Three-Dimensional Cuprous Lead Bromide Framework with Highly Efficient and Stable Blue Photoluminescence Emission.

Considering the instability and low photoluminescence quantum yield (PLQY) of blue-emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4 )2 ]CuPbBr5 with new type of three-dimensional (3D) anionic framework. [(NH4 )2 ]CuPbBr5 exhibits strong band-edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4 )2 ]CuPbBr5 also displays broadband red light emissions derived from self-trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non-perovskite bimetallic halide with highly efficient and stable blue light emission.

Protective effect of lycopene on human spermatozoa during cryopreservation and its mechanism / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of lycopene against cryopreservation injury of post-thawing human sperm and its mechanism.</p><p><b>METHODS</b>Semen samples were collected from 25 volunteers, each sample equally divided into four parts to be cryopreserved with cryoprotectant only (Ly0 control) or cryoprotectant + lycopene at the concentrations of 2 (Ly2), 5 (Ly5), and 10 µmol/L (Ly10), respectively. Before and after thawing, the semen samples were subjected to computer-assisted semen analysis ( CASA) for sperm kinematics, flow cytometry for sperm apoptosis, thiobarbituric acid assay for malondialdehyde (MDA) concentration, and JC-1 fluorescent staining for the sperm mitochondrial membrane potential (MMP).</p><p><b>RESULTS</b>After cryopreservation, sperm motility was markedly decreased in all the groups (P < 0.01). The rate of sperm apoptosis was significantly lower in the Ly5 group than in the Ly0 control ([25.68 ± 4.36]% vs [33.26 ± 4.78]%, P < 0.05), while sperm MMP remarkably higher in the former than in the latter ([66.18 ± 14.23]% vs [55.24 ± 12.31]%, P < 0.05). The Ly2, Ly5 and Ly10 groups showed no statistically significance differences in the MDA level from the Ly0 control (P > 0.05).</p><p><b>CONCLUSION</b>Addition of lycopene at a proper concentration to cryoprotectant may reduce oxidative damage to sperm mitochondria in the freezing-thawing process, attenuate oxidative stress injury induced by reactive oxygen species to sperm plasma membrane, and improve the anti-apoptosis ability of sperm.</p>