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Visalli A, Capizzi M, Ambrosini E, Kopp B, Vallesi A. P3-like signatures of temporal predictions: a computational EEG study. Exp Brain Res 2023:10.1007/s00221-023-06656-z. [PMID: 37354350 DOI: 10.1007/s00221-023-06656-z] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 06/18/2023] [Indexed: 06/26/2023]
Abstract
Many cognitive processes, ranging from perception to action, depend on the ability to predict the timing of forthcoming events. Yet, how the brain uses predictive models in the temporal domain is still an unsolved question. In previous work, we began to explore the neural correlates of temporal predictions by using a computational approach in which an ideal Bayesian observer learned the temporal probabilities of target onsets in a simple reaction time task. Because the task was specifically designed to disambiguate updating of predictive models and surprise, changes in temporal probabilities were explicitly cued. However, in the real world, we are usually incidentally exposed to changes in the statistics of the environment. Here, we thus aimed to further investigate the electroencephalographic (EEG) correlates of Bayesian belief updating and surprise associated with incidental learning of temporal probabilities. In line with our previous EEG study, results showed distinct P3-like modulations for updating and surprise. While surprise was indexed by an early fronto-central P3-like modulation, updating was associated with a later and more posterior P3 modulation. Moreover, updating was associated with a P2-like potential at centro-parietal electrodes, likely capturing integration processes between prior beliefs and likelihood of the observed event. These findings support previous evidence of trial-by-trial variability of P3 amplitudes as an index of dissociable inferential processes. Coupled with our previous findings, the present study strongly bolsters the view of the P3 as a key brain signature of temporal Bayesian inference. Data and scripts are shared on OSF: osf.io/sdy8j/.
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Affiliation(s)
- Antonino Visalli
- Department of Neuroscience, University of Padova, 35121, Padua, Italy.
- Padova Neuroscience Center, University of Padova, Padua, Italy.
- IRCCS San Camillo Hospital, 30126, Venice, Italy.
| | - M Capizzi
- Brain and Behavior Research Center (CIMCYC), Department of Experimental Psychology, University of Granada, Granada, Spain
| | - E Ambrosini
- Department of Neuroscience, University of Padova, 35121, Padua, Italy
- Padova Neuroscience Center, University of Padova, Padua, Italy
- Department of General Psychology, University of Padova, Padua, Italy
| | - B Kopp
- Department of Neurology, Hannover Medical School, 30625, Hannover, Germany
| | - Antonino Vallesi
- Department of Neuroscience, University of Padova, 35121, Padua, Italy.
- Padova Neuroscience Center, University of Padova, Padua, Italy.
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2
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Capizzi M, Visalli A, Wiener M, Mioni G. The contribution of the supplementary motor area to explicit and implicit timing: A high-definition transcranial Random Noise Stimulation (HD-tRNS) study. Behav Brain Res 2023; 445:114383. [PMID: 36878287 DOI: 10.1016/j.bbr.2023.114383] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 02/13/2023] [Accepted: 03/03/2023] [Indexed: 03/07/2023]
Abstract
It is becoming increasingly accepted that timing tasks, and underlying temporal processes, can be partitioned on the basis of whether they require an explicit or implicit temporal judgement. Most neuroimaging studies of timing associated explicit timing tasks with activation of the supplementary motor area (SMA). However, transcranial magnetic stimulation (TMS) studies perturbing SMA functioning across explicit timing tasks have generally reported null effects, thus failing to causally link SMA to explicit timing. The present study probed the involvement of SMA in both explicit and implicit timing tasks within a single experiment and using High-Definition transcranial Random Noise Stimulation (HD-tRNS), a previously less used technique in studies of the SMA. Participants performed two tasks that comprised the same stimulus presentation but differed in the received task instructions, which might or might not require explicit temporal judgments. Results showed a significant HD-tRNS-induced shift of perceived durations (i.e., overestimation) in the explicit timing task, whereas there was no modulation of implicit timing by HD-tRNS. Overall, these results provide initial non-invasive brain stimulation evidence on the contribution of the SMA to explicit and implicit timing tasks.
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Affiliation(s)
- M Capizzi
- Department of Experimental Psychology, University of Granada, Spain; Mind, Brain and Behavior Research Center (CIMCYC), University of Granada, Spain.
| | - A Visalli
- IRCCS San Camillo Hospital, Venice Lido, Italy
| | - M Wiener
- George Mason University, Fairfax, VA, USA
| | - G Mioni
- Department of General Psychology, University of Padova, Italy.
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3
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Tedeschi D, De Luca M, Granados Del Águila A, Gao Q, Ambrosio G, Capizzi M, Tan HH, Christianen PCM, Jagadish C, Polimeni A. Value and Anisotropy of the Electron and Hole Mass in Pure Wurtzite InP Nanowires. Nano Lett 2016; 16:6213-6221. [PMID: 27676609 DOI: 10.1021/acs.nanolett.6b02469] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effective mass of electrons and holes in semiconductors is pivotal in determining the dynamics of carriers and their confinement energy in nanostructured materials. Surprisingly, this quantity is still unknown in wurtzite (WZ) nanowires (NWs) made of III-V compounds (e.g., GaAs, InAs, GaP, InP), where the WZ phase has no bulk counterpart. Here, we investigate the magneto-optical properties of InP WZ NWs grown by selective-area epitaxy that provides perfectly ordered NWs featuring high-crystalline quality. The combined analysis of the energy of free exciton states and impurity levels under magnetic field (B up to 29 T) allows us to disentangle the dynamics of oppositely charged carriers from the Coulomb interaction and thus to determine the values of the electron and hole effective mass. By application of B⃗ along different crystallographic directions, we also assess the dependence of the transport properties with respect to the NW growth axis (namely, the WZ ĉ axis). The effective mass of electrons along ĉ is me∥ = (0.078 ± 0.002) m0 (m0 is the electron mass in vacuum) and perpendicular to ĉ is me⊥ = (0.093 ± 0.001) m0, resulting in a 20% mass anisotropy. Holes exhibit a much larger (∼320%) and opposite mass anisotropy with their effective mass along and perpendicular to ĉ equal to mh∥ = (0.81 ± 0.18) m0 and mh⊥ = (0.250 ± 0.016) m0, respectively. While no full consensus is found with current theoretical results on WZ InP, our findings show trends remarkably similar to the experimental data available in WZ bulk materials, such as InN, GaN, and ZnO.
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Affiliation(s)
- D Tedeschi
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - M De Luca
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - A Granados Del Águila
- High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands
| | - Q Gao
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - G Ambrosio
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - M Capizzi
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - H H Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - P C M Christianen
- High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands
| | - C Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - A Polimeni
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
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Di Trolio A, Alippi P, Bauer EM, Ciatto G, Chu MH, Varvaro G, Polimeni A, Capizzi M, Valentini M, Bobba F, Di Giorgio C, Amore Bonapasta A. Ferromagnetism and Conductivity in Hydrogen Irradiated Co-Doped ZnO Thin Films. ACS Appl Mater Interfaces 2016; 8:12925-12931. [PMID: 27123761 DOI: 10.1021/acsami.6b04203] [Citation(s) in RCA: 4] [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] [Indexed: 06/05/2023]
Abstract
Impressive changes in the transport and ferromagnetic properties of Co-doped ZnO thin films have been obtained by postgrowth hydrogen irradiation at temperatures of 400 °C. Hydrogen incorporation increases the saturation magnetization by one order of magnitude (up to ∼1.50 μB/Co) and increases the carrier density and mobility by about a factor of two. In addition to the magnetic characterization, the transport and structural properties of hydrogenated ZnO:Co have been investigated by Hall effect, local probe conductivity measurements, micro-Raman, and X-ray absorption spectroscopy. Particular care has been given to the detection of Co oxides and metal Co nanophases, whose influence on the increase in the transport and ferromagnetic properties can be excluded on the ground of the achieved results. The enhancement in ferromagnetism is directly related to the dose of H introduced in the samples. On the contrary, despite the shallow donor character of H atoms, the increase in carrier density n is not related to the H dose. These apparently contradictory effects of H are fully accounted for by a mechanism based on a theoretical model involving Co-VO (Co-O vacancy) pairs.
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Affiliation(s)
- A Di Trolio
- CNR-Istituto dei Sistemi Complessi, U.O.S. di Tor Vergata , Via del Fosso del Cavaliere 100, 00133 Roma, Italy
- Laboratori Nazionali di Frascati, INFN , Via E. Fermi 27, Frascati, RM 00044, Italy
| | - P Alippi
- CNR-Istituto di Struttura della Materia, Via Salaria Km. 29,300, 00015 Monterotondo, Scalo, Italy
| | - E M Bauer
- CNR-Istituto di Struttura della Materia, Via Salaria Km. 29,300, 00015 Monterotondo, Scalo, Italy
| | - G Ciatto
- Synchrotron Soleil, L'Orme des merisiers, Saint-Aubin, BP48, 91192 Gif-sur Yvette, Cedex, France
| | - M H Chu
- Synchrotron Soleil, L'Orme des merisiers, Saint-Aubin, BP48, 91192 Gif-sur Yvette, Cedex, France
| | - G Varvaro
- CNR-Istituto di Struttura della Materia, Via Salaria Km. 29,300, 00015 Monterotondo, Scalo, Italy
| | - A Polimeni
- Dipartimento di Fisica, Sapienza Universitá di Roma , P.le A. Moro 2, 00185 Roma, Italy
| | - M Capizzi
- Dipartimento di Fisica, Sapienza Universitá di Roma , P.le A. Moro 2, 00185 Roma, Italy
| | - M Valentini
- Dipartimento di Fisica, Sapienza Universitá di Roma , P.le A. Moro 2, 00185 Roma, Italy
- Casaccia Research Center, ENEA , via Anguillarese 301, 00060 Roma, Italy
| | - F Bobba
- Dipartimento di Fisica, Universitá di Salerno , Via Giovanni Paolo II, Fisciano, SA 84084, Italy
| | - C Di Giorgio
- Dipartimento di Fisica, Universitá di Salerno , Via Giovanni Paolo II, Fisciano, SA 84084, Italy
| | - A Amore Bonapasta
- CNR-Istituto di Struttura della Materia, Via Salaria Km. 29,300, 00015 Monterotondo, Scalo, Italy
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Tedeschi D, De Luca M, Fonseka HA, Gao Q, Mura F, Tan HH, Rubini S, Martelli F, Jagadish C, Capizzi M, Polimeni A. Long-Lived Hot Carriers in III-V Nanowires. Nano Lett 2016; 16:3085-93. [PMID: 27104870 DOI: 10.1021/acs.nanolett.6b00251] [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] [Indexed: 05/05/2023]
Abstract
Heat management mechanisms play a pivotal role in driving the design of nanowire (NW)-based devices. In particular, the rate at which charge carriers cool down after an external excitation is crucial for the efficiency of solar cells, lasers, and high-speed transistors. Here, we investigate the thermalization properties of photogenerated carriers by continuous-wave (cw) photoluminescence (PL) in InP and GaAs NWs. A quantitative analysis of the PL spectra recorded up to 310 K shows that carriers can thermalize at a temperature much higher than that of the lattice. We find that the mismatch between carrier and lattice temperature, ΔT, increases exponentially with lattice temperature and depends inversely on the NW diameter. ΔT is instead independent of other NW characteristics, such as crystal structure (wurtzite vs zincblende), chemical composition (InP vs GaAs), shape (tapered vs columnar NWs), and growth method (vapor-liquid-solid vs selective-area growth). Remarkably, carrier temperatures as high as 500 K are reached at the lattice temperature of 310 K in NWs with ∼70 nm diameter. While a population of nonequilibrium carriers, usually referred to as "hot carriers", is routinely generated by high-power laser pulses and detected by ultrafast spectroscopy, it is quite remarkable that it can be observed in cw PL measurements, when a steady-state population of carriers is established. Time-resolved PL measurements show that even in the thinnest NWs carriers have enough time (∼1 ns) after photoexcitation to interact with phonons and thus to release their excess energy. Nevertheless, the inability of carriers to reach a full thermal equilibrium with the lattice points to inhibited phonon emission primarily caused by the large surface-to-volume ratio of small diameter NWs.
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Affiliation(s)
- D Tedeschi
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - M De Luca
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - H A Fonseka
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - Q Gao
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - F Mura
- Dipartimento di Chimica and Sapienza Nanoscience & Nanotechnology Lab (SNN-LAB), Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - H H Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - S Rubini
- Istituto Officina dei Materiali CNR , Basovizza SS 14 km 163.5, 34149 Trieste, Italy
| | - F Martelli
- Istituto per la Microelettronica e i Microsistemi CNR , Via del fosso del cavaliere 100, 00133 Roma, Italy
| | - C Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia
| | - M Capizzi
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
| | - A Polimeni
- Dipartimento di Fisica, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
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6
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De Luca M, Polimeni A, Fonseka HA, Meaney AJ, Christianen PCM, Maan JC, Paiman S, Tan HH, Mura F, Jagadish C, Capizzi M. Magneto-optical properties of wurtzite-phase InP nanowires. Nano Lett 2014; 14:4250-4256. [PMID: 24972081 DOI: 10.1021/nl500870e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The possibility to grow in zincblende (ZB) and/or wurtzite (WZ) crystal phase widens the potential applications of semiconductor nanowires (NWs). This is particularly true in technologically relevant III-V compounds, such as GaAs, InAs, and InP, for which WZ is not available in bulk form. The WZ band structure of many III-V NWs has been widely studied. Yet, transport (that is, carrier effective mass) and spin (that is, carrier g-factor) properties are almost experimentally unknown. We address these issues in a well-characterized material: WZ indium phosphide. The value and anisotropy of the reduced mass (μ exc) and g-factor (g exc) of the band gap exciton are determined by photoluminescence measurements under intense magnetic fields (B, up to 28 T) applied along different crystallographic directions. μ exc is 14% greater in WZ NWs than in a ZB bulk reference and it is 6% greater in a plane containing the WZ ĉ axis than in a plane orthogonal to ĉ. The Zeeman splitting is markedly anisotropic with g exc = |ge| = 1.4 for B⊥ĉ (where ge is the electron g-factor) and g exc = |ge - gh,//| = 3.5 for B//ĉ (where gh,// is the hole g-factor). A noticeable B-induced circular dichroism of the emitted photons is found only for B//ĉ, as expected in WZ-phase materials.
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Affiliation(s)
- M De Luca
- Dipartimento di Fisica and CNISM, Sapienza Università di Roma , Piazzale A. Moro 2, 00185 Roma, Italy
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7
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Zampetti S, Spoletini M, Petrone A, Capizzi M, Arpi ML, Tiberti C, Di Pietro S, Bosi E, Pozzilli P, Giorgino F, Buzzetti R. Association of TCF7L2 gene variants with low GAD autoantibody titre in LADA subjects (NIRAD Study 5). Diabet Med 2010; 27:701-4. [PMID: 20546291 DOI: 10.1111/j.1464-5491.2010.02997.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIMS We previously demonstrated the presence of two different populations among adult-onset autoimmune diabetes (latent autoimmume diabetes of adults; LADA) having high or low titre of antibodies to glutamic acid decarboxylase (GADA). The transcription factor 7-like 2 (TCF7L2) gene has been recognized as the major gene associated with Type 2 diabetes. The aim of the present study was to evaluate whether the phenotypic heterogeneity of LADA based on GADA titre is associated with TCF7L2 polymorphisms. METHODS Two hundred and fifty patients identified as LADA, divided into two subgroups with low (< or = 32 arbitrary units) or high (> 32 units) GADA titre, 620 subjects with Type 2 diabetes [from the Non-Insulin Requiring Autoimmune Diabetes (NIRAD) study cohort of 5330 subjects] in addition to 551 consecutive cases of Type 1 diabetes and 545 normoglycaemic subjects were analysed for the rs12255372 and rs7903146 polymorphisms of the TCF7L2 gene using Taqman. RESULTS The genotype and allele distributions of the two polymorphisms revealed similar frequencies in subjects with low GADA titre and Type 2 diabetes. High GADA titre, Type 1 diabetes and controls also showed comparable frequencies. A significant increase of GT/TT genotypes of the rs12255372 single-nucleotide polymorphism (SNP) and CT/TT genotypes of the rs7903146 SNP was observed in low GADA titre and Type 2 diabetes compared with high GADA titre, Type 1 diabetes and controls (P < or = 0.04 for both comparisons). The risk alleles of both variants were increased in low GADA titre and Type 2 diabetes compared with high GADA titre, Type 1 diabetes and control subjects (P < 0.02 for all comparisons). CONCLUSIONS TCF7L2 common genetic variants of susceptibility are associated only with low GADA antibody titre in LADA patients.
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Affiliation(s)
- S Zampetti
- Department of Clinical Sciences, Sapienza University, Rome, Italy
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8
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Hantke K, Horst S, Chatterjee S, Klar PJ, Volz K, Stolz W, Rühle WW, Masia F, Pettinari G, Polimeni A, Capizzi M. Zero-phonon lines of nitrogen-cluster states in GaN x As 1-x : H identified by time-resolved photoluminescence. J Mater Sci 2008; 43:4344-4347. [PMID: 34341608 PMCID: PMC8319878 DOI: 10.1007/s10853-008-2643-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 04/09/2008] [Indexed: 06/13/2023]
Affiliation(s)
- K. Hantke
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
- Present Address: Max-Planck-Institute for Dynamics and Self-Organization, Bunsenstraße 10, 37073 Gottingen, Germany
| | - S. Horst
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - S. Chatterjee
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - P. J. Klar
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
- Present Address: Institute of Experimental Physics I, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany
| | - K. Volz
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - W. Stolz
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - W. W. Rühle
- Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany
| | - F. Masia
- CNISM and Dipartimento di Fisica, Sapienza Universitá di Roma, Piazzale A. Moro 2, 00185 Rome, Italy
| | - G. Pettinari
- CNISM and Dipartimento di Fisica, Sapienza Universitá di Roma, Piazzale A. Moro 2, 00185 Rome, Italy
| | - A. Polimeni
- CNISM and Dipartimento di Fisica, Sapienza Universitá di Roma, Piazzale A. Moro 2, 00185 Rome, Italy
| | - M. Capizzi
- CNISM and Dipartimento di Fisica, Sapienza Universitá di Roma, Piazzale A. Moro 2, 00185 Rome, Italy
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9
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Bisognin G, De Salvador D, Napolitani E, Berti M, Polimeni A, Capizzi M, Rubini S, Martelli F, Franciosi A. High-resolution X-ray diffractionin situstudy of very small complexes: the case of hydrogenated dilute nitrides. J Appl Crystallogr 2008. [DOI: 10.1107/s0021889807068094] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In this work it is demonstrated howin situhigh-resolution X-ray diffraction (HRXRD), performed during thermal annealing and employing a conventional laboratory source, can be used to obtain information on the evolution kinetics of very small complexes formed in an epitaxial layer. HRXRD allows the measurement of changes in the lattice parameter of the layer (i.e.the layer strain) with different annealing strategies (by linear temperature ramp or isothermal annealing). On the basis of these data and using an appropriate model, the dissolution energy values of the complexes can be extracted. The underlying idea is that every type of complex present in the layer gives a specific lattice strain which varies under annealing, allowing their evolution to be traced accurately. As an example, this methodology is applied to the study of N–H complexes formed in hydrogen-irradiated GaAs1−xNx/GaAs layers.
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10
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Spoletini M, Petrone A, Zampetti S, Capizzi M, Zavarella S, Osborn J, Foffi C, Tuccinardi D, Pozzilli P, Buzzetti R. Low-risk HLA genotype in Type 1 diabetes is associated with less destruction of pancreatic B-cells 12 months after diagnosis. Diabet Med 2007; 24:1487-90. [PMID: 17971177 DOI: 10.1111/j.1464-5491.2007.02292.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS The role of human leukocyte antigen (HLA) genes in the susceptibility to Type 1 diabetes (T1DM) is well known. However, we do not know whether the degree of pancreatic B-cell destruction depends on different HLA genetic risk. The aim of this study was to analyse the influence of DRB1* and DQB1* genes on the rate of pancreatic B-cell loss in a prospective series of 120 consecutive newly diagnosed T1DM subjects in the first 12 months after diagnosis. METHODS Patients were typed for HLA-DRB1* and DQB1* loci by a reverse line blot assay using an array of immobilized sequence-specific oligonucleotide probes. C-peptide, insulin requirement and glycated haemoglobin (HbA(1c)) were determined at diagnosis and every 3 months for 12 months. The variance of C-peptide as evidence of B-cell loss during follow-up was analysed using the general linear model for repeated-measures procedure. RESULTS Fasting C-peptide in T1DM subjects with low HLA genetic risk was significantly higher when compared with subjects with moderate or high HLA genetic risk from time of diagnosis up to 12 months (P = 0.007 and P = 0.0002, respectively). Nonetheless, the changes in C-peptide levels over a 12-month period did not differ significantly between T1DM subjects with different HLA genetic risks. CONCLUSIONS Low-risk HLA genotype in T1DM is associated with less destruction of pancreatic B-cells up to 12 months after diagnosis. These results are useful when designing trials for therapies aimed to prevent the progression of B-cell destruction in recent-onset T1DM.
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Affiliation(s)
- M Spoletini
- Endocrinology, Department of Clinical Science, Sapienza University, Rome, Italy
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11
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12
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Pettinari G, Polimeni A, Masia F, Trotta R, Felici M, Capizzi M, Niebling T, Stolz W, Klar PJ. Electron mass in dilute nitrides and its anomalous dependence on hydrostatic pressure. Phys Rev Lett 2007; 98:146402. [PMID: 17501294 DOI: 10.1103/physrevlett.98.146402] [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] [Received: 11/04/2006] [Indexed: 05/15/2023]
Abstract
The dependence of the electron mass on hydrostatic pressure P in N-diluted GaAs1-xNx (x=0.10% and 0.21%) is investigated by magnetophotoluminescence. Exceedingly large fluctuations (up to 60%/kbar) in the electron mass with increasing P are found. These originate from a pressure-driven tuning of the hybridization degree between the conduction band minimum and specific nitrogen-related states. Present results suggest a hierarchy between different nitrogen complexes as regards the extent of the perturbation these complexes exert on the electronic properties of the GaAs host.
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Affiliation(s)
- G Pettinari
- CNISM and Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma, Italy
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13
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Affiliation(s)
- G. A. Thomas
- a Bell Laboratories , Murray Hill , New Jersey , 07974 , U.S.A
| | - M. Capizzi
- a Bell Laboratories , Murray Hill , New Jersey , 07974 , U.S.A
- b Istituto di Fisica G. Marconi , Piazzale delle Scienze, 5, Rome , Italy
| | - F. Derosa
- a Bell Laboratories , Murray Hill , New Jersey , 07974 , U.S.A
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Lucarelli A, Lupi S, Ortolani M, Calvani P, Maselli P, Capizzi M, Giura P, Eisaki H, Kikugawa N, Fujita T, Fujita M, Yamada K. Phase diagram of La2-xSrxCuO4 probed in the infared: imprints of charge stripe excitations. Phys Rev Lett 2003; 90:037002. [PMID: 12570518 DOI: 10.1103/physrevlett.90.037002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2002] [Indexed: 05/24/2023]
Abstract
While there is increasing evidence for antiferromagnetic (AF) ordering in the Cu-O planes of high-T(c) superconductors, either static or fluctuating, there is no direct evidence so far for the charge stripes that should separate the AF domains. By investigating the optical response of La2-xSrxCuO4 for 0<or=x<or=0.26 and 30<or=T<or=295 K, we identify strong far infrared peaks whose energy, width, and intensity are consistent with a scenario of charge stripe dynamics in the Cu-O planes.
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Affiliation(s)
- A Lucarelli
- Coherentia-INFM and Dipartimento di Fisica, Università di Roma La Sapienza, Piazzale Aldo Moro 2, I-00185 Roma, Italy
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15
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Bonapasta AA, Filippone F, Giannozzi P, Capizzi M, Polimeni A. Structure and passivation effects of mono- and dihydrogen complexes in GaAsyN(1-y) alloys. Phys Rev Lett 2002; 89:216401. [PMID: 12443436 DOI: 10.1103/physrevlett.89.216401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2002] [Indexed: 05/24/2023]
Abstract
In GaAsyN(1-y), the presence of a few percent of N induces a large reduction of the GaAs band gap that vanishes upon hydrogenation. In the present Letter, the energetics of N-H complexes and their effects on the band structure of the GaAs0.97N0.03 alloy have been investigated by first-principles density functional methods. We find that monohydrogen N-H+ and dihydrogen N-H* 2 complexes are formed depending on doping. Moreover, only N-H* 2 complexes account for the neutralization of nitrogen effects. A model is proposed that clarifies the passivation mechanism of nitrogen by H.
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Affiliation(s)
- A Amore Bonapasta
- CNR-Istituto di Struttura della Materia (ISM), Via Salaria Km 29.5, CP 10, 00016 Monterotondo Stazione, Italy.
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16
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Petrone A, Giorgi G, Mesturino CA, Capizzi M, Cascino I, Nistico L, Osborn J, Di Mario U, Buzzetti R. Association of DRB1*04-DQB1*0301 haplotype and lack of association of two polymorphic sites at CTLA-4 gene with Hashimoto's thyroiditis in an Italian population. Thyroid 2001; 11:171-5. [PMID: 11288988 DOI: 10.1089/105072501300042901] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hashimoto's thyroiditis (HT) is an autoimmune disease resulting from a complex interaction between genetic and environmental factors. The genetic loci conferring susceptibility need to be still defined. The aim of the present study was to determine whether Cytotoxic T-Lymphocyte-Associated Antigen-4 (CTLA-4), HLA DRB1, and DQB1 genes were associated to HT in an Italian population. We evaluated the allele distribution of the following loci: CTLA-4 exon 1 A49G dimorphism, which resulted in an amino acidic exchange (Thr/Ala) in the leader peptide, CTLA-4 3' microsatellite, HLA DRB1 and DQB1 in 126 patients with HT and in 301 control subjects from an Italian population (Lazio region). CTLA-4 exon 1 A49G dimorphism was typed by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP); CTLA-4 3' microsatellite alleles were defined using a fluorescence-based method. HLA DRB1 and DQB1 alleles were typed using a SSO reverse line blot method and a probeless procedure based on allele group-specific amplification followed by DNA heteroduplex analysis, respectively. Data were initially analyzed by chi2 test or Fisher's exact test. Multiple logistic regression analysis was then applied on factors with significant crude odds ratios and on CTLA-4 exon 1 A49G dimorphism to investigate their independent effects. The two polymorphic sites at CTLA-4 gene did not increase the risk for HT. The distribution of HLA DRB1 and DQB1 alleles did not show any significant difference between patients and controls, however, the DRB1*04-DQB1*0301 haplotype was significantly increased in patients. Other factors that increase the risk of disease were gender and age. Females showed approximately 18 times more risk than males; subjects older than 50 years had an odds ratio of 6.6. These data suggest that these two polymorphic sites at CTLA-4 do not play a major role in the susceptibility of the disease in an Italian population while female gender, age over 50 years, HLA DRB1*04-DQB1*0301 haplotype increase the risk of developing HT.
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Affiliation(s)
- A Petrone
- Dipartimento di Scienze Cliniche, Università di Roma La Sapienza, Rome, Italy
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17
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Orani D, Polimeni A, Patanè A, Capizzi M, Martelli F, D'Andrea A, Tomassini N, Borri P, Gurioli M, Colocci M. Binding Energy and Lifetime of Excitons in InxGa1—xAs/GaAs Quantum Wells. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/1521-396x(199711)164:1<107::aid-pssa107>3.0.co;2-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Patanè A, Grassi Alessi M, Intonti F, Polimeni A, Capizzi M, Martelli F, Geddo M, Bosacchi A, Franchi S. Evolution of the Optical Properties of InAs/GaAs Quantum Dots for Increasing InAs Coverages. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/1521-396x(199711)164:1<493::aid-pssa493>3.0.co;2-d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Polimeni A, Patanè A, Alessi MG, Capizzi M, Martelli F, Bosacchi A, Franchi S. Stokes shift in quantum wells: Trapping versus thermalization. Phys Rev B Condens Matter 1996; 54:16389-16392. [PMID: 9985751 DOI: 10.1103/physrevb.54.16389] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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20
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Martelli F, Polimeni A, Patanè A, Capizzi M, Borri P, Gurioli M, Colocci M, Bosacchi A, Franchi S. Exciton localization by potential fluctuations at the interface of InGaAs/GaAs quantum wells. Phys Rev B Condens Matter 1996; 53:7421-7425. [PMID: 9982190 DOI: 10.1103/physrevb.53.7421] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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21
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Polimeni A, Patanè A, Capizzi M, Martelli F, Nasi L, Salviati G. Self-aggregation of quantum dots for very thin InAs layers grown on GaAs. Phys Rev B Condens Matter 1996; 53:R4213-R4216. [PMID: 9984072 DOI: 10.1103/physrevb.53.r4213] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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22
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Calvani P, Capizzi M, Lupi S, Maselli P, Paolone A, Roy P. Polaronic optical absorption in electron-doped and hole-doped cuprates. Phys Rev B Condens Matter 1996; 53:2756-2766. [PMID: 9983786 DOI: 10.1103/physrevb.53.2756] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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23
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Capizzi M. Theory of hydrogen-decorated gallium vacancies in GaAs and of their radiative complexes. Phys Rev B Condens Matter 1995; 52:11044-11051. [PMID: 9980202 DOI: 10.1103/physrevb.52.11044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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24
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Patanè A, Polimeni A, Capizzi M, Martelli F. Linewidth analysis of the photoluminescence of InxGa1-xAs/GaAs quantum wells (x=0.09, 0.18, 1.0). Phys Rev B Condens Matter 1995; 52:2784-2788. [PMID: 9981348 DOI: 10.1103/physrevb.52.2784] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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25
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Martelli F, Capizzi M, Frova A, Polimeni A, Sarto F, Bruni MR, Simeone MG. Exciton confinement in GaAs quantum barriers. Phys Rev B Condens Matter 1993; 48:1643-1646. [PMID: 10008525 DOI: 10.1103/physrevb.48.1643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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26
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Capizzi M, Emiliani V, Frova A, Sarto F, Sacks RN. Hydrogen-donor-induced free-exciton splitting in GaAs. Phys Rev B Condens Matter 1993; 47:12563-12567. [PMID: 10005450 DOI: 10.1103/physrevb.47.12563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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27
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Calvani P, Capizzi M, Donato F, Lupi S, Maselli P, Peschiaroli D. Observation of a midinfrared band in SrTiO3-y. Phys Rev B Condens Matter 1993; 47:8917-8922. [PMID: 10004938 DOI: 10.1103/physrevb.47.8917] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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28
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Capizzi M, Emiliani V, Frova A, Sarto F. Effect of ion-gun hydrogenation on the photoluminescence of degenerate n-type GaAs:Si. Phys Rev B Condens Matter 1993; 47:4301-4306. [PMID: 10006576 DOI: 10.1103/physrevb.47.4301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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29
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Lupi S, Calvani P, Capizzi M, Maselli P, Sadowski W, Walker E. Infrared optical conductivity of the Nd-Ce-Cu-O system. Phys Rev B Condens Matter 1992; 45:12470-12477. [PMID: 10001284 DOI: 10.1103/physrevb.45.12470] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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30
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Bonapasta AA, Giannozzi P, Capizzi M. Silicon-hydrogen-acceptor complexes in crystalline silicon. Phys Rev B Condens Matter 1992; 45:11744-11748. [PMID: 10001189 DOI: 10.1103/physrevb.45.11744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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31
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Cannelli G, Cantelli R, Capizzi M, Coluzza C, Cordero F, Frova A. Reorientation of the B-H complex in silicon by anelastic relaxation experiments. Phys Rev B Condens Matter 1991; 44:11486-11489. [PMID: 9999273 DOI: 10.1103/physrevb.44.11486] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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32
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Giannozzi P, Capizzi M. Structural and vibrational properties of the Si-H-Al complex in crystalline silicon. Phys Rev B Condens Matter 1991; 44:3399-3402. [PMID: 9999952 DOI: 10.1103/physrevb.44.3399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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33
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Calvani P, Capizzi M, Lupi S, Maselli P, Virgilio M, Fabrizi A, Pompa M, Sadowski W, Walker E. Normal state reflectance of NdCeCuO single crystals. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0022-5088(90)90483-z] [Citation(s) in RCA: 4] [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: 10/27/2022]
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34
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Bonapasta AA, Giannozzi P, Capizzi M. Vibrational frequencies of Si-P-H complexes in crystalline silicon: A theoretical study. Phys Rev B Condens Matter 1990; 42:3175-3178. [PMID: 9995818 DOI: 10.1103/physrevb.42.3175] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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35
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Cooper SL, Thomas GA, Orenstein J, Rapkine DH, Capizzi M, Timusk T, Millis AJ, Schneemeyer LF, Waszczak JV. Properties of optical features in YBa2Cu3O7- delta. Phys Rev B Condens Matter 1989; 40:11358-11361. [PMID: 9991717 DOI: 10.1103/physrevb.40.11358] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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36
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Lapiccirella A, Tomassini N, Capizzi M. Si-P-H complexes in crystal silicon: A theoretical study. Phys Rev B Condens Matter 1989; 39:12630-12632. [PMID: 9948130 DOI: 10.1103/physrevb.39.12630] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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37
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Thomas GA, Orenstein J, Rapkine DH, Capizzi M, Millis AJ, Bhatt RN, Schneemeyer LF, Waszczak JV. Ba2YCu3O7- delta : Electrodynamics of crystals with high reflectivity. Phys Rev Lett 1988; 61:1313-1316. [PMID: 10038760 DOI: 10.1103/physrevlett.61.1313] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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38
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Lapiccirella A, Tomassini N, Capizzi M. Hydrogen passivation of shallow acceptors in c-Si: An ab initio approach. Phys Rev B Condens Matter 1987; 36:6228-6230. [PMID: 9942325 DOI: 10.1103/physrevb.36.6228] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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39
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Ng HK, Capizzi M, Thomas GA, Bhatt RN, Gossard AC. Short-length-scale conductivity enhancement in a superlattice. Phys Rev B Condens Matter 1986; 33:7329-7331. [PMID: 9938084 DOI: 10.1103/physrevb.33.7329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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40
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Dedè A, Capizzi M. [Familial studies of 2 cases of trisomy 4p]. Minerva Pediatr 1979; 31:1281-4. [PMID: 537593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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41
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Cavagna G, Locati G, Capizzi M. [Study of the metabolism of catecholamines in experimental chronic nitroglycol poisoning. I. The catecholamine content of the myocardium]. Med Lav 1968; 59:772-7. [PMID: 5729813] [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: 01/16/2023]
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