• Journal of Korean Neurosurgical Society
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• v.53 no.4
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• pp.207-212
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• 2013

Objective : Recent studies have shown encouraging progress toward the use of autogenic and allogenic mesenchymal stem cells (MSCs) to arrest, or even lead to partial regeneration in, intervertebral disc (IVD) degeneration. However, this technology is still in its infancy, and further development is required. The aim of this study was to analyze whether rat adipose-derived mesenchymal stem cells (ADMSC) can differentiate towards IVD-like cells after treatment with transforming growth factor ${\beta}3$ (TGF-${\beta}3$) in vitro. We also performed quantitative analysis of gene expression for ADMSC only, ADMSCs treated with TGF-${\beta}3$, and co-cultured ADMSCs treated with TGF-${\beta}3$. Methods : ADMSCs were sub-cultured to homogeneity and used in fluorocytometry assays for CD11, CD45, and CD90/Thy1. ADMSCs were differentiated in spheroid culture towards the chondrogenic lineage by the presence of TGF-${\beta}3$, dexamethasone, and ascorbate. We also co-cultured pure ADMSCs and nucleus pulposus cells in 24-well plates, and performed immunohistochemical staining, western blotting, and RT-PCR for quantitative analysis of gene expression. Results : Results of fluorocytometry were positive for CD90/Thy1 and negative for CD11 and CD45. TGF-${\beta}3$-mediated induction of ADMSCs led to the expression of the differentiation markers of intervertebral disc-like cells, such as aggrecan, collagen II, and sox-9. Co-cultured ADMSCs treated with TGF-${\beta}3$ showed higher expression of differentiation markers and greater extracellular matrix production compared with ADMSCs treated with TGF-${\beta}3$ alone. Conclusion : ADMSC treated with TGF-${\beta}3$ may be an attractive source for regeneration therapy in degenerative IVD. These findings may also help elucidate the pathologic mechanism of MSC therapy in the degeneration of IVD in vivo.

• Polymer(Korea)
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• v.34 no.1
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• pp.1-7
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• 2010

To enhance the transport properties of gas separation membrane, we prepared 6FDA-6FpDA based polyimide membrane with PMMA-graft-silica nanoparticles. The silica was grafted PMMA which is miscible with 6FDA-based polyimide after surface treatment by 3-methacryloxypropyltrimethoxysilane ($\gamma$-MPS). The untreated silica/6FDA-6FpDA membrane showed greater permeability and less selectivity than PMMA-g-silica/6FDA-6FpDA due to its low dispersion. The transport properties of PMMA-g-silica/6FDA-GFpDA membrane were measured as a function of filler concentration. These membranes were evaluated using pure gases (He, $O_2$, $N_2$, $CO_2$). The increase in permeation was attributed to changes in the free volume distribution until 1 wt%. After 1 wt%, the permeability was decreased by excess silica which decreased effective area in polymer matrix. The selectivity was decreased with increasing permeability on the whole. However, the selectivity of $CO_2$ showed more enhance value.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.55-61
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• 2000

The sintering characteristics of PVA-Al(III) complex added $UO_2$ pellet and AlOOH added $UO_2$pellet were compared. The major phase of PVA-Al(III) complex and AlOOH decomposed at $1000^{\circ}C$ in $H_2$atmosphere was $\theta-Al_2O_3$. Compared with the apparent density of pure $UO_2$, that of AlOOH added $UO_2$ powder was higher but that of PVA-Al(III) complex was lower. the densification of AlOOH added $UO_2$ pellet was initiated at about $800^{\circ}C$, the densification of PVA-Al(III) complex added $UO_2$ pellet was initiated at about $900^{\circ}C$ respectively. In a view of pore size distribution, the PVA-Al(III) complex added $UO_2$ pellet appeared as monomodal type, whereas the AlOOH added $UO_2$ pellet appeared as bimodal type. The grain size of AlOOH added $UO_2$ pellet was about $13\mu\textrm{m}$ but the grain size of PVA-Al(III) complex added $UO_2$ pellet was increased up to about $36\mu\textrm{m}$.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7523-7527
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• 2015

Background: Pediatric acute lymphoblastic leukemia (pALL) patients at King Abdulaziz Medical City represent a pure Saudi Arabian population. ETV6-RUNX1 positive pALL patients have good prognosis as compared to ETV6-RUNX1 negative counterparts. Therefore, frequencies of these two patient groups have a huge consideration in treatment strategies of pALL in a given population. Different geographical locations have been reported to have different frequencies of ETV6-RUNX1 ranging from 10% in Southeast Asia to 30% in Australia. Aim: Therefore, the objective of this study was to establish the ETV6-RUNX1 status of Saudi Arabian pALL patients and its association with clinical parameters and early remission. Materials and Methods: Clinical parameters and ETV6-RUNX1 status (using FISH technique) of pALL patients attending the Pediatric Oncology Clinic, King Abdulaziz Medical City, Riyadh from 2006 to 2011 were studied. Comparisons between ETV6-RUNX1 positive and negative groups were accomplished using chi-square test or Fisher's exact test. All statistical analyses were performed using SAS version 9.2 (SAS Institute, Inc., Cary, NC). Results: Out of 54 patients, 33 were male and 21 were females (ratio 1.57:1). B- and T-cell lineages were found in 47 (87%) and 7 (13%) patients respectively. Only 5 (9.3%) patients were ETV6-RUNX1 positive while 49(80.7%) were ETV6-RUNX1 negative. All ETV6-RUNX1 patients (100%) were of B-cell lineage and 80% (4/5) were in the 3-7 year age group. None of the ETV6-RUNX11 patients had ${\geq}5%$ blasts (no remission) at day 14 as compared with 9% in the ETV6-RUNX1 negative group (Figure 1). Conclusions: Frequency of ETV6-RUNX1 positive patients (less than 10%) in our pALL patients is much lower than reported for most European countries, North America, Australia and Japan while it is in accordance with ETV6-RUNX1 frequencies from Egypt (11.6%), Pakistan (10%), Spain (2%) and India (5-7%). This shows ethnic differences in genetics of pALL as well as higher frequencies of ETV6-RUNX1 positive pALL mostly in more industrialized countries, probably due to some industrial pollutants or westernized lifestyle.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.766-770
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• 2010

This is the study of magnetic properties of transition metal doped diluted magnetic semiconductors(DMSs). The wurtzite structure samples were synthesized by the sol-gel method. The thermodynamic characteristics and magnetic properties of $Zn_{1-x}Co_xO$ single phase was investigated for different doping concentration (x = 0%, 1%, 2%, 3%, 4%, 5%, 10%, 15%). The property of diluted magnetic semiconductors has been comfirmed by X-ray diffraction (XRD), Scanning Electronic Microscope (SEM) and Vibrating sample magnetometer (VSM). The magnetic properties of pure $Zn_{1-x}Co_xO$ is found to be dominated by the ferromagnetic interaction between doped transition metal ions, where by the ferromagnetic coupling strength is simply increased with the concentration(>5%) of the doped transition metal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.559-568
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• 2020

Epidermal growth factor (EGF) is a hormone protein that affects cell growth and proliferation, and has various medical applications. In the present study, the gene of human EGF was codon-optimized with E. coli and the expression vector was constructed by cloning into pRSET. In order to obtain the recombinant human EGF in an active form rather than an inclusion body, chaperone co-expression was attempted along with codon optimization, for the first time. The expressed human EGF was isolated in the pure form by performing Ion Exchange Chromatography in two consecutive runs. ELISA analysis showed that the activity of purified EGF was greater than 99%, which is similar to commercially available EGF. Cell proliferation test confirmed that the recombinant human EGF has the ability to promote cell proliferation of human skin fibroblasts. The human EGF expression system of this study gives a significant amount of protein, and does not require the renaturation step and the additional chromatographic system to remove a fusion contaminant, thereby providing a very useful alternative to conventional expression systems for the preparation of recombinant human EGF.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.97-97
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• 2009

The use of thin plate increases due to the need for light weight in large ship. Thin plate is easily distorted and has residual stress by welding heat. Therefore, the thin plate should be carefully joined to minimize the welding deformation which costs time and money for repair. For one effort to reduce welding deformation, it is very useful to predict welding deformation before welding execution. There are two methods to analyze welding deformation. One is simple linear analysis. The other is nonlinear analysis. The simple linear analysis is elastic analysis using the equivalent load method or inherent strain method from welding experiments. The nonlinear analysis is thermo-elastic analysis which gives consideration to the nonlinearity of material dependent on temperature and time, welding current, voltage, speed, sequence and constraint. In this study, the welding deformation is analyzed by using thermo-elastic method for PCTC(Pure Car and Truck Carrier) which carries cars and trucks. PCTC uses thin plates of 6mm thickness which is susceptible to welding heat. The analysis dimension is 19,200mm(length) * 13,825mm(width) * 376mm(height). MARC and MENTAT are used as pre and post processor and solver. The boundary conditions are based on the real situation in shipyard. The simulations contain convection and gravity. The material of the thin block is mild steel with $235N/mm^2$ yield strength. Its nonlinearity of conductivity, specific heat, Young's modulus and yield strength is applied in simulations. Welding is done in two pass. First pass lasts 2,100 second, then it rests for 900 second, then second pass lasts 2,100 second and then it rests for 20,000 second. The displacement at 0 sec is caused by its own weight. It is maximum 19mm at the free side. The welding line expands, shrinks during welding and finally experiences shrinkage. It results in angular distortion of thin block. Final maximum displacement, 17mm occurs around welding line. The maximum residual stress happens at the welding line, where the stress is above the yield strength. Also, the maximum equivalent plastic strain occurs at the welding line. The plastic strain of first pass is more than that of second pass. The flatness of plate in longitudinal direction is calculated in parallel with the direction of girder and compared with deformation standard of ${\pm}15mm$. Calculated value is within the standard range. The flatness of plate in transverse direction is calculated in perpendicular to the direction of girder and compared with deformation standard of ${\pm}6mm$. It satisfies the standard. Buckle of plate is calculated between each longitudinal and compared with the deformation standard. All buckle value is within the standard range of ${\pm}6mm$.

• Journal of Life Science
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• v.26 no.1
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• pp.123-128
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• 2016

The object of this study was to obtain accurate information about the co-administration effects of cardiotonic pills on the pharmacokinetics of cilostazol were observed as a process of the comprehensive and integrative medicine. Cilostazol is a synthetic anti-platelet and vasodilator agent developed for the treatment of intermittent claudication resulting from peripheral arterial disease. By increasing intracellular cyclic adenosine monophosphate (cAMP), cilostazol induces the activation of protein kinase A, which activates endothelial nitric oxide synthase. In order to evaluate the effect of a single or repeated cardiotonic pill dose on the pharmacokinetics of cilostazol, a single dose of pure_distilled water or a colloidal suspension of distilled water and cardiotonic pills were administered to the control and test groups, respectively. After 30 min, both groups were administered cilostazol. Plasma was collected 30min before administration, and 0.25, 0.5, 0.45, 1, 2, 4, 6, 8, and 24h after the end of cilostazol treatment. We then evaluated the pharmacokinetic changes observed with cilostazol between the control and test groups. No statistically significant differences were observed. These findings demonstrated that a single dose of cardiotonic pills did not affect the pharmacokinetics of cilostazol. The results obtained in this study suggest that co-administration of cardiotonic pills and cilostazol may not affect the bioavailability of cilostazol as a potential drug interaction.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.479-486
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• 2010

The purposes of this study are to investigate the description of scientifically debatable carbonic acid in the Korean high school textbooks, characterize the physical properties of 'carbonic acid solutions' by using an MBL set-up and compare the properties with textual ones. Four different aqueous solutions of carbon dioxide have been prepared and analyzed: naturally aerated aqueous solution, dry ice-dissolving solution, $CO_2$-bubbling solution and commercial carbonic acid water. Experimental findings showed that pH and conductivity of these 4 solutions ranged from 3.85 to 5.66 and from 0.21 ${\mu}S$/cm to 272.1 ${\mu}S$/cm, respectively. Out of these solutions, the dissociation constant($K_{a1}$) of the bubbling solution at room temperature could be calculated to $5.7{\times}10^{-7}$ which value is comparable to the textual $4.3{\times}10^{-7}$ within experimental errors, which means that textual compound is not pure carbonic acid but the equilibrated mixture of carbonic acid and the aqueous solution of carbon dioxide. On the other hand, textual analysis showed that most of high school textbooks used carbonic acid as an example of weak acid and buffer solution of the blood but none of them distinguished the carbonic acid from the aqueous solution of carbon dioxide. Only one textbook, however, tiered two species in the chemical equation.

• Journal of Ecology and Environment
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• v.41 no.12
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• pp.328-335
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• 2017

Background: Some researchers have attempted to evaluate the ecological function of various additional services, away from the main point of view on the timber production of Korean forests. However, basic data, evaluation models, or studies on the absorption of air pollutants related to major plant communities in Korea are very rare. Therefore, we evaluated the functional value of the forest ecosystem in Gongju-city. Plantation manual for air purification, supplied from the Ministry of Environment in Japan, was referred to process and method for assessment of air pollutant absorption. Results: Gross primary production was calculated about average 18.2 t/ha/year. It was a relatively low value in forests mixed with deciduous broad and evergreen coniferous compared to pure coniferous forest. Net primary production was the highest value in deciduous coniferous and was the lowest value in mixed forest with deciduous broad and evergreen broad. And the mean sequestration amount of each air pollutant per unit area per year assessed from gross primary production and concentration of gas was the highest with 75.81 kg/ha/year in $O_3$ and was 16.87 and 6.04 kg/ha/year in $NO_2$ and $SO_2$, respectively. In addition, total amounts of $CO_2$ absorption and $O_2$ production were 716,045 t $CO_2$/year and 520,760 t $O_2$/year in all forest vegetation in Gongju-city. Conclusions: In this study, we evaluated the absorption ability of air pollutant in 2014 on forest in Gongju-city area. Gongju-city has the broad mountain area about 70.3%, and area of deciduous broad leaves forest was established the broadest with 47.4% of genus Quercus. Pg was calculated about average 18.2 t/ha/year. The mean sequestration amount of each air pollutant per unit area per year assessed from Pg and $C_{gas}$ was the highest with 75.81 kg/ha/year in $O_3$ and were 16.87 and 6.04 kg/ha/year in $NO_2$ and $SO_2$, respectively. Absorption rates of $O_3$, $NO_2$, and $SO_2$ were the highest in evergreen coniferous forest about $14.87kgO_3/ha/year$, $3.30kgNO_2/ha/year$, $1.18kgSO_2/ha/year$, and the lowest were $5.95kgO_3/ha/year$, $1.32kgNO_2/ha/year$, and $0.47kgSO_2/ha/year$ in deciduous broad forest. In conclusion, it was evaluated that Japanese model is suitable for estimating air pollutants in Japan to Korean vegetation. However, in Korea, there is a very limited basic data needed to assess the ability of forests to absorption of air pollutants. In this study, the accuracy of a calculated value is not high because the basic data of trees with similar life form are used in evaluation.