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Deep ultraviolet (DUV) nonlinear optical (NLO) crystals with balanced performance are crucial for extending laser wavelengths into the DUV region, essential for various laser applications. However, developing ideal DUV crystals is challenging due to stringent requirements: strong second‐harmonic generation (SHG) response, short cut‐off wavelength, and effective phase‐matching behavior. DUV NLO borates, which feature π‐conjugated groups, have garnered attention for their higher SHG coefficients compared to phosphates. However, phosphates typically show short UV cut‐off edges due to the large HOMO‐LUMO gap (approximately 9.6 eV) of the [PO₄] units. To enhance the SHG effect while maintaining DUV transparency in phosphates, several strategies have been proposed: 1) using distorted polymerized P−O groups like isolated C₁‐[P₃O₁₀]⁵− and [P₂O₇]⁴−; 2) aligning isolated [PO₄]3− tetrahedra along the polar screw axis; 3) introducing additional NLO‐active units; and 4) exploring new units derived from [PO₄]3−, such as [PO₃F]2− tetrahedra. These strategies have led to the successful development of various non‐centrosymmetric phosphates, highlighting their potential as DUV NLO candidates. This review explores the relationship between their crystal structures and DUV NLO performance, and proposes future directions for developing ideal DUV NLO materials. [ABSTRACT FROM AUTHOR]

In the deep‐ultraviolet (DUV) region, nonlinear optical (NLO) crystals must meet stringent requirements, including a large optical band gap and sufficient second harmonic generation (SHG) response. Typically, these criteria are fulfilled by borates, carbonates and nitrates containing π‐conjugated groups. In contrast, sulfates and phosphates, with polarizabilities significantly smaller than those of π‐conjugated groups, struggle to achieve similar performance. Here, we present the discovery of Mg2PO4Cl, a magnesium‐based phosphate, identified from over 10,000 phosphates based on a polar‐axial‐symmetry screening strategy, which exhibits the highest SHG response (5.2×KH2PO4 (KDP)) with phase‐matching ability among non‐π‐conjugated DUV transparent NLO crystals. This compound belongs to the Pna21 space group, with [PO4] units consistently aligned along the 21 screw axis and glide planes throughout its crystal structure. Theoretical calculations attribute its remarkable SHG effect to the orderly arrangement of heteroanionic [MgO5Cl] and [MgO4Cl2] polyhedra alongside isolated [PO4] tetrahedra, supported by Berry phase analysis. Furthermore, a crystallographic structure analysis of phosphates and sulfates with significant SHG effects validates the effectiveness of our screening strategy. These findings offer valuable insights into the origins of NLO effects in non‐π‐conjugated compounds from both a material design and structural chemistry perspective, inspiring future efforts to revitalize DUV phosphates. [ABSTRACT FROM AUTHOR]

Trichloroethylene (TCE) is a metal detergent commonly used in industry that can enter the human body through the respiratory tract and skin, causing occupational medicamentosa-like dermatitis due to TCE (OMDT) and multiple organ damage, including liver failure. However, the pathogenesis of liver injury remains unclear. Kupffer cells (KCs) are important tissue macrophages in the body because the polarization of KCs plays a crucial role in immune-mediated liver injury. However, the mechanism of KCs polarization in TCE-induced immune liver injury has not been thoroughly elucidated. In this study, we investigated the effect of TCE-induced KCs polarization on liver function and signal transduction pathways using the TCE sensitization model developed by our group. BALB/c mouse skin was exposed to TCE for sensitization, and an increase in the expression of M1 macrophage-specific markers (CD16/CD32, iNOS), M1 macrophage-specific cytokines IL-1β, and IFN-γ, P-JAK-1 and P-STAT1 levels were also found to be dramatically increased. When using low doses of gadolinium trichloride (GdCl3), the expression of these proteins and mRNA was significantly reduced. This phenomenon indicates that GdCl3 blocks TCE-induced polarization of KCs and suggests that the IFN-γ/STAT1 signaling pathway may be involved in the polarization process of KCs. These findings clarify the relationship between the polarization of KCs and immune liver injury and highlight the importance of further study of immune-mediated liver injury in TCE-sensitized mice. [ABSTRACT FROM AUTHOR]