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Calleja F, Ondiviela B, Puente A, Juanes JA. Can seedlings' physiological information improve vegetation distribution predictions at local scales? Biol Invasions 2020. [DOI: 10.1007/s10530-020-02266-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Navarro JJ, Pisarra M, Nieto-Ortega B, Villalva J, Ayani CG, Díaz C, Calleja F, Miranda R, Martín F, Pérez EM, Vázquez de Parga AL. Graphene catalyzes the reversible formation of a C-C bond between two molecules. Sci Adv 2018; 4:eaau9366. [PMID: 30555920 PMCID: PMC6294602 DOI: 10.1126/sciadv.aau9366] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/14/2018] [Indexed: 06/09/2023]
Abstract
Carbon deposits are well-known inhibitors of transition metal catalysts. In contrast to this undesirable behavior, here we show that epitaxial graphene grown on Ru(0001) promotes the reversible formation of a C-C bond between -CH2CN and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ). The catalytic role of graphene is multifaceted: First, it allows for an efficient charge transfer between the surface and the reactants, thus favoring changes in carbon hybridization; second, it holds the reactants in place and makes them reactive. The reaction is fully reversible by injecting electrons with an STM tip on the empty molecular orbitals of the product. The making and breaking of the C-C bond is accompanied by the switching off and on of a Kondo resonance, so that the system can be viewed as a reversible magnetic switch controlled by a chemical reaction.
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Affiliation(s)
- J. J. Navarro
- Dep. Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - M. Pisarra
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
- Dep. Química Módulo 13, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - B. Nieto-Ortega
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - J. Villalva
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - C. G. Ayani
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - C. Díaz
- Dep. Química Módulo 13, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Institute for Advanced Research in Chemistry (IAdChem), Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Cantoblanco, 28049 Madrid, Spain
| | - F. Calleja
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - R. Miranda
- Dep. Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Cantoblanco, 28049 Madrid, Spain
| | - F. Martín
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
- Dep. Química Módulo 13, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Cantoblanco, 28049 Madrid, Spain
| | - E. M. Pérez
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
| | - A. L. Vázquez de Parga
- Dep. Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- IMDEA Nanociencia, Calle Faraday 9, Cantoblanco, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Cantoblanco, 28049 Madrid, Spain
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Maccariello D, Al Taleb A, Calleja F, Vázquez de Parga AL, Perna P, Camarero J, Gnecco E, Farías D, Miranda R. Observation of Localized Vibrational Modes of Graphene Nanodomes by Inelastic Atom Scattering. Nano Lett 2016; 16:2-7. [PMID: 26630565 DOI: 10.1021/acs.nanolett.5b02887] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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
Inelastic helium atom scattering (HAS) is suitable to determine low-energy (few meV) vibrations spatially localized on structures in the nanometer range. This is illustrated for the nanodomes that appear often on graphene (Gr) epitaxially grown on single crystal metal surfaces. The nature of the inelastic losses observed in Gr/Ru(0001) and Gr/Cu/Ru(0001) has been clarified by intercalation of Cu below the Gr monolayer, which decouples the Gr layer from the Ru substrate and changes substantially the out-of-plane, flexural phonon dispersion of epitaxial Gr, while maintaining the nanodomes and their localized vibrations. He diffraction proves that the Cu-intercalated Gr layer is well ordered structurally, while scanning tunneling microscopy reveals the persistence of the (slightly modified) periodic array of Gr nanodomes. A simple model explains the order of magnitude of the energy losses associated with the Gr nanodomes and their size dependence. The dispersionless, low-energy phonon branches may radically alter the transport of heat in intercalated Gr.
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Affiliation(s)
- D Maccariello
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | | | - F Calleja
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | - A L Vázquez de Parga
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | - P Perna
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | - J Camarero
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | - E Gnecco
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | | | - R Miranda
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
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Dubout Q, Donati F, Wäckerlin C, Calleja F, Etzkorn M, Lehnert A, Claude L, Gambardella P, Brune H. Controlling the spin of co atoms on pt(111) by hydrogen adsorption. Phys Rev Lett 2015; 114:106807. [PMID: 25815958 DOI: 10.1103/physrevlett.114.106807] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Indexed: 06/04/2023]
Abstract
We investigate the effect of H adsorption on the magnetic properties of individual Co atoms on Pt(111) with scanning tunneling microscopy. For pristine Co atoms, we detect no inelastic features in the tunnel spectra. Conversely, CoH and CoH2 show a number of low-energy vibrational features in their differential conductance identified by isotope substitution. Only the fcc-adsorbed species present conductance steps of magnetic origin, with a field splitting identifying their effective spin as Seff=2 for CoH and 3/2 for CoH2. The exposure to H2 and desorption through tunnel electrons allow the reversible control of the spin in half-integer steps. Because of the presence of the surface, the hydrogen-induced spin increase is opposite to the spin sequence of CoHn molecules in the gas phase.
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Affiliation(s)
- Q Dubout
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - F Donati
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - C Wäckerlin
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - F Calleja
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, E-28049 Madrid, Spain
| | - M Etzkorn
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - A Lehnert
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - L Claude
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
| | - P Gambardella
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
- Department of Materials, ETH Zürich, Hönggerbergring 64, CH-8093 Zürich, Switzerland
| | - H Brune
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland
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Avendaño-Herrera R, Maldonado JP, Tapia-Cammas D, Feijóo CG, Calleja F, Toranzo AE. PCR protocol for detection of Vibrio ordalii by amplification of the vohB (hemolysin) gene. Dis Aquat Organ 2014; 107:223-234. [PMID: 24429473 DOI: 10.3354/dao02684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Vibrio ordalii is the causative agent of atypical vibriosis and has the potential to cause severe losses in salmonid aquaculture. To prevent and control outbreaks, a rapid, reproducible, sensitive, and effective diagnostic method is needed. We evaluated a new conventional polymerase chain reaction (PCR) and real-time PCR (qPCR) protocol using a primer set (VohB_Fw-VohB_Rv) designed to amplify a 112 bp fragment flanking the vohB gene (coding for hemolysin production), against 24 V. ordalii strains isolated from different fish species, the V. ordalii type strain, and 42 representative related and unrelated bacterial species. The primer set was species-specific, recognizing all V. ordalii strains evaluated, with no cross-reaction with the other bacterial species. A sensitivity of 103 copies of the vohB gene was obtained with a standard curve. When the VohB_Fw-VohB_Rv qPCR protocol was applied to Atlantic salmon seeded tissues (kidney, liver, spleen, and muscle), the detection limit ranged from 5.27 × 102 to 4.13 × 103 V. ordalii CFU ml-1, i.e. 62 to 145 copies of the vohB gene, using the previously calculated standard curve. The conventional PCR also detected V. ordalii, but the total reaction time was 1 h longer. When the qPCR protocol was applied to naturally infected cage-cultured Atlantic salmon samples, 5 of 8 fish tested positive for V. ordalii, but only one of them was diagnosed as positive by direct cultivation on agar. We conclude that the PCR protocol evaluated is fast, specific, and sensitive enough to detect V. ordalii in infected tissues and is an important tool for secure diagnosis of atypical vibriosis, and is therefore helpful for the control of the disease through the prompt detection within fish populations.
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Affiliation(s)
- R Avendaño-Herrera
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile
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Donati F, Dubout Q, Autès G, Patthey F, Calleja F, Gambardella P, Yazyev OV, Brune H. Magnetic moment and anisotropy of individual Co atoms on graphene. Phys Rev Lett 2013; 111:236801. [PMID: 24476294 DOI: 10.1103/physrevlett.111.236801] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Indexed: 06/03/2023]
Abstract
We report on the magnetic properties of single Co atoms on graphene on Pt(111). By means of scanning tunneling microscopy spin-excitation spectroscopy, we infer a magnetic anisotropy of K=-8.1 meV with out-of-plane hard axis and a magnetic moment of 2.2μ(B). Co adsorbs on the sixfold graphene hollow site. Upon hydrogen adsorption, three differently hydrogenated species are identified. Their magnetic properties are very different from those of clean Co. Ab initio calculations support our results and reveal that the large magnetic anisotropy stems from strong ligand field effects due to the interaction between Co and graphene orbitals.
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Affiliation(s)
- F Donati
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - Q Dubout
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - G Autès
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - F Patthey
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
| | - F Calleja
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland and Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, E-28049 Madrid, Spain
| | - P Gambardella
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland and Catalan Institute of Nanoscience and Nanotechnology (ICN2), UAB Campus, E-08193 Barcelona, Spain and Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - O V Yazyev
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - H Brune
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015, Switzerland
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Bernal-Lopez MR, Llorente-Cortes V, Calleja F, Lopez-Carmona D, Mayas MD, Gomez-Huelgas R, Badimon L, Tinahones FJ. Effect of different degrees of impaired glucose metabolism on the expression of inflammatory markers in monocytes of patients with atherosclerosis. Acta Diabetol 2013; 50:553-62. [PMID: 21997325 DOI: 10.1007/s00592-011-0337-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [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] [Received: 08/05/2011] [Accepted: 09/26/2011] [Indexed: 12/11/2022]
Abstract
Inflammatory markers are elevated in type 2 diabetic patients (DP) and may predict the development of type 2 diabetes. Our aims were to analyze differences in the expression of inflammatory and immunological molecules between DP and healthy subjects and to investigate whether glycemic control might prevent the overexpression of inflammatory markers in DP. Twenty-two DP with advanced atherosclerosis and eight healthy blood donors were included. DP were classified as well (HbA1c ≤ 6.5) or poorly controlled (HbA1c > 6.5). In "in vitro" studies, monocytes were exposed to low (5.5 mM) or high glucose (26 mM) concentrations in the absence or presence of insulin. Expression profiling of 14 inflammatory genes was analyzed using TLDA analysis. "In vivo" results show that monocytes from DP had increased levels of monocyte chemoattractant protein (MCP-1) and interleukin 6 (IL6) and lower levels of Toll-like receptor 2 (TLR2) mRNA than healthy subjects. Well-controlled DP had lower levels of IL-6 than poorly controlled DP, suggesting that glycemic control may prevent IL6 mRNA alterations associated with diabetes. "In vitro" results demonstrate that glucose directly and significantly induced MCP-1 and IL6 and reduced TLR2 mRNA expression. Insulin at high dose (100 IU/ml) dramatically enhanced the upregulatory effects of glucose on MCP-1 and IL-6 and reduced per se TLR2 mRNA expression. MCP-1, IL-6 and TLR2 are key inflammatory players altered in monocytes from type 2 DP. Both hyperinsulinemia and hyperglycemia contribute to alter the expression of these genes. The glycemic control only significantly prevented IL6 overexpression in this group of patients.
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Affiliation(s)
- M R Bernal-Lopez
- Biomedical Research Laboratory, Endocrinology Department, Hospital Virgen de la Victoria, Malaga, Spain
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8
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Borca B, Calleja F, Hinarejos JJ, Vázquez de Parga AL, Miranda R. Reactivity of periodically rippled graphene grown on Ru(0001). J Phys Condens Matter 2009; 21:134002. [PMID: 21817477 DOI: 10.1088/0953-8984/21/13/134002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report here the reactivity of epitaxial graphene islands and complete monolayers on Ru(0001) towards molecular oxygen and air. The graphene is prepared by thermal decomposition of ethylene molecules pre-adsorbed on an Ru(0001) surface in an ultra-high vacuum chamber. The graphene layer presents a periodically rippled structure that is dictated by the misfit between graphene and Ru(0001) lattice parameters. The periodic ripples produce spatial charge redistribution in the graphene and modifies its electronic structure around the Fermi level. In order to investigate the reactivity of graphene we expose graphene islands to a partial pressure of oxygen and following the evolution of the surface by STM during the exposure. For the exposure to air we removed the sample from the UHV chamber and we re-introduce it after several hours, taking STM images before and after. The surface areas not covered by the graphene islands present a dramatic change but the graphene structure, even the borders of the islands, remain intact. In the case of a complete graphene monolayer the exposure to oxygen or to air does not affect or destroy the rippled structure of the graphene monolayer.
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Affiliation(s)
- B Borca
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
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Bernal-Lopez M, Mayas M, Porras J, Calleja F, Tinahones F, Gomez-Huelgas R. ATHEROMATOUS PLAQUE FROM HUMAN POPLITEUS ARTERY: POTENTIAL INVOLVEMENT OF THE CANNABINOID SYSTEM. ATHEROSCLEROSIS SUPP 2008. [DOI: 10.1016/s1567-5688(08)71056-0] [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: 10/22/2022]
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Vázquez de Parga AL, Calleja F, Borca B, Passeggi MCG, Hinarejos JJ, Guinea F, Miranda R. Periodically rippled graphene: growth and spatially resolved electronic structure. Phys Rev Lett 2008; 100:056807. [PMID: 18352412 DOI: 10.1103/physrevlett.100.056807] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Indexed: 05/26/2023]
Abstract
We grow epitaxial graphene monolayers on Ru(0001) that cover uniformly the substrate over lateral distances larger than several microns. The weakly coupled graphene monolayer is periodically rippled and it shows charge inhomogeneities in the charge distribution. Real space measurements by scanning tunneling spectroscopy reveal the existence of electron pockets at the higher parts of the ripples, as predicted by a simple theoretical model. We also visualize the geometric and electronic structure of edges of graphene nanoislands.
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Affiliation(s)
- A L Vázquez de Parga
- Departamento de Física de la Materia Condensada e Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Calleja F, Passeggi MCG, Hinarejos JJ, de Parga ALV, Miranda R. Real-space direct visualization of the layer-dependent roughening transition in nanometer-thick Pb films. Phys Rev Lett 2006; 97:186104. [PMID: 17155558 DOI: 10.1103/physrevlett.97.186104] [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: 08/07/2006] [Indexed: 05/12/2023]
Abstract
By means of variable-temperature scanning tunneling microscopy and spectroscopy we studied the thickness-dependent roughening temperature of Pb films grown on Cu(111), whose electronic structure and total energy is controlled by quantum well states created by the spatial confinement of electrons. Large scale STM images are employed to quantify the layer population, i.e., the fraction of the surface area covered by different Pb thicknesses, directly in the real space as a function of temperature. The roughening temperature oscillates repeatedly with bilayer periodicity plus a longer beating period, mirroring the thickness dependence of surface energy calculations. Conditions have been found to stabilize at 300 K Pb films of particular magic thicknesses, atomically flat over microns.
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Affiliation(s)
- F Calleja
- Departamento de Física de la Materia Condensada e Instituto de Ciencia de Materiales N. Cabrera, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Corriol C, Calleja F, Arnau A, Hinarejos J, Vázquez de Parga A, Hofer W, Miranda R. Role of surface geometry and electronic structure in STM images of O/Ru(0001). Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.02.026] [Citation(s) in RCA: 18] [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: 10/25/2022]
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13
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Calleja F, Arnau A, Hinarejos JJ, Vázquez de Parga AL, Hofer WA, Echenique PM, Miranda R. Contrast reversal and shape changes of atomic adsorbates measured with scanning tunneling microscopy. Phys Rev Lett 2004; 92:206101. [PMID: 15169369 DOI: 10.1103/physrevlett.92.206101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Revised: 02/12/2004] [Indexed: 05/24/2023]
Abstract
Systematic, quantitative comparisons between scanning tunneling microscopy (STM) experiments and first principles simulations of O(2 x 2)/Ru(0001) have been performed. The shape of the atomic adsorbates in the images depends strongly on the tunneling resistance and changes reversibly from circular (high resistance) to triangular (low resistance). In addition, after adsorption of oxygen on the STM tip we observe a contrast reversal on the surface, confirmed by extensive numerical simulations.
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Affiliation(s)
- F Calleja
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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14
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Affiliation(s)
- C Sierra
- Department of Pediatric Gastroenterology, Women and Children's Hospital, Málaga, Spain
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15
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Calleja F, Martinez JL, Gonzales De Vega N. Mitral valve surgery through right thoracotomy. J Cardiovasc Surg (Torino) 1996; 37:49-52. [PMID: 10064348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
UNLABELLED Two years ago we had, for technical reason to resuscitate right thoracotomy (RT) to approach the mitral valve. Since then we have used it in 23 patients. 18 of them had had at least one operation through a medium sternotomy. In 5 cases the right approach was electively used, as first choice to repair or replace the mitral valve. Intracardiac surgery was performed routinely with moderate hypothermia and controlled ventricular fibrillation with the aorta unclamped. Only in one case, an unexpected aortic incompetence forced us to cross-clamp the aorta and replace the valve using crystalloid cold cardioplegia. 14 patients underwent mitral valve replacement. In 5 cases a leaking mitral prosthesis was successfully reattached and in 4 cases the native valve was repaired. 2 patients died (9%) for reasons unrelated to the technique. We did not have any case of air embolism. CONCLUSION 1) RT is very useful to approach the mitral valve, specially in patients who previously had: a) several sternotomies, b) postoperative mediastinitis, specially if treated by omentoplasty, c) coronary artery bypass; 2) the good view to the mitral valve obtained with the aorta unclamped, make us think if the mitral repair should elective done through this approach.
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Affiliation(s)
- F Calleja
- Department of Cardiovascular Surgery, Hospital Materno-Infantil Arroyo de los Angeles, Malaga, España
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Chacón-Quevedo A, Eguaras MG, Calleja F, Garcia MA, Roman M, Casares J, Muñoz I, Concha M. Comparative evaluation of pentoxifylline, buflomedil, and nifedipine in the treatment of intermittent claudication of the lower limbs. Angiology 1994; 45:647-53. [PMID: 8024164 DOI: 10.1177/000331979404500708] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the light of the current controversy surrounding the use of hemorheologic and vasodilator drugs in the treatment of peripheral arteriosclerosis, a comparative study was designed in order to evaluate the efficacy of pentoxifylline, buflomedil, and nifedipine in 45 patients with peripheral arterial disease (Fontaine stage II). The patients in this prospective randomized study were divided into three groups: 15 patients received pentoxifylline treatment (1,200 mg/day), 15 were treated with buflomedil (600 mg/day), and 15 with nifedipine (60 mg/day). Response to treatment was assessed at the start of the study and after forty-five and ninety days, by clinical examination, Doppler test, strain test, and digital occlusion plethysmography using a strain gauge ring. Pentoxifylline was significantly more effective (P < 0.05) than buflomedil and nifedipine at ninety days in improving walking performance, resting toe pressure, resting and postexercise ankle/brachial pressure ratio, and basal/postischemic toe-pulse ratio. Significant differences within groups were also noted for initial claudication, toe peak-flow time, pulse reappearance time (PRT/2), and maximum postischemic flow time, together with significant intergroup variables. In conclusion, pentoxifylline proved more effective than the other drugs tested in: 1. improving distal pressure and resting microcirculatory blood flow; 2. increasing postexercise distal flow, ratios, and pressures and enabling faster recuperation of basal pulse rates; 3. increasing initial claudication distance in the strain test within the test group and achieving a greater absolute subjective claudication distance than that obtained using the other treatments.
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Calleja F, García Jiménez MA, Roman M, Canis M, Concha M. Operative management of a persistent sciatic artery aneurysm. Cardiovasc Surg 1994; 2:281-3. [PMID: 8049963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A 60-year-old man with a painful pulsatile mass approximately 8 cm in diameter in the right buttock was diagnosed using angiography as having a complete unilateral persistent sciatic artery aneurysm. The lesion was obliterated by proximal and distal ligation of the sciatic artery at the pelvis and the adductor magnus canal. A femoropopliteal bypass was performed with inverted autologous saphenous vein. The residual mass was subsequently drained because of persistent symptoms. Postoperative recovery was good.
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Affiliation(s)
- F Calleja
- Department of Cardiovascular Surgery, Reina Sofía Hospital, Cordoba University, Spain
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18
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Eguaras MG, Garcia Jimenez MA, Calleja F, Roman M, Casares J, Fresneda P, Concha M. Early open mitral commissurotomy: long-term results. J Thorac Cardiovasc Surg 1993; 106:421-6. [PMID: 8361182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It has frequently been suggested that early mitral commissurotomy could improve long-term results in patients with severe mitral stenosis. However, the real advantages of this procedure have yet to be demonstrated. To evaluate this hypothesis, we retrospectively studied 397 patients who underwent operation for mitral stenosis in our unit between 1978 and 1988. Forty of these patients (group I) fulfilled the criteria for early mitral commissurotomy: being young (average age 33 years), being asymptomatic or showing few symptoms, and being in sinus rhythm. The remaining 357 patients who underwent operation during the same period of time served as control (group II). Mitral valve replacement (p < 0.05) and associated tricuspid annuloplasty (p < 0.05) occurred less frequently in patients from group I than it did in patients from group II. Survival after 11 years for patients with early mitral commissurotomy was 100%, 90% of whom were in functional class I, were in sinus rhythm, and were receiving no medication whatsoever. Ninety-six percent of these patients were free of complications after 11 years, compared with 73% of patients in group II (p < 0.05). In our opinion, these results support the use of early mitral commissurotomy for young patients in sinus rhythm, who are symptom free, who are and who have a mitral valve area is 1.3 cm2 or less.
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Affiliation(s)
- M G Eguaras
- Hospital Reina Sofia, Servicio de Cirugia Cardiovascular, Cordoba, Spain
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19
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Arizón JM, Anguita M, Vallés F, Montero A, Sancho M, López-Rubio F, Latre JM, Calleja F, Casares J, Román M. Preliminary experience with deflazacort, a new synthetic steroid with fewer undesirable side effects, in heart transplant patients. J Heart Lung Transplant 1993; 12:445-8; discussion 448-9. [PMID: 8329416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Prednisone is widely used by most heart transplant units, despite its frequent side effects. Deflazacort, a new oral synthetic steroid with fewer side effects, has not been studied in heart transplant patients. Our initial experience with 26 heart transplant patients in whom prednisone was replaced by deflazacort at 11 +/- 11 months after transplantation is reported. After the switch to deflazacort, a significant decreased was noted in glycemia, total cholesterol, and LDL-cholesterol (p < 0.001). No difference was noted in severity or frequency of rejection and infection between patients being treated with deflazacort and another 26 patients who continued to be treated with prednisone over a comparable period of time after transplantation.
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Affiliation(s)
- J M Arizón
- Heart Transplantation Unit, Hospital Reina Sofía, University of Córdoba, Spain
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20
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Concha M, Montero A, Arizón JM, Anguita M, Vallés F, Calleja F, Román M, Casares J, Jiménez MA, Alvarez F. [Orthotopic heart transplant. Study of early morbimortality (< or = 30 days). Experience at the Reina Sofía Hospital (Córdoba)]. Rev Esp Cardiol 1993; 46:93-100. [PMID: 8451489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
From may 1986 to december 1991, we have performed 90 heart transplantation in the Hospital "Reina Sofía" from Córdoba. In the present study we analyze the early morbidity and mortality in a retrospective study on complications and factors determining its incidence. Seventy patients were male (86%) and 13 female (14%). Age ranged from 12 and 65 years. The 31% of patients needed in pharmacological support before transplantation, 15 of them were operated in a emergency situation because of cardiogenic shock. The pulmonary resistances oscillated between 0.5 and 8.7 units/m2 (Wood) (mean 2.5 +/- 1.4 units/m2). The mean time of ischaemia was 136 +/- 38 minutes (range 5-255 min). Hospital mortality (< or = 30 days) was 8.8% (8/90). No predictive factors from donor and recipient were found. Three main influences on complications were analyzed: a) influence of myocardial temperature, b) role of hematic cardioplegia, and c) usefulness of Aprotinin. Eighteen patients (20%) developed severe bradyarrhythmia needing a pacemaker in the post-operative period. We found a significant relationship with myocardial temperature (4.3 +/- 2.1 vs 6.2 +/- 2.6; p < 0.05) and transport solution temperature (5.8 +/- 2.3 vs 7.3 +/- 1.9; p < 0.05). No significant influence was found on the time of ischaemia, previous heart disease, previous treatment with Amiodarona, clinical condition, etc.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Concha
- Servicio de Cirugía Cardiovascular, Hospital Universitario Reina Sofía, Córdoba
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21
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Montero JA, Anguita M, Concha M, Villarrubia A, García J, Arizón JM, Calleja F, Vallés F. Pacing requirements after orthotopic heart transplantation: incidence and related factors. J Heart Lung Transplant 1992; 11:799-802. [PMID: 1498147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To assess the incidence of severe bradyarrhythmia and pacing requirements after orthotopic heart transplantation, as well as the possible causal mechanisms, we have reviewed our experience on 52 consecutive transplant patients. The overall incidence of bradyarrhythmia requiring pacing for at least 24 hours after transplantation was 27% (14 patients). The conditions of three of them required pacing for less than 1 week; the conditions of the other 11 patients (21%) required pacing for more than 1 week. Normal sinus rhythm resumed in all but four patients within 3 weeks; a permanent pacemaker was implanted in these four patients (7.6% of all 52 patients and 28% of patients requiring temporary pacing). Late complete heart block associated with acute rejection developed in two patients whose conditions required implantation of a permanent pacemaker. The age and sex of the recipient and donor were similar for patients with or without bradyarrhythmia. The percentage of patients with or without bradyarrhythmias taking amiodarone before transplantation (57% and 46%, respectively), total ischemic time (133 +/- 33 and 123 +/- 37 minutes, respectively), and cardiopulmonary bypass time (117 +/- 17 and 132 +/- 65 minutes, respectively) were not significantly different for either group of patients. The initial temperature of cardioplegic solution for organ storage and the preimplantation myocardial temperature were, however, significantly lower in patients whose conditions required pacing immediately after transplantation than in those whose conditions did not require pacing (5.3 +/- 1.7 degrees C versus 6.5 +/- 1.5 degrees C, p less than 0.05, and 3.9 +/- 1.6 degrees C versus 5.7 +/- 2.6 degrees C, p less than 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J A Montero
- Heart Transplantation Unit, Hospital Reina Sofía, Córdoba, Spain
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22
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Calleja F, Eguaras MG, Chacon A, Vivancos R, Montero A, Concha M. Pulmonary valve endocarditis during puerperal sepsis. J Cardiovasc Surg (Torino) 1992; 33:292-4. [PMID: 1601910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A case of pulmonary valve endocarditis caused by Staphylococcus aureus during puerperal sepsis in a female patient is reported. The M-mode and two dimensional echocardiographic finding are described. A review of the literature shows that this entity is rare. A large vegetation in the leaflet of the pulmonary valve was excised and the patient recovered after a full course of antibiotics.
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Affiliation(s)
- F Calleja
- Department of Cardiovascular Surgery, Hospital Regional Reina Sofia, Cordoba, Spain
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23
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Calleja F, Membrives A, Eguaras MG, Montero A, García MA, Román M, Chacón A, Villarrubia A, Gómez S, Concha M. [Myocardial revascularization and complete correction of tetralogy of Fallot in an adult. A case report]. Rev Esp Cardiol 1991; 44:344-6. [PMID: 1852965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The case is reported of a 62 year-old male having a clinical history of grade II dyspnoea from 9 year ago and recently showing grade II angina. He had presented mild cyanosis. Suspecting the existence of coronary arteriosclerosis, and with the clinical diagnosis of tetralogy of Fallot based particularly on two-dimensional and M-mode echocardiography, and angio-hemodynamic study was made which confirmed the presence of congenital heart disease and also revealed significant coronary lesions of the circumflex and right coronary arteries. The patient underwent surgery which involved complete correction of the tetralogy of Fallot and the placing of two aortocoronary grafts onto the circumflex and right coronary arteries. Favorable progress was noted both immediately after operation and 6 months later. Although cases have been described of Fallot disease associated with acute myocardial infarction, we believe that this is the first time a patient has undergone myocardial revascularization at the same time as undergoing complete correction of the congenital heart disease.
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Affiliation(s)
- F Calleja
- Servicio de Cirugía Cardiovascular, Hospital Regional Reina Sofía, Universidad de Córdoba
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Eguaras MG, Luque I, Montero A, García MA, Calleja F, Román M, Concha M, Ocerín JM. A comparison of repair and replacement for mitral stenosis with partially calcified valve. J Thorac Cardiovasc Surg 1990; 100:161-6. [PMID: 2385113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
From January 1978 to December 1987 we operated on 135 patients with calcified mitral stenosis. In 60 patients a conservative operation was performed (group I). Nine patients required mitral annuloplasty associated with the commissurotomy. The other 75 patients underwent mitral valve replacement (group II). In 37 patients a mechanical prosthesis was used and in 38 a biologic one. The patients given mitral valve replacement had a more heavily calcified valve than those undergoing a conservative procedure. Twenty-one patients (12 from group I and 13 from group II) required associated tricuspid annuloplasty. The mean follow-up time was 69.1 months (1 months to 10 years). There were no significant differences between the two groups in terms of operative death (0% and 4%, respectively), postoperative functional class, actuarial survival rate at 10 years (84% and 96%, respectively), and probability of freedom from thromboemboli at 10 years (98% and 96%, respectively). However, the probability of freedom from reoperation at 10 years significantly favored the conservative surgery group (84% and 69%, respectively, p less than 0.01). Finally, the probability of freedom from complications at 10 years was also significantly higher in the conservative surgery group (82% and 64%, respectively, p less than 0.005). Because of these results we believe that conservative surgery is, at present, a better alternative than mitral valve replacement for patients with partially calcified mitral stenosis.
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Affiliation(s)
- M G Eguaras
- Service of Cardiovascular Surgery, Hospital Reina Sofia, University of Cordoba, Spain
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Calleja F, Eguaras M, Montero J, Granados J, García Jimenez MA, Suarez de Lezo J, Villarubia A, Chacón A, Concha M. Aberrant right subclavian artery associated with common carotid trunk. A rare cause of vascular ring. Eur J Cardiothorac Surg 1990; 4:568-70. [PMID: 2245052 DOI: 10.1016/1010-7940(90)90147-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [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: 12/30/2022] Open
Abstract
We have reviewed four cases of incomplete vascular rings caused by the presence of a common carotid trunk from which arose both carotid arteries associated with an aberrant right subclavian artery. The patients were aged between 3 and 9 months. All patients presented with recurrent respiratory tract infections. Three patients showed signs of malnutrition and failure to thrive caused by episodes of bronchial aspiration from extrinsic compression of the oesophagus. One patient presented with dyspnoea induced by feeding and another had stridor. A common carotid trunk associated with an aberrant subclavian artery was confirmed in all cases. No other associated anomaly was observed in any patient. Ligature and section of the anomalous right subclavian artery was performed in all patients. The low incidence of this type of vascular ring, its physiopathological mechanism and surgical management are discussed.
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Affiliation(s)
- F Calleja
- Department of Cardiovascular Surgery, Hospital Reina Sofia, Cordoba, Spain
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Salas J, Calleja F, de Vega NG, Castillo JL, Alvarez de Cienfuegos F, Hernandez JM. Post-coronariography dissection of the right coronary artery. J Cardiovasc Surg (Torino) 1988; 29:614-6. [PMID: 3263377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The case of a patient undergoing an emergency aortocoronary bypass to the right coronary artery after its acute dissection at coronariography is presented. Surgery was carried out two hours after the incident. After successful recovery and postoperative study, it was concluded that the main technical problem posed by this operation which was whether or not to ligate proximally the right coronary was satisfactorily solved by the initial decision not to ligate it.
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Affiliation(s)
- J Salas
- Service of Cardiovascular Surgery and Cardiology, Hospital Regional Carlos Haya, Málaga, Spain
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