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41.
本文报道了Na_2O·Al_2O_3·B_2O_3·P_2O_5磷酸盐玻璃的制备。利用单晶X射线荧光光谱仪研究了它们的配位状态变化规律,确定了四、六配位的定量关系。 相似文献
42.
Yujia Zheng Qianqian Li Jing Wu Ziyi Luo Wenyi Zhou Anguo Li Yanling Chen Tuerxunayi Rouzi Tian Tian Hui Zhou Xiaodong Zeng Yang Li Xiaoding Cheng Yongchang Wei Zixin Deng Fuling Zhou Xuechuan Hong 《Chemical science》2021,12(5):1843
Small-molecule subcellular organelle-targeting theranostic probes are crucial for early disease diagnosis and treatment. The imaging window of these molecules is mainly focused on the visible and near-infrared region (below ∼900 nm) which limits the tissue penetration depth and therapeutic effects. Herein, a novel NIR-II small-molecule probe H4–PEG-Glu with a thiopyrylium cation was synthesized. H4–PEG-Glu not only can quickly and effectively image mitochondria in acute myeloid leukemia (AML) cells, and induce G0/G1 phase arrest by the intrinsic mitochondrial apoptosis pathway w/o irradiation, but also exhibit moderate cytotoxicity against AML cancer cells in a dose dependent-manner without laser irradiation. The THP-1 cells treated with H4–PEG-Glu upon NIR laser irradiation showed enhanced chemo- and photothermal therapy (CPTT) with 93.07% ± 6.43 apoptosis by Annexin V staining. Meanwhile, H4–PEG-Glu displayed high synergistic CPTT effects in vivo, as well as specific NIR-II tumor imaging in AML patient derived PDX mouse models for the first time. Our work lays down a solid foundation for designing small-molecule NIR-II mitochondria-selective theranostic probes.Small-molecule subcellular organelle-targeting theranostic probes are crucial for early disease diagnosis and treatment. 相似文献
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Cobalt particle size effects in the Fischer-Tropsch reaction studied with carbon nanofiber supported catalysts 总被引:1,自引:0,他引:1
Bezemer GL Bitter JH Kuipers HP Oosterbeek H Holewijn JE Xu X Kapteijn F van Dillen AJ de Jong KP 《Journal of the American Chemical Society》2006,128(12):3956-3964
The influence of cobalt particle size in the range of 2.6-27 nm on the performance in Fischer-Tropsch synthesis has been investigated for the first time using well-defined catalysts based on an inert carbon nanofibers support material. X-ray absorption spectroscopy revealed that cobalt was metallic, even for small particle sizes, after the in situ reduction treatment, which is a prerequisite for catalytic operation and is difficult to achieve using traditional oxidic supports. The turnover frequency (TOF) for CO hydrogenation was independent of cobalt particle size for catalysts with sizes larger than 6 nm (1 bar) or 8 nm (35 bar), while both the selectivity and the activity changed for catalysts with smaller particles. At 35 bar, the TOF decreased from 23 x 10(-3) to 1.4 x 10(-3) s(-1), while the C5+ selectivity decreased from 85 to 51 wt % when the cobalt particle size was reduced from 16 to 2.6 nm. This demonstrates that the minimal required cobalt particle size for Fischer-Tropsch catalysis is larger (6-8 nm) than can be explained by classical structure sensitivity. Other explanations raised in the literature, such as formation of CoO or Co carbide species on small particles during catalytic testing, were not substantiated by experimental evidence from X-ray absorption spectroscopy. Interestingly, we found with EXAFS a decrease of the cobalt coordination number under reaction conditions, which points to reconstruction of the cobalt particles. It is argued that the cobalt particle size effects can be attributed to nonclassical structure sensitivity in combination with CO-induced surface reconstruction. The profound influences of particle size may be important for the design of new Fischer-Tropsch catalysts. 相似文献
44.
An Intracellular H2O2‐Responsive AIEgen for the Peroxidase‐Mediated Selective Imaging and Inhibition of Inflammatory Cells 下载免费PDF全文
Dr. Yong Cheng Dr. Jun Dai Dr. Chunli Sun Dr. Rui Liu Prof. Tianyou Zhai Prof. Xiaoding Lou Prof. Fan Xia 《Angewandte Chemie (International ed. in English)》2018,57(12):3123-3127
Inflammatory cells have gained widespread attention because inflammatory diseases increase the risk for many types of cancer. Therefore, it is urgent and important to implement detection and treatment methods for inflammatory cells. Herein, we constructed a theranostic probe with aggregation‐induced emission (AIE) characteristics, in which tetraphenylethene (TPE) was modified with two tyrosine (Tyr) moieties. Owing to the H2O2‐dependent, enzyme‐catalyzed dityrosine formation, Tyr‐containing TPE ( TT ) molecules crosslink through dityrosine linkages to induce the formation of hydrophobic aggregates, activating the AIE process in inflammatory cells that contain H2O2 and overexpress myeloperoxidase. The emission turn‐on resulting from the crosslinking of TT molecules could be used to distinguish between inflammatory and normal cells. Moreover, the massive TT aggregates induced mitochondria damage and cell apoptosis. This study demonstrates that the H2O2‐responsive peroxidase‐activated AIEgen holds great promise for inflammatory‐cell selective imaging and inhibition. 相似文献
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Xiaoding Cheng Yunlong Zhu Chiyuan Wang Shuailong Li 《International Journal of Computational Fluid Dynamics》2017,31(10):450-462
Three-dimensional computations on the basis of the index-function lattice Boltzmann method are performed to simulate the process of multiple droplets impinging and coalescing into a line pattern on a solid substrate. The employed calculation model is validated by theoretical calculated values and experimental data from the literature. The influences of the equilibrium contact angle, droplet spacing and impinging velocity on the droplets impingement and coalescence behaviours are investigated. Numerical results demonstrate the width of the formed line depends significantly on the equilibrium contact angle and droplet spacing. The droplet spacing plays a significant role in controlling the coalescence moment of multiple droplets. The resolution of the printed pattern can be slightly increased with increase in impinging velocity. 相似文献
48.
强流电子束束参数瞬态测量系统在直线感应加速器的复杂电磁环境中会受到强电磁的干扰,主要包括:干扰特性、干扰机理、数学描述、抑制措施、防范措施等,这些干扰既针对电路又针对系统,从而对束参数瞬态测量系统测量的稳定性以及测量数据的有效性都有很大的影响。介绍时间分辨测量系统的原理,分析了瞬态脉冲干扰的成因和抑制方法,给出了束参数测量系统的实验布局和特点,进一步探讨电子器件电性能受瞬态脉冲干扰后的抑制措施,其目的是为了达到减少或消除干扰,破坏干扰信号的传输条件,从而提高整个系统的抗干扰能力及可靠性。通过采用光纤传输控制信号可以很好地传输窄脉冲,减少信号延时抖动,以达到高速信号的可靠稳定传输;利用紧凑嵌入式方法,提高了抗电磁干扰的能力,可以更好保护测量系统电子器件,提高整个系统的抗干扰能力。 相似文献
49.
Science China Chemistry - Precisely analyzing the target materials in living cells can reveal the essence and mystery of life at a deeper level, which will provide reliable theoretical basis for... 相似文献
50.
We report a simple fluorescence method for detection of cyanide sensitively and selectively based on the dissolution of polymer-coated gold nanoparticles by cyanide. The lowest concentration for quantification of cyanide ions was 3.0×10(-7) M, and other common anions nearly have no influence. Furthermore, several real water samples spiked with cyanide, including local groundwater, tap water, boiled water, and lake water, were analyzed, and the experimental results demonstrated that our sensing system worked well in the above water samples, with a good linear correlation. 相似文献