Hollow prism-like NiCo
S
materials (NiCo
S
HNPs) were successfully fabricated by a two-step method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and powder X-ray ...diffraction (XRD) confirmed the morphology and structure of the as-prepared NiCo
S
nanoprisms. A non-enzymatic sensor based on NiCo
S
HNPs was constructed with outstanding electrochemical activity towards glucose oxidation in alkaline medium. The sensor showed a rapid response time (∼0.1 s), a high sensitivity of 82.9 μA mM
cm
, a wide linear range (0.005-20.2 mM) and a detection limit of 0.8 μM (S/N = 3) with a good selectivity and reproducibility. Additionally, the proposed electrode also confirmed the feasibility in practical blood serum. These results indicate that NiCo
S
/ITO has great potential in the development of non-enzymatic glucose sensor applications.
Abstract
Introduction
Congenital Central Hypoventilation Syndrome (CCHS) is a genetic disorder that results in the loss of autonomic ventilatory control, and patients require ventilatory support ...during sleep or both sleep and wakefulness. One method of ventilatory support is diaphragm pacing (DP), where electrodes surgically placed on the phrenic nerve are connected to subcutaneously implanted receivers that communicate with external antennas and transmitter. There are limited data on the frequency of DP malfunctions that require surgical revision.
Methods
We reviewed the records of 24 CCHS patients ventilated by DP followed at CHLA from 1990-2019. Records were examined for demographics, PHOX2B mutation, pacing duration/day, date and type of malfunctions, age and time since implantation at malfunction occurrence, and repair success rate.
Results
All 24 patients had thoracoscopic electrode placement. 17/24 (71%) of patients used DP while asleep; 3/24 (13%) during wakefulness only. 4/24 (17%) were not currently using their pacers. 10/24 (42%) patients required at least one surgical intervention (Age at implantation 9 ± 4.6 (SD) years; age at malfunction 12.5 ± 7.4 years). The average time from pacer implantation to malfunction was 3.8 ± 3.5 years. Malfunctions included defective receivers (6), insulation leaks (1), defective electrodes (4), and hardware infection (1). Of 12 unique component repairs, 6/12 (50%) involved changing receivers, 1/12 (8%) involved repairing an insulation leak, 4/12 (33%) involved replacing the electrodes and receivers, and 1/12 (8%) involved hardware extraction. Of the 12 malfunctions, 10 (83%) had successful surgical revision. 2/12 (17%) repairs were not attempted. While awaiting surgical revision, patients were successfully ventilated by unilateral DP.
Conclusion
Nearly half of CCHS patients on DP experienced malfunctions within 11 years of implantation. The most common DP repair was receiver replacement. Patients who are waiting for repair often successfully ventilate while pacing unilaterally.
Support
None
Abstract
Introduction
Upper airway stimulation is a option for CPAP-intolerant patients. Device activation is typically ~4 weeks after the implant procedure.
Report of Case
A 61yo male with severe ...OSA had an upper airway stimulation device placed by ENT. At that time, stimulation produced bilateral tongue protrusion. In the immediate post-operative period, after closure, a hematoma, at the inferior chest incision, was discovered and drained with cauterization of the bleeding vessel. Seven weeks after implant, patient reported to our sleep clinic for activation of the device; and at that time, there was no sensation or activation up to the maximum amplitude of 5mV. The device reported an acceptable respiratory waveform, and triggering on and off sets but without sensory outcomes. Changing of the electrode configuration with advanced settings had no effect. Impedance values were acceptable. Tongue movements were grossly intact. At 2 months, ENT evaluation found mild hypoglossal nerve neuropraxia. To assess for a device related issue, x-rays of the neck and chest were performed and showed proper placement of the device. At 3.5 months, neuropraxia had resolved but device activation was unsuccessful, with no sensory or motor activation to 5mV stimulation. Plans were made for a procedure during which the lead electrode or implantable pulse generator would be assessed or replaced. At 4 months after implantation, in a multidisciplinary appointment with Sleep, ENT and the device representative, with a 3 electrode negative pole and the generator as the + pole, at 2.3mV, the device was activated. At the present time, the patient is exploring higher and lower mV settings and a PSG titration is scheduled.
Conclusion
This is the longest recorded duration (3.5+ months) of unsuccessful post-operative activation; and it occurred ~2 months after clinical signs of hypoglossal nerve neuropraxia had resolved.
We have successfully observed Faradaic current in cyclic voltammetry of an amorphous Ge.sub.2Sb.sub.3.4Te.sub.6.2 film with Ag electrodes. The Faradaic current peak was attributed to a non-reversible ...redox process limited by diffusion of Ag cations. The Ag cations can be generated by anodic dissolution under applied bias voltage or may exist before the voltage application as "ready-made" ions. The cyclic voltammetry demonstrated the existence of ready-made Ag cations. The concentration of the ready-made cations was 0.008 mol/cm.sup.3, which was about one-tenth of the cations formed by a voltage sweep at 3.6 V/s, and was about one-hundredth of those formed at 0.3 V/s.
Although Li-ion batteries have emerged as the battery of choice for electric vehicles and large-scale smart grids, significant research efforts are devoted to identifying materials that offer higher ...energy density, longer cycle life, lower cost, and/or improved safety compared to those of conventional Li-ion batteries based on intercalation electrodes. By moving beyond intercalation chemistry, gravimetric capacities that are 2–5 times higher than that of conventional intercalation materials (e.g., LiCoO2 and graphite) can be achieved. The transition to higher-capacity electrode materials in commercial applications is complicated by several factors. This Review highlights the developments of electrode materials and characterization tools for rechargeable lithium-ion batteries, with a focus on the structural and electrochemical degradation mechanisms that plague these systems.
We have developed high- Formula Omitted superconducting quantum interference devices (SQUIDs) containing ramp-edge-type Josephson junctions and oxide multilayer structures. In this work, we propose a ...new design for a small biaxial gradiometric SQUID and report its successful fabrication. It is comprised of two gradiometric SQUIDs with a baseline length of 30 microns. The biaxial gradiometric SQUID contains four junctions and many crossovers and superconducting contacts between counter and base electrodes. When the counter electrode is deposited, the junctions and the superconducting contacts are simultaneously prepared. We developed a new technique to realize the distinguishing preparation of the junctions and the contacts. The ion irradiation procedure for the ramp surfaces of the base electrode prior to counter-electrode deposition is crucially important. We prepared modified layers suitable to form the junctions and the contacts through the irradiation process. The preparation was achieved by controlling the ion incident angle against the ramp surface during irradiation. In a fabricated chip, proper operations of gradiometers crossing at right angles were independently confirmed without appreciable crosstalk by passing a current through feedback coils.
A challenge still remains to develop high-performance and cost-effective air electrode for Li-O2 batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) ...despite recent advances in this field. In this work, a new design of binder-free air electrode composed of three-dimensional (3D) graphene (G) and flower-like delta-MnO2 (3D-G-MnO2) has been proposed. In this design, graphene and delta-MnO2 grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li-O2 batteries with 3D-G-MnO2 electrode can yield a high discharge capacity of 3660 mAh g-1 at 0.083 mA cm-2. The battery can sustain 132 cycles at a capacity of 492 mAh g-1 (1000 mAh gcarbon -1) with low overpotentials under a high current density of 0.333 mA cm-2. A high average energy density of 1350 Wh Kg-1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D-G-MnO2 makes it an attractive air electrode for high-performance Li-O2 batteries. PUBLICATION ABSTRACT
Developing high‐capacity electrodes requires the evaluation of electrochemical behaviors with an increasing current density. Currently, the current density for evaluation of high‐capacity electrodes ...has reached a new stage where the polarization at the lithium counter electrode has become a technical barrier for the accurate evaluation of battery electrodes, resulting in severe performance and mechanism mischaracterizations. Here, the accurate electrochemical behavior for high‐capacity electrodes via a single‐channel three‐electrode vehicle is decoupled, by which the impact of lithium counter electrode is minimized. The testing high‐capacity graphite electrode is capable of delivering an excellent rate capability with 81.7% capacity retention at 0.3 C, as well as stable cycling performance retaining 97.5% practical reversible capacity after 225 cycles, much higher than the graphite electrode tested with traditional half‐cell testing vehicle but in close agreement with the results obtained from a well‐matched full cell, reflecting accurate electrochemical performance evaluations of high‐capacity electrodes. Moreover, detailed electrochemical mechanisms of impedance and diffusion properties for working electrodes are also successfully decoupled individually. This work uncovers the mismatch between traditional evaluation configuration and increasing testing current density and provides a guideline for accurate electrochemical evaluation for ever‐increasing high‐capacity electrodes, which is of great significance for high‐energy lithium or other alkali‐metal ion batteries.
A technique for assessing accurate electrochemical behavior for high‐capacity electrodes is reported, that revives a single‐channel three‐electrode testing vehicle to mitigate the mismatch between traditional evaluation configurations and testing at increased current density.
The rise of portable and wearable electronics has largely stimulated the development of flexible energy storage and conversion devices. As one of the essential parts, the electrode plays critical ...role in determining the device performance, which required to be highly flexible, light‐weight, and conformable for flexible and wearable applications. However, it remains a formidable challenge in the design of appropriate flexible electrodes. Thus, considerable effort has been making to develop various flexible materials/substrates to fabricate flexible energy devices. Here, this review aims to provide a comprehensive survey on the recently developed free‐standing and flexible electrode materials/substrates for flexible electrochemical energy storage devices, which are categorized into four different types including metal‐based, carbon‐based, polymer‐based, and micro‐patterned flexible electrodes. The specific characteristics, fabrication methods, properties, and pros and cons of each type of materials are thoroughly analysed. Furthermore, challenges and future directions for designing flexible electrode materials are also discussed.
The next‐generation flexible and wearable electronics lies on the flexible power supply devices, and the exploration of flexible materials is the prerequisite to fabricate flexible energy storage devices. Herein, the various types of flexible electrode materials/substrates are overviewed to show a roadmap of the current status, aiming to provide some guidance in the way toward future flexible devices.
Norcorrole In article number 2301443, Jinkwang Hwang, Ji‐Young Shin and co‐workers investigate covalently manipulated novel ferrocenyl Ni(II) norcorrole as a practical organic electrode material, ...accomplishing a durable multi‐redox implementation that enables secondary organic batteries with superior performance when compared to parallel ferrocenyl Ni(II) porphyrin, and simple Ni(II) norcorrole.
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