http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Magnetic Separation of Malaria-Infected Red Blood Cells in Various Developmental Stages
Nam, Jeonghun,Huang, Hui,Lim, Hyunjung,Lim, Chaeseung,Shin, Sehyun American Chemical Society 2013 ANALYTICAL CHEMISTRY - Vol.85 No.15
<P>Malaria is a serious disease that threatens the public health, especially in developing countries. Various methods have been developed to separate malaria-infected red blood cells (i-RBCs) from blood samples for clinical diagnosis and biological and epidemiological research. In this study, we propose a simple and label-free method for separating not only late-stage but also early-stage i-RBCs on the basis of their paramagnetic characteristics due to the malaria byproduct, hemozoin, by using a magnetic field gradient. A polydimethylsiloxane (PDMS) microfluidic channel was fabricated and integrated with a ferromagnetic wire fixed on a glass slide. To evaluate the performance of the microfluidic device containing the ferromagnetic wire, lateral displacement of NaNO<SUB>2</SUB>-treated RBCs, which also have paramagnetic characteristics, was observed at various flow rates. The results showed excellent agreement with theoretically predicted values. The same device was applied to separate i-RBCs. Late-stage i-RBCs (trophozoites and schizonts), which contain optically visible black dots, were separated with a recovery rate of approximately 98.3%. In addition, using an optimal flow rate, early-stage (ring-stage) i-RBCs, which had been difficult to separate because of their low paramagnetic characteristics, were successfully separated with a recovery rate of 73%. The present technique, using permanent magnets and ferromagnetic wire in a microchannel, can effectively separate i-RBCs in various developmental stages so that it could provide a potential tool for studying the invasion mechanism of the malarial parasite, as well as performing antimalarial drug assays.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2013/ancham.2013.85.issue-15/ac4012057/production/images/medium/ac-2013-012057_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac4012057'>ACS Electronic Supporting Info</A></P>
A Brain–Computer Interface-Based Action Observation Game That Enhances Mu Suppression
Lim, Hyunmi,Ku, Jeonghun IEEE 2018 IEEE transactions on neural systems and rehabilita Vol.26 No.12
<P>Action observation training based on the theory of activation of the mirror-neuron system has been used for the rehabilitation of patients with stroke. In this paper, we sought to assess whether a brain–computer interface (BCI)-based action observation rehabilitation game, using a flickering action video, could preferentially activate the mirror-neuron system. Feedback of stimulus observation, evoked by the flickering action video, was provided using steady state visually evoked potential and event-related desynchronization. Fifteen healthy subjects have experienced the game with BCI interaction (game and interaction), without BCI interaction (game without interaction), observed non-flickering stimuli, and flickering stimuli without the game background (stimuli only) in a counter-balanced order. The game and interface condition was resulted in significantly stronger activation of the mirror-neuron system than did the other three conditions. In addition, the amount of mirror-neuron system activation is gradually decreased in the game without interface, non-flickering stimuli, and stimuli only conditions in a time-dependent manner; however, in the game and interface condition, the amount of mirror-neuron system activation was maintained until the end of the training. Taken together, these data suggest that the proposed game paradigm, which integrates the action observation paradigm with BCI technology, could provide interactive responses for whether watching video clips can engage patients and enhance rehabilitation.</P>
Lim, Jeongmin,Ryu, Sang Yeoul,Kim, Jeonghun,Jun, Yongseok Springer 2013 NANOSCALE RESEARCH LETTERS Vol.8 No.1
<P>This study describes a systematic approach of TiO<SUB>2</SUB>/carbon black nanoparticles with respect to the loading amount in order to optimize the catalytic ability of triiodide reduction for dye-sensitized solar cells. In particular, the cell using an optimized TiO<SUB>2</SUB> and carbon black electrode presents an energy conversion efficiency of 7.4% with a 5:1 ratio of a 40-nm TiO<SUB>2</SUB> to carbon black. Based on the electrochemical analysis, the charge-transfer resistance of the carbon counter electrode changed based on the carbon black powder content. Electrochemical impedance spectroscopy and cyclic voltammetry study show lower resistance compared to the Pt counter electrode. The obtained nanostructures and photo electrochemical study were characterized.</P>
Formation of size-controllable tumour spheroids using a microfluidic pillar array (μFPA) device
Lim, Wanyoung,Hoang, Hong-Hoa,You, Daeun,Han, Jeonghun,Lee, Jeong Eon,Kim, Sangmin,Park, Sungsu The Royal Society of Chemistry 2018 The Analyst Vol.143 No.23
<P>Spheroids are recognized for replicating the physiological microenvironment of tumours. However, because of the lack of controllability of the spheroid size, the response to anticancer drugs is variable in conventional spheroid culture methods. In this paper, we describe a method to generate several hundreds of spheroids of various types of cancer cells including patient derived cancer cells (PDCs) using a microfluidic device with pillars (diameter: 40 μm, height: 70 μm, center-to-center distance: 140 μm), called a microfluidic pillar array (μFPA) device. About three hundred glioma (U87) spheroids were obtained in the μFPA device within 3 days, and about 90% of them ranged from 175 to 225 μm. These spheroids were more resistant to doxorubicin at 10 μM than U87 cells in a monolayer. The former showed higher expression of CD133, a cancer stem cell marker, than the latter. Hypoxia inducible factor-1α (HIF-1α), another cancer stem cell marker, was found in the nucleus of the former, but found in the cytoplasm of the cells in a monolayer. Drug responses of spheroids of another glioma cell line (U251) and triple negative breast cancer (TNBC) primary cells were also easily quantified by measuring changes in spheroid size at different concentrations of their respective drug on the μFPA device. The μFPA device can be a powerful platform for obtaining uniform spheroids and monitoring the drug response of cancer cells including PDCs.</P>