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Georgopoulou A, Filippi M, Stefani L, Drescher F, Balciunaite A, Scherberich A, Katzschmann R, Clemens F. Bioprinting of Stable Bionic Interfaces Using Piezoresistive Hydrogel Organoelectronics. Adv Healthc Mater 2024:e2400051. [PMID: 38666593 DOI: 10.1002/adhm.202400051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/23/2024] [Indexed: 05/04/2024]
Abstract
Bionic tissues offer an exciting frontier in biomedical research by integrating biological cells with artificial electronics, such as sensors. One critical hurdle is the development of artificial electronics that can mechanically harmonize with biological tissues, ensuring a robust interface for effective strain transfer and local deformation sensing. In this study, a highly tissue-integrative, soft mechanical sensor fabricated from a composite piezoresistive hydrogel. The composite not only exhibits exceptional mechanical properties, with elongation at the point of fracture reaching up to 680%, but also maintains excellent biocompatibility across multiple cell types. Furthermore, the material exhibits bioadhesive qualities, facilitating stable cell adhesion to its surface. A unique advantage of the formulation is the compatibility with 3D bioprinting, an essential technique for fabricating stable interfaces. A multimaterial sensorized 3D bionic construct is successfully bioprinted, and it is compared to structures produced via hydrogel casting. In contrast to cast constructs, the bioprinted ones display a high (87%) cell viability, preserve differentiation ability, and structural integrity of the sensor-tissue interface throughout the tissue development duration of 10 d. With easy fabrication and effective soft tissue integration, this composite holds significant promise for various biomedical applications, including implantable electronics and organ-on-a-chip technologies.
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Affiliation(s)
- Antonia Georgopoulou
- High Performance Ceramics Laboratory, Empa, Swiss Federal Laboratories for Material Science and Technology, Dübendorf, 8600, Switzerland
| | - Miriam Filippi
- Soft Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Lisa Stefani
- Soft Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, 8092, Switzerland
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Felix Drescher
- Soft Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Aiste Balciunaite
- Soft Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Arnaud Scherberich
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Robert Katzschmann
- Soft Robotics Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, 8092, Switzerland
| | - Frank Clemens
- High Performance Ceramics Laboratory, Empa, Swiss Federal Laboratories for Material Science and Technology, Dübendorf, 8600, Switzerland
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Georgopoulou A, Diethelm P, Wagner M, Spolenak R, Clemens F. Soft Self-Regulating Heating Elements for Thermoplastic Elastomer-Based Electronic Skin Applications. 3D Print Addit Manuf 2024; 11:e828-e838. [PMID: 38689932 PMCID: PMC11057689 DOI: 10.1089/3dp.2022.0242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Resistive heating elements can be of particular interest for many applications, such as e-skin. In this study, soft heating elements were developed by combining thermoplastic polyurethane (TPU) with carbon black. In contrast to previous studies on thermoplastic polymer-based thermistors, the heating elements could endure elongations above 100%. Due to the high melting point of the TPU and the carbon filler, the thermistors could be heated up to 180°C without significant deformation. The heating elements were extruded on TPU substrates using material extrusion additive manufacturing in one-step process. Self-regulating behavior to control the maximum temperature was achieved with the application of two different voltages (20 and 25 V) and different current thresholds, between 100 and 800 mA. The heating performance was adjusted by changing the geometry of the sensing elements; an increase in cross section resulted in a lower current density and lower temperature. For the heating elements, variation of the additive manufacturing parameters such as offset, layer height, nozzle speed, and extrusion multiplier resulted in a different width/height aspect ratio of the cross section of the extruded lines, affecting the initial resistivity of the thermistor. Orientation of the carbon filler during extrusion process is one reason for the small change of the longitudinal conductivity of the heating elements. The resulting skin with the integrated heating elements allowed the possibility to perform the in situ heating for the localized healing of structural damage, while maintaining the softness required for the application of soft robotic electronic skin.
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Affiliation(s)
- Antonia Georgopoulou
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
- Brubotics, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Pascal Diethelm
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Marius Wagner
- Laboratory for Nanometallurgy, Department of Materials, ETH Zürich, Zürich, Switzerland
| | - Ralph Spolenak
- Laboratory for Nanometallurgy, Department of Materials, ETH Zürich, Zürich, Switzerland
| | - Frank Clemens
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
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Promsung R, Chuaybamrung A, Georgopoulou A, Clemens F, Nakaramontri Y, Johns J, Lehman N, Songtipya L, Kalkornsurapranee E. Rapid formation of carbon nanotubes-natural rubber films cured with glutaraldehyde for reducing percolation threshold concentration. Discov Nano 2024; 19:30. [PMID: 38372836 PMCID: PMC10876504 DOI: 10.1186/s11671-024-03970-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/07/2024] [Indexed: 02/20/2024]
Abstract
Carbon nanotubes (CNTs) filled natural rubber (NR) composites with various CNT contents at 0, 1, 2, 3, 4 and 5 phr were prepared by latex mixing method using glutaraldehyde as curing agent. This work aims to improve the electrical and mechanical properties of CNT filled NR vulcanizates. The CNT dispersion of NR composites was clarified using dispersion grader, optical microscopy and scanning electron microscopy. The electrical properties of NR composites in the existing of CNT networks were studied by following the well-known percolation theory. It was observed that the NR composites exhibited low percolation threshold at 0.98 phr of CNT. Moreover, a three-dimensional network formation of CNT in the NR composites was observed and it is indicated by the t-value of 1.67. The mechanical properties of NR composites in terms of modulus, tensile strength and hardness properties were increased upon the addition of CNT to the optimum mechanical properties at 1 phr of CNT. Therefore, the present work is found the novelty of the study that the conductive rubber latex film can be produced using GA as low-temperature curing agent which enhanced good electrical properties. Moreover, this work is found to be beneficial in case of conductive rubber latex film that requires high modulus at low strain. The additional advantage of this system is the curing process occurs at low-temperature using GA and it can be easily processed.
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Affiliation(s)
- Rawiporn Promsung
- Division of Physical Sciences, Faculty of Science, Prince of Songkla University, Hat-Yai, Thailand
- Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Arthittaya Chuaybamrung
- Division of Physical Sciences, Faculty of Science, Prince of Songkla University, Hat-Yai, Thailand
| | - Antonia Georgopoulou
- Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Frank Clemens
- Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Yeampon Nakaramontri
- Sustainable Polymer and Innovative Composite Materials Research Group, Department of Chemistry, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Jobish Johns
- Department of Physics, Rajarajeswari College of Engineering, Bangalore, India
| | - Nussana Lehman
- Division of Physical Sciences, Faculty of Science, Prince of Songkla University, Hat-Yai, Thailand
| | - Ladawan Songtipya
- Center of Excellence in Bio-Based Materials and Packaging Innovation, Faculty of Agro-Industry, Prince of Songkla University, Hat-Yai, Thailand
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Georgopoulou A, Hardman D, Thuruthel TG, Iida F, Clemens F. Sensorized Skin With Biomimetic Tactility Features Based on Artificial Cross-Talk of Bimodal Resistive Sensory Inputs. Adv Sci (Weinh) 2023; 10:e2301590. [PMID: 37679081 PMCID: PMC10602557 DOI: 10.1002/advs.202301590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/15/2023] [Indexed: 09/09/2023]
Abstract
Tactility in biological organisms is a faculty that relies on a variety of specialized receptors. The bimodal sensorized skin, featured in this study, combines soft resistive composites that attribute the skin with mechano- and thermoreceptive capabilities. Mimicking the position of the different natural receptors in different depths of the skin layers, a multi-layer arrangement of the soft resistive composites is achieved. However, the magnitude of the signal response and the localization ability of the stimulus change with lighter presses of the bimodal skin. Hence, a learning-based approach is employed that can help achieve predictions about the stimulus using 4500 probes. Similar to the cognitive functions in the human brain, the cross-talk of sensory information between the two types of sensory information allows the learning architecture to make more accurate predictions of localization, depth, and temperature of the stimulus contiguously. Localization accuracies of 1.8 mm, depth errors of 0.22 mm, and temperature errors of 8.2 °C using 8 mechanoreceptive and 8 thermoreceptive sensing elements are achieved for the smaller inter-element distances. Combining the bimodal sensing multilayer skins with the neural network learning approach brings the artificial tactile interface one step closer to imitating the sensory capabilities of biological skin.
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Affiliation(s)
- Antonia Georgopoulou
- Department of Functional MaterialsEmpa ‐ Swiss Federal Laboratories for Materials Science and Technology8600Switzerland
| | - David Hardman
- Bio‐Inspired Robotics LabDepartment of EngineeringUniversity of CambridgeCB2 1PZUK
| | - Thomas George Thuruthel
- Bio‐Inspired Robotics LabDepartment of EngineeringUniversity of CambridgeCB2 1PZUK
- Department of Computer ScienceUniversity College LondonE20 2AFUK
| | - Fumiya Iida
- Bio‐Inspired Robotics LabDepartment of EngineeringUniversity of CambridgeCB2 1PZUK
| | - Frank Clemens
- Department of Functional MaterialsEmpa ‐ Swiss Federal Laboratories for Materials Science and Technology8600Switzerland
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Georgopoulou A, Srisawadi S, Wiroonpochit P, Clemens F. Soft Wearable Piezoresistive Sensors Based on Natural Rubber Fabricated with a Customized Vat-Based Additive Manufacturing Process. Polymers (Basel) 2023; 15:polym15102410. [PMID: 37242985 DOI: 10.3390/polym15102410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/09/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023] Open
Abstract
Piezoresistive sensors for monitoring human motions are essential for the prevention and treatment of injury. Natural rubber is a material of renewable origin that can be used for the development of soft wearable sensors. In this study, natural rubber was combined with acetylene black to develop a soft piezoresistive sensing composite for monitoring the motion of human joints. An additive manufacturing technique based on stereolithography was used, and it was seen that the sensors produced with the method could detect even small strains (<10%) successfully. With the same sensor composite fabricated by mold casting, it was not possible to detect low strains reliably. TEM microscopy revealed that the distribution of the filler was not homogeneous for the cast samples, suggesting a directionality of the conductive filler network. For the sensors fabricated through the stereolithography-based method, a homogeneous distribution could be achieved. Based on mechano-electrical characterization, it was seen that the samples produced with AM combined the ability to endure large elongations with a monotonic sensor response. Under dynamic conditions, the sensor response of the samples produced by 3D printing showed lower drift and lower signal relaxation. The piezoresistive sensors were examined for monitoring the motion of the human finger joints. By increasing the bending angle of the sensor, it was possible to increase the sensitivity of the response. With the renewable origin of natural rubber and manufacturing method, the featured sensors can expand the applicability of soft flexible electronics in biomedical applications and devices.
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Affiliation(s)
- Antonia Georgopoulou
- Department of Advanced Materials and Surfaces, Empa-Swiss Federal Laboratories for Material Science and Technology, Ueberlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Sasitorn Srisawadi
- National Metal and Materials Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Panithi Wiroonpochit
- National Metal and Materials Technology Center, National Science and Technology Development Agency, 114 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Frank Clemens
- Department of Advanced Materials and Surfaces, Empa-Swiss Federal Laboratories for Material Science and Technology, Ueberlandstrasse 129, 8600 Dübendorf, Switzerland
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Sripornsawat B, Georgopoulou A, Tulaphol S, Thitithammawong A, Johns J, Nakaramontri Y, Clemens F. Use of modified deep eutectic solvent as an additional chemical in a flexible conductive natural rubber sensor for motion analysis. EXPRESS POLYM LETT 2023. [DOI: 10.3144/expresspolymlett.2023.6] [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: 11/06/2022] Open
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Hardman D, George Thuruthel T, Georgopoulou A, Clemens F, Iida F. 3D Printable Soft Sensory Fiber Networks for Robust and Complex Tactile Sensing. Micromachines (Basel) 2022; 13:1540. [PMID: 36144163 PMCID: PMC9502117 DOI: 10.3390/mi13091540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
The human tactile system is composed of multi-functional mechanoreceptors distributed in an optimized manner. Having the ability to design and optimize multi-modal soft sensory systems can further enhance the capabilities of current soft robotic systems. This work presents a complete framework for the fabrication of soft sensory fiber networks for contact localization, using pellet-based 3D printing of piezoresistive elastomers to manufacture flexible sensory networks with precise and repeatable performances. Given a desirable soft sensor property, our methodology can design and fabricate optimized sensor morphologies without human intervention. Extensive simulation and experimental studies are performed on two printed networks, comparing a baseline network to one optimized via an existing information theory based approach. Machine learning is used for contact localization based on the sensor responses. The sensor responses match simulations with tunable performances and good localization accuracy, even in the presence of damage and nonlinear material properties. The potential of the networks to function as capacitive sensors is also demonstrated.
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Affiliation(s)
- David Hardman
- Bio-Inspired Robotics Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
| | - Thomas George Thuruthel
- Bio-Inspired Robotics Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
| | - Antonia Georgopoulou
- Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Duebendorf, Switzerland
- Brubotics, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels, Belgium
| | - Frank Clemens
- Department of Functional Materials, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Duebendorf, Switzerland
| | - Fumiya Iida
- Bio-Inspired Robotics Laboratory, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK
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Georgopoulou A, Vanderborght B, Clemens F. Fabrication of a Soft Robotic Gripper With Integrated Strain Sensing Elements Using Multi-Material Additive Manufacturing. Front Robot AI 2021; 8:615991. [PMID: 35372524 PMCID: PMC8965514 DOI: 10.3389/frobt.2021.615991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 09/24/2021] [Indexed: 01/01/2023] Open
Abstract
With the purpose of making soft robotic structures with embedded sensors, additive manufacturing techniques like fused deposition modeling (FDM) are popular. Thermoplastic polyurethane (TPU) filaments, with and without conductive fillers, are now commercially available. However, conventional FDM still has some limitations because of the marginal compatibility with soft materials. Material selection criteria for the available material options for FDM have not been established. In this study, an open-source soft robotic gripper design has been used to evaluate the FDM printing of TPU structures with integrated strain sensing elements in order to provide some guidelines for the material selection when an elastomer and a soft piezoresistive sensor are combined. Such soft grippers, with integrated strain sensing elements, were successfully printed using a multi-material FDM 3D printer. Characterization of the integrated piezoresistive sensor function, using dynamic tensile testing, revealed that the sensors exhibited good linearity up to 30% strain, which was sufficient for the deformation range of the selected gripper structure. Grippers produced using four different TPU materials were used to investigate the effect of the Shore hardness of the TPU on the piezoresistive sensor properties. The results indicated that the in situ printed strain sensing elements on the soft gripper were able to detect the deformation of the structure when the tentacles of the gripper were open or closed. The sensor signal could differentiate between the picking of small or big objects and when an obstacle prevented the tentacles from opening. Interestingly, the sensors embedded in the tentacles exhibited good reproducibility and linearity, and the sensitivity of the sensor response changed with the Shore hardness of the gripper. Correlation between TPU Shore hardness, used for the gripper body and sensitivity of the integrated in situ strain sensing elements, showed that material selection affects the sensor signal significantly.
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Affiliation(s)
- Antonia Georgopoulou
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
- Department of Mechanical Engineering (MECH), Vrije Universiteit Brussel (VUB), and Flanders Make, Brussels, Belgium
- *Correspondence: Antonia Georgopoulou, ; Frank Clemens,
| | - Bram Vanderborght
- Department of Mechanical Engineering (MECH), Vrije Universiteit Brussel (VUB), and Flanders Make, Brussels, Belgium
| | - Frank Clemens
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
- *Correspondence: Antonia Georgopoulou, ; Frank Clemens,
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Georgopoulou A, Michel S, Clemens F. Sensorized Robotic Skin Based on Piezoresistive Sensor Fiber Composites Produced with Injection Molding of Liquid Silicone. Polymers (Basel) 2021; 13:polym13081226. [PMID: 33920142 PMCID: PMC8070002 DOI: 10.3390/polym13081226] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 11/16/2022] Open
Abstract
Soft robotics and flexible electronics are rising in popularity and can be used in many applications. However, there is still a need for processing routes that allow the upscaling in production for functional soft robotic parts in an industrial scale. In this study, injection molding of liquid silicone is suggested as a fabrication method for sensorized robotic skin based on sensor fiber composites. Sensor fibers based on thermoplastic elastomers with two different shore hardness (50A and 70A) are combined with different silicone materials. A mathematical model is used to predict the mechanical load transfer from the silicone matrix to the fiber and shows that the matrix of the lowest shore hardness should not be combined with the stiffer fiber. The sensor fiber composites are fixed on a 3D printed robotic finger. The sensorized robotic skin based on the composite with the 50A fiber in combination with pre-straining gives good sensor performance as well as a large elasticity. It is proposed that a miss-match in the mechanical properties between fiber sensor and matrix should be avoided in order to achieve low drift and relaxation. These findings can be used as guidelines for material selection for future sensor integrated soft robotic systems.
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Affiliation(s)
- Antonia Georgopoulou
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
- Department of Mechanical Engineering (MECH), Vrije Universiteit Brussel (VUB), and Flanders Make Pleinlaan 2, B-1050 Brussels, Belgium
- Correspondence: (A.G.); (F.C.)
| | - Silvain Michel
- Department of Engineering Sciences, Empa–Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland;
| | - Frank Clemens
- Department of Functional Materials, Empa–Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
- Correspondence: (A.G.); (F.C.)
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Thuruthel TG, Hughes J, Georgopoulou A, Clemens F, Iida F. Using Redundant and Disjoint Time-Variant Soft Robotic Sensors for Accurate Static State Estimation. IEEE Robot Autom Lett 2021. [DOI: 10.1109/lra.2021.3061399] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Clemens F, Melnykowycz M, Bar F, Goldenstein D, Georgopoulou A. 2D Printing of Piezoresistive Auxetic Silicone Sensor Structures. IEEE Robot Autom Lett 2021. [DOI: 10.1109/lra.2021.3062000] [Citation(s) in RCA: 3] [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: 11/09/2022]
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Mylona V, Vaki I, Lymberopoulou K, Marioli A, Georgopoulou A, Lada M, Giamarellos-Bourboulis E, Koratzanis G. Alterations of the immune system in acute pancreatitis and systematic inflammatory response syndrome. Crit Care 2009. [PMCID: PMC4084033 DOI: 10.1186/cc7311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Choustoulakis I, Bornivelli C, Georgopoulou A, Karkazis E. Consumption of alcohol from adolescents students of school in Greece. Eur Psychiatry 2008. [DOI: 10.1016/j.eurpsy.2008.01.1050] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Heras P, Kritikos K, Georgopoulou A, Hatzopoulos A, Kritikos N. Spirituality and religion in terminally ill patients with cancer. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.19587] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
19587 Background: The importance of spirituality and religion in coping with a terminal illness is becoming increasingly recognised. We aimed to assess the relation between spiritual well-being, religiosity, depression, and end-of-life despair in terminally-ill cancer patients. Methods: One hundred forty three terminally ill cancer patients with a life expectancy of less than 6 months were interviewed with a series of standardised instruments, including the FACIT Spiritual Well-Being Scale, a religiosity index similar to those used in previous research, the Hamilton depression rating scale, the Memorial Symptom Assessment Scale and the Duke-UNC Functional Social Support Questionnaire. Results: A strong negative association was observed between the FACIT Spiritual Well-Being scale and the HDRS, but no such relationship was found for religiosity. Similar patterns were observed for the FACIT subscales, finding a strong negative association between the meaning and peace subscale (which corresponds to the more existential aspects of spirituality) and HDRS scores, whereas a positive, albeit nonsignificant, association was observed for the faith subscale (which corresponds more closely to religiosity). Conclusions: These results suggest that the beneficial aspects of religion may be primarily those that relate to spiritual well-being rather than to religious practices per se. Spiritual well-being offers some protection against end-of-life despair in those for whom death is imminent. The area of spiritual work is fertile ground for further investigation, especially interventions aimed at improving spiritual health and general quality of life among terminally ill patients with cancer. No significant financial relationships to disclose.
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Affiliation(s)
- P. Heras
- Hellenic Med Soc Study Phychosomatic Disorders, Athens, Greece
| | - K. Kritikos
- Hellenic Med Soc Study Phychosomatic Disorders, Athens, Greece
| | - A. Georgopoulou
- Hellenic Med Soc Study Phychosomatic Disorders, Athens, Greece
| | - A. Hatzopoulos
- Hellenic Med Soc Study Phychosomatic Disorders, Athens, Greece
| | - N. Kritikos
- Hellenic Med Soc Study Phychosomatic Disorders, Athens, Greece
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Heras P, Hatzopoulos A, Georgopoulou A, Kritikos K. CLC031 POSTER Effectiveness of zoladronic acid (ZA) in lung cancer patients with bone metastases. Lung Cancer 2007. [DOI: 10.1016/s0169-5002(07)70031-4] [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: 10/23/2022]
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Heras P, Hatzopoulos A, Kritikos K, Georgopoulou A. CLC035 POSTER The level of thyroid hormones in patients of different ages groups with lung cancer and non-tumor lung diseases. Lung Cancer 2007. [DOI: 10.1016/s0169-5002(07)70035-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Heras P, Hatzopoulos A, Kritikos K, Georgopoulou A. CLC036 POSTER Relationship between age treatment and overall survival in patients with non-small cell lung cancer (NSCLC). Lung Cancer 2007. [DOI: 10.1016/s0169-5002(07)70036-3] [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: 11/25/2022]
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Heras P, Hatzopoulos A, Kritikos K, Georgopoulou A. CLC029 POSTER Epoetin beta (30000 IU) vs. Epoetin alfa (40000 IU) for chemotherapy induced anemia in patients with lung cancer: a randomized comparative study. Lung Cancer 2007. [DOI: 10.1016/s0169-5002(07)70029-6] [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: 11/15/2022]
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Heras P, Hatzopoulos A, Kritikos K, Georgopoulou A. CLC034 POSTER Death predictive symptoms in patients with lung cancer. Lung Cancer 2007. [DOI: 10.1016/s0169-5002(07)70034-x] [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: 10/23/2022]
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Abstract
18569 The aim of this study was to identify and describe the importance of information for patients about sexuality related issues during hospitalization. 112 patients (87 with colorectal cancer) completed the structural questionnaire. Most colorectal cancer patients (71%) reported that their disease or its treatment had affected their sexuality. Men reported slightly more adverse effects of disease or treatment on their sexuality than did women. Effects on sexuality were reported by 77% of men and 64% of women (p=0,041) having colorectal cancer. Among younger colorectal cancer patients reported more often effects of disease than did older colorectal cancer respondents. Over than half, 75% (n=84) of respondents under 40 and 67% (n= 75) of respondents over 50 years old complained effect on sexuality. Most colorectal cancer patients (72%) stated that it is necessary to discuss about the effect of the disease and of its treatment on sexuality during hospitalization. Most colorectal cancer patients (87%) wanted the health care personnel to take the initiative for the discussion of sexuality related issues. Only 12% expressed the wish that the initiative should come from the patient. It is important that health care professionals provide colorectal cancer patients with an opportunity to discuss sexuality related issues. The caring organization should develop, introduce and evaluate action models to facilitate especially opening discussion for these sensitive issues. No significant financial relationships to disclose.
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Affiliation(s)
- S. Karagiannis
- General Hospital of Nafplio, Nafplio, Greece; General Hospital of Nafplio, Athens Kypseli, Greece
| | - P. Heras
- General Hospital of Nafplio, Nafplio, Greece; General Hospital of Nafplio, Athens Kypseli, Greece
| | - A. Hatzopoulos
- General Hospital of Nafplio, Nafplio, Greece; General Hospital of Nafplio, Athens Kypseli, Greece
| | - A. Georgopoulou
- General Hospital of Nafplio, Nafplio, Greece; General Hospital of Nafplio, Athens Kypseli, Greece
| | - K. Kritikos
- General Hospital of Nafplio, Nafplio, Greece; General Hospital of Nafplio, Athens Kypseli, Greece
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21
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Markoulatos P, Georgopoulou A, Siafakas N, Plakokefalos E, Tzanakaki G, Kourea-Kremastinou J. Laboratory diagnosis of common herpesvirus infections of the central nervous system by a multiplex PCR assay. J Clin Microbiol 2001; 39:4426-32. [PMID: 11724856 PMCID: PMC88560 DOI: 10.1128/jcm.39.12.4426-4432.2001] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [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: 11/20/2022] Open
Abstract
A sensitive multiplex PCR assay for single-tube amplification that detects simultaneous herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), varicella-zoster virus (VZV), human cytomegalovirus (CMV), and Epstein-Barr virus (EBV) is reported with particular emphasis on how the method was optimized and carried out and its sensitivity was compared to previously described assays. The assay has been used on a limited number of clinical samples and must be thoroughly evaluated in the clinical context. A total of 86 cerebrospinal fluid (CSF) specimens from patients which had the clinical symptoms of encephalitis, meningitis or meningoencephalitis were included in this study. The sensitivity of the multiplex PCR was determined to be 0.01 and 0.03 50% tissue culture infective doses/the reciprocal of the highest dilution positive by PCR for HSV-1 and HSV-2 respectively, whereas for VZV, CMV and EBV, 14, 18, and 160 ag of genomic DNA were detected corresponding to 48, 66, and 840 genome copies respectively. Overall, 9 (10.3%) of the CSF samples tested were positive in the multiplex PCR. HSV-1 was detected in three patients (3.5%) with encephalitis, VZV was detected in four patients (4.6%) with meningitis, HSV-2 was detected in one neonate (1.16%), and CMV was also detected in one neonate (1.16%). None of the samples tested was positive for the EBV genome. None of the nine positive CSF samples presented herpesvirus coinfection in the central nervous system. Failure of DNA extraction or failure to remove any inhibitors of DNA amplification from CSF samples was avoided by the inclusion in the present multiplex PCR assay of alpha-tubulin primers. The present multiplex PCR assay detects simultaneously five different herpesviruses and sample suitability for PCR in a single amplification round of 40 cycles with an excellent sensitivity and can, therefore, provide an early, rapid, reliable noninvasive diagnostic tool allowing the application of antiviral therapy on the basis of a specific viral diagnosis. The results of this preliminary study should prompt a more exhaustive analysis of the clinical value of the present multiplex PCR assay.
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Affiliation(s)
- P Markoulatos
- Department of Virology, Hellenic Pasteur Institute, Athens, Greece.
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22
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Georgopoulou A, Markoulatos P, Spyrou N, Vakalis N, Bei TA, Vamvakopoulos NC. High sequence divergence in the 5' non-coding region of reference Coxsackie B and ECHO viral strains and clinical isolates revealed by restriction fragment length polymorphism analysis. Mol Cell Probes 2001; 15:317-27. [PMID: 11851375 DOI: 10.1006/mcpr.2001.0380] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report the restriction fragment length polymorphism (RFLP) patterns of a 440-bp-long 5' non-coding region (5' NCR) amplification target of all 34 reference Coxsackie B and ECHO (enteric cytopathic human orphan) enterovirus strains and a total of 42 serotypically pre-assigned clinical isolates, in order to afford meaningful comparisons among these patterns and those of polioviruses. The RFLP patterns of reference Coxsackie B strains differed from one another and from those of polio and ECHO reference enteroviruses except from Coxsackie B1 and B2, which, although they differed from one another, had identical RFLP patterns with ECHO 17 and 13, respectively. The 28 ECHO reference strains formed a more variable viral group including strains with RFLP patterns distinct from one another and from those of polio and Coxsackie B enteroviruses, and others with RFLP pattern identities common to other ECHO viruses and Coxsackie B1 and B2 but not polioviruses. The RFLP patterns of the clinical isolates and their corresponding serotypically assigned reference Coxsackie B and ECHO strains presented the most notable variations. The observed differences between serotype and genotype-dependent assignments within the 440-bp long 5' NCR target sequence of Coxsackie B and ECHO enteroviruses were in sharp contrast to the analogous situation with polioviruses. These findings support the specificity of the described method for clinical diagnostic genotyping of polioviruses and demonstrate that the 440-bp-long target sequence follows a different evolutionary process in polio and non-polio enteroviruses that is particularly prominent between reference non-polio strains and their serotypically assigned clinical isolates.
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Affiliation(s)
- A Georgopoulou
- Department of Virology, Hellenic Pasteur Institute, 127 Vas. Sofias Ave, Athens 11521, Greece
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23
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Abstract
Attenuated strains of the Sabin oral poliovirus vaccine replicate in the human gut and, in rare cases, cause vaccine-associated paralytic poliomyelitis. In the present study, 15 vaccine-derived strains isolated from patients with vaccine-associated paralytic poliomyelitis and from healthy vaccinees were examined. Four distant sequences of the poliovirus genome (5' NCR, VP3/VP1, VP1/2A, and 3DPol/3' NCR) were targeted, and the reverse-transcribed segments were amplified by polymerase chain reaction followed by restriction fragment length polymorphism analysis with four restriction enzymes. Among the 15 isolates (11 Sabin type 2, 3 Sabin type 1, and 1 Sabin type 3), four Sabin type 2 isolates (36%) were found to be intertypic vaccine/vaccine recombinant in the 3DPol/3' NCR region of the viral genome. The recombinant genotypes identified were S2/S2/S1 for two isolates and S2/S2/S2/S3 and S2/S2/S1/S2 for each of the other two isolates, respectively. Recombinant viruses with unmodified segments in the 5' NCR and the VP3/VP1 regions of the viral genome, a modified segment in the VPI/2A region only for one strain, and an often recombinant segment in the 3DPol/3' NCR parts of the genome were so identified. These findings provide strong evidence that recombination is a frequent phenomenon in type 2 poliovirus vaccine strains and suggest that recombination may be an important mechanism of the natural evolution of polioviruses of Sabin type 2 origin, perhaps even one of the mechanisms of reversion of attenuated vaccine strains toward neurovirulence.
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Affiliation(s)
- A Georgopoulou
- Enterovirus Reference Center for South Greece, Department of Virology, Hellenic Pasteur Institute, Athens
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Siafakas N, Georgopoulou A, Markoulatos P, Spyrou N, Stanway G. Molecular detection and identification of an enterovirus during an outbreak of aseptic meningitis. J Clin Lab Anal 2001; 15:87-95. [PMID: 11291111 PMCID: PMC6808114 DOI: 10.1002/jcla.7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Stool samples from sixteen cases of children with meningitis originating from four different and geographically isolated parts of Greece were investigated for enteroviruses. The conventional method of cell culture in four different cell lines was initially used for the isolation of enteroviruses. The results showed a cytopathic effect (CPE) in all cases after two, or even more successive passages in only one cell line (RD), although a less-than-satisfactory CPE was obtained in many cases. Seroneutralization with RIVM mixed hyperimmune antisera followed and the isolates were typed as Coxsackie B viruses. The method of RT-PCR with enterovirus-specific primers targeted to the highly conserved 5'-UTR of the genome was initially used for the detection of enteroviruses from the inoculated cell cultures. A positive RT-PCR result was obtained for all of the clinical samples rapidly and accurately and the isolates were further characterized with the aid of Restriction Fragment Length Polymorphism (RFLP) analysis and Single Strand Conformation Polymorphism analysis (SSCP) of the amplicons. The RFLP analysis showed first of all that the isolates had an identical restriction pattern with Coxsackie B5 Faulkner reference strain with 4 out of 5 restriction enzymes and secondly, both RFLP and SSCP analysis indicated the epidemiological association of the isolates. The speed of the molecular methodology that was used in comparison with the conventional methods and its possible significance for the description of virus evolution and circulation in the populations is discussed.
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Affiliation(s)
- N Siafakas
- University of Essex, Department of Biological Sciences, John Tabor Laboratories, Essex, England
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25
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Georgopoulou A, Markoulatos P, Spyrou N, Vamvakopoulos NC. Improved genotyping vaccine and wild-type poliovirus strains by restriction fragment length polymorphism analysis: clinical diagnostic implications. J Clin Microbiol 2000; 38:4337-42. [PMID: 11101561 PMCID: PMC87602 DOI: 10.1128/jcm.38.12.4337-4342.2000] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The combination of preventive vaccination and diagnostic typing of viral isolates from patients with clinical poliomyelitis constitutes our main protective shield against polioviruses. The restriction fragment length polymorphism (RFLP) adaptation of the reverse transcriptase (RT)-PCR methodology has advanced diagnostic genotyping of polioviruses, although further improvements are definitely needed. We report here on an improved RFLP procedure for the genotyping of polioviruses. A highly conserved segment within the 5' noncoding region of polioviruses was selected for RT-PCR amplification by the UC(53)-UG(52) primer pair with the hope that it would be most resistant to the inescapable genetic alteration-drift experienced by the other segments of the viral genome. Complete inter- and intratypic genotyping of polioviruses by the present RFLP method was accomplished with a minimum set of four restriction endonucleases (HaeIII, DdeI, NcoI, and AvaI). To compensate for potential genetic drift within the recognition sites of HaeIII, DdeI, or NcoI in atypical clinical samples, the RFLP patterns generated with HpaII and StyI as replacements were analyzed. The specificity of the method was also successfully assessed by RFLP analysis of 55 reference nonpoliovirus enterovirus controls. The concerted implementation of these conditional protocols for diagnostic inter- and intratypic genotyping of polioviruses was evaluated with 21 clinical samples with absolute success.
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Affiliation(s)
- A Georgopoulou
- Department of Virology, Hellenic Pasteur Institute, 11521, Athens, Greece
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Markoulatos P, Georgopoulou A, Kotsovassilis C, Karabogia-Karaphillides P, Spyrou N. Detection and typing of HSV-1, HSV-2, and VZV by a multiplex polymerase chain reaction. J Clin Lab Anal 2000; 14:214-9. [PMID: 11018799 PMCID: PMC6807757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The development of a multiplex polymerase chain reaction method for the rapid and accurate detection and typing of HSV-1, HSV-2, and VZV from clinical specimens is described. A sensitive multiplex polymerase chain reaction was achieved by optimization of parameters such as the primers, magnesium, and dNTPs concentrations. False-negative results that sometimes arise due to inhibitors of DNA amplification or failure of DNA extraction procedure used may be avoided by assaying each specimen with alpha-tubulin primers. Multiplex PCR amplified viral sequences from all 55 specimens obtained from patients with clinical evidence of HSV or VZV infection indicated 100% sensitivity. From 55 patients who were investigated by multiplex PCR, HSV-1 was detected in 28, HSV-2 in 20, and VZV in 7 specimens. The reported results indicate that the present multiplex PCR assay has a potential application in clinical diagnosis when a rapid and accurate detection and typing of involved viruses HSV-1, HSV-2, or VZV is needed.
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Affiliation(s)
- P Markoulatos
- Hellenic Pasteur Institute, Department of Virology, Athens, Greece.
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