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991.
992.
993.
Juanjuan Zhou Dr. Kai Huang Shaochen Lin Nan Zhang Xin Wang Dr. Yang Li Prof. Zhanjun Li Prof. Gang Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(26):e202104366
While concerns about improving recharged afterglow intensity in vivo still motivate further exploration, afterglow nanoparticles (AGNP) offer unique optical merit for autofluorescence-free biological imaging. Apart from efforts enhancing the afterglow emission properties of AGNP, improving afterglow excitation response to visible or near infrared light is important but has lacked success. Dye sensitization has been used to improve the optical response of photovoltaic nanomaterials and to enhance upconversion luminescence efficiency. This concept has recently been expanded and applied to AGNPs. As a new multifunctional nanoprobe, such dye-sensitized AGNP takes advantage of both high spatial resolution fluorescence imaging and sensitive afterglow imaging. This Concept introduces the background, the concept, mechanism, and related imaging application, as well as reviewing existing challenges and proposing future developmental directions for the dye-sensitized AGNPs. 相似文献
994.
Dr. Toshiro Takao Dr. Yuta Takahashi Masataka Kai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(29):e202200327
A dicationic triruthenium complex containing a μ3-η3-C3 ring, [(Cp*Ru)3(μ3-η3-C3MeH2−)(μ3-CH)(μ-H)]2+ ( 1 a , Cp*=η5-C5Me5), reacted with ammonia to yield a μ-amido complex, [(Cp*Ru)3(μ3-η3-CHCMeCH) (μ3-CH)(μ-NH2)]2+ ( 5 ), via N−H bond scission. Subsequent treatment with base resulted in C−N bond formation to yield a μ3-η2:η2-1-azabutadien-4-yl complex, [(Cp*Ru)3(μ3-CH)(μ3-η2:η2-NH=CH−CMe=CH−)]+ ( 6 a ). The azaruthenacyclopentadiene skeleton was alternatively synthesized by the photolysis of mono-cationic complex [(Cp*Ru)3(μ3-η3-C3RH2−)(μ3-CH)]+ ( 2 a ; R=Me, 2 b ; R=H) in the presence of ammonia. The C3 ring skeleton was broken via the electron transfer to the π*(C−C) orbital in the C3 ring, and a transiently generated unsaturated μ3-allylic species can take up ammonia, resulting in N−H bond scission followed by C−N bond formation. 相似文献
995.
Qingqing Ma Shanlin Xu Zhaodong Zhai Kai Wang Xueli Liu Prof. Haibin Xiao Prof. Shuping Zhuo Prof. Yuying Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(39):e202200828
Peroxynitrite (ONOO−) as a major reactive oxygen species plays important roles in cellular signal transduction and homeostatic regulation. Precise detection of ONOO− in biological systems is vital for exploring its physiological and pathological function. Among numerous detection methods, fluorescence imaging technology using fluorescent probes offers some advantages, including simple operation, high sensitivity and selectivity, as well as real-time and nondestructive detection. In particular, ratiometric fluorescent probes, in which the built-in calibration of the two emission bands prevents interference from the biological environment, have been extensively employed to monitor the fluctuation of bioactive species. In this review, we will discuss small-molecule ratiometric fluorescent probes for ONOO− in live cells or in vivo, which involves chemical structures, response mechanisms, and biological applications. Moreover, the challenges and future prospects of ONOO−-responsive ratiometric fluorescent probe are also proposed. 相似文献
996.
Kai Liu Dr. Min Shuai Dr. Dong Chen Michael Tuchband Dr. Jennifer Y. Gerasimov Juanjuan Su Qing Liu Wojciech Zajaczkowski Dr. Wojciech Pisula Prof. Dr. Klaus Müllen Prof. Noel A. Clark Prof. Dr. Andreas Herrmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):4898-4903
As DNA exhibits persistent structures with dimensions that exceed the range of their intermolecular forces, solid‐state DNA undergoes thermal degradation at elevated temperatures. Therefore, the realization of solvent‐free DNA fluids, including liquid crystals and liquids, still remains a significant challenge. To address this intriguing issue, we demonstrate that combining DNA with suitable cationic surfactants, followed by dehydration, can be a simple generic scheme for producing these solvent‐free DNA fluid systems. In the anhydrous smectic liquid crystalline phase, DNA sublayers are intercalated between aliphatic hydrocarbon sublayers. The lengths of the DNA and surfactant are found to be extremely important in tuning the physical properties of the fluids. Stable liquid‐crystalline and liquid phases are obtained in the ?20 °C to 200 °C temperature range without thermal degradation of the DNA. Thus, a new type of DNA‐based soft biomaterial has been achieved, which will promote the study and application of DNA in a much broader context. 相似文献
997.
Yinlong Du Shuling Zhang Xu Jiang Kai Zhu Zhi Geng Yu Fang Pengfei Huo Chuan Liu Yinglin Song Guibin Wang 《Journal of polymer science. Part A, Polymer chemistry》2014,52(9):1282-1290
A series of novel soluble poly(aryl ether ketone)s (PAEKs) based on 5,10‐bis(4‐hydroxyphenyl)?15,20‐diphenylporphyrin (cis‐DHTPP), 4,4′‐(hexafluoroisopropylidene) diphenol (6FBPA) and 4,4′‐difluorobenzophenone (DFB) were synthesized and characterized by FT‐IR, 1H‐NMR, UV–vis and fluorescence spectroscopies. The intrinsic photophysical properties of porphyrins were preserved because of the absence of photoinduced electron transfer in the polymer chains. Investigation of the copolymers thermal properties indicated that these polymers had high glass transition temperatures and excellent thermal stabilities. The results of Z‐scan and optical limiting measurements manifested that incorporation of the porphyrin chromophore into the main chain engendered the novel PAEKs with superior nonlinear optical properties and optical limiting function, which could be effectively tuned by varying the molar ratio of porphyrin monomers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1282–1290 相似文献
998.
A nonanuclear Cu4^ⅡTi5^Ⅳheterometallic cluster,[Ti5 Cu4 O6(ba)(16)](1,Hba=benzoic acid)was synthesized in one-pot reaction under the solvothermal condition.The metallic skeleton 1 contains a Ti5 core constructed from two vertex-shared Ti3 triangles and four separated Cu atoms outside which are connected together byμ3-O^2- ions.Total 16 ba ligands adoptμ2-η^1:η^1 coordination mode to protect the overall hetero metallic co re.Due to the unique d-d transitions of Cu^Ⅱion,the reflectance spectrum of 1 displays broad and strong absorption towards visible light extending to the near-infrared region.Moreover,1 shows almost purely paramagnetic behavior with the presence of weak antiferromagnetic interactions at low temperatures. 相似文献
999.
Xu Ziyi Fu Taotao Zhu Chunying Jiang Shaokun Ma Youguang Wang Kai Luo Guangsheng 《Electrophoresis》2019,40(3):376-387
For revealing the dynamics of partially obstructed breakup of bubbles in microfluidic Y‐junctions, the combination of dimensionless power‐law and geometric model was applied to study the effects of capillary number, bubble length, and channel angle on the bubble rupture process. In the squeezing process, the gas‐liquid interface curve follows the parabolic model. For the evolution of the bubble neck during breakup, the increase of the bubble length, the channel angle, and the capillary number leads to the decrease of the focus distance α. The chord m increases with the increase of the capillary number and the decrease of the bubble length, and it would reach the maximum value when the channel angle is 90°. In the fast pinch‐off stage during bubble breakup, the bubble's neck curve no longer conforms to the parabolic model so the focus and chord no longer exist. For the evolution of the bubble head during breakup, the value of γ approaches 1 with the increase of the capillary number and the bubble length, and with the close of the channel angle to 90°. It is found that the quadrilateral model can be applied for the partially obstructed rupture of bubbles in the symmetrical microfluidic Y‐junction. 相似文献
1000.
Nonlinear Dynamics - The self-excitation of spring–mass system subjected to dry friction has been studied for decades because of its interesting and complex nonlinear dynamics behaviors. In... 相似文献