Browsing by Author "Li, Chun-Hsien"

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Capillary hydrodynamic chromatography reveals temporal profiles of cell aggregates
(2016-03-03)
Tang, Ya-Ru
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Huang, Hsin-Yi
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Hu, Jie-Bi
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Rattinam, Rajesh
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Li, Chun-Hsien
Microbial cells are known to form aggregates. Such aggregates can be found in various matrices; for example, functional drinks. Capillary hydrodynamic chromatography (HDC) enables separation of particles by size using nanoliter-scale volumes of samples. Here we propose an approach based on HDC for characterisation of real samples containing aggregated and non-aggregated bacterial and fungal cells. Separation of cells and cell aggregates in HDC arises from the parabolic flow profile under laminar flow conditions. In the presented protocol, hydrodynamic separation is coupled with different on-line and offline detectors (light absorption/scattering and microscopy). The method has successfully been applied in the monitoring of dynamic changes in the microbiome of probiotic drinks. Chromatographic profiles of yogurt and kefir samples obtained at different times during fermentation are in a good agreement with microscopic images. Moreover, thanks to the implementation of an area imaging detector, capillary HDC could be multiplexed and used to profile spatial gradients in cell suspensions, which arise in the course of sedimentation of cells and cell aggregates. This result shows compatibility of sedimentation analysis and capillary HDC. We believe that the approach may find applications in the profiling of functional foods and other matrices containing aggregated bioparticles. (C) 2016 Elsevier B.V. All rights reserved.
Inhibition of the lethality of Shiga-like toxin-1 by functional gold nanoparticles
(2018-01-01)
Li, Chun-Hsien
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Bai, Yi-Ling
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Chen, Yu-Chie
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應用化學系
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Department of Applied Chemistry
Escherichia coli O157:H7 is a pathogen, which can generate Shiga-like toxins (SLTs) and cause hemolytic-uremic syndrome. Foodborne illness outbreaks caused by E. coli O157:H7 have become a global issue. Since SLTs are quite toxic, effective medicines that can reduce the damage caused by SLTs should be explored. SLTs consist of a single A and five B subunits, which can inhibit ribosome activity for protein synthesis and bind with the cell membrane of host cells, respectively. Pigeon ovalbumin (POA), i.e. a glycoprotein, is abundant in pigeon egg white (PEW) proteins. The structure of POA contains Gal-(14)-Gal-(14)-GlcNAc ligands, which have binding affinity toward the B subunit in SLT type-1 (SLT-1B). POA immobilized gold nanoparticles (POA-Au NPs) can be generated by reacting PEW proteins with aqueous tetrachloroauric acid in one-pot. The generated POA-Au NPs have been demonstrated to have selective trapping-capacity toward SLT-1B previously. Herein, we explore that POA-Au NPs can be used as protective agents to neutralize the toxicity of SLT-1 in SLT-1-infected model cells. The results show that the cells can be completely rescued when a sufficient amount of POA-Au NPs is used to treat the SLT-1-infected cells within 1h.
NV-BNN: An Accurate Deep Convolutional Neural Network Based on Binary STT-MRAM for Adaptive AI Edge
(2019-01-01)
Chang, Chih-Chcng
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Wu, Ming-Hung
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Lin, Jia-Wei
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Li, Chun-Hsien
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Parmar, Vivek
Binary STT-MRAM is a highly anticipated embedded non-volatile memory technology in advanced logic nodes <28 nm. How to enable its in-memory computing (IMC) capability is critical for enhancing AI Edge. Based on the soon-available STT-MRAM, we report the first binary deep convolutional neural network (NV-BNN) capable of both local and remote learning. Exploiting intrinsic cumulative switching probability, accurate online training of CIFAR-10 color images (similar to 90%) is realized using a relaxed endurance spec (switching <= 20 times) and hybrid digital/IMC design. For offline training, the accuracy loss due to imprecise weight placement can be mitigated using a rapid non-iterative training-with-noise and fine-tuning scheme.
Selective Detection of Shiga-like Toxin 1 from Complex Samples Using Pigeon Ovalbumin Functionalized Gold Nanoparticles as Affinity Probes
(2017-05-31)
Li, Chun-Hsien
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Bai, Yi-Ling
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Selvaprakash, Karuppuchamy
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Mong, Kwok-Kong Tony
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Chen, Yu-Chie
Escherichia coli 0151:H7 is a foodborne pathogen. This bacterial strain can generate Shiga-like toxins (SLTs), which can cause serious sickness and even death. Thus, it is important to develop effective and sensitive methods that can be used to rapidly identify the presence of SLTs from complex samples. Pigeon egg white (PEW) contains abundant glycoproteins, including pigeon ovalbumin (POA) (similar to 60%). POA possesses Gal-alpha(1 -> 4)-Gal-beta(1 -> 4)-GlcNAc termini,. which can recognize the B subunits in SLT type 1 (SLT-1B). Thus, POA is a suitable probe for trapping SLT-1B. In this work, we used PEW proteins as starting materials to react with aqueous tetrachloroauric acid for generation of PEW-protein-immobilized gold nanoparticles (AuNPs@PEW) via one-pot reactions. We demonstrated that the generated AuNPs@PEW were mainly dominated by POA-immobilized Au NPs. The as-prepared AuNPs@PEW were used as affinity probes to selectively probe SLT-1B from complex cell lysates derived from E. coli 0157:H7. The selective trapping step can be completed within similar to 90 s under microwave heating (power = 450 W) to enrich sufficient SLT-1B for Matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analysis. Furthermore; this approach:can be used to detect SLT-1B at a concentration as low as similar to 40 pM. The feasibility of using the proposed method to selectively detect SLT-1B from ham contaminated by E. coli 0157:H7 was also demonstrated.