Rodents are popular biological models for physiological and behavioral research in neuroscience and rats are better models than mice due to their higher genome similarity to human and more accessible surgical procedures.However,rat brain is larger than mice brain and it needs powerful imaging tools to implement better penetration against the scattering of the thicker brain tissue.Three-photon fluorescence microscopy(3PFM)combined with near-infrared(NIR)excitation has great potentials for brain circuits imaging beause of its abilities of anti scattering,deep-tissue imaging,and high signal-to-noise ratio(SNR).In this work,a type of AIE lumninogen with red fuorescence was synthesized and encapsulated with Pluronic F-127 to make up form nano-particles(NPs).Bright DCDPP-2TPA NPs were employed for in trino three-photon fuorescent laser scanning microscopy of blood vessels in rats brain under 1550 nm femtosecond laser exci-tation.A fine three-dimensional(3D)reconstruction up to the deepness of 600 pm was achieved and the blood flow velocity of a selected vessel was measured in vrito as well.Our 3PFM deep brain imaging method simultaneously recorded the morphology and function of the brain blood vessels in vivo in the rat model.Using this angiography combined with the arsenal of rodent's brain disease,models can accelerate the neuroscience research and clinical diagnosis of brain disease in the future.
Two new multibranched thiophene-based triarylamine derivatives with 1,3,5-triazine core are synthesized and characterized. Their one-and two-photon absorption properties and aggregation-induced emission effect have been investigated. Both the STAPA-based compounds are AIE active. The two-photon absorption (2PA) cross sections measured by the open aperture Z-scan technique are determined to be 620 and 1610 GM for STAPA-a and STAPA-b in chloroform,respectively, which dramatically increase with the introduction of alkyl chains. The relationship between their structures and properties on one-and two-photon absorption and aggregation-induced emission is discussed, which allows us to examine the effect of introducing alkyl chains. In addition, solvent effects also show a significant influence on the 2PA cross section. The two compounds with excellent AIE and 2PA properties provide attractive alternatives for the biophotonic materials.
GAO YuTingZHANG HaoJIANG TaoYANG JiLI BoLI ZhenHUA JianLi
Efficient room temperature phosphorescence is observed in natural compounds and polymers such as starch, cellulose, bovine serum albumin (BSA), and some other carbohydrates. Whereas being practically nonluminescent in solutions and TLC plates, they emit bright phosphorescence in the crystalline states with lifetime up to microseconds, exhibiting crystallization-induced phosphorescence (CIP) characteristics. The CIP of these natural products without any conventional chromophores offers a new platform for the exploration of conceptually novel luminogens.
GONG YongYangTAN YeQiangMEI JuZHANG YiRenYUAN WangZhangZHANG YongMingSUN JingZhiTANG Ben Zhong
Efficient room temperature phosphorescence (RTP) is rarely observed in pure organic luminogens. However, we have newly observed that benzil and its derivatives are nonluminescent in solvents and thin layer chromatography (TLC) plates, but become highly phosphorescent in crystal state at room temperature, exhibiting typical crystallization-induced phosphorescence (CIP) characteristics. The CIP phenomenon is ascribed to the restriction of intramolecular rotations in crystals owing to effective intermolecular interactions. Such intermolecular interactions greatly rigidify the molecular conformation and significantly decrease the nonradiative deactivation channels of the triplet excitons, thus giving boosted phosphorescent emission at room temperature.
GONG YongYangTAN YeQiangLI HongZHANG YiRenYUAN WangZhangZHANG YongMingSUN JingZhiTANG Ben Zhong
The new approaches to construct deep blue aggregation-induced emission(AIE) materials have been explored, which control the conjugation by two different strategies, to make a great step for the commercialization of organic light-emitting diodes. In order to shorten the intramolecular conjugation length, triphenylethylene(t PE)was utilized to construct blue AIEgens as peripheral groups,instead of tetraphenylethylene(TPE), the famous AIE star molecule, to yield three blue AIEgens of 3,4-Bt PE-PI, 4,4-Bt PE-PI and 4,4-Bt PE-PPI. Nondoped electroluminescence devices are fabricated by using these three AIEgens as the emitting material layer, the best performance of 3.8 cd/A as the maximum current efficiency achieved at the commission internationale de l'Eclairage coordinates of(0.17, 0.18).
Can WangLe LiXuejun ZhanZhijun RuanYujun XieQuanyuan HuShanghui YeQianqian LiZhen Li
