Oxygen Vacancy and Bandgap Simultaneous Modulation to Achieve High Lithiophilicity and Mechanical Strength of Lithium Metal Anodes.

Metal oxides with conversion and alloying mechanisms are more competitive in suppressing lithium dendrites. However, it is difficult to simultaneously regulate the conversion and alloying reactions. Herein, conversion and alloying reactions are regulated by modulation of the zinc oxide bandgap and oxygen vacancies. State-of-the-art advanced characterization techniques from a microcosmic to a macrocosmic viewpoint, including neutron diffraction, synchrotron X-ray absorption spectroscopy, synchrotron X-ray microtomography, nanoindentation, and ultrasonic C-scan demonstrated the electrochemical gain benefit from plentiful oxygen vacancies and low bandgaps due to doping strategies. In addition, high mechanical strength 3D morphology and abundant mesopores assist in the uniform distribution of lithium ions. Consequently, the best-performed ZnO-2 offers impressive electrochemical properties, including symmetric Li cells with 2000 h and full cells with 81% capacity retention after 600 cycles. In addition to providing a promising strategy for improving the lithiophilicity and mechanical strength of metal oxide anodes, this work also sheds light on lithium metal batteries for practical applications.

The impact of selective HDAC inhibitors on the transcriptome of early mouse embryos.

BACKGROUND: Histone acetylation, which is regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), plays a crucial role in the control of gene expression. HDAC inhibitors (HDACi) have shown potential in cancer therapy; however, the specific roles of HDACs in early embryos remain unclear. Moreover, although some pan-HDACi have been used to maintain cellular undifferentiated states in early embryos, the specific mechanisms underlying their effects remain unknown. Thus, there remains a significant knowledge gap regarding the application of selective HDACi in early embryos. RESULTS: To address this gap, we treated early embryos with two selective HDACi (MGCD0103 and T247). Subsequently, we collected and analyzed their transcriptome data at different developmental stages. Our findings unveiled a significant effect of HDACi treatment during the crucial 2-cell stage of zygotes, leading to a delay in embryonic development after T247 and an arrest at 2-cell stage after MGCD0103 administration. Furthermore, we elucidated the regulatory targets underlying this arrested embryonic development, which pinpointed the G2/M phase as the potential period of embryonic development arrest caused by MGCD0103. Moreover, our investigation provided a comprehensive profile of the biological processes that are affected by HDACi, with their main effects being predominantly localized in four aspects of zygotic gene activation (ZGA): RNA splicing, cell cycle regulation, autophagy, and transcription factor regulation. By exploring the transcriptional regulation and epigenetic features of the genes affected by HDACi, we made inferences regarding the potential main pathways via which HDACs affect gene expression in early embryos. Notably, Hdac7 exhibited a distinct response, highlighting its potential as a key player in early embryonic development. CONCLUSIONS: Our study conducted a comprehensive analysis of the effects of HDACi on early embryonic development at the transcriptional level. The results demonstrated that HDACi significantly affected ZGA in embryos, elucidated the distinct actions of various selective HDACi, and identified specific biological pathways and mechanisms via which these inhibitors modulated early embryonic development.

SAXS unveils porous anodes for potassium-ion batteries: dynamic evolution of pore structures in Fe@Fe2O3/PCNFs composite nanofibers.

The porous structure of composite nanofibers plays a key role in improving their electrochemical performance. However, the dynamic evolution of pore structures and their action during ion intercalation/extraction processes for negative electrodes are not clear. Herein, porous carbon composite nanofibers (Fe@Fe2O3/PCNFs) were prepared as negative electrode materials for potassium-ion batteries. Electrochemical test findings revealed that the composites had good electrochemical characteristics, and the porous structure endowed composite electrodes with pseudo-capacitive behaviors. After 1500 discharge/charge cycles at a current density of 1000 mA g-1, the specific capacity of the potassium-ion batteries was 144.8 mAh g-1. We innovatively used synchrotron small-angle X-ray scattering (SAXS) technique to systematically investigate the kinetic process of potassium formation in composites and showed that the kinetic process of potassium reaction in composites can be divided into four stages, and the pores with smaller average diameter distribution are more sensitive to changes in the reaction process. This work paves a new way to study the deposition kinetics of potassium in porous materials, which facilitates the design of porous structures and realizes the development of alkali metal ion-anode materials with high energies.

Targeted Elimination of Surface Defects in Carbon Fibers: Formation of a Hybrid Structure Combining Rigidity with Flexibility from Sonochemical-Induced Directional Growth of Nano-ZIF-8 and Subsequent Annealing.

Currently, the mechanical performance of carbon fibers (CFs) has yet to fully realize its theoretical potential. This is predominantly attributed to the significant constraints posed by surface defects, greatly impeding the widespread application of carbon fibers. In order to address this issue, we employed a sonochemical-induced approach in this study to achieve in situ growth of nanoscale zeolitic imidazolate framework-8 (ZIF-8) at the surface defects of carbon fibers. After high-temperature treatment, the structure of ZIF-8 decomposed into ZnO and inorganic carbon, reinforcing the carbon fiber structure from both flexible and rigid aspects. Our research indicates that when the temperature reaches 500 °C, a substantial portion of ZIF-8 undergoes thermal decomposition, giving rise to zinc oxide and inorganic carbon. The flexible inorganic carbon and rigid ZnO form a meshlike structure, which welds to the surface defects of carbon fibers, resulting in strong interactions and contributing to the delay of fiber fracture. Compared to unmodified carbon fibers, the mechanical performance increased by approximately 15.86%. Based on the aforementioned analysis, this method can be considered a direct and effective approach for reinforcing carbon fiber structures, presenting a novel approach for the precise elimination of surface defects on carbon fibers.

Structural insights into the functions of Raf1 and Bsd2 in hexadecameric Rubisco assembly.

Hexadecameric form I Rubisco, which consisting consists of eight large (RbcL) and eight small (RbcS) subunits, is the most abundant enzyme on earth. Extensive efforts to engineer an improved Rubisco to speed up its catalytic efficiency and ultimately increase agricultural productivity. However, difficulties with correct folding and assembly in foreign hosts or in vitro have hampered the genetic manipulation of hexadecameric Rubisco. In this study, we reconstituted Synechococcus sp. PCC6301 Rubisco in vitro using the chaperonin system and assembly factors from cyanobacteria and Arabidopsis thaliana (At). Rubisco holoenzyme was produced in the presence of cyanobacterial Rubisco accumulation factor 1 (Raf1) alone or both AtRaf1 and bundle-sheath defective-2 (AtBsd2) from Arabidopsis. RbcL released from GroEL is assembly capable in the presence of ATP, and AtBsd2 functions downstream of AtRaf1. Cryo-EM structures of RbcL8-AtRaf18, RbcL8-AtRaf14-AtBsd28, and RbcL8 revealed that the interactions between RbcL and AtRaf1 are looser than those between prokaryotic RbcL and Raf1, with AtRaf1 tilting 7° farther away from RbcL. AtBsd2 stabilizes the flexible regions of RbcL, including the N and C termini, the 60s loop, and loop 6. Using these data, combined with previous findings, we propose the possible biogenesis pathways of prokaryotic and eukaryotic Rubisco.

Fe2O3 for stable K-ion storage: mechanism insight into dimensional construction from stress distribution and micro-tomography.

Fe2O3 is considered a potential electrode material owing to its high theoretical capacity, low cost, and non-toxic characteristics. However, the significant volume expansion and structural degradation during charging and discharging hinder its application in potassium ion batteries. The electrochemical properties of the electrode material are primarily influenced by the diffusion efficiency of ions and the mechanics of the object. From the construction of a one dimensional structure, a three-dimensional flower-like Fe2O3 with a high specific surface and low-dimensional spherical Fe2O3 were prepared. Considering the convenience and visualization of the research, micron-scale Fe2O3 was prepared, although the larger particle size will lose part of the capacity. Notably, compared with the spherical structure, the specific capacity of the flower structure was increased by about 100%. The von Mises stress distribution on the two structures was simulated by the finite element method, revealing the mechanism of electrode failure induced by volume expansion and confirming the vital role of the multidimensional system in relieving stress concentration and improving electrochemical performance. Furthermore, synchrotron radiation soft X-ray absorption spectrum and X-ray micro-tomography revealed the phase transformation process and reaction mechanism of Fe2O3 in potassium ion batteries. The dimensional structure construction strategy reported here can provide theoretical support for modifying transition metal oxides.

Graphene oxide membranes with a confined mass transfer effect for Li+/Mg2+ separation: a molecular dynamics study.

Membrane separation technology represented by graphene oxide (GO) membranes has been widely used in lithium extraction from salt lakes. It is extraordinary to study the extraction of Li+ by GO membranes from the perspective of the confined mass transfer effect. This study establishes a GO channel model with the confined mass transfer effect to closely fit the actual mass transfer process. Meanwhile, this study investigates the dynamic fluid characteristics in the separation of Li+/Mg2+ by GO membranes using molecular dynamics simulations. The results showed that the Li+/Mg2+ separation ratio is maximum at 1.0 nm layer spacing and 10% oxidation degree of the GO membrane. Water molecules form a bilayer within the channel at the appropriate interlayer channel (1 nm) and oxidation level (10%), which accelerates the ion transport rate. Furthermore, the GO oxidation group has the weakest hydrogen bonding effect on water which promotes the passage of water. Finally, the maximum separation ratio is reached due to the fact that the binding force of Li+ to water molecules in the channel is lower than that of Mg2+. The results of this study will provide theoretical consideration for the design of high-performance Li+/Mg2+ separation membranes.

Micro-flower like Core-shell structured ZnCo@C@1T-2H-MoS2 composites for broadband electromagnetic wave absorption and photothermal performance.

Core-shell structure has been receiving extensive attention to enhance the electromagnetic wave (EMW) absorption performance due to its unique interface effect. In this paper, a micro-flower like ZnCo@C@1T-2H-MoS2 was prepared through MOF self-template method. The introduction 1T-2H-MoS2 shell helps optimize impedance matching of the CoZn@C particles to improve the EMW absorption ability. The minimal reflection loss (RLmin) value of ZnCo@C@1T-2H-MoS2 is -35.83 dB with a thickness of 5.0 mm at 5.83 GHz and the effective absorption (RL < -10 dB) bandwidth up to 4.56 GHz at 2.0 mm thickness. Meanwhile, the overall effective absorption bandwidth (OEAB) can reach up to 13.44 GHz from 4.56 to 18.0 GHz. Moreover, ultrafast photothermal performances are also achieved, which can guarantee the normal functioning of ZnCo@C@1T-2H-MoS2 materials in cold conditions. The excellent EMW absorption and photothermal performance are attributed to the unique structure designed with the core of magnetic ZnCo@C rhombic dodecahedral and the shell of dielectric micro-flower like 1T-2H-MoS2 optimize impedance matching.

Totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage.

In multicellular organisms, oocytes and sperm undergo fusion during fertilization and the resulting zygote gives rise to a new individual. The ability of zygotes to produce a fully formed individual from a single cell when placed in a supportive environment is known as totipotency. Given that totipotent cells are the source of all multicellular organisms, a better understanding of totipotency may have a wide-ranging impact on biology. The precise delineation of totipotent cells in mammals has remained elusive, however, although zygotes and single blastomeres of embryos at the two-cell stage have been thought to be the only totipotent cells in mice. We now show that a single blastomere of two- or four-cell mouse embryos can give rise to a fertile adult when placed in a uterus, even though blastomere isolation disturbs the transcriptome of derived embryos. Single blastomeres isolated from embryos at the eight-cell or morula stages and cultured in vitro manifested pronounced defects in the formation of epiblast and primitive endoderm by the inner cell mass and in the development of blastocysts, respectively. Our results thus indicate that totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage.