Design and Optimization of Composite Cathodes for Solid-State Batteries Using Hybrid Carbon Networks with Facile Electronic and Ionic Percolation Pathways.

Solid-state batteries (SSBs) have emerged as a promising alternative to conventional liquid electrolyte batteries due to their potential for higher energy density and improved safety. However, achieving high performance in SSBs is difficult because of inadequate contact and interfacial reactions that generate high interfacial resistance, as well as inadequate solid-solid contact between electrodes. These chronic issues are associated with inhomogeneous ion and electron transport networks owing to imperfect solid-solid interfacial contact. This study developed an optimal interfacial engineering strategy to facilitate an ion-electron transport network by designing an active material (NCM622) uniformly filled with a thin layer of a solid electrolyte (garnet-type Li6.25Ga0.25La3Zr2O12) and conductive additives. The optimal composite electrode architecture enhanced the high capacity, high rate capability, and long-term cycle stability, even at room temperature, owing to the percolating network for facile ionic conduction that assured a homogeneous reaction. In addition to mitigating the mechanical degradation of the cathode electrode, it also reduced the crosstalk effects on the anode-solid electrolyte interface. Effectively optimizing the selection and use of conductive additives in composite electrodes offers a promising approach to addressing key performance-limiting factors in SSBs, including interfacial resistance and solid-solid contact issues. This study underscores the critical importance of cathode architecture design for achieving high-performance SSBs by ensuring that the interfaces are intact with solid electrolytes at both the cathode and anode interfaces while promoting uniform reactions. This study provides valuable insights into the development of SSBs with improved performance, which could have significant implications for a wide range of applications.

Angelica gigas NAKAI and Its Active Compound, Decursin, Inhibit Cellular Injury as an Antioxidant by the Regulation of AMP-Activated Protein Kinase and YAP Signaling.

Natural products and medicinal herbs have been used to treat various human diseases by regulating cellular functions and metabolic pathways. Angelica gigas NAKAI (AG) helps regulate pathological processes in some medical fields, including gastroenterology, gynecology, and neuropsychiatry. Although some papers have reported its diverse indications, the effects of AG against arachidonic acid (AA)+ iron and carbon tetrachloride (CCl4) have not been reported. In HepG2 cells, AA+ iron induced cellular apoptosis and mitochondrial damage, as assessed by mitochondrial membrane permeability (MMP) and the expression of apoptosis-related proteins. On the other hand, AG markedly inhibited these detrimental phenomena and reactive oxygen species (ROS) production induced by AA+ iron. AG activated the liver kinase B1 (LKB1)-dependent AMP-activated protein kinase (AMPK), which affected oxidative stress in the cells. Moreover, AG also regulated the expression of yes-associated protein (YAP) signaling as mediated by the AMPK pathways. In mice, an oral treatment of AG protected against liver toxicity induced by CCl4, as indicated by the plasma and histochemical parameters. Among the compounds in AG, decursin had antioxidant activity and affected the AMPK pathway. In conclusion, AG has antioxidant effects in vivo and in vitro, indicating that natural products such as AG could be potential candidate for the nutraceuticals to treat various disorders by regulating mitochondrial dysfunction and cellular metabolic pathways.

The ISWI chromatin remodelling factor NURF is not required for mitotic male X chromosome organisation.

The nucleosome remodelling factor (NURF) is an ISWI-class ATP-dependent chromatin remodeling enzyme required both for gene expression and higher order chromatin organisation. NURF binds to histone modifications that decorate the Drosophila polytene male X chromosome and is required to maintain correct organisation of this chromosome. NURF mutants exhibit distorted and decondensed polytene male X chromosomes dependent on the presence of the male-specific lethal (MSL) complex. Here we tested whether mitotic chromosomes similarly require NURF to maintain correct morphology. Surprisingly, although the MSL complex remains associated with mitotic male X chromosomes, NURF is not required to maintain morphology. While the ISWI subunit of NURF is known to remain associated with mitotic chromosomes we show that the NURF specificity subunit Nurf301/BPTF dissociates from chromatin during both Drosophila and human mitosis, further illuminating that NURF is dispensable for mitotic chromosome organisation.

Exon junction complex proteins bind nascent transcripts independently of pre-mRNA splicing in Drosophila melanogaster.

Although it is currently understood that the exon junction complex (EJC) is recruited on spliced mRNA by a specific interaction between its central protein, eIF4AIII, and splicing factor CWC22, we found that eIF4AIII and the other EJC core proteins Y14 and MAGO bind the nascent transcripts of not only intron-containing but also intronless genes on Drosophila polytene chromosomes. Additionally, Y14 ChIP-seq demonstrates that association with transcribed genes is also splicing-independent in Drosophila S2 cells. The association of the EJC proteins with nascent transcripts does not require CWC22 and that of Y14 and MAGO is independent of eIF4AIII. We also show that eIF4AIII associates with both polysomal and monosomal RNA in S2 cell extracts, whereas Y14 and MAGO fractionate separately. Cumulatively, our data indicate a global role of eIF4AIII in gene expression, which would be independent of Y14 and MAGO, splicing, and of the EJC, as currently understood.

Genome-Wide Mapping Targets of the Metazoan Chromatin Remodeling Factor NURF Reveals Nucleosome Remodeling at Enhancers, Core Promoters and Gene Insulators.

NURF is a conserved higher eukaryotic ISWI-containing chromatin remodeling complex that catalyzes ATP-dependent nucleosome sliding. By sliding nucleosomes, NURF is able to alter chromatin dynamics to control transcription and genome organization. Previous biochemical and genetic analysis of the specificity-subunit of Drosophila NURF (Nurf301/Enhancer of Bithorax (E(bx)) has defined NURF as a critical regulator of homeotic, heat-shock and steroid-responsive gene transcription. It has been speculated that NURF controls pathway specific transcription by co-operating with sequence-specific transcription factors to remodel chromatin at dedicated enhancers. However, conclusive in vivo demonstration of this is lacking and precise regulatory elements targeted by NURF are poorly defined. To address this, we have generated a comprehensive map of in vivo NURF activity, using MNase-sequencing to determine at base pair resolution NURF target nucleosomes, and ChIP-sequencing to define sites of NURF recruitment. Our data show that, besides anticipated roles at enhancers, NURF interacts physically and functionally with the TRF2/DREF basal transcription factor to organize nucleosomes downstream of active promoters. Moreover, we detect NURF remodeling and recruitment at distal insulator sites, where NURF functionally interacts with and co-localizes with DREF and insulator proteins including CP190 to establish nucleosome-depleted domains. This insulator function of NURF is most apparent at subclasses of insulators that mark the boundaries of chromatin domains, where multiple insulator proteins co-associate. By visualizing the complete repertoire of in vivo NURF chromatin targets, our data provide new insights into how chromatin remodeling can control genome organization and regulatory interactions.

Role of Drosophila EDEMs in the degradation of the alpha-1-antitrypsin Z variant.

The synthesis of proteins in the endoplasmic reticulum (ER) that exceeds the protein folding capacity of this organelle is a frequent cause of cellular dysfunction and disease. An example of such a disease is alpha-1-antitrypsin (A1AT) deficiency, caused by destabilizing mutations in this glycoprotein. It is considered that the mutant proteins are recognized in the ER by lectins and are subsequently degraded through the proteasome, leading to a deficiency in this enzyme in the afflicted patients. We previously established a Drosophila model of this disease by overexpressing the null Hong Kong (NHK) allele of this gene and found that the Drosophila lectin, ER degradation-enhancing α-mannosidase-like protein 2 (EDEM2), can accelerate the degradation of A1AT when overexpressed. NHK is a rare allele, and in this study, we investigated in depth the mechanisms through which Drosophila EDEMs affect the degradation of the Z variant, which is the predominant disease allele. Specifically, we report that the Z allele does not activate ER stress signaling as prominently as the NHK allele, but similarly requires both Drosophila EDEM1 and EDEM2 for the degradation of the protein. We demonstrate that EDEMs are required for their ubiquitination, and without EDEMs, glycosylated A1AT mutants accumulate in cells. These results support the role of the EDEM-mediated ubiquitination of the alpha-1-antitrypsin Z (ATZ) allele, and establish a Drosophila model for the study of this protein and disease.

A Modified Oxidative Refinement Process for Removing Boron from Molten Silicon Under Enhanced Electromagnetic Force.

The removal of boron is one of the main challenges in the purification of metallurgical grade silicon destined for low-cost photovoltaic applications. However, boron is very difficult to remove in its elemental form due to its large segregation coefficient in silicon and its low vapor pressure. The removal of boron by slag treatment is today regarded as a highly promising method, but its refining efficiency is relatively low. Also, the reduction of boron by plasma treatment exhibits a high refining efficiency, but the processing cost is high due to the large amount of electricity consumed by the process. In this regard, the use of an oxidizing reactive gas in the refinement process offers some advantages both in terms of low energy consumption and promising refinement rates. Boron can be extracted in various gaseous forms as B(x)O(y) and/or B(x)H(z)O(y) phases, but the vapor pressure of B(x)H(z)O(y) is much greater than that of the other specie at a temperature of 1700 K. The present study reports a modified oxidative refining method designed to enhance the vaporization of boron as B(x)H(z)O(y) by blowing gaseous water onto the silicon melt in a segmented crucible to enhance the electromagnetic force, whereby the processing cost can be dramatically reduced due to the use of a reusable quartz crucible in a graphite crucible. An initial boron content of 13 ppm in the metallurgical grade silicon was significantly decreased to 0.3 ppm by the employment of 1.7SLM Ar + 100 ml/h H2O. Also, a mechanism capable of reducing boron based on thermodynamic considerations is proposed.

Numerical simulation of solid liquid interface behavior during continuous strip casting process.

A new metal-strip-casting process called continuous strip-casting (CSC) has been developed for making thin metal strips. A numerical simulation model to help understand solid-liquid interface behavior during CSC has been developed and used to identify the solidification morphologies of the strips and to determine the optimum processing conditions. In this study, we used a modified level contour reconstruction method (LCRM) and the sharp interface method to modify interface tracking, and performed a simulation analysis of the CSC process. The effects of process parameters such as heat-transfer coefficient and extrusion velocity on the behavior of the solid-liquid interface were estimated and used to improve the apparatus. A Sn (Tin) plate of dimensions 200 x 50 x 1 mm3 was successfully produced by CSC for a heat-transfer coefficient of 104 W/m2 K and an extrusion velocity of 0.2 m/s.

Numerical simulation and fabrication of silicon sheet via spin casting.

A spin-casting process for fabricating polycrystalline silicon sheets for use as solar cell wafers is proposed, and the parameters that control the sheet thickness are investigated. A numerical study of the fluidity of molten silicon indicates that the formation of thin silicon sheets without a mold and via spin casting is feasible. The faster the rotation speed of graphite mold, the thinner the thickness of sheet. After the spread of the molten silicon to cover the graphite mold with rotation speed of above 500 rpm, the solidification has to start. Silicon sheets can be produced by using the centrifugal force under appropriate experimental conditions. The spin-cast sheet had a vertical columnar microstructure due to the normal heat extraction to the substrate, and the sheet lifetime varied from 0.1 microS to 0.3 microS measured by using the microwave photoconductance decay (MW-PCD) to confirm that the spin-cast silicon sheet is applicable to photovoltaics.

Study of the microstructures and lifetime of spin-cast silicon sheets for photovoltaics.

Silicon sheets were fabricated by a new fabricating method, spin casting with various rotation speeds of the graphite mold. The microstructure of spin-cast silicon sheets were investigated using an electron probe microanalyzer (EPMA) and scanning electron microscope/electron backscatter diffraction/orientation image micrograph, and the lifetime of the sheets was mapped using microwave photoconductance decay. The silicon sheets were vertically aligned, with sizes ranging from tens of microns to one hundred microns. The as-grown lifetime was measured and found to range from 0.049 micros to 0.250 micros. The ASTM number was plotted against the lifetime using ASTM E112 to estimate the grain size. Approximately half of the grain boundaries seemed electrically inactive with meaning of no recombination center since the grains were growth directionally, especially in a longitudinal aligned. It was confirmed that the lifetime of spin-cast sheets makes them suitably applicable for photovoltaics compared to those produced by alternative ribbon-producing methods.

Formation of silicon sheet on a rotating substrate.

A spin casting process to fabricate polycrystalline silicon sheets for use as solar cell wafers is presented and the parameters that control the sheet thickness are investigated. The computational model for the spin casting is proposed in order to understand the melt flow and solidification behaviors in the mold. The effect of the rotating speed of the mold and substrate morphology on the silicon sheets is studied via computer simulations, and the simulation results are compared with the experimental results. The numerical study of the fluidity and solidification behavior of the silicon predicted that the formation of rectangular sheets via spin casting is feasible, and the subsequent experiment confirmed this prediction. Using a square mold, rectangular silicon sheets can be produced under appropriate experimental conditions. Microstructural analyses verified the presence of long columnar structures on the sheets.

Development of a simple cell lysis method for recombinant DNA using bacteriophage lambda lysis genes.

In this study, we describe the development of a simple and efficient method for cell lysis via the insertion of a bacteriophage lambda lysis gene cluster into the pET22b expression vector in the following order; the T7 promoter, a gene for a target protein intended for production, Sam7 and R. This insertion of R and Sam7 into pET22b exerted no detrimental effects on cellular growth or the production of a target protein. The induction of the T7 promoter did not in itself result in the autolysis of cells in culture but the harvested cells were readily broken by freezing and thawing. We compared the efficiency of the cell lysis technique by freezing and thawing to that observed with sonication, and determined that both methods completely disintegrated the cells and released proteins into the solution. With our modification of pET22b, the lysis of cells became quite simple, efficient, and reliable. This strategy may prove useful for a broad variety of applications, particularly in experiments requiring extensive cell breakage, including library screening and culture condition exploration, in addition to protein purification.