| 1. |
- Ek, Patrik, et al.
(författare)
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Electrospray Ionization from an Adjustable Gap between two Silicon Chips
- 2009
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 44:2, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a silicon chip - based electrospray emitter with a variable orifice size is presented. The device consists of two chips, with a thin beam elevating from the center of each of the chips. The chips are individually mounted to form an open gap of a narrow, uniform width between the top areas of the beams. The electrospray is generated at the endpoint of the gap, where the spray point is formed by the very sharp intersection between the crystal planes of the < 100 > silicon chips. Sample solution is applied to the rear end of the gap from a capillary via a liquid bridge, and capillary forces ensure a spontaneous imbibition of the gap. The sample solution is confined to the gap by means of a hydrophobic treatment of the surfaces surrounding the gap, as well as the geometrical boundaries formed by the edges of the gap walls. The gap width could be adjusted between 1 and 25 μm during electrospray experiments without suffering from any interruption of the electrospray process. Using a peptide sample solution, a shift toward higher charge states and increased signal-to-noise ratios was observed when the gap width was decreased. The limit of detection for the peptide insulin (chain B, oxidized) was approximately 4 nM. We also show a successful interfacing of the electrospray setup with capillary electrophoresis.
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| 2. |
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| 3. |
- Khalifa, Shaden Ali M., et al.
(författare)
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Guidance of spiral ganglion neurons over 3 mm using protein patterned surfaces in Co-culture
- 2014
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Ingår i: Tissue Engineering and Regenerative Medicine. - : Kluwer Academic Publishers. - 1738-2696 .- 2212-5469. ; 11:3, s. 187-194
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Tidskriftsartikel (refereegranskat)abstract
- Despite considerable advances in neural prosthetics there are still few clinical devices capable of effectively compensating for the loss of a physiological function. By far the most successful to date are cochlear implants, which can restore the auditory function in patients with severe sensorineural impairment. These implants have electrode arrays that directly stimulate the remaining neurons and several strategies are applied to encourage neurons to interact intimately with the electrodes. Integration of the residual neurons into the circuits can be aided by appropriate micro-patterning on the electrodes' surfaces to guide the regenerating neurons. Here we describe experiments revealing key features of the interface between auditory cell cultures and surface patterning. In the presented study linear regenerative outgrowth of spiral ganglion axons occurred over distances of several hundred micrometers in the presence of extracellular protein cues placed precisely on surfaces by micro-contact printing. The protein pattern guided the outgrowth of spiral ganglion neurons along interconnected networks of non-neuronal cells. High-precision alignment of axons with no branching or deviation was influenced by, but not dependent upon, the presence of non-glial cells. The findings show that micro-patterning provides a versatile, robust system that can not only guide the outgrowth of individual neurons but also regulate the orientation of diverse cell types in culture. © 2014 The Korean Tissue Engineering and Regenerative Medicine Society and Springer Science+Business Media Dordrecht.
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| 4. |
- Schönberg, Tommy, et al.
(författare)
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Surface embedded temperature sensor on tool part for real time injection moulding process monitoring
- 2013
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Ingår i: 2013 Transducers and Eurosensors XXVII. - 9781467359818 ; , s. 116-119
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Konferensbidrag (refereegranskat)abstract
- This paper reports successful temperature measurements from a real time production process using surface integrated sensors. K-type thermocouples were fabricated directly on the surface of a tool part using Direct Write Thermal Spray and the process temperature cycle from an injection moulding process was measured under real running conditions. The metal-polymer interface never got hotter than 100 °C as the >200 °C molten polymer is instantly solidified as it reaches the cold metal surface.
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| 5. |
- Yaka, Cane, et al.
(författare)
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A novel in vitro injury model based on microcontact printing demonstrates negative effects of hydrogen peroxide on axonal regeneration both in absence and presence of glia
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 30:5, s. 392-402
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Tidskriftsartikel (refereegranskat)abstract
- The molecular processes involved in axonal regeneration after traumatic brain injury (TBI) are still not fully understood. In this study, we have established a novel in vitro injury model of TBI based on microcontact printing (μCP) that enables close-up investigations of injured neurons. The model is also suitable for quantitative measurements of axonal outgrowth, making it a useful tool in the studies of basic mechanisms behind axonal regeneration. Cortical neurons from mouse embryos are cultured on μCP cover-slips for 8 days, and the neurons are then injured in a precise manner using a thin plastic tip that does not affect the μCP pattern of extracellular matrix proteins. By close-up time-lapse experiments and immunostainings, we show that the neurons have a tremendous capacity to regenerate their neurites after injury. The cut induces growth cone formation, and the regenerating axons strictly follow the μCP pattern. Moreover, by using the injury model, we demonstrate that hydrogen peroxide (H2O2) decreases axonal regeneration after injury without affecting the neurons' ability to form growth cones. Co-culture with glial cells does not rescue the axonal regeneration, indicating that the mechanism by which H2O2 affects axonal regeneration differ from its cytotoxic effect.
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