emit electrons. In a previous study (Zanin et al. 2016 Proc. R. Soc. A 472, 20160475. (doi:10.1098/rspa.2016.0475)), the field-emitted current was found to change by approximately 1% at a monatomic surface step (approx. 200 pm thick). Here we prepare surface domains of adjacent different materials that, in some instances, have a topographic contrast smaller than 15 pm. Nevertheless, we observe a contrast in the field-emitted current as high as 10%. This non-topographic collector material dependence is a yet unexplored degree of freedom calling for a new understanding of the quantum mechanical tunnelling barrier at the source site that takes into account the properties of the material at the collector site.
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Affiliation(s)
- G. Bertolini
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - O. Gürlü
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - R. Pröbsting
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D. Westholm
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - J. Wei
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - U. Ramsperger
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D. A. Zanin
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - H. Cabrera
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D. Pescia
- Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - J. P. Xanthakis
- Electrical and Computer Engineering Department, National Technical University of Athens, Athens 15700, Greece
| | - M. Schnedler
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - R. E. Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
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Ebrahimpour Z, Pliekhova O, Cabrera H, Abdelhamid M, Korte D, Segbéya Gadedjisso-Tossou K, Niemela J, Lavrencic Stangar U, Franko M. Photodegradation mechanisms of reactive blue 19 dye under UV and simulated solar light irradiation. Spectrochim Acta A Mol Biomol Spectrosc 2021; 252:119481. [PMID: 33524821 DOI: 10.1016/j.saa.2021.119481] [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: 10/13/2020] [Revised: 01/01/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
In this work we performed dye photodegradation experiments in presence of TiO2 and Cu/Zr modified TiO2. The changes in the shape of the spectra of RB19 caused by photocatalysts under the simulated solar or UV light were monitored. Since the predominant photocatalytic mechanism can only be observed in very dilute solution of RB19, UV-Vis absorption spectrometry for higher concentrations and thermal lens spectrometry for lower concentrations have been applied to elucidate the mechanistic details of degradation processes. Bleaching of the dye was a characteristic feature, that occurred under both simulated solar and UV lights. It was also evident, that the absorption peak with maximum centered at 592 nm undergoes a slight blue shift during irradiation. The experiments carried out using UV and simulated solar light demonstrated, that two different processes responsible for the RB19 dye degradation occurred. In the initial stage of irradiation one of the processes appears under the UV light and can be recognized by a characteristic blue shift in the absorption spectrum of the solution. The second process is characteristic for irradiation by the simulated solar light which involve a blue shift at longer periods (100 min). These phenomena were attributed to the photocatalytic and photosensitization mechanisms, respectively. However, photocatalytic mechanism was also observed under simulated solar radiation, when the initial dye concentration was decreased to 5 mgL-1, and was recognized by the increase of the thermal lens signal during the initial stages of degradation process. This was possible because the thermal lens spectroscopy technique provides a limit of quantification for RB19 at the concentration level of 0.12 mg L-1, while UV-Vis spectrometry enables quantification of RB19 only down to 4 mg L-1 levels.
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Affiliation(s)
- Zeinab Ebrahimpour
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Olena Pliekhova
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia
| | - Humberto Cabrera
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy.
| | - Mahmoud Abdelhamid
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza, Egypt
| | - Dorota Korte
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia.
| | - Komlan Segbéya Gadedjisso-Tossou
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; Laboratoire de Physique des Matériaux et Composants à Semi-conducteurs (LPMCS), Département de Physique, Université de Lomé, Togo
| | - Joseph Niemela
- Optics Lab., The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Urska Lavrencic Stangar
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, 1000 Ljubljana, Slovenia
| | - Mladen Franko
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, Nova Gorica 5000, Slovenia
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Stoychev LI, Cabrera H, Suárez-Vargas JJ, Baruzzo M, Gadedjisso-Tossou KS, Nikolov IP, Sigalotti P, Demidovich AA, Mocchiutti E, Pizzolotto C, Niemela J, Toci G, Danailov MB, Vacchi A. DFG-based mid-IR tunable source with 0.5 mJ energy and a 30 pm linewidth. Opt Lett 2020; 45:5526-5529. [PMID: 33001937 DOI: 10.1364/ol.405272] [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: 08/12/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
We report on a laser system based on difference frequency generation (DFG) to produce tunable, narrow-linewidth (<30pm), and comparatively high-energy mid-IR radiation in the 6.8 µm region. The system exploits a lithium thioindate (LiInS2) nonlinear crystal and nanosecond pulses generated by single-frequency Nd:YAG and Cr:forsterite lasers at 1064 and 1262 nm, respectively. Two experimental configurations are used: in the first one, single-pass, the mid-IR energy achieved is 205 µJ. Additional increments, up to 540 µJ, are obtained by performing double-pass through the nonlinear crystal. This laser has been developed for high-resolution photon-hungry spectroscopy in the mid-IR.
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14
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Cabrera H, Goljat L, Korte D, Marín E, Franko M. A multi-thermal-lens approach to evaluation of multi-pass probe beam configuration in thermal lens spectrometry. Anal Chim Acta 2020; 1100:182-190. [PMID: 31987139 DOI: 10.1016/j.aca.2019.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 11/24/2022]
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15
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Stoychev LI, Cabrera H, Gadedjisso-Tossou KS, Vasiliev N, Zaporozhchenko Y, Nikolov IP, Sigalotti P, Demidovich AA, Suárez-Vargas JJ, Mocchiutti E, Pizzolotto C, Niemela J, Baruzzo M, Danailov MB, Vacchi A. 24 mJ Cr +4:forsterite four-stage master-oscillator power-amplifier laser system for high resolution mid-infrared spectroscopy. Rev Sci Instrum 2019; 90:093002. [PMID: 31575267 DOI: 10.1063/1.5115105] [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] [Received: 06/14/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
We present the design of a Cr:forsterite based single-frequency master-oscillator power-amplifier laser system delivering much higher output energy compared to previous literature reports. The system has four amplifying stages with two-pass configuration each, thus enabling the generation of 24 mJ output energy in the spectral region around 1262 nm. It is demonstrated that the presented Cr:forsterite amplifier preserves high spectral and pulse quality, allowing a straightforward energy scaling. This laser system is a promising tool for tunable nonlinear down-conversion to the mid-infrared spectral range and will be a key building block in a system for high-resolution muonic hydrogen spectroscopy in the 6.8 μm range.
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Affiliation(s)
- Lyubomir I Stoychev
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
| | - Humberto Cabrera
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
| | | | | | | | | | | | | | | | - Emiliano Mocchiutti
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
| | - Cecilia Pizzolotto
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
| | - Joseph Niemela
- Optics Lab, The Abdus Salam International Centre for Theoretical Physics, Trieste 34151, Italy
| | - Marco Baruzzo
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
| | | | - Andrea Vacchi
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Trieste 34149, Italy
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16
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Farzam Rad V, Ramírez-Miquet EE, Cabrera H, Habibi M, Moradi AR. Speckle pattern analysis of crumpled papers. Appl Opt 2019; 58:6549-6554. [PMID: 31503584 DOI: 10.1364/ao.58.006549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
In this paper, we show that laser speckle analysis (LSA) can provide valuable information about the structure of crumpled thin sheets. Crumpling and folding of slender objects are present in several phenomena and in various ranges of size, e.g., paper compaction, cortical folding in brains, DNA packing in viral capsids, and flower buds, to name a few. The analysis of laser speckles, both numerical and graphical, is a source of information about the activity of biological or non-biological materials, and the development of digital electronics, which brought the ease of image processing, has opened new perspectives for a spectrum of LSA applications. LSA is applied on randomly crumpled and one-, two-, and three-times folded papers, and appreciable differences in LSA parameters are observed. The methodology can be applied for easy-to-implement quantitative assessment of similar phenomena and samples.
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17
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Hernández-Carabalí LA, Cedeño E, Mantilla A, Alvarado S, Cabrera H, Mansanares AM, Calderón A, Marín E. Application of thermal lens microscopy (TLM) for measurement of Cr(VI) traces in wastewater. J Environ Manage 2019; 232:305-309. [PMID: 30496959 DOI: 10.1016/j.jenvman.2018.11.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 11/11/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
In this work, we demonstrate for the first time that Thermal Lens Microscopy technique (TLM) can be applied to monitor the dynamics of a photocatalytic process in-situ. The photocatalytic reduction of hexavalent chromium -Cr(VI)- in aqueous solution using CdS and irradiated with visible light is monitored by TLM. Since the values of Cr(VI) concentration obtained after the photocatalytic process were close to those imposed by the international regulations for drinking water, the use of TLM allowed its measurement with a better reliability than with UV spectroscopy, usually used in this kind of analysis.
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Affiliation(s)
- L A Hernández-Carabalí
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico
| | - E Cedeño
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico
| | - A Mantilla
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico.
| | - S Alvarado
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico
| | - H Cabrera
- National Institute for Nuclear Physics (INFN), Sezione di Trieste, Via A. Valerio 2, 34127, Trieste, Italy; The Abdus Salam International Centre for Theoretical Physics, Trieste 34151, Italy
| | - A M Mansanares
- Gleb Wataghin Physics Institute, U. of Campinas-UNICAMP, 13083-859, Campinas, SP, Brazil
| | - A Calderón
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico
| | - E Marín
- Instituto Politécnico Nacional, CICATA Legaria, Legaria 694, Colonia Irrigación, CP 11500, Ciudad de México, Mexico
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Cabrera H, Akbar J, Korte D, Ashraf I, Ramírez-Miquet EE, Marín E, Niemela J. Absorption Spectra of Ethanol and Water Using a Photothermal Lens Spectrophotometer. Appl Spectrosc 2018; 72:1069-1073. [PMID: 29381092 DOI: 10.1177/0003702818759073] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work we report on the absorption spectra of ethanol and water in the region 430-700 nm using a homemade halogen lamp-based photothermal lens spectrophotometer with a multipass probe-beam configuration. The spectra also include well resolved, higher absorption overtones. The instrument achieves high sensitivity due to multiple reflections within the optical cavity containing the sample. Finally, an Arduino board was used for collecting and digitizing the signal, thus enabling a more compact device.
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Affiliation(s)
- Humberto Cabrera
- 1 The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
| | - Jehan Akbar
- 1 The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
- 2 Department of Physics, Hazara Univerity, Mansehra, Pakistan
| | - Dorota Korte
- 3 Laboratory of Environmental and Life Sciences, University of Nova Gorica, Nova Gorica, Slovenia
| | - Imrana Ashraf
- 4 Department of Physics, Quaid-I-Azam University, Islamabad, Pakistan
| | - Evelio E Ramírez-Miquet
- 5 Matériaux et Phénomènes Quantiques, Université Paris Diderot, Sorbonne Paris-Cité, Paris, France
| | - Ernesto Marín
- 6 Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Mexico City, Mexico
| | - Joseph Niemela
- 1 The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
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19
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Cabrera H, Akbar J, Korte D, Ramírez-Miquet EE, Marín E, Niemela J, Ebrahimpour Z, Mannatunga K, Franko M. Trace detection and photothermal spectral characterization by a tuneable thermal lens spectrometer with white-light excitation. Talanta 2018; 183:158-163. [PMID: 29567158 DOI: 10.1016/j.talanta.2018.02.073] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [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: 11/20/2017] [Revised: 02/13/2018] [Accepted: 02/16/2018] [Indexed: 11/26/2022]
Abstract
In the thermal lens experimental set-up we replaced the commonly employed pump laser by a halogen lamp, combined with an interference filter, providing a tuneable, nearly monochromatic pump source over the range of wavelengths 430-710 nm. Counter-propagating pump and probe beams are used and a 1 mm path-length sample cell together with the interference filter makes an optical cavity, providing amplification of the thermal lens signal, which leads to enhancement of the measurement sensitivity, and enables detection of absorbances on the order of 5 × 10-6. Amplified thermal lens signal allows us to replace the typical lock-in amplifier and digital oscilloscope with a silicon photodetector, Arduino, and a personal computer, offering the possibility for a compact, robust and portable device, useful for in-field absorption measurements in low concentration or weakly absorbing species. The use of a white light source for optical pumping, an interference filter for wavelength selection and direct diagnostic of the thermal lens signal increase the versatility of the instrument and simplifies substantially the experimental setup. Determination of Fe(II) concentrations at parts per billion levels was performed by the described white-light thermal lens spectrophotometer and the absorption spectrum for 50 μgL-1 Fe(II)-1,10-phenanthroline was well reproduced with an average measurement precision of 4%. The obtained limits of detection and quantitation of Fe(II) determination at 510 nm are 3 µgL-1 and 11 µgL-1, respectively. The calibration curve was linear in the concentration range of LOQ-500 µgL-1 with reproducibility between 2% and 6%, confirming that this instrument provides good spectrometric capabilities such as high sensitivity, tuneability and good reproducibility. In addition, the versatility of the instrument was demonstrated by recording the photothermal spectrum of gold nanostructured material and determination of excitation wavelength with most efficient optical to thermal energy conversion, which differs considerably (cca 100 nm) from the absorption maximum of the investigated sample.
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Affiliation(s)
- Humberto Cabrera
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy.
| | - Jehan Akbar
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; Department of Physics, Hazara University Mansehra, Pakistan
| | - Dorota Korte
- Laboratory of Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
| | - Evelio E Ramírez-Miquet
- Matériaux et Phénomènes Quantiques, Université Paris Diderot, CNRS UMR 7162, Sorbonne Paris-Cité, 10 rue Alice Domon et Léonie Duquet, Paris 75013, France
| | - Ernesto Marín
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Col. Irrigación, Mexico City 11500, Mexico
| | - Joseph Niemela
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Zeinab Ebrahimpour
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Kasun Mannatunga
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy; University of Sri Jayewardenepura, Sri Lanka
| | - Mladen Franko
- Laboratory of Environmental and Life Sciences, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
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20
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Vargas E, Cifuentes A, Alvarado S, Cabrera H, Delgado O, Calderón A, Marín E. Thermal diffusivity measurement in thin metallic filaments using the mirage method with multiple probe beams and a digital camera. Rev Sci Instrum 2018; 89:024904. [PMID: 29495871 DOI: 10.1063/1.5006942] [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
Photothermal beam deflection is a well-established technique for measuring thermal diffusivity. In this technique, a pump laser beam generates temperature variations on the surface of the sample to be studied. These variations transfer heat to the surrounding medium, which may be air or any other fluid. The medium in turn experiences a change in the refractive index, which will be proportional to the temperature field on the sample surface when the distance to this surface is small. A probe laser beam will suffer a deflection due to the refractive index periodical changes, which is usually monitored by means of a quadrant photodetector or a similar device aided by lock-in amplification. A linear relationship that arises in this technique is that given by the phase lag of the thermal wave as a function of the distance to a punctual heat source when unidimensional heat diffusion can be guaranteed. This relationship is useful in the calculation of the sample's thermal diffusivity, which can be obtained straightforwardly by the so-called slope method, if the pump beam modulation frequency is well-known. The measurement procedure requires the experimenter to displace the probe beam at a given distance from the heat source, measure the phase lag at that offset, and repeat this for as many points as desired. This process can be quite lengthy in dependence of the number points. In this paper, we propose a detection scheme, which overcomes this limitation and simplifies the experimental setup using a digital camera that substitutes all detection hardware utilizing motion detection techniques and software digital signal lock-in post-processing. In this work, the method is demonstrated using thin metallic filaments as samples.
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Affiliation(s)
- E Vargas
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, 11500 Ciudad de México, Mexico
| | - A Cifuentes
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, 11500 Ciudad de México, Mexico
| | - S Alvarado
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, 11500 Ciudad de México, Mexico
| | - H Cabrera
- Multidisciplinary Laboratory, International Centre for Theoretical Physics, Trieste 34151, Italy
| | - O Delgado
- Universidad Politécnica Metropolitana de Hidalgo, Boulevard Acceso a Tolcayuca # 1009, Exhacienda de San Javier, 43860 Tolcayuca, Hidalgo, Mexico
| | - A Calderón
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, 11500 Ciudad de México, Mexico
| | - E Marín
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, 11500 Ciudad de México, Mexico
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21
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De Pietro L, Bertolini G, Peter Q, Cabrera H, Vindigni A, Gürlü O, Pescia D, Ramsperger U. Spin-polarised electrons in a one-magnet-only Mott spin junction. Sci Rep 2017; 7:13237. [PMID: 29038570 PMCID: PMC5643535 DOI: 10.1038/s41598-017-13453-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/22/2017] [Indexed: 11/08/2022] Open
Abstract
The current flowing through a Mott spin junction depends on the relative spin orientation of the two ferromagnetic layers comprising the "source" and "drain" sides of the junction. The resulting current asymmetry is detected as giant or tunnelling magnetoresistance depending on whether the two ferromagnets are separated by a metal or an insulator. Based on the fundamental principles of reciprocity for spin-dependent electron scattering, one can envisage a one-magnet-only spin junction in which the source is non-magnetic, and the spin information is encoded by the spin polarisation of the electrons that have crossed or are backscattered from the drain magnetic layer. The practical significance of using an unpolarised source is that the state of the magnetic layer can be modified without affecting the process of probing it. Whether this reciprocity is realised in the actual junctions is not yet known. Here, we demonstrate a nano-sized, one-magnet-only Mott spin junction by measuring the finite spin polarisation of the backscattered electrons. Based on this finding, we conclude that since the junction acts as a spin filter, the magnetic layer must experience a spin transfer that could become detectable in view of the high current densities achievable in this technology.
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Affiliation(s)
- L De Pietro
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - G Bertolini
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - Q Peter
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - H Cabrera
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - A Vindigni
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - O Gürlü
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
- Department of Physics, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey
| | - D Pescia
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland
| | - U Ramsperger
- Laboratorium fur Festkörperphysik, ETH Zürich, Zürich, 8093, Switzerland.
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22
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Cedeño E, Cabrera H, Delgadillo-López A, Delgado-Vasallo O, Mansanares A, Calderón A, Marín E. High sensitivity thermal lens microscopy: Cr-VI trace detection in water. Talanta 2017; 170:260-265. [DOI: 10.1016/j.talanta.2017.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 11/16/2022]
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23
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Ros Forteza FJ, Cabrera H, Bousende M. Malnutrition in the elderly and Wernicke encephalopathy. Neurologia 2017; 34:543-546. [PMID: 28363380 DOI: 10.1016/j.nrl.2017.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/23/2016] [Accepted: 01/01/2017] [Indexed: 11/17/2022] Open
Affiliation(s)
- F J Ros Forteza
- Serviço de Neurologia, Unidade Local de Saúde da Guarda, EPE, Guarda, Portugal; Departamento de Ciências Médicas, Faculdade de Ciências da Saúde (UBI) , Covilhã, Portugal.
| | - H Cabrera
- Departamento de Ciências Médicas, Faculdade de Ciências da Saúde (UBI) , Covilhã, Portugal; Serviço de Medicina Interna, ULS-Guarda, EPE, Guarda, Portugal
| | - M Bousende
- Serviço de Neurorradiologia, Centro Hospitalar São João, EPE, Porto, Portugal
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Alvarez ED, Laffita YM, Montoro LA, Della Santina Mohallem N, Cabrera H, Pérez GM, Frutis MA, Cappe EP. Electrical, thermal and electrochemical properties of disordered carbon prepared from palygorskite and cane molasses. J SOLID STATE CHEM 2017. [DOI: 10.1016/j.jssc.2016.09.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Zanin DA, De Pietro LG, Peter Q, Kostanyan A, Cabrera H, Vindigni A, Bähler T, Pescia D, Ramsperger U. Thirty per cent contrast in secondary-electron imaging by scanning field-emission microscopy. Proc Math Phys Eng Sci 2016; 472:20160475. [PMID: 27956876 PMCID: PMC5134307 DOI: 10.1098/rspa.2016.0475] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We perform scanning tunnelling microscopy (STM) in a regime where primary electrons are field-emitted from the tip and excite secondary electrons out of the target—the scanning field-emission microscopy regime (SFM). In the SFM mode, a secondary-electron contrast as high as 30% is observed when imaging a monoatomic step between a clean W(110)- and an Fe-covered W(110)-terrace. This is a figure of contrast comparable to STM. The apparent width of the monoatomic step attains the 1 nm mark, i.e. it is only marginally worse than the corresponding width observed in STM. The origin of the unexpected strong contrast in SFM is the material dependence of the secondary-electron yield and not the dependence of the transported current on the tip–target distance, typical of STM: accordingly, we expect that a technology combining STM and SFM will highlight complementary aspects of a surface while simultaneously making electrons, selected with nanometre spatial precision, available to a macroscopic environment for further processing.
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Affiliation(s)
- D A Zanin
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - L G De Pietro
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - Q Peter
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - A Kostanyan
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - H Cabrera
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - A Vindigni
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - Th Bähler
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - D Pescia
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
| | - U Ramsperger
- Laboratory for Solid State Physics , ETH Zurich , 8093 Zurich, Switzerland
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Grassi HC, García LC, Lobo-Sulbarán ML, Velásquez A, Andrades-Grassi FA, Cabrera H, Andrades-Grassi JE, Andrades EDJ. Quantitative Laser Biospeckle Method for the Evaluation of the Activity of Trypanosoma cruzi Using VDRL Plates and Digital Analysis. PLoS Negl Trop Dis 2016; 10:e0005169. [PMID: 27918574 PMCID: PMC5137869 DOI: 10.1371/journal.pntd.0005169] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/07/2016] [Indexed: 11/19/2022] Open
Abstract
In this paper we report a quantitative laser Biospeckle method using VDRL plates to monitor the activity of Trypanosoma cruzi and the calibration conditions including three image processing algorithms and three programs (ImageJ and two programs designed in this work). Benznidazole was used as a test drug. Variable volume (constant density) and variable density (constant volume) were used for the quantitative evaluation of parasite activity in calibrated wells of the VDRL plate. The desiccation process within the well was monitored as a function of volume and of the activity of the Biospeckle pattern of the parasites as well as the quantitative effect of the surface parasite quantity (proportion of the object's plane). A statistical analysis was performed with ANOVA, Tukey post hoc and Descriptive Statistics using R and R Commander. Conditions of volume (100μl) and parasite density (2-4x104 parasites/well, in exponential growth phase), assay time (up to 204min), frame number (11 frames), algorithm and program (RCommander/SAGA) for image processing were selected to test the effect of variable concentrations of benznidazole (0.0195 to 20μg/mL / 0.075 to 76.8μM) at various times (1, 61, 128 and 204min) on the activity of the Biospeckle pattern. The flat wells of the VDRL plate were found to be suitable for the quantitative calibration of the activity of Trypanosoma cruzi using the appropriate algorithm and program. Under these conditions, benznidazole produces at 1min an instantaneous effect on the activity of the Biospeckle pattern of T. cruzi, which remains with a similar profile up to 1 hour. A second effect which is dependent on concentrations above 1.25μg/mL and is statistically different from the effect at lower concentrations causes a decrease in the activity of the Biospeckle pattern. This effect is better detected after 1 hour of drug action. This behavior may be explained by an instantaneous effect on a membrane protein of Trypanosoma cruzi that could mediate the translocation of benznidazole. At longer times the effect may possibly be explained by the required transformation of the pro-drug into the active drug.
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Affiliation(s)
| | - Lisbette C. García
- Facultad de Farmacia y Bionálisis, Universidad de Los Andes, Mérida, Venezuela
| | - María Lorena Lobo-Sulbarán
- Cátedra de Farmacología y Terapéutica, Departamento de Biopatología, Facultad de Odontología, Universidad de Los Andes, Mérida, Venezuela
| | - Ana Velásquez
- Centro Multidisciplinario de Ciencias, Instituto Venezolano de Investigaciones Científicas, Mérida, Venezuela
| | | | - Humberto Cabrera
- Centro Multidisciplinario de Ciencias, Instituto Venezolano de Investigaciones Científicas, Mérida, Venezuela
- SPIE-ICTP Anchor Research in Optics Program Laboratory, International Centre for Theoretical Physics, Trieste, Italy
- * E-mail:
| | - Jesús E. Andrades-Grassi
- Facultad de Ciencias Forestales y Ambientales, Departamento de Ordenación de Cuencas, Universidad de Los Andes Mérida, Venezuela
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Batalla J, Cabrera H, San Martín-Martínez E, Korte D, Calderón A, Marín E. Encapsulation efficiency of CdSe/ZnS quantum dots by liposomes determined by thermal lens microscopy. Biomed Opt Express 2015; 6:3898-906. [PMID: 26504640 PMCID: PMC4605049 DOI: 10.1364/boe.6.003898] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/06/2015] [Accepted: 08/10/2015] [Indexed: 05/30/2023]
Abstract
In this study the encapsulation of core shell carboxyl CdSe/ZnS quantum dots (QDs) by phospholipids liposome complexes is presented. It makes the quantum dots water soluble and photo-stable. Fluorescence self-quenching of the QDs inside the liposomes was observed. Therefore, the thermal lens microscopy (TLM) was found to be an useful tool for measuring the encapsulation efficiency of the QDs by the liposomes, for which an optimum value of 36% was determined. The obtained limit of detection (LOD) for determining QDs concentration by TLM was 0.13 nM. Moreover, the encapsulated QDs showed no prominent cytotoxicity toward Breast cancer cells line MDA-MB-231. This study was supported by UV-visible spectroscopy, high resolution transmission electron microscopy (HRTEM) and dynamic light scattering measurements (DLS).
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Affiliation(s)
- Jessica Batalla
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, México D.F. 11500, Mexico
| | - Humberto Cabrera
- SPIE-ICTP Anchor Research Laboratory, International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste 34151, Italy
- Centro Multidisciplinario de Ciencias, Instituto Venezolano de Investigaciones Científicas (IVIC), Mérida 5101, Venezuela
| | - Eduardo San Martín-Martínez
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, México D.F. 11500, Mexico
| | - Dorota Korte
- Laboratory for Environmental Research, University of Nova Gorica,, Vipavska 13, 5000 Nova Gorica, Slovenia
| | - Antonio Calderón
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, México D.F. 11500, Mexico
| | - Ernesto Marín
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, México D.F. 11500, Mexico
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Abstract
We report a thermal lens microscope (TLM) based on an optimized mode-mismatched configuration. It takes advantage of the coaxial counter propagating tightly focused excitation and collimated probe beams, instead of both focused at the sample, as it is in currently known TLM setups. A simple mathematical model that takes into account the main features of the instrument is presented. The confocal detection scheme and the introduction of highly collimated probe beam allow enhancing the versatility, limit of detection (LOD), and sensitivity of the instrument. The theory is experimentally verified measuring ethanol's absorption coefficient at 532.8 nm. Additionally, the presented technique is applied for detection of ultra-trace amounts of Cr(III) in liquid solution. The achieved LOD is 1.3 ppb, which represents 20-fold enhancement compared to transmission mode spectrometric techniques and a 7.5-fold improvement compared to previously reported methods for Cr(III) based on thermal lens effect.
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Affiliation(s)
- Humberto Cabrera
- SPIE-ICTP Anchor Research Laboratory, International Centre for Theoretical Physics (ICTP), Strada Costiera 11, Trieste, Italy
| | - Dorota Korte
- Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
| | - Mladen Franko
- Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia
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Michaels TCT, Cabrera H, Zanin DA, De Pietro L, Ramsperger U, Vindigni A, Pescia D. Scaling theory of electric-field-assisted tunnelling. Proc Math Phys Eng Sci 2014; 470:20140014. [PMID: 25002824 PMCID: PMC4032555 DOI: 10.1098/rspa.2014.0014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 04/02/2014] [Indexed: 11/17/2022] Open
Abstract
Recent experiments report the current (I) versus voltage (V) characteristics of a tunnel junction consisting of a metallic tip placed at a distance d from a planar electrode, d varying over six orders of magnitude, from few nanometres to few millimetres. In the ‘electric-field-assisted’ (or ‘field emission’) regime, as opposed to the direct tunnelling regime used in conventional scanning tunnelling microscopy, all I–V curves are found to collapse onto one single graph when d is suitably rescaled, suggesting that the current I=I(V,d) is in reality a generalized homogeneous function of one single variable, i.e. I=I(V⋅d−λ), where λ being some characteristic exponent and I(x) being a scaling function. In this paper, we provide a comprehensive explanation—based on analytical arguments, numerical simulations and further experimental results—for the scaling behaviour that we show to emerge for a variety of tip–plane geometries and thus seems to be a general feature of electric-field-assisted tunnelling.
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Affiliation(s)
- Thomas C T Michaels
- Department of Chemistry , University of Cambridge , Lensfield Road, Cambridge CB2 1EW, UK
| | - H Cabrera
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
| | - D A Zanin
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
| | - L De Pietro
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
| | - U Ramsperger
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
| | - A Vindigni
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
| | - D Pescia
- Laboratory for Solid State Physics , ETH Zurich , Zurich 8093, Switzerland
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Dimberg L, Cabrera H, Menke C, Behbakht K, Porter C, Taan A, Thorburn A, Ford H. 100 Use of a Genome-wide Loss-of-function Screen to Identify Novel Mechanisms of Resistance to TRAIL Induced Apoptosis. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71898-1] [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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Cabrera H, Hermida M, Griffa E, García S, Elías Costa M. Cutaneous strongyloidiasis: direct finding of worms on skin potassium hydroxide examination. Br J Dermatol 2012; 168:891-2. [PMID: 23039845 DOI: 10.1111/bjd.12084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Affiliation(s)
- Humberto Cabrera
- CEIF, Instituto Venezolano de Investigaciones Científicas, Mérida, Venezuela.
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Cabrera H, Martí-López L, Sira E, Rahn K, García-Sucre M. Thermal lens measurement of the Soret coefficient in acetone/water mixtures. J Chem Phys 2009; 131:031106. [DOI: 10.1063/1.3182806] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [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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Guerra M, Taouri A, Marcano O A, Cabrera H, Sylla M. Measurement of nonlinear absorption coefficients of organic materials by mode-mismatched Z-scan thermal lensing technique. Appl Spectrosc 2007; 61:1128-1133. [PMID: 17958965 DOI: 10.1366/000370207782217716] [Citation(s) in RCA: 1] [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: 05/25/2023]
Abstract
We evaluate a new pump-probe mode-mismatched thermal lens (TL) scheme for the measurement of nonlinear absorption in nitrobenzene, benzene, and chloroform. In this new scheme the pump beam is focused in the presence of a collimated probe beam. Values of the nonlinear absorption coefficients of the materials studied for the wavelength of 532 nm are reported, and we compare the proposed technique with the well-known open Z-scan method.
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Affiliation(s)
- M Guerra
- Laboratoire des Proprietés Optiques de Matériaux et Applications, UMR-CNRS 6236, 2, Bd Lavoisier 49045 Angers Cedex, France
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Abstract
BACKGROUND Brooke-Spiegler syndrome is a well known but rare cutaneous disorder characterized by the presence of multiple trichoepitheliomas and cylindromas. METHODS Four families with Brooke-Spiegler syndrome are described. RESULTS Spiradenomas developed on the back in two patients. A CO(2) laser was used to treat facial trichoepitheliomas in two patients with good results. CONCLUSIONS The large number of facial lesions in this syndrome often produce a significant emotional impact. We believe that it is important to provide patients with a good therapeutic option. CO(2) laser therapy may fill this role.
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MESH Headings
- Adenoma, Sweat Gland/pathology
- Adenoma, Sweat Gland/surgery
- Adult
- Aged
- Carcinoma, Adenoid Cystic/pathology
- Carcinoma, Adenoid Cystic/surgery
- Child
- Face/pathology
- Female
- Humans
- Laser Therapy
- Male
- Middle Aged
- Neoplasms, Adnexal and Skin Appendage/pathology
- Neoplasms, Adnexal and Skin Appendage/surgery
- Neoplasms, Multiple Primary/pathology
- Neoplasms, Multiple Primary/surgery
- Neoplastic Syndromes, Hereditary/pathology
- Neoplastic Syndromes, Hereditary/surgery
- Scalp/pathology
- Skin Neoplasms/pathology
- Skin Neoplasms/surgery
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Affiliation(s)
- Roberto Adrián Retamar
- Department of Dermatology, Hospital Cosme Argerich and CHOUELA DERMATOLOGIA Center, Buenos Aires, Argentina.
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Abstract
In this study we investigated the population genetic structure of the queenless ant Diacamma cyaneiventre. This species, lacking winged queens, is likely to have a restricted female dispersal. We used both mitochondrial and microsatellite markers to assess the consequence of such restricted female dispersal at three geographical scales: within a given locality (< 1 km), between localities within a given region (< 10 km) and between regions (> 36 km). Within a locality, a strong population structure was observed for mitochondrial DNA (mtDNA) whereas weak or nonexistent population genetic structure was observed for the microsatellites (around 5% of the value for mtDNA). Male gene flow was estimated to be about 20-30 times higher than female gene flow at this scale. At a larger spatial scale, very strong genetic differentiation for both markers was observed between localities - even within a single region. Female dispersal is nonexistent at these scales and male dispersal is very restricted, especially between regions. The phylogeographical structure of the mtDNA haplotypes as well as the very low genetic diversity of mtDNA within localities indicate that new sites are colonized by a single migration event from adjacent localities, followed by successive colony fissions. These patterns of genetic variability and differentiation agree with what is theoretically expected when colonization events are kin-structured and when, following colonization, dispersion is mainly performed by males.
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Affiliation(s)
- Claudie Doums
- Laboratoire d'Ecologie, UMR 7625 CNRS, Universite Pierre et Marie Curie, Bat. A 7eme étage, 7 quai St Bernard, F-75252 Paris Cedex 05, France.
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Losada R, Cabrera H, Hernández P, Hernández C, Menéndez A, Mesa J, Plascencia A, Ramón L, Agramonte O, Espinosa E. Bone marrow reticulin fibrosis at diagnosis in promyelocytic leukaemia treated with all-trans retinoic acid has no adverse prognosis. Acta Haematol 2002; 108:111-2. [PMID: 12187033 DOI: 10.1159/000064753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Rafael Losada
- Instituto de Hematología e Inmunología, La Habana, Cuba.
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Abstract
Giant congenital melanocytic nevi (GCMN) are rare and occur in about one out of every 200,000-500,000 births. Their importance resides in the aesthetic alteration they produce and in the possibility of malignant transformation or in their association with nevi in the central nervous system as a distinctive syndrome: neurocutaneous melanoblastosis or nevomatosis, due to the fact that nervous system lesions are produced by infiltration of nevus cells. We present here a patient with a combination of GCMN with an outstanding lipomatosis located on the same area.
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Affiliation(s)
- H Cabrera
- Department of Dermatology, School of Medicine of Buenos Aires University, Argentina, Hospital Posadas.
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Menéndez A, González A, Cabrera H, Mesa J, Martínez G, Espinoza E, Hernández P. Clinical spectrum of extramedullary acute promyelocytic leukemia. Eur J Haematol 2000; 64:201-3. [PMID: 10997887 DOI: 10.1034/j.1600-0609.2000.70424.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Carbonell N, Cabrera H, Hernández P, Hernández C, Losada R, Espinosa E. [Necrotizing lymphoma]. Sangre (Barc) 1994; 39:61-2. [PMID: 8197525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Affiliation(s)
- R Barrio
- Departamento de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
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Cabrera H, Dawson SV, Stromberg C. A California air standard to protect vegetation from ozone. Environ Pollut 1988; 53:397-408. [PMID: 15092565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Evidence shows that the current national primary ambient air quality standard, if attained, would still permit substantial injury to vegetation. Thus, in March 1987, the California Air Resources Board (CARB) began consideration of the evidence for the effects of ozone (O3) on vegetation, and of several possible state ambient air quality standards designed to protect vegetation, especially crops, from O3 injury. In its review, the CARB addressed a number of issues relevant to such a standard. One issue considered by the CARB is the relationship of an ambient air quality standard to natural background levels of O3, which would greatly influence the practicality of attainment. Attainment of a standard close to natural background could entail excessive costs. Another issue considered is the occurrence of oxidants other than O3 that can damage vegetation. Throughout much of California, O3 accounts for over 90% of the oxidant air pollutants, and the CARB considered whether, in keeping with current practice, O3 should be used as a surrogate for total oxidant air pollutants. A major new piece of information presented to the CARB was an assessment of the economic effects of several potential standards. This assessment, produced by University of California scientists at Riverside and Davis, calculated the benefits of the potential standards in comparison to current O3 levels and estimated natural O3 background. This assessment was developed using field chamber response data, local crop data, and local O3 concentration data as inputs to the California Agricultural Resources Model, which accounts for both supply and demand effects. Because of California's varied climate, agricultural production occurs on a year-round basis, with overlapping growing seasons for many crops. Over long periods of time, O3 levels may vary markedly because of the influence of various factors, and a 1-h standard may not be an accurate indicator of growing season O3 exposure. A moving three-month averaging time has been proposed as a way to approximate the growing seasons of California's 200 crops. However, a sufficiently stringent 1-h standard would serve as a surrogate for a growing season standard. The CARB reviewed evidence supporting both long-term and short-term standards. Agriculture dominates the economies of some regions within California but is a minor components of other regional economies. Because the San Joaquin Valley is California's most important agricultural area, the CARB reviewed evidence for a regional standard for this area that would be more stringent than standards for other parts of the state.
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Affiliation(s)
- H Cabrera
- Research Division, California Air Resources Board, Sacramento, California 95812, USA
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Furste W, Parsons JN, Cabrera H. Tetanus prevention. Compr Ther 1981; 7:49-57. [PMID: 7030610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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