• 한국가시화정보학회지
• /
• 제21권3호
• /
• pp.93-100
• /
• 2023

The yeast Saccharomyces cerevisiae (S. cerevisiae) is considered an ideal eukaryotic model and has long been recognized for its pivotal role in numerous industrial production processes. Depending on the cell cycle phases, microenvironment, and species, S. cerevisiae varies in shape and has different sizes of each shape such as singlets, doublets, and clusters. Obtaining high-purity populations of uniformly shaped S. cerevisiae cells is crucial in fundamental biological research and industrial operations. In this study, we propose an acoustofluidic method for separating S. cerevisiae cells based on their size using surface acoustic wave (SAW)-induced acoustic radiation force (ARF). The SAW-induced ARF increased with cell diameter, which enabled a successful size-based separation of S. cerevisiae cells using an acoustofluidics device. We anticipate that the proposed acoustofluidics approach for yeast cell separation will provide new opportunities in industrial applications.

• 보존과학연구
• /
• 통권7호
• /
• pp.246-264
• /
• 1986

Micoromorphological alterations of sea-waterlogged woods by marinemicro-oragnisms were investigated by the light and scanning electron microscopy as a part of serial investigations on the shipwrecked materials which were excavated at the sea shore of Wando-Kun, southern coast of Korea in 1984.Deterioration of sea-waterlogged wood by marine microorganisms were varied with the wood species. The degree of deterioration even in the same wood specieswas different according to the part where it was in mud of sea-water. However, the resistance of Torreya nucifera over the marine organisms was marked. Deterioration in cell wall may be classified into three types; thinning of cell wall, separation of secondary wall from compound middle lamella and tunneling of cell wall. Thinning and separation were frequently observed, while the tunneling was rare. Among the wood cell elements of hardwoods, vessel wall was the least deteriorated. The difference degree of degradation of cell wall constituents and the accumulation of inorganic substances in cell lumen indicate that some factors to be considered for the conservation treatment were discussed. The kinds of marine microorganisms invading and/or inhabiting in wrecked wooden ship were also discussed.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제7권6호
• /
• pp.357-361
• /
• 2002

Continuous production of lactic acid from glucose by Lactobacillus rhamnosus with cell recycling using an acoustic cell settler was carried out. The performance of the system, such as the concentration of cell and product were compared with the control experiment without recycling. The acoustic settler showed cell separation efficiency of 67% during the continuous operation and the cell concentration in the fermentor with recycle exceeded that of the control by 29%. Com-pared with the control, tactic acid production was increased by 40%, while glucose consumption was only increased by 8%. The higher value of lactic acid production to substrate consumption (Yp/s, product yield coefficient) achieved by cell recycling is interpreted to indicate that the recycled cell mass consumes less substrate to produce the same amount of product than the control Within system environmental changes due to the longer mean cell residence time induced the cells maintaining the metabolic pathways to produce Less by-Product but more product, lactic acid.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.276-276
• /
• 2013

Here we report an integrated microdevice consisting of an efficient passive mixer, a magnetic separation chamber, and a capillary electrophoretic microchannel in which DNA barcode assay, target pathogen separation, and barcode DNA capillary electrophoretic analysis were performed sequentially within 30 min for multiplex pathogen detection at the single-cell level. The intestine-shaped serpentine 3D micromixer provides a high mixing rate to generate magnetic particle-pathogenic bacteria-DNA barcode labelled AuNP complexes quantitatively. After magnetic separation and purification of those complexes, the barcode DNA strands were released and analyzed by the microfluidic capillary electrophoresis within 5 min. The size of the barcode DNA strand was controlled depending on the target bacteria (Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella typhimurium), and the different elution time of the barcode DNA peak in the electropherogram allows us to recognize the target pathogen with ease in the monoplex as well as in the multiplex analysis. In addition, the quantity of the DNA barcode strand (~104) per AuNP is enough to be observed in the laser-induced confocal fluorescence detector, thereby making single-cell analysis possible. This novel integrated microdevice enables us to perform rapid, sensitive, and multiplex pathogen detection with sample-in-answer-out capability to be applied for biosafety testing, environmental screening, and clinical trials.

• 한국전기전자재료학회논문지
• /
• 제17권1호
• /
• pp.59-64
• /
• 2004

We have fabricated the polymer dispersed liquid crystal (PDLC) cell where a control of phase separation is very important. The factors to influence the phase separation are mixing ratio of LC and polymer, curing temperature and UV intensity. In this paper, we inspected the change of a phase separation as a function of curing temperature for the mixture of E7 and. NOA65 with different ratios. When the LC concentration is less than polymer such as LC:NOA65 = 40:60wt％, the PDLC cell is influenced strongly by the curing temperature. However, when the LC concentration is much less than polymer such as LC:NOA65 = 80:20wt％, it is influenced slightly by the curing temperature. The reason is because the mixture shows upper critical solution temperature behavior and therefore it is important to know the behavior of phase separation as a function of curing temperature of the mixture.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2013년도 추계학술대회
• /
• pp.943-945
• /
• 2013

슈반세포의 수초화에 대한 연구는 일차 슈반세포의 분리와 배양의 성공에 의해 가능해지고 있다. 본 연구에서는 슈반세포의 근원으로서 마우스 배아의 척수신경절이 사용되었다. 이 방법에는 세 가지 단계가 있다. 첫 단계는 배아의 척수신경절의 파쇄이고 두 번째 단계는 섬유아세포로부터 슈반세포-뉴런 연합체의 기계적인 분리에 의한 슈반세포의 전구세포의 확장이며 세 번째 단계는 뉴런으로 부터 슈반세포의 분리와 분리된 슈반세포의 확장이다. 우리는 본 과정을 통해 짧은 시간이내에 슈반세포-뉴런 연합체와 슈반세포를 고순도로 분리하였다.

• Bulletin of the Korean Chemical Society
• /
• 제22권6호
• /
• pp.616-622
• /
• 2001

Split-flow thin (SPLITT) cell Fractionation(SF) is a technique that allows separation of particulates and macromolecules into two fractions. A gravitational SF(GSF) system is constructed and tested for its applicability for separation of dust and ground water particulates. When tested with polystyrene latex particles, experimental data were in good agreements with theory. The 9.8 and 21.4㎛ polystyrene particles were successuflly separated in a continuous mode, where the mixture is continuously fed into the GSF channel allowing separation in a large sacle. The GSF system is successfully applied to continuous separation of dust and ground water particels based on the sedimentation coefficient, which is closely related to the particle size. The separations were confirmed by microscopy and energy-dispersive X-ray (EDX) analysos.

• KSBB Journal
• /
• 제13권5호
• /
• pp.511-517
• /
• 1998

Temperature and pH conditions were studied for an effective biosurfactant production by Pseudomonas aeruginosa YPJ-80. Efficient methods of biosurfactant separation were also investigated. pH-uncontrolled experiments at 35$^{\circ}C$ and an initial pH of 8 resulted in the best cell growth (3.6 g/L) and biosurfactant production (0.073 g biosurfactant/g cell). Biosurfactant separation was most efficient using solvent extraction with chloroform/methanol (2:1 vol%) followed by acidification using 1N HCl.

• BMB Reports
• /
• 제51권7호
• /
• pp.317-318
• /
• 2018

Plants are unable to relocate themselves to a more favorable location and thus have to deal with developmental programs and environmental cues wherever they happen to be. It is yet largely unknown how plant cells coordinate cellular activities and architectures to accomplish developmental processes and respond to environmental changes. By identifying and establishing a new cellular model system, we have discovered that two neighboring cell types in the abscission zone (AZ) of Arabidopsis flowers coordinate their activities to ensure a precise "cut" through a highly restricted area of plant tissue to bring about organ separation. From this perspective, we further discuss the essence of cellular coordination in AZ, the key molecules controlling the organ separation, and relevant implications.

• Journal of Information Display
• /
• 제7권1호
• /
• pp.7-11
• /
• 2006

In this paper, we report the fabrication of high quality polymer walls by using a monomer containing fluorine (F-monomer). Polymer walls with no phase retardation were fabricated by using photo-polymerization induced anisotropic phase separation of the mixture composed of liquid crystal (LC) and F-monomer. Thanks to the immiscibility of fluoride, we could form high quality polymer walls with no light leakage. We measured electro-optic characteristics of a twisted-nematic (TN) LC cell whose polymer walls were fabricated by using the F-monomer, and the measurements were compared with that fabricated by using the monomer without fluorine.