- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Chromophore Arrays Constructed in the Major Groove of DNA Duplexes Using a Post-Synthetic Strategy
摘要： The construction of zipper-like chromophore-arrays in the major groove of duplex DNA remains a challenge because only a few chromophores for this application have been discovered. To address the challenge, dual-chromophore labeled DNAs having a self-complementary sequence were prepared using a solid-phase, post-synthetic, copper-catalyzed, alkyne-azide cycloaddition. The resulting chromophore-arrays on the labeled DNA duplexes were characterized. The dual-tetraphenylethene (TPE) or dual-pyrene (Py) labeled DNA formed self-complementary B-form duplexes and resulted in the construction of chromophore-arrays in the major groove. The TPE-arrays, in which TPEs were arranged in a zipper-like fashion, slightly destabilized the duplex because of their bulkiness and exhibited aggregation-induced-emission. The Py-arrays, in which Pys were not arranged in a zipper-like fashion, had no effect on duplex stability and exhibited weak excimer emission because Py was sufficiently small for free rotation in the major groove.
关键词： Click chemistry,Aggregation,Tetraphenylethene,Pyrene,Oligonucleotides
更新于2025-09-19 17:15:36
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[IEEE 2018 Digital Image Computing: Techniques and Applications (DICTA) - Canberra, Australia (2018.12.10-2018.12.13)] 2018 Digital Image Computing: Techniques and Applications (DICTA) - Adversarial Context Aggregation Network for Low-Light Image Enhancement
摘要： Image captured in the low-light environments usually suffers from the low dynamic ranges and noise which degrade the quality of the image. Recently, convolutional neural network (CNN) has been employed for low-light image enhancement to simultaneously perform the brightness enhancement and noise removal. Although conventional CNN based techniques exhibit superior performance compared to traditional non-CNN based methods, they often produce the image with visual artifacts due to the small receptive field in their network. In order to cope with this problem, we propose an adversarial context aggregation network (ACA-net) for low-light image enhancement, which effectively aggregates the global context via full-resolution intermediate layers. In the proposed method, we first increase the brightness of a low-light image using the two different gamma correction functions and then feed the brightened images to CNN to obtain the enhanced image. To this end, we train ACA network using L1 pixel-wise reconstruction loss and adversarial loss which encourages the network to generate a natural image. Experimental results show that the proposed method achieves state-of-the-art results in terms of peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM).
关键词： context aggregation,Low-light image enhancement,Convolutional neural network,generative adversarial network
更新于2025-09-19 17:15:36
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Aggregation-induced emission (AIE)-active molecules bearing singlet oxygen generation activities: the tunable singlet–triplet energy gap matters
摘要： Herein, a series of photosensitizers were constructed of a, b and c-isomers of terpyridine and the corresponding N-methylation derivatives. Benefiting from the tunable singlet–triplet energy gap and aggregation-induced emission characteristics, two-photon active photosensitizers L2b and L2c showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation.
关键词： Aggregation-induced emission,singlet oxygen generation,photodynamic therapy,photosensitizers,two-photon excitation
更新于2025-09-19 17:15:36
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Ultrafast fabrication of fluorescent organic nanoparticles with aggregation-induced emission feature through the microwave-assisted Biginelli reaction
摘要： Because of its unique optical properties, the aggregation-induced emission (AIE) dye has attracted extensive attention for various applications. Especially, the utilization of AIE-active dyes for fabrication of fluorescent organic nanoparticles (FONs) has attracted the most research interest for biomedical applications. Therefore, the development of novel and effective strategies to design and prepare AIE-active FONs should be of great importance for the biomedical applications of AIE-active FONs. In this report, we reported an ultrafast strategy that based on the one-pot microwave-assisted Biginelli reaction for fabrication of AIE-active poly(AA-AEMA-TPE) copolymers, which use the 2-(methacryloyoxy) ethylacet, acrylic acid (AA) and 4',4'''-(1,2-diphenylethene-1,2-diyl) bis([1,1'-biphenyl]-4-carbaldehyde) (TPE-CHO) as the substrates. The microwave-assisted Biginelli reaction is simple, efficient and atom-economical and can be accomplished within 3 min. Owing to their amphiphilicity, poly(AA-AEMA-TPE) copolymers will self-assemble into FONs with small size and high water dispersibility. The proton nuclear magnetic resonance (1H NMR) spectroscopy, UV-Vis spectrum and fluorescence spectrometer were used to characterize the resultant copolymers. We demonstrated that poly(AA-AEMA-TPE) FONs possess many excellent properties, such as high water dispersibility, intense fluorescence, obvious AIE feature and favorable biocompatibility. The above results suggest that poly(AA-AEMA-TPE) FONs are of great potential for fluorescent imaging. Moreover, the microwave-assisted Biginelli reaction can occur under a rather benign environment with high efficiency and good substrate adaptability. Therefore, we believe that the method developed in this work could greatly advance the applications of AIE-active functional materials.
关键词： microwave-assisted Biginelli reaction,biological imaging,fluorescent polymer nanoparticles,Aggregation-induced emission,living controlled polymerization
更新于2025-09-19 17:15:36
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Luminescent Cyclic Trinuclear Coinage Metal Complexes with Aggregation-Induced Emission (AIE) Performance
摘要： A series of AIE active cyclic trinuclear complexes (Au3, Ag3, and Cu3) have been successfully prepared and elucidated by X-ray crystallography. These complexes showed excellent AIE properties and their quantum yields (QYs) were significantly increased compared to that of the free ligands. The remarkable solution induced AIE activity in atom-precise coinage metal complexes is still scarce, and this work opens a promising avenue for the development of easily prepared metal-based AIE luminogens with high emission efficiency.
关键词： Aggregation-Induced Emission,X-ray Crystallography,Quantum Yields,Coinage Metal Complexes,Luminescence
更新于2025-09-19 17:15:36
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Natural organic matter inhibits aggregation of few-layered black phosphorus in mono- and divalent electrolyte solutions
摘要： Extensive synthesis and applications of few-layered black phosphorus (BPs) are accompanied by increasing concern over its stability and potential risk. However, the colloidal stability of BPs under environmentally relevant conditions remains unclear. Hence, we investigated the influences of two representative electrolytes (i.e., NaCl and CaCl2) and natural organic matter (NOM) on the aggregation behavior of BPs. Ca2+ ions exhibited a stronger destabilization effect on BPs than Na+ due to their stronger surface charge screening as well as intersheet bridging by the complexes of Ca2+ ions and oxidized phosphorus (POx) species on the BPs surface. Apart from the Ca2+-induced enhanced aggregation in the presence of high concentration of Ca2+, the aggregation behavior of BPs in the two electrolytes at different concentrations and their ratios of critical coagulation concentrations (CCCs) generally followed classical colloidal theory such as the Schulze–Hardy rule. Moreover, in the presence of 10 mg C/L NOM the CCC values of BPs in NaCl and CaCl2 solutions were both three times higher than that obtained without NOM, and the aggregation kinetics of BPs in these electrolytes containing NOM were qualitatively consistent with extended DLVO theory. Specifically, NOM significantly improved the stabilization of BPs in CaCl2 solutions via steric repulsion and isolation of Ca2+ ions from interaction with POx species on the surface of BPs. This stabilization mechanism derived from “NOM corona” structures was elucidated by a wide spectrum of characterization and quantification techniques. These findings provide new insights into evaluating the stability and fate of this nanomaterial in natural aquatic environments.
关键词： few-layered black phosphorus,colloidal stability,NOM corona,aggregation,electrolytes,natural organic matter
更新于2025-09-19 17:15:36
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Imidazole-containing cyanostilbene-based molecules with aggregation-induced emission characteristics: photophysical and electroluminescent properties
摘要： Organic luminogens with aggregation-induced emission (AIE) characteristics have recently attracted great research interest due to their excellent luminescence behavior in the aggregate state. Cyanostilbene is a well-known AIE-active moiety due to its unique luminescence mechanism and widespread use in the design of optical materials. In this work, we report two symmetrical imidazole-containing cyanostilbene derivatives with AIE activity, abbreviated as TPIA and PPIA, whose chemical structures only differ by a C–C bond. Both molecules are thermally stable and fabricated as electroluminescent (EL) devices. On one hand, the study of their photophysical properties confirms that the restricted intramolecular rotation (RIR) effect is still the dominant factor for the AIE effect in these two cyanostilbene-based molecules. On the other hand, the EL results reveal that a more conjugated molecular structure is beneficial for the EL properties. Moreover, the optimization of the device configuration with an electron-blocking layer significantly improves the EL performance. The orange-emissive PPIA-based device shows a high external quantum efficiency of 1.02% with a small efficiency roll-off.
关键词： Imidazole,Aggregation-induced emission,Cyanostilbene,OLEDs,Electroluminescence
更新于2025-09-19 17:15:36
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Aggregation-induced chiroptical generation and photoinduced switching of achiral azobenzene- <i>alt</i> -fluorene copolymer endowed with left- and right-handed helical polysilanes
摘要： The left and right helicities of azobenzene (Azo)-containing main-chain polymer (PF8Azo) were successfully controlled with an enantiomeric pair of rigid rod-like helical polysilanes carrying (S)- and (R)-2-methylbutyl groups (PSi-S and PSi-R, respectively) as their hetero-aggregates in a mixture of chloroform and methanol solvents and in the solid state. Optimizing the good and poor cosolvents and their volume fractions showed that the molar ratio of PF8Azo to PSi-S/-R and the molecular weight of PF8Azo were crucial to boost the CD amplitudes of PF8Azo/PSi-S and PF8Azo/PSi-R hetero-aggregates. The photoresponsive trans–cis transformation caused noticeable changes in the sign and magnitude of the chiroptical behavior due to the hetero-aggregates. Moreover, the optically active PF8Azo homo-aggregates were produced by complete photoscissoring reactions at 313 nm, which could be assigned to the Sis–Sis* transitions of PSi-S and PSi-R.
关键词： achiral azobenzene-alt-fluorene copolymer,helical polysilanes,photoinduced switching,Aggregation-induced chiroptical generation
更新于2025-09-19 17:15:36
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Rhodamine-naphthalimide demonstrated a distinct aggregation-induced emission mechanism: elimination of dark-states <i>via</i> dimer interactions (EDDI)
摘要： Rhodamine B-naphthalimide (RhB-Naph) demonstrated a distinct aggregation-induced emission (AIE) mechanism, different from the restriction of intramolecular rotations or vibrations as in traditional AIE molecules. The monomers of RhB-Naph were non-emissive, due to the presence of a dark S1 state. Upon molecular aggregation, intermolecular interactions significantly altered the electronic properties of RhB-Naph, leading to the formation of a bright S1 state and endowing RhB-Naph with notable AIE properties. Besides, we demonstrated that RhB-Naph enabled the development of a solid-state three-color fluorescent switch upon multi-external stimuli.
关键词： fluorescent switch,dark state,dimer interactions,rhodamine-naphthalimide,aggregation-induced emission
更新于2025-09-19 17:15:36
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[IEEE 2018 International Conference on Applied Electromagnetics, Signal Processing and Communication (AESPC) - Bhubaneswar, India (2018.10.22-2018.10.24)] 2018 International Conference on Applied Electromagnetics, Signal Processing and Communication (AESPC) - Temperature effect on a-SiCN:H waveguide for application of sensing
摘要： Long term evolution-wireless local area network (LTE-WLAN) aggregation (LWA) has recently emerged as a promising third generation partnership project (3GPP) Release 13 technology to efficiently aggregate LTE and WLAN at the packet data convergence protocol layer, allowing uplink traffic to be carried on LTE and downlink on both LTE and WLAN. This removes all the contention asymmetry problems of WLAN and allows an optimum usage of both licensed and unlicensed band for downlink. In this paper, we present a new feature of LWA, its flow control scheme, which controls how to aggregate downlink traffic in licensed and unlicensed bands. This aggregation technique exploits user equipment-based flow control feedback in the form of LWA status reports, and can be expanded to work with any number of frequency bands and radio technologies. The same concepts apply to 5G networks, although the performance evaluation provided here is in the context of LTE-Advanced Pro. Simulation results in a typical enterprise scenario show that LWA can enhance user performance up to 8 times over LTE-only, and 3.7 times over WLAN only networks, respectively. The impact of the file size and LWA status report frequency on network performance is also investigated.
关键词： wireless local area network (WLAN),aggregation,LTE WLAN aggregation (LWA),flow control,long term evolution (LTE),Cellular networks
更新于2025-09-19 17:13:59