Reactivated memory undergoes a rebuilding process that depends on de novo protein synthesis. This suggests that retrieval is dynamic and serves to incorporate new information into preexisting ...memories. However, little is known about whether or not protein degradation is involved in the reorganization of retrieved memory. We found that postsynaptic proteins were degraded in the hippocampus by polyubiquitination after retrieval of contextual fear memory. Moreover, the infusion of proteasome inhibitor into the CA1 region immediately after retrieval prevented anisomycin-induced memory impairment, as well as the extinction of fear memory. This suggests that ubiquitin- and proteasome-dependent protein degradation underlies destabilization processes after fear memory retrieval. It also provides strong evidence for the existence of reorganization processes whereby preexisting memory is disrupted by protein degradation, and updated memory is reconsolidated by protein synthesis.
Lithium-impregnated metal foam anodes (LIMFAs) are fabricated and investigated. The LIMFAs are prepared by the impregnation of lithium into molten-salt-coated nickel metal foam. A single cell with ...the LIMFA exhibits a specific capacity of 3009 As g−1. For comparison, a single cell with a LiSi alloy anode is also discharged, demonstrating a specific capacity of 1050 As g−1. These significant improvements can be attributed to the large amount of lithium impregnated into the metal foam as well as the molten lithium holding capability of the foam. Due to their excellent electrochemical properties, LIMFAs are suitable for use in thermal batteries.
•We investigated an alternative to the conventional Li–Si anode for thermal batteries.•The LIMFAs are prepared by the impregnation of lithium into salt-coated metal foam.•The LIMFA has a higher specific capacity than the conventional Li–Si alloy anode.
In this study, a nickel (Ni)-doped 1T-MoS2 catalyst, an efficient tri-functional hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) catalyst, was ...massively synthesized at high pressure (over 15 bar). The morphology, crystal structure, and chemical and optical properties of the Ni-doped 1T-MoS2 nanosheet catalyst were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ring rotating disk electrodes (RRDE), and the OER/ORR properties were characterized using lithium-air cells. Our results confirmed that highly pure, uniform, monolayer Ni-doped 1T-MoS2 can be successfully prepared. The as-prepared catalysts exhibited excellent electrocatalytic activity for OER, HER, and ORR owing to the enhanced basal plane activity of Ni doping and formidable active edge sites resulting from the phase transition to a highly crystalline 1T structure from 2H and amorphous MoS2. Therefore, our study provides a massive and straightforward strategy to produce tri-functional catalysts.
In South Korea, a November 2021 outbreak caused by severe acute respiratory syndrome coronavirus 2 Omicron variant originated from 1 person with an imported case and spread to households, ...kindergartens, workplaces, restaurants, and hospitals, resulting in 11 clusters within 3 weeks. An epidemiologic curve indicated rapid community transmission of the Omicron variant.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The enhancement of the capacitance can be attributed to the synergistic effect of the increased electrochemical activity in the AC and mesopore volume, which were induced by the phosphoric acid ...treatment Display omitted .
► The H3PO4 treated AC samples showed the enhanced specific capacitances. ► The texture properties of AC increased due to phosphoric acid treatment. ► The CO groups onto the surface of AC increased via phosphoric acid treatment. ► The etching and introduction of CO groups proved effective in the capacity.
To improve the electrochemical performance of an activated carbon (AC)-based electric double-layer capacitor (EDLC), the AC surface, which is used as an electrode, was modified using different concentrations of phosphoric acid. The effects of the treatment on the surface and electrochemical properties of the AC electrodes were investigated. The specific capacitance increased from 256F/g for an untreated sample to 452F/g for a sample treated with a 2M solution at a scan rate of 5mV/s. This increase can be attributed to an increase in the mesopore volume caused by the etching effect of the reaction between the carbon surfaces and phosphoric acid. In addition, oxygen functional groups, which were introduced by the treatment, improved the electrochemical properties of the resulting AC-based electrode. Therefore, simultaneous etching and oxygen introduction with phosphoric acid can easily bind oxygen functional groups (particularly CO) onto the surface of an AC electrode. This method is effective at preparing AC for use in an EDLC with improved electrochemical properties.
To determine optimal quarantine duration, we evaluated time from exposure to diagnosis for 107 close contacts of severe acute respiratory syndrome coronavirus 2 Omicron variant case-patients. Average ...time from exposure to diagnosis was 3.7 days; 70% of diagnoses were made on day 5 and 99.1% by day 10, suggesting 10-day quarantine.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Display omitted
•Fluorinated Fe powders resulted in a significant increase in the wettability of molten Li.•The Fe-F layer was grown on the surface of the Fe powder was lipophilic and showed good ...wettability.•Fluorinated Fe-Li metal showed no evidence of short circuits or dendrite formation after a cycle test at 0.1 and 0.2 mA cm−2.•This proposed method will further develop rechargeable lithium-metal battery technology.
Multiple studies attempted mixing Li with microparticle metal powders or using it to impregnate a porous media to utilize for thermal batteries. The infusion of Li into porous structures or powders is challenging as most materials used in battery fabrication are lithiophobic to molten Li. Optimizing and improving the wettability of molten Li is one approach to address this. Herein, we propose an efficient and facile direct fluorination method for achieving an ultra-lithiophilic fluoride layer on the surface of a Fe powder. Fluorination of Fe powders resulted in a significant increase in the wettability of molten Li by growing a Fe-F layer on the surface of the Fe powder. This layer was lithiophilic and showed good wettability. An anode prepared using fluorinated Fe-Li metal showed no evidence of short circuits or dendrite formation after a cycle test at 0.2 mA cm−2. Both a pure Li anode and pristine Fe powder showed unstable charge–discharge characteristics when used as an anode in cycle tests. This proposed method will further develop rechargeable lithium-metal battery technology.
Herein, the discharge properties of lithium (Li) anode with FeS2 cathode system are investigated under different pressure loads, weight percent of Li, temperatures, and current densities to provide a ...fundamental understanding of the operational safety, electrochemical properties, and optimization parameters for Li anode‐based thermal batteries. The lithium anode was prepared via physically mixing Li with Fe powder. The Li−Si alloy, the most common anode for thermal batteries, was investigated simultaneously to show the clear distinction in electrochemical performance between the Li anode and Li−Si anode. For achieving high operational safety and discharge performance with Li anode, the recommended pressure load and weight percent of Li are below 6 kgf cm−2 and 15 wt%, respectively, to prevent any leakage or short‐circuiting problems. The discharge at 500 °C and 0.2–0.4 A cm−2 exhibits the optimal performance for the Li anode and FeS2 cathode system. Finally, the thermal batteries with 17 cells are manufactured to confirm the aforementioned parameters at −32 and 63 °C to demonstrate that the previous results coincide with the actual battery level experiments. Due to the intertwined nature of the parameters, the optimization should always be conducted in a holistic manner to obtain high‐performance thermal batteries for future military applications.
Thermal battery: The application of lithium metal embedded in Fe powder matrix as the high power thermal battery anode for military application is investigated in this work along with several optimization parameters that must be considered in order to manufacture safe, reliable thermal battery – Li loading, pressure, current density, and temperature. The detailed electrochemical experiments including EIS and actual battery‐level discharge were studied to discover the underlying mechanism for such high performance.
In this study, the breakthrough curve behaviors of aminated carbon molecular sieves (CMSs) were investigated for a CO2/CH4 mixed gas, and the selective separation of CO2 was demonstrated. Nitrogen ...functional groups were effectively introduced onto the surfaces of the a-CMSs, and they attached themselves to the pores of the CMSs as the ammonium hydroxide concentration was increased. Nitrogen functional groups on the surfaces of the aminated CMSs, such as NH2 and CN, played an important role in guiding CO2 into the micropores via the attractive forces felt by the electrons in the CO2 molecules.
Micro/meso-porous reduced graphite oxide (MMRGO) nanosheets were produced using precursor carbide-derived carbon (CDC), which was produced at a high temperature of 1200°C, through a massive wet ...chemistry synthetic route involving graphite oxidation and microwave reduction. X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that the MMRGO nanosheets were fabricated with 2–3 layers and ripple-like corrugations. N2 sorption isotherms confirmed that micro/meso-pores coexisted in the RGO sample from CDC. In the anode application of Li-ion batteries, this RGO sample had an enhanced capacity performance at the 0.1 C rate and 1 C rate, with ∼1200mAhg−1 at the 100th cycle and ∼1000mAhg−1 at the 200th cycle, respectively.
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