Amorphous Structure Benefits in MgV2O4/V2O3 Composites for Zinc-Ion Storage: An Integration of Computational and Experimental Studies.

This study investigates the electrochemical properties of MgV2O4/V2O3 composites for Aqueous Zinc-Ion Batteries (AZIBs) using both Density Functional Theory (DFT) calculations and experimental validation. DFT analysis reveals significant electron mobility and reactivity at the MgV2O4/V2O3 interface, enhancing Zn2+ storage capabilities. This theoretical prediction is confirmed experimentally by synthesizing a novel MgV2O4/V2O3 composite that demonstrates superior electrochemical performance compared to pristine phases. Notably, the transition of the MgV2O4/V2O3 composite into an amorphous structure during electrochemical cycling is pivotal, providing enhanced diffusion pathways and increased conductivity. The composite delivers a consistent specific capacity of 330.2 mAh g-1 over 50 cycles at 0.1 A g-1 and maintains 152.7 mAh g-1 at an elevated current density of 20 A g-1 after 2000 cycles, validating the synergy between DFT insights and experimental outcomes, and underscoring the potential of amorphous structures in enhancing battery performance.

Empirical Confirmation of Theoretical Predictions for Amorphous H/VO4 Cathodes: Advancing Durability and Efficiency in Zinc-Ion Batteries.

Advancing cathode materials is crucial for the broader application of aqueous zinc-ion batteries (ZIBs) in energy storage systems. This study presents amorphous H/VO4 (HVO), a novel cathode material engineered by substituting H+ for Mg2+ in Mg2VO4 (MgVO), designed to enhance performance of ZIBs. Initial exploration of MgVO through ab initio molecular dynamics (AIMD) simulations and density functional theory (DFT) calculations revealed a favorable Mg2+ and Zn2+ exchange mechanism. This mechanism notably reduces electrostatic interactions and facilitates ion diffusion within the host lattice. Building upon these findings, in this work, theoretical calculations analysis indicated that amorphous HVO offers a higher diffusion coefficient for Zn2+ ions and fewer electrostatic interactions compared to its crystalline MgVO precursor. Subsequent empirical validation is achieved by synthesizing amorphous HVO using a rapid ion-exchange process, effectively replacing Mg2+ with H+ ions. The synthesized amorphous HVO demonstrated 100% capacity retention after 18000 cycles at a current density of 2 A g-1 and exhibited exceptional rate performance. These findings underscore the significant potential of HVO cathodes to enhance the durability and efficiency of aqueous ZIBs, positioning them as promising candidates for future energy storage technologies.

Lipid Metabolic Disorders Induced by Organophosphate Esters in Silver Carp from the Middle Reaches of the Yangtze River.

The Yangtze River fishery resources have declined strongly over the past few decades. One suspected reason for the decline in fishery productivity, including silver carp (Hypophthalmichthys molitrix), has been linked to organophosphate esters (OPEs) contaminant exposure. In this study, the adverse effect of OPEs on lipid metabolism in silver carp captured from the Yangtze River was examined, and our results indicated that muscle concentrations of the OPEs were positively associated with serum cholesterol and total lipid levels. In vivo laboratory results revealed that exposure to environmental concentrations of OPEs significantly increased the concentrations of triglyceride, cholesterol, and total lipid levels. Lipidome analysis further confirmed the lipid metabolism dysfunction induced by OPEs, and glycerophospholipids and sphingolipids were the most affected lipids. Hepatic transcriptomic analysis found that OPEs caused significant alterations in the transcription of genes involved in lipid metabolism. Pathways associated with lipid homeostasis, including the peroxisome proliferator-activated receptor (PPAR) signal pathway, cholesterol metabolism, fatty acid biosynthesis, and steroid biosynthesis, were significantly changed. Furthermore, the affinities of OPEs were different, but the 11 OPEs tested could bind with PPARγ, suggesting that OPEs could disrupt lipid metabolism by interacting with PPARγ. Overall, this study highlighted the harmful effects of OPEs on wild fish and provided mechanistic insights into OPE-induced metabolic disorders.

Field and Laboratory Evidence That Chlorpyrifos Exposure Reduced the Population Density of a Freshwater Snail by Increasing Juvenile Mortality.

Pesticides have been frequently detected in global freshwater ecosystems, but attempts to document changes in population dynamics of organisms upon exposure to pesticides, establish a causal relationship between exposure and population effects, and identify the key toxic events within individuals under natural field conditions remain rare. Here, we used a field survey, a reciprocal cross-transplant experiment, and a laboratory toxicity experiment to build a compelling case that exposure to the insecticide chlorpyrifos was responsible for differences in snail (Bellamya aeruginosa) densities in eastern (ELL) and western basins of Liangzi Lake in China. Our field survey and reciprocal cross-transplant experiment revealed significant differences in snail densities, juvenile percentage, survival, and relative telomere length (RTL) in the two basins. The insecticide chlorpyrifos detected in snail tissues was negatively correlated with snail densities, the percentage of juvenile snails, and RTL and had an extremely high risk quotient in ELL. In the laboratory experiment, tissue concentrations of chlorpyrifos detected in ELL were associated with reduced RTL and increased juvenile mortality in B. aeruginosa. These results support the hypothesis that chlorpyrifos exposure in ELL reduced the density of snails by reducing juvenile survival and, consequently, recruitment to the adult population.

A first-principles study of the BC3N2 monolayer and a BC3N2/graphene heterostructure as promising anode materials for sodium-ion batteries.

High-performance sodium-ion batteries (SIBs) require anode materials with high capacity and fast kinetics. Based on first-principles calculations, we propose BC3N2 and BC3N2/graphene (B/G) heterostructure as potential SIB anode materials. The BC3N2 monolayer exhibits intrinsic metallic behavior. In addition, BC3N2 possesses a low Na+ diffusion barrier (0.15 eV), a high storage capacity (777 mA h g-1), a low open-circuit voltage (0.72 V), and a tiny axial expansion (0.36%). Compared with the BC3N2 monolayer, the B/G heterostructure exhibits a lower diffusion barrier of 0.027 eV, suggesting a much faster diffusion. More importantly, although the B/G heterostructure possesses heavier molar weight, its theoretical capacity (689 mA h g-1) is comparable to that of the BC3N2 monolayer. Based on the above-mentioned properties, we hope both the BC3N2 monolayer and the B/G heterostructure would be promising anodes for SIBs.

Two-dimensional graphene+ as an anode material for calcium-ion batteries with ultra-high capacity: a first-principles study.

Multivalent-ion batteries have garnered significant attention due to their high energy density, low cost, and superior safety. Calcium-ion batteries (CIBs) are regarded as the next-generation energy storage systems for their abundant natural resources and bivalent characteristics. However, the absence of high-performance anode materials poses a significant obstacle to the progress of battery technology. Two-dimensional (2D) Dirac materials have excellent conductivity and abundant active sites, rendering them promising candidates as anode materials. A novel 2D Dirac material known as "graphene+" has been theoretically reported, exhibiting prominent properties including good stability, exceptional ductility, and remarkable electronic conductivity. By using first-principles calculations, we systematically investigate the performance of graphene+ as an anode material for CIBs. Graphene+ exhibits an ultra-high theoretical capacity (1487.7 mA h g-1), a small diffusion barrier (0.21 eV), and a low average open-circuit voltage (0.51 V). Furthermore, we investigate the impact of the electrolyte solvation on the performance of Ca-ion adsorption and migration. Upon contact with electrolyte solvents, graphene+ exhibits strong adsorption strength and rapid migration of Ca-ions on its surface. These results demonstrate the promising potential of graphene+ as a high-performance anode material for CIBs.

Two-dimensional monolayer C5-10-16: a metallic carbon allotrope as an anode material for high-performance sodium/potassium-ion batteries.

Carbonaceous materials are promising candidates as anode materials for non-lithium-ion batteries (NLIBs) due to their appealing properties such as good electrical conductivity, low cost, and high safety. However, graphene, a classic two-dimensional (2D) carbon material, is chemically inert to most metal atoms, hindering its application as an electrode material for metal-ion batteries. Inspired by the unique geometry of a four-penta unit, we explore a metallic 2D carbon allotrope C5-10-16 composed of 5-10-16 carbon rings. The C5-10-16 monolayer is free from any imaginary frequencies in the whole Brillouin zone. Due to the introduction of a non-sp2 hybridization state into C5-10-16, the extended conjugation of π-electrons is disrupted, leading to the enhanced surface activity toward metal ions. We investigate the performance of C5-10-16 as the anode for sodium/potassium-ion batteries by using first-principles calculations. The C5-10-16 sheet has high theoretical specific capacities of Na (850.84 mA h g-1) and K (743.87 mA h g-1). Besides, C5-10-16 exhibits a moderate migration barrier of 0.63 (0.32) eV for Na (K), ensuring rapid charging/discharging processes. The average open-circuit voltages of Na and K are 0.33 and 0.62 V, respectively, which are within the voltage acceptance range of anode materials. The fully sodiated (potassiated) C5-10-16 shows tiny lattice expansions of 1.4% (1.3%), suggesting the good reversibility. Moreover, bilayer C5-10-16 significantly affects both the adsorption strength and the mobility of Na or K. All these results show that C5-10-16 could be used as a promising anode material for NLIBs.

Therapeutic potential of xtr-miR-22-3p from Plastrum testudinis in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is marked by a block at the promyelocyte stage. Treatments like ATRA and ATO face resistance and relapse issues. Plastrum testudinis, a traditional Chinese medicine, may offer therapeutic potential. This study investigated xtr-miR-22-3p from P. testudinis for treating APL. High expression of xtr-miR-22-3p was confirmed, with target prediction indicating interactions with key genes, including PML. xtr-miR-22-3p reduced HL-60 leukemia cell growth, altered the cell cycle, and selectively inhibited HL-60 proliferation while promoting BMSC growth, suggesting its potential as a targeted APL therapy.

The effect of miR-381 on proliferation and prognosis of breast cancer by altering CCNA2 expression.

BACKGROUND: MiR-381 can regulate the expression of cyclin A2 (CCNA2) to inhibit the proliferation and migration of bladder cancer cells, but whether miR-381 has the same function in breast cancer is not well know. METHODS: The over express or silence miR-381 expressing cell lines were constructed by lentivirus infection to reveal the biological functions of miR-381 in vitro. The expression of miR-381 and CCNA2 in 162 breast cancer patients were detected to further reveal their impact and predictive value on progression-free survival (PFS) and overall survival (OS). RESULTS: After transfection of MDA-MB-231 and MCF-7 cells with miR-381 mimics, the expression of miR-381 was effectively up-regulated and CCNA2 was effectively down-regulated, while the opposite results were observed in tumour cell which transfected with miR-381 inhibitors. After transfection of cell lines with miR-381 mimics, tumour cell activity was significantly reduced, while the opposite results were observed in tumour cell which transfected with miR-381 inhibitors. The area under curves (AUCs) of miRNA-381 and CCNA2 for predicting PFS and OS were 0.711, 0.695, 0.694 and 0.675 respectively. Cox regression analysis showed that miRNA-381 ≥ 1.65 2-ΔΔCt and CCNA ≥ 2.95 2-ΔΔCt were the influence factors of PFS and OS, the hazard ratio (HR) values were 0.553, 2.075, 0.462 and 2.089, respectively. CONCLUSION: miR-381 inhibitors breast cancer cells proliferation and migration by down-regulating the expression of CCNA2, both of them can predict the prognosis of breast cancer.

miR-381 can regulate the expression of cyclin A2 and inhibit the proliferation and migration of bladder cancer cells, but whether miR-381 has the same function in breast cancer is not well know. We analysed the levels of miR-381 and cyclin A2 in breast cancer patients and breast cancer cells to reveal the mechanism of miR-381 affecting the expression of cyclin A2. We found miRNA-381 affects the proliferation and migration of breast cancer cells by down-regulating the expression of cyclin A2. The expression of serum miR-381 and cyclin A2 have important values in predicting the prognosis of breast cancer. Our findings provide mechanistic insights into how miR-381 regulates the proliferation and migration of breast cancer, as well as a new target for clinical treatment. Future research may focus on how to improve patient prognosis by up-regulating expression of miR-381 and down-regulating the expression of cyclin A2.

Effect of faba bean Vicia faba L. water/alcohol extract on growth performance, antioxidant capacity, textural properties, and collagen deposition in the swim bladder of juvenile Nibea coibor.

Faba bean has gained attention as a cost-effective protein source with the potential to enhance product quality (texture properties, collagen content, etc.) in fish. However, its anti-nutrition factor, high feed conversion ratio, poor growth performance, etc. limit the widely application as a dietary source, especially in carnivorous fish. The water or alcohol extract of faba bean might resolve the problem. In this study, the juvenile Nibea coibor, known for their high-protein, large-sized, and high-grade swim bladder, were fed with seven isoproteic and isolipid experimental diets with the additive of faba bean water extract (1.25%, 2.5%, and 5%) or faba bean alcohol extract (0.9%, 1.8%, and 3.6%), with a control group without faba bean extract. After the 10-week feeding trail, the growth, antioxidant capacity, textural properties, and collagen deposition of the swim bladder were analyzed. Results showed that the 1.25% faba bean water extract group could significantly promote growth, textural quality of the swim bladder, and have beneficial effects on antioxidant response of fish. Conversely, dietary supplementation of faba bean alcohol extract resulted in reduced growth performance in a dose-dependent manner. Furthermore, fish fed diet with 1.25% faba bean water extract exhibited increased collagen content and upregulated collagen-related gene expression in the swim bladder, which was consistent with the Masson stain analysis for collagen fiber. Our results suggested that the anti-nutrient factor and bioactive component of faba bean may mainly be enriched in alcohol extract and water extract of faba bean, respectively. Besides, the appropriate addition of water extract of faba bean may improve the texture quality of the swim bladder by promoting collagen deposition. This study would provide a theoretical basis for the formulated diets with faba bean extract to promote product quality of marine fish.

[Evaluation of nutritional value of Bambusae Concretio Silicea based on content of 15 amino acids].

The content of 15 total amino acids(TAAs) in Bambusae Concretio Silicea was determined by HPLC with phenyl-isothiocyanate(PITC) for pre-column derivatization. The results showed that the content of TAA was 0.61-12.25 mg·g~(-1), and aspartic acid(Asp), glutamic acid(Glu), proline(Pro), glycine(Gly), and valine(Val) were the top five amino acids in terms of the average content. The content of essential amino acids(EAAs), conditionally essential amino acids(CEAAs), non-essential amino acids(NEAAs), and medicinal amino acids(MAAs) was 0.24-4.75, 0.30-4.73, 0.40-7.50, and 0.36-6.51 mg·g~(-1), respectively. Among the delicious amino acids, sweet amino acids(SAA), bitter amino acids(BAA), fresh-taste amino acids(FAAs), and odourless amino acids(OAAs) had the content of 0.22-4.70, 0.19-4.03, 0.13-2.26, and 0.06-1.26 mg·g~(-1), respectively. The 21 batches of Bambusae Concretio Silicea samples presented the same composition but significant differences in the content of amino acids. Among the three producing areas, Guangdong was the area where the samples had the highest content of TAAs, EAAs, CEAAs, NEAAs, MAAs, and delicious amino acids. Furthermore, the ratio of amino acid(RAA), ratio coefficient of amino acid(RCAA), and score of ratio coefficient of amino acid(SRCAA) were calculated to evaluate the nutritional value of Bambusae Concretio Silicea. The results showed that the Bambusae Concretio Silicea samples from Guangdong had better nutritional value. The nutritional value evaluation based on the content of 15 amino acids was proposed to provide data support for the quality grading of Bambusae Concretio Silicea and lay a foundation for the development and utilization of the medicinal material resources.

[Construction of ATMT system of Fusarium oxysporum and evaluation of its promoting effect on Glycyrrhiza uralensis].

This study aims to evaluate the in vivo function of Fusarium oxysporum in Glycyrrhiza uralensis by salt tolerance,indoleacetic acid(IAA) production capacity, phosphate-dissolving capacity, and iron carrier production capacity. The stable genetic transformation system of the F. oxysporum was established by Agrobacterium tumefaciens-mediated genetic transformation( ATMT)technology, and the stability and staining efficiency of transformants were detected by the cloning of the marker gene green fluorescent protein(GFP) and the efficiency of ß-glucuronidase staining(GUS). Efficient and stable transformants were selected for restaining G. uralensis and evaluating its influence on the growth of the G. uralensis seedlings. The results show that F. oxysporum has good salt tolerance and could still grow on potato glucose agar(PDA) medium containing 7% sodium chloride, but the growth rate slows down with the increase in sodium chloride content in PDA medium. F. oxysporum has the function of producing indoleacetic acid, and the concentration of IAA in its fermentation broth is about 3. 32 mg · m L~(-1). In this study, the genetic transformation system of F. oxysporum is successfully constructed, and the ATMT system is efficient and stable. One transformant with both high staining efficiency and genetic stability is selected, and the restaining rate of the transformant in G. uralensis is 76. 92%, which could significantly improve the main root length of one-month-old G. uralensis seedlings and promote the growth and development of G. uralensis seedlings. The results of this study can lay the foundation for the development of biological bacterial fertilizer and the growth regulation of high-quality G. uralensis.

[Wireless Pulse Wave Monitoring System Based on Reflective Flexible Probe and AFE4490].

Pulse rate and blood oxygen levels are crucial physiological parameters that reflect physiological and pathological information within the human body. The system designs a wireless pulse wave monitoring system utilizing a flexible reflective probe and the AFE4490, which is capable of monitoring pulse wave and blood oxygen levels on the human forehead. The system is predominantly based on a reflective flexible probe, the AFE4490, a power supply module, a control microcontroller unit (MCU), and a Wi-Fi module. Post-processing by a slave computer, the collected pulse wave data is wirelessly transmitted to a smartphone. The real-time pulse waveform, pulse rate, and blood oxygen levels are displayed on an application. Following relevant tests and verifications, the system can accurately detect pulse wave signals, meet the requirements for wearable technology, and possesses significant market application potential.

[Development of Wireless Wearable Sleep Monitoring System Based on EEG Signal].

A wireless wearable sleep monitoring system based on EEG signals is developed. The collected EEG signals are wirelessly sent to the PC or mobile phone Bluetooth APP for real-time display. The system is small in size, low in power consumption, and light in weight. It can be worn on the patient's forehead and is comfortable. It can be applied to home sleep monitoring scenarios and has good application value. The key performance indicators of the system are compared with the industry-related medical device measurement standards, and the measurement results are better than the special standards.

Identification of a Novel Coumarins Biosynthetic Pathway in the Endophytic Fungus Fusarium oxysporum GU-7 with Antioxidant Activity.

Coumarins are generally considered to be produced by natural plants. Fungi have been reported to produce coumarins, but their biosynthetic pathways are still unknown. In this study, Fusarium oxysporum GU-7 and GU-60 were isolated from Glycyrrhiza uralensis, and their antioxidant activities were determined to be significantly different. Abundant dipeptide, phenolic acids, and the plant-derived coumarins fraxetin and scopoletin were identified in GU-7 by untargeted metabolomics, and these compounds may account for its stronger antioxidant activity compared to GU-60. Combined with metabolome and RNA sequencing analysis, we identified 24 potentially key genes involved in coumarin biosynthesis and 6 intermediate metabolites. Interestingly, the best hit of S8H, a key gene involved in hydroxylation at the C-8 position of scopoletin to yield fraxetin, belongs to a plant species. Additionally, nondestructive infection of G. uralensis seeds with GU-7 significantly improved the antioxidant activity of seedlings compared to the control group. This antioxidant activity may depend on the biological characteristics of endophytes themselves, as we observed a positive correlation between the antioxidant activity of endophytic fungi and that of their nondestructively infected seedlings. IMPORTANCE Plant-produced coumarins have been shown to play an important role in assembly of the plant microbiomes and iron acquisition. Coumarins can also be produced by some microorganisms. However, studies on coumarin biosynthesis in microorganisms are still lacking. We report for the first time that fraxetin and scopoletin were simultaneously produced by F. oxysporum GU-7 with strong free radical scavenging abilities. Subsequently, we identified intermediate metabolites and key genes in the biosynthesis of these two coumarins. This is the first report on the coumarin biosynthesis pathway in nonplant species, providing new strategies and perspectives for coumarin production and expanding research on new ways for plants to obtain iron.

Transcriptomic analysis revealed the dynamic response mechanism to acute ammonia exposure in the ivory shell, Babylonia areolata.

The ivory shell (Babylonia areolata) is an economically important shellfish in tropical and subtropical regions, but its intensive culture and biological characteristic of hiding in the sandy substrate make it highly susceptible to ammonia stress. In this study, we investigated the dynamic changes in histopathology, oxidative stress, and transcriptome of the ivory shell at different time points under high concentration (60 mg/L) ammonia exposure. With prolonged exposure to stress, vacuoles appeared in the hepatopancreas while cell volume and intercellular space increased. The activities of superoxide dismutase (SOD) and catalase (CAT) decreased significantly under high concentrations of ammonia-induced stress while malondialdehyde (MDA) levels increased significantly. Integrated analysis of differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA), and quantitative real-time polymerase chain reaction (qRT-PCR) revealed that lipid transport primarily contributed to maintaining cellular homeostasis during the early stage of stress (6 and 12 h). Subsequently, a significant upregulation of oxidation-reduction reactions occurred at the middle stage (24 h), leading to oxidative stress. Finally, during the later stage (48 h), metabolic decomposition provided energy for survival maintenance. Additionally, lysosome and apoptosis were identified as potential key pathways in response to acute ammonia toxicity. Overall, our findings suggest that ivory shells can respond to acute ammonia toxicity via immune and antioxidant defense mechanisms but sustained high concentrations may cause irreversible damage. This study provides valuable insights into the response mechanism of mollusks towards ammonia and serves as a data reference for breeding ammonia-tolerant varieties of ivory shells.

TroTNFSF6, a tumor necrosis factor ligand superfamily member, promotes antibacterial immune response of golden pompano, Trachinotus ovatus.

Tumor necrosis factor ligand superfamily member 6 (TNFSF6), also known as FasL/CD95L, is essential for maintaining the body's immune homeostasis. However, the current reports on TNFSF6 in fish are relatively scarce. In the present study, we conducted functional analyses of a TNFSF6 (TroTNFSF6) from the teleost fish golden pompano (Trachinotus ovatus). TroTNFSF6 is composed of 228 amino acids and has a low similarity with other species (9.65%-58.79%). TroTNFSF6 was expressed in the 11 tissues tested and was significantly up-regulated after Edwardsiella tarda infection. In vivo, overexpression of TroTNFSF6 effectively stimulated the AKP and ACP activities, and reduced bacterial infection in fish tissues. Correspondingly, knockdown of TroTNFSF6 expression resulted in increasing bacterial dissemination and colonization in fish tissues. In vitro, recombinant TroTNFSF6 protein promoted the proliferation of T. ovatus head kidney lymphocytes (HKLs), and promoted the apoptosis of murine liver cancer cells (Hepa1-6). The results indicated that TroTNFSF6 plays an important role in the T. ovatus antibacterial immunity. These observations will facilitate the future in-depth study of teleost TNFSF6.

Monolayer α-beryllene as an anode material for magnesium ion batteries with high capacity and low diffusion energy barrier.

High specific capacity and fast charge/discharge rate are important indicators for the development of next-generation ion batteries. Compared with conventional monovalent ion batteries like lithium-ion batteries and sodium-ion batteries, multivalent ion batteries have attracted extensive attention owing to their high energy densities. Here, we systematically explore the interactions between Mg atoms and α-beryllene monolayers by means of density functional theory calculations. Mg atoms can be adsorbed stably on α-beryllene monolayers with the adsorption energy of -0.24 eV. The low diffusion energy barriers (0.099/0.101 eV) indicate the rapid mobility of Mg during the charge/discharge process. Moreover, the α-beryllene monolayer exhibits an ultra-high theoretical specific capacity of 5956 mA h g-1 for Mg, a low average open-circuit voltage of 0.24 V, and a tiny volume change of -1.08%. Finally, the constructed h-BN/α-beryllene heterostructure shows that h-BN can serve as a protective cover to preserve pristine α-beryllene in respect of metallicity, Mg adsorption capability, and fast ionic mobility. The above mentioned outstanding results make α-beryllene a promising anode material for magnesium-ion batteries.

Momentum matching induced giant magnetoresistance in two-dimensional magnetic tunnel junctions.

Giant magnetoresistance was first experimentally discovered in three-dimensional magnetic tunnel junctions (MTJs) in the late 1980s and is of great importance in nonvolatile memory applications. How to achieve a magnetoresistance as large as possible is always a central task in the study of MTJs. However, it is normally only of the order of magnitude of tens of percent in traditional MTJs. The ideal situation is the metal-insulator transition together with the magnetization reversal of one magnetic lead. In this work, we will show that this can be achieved using a two-dimensional ferromagnetic zigzag SiC nanoribbon junction based on quantum transport calculations performed with a combination of density functional theory and non-equilibrium Green's function. Specifically, with the magnetization configuration switching of the two leads from parallel to anti-parallel, the junction will change abruptly from a conducting state to an insulating state, although the two leads are always metallic, with both spin up and spin down channels crossing the Fermi level simultaneously. Extensive analysis indicates that the insulating state in the anti-parallel magnetic configuration originates not from any present mechanisms that cause full suppression of electron transmission but from momentum direction mismatching. This finding suggests a fantastic mechanism for achieving magnetoresistance or electrical switching in nanoscale devices by manipulating band dispersion.

Effect of external electric field on the electronic properties of the AlAs/SiC van der Waals heterostructure.

Type-II van der Waals (vdW) heterostructures are regarded as the optimum candidates for unipolar electronic device applications due to their capacity for spontaneous electron-hole separation. Here, we studied the electronic properties of the AlAs/SiC vdW heterostructure via density functional theory calculations. Results show that the conduction band minimum (CBM) and valence band maximum (VBM) of this heterostructure are mainly contributed by different materials, illustrating that the AlAs/SiC heterostructure has a type-II band alignment. Interestingly, this heterostructure possesses flat valence bands near the Fermi level. In addition, under the modulation of external electric field ranging between -1 V Å-1∼0.8 V Å-1, the band gap of the heterostructure can be tuned continuously, while the band structure maintains a stable type-II band alignment with flat top valence bands. When the electric field exceeds -1 or 0.8 V Å-1, the heterostructure transitions from semiconductor material to metal, indicating the tunability of electronic properties under external fields. These results indicate that the AlAs/SiC heterostructure shows great potential for application in high-performance optoelectronic devices and a strong correlation may exist in this system.