Prognostic Analysis of Lactic Acid Metabolism Genes in Oral Squamous Cell Carcinoma.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral and maxillofacial region. Lactic acid accumulation in the tumour microenvironment (TME) has gained attention for its dual role as an energy source for cancer cells and an activator of signalling pathways crucial to tumour progression. This study aims to reveal the impact of lactate-related genes (LRGs) on the prognosis, TME, and immune characteristics of OSCC, with the ultimate goal of developing a novel prognostic model. METHODS: Unsupervised clustering analysis of LRGs in OSCC patients from The Cancer Genome Atlas database was conducted to evaluate and compare TME, immune features, and clinical characteristics across various lactate subtypes. A refined prognostic model was developed through the application of Cox and Least absolute shrinkage and selection operator (LASSO) regression techniques. External validation sets were then utilised to improve model accuracy, along with a detailed correlation analysis of drug sensitivity. RESULTS: The Cancer Genome Atlas-OSCC patients were categorised into 4 distinct lactate subtypes based on LRGs. Notably, patients in subtype 1 and subtype 2 exhibited the least and most favourable prognoses, respectively. Subtype 1 patients showed elevated expression levels of immune checkpoint genes. Further analysis identified 1086 genes with significant expression differences between cancer and noncancer tissues, as well as between subtype 1 and subtype 2 patients. Selected genes for the prognostic model included ZNF662, CGNL1, VWCE, and ZFP42. The high-risk group defined by this model had a significantly poorer prognosis (P < .0001) and functioned as an independent prognostic factor (P < .001), accurately predicting 1-, 3-, and 5-year survival rates. Additionally, individuals in the high-risk category exhibited heightened sensitivity to chemotherapy drugs such as AZ6102 and Venetoclax. CONCLUSIONS: The predictive model based on the genes ZNF662, CGNL1, VWCE, and ZFP42 can serve as a reliable biomarker, providing accurate prognostic predictions for OSCC patients and potential opportunities for pharmaceutical interventions.

Tunable interstitial anionic electrons in layered MXenes.

Electrides with spatial electrons serving as 'anions' in the cavities or channels exhibit intriguing properties which can be applied in electron injection/emission and high-speed devices. Here, we report a new group of layered electrides, M2X (M = Ti, V, and Cr; X = C and N) with electrons distributed in the interlayer spacings. We find that the interstitial electrons tend to be delocalized from the Ti-based structures to the Cr-based ones. We show that the interstitial electrons originate from thed-electrons of transition metal atoms. Our findings prove the existence of tunable interstitial electrons with rich electronic properties in layered MXenes and provide valuable insights into the design and fabrication of new materials with multiple applications.

M4 B6 X6 as a New Family of High-Efficient Electrocatalysts: The Role of Surface Reconstruction in Water Oxidization.

Searching for highly-efficient electrocatalysts for water splitting has been greatly endowed due to the huge demand for green energy sources. Two-dimensional (2D) materials are widely explored for the purpose because of their unique physical and chemical properties, abundant active sites, and easy fabrication. Here, we present a new family of 2D M4 B6 X6 (2D Boridenes) and investigate their physical and chemical properties for their potential applications into electrocatalysis based on first-principles calculations. We demonstrate that 2D M4 B6 X6 (M=Cr, Mo, and W; X=O and F) are dynamically, thermodynamically, and mechanically stable, and show intriguing electronic and catalytic properties. Importantly, we find that M4 B6 O6 are intrinsically active for oxygen evolution reaction (OER). Our results demonstrate that: (1) the adsorbate-escape mechanism dominates the OER process with a low overpotential of 0.652 V on Cr4 B6 O6 ; (2) the partial surface-oxidization can improve the catalytic performance of M4 B6 F6 dramatically; and (3) the surface reconstruction greatly affects the OER performance of M4 B6 X6 . Our findings illustrate that the surface reconstruction is critical to the OER activity, which may provide a new strategy on the design of 2D materials for electrocatalysis and offer theoretical insight into the catalytic mechanism.

Stacking-Dependent Interlayer Ferroelectric Coupling and Moiré Domains in a Twisted AgBiP2Se6 Bilayer.

Rotation/twisting of bilayers could induce unprecedented new physics due to stacking-dependent electronic properties and interlayer coupling, such as the superconductivity in twisted bilayer graphene, which can find applications in electronics. However, deep understanding at the atomic/electronic levels is limited by the capability of accurate theoretical simulations. Here, from first-principles simulations, we found that the AgBiP2Se6 bilayer has stacking-dependent ferroelectric ground states due to interlayer polarization coupling. Interlayer ferroelectric coupling is preferred in an AA-stacked AgBiP2Se6 bilayer, but antiferroelectric coupling is preferred in AB- or AC-stacked configurations. The ferroelectric Moiré patterns are thus observed in a twisted AgBiP2Se6 bilayer with ferroelectric (antiferroelectric) interlayer couplings in the AA (AB/AC)-stacked areas. Our work for the first time unveils the effects of twisting/rotation on interlayer polarization coupling and provides a real example of ferroelectric Moiré patterns.

Two-Dimensional Dirac Nodal Line Carbon Nitride to Anchor Single-Atom Catalyst for Oxygen Reduction Reaction.

Two-dimensional carbon nitride (2DCN) materials have emerged as an important class of 2D materials beyond graphene. However, 2DCN materials with nodal-line semimetal characteristic are rarely reported. In this work, a new nodal-line semimetal 2DCN with the stoichiometry C4 N4 is designed by using density functional theory (DFT) calculations and its application to anchor single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) is investigated. C4 N4 is a planar covalent network (sp2 hybridization) with regular holes formed by the four N atoms, which is dynamically, thermodynamically, and mechanically stable. The nodal line is contributed by the pz orbitals of C and px/y orbitals of N atoms. C4 N4 shows an anisotropic Fermi velocity and high electron mobility. Because of its porous structure, C4 N4 can anchor heteroatoms as SACs for electrocatalysis. C4 N4 anchored with Fe or Co is shown to be highly active for the ORR with a rather high half-wave potential of around 0.90 V, which is higher than those of SACs on other carbon nitrides. These findings may provide a new strategy to design novel substrates for SACs.

Intercorrelated ferroelectrics in 2D van der Waals materials.

2D intercorrelated ferroelectrics, exhibiting a coupled in-plane and out-of-plane ferroelectricity, is a fundamental phenomenon in the field of condensed-mater physics. The current research is based on the paradigm of bi-directional inversion asymmetry in single-layers, which restricts 2D intercorrelated ferroelectrics to extremely few systems. Herein, we propose a new scheme for achieving 2D intercorrelated ferroelectrics using van der Waals (vdW) interaction, and apply this scheme to a vast family of 2D vdW materials. Using first-principles, we demonstrate that 2D vdW multilayers, for example, BN, MoS2, InSe, CdS, PtSe2, TI2O, SnS2, Ti2CO2etc., can exhibit coupled in-plane and out-of-plane ferroelectricity, thus yielding 2D intercorrelated ferroelectric physics. We further predict that such intercorrelated ferroelectrics could demonstrate many distinct properties, for example, electrical full control of spin textures in trilayer PtSe2 and electrical permanent control of valley-contrasting physics in four-layer VS2. Our finding opens a new direction for 2D intercorrelated ferroelectric research.

Single-Layer PtI2: A Multifunctional Material with Promising Photocatalysis toward the Oxygen Evolution Reaction and Negative Poisson's Ratio.

Exploring novel two-dimensional multifunctional materials with distinguished properties lies at the core of materials innovation. Here, we identify a hitherto-neglected single-layer PtI2, which can readily be exfoliated from its bulk experimentally, with appealing multifunctional properties through first-principles calculations. Single-layer PtI2 is an indirect-gap semiconductor with a band gap of 2.56 eV, and its band gap is extremely robust against external strain. We find that it is a promising two-dimensional photocatalyst, exhibiting outstanding catalytic performances toward oxygen evolution reactions, with the water oxidation reaction occurring spontaneously under light irradiation. Moreover, we unveil that single-layer PtI2 is a long-sought auxetic material with a negative Poisson's ratio of -0.54, arising from its particular puckered hinge crystal. Our findings highlight single-layer PtI2 as a promising multifunctional material for nanoscale mechanical and photocatalytic applications.

Robust two-dimensional ferroelectricity in single-layer γ-SbP and γ-SbAs.

Currently, two-dimensional ferroelectricity has attracted considerable attention due to its fascinating properties and promising applications. Herein, by means of first-principles calculations, we propose a series of excellent ferroelectric materials, single-layer γ-SbX (X = As, P). Both systems exhibit excellent 2D ferroelectricity with an in-plane spontaneous polarization around 3.80 × 10-10 C m-1 (γ-SbAs) and 3.47 × 10-10 C m-1 (γ-SbP). More importantly, the ferroelectricity of SL γ-SbAs (γ-SbP) has been maintained well at 700 K (600 K), much higher than room temperature. These properties indicate that SL γ-SbX are robust ferroelectric materials, which could be promising for nonvolatile memory devices and nanoscale electronics. The Landau theory is employed to explain the mechanism of the ferroelectric phase transition, which provides a better understanding of the universal critical properties of 2D materials.

Effect of technetium-99 conjugated with methylene diphosphonate (99 Tc-MDP) on OPG/RANKL/RANK system in vitro.

BACKGROUND: RANKL and RANK play an important role in jaw resorption during the development of the ameloblastomas. Therefore, the aim of this study was to explore the effect of 99 Tc-MDP on OPG/RANKL/RANK system on RAW264.7 and MC3T3-E1 cell lines in vitro and provide the theoretical basis for the clinical treatment of the jaw ameloblastoma. METHODS: Different concentrations of 99 Tc-MDP were used to treat RAW264.7 and MC3T3-E1 cell lines. The cell proliferative inhibition rate was analyzed by CCK-8. Cell apoptosis and cell cycle were detected by flow cytometry. Western blot was used to detect the expression of OPG, RANKL, and RANK. RESULTS: Treatment of RAW264.7 cell lines with different concentrations of 99 Tc-MDP had inhibitory effects and decreased the expression of RANK protein. The cell proliferation of 99 Tc-MDP on MC3T3-E1 cell lines was stronger at 48 hours than at 24 hours except for 100 µg/mL concentration group. Compared with the concentration of 0.01 µg/mL, the treatment of MC3T3-E1 cells with 100 µg/mL 99 Tc-MDP showed that the cell proliferative effect decreased at 24 hours and 48 hours (P < 0.05). After treatment with 0.01 µg/mL 99 Tc-MDP, the expression of OPG in MC3T3-E1 cells was significantly increased (P < 0.05). Compared with 0.01 µg/mL, the expression of RANKL was decreased after treatment with 100 µg/mL 99 Tc-MDP (P < 0.05). CONCLUSION: 99 Tc-MDP can induce apoptosis of RAW264.7 cells and inhibit the expression of RANK protein. The effect of 0.01 µg/mL of low concentration of 99 Tc-MDP can promote the proliferation of MC3T3-E1 cells and increase the expression of OPG and RANKL protein. 99 Tc-MDP may have adjuvant therapeutic effects on the treatment of jaw ameloblastoma.

Maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle

BACKGROUND: Maxillary reconstruction using various pedicled and free-tissue transfer techniques with bone graft or without bone graft has some drawbacks. In this study, we demonstrate maxillary reconstruction using femoris rectus muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle through the modified lateral lip-submandibular approach. MATERIAL AND METHODS: Nine patients suffering from maxillary defects secondary to maxillary cancer ablation, who underwent maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle, were enrolled into this study between November 2015 and August 2017. RESULTS: All patients who underwent the maxillary reconstruction using femoris rectus muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle presented satisfactory postoperative function, with adequate mouth opening, optimal esthetic outcome and no restrictions on the diet. Every rectus femoris muscle flaps mucosalized well within five weeks. No donor site functional impairment or complications were observed. CONCLUSIONS: The technique is a feasible and acceptable technique for the maxillary reconstructions. It is safe, quick and simple to harvest. It also presents an optimal esthetic and satisfactory functional outcome with the advantage of low morbidity of the donor site. Combined with the three-dimension reconstruction, this technique can improve the postoperative outcomes

Tl2S: a metal-shrouded two-dimensional semiconductor.

Recently, the family of metal-shrouded two-dimensional (2D) crystals has expanded rapidly, although most of these crystals are metallic. Using first-principles, we identify a semiconducting 2D metal-shrouded crystal, namely the Tl2S monolayer, which is found to be thermally and dynamically stable, and should be readily exfoliated experimentally. Most importantly, Tl2S monolayers exhibit compelling electronic and photovoltaic properties, i.e., modulable bandgaps of 1.89-2.31 eV, strong light absorption and ideal photo-electricity transduction properties. Additionally, the unique metal-shrouded structure, that has rarely been found in other 2D semiconductors, endows monolayer Tl2S with the potential to form excellent contacts with electrode materials in device applications. An intriguing large conduction band spin-valley coupling is also obtained in 2H-Tl2S due to the strong spin-orbit coupling and breaking of inversion symmetry. These exotic properties render Tl2S an excellent candidate for a wide range of applications in electronic and photovoltaic devices.