Nano spinel NiAl2O4: structure, optical and photocatalytic performance evaluation and optimization.

Four kinds of spinel NiAl2O4were synthesized by the polyacrylamide gel method using Al2(SO4)3·18H2O and Al(NO3)3·9H2O as aluminum salts and anhydrous NiSO4and NiSO4·6H2O as nickel salts. The effects of different aluminum salts and nickel salts on the structure, optical and photocatalytic activity of spinel NiAl2O4were confirmed by various characterizations. There is no NiO impurity in the spinel NiAl2O4synthesized with Al2(SO4)3·18H2O as aluminum salt, while NiAl2O4, NiO and C-O functional group coexist in the target product with Al(NO3)3·9H2O as aluminum salt, and C-O functional group and NiO inhibits the photocatalytic activity of the system. Based on photocatalytic experiment, response surface methodology and free radical verification experiment, the influence of experimental parameters including synthesis pathway, initial drug concentration, initialpHand catalyst content on the photocatalytic activity of spinel NiAl2O4and the main active species involved in the reaction were investigated. The degradation percentage of spinel NiAl2O4synthesized with Al2(SO4)3·18H2O as aluminum salt and NiSO4·6H2O as nickel salt was 86.3% at the initial concentration of 50 mg l-1,pH= 5.33 and catalyst content of 1 g l-1. The mechanism investigation confirmed that the C-O functional group plays the dual role of impurity level and electron transfer in the degradation of tetracycline hydrochloride by spinel NiAl2O4.

BaLa5V2O3N7: a novel anti-perovskite oxynitride for electrode applications.

The exploration of transition metal oxynitrides has garnered significant interest due to their intriguing property diversity. Herein, we present a promising new transition metal oxynitride BaLa5V2O3N7, which features an anti-perovskite structure type. This unique structural configuration endows the material with remarkable conductivity, particularly at low temperatures, paving the way for the material to be used in a wide range of technological applications.

Enhanced soft magnetic properties and high-frequency stability of FeNiMo powder cores by coating SiO2 insulation layer.

FeNiMo/SiO2 powder cores were prepared using the sol-gel method. Tetraethyl orthosilicate (TEOS) was added to produce an amorphous SiO2 coating outside the FeNiMo particles to form a core-shell structure. The thickness of the SiO2 layer was designed by varying the concentration of TEOS, and the optimized permeability and magnetic loss of the powder core could achieve 78.15 and 633.44 kW m-3 at 100 kHz and 100 mT, respectively. Compared with other soft magnetic composites, these FeNiMo/SiO2 powder cores have a significantly higher effective permeability and a lower core loss. Surprisingly, the high-frequency stability of permeability could be substantially enhanced through the insulation coating process in which µf/µ100 kHz could reach 98.7% at 1 MHz. In comparison with 60µ commercial products, the comprehensive soft magnetic properties of the FeNiMo/SiO2 cores were superior to most manufacturers, which would be potentially applied to high-performance inductance devices in high-frequency ranges.

Polar Nitride Perovskite LaWN3-δ with Orthorhombic Structure.

Nitride perovskite LaWN3 has been predicted to be a promising ferroelectric material with unique properties for diverse applications. However, due to the challenging sample preparation at ambient pressure, the crystal structure of this nitride remains unsolved, which results in many ambiguities in its properties. Here, the authors report a comprehensive study of LaWN3 based on high-quality samples synthesized by a high-pressure method, leading to a definitive resolution of its crystal structure involving nitrogen deficiency. Combined with theoretical calculations, these results show that LaWN3 adopts an orthorhombic Pna21 structure with a polar symmetry, possessing a unique atomic polarization along the c-axis. The associated atomic polar distortions in LaWN3 are driven by covalent hybridization of W: 5d and N: 2p orbitals, opening a direct bandgap that explains its semiconducting behaviors. The structural stability and electronic properties of this nitride are also revealed to be closely associated with its nitrogen deficiency. The success in unraveling the structural and electronic ambiguities of LaWN3 would provide important insights into the structures and properties of the family of nitride perovskites.

Pressure-Stabilized High-Entropy (FeCoNiCuRu)S2 Sulfide Anode toward Simultaneously Fast and Durable Lithium/Sodium Ion Storage.

Pressure-stabilized high-entropy sulfide (FeCoNiCuRu)S2 (HES) is proposed as an anode material for fast and long-term stable lithium/sodium storage performance (over 85% retention after 15 000 cycles @10 A g-1 ). Its superior electrochemical performance is strongly related to the increased electrical conductivity and slow diffusion characteristics of entropy-stabilized HES. The reversible conversion reaction mechanism, investigated by ex-situ XRD, XPS, TEM, and NMR, further confirms the stability of the host matrix of HES after the completion of the whole conversion process. A practical demonstration of assembled lithium/sodium capacitors also confirms the high energy/power density and long-term stability (retention of 92% over 15 000 cycles @5 A g-1 ) of this material. The findings point to a feasible high-pressure route to realize new high-entropy materials for optimized energy storage performance.

Bioinformatics Analysis Highlight Differentially Expressed CCNB1 and PLK1 Genes as Potential Anti-Breast Cancer Drug Targets and Prognostic Markers.

Breast cancer is one of the most common malignant tumors in women worldwide. Early diagnosis, treatment, and prognosis of breast cancer are global challenges. Identification of valid predictive diagnosis and prognosis biomarkers and drug targets are crucial for breast cancer prevention. This study characterizes differentially expressed genes (DEGs) based on the TCGA database by using DESeq2, edgeR, and limma. A total of 2032 DEGs, including 1026 up-regulated genes and 1006 down-regulated genes were screened. Followed with WGCNA, PPI analysis, GEPIA 2, and HPA database verification, thirteen hub genes including CDK1, BUB1, BUB1B, CDC20, CCNB2, CCNB1, KIF2C, NDC80, CDCA8, CENPF, BIRC5, AURKB, PLK1, MAD2L1, and CENPE were obtained, and they may serve as potential therapeutic targets of breast cancer. Especially, overexpression of CCNB1 and PLK1 are strongly associated with the low survival rate of breast cancer patients, demonstrating their potentiality as prognostic markers. Moreover, CCNB1 and PLK1 are highly expressed in all breast cancer stages, suggesting that they could be further studied as potential drug targets. Taken together, our study highlights CCNB1 and PLK1 as potential anti-breast cancer drug targets and prognostic markers.

Alternative Splicing and Isoforms: From Mechanisms to Diseases.

Alternative splicing of pre-mRNA is a key mechanism for increasing the complexity of proteins in humans, causing a diversity of expression of transcriptomes and proteomes in a tissue-specific manner. Alternative splicing is regulated by a variety of splicing factors. However, the changes and errors of splicing regulation caused by splicing factors are strongly related to many diseases, something which represents one of this study's main interests. Further understanding of alternative splicing regulation mediated by cellular factors is also a prospective choice to develop specific drugs for targeting the dynamic RNA splicing process. In this review, we firstly concluded the basic principle of alternative splicing. Afterwards, we showed how splicing isoforms affect physiological activities through specific disease examples. Finally, the available treatment methods relative to adjusting splicing activities have been summarized.

Sound Velocities, Elasticity, and Mechanical Properties of Stoichiometric Submicron Polycrystalline δ-MoN at High Pressure.

Acoustic velocities and elasticity of stoichiometric submicron polycrystalline δ-MoN have been reported at high pressure using ultrasonic measurements and first-principles calculations. Using the finite-strain equation-of-state approach, the bulk modulus and shear rigidity, as well as their pressure derivatives, are derived from the current experimental data, yielding BS0 = 360.0(8) GPa, G0 = 190.0(5) GPa, ∂BS/∂P = 3.4(2), and ∂G/∂P = 1.4(1). Based on our experimental data and the velocity-elasticity correlated models, the mechanical/thermal properties (i.e., hardness, fracture toughness, Grüneisen parameter, Debye temperature, Poisson's ratio) are also derived. Interestingly, we find that hexagonal δ-MoN is almost as incompressible as superhard cubic boron nitride (cBN) (∼384 GPa) and its hexagonal ε-NbN (∼373 GPa) counterpart, and its shear rigidity (G = 190 GPa) is comparable to that of the superhard diamond composite (G = 204 GPa). Moreover, the fracture toughness of submicron δ-MoN polycrystals is achieved up to ∼4.3 MPa·m1/2, which is comparable to superhard diamond (4-7 MPa·m1/2) and cBN (2-5 MPa·m1/2). The Vickers hardness of submicron δ-MoN is estimated to be Hv ≈ 17.4 GPa using Chen's model, which is found to be almost as hard as hexagonal ε-NbN and δ-WN, and may be very important for its applications in extreme environments.

A wide-frequency range dielectric tuning of BaTiO3 by embedding metal nanocrystals.

Fe nanocrystals (NCs) were embedded into the epitaxial BaTiO3 (BTO) matrix. According to optimized growth processes, a novel nanocomposite system was constructed, which consisted a well epitaxial BTO layer and three-dimensional Fe NCs. Based on this, the different dielectric response in the regions of low temperature-high frequency and low frequency-high temperature were revealed by the contribution of hopping and interfacial polarizations, respectively. With the increased amount of Fe NCs, the obvious enhancement in the low-frequency conductivity, middle frequency capacitance, and high-frequency inductive effect was found. The embedded metal NCs play an important role in tuning the dielectric behaviors and AC conductivity of oxide dielectrics. This significant rectification effect in wide-frequency ranges opens up a new direction for designing embedded nano-capacitors.

Pressure-driven electronic phase transition in the high-pressure phase of nitrogen-rich 1H-tetrazoles.

High-energy-density materials (HEDMs) require new design rules collected from experimental and theoretical results and a proposed mechanism. One of the targeted systems is the nitrogen-rich compounds as precursors for possible polymeric nitrogen or its counterpart in a reasonable pressure range. 1H-tetrazole (CH2N4) with hydrogen bonds was studied under pressure by both diffraction and spectroscopy techniques. The observed crystal structure phase transition and hydrogen bond-assisted electronic structure anomaly were confirmed by first-principles calculation. The rearrangement of the hydrogen bonds under pressure elucidates the bonding interactions of the nitrogen-rich system in local 3D chemical environments, allowing the discovery and design of a feasible materials system to make new-generation high-energy materials.

Time dependence of domain structures in potassium sodium niobate-based piezoelectric ceramics.

Piezoelectric materials, which can convert energy between electrical and mechanical forms, are widely used in modern industry. (K,Na)NbO3-based ceramics have attracted extensive attention due to their excellent performance characteristics among the lead-free materials. Piezoelectric properties are closely related to ferroelectric domain structures including the domain morphology and domain wall motion. However, time dependence of ferroelectric domains in (K,Na)NbO3-based ceramics has barely been studied. Here, we synthesized Li-doped KNN ceramics. The morphologies and crystallographic parameters of the domain structures were characterized. Two ferroelectric domains, the 60°/120° and 180° domains, were identified in the ceramic. Surprisingly, the domain structure changed naturally as time passed, and most of the change occurred in the 180° domain wall, while the 60°/120° domains remained nearly unchanged. Our results are different from those of previous studies, which showed that the non-180° domain wall was more prone to movement than the 180° domain wall.

Insights into the Bond Behavior and Mechanical Properties of Hafnium Carbide under High Pressure and High Temperature.

Hafnium carbide (HfC) is a potential candidate of ultrahigh-temperature ceramics (UHTCs) and has attracted significantly widespread interest in recent years. Here, we have synthesized high-purity HfC samples with NaCl-type structure by using a high-pressure solid-solid reaction. The structural stability, equation of state, plastic deformation, yield strength, and bonding properties under high pressure are investigated by a series of in situ high-pressure synchrotron-radiation angle-dispersive X-ray diffraction experiments combined with first-principles calculations. The yield strength of HfC (∼18 GPa) is obtained from analyzing the plastic deformation behavior under high pressure. In addition, we have successfully prepared bulk HfC ceramics with high density using a high-pressure and high-temperature method. The synthesized sample possesses a desirable Vickers hardness of 24.2 GPa and an excellent fracture toughness of 5.0 MPa·m1/2. The present results offer insights into the achievable application of HfC ceramics under extreme conditions and provide a powerful guide for the further design and synthesis of other high-performance UHTCs.

The effect of size matching between anvils and the pressure transmitting medium on the pressure-generation efficiency and sealing performance for a large volume cubic pressure cell.

Size matching between anvils and the pressure transmitting medium (PTM) is a key factor that affects pressure generation and sealing for a large volume cubic press. In this work, we studied the influence of PTM sizes from 30.5 mm to 34.5 mm at a fixed anvil geometry dimension (23.5 mm) on the pressure efficiency and sealing performance by measuring the pressure of the gasket and cell simultaneously at room temperature. Wires made of Bi, Tl, Ba, or Manganin were used for pressure calibration experiments within a pressure range of up to 6 GPa. It was found that a PTM with an edge length of 33.5 mm had the highest pressure-generation efficiency, but its sealing performance was the worst. Furthermore, it was confirmed that a PTM with an edge length of 32.5 mm had the best overall performance for a 23.5 mm anvil when both efficiency and sealing were considered. The results show that the pressure-generation efficiency and sealing performance are highly sensitive to PTM size. It is less rigorous to gauge the performance of the assembly only by the pressure-generation efficiency. This work provides practical guidelines and contributes to optimizing the design of the high-pressure assembly.

Pressure-driven switching of magnetism in layered CrCl3.

Layered transition-metal compounds with controllable magnetic behaviors provide many fascinating opportunities for the fabrication of high-performance magneto-electric and spintronic devices. The tuning of their electronic and magnetic properties is usually limited to the change of layer thickness, electrostatic doping, and the control of electric and magnetic fields. However, pressure has been rarely exploited as a control parameter for tailoring their magneto-electric properties. Here, we report a unique pressure-driven isostructural phase transition in layered CrCl3 accompanied by a simultaneous switching of magnetism from a ferromagnetic to an antiferromagnetic ordering. Our experiments, in combination with ab initio calculations, demonstrate that such a magnetic transition hinders the bandgap collapse under pressure, leading to an anomalous semiconductor-to-semiconductor transition. Our findings not only reveal the potential applications of this material in electronic and spintronic devices but also establish the basis for exploring unusual phase transitions in layered transition-metal compounds.

Tailoring Morphologies, Photocatalytic Activity, and Energy Bands of Bi25FeO40 via Valence State Transformation of Doped V Ions.

Photocatalysts with suitable nanostructures and excellent photocatalytic activity driven by solar light are in great demand for rapidly eliminating the organic pollutants from wastewater. In order to improve the photocatalytic activities, three main factors should be considered, including band gap, band structure, and morphologies. Most of the previous studies only focused on manipulating one factor, such as the band gap by element doping. However, studies on enhancing photocatalytic activities by designing the band structure and morphologies are challenging, due to the difficulity to control the three parameters at the same time. Here, the V-doped Bi25FeO40 (Bi25Fe1- xV xO40) was demonstrated as a great system to manipulate the photocatalytic activities by designing the band structure and morphologies. With the simple hydrothermal methods, Bi25Fe1- xV xO40 with different flower-like morphologies and band structures were prepared. Surprisingly, the blooming and withering processes of the artificial architectures could be precisely tuned through different V concentrations. The controllable microstructures possess the high visible light absorption and enhanced photocatalytic activity. These results offer a model to reveal how the doping element can synchronously manipulate the particle morphology, band gap, and band structures, which is a key step to design new photocatalytic materials.

Pressure-Induced Diels-Alder Reactions in C6 H6 -C6 F6 Cocrystal towards Graphane Structure.

Pressure-induced polymerization (PIP) of aromatics is a novel method for constructing sp3 -carbon frameworks, and nanothreads with diamond-like structures were synthesized by compressing benzene and its derivatives. Here by compressing a benzene-hexafluorobenzene cocrystal (CHCF), H-F-substituted graphane with a layered structure in the PIP product was identified. Based on the crystal structure determined from the in situ neutron diffraction and the intermediate products identified by gas chromatography-mass spectrum, we found that at 20 GPa CHCF forms tilted columns with benzene and hexafluorobenzene stacked alternatively, and leads to a [4+2] polymer, which then transforms to short-range ordered H-F-substituted graphane. The reaction process involves [4+2] Diels-Alder, retro-Diels-Alder, and 1-1' coupling reactions, and the former is the key reaction in the PIP. These studies confirm the elemental reactions of PIP of CHCF for the first time, and provide insight into the PIP of aromatics.

In situ high-pressure measurement of crystal solubility by using neutron diffraction.

Crystal solubility is one of the most important thermo-physical properties and plays a key role in industrial applications, fundamental science, and geoscientific research. However, high-pressure in situ measurements of crystal solubility remain very challenging. Here, we present a method involving high-pressure neutron diffraction for making high-precision in situ measurements of crystal solubility as a function of pressure over a wide range of pressures. For these experiments, we designed a piston-cylinder cell with a large chamber volume for high-pressure neutron diffraction. The solution pressures are continuously monitored in situ based on the equation of state of the sample crystal. The solubility at a high pressure can be obtained by applying a Rietveld quantitative multiphase analysis. To evaluate the proposed method, we measured the high-pressure solubility of NaCl in water up to 610 MPa. At a low pressure, the results are consistent with the previous results measured ex situ. At a higher pressure, more reliable data could be provided by using an in situ high-pressure neutron diffraction method.

A comparative study of ZnAl2O4 nanoparticles synthesized from different aluminum salts for use as fluorescence materials.

Three ZnAl2O4 samples were prepared via a modified polyacrylamide gel method using a citric acid solution with different aluminum salt starting materials, including AlCl3 ∙ 6H2O, Al2(SO4)3 ∙ 18H2O, and Al(NO3)3 ∙ 9H2O under identical conditions. The influence of different aluminum salts on the morphologies, phase purity, and optical and fluorescence properties of the as-prepared ZnAl2O4 nanoparticles were studied. The experimental results demonstrate that the phase purity, particle size, morphology, and optical and fluorescence properties of ZnAl2O4 nanoparticles can be manipulated by the use of different aluminum salts as starting materials. The energy bandgap (Eg) values of ZnAl2O4 nanoparticles increase with a decrease in particle size. The fluorescence spectra show that a major blue emission band around 400 nm and two weaker side bands located at 410 and 445 nm are observed when the excitation wavelength is 325 nm. The ZnAl2O4 nanoparticles prepared from Al(NO3)3 ∙ 9H2O exhibit the largest emission intensity among the three ZnAl2O4 samples, followed in turn by the ZnAl2O4 nanoparticles prepared from Al2(SO4)3 ∙ 18H2O and AlCl3∙6H2O. These differences are attributed to combinational changes in Eg and the defect types of the ZnAl2O4 nanoparticles.