• The Journal of Advanced Prosthodontics
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• v.13 no.3
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• pp.180-190
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• 2021

Purpose. This study aimed to assess the influence of various micromechanical surface conditioning (MSC) strategies with or without coupling agent (silane) application on the micro-shear bond strength (µSBS) of resin- matrix ceramics (RMCs). Materials and Methods. GC Cerasmart (GC), Lava Ultimate (LU), Vita Enamic (VE), Voco Grandio (VG), and Brilliant Crios (BC) were cut into 1.0-mm-thick slices (n = 32 per RMC) and separated into four groups according to the MSC strategy applied: control-no conditioning (C), air-borne particle abrasion with aluminum oxide particles (APA), 2W- and 3W-Er,Cr:YSGG group coding is missing. The specimens in each group were further separated into silane-applied and silane-free subgroups. Each specimen received two resin cement microtubules (n = 8 per subgroup). A shear force was applied to the adhesive interface through a universal test machine and µSBS values were measured. Data were statistically analyzed by using 3-way ANOVA and Tukey HSD test. Failure patterns were scrutinized under stereomicroscope. Results. RMC material type, MSC strategy, and silanization influenced the µSBS values (P<.05). In comparison to the control group, µSBS values increased after all other MSC strategies (P<.05) while the differences among these strategies were insignificant (P>.05). For control and APA, there were insignificant differences between RMCs (P>.05). The silanization decreased µSBS values of RMCs except for VE. Considerable declines were observed in GC and BC (P<.05). Conclusion. MSC strategies can enhance bond strength values at the RMC - cement interface. However, the choice of MSC strategy is dependent on RMC material type and each RMC can require a dedicated way of conditioning.

• Advances in concrete construction
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• v.16 no.4
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• pp.177-188
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• 2023

In the context of the shortage of river sand, two types of manufactured sand (MS) were used to partially replace river sand (RS) to design manufactured sand concrete (MSC). A total of 81 specimens were designed for uniaxial compression test and beam flexure test. Two parameters were considered in the tests, including the types of MS (i.e. limestone manufactured sand (LMS), pebble manufactured sand (PMS)) and the MS replacement percentage (i.e., 0%, 25%, 50%, 75%, 100%). The stress-strain curves of MSC were obtained. The effects of these parameters on the compressive strength, elastic modulus, peak strain, toughness and flexural strength were discussed. Additionally, the sensitivity of particle size distributions to the performance of MSC was evaluated based on the grey correlation analysis. The results showed that compared with river sand concrete (RSC), the rising slope of the stress-strain curves of limestone manufactured sand concrete (LMSC) and pebble manufactured sand concrete (PMSC) were higher, the descending phrase of LMSC were gentle but that of PMSC showed an opposite trend. The physical and mechanical properties of MSC were affected by the MS replacement percentage except the compressive strength of PMSC. When the replacement percentage of LMS and PMS were 50% and 25% respectively, the corresponding performances of LMSC and PMSC were better. In generally, when the replacement percentage of LMS and PMS were same, the comprehensive performance of LMSC were better than that of PMSC. The constitutive model and the equations for mechanical properties were proposed. The influence of particle ranging from 0.15 mm to 0 mm on the performance of MSC was lower than particle ranging from 4.75 mm to 0.15 mm but this influence should not be ignored.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.361-368
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• 2002

The aim of this study was to investigate the effect of preprocessing the transmitted energy spectrum data on development of a robust model to predict the sugar content in intact apples. The spectrum data were measured from 120 Fuji apple samples conveying at the speed of 2 apples per second. Computer algorithms of preprocessing methods such as MSC, SNV, first derivative, OSC and their combinations were developed and applied to the raw spectrum data set. The results indicated that correlation coefficients between the transmitted energy values at each wavelength and sugar contents of apples were significantly improved by the preprocessing of MSC and SNV in particular as compared with those of no-preprocessing. SEPs of the prediction models showed great difference depending on the preprocessing method of the raw spectrum data, the largest of 1.265%brix and the smallest of 0.507% brix. Such a result means that an appropriate preprocessing method corresponding to the characteristics of the spectrum data set should be found or developed for minimizing the prediction errors. It was observed that MSC and SNV are closely related to prediction accuracy, OSC is to number of PLS factors and the first derivative resulted in decrease of the prediction accuracy. A robust calibration model could be d3eveloped by the combined preprocessing of MSC and OSC, which showed that SEP=0.507%brix, bias=0.0327 and R2=0.8823.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1964-1971
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• 2015

Human bone marrow or human umbilical cord vein derived-mesenchymal stem cells (hBM-MSCs or hUC-MSCs) have known as a potentially useful cell type for clinical therapeutic applications. We investigated two-pore domain potassium (K2P) channels in these cells. K2P channels play a major role in setting the resting membrane potential in many cell types. Among them, TREK1 is targets of hydrogen, hypoxia, polyunsaturated fatty acids, antidepressant, and neurotransmitters. We investigated whether hBM-MSCs and hUC-MSCs express functional TREK1 channel using RT-PCR analysis and patch clamp technique. Potassium channel with a single channel conductance of 100 pS was found in hUC-MSCs and BM-MSCs and the channel was activated by membrane stretch (-5 mmHg ~ -15 mmHg), arachidonic acid ($10{\mu}M$) and intracellular acidosis (pH 6.0). These electrophysiological properties were similar to those of TREK1. Our results suggest that TREK1 is functionally present in hBM-MSCs and hUC-MSCs, where they contribute to its resting membrane potential.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1337-1345
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• 2006

Hypercholesterolemia is a pivotal pathogenic factor for the development and maintenance of atherosclerosis. The present study was designed to evaluate whether the methanol extract of Sorbus commixta cortex (MSC) restores vascular dysfunction in association with the aortic expressions of proinflarnmatory and adhesion molecules in high cholesterol (HC) diet-rats. Chronic treatment with low (100 mg/kg/day) or high doses (200 mg/kg/day) of MSC lowered the increase in plasma levels of triglyceride (TG) and low-density lipoprotein (LDL) cholesterol induced by a cholesterol-enriched diet without affecting on the plasma level of high density lipoprotein (HDL)-cholesterol. Vascular tone attenuated in the HC-diet rats was restored by administration with MSC. Treatment with MSC also suppressed the HC-induced increase in the monocyte chemoattractant protein-1 (MCP-1) and nuclear factor-$_K$B (NF-$_K$B) p65 expressions as well as expressions levels of adhesion molecules including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (ICAM-1), and E-selectin in aorta. The present study also showed that MSC inhibited the HC-mediated induction of ET-1 and ACE expression. In histopathological examination, aortic segments in the HC-diet rat revealed thickening intima and media, which were blocked by administration with MSC. Taken together, MSC could suppress the development of atherosclerosis in the HC-diet rat model through the inhibition of the aortic expression levels of pro-inflammatory and adhesion molecules.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.433-434
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• 2009

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.527-527
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• 2006

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.738-739
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• 2010

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.273-280
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• 2008

In WSN(Wireless Sensor Network) many routing algorithms such as LEACH, PEGASIS and PEDEP consisting of sensor nodes with limited energy have been proposed to extend WSN lifetime. Under the assumption of perfect fusion, these algorithms used convergecast that periodically collects sensed data from all sensor nodes to a base station. But because these schemes studied less energy consumption for a convergecast as well as fairly energy consumption altogether, the minimum energy consumption for a convergecast was not focused enough nor how topology influences to energy consumption. This paper deals with routing topology and energy consumption for a single convergecast in the following ways. We chose major WSN topology as MSC(Minimum Spanning Chain)s, MSTs, PEGASIS chains and proposed LECSEN chains. We solved the MSC length by Linear Programming(LP) and propose the LECSEN chain to compete with MST and MSC. As a result of simulation by Monte Carlo method for calculation of the topology length and standard deviation of link length, we learned that LECSEN is competitive with MST in terms of total energy consumption and shows the best with the view of even energy consumption at the sensor nodes. Thus, we concluded LECSEN is a very useful routing topology in WSN.

• Gut and Liver
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• v.12 no.6
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• pp.664-673
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• 2018

Background/Aims: Regulatory dendritic cells (rDCs), which can be induced by mesenchymal stem cells (MSCs), play an important role in inducing and maintaining homeostasis of regulatory T cells and exhibit anti-inflammatory functions. In this study, we investigated whether MSCs could differentiate DCs into rDCs and compared the therapeutic effects of rDCs and MSCs on dextran sodium sulfate (DSS)-induced chronic colitis mice. Methods: Immature DCs (imDCs) and lipopolysaccharide (LPS)-treated mature DCs (mDCs) were co-cultured with MSCs for 48 hours, and then the profiles of surface markers and cytokines and regulatory roles of these DCs for primary splenocytes were analyzed. In addition, the therapeutic effects of MSCs and DCs co-cultured with MSCs were compared in chronic colitis mice. Results: After co-culture of imDCs (MSC-DCs) or LPS-treated mDCs (LPS+MSC-DCs) with MSCs, the expression of CD11c, CD80, CD86, interleukin 6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and interferon-${\gamma}$ (IFN-${\gamma}$), was decreased, but that of CD11b, IL-10, and transforming growth factor-${\beta}$ (TGF-${\beta}$) was increased. Furthermore, MSC-DCs and LPS+MSC-DCs induced the expression of CD4, CD25, and Foxp3 in primary splenocytes isolated from mice. In DSS-induced colitis mice, MSCs and MSC-DCs increased colon length, body weight, and survival rate and induced histological improvement. Moreover, in the colon tissues, the expression of IL-6, TNF-${\alpha}$, and IFN-${\gamma}$ decreased, but that of IL-10, TGF-${\beta}$, and Foxp3 increased in the MSC- and MSC-DC-injected groups. Conclusions: Our data suggest that MSCs differentiate DCs into rDCs, which ameliorate chronic colitis. Thus, rDCs stimulated by MSCs may be therapeutically useful for the treatment of chronic inflammatory diseases.