Search results for "Microelectrode"
showing 10 items of 64 documents
Optimization of the KNN Supervised Classification Algorithm as a Support Tool for the Implantation of Deep Brain Stimulators in Patients with Parkins…
2019
Deep Brain Stimulation (DBS) of the Subthalamic Nuclei (STN) is the most used surgical treatment to improve motor skills in patients with Parkinson&rsquo
Computer simulation of oxygen tension histograms--a possibility for interpretation of microelectrode measurements.
1972
Mit Sauerstoff-Mikroelektroden werden die lokalen Werte des Sauerstoffpartialdruckes im Mikrobereich der Organe gemessen und graphisch als Haufigkeitsverteilungen (Histogramme) dargestellt. Theoretisch wird der Einfluss der Kapillaranordnung (Gleich-, Gegenstromsystem und Kapillarnetzwerk) auf die Haufigkeitsverteilung der P02 Werte untersucht. Die fur zweidimensionale Modelle durchgefuhrte Analyse zeigt, dass Unterschiede in der Durchblutung, wie sie in den einzelnen Zweigen der Kapillarnetzwerke auftreten, einen starken Einfluss auf die Histogramme haben.
Electrochemical study of intramolecular charge transfer complexes derived from 1,4-naphthoquinone Part 1. Electroreduction
1995
Abstract Electrochemical investigations (polarography, cyclic voltammetry, rotating ring-disk electrode voltammetry) of intramolecular charge transfer complexes (AC) derived from 1,4-naphthoquinone were performed in acetonitrile. It is concluded that in the first one-electron stage of its electrochemical reduction the AC is in a complexed form. At the same time the amino moiety, which shows a marked inductive (−I) effect, acts as an electron donor in the donor-acceptor (D-A) interaction. Facilitation of the reduction of the quinone part by the aryl amine residue is compensated by the D-A interaction, which makes the electroreduction more difficult. By using ultramicroelectrodes it was shown…
Eh and pH gradients in Camembert cheese during ripening: Measurements using microelectrodes and correlations with texture
2007
International audience; This study investigated the use of microelectrodes to continuously and simultaneously monitor pH and redox potential (Eh) gradients in Camembert cheeses from the rind to the core, as a function of ripening time (15 and 35 days). Cheeses were shown to be heterogeneous throughout their mass. An Eh gradient existed from the rind to the core. The surface was oxidizing (+330 to +360 mV) and the core was reducing and became more so in the course of ripening (−300 to −360 mV). A relationship between firmness and Eh was shown. pH gradients were in line with those previously described in the literature and related to ammonium and lactate gradients. Gradients evolved from the …
Direct Writing on Copper Ion Doped Silica Films by Electrogeneration of Metallic Microstructures
2017
International audience; A facile and rapid localized electrochemical reduction of colloid copper particles is proposed using the scanning electrochemical,microscope (SECM), technique. In this purpose, thin films of composite silica :glass containing copper salts were prepared by the sol-gel method via the dip coating technique. Acid-catalyzed tetraethylorthosilane (TEOS) solutions charged with copper nitrate were used as precursors. This one-pot experiment can be performed in mild conditions. The localized generation of copper metallic nanostructures on silica film has been performed by electroreduction of methyl viologen on an ultramicroelectrode (UME). The UME generates reducing species, …
Quantitative measurements of non-covalent interactions with diamond based magnetic imaging
2018
We present a technique employing dielectrophoretic (DEP) manipulation of surface immobilized complexes integrated with a magnetic imaging platform based on nitrogen-vacancy (NV) centers in diamond for the quantitative measurements of non-covalent interactions. The interdigitated microelectrodes closely spaced to the functionalized surface of the diamond plate provide a wide range of applied DEP forces for noninvasive manipulation of various molecular interactions, while the NV layer under the surface reports the unbinding dynamics. Given that biological samples do not present significant magnetic background and do not screen magnetic fields, our approach has many advantages over the fluores…
TISSUE pH-DISTRIBUTION WITHIN MALIGNANT TUMORS AS MEASURED WITH ANTIMONY MICROELECTRODES
1981
Publisher Summary Recent experiments using glass microelectrodes have demonstrated that very low tissue pH-values are prevalent in C3H mouse mammary carcinomas. The acidification of the tumor tissue is the result of an elevated lactic acid production and its inadequate removal. As a consequence of heterogeneities in tumor blood flow and in substrate supply, tissue pH values are distributed heterogeneously within solid tumors. Although glass microelectrodes with tip diameters of about 1 μm and a sensitive length of 10–50 μm have been used, the spatial resolution can be improved utilizing glass coated antimony microelectrodes the sensitive areas of that are restricted to their very tips. This…
Aligned microcontact printing of biomolecules on microelectronic device surfaces
2001
Microcontact printing (/spl mu/CP) of extracellular matrix proteins is a fascinating approach to control cell positioning and outgrowth, which is essential in the development of applications ranging from cellular biosensors to tissue engineering. Microelectronic devices can be used to detect the activity from a large number of recording sites over the long term. However, signals from cells can only be recorded at small sensitive spots. Here, the authors present an innovative setup to perform aligned /spl mu/CP of extracellular matrix proteins on microelectronic devices in order to guide the growth of electrogenic cells specifically to these sensitive spots. The authors' system is based on t…
Chronic neural probe for simultaneous recording of single-unit, multi-unit, and local field potential activity from multiple brain sites
2017
Drug resistant focal epilepsy can be treated by resecting the epileptic focus requiring a precise focus localisation using stereoelectroencephalography (SEEG) probes. As commercial SEEG probes offer only a limited spatial resolution, probes of higher channel count and design freedom enabling the incorporation of macro and microelectrodes would help increasing spatial resolution and thus open new perspectives for investigating mechanisms underlying focal epilepsy and its treatment. This work describes a new fabrication process for SEEG probes with materials and dimensions similar to clinical probes enabling recording single neuron activity at high spatial resolution.Polyimide is used as a bi…