Search

Luminescent metal halides doped with ns2-metal ions such as 6s2-metal Bi3+ have aroused reviving interest owing to their outstanding optical properties; however, the origin of the photoluminescence (PL) remains controversial and unclear. Herein, we report a strategy for the controlled synthesis of Bi3+-doped vacancy-ordered double perovskite Cs2SnCl6 nanocrystals (NCs) and unravel the triplet excited-state dynamics of Bi3+ through temperature-dependent PL and ultrafast femtosecond transient absorption spectroscopies. Owing to the aliovalent Bi3+ doping in the spatially confined zero-dimensional (0D) structure of Cs2SnCl6, Bi3+ ions experience an enhancive Jahn-Teller distortion in the excited state, which results in intense broadband blue PL originating from the inter-configurational 3P0,1 → 1S0 transitions of Bi3+ at 450 nm, with a large Stokes shift and a quantum yield of 35.2%. Specifically, an unusual thermal-enhanced Jahn-Teller splitting of the excitation band and a remarkable transition of the PL lifetime from ms at 10 K to µs at 300 K were observed, as solid evidence for the isolated Bi3+ emission. These findings clarify the controversy about the PL origin in ns2-metal ion-doped lead-free luminescent metal halides, thereby paving the way for exploring their optoelectronic applications. [ABSTRACT FROM AUTHOR]

All‐inorganic lead‐free perovskite‐derivative metal halides have shown great promise in optoelectronics, however, it remains challenging to realize efficient near‐infrared (NIR) luminescence in these materials. Herein, we report a novel strategy based on Te4+/Ln3+ (Ln=Er, Nd, and Yb) co‐doping to achieve efficient NIR luminescence in vacancy‐ordered double perovskite Cs2ZrCl6 phosphors, which are excitable by a low‐cost near‐ultraviolet light‐emitting diode (LED) chip. Through sensitization by the spin‐orbital allowed 1S0→3P1 transition of Te4+, intense and multi‐wavelength NIR luminescence originating from the 4f→4f transitions of Er3+, Nd3+, and Yb3+ was acquired, with a quantum yield of 6.1 % for the Er3+ emission. These findings provide a general approach to achieve efficient NIR emission in lead‐free metal halides through ns2‐metal and lanthanide ion co‐doping, thereby opening up a new avenue for exploring NIR‐emitting perovskite derivatives towards versatile applications such as NIR‐LEDs and bioimaging. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer presents high risk of metastasis and chemotherapy resistance. Hence, it is important to understand the mechanisms of gastric cancer distant metastasis and chemotherapeutic resistance. Our previous study has revealed Four and a Half LIM Domains 3 (FHL3) plays as a binding partner of Glycogen Synthase Kinase 3 Beta (GSK3 β), promoted tumor metastasis in pancreatic cancer. However, the role of FHL3 in gastric cancer still remains unclear. Methods: TCGA database and clinical samples are used for exploring the role of FHL3 in disease progression and prognosis. Oxaliplatin (OHP) resistance cell lines were established to study the role of FHL3 in chemotherapy resistance. The experiments about cell proliferation, apoptosis, and metastasis were performed to measure the chemotherapy effects of sh-FHL3 on gastric cancer cell lines and in vivo. That FHL3 changed the EMT phenotype was verified by western blot. Finally, we explored the mechanism of FHL3-mediated EMT and chemotherapy resistance. Results: mRNA and protein level of FHL3 were significantly up-regulated in gastric cancer tissues when compared with adjacent tissue. FHL3 higher expression is always accompanied with higher TNM stage and worse overall survival. FHL3 over-expressed could lead to OHP resistance. Knockdown of FHL3 slightly inhibited the cell growth, while it obviously sensitized the chemotherapy in vivo and in vitro. In addition, down-regulation of FHL3 increased the mesenchymal markers, such as Slug, Snail, Twist Family BHLH Transcription Factor 1 (Twist1), and Vimentin, while it decreased the epithelial marker E-cadherin. Cell and animal experiments also proved that down-regulation of FHL3 can decrease cancer cell metastasis. For mechanism study, FHL3 knockdown down-regulated the expression level of Mitogen-Activated Protein Kinase (MAPK)/Extracellular Regulated Protein Kinase (ERK) pathway and Transforming Growth Factor- β (TGF β)/Phosphatidylinositol 3-Kinase (PI3K)/protein kinase B(Akt)/GSK3 β -(Ring Finger Protein 146) RNF146/ubiquitin pathway. FHL3 competitively bonded the ubiquitin complex (Slug/GSK3β/RNF146) with Slug and inhibited ubiquitination of Slug. Mesenchymal phenotype cells hold higher level of Multidrug Resistance Gene1 (MDR1), and the FHL3 knockdown reverts the MDR1 in this type cell. Conclusion: FHL3 high expression contributed to EMT and chemotherapy resistance via MAPK, and PI3K pathways were activated. FHL3 competitively bonded the ubiquitin complex with Slug, resulting in the up-regulation of Slug and leading to metastasis of gastric cancer. [ABSTRACT FROM AUTHOR]

All-inorganic lead-free perovskite-derivative metal halides have shown great promise in optoelectronics, however, it remains challenging to realize efficient near-infrared (NIR) luminescence in these materials. Herein, we report a novel strategy based on Te 4+ /Ln 3+ (Ln=Er, Nd, and Yb) co-doping to achieve efficient NIR luminescence in vacancy-ordered double perovskite Cs 2 ZrCl 6 phosphors, which are excitable by a low-cost near-ultraviolet light-emitting diode (LED) chip. Through sensitization by the spin-orbital allowed 1 S 0 → 3 P 1 transition of Te 4+ , intense and multi-wavelength NIR luminescence originating from the 4f→4f transitions of Er 3+ , Nd 3+ , and Yb 3+ was acquired, with a quantum yield of 6.1 % for the Er 3+ emission. These findings provide a general approach to achieve efficient NIR emission in lead-free metal halides through ns 2 -metal and lanthanide ion co-doping, thereby opening up a new avenue for exploring NIR-emitting perovskite derivatives towards versatile applications such as NIR-LEDs and bioimaging., (© 2022 Wiley-VCH GmbH.)