Application of the Multi-Electrode in the Degradation of Alizarin Red Induced by Glow Discharge Plasma

This paper presents a novel set-up to be used in the degradation of dye, Various influencing factors, such as the voltage, the number of the anodes, and the catalytic action of Fe^2＋, were examined. Chemical oxygen demand （COD）, ultraviolet （UV）, FTIR absorption spectra, and atomic force microscopy （AFM） were used to monitor the degradation process. The results showed that the efficiency of degradation is raised by increasing the applied voltage, and is further improved when two or three anodes are used. Moreover, the use of Fe^2＋ ion can promote the degradation reaction and shorten the degradation time. So the multi-electrode instrument is more efficient in degrading the dye and should be further studied.

Efficient direction-independent fog harvesting using a corona discharge device with a multi-electrode structure

Efflcient collection of water from fog can effectively alleviate the problem of water shortages in foggy but water-scarce areas,such as deserts,islands and so on.Unlike inefflcient fog meshes,corona discharge can charge water droplets and further enhance the water-collecting effect.This study proposes a novel multi-electrode collecting structure that can achieve efflcient and direction-independent water collection from fog.The multi-electrode structure consists of three parts:a charging electrode,an intercepting electrode and a ground electrode.Four types of watercollecting structures are compared experimentally,and the collection rates from a traditional fog mesh,a wire-mesh electrode with fog coming from a high-voltage electrode,a wire-mesh electrode with fog coming from a ground electrode and a multi-electrode structure are 2–3 g h^(-1),100–120 g h^(-1),60–80 g h^(-1)and 200–220 g h^(-1),respectively.The collection rate of the multielectrode structure is 100–150 times that of a traditional fog mesh and 2–4 times that of a wiremesh electrode.These results demonstrate the superiority of the multi-electrode structure in fog collection.In addition,the motion equation of charged droplets in an electric fleld is also derived,and the optimization strategy of electrode spacing is also discussed.This structure can be applied not only to fog collection,but also to air puriflcation,factory waste gas treatment and other flelds.

Simultaneous Measurement of Neural Activities of Acute Mouse Hippocampal Slices Using Multi-Electrode Array System and Laser Confocal Calcium Imaging

Recently, non-invasive, real-time and multi-point measurement of neural activities has become possible by using a multi-electrode array (MEA). Another method for multi-point measurement is the fluorescent imaging technique using voltage indicator dyes or calcium indicator dyes. Especially, calcium imaging using fluorescent calcium indicator dyes is often more useful, because they exhibit larger changes in the fluorescence intensity than voltage indicator dyes and their fluorescence changes can be detect easily. Additionally, calcium signals play key roles in the brain function, such as the long-term potentiation (LTP) in the hippocampus, and calcium imaging can be a powerful tool to elucidate the brain function. In this study, we constructed a measurement apparatus combining the MEA system and laser confocal calcium imaging and simultaneously measured electric signals and calcium signals in acute mouse hippocampal slices. The obtained results showed the availability of the present method.

Use of multi-electrode array recordings in studies of network synaptic plasticity in both time and space

Simultaneous multisite recording using multi-electrode arrays（MEAs） in cultured and acutely-dissociated brain slices and other tissues is an emerging technique in the field of network electrophysiology.Over the past 40 years,great efforts have been made by both scientists and commercial concerns,to advance this technique.The MEA technique has been widely applied to many regions of the brain,retina,heart and smooth muscle in various studies at the network level.The present review starts from the development of MEA techniques and their uses in brain preparations,and then specifically concentrates on the use of MEA recordings in studies of synaptic plasticity at the network level in both the temporal and spatial domains.Because the MEA technique helps bridge the gap between single-cell recordings and behavioral assays,its wide application will undoubtedly shed light on the mechanisms underlying brain functions and dysfunctions at the network level that remained largely unknown due to the technical difficulties before it matured.

Paired associative stimulation improves synaptic plasticity and functional outcomes after cerebral ischemia

Paired associative stimulation is a relatively new non-invasive brain stimulation technique that combines transcranial magnetic stimulation and peripheral nerve stimulation. The effects of paired associative stimulation on the excitability of the cerebral cortex can vary according to the time interval between the transcranial magnetic stimulation and peripheral nerve stimulation. We established a model of cerebral ischemia in rats via transient middle cerebral artery occlusion. We administered paired associative stimulation with a frequency of 0.05 Hz 90 times over 4 weeks. We then evaluated spatial learning and memory using the Morris water maze. Changes in the cerebral ultra-structure and synaptic plasticity were assessed via transmission electron microscopy and a 64-channel multi-electrode array. We measured mRNA and protein expression levels of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 in the hippocampus using a real-time polymerase chain reaction and western blot assay. Paired associative stimulation treatment significantly improved learning and memory in rats subjected to cerebral ischemia. The ultra-structures of synapses in the CA1 area of the hippocampus in rats subjected to cerebral ischemia were restored by paired associative stimulation. Long-term potentiation at synapses in the CA3 and CA1 regions of the hippocampus was enhanced as well. The protein and mRNA expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 increased after paired associative stimulation treatment. These data indicate that paired associative stimulation can protect cog-nition after cerebral ischemia. The observed effect may be mediated by increases in the mRNA and protein expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1, and by enhanced synaptic plasticity in the CA1 area of the hippocampus. The animal experiments were approved by the Animal Ethics Committee of Tongji Medical College, Huazhong University of Science & Technology, China(approval No. TJ-A20151102) on July 11, 2015.

A 16-channel high-voltage reconfigurable and flexible-controlled implantable wireless closed-loop system for SCI repair

An adaptive closed-loop system for spinal cord injury(SCI) repair is designed. It integrates stimulation and recording on 16 pairs of electrodes. Two switches(SAS3 T16/SAS1 T16 X2) fabricated in high-voltage 0.8 μm process with online re-configurable function are proposed. These two switches are combined with commercial off-the-shelf(COTS) electronics to implement the closed-loop implantable system in compact module. The system includes amplifier for recording neural signals, high-voltage stimulator, power transmission device, central processing module and flexible implantable electrodes. Two customized switches route any electrode to amplifier or stimulator, and nerve stimulation and signal recording are performed through lead wire-driven channels. The entire system is able to operate at up to 28 V, and is a biocompatible package with a volume of 42 mm×35 mm×8 mm. This system solves several problems encountered in implantable devices: low flexibility, negative influence of stimulus artifacts on neural detection and low integration of electrodes.