TY  - JOUR
A1  - Dohrmann, Ulrike
A1  - Edgar, David
A1  - Sendtner, Michael
A1  - Thoenen, Hans
T1  - Muscle-derived factors that support survival and promote fiber outgrowth from embryonic chick spinal motor neurons in culture
N2  - The purpose of the experiments reported is to provide an unambiguous demonstration that embryonie skeletal muscle contains factors that act directly on embryonie spinal motor neurons both to support their survival and to stimulate the outgrowth of neurites. Cells of lumbar and brachial ventral spinal cords from 6-day-old chick embryos were separated by centrifugation in a two-step metrizamide gradient, and a motor neuron enriched fraction was obtained. Motor neurons were identified by retrogradely labeling with rhodamine isothiocyanate, and were enriched fourfold in the motor neuron fraction relative to unfractionated cells. In culture, the isolated motor neurons died within 3-4 days unless they were supplemented with embryonie chick skeletal muscle extract. Two functionally distinct entities separable by ammonium sulfate precipitation were responsible for the effects of muscle extracts on motor neurons. The 0-25% ammonium sulfate precipitate contained molecules that alone bad no effect on neuronal survival but when bound to polyornithine-coated culture substrata, stimulated neurite outgrowth and potentiated the survival activity present in muscle. Most of this activity was due to a laminin-like molecule being immunoprecipitated with antisera against laminin, and immunoblotting demonstrated the presence of both the A and B chains of laminin. A long-term survival activity resided in the 25-70% ammonium sulfate fraction, and its apparent total and specific activities were strongly dependent on the culture substrate. In contrast to the motor neurons, the cells from the other metrizamide fraction (including neuronal cells) could be kept in culture for a prolonged time without addition of exogenous factor(s).
KW  - Nervenzelle
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72862
ER  - 
TY  - JOUR
A1  - Rothmayr, Florian
A1  - Guarin Castro, Edgar David
A1  - Hartmann, Fabian
A1  - Knebl, Georg
A1  - Schade, Anne
A1  - Höfling, Sven
A1  - Koeth, Johannes
A1  - Pfenning, Andreas
A1  - Worschech, Lukas
A1  - Lopez-Richard, Victor
T1  - Resonant tunneling diodes: mid-infrared sensing at room temperature
JF  - Nanomaterials
N2  - Resonant tunneling diode photodetectors appear to be promising architectures with a simple design for mid-infrared sensing operations at room temperature. We fabricated resonant tunneling devices with GaInAsSb absorbers that allow operation in the 2–4 μm range with significant electrical responsivity of 0.97 A/W at 2004 nm to optical readout. This paper characterizes the photosensor response contrasting different operational regimes and offering a comprehensive theoretical analysis of the main physical ingredients that rule the sensor functionalities and affect its performance. We demonstrate how the drift, accumulation, and escape efficiencies of photogenerated carriers influence the electrostatic modulation of the sensor's electrical response and how they allow controlling the device's sensing abilities.
KW  - resonant tunneling diode
KW  - mid-infrared sensing
KW  - photosensor
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267152
SN  - 2079-4991
VL  - 12
IS  - 6
ER  -