• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.145-154
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• 1999

A novel retinol derivative, polyethoxylated retinamide(Medimin A) was synthesized, as an anti-aging agent. Collagen synthesis, skin permeation, stability, and toxicity of Medimin A were evaluated and compared with those of retinol and retinyl palmitate. In vitro collagen synthesis was evaluated by quantitative assay of $[^3H]-proline$ incorporation into collagenase sensitive protein in fibroblast cultures. For in vitro skin permeation experiments, Franz diffusion cells(effective diffusion area: 1,766 $cm^2$) and the excised skin of female hairless mouse aged 8 weeks were used, The stabilities of retinoids were evaluated at two different temperature($25^{\circ}C\;and\;40^{\circ}C$) and under UV in solubilized state and in O/W emulsion. To estimate the safety, acute oral toxicity, acute dermal toxicity, primary skin irritation, acute eye irritation and human patch test were performed. The effect of Medimin A on collagen synthesis was similar to that of retinol. The skin permeability of Medimin A was higher than those of retinol and retinyl palmitate. The Medimin A was more stable than retinol and retinyl palmitate. Medimin A was nontoxic in various toxicological tests. These results suggest that Medimin A would be a good anti-aging agent for enhancing bioavailability and stability.

• Resources Recycling
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• v.5 no.1
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• pp.21-28
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• 1996

Burmng method tn Bnidi-ied beds 101 the effectlvr reclamation of Sunn fi,uadry sand war u~ed lather tl~an rncchan1c;ll or p~~cumatiace thodq. which are co~nmonlyu scd in foundry factoricr in Kojcu In olrlcr to rcrnuvc hlc;~ns and ha~doersi ~nm foundry sand sndaces in the fluidized bcd, the lnnsl sffccuve lcmpemture mge was h00-70W. Sulbcr slab~l~liyn dca and comliresslvc streugtli oL rccla~mcd sand recyclcd by the burning luctllod wcre lalgcr dao those of rcclalmcd a n d by lllc pncumatlc mctllod. Tile energy cost IOIt he bummy mctliod was cstimalcd al SlZ0011'on oi llie iccl;~~rncds md. The coql l~ductlon in pul.chasing nzw s;od as well as the prevenllon or cnv~conmcnl.il contamlnallnn could hc hmefitcrl hy usl~lg Ihc rec1;~rnnl~oonf liisndry siod ~ecycledb y the method rleieloped in thls sludy

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.161-167
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• 2007

In this study, we constructed and tested retrovirus vectors designed to express the human thrombopoietin gene under the control of the tetracycline-inducible promoters. To increase the hTPO gene expression at him-on state, WPRE sequence was also introduced into retrovirus vector at downstream region of either the hTPO gene or the sequence encoding reverse tetracycline-controlled transactivator (rtTA). Primary culture cells (PFF, porcine fetal fibroblast; CEF, chicken embryonic fibroblast) infected with the recombinant retrovirus were cultured in the medium supplemented with or without doxycycline for 48hr, and induction efficiency was measured by comparing the hTPO gene expression level using RT-PCR, western blot and ELISA. Higher hPTO expression and tighter expression control were observed from the vector in which the WPRE sequence was placed at downstream of the hTPO (in CEF) or rtTA(in PFF) gene. This resulting tetracycline inducible vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.507-513
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• 2001

An effective extraction methods of a garlic were investigated in order to improve the functional properties of the extracts. The solid yield, electron donating ability (EDA), nitrite-scavenging effects (NSE), peroxide value (POV) and total thiosulfinates contents of garlic extracts were determined. In order to improve the functional properties of extracts prepared with several organic solvents and acids, concentration and pH adjustment of the selected solvent and addition of acids and salts to solvents were also examined. Among the solvents tested, the methanol and ethanol extracts were found to be the most effective on the base of functionality and solid yields. The highest EDA, NSE and thiosulfinate value were obtained with 50% ethanol. The pH control of solvent and addition of citric acid, NaCl and phosphates to 50% ethanol did not affect on the functionality of the extracts. Therefore the optimal solvent for the best functional properties of garlic extract was 50% ethanol.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.460-467
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• 2010

For D-WTP's sedimentation basin and distribution reservoir, and water tap the predictive models proposed tentatively herein included the models for estimating TTHM concentration in precipitated water, for treated water and for tap water, and the estimated correlation formula between treated water's TTHM concentration and tap water. As for TTHM-concentration predictive model in sedimentation water, the coefficient of determination is 0.866 for best-fitted short-term $DOC{\times}UV_{254}$ based Model (TTHM). As for $HAA_5$-concentration predictive model in sedimentation water, the coefficient of determination is 0.947 for the suitable $UV_{254}$-based model ($HAA_5$). In case of the predictive model in treated water, the coefficient of determination is 0.980 for best-fitted $DOC{\times}UV_{254}$ based model (TTHM) using coagulated waters, while the coefficient of determination is 0.983 for best-fitted $DOC{\times}UV_{254}$ based model ($HAA_5$) using coagulated waters, which described the $HAA_5$ concentration well. However, the predictive model for tap water could not be compatible with the one for treated water, only except for possibility inducing correlation formula for prediction, [i.e., the correlation formula between TTHM concentration and tap water was verified as TTHM (tap water) = $1.162{\times}TTHM$ (treated water), while $HAA_5$ (tap water) = $0.965{\times}HAA_5$ (treated water).] The correlation analysis between DOC and $KMnO_4$ consumption by process resulted in higher relationship with filtrated water, showing that its regression is $DOC=0.669{\times}KMnO_4$ consumption - 0.166 with 0.689 of determination coefficient. By substituting it to the existing DOC-based model ($HAA_5$) for treated water, the consequential model formula was made as follows; $HAA_5=8.35(KMnO_4\;consumption{\times}0.669-0.166)^{0.701}(Cl_2)^{0.577}t^{0.150}0.9216^{(pH-7.5)}1.022^{(Temp-20^{\circ}C)}$

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.69.1-69.1
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• 2015

Classical T Tauri star DG Tau is suggested as the driving source of parsec-scale jet which expands up to 650" (0.4 pc). To investigate the kinematics and physical properties of the jet, we have obtained the optical emission lines of $H{\alpha}$, [O I] ${\lambda}{\lambda}$6300, 6363, [N II] ${\lambda}{\lambda}$6548,6584, and [S II] ${\lambda}{\lambda}$6716, 6731 from HH 158 ad HH 702. The radial velocity of HH 158 is in the range of -50 to $-250km\;s^{-1}$. For HH 702, located at 650" from the source, it shows ~ $-80km\;s^{-1}$. In HH 158, the electron density ($n_e$) close to the star is ${\sim}10^4cm^{-3}$ and it decreases to ${\sim}10^2cm^{-3}$ at 14" away from the star. Electron temperature ($T_e$) is decreasing from >15,000 K to ~5,000 K with distance. Ionization fraction ($x_e$) is increasing from almost zero to > 0.4 along the distance. In HH 702, the values of $n_e$, $T_e$, and $x_e$ are similar to those estimated at 14" from source, where knot C of HH 158 is located. This may imply that the physical properties of the knot could persist through such a long distance in the space, and the gas could be re-excited by the shock during propagation of the jet. On the other hand, we cannot avoid the possibility that HH 702 is driven by another source rather than DG Tau because HH 158 and HH 702 show somewhat large difference in their inclination angles (${\Delta}i=21-35^{\circ}$).

• Journal of Digital Convergence
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• v.11 no.12
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• pp.515-522
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• 2013

The purpose of this study was to closely examine the inhibitive effect of erythritol on growth and acidogenic ability of Streptococcus mutans. As expected, the growth of S. mutans was comparably increased with the addition of sucrose. However, xylitol and erythritol remarkably reduced the growth of S. mutans. Growth inhibition was detected at more than 5% of erythritol although xylitol showed growth inhibition effect at all concentrations tested. Growth inhibition effect was monitored with the combination of same concentration of erythritol and other carbohydrates. Combination of 5% or 10% erythritol with xylitol showed effective growth inhibition. Addition of 2.5%, 5%, or 10% erythritol with sorbitol also showed growth inhibition. From these results, erythritol showed potency of growth inhibition of S. mutans, which is involved in dental caries, and was confirmed to be an excellent sugar substitute, which has effect on preventing caries.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.165-170
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• 2015

Ceramics biomaterials are useful as implant materials in orthopedic surgery. In this study, porous HA(hydroxyapatite)/${\beta}$-TCP(tricalcium phosphate) composite biomaterials were successfully fabricated using HA/${\beta}$-TCP powders with 10-30 wt% $NH_4HCO_3$ as a space holder(SH) and $TiH_2$ as a foaming agent, and MgO powder as a binder. The HA/${\beta}$-TCP powders were consolidated by spark plasma sintering(SPS) process at $1000^{\circ}C$ under 20 MPa conditions. The effect of SH content on the pore size and distribution of the HA/${\beta}$-TCP composite was observed by scanning electron microscopy(SEM) and a microfocus X-ray computer tomography system(SMX-225CT). These microstructure observations revealed that the volume fraction of the pores increased with increasing SH content. The pore size of the HA/${\beta}$-TCP composites is about $400-500{\mu}m$. The relative density of the porous HA/${\beta}$-TCP composite increased with decreasing SH content. The porous HA/${\beta}$-TCP composite fabricated with 30%SH exhibited an elastic modulus similar to that of cortical bone; however, the compression strength of this composite is higher than that of cortical bone.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.19-35
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• 1984

Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

• Environmental Mutagens and Carcinogens
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• v.26 no.4
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• pp.125-132
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• 2006

Previous studies showed that epigallocatechin gallate(EGCG) have substantial effects of suppressing the N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)-initiated cell transformation process on the bases of foci formation frequency and loss of anchorage dependency. In this study we tried to clarify the molecular mechanism of suppressing the cell transformation process. Mouse cell line balb/c 3T3 A31-1-1 was exposed 2 days to MNNG followed by 15 days 12-O-tetradecanoylphorbol-13-acetate(TPA) treatment for our transformation process. EGCG was added after the time point of 24 hours exposure to TPA and incubated for 19 days. 2029 genes were selected in our transformation process that showed fold change value of 1.5 or more in the microarray gene expression analysis covering the mouse full genome. These genes were found to be involved mainly in the cell cycle pathway, focal adhesion, adherens junction, TGE-$\beta$ signaling, apoptosis, lysine degradation, insulin signaling, ECM-receptor interaction. Among the genes, we focused on the 631 genes(FC>0.5) reciprocally affected by EGCG treatment. Our study suggest that EGCG down-regulate the gene expressions of up stream signaling factors such as nemo like kinase with MAPK activity and PI3-Kinase, Ras GTPase and down stream factors such as cyclin D1, D2, H, T2, cdk6.