Sponge Electrodes Research Articles

Development of flexible supercapacitors using an inexpensive graphene/PEDOT/MnO2 sponge composite

It remains a formidable challenge to develop supercapacitors having both high stretchability and electrochemical performance. A ternary polymer composite was herein developed by engineering graphene platelets (GnPs), poly (3,4-ethylenedioxythiophene) (PEDOT) and manganese dioxide (MnO2) into a kitchen sponge. Cost-effective GnPs having an electrical conductivity of 1460Scm−1 were deposited onto the sponge pore surface by a simple dipping and drying process, followed by in situ polymerization of 3,4-ethylenedioxythiophene. MnO2 was then deposited onto the GnPs and PEDOT layers through soaking the GnP/PEDOT sponge into KMnO4 solution. When the composite was used as the electrodes for a flexible, stretchable supercapacitor, we obtained not only high specific capacitance but a high stretchability up to 400%. The supercapacitor demonstrated a specific capacitance of 802.99Fg−1 and an energy density of 55.76Whkg−1, with 99% capacitance retention over 1000 stretching cycles; these are attributed to the synergy between the composite components as well as the wavy device structure. The mass and thickness of the MnO2 layer was found to increase with the soak, leading to the enhancement of electrochemical performance of GnP/PEDOT/MnO2 sponge electrodes, i.e. 368.96Fg−1 for 5min and 740.25Fg−1 for 10min.

Amorphous Ge/C Composite Sponges: Synthesis and Application in a High-Rate Anode for Lithium Ion Batteries.

A Ge/C spongelike composite is prepared by the facile and scalable single-step pyrolysis of the GeOx/ethylenediamine gel process, which has a feature with three-dimensional interconnected pore structures and is hybridized with nitrogen-doped carbon. A detailed investigation shows that the pore in the sponge is formed for the departure of the gaseous products at the evaluated temperature. As an anode for lithium ion batteries, the obtained composite exhibits superior specific capacity in excess of 1016 mA h g-1 at 100 mA g-1 after 100 cycles. Moreover, the amorphous Ge/C sponge electrode also has a good rate capacity and stable cycling performance. The obtained amorphous Ge/C sponges are a good candidate anode for next-generation lithium ion batteries.

P097 Direct measurement of electric fields in human and monkeys during transcranial electric stimulation

Introduction Transcranial electric stimulation (TES) is an emerging technique to non-invasively modulate brain function. However, the spatiotemporal distribution of electric fields during TES remains poorly understood. Objectives In this study we perform direct intracranial measurements of the electric field generated by transcranial alternating current (tACS) in epilepsy patients and cebus monkeys and evaluate the capacity of finite element method (FEM) models to predict the spatial distribution of measured electric fields. Methods Two presurgical epilepsy patients, with ca. 100 intracranially implanted electrodes participated in a single TES session. Two sponge electrodes (25 cm2) were attached over the left and right temporal cortex and a current of 1 mA with a frequency of 1 Hz was applied for 2 min. In two cebus monkeys three electrodes, with a total of 32 contacts were permanently implanted with posterior-anterior orientation. In multiple sessions intracranial EEG was recorded during TES. We varied the frequency of stimulation from 1–150 Hz and computed amplitude and phase relationships of recorded voltages. We constructed FEM models with increasing anatomical complexity for one epilepsy patient and compared the measured and simulated electric fields. Results Voltage magnitude slightly decreased with stimulation frequency up to 10% and small phase differences between electrode contacts up to a few degrees were observed. Electric field strengths were strongest in superficial brain regions with maximum values of 0.5 mV/mm ( Download : Download high-res image (1MB) Download : Download full-size image Fig. 1). Comparison of measured and simulated potentials and electric fields showed very high correlation values for the potentials (r = 0.95) and correlations of r = 0.7 for the electric fields. Evaluating the predictive value of increasingly complex FEM models highlighted the importance of accurate skull modeling especially in the vicinity of skull defects ( Download : Download high-res image (746KB) Download : Download full-size image Fig. 2). Conclusion We conducted a comprehensive evaluation of intracranial electric field during TES in both human patients and monkeys. Our results indicate that TES currents spread in a linear ohmic manner and capacitive effects are small indicating that the quasi-static approximation is well justified in the low frequency range. The spatial variation of the electric fields can be captured using realistic FEM models.

P096 COMETS2: A MATLAB toolbox for numerical simulation of electric fields generated by transcranial direct current stimulation

Since there is no way to directly measure the electric current flow inside the human head and no imaging modality can visualize the electric field generated by transcranial direct current stimulation (tDCS), numerical analysis based on finite element method (FEM) has been widely studied. However, because there has been no open software package designed to simulate electric fields generated by tDCS, only a few research groups could use this important technology. In 2013, our group released a GUI-based MATLAB toolbox named COMETS (COMputation of Electric field due to Transcranial current Stimulation), which could simulate various electrode montages in a standard head model. Now, we are releasing a next version of COMETS, named COMETS2, which not only fixed several problems of the previous version but also adopted a realistic but computationally efficient electrode modeling method. COMETS2 is a MATLAB toolbox running under Windows environment. FEM is used for the electric field analysis, and a 4-layer realistic head model is adopted. In COMETS2, we implemented functions for generating realistic saline-soaked sponge electrode models on user selected spots, and applied a new method to reduce the overall computational cost. We used NODE and ELE files supported by TETGEN, and superimposed the analyzed electric potential distribution, electric field intensity, and electric current density on the cortical surface ( Download : Download high-res image (626KB) Download : Download full-size image Fig. 1). Any other head models formatted as NODE and ELE can be applied for individualized tDCS study. COMETS2 can help researchers who are not familiar with numerical methods to analyze electric field distribution generated by tDCS. In particular, our new algorithm accelerating the computational speed might be useful for studies needing repetitive computations, for example, finding optimal electrode positions to stimulate a specific target area. COMETS2 will be available from September 2016 at http://www.cometstool.com .

Abstract TP145: Anodal 2mA Transcranial Direct Current Stimulation Over Affected Parietal-Insular-vestibular Cortex Shows No Effect on Lateropulsion Following Strokei

Objective: To assess the effects of 2mA transcranial Direct Current Stimulation (tDCS) over the affected Parietal-Insular-Vestibular Cortex (PIVC) on seated posture of patients with lateropulsion following stroke. We hypothesized that bilateral electrode placement over PIVC (vs active control) would produce a change in seated posture. Background: Lateropulsion following stroke (Pusher Syndrome) is characterized by lateral displacement of subjective postural vertical toward the weak side. It is caused by lesions affecting vestibular projections to the Ventral Lateral Thalamus (VLT) or projections from the VLT to the Parietal-Insular-Vestibular Cortex (PIVC). Methods: Seventeen subjects with Burke Lateropulsion Scale scores ≥ 2 within 30 days of an ischemic stroke signed an IRB-approved consent. They received 2mA tDCS delivered using 25cm 2 saline soaked sponge electrodes via one of two montages: Test (anode over the affected PIVC and cathode opposite PIVC) versus Active Control (anode over the affected PIVC and cathode over the opposite supra-orbital region). PIVC was defined using EEG 10/20 coordinates. Seated medial-lateral center of pressure (COP-X) was measured using a custom-designed chair mounted on an AMTI™ analog-to-digital forceplate. An inclinometer strapped to the chest and aligned with the sternum measured lateral trunk tilt. Data were collected prior to, then at 5, 10, and 15 minutes during tDCS and 5 min following tDCS. Results: Repeated Measures Analysis of Variance rejected the hypothesis of an interaction between Montage and Time for: mean COP-X displacement (in) (Wilks’ λ F = 0.647 df =(4, 13), P = 0.639); mean speed of COP-X (in/s) (Wilks’ λ F = 0.740 df =(4, 13), P =0.581); mean inclinometer tilt (degrees) (Wilks’ λ F = 0.740 df =(4, 13), P =0.581). Conclusion: Neither tDCS montage showed improvement in COP-X displacement, COP-X movement velocity or inclinometer readings. These negative results are important to encourage the development of alternative tDCS stimulation parameters or identification of alternative cortical or vestibular tDCS targets for the treatment of Lateropulsion Following Stroke.

Freeze-dried MoS2 sponge electrodes for enhanced electrochemical energy storage.

In the present study, we have synthesized high surface area MoS2 sponge electrodes via a facile hydrothermal method followed by a freeze drying process. The performance of the MoS2 based symmetric capacitor showed a high specific capacitance value of around 128 F g-1 at a scan rate of 2 mV s-1, and also a single electrode showed a specific capacitance of 510 F g-1, which is a remarkable value to be reported for a MoS2 based material in a symmetric device configuration. Also, a high energy density of around 6.15 Wh kg-1 and a good cyclic stability over 4000 cycles are obtained for the symmetrical cell.

Highly Oriented Graphene Sponge Electrode for Ultra High Energy Density Lithium Ion Hybrid Capacitors.

Highly oriented rGO sponge (HOG) can be easily synthesized as an effective anode for application in high-capacity lithium ion hybrid capacitors. X-ray diffraction and morphological analyses show that successfully exfoliated rGO sponge on average consists of 4.2 graphene sheets, maintaining its three-dimensional structure with highly oriented morphology even after the thermal reduction procedure. Lithium-ion hybrid capacitors (LIC) are fabricated in this study based on a unique cell configuration which completely eliminates the predoping process of lithium ions. The full-cell LIC consisting of AC/HOG-Li configuration has resulted in remarkably high energy densities of 231.7 and 131.9 Wh kg(-1) obtained at 57 W kg(-1) and 2.8 kW kg(-1). This excellent performance is attributed to the lithium ion diffusivity related to the intercalation reaction of AC/HOG-Li which is 3.6 times higher that of AC/CG-Li. This unique cell design and configuration of LIC presented in this study using HOG as an effective anode is an unprecedented example of performance enhancement and improved energy density of LIC through successful increase in cell operation voltage window.

Facile synthesis of self-supported Ni2P nanosheet@Ni sponge composite for high-rate battery

Abstract To meet the requirements for high-rate battery with desirable performance, a self-supported Ni 2 P@Ni sponge electrode is synthesized via simple steps, in which the Ni sponge substrate is synthesized by a one-pot hydrothermal method and the Ni 2 P nanosheets grown on the novel substrate are converted from Ni(OH) 2 via a phosphorization reaction. This hybrid composite combines the 3D porous structure of Ni sponge and high capacity of Ni 2 P nanosheets, which exhibits lightweight, flexible and highly-conductive properties, resulting in an excellent specific capacity of 430.3 mAh g −1 at a current density of 1 A g −1 and remaining as high as 77.0% capacity even at 40 A g −1 . More importantly, the Ni 2 P@Ni sponge//C cell exhibits the maximum energy density of 182.1 W h kg −1 at a power density of 205 W kg −1 along with superior capacity retention of 85.2% after 3000 cycles. It is suggested that the Ni 2 P nanosheet@ Ni sponge composite is a promising electrode material for high-rate batteries.

EP 134. Effect of transcranial random noise stimulation depends on sensitivity to sham stimulation

Introduction Tranccranial random noise stimulation (tRNS) induces a consistent excitability increase lasting at least 60 min after 10 min of stimulation, as demonstrated by both physiological measures and behavioural Tasks ( Terney et al., 2008 ). The present study tests whether the tRNS-induced changes in corticospinal excitability varies as a function of individual differences in sensitivity to sham stimulation. Methods The study was approved by the Ethic Committee of the Faculty of Medicine Christian-Albrechts University Kiel. 24 participants, aged between 18 and 30 years, participated in the study. All subjects were right-handed according to the Edinburgh handedness inventory ( Oldfield, 1971 ). Stimulation techniques : tRNS (1 mA, 10 min) was applied through a pair of saline-soaked surface sponge electrodes (5 × 7 cm). The minimum period between sessions for a single subject was 7 days, and sessions were applied in randomized order. Monitoring of motor cortical excitability: To examine changes in corticospinal excitability, motor evoked potentials (MEPs) of the right first dorsal interosseous muscle (FDI) were recording following stimulation of its motor-cortical representation field by single-pulse TMS. For further analysis we divided three subgroups according to excitatory (‘Excitatory group’, n = 9), inhibitory (‘Inhibitory group’, n = 7) or no respond (‘Non responder group’, n = 8) to sham- stimulation (Wilcoxon signed-rank test for dependent sampling). For this, we compared the MEP-amplitude in mean of the three time points after stimulation with the MEP-amplitude in mean before. Results In all subjects the tRNS was well tolerated. The general finding of present study is that sensitivity to sham stimulation has impact on effect of tRNS; namely, ‘Excitatory group’ resulted in inhibition of tRNS, whereas inhibitory group shows excitation of tRNS. For ‘Non responder group’ the 1 mA tRNS resulted in a significant increase of MEP amplitudes compared to sham stimulation, which is consistent with the literature Conclusion Accounting for variation in individual sensitivity to sham stimulation, stimulation may influence the utility of tRNS as a tool for understanding brain-behavior interactions and as a method for clinical interventions.

Returning to Zinc to Meet the Challenges for Next-Generation Energy Storage

The number of battery chemistries that check the boxes of high specific energy (>100 W h kg–1), rechargeability, power performance, inherent safety, low cost, and worldwide abundance is a short list. While lithium-based batteries continue to permeate the energy-storage landscape, many safety and supply concerns remain. Aqueous-electrolyte batteries meet many of the requirements for next-generation energy storage devices, but depending on the chemistry (Pb acid, Ni–MH, Ni–Zn, Zn–Air) often fail when it comes to safety, specific energy, and/or rechargeability. The radar chart below reveals the advantages and disadvantages of several battery technologies and especially highlights that improvements to rechargeable Zn-based batteries will propel them to the forefront of the energy landscape. The historical hindrance to broader use of Zn-based batteries is the poor rechargeability of the Zn electrode, especially when formulated as a powder-bed electrode that is too prone to launch dendrites upon cycling, which then short-circuit battery operation. The U.S. Naval Research Laboratory has redesigned the Zn electrode into a monolithic, metallically interconnected three-dimensional sponge form factor that supports a more uniform current distribution, thereby allowing nearly complete utilization of the Zn active material (>90%; projecting to ~450 W h kg–1) and avoiding the local critical current density required to spawn dendrites upon cycling. We established the reversibility of our 3D Zn sponge electrodes by cycling in Ni–3D Zn coin cells with particular emphasis on suitability in next-generation electric and start–stop vehicles. The lessons derived from studying Ni–3D Zn deep cycling allow us to demonstrate preliminary cycling performance of 3D Zn–air cells and offer prescriptions on appropriate electrolytes, current collectors, cell-fabrication particulars, and the future of Zn-based batteries. Figure 1

Transcranial direct current stimulation improves seizure control in patients with Rasmussen encephalitis.

Rasmussen encephalitis is associated with severe seizures that are unresponsive to antiepileptic drugs, as well as immunosuppressants. Transcranial direct current stimulation (t-DCS) is a non-invasive and safe method tried mostly for focal epilepsies with different aetiologies. To date, there is only one published study with two case reports describing the effect of t-DCS in Rasmussen encephalitis. Our aim was to investigate the effect of t-DCS on seizures in Rasmussen encephalitis and to clarify its safety. Five patients (mean age: 19; three females), diagnosed with Rasmussen encephalitis were included in this study. Patients received first cathodal, then anodal (2mA for 30 minutes on three consecutive days for non-sham stimulations), and finally sham stimulation with two-month intervals, respectively. Three patients received classic (DC) cathodal t-DCS whereas two patients received cathodal stimulation with amplitude modulation at 12Hz. Afterwards, all patients received anodal stimulation with amplitude modulation at 12Hz. In the last part of the trial, sham stimulation (a 60-second stimulation with gradually decreasing amplitude to zero in the last 15 seconds) was applied to three patients. Maximum current density was 571mA/m2 using 70mm x 50mm wet sponge electrodes with 2-mA maximum, current controlled stimulator, and maximum charge density was 1028C/m2 for a 30-minute stimulation period. After cathodal stimulation, all but one patient had a greater than 50% decrease in seizure frequency. Two patients who received modulated cathodal t-DCS had better results. The longest positive effect lasted for one month. A second trial with modulated anodal stimulation and a third with sham stimulation were not effective. No adverse effect was reported with all types of stimulations. Both classic and modulated cathodal t-DCS may be suitable alternative methods for improving seizure outcome in Rasmussen encephalitis patients.

Electrocatalytic Activity of Three Carbon Materials for the In-situ Production of Hydrogen Peroxide and Its Application to the Electro-Fenton Heterogeneous Process

Abstract The in-situ generation of hydrogen peroxide in the electro-Fenton process is paramount. For this reason, in this research the electrocatalytic activity of three carbon materials was evaluated in the reaction of oxygen reduction via two electrons. Furthermore, in order to eliminate the use of iron salts in solution (homogeneous process), the iron was electrodeposited on the surface of the carbon material and was applied in a heterogeneous electro-Fenton process for the degradation of methyl orange dye. The largest amount of generated H2O2 was achieved with the Carbon Felt (CF) electrode (460 mg L−1) without iron after 60 minutes. The electrodes with electrodeposited iron were characterized by SEM and EDS, which showed that the surface of the Carbon Sponge (CS) electrode had the largest amount of iron (23.84 %). However, the CF electrode showed a greater and faster degradation of the dye (98 %) after 30 minutes of treatment. The CF material was the best and most-viable choice of material compared to the CS and Carbon Cloth (CC) for industrial application in electro-Fenton processes, due to its greater catalytic activity in the production of H2O2, uniform distribution of iron, more efficient TOC removal and lower cost per cm2 of material.

The optimal design of Co catalyst morphology on a three-dimensional carbon sponge with low cost, inducing better sodium borohydride electrooxidation activity

A low-cost nano-flake Co@carbon sponge (Co NF@carbon sponge) electrode is prepared by a simple sponge carbonization method coupled with direct Co growth on the carbon sponge surface using pulsed electrodeposition.

Cathodal HD-tDCS on the right V5 improves motion perception in humans.

Brain lesions in the visual associative cortex are known to impair visual perception, i.e., the capacity to correctly perceive different aspects of the visual world, such as motion, color, or shapes. Visual perception can be influenced by non-invasive brain stimulation such as transcranial direct current stimulation (tDCS). In a recently developed technique called high definition (HD) tDCS, small HD-electrodes are used instead of the sponge electrodes in the conventional approach. This is believed to achieve high focality and precision over the target area. In this paper we tested the effects of cathodal and anodal HD-tDCS over the right V5 on motion and shape perception in a single blind, within-subject, sham controlled, cross-over trial. The purpose of the study was to prove the high focality of the stimulation only over the target area. Twenty one healthy volunteers received 20 min of 2 mA cathodal, anodal and sham stimulation over the right V5 and their performance on a visual test was recorded. The results showed significant improvement in motion perception in the left hemifield after cathodal HD-tDCS, but not in shape perception. Sham and anodal HD-tDCS did not affect performance. The specific effect of influencing performance of visual tasks by modulating the excitability of the neurons in the visual cortex might be explained by the complexity of perceptual information needed for the tasks. This provokes a “noisy” activation state of the encoding neuronal patterns. We speculate that in this case cathodal HD-tDCS may focus the correct perception by decreasing global excitation and thus diminishing the “noise” below threshold.

Highly compressible and all-solid-state supercapacitors based on nanostructured composite sponge.

Based on polyaniline-single-walled carbon nanotubes -sponge electrodes, highly compressible all-solid-state supercapacitors are prepared with an integrated configuration using a poly(vinyl alcohol) (PVA)/H2 SO4 gel as the electrolyte. The unique configuration enables the resultant supercapacitors to be compressed as an integrated unit arbitrarily during 60% compressible strain. Furthermore, the performance of the resultant supercapacitors is nearly unchanged even under 60% compressible strain.

Platinum-modified cobalt nanosheets supported on three-dimensional carbon sponge as a high-performance catalyst for hydrogen peroxide electroreduction

Pt-modified Co nanosheet@carbon sponge (Pt-Co NS@carbon sponge) electrode is synthesized via a facile sponge carbonization method coupled with a direct Co electrodeposition and Pt chemical-deposition. The obtained electrodes are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The catalytic performances of H2O2 electroreduction in alkaline medium are investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The Pt-Co NS@carbon sponge electrode exhibits unique nanosheet structure on the three-dimensional (3D) porous network skeleton with a large surface area and displays excellent catalytic performance. The Pt-Co NS@carbon sponge electrode achieves a reduction current density of −1.38 A cm−2 mg−1 in 3.0mol L−1 KOH and 1.5mol L−1 H2O2 at −0.50V (vs. Ag/AgCl) accompanied with a desirable stability, which is significantly higher than the catalytic activity of H2O2 electroreduction achieved previously with precious metals as catalysts. The impressive electrocatalytic performance is largely attributed to the superior 3D open structure and high electronic conductivity, which ensures the full utilization of Pt surfaces and makes the electrode have higher electrochemical activity. Original Pt-Co NS@carbon sponge electordes have a great potential for the application in fuel cells due to its facile preparation, high performance and low cost.

Long-life Li/polysulphide batteries with high sulphur loading enabled by lightweight three-dimensional nitrogen/sulphur-codoped graphene sponge.

Lithium–sulphur batteries with a high theoretical energy density are regarded as promising energy storage devices for electric vehicles and large-scale electricity storage. However, the low active material utilization, low sulphur loading and poor cycling stability restrict their practical applications. Herein, we present an effective strategy to obtain Li/polysulphide batteries with high-energy density and long-cyclic life using three-dimensional nitrogen/sulphur codoped graphene sponge electrodes. The nitrogen/sulphur codoped graphene sponge electrode provides enough space for a high sulphur loading, facilitates fast charge transfer and better immobilization of polysulphide ions. The hetero-doped nitrogen/sulphur sites are demonstrated to show strong binding energy and be capable of anchoring polysulphides based on first-principles calculations. As a result, a high specific capacity of 1,200 mAh g−1 at 0.2C rate, a high-rate capacity of 430 mAh g−1 at 2C rate and excellent cycling stability for 500 cycles with ∼0.078% capacity decay per cycle are achieved.

3D Zinc Sponge Anodes: Towards Next-Generation Ni-Zn Batteries

Zinc-based batteries (e.g., Zn–air, Ag–Zn, Ni–Zn) are endowed with high specific energy (up to 400 Wh kg–1), high specific power, nonflammable alkaline electrolytes, and an earth-abundance of active materials. The advantages of zinc-based batteries make them the ideal energy storage solution to address the pitfalls of its battery-chemistry competitors—from the toxicity and low specific energy of Pb-acid to the flammability of Li-ion. The historical failure of zinc to be recognized as a worthy competitor to other technologies lies in its bedeviled non-rechargeability and modest zinc utilization (typically <60% of theoretical discharge capacity), especially when constructed as an ad-hoc powder composited electrode. Traditionally, when Zn is oxidized to Zn2+ during discharge, it forms zincate complexes (e.g. Zn(OH)4 2– (aq) ) that are soluble in the alkaline electrolyte. These mobile Zn-carriers can diffuse beyond the site of generation but eventually supersaturate and precipitate as poorly conductive ZnO. The reverse step (charging) is initiated by re-dissolution of the ZnO to zincate prior to reduction back to Zn0. Multiple iterations of the above processes eventually lead to electronic isolation of portions of the electrode, hotspots of high-current density, and growth of short-inducing dendrites. To circumvent these problems, we design and fabricate 3D zinc "sponge" anodes that are monolithic and comprise an interpenetrating, co-continuous network of solid and void [1]. The electrode—now wired in 3D—enables low cell resistances throughout discharge that allow access to >90% of the zinc [2]. The morphology of the discharged sponges reveals a uniform deposition of ZnO on the inner walls of the sponge electrode, providing a core–shell 3D structure with an 3D-wired inner Zn metallic core that is ideal for electrochemical recharge with 100% capacity retention. We have identified the Ni–Zn battery system, with its established and rechargeable NiOOH cathode, as a prime candidate to begin implementing 3D-Zn sponge electrodes towards next-generation alternatives to Pb-acid, Ni–Cd, Ni–MH, and Li-ion batteries. We present the design and fabrication of 3D-Zn sponge anodes and their cycling performance in Ni–Zn full cells, with specific emphasis on cell fabrication, electrolyte composition, and post-mortem analysis. The information, data, or work presented herein was funded in part by the Office of Naval Research and by the Advanced Research Projects Agency–Energy (ARPA–E), U.S. Department of Energy, under Award Number DE-AR-0000391; the work has been Approved for Public Release, Distribution Unlimited. [1] J.F. Parker, C.N. Chervin, E.S. Nelson, J.W. Long, D.R. Rolison, Energy Environ. Sci. 7 (2014) 1117–1124. [2] J.F. Parker, E.S. Nelson, M.D. Wattendorf, C.N. Chervin, J.W. Long, D.R. Rolison, ACS Appl. Mater. Interfaces, in the press.

Transcranial direct current stimulation and exercises for treatment of chronic temporomandibular disorders: a blind randomised‐controlled trial

To evaluate the effect of adding transcranial direct current stimulation (tDCS) to exercises for chronic pain, dysfunction and quality of life in subjects with temporomandibular disorders (TMD). Participants were selected based on the RDC/TMD criteria and assessed for pain intensity, pressure pain threshold over temporomandibular joint and cervical muscles and quality of life. After initial assessment, all individuals underwent a 4-week protocol of exercises and manual therapy, together with active or sham primary motor cortex tDCS. Stimulation was delivered through sponge electrodes, with 2 mA amplitude, for 20 min daily, over the first 5 days of the trial. A total of 32 subjects (mean age 24.7 ± 6.8 years) participated in the evaluations and treatment protocol. Mean pain intensity pre-treatment was 5.5 ± 1.4 for active tDCS group, and 6.3 ± 1.2 for sham tDCS. Both groups showed a decrease in pain intensity scores during the trial period (time factor--F(4.5,137.5) = 28.7, P < 0.001; group factor--F(1.0,30.0 = 7.7), P < 0.05). However, there were no differences between the groups regarding change in pain intensity (time*group interaction--F(4.5,137.5) = 1.5, P = 0.137). This result remained the same after 5 months (t-test t = 0.29, P > 0.05). Pressure pain thresholds decrease and improvement in quality of life were also noticeable in both groups, but again without significant differences between them. Absolute benefit increase was 37.5% (CI 95%: -15.9% to 90.9%), and number needed to treat was 2.66. This study suggests that there is no additional benefit in adding tDCS to exercises for the treatment of chronic TMD in young adults.

Highly porous nickel@carbon sponge as a novel type of three-dimensional anode with low cost for high catalytic performance of urea electro-oxidation in alkaline medium

Highly porous nickel@carbon sponge electrode with low cost is synthesized via a facile sponge carbonization method coupled with a direct electrodeposition of Ni. The obtained electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The catalytic performances of urea electro-oxidation in alkaline medium are investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The Ni@carbon sponge electrode exhibits three-dimensional open network structures with a large surface area. Remarkably, the Ni@carbon sponge electrode shows much higher electrocatalytic activity and lower onset oxidation potential towards urea electro-oxidation compared to a Ni/Ti flat electrode synthesized by the same procedure. The Ni@carbon sponge electrode achieves an onset oxidation potential of 0.24 V (vs. Ag/AgCl) and a peak current density of 290 mA cm−2 in 5 mol L−1 NaOH and 0.10 mol L−1 urea solutions accompanied with a desirable stability. The impressive electrocatalytic activity is largely attributed to the high intrinsic electronic conductivity, superior porous network structures and rich surface Ni active species, which can largely boost the interfacial electroactive sites and charge transfer rates for urea electro-oxidation in alkaline medium, indicating promising applications in fuel cells.