Surface-modified LiNi0.8Co0.1Mn0.1O2 cathode with different coating amounts of SiO2 (0.25–1 wt%) is successfully synthesized and its electrochemical performances are investigated. Compared to bare ...LiNi0.8Co0.1Mn0.1O2, the 0.25 wt% SiO2 coated LiNi0.8Co0.1Mn0.1O2 delivers an initial capacity of 200.7 mAh g−1 as well as the excellent cyclability (capacity retention of 87.3% after 100 cycles at 0.5C) and rate capability (82.2% at 2C). Furthermore, 0.25 wt% SiO2 coated LiNi0.8Co0.1Mn0.1O2 exhibits the stable cycle performance at 55 °C (84.5% after 100 cycles at 0.5C). Such improvements are attributed to the SiO2 coating, which can suppress the irreversible phase transformation and play a role in obstacle to protect the LiNi0.8Co0.1Mn0.1O2 from electrolyte.
•SiO2 coating was prepared with high crystallinity.•SiO2 coating has a discharge capacity of 200.7 mAh g−1.•SiO2 coating shows a rate capability of 82.2% at 2C.•SiO2 coating shows a stable cyclability of 84.5%, after 100 cycles.
As large molecular tertiary structures, some proteins can act as small robots that find, bind, and chaperone target protein clients, showing the potential to serve as smart building blocks in ...self-assembly fields. Instead of using such intrinsic functions, most self-assembly methodologies for proteins aim for de novo-designed structures with accurate geometric assemblies, which can limit procedural flexibility. Here, a strategy enabling polymorphic clustering of quaternary proteins, exhibiting simplicity and flexibility of self-assembling paths for proteins in forming monodisperse quaternary cage particles is presented. It is proposed that the enzyme protomer DegQ, previously solved at low resolution, may potentially be usable as a threefold symmetric building block, which can form polyhedral cages incorporated by the chaperone action of DegQ in the presence of protein clients. To obtain highly monodisperse cage particles, soft, and hence, less resistive client proteins, which can program the inherent chaperone activity of DegQ to efficient formations of polymorphic cages, depending on the size of clients are utilized. By reconstructing the atomic resolution cryogenic electron microscopy DegQ structures using obtained 12- and 24-meric clusters, the polymorphic clustering of DegQ enzymes is validated in terms of soft and rigid domains, which will provide effective routes for protein self-assemblies with procedural flexibility.
The increasing appearance of multidrug-resistant pathogens has created an urgent need for suitable alternatives to current antibiotics. Antimicrobial peptides (AMPs), which act as defensive weapons ...against microbes, have received great attention because of broad-spectrum activities, unique action mechanisms and rare antibiotic-resistant variants. Despite desirable characteristics, they have shown limitations in pharmaceutical development due to toxicity, stability and manufacturing costs. Because of these drawbacks, only a few AMPs have been tested in Phase III clinical trials and no AMPs have been approved by the US FDA yet. However, these obstacles could be overcome by well-known methods such as changing physicochemical characteristics and introducing nonnatural amino acids, acetylation or amidation, as well as modern techniques like molecular targeted AMPs, liposomal formulations and drug delivery systems. Thus, the current challenge in this field is to develop therapeutic AMPs at a reasonable cost as well as to overcome the limitations.
Toxin–antitoxin (TA) systems regulate key cellular functions in bacteria. Here, we report a unique structure of the Streptococcus pneumoniae HigBA system and a novel antimicrobial agent that ...activates HigB toxin, which results in mRNA degradation as an antibacterial strategy. In this study, protein structure‐based peptides were designed and successfully penetrated the S. pneumoniae cell membrane and exerted bactericidal activity. This result represents the time during which inhibitors triggered S. pneumoniae cell death via the TA system. This discovery is a remarkable milestone in the treatment of antibiotic‐resistant S. pneumoniae, and the mechanism of bactericidal activity is completely different from those of current antibiotics. Furthermore, we found that the HigBA complex shows a crossed‐scissor interface with two intermolecular β‐sheets at both the N and C termini of the HigA antitoxin. Our biochemical and structural studies provided valuable information regarding the transcriptional regulation mechanisms associated with the structural variability of HigAs. Our in vivo study also revealed the potential catalytic residues of HigB and their functional relationships. An inhibition study with peptides additionally proved that peptide binding may allosterically inhibit HigB activity. Overall, our results provide insights into the molecular basis of HigBA TA systems in S. pneumoniae, which can be applied for the development of new antibacterial strategies.
Databases
Structural data are available in the PDB database under the accession number 6AF4.
HigBA complex shows a crossed‐scissor interface with two intermolecular β‐sheets at both the N and C termini of the HigA antitoxin. The crossed‐scissor constitutes a new type of interface between HigB and HigA. We report a unique structure of the Streptococcus pneumoniae HigBA system and a novel antimicrobial agent that activates HigB toxin, which results in mRNA degradation as an antibacterial strategy.
Nylon fishing nets have excellent strength and durability, but when lost at sea, their insufficient decomposition destroys habitats and spawning grounds, and pollutes the marine environment. This led ...to the development of poly(butylene succinate) (PBS) resin for biodegradable fishing gear based on aliphatic fibers. Prompted by the low stiffness and elastic recovery of PBS, we introduced two additional components into the molecular structure of PBS: adipic acid and ethylene glycol. These two new components were combined with succinic acid and 1,4-butanediol, the existing components of PBS, to synthesize poly(butylene adipate-co-butylene succinate-co-ethylene adipate-co-ethylene succinate) (PBEAS) resin via esterification and polycondensation reactions of a quaternary aliphatic copolyester. Although the molecular weight and molecular weight distribution of PBEAS are similar to those of PBS, it has excellent tensile strength, stiffness, elastic recovery, and biodegradability, with a low melting point for good production efficiency. These improvements are expected to allow PBEAS resin to be applied to gill nets for fish that require high stiffness, thereby expanding the use of biodegradable fishing gear.
•We improve the stiffness and elastic recovery of poly(butylene succinate) resin.•We introduce two components into PBS: adipic acid and ethylene glycol.•Good tensile strength, stiffness, elastic recovery, and biodegradability are achieved.•The resin can be applied to gill nets for fish that require high stiffness.
Brain tumor patients experience physical, psychological, social, and cognitive changes. These changes are challenging for both the patients and their families. These patients and their families need ...to adapt together on the cancer treatment path. This study aimed to identify the factors affecting adaptation in families of adult patients with brain tumors. A quantitative, cross-sectional study of 165 families of adult patients with primary brain tumors was conducted using a self-administered questionnaire. Partial least squares structural equation modeling was used to test a hypothetical model. The results showed that family stress, family functioning, and family resources influenced on family adaptation in families of adult patients with primary brain tumors. Among these factors, family resources were identified to be the strongest factor associated with family adaptation. The results of this study may be utilized as a theoretical basis in nursing to improve the family adaptation of patients with brain tumors. Regarding nursing practices, the results suggest that nurses should provide family-centered nursing interventions and promote family resources to help brain tumor patients and their families to adapt.
Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the brain; however, the roles of GABA in antimicrobial host defenses are largely unknown. Here we demonstrate that ...GABAergic activation enhances antimicrobial responses against intracellular bacterial infection. Intracellular bacterial infection decreases GABA levels in vitro in macrophages and in vivo in sera. Treatment of macrophages with GABA or GABAergic drugs promotes autophagy activation, enhances phagosomal maturation and antimicrobial responses against mycobacterial infection. In macrophages, the GABAergic defense is mediated via macrophage type A GABA receptor (GABA
R), intracellular calcium release, and the GABA type A receptor-associated protein-like 1 (GABARAPL1; an Atg8 homolog). Finally, GABAergic inhibition increases bacterial loads in mice and zebrafish in vivo, suggesting that the GABAergic defense plays an essential function in metazoan host defenses. Our study identified a previously unappreciated role for GABAergic signaling in linking antibacterial autophagy to enhance host innate defense against intracellular bacterial infection.
Over the last few decades, the research on ferroelectric memories has been limited due to their dimensional scalability and incompatibility with complementary metal-oxide-semiconductor (CMOS) ...technology. The discovery of ferroelectricity in fluorite-structured oxides revived interest in the research on ferroelectric memories, by inducing nanoscale nonvolatility in state-of-the-art gate insulators by minute doping and thermal treatment. The potential of this approach has been demonstrated by the fabrication of sub-30 nm electronic devices. Nonetheless, to realize practical applications, various technical limitations, such as insufficient reliability including endurance, retention, and imprint, as well as large device-to-device-variation, require urgent solutions. Furthermore, such limitations should be considered based on targeting devices as well as applications. Various types of ferroelectric memories including ferroelectric random-access-memory, ferroelectric field-effect-transistor, and ferroelectric tunnel junction should be considered for classical nonvolatile memories as well as emerging neuromorphic computing and processing-in-memory. Therefore, from the viewpoint of materials science, this review covers the recent research focusing on ferroelectric memories from the history of conventional approaches to future prospects.
Abstract
Background
Malaria chemoprophylaxis using chloroquine (CQ) and primaquine (PQ) has been administered to resident soldiers in the 3rd Army of Republic of Korea (ROK) to prevent malaria ...infection since the year 1997. Due to mass chemoprophylaxis against malaria, concern exists about the occurrence of chloroquine resistance (CQR). This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the
Plasmodium vivax
multi-drug resistance protein-1 (
pvmdr-1
) gene to monitor the risk of CQR.
Methods
SNPs of the
pvmdr-1
gene were analysed in 73 soldiers of the 3
rd
Army of ROK diagnosed with infection by
P. vivax
.
Results
Quintuple mutations (G698S, L845F, M908L, T958M, and F1076L) were detected in 73 soldiers. A newly identified non-synonymous mutation in the Y541C position had been introduced into
P. vivax
malaria-endemic areas in ROK, at a frequency of 1.3% (1/73). In addition, synonymous mutations were detected at positions K44 (38.4%, 28/73), L493 (26%, 19/73), T529 (61.6%, 45/73), and E1233 (52.1%, 38/73). Based on these SNPs,
pvmdr-1
sequences of ROK were classified into 6 haplotypes. The phylogenetic analysis closed to the type of North Korean showed that
P. vivax
malaria of ROK could be a reason of influx from North Korea.
Conclusions
This study showed that synonymous and non-synonymous mutations of
pvmdr-1
were observed in the malaria chemoprophylaxis-executed regions of ROK from 2016 to 2017. Based on the rapid transition of
pvmdr-1
SNPs, continuous surveillance for SNPs of
pvmdr-1
related to CQR in the malaria-endemic regions of ROK is essential.
Zinc oxide (ZnO) films reportedly exhibit a rubbing effect for liquid crystal (LC) alignment. In this study, we investigated the LC alignment characteristics of solution-derived ZnO films according ...to the number of rubbing iterations. Uniform and homogeneous LC alignments were achieved on the rubbed ZnO films, regardless of the number of rubbing iterations. As the number of rubbing iterations increased, the surface energies of the rubbed ZnO films were similar to 42.20 mJ/m2, but the polar energy increased from 4.288 mJ/m2 to 6.470 mJ/m2. Additionally, the electro-optical characteristics of the twisted-nematic (TN) LC cells fabricated by rubbed ZnO films showed the best performance when the number of rubbing iterations was at five. By confirming that the ZnO film with improved physical, chemical, and electro-optical characteristics compared to the polyimide film achieved a perfect LC alignment through the conventional rubbing process, it indicates that the ZnO film can be an excellent substitute for the LC alignment film. In addition, it is expected that it can be applied to an LC-based virtual reality (VR)/augmented reality (AR) display system that requires a very fast response time through the excellent EO characteristics of the TN LC cell of the solution-derived ZnO film through the rubbing process.
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