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Aim: Apical periodontitis is an inflammatory disorder triggered by an immune response to bacterial infection, leading to the periapical tissue damage and alveolar resorption. However, the underlying mechanisms driving this process remain elusive, due to the complex and interconnected immune microenvironment within the local lesion site. In this study, the influence of Nlrp3 inflammasome‐mediated immune response on the apical periodontitis was investigated. Methodology: RNA sequencing, immunohistochemistry and ELISA assay were performed to investigate the activation of Nlrp3 inflammasome signalling pathways in the human periapical tissues, including radicular cysts, periapical granulomas and healthy oral mucosa. A mouse model of apical periodontitis was established to study the role of Nlrp3 knockout in periapical bone resorption and Treg cell stability, and the underlying mechanism was explored through in vitro experiments. In vivo Treg cell adoptive transfer was performed to investigate the effects of Treg cells on the progression of apical periodontitis. Results: Our findings find that the hyperactivated Nlrp3 inflammasome is present in human periapical lesions and plays a vital role in the immune‐related periapical bone loss. Using a mouse model of apical periodontitis, we observe that Nlrp3 deficiency is resistant to bone resorption. This protection was accompanied by elevated generation and infiltration of local Treg cells that displayed a notable ability to suppress RANKL‐dependent osteoclast differentiation. In terms of the mechanism of action, Nlrp3 deficiency directly inhibits the osteoclast differentiation and bone loss through JNK/MAPK and NF‐κB pathways. In addition, Nlrp3 induces pyroptosis in the stem cells from apical papilla (SCAPs), and the subsequent release of cytokines affects the stability of Treg cell in periapical lesions, leading indirectly to enhanced bone resorption. In turn, adoptive transfer of both Nlrp3‐deficient and wild‐type Treg cells effectively prevent the bone erosion during apical periodontitis. Conclusions: Together, our data identify that the Nlrp3 inflammasome modulates the Treg cell stability and osteoclastogenesis in the periapical inflammatory microenvironment, thus determining the progression of bone erosion. [ABSTRACT FROM AUTHOR]

Recent studies on microencapsulated self-healing cementitious materials have primarily focused on the particle size and preparation methods of the microcapsules. However, there has been limited attention paid to the microscopic aspects, such as the selection of curing agents and the curing duration of these materials. In this study, urea-formaldehyde resin/epoxy resin E-51 microcapsules were synthesized through in situ polymerization. This research investigates the feasibility of self-healing from a molecular mechanism perspective and evaluates the repair performance of microencapsulated self-healing cement mortar with varying microcapsule concentrations, curing agent types, and curing ages. The findings demonstrate that the microcapsule shells bond effectively with the cementitious matrix, with radial distribution function peaks all located within 3.5 Å. The incorporation of microcapsules enhanced the tensile strength of the modified cement mortar by 116.83% and increased the failure strain by 110%, indicating improved adhesion and mechanical properties. The restorative agent released from the microcapsule core provided greater strength after curing compared to the uncured state. Although the overall strength of the microencapsulated self-healing cement mortar decreased with higher microcapsule concentrations, the repair efficiency improved. The strength recovery rate of 28-day aged modified cement mortar had a significant improvement with the addition of X and Y curing agents, respectively. [ABSTRACT FROM AUTHOR]

The latest discovery of high temperature superconductivity near 80 K in La3Ni2O7 under high pressure has attracted much attention. Many proposals are put forth to understand the origin of superconductivity. The determination of electronic structures is a prerequisite to establish theories to understand superconductivity in nickelates but is still lacking. Here we report our direct measurement of the electronic structures of La3Ni2O7 by high-resolution angle-resolved photoemission spectroscopy. The Fermi surface and band structures of La3Ni2O7 are observed and compared with the band structure calculations. Strong electron correlations are revealed which are orbital- and momentum-dependent. A flat band is formed from the Ni-3d z 2 orbitals around the zone corner which is ~ 50 meV below the Fermi level and exhibits the strongest electron correlation. In many theoretical proposals, this band is expected to play the dominant role in generating superconductivity in La3Ni2O7. Our observations provide key experimental information to understand the electronic structure and origin of high temperature superconductivity in La3Ni2O7. Recently, superconductivity near 80 K was observed in La3Ni2O7 under high pressure, but the mechanism is debated. Here the authors report angle-resolved photoemission spectroscopy measurements under ambient pressure, revealing flat bands with strong electronic correlations that could be linked to superconductivity. [ABSTRACT FROM AUTHOR]

Mitochondrial transfer is emerging as a promising therapeutic strategy for tissue repair, but whether it protects against pulpitis remains unclear. Here, we show that hyperactivated nucleotide‐binding domain and leucine‐rich repeat protein3 (NLRP3) inflammasomes with pyroptotic cell death was present in pulpitis tissues, especially in the odontoblast layer, and mitochondrial oxidative stress (OS) was involved in driving this NLRP3 inflammasome‐induced pathology. Using bone marrow mesenchymal stem cells (BMSCs) as mitochondrial donor cells, we demonstrated that BMSCs could donate their mitochondria to odontoblasts via tunnelling nanotubes (TNTs) and, thus, reduce mitochondrial OS and the consequent NLRP3 inflammasome‐induced pyroptosis in odontoblasts. These protective effects of BMSCs were mostly blocked by inhibitors of the mitochondrial function or TNT formation. In terms of the mechanism of action, TNF‐α secreted from pyroptotic odontoblasts activates NF‐κB signalling in BMSCs via the paracrine pathway, thereby promoting the TNT formation in BMSCs and enhancing mitochondrial transfer efficiency. Inhibitions of NF‐κB signalling and TNF‐α secretion in BMSCs suppressed their mitochondrial donation capacity and TNT formation. Collectively, these findings demonstrated that TNT‐mediated mitochondrial transfer is a potential protective mechanism of BMSCs under stress conditions, suggesting a new therapeutic strategy of mitochondrial transfer for dental pulp repair. [ABSTRACT FROM AUTHOR]

Kagome lattices of various transition metals are versatile platforms for achieving anomalous Hall effects, unconventional charge-density wave orders and quantum spin liquid phenomena due to the strong correlations, spin-orbit coupling and/or magnetic interactions involved in such a lattice. Here, we use laser-based angle-resolved photoemission spectroscopy in combination with density functional theory calculations to investigate the electronic structure of the newly discovered kagome superconductor CsTi3Bi5, which is isostructural to the AV3Sb5 (A = K, Rb or Cs) kagome superconductor family and possesses a two-dimensional kagome network of titanium. We directly observe a striking flat band derived from the local destructive interference of Bloch wave functions within the kagome lattice. In agreement with calculations, we identify type-II and type-III Dirac nodal lines and their momentum distribution in CsTi3Bi5 from the measured electronic structures. In addition, around the Brillouin zone centre, Z 2 nontrivial topological surface states are also observed due to band inversion mediated by strong spin-orbit coupling. Kagome superconductors host a panoply of condensed matter phenomena, some of which are mediated by band topology. Here, authors use ARPES and DFT to identify type-II and type-III Dirac nodal lines, flat bands and topological surface states in the kagome metal CsTi3Bi5. [ABSTRACT FROM AUTHOR]

The Kagome superconductors AV3Sb5 (A = K, Rb, Cs) have received enormous attention due to their nontrivial topological electronic structure, anomalous physical properties and superconductivity. Unconventional charge density wave (CDW) has been detected in AV3Sb5. High-precision electronic structure determination is essential to understand its origin. Here we unveil electronic nature of the CDW phase in our high-resolution angle-resolved photoemission measurements on KV3Sb5. We have observed CDW-induced Fermi surface reconstruction and the associated band folding. The CDW-induced band splitting and the associated gap opening have been revealed at the boundary of the pristine and reconstructed Brillouin zones. The Fermi surface- and momentum-dependent CDW gap is measured and the strongly anisotropic CDW gap is observed for all the V-derived Fermi surface. In particular, we have observed signatures of the electron-phonon coupling in KV3Sb5. These results provide key insights in understanding the nature of the CDW state and its interplay with superconductivity in AV3Sb5 superconductors. The impact of the charge density wave (CDW) state to the electronic structure in the Kagome superconductors AV3Sb5 remains unclear. Here, the authors observe CDW-induced Fermi surface reconstruction with a strongly anisotropic CDW gap and signatures of the electron-phonon coupling for all V-derived bands. [ABSTRACT FROM AUTHOR]

Impurity pinning has long been discussed to have a profound effect on the dynamics of an incommensurate charge density wave (CDW), which would otherwise slide through the lattice without resistance. Here, we visualize the impurity pinning evolution of the CDW in ZrTe_{3} using the variable temperature scanning tunneling microscopy. At low temperatures, we observe a quasi-1D incommensurate CDW modulation moderately correlated to the impurity positions, indicating a weak impurity pinning. As we raise the sample temperature, the CDW modulation gets progressively weakened and distorted, while the correlation with the impurities becomes stronger. Above the CDW transition temperature, short-range modulations persist with the phase almost all pinned by impurities. The evolution from weak to strong impurity pinning through the CDW transition can be understood as a result of losing phase rigidity.