• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.53-58
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• 2005

We present a high-throughput continuous cell separation chip using hydrodynamic dielectrophoresis (DEP) process. The continuous cell separation chip uses three planar electrodes in a separation channel, where the positive DEP cells are moved away from the central streamline while the negative DEP cells remain in the central streamline. In the experimental study, we use the mixture of viable (live) and nonviable (dead) yeast cells in order to obtain the continuous cell separation conditions. For the conditions of the electric fields frequency of 5MHz and the medium conductivity of $5{\mu}S/cm$, the fabricated chip performs a continuous separation of the yeast cell mixture at the varying flow-rate in the range of $0.1{\sim}{\mu{\ell}/min$.; thereby, resulting in the purity ranges of $95.9{\sim}97.3\%\;and\;64.5{\sim}74.3\%$ respectively for the viable and nonviable yeast cells. present chip demonstrates the constant cell separation performance for varying mixture flow-rates.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.567-570
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• 2007

Cell gap dependence on anisotropic phase separation was studied. The results showed that the morphology of phase separation depended on cell gap and material parameters. With numerical simulation and experiments, the optimal range of cell gap in the formation of polymer layer and liquid crystal was suggested for given material parameters.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.21-25
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• 2010

In response to the industrial needs for automated handling of very thin solar cell wafers, this paper presents the design concept for the individual wafer separation from the stacked wafers by utilizing continuous water jet. The experimental apparatus for automated wafer separation was constructed and it includes the water jet system and the microprocessor controlled wafer stack advancing system. Through a series of tests, the performance of the proposed design is quantified into the success rate of single wafer separation and the rapidity of processing wafer stack. Also, the inclination angle of wafer equipped cartridge and the water jet flowrate are found to be important parameters to be considered for process optimization. The proposed design shows the concept for fast and efficient processing of wafer separation and can be implemented in the automated manufacturing of silicon based solar cell wafers.

• International Journal of Control, Automation, and Systems
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• v.2 no.2
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• pp.135-143
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• 2004

Recently, high throughput screening for microorganisms with desired characteristics from a large heterogeneous population has become possible. Single cell separation has taken on increasing significance in recent years, and several different methods have been proposed so far. In this paper, we introduce several cell manipulation methods aiming at single cell separation and investigation. At first, methods for the separation of microorganisms are classified. Then, we introduce two different approaches, that is, (1) indirect manipulation using laser trapped microtools and (2) thermal gelation.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.1-6
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• 1994

Many useful biomaterials like enzymes are contained in yeast cells. However, the release of these intracellular biomateriais from the cells is required to recover them with hot water, solvent or various cell breakage methods of mechanical or non mechanical ones. The cell lysis or breakage of yeast is usually made by solvent like ethyl acetate and mechanical disintrgration with high pressure homogenizer or agitating beads mill. The separation of cell debris (i.e. solid liquid separation) is done by centrifuge or membrane depending on the recovery conditions. The features of both separation methods are shown in Tables 1 and 2. As it is often difficult to obtain a clear supernatant by centrifuge from the suspension containing cell debris, the membrane separation is also often used to gel a clear supernatant. In this report we introduce the several applications of membrane separation to separate the cell debris of yeast disintegrated chemically or mechanically and to recover the intracellular biomaterials.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.91-99
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• 2019

Objectives The loss of maternal care during early postnatal period may increase development of mood-related disorders, such as depression, anxiety, and personality disorders. In this study, the effect of acupuncture on depression in relation with cell proliferation in the hippocampal gyrus dentatus was investigated using maternal-separated rat pups. Methods On the postnatal 14th day, rat pups from six dams were grouped into following groups: maternal care group, maternal separation group, maternal separation and non-acupoint-acupunctured group, maternal separation and Zusanli-acupunctured group, and maternal separation and fluoxetine-treated group. Acupuncture was performed from postnatal 28th day to postnatal 37th day. The rat pups that belong in the maternal separation and fluoxetine-treated group were injected subcutaneously with 5 mg/kg fluoxetine hydrochloride once a day for the same period of time. To evaluate activity of the rat pups, open field test was performed. Immunohistochemistry for serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase (TPH) in the dorsal raphe and for 5-bromo-2'-deoxyuridine (BrdU) in the hippocampal gyrus dentatus was conducted. Results The present results reveal that the activity was decreased by maternal separation. In contrast, acupuncture at Zusanli overcame maternal separation-induced hypoactivity. Maternal separation suppressed TPH expression and 5-HT synthesis in the dorsal raphe and decreased cell proliferation in the hippocampal gyrus dentatus of rat pups. In contrast, acupuncture at Zusanli alleviated maternal separation-induced decrease of 5-HT synthesisand TPH expression. Conclusions The present results demonstrate that acupuncture at Zusanli ameliorated depressive state through increasing cell proliferation and enhancing 5-HT synthesis.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.141-150
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• 2019

The spatial landmark protein Bud8 plays a crucial role in bipolar budding in the budding yeast Saccharomyces cerevisiae. The unconventional yeast Yarrowia lipolytica can also bud in a bipolar pattern, but is evolutionarily distant from S. cerevisiae. It encodes the protein YALI0F12738p, which shares the highest amino acid sequence homology with S. cerevisiae Bud8, sharing a conserved transmembrane domain at the C-terminus. Therefore, we named it YlBud8. Deletion of YlBud8 in Y. lipolytica causes cellular separation defects, resulting in budded cells remaining linked with one another as cell chains or multiple buds from a single cell, which suggests that YlBud8 may play an important role in cell separation, which is distinct from the function of Bud8 in S. cerevisiae. We also show that the YlBud8-GFP fusion protein is located at the cell membrane and enriched in the bud cortex, which would be consistent with a role in the regulation of cell separation. The coiled-coil domain at the N-terminus of YlBud8 is important to the correct localization and function of YlBud8, as truncated proteins that do not contain the coiled-coil domain cannot rescue the defects observed in $Ylbud8{\Delta}$. This finding suggests that a new signaling pathway controlled by YlBud8 via regulation of cell separation may exist in Y. lipolytica.

• KSBB Journal
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• v.4 no.3
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• pp.281-287
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• 1989

The experimental study reported herein was to investigate to separation characteristics of a tangential flow membrane in a continuous recycle situation. Physical and dynamic analyses are performed on the membrane system in order to relate relevant variables to the capacity of separation. The results of separation process may be summarized by a proposed equation:Sh=A(Re.Sc.dh/L)1/3. It was shown also by the analyses that effective separation of sugar and cell was attainable by means of tangential membranes, thereby enhancing ethanol productivity in fermentation with continuous cell and substrate recycle.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.743-747
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• 2004

In this study, micro blood separators capable of separating blood cell and blood plasma using microstructure are fabricated and their feasibility and separation performance are evaluated. Test results show the possibility of separating blood cell and blood plasma using microstructure. To improve separation performance and anti-clogging characteristic, technical points of tested micro blood separators are discussed and improved designs are presented.

• Journal of information and communication convergence engineering
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• v.13 no.3
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• pp.215-219
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• 2015

Cells in a culture process transform with time and produce many overlapping cells in their vicinity. We are interested in a separation algorithm for images of overlapping cells taken using a fluorescence optical microscope system during a cell culture process. In this study, all cells are assumed to have an ellipse-like shape. For an ellipse fitting-based method, an improved least squares method is used by decomposing the design matrix into quadratic and linear parts for the separation of overlapping cells. Through various experiments, the improved least squares method (numerically stable direct least squares fitting [NSDLSF]) is compared with the conventional least squares method (direct least squares fitting [DLSF]). The results reveal that NSDLSF has a successful separation ratio with an average accuracy of 95% for two overlapping cells, an average accuracy of 91% for three overlapping cells, and about 82% accuracy for four overlapping cells.