1
|
Clément P, Ackermann J, Sahin-Solmaz N, Herbertz S, Boero G, Kruss S, Brugger J. Comparison of electrical and optical transduction modes of DNA-wrapped SWCNT nanosensors for the reversible detection of neurotransmitters. Biosens Bioelectron 2022; 216:114642. [DOI: 10.1016/j.bios.2022.114642] [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: 06/08/2022] [Revised: 08/05/2022] [Accepted: 08/15/2022] [Indexed: 11/02/2022]
|
2
|
Gompelmann D, Sinn K, Brugger J, Bernitzky D, Mosleh B, Prosch H, Geleff S, Blessing A, Tiefenbacher A, Hoetzenecker K, Idzko M, Hoda MA. Correlation of PD-L1 expression on tumour cells between diagnostic biopsies and surgical specimens of lung cancer in real life with respect to biopsy techniques and neoadjuvant treatment. J Cancer Res Clin Oncol 2022; 149:1747-1754. [PMID: 35708777 PMCID: PMC10097774 DOI: 10.1007/s00432-022-04080-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/19/2022] [Indexed: 12/25/2022]
Abstract
PURPOSES Programmed death-ligand 1 (PD-L1) testing is performed mainly on biopsy specimens in patients with advanced lung cancer. It is questionable whether the small amount of tissue analysed in biopsies may represent the true PD-L1 expression of a tumour. METHODS In this retrospective study, PD-L1 expression on tumour cells derived from bronchoscopy brush cytology, endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA), endobronchial biopsy, transbronchial biopsy (TBB) and computed tomography (CT)-guided transthoracic biopsy was compared to the PD-L1 expression of the corresponding surgical resection in lung cancer patients with regard to neoadjuvant treatment in-between. RESULTS A quantitative comparison between the diagnostic biopsy of the primary tumour with corresponding resected surgical specimens in a total of 113 lung cancer patients (60% male, mean age 65 ± 9 years) revealed a statistically significant correlation of PD-L1 expression on tumour cells (r = 0.58, p< 0.001), for patients without neoadjuvant treatment in-between and for patients who underwent neoadjuvant treatment (both p < 0.001). Using a cut-off value of ≥ 50% PD-L1 TPS for comparing the biopsy samples and resected specimens, the concordance rate was 78% with a Cohen's Kappa of 0.45. CONCLUSION A statistically significant concordance for PD-L1 expression on tumour cells between biopsies from primary lung tumour and resected specimen was found, but of uncertain clinical accuracy. The use of a cut-off value of ≥ 50% PD-L1 TPS resulted only in a moderate agreement. Therefore, the interpretation of the PD-L1 determined form biopsy specimens status should only be considered with caution for treatment decisionsQuery.
Collapse
Affiliation(s)
- D Gompelmann
- Division of Pulmonology, Department of Internal Medicine II, Medical University Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
| | - K Sinn
- Department of Thoracic Surgery, Medical University Vienna, Vienna, Austria
| | - J Brugger
- Department for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - D Bernitzky
- Division of Pulmonology, Department of Internal Medicine II, Medical University Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - B Mosleh
- Department of Thoracic Surgery, Medical University Vienna, Vienna, Austria
| | - H Prosch
- Department for Biomedical Imaging and Image-Guided Therapy, Medical University Vienna, Vienna, Austria
| | - S Geleff
- Department of Pathology, Medical University Vienna, Vienna, Austria
| | - A Blessing
- Department of Pathology, Medical University Vienna, Vienna, Austria
| | - A Tiefenbacher
- Department of Pathology, Medical University Vienna, Vienna, Austria
| | - K Hoetzenecker
- Department of Thoracic Surgery, Medical University Vienna, Vienna, Austria
| | - M Idzko
- Division of Pulmonology, Department of Internal Medicine II, Medical University Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - M A Hoda
- Department of Thoracic Surgery, Medical University Vienna, Vienna, Austria
| |
Collapse
|
3
|
Fischer A, Siebenrock T, Liebau K, Hertwig A, Hahn R, Anwar M, Pesta M, Timmermann I, Brugger J, Posch M, Tamandl D, Ringl H, Hiesmayr M. Association of ct skeletal muscle area and density with age: a prospective study in 200 non-critically ill patients. Clin Nutr ESPEN 2021. [DOI: 10.1016/j.clnesp.2021.09.176] [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: 10/19/2022]
|
4
|
Meligrana G, Ferrari S, Lucherini L, Celè J, Colò F, Brugger J, Ricciardi C, Ruffo R, Gerbaldi C. Na
3
V
2
(PO
4
)
3
‐Supported Electrospun Carbon Nanofiber Nonwoven Fabric as Self‐Standing Na‐Ion Cell Cathode. ChemElectroChem 2020. [DOI: 10.1002/celc.202000345] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- G. Meligrana
- Group for Applied Materials and Electrochemistry (GAME Lab) Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
| | - S. Ferrari
- Department of Pharmacy University of Chieti Pescara “G. d'Annunzio” Via dei Vestini 31 66100 Chieti Italy
| | - L. Lucherini
- Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
- Microsystems Laboratory École Polytechnique Fédérale de Lausanne – EPFL 1015 Lausanne Switzerland
| | - J. Celè
- Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
- Microsystems Laboratory École Polytechnique Fédérale de Lausanne – EPFL 1015 Lausanne Switzerland
| | - F. Colò
- Group for Applied Materials and Electrochemistry (GAME Lab) Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
| | - J. Brugger
- Microsystems Laboratory École Polytechnique Fédérale de Lausanne – EPFL 1015 Lausanne Switzerland
| | - C. Ricciardi
- Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
| | - R. Ruffo
- Department of Materials Science Università di Milano-Bicocca Via Roberto Cozzi 55 20125 Milano Italy
| | - C. Gerbaldi
- Group for Applied Materials and Electrochemistry (GAME Lab) Department of Applied Science and Technology (DISAT) Politecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
| |
Collapse
|
5
|
Altree-Williams A, Brugger J, Pring A, Bedrikovetsky P. Coupled reactive flow and dissolution with changing reactive surface and porosity. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.05.016] [Citation(s) in RCA: 9] [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: 11/27/2022]
|
6
|
Altree-Williams A, Brugger J, Pring A, Bedrikovetsky P. Exact Solution for Coupled Reactive Flow and Dissolution with Porosity Changes. Transp Porous Media 2018. [DOI: 10.1007/s11242-018-1088-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Montinaro E, Grisi M, Letizia MC, Pethö L, Gijs MAM, Guidetti R, Michler J, Brugger J, Boero G. 3D printed microchannels for sub-nL NMR spectroscopy. PLoS One 2018; 13:e0192780. [PMID: 29742104 PMCID: PMC5942786 DOI: 10.1371/journal.pone.0192780] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/30/2018] [Indexed: 11/19/2022] Open
Abstract
Nuclear magnetic resonance (NMR) experiments on subnanoliter (sub-nL) volumes are hindered by the limited sensitivity of the detector and the difficulties in positioning and holding such small samples in proximity of the detector. In this work, we report on NMR experiments on liquid and biological entities immersed in liquids having volumes down to 100 pL. These measurements are enabled by the fabrication of high spatial resolution 3D printed microfluidic structures, specifically conceived to guide and confine sub-nL samples in the sub-nL most sensitive volume of a single-chip integrated NMR probe. The microfluidic structures are fabricated using a two-photon polymerization 3D printing technique having a resolution better than 1 μm3. The high spatial resolution 3D printing approach adopted here allows to rapidly fabricate complex microfluidic structures tailored to position, hold, and feed biological samples, with a design that maximizes the NMR signals amplitude and minimizes the static magnetic field inhomogeneities. The layer separating the sample from the microcoil, crucial to exploit the volume of maximum sensitivity of the detector, has a thickness of 10 μm. To demonstrate the potential of this approach, we report NMR experiments on sub-nL intact biological entities in liquid media, specifically ova of the tardigrade Richtersius coronifer and sections of Caenorhabditis elegans nematodes. We show a sensitivity of 2.5x1013 spins/Hz1/2 on 1H nuclei at 7 T, sufficient to detect 6 pmol of 1H nuclei of endogenous compounds in active volumes down to 100 pL and in a measurement time of 3 hours. Spectral resolutions of 0.01 ppm in liquid samples and of 0.1 ppm in the investigated biological entities are also demonstrated. The obtained results may indicate a route for NMR studies at the single unit level of important biological entities having sub-nL volumes, such as living microscopic organisms and eggs of several mammalians, humans included.
Collapse
Affiliation(s)
- E. Montinaro
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - M. Grisi
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - M. C. Letizia
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - L. Pethö
- Swiss Federal Laboratories for Materials Science and Technology (EMPA), Laboratory for Mechanics of Materials and Nanostructures, Thun, Switzerland
| | - M. A. M. Gijs
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - R. Guidetti
- University of Modena and Reggio Emilia, Department of Life Sciences, Modena, Italy
| | - J. Michler
- Swiss Federal Laboratories for Materials Science and Technology (EMPA), Laboratory for Mechanics of Materials and Nanostructures, Thun, Switzerland
| | - J. Brugger
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - G. Boero
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| |
Collapse
|
8
|
Missen OP, Mills SJ, Welch MD, Spratt J, Rumsey MS, Birch WD, Brugger J. The crystal structure of cesbronite, Cu 3TeO 4(OH) 4: a novel sheet tellurate topology. Acta Crystallogr B Struct Sci Cryst Eng Mater 2018. [DOI: 10.1107/s205252061701647x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The crystal structure of cesbronite has been determined using single-crystal X-ray diffraction and supported by electron-microprobe analysis, powder diffraction and Raman spectroscopy. Cesbronite is orthorhombic, space group Cmcm, with a = 2.93172 (16), b = 11.8414 (6), c = 8.6047 (4) Å and V = 298.72 (3) Å3. The chemical formula of cesbronite has been revised to CuII
3TeVIO4(OH)4 from CuII
5(TeIVO3)2(OH)6·2H2O. This change has been accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association, Proposal 17-C. The previously reported oxidation state of tellurium has been shown to be incorrect; the crystal structure, bond valence studies and charge balance clearly show tellurium to be hexavalent. The crystal structure of cesbronite is formed from corrugated sheets of edge-sharing CuO6 and (Cu0.5Te0.5)O6 octahedra. The structure determined here is an average structure that has underlying ordering of Cu and Te at one of the two metal sites, designated as M, which has an occupancy Cu0.5Te0.5. This averaging probably arises from an absence of correlation between adjacent polyhedral sheets, as there are two different hydrogen-bonding configurations linking sheets that are related by a ½a offset. Randomised stacking of these two configurations results in the superposition of Cu and Te and leads to the Cu0.5Te0.5 occupancy of the M site in the average structure. Bond-valence analysis is used to choose the most probable Cu/Te ordering scheme and also to identify protonation sites (OH). The chosen ordering scheme and its associated OH sites are shown to be consistent with the revised chemical formula.
Collapse
|
9
|
Gauvin M, Alnasser T, Terver E, Abid I, Mlayah A, Xie S, Brugger J, Viallet B, Ressier L, Grisolia J. Plasmonic photo-current in freestanding monolayered gold nanoparticle membranes. Nanoscale 2016; 8:16162-16167. [PMID: 27714145 DOI: 10.1039/c6nr05091c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on photo-current generation in freestanding monolayered gold nanoparticle membranes excited by using a focused laser beam. The absence of a substrate leads to a 50% increase of the photo-current at the surface plasmon resonance. This current is attributed to a combination of trap state dynamics and bolometric effects in a nanocomposite medium yielding a temperature rise of 40 K.
Collapse
Affiliation(s)
- M Gauvin
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - T Alnasser
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - E Terver
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France. and Université de Toulouse, CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4, France
| | - I Abid
- Université de Toulouse, CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4, France
| | - A Mlayah
- Université de Toulouse, CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4, France
| | - S Xie
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - J Brugger
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - B Viallet
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - L Ressier
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - J Grisolia
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| |
Collapse
|
10
|
Gauvin M, Grisolia J, Alnasser T, Viallet B, Xie S, Brugger J, Ressier L. Electro-mechanical sensing in freestanding monolayered gold nanoparticle membranes. Nanoscale 2016; 8:11363-11370. [PMID: 27194578 DOI: 10.1039/c6nr02004f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The electro-mechanical sensing properties of freestanding monolayered membranes of dodecanethiol coated 7 nm gold nanoparticles (NPs) are investigated using AFM force spectroscopy and conductive AFM simultaneously. The electrical resistance of the NP membranes increases sensitively with the point-load force applied in the center of the membranes using an AFM tip. Numerical simulations of electronic conduction in a hexagonally close-packed two-dimensional (2D) array of NPs under point load-deformation are carried out on the basis of electronic transport measurements at low temperatures and strain modeling of the NP membranes by finite element analysis. These simulations, supporting AFM-based electro-mechanical measurements, attribute the high strain sensitivity of the monolayered NP membranes to the exponential dependence of the tunnel electron transport in 2D NP arrays on the strain-induced length variation of the interparticle junctions. This work thus evidences a new class of highly sensitive nano-electro-mechanical systems based on freestanding monolayered gold NP membranes.
Collapse
Affiliation(s)
- M Gauvin
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - J Grisolia
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - T Alnasser
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - B Viallet
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| | - S Xie
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - J Brugger
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne, Station 17, 1015 Lausanne, Switzerland
| | - L Ressier
- Université de Toulouse, LPCNO, INSA-CNRS-UPS, 135 avenue de Rangueil, Toulouse 31077, France.
| |
Collapse
|
11
|
Abstract
This letter reports on a novel fabrication method for 3D metal nanostructures using high-throughput nanostencil lithography. Aperture clogging, which occurs on the stencil membranes during physical vapor deposition, is leveraged to create complex topographies on the nanoscale. The precision of the 3D nanofabrication method is studied in terms of geometric parameters and material types. The versatility of the technique is demonstrated by various symmetric and chiral patterns made of Al and Au.
Collapse
Affiliation(s)
- F Yesilkoy
- EPFL STI IMT LMIS1, CH-1015 Lausanne, Switzerland. and The University of Tokyo IIS CIRMM, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - V Flauraud
- EPFL STI IMT LMIS1, CH-1015 Lausanne, Switzerland.
| | - M Rüegg
- EPFL STI IMT LMIS1, CH-1015 Lausanne, Switzerland.
| | - B J Kim
- The University of Tokyo IIS CIRMM, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - J Brugger
- EPFL STI IMT LMIS1, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
12
|
Yesilkoy F, Ueno R, Desbiolles BXE, Grisi M, Sakai Y, Kim BJ, Brugger J. Highly efficient and gentle trapping of single cells in large microfluidic arrays for time-lapse experiments. Biomicrofluidics 2016; 10:014120. [PMID: 26909126 PMCID: PMC4760974 DOI: 10.1063/1.4942457] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 02/09/2016] [Indexed: 05/24/2023]
Abstract
The isolation of single biological cells and their further cultivation in dedicated arrayed chambers are key to the collection of statistically reliable temporal data in cell-based biological experiments. In this work, we present a hydrodynamic single cell trapping and culturing platform that facilitates cell observation and experimentation using standard bio-lab equipment. The proposed design leverages the stochastic position of the cells as they flow into the structured microfluidic channels, where hundreds of single cells are then arrayed in nanoliter chambers for simultaneous cell specific data collection. Numerical simulation tools are used to devise and implement a hydrodynamic cell trapping mechanism that is minimally detrimental to the cell cycle and retains high overall trapping efficiency (∼70%) with the capability of reaching high fill factors (>90%) in short loading times (1-4 min) in a 400-trap device. A Monte Carlo model is developed using the design parameters to estimate the system trapping efficiencies, which show strong agreement with the experimentally acquired data. As proof of concept, arrayed mammalian tissue cells (MIA PaCa-2) are cultured in the microfluidic chambers for two days without viability problems.
Collapse
Affiliation(s)
| | - R Ueno
- Institute of Industrial Science, The University of Tokyo , Meguro-ku, Tokyo 153-8505, Japan
| | - B X E Desbiolles
- Microsystems Laboratory, Ecole Polytechnique Federale de Lausanne , 1015 Lausanne, Switzerland
| | - M Grisi
- Microsystems Laboratory, Ecole Polytechnique Federale de Lausanne , 1015 Lausanne, Switzerland
| | - Y Sakai
- Institute of Industrial Science, The University of Tokyo , Meguro-ku, Tokyo 153-8505, Japan
| | - B J Kim
- Institute of Industrial Science, The University of Tokyo , Meguro-ku, Tokyo 153-8505, Japan
| | - J Brugger
- Microsystems Laboratory, Ecole Polytechnique Federale de Lausanne , 1015 Lausanne, Switzerland
| |
Collapse
|
13
|
Choi JH, Kim YH, Jacot-Descombes L, Brugger J, Kim GM. Fabrication of HepG2 Cell Laden Collagen Microspheres using Inkjet Printing. ACTA ACUST UNITED AC 2014. [DOI: 10.7736/kspe.2014.31.8.743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
14
|
Boero G, Gualco G, Lisowski R, Anders J, Suter D, Brugger J. Room temperature strong coupling between a microwave oscillator and an ensemble of electron spins. J Magn Reson 2013; 231:133-140. [PMID: 23644353 DOI: 10.1016/j.jmr.2013.04.004] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/05/2013] [Accepted: 04/06/2013] [Indexed: 06/02/2023]
Abstract
We demonstrate theoretically and experimentally the possibility to achieve the strong coupling regime at room temperature with a microwave electronic oscillator coupled with an ensemble of electron spins. The coupled system shows bistable behaviour, with a broad hysteresis and sharp transitions. The coupling strength and the hysteresis width can be adjusted through the number of spins in the ensemble, the temperature, and the microwave field strength.
Collapse
Affiliation(s)
- G Boero
- Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland.
| | | | | | | | | | | |
Collapse
|
15
|
Fairbrother L, Etschmann B, Brugger J, Shapter J, Southam G, Reith F. Biomineralization of gold in biofilms of Cupriavidus metallidurans. Environ Sci Technol 2013; 47:2628-2635. [PMID: 23405956 DOI: 10.1021/es302381d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cupriavidus metallidurans, a bacterium capable of reductively precipitating toxic, aqueous gold(I/III)-complexes, dominates biofilm communities on gold (Au) grains from Australia. To examine the importance of C. metallidurans biofilms in secondary Au formation, we assessed the biomineralization potential of biofilms growing in quartz-sand-packed columns to periodic amendment with Au(I)-thiosulfate. In these experiments, >99 wt % of Au, was retained compared to <30 wt % in sterilized and abiotic controls. Biomineralization of Au occurred in the presence of viable biofilms via the formation of intra- and extra-cellular spherical nanoparticles, which aggregated into spheroidal and framboidal microparticles of up to 2 μm in diameter. Aggregates of Au formed around cells, eventually encapsulating and ultimately replacing them. These particles were morphologically analogous to Au-particles commonly observed on natural Au grains. Bacterial cells were connected via exopolymer or nanowires to μm-sized, extracellular Au-aggregates, which would intuitively improve the flow of electrons through the biofilm. This study demonstrates the importance of C. metallidurans biofilms for the detoxification of Au-complexes and demonstrates a central role for bacterial biomineralization in the formation of highly pure Au in surface environments.
Collapse
Affiliation(s)
- L Fairbrother
- School of Chemical and Physical Sciences, Flinders University, Adelaide, SA 5001, Australia
| | | | | | | | | | | |
Collapse
|
16
|
Brigo L, Auzelyte V, Lister KA, Brugger J, Brusatin G. Phenyl-bridged polysilsesquioxane positive and negative resist for electron beam lithography. Nanotechnology 2012; 23:325302. [PMID: 22825028 DOI: 10.1088/0957-4484/23/32/325302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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 present and characterize an organic-inorganic hybrid sol-gel material, phenyl-bridged polysilsesquioxane (ph-PSQ), for use as a new high resolution resist for electron beam lithography (EBL). The resist has a unique characteristic as the only positive tone silica-based resist available for EBL. Exploring the processing parameters has revealed that it is possible to switch the behaviour from negative to positive tone by application of a post-exposure bake (PEB). Based on the results from micro-FTIR spectroscopy, a description of the tone switching mechanisms is proposed. The negative tone behaviour is explained by the etch rate difference between silanol groups and cross-linked silica, present in unexposed and in exposed areas of the films, respectively. In the case of positive tone, after a PEB, the etch rate difference between a thermally densified cross-linked silica network and cage-like silica structures allows us to reveal the pattern. Contrast and sensitivity are estimated under different processing conditions, and the significant parameters for line edge roughness minimization are pointed out. Dense patterns down to 25 nm half-pitch and isolated structures down to 30 nm are demonstrated, exploiting the positive tone, and dense patterns down to 60 nm half-pitch are demonstrated in the negative tone. Etching selectivities in fluorinated gases for ph-PSQ nanostructures on silicon substrates are 1-9 for the positive tone and 1-12 for the negative tone.
Collapse
Affiliation(s)
- L Brigo
- Industrial Engineering Department, University of Padova, Padova, 35131, Italy.
| | | | | | | | | |
Collapse
|
17
|
Binetti E, Ingrosso C, Striccoli M, Cosma P, Agostiano A, Pataky K, Brugger J, Curri ML. Nanocomposites based on highly luminescent nanocrystals and semiconducting conjugated polymer for inkjet printing. Nanotechnology 2012; 23:075701. [PMID: 22261314 DOI: 10.1088/0957-4484/23/7/075701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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
In this work nanocomposites based on organic-capped semiconductor nanocrystals formed of a core of CdSe coated with a shell of ZnS (CdSe@ZnS), with different sizes, and a semiconducting conjugated polymer, namely poly[(9,9-dihexylfluoren-2,7-diyl)-alt- (2,5-dimethyl-1,4-phenylene)] (PF-DMB) have been investigated. The nanocomposites are prepared by mixing the pre-synthesized components in organic solvents, thereby assisting the dispersion of the organic-coated nano-objects in the polymer host. UV-vis steady state and time-resolved spectroscopy along with (photo)electrochemical techniques have been performed to characterize the obtained materials. The study shows that the embedded nanocrystals increase the PF-DMB stability against oxidation and, at the same time, extend the light harvesting capability to the visible spectral region, thus resulting in detectable photocurrent signals. The nanocomposites have been dispensed by means of a piezo-actuated inkjet system. Such inks present viscosity and surface tension properties well suited for stable and reliable drop-on-demand printing using an inkjet printer. The fabrication of arrays of single-color pixels made of the nanocomposites and micrometers in size has been performed. Confocal and atomic force microscopy have confirmed that inkjet-printed microstructures present the intrinsic emission properties of both the embedded nanocrystals and PF-DMB, resulting in a combined luminescence. Finally, the morphology of the printed pixels is influenced by the embedded nanofillers.
Collapse
Affiliation(s)
- E Binetti
- Chemistry Department, University 'Aldo Moro' of Bari, via Orabona 4, I-70126 Bari, Italy
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Cadarso VJ, Perera-Núñez J, Jacot-Descombes L, Pfeiffer K, Ostrzinski U, Voigt A, Llobera A, Grützer G, Brugger J. Microlenses with defined contour shapes. Opt Express 2011; 19:18665-18670. [PMID: 21935235 DOI: 10.1364/oe.19.018665] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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
Ink-jet printing of optical ink over SU-8 pillars is here proposed as a technology for obtaining microlenses with shape control. To demonstrate the flexibility of this method, microlenses with five different contour shapes (ranging from circular and elliptical to toric or more advanced geometries) have been fabricated. Furthermore, the optical properties of the different fabricated lenses have been experimentally investigated. Focal distance, numerical aperture (NA) and full-width at half maximum (FWHM) of the microlenses have been determined. Arrays of microlenses showed an identical behavior with a standard deviation in the total intensity of only 7%. Additionally, the focal plane of the fabricated symmetric microlenses and the Sturm interval of the non-symmetric ones have been obtained. The experimental results demonstrate the validity and flexibility of the proposed technology.
Collapse
Affiliation(s)
- V J Cadarso
- Microsystems laboratory (LMIS1), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Llobera A, Cadarso VJ, Carregal-Romero E, Brugger J, Domínguez C, Fernández-Sánchez C. Fluorophore-doped xerogel antiresonant reflecting optical waveguides. Opt Express 2011; 19:5026-5039. [PMID: 21445138 DOI: 10.1364/oe.19.005026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Rhodamine B and Alexa Fluor 430 fluorophores have been used as doping agents for xerogel waveguides defined over an antiresonant (ARROW) filter. This configuration has a significant level of integration, since it merges the waveguide, the light emitter and the filter in a single photonic element. Different technologies have been combined for their implementation, namely soft lithography, standard silicon-based technology and silicon bulk micromachining. The spectral response of 15-mm long waveguides without fluorophore is first analyzed as a function of the waveguide width. Here, it has been observed how the xerogel used has a high transparency in the visible spectra, having only significant absorption at the wavelength where the ARROW filter is in resonance. In a second step, identical waveguides but doped with two different concentrations of Rhodamine B and Alexa Fluor 430 are studied. In addition to the effect of the filter, fluorophore-doped xerogel waveguides show losses close to -2 dB (equivalent to 2 dB of light emission). In addition, it has been observed how an increase of the fluorophore concentration within the xerogel matrix does not provide with a emission increase, but saturation or even a decrease of this magnitude due to self-absorption. Finally, the total losses of the proposed waveguides are analyzed as a function of their width, obtaining losses close to 5 dB for waveguide widths higher than 50 µm.
Collapse
Affiliation(s)
- A Llobera
- Institut de Microelectrònica de Barcelona (IMB-CNM-CSIC), Campus UAB 08193 Barcelona, Spain.
| | | | | | | | | | | |
Collapse
|
20
|
Gullo MR, Jacot-Descombes L, Aeschimann L, Brugger J. Characterization of Hydrophobic Forces for in Liquid Self-Assembly of Micron-Sized Functional Building Blocks. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/opl.2011.466] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThis paper presents the experimental and numerical study of hydrophobic interaction forces at nanometer scale in the scope of engineering micron-sized building blocks for self-assembly in liquid. The hydrophobic force distance relation of carbon, Teflon and dodeca-thiols immersed in degassed and deionized water has been measured by atomic force microscopy. Carbon and dodeca-thiols showed comparable attractive and binding forces in the rage of pN/nm2. Teflon showed the weakest binding and no attractive force. Molecular dynamic simulations were performed to correlate the molecular arrangement of water molecules and the hydrophobic interactions measured by atomic force microscopy. The simulations showed a depletion zone of 2Å followed by a layered region of 8Å in the axis perpendicular to the hydrophobic surface.
Collapse
|
21
|
Kiefer T, Villanueva LG, Fargier F, Favier F, Brugger J. Fast and robust hydrogen sensors based on discontinuous palladium films on polyimide, fabricated on a wafer scale. Nanotechnology 2010; 21:505501. [PMID: 21098952 DOI: 10.1088/0957-4484/21/50/505501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [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
Fast hydrogen sensors based on discontinuous palladium (Pd) films on supporting polyimide layers, fabricated by a cost-efficient and full-wafer compatible process, are presented. The films, deposited by electron-beam evaporation with a nominal thickness of 1.5 nm, consist of isolated Pd islands that are separated by nanoscopic gaps. On hydrogenation, the volume expansion of Pd brings initially separated islands into contact which leads to the creation of new electrical pathways through the film. The supporting polyimide layer provides both sufficient elasticity for the Pd nanoclusters to expand on hydrogenation and a sufficiently high surface energy for good adhesion of both film and contacting electrodes. The novel order of the fabrication processes involves a dicing step prior to the Pd deposition and stencil lithography for the patterning of microelectrodes. This allows us to preserve the as-deposited film properties. The devices work at room temperature, show response times of a few seconds and have a low power consumption of some tens of nW.
Collapse
Affiliation(s)
- T Kiefer
- Microsystems Laboratory, Station 17, École Polytéchnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | | | | | | |
Collapse
|
22
|
Abstract
A quantitative analysis of blurring and its dependence on the stencil-substrate gap and the deposition parameters in stencil lithography, a high resolution shadow mask technique, is presented. The blurring is manifested in two ways: first, the structure directly deposited on the substrate is larger than the stencil aperture due to geometrical factors, and second, a halo of material is formed surrounding the deposited structure, presumably due to surface diffusion. The blurring is studied as a function of the gap using dedicated stencils that allow a controlled variation of the gap. Our results show a linear relationship between the gap and the blurring of the directly deposited structure. In our configuration, with a material source of approximately 5 mm and a source-substrate distance of 1 m, we find that a gap size of approximately 10 microm enlarges the directly deposited structures by approximately 50 nm. The measured halo varies from 0.2 to 3 microm in width depending on the gap, the stencil aperture size and other deposition parameters. We also show that the blurring can be reduced by decreasing the nominal deposition thickness, the deposition rate and the substrate temperature.
Collapse
Affiliation(s)
- O Vazquez-Mena
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.
| | | | | | | | | | | |
Collapse
|
23
|
Grisolia J, Viallet B, Amiens C, Baster S, Cordan AS, Leroy Y, Soldano C, Brugger J, Ressier L. 99% random telegraph signal-like noise in gold nanoparticle micro-stripes. Nanotechnology 2009; 20:355303. [PMID: 19671965 DOI: 10.1088/0957-4484/20/35/355303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this paper, we report on a process to prepare gold nanoparticle stripes on SiO(2) by convective/capillary assembly without any patterning of the substrate. Electrical devices were then fabricated using stencil lithography in order to avoid any contamination. I(V) measurements at room temperature show that these stripes have an ohmic behavior between +/- 0.5 V with a resistivity ranging from one to two orders higher than the gold bulk value. Furthermore, I(V) and I(t) measurements reveal current fluctuations that were interpreted in terms of charging and discharging of nanoparticle islands leading to a very large electrostatic perturbation of current conduction paths. Unconventional relative amplitudes of up to 99% RTS fluctuations were observed.
Collapse
Affiliation(s)
- J Grisolia
- LPCNO INSA-UPS-CNRS, Université de Toulouse, 135 avenue de Rangueil, Toulouse, France
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Kim JY, Ingrosso C, Fakhfouri V, Striccoli M, Agostiano A, Curri ML, Brugger J. Inkjet-printed multicolor arrays of highly luminescent nanocrystal-based nanocomposites. Small 2009; 5:1051-7. [PMID: 19199336 DOI: 10.1002/smll.200801315] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [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
Inkjet technology is a compelling method for the flexible and cost-effective printing of functional inks. We show that nanocomposite solutions based on polystyrene and differently sized core/shell-type nanocrystals (NCs) formed by a CdSe core coated with a shell of ZnS (CdSe@ZnS) in a single solvent, chloroform, can be reliably dispensed into luminescent, multicolor pixel arrays. This study demonstrates the relevance of parameters like polymer concentration and nozzle diameter, highlighting how the optimal conditions to print NCs embedded in 5 wt% polystyrene nanocomposite are given by a 70-microm-diameter nozzle. The obtained structures show that the bright size-dependent emission of the NCs in the nanocomposite is retained in the printed pixels.
Collapse
Affiliation(s)
- Joo Yeon Kim
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | | | | | | | | | | |
Collapse
|
25
|
Vazquez-Mena O, Villanueva G, Savu V, Sidler K, van den Boogaart MAF, Brugger J. Metallic nanowires by full wafer stencil lithography. Nano Lett 2008; 8:3675-82. [PMID: 18817451 DOI: 10.1021/nl801778t] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Aluminum and gold nanowires were fabricated using 100 mm stencil wafers containing nanoslits fabricated with a focused ion beam. The stencils were aligned and the nanowires deposited on a substrate with predefined electrical pads. The morphology and resistivity of the wires were studied. Nanowires down to 70 nm wide and 5 mum long have been achieved showing a resistivity of 10 microOmegacm for Al and 5 microOmegacm for Au and maximum current density of approximately 10(8) A/cm(2). This proves the capability of stencil lithography for the fabrication of metallic nanowires on a full wafer scale.
Collapse
Affiliation(s)
- O Vazquez-Mena
- Microsystems Laboratory, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland.
| | | | | | | | | | | |
Collapse
|
26
|
Arcamone J, van den Boogaart MAF, Serra-Graells F, Fraxedas J, Brugger J, Pérez-Murano F. Full-wafer fabrication by nanostencil lithography of micro/nanomechanical mass sensors monolithically integrated with CMOS. Nanotechnology 2008; 19:305302. [PMID: 21828759 DOI: 10.1088/0957-4484/19/30/305302] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Wafer-scale nanostencil lithography (nSL) is used to define several types of silicon mechanical resonators, whose dimensions range from 20 µm down to 200 nm, monolithically integrated with CMOS circuits. We demonstrate the simultaneous patterning by nSL of ∼2000 nanodevices per wafer by post-processing standard CMOS substrates using one single metal evaporation, pattern transfer to silicon and subsequent etch of the sacrificial layer. Resonance frequencies in the MHz range were measured in air and vacuum. As proof-of-concept towards an application as high performance sensors, CMOS integrated nano/micromechanical resonators are successfully implemented as ultra-sensitive areal mass sensors. These devices demonstrate the ability to monitor the deposition of gold layers whose average thickness is smaller than a monolayer. Their areal mass sensitivity is in the range of 10(-11) g cm(-2) Hz(-1), and their thickness resolution corresponds to approximately a thousandth of a monolayer.
Collapse
Affiliation(s)
- J Arcamone
- CNM-IMB (CSIC), Campus UAB, E-08193 Bellaterra (Barcelona), Spain
| | | | | | | | | | | |
Collapse
|
27
|
Krishnamoorthy S, Gerbig Y, Hibert C, Pugin R, Hinderling C, Brugger J, Heinzelmann H. Tunable, high aspect ratio pillars on diverse substrates using copolymer micelle lithography: an interesting platform for applications. Nanotechnology 2008; 19:285301. [PMID: 21828729 DOI: 10.1088/0957-4484/19/28/285301] [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] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We demonstrate the use of copolymer micelle lithography using polystyrene-block-poly(2-vinylpyridine) reverse micelle thin films in their as-coated form to create nanopillars with tunable dimensions and spacing, on different substrates such as silicon, silicon oxide, silicon nitride and quartz. The promise of the approach as a versatile application oriented platform is highlighted by demonstrating its utility for creating super-hydrophobic surfaces, fabrication of nanoporous polymeric membranes, and controlling the areal density of physical vapor deposition derived titanium nitride nanostructures.
Collapse
Affiliation(s)
- S Krishnamoorthy
- Centre Suisse d'Electronique et de Microtechnique SA, Jaquet Droz 1, CH-2007 Neuchâtel, Switzerland
| | | | | | | | | | | | | |
Collapse
|
28
|
Krishnamoorthy S, Pugin R, Hinderling C, Brugger J, Heinzelmann H. The systematic tunability of nanoparticle dimensions through the controlled loading of surface-deposited diblock copolymer micelles. Nanotechnology 2008; 19:175301. [PMID: 21825665 DOI: 10.1088/0957-4484/19/17/175301] [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] [Indexed: 05/07/2023]
Abstract
The continuous tunability of iron oxide nanoparticle dimensions is demonstrated using the pH controlled loading of ferric nitrate from aqueous solution into polystyrene-block-polyacrylic acid reverse micelles deposited on a silicon substrate. Quasi-hexagonally ordered two-dimensional arrays of iron oxide nanoparticles with a systematic tunability of particle heights in the sub-10 nm regime and a constant periodicity are obtained and characterized with atomic force microscopy and x-ray photoelectron spectroscopy.
Collapse
Affiliation(s)
- S Krishnamoorthy
- Centre Suisse d'Electronique et de Microtechnique SA, Jaquet Droz 1, CH-2007 Neuchâtel, Switzerland
| | | | | | | | | |
Collapse
|
29
|
Kiefer T, Favier F, Vazquez-Mena O, Villanueva G, Brugger J. A single nanotrench in a palladium microwire for hydrogen detection. Nanotechnology 2008; 19:125502. [PMID: 21817729 DOI: 10.1088/0957-4484/19/12/125502] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [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
The hydrogen sensing characteristics of a single nanotrench fabricated by focused ion beam milling (FIB) in an evaporated palladium microwire are presented. In situ atomic force microscopy (AFM) measurements proved that, in the presence of H(2), the trench closes and electrically connects the initially separated parts of the wire due to the increase in volume of the material. Therewith, an electrical current can be switched through the wire. With experiments under various H(2) concentrations and a mathematical model, we describe the closing mechanism of the trench with respect to various parameters, including the substrate material, film thickness, trench size and wire dimensions. Results have been compared with those from equivalent continuous wires. Thin SiO(2) and polyimide (PI) layers on silicon were used to study the effect of substrate elasticity. Sufficient lateral expansion of Pd to close trenches of up to 70 nm in width has only been observed on PI, which we attribute to its advantageous elastic properties. The scale of the response times allowed the observation of two superposing effects: the chemical conversion of Pd to PdH(x) and the mechanical closing of the trench.
Collapse
Affiliation(s)
- T Kiefer
- Microsystems Laboratory, Station 17, École Polytéchnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | | | | | | | | |
Collapse
|
30
|
Stahl C, Möller K, Schumann S, Brugger J, Guttmann J. Crit Care 2006; 10:P18. [DOI: 10.1186/cc4365] [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: 11/10/2022] Open
|
31
|
Bissinger AL, Brugger J, Grigoleit GU, Gründemann C, Hebart H, Einsele H, Jahn G. Visualization and microscopic quantification of HCMV-peptide-specific cytotoxic T lymphocytes using tetramer binding. Viral Immunol 2005; 18:534-8. [PMID: 16212532 DOI: 10.1089/vim.2005.18.534] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
To monitor the frequencies of virus-specific cytotoxic T lymphocytes (CTLs), FACS analyses were performed detecting lymphocyte-specific surface molecules and tetramer binding, as marker for peptide-specificity. Aim of this investigation was to establish an alternative protocol for the quantification of virus-specific CTLs using tetramer binding and microscopic analyzing. The frequencies of HCMV-pp65-peptide-specific CTLs in the blood of eight different HLA-A*0201-positive, HCMV-IgG antibody-positive donors were analyzed with both methods. Using FACS analyses, a median of 0.8% and, using the microscopic analyses, a median of 3.0% was detected in the CD3+CD8+ cells. After enrichment of HCMV-pp65-peptide-specific CTLs using the interferon-gamma secretion assay followed by expansion in cell culture, a median of 90.6% using FACS analyses and a median of 87.1% using the microscopic analyses was detected. Thus, the staining protocol presented in this investigation is an alternative approach to detect and to quantify virus-specific CTLs in low as well as in high frequencies.
Collapse
Affiliation(s)
- A L Bissinger
- Institut für Medizinische Virologie, Universitätsklinikum Tübingen, Elfriede-Aulhom-Strasse 6, D-72072 Tübingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
32
|
Kis A, Csányi G, Salvetat JP, Lee TN, Couteau E, Kulik AJ, Benoit W, Brugger J, Forró L. Reinforcement of single-walled carbon nanotube bundles by intertube bridging. Nat Mater 2004; 3:153-157. [PMID: 14991016 DOI: 10.1038/nmat1076] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Accepted: 01/19/2004] [Indexed: 05/24/2023]
Abstract
During their production, single-walled carbon nanotubes form bundles. Owing to the weak van der Waals interaction that holds them together in the bundle, the tubes can easily slide on each other, resulting in a shear modulus comparable to that of graphite. This low shear modulus is also a major obstacle in the fabrication of macroscopic fibres composed of carbon nanotubes. Here, we have introduced stable links between neighbouring carbon nanotubes within bundles, using moderate electron-beam irradiation inside a transmission electron microscope. Concurrent measurements of the mechanical properties using an atomic force microscope show a 30-fold increase of the bending modulus, due to the formation of stable crosslinks that effectively eliminate sliding between the nanotubes. Crosslinks were modelled using first-principles calculations, showing that interstitial carbon atoms formed during irradiation in addition to carboxyl groups, can independently lead to bridge formation between neighbouring nanotubes.
Collapse
Affiliation(s)
- A Kis
- Institute of Physics of Complex Matter, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Kim GM, Kim BJ, Ten Have ES, Segerink F, Van Hulst NF, Brugger J. Photoplastic near-field optical probe with sub-100 nm aperture made by replication from a nanomould. J Microsc 2003; 209:267-71. [PMID: 12641773 DOI: 10.1046/j.1365-2818.2003.01134.x] [Citation(s) in RCA: 7] [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: 11/20/2022]
Abstract
Polymers have the ability to conform to surface contours down to a few nanometres. We studied the filling of transparent epoxy-type EPON SU-8 into nanoscale apertures made in a thin metal film as a new method for polymer/metal near-field optical structures. Mould replica processes combining silicon micromachining with the photo-curable SU-8 offer great potential for low-cost nanostructure fabrication. In addition to offering a route for mass production, the transparent pyramidal probes are expected to improve light transmission thanks to a wider geometry near the aperture. By combining silicon MEMS, mould geometry tuning by oxidation, anti-adhesion coating by self-assembled monolayer and mechanical release steps, we propose an advanced method for near-field optical probe fabrication. The major improvement is the possibility to fabricate nanoscale apertures directly on wafer scale during the microfabrication process and not on free-standing tips. Optical measurements were performed with the fabricated probes. The full width half maximum after a Gaussian fit of the intensity profile indicates a lateral optical resolution of approximately 60 nm.
Collapse
Affiliation(s)
- G M Kim
- Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland MESA Research Institute, University of Twente, The Netherlands.
| | | | | | | | | | | |
Collapse
|
34
|
Kim GM, Kovalgin A, Holleman J, Brugger J. Replication molds having nanometer-scale shape control fabricated by means of oxidation and etching. J Nanosci Nanotechnol 2002; 2:55-59. [PMID: 12908321 DOI: 10.1166/jnn.2002.073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A means of accurate control of the curvature radius of molds that are used in nanostructure replication techniques is presented. The local non-uniform growth of SiO2 at regions with high curvature is used to fabricate molds with a curvature radius ranging anywhere between 10 and 250 nm. The mold radius is predicted by numerical simulation as a function of oxidation temperature and time and confirmed by a series of oxidation and etching experiments. The silicon, silicon dioxide, and polymer nanostructures are analyzed by scanning electron microscopy and compared with the theory. Replication into photo-plastic polymer from various sharp and round molds is performed, and their properties are discussed. Our results are useful for designing nanostructures in the area of soft lithography and nanoprobe engineering.
Collapse
Affiliation(s)
- G M Kim
- Institute of Microelectronics and Microsystems, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | | | | | | |
Collapse
|
35
|
Abstract
The inexpensive fabrication of high-quality probes for near-field optical applications is still unsolved although several methods for integrated fabrication have been proposed in the past. A further drawback is the intensity loss of the transmitted light in the 'cut-off' region near the aperture in tapered optical fibres typically used as near-field probes. As a remedy for these limitations we suggest here a new wafer-scale semibatch microfabrication process for transparent photoplastic probes. The process starts with the fabrication of a pyramidal mould in silicon by using the anisotropic etchant potassium hydroxide. This results in an inverted pyramid limited by < 111 > silicon crystal planes having an angle of approximately 54 degrees. The surface including the mould is covered by a approximately 1.5 nm thick organic monolayer of dodecyltrichlorosilane (DTS) and a 100-nm thick evaporated aluminium film. Two layers of photoplastic material are then spin-coated (thereby conformal filling the mould) and structured by lithography to form a cup for the optical fibre microassembly. The photoplastic probes are finally lifted off mechanically from the mould with the aluminium coating. Focused ion beam milling has been used to subsequently form apertures with diameters in the order of 80 nm. The advantage of our method is that the light to the aperture area can be directly coupled into the probe by using existing fibre-based NSOM set-ups, without the need for far-field alignment, which is typically necessary for cantilevered probes. We have evidence that the aluminium layer is considerably smoother compared to the 'grainy' layers typically evaporated on free-standing probes. The optical throughput efficiency was measured to be about 10-4. This new NSOM probe was directly bonded to a tuning fork sensor for the shear force control and the topography of a polymer sample was successfully obtained.
Collapse
Affiliation(s)
- B J Kim
- Strategic Research Orientation NanoLink and Applied Optics Group, MESA+ Research Institute, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | | | | | | | | | | |
Collapse
|
36
|
Tschudi J, Wagner M, Klaiber C, Brugger J, Frei E, Krähenbühl L, Inderbitzi R, Hüsler J, Hsu Schmitz S. Controlled multicenter trial of laparoscopic transabdominal preperitoneal hernioplasty vs Shouldice herniorrhaphy. Early results. Surg Endosc 1996; 10:845-7. [PMID: 8694951 DOI: 10.1007/bf00189547] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND In February 1993 a prospective randomized multicenter trial was initiated to compare laparoscopic transabdominal preperitoneal hernioplasty to Shouldice herniorrhaphy as performed by surgeons of nonspecialized clinics. METHODS Until January 1994, 87 patients with 108 hernias took part in the trial (43 Shouldice and 44 laparoscopic repairs). RESULTS The laparoscopic procedure took significantly longer than did the open operation but caused less pain as measured by pain analogue score and consumption of paracetamol and narcotics. The postoperative complication rate was 26% in the open and 16% in the laparoscopic group. The patients in the laparoscopic group were discharged earlier and their convalescence was shorter than after open hernia repair. There has been one early recurrence in the laparoscopic and two in the open group to date with a mean follow-up of 201 days. CONCLUSIONS Laparoscopic hernia repair causes less pain than the conventional operation and enables the patient to return to full work and usual activities earlier. The recurrence rate will not be known for 5 years.
Collapse
Affiliation(s)
- J Tschudi
- Department of Surgery, Aarberg Hospital, CH-3270 Aarberg, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Lindsay RM, Burbank J, Brugger J, Bradfield E, Kram R, Malek P, Blake PG. A device and a method for rapid and accurate measurement of access recirculation during hemodialysis. Kidney Int 1996; 49:1152-60. [PMID: 8691737 DOI: 10.1038/ki.1996.166] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- R M Lindsay
- Optimal Dialysis Research Unit, Victoria Hospital, London, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
38
|
|