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Encapsulation of zinc phthalocyanine into bovine serum albumin aggregates
摘要： Artificial hybridization of molecules with proteins is beneficial for biomedical applications. Herein, we describe a novel method for encapsulation of zinc phthalocyanine (ZnPc) aggregates into bovine serum albumin (BSA) aggregates, but not monomeric BSA. This property is potentially useful for not only photodynamic or photothermal therapy but also development of a novel delivery system for hydrophobic drug molecules.
关键词： Gel-filtration chromatography,Photosensitizer,Aggregation,Bovine serum albumin,Phthalocyanine,Photodynamic therapy
更新于2025-09-23 15:22:29
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‘Planetary’ silver nanoparticles originating from a magnetron sputter plasma
摘要： In a gas aggregation cluster source, nanoparticles are formed by aggregation of single atoms to particles as well as by agglomeration of smaller particles to form larger particles. Because the small particles are often electrically charged, it is possible that particles are mutually attracted or repelled by electric forces. In this work we report the observation of bound multi-nanoparticle systems which are the result of the electrical and centrifugal forces acting on nanoparticles in a magnetron sputtering cluster source. Transmission electron microscopy analysis of the deposited ‘planetary’ nanoparticle systems exhibits characteristic inter-particle distances and sizes, consistent with different charge states of the particles. Simulations confirm the presence of metastable bound nanoparticle systems up to at least 7/8 satellites. The discovery of such ‘planetary’ nanoparticle systems inside a cluster source opens up possibilities for more research into their properties and how they can be further controlled and explored.
关键词： planetary,silver nanoparticles,particle orbits,satellites,gas aggregation cluster source,magnetron sputtering
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Road Segmentation of UAV RS Image Using Adversarial Network with Multi-Scale Context Aggregation
摘要： Semantic segmentation using adversarial networks has been approved to produce the better artificial results in image processing fields. Focused on current Deep Convolutional Neural Networks (DCNNs), since the convolutional kernel size has been fixed in every convolutional operation, the small objects would be ignored with large convolutional kernel size, and the segmentation result of large objects is not continuous with small convolutional kernel size. The paper developed a semantic segmentation model that combined the adversarial networks with multi-scale context aggregation. Further, the model was applied to road segmentation of UAV RS images. The experimental results of this semantic segmentation model with multi-scale context aggregation has a better performance for road segmentation and fit well with the reference standard results. It can improve the road segmentation accuracy obviously in the situation where there are other small regions whose shape or color is similar to road regions in UAV RS images.
关键词： Road Segmentation,Adversarial Network,UAV image,Image processing,multi-scale context aggregation
更新于2025-09-23 15:22:29
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Enhanced Raman Scattering by Molecular Nanoaggregates
摘要： The formation of a molecular aggregate in a confined, nanodimensioned region of space leads to what might be termed a 'molecular nanoaggregate'. The present review deals with a theoretical formulation termed 'aggregation-enhanced Raman scattering' (AERS), and its use in discussion of relative Raman band intensities and selection rules for nanoaggregates. AERS represents a concept for discussion of nanoaggregates that is different from those provided by resonance Raman scattering, surface-enhanced Raman scattering and Mie scattering, all of which ignore the impact of aggregation of molecules on Raman scattering. Beyond the theoretical formulation behind the AERS phenomenon, also outlined in this review are representative samples of publications of other authors and researchers using AERS to provide explanations for experimental findings. In addition to clarifying issues regarding the use of nanocomposites involving aggregated molecules, it is found that increasing use of AERS concepts is being made to rationalize Raman spectral observations in a range of other disciplines that fall in both the physical sciences and the medical fields.
关键词： Aggregation,Porphyrins,Nano,Cyanines,Raman
更新于2025-09-23 15:22:29
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Aggregation-Induced Absorption Enhancement for Deep Near-Infrared II Photoacoustic Imaging of Brain Gliomas In Vivo
摘要： The delineation of brain gliomas margins still poses challenges to precise imaging and targeted therapy, mainly due to strong light attenuation of the skull and high background interference. With deep penetration and high sensitivity, photoacoustic (PA) imaging (PAI) in the second near-infrared (NIR II) window holds great potential for brain gliomas imaging. Herein, mesoionic dye A1094 encapsulated in Arg-Gly-Asp-modified hepatitis B virus core protein (RGD-HBc) is designed and synthesized for effective NIR II PAI of brain gliomas. An aggregation-induced absorption enhancement mechanism is discovered in vitro and in vivo. It is also demonstrated that A1094@RGD-HBc, with an enhanced absorption in the NIR II window, displays ninefold PA signal amplification in vivo, allowing for precise PAI of the brain gliomas at a depth up to 5.9 mm. In addition, with the application of abovementioned agent, high-resolution PAI and ultrasensitive single photon emission computed tomography images of brain gliomas are acquired with accurate co-localization. Collectively, the results suggest great promise of A1094@RGD-HBc for diagnostic imaging and precise delineation of brain gliomas in clinical applications.
关键词： mesoionic dyes,brain gliomas,aggregation-induced absorption enhancement,second near-infrared window,deep photoacoustic imaging
更新于2025-09-23 15:22:29
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Phase transformations of bovine serum albumin: Evidences from Rayleigh-Brillouin light scattering
摘要： Rayleigh‐Brillouin light‐scattering studies of a high‐concentration solution of bovine serum albumin (BSA, pH = 7.45, C = 100 mg/ml) in a sodium phosphate buffer in the temperature range 300–370 K are presented. It is shown that the temperature dependences of relative changes in the Brillouin shift and half width at half maximum and intensity of the Brillouin doublet and intensity of Rayleigh components exhibit anomalies in the vicinity of 335, 345, and 363 K. Analysis of the literature data allowed us to construct a phase diagram showing a sequence of BSA phase transformations in the temperature range from 300 to 375 K and to correlate the anomalies in the scattering spectra to the regions of phase transformations. The anomalies in the behavior of the light‐scattering spectra in the vicinity of Tm = 335 K are attributable to the melting temperature and the formation of BSA self‐assembled aggregates. The formation of a phase with oriented β‐sheet rich mature fibrils at Tm < T < 347 K is confirmed by elastic light scattering experiments. This phase passes into a gel‐like phase in which the aggregates are rearranged and a polymer network, which is finally converted to a gel in the vicinity of 363 K is formed. Thus, the Rayleigh‐Brillouin scattering experiments demonstrated the evolution of the structure, which manifested itself in the anomalous temperature behavior of the intensities of the Rayleigh and Brillouin components in the light‐scattering spectra. The anomalous low‐frequency dynamics of the BSA solution at denaturing and transition into a gel phase was clearly observed in the anomalous Brillouin shift behavior in the vicinity of 335 and 363 К. The sequence of phase transformations in BSA at heating from 300 to 375 K in the phase diagram correlates well with the anomalies observed in the evolution of Rayleigh‐Brillouin light scattering.
关键词： transformation,proteins,aggregation,phase,Brillouin spectroscopy,gelation
更新于2025-09-23 15:22:29
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AIE-active Metal-organic Coordination Complexes Based on Tetraphenylethylene Unit and Their Applications
摘要： Tetraphenylethylene (TPE) and its derivatives, as the widely used aggregation-induced emission (AIE) fluorophores, have attracted rapidly growing interest in the fields of material science and biological technology due to their unique light-emitting mechanism—they are nearly non-emissive in dilute solution but emit brilliant fluorescence in the aggregate state because of the restriction of intramolecular motion. Coordination-driven self-assembly, which provides a highly effective method to put the individual chromophores together, is consistent with the AIE mechanism of TPE. During the past few years, some AIE-active metal-organic coordination complexes have been successfully constructed via coordination-driven self-assembly, and their AIE properties and applications have been investigated. In this review, we survey the recent progress on TPE-based metal-organic coordination complexes and their applications in fluorescence sensors, cell imaging, and light-emitting materials. We will introduce them from three different types of structures: metallacycles, metallacages, and metal-organic frameworks (MOFs).
关键词： Tetraphenylethylene,Self-assembly,Aggregation-induced emission,Sensor,Metal-organic coordination complexes
更新于2025-09-23 15:22:29
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Physiologically Stable Hydrophilic C60 Nanoparticles for Photodynamic Therapy
摘要： Hydrophilic C60 nanoparticles that are highly stable in living systems were prepared with sugammadex, an anionic γ-cyclodextrin derivative, via a simple procedure for use in biological applications. The prepared C60/sugammadex nanoparticles showed outstanding stability under physiological conditions and even in much harsher conditions. The sugammadex interacted with C60 nanoparticles through strong host-guest interactions on the particle surface, producing a negatively charged layer on the surface of nanoparticles, which contributed to the high stability of the nanoparticles. In addition, the nanoparticles were highly stable in the presence of singly charged cations which are present in abundance in living systems. The stable C60/sugammadex nanoparticles showed a significantly different biological behavior compared to less stable C60 nanoparticles after intravenous administration. Most of the C60 particles accumulated and remained in organs of the reticuloendothelial system (RES) after administration, which are susceptible to forming aggregates in physiological conditions. On the other hand, the C60/sugammadex nanoparticles showed a completely different biological behavior, i.e. longer blood circulation, low RES uptake and elimination with time from organs. The photodynamic activity of C60/sugammadex nanoparticles was evaluated both in vitro and in vivo, and an outstanding antitumor effect was achieved based on the generation of reactive oxygen species under light irradiation. We envision that such stable C60 nanoparticles would be a desirable approach for extending the biological applications of these materials and the precise evaluation of C60 activity in living systems.
关键词： nanoparticle,biodistribution,in vivo aggregation,photodynamic therapy,fullerene
更新于2025-09-23 15:22:29
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Aggregation-amplified circularly polarized luminescence from axial chiral boron difluoride complexes
摘要： The development of small organic molecules with intense and switchable circularly polarized luminescence (CPL) is currently attracting great interest due to their promising applications in chiroptical devices and sensors. In this paper, CPL-active BF2-bridged azaanthracene dimers (BA1 and BA2) were facilely synthesized by incorporating boron difluoride unit to the bi-naphthalene. BA1 and BA2 show moderate CPL in diluted solutions, however, BA2 exhibited aggregation-amplified red CPL with large dissymmetry factor up to 1.6×10?2. Moreover, acid-/base-triggered CPL switch off/on were also realized via disaggregation/aggregation of BA2 in tetrahydrofuran (THF)/water binary solvents.
关键词： aggregation-induced emission,bodipy,circularly polarized luminescence,switch,dyes and pigments
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Main Aortic Segmentation from CTA with Deep Feature Aggregation Network
摘要： In this study, we propose a Deep Feature Aggregation network (DFA-Net) for main aortic segmentation from CTA(Computed Tomography Angiography) by aggregating features from forwarding layers to leverage more visual information. To practically verify the effectiveness of our method, we collect 90 CTA volumes from Beijing AnZhen Hospital up to over 60 thousands 2-D slices. First, we use a level-set based algorithm to efficiently generate the dataset for training and validating the deep model. Then the dataset is divided into three parts, 70 instances are used for training and 5 instances are used for validating the best parameters, and the rest 15 instances are used for testing the generalization of the model. Finally, the testing result shows that mIoU(mean Intersection-over-Union) of the segmentation result is 0.943, which indicates that by properly aggregating more visual features in a deep network the segmentation model can achieve state-of-the-art performance.
关键词： CTA,feature aggregation,level set,main aortic segmentation
更新于2025-09-23 15:22:29