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Ouyang G.,Hong Kong Baptist University | Sommer W.,Humboldt University of Berlin | Zhou C.,Hong Kong Baptist University | Zhou C.,HKBU Institute of Research and Continuing Education | Zhou C.,Beijing Computational Science Research Center
Psychophysiology | Year: 2015

Trial-to-trial latency variability pervades cognitive EEG responses and may mix and smear ERP components but is usually ignored in conventional ERP averaging. Existing attempts to decompose temporally overlapping and latency-variable ERP components show major limitations. Here, we propose a theoretical framework and model of ERPs consisting of temporally overlapping components locked to different external events or varying in latency from trial to trial. Based on this model, a new ERP decomposition and reconstruction method was developed: residue iteration decomposition (RIDE). Here, we describe an update of the method and compare it to other decomposition methods in simulated and real datasets. The updated RIDE method solves the divergence problem inherent to previous latency-based decomposition methods. By implementing the model of ERPs as consisting of time-variable and invariable single-trial component clusters, RIDE obtains latency-corrected ERP waveforms and topographies of the components, and yields dynamic information about single trials. © 2015 Society for Psychophysiological Research.

Cheung Y.-M.,Hong Kong Baptist University | Cheung Y.-M.,United International College | Cheung Y.-M.,HKBU Institute of Research and Continuing Education | Peng Q.,Hong Kong Baptist University
IEEE Transactions on Human-Machine Systems | Year: 2015

This paper addresses the eye gaze tracking problem using a low cost and more convenient web camera in a desktop environment, as opposed to gaze tracking techniques requiring specific hardware, e.g., infrared high-resolution camera and infrared light sources, as well as a cumbersome calibration process. In the proposed method, we first track the human face in a real-time video sequence to extract the eye regions. Then, we combine intensity energy and edge strength to obtain the iris center and utilize the piecewise eye corner detector to detect the eye corner. We adopt a sinusoidal head model to simulate the 3-D head shape, and propose an adaptive weighted facial features embedded in the pose from the orthography and scaling with iterations algorithm, whereby the head pose can be estimated. Finally, the eye gaze tracking is accomplished by integration of the eye vector and the head movement information. Experiments are performed to estimate the eye movement and head pose on the BioID dataset and pose dataset, respectively. In addition, experiments for gaze tracking are performed in real-time video sequences under a desktop environment. The proposed method is not sensitive to the light conditions. Experimental results show that our method achieves an average accuracy of around 1.28° without head movement and 2.27° with minor movement of the head. © 2013 IEEE.

Chan C.-F.,Hong Kong Baptist University | Xie C.,Hong Kong Baptist University | Tsang M.-K.,Hong Kong Polytechnic University | Lear S.,Durham University | And 10 more authors.
European Journal of Inorganic Chemistry | Year: 2015

In this work, the shape effect of our same-sized hybrid nanomaterials conjugated with two different Plk1-specific peptides had been investigated in terms of their photophysical properties, cellular uptake efficiencies, and selective inhibitory effects towards cancer and normal cells. The results clearly indicate that our spherical NaGdF4 at SiO2-P1 nanoparticles achieve the best performance for in vitro imaging, G2 phase cell arrest, and, hence, cell cycle inhibition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Guan Y.-F.,Hong Kong Baptist University | Guan Y.-F.,HKBU Institute of Research and Continuing Education | Song X.,Hong Kong Baptist University | Song X.,Shenzhen University | And 11 more authors.
Chemical Biology and Drug Design | Year: 2016

Tuberculosis (TB) is a highly contagious disease mainly caused by Mycobacterium tuberculosis H37RV. Antitubercular (anti-TB) bioassay-guided isolation of the CHCl3 extract of the leaves and stems of the medicinal plant Ardisia gigantifolia led to the isolation of two anti-TB 5-alkylresorcinols, 5-(8Z-heptadecenyl) resorcinol (1) and 5-(8Z-pentadecenyl) resorcinol (2). We further synthesized 15 derivatives based on these two natural products. These compounds (natural and synthetic) were evaluated for their anti-TB activity against Mycobacterium tuberculosis H37RV. Resorcinols 1 and 2 exhibited anti-TB activity with MIC values at 34.4 and 79.2 μm in MABA assay, respectively, and 91.7 and 168.3 μm in LORA assay, respectively. Among these derivatives, compound 8 was found to show improved anti-TB activity than its synthetic precursor (2) with MIC values at 42.0 μm in MABA assay and 100.2 μm in LORA assay. The active compounds should be regarded as new hits for further study as a novel class of anti-TB agents. The distinct structure–activity correlations of the parent compound were elucidated based on these derivatives. © 2016 John Wiley & Sons A/S

Li D.,Hong Kong Baptist University | Li D.,HKBU Institute of Research and Continuing Education | Li D.,China Institute of Technology | Liu J.,Hong Kong Baptist University | And 67 more authors.
Nature Communications | Year: 2016

Emerging evidence indicates that osteoclasts direct osteoblastic bone formation. MicroRNAs (miRNAs) have a crucial role in regulating osteoclast and osteoblast function. However, whether miRNAs mediate osteoclast-directed osteoblastic bone formation is mostly unknown. Here, we show that increased osteoclastic miR-214-3p associates with both elevated serum exosomal miR-214-3p and reduced bone formation in elderly women with fractures and in ovariectomized (OVX) mice. Osteoclast-specific miR-214-3p knock-in mice have elevated serum exosomal miR-214-3p and reduced bone formation that is rescued by osteoclast-targeted antagomir-214-3p treatment. We further demonstrate that osteoclast-derived exosomal miR-214-3p is transferred to osteoblasts to inhibit osteoblast activity in vitro and reduce bone formation in vivo. Moreover, osteoclast-targeted miR-214-3p inhibition promotes bone formation in ageing OVX mice. Collectively, our results suggest that osteoclast-derived exosomal miR-214-3p transfers to osteoblasts to inhibit bone formation. Inhibition of miR-214-3p in osteoclasts may be a strategy for treating skeletal disorders involving a reduction in bone formation.

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