80,413 research outputs found
Bio-vison 2016: The second national framework plan for biotechnology promotion in Korea
No full textThis research was funded by the Specific Research
and Development Project of the Ministry of Science
and Technology.This material is based on Bio-Vision
2016 and its Report [5, 6].We are very grateful to the
following members of the Biotechnology Policy Research
Center: Young-Cheol Kim, Dong-Sub Yoon,
Moo Woong Kim, Eun Jung Kim, Su Gil Kim, Mi jeong
Park, Seong-Hoon Park, Oh-Min Joung, and Seung-
Hoo Shin
5,7-dihydroxy-3,4,6-trimethoxyflavone inhibits the inflammatory effects induced by Bacteroides fragilis enterotoxin via dissociating the complex of heat shock protein 90 and I kappa B alpha and I kappa B kinase-gamma in intestinal epithelial cell culture
No full textEnterotoxin produced by enterotoxigenic Bacteroides fragilis (BFT) has been associated with mucosal inflammation and diarrhoeal diseases. In this study, the anti-inflammatory molecular mechanism of 5,7-dihydroxy-3,4,6-trimethoxyflavone (eupatilin) was characterized in an HT-29 intestinal epithelial cell line stimulated with BFT. Pre-treatment of HT-29 cells with eupatilin decreased the production significantly of both interleukin (IL)-8 and prostaglandin E(2) induced by BFT in a dose-dependent manner. BFT-activated nuclear factor-kappaB (NF-kappa B) signals in HT-29 cells and pretreatment with eupatilin suppressed NF-kappa B activation that resulted in the significant inhibition of IL-8 and cyclo-oxygenase-2 expression. BFT-induced phosphorylation of both I kappa B alpha and I kappa B kinase (IKK) signals was prevented in eupatilin-pretreated HT-29 cells. Transfection of siRNA for IKK-alpha and IKK-beta decreased the production of IL-8 and prostaglandin E(2); however, the transfection of IKK-beta siRNA showed a more significant reduction of BFT-induced I kappa B alpha phosphorylation compared with that of IKK-alpha siRNA. In addition, herbimycin A, a specific inhibitor of heat shock protein 90 (Hsp90), decreased the BFT-induced activation of IKK and NF-kappa B, suggesting that Hsp90 is associated with a pathway of IKK-NF-kappa B-IL-8/cyclo-oxygenase-2 gene signalling. Furthermore, eupatilin dissociated the complex between Hsp90 and IKK-gamma in BFT-stimulated HT-29 cells. These results suggest that eupatilin can suppress the NF-kappa B signalling pathway by targeting the Hsp90-IKK-gamma complex in intestinal epithelial cells and may attenuate BFT-induced inflammatory responses.J. M. Kim and D. H. Lee contributed equally to this work. We thank Dr Martin F. Kagnoff and Dr Joseph A. DiDonato for providing the reporter gene plasmids and Sung-Hee Yang, Jung Sang Youn and Han Jin Lee for their expert technical assistance. This work was supported by a grant from Seoul R&BD Program and the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (R11-2008-044-01004-0)
A 16b quadrature direct digital frequency synthesizer using interpolative angle rotation algorithm
No full textAn area-efficient implementation of digital-IF QAM coherent demodulator for software-defined radio receivers
No full textBiomechanical characterization with inverse FE model parameter estimation: Macro and micro applications
No full textEffect of annealing temperature on the electrical transport properties of CaRuO3-delta thin films directly deposited on the Si substrate
No full textWe investigate the effect of annealing temperature on the preferentially (110)-oriented CaRuO3-delta, (CRO) thin films directly prepared on Si(100) substrate by rf magnetron sputtering. Crystalline quality and electrical transport properties of the CRO thin films were modified by post-annealing treatment. It was obvious that 700 degrees C post-annealing brought about excellent metallic characteristics with the elevation of carrier concentration and mobility. From this result, we suggested that enhanced (110) orientation, and the ratio of chemical composition Ru4+/Ca2+ ion were responsible for the transport properties of CRO thin film. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.‘Brain Korea 21’ project. We appreciate the measurement of transport property using a He cryostat (Korea Basic Science Institute), and also thanks to Mr. Yunseok
Kim for measuring of atomic force microscopy (KAIST)
The dynamic healing profile of human periodontal ligament stem cells: histological and immunohistochemical analysis using an ectopic transplantation model
No full textKim Y-T, Park J-C, Choi S-H, Cho K-S, Im G-I, Kim B-S, Kim C-S. The dynamic healing profile of human periodontal ligament stem cells: histological and immunohistochemical analysis using an ectopic transplantation model. J Periodont Res 2012; 47: 514524. (c) 2012 John Wiley & Sons A/S Background and Objective: Human periodontal ligament stem cells (hPDLSCs) have been reported to play the pivotal role in periodontal regeneration. However, the dynamic cellular healing process initiated by hPDLSCs still remains to be elucidated. In the present study, the sequence of regeneration by hPDLSCs was assessed using histological and immunohistochemical observation in an ectopic transplantation model, which is a well-standardized assessment tool that excludes the innate healing factors from the animals. Material and Methods: Human periodontal ligament stem cells that were isolated and characterized from teeth (n = 12) extracted for the purpose of orthodontic treatment were transplanted with carriers into ectopic subcutaneous pouches in immunocompromised mice (n = 20). Animals were killed after several different healing periods: 3 d (n = 4), 1 (n = 4), 2 (n = 4), 4 (n = 4) and 8 wk (n = 4). Histological analysis for regenerated tissues formed by hPDLSCs was conducted using hematoxylin and eosin, Massons trichrome and picrosirius red staining. In addition, immunohistochemical staining was performed to observe the sequential expression of osteogenic/cementogenic and periodontal ligament tissue-specific markers associated with periodontal regeneration. Results: The whole healing process by transplanted hPDLSCs could be broadly divided into four distinctive phases. In the first phase, proliferated hPDLSCs migrated evenly all over the carrier, and collagenous tissues appeared in the form of amorphous collagen matrices. In the second phase, collagen fibers were well arranged among the carriers, and cementoid-like tissues were observed. In the third phase, the formation of mature collagen fibers, resembling Sharpeys fibers, was associated with active mineralization of cementum-like tissues, and in the fourth phase, the maturation of cementum-like tissues was observed on carrier surfaces. Various osteogenic/cementogenic markers related to the regeneration processes were expressed in a well-orchestrated time order. Interestingly, well-organized cementum-like and periodontal ligament fiber-like tissues and cells with early and late osteogenic/cementogenic markers were frequently observed in the secluded area of carrier surfaces. We termed this area the cell-rich zone. Conclusion: The results from this study clearly demonstrated the sequential histological changes during periodontal tissue regeneration by hPDLSCs. Understanding of this process would potentially enable us to develop better cell-based treatment techniques.N
A compact and stable incidence-plane-rotating second harmonics detector
No full text© 2021 Author(s).We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m2 and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe2, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.11Nsciescopu
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