• Title/Summary/Keyword: Small cells

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Retention of Endothelial Cells adhered on Polyurethane Surface under Flow Condition

  • Chang, Jun-Keun;Chang, Hyun-A;Kim, Jin-Hee;Kim, Jong-Won;Han, Dong-Chul;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
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    • v.17 no.3
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    • pp.355-364
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    • 1996
  • Construction of the stable monolayer of endothelial cells onto physicochemically modified polymeric surFace is one of the appropriate method to develop the small caliber vascular graft with the long-term patency. In this study, we constructed the monolayer of endothelial cells on the fibronectin rind the extracellular matrix-coated polyurethane surface derived from human fibroblast cells. To elucidate the adhesion strength of endothelial cells on the extracellular matrix-coated polyurethane, a laminar flow chamber apparatus was developed to exposure the shear stress on the apical membrane of ondothelial cells. Endothelial cells show the strongest adhesion after two days of seeding onto the fibronectin-coated polyurethane surface, whereas endothelial cells on the extracellular matrix derived from the human flbroblast cells show the minimal doubling time of cellular growth.

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Distributed BS Transmit Power Control for Utility Maximization in Small-Cell Networks (소형 셀 환경에서 유틸리티 최대화를 위한 분산화된 방법의 기지국 전송 전력 제어)

  • Lee, Changsik;Kim, Jihwan;Kwak, Jeongho;Kim, Eunkyung;Chong, Song
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.12
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    • pp.1125-1134
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    • 2013
  • Small cells such as pico or femto cells are promising as a solution to cope with higher traffic explosion and the large number of users. However, the users within small cells are likely to suffer severe inter-cell interference (ICI) from neighboring base stations (BSs). To tackle this, several papers suggest BS transmit power on/off control algorithms which increase edge user throughput. However, these algorithms require centralized coordinator and have high computational complexity. This paper makes a contribution towards presenting fully distributed and low complex joint BS on/off control and user scheduling algorithm (FDA) by selecting on/off pattern of BSs. Throughput the extensive simulations, we verify the performance of our algorithm as follows: (i) Our FDA provides better throughput performance of cell edge users by 170% than the algorithm without the ICI management. (ii) Our FDA catches up with the performance of optimal algorithm by 88-96% in geometric average throughput and sufficiently small gap in edge user throughput.

Effects of Yijin-tang on Pacemaker Potentials in Interstitial Cells of Cajal of Murine Small Intestine (이진탕의 생쥐 소장 카할세포 향도잡이 전압에 미치는 효능에 관한 연구)

  • Han, Donghun;Kim, Jeong Nam;Kim, Byung Joo
    • Herbal Formula Science
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    • v.28 no.1
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    • pp.71-80
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    • 2020
  • Obejectives : The purpose of this study was to investigate the effects of Yijin-tang on pacemaker potentials of small intestinal interstitial Cells of Cajal (ICC). Methods : To dissociate the ICC, we used enzymatic digestions from the small intestine in mice. The electrophysiological whole-cell patch-clamp configuration was used to record pacemaker potentials in the cultured ICC and the in vivo effects of Yijin-tang on GI motility were investigated by calculating percent intestinal transit rates (ITR). Results : 1. The ICC generated pacemaker potentials in the murine small intestine. Yijin-tang produced membrane depolarization with concentration-dependent manners in the current clamp mode. 2. Pretreatment with a Ca2+ free solution and thapsigargin, a Ca2+-ATPase inhibitor in the endoplasmic reticulum, stopped the pacemaker potentials. In the case of Ca2+-free solutions and thapsigargin, Yijin-tang did not induce membrane potential depolarizations. 3. U73122, a phospholipase C (PLC) inhibitors, blocked the Yijin-tang-induced membrane potential depolarizations. However, U73343, an inactive PLC inhibitors, did not block. 4. In the presence of protein kinase C (PKC) inhibitors, staurosporine or Rottlerin, Yijin-tang depolarized the pacemaker potentials. However, in the presence of Go6976, Yijin-tang did not depolarize the pacemaker potentials. 5. In mice, intestinal transit rate (ITR) values were significantly and dose-dependently increased by the intragastric administration of Yijin-tang. Conclusions : These results suggest that Yijin-tang can modulate the pacemaker activity of ICC through an internal/external Ca2+ and PLC/PKC-dependent pathway in ICC. In addition, Yijin-tang is a good candidate for the development of a prokinetic agent.

Effect of Surface Microstructure of Silicon Substrate on the Reflectance and Short-Circuit Current (실리콘 기판 표면 형상에 따른 반사특성 및 광 전류 개선 효과)

  • Yeon, Chang Bong;Lee, Yoo Jeong;Lim, Jung Wook;Yun, Sun Jin
    • Korean Journal of Materials Research
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    • v.23 no.2
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    • pp.116-122
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    • 2013
  • For fabricating silicon solar cells with high conversion efficiency, texturing is one of the most effective techniques to increase short circuit current by enhancing light trapping. In this study, four different types of textures, large V-groove, large U-groove, small V-groove, and small U-groove, were prepared by a wet etching process. Silicon substrates with V-grooves were fabricated by an anisotropic etching process using a KOH solution mixed with isopropyl alcohol (IPA), and the size of the V-grooves was controlled by varying the concentration of IPA. The isotropic etching process following anisotropic etching resulted in U-grooves and the isotropic etching time was determined to obtain U-grooves with an opening angle of approximately $60^{\circ}$. The results indicated that U-grooves had a larger diffuse reflectance than V-grooves and the reflectances of small grooves was slightly higher than those of large grooves depending on the size of the grooves. Then amorphous Si:H thin film solar cells were fabricated on textured substrates to investigate the light trapping effect of textures with different shapes and sizes. Among the textures fabricated in this work, the solar cells on the substrate with small U-grooves had the largest short circuit current, 19.20 mA/$cm^2$. External quantum efficiency data also demonstrated that the small, U-shape textures are more effective for light trapping than large, V-shape textures.

Chemical Genomics and Medicinal Systems Biology: Chemical Control of Genomic Networks in Human Systems Biology for Innovative Medicine

  • Kim, Tae-Kook
    • BMB Reports
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    • v.37 no.1
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    • pp.53-58
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    • 2004
  • With advances in determining the entire DNA sequence of the human genome, it is now critical to systematically identify the function of a number of genes in the human genome. These biological challenges, especially those in human diseases, should be addressed in human cells in which conventional (e.g. genetic) approaches have been extremely difficult to implement. To overcome this, several approaches have been initiated. This review will focus on the development of a novel 'chemical genetic/genomic approach' that uses small molecules to 'probe and identify' the function of genes in specific biological processes or pathways in human cells. Due to the close relationship of small molecules with drugs, these systematic and integrative studies will lead to the 'medicinal systems biology approach' which is critical to 'formulate and modulate' complex biological (disease) networks by small molecules (drugs) in human bio-systems.

Morphological Review on Mitochondria Damage by Irradiation (방사선에 의한 미토콘드리아 손상의 형태학적 고찰)

  • JI, Tae-Jeong
    • Journal of radiological science and technology
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    • v.43 no.1
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    • pp.29-34
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    • 2020
  • Mitochondria was observed much around the nuclear membrane of liver tissue where the energy metabolism process is active. Testis tissue had a large number of undifferentiated cells, and cristae in Inner membrane of Mitochondria was not observed clearly. Morphological damage occurred first in Inner membrane rather than the outer membrane. The kidney tissue was clearly observed in the form of cristae. Radiation-induced damage occurred at the edges of both ends, and the membrane was observed bursting with the thickness of the outer membrane. Small intestine cells were observed in many mitochondria in the tissues around the villus, where bowel movements were active. Morphological damage occurred with the outer and inner membranes getting tangled. Mitochondria sensitivity to radiation was sensitized in testis and small intestine tissues, and kidney, ovary and liver tissues were found to be resistant.

Predictive Role of Computer Simulation in Assessing Signaling Pathways of Crizotinib-treated A549 Lung Cancer Cells

  • Xia, Pu;Mou, Fei-Fei;Wang, Li-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3119-3121
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    • 2012
  • Non-small-cell lung cancer (NSCLC) is a leading cause of cancer deaths worldwide. Crizotinib has been approved by the U.S. Food and Drug Administration for the treatment of patients with advanced NSCLC. However, understanding of mechanisms of action is still limited. In our studies, we confirmed crizotinib-induced apoptosis in A549 lung cancer cells. In order to assess mechanisms, small molecular docking technology was used as a preliminary simulation of signaling pathways. Interesting, our results of experiments were consistent with the results of computer simulation. This indicates that small molecular docking technology should find wide use for its reliability and convenience.

Clostridium perfringens type A associated enteritis in a Shitzu dog

  • Byun, Jae-Won;Yoon, Soon-Seek;Lim, Suk-Kyung;Lee, O-Soo
    • Korean Journal of Veterinary Service
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    • v.29 no.4
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    • pp.497-501
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    • 2006
  • Acute hemorrhagic enteritis was diagnosed in a seven-month-old male Shitzu dog dying of blood stained diarrhea and vomiting. Clinical findings were anorexia, dullness and sudden death after massive bloody diarrhea. At necropsy, main lesion was the hemorrhage in small intestine, mainly duodenum and jejunum. Microscopically, Gram positive long bacilli were massively detected on the mucose epithelial cells and necrotic debris of small intestine. Coagulative necrosis of epithelial cells and thrombosis of small intestine were also identified. However, there was no lesion of crypt epithelium. Mineral infiltration in both gastric mucosa and renal tubules was detected and proliferation of fibrous tissue was also shown in corticomedullary regions. In bacterial examination, C perfringens was isolated in anaerobic culture and it was confirmed to type A by multiplex PCR. Therefore, the dog was diagnosed as C perfringens type A associated enteritis with uremia.

3GPP Standardization Activity for Small Cell Enhancement (3GPP 소형셀 향상 표준화 기술 동향)

  • Baek, SeungKwon;Chang, SungCheol
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.628-631
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    • 2014
  • Recently, the proliferation of new applications, e.g., mobile TV, Internet gaming, large file transfer, and the various of user terminals, e.g., smart phones and notebooks, has dramatically increased user traffic and network load. In order to meet this traffic growth, vendors and cellular operators are working on the development of new technologies and cellular standards. Within them, small cell deployment has been heralded as one of most promising way to increase both coverage and capacity of future cellular network. Small cell technology enables to improve capacity of cellular radio network by tight cooperation between small cell and macro cell in multi-tier network where small cells are densely deployed within macro cell coverage. In this paper, we describe the deployment scenarios for cooperation between macro cell and small cells and state-of-the-art technologies related to dense small cell deployment. Then, we also provide design principles and standardization trends for small cell enhancement in 3GPP.

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FBW7 Upregulation Enhances Cisplatin Cytotoxicity in Non-small Cell Lung Cancer Cells

  • Yu, Hao-Gang;Wei, Wei;Xia, Li-Hong;Han, Wei-Li;Zhao, Peng;Wu, Sheng-Jun;Li, Wei-Dong;Chen, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6321-6326
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    • 2013
  • Introduction: Lung cancer is extremely harmful to human health and has one of the highest worldwide incidences of all malignant tumors. Approximately 80% of lung cancers are classified as non-small cell lung cancers (NSCLCs). Cisplatin-based multidrug chemotherapy regimen is standard for such lesions, but drug resistance is an increasing problem. F-box/WD repeat-containing protein 7 (FBW7) is a member of the F-box protein family that regulates cell cycle progression, and cell growth and differentiation. FBW7 also functions as a tumor suppressor. Methods: We used cell viability assays, Western blotting, and immunofluorescence combined with siRNA interference or plasmid transfection to investigate the underlying mechanism of cisplatin resistance in NSCLC cells. Results: We found that FBW7 upregulation significantly increased cisplatin chemosensitivity and that cells expressing low levels of FBW7, such as NCI-H1299 cells, have a mesenchymal phenotype. Furthermore, siRNA-mediated silencing or plasmid-mediated upregulation of FBW7 resulted in altered epithelial-mesenchymal transition (EMT) patterns in NSCLC cells. These data support a role for FBW7 in regulating the EMT in NSCLC cells. Conclusion: FBW7 is a potential drug target for combating drug resistance and regulating the EMT in NSCLC cells.