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The Effects of Boron on the Proliferation of Osteoblastic and Neuroblastoma Cells
Choi, Hye-Sook,Hang, Do,Choi, Mi-Kyeong,Lee, Sung-Ryul,Pyo, Suhkneung,Son, Eun-Wha,Kim, Mi-Hyun The Korean Society of Food Science and Nutrition 2005 Preventive Nutrition and Food Science Vol.10 No.4
It has been recently reported that boron affects bone metabolism in humans and animals. In this study we examined whether boron affects the proliferation on various cell types, MG-63, HOS, Raw 264.7 and SK-N-SH. When treated with different concentrations of boron $(1,\;10,\;100{\mu}M)$ for 24 and 48 hr, the proliferation of MG-63 cells was enhanced at $10{\mu}M\;(p<0.05)$, for 24 hr. In HOS cells, boron had no effect on cell proliferation at 24 or 48 hr. In addition, treatment of pre-osteoclastic cells (Raw 264.7) with 1, 10, $100{\mu}M$ boron resulted in no effect on cell proliferation. Proliferation of neuronal cells (SK-N-SH) was enhanced by boron in a concentration dependent manner at low concentrations (0.1, 0.5, $1{\mu}M$). Besides proliferation activity, boron has an effect on the enhancement of NO production in SK-N-SH cells in a concentration-dependent manner. These studies showed that boron enhances proliferation of osteoblastic cells (especially MG-63), depending upon the concentration of boron. These results also provide further evidence of the positive effects of boron in neuronal disease.
A Position based Kinematic Method for the Analysis of Human Gait
Choi Ahn Ryul,Rim Yong Hoon,Kim Youn Soo,Mun Joung Hwan The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.10
Human joint motion can be kinematically described in three planes, typically the frontal, sagittal, and transverse, and related to experimentally measured data. The selection of reference systems is a prerequisite for accurate kinematic analysis and resulting development of the equations of motion. Moreover, the development of analysis techniques for the minimization of errors, due to skin movement or body deformation, during experiments involving human locomotion is a critically important step, without which accurate results in this type of experiment are an impossibility. The traditional kinematic analysis method is the Angular-based method (ABM), which utilizes the Euler angle or the Bryant angle. However, this analysis method tends to increase cumulative errors due to skin movement. Therefore, the objective of this study was to propose a new kinematic analysis method, Position-based method (PBM), which directly applies position displacement data to represent locomotion. The PBM presented here was designed to minimize cumulative errors via considerations of angle changes and translational motion between markers occurring due to skin movements. In order to verify the efficacy and accuracy of the developed PBM, the mean value of joint dislocation at the knee during one gait cycle and the pattern of three dimensional translation motion of the tibiofemoral joint at the knee, in both flexion and extension, were accessed via ABM and via new method, PBM, with a Local Reference system (LRS) and Segmental Reference system (SRS), and then the data were compared between the two techniques. Our results indicate that the proposed PBM resulted in improved accuracy in terms of motion analysis, as compared to ABM, with the LRS and SRS.
Choi, Choeng-Ryul,Kim, Chang-Nyung The Korean Society of Mechanical Engineers 2000 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.14 No.12
Two phase flows have been numerically calculated to analyze plume characteristics and liquid circulation in gas injection through a porous plug. The Eulerian approach has been for formulation of both the continuous and dispersed phases. The turbulence in the liquid phase has been modeled using the standard $textsc{k}$-$\varepsilon$ turbulence model. The interphase friction coefficient has been calculated using correlations available in the literature. The turbulent dispersion of the phase has been modeled by the "dispersion Prand시 number". The predicted mean flows is compared well with the experimental data. The plume region area and the axial velocities are increased with the gas flow rate and with the decrease in the inlet area. The turbulent intensity also shows the same trend. Also, the space-averaged turbulent kinetic energy for various gas flow rates and inlet areas has been obtained. The results are of interest in the design and operation of a wide variety of materials and chemical processing operations.
Choi, Jong-Ryul,Hong, Sung-Woon,Kim, Yu-Ri,Jang, Se-Eun,Kim, Nam-Jae,Han, Myung-Joo,Kim, Dong-Hyun The Korean Society of Ginseng 2011 Journal of Ginseng Research Vol.35 No.3
To evaluate the difference in expressing pharmacological effects of ginseng by intestinal microflora between Koreans, metabolic activities of ginseng, ginsenoside $Rb_1$ and $Rg_1$ by 100 fecal specimens were measured. The ${\beta}$-glucosidase activity for p-nitrophenyl-${\beta}$-D-glucopyranoside was 0 to 0.42 mmol/min/mg and its average activity (mean${\pm}$SD) was $0.10{\pm}0.07$ mmol/min/mg. The metabolic activities of ginsenosides Rb1 and Rg1 were 0.01 to 0.42 and 0.01 to 0.38 pmol/min/mg, respectively. Their average activities were $0.25{\pm}0.08$ and $0.15{\pm}0.09$ pmol/min/mg, respectively. The compound K-forming activities from ginsenoside Rb1 and ginseng extract were 0 to 0.11 and 0 to 0.02 pmol/min/mg, respectively. Their average compound K-forming activities were $0.24{\pm}0.09$ pmol/min/ mg and $2.14{\pm}3.66$ fmol/min/mg, respectively. These activities all were not different between males and females, or between ages. Although compound K-forming activity from the aqueous extract of ginseng was low compared to that from ginenoside $Rb_1$, their profiles were similar to those of isolated compounds. Based on these findings, we believe that the intestinal bacterial metabolic activities of ginseng components are variable in individuals and may be used as selection markers for responders to ginseng.
Measurement of Fiber Board Poisson's Ratio using High-Speed Digital Camera
Choi, Seung-Ryul,Choi, Dong-Soo,Oh, Sung-Sik,Park, Suk-Ho,Kim, Jin-Se,Chun, Ho-Hyun Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.4
Purpose: The finite element method (FEM) is advantageous because it can save time and cost by reducing the number of samples and experiments in the effort to identify design factors. In computational problem-solving it is necessary that the exact material properties are input for achieving a reliable analysis. However, in the case of fiber boards, it is difficult to measure their cross-directional material properties because of their small thickness. In previous research studies, the Poisson's ratio was measured by analyzing ultrasonic wave velocities. Recently, the Poisson's ratio was measured using a high-speed digital camera. In this study, we measured the transverse strain of a fiber board and calculated its Poisson's ratio using a high-speed digital camera in order to apply these estimates to a FEM analysis of a fiber board, a corrugated board, and a corrugated box. Methods: Three different fiber board samples were used in a uniaxial tensile test. The longitudinal strain was measured using the Universal Testing Machine. The transverse strain was measured using an image processing method. To calculate the transverse strain, we acquired images of the fiber board before the test onset and before the fracture occurred. Acquired images were processed using the image processing program MATLAB. After the images were converted from color to binary, we calculated the width of the fiber board. Results: The calculated Poisson's ratio ranged between 0.2968-0.4425 (Machine direction, MD) and 0.1619-0.1751 (Cross machine direction, CD). Conclusions: This study demonstrates that measurement of the transverse properties of a fiber board is possible using image processing methods. Correspondingly, these processing methods could be used to measure material properties that are difficult to measure using conventional measuring methodologies that employ strain gauge extensometers.
Cereblon Maintains Synaptic and Cognitive Function by Regulating BK Channel
Choi, Tae-Yong,Lee, Seung-Hyun,Kim, Yoon-Jung,Bae, Jae Ryul,Lee, Kwang Min,Jo, Youhwa,Kim, Soo-Jeong,Lee, A-Ram,Choi, Sekyu,Choi, La-Mee,Bang, Sunhoe,Song, Mi-Ryoung,Chung, Jongkyeong,Lee, Kyung Jin,K The Society 2018 The Journal of neuroscience Vol.38 No.14
<P>Mutations in the cereblon (CRBN) gene cause human intellectual disability, one of the most common cognitive disorders. However, the molecular mechanisms of CRBN-related intellectual disability remain poorly understood. We investigated the role of CRBN in synaptic function and animal behavior using male mouse and Drosophila models. Crbn knock-out (KO) mice showed normal brain and spine morphology as well as intact synaptic plasticity; however, they also exhibited decreases in synaptic transmission and presynaptic release probability exclusively in excitatory synapses. Presynaptic function was impaired not only by loss of CRBN expression, but also by expression of pathogenic CRBN mutants (human R419X mutant and Drosophila G552X mutant). We found that the BK channel blockers paxilline and iberiotoxin reversed this decrease in presynaptic release probability in Crbn KO mice. In addition, paxilline treatment also restored normal cognitive behavior in CrbnKOmice. These results strongly suggest that increased BK channel activity is the pathological mechanism of intellectual disability in CRBN mutations.</P>