Southeast University

About: Southeast University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Computer science & MIMO. The organization has 66363 authors who have published 79434 publications receiving 1170576 citations. The organization is also known as: SEU.

Visualizing of the cellular uptake and intracellular trafficking of exosomes by live-cell microscopy.

Abstract: Cells release exosomes to transfer various molecules to other cells. Exosomes are involved in a number of physiological and pathological processes. They are emerging great potential utility for diseases diagnosis and treatment recently. However, the internalization and intracellular trafficking of exosomes have not been described clearly. In this work, exosomes were isolated from the culture medium of PC12 cells, labeled by lipophilic dye and amino-reactive fluorophore, incubated with resting PC12 cells. The results of live-cell microscopy indicated that exosomes were internalized through endocytosis pathway, trapped in vesicles, and transported to perinuclear region. Particle tracking fluorescent vesicles suggested that the active transport of exosomes may be mediated by cytoskeleton. The proteins on exosome membrane were found to be released from exosomes and trapped in lysosome. The inverted transport of lipophilic dye from perinuclear region to cell peripheries was revealed, possibly caused by recycling of the exosome lipids. This study provides new sight into the mechanisms of exosome uptake and intracellular fate.

P53-regulated long non-coding RNA TUG1 affects cell proliferation in human non-small cell lung cancer, partly through epigenetically regulating HOXB7 expression

Abstract: Recently, a novel class of transcripts, long non-coding RNAs (lncRNAs), is being identified at a rapid pace These RNAs have critical roles in diverse biological processes, including tumorigenesis Here we report that taurine-upregulated gene 1 (TUG1), a 71-kb lncRNA, recruiting and binding to polycomb repressive complex 2 (PRC2), is generally downregulated in non-small cell lung carcinoma (NSCLC) tissues In a cohort of 192 NSCLC patients, the lower expression of TUG1 was associated with a higher TNM stage and tumor size, as well as poorer overall survival (P<0001) Univariate and multivariate analyses revealed that TUG1 expression serves as an independent predictor for overall survival (P<0001) Further experiments revealed that TUG1 expression was induced by p53, and luciferase and chromatin immunoprecipitation (ChIP) assays confirmed that TUG1 was a direct transcriptional target of p53 TUG1 knockdown significantly promoted the proliferation in vitro and in vivo Moreover, the lncRNA-mediated regulation of the expression of HOX genes in tumorigenesis and development has been recently receiving increased attention Interestingly, inhibition of TUG1 could upregulate homeobox B7 (HOXB7) expression; ChIP assays demonstrated that the promoter of HOXB7 locus was bound by EZH2 (enhancer of zeste homolog 2), a key component of PRC2, and was H3K27 trimethylated This TUG1-mediated growth regulation is in part due to specific modulation of HOXB7, thus participating in AKT and MAPK pathways Together, these results suggest that p53-regulated TUG1 is a growth regulator, which acts in part through control of HOXB7 The p53/TUG1/PRC2/HOXB7 interaction might serve as targets for NSCLC diagnosis and therapy

Preparation of Gold Nanoparticle/Graphene Composites with Controlled Weight Contents and Their Application in Biosensors

Abstract: Positively charged gold nanoparticles (GNPs) with diameters of 2−6 nm were self-assembled onto the surfaces of 1-pyrene butyric acid functionalized graphene (PFG) sheets simply by mixing their aqueous dispersions. The amount of GNPs assembled on PFG sheets can be easily modulated by controlling the feeding weight ratio of both components. Furthermore, it was found that PFG sheets had a high loading capability of GNPs, and the maximum value was determined to be about 300 times the PFG’s own weight. Glassy carbon (GC) electrodes modified with the composite of GNPs and PFG (GNP−PFG composite) showed strong electrocatalytic activity and high electrochemical stability. A uric acid electrochemical sensor based on the composite modified electrode exhibited rapid response and high sensitivity.

Anisotropic coding metamaterials and their powerful manipulation of differently polarized terahertz waves

Abstract: Metamaterials based on effective media can be used to produce a number of unusual physical properties (for example, negative refraction and invisibility cloaking) because they can be tailored with effective medium parameters that do not occur in nature. Recently, the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements ‘0’ and ‘1,' which possess opposite phase responses. Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves. We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements. By encoding the elements with elaborately designed coding sequences (both 1-bit and 2-bit sequences), the x- and y-polarized waves can be anomalously reflected or independently diffused in three dimensions. The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface, and the results are consistent with the measured results. We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions, thus providing powerful control of differently polarized electromagnetic waves. The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices. An artificial material that controls electromagnetic waves of different polarization independently has been demonstrated by a team in China. Tie Jun Cui from the Southeast University and co-workers have created a metamaterial that can, for example, split incoming unpolarized radiation so that horizontally polarized light goes one way while vertically polarized light goes the other. Metamaterials are structures that can be engineered to have optical properties not found in natural materials, and they consist of a repeated pattern of elements that are smaller than the wavelength of light. The researchers used two types of element, simple squares and dumbbells, which enabled them to independently control beams of long-wavelength radiation known as terahertz waves having differing polarizations. By reducing the size of the metamaterial elements, the same idea could also be applied to visible light.