| 1. |
- Zhang, Xin, et al.
(author)
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Light-Up Lipid Droplets Dynamic Behaviors Using a Red-Emitting Fluorogenic Probe
- 2020
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In: Analytical Chemistry. - : AMER CHEMICAL SOC. - 0003-2700 .- 1520-6882. ; 92:5, s. 3613-3619
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Journal article (peer-reviewed)abstract
- Intracellular lipid metabolism occurs in lipid droplets (LDs), which is critical to the survival of cells. Imaging LDs is an intuitive way to understand their physiology in live cells. However, this is limited by the availability of specific probes that can properly visualize LDs in vivo. Here, an LDs-specific red-emitting probe is proposed to address this need, which is not merely with an ultrahigh signal-to-noise (S/N) ratio and a large Stokes shift (up to 214 nm) but also with superior resistance to photobleaching. The probe has been successfully applied to real-time tracking of intracellular LDs behaviors, including fusion, migration, and lipophagy processes. We deem that the proposed probe here offers a new possibility for deeper understanding of LDs-associated behaviors, elucidation of their roles and mechanisms in cellular metabolism, and determination of the transition between adaptive lipid storage and lipotoxicity as well.
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| 2. |
- Wang, Hong, et al.
(author)
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Real-time tracking of mitochondrial dynamics by a dual-sensitive probe
- 2020
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In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 320
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Journal article (peer-reviewed)abstract
- Tracking of mitochondrial dynamic processes including their morphology, biogenesis and elimination is of significance to deeply understand mitochondrial physiology and related diseases, which requires simultaneous and discriminative labeling of both mitochondria themselves and correlated downstream organelles. However, the combination of multiple fluorescent probes will bring the large invasive effect that seriously impacts the normal physiological processes of mitochondria within live cells. To address this issue, we herein construct a single molecular probe through the combination of two pH-sensitive fluorogens, hydroxyl-coumarin and rhodamine B, enabling the detection of intracellular microenvironmental pH variations. Importantly, the as-synthesized probe not only accumulates into mitochondria, indicated by cyan emission from hydroxyl-coumarin but also can be delivered to the downstream acidic autolysosomes upon the occurrence of mitophagy, indicated by red emission from rhodamine B. Taking advantage of a two-channel confocal microscopy strategy, we have achieved to real-time track the processes of mitochondrial replication, merge and autophagy.
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| 3. |
- zhang, xin, 1990-, et al.
(author)
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Single-wavelength-excited fluorogenic nanoprobe for accurate real-time ratiometric analysis of broad pH fluctuations in mitophagy
- 2022
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In: Nano Reseach. - : Tsinghua University Press. - 1998-0124 .- 1998-0000. ; 15, s. 6515-6521
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Journal article (peer-reviewed)abstract
- Mitophagy has a critical role in maintaining cellular homeostasis through acidic lysosomes engulfing excess or impaired mitochondria, thereby pH fluctuation is one of the most significant indicators for tracking mitophagy. Then such precise pH tracking demands the fluorogenic probe that has tailored contemporaneous features, including mitochondrial-specificity, excellent biocompatibility, wide pH-sensitive range of 8.0-4.0, and especially quantitative ability. However, available molecular probes cannot simultaneously meet all the requirements since it is extremely difficult to integrate multiple functionalities into a single molecule. To fully address this issue, we herein integrate two fluorogenic pH sensitive units, a mitochondria-specific block, cell-penetrating facilitator, and biocompatible segments into an elegant silica nano scaffold, which greatly ensures the applicability for real-time tracking of pH fluctuations in mitophagy. Most significantly, at a single wavelength excitation, the integrated pH-sensitive units have spectra-distinguishable fluorescence towards alkaline and acidic pH in a broad range that covers mitochondrial and lysosomal pH, thus enabling a ratiometric analysis of pH variations during the whole mitophagy. This work also provides constructive insights into the fabrication of advanced fluorescent nanoprobes for diverse biomedical applications.
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| 4. |
- Hu, Zhang-Jun, et al.
(author)
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Real-time visualizing the regulation of reactive oxygen species on Zn2+ release in cellular lysosome by a specific fluorescent probe
- 2018
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In: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 264, s. 419-425
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Journal article (peer-reviewed)abstract
- Reactive oxygen species (ROS) regulating the release of free zinc ions (Zn2+) in cellular lysosome is closely related to various pathways of cellular signal transduction, such as inflammation and oxidative stress. Directly visualizing Zn2+ release in lysosome is essential for in-depth understanding these physiological processes, and is still an atelic challenge. In this work, we successfully fabricate a lysosome-specific Zn2+ fluorescent probe and achieve the visualization of ROS-induced Zn2+ release in lysosome of inflammatory cells. The as-prepared probe combines a green fluorophore, an ionophore with five-dentate sites, and a morpholine as the lysosome-specific localization moiety. The fluorescence of the fluorophore in the free probe is suppressed by a photoinduced electron transfer (PET) process from nitrogen atoms in the ionophore. Upon the addition of Zn2+, the fluorescence can be promoted immediately, achieving the real-time detection. Meanwhile, the probe is sensitive and selective to Zn2+, which provides the capability to detect low-concentration of free Zn2+ in lysosomes. Accordingly, the Zn2+ release was clearly observed in lysosome with the increase of ROS levels when the inflammation occurred in living cells. (c) 2018 Published by Elsevier B.V.
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| 5. |
- Ou, Pan, et al.
(author)
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Gasotransmitter Regulation of Phosphatase Activity in Live Cells Studied by Three-Channel Imaging Correlation
- 2019
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In: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:8, s. 2261-2265
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Journal article (peer-reviewed)abstract
- Enzyme activity in live cells is dynamically regulated by small-molecule transmitters for maintaining normal physiological functions. A few probes have been devised to measure intracellular enzyme activities by fluorescent imaging, but the study of the regulation of enzyme activity via gasotransmitters in situ remains a long-standing challenge. Herein, we report a three-channel imaging correlation by a single dual-reactive fluorescent probe to measure the dependence of phosphatase activity on the H2S level in cells. The two sites of the probe reactive to H2S and phosphatase individually produce blue and green fluorescent responses, respectively, and resonance energy transfer can be triggered by their coexistence. Fluorescent analysis based on the three-channel imaging correlation shows that cells have an ideal level of H2S to promote phosphatase activity up to its maximum. Significantly, a slight deviation from this H2S level leads to a sharp decrease of phosphatase activity. The discovery further strengthens our understanding of the importance of H2S in cellular signaling and in various human diseases.
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| 6. |
- Shen, Jie, et al.
(author)
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Real-time monitoring of lipid droplets growth via the fusion with fluorescent dye-labeled adiposomes
- 2020
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In: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 182
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Journal article (peer-reviewed)abstract
- Investigating lipid droplets (LDs) behaviours is essential to deeply understand the physiology of LDs, such as their growths, movements, fusion/division, and autophagy. Among these behaviours, the growth of LDs is one of the most difficult to track due to the very subtle morphology evolution in a short time window. The major obstacle is that conventional LDs-specific dyes with low photostability cannot indicate the LDs size change. To address this issue, we synthesize a hydrophobic and photostable fluorescent dye (TPA-AD) and load it into the neutral lipid micelles (as artificial adiposomes). The highly hydrophobic TPA-AD enables the specific accumulation into intracellular LDs and the ready loading artificial adiposomes. When the intracellular LDs take TPA-AD-labeled adiposomes, by fusion, the sizes of LDs gradually grow, and LDs are simultaneously lighted up by the fluorescence of TPA-AD. Importantly, the high photostability of TPA-AD ensures the enhanced fluorescence signals. The finding here will further strengthen the understanding of LDs dynamics and fat metabolism.
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| 7. |
- Yang, Guanqing, et al.
(author)
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A Multi-responsive Fluorescent Probe Reveals Mitochondrial Nucleoprotein Dynamics with Reactive Oxygen Species Regulation through Super-resolution Imaging
- 2020
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In: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 59:37, s. 16154-16160
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Journal article (peer-reviewed)abstract
- Understanding the biomolecular interactions in a specific organelle has been a long-standing challenge because it requires super-resolution imaging to resolve the spatial locations and dynamic interactions of multiple biomacromolecules. Two key difficulties are the scarcity of suitable probes for super-resolution nanoscopy and the complications that arise from the use of multiple probes. Herein, we report a quinolinium derivative probe that is selectively enriched in mitochondria and switches on in three different fluorescence modes in response to hydrogen peroxide (H2O2), proteins, and nucleic acids, enabling the visualization of mitochondrial nucleoprotein dynamics. STED nanoscopy reveals that the proteins localize at mitochondrial cristae and largely fuse with nucleic acids to form nucleoproteins, whereas increasing H(2)O(2)level leads to disassociation of nucleic acid-protein complexes.
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| 8. |
- Wang, Mengmeng, et al.
(author)
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Statistical analysis of whistler precursors upstream of foreshock transient shocks : MMS observations
- 2024
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In: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 51:8
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Journal article (peer-reviewed)abstract
- Using the high-time-resolution data from the Magnetospheric Multiscale mission, precursor waves upstream of foreshock transient (FT) shocks are statistically investigated using the four-spacecraft timing method. The wave frequencies and wave vectors determined in the plasma rest frame (PRF) are shown to follow the cold plasma dispersion relation for whistler waves. Combining with the feature of the right-hand polarization in the PRF, the precursors are identified as whistler-mode waves around the lower hybrid frequency. The occurrence of whistler precursors is independent of the Alfvén Mach number and the FT shock normal angle. More importantly, all the whistler precursors have group velocities pointing upstream in the shock frame, suggesting the dispersive radiation to be a possible generation mechanism. The study improves the understanding of not only the whistler precursors but also the overall FT shock dynamics.
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| 9. |
- Ren, Shan, et al.
(author)
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An Advanced Operation Mode with Product-Service System Using Lifecycle Big Data and Deep Learning
- 2022
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In: International Journal of Precision Engineering and Manufacturing-Green Technology. - : Springer Science and Business Media LLC. - 2288-6206 .- 2198-0810. ; 9:1, s. 287-303
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Journal article (peer-reviewed)abstract
- As a successful business strategy for enhancing environmental sustainability and decreasing the natural resource consumption of societies, the product-service system (PSS) has raised significant interests in the academic and industrial community. However, with the digitisation of the industry and the advancement of multisensory technologies, the PSS providers face many challenges. One major challenge is how the PSS providers can fully capture and efficiently analyse the operation and maintenance big data of different products and different customers in different conditions to obtain insights to improve their production processes, products and services. To address this challenge, a new operation mode and procedural approach are proposed for operation and maintenance of bigger cluster products, when these products are provided as a part of PSS and under exclusive control by the providers. The proposed mode and approach are driven by lifecycle big data of large cluster products and employs deep learning to train the neural networks to identify the fault features, thereby monitoring the products health status. This new mode is applied to a real case of a leading CNC machine provider to illustrate its feasibility. Higher accuracy and shortened time for fault prediction are realised, resulting in the providers saving of the maintenance and operation cost.
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