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[Display omitted] • Ionic liquid (IL)-adsorbed catalyst changes the morphology of the catalyst layer. • IL adsorption reduces the ORR charge transfer resistance in the electrode. • IL adsorption enhances the stability under the accelerated durability test. A majority of studies focus on developing oxygen reduction reaction (ORR) catalysts and cathode configurations to enhance the performance and durability of polymer electrolyte membrane fuel cells (PEMFCs). In this study, resistance analyses of the membrane electrode assembly (MEA) are conducted to elaborate on the performance and durability improvements induced by the adsorption of [MTBD][beti] ionic liquid (IL) on the commercial PtCo/C catalyst. The morphological changes caused by IL adsorption are observed on micro and macro scales via physicochemical methods. From the half-cell measurement, when the 4 wt% IL was adsorbed, a 15 mV improvement in ORR activity occurred, and as the adsorption amount increased, the activity decreased. The MEA using 8 wt% IL adsorbed catalyst outperforms 1.7 times higher current density at 0.8 V and 40 % lower charge transfer resistance. Distribution of relaxation time resistance analysis reveals that oxygen mass transfer resistance (R mass), ORR charge transfer resistance (R ORR), and proton charge transfer resistance (R proton) decrease due to IL adsorption. During accelerated durability tests, IL 8 % MEA showed a 58 % increase in durability, and a lower degradation of R ORR and R proton encouraged improved durability. The resistance analyses in this study contribute to identifying the factors responsible for the performance and durability enhancement of PEMFC. [ABSTRACT FROM AUTHOR]

In the membrane electrode assembly (MEA) of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs), many types of resistance existed, but they have not been distinctly characterized in previous research. In this study, the distribution of relaxation times (DRT) methodology is employed, in conjunction with a home-built electrochemical electrode analysis system (EEAS), to figure out the specific resistance components in the cathode gas diffusion electrode (GDE). The impedance analysis by the DRT method was conducted using the electrochemical impedance spectrum obtained at different temperatures and current densities of the cathode only, isolated from the MEA environment. The four peaks (designated as Peak 0 to 3) were depicted at DRT plots of cathode GDE below 103 Hz. By comparing the DRT plots for different conditions and considering the EEAS structure, the four peaks were explained to be caused by distinct resistances occurring at the electrode and interface. The regions of each peak were distinguished according to their position changes with temperature and current density. Furthermore, by contrasting the DRT plots of the cathode GDE with those of MEA containing the same cathode, an additional peak (referred to as Peak 4) is identified between 103 Hz and 104 Hz, which was attributed to resistance originating from the anode. This study could provide a new approach for future research of new catalysts and electrodes utilizing the resistance analysis of MEA for HT-PEMFC. [Display omitted] • The EEAS was utilized to perform electrochemical analysis of the GDE. • DRT method separates resistances as peaks in the cathode GDE of HT-PEMFCs. • Each peak from the DRT plot is assigned according to the origin of resistance. • Comparative study with MEA differentiates the resistance from electrodes. [ABSTRACT FROM AUTHOR]

Electrolyte-gated transistors (EGTs) are promising candidates for artificial synaptic devices, due to lower energy consumption by forming the electric double layer to modulate the channel conductance. In this work, we propose a three-terminal artificial synapse transistor employing HfO 2 electrolyte-gate insulator (EGI). The inorganic HfO 2 thin film with high dielectric constant was chosen as a good candidate of an EGI to improve the operational stability and energy consumption for the synapse transistor. Mobile hydrogen ions incorporated in the HfO 2 EGI were revealed to be generated during the ALD process at a temperature as low as 100 °C. The synaptic plasticity of the fabricated synapse transistor could be gradually modulated by the movement of mobile ions in the EGI, which were examined to be dependent on the applied pulse conditions. The fabricated synapse transistor emulated biological synaptic functions, including excitatory/inhibitory post-synaptic current (EPSC/IPSC) and paired-pulse facilitation/depression (PPF/PPD). Furthermore, by controlling the pulse spike conditions, the conversion from short-term plasticity (STP) to long-term plasticity (LTP) was successfully verified. The LTP characteristics were demonstrated to be far enhanced with the EGI film thickness by means of magnifying the amounts of incorporated mobile ions. In addition, the long-term reliability and operational repeatability of the fabricated synapse transistor were well verified thanks to the choice of HfO 2 EGI. The energy consumption required for single spike event was estimated to be a value as low as 0.26 pJ, thus demonstrating considerable potential as an artificial synapse device. [ABSTRACT FROM AUTHOR]

• Extinction increased c-Fos levels in the lateral habenula. • Extinction decreased c-Fos levels in the SNc/VTA. • Slower extinction in rats with lateral habenula lesions. Following the association of a neutral stimulus (conditioned stimulus, CS) with a biologically significant stimulus (unconditioned stimulus, US), CS-alone presentations generate extinction: a decline in the conditioned response. Many studies have revealed the neural substrates of fear extinction; however, a few have identified the brain regions responsible for appetitive extinction. Midbrain dopamine neurons are activated by presenting a reward or predictable reward cue, whereas the cue signaling the absence of reward activates the lateral habenula (LHb) neurons. We examined the engagement of the LHb in appetitive extinction. In the first phase, rats first received pairings of a CS (light) with US delivery (food pellets). In the second phase, rats in the CS-alone group underwent four CS-alone presentations, whereas those in the paired group received four pairings of light with food pellets. We also included a comparison group for CS-alone presentations: rats were placed in the training box without CS or US exposures in the first phase and received four CS-alone presentations in the second phase. Thirty minutes after the second phase, c-Fos levels in the ventral tegmental area (VTA), substantia nigra pars compacta (SNc), and LHb in these groups were measured. c-Fos levels in the LHb were higher in the paired-CS-alone group than in the paired-paired and comparison groups, while those in the VTA and SNc were significantly higher in the paired-paired group than in the other groups. On examination of LHb neurotoxic lesion effects on the decline of conditioned food-cup responses when a CS was repeatedly presented with no US, LHb lesions decelerated the decline in conditioned food-cup responses, suggesting a crucial role of LHb in appetitive extinction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of a nitrogen-doped mesoporous carbon (NMC) on the pGF electrode. • NMC changes the structures and physicochemical properties of the pGF electrode. • NMC enables strong B r 2 / B r n + 2 - adsorption within the positive electrode. • NMC realizes a flowless zinc-bromine battery with superior performance and durability. The flowless zinc-bromine battery (FLZBB) is non-flammable as it is based on an aqueous electrolyte and is considered an alternative to redox flow batteries because of its cost-effectiveness using a simple cell platform. However, it faces challenges related to self-discharge caused by the crossover of bromine (Br 2) and polybromide anions (B r n + 2 -) formed at the positive electrode during the charging process. The self-discharge reaction consumes the charging active materials, thereby decreasing battery performance and lifespan. To address the critical issues, this study introduces the development of a revolutionary positive electrode: a nitrogen-doped mesoporous carbon-coated thick graphite felt (NMC/GF). This positive electrode effectively suppresses the crossover of active materials and prevents the self-discharge reaction. The mesopores, strategically embedded with nitrogen sites, serve as a stronghold, capturing and immobilizing bromine and polybromide anions, significantly reducing their undesirable effects. Furthermore, we enhanced the electrochemical performance of the NMC/GF electrode by modifying it to be ultrahydrophilic. Abundant oxygen and nitrogen functional groups were incorporated onto the electrode, resulting in an amplified affinity with the aqueous electrolyte. This modification led to improved bromine redox reaction kinetics. Demonstrating an excellent Coulombic efficiency surpassing 96 % and an energy efficiency of over 76 % at a current density of 20 mA cm−2 with a high-rate areal capacity of 2 mAh cm−2, this novel positive electrode achieves a previously unattained milestone; cyclability unprecedentedly extended to 10,000 cycles. The development of NMC/GF positive electrodes further advances the FLZBB system, and large-area scale-up research of these carbon electrodes makes looking forward to practical uses in energy storage systems. [ABSTRACT FROM AUTHOR]

Peroxiredoxin 2 (Prx2) regulates oxidative stress response in neuronal injury. The present study examined the effects of Prx2 deletion on transient global ischemia-induced hippocampal-dependent memory impairment. First, 20-min bilateral common carotid artery occlusion (BCCAO)-reperfusion and sham-operated control procedures were conducted in 6- or 7-month-old Prx2 knockout and wild-type mice. The cognitive status of these mice was assessed using the Morris water maze task with a hidden platform and a novel object recognition task 7 days after the 20-min BCCAO. Next, to evaluate neuronal degeneration and oxidative stress in the CA1 subregion of the hippocampus critical for learning and memory, we measured immunoreactive Fluoro-jade C (FJC)-positive signals and 4-hydroxy-2- trans -nonenal (4-HNE) levels, respectively. The 20-min BCCAO induced cognitive impairments and increased the intensity of FJC-positive signals and 4-HNE levels of CA1 in Prx2 knockout mice but not in wild-type mice. These results suggest that Prx2 deficiency reduces resilience to transient global ischemia. • Effects of Prx2 deletion on the transient BCCAO-induced hippocampal impairments. • Impaired recognition memory in Prx2 knockout mice with transient BCCAO. • Impaired spatial memory in Prx2 knockout mice with transient BCCAO. • Increased oxidative stress in Prx2 knockout mice with transient BCCAO. [ABSTRACT FROM AUTHOR]

We evaluated the neuroprotective effect of L-theanine in Parkinson's disease and the underlying mechanism focusing on WNT/β-catenin signaling mediated by the MAPK pathway. We treated MPTP-induced SH-SY5Y cells with various concentrations of L-theanine (50, 100, 200, and 500 μg/mL), and we also treated Parkinson's model mice with L-theanine. L-theanine treatment effectively reduced the immunohistochemical hallmarks of Parkinson's disease, particularly Lewy bodies and α-synuclein, and increased the number of tyrosine hydroxylase-positive cells. L-theanine also improved the motor dysfunction in MPTP-induced Parkinson's disease model mice as measured by the rotarod test. The levels of several pro-inflammatory mediators that are overexpressed in Parkinson's disease, namely TNF-α, IL-6, COX-2, and MAC-1, were reduced following L-theanine treatment, and the levels of the pro-apoptotic proteins Bcl-2, caspase-3, p53, and PARP-1 were significantly reduced. L-theanine regulated the oxidative stress-related factors SOD-1, GST, and NOX-4 by targeting several proteins related to WNT/β-catenin signaling, i.e., β-catenin, WNT-3a, WNT-5a, TCF1/TCF7, and LEF1, via the MAPK pathway (p -JNK, p -ERK, and p -p38). Our results indicate that L-theanine is neuroprotective and has anti-inflammatory effects that could be beneficial for treating Parkinson's disease. L-Theanine facilitated the neuroprotective effect by mediating the Wnt/b-catenin signaling pathways. L-theanine has activated both Wnt/β-catenin signaling and the MAPK signaling pathways, subsequently downregulating the pro-inflammation, apoptosis, and oxidative stress mediators and enhancing the motor function. [Display omitted] [ABSTRACT FROM AUTHOR]

Four commercial gas diffusion layers (GDLs) are applied to high-temperature polymer electrolyte fuel cell anodes to investigate the relationship between microporous layer (MPL) properties and the performance of membrane electrode assembly. Subsequently, the physical properties such as the crack area and porosity of the MPL are analyzed via various methods. It is found that the capillary pressure of phosphoric acid (PA) from several theories is inversely related to the mass transfer capability (MTC) of the MPL. Finally, a new transport property named PA MTC of the MPL is proposed using the PA capillary pressure and MTC in MPL. The results indicate that the voltage at both low and high current densities increases separately as the PA MTC in the MPL adjusts to 0.5 MPa mm-1. Subsequently, the voltage beyond 0.5 MPa mm-1 increases in low current density contrary to the voltage at a high current density. • Anode GDLs are applied to high-temperature polymer electrolyte fuel cell. • The crack area of MPL has a high correlation with its porosity. • A new transport property called PA MTC in the MPL is proposed. [ABSTRACT FROM AUTHOR]

Kyphoplasty (KP) is a surgery used to reduce pain and increase stability by injecting medical bone cement into broken vertebrae. The purpose of this study was to determine the ideal amount of cement and injection site by analyzing forces with the finite element method. We modeled the anatomical structure of the vertebra and injected the cement at T12. By increasing the amount of cement from 1 cc to 22 cc, stress applied to T11 and L1 cortical was calculated. In addition, stress applied to the adjacent KP level was calculated with different injection sites (medial, anterosuperior, posterosuperior, anteroinferior, and posteroinferior). After 5 cc cement was inserted, adjacent end plate stress was analyzed. In this study, break point adjacent bone stress according to the capacity of cement was bimodal. Flexion/extension and lateral bending conditions showed similar break points (11.5–11.7 cc and 18.5–18.6 cc, respectively). When cement injection was changed, front under and back under had the highest stress values among various parts, whereas the center position showed the lowest stress value. With increasing amount of bone cement, stress on the upper and lower end plates of the cemented segment increased significantly. Thus, increasing cement amount to be more than 11.5 cc has a potential risk of adjacent fracture. Centrally injected bone cement can lower the risk of adjacent fracture after percutaneous KP. [ABSTRACT FROM AUTHOR]

The development of osteoarthritis (OA), the most common form of arthritis, is commonly associated with oxidative stress. Indeed, the lack of antioxidant responses largely increases OA incidence. OA is a leading cause of disability in the elderly, which reduces the quality of life and places high socioeconomic burdens on them. Several polyphenolic compounds, including chlorogenic acid (CGA), have shown cytoprotective effects via their antioxidant activity, but the exact mechanism (s) remain elusive. In this study, we demonstrated how CGA protects human chondrocytes against H 2 O 2 -induced apoptosis. The cytoprotective effect by CGA in 500 μM hydrogen peroxide-treated C28/I2 cells was evaluated by cell viability, TUNEL assay, and Western blotting analyses, and autophagy assessment was further performed by AO and MDC staining and tandem mRFP-GFP fluorescence analyses. Treatment of CGA to the human chondrocytes under oxidative stress significantly decreased apoptosis markers, such as cleaved caspase 3 and cleaved PARP, and increased anti-apoptotic marker Bcl-xL and the antioxidant response proteins NRF2 and NF-κB. Furthermore, CGA-dependent activation of antioxidant response proteins NRF2 and NF-κB and its protective effects in chondrocytes depended on autophagy. Indeed, CGA treatment and autophagy induction significantly decreased reactive oxygen species (ROS)–induced apoptosis. CGA exhibited the protective effect to human chondrocyte C28/I2 cells against oxidative stress-induced cell death by activating autophagy. These findings indicate that CGA is a potential therapeutic agent for the development of OA drugs. [ABSTRACT FROM AUTHOR]