• Title, Summary, Keyword: single-cell

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Every Single Cell Clones from Cancer Cell Lines Growing Tumors In Vivo May Not Invalidate the Cancer Stem Cell Concept

  • Li, Fengzhi
    • Molecules and Cells
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    • v.27 no.4
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    • pp.491-492
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    • 2009
  • We present the result of our research on the tumorigenic ability of single cell clones isolated from an aggressive murine breast cancer cell line in a matched allografting mouse model. Tumor formation is basically dependent on the cell numbers injected per location. We argue that in vivo tumor formation from single cell clones, isolated in vitro from cancer cell lines, may not provide conclusive evidence to disprove the cancer stem cell (CSC) theory without additional data.

Dissecting Cellular Heterogeneity Using Single-Cell RNA Sequencing

  • Choi, Yoon Ha;Kim, Jong Kyoung
    • Molecules and Cells
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    • v.42 no.3
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    • pp.189-199
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    • 2019
  • Cell-to-cell variability in gene expression exists even in a homogeneous population of cells. Dissecting such cellular heterogeneity within a biological system is a prerequisite for understanding how a biological system is developed, homeostatically regulated, and responds to external perturbations. Single-cell RNA sequencing (scRNA-seq) allows the quantitative and unbiased characterization of cellular heterogeneity by providing genome-wide molecular profiles from tens of thousands of individual cells. A major question in analyzing scRNA-seq data is how to account for the observed cell-to-cell variability. In this review, we provide an overview of scRNA-seq protocols, computational approaches for dissecting cellular heterogeneity, and future directions of single-cell transcriptomic analysis.

Effects of nutrient and inorganic carbon on single cell formation of Pediastrum duplex (Pediastrum duplex의 single cell 형성에 미치는 영양염류 및 무기탄소의 영향)

  • Cho, Jae-Hyung;Noh, Kyung-Ho;Park, Kyu-Hyun;Jang, Jung-Seok;Nam, Gui-Sook;Hwang, Sun-Jin
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.2
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    • pp.153-158
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    • 2018
  • In this study, effects of nutrient and inorganic carbon on single cell emergence during the cultivation of microalgae were observed using colonial green algae, Pediastrum duplex. The concentration of inorganic carbon had significant effect on single cell emergence and its growth, but nitrogen and phosphorus concentration showed minor effects. According to P. duplex cultivation experiment, single cell started to be emerged around 500~750 mg-C/L of inorganic carbon concentration and it was bloomed dramatically at the higher values. And growth of P. duplex was started to be surpressed at the single cell formation concentration. From the results, it could be said that when we operate the microalgae systems for cultivation/harvesting or wastewater treatment, in order to avoid single cell formation, inorganic carbon should be maintained to the proper level.

Engineered microdevices for single cell immunological assay

  • Choi, Jong-Hoon
    • Interdisciplinary Bio Central
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    • v.2 no.2
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    • pp.1.1-1.8
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    • 2010
  • Microdevices have been used as effective experimental tools for the rapid and multiplexed analysis of individual cells in single-cell assays. Technological advances for miniaturizing such systems and the optimization of delicate controls in micron-sized space homing cells have motivated many researchers from diverse fields (e.g., cancer research, stem cell research, therapeutic agent development, etc.) to employ microtools in their scientific research. Microtools allow high-throughput, multiplexed analysis of single cells, and they are not limited by the lack of large samples. These characteristics may significantly benefit the study of immune cells, where the number of cells available for testing is usually limited. In this review, I present an overview of several microtools that are currently available for single-cell analyses in two popular formats: microarrays and microfluidic microdevices. Then, I discuss the potential to study human immunology on the single-cell level, and I highlight several recent examples of immunoassays performed with single-cell microdevice assays. Finally, I discuss the outlook for the development of optimized assay platforms to study human immune cells. The development and application of microdevices for studies on single immune cells presents novel opportunities for the qualitative and quantitative characterization of immune cells and may lead to a comprehensive understanding of fundamental aspects of human immunology.

A study of Polarization Modulator to Single-cell type in Polarized Glasses 3D Display System Using Binocular Parallax

  • Kong, Kyung-Bae;Kwon, Jung-Jang
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.11
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    • pp.71-78
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    • 2019
  • Most 3D displays that are currently in the market adopt the binocular disparity method creating a different image for the left and right eye for a 3 dimensional effect. However, commercialized 3D image output devices lack in performance making it uncomfortable for the viewer and restrict the viewer to certain positions. In this paper, we propose a single-cell polarized lens type stereoscopic system which has a smaller viewing angle and reduced crosstalk, with improved light penetration compared to existing double-cell structures; and analyzed the single-cell polarized lens type stereoscopic system properties, and conducted an effect analysis of performance improvement compared to the dual-cell type. Results showed that the single-cell type had a 25% improved performance, and the 3D crosstalk index which is an important index for quality characteristics of stereoscopic systems, increased over about 37%, compared to the dual-cell type.

Effects of electrode fabrication conditions on performance characteristics of phosphoric acid fuel cell (인산형 연료전지 성능 특성에 미치는 전극 제조 조건의 영향)

  • 송락현;김창수;신동렬
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.2
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    • pp.224-229
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    • 1996
  • Performance characteristics of single cell in phosphoric acid fuel cell were studied for various electrode fabrication parameters such as teflon content, electrode structure, thickness of electrocatalyst layer, platinum content and electrode area. The performance of single cell was decided from the measured voltage-current through a load change. The electrode of 40wt.% teflon exhibited high initial performance of single cell, but in the long term operation, the cell performance of 45 wt.% teflon was better. Also the single cell appeared good performance in case of electrodes with duplicate structure, thin electrocatalyst in thickness, more platinum content, and small area. These results of cell performance were discussed as related to the electrolyte flooding, formation of 3 phase boundary area, internal resistance of electrode, and microstructure of electrode.

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Single-cell RNA-Seq unveils tumor microenvironment

  • Lee, Hae-Ock;Park, Woong-Yang
    • BMB Reports
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    • v.50 no.6
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    • pp.283-284
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    • 2017
  • Single cell transcriptome analysis is a powerful tool for defining cell types or sub-populations within a heterogeneous bulk population. Tumor-associated microenvironment is a complex ecosystem consisting of numerous cell types that support tumor growth, angiogenesis, immune evasion, and metastasis. With the success of checkpoint inhibitors targeting the immune cell compartment, tumor microenvironment is emerging as a potential anti-cancer target, and understanding it has become an imminent subject in cancer biology.

Performance Characteristics of Porous Plate Single Cell For PAFC (다공성 바이폴라 사용 단위전지 성능 특성)

  • Kim, Chang-Soo;Chun, Young-Gab;Song, Rak-Hyun;Choi, Byung-Woo;Shin, Dong-Ryul;Choi, Soo-Hyun
    • Proceedings of the KIEE Conference
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    • pp.1707-1709
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    • 1996
  • For the improvement of the performance and life time of phosphoric acid fuel cell, the management of electrolyte in the electrocatalyst layer and electrolyte matrix in the cell structure is very important. Porous bipolar pinto structure, that is known as an advanced type, is generally used for the storage of electrolyte in the cell. In this paper, the single cell was made of the electrode by coating directly electrocatalyst layer on porous bipolar plate. The single cell showed $186\;mA/cm^2$ at 0.6V. This performance is similar to the performance of the conventional nonporous plate single cell. The technology of porous plate single cell could be directly used to the fabrication of stack in order to improve the performance and life time of phosphoric acid fuel cell.

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A Study on the Performance of the Polymer Electrolyte Membrane Fuel Cell Using the Metal Bipolar Plates (금속분리판을 이용한 고분자전해질 연료전지의 성능에 관한 연구)

  • Jeon, U.-S.;Cho, E.A.;Ha, H.-Y.;Hong, S.-A.;Oh, I.-H.
    • Transactions of the Korean hydrogen and new energy society
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    • v.13 no.4
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    • pp.313-320
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    • 2002
  • The characteristics of the AISI bipolar plates have been investigated to replace the expensive graphite bipolar plates. It was found from the contact resistance evaluation of graphites, composites, and AISI that the contact resistance of AISI was the lowest, but it could approach to that of composites at higher compression forces. The single cell operation using the AISI bipolar plates revealed that the lower performance of the AISI single cell compared to the graphite one was due to not only the higher contact resistance but the flooding effect caused by high wettability of AISI. The performance of the AISI single cell could be improved if the channels were modified appropriately. The large size AISI single cell was operated to investigated the size effect on the performance.

A Study on Performance of Polymer Electrolyte Membrane Fuel Cell Using Metal Foam (Metal foam을 사용한 고분자 전해질 연료전지 성능 연구)

  • KIM, MYO-EUN;KIM, CHANG-SOO;SOHN, YOUNG-JUN
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.6
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    • pp.554-559
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    • 2015
  • Single cell of PEMFC (polymer electrolyte membrane fuel cell) is composed of bipolar plates, gasket, GDL and the MEA. Bipolar plate's function is the collecting electricity, helping oxygen/hydrogen gas diffuse evenly and draining the water and heat. In this work, we have conducted experiments to low contact resistance and improve the performance of a $25cm^2$ single cell by using metal forms. We have following experimental cases: 1) Conventional graphite serpentine channel bipolar plate; 2) Channel-less bipolar plate with nickel(Ni) based metal foam which coated by various materials. We focused the difference in contact resistance and performance of the single cell with metal foam depending on various coating materials. The experimental results show the similar performance of single cells between with serpentine channel bipolar plates and with channel-less bipolar plate using metal foams. In addition, single cell with metal foam shows potential to higher performance than conventional channel.