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Schott M, Repetto L, Savio RL, Firpo G, Angeli E, Valbusa U. Identification of the seeding mechanism in the spinodal instability of dewetting liquids. J Colloid Interface Sci 2022; 632:65-73. [DOI: 10.1016/j.jcis.2022.11.028] [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] [Received: 10/04/2022] [Revised: 11/03/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022]
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Guida P, Piscitelli E, Marrese M, Martino V, Cirillo V, Guarino V, Angeli E, Cocola C, Pelucchi P, Repetto L, Firpo G, Karnavas T, Gotte M, Gritzapis A, D'Albore M, Repetto D, Pezzuoli D, Missitzis I, Porta G, Bertalot G, Bellipanni G, Zucchi I, Ambrosio L, Valbusa U, Reinbold RA. Integrating Microstructured Electrospun Scaffolds in an Open Microfluidic System for in Vitro Studies of Human Patient-Derived Primary Cells. ACS Biomater Sci Eng 2020; 6:3649-3663. [PMID: 33463182 DOI: 10.1021/acsbiomaterials.0c00352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Recent studies have suggested that microenvironmental stimuli play a significant role in regulating cellular proliferation and migration, as well as in modulating self-renewal and differentiation processes of mammary cells with stem cell (SCs) properties. Recent advances in micro/nanotechnology and biomaterial synthesis/engineering currently enable the fabrication of innovative tissue culture platforms suitable for maintenance and differentiation of SCs in vitro. Here, we report the design and fabrication of an open microfluidic device (OMD) integrating removable poly(ε-caprolactone) (PCL) based electrospun scaffolds, and we demonstrate that the OMD allows investigation of the behavior of human cells during in vitro culture in real time. Electrospun scaffolds with modified surface topography and chemistry can influence attachment, proliferation, and differentiation of mammary SCs and epigenetic mechanisms that maintain luminal cell identity as a function of specific morphological or biochemical cues imparted by tailor-made fiber post-treatments. Meanwhile, the OMD architecture allows control of cell seeding and culture conditions to collect more accurate and informative in vitro assays. In perspective, integrated systems could be tailor-made to mimic specific physiological conditions of the local microenvironment and then analyze the response from screening specific drugs for more effective diagnostics, long-term prognostics, and disease intervention in personalized medicine.
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Affiliation(s)
- Patrizia Guida
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Eleonora Piscitelli
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy
| | - Marica Marrese
- Institute of Composite and Biomedical Materials, National Research Council of Italy, Mostra D'Oltremare, Pad. 20, viale Kennedy 54, 80125 Naples, Italy
| | - Valentina Martino
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy
| | - Valentina Cirillo
- Institute of Composite and Biomedical Materials, National Research Council of Italy, Mostra D'Oltremare, Pad. 20, viale Kennedy 54, 80125 Naples, Italy
| | - Vincenzo Guarino
- Institute for Polymers, Composites & Biomaterials, National Research Council of Italy, Mostra d'Oltremare, Pad. 20, viale Kennedy 54, 80125 Naples, Italy
| | - Elena Angeli
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Cinzia Cocola
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy.,Consorzio Italbiotech, via Fantoli 15/16, 20138 Milan, Italy
| | - Paride Pelucchi
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy
| | - Luca Repetto
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Giuseppe Firpo
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Theodoros Karnavas
- Columbia University, Department of Genetics & Development, New York, 10032 United States
| | - Martin Gotte
- Department of Gynecology and Obstetrics, Münster University Hospital, 48149 Münster, Germany
| | - Angelos Gritzapis
- Department of Breast Cancer Surgery, Hospital "Agios Savvas", Leoforos Alexandras Avenue, 171, 11522 Athens, Greece
| | - Marietta D'Albore
- Institute of Composite and Biomedical Materials, National Research Council of Italy, Mostra D'Oltremare, Pad. 20, viale Kennedy 54, 80125 Naples, Italy
| | - Diego Repetto
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Denise Pezzuoli
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Ioannis Missitzis
- Department of Breast Cancer Surgery, Hospital "Agios Savvas", Leoforos Alexandras Avenue, 171, 11522 Athens, Greece
| | - Giovanni Porta
- Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Giovanni Bertalot
- IEO, European Institute of Oncology IRCCS, via G Ripamonti, 435, 20141 Milan, Italy
| | - Gianfranco Bellipanni
- Center for Biotechnology, Sbarro Institute for Research and Molecular Medicine and Department of Biology, Temple University, Philadelphia 19122, United States
| | - Ileana Zucchi
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy
| | - Luigi Ambrosio
- Institute for Polymers, Composites & Biomaterials, National Research Council of Italy, Mostra d'Oltremare, Pad. 20, viale Kennedy 54, 80125 Naples, Italy
| | - Ugo Valbusa
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy
| | - Rolland A Reinbold
- Institute of Biomedical Technologies, National Research Council of Italy, via F.lli Cervi 93, 20090 Segrate, Milan, Italy
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Benedetti V, Brizi V, Guida P, Tomasoni S, Ciampi O, Angeli E, Valbusa U, Benigni A, Remuzzi G, Xinaris C. Engineered Kidney Tubules for Modeling Patient-Specific Diseases and Drug Discovery. EBioMedicine 2018; 33:253-268. [PMID: 30049385 PMCID: PMC6085557 DOI: 10.1016/j.ebiom.2018.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/25/2018] [Accepted: 06/06/2018] [Indexed: 12/18/2022] Open
Abstract
The lack of engineering systems able to faithfully reproduce complex kidney structures in vitro has made it difficult to efficiently model kidney diseases and development. Using polydimethylsiloxane (PDMS) scaffolds and a kidney-derived cell line we developed a system to rapidly engineer custom-made 3D tubules with typical renal epithelial properties. This system was successfully employed to engineer patient-specific tubules, to model polycystic kidney disease (PKD) and test drug efficacy, and to identify a potential new pharmacological treatment. By optimizing our system we constructed functional ureteric bud (UB)-like tubules from human induced pluripotent stem cells (iPSCs), and identified a combination of growth factors that induces budding morphogenesis like embryonic kidneys do. Finally, we applied this assay to investigate budding defects in UB-like tubules derived from a patient with a PAX2 mutation. Our system enables the modeling of human kidney disease and development, drug testing and discovery, and lays the groundwork for engineering anatomically correct kidney tissues in vitro and developing personalized medicine applications.
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Affiliation(s)
- Valentina Benedetti
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
| | - Valerio Brizi
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
| | - Patrizia Guida
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Susanna Tomasoni
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
| | - Osele Ciampi
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
| | - Elena Angeli
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Ugo Valbusa
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy; 'L. Sacco' Department of Biomedical and Clinical Sciences, University of Milan, 20157 Milan, Italy; Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, 24127 Bergamo, Italy
| | - Christodoulos Xinaris
- IRCCS - Istituto di Ricerche Farmacologiche 'Mario Negri', Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, 24126 Bergamo, Italy.
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Abstract
In recent years there has been a rapid increase in nanotechnology applications to medicine in order to prevent and treat diseases in the human body. The established and future applications have the potential to dramatically change medical science. The present paper will give a few examples that could transform common medical procedures.
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Affiliation(s)
- Elena Angeli
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Renato Buzio
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Giuseppe Firpo
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Raffaella Magrassi
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Valentina Mussi
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Luca Repetto
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
| | - Ugo Valbusa
- NanoMed Labs, Centro di Biotecnologie Avanzate CBA and Dipartimento di Fisica dell'Università di Genova, Genoa, Italy
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Nicastro KR, Lo Savio R, McQuaid CD, Madeira P, Valbusa U, Azevedo F, Casero M, Lourenço C, Zardi GI. Plastic ingestion in aquatic-associated bird species in southern Portugal. Mar Pollut Bull 2018; 126:413-418. [PMID: 29421119 DOI: 10.1016/j.marpolbul.2017.11.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 11/14/2017] [Accepted: 11/22/2017] [Indexed: 06/08/2023]
Abstract
Excessive use of plastics in daily life and the inappropriate disposal of plastic products are severely affecting wildlife species in both coastal and aquatic environments. Birds are top-predators, exposed to all threats affecting their environments, making them ideal sentinel organisms for monitoring ecosystems change. We set a baseline assessment of the prevalence of marine plastic litter affecting multi-species populations of aquatic birds in southern Portugal. By examining 160 stomach contents from 8 species of aquatic birds, we show that 22.5% were affected by plastic debris. Plastic was found in Ciconia ciconia, Larus fuscus and L. michahellis. Ciconia ciconia ingested the highest amount (number of items and total mass) of plastic debris. Polydimethylsiloxane (PDMS, silicones) was the most abundant polymer and was recorded only in C. ciconia. Plastic ingestion baseline data are of crucial importance to evaluate changes through time and among regions and to define management and conservation strategies.
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Affiliation(s)
- Katy R Nicastro
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
| | - Roberto Lo Savio
- Department of Physics, Università degli Studi di Genova, Genoa, Italy
| | | | - Pedro Madeira
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Ugo Valbusa
- Department of Physics, Università degli Studi di Genova, Genoa, Italy
| | - Fábia Azevedo
- Centro de Recuperação e Investigação de Animais Selvagens (RIAS) - Associação ALDEIA, Parque Natural da Ria Formosa, Olhão, Portugal
| | - Maria Casero
- Centro de Recuperação e Investigação de Animais Selvagens (RIAS) - Associação ALDEIA, Parque Natural da Ria Formosa, Olhão, Portugal
| | - Carla Lourenço
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Gerardo I Zardi
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
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6
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Ierardi V, Domenichini P, Reali S, Chiappara GM, Devoto G, Valbusa U. Klebsiella pneumoniae antibiotic resistance identified by atomic force microscopy. J Biosci 2017; 42:623-636. [DOI: 10.1007/s12038-017-9713-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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7
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Angeli E, Volpe A, Fanzio P, Repetto L, Firpo G, Guida P, Savio RL, Wanunu M, Valbusa U. Simultaneous Electro-Optical Tracking for Nanoparticle Recognition and Counting. Nano Lett 2015; 15:5696-5701. [PMID: 26225640 PMCID: PMC5146980 DOI: 10.1021/acs.nanolett.5b01243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present the first detailed experimental observation and analysis of nanoparticle electrophoresis through a nanochannel obtained with synchronous high-bandwidth electrical and camera recordings. Optically determined particle diffusion coefficients agree with values extracted from fitting electrical transport measurements to distributions from 1D Fokker-Planck diffusion-drift theory. This combined tracking strategy enables optical recognition and electrical characterization of nanoparticles in solution, which can have a broad range of applications in biology and materials science.
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Affiliation(s)
- Elena Angeli
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
- Corresponding Authors. ,
| | - Andrea Volpe
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Paola Fanzio
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Luca Repetto
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Giuseppe Firpo
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Patrizia Guida
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Roberto Lo Savio
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
| | - Meni Wanunu
- Department of Physics and Chemistry/Chemical Biology, Northeastern University, Boston 02115, Massachusetts, United States
- Corresponding Authors. ,
| | - Ugo Valbusa
- Nanomed Laboratories, Dipartimento di Fisica, Università di Genova, 16146 Genova, Italy
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8
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Manneschi C, Fanzio P, Ala-Nissila T, Angeli E, Repetto L, Firpo G, Valbusa U. Stretching of DNA confined in nanochannels with charged walls. Biomicrofluidics 2014; 8:064121. [PMID: 25553196 PMCID: PMC4265123 DOI: 10.1063/1.4904008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/01/2014] [Indexed: 05/04/2023]
Abstract
There is currently a growing interest in control of stretching of DNA inside nanoconfined regions due to the possibility to analyze and manipulate single biomolecules for applications such as DNA mapping and barcoding, which are based on stretching the DNA in a linear fashion. In the present work, we couple Finite Element Methods and Monte Carlo simulations in order to study the conformation of DNA molecules confined in nanofluidic channels with neutral and charged walls. We find that the electrostatic forces become more and more important when lowering the ionic strength of the solution. The influence of the nanochannel cross section geometry is also studied by evaluating the DNA elongation in square, rectangular, and triangular channels. We demonstrate that coupling electrostatically interacting walls with a triangular geometry is an efficient way to stretch DNA molecules at the scale of hundreds of nanometers. The paper reports experimental observations of λ-DNA molecules in poly(dimethylsiloxane) nanochannels filled with solutions of different ionic strength. The results are in good agreement with the theoretical predictions, confirming the crucial role of the electrostatic repulsion of the constraining walls on the molecule stretching.
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Affiliation(s)
| | - Paola Fanzio
- Nanomed Labs, Department of Physics, University of Genova , via Dodecaneso 33, 16146 Genova, Italy
| | - Tapio Ala-Nissila
- Department of Applied Physics and COMP Center of Excellence, Aalto University School of Science , P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland and Department of Physics, Brown University , Providence, Rhode Island 02912-1843, USA
| | - Elena Angeli
- Nanomed Labs, Department of Physics, University of Genova , via Dodecaneso 33, 16146 Genova, Italy
| | - Luca Repetto
- Nanomed Labs, Department of Physics, University of Genova , via Dodecaneso 33, 16146 Genova, Italy
| | - Giuseppe Firpo
- Nanomed Labs, Department of Physics, University of Genova , via Dodecaneso 33, 16146 Genova, Italy
| | - Ugo Valbusa
- Nanomed Labs, Department of Physics, University of Genova , via Dodecaneso 33, 16146 Genova, Italy
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9
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Fanzio P, Mussi V, Menotta M, Firpo G, Repetto L, Guida P, Angeli E, Magnani M, Valbusa U. Selective protein detection with a dsLNA-functionalized nanopore. Biosens Bioelectron 2014; 64:219-26. [PMID: 25218776 DOI: 10.1016/j.bios.2014.08.081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/10/2014] [Accepted: 08/27/2014] [Indexed: 12/19/2022]
Abstract
In the last years, nanopore technology has been increasingly exploited for biomolecule detection and analysis. Recently, the main focus of the research has moved from the study of nucleic acids to the analysis of proteins and DNA-protein complexes. In this paper, chemically functionalized solid-state nanopore has been used to recognize Nuclear Factor-kappa B proteins (NF-κB), that are involved in several disorders and inflammation processes, so that their identification is of crucial importance for prognostic applications. In particular, we show that it is possible to electrically detect the specific interaction between p50, a protein belonging to the NF-κB family, and dsLNA probe molecules covalently attached to the surface of a FIB fabricated SiN pore. The obtained results have been compared with those related to BSA protein, which does not interact with the used probes. Finally, the potential of the device has been further tested by analyzing a whole cell extract. In this case, three principal peaks in the distribution of electrical event duration can be identified, corresponding to different interacting NF-κB complexes, so that the methodology appears to be effective also to study biological samples of considerable complexity. Ultimately, the presented data emphasize the selectivity and versatility of the functionalized nanopore device, demonstrating its applicability in bioanalytics and advanced diagnostics.
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Affiliation(s)
- Paola Fanzio
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
| | - Valentina Mussi
- National Research Council, Institute for Complex Systems ISC-CNR, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino 'Carlo Bo', Via Saffi 2, 61029 Urbino, PU, Italy
| | - Giuseppe Firpo
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
| | - Luca Repetto
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
| | - Patrizia Guida
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
| | - Elena Angeli
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino 'Carlo Bo', Via Saffi 2, 61029 Urbino, PU, Italy
| | - Ugo Valbusa
- Department of Physics, University of Genoa, via Dodecaneso 33, 16146 Genova, Italy
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10
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Ierardi V, Ferrera F, Millo E, Damonte G, Filaci G, Valbusa U. Bioactive surfaces for antibody-antigen complex detection by Atomic Force Microscopy. ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/439/1/012001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Affiliation(s)
- Chiara Manneschi
- Nanomed Laboratories, Dipartimento
di Fisica, Università di Genova,
via Dodecaneso 33, 16146 Genova, Italy
| | - Elena Angeli
- Nanomed Laboratories, Dipartimento
di Fisica, Università di Genova,
via Dodecaneso 33, 16146 Genova, Italy
| | - Tapio Ala-Nissila
- COMP Centre of Excellence, Department
of Applied Physics, Aalto University School of Science, P.O. Box 11000, FIN-00076 Aalto, Espoo, Finland
| | - Luca Repetto
- Nanomed Laboratories, Dipartimento
di Fisica, Università di Genova,
via Dodecaneso 33, 16146 Genova, Italy
| | - Giuseppe Firpo
- Nanomed Laboratories, Dipartimento
di Fisica, Università di Genova,
via Dodecaneso 33, 16146 Genova, Italy
| | - Ugo Valbusa
- Nanomed Laboratories, Dipartimento
di Fisica, Università di Genova,
via Dodecaneso 33, 16146 Genova, Italy
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12
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Mussi V, Fanzio P, Firpo G, Repetto L, Valbusa U. Size and functional tuning of solid state nanopores by chemical functionalization. Nanotechnology 2012; 23:435301. [PMID: 23060606 DOI: 10.1088/0957-4484/23/43/435301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We demonstrate the possibility of using a simple functionalization procedure, based on an initial vapour-phase silanization, to control the size and functionality of solid state nanopores. The presented results show that, by varying the silanization time, it is possible to modify the efficiency of probe molecule attachment, thus shrinking the pore to the chosen size, while introducing a specific sensing selectivity. The proposed method allows us to tune the nanopore biosensor adapting it to the specific final application, and it can be efficiently applied when the pore initial diameter does not exceed a limit dimension related to the mean free path of the silane molecules at the working pressure.
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Affiliation(s)
- Valentina Mussi
- Nanomed Labs, Physics Department, University of Genova, Via Dodecaneso, 33 Genova, I-16146, Italy.
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13
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Buzio R, Repetto L, Giacopelli F, Ravazzolo R, Valbusa U. Label-free, atomic force microscopy-based mapping of DNA intrinsic curvature for the nanoscale comparative analysis of bent duplexes. Nucleic Acids Res 2012; 40:e84. [PMID: 22402493 PMCID: PMC3367213 DOI: 10.1093/nar/gks210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We propose a method for the characterization of the local intrinsic curvature of adsorbed DNA molecules. It relies on a novel statistical chain descriptor, namely the ensemble averaged product of curvatures for two nanosized segments, symmetrically placed on the contour of atomic force microscopy imaged chains. We demonstrate by theoretical arguments and experimental investigation of representative samples that the fine mapping of the average product along the molecular backbone generates a characteristic pattern of variation that effectively highlights all pairs of DNA tracts with large intrinsic curvature. The centrosymmetric character of the chain descriptor enables targetting strands with unknown orientation. This overcomes a remarkable limitation of the current experimental strategies that estimate curvature maps solely from the trajectories of end-labeled molecules or palindromes. As a consequence our approach paves the way for a reliable, unbiased, label-free comparative analysis of bent duplexes, aimed to detect local conformational changes of physical or biological relevance in large sample numbers. Notably, such an assay is virtually inaccessible to the automated intrinsic curvature computation algorithms proposed so far. We foresee several challenging applications, including the validation of DNA adsorption and bending models by experiments and the discrimination of specimens for genetic screening purposes.
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Affiliation(s)
- Renato Buzio
- S.C. Nanobiotecnologie, National Institute for Cancer Research IST, Genova, Italy
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14
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Scaglione S, Giannoni P, Bianchini P, Sandri M, Marotta R, Firpo G, Valbusa U, Tampieri A, Diaspro A, Bianco P, Quarto R. Order versus Disorder: in vivo bone formation within osteoconductive scaffolds. Sci Rep 2012; 2:274. [PMID: 22355786 PMCID: PMC3281274 DOI: 10.1038/srep00274] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 01/31/2012] [Indexed: 11/24/2022] Open
Abstract
In modern biomaterial design the generation of an environment mimicking some of the extracellular matrix features is envisaged to support molecular cross-talk between cells and scaffolds during tissue formation/remodeling. In bone substitutes chemical biomimesis has been particularly exploited; conversely, the relevance of pre-determined scaffold architecture for regenerated bone outputs is still unclear. Thus we aimed to demonstrate that a different organization of collagen fibers within newly formed bone under unloading conditions can be generated by differently architectured scaffolds. An ordered and confined geometry of hydroxyapatite foams concentrated collagen fibers within the pores, and triggered their self-assembly in a cholesteric-banded pattern, resulting in compact lamellar bone. Conversely, when progenitor cells were loaded onto nanofibrous collagen-based sponges, new collagen fibers were distributed in a nematic phase, resulting mostly in woven isotropic bone. Thus specific biomaterial design relevantly contributes to properly drive collagen fibers assembly to target bone regeneration.
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Abstract
We present the development and the electrical characterization of a polymeric nanochannel device. Standard microfabrication coupled to Focused Ion Beam (FIB) nanofabrication is used to fabricate a silicon master, which can be then replicated in a polymeric material by soft lithography. Such an elastomeric nanochannel device is used to study DNA translocation events during electrophoresis experiments. Our results demonstrate that an easy and low cost fabrication technique allows creation of a low noise device for single molecule analysis.
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Affiliation(s)
- Paola Fanzio
- Nanomed Labs, Dipartimento di Fisica, Università di Genova, via Dodecaneso 33, 16146 Genova, Italy.
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16
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Mussi V, Fanzio P, Repetto L, Firpo G, Stigliani S, Tonini GP, Valbusa U. "DNA-Dressed NAnopore" for complementary sequence detection. Biosens Bioelectron 2011; 29:125-31. [PMID: 21868212 DOI: 10.1016/j.bios.2011.08.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 07/29/2011] [Accepted: 08/02/2011] [Indexed: 11/26/2022]
Abstract
Single molecule electrical sensing with nanopores is a rapidly developing field with potential revolutionary effects on bioanalytics and diagnostics. The recent success of this technology is in the simplicity of its working principle, which exploits the conductance modulations induced by the electrophoretic translocation of molecules through a nanometric channel. Initially proposed as fast and powerful tools for molecular stochastic sensing, nanopores find now application in a range of different domains, thanks to the possibility of finely tuning their surface properties, thus introducing artificial binding and recognition sites. Here we show the results of DNA translocation and hybridization experiments at the single molecule level by a novel class of selective biosensor devices that we call "DNA-Dressed NAnopore" (DNA(2)), based on solid state nanopore with large initial dimensions, resized and activated by functionalization with DNA molecules. The presented data demonstrate the ability of the DNA(2) to selectively detect complementary target sequences, that is to distinguish between molecules depending on their affinity to the functionalization. The DNA(2) can thus constitute the basis for the design of integrable parallel devices for mutation DNA analysis, diagnostics and bioanalytic investigations.
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Affiliation(s)
- Valentina Mussi
- Nanomed Labs, Physics Department, University of Genova, and Nanobiotechnologies, National Institute for Cancer Research (IST), Largo R. Benzi, 10, Genova 16132, Italy.
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17
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Angeli E, Manneschi C, Repetto L, Firpo G, Valbusa U. DNA manipulation with elastomeric nanostructures fabricated by soft-moulding of a FIB-patterned stamp. Lab Chip 2011; 11:2625-9. [PMID: 21677946 DOI: 10.1039/c1lc20411d] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A Focused Ion Beam (FIB)-patterned silicon mould is used to fabricate elastomeric nanostructures, whose cross-section can be dynamically and reversibly tuned by applying a controlled mechanical stress. Direct-write, based on FIB milling, allows the fabrication of nanostructures with a variety of different geometries, aspect ratio, spacing and distribution offering a higher flexibility compared to other nanopatterning approaches. Moreover, a simple double replication process based on poly(dimethylsiloxane) permits a strong reduction of the fabrication costs that makes this approach well-suited for the production of low cost nanofluidic devices. DNA stretching and single molecule manipulation capabilities of these platforms have been successfully demonstrated.
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Affiliation(s)
- Elena Angeli
- Nanomed Labs, Dipartimento di Fisica, Università di Genova, via Dodecaneso 33, 16146 Genova, Italy.
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18
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Menotta M, Crinelli R, Carloni E, Mussi V, Valbusa U, Magnani M. Binding force measurement of NF-κB-ODNs interaction: an AFM based decoy and drug testing tool. Biosens Bioelectron 2011; 28:158-65. [PMID: 21802937 DOI: 10.1016/j.bios.2011.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 07/05/2011] [Accepted: 07/08/2011] [Indexed: 01/22/2023]
Abstract
Interaction between transcription factors and DNA are essential for regulating gene transcription. The Nuclear factor-κB (NF-κB) is a ubiquitous transcription factor involved in cell signalling and its failure is a principal cause of several autoimmune and auto-inflammatory disorders. In this paper we have developed an atomic force microscopy (AFM) method to quantitatively characterise the interaction force between NF-κB and DNA or LNA (locked nucleic acid) double strand molecules containing the NF responsive elements (RE). This process allows the simple testing and selection of LNA based decoy molecules to be used in NF-κB modulation decoy strategies. Furthermore the proposed methodology is also suitable for testing drug efficacy on the modulation of NF-κB binding to its nucleic acid target sequence. A biological AFM based sensor is therefore considered appropriate for characterising transcription factors and selecting molecules to modulate their activity.
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Affiliation(s)
- Michele Menotta
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Via Saffi 2, 61029 Urbino (PU), Italy
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19
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Mussi V, Fanzio P, Repetto L, Firpo G, Scaruffi P, Stigliani S, Menotta M, Magnani M, Tonini GP, Valbusa U. Electrical characterization of DNA-functionalized solid state nanopores for bio-sensing. J Phys Condens Matter 2010; 22:454104. [PMID: 21339592 DOI: 10.1088/0953-8984/22/45/454104] [Citation(s) in RCA: 5] [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: 05/30/2023]
Abstract
We present data concerning the electrical properties of a class of biosensor devices based on bio-functionalized solid state nanopores able to detect different kinds of interactions between probe molecules, chemically attached to the pore surface, and target molecules present in solution and electrophoretically drawn through the nanometric channel. The great potentiality of this approach resides in the fact that the functionalization of a quite large pore (up to 50-60 nm) allows a sufficient diameter reduction for the attainment of a single molecule sensing dimension and selective activation, without the need for further material deposition, such as metal or oxides, or localized surface modification. The results indicate that it will be possible, in the near future, to conceive and design devices for parallel analysis of biological samples made of arrays of nanopores differently functionalized, fabricated by standard lithographic techniques, with important applications in the field of molecular diagnosis.
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Affiliation(s)
- V Mussi
- Nanomed Labs, Physics Department, University of Genova, and Nanobiotechnologies, National Institute of Cancer Research (IST), Largo R Benzi, 10 Genova, 16132, Italy.
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20
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Menotta M, Crinelli R, Carloni E, Bianchi M, Giacomini E, Valbusa U, Magnani M. Label-free quantification of activated NF-κB in biological samples by atomic force microscopy. Biosens Bioelectron 2010; 25:2490-6. [DOI: 10.1016/j.bios.2010.04.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 04/12/2010] [Accepted: 04/14/2010] [Indexed: 11/17/2022]
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21
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Pierno M, Bruschi L, Fois G, Mistura G, Boragno C, de Mongeot FB, Valbusa U. Nanofriction of neon films on superconducting lead. Phys Rev Lett 2010; 105:016102. [PMID: 20867468 DOI: 10.1103/physrevlett.105.016102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Indexed: 05/29/2023]
Abstract
With a quartz crystal microbalance technique we have studied the nanofriction of neon monolayers deposited on a lead surface at a temperature around 7 K. Unlike heavier adsorbates, Ne is found to systematically slide at such low temperatures without any evidence of pinning. The crossing of the Pb superconducting-metal transition is not accompanied by any change in dissipation, suggesting that the electronic contribution to friction is negligible for this system.
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Affiliation(s)
- M Pierno
- CNISM and Dipartimento di Fisica G. Galilei, Università di Padova, via Marzolo 8, 35131 Padova, Italy
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22
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Mussi V, Fanzio P, Repetto L, Firpo G, Scaruffi P, Stigliani S, Tonini GP, Valbusa U. DNA-functionalized solid state nanopore for biosensing. Nanotechnology 2010; 21:145102. [PMID: 20220223 DOI: 10.1088/0957-4484/21/14/145102] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The possible use of nanopores for single DNA molecules biosensing has been demonstrated, but much remains to do in order to develop advanced engineered devices with enhanced stability, and controlled geometry and surface properties. Here we present morphological and electrical characterization of solid state silicon nitride nanopores fabricated by focused ion beam direct milling and chemically functionalized by probe oligonucleotides, with the final aim of developing a versatile tool for biosensing and gene expression profiling.
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Affiliation(s)
- V Mussi
- Nanomed Labs, Physics Department, University of Genova, Advanced Biotechnology Center, Largo R. Benzi, Genova, Italy.
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23
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Albini A, Mussi V, Parodi A, Ventura A, Principi E, Tegami S, Rocchia M, Francheschi E, Sogno I, Cammarota R, Finzi G, Sessa F, Noonan DM, Valbusa U. Interactions of single-wall carbon nanotubes with endothelial cells. Nanomedicine: Nanotechnology, Biology and Medicine 2010; 6:277-88. [DOI: 10.1016/j.nano.2009.08.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 07/07/2009] [Accepted: 08/02/2009] [Indexed: 10/20/2022]
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24
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Abstract
We review results relative to the formation of regular nanoscale patterns on metal substrates exposed to defocused ion beam irradiation. Particular emphasis is placed on work which demonstrates the possibility of controllably modifying chemico-physical properties of the material by tailoring the nanoscale morphology during IBS patterning. Starting from the well-established results found on single-crystal model systems, we show how the controlled modification of the atomic step termination can deeply affect chemical reactivity or magnetic anisotropy. We then look in greater detail at the more recent attempts focused on the extension of IBS patterning on supported polycrystalline metal films, a promising class of systems in view of potential applications. A modification of the functional properties of metal films can also be obtained by forcing a shape anisotropy of the nanostructures. The modification of the optical response of polycrystalline metal nanowires supported on anisotropic templates produced by IBS provides a clear example of this.
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25
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Moroni R, Buzio R, Chincarini A, Valbusa U, de Mongeot FB, Bogani L, Caneschi A, Sessoli R, Cavigli L, Gurioli M. Optically addressable single molecule magnet behaviour of vacuum-sprayed ultrathin films. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b712913k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Buzio R, Bosca A, Krol S, Marchetto D, Valeri S, Valbusa U. Deformation and adhesion of elastomer poly(dimethylsiloxane) colloidal AFM probes. Langmuir 2007; 23:9293-302. [PMID: 17655336 DOI: 10.1021/la700941c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We report on the synthesis and characterization of elastomer colloidal AFM probes. Poly(dimethylsiloxane) microparticles, obtained by water emulsification and cross-linking of viscous prepolymers, are glued to AFM cantilevers and used for contact mechanics investigations on smooth substrates: in detail cyclic loading-unloading experiments are carried on ion-sputtered mica, the deformation rate and dwell time being separately controlled. We analyze load-penetration curves and pull-off forces with models due respectively to Zener; Maugis and Barquins; and Greenwood and Johnson and account for bulk creep, interfacial viscoelasticity, and structural rearrangements at the polymer-substrate interface. A good agreement is found between experiments and theory, with a straightforward estimation of colloidal probes' material parameters. We suggest the use of such probes for novel contact mechanics experiments involving fully reversible deformations at the submicrometer scale.
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Affiliation(s)
- Renato Buzio
- Nanomed Labs, ABC-Advanced Biotechnology Center, Largo R. Benzi 10, Genova, Italy.
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27
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Abstract
We have used friction force microscopy to probe friction laws for nanoasperities sliding on atomically flat substrates under controlled atmosphere and liquid environment, respectively. A power law relates friction force and normal load in dry air, whereas a linear relationship, i.e., Amontons' law, is observed for junctions fully immersed in model lubricants, namely, octamethylciclotetrasiloxane and squalane. Lubricated contacts display a remarkable friction reduction, with liquid and substrate specific friction coefficients. Comparison with molecular dynamics simulations suggests that load-bearing boundary layers at junction entrance cause the appearance of Amontons' law and impart atomic-scale character to the sliding process; continuum friction models are on the contrary of limited predictive power when applied to lubrication effects. An attempt is done to define general working conditions leading to the manifestation of nanoscale lubricity due to adsorbed boundary layers.
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Affiliation(s)
- R Buzio
- CNR-INFM Genova, Dipartimento di Fisica, Via Dodecaneso 33, 16146 Genova, Italy.
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28
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Bruschi L, Fois G, Pontarollo A, Mistura G, Torre B, Buatier de Mongeot F, Boragno C, Buzio R, Valbusa U. Structural depinning of Ne monolayers on Pb at T < 6/5 K. Phys Rev Lett 2006; 96:216101. [PMID: 16803253 DOI: 10.1103/physrevlett.96.216101] [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: 01/25/2006] [Indexed: 05/10/2023]
Abstract
We have studied the nanofriction of Ne monolayers with a quartz-crystal microbalance technique at temperatures below 6.5 K and in ultrahigh-vacuum conditions. Very homogeneous and smooth lead electrodes have been physically deposited on a quartz blank at 150 K and then annealed at room temperatures. With such a Pb-plated quartz-crystal microbalance, we have observed a pronounced depinning transition separating a low-coverage region, where the film is nearly locked to the oscillating electrode, from a high-coverage region characterized by slippage at the solid-fluid boundary. Such a behavior has been found to be very reproducible. These data are suggestive of a structural depinning of the solid Ne film when it becomes incommensurate with the lead substrate, in agreement with the results of an extensive molecular-dynamics study.
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Affiliation(s)
- L Bruschi
- Dipartimento di Fisica G. Galilei, Università di Padova, via Marzolo 8, 35131 Padova, Italy
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29
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Gerbi A, Vattuone L, Rocca M, Valbusa U, Pirani F, Cappelletti D, Vecchiocattivi F. New insights on the stereodynamics of ethylene adsorption on an oxygen-precovered silver surface. J Chem Phys 2005; 123:224709. [PMID: 16375497 DOI: 10.1063/1.2136159] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The control of spatial orientation of molecules has a great influence on the stereodynamics of elementary processes occurring both in homogeneous and heterogeneous phases. Nonpolar molecules have so far escaped direct experimental investigations because of their poor sensitivity to several external constraints. Recently, it has been shown that the collisional alignment produced in supersonic expansions coupled with molecular-beam velocity selection can help solve such problems. Here we show that the sticking probability of ethylene, a nonpolar molecule prototypical of unsaturated hydrocarbons, on an O(2)-precovered Ag(001) surface is larger for molecules approaching in a helicopter-like motion than for those cartwheeling. A mechanism involving a weakly bound precursor state is suggested, with helicopter molecules having a lower chance of being scattered back into the gas phase than cartwheels when colliding with preadsorbed ethylene.
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Affiliation(s)
- Andrea Gerbi
- Istituto Nazionale per la Fisica della Materia, Unità di Genova, Dipartimento di Fisica, Università di Genova, 16146 Genoa, Italy
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30
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Gerbi A, Vattuone L, Rocca M, Pirani F, Valbusa U, Cappelletti D, Vecchiocattivi F. Stereodynamic Effects in the Adsorption of Propylene Molecules on Ag(001). J Phys Chem B 2005; 109:22884-9. [PMID: 16853981 DOI: 10.1021/jp0542571] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report on the experimental evidence of the role of rotational alignment of the gas-phase molecules in the interaction of propylene with Ag(001). Molecular alignment has been controlled by a velocity selection of the impinging molecules, flying in a supersonic seeded molecular beam. The experimental findings indicate that at low surface coverage the sticking probability is independent of molecular alignment, while when coverage exceeds few percent of a monolayer, molecules impinging rotating parallel to the surface (helicopter-like configuration) achieve a higher chance to be trapped than those which impinge rotating perpendicularly (cartwheels). The sudden appearance of a large stereodynamic effect suggests that the adsorption proceeds via a mobile precursor state and is tentatively correlated with a change in the configuration of the added propylene molecules, which adsorb tilted rather than flat at the surface.
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Affiliation(s)
- A Gerbi
- Dipartimento di Fisica, Universita Genova, Via Dodecaneso 33, Genova, Italy
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31
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Baraldi A, Giacomello D, Rumiz L, Moretuzzo M, Lizzit S, Buatier de Mongeot F, Paolucci G, Comelli G, Rosei R, Nieuwenhuys BE, Valbusa U, Kiskinova MP. Unexpected Behavior of the Surface Composition of PtRh Alloys during Chemical Reaction. J Am Chem Soc 2005; 127:5671-4. [PMID: 15826207 DOI: 10.1021/ja044372+] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The changes in the surface composition of a Pt(50)Rh(50)(100) alloy due to an ongoing 2H(2) + O(2)-->2H(2)O chemical reaction have been studied in situ. Exploiting the high-energy resolution and surface sensitivity of synchrotron radiation core-level spectroscopy it was possible to monitor the population of the two transitions metals atoms at the gas-surface interface. Sequences of fast high-resolution core-level spectra of the Rh3d(5/2), Pt4f(7/2), and O1s core levels showed a continuous exchange of atoms between the first and subsurface layers. An unexpected Pt surface enrichement was found under slightly oxidizing conditions, opposite to what found in a highly oxidizing atmosphere.
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Affiliation(s)
- Alessandro Baraldi
- Dipartimento di Fisica, Università di Trieste, Via Valerio 2, 34127 Trieste, Italy.
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32
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Molle A, Buatier de Mongeot F, Molinari A, Xiaerding F, Boragno C, Valbusa U. Self-organized formation of rhomboidal nanopyramids on fcc(110) metal surfaces. Phys Rev Lett 2004; 93:256103. [PMID: 15697917 DOI: 10.1103/physrevlett.93.256103] [Citation(s) in RCA: 2] [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: 09/21/2004] [Indexed: 05/24/2023]
Abstract
We report on the far from equilibrium self-organized morphologies obtained after Xe ion irradiation of the Rh(110) and Cu(110) surfaces. Here we experimentally identify by means of high resolution LEED a novel interfacial state characterized by a rhomboidal pyramid islanding with majority steps oriented along nonequilibrium low-symmetry directions. The formation of the novel rhomboidal pyramid state and the transition to the well-known rippled phases results from a delicate interplay of kinetic processes which are controlled by acting on temperature, ion flux, and impact energy.
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Affiliation(s)
- A Molle
- Dipartimento di Fisica and INFM-Unità di Genova, Via Dodecaneso 33, I-16146 Genova, Italy
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33
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Vattuone L, Gerbi A, Rocca M, Valbusa U, Pirani F, Vecchiocattivi F, Cappelletti D. Stereodynamic Effects in the Adsorption of Ethylene onto a Metal Surface. Angew Chem Int Ed Engl 2004; 43:5200-3. [PMID: 15455413 DOI: 10.1002/anie.200461302] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Luca Vattuone
- INFM Unità di Genova, Dipartimento di Fisica, Università di Genova, Imem-CNR Sezione di Genova, Via Dodecaneso 33, Genoa, Italy.
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34
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Vattuone L, Gerbi A, Rocca M, Valbusa U, Pirani F, Vecchiocattivi F, Cappelletti D. Stereodynamic Effects in the Adsorption of Ethylene onto a Metal Surface. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200461302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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Buzio R, Malyska K, Rymuza Z, Boragno C, Biscarini F, De Mongeot FB, Valbusa U. Experimental investigation of the contact mechanics of rough fractal surfaces. IEEE Trans Nanobioscience 2004; 3:27-31. [PMID: 15382640 DOI: 10.1109/tnb.2003.820264] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The nonstationary character of roughness is a widely recognized property of surface morphology and suggests modeling several solid surfaces by fractal geometry. In the field of contact mechanics, this demands novel investigations attempting to clarify the role of multiscale roughness during physical contact. Here we review the results we recently obtained in the characterization of the contact mechanics of fractal surfaces by depth-sensing indentation. One class of experiments was conducted on organic thin films, load-displacement curves being acquired by atomic force microscopy using custom-designed tips. Another class of experiments focused on well-defined crystalline and mechanically polished ceramic substrates probed by a traditional nanoindenter. We observed the first-loading cycle to be considerably affected by surface roughness. Plastic failure was found to dominate incipient contact while contact stiffness increased on decreasing fractal dimension and roughness. Our findings suggest fractal parameters to drive contact mechanics whenever the penetration depth is kept below the interface width.
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Affiliation(s)
- R Buzio
- INFM-UdR Genova and Dipartimento di Fisica, 16146 Genova, Italy
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36
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Zhu W, Buatier de Mongeot F, Valbusa U, Wang EG, Zhang Z. Adatom ascending at step edges and faceting on fcc metal (110) surfaces. Phys Rev Lett 2004; 92:106102. [PMID: 15089219 DOI: 10.1103/physrevlett.92.106102] [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: 07/21/2003] [Indexed: 05/24/2023]
Abstract
Using first-principles total-energy calculations, we show that an adatom can easily climb up at monatomic-layer-high steps on several representative fcc metal (110) surfaces via a place exchange mechanism. Inclusion of such novel adatom ascending processes in kinetic Monte Carlo simulations of Al(110) homoepitaxy as a prototypical model system can lead to the existence of an intriguing faceting instability, whose dynamical evolution and kinetic nature are explored in comparison with experimental observations.
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Affiliation(s)
- Wenguang Zhu
- International Center for Quantum Structures and Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China
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37
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Moroni R, Sekiba D, Buatier de Mongeot F, Gonella G, Boragno C, Mattera L, Valbusa U. Uniaxial magnetic anisotropy in nanostructured Co/Cu(001): from surface ripples to nanowires. Phys Rev Lett 2003; 91:167207. [PMID: 14611439 DOI: 10.1103/physrevlett.91.167207] [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: 02/28/2003] [Indexed: 05/24/2023]
Abstract
We have investigated the correlation between morphology and magnetic anisotropy in nanostructured Co films on Cu(001). The formation of nanoscale ripples by ion erosion is found to deeply affect the magnetic properties of the Co film. A surface-type uniaxial magnetic anisotropy with easy axis parallel to the ripples is observed. The origin of the magnetic anisotropy has been identified with the modification of thermodynamic-step distribution induced by ripple formation. At higher ion doses, when Co ripples detach and crystalline nanowires form, a strong enhancement of the magnetic anisotropy due to magnetostatic contributions is observed.
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Affiliation(s)
- R Moroni
- Unità INFM di Genova, Dipartimento di Fisica dell'Università di Genova, and IMEM-CNR Sezione di Genova, via Dodecaneso 33, I-16146 Genova, Italy
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38
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Buatier de Mongeot F, Zhu W, Molle A, Buzio R, Boragno C, Valbusa U, Wang EG, Zhang Z. Nanocrystal formation and faceting instability in Al(110) homoepitaxy: true upward adatom diffusion at step edges and island corners. Phys Rev Lett 2003; 91:016102. [PMID: 12906556 DOI: 10.1103/physrevlett.91.016102] [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: 12/19/2002] [Indexed: 05/24/2023]
Abstract
Using atomic force microscopy and spot-profile analyzing low energy electron diffraction, we have observed the existence of a striking faceting instability in Al(110) homoepitaxy, characterized by the formation of nanocrystals with well-defined facets. These hut-shaped nanocrystals are over tenfold higher than the total film coverage, and coexist in a bimodal growth mode with much shallower and more populous surface mounds. We further use density functional theory calculations to elucidate the microscopic origin of the faceting instability, induced by surprisingly low activation barriers for adatom ascent at step edges and island corners.
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Buzio R, Boragno C, Biscarini F, Buatier de Mongeot F, Valbusa U. The contact mechanics of fractal surfaces. Nat Mater 2003; 2:233-236. [PMID: 12690395 DOI: 10.1038/nmat855] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2002] [Accepted: 12/12/2002] [Indexed: 05/24/2023]
Abstract
The role of surface roughness in contact mechanics is relevant to processes ranging from adhesion to friction, wear and lubrication. It also promises to have a deep impact on applied science, including coatings technology and design of microelectromechanical systems. Despite the considerable results achieved by indentation experiments, particularly in the measurement of bulk hardness on nanometre scales, the contact behaviour of realistic surfaces, showing random multiscale roughness, remains largely unknown. Here we report experimental results concerning the mechanical response of self-affine thin films indented by a micrometric flat probe. The specimens, made of cluster-assembled carbon or of sexithienyl, an organic molecular material, were chosen as prototype systems for the broad class of self-affine fractal interfaces, today including surfaces grown under non-equilibrium conditions, fractures, manufactured metal surfaces and solidified liquid fronts. We observe that a regime exists in which roughness drives the contact mechanics: in this range surface stiffness varies by a few orders of magnitude on small but significant changes of fractal parameters. As a consequence, we demonstrate that soft solid interfaces can be appreciably strengthened by reducing both fractal dimension and surface roughness. This indicates a general route for tailoring the mechanical properties of solid bodies.
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Affiliation(s)
- Renato Buzio
- INFM-Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
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Este GO, Knight DG, Scoles G, Valbusa U, Grein F. Interaction of hydrogen atoms with polyatomic molecules studied by means of scattering experiments and hybrid Hartree-Fock plus damped dispersion calculations. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100238a016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vattuone L, Burghaus U, Savio L, Rocca M, Costantini G, Buatier de Mongeot F, Boragno C, Rusponi S, Valbusa U. Oxygen interaction with disordered and nanostructured Ag(001) surfaces. J Chem Phys 2001. [DOI: 10.1063/1.1386432] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Costantini G, Buatier de Mongeot F, Boragno C, Valbusa U. Is ion sputtering always a "negative homoepitaxial deposition"? Phys Rev Lett 2001; 86:838-841. [PMID: 11177953 DOI: 10.1103/physrevlett.86.838] [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: 06/26/2000] [Indexed: 05/23/2023]
Abstract
We present a scanning tunneling microscopy study of the direct comparison between homoepitaxial deposition and surface ion sputtering on the Ag(001) system. At a temperature of 200 K, sputtering results in mound formation similar to the epitaxy case, while at higher temperatures an erosive regime sets in with the appearance of regular square pits. Contrary to the conventional wisdom, which considers ion sputtering as a deposition of vacancies, the analysis of single ion impact events reveals that the process produces both adatom and vacancy clusters. The key parameter determining the temperature dependence of surface morphology turns out to be the mobility of the adatom clusters which exceeds that of vacancy clusters.
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Affiliation(s)
- G Costantini
- INFM-Unità di Ricerca di Genova, Centro CFSBT-CNR and Dipartimento di Fisica, Via Dodecaneso 33, I-16146 Genova, Italy
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Vattuone L, Savio L, Valbusa U, Rocca M. Switching from molecular to dissociative adsorption with vibrational energy: ethylene on Ag(001). Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)01224-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Costantini G, Buatier de Mongeot F, Rusponi S, Boragno C, Valbusa U, Vattuone L, Burghaus U, Savio L, Rocca M. Tuning surface reactivity byin situsurface nanostructuring. J Chem Phys 2000. [DOI: 10.1063/1.481259] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
We have investigated the homoepitaxial growth of Ag(110) in the multilayer regime. After deposition of 30 monolayers of Ag at a temperature of 210 K a ripplelike surface instability is produced and the ridges of the ripples, as well as the majority steps, are found to be parallel to <11;0> which is the thermodynamically favored orientation. As the deposition temperature is decreased to 130 K, an unexpected 90 degrees switch of the ripple orientation is observed. The ridges of the ripples and the steps are in this case parallel to <100>. In the intermediate temperature range a checkerboard of rectangular mounds results. We interpret our results in terms of the peculiar hierarchy of interlayer and intralayer diffusion barriers present on the anisotropic Ag(110) surface.
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Vattuone L, Gambardella P, Burghaus U, Cemič F, Cupolillo A, Valbusa U, Rocca M. Collision induced desorption and dissociation of O2 chemisorbed on Ag(001). J Chem Phys 1998. [DOI: 10.1063/1.476820] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Vattuone L, Gambardella P, Cemič F, Valbusa U, Rocca M. Enhanced collision induced desorption and dissociation of O2 chemisorbed on Ag(001) at grazing incidence. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00998-6] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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