Failure mechanisms of layered LiNixCoyMn1-x-yO2 cathodes for Li-ion batteries

Department of Energy Engineering (Battery Science and Technology)As the promising cathode material, Ni-containing layered Li NCM oxide has several advantages; low-cost, high capacity, etc. but hard to commercialize because of its poor cycle performance. About this, many researchers studied the failure mechanisms and regard the surface part problems as the failure mechanism of layered LI NCM oxide. However, apart from surface part problem, there are other failure mechanisms affect to the poor cycle performance of Li NCM. Among them, we focus and suggest new kinds of failure mechanism; Ni disordering as bulk part problem. To identify, at first, the half cell test shows that the poor cycle performance of Li NCM in several factors, and the degree of Ni disordering during cycling is analyzed using Rietveld refinement method. As results, when the Ni disordering is increased during cycling, the capacity of Li NCM is decreased more and more, and this indicates that Ni disordering can affect the cycle performance of Li NCM during cycling, so it is demonstrated that the Ni disordering is one of the failure mechanism of poor cycle performance of layered LI NCM. Moreover, we suggest new type solution to improve; Mg doping at Li layer of Li NCM. Several analyses, such as TEM, refinement data show the Mg is successfully doped into Li layer, and the half cell test shows its better cycle performance than bare Li NCM (1C, 30℃). Also, through refinement analysis of cycled Mg-doped Li NCM electrode, we observe that the Ni disordering is also inhibited somewhat, comparing the bare Li NCM results.ope

Characterization of the ATP transporter in the reconstituted rough endoplasmic reticulum proteoliposomes

AbstractAdenosine triphosphate (ATP) transporter from rat liver rough endoplasmic reticulum (RER) was solubilized and reconstituted into phosphatidylcholine liposomes. The RER proteoliposomes, resulting from optimizing some reconstitution parameters, had an apparent Km value of 1.5 μM and a Vmax of 286 pmol min−1 (mg protein)−1 and showed higher affinity for ATP and a lower Vmax value than intact RER (Km of 6.5 μM and Vmax of 1 nmol). ATP transport was time- and temperature-dependent, inhibited by 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid, which is known as an inhibitor of anion transporters including ATP transporter, but was not affected by atractyloside, a specific inhibitor of mitochondrial ADP/ATP carrier. The internal and external effects of various nucleotides on the ATP transport were examined. ATP transport was cis-inhibited strongly by ADP and weakly by AMP. ADP-preloaded RER proteoliposomes showed a specific increase of ATP transport activity while AMP-preloaded RER proteoliposomes did not show the enhanced overshoot peak in the ATP uptake plot. These results demonstrate the ADP/ATP antiport mechanism of ATP transport in rat liver RER

Effects of Glycyrrhizae Radix Pharmacopuncture Intravenous Injection on Ischemia-induced Acute Renal Failure in Rabbits

Objectives: The present study was undergone to determine whether Glycyrrhizae Radix pharmacopuncture intravenous injection exerts beneficial effect against the ischemia-induced acute renal failure in rabbits. Methods: Rabbits were treated with Glycyrrhizae Radix pharmacopuncture via i.v., followed by renal ischemia/reperfusion. The fractional excretion of glucose and phosphate were measured and the malondialdehyde content was also determined. The morphological changes of cortical part of kidney also observed with light microscope. Results: Renal ischemia/reperfusion caused increase of the fractional excretion of glucose and phosphate in ischemia-induced animals, which was prevented by Radix Glycyrrhizae extract treatment. Ischemia/reperfusion increased lipid peroxidation, which was prevented and morphological changes also altered by Radix Glycyrrhizae pharmacopuncture administration. Conclusions: These results indicate that lipid peroxidation plays a critical role in ischemia-induced acute renal failure and Glycyrrhizae Radix pharmacopuncture exerts the protective effect against acute renal failure induced by renal ischemia/reperfusion

Intracellular Membrane Association of the Aplysia cAMP Phosphodiesterase Long and Short Forms via Different Targeting Mechanisms

Phosphodiesterases (PDEs) play key roles in cAMP compartmentalization, which is required for intracellular signaling processes, through specific subcellular targeting. Previously, we showed that the long and short forms of Aplysia PDE4 (ApPDE4), which are localized to the membranes of distinct subcellular organelles, play key roles in 5-hydroxytryptamineinduced synaptic facilitation in Aplysia sensory and motor synapses. However, the molecular mechanism of the isoform-specific distinct membrane targeting was not clear. In this study, we further investigated the molecular mechanism of the membrane targeting of the ApPDE4 long and short forms. We found that the membrane targeting of the long form was mediated by hydrophobic interactions, mainly via 16 amino acids at the N-terminal region, whereas the short form was targeted solely to the plasma membrane, mainly by nonspecific electrostatic interactions between theirNtermini and the negatively charged lipids such as the phosphatidylinositol polyphosphates PI4P and PI(4,5)P<inf>2</inf>, which are embedded in the inner leaflet of the plasma membrane. Moreover, oligomerization of the long or short form by interaction of their respective upstream conserved region domains, UCR1 and UCR2, enhanced their plasma membrane targeting. These results suggest that the long and short forms of ApPDE4 are distinctly targeted to intracellular membranes through their direct association with the membranes via hydrophobic and electrostatic interactions, respectively. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.1

Impact of Polymer Structure in Polyurethane Topcoats on Anti-Icing Properties

Icing on the topcoat layer of structures or mobility systems can be a factor leading to functional failures or accidents. Material engineering approach to prevent icing involves creating hydrophobic surfaces. In this study, it was confirmed that the method of controlling the structure of polymers using solvents to adjust surface hydrophobicity and ice prevention effects is effective. Polyurethane (PU) topcoats are primarily used on the exterior of mobility devices; therefore, structure of PU was manipulated using xylene. Through the adjustment of the ratio between PU and xylene, changes in the curing enthalpy and crystal structure were observed, which led to alterations in tensile strength. Additionally, changes in surface energy and contact angle occurred depends on xylene content, and de-icing property of PU topcoat was enhanced by 66 % on the surface of the 20 vol% xylene PU topcoat, compared to the pure PU topcoat. It was confirmed that the basic method of manipulating the polymer structure through solvent amount in topcoats could be utilized as a technique in hydrophobic surface research, such as ice prevention

Precise Modulation of Triple-Phase Boundaries towards a Highly Functional Exsolved Catalyst for Dry Reforming of Methane under a Dilution-Free System

Dry reforming of methane (DRM) has been emerging as a viable solution to achieving carbon neutrality enhanced by the Paris Agreement as it converts the greenhouse gases of CO2 and CH4 into industrially useful syngas. However, there have been limited studies on the DRM catalyst under mild operating conditions with a high dilution gas ratio due to their deactivation from carbon coking and metal sintering. Herein, we apply the triple-phase boundary (TPB) concept to DRM catalyst via exsolution phenomenon that can secure elongated TPB by controlling the Fe-doping ratio in perovskite oxide. Remarkably, the exsolved catalyst with prolongated TPB shows exceptional CO2 and CH4 conversion rates of 95.9 % and 91.6 %, respectively, stable for 1000 hours under a dilution-free system. DFT calculations confirm that the Lewis acid of support and Lewis base of metal at the TPB promote the adsorption of reactants, resulting in lowering the overall CO2 dissociation and CH4 dehydrogenation energy

Development and Validation of an Arterial Pressure-Based Cardiac Output Algorithm Using a Convolutional Neural Network: Retrospective Study Based on Prospective Registry Data

Background: Arterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released. Objective: In this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique. Methods: A retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC. Results: A total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P<.001). Conclusions: The deep learning-based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care. © Hyun-Lim Yang, Chul-Woo Jung, Seong Mi Yang, Min-Soo Kim, Sungho Shim, Kook Hyun Lee, Hyung-Chul Lee. Originally published in JMIR Medical Informatics (https://medinform.jmir.org), 16.08.2021. This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Medical Informatics, is properly cited. The complete bibliographic information, a link to the original publication on https://medinform.jmir.org/, as well as this copyright and license information must be included.1