• KSBB Journal
• /
• 제13권4호
• /
• pp.438-443
• /
• 1998

Effects of various environmental factors on cell size index(FCW/DCW) in Thalictrum rugosum. Lithospermum erythrorhizon and Taxus cuspidata plant cell suspension cultures were investigated. Time course change of cell size index were also observed. In batch cultures, FCW/DCW increased according to the decrease of sugar concentration. For short-term experiment within 24 hr, FCW/DCW value could be reduced significantly by increasing sugar concentration. When an osmoticum such as mannitol was added, FCW/DCW converged to a low value. Therefore, it was confirmed that osmolality of the medium was important in determining cell size or water content of the cells. Inorganic salts or treatment with organic solvent also exhibited some effect on the cell size index. However, pH and centrifugal force did not show any influences. On the other hand, it was found that the addition of Pluronic F-68 reduced FCW/DCW. By combining these results effectively, it may be possible to increase the cell concentration in high density culture to a higher extent.

• Applied Microscopy
• /
• 제18권2호
• /
• pp.1-20
• /
• 1988

The species of the slug used in the experiment is Limax flavus L. For identifying the chemical characteristics of the epidermis, granules and mucus-producing cell of this animal is examined with methylene blue-basic fuchsin double stain and PAS-alcian blue reagent. For the ultrastructural research of the epidermal free surface, the epitheial cell and the parenchymal cell are used with scanning electron microscope and transmission elec-tron microscope respectively. I . Epidermal tissue The epidermal tissue of the slug is observed being divided into the dorsal and the ventral side(toot pad) respectively. 1) Dorsal epidermal tissue The dorsal epidermis of the slug is constituted with the simple columnar epithelium and the microvilli are compacted on the epidermal free surface. Two different types of the secretory granules of the neutral and the acid mucus are observed between the epithelial cells, and the neutral mucous granules are highest electron-dense but the acid mucous granules are observed to be electron-lucent. 2) Foot epidermal tissue The Foot epidermis is formed with the taller simple columnar epithelium than the dorsal epidermis and these cells have both a large number of the microvilli and a few number of the large villi. The secretory granules of three different types, which are acid, neutral and mixed mucous granule of two different types are observed between the epithelial cells. The neutral mucous granules are highest electron dense but the acid mucous granules are observed to be electron-lucent. II . Mucous granule-producing cell and mucus-producing cells Seven different types of the granules-producing cell and the mucus-producing cells are observed between the parenchyma. 1) A-type of acid mucous granule-producing cell The electron-lucent granules are largely occupied in the cytoplasm of these cells and then the granules are surrounded by irregular membrane. These electron-lucent granules exhibit alcianophilia with PAS-alcian blue reaction, so these granules are certified to be acid mucopolysaccharide. 2) B-type of acid mucus-producing cell The nucleus and the cytoplasm of these cells are pushed by the acid mucus of the electron-lucent toward the cell membrane. This mucus has been confirmed to be the acid mucopolysaccharide with PAS-alcian blue reagent. 3) A-type of neutral mucous granule-producing cell These cells contain the electron-dense round granules with approximately $1{\mu}m$ in diameter, which exhibit strongly PAS-positive reaction. These granules are confirmed to be the neutral mucoplysaccharide. 4) B-type of neutral mucous granule-producing cell These cells contain two different types of electron dense granules and electron-lucent granules; The former exhibits to be strongly PAS-positive and the latter to have alcianophilia reaction respectively. 5) C-type of neutral mucus-producing cell These cells are similar to the shape and the size of the B-type of mucus-producing cell but these two different types of cells are stained with reversing properties to each other. The mucus of the C-type cell that electron-lucent is largely occupied in the cytoplasm that exhibits strongly PAS-positive reaction. 6) D-type of neutral mucous granule-producing cell These cells contain round granules about $1{\mu}m$ in size which are observed to be medium electron-dense granules and those granules are stained brightly red with PAS-weak positive reaction. The granules are certified to be neutral mucopolysaccharide. 7) E-type of neutral mucous granule-producing cell These cells are similar to the shape and the size of the D-type of neutral mucous granule-producing cell. These cells contain a large number of granules with about $1{\mu}m$ in diameter showing electron-lucent and then granules are seen to be PAS-weak positive reaction. III. Parenchyma The clear cell and dark cell are found in the parenchyma of the Limax flavus L. 1) Clear cell These cells are round formed and the nucleus of the cells are larger than cytoplasm. These cells which have the electron-lucent cytosol possess poorly developed organelles. 2) Dark cell These cells are found to be dark cells due to high electron-density, which exhibit strongly methylene-blue reaction from double stain of methylene blue-basic fuchsin.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
• /
• pp.82-82
• /
• 2015

Industrial crystalline silicon (c-Si) solar cells with using a screen printing technology share the global market over 90% and they will continue to be the same for at least the next decade. It seems that the $2^{nd}$ generation and the $3^{rd}$ generation technologies have not yet demonstrated competitiveness in terms of performance and cost. In 2014, new world record efficiency 25.6% (Area-$143.7cm^2$, Voc-0.740V, $Jsc-41.8mA/cm^2$, FF-0.827) was announced from Panasonic and its cell structure is Back Contact $HIT^*$ c-Si solar cell. Here, amorphous silicon passivated contacts were newly applied to back contact solar cell. On the other hand, 24.9% $TOPCon^{**}$ cell was announced from Fraunhofer ISE and its key technology is an excellent passivation quality applying tunnel oxide (<2 nm) between metal and silicon or emitter and base. As a result, to realize high efficiency, high functional technologies are quite required to overcome a theoretical limitation of c-Si solar cell efficiency. In this presentation, Si solar cell technology summarized in the International Technology Roadmap for Photovoltaics ($^{***}ITRPV$ 2014) is introduced, and the present status of R&D associated with various c-Si solar cell technologies will be reviewed. In addition, national R&D projects of c-Si solar cells to be performed by Korea University are shown briefly.

• IMMUNE NETWORK
• /
• 제12권6호
• /
• pp.223-229
• /
• 2012

Clinical and preclinical in vivo immune cell imaging approaches have been used to study immune cell proliferation, apoptosis and interaction at the microscopic (intra-vital imaging) and macroscopic (whole-body imaging) level by use of ex vivo or in vivo labeling method. A series of imaging techniques ranging from non-radiation based techniques such as optical imaging, MRI, and ultrasound to radiation based CT/nuclear imaging can be used for in vivo immune cell tracking. These imaging modalities highlight the intrinsic behavior of different immune cell populations in physiological context. Fluorescent, radioactive or paramagnetic probes can be used in direct labeling protocols to monitor the specific cell population. Reporter genes can also be used for genetic, indirect labeling protocols to track the fate of a given cell subpopulation in vivo. In this review, we summarized several methods dealing with dendritic cell, macrophage, and T lymphocyte specifically labeled for different macroscopic whole-body imaging techniques both for the study of their physiological function and in the context of immunotherapy to exploit imaging-derived information and immune-based treatments.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.748-753
• /
• 2008

Bi-directional load test is one of O-cell tests. The O-cell test is a system which may be used for performing static load tests on cast in situ reinforced concrete bored piles. The technique was devised and developed by Osterberg of Northwestern University(USA) and has been in use around the world. The principle of the method is that an O-cell is installed in a cast in situ bored pile base. Once the pile concrete reaches its design strength the cell is connected to an hydraulic pump and pressured. Pressurisation causes the cell to expand, developing an upward force on the section of pile above the cell loads, pile movements and strains within the pile then enable the capacity of the pile and its load settlement curves to be ascertained. Bi-directional load tests using O-cell are now becoming common practice around the world, particularly where the loads to be applied are high or where it is not convenient to perform top-down loading tests. In the study, calculate ultimate capacity of bi-directional load test using FEM and beam on elasto-plastic foundation theory.

• Journal of Microbiology and Biotechnology
• /
• 제32권1호
• /
• pp.126-140
• /
• 2022

Stem cells can be applied usefully in basic research and clinical field due to their differentiation and self-renewal capacity. The aim of this study was to establish an effective novel therapeutic cellular source and create its molecular expression profile map to elucidate the possible therapeutic mechanism and signaling pathway. We successfully obtained a mesenchymal stem cell population from human embryonic stem cells (hESCs) cultured on chemically defined feeder-free conditions and treated with connective tissue growth factor (CTGF) and performed the expressive proteomic approach to elucidate the molecular basis. We further selected 12 differentially expressed proteins in CTGF-induced hESC-derived mesenchymal stem cells (C-hESC-MSCs), which were found to be involved in the metabolic process, immune response, cell signaling, and cell proliferation, as compared to bone marrow derived-MSCs(BM-MSCs). Moreover, these up-regulated proteins were potentially related to the Wnt/β-catenin pathway. These results suggest that C-hESC-MSCs are a highly proliferative cell population, which can interact with the Wnt/β-catenin signaling pathway; thus, due to the upregulated cell survival ability or downregulated apoptosis effects of C-hESC-MSCs, these can be used as an unlimited cellular source in the cell therapy field for a higher therapeutic potential. Overall, the study provided valuable insights into the molecular functioning of hESC derivatives as a valuable cellular source.

• KSBB Journal
• /
• 제4권1호
• /
• pp.11-14
• /
• 1989

Tower fermentor를 이용한 연속 알콜발효에서 cell re-cycle과 aeration에 대한 영향을 검토하였다. 균주는 floc-culationg 효모인 Saccharomyces cerecisiae TS4를 를 사용하였다. 15% glucose를 사용한 cell recycle system의 연속 알콜발효에서 cell 농도는 50%/1였고, ethanol productiv는 26.4g EtOH/l-hr로서 cell농도가 가장 높은 값을 나타내었으며, aeration rate는 3.8$\times$ $10^-^3$ VVM이상부터는 ethanol pro-ductivity가 감소하였다.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
• /
• pp.121-124
• /
• 1996

In general, cellular manufacturing system can be constructed by the following two steps. The first step forms machine cells and part families, and the second step determines cell layout based on the result of first step. Cell layout has to be considered when cell is formed becauese the result of cell formation affects it. This paper presents a cell formation algorithm and proposes an integrated mathematical model for cell formation and cell layout. The cell formation algorithm minimizes the number of exceptional element in cellular manufacturing system. New concept for similarity and incapability is introduced, based on machine-operation incidence matrix and part-operation incidence matrix. One is similarity between the machines, the other is similarity between preliminary machine cells and machines. The incapability identifies relations between machine cells and parts. In this procedure, only parts without an exceptional element are assigned to machine cell. Bottleneck parts are considered with cell layout design in an integrated mathematical model. The integrated mathematical model determines cell layout and assigns bottleneck parts to minimize the number of exceptional element and intercell moving distance, based on linearixed 0-1 integer programming. The proposed algorithm is illustrated by using numerical examples.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권10호
• /
• pp.4703-4723
• /
• 2018

In recent years, dense small cell network has been deployed to address the challenge that has resulted from the unprecendented growth of mobile data traffic and users. It has proven to be a cost efficeient solution to offload traffic from macro-cells. Software defined heterogeneous wireless network can decouple the control plane from the data plane. The control signal goes through the macro-cell while the data traffic can be offloaded by small cells. In this paper, we propose a framework for cell virtualization and user association in order to satisfy versatile requirements of multiple tenants. In the proposed framework, we propose an interference graph partioning based virtual-cell association and customized physical-cell association for multi-homed users in a software defined small cell network. The proposed user association scheme includes 3 steps: initialization, virtual-cell association and physical-cell association. Simulation results show that the proposed virtual-cell association outperforms the other schemes. For physical-cell association, the results on resource utilization and user fairness are examined for mobile users and infrastructure providers.

• Molecules and Cells
• /
• 제44권3호
• /
• pp.127-135
• /
• 2021

Since the introduction of RNA sequencing (RNA-seq) as a high-throughput mRNA expression analysis tool, this procedure has been increasingly implemented to identify cell-level transcriptome changes in a myriad of model systems. However, early methods processed cell samples in bulk, and therefore the unique transcriptomic patterns of individual cells would be lost due to data averaging. Nonetheless, the recent and continuous development of new single-cell RNA sequencing (scRNA-seq) toolkits has enabled researchers to compare transcriptomes at a single-cell resolution, thus facilitating the analysis of individual cellular features and a deeper understanding of cellular functions. Nonetheless, the rapid evolution of high throughput single-cell "omics" tools has created the need for effective hypothesis verification strategies. Particularly, this issue could be addressed by coupling cell engineering techniques with single-cell sequencing. This approach has been successfully employed to gain further insights into disease pathogenesis and the dynamics of differentiation trajectories. Therefore, this review will discuss the current status of cell engineering toolkits and their contributions to single-cell and genome-wide data collection and analyses.