291 research outputs found

    Electronic structures of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

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    We investigated the electronic structure of multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using both optical spectroscopy and first-principles calculations. Using artificially stabilized hexagonal RMnO3, we extended the optical spectroscopic studies on the hexagonal multiferroic manganite system. We observed two optical transitions located near 1.7 eV and 2.3 eV, in addition to the predominant absorption above 5 eV. With the help of first-principles calculations, we attribute the low-lying optical absorption peaks to inter-site transitions from the oxygen states hybridized strongly with different Mn orbital symmetries to the Mn 3d3z2-r2 state. As the ionic radius of the rare earth ion increased, the lowest peak showed a systematic increase in its peak position. We explained this systematic change in terms of a flattening of the MnO5 triangular bipyramid

    ์ผ์ธก์„ฑ ๊ตฌ์ˆœ์—ด ํ™˜์ž์—์„œ 3์ฐจ์› ์ˆ˜์น˜์‚ฌ์ง„์ธก๋Ÿ‰ ์Šค์บ”๊ณผ ์ง์ ‘๊ณ„์ธก ๋ฐฉ๋ฒ•์˜ ๋น„๊ต

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    Background: In cleft lip patients, the necessity of a thorough preoperative analysis of facial deformities before reconstruction is unquestioned. The surgical plan of cleft lip patient is based on the information gained from our preoperative anthropometric evaluation. A variety of commercially available three-dimensional (3D) surface imaging systems are currently introduced to us in plastic surgery for these use. However, few studies have been published on the soft tissue morphology of unrepaired cleft infants described by these 3D surface imaging systems.Methods: The purpose of this study is to determine the accuracy of facial anthropometric measurements obtained through digital 3D photogrammetry and to compare with direct anthropometry for measurement in unilateral cleft lip patients. We compared our patients with three measurements of dimension made on both sides: heminasal width, labial height, and transverse lip length.Results: The preoperative measurements were not significantly different in both side of labial height and left side of heminasal width. Statistically significant differences were found on both side of transverse lip length and right side of heminasal width. Although the half of preoperative measurements were significantly different, trends of results showed average results were comparable.Conclusion: This is the first study in Korea to simultaneously compare digital 3D photogrammetry with traditional direct anthropometry in unilateral cleft lip patients. We desire this study could contribute the methodological choice of the many researchers for proper surgical planning in cleft lip reconstruction field.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000004298/10SEQ:10PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000004298ADJUST_YN:YEMP_ID:A072100DEPT_CD:852FILENAME:๊น€์„ํ™”-3d-nose-2013.pdfDEPT_NM:์น˜์˜๊ณผํ•™๊ณผSCOPUS_YN:NCONFIRM:

    Zinc-chelated Vitamin C Stimulates Adipogenesis of 3T3-L1 Cells

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    Adipose tissue development and function play a critical role in the regulation of energy balance, lipid metabolism, and the pathophysiology of metabolic syndromes. Although the effect of zinc ascorbate supplementation in diabetes or glycemic control is known in humans, the underlying mechanism is not well described. Here, we investigated the effect of a zinc-chelated vitamin C (ZnC) compound on the adipogenic differentiation of 3T3-L1 preadipocytes. Treatment with ZnC for 8 d significantly promoted adipogenesis, which was characterized by increased glycerol-3-phosphate dehydrogenase activity and intracellular lipid accumulation in 3T3-L1 cells. Meanwhile, ZnC induced a pronounced up-regulation of the expression of glucose transporter type 4 (GLUT4) and the adipocyte-specific gene adipocyte protein 2 (aP2). Analysis of mRNA and protein levels further showed that ZnC increased the sequential expression of peroxisome proliferator-activated receptor gamma (PPARฮณ) and CCAAT/enhancer-binding protein alpha (C/EBPฮฑ), the key transcription factors of adipogenesis. These results indicate that ZnC could promote adipogenesis through PPARฮณ and C/EBPฮฑ, which act synergistically for the expression of aP2 and GLUT4, leading to the generation of insulin-responsive adipocytes and can thereby be useful as a novel therapeutic agent for the management of diabetes and related metabolic disorders

    Suppression of STAT3 and HIF-1 Alpha Mediates Anti-Angiogenic Activity of Betulinic Acid in Hypoxic PC-3 Prostate Cancer Cells

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    Background: Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. Methodology/Principal Findings: BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1a (HIF-1a) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1a and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia. Conclusions/Significance: Taken together, our results suggest that BA has anti-angiogenic activity by disturbing th

    Zebrafish as an animal model in epilepsy studies with multichannel EEG recordings

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    Despite recent interest in using zebrafish in human disease studies, sparked by their economics, fecundity, easy handling, and homologies to humans, the electrophysiological tools or methods for zebrafish are still inaccessible. Although zebrafish exhibit more significant larval-adult duality than any other animal, most electrophysiological studies using zebrafish are biased by using larvae these days. The results of larval studies not only differ from those conducted with adults but also are unable to delicately manage electroencephalographic montages due to their small size. Hence, we enabled noninvasive long-term multichannel electroencephalographic recording on adult zebrafish using customdesigned electrodes and perfusion system. First, we exploited demonstration of long-term recording on pentylenetetrazole-induced seizure models, and the results were quantified. Second, we studied skin- electrode impedance, which is crucial to the quality of signals. Then, seizure propagations and gender differences in adult zebrafish were exhibited for the first time. Our results provide a new pathway for future neuroscience research using zebrafish by overcoming the challenges for aquatic organisms such as precision, serviceability, and continuous water seepage. ยฉ The Author(s) 2017.1

    Chronic gastrointestinal symptoms and quality of life in the Korean population

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    AIM: To evaluate the prevalence of chronic gastrointestinal symptoms and their impact on health-related quality of life (HRQOL) in the Korean population

    Characteristics of primary and immortalized fibroblast cells derived from the miniature and domestic pigs

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    <p>Abstract</p> <p>Background</p> <p>The pig, <it>Sus scrofa domestica </it>includes both the miniature and commercial domestic breed. These animals have influenced the human life and economies and have been studied throughout history. Although the miniature breeds are more recent and have increasingly been used in a variety of biomedical studies, their cell lines have rarely been established. Therefore, we sought to establish primary and immortal cell lines derived from both the miniature and domestic pig to better enable insight into possible <it>in vivo </it>growth differences.</p> <p>Results</p> <p>The <it>in vitro </it>lifespan of primary domestic pig fibroblast (PF) and miniature pig fibroblast (MPF) cells using a standard 3T3 protocol was determined. Both of the primary PF and MPF cells were shown to have a two-step replicative senescence barrier. Primary MPF cells exhibited a relatively shorter lifespan and slower proliferation rate compared to those of primary PF cells. Beyond senescence barriers, lifespan-extended PF and MPF cells were eventually established and indicated spontaneous cellular immortalization. In contrast to the immortalized PF cells, immortal MPF cells showed a transformed phenotype and possessed more frequent chromosomal abnormalities and loss of p53 regulatory function. The lifespan of primary MPF and PF cells was extended by inactivation of the p53 function using transduction by SV40LT without any detectable senescent phenotype.</p> <p>Conclusion</p> <p>These results suggest that p53 signaling might be a major determinant for the replicative senescence in the MPF cells that have the shorter lifespan and slower growth rate compared to PF cells <it>in vitro</it>.</p
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