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Sexton, Alexander Harold; Knaapila, Matti Pekka; Fossum, Jon Otto & Martinsen, Ørjan Grøttem
(2022).
Monitoring lifetime of thermoplastic composites by combining analytics and
machine learning.
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Schuelke, Christin; Cunha, Andrè Bastos da; Heiskanen, Arto; Asif, Afia; Keller, Stephan S. & Martínez-Serrano, Alberto
[Vis alle 8 forfattere av denne artikkelen]
(2020).
Neural Stem Cell Characterization and Detection of Neurotransmitter release using Bioimpedance and Electrochemistry.
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The goal of the Training4CRM project is to develop a device for personalized medicine to treat neurodegenerative disorders (Parkinson´s Disease, Huntington´s Disease, and Epilepsy). This future device includes a bioimplant consisting of a 3D scaffold, electronics, a light source and optogenetically modified neuronal cells that will be operated into the patient’s brain to release disease-specific neurotransmitters.
The aim of this work is the non-invasive observation of cell proliferation and neuronal differentiation, as well as detection of neurotransmitter release. Electrical Impedance Spectroscopy (EIS) and amperometry provide excellent tools for investigation of various cellular phenomena. EIS can be used to monitor different cellular changes like proliferation, apoptosis, migration, changes in morphology and also (neuronal) differentiation. Compared to most molecular biological methods, bioimpedance measurements are non-invasive and allow for repeated analysis of the same cell population. Human neural stem cells were cultured as monolayer on 2D carbon electrode chips. Bioimpedance measurements were performed every second day to follow the proliferation of hNSCs. Cells impede the flow of current between electrodes. Therefore, an increasing number of cells results in an increased impedance. Amperometry was used to detect the release of neurotransmitters (especially dopamine) after triggered depolarization by stimulation of neurons with a high K+ buffer. Release of oxidizable molecules leads to increased current visible as oxidation peak.
This work demonstrates the principle of bioimpedance and electrochemical detection of neurotransmitter release. With EIS, proliferation can be monitored noninvasively over time. With amperometry, detection of repeated depolarization is possible and cells remain active over several days.
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Elvebakk, Ole; Tronstad, Christian; Birkeland, Kåre Inge; Jenssen, Trond Geir; Bjørgaas, Marit Ragnhild Rokne & Frøslie, Kathrine Frey
[Vis alle 10 forfattere av denne artikkelen]
(2019).
Author Correction: Evaluation of Hypoglycaemia with Non-Invasive Sensors in People with Type 1 Diabetes and Impaired Awareness of Hypoglycaemia (Scientific Reports, (2018), 8, 1, (14722), 10.1038/s41598-018-33189-1).
Scientific Reports.
ISSN 2045-2322.
9(1).
doi:
10.1038/s41598-019-42218-6.
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Azumah, Joseph; Smistad, Gro; Martinsen, Ørjan Grøttem & Hiorth, Marianne
(2019).
Development of alginate coated liposomes with potential of being used in treatment of dry mouth.
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Azumah, Joseph; Hiorth, Marianne; Smistad, Gro & Martinsen, Ørjan Grøttem
(2019).
Development of alginate and chitosan coated liposomes intended to use in the treatment of xerostomia.
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Azumah, Joseph; Hiorth, Marianne; Smistad, Gro & Martinsen, Ørjan Grøttem
(2019).
Alginate and chitosan coated liposomes intended for treatment of dry mouth.
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Martinsen, Ørjan Grøttem
(2016).
The dark side of open access.
Journal of Electrical Bioimpedance.
ISSN 1891-5469.
7,
s. 1–1.
doi:
10.5617/jeb.2960.
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Martinsen, Ørjan Grøttem; Abie, Sisay Mebre; Bergli, Joakim & Galperin, Yuri
(2016).
Universality of low frequency conductance of human hair.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Pettersen, Fred Johan; Martinsen, Ørjan Grøttem; Høgetveit, Jan Olav; Flattum, M.; Kalvøy, Håvard & Odland, Hans Henrik
(2016).
Using pacemaker leads for bioimpedance and electromyography.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Kalvøy, Håvard; Sauter, Axel Rudolf; Tronstad, Christian & Martinsen, Ørjan Grøttem
(2016).
Neural tissue discrimination with machine learning methods.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Pabst, Oliver; Tronstad, Christian; Martinsen, Ørjan Grøttem & Grimnes, Sverre
(2016).
Comparison between AC and DC exosomatic EDA measuring methods.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Strand-Amundsen, Runar James; Tronstad, Christian; Martinsen, Ørjan Grøttem; Høgetveit, Jan Olav; Ruud, TE & Tønnessen, Tor Inge
(2016).
Bioimpedance - in vivo vs in vitro ischemic small intestine.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Broeze, K.; Elzen, R. van der; Rijssel, M.J. van; Eijnatten, M.A. van; Verdaasdonk, R.M. & Martinsen, Ørjan Grøttem
[Vis alle 7 forfattere av denne artikkelen]
(2016).
The X-point in the ICGmarks aortic valves closure.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Broeze, K.; Elzen, R. van der; Rijssel, M.J. van; Eijnatten, M.A. van; Verdaasdonk, R.M. & Martinsen, Ørjan Grøttem
[Vis alle 7 forfattere av denne artikkelen]
(2016).
Quest for the proper B-point in the ICG by echocardiography.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Pabst, Oliver & Martinsen, Ørjan Grøttem
(2016).
Investigating the memristive properties of skin.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Tronstad, Christian; Elvebakk, Ole; Martinsen, Ørjan Grøttem; Kalvøy, Håvard & Høgetveit, Jan Olav
(2016).
Bioimpedance for prediction of hypoglycemic trends.
Proceedings of the 16th International Conference on Electrical Bioimpedance.
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Bergli, Joakim; Galperin, Yuri; Martinsen, Ørjan Grøttem & Abie, Sisay Mebre
(2016).
Universality of AC conductance in human hair.
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Skjærvø, Øystein; Brandtzæg, Ole Kristian Merkesvik; Martinsen, Ørjan Grøttem; Lundanes, Elsa & Wilson, Steven Ray Haakon
(2016).
Characterization of polymer layer open tubular columns for liquid chromatography and open tubular enzyme reactors for on-line sample preparation.
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Skjærvø, Øystein; Wilson, Steven Ray Haakon; Lundanes, Elsa; Brandtzaeg, Ole Kristian & Martinsen, Ørjan Grøttem
(2016).
Characterization of open tubular enzyme
reactors and polymer layer open tubular
columns for liquid chromatography.
Universitetet i Oslo.
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The structure, thickness and characteristics of liquid chromatography (LC) column materials are central factors regarding their performance. However, miniaturized capillaries (sub 20.0 μm inner diameter, typically used for small sample analysis) are difficult to characterize. The main goal of this work was to develop a simple, yet accurate, electrochemical impedance spectroscopy (EIS) method for characterization of the polymer layers of narrow open tubular (OT) columns. In situ prepared polymerized capillaries (poly(styrene-co-divinylbenzene) and poly(2-hydroxyethyl methacrylate-co-2-vinyl-4,4-dimethyl azlactone) OT capillaries were characterized. The developed EIS method proved simplicity in terms of providing layer thickness determinations compared to determination by scanning electron microscope (SEM). In addition, screening of the polymer layer homogeneity throughout the capillaries was simplified by EIS. The porosity of the polymer layer OT columns was investigated by EIS, SEM and sample loading capacity measurements (using LC). Under pore-blocking conditions, none of the polymerized capillaries could be shown to have porosity, so it was assumed that a thin polymer layer is beneficial for both types of capillaries in order to provide a high surface area, i.e. more available functional groups. EIS methods have not been published for capillary characterization by date. However, the method showed promising results and has great potential for future applications regarding characterization and preparation optimization of polymerized capillaries.
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