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21.
Conjugated polymer nanoparticles with aggregation induced emission characteristics for intracellular Fe3+ sensing
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Dongliang Yang Fei Li Zhimin Luo Biqing Bao Yanling Hu Lixing Weng Yixiang Cheng Lianhui Wang 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1686-1693
In this article, a novel zwitterionic conjugated polyelectrolyte containing tetraphenylethene unit was synthesized via Pd‐catalyzed Sonogashira reaction. The resulting polymer (P2), which exhibited typical aggregation‐induced emission (AIE) properties, was weakly fluorescent in dilute DMSO solution and showed bright fluorescence emissions when aggregated in DMSO/water mixtures or fabricated into conjugated polymer nanoparticles (CPNs). The nanoparticles from P2 could be prepared by reprecipitation method with an average diameter around 23 nm. Notably, the cell‐staining efficiencies of lipid‐P2 nanoparticles could be enhanced with lipid encapsulation and these nanoparticles were endocytosed via caveolae‐mediated and clathrin‐mediated endocytosis pathways. Furthermore, the lipid‐P2 nanoparticles with low cytotoxicity, high photostability and efficient cell staining ability could be employed for in vitro detection of Fe3+ ions in A549 cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1686–1693 相似文献
22.
The microwave plasma atomic spectrometry is an important branch of the plasma atomic spectrometry. Since the first use of microwave induced plasma(MIP) as an excitation source for spectral Chemical analysis by Broida and Chapmanin in 1958, especially the introduction of TM_(010) cavity by Beenakker in 1976 and of surfatron by Moisan in 1979 with which an atmospheric pressure helium MIP could be obtained, MIP has received considerable attention as a new excitation source for spectrometric analysis. However, since MIP suffers from the in ability to analyse the aqueous sam- 相似文献
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Since the most sensitive resonance lines of nonmetallic elements are situated in vacuum ultraviolet region (below 190 nm), they can not be directly determined with a common AAS instrument covering the spectral range from 190 to 700 nm. The molecular absorption spectrometry is often used for the determination of nonmetallic elements. Syty et al. used vapor molecular absorption spectrometry(VMAS) to determine the sulfur dioxide and sulfide, in which a hydrogen hollow cathode lamp was used as a continuum source to determine SO_2 at 210 nm and a deuterium arc 相似文献
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Based on D.P. Chen and Haus' theory, a theoretical method was presented to analyze dispersion characteristics of SH-type surface acoustic waves (SAWs) propagating on periodic metallic grating structures with a variational principle and coupling-of-modes equation. Without using complicated Green's function, the calculating results of the method agree well with those of Hashimoto's theory. On the other hand, Hashimoto's method is helpless for calculating the dispersion relation of short-circuited gratings on ST-90°X quartz etc. However, the method developed in this paper can successfully calculate it. 相似文献
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For segmentation method to be useful it must be fast, easy to use, and produce high quality segmentations, but few algorithms can offer this in various conditions and applications. In this paper, we propose a context dependent graph-based method for transition region extraction and thresholding. The graph-based approach is introduced into image thresholding, and context dependent graph is constructed from a given image, which can adaptively extract the pixel context and shape information because of the scalable neighborhood. Then an edge weight function is defined as the measure of possible transition pixels, and a robust fully automatic scheme for the optimal threshold is also presented. The proposed approach is validated both quantitatively and qualitatively. Compared with the traditional state-of-art algorithms on synthetic and real images, as well as laser cladding images, the experimental results suggest that the new proposal is efficient and effective. 相似文献
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A new ratiometric fluorescent chemosensor based on a polyimine macrocycle ligand 1 has been synthesized. The chemosensor can exhibit a pronounced fluorescence response and high selectivity to Zn2+ ion over other 15 metal ions, including Cd2+. Sensor 1 appears an emission peak at 370 nm. Upon the addition of Zn2+ ion, the typical emission peak for 1 at 370 nm is obviously quenched, but a new emission peak at around 470 nm appears and shows a large enhancement due to the formation of a 1:1 Zn2+-1 complex. In addition, there is a good linear relationship between the fluorescence ratio I470nm/I370nm and the concentration of Zn2+, which makes a ratiometric assay of Zn2+ ion possible. 相似文献
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Junfeng Li Fengyan Song Lu Wang Jieming Jiao Yixiang Cheng Chengjian Zhu 《Macromolecular rapid communications》2012,33(15):1268-1272
A novel polymer P‐1 is prepared by the reaction of the monomer 5,5′‐divinyl‐2,2′‐bipyridine and Salen‐Zn(II) via Heck cross coupling. Interestingly, P‐1 can further incorporate with Eu(TTA)3·2H2O to generate copolymer P‐2 with two different metal centers. P‐2 exhibits exceptional dual emissive properties which can be tuned by excitation wavelength. For example, an orange fluorescence can be obtained when P‐2 is excited at 430 nm, whereas a red emission with a huge Stoke shift of 57 nm is observed when it is excited at 345 nm. The high wavelength emission can be attributed to Eu(III) (5D0→7F2), which is lit by an effective photoinduced energy transfer process between P‐1 and the Eu(TTA)3 complex. The properties of P‐2 have led to a better understanding of the energy transfer process between P‐1 and Eu(TTA)3 moieties. 相似文献