SummaryGlucagon-like peptide 1 (GLP-1) plays an important role in regulating bone remodeling, and GLP-1 receptor agonist shows a positive relationship with osteoblast activity. However, GLP-1 receptor is not found in osteoblast, and the mechanism of GLP-1 receptor agonist on regulating bone remodeling is unclear. Here, we show that the GLP-1 receptor agonist exendin-4 (Ex-4) promoted bone formation and increased bone mass and quality in a rat unloading-induced bone loss model. These functions were accompanied by an increase in osteoblast number and serum bone formation markers, while the adipocyte number was decreased. Furthermore, GLP-1 receptor was detected in bone marrow stromal cells (BMSCs), but not in osteoblast. Activation of GLP-1 receptor by Ex-4 promoted the osteogenic differentiation and inhibited BMSC adipogenic differentiation through regulating PKA/β-catenin and PKA/PI3K/AKT/GSK3β signaling. These findings reveal that GLP-1 receptor regulates BMSC osteogenic differentiation and provide a molecular basis for therapeutic potential of GLP-1 against osteoporosis.

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Ferroelectric (FE) materials are thought to be promising materials for self-powered ultraviolet (UV) photodetector applications because of their photovoltaic effects. However, FE-based photodetectors exhibited poor performance because of the weak photovoltaic effect of FE depolarization field (E dp) on the separation of photo-generated carriers. In this work, self-powered photodetectors based on both E dp and built-in electric field at the p-n junction (E p‑n) were designed to obtain enhanced device performance. A NiO/Pb0.95La0.05Zr0.54Ti0.46O3 (PLZT) heterojunction-based device is constructed to take advantage of energy level alignments that favor electron extraction. The device exhibits a tunable performance upon varying the polarization direction of PLZT. The NiO/PLZT heterojunction-based device with the PLZT layer in the poling down state shows a higher responsivity [R = (1.8 ± 0.12) × 10–4 A/W] and detectivity [D* = (3.69 ± 0.2) × 109 Jones], a faster response speed (τr = 0.34 ± 0.03 s, τd = 0.36 ± 0.02 s), and a lower dark current [I dark = (1.3 ± 0.19) × 10–12 A] under zero bias than the PLZT-based device because of the synergistic effects of E dp and E p‑n. Moreover, under weak-light illumination (0.1 mW/cm2), it exhibits even higher R [(6.3 ± 1.2) × 10–4 A/W] and D* [(1.29 ± 0.26) × 1010 Jones] values, which surpass those of most previously reported FE-based self-powered photodetectors. Our work emphasizes the role of the coupling effect between E p‑n and E dp in the photovoltaic process of NiO/PLZT heterojunction-based devices and provides an effective way to promote the self-powered UV photodetector applications.

All-inorganic cesium lead halide perovskite materials, such as CsPbBr 3 and CsPb 2 Br 5 , have drawn immense attention recently due to their potential applications in optoelectronics. However, unlike the extensivelystudied CsPbBr 3 , many of the fundamental properties of CsPb 2 Br 5 remain unclear, such as its electronic structure and photoluminescence (PL) mechanism. In this work, we developed a novel environmentally friendly chemical method to synthesize CsPb 2 Br 5 , where only water and ethanol were used as solvents.The optical property and electronic structure of CsPb 2 Br 5 were then examined both experimentally and theoretically. For the first time we found that the band-edge emission of CsPb 2 Br 5 was not in the visible range as reported in the literature but rather located in the ultraviolet range. By monitoring the PL property during phase conversion between CsPb 2 Br 5 and CsPbBr 3 , we propose that previously-reported visible emission might be due to the involvement of CsPbBr 3 during sample preparation. Overall, this study presents a novel green method for the preparation of CsPb 2 Br 5 and clarifies the optical properties and electronic structure of CsPb 2 Br 5 .