• Journal of the Korean Chemical Society
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• v.33 no.2
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• pp.232-237
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• 1989

The elution mechanism of rare earth elements in cation exchange resin which was substituted with $NH_4^+,\;Zn^{2+}\;or\;Al^{3+}$ as a retaining ion had been investigated. Rare earths or rare earths-EDTA complex solution was loaded on the top of resin bed and eluted with 0.0269M EDTA solution. When the rare earth-EDTA complex was adsorbed on the $Zn^{2+}\;or\;Al^{3+}$ resin form, retaining ion was complexed with EDTA and liberated rare earths was adsorbed in the resin again. Adsorbed rare earths in resin phase could be eluted by the complexation reaction with EDTA eluent. On $NH_4^+$ resin form, the rare earth-EDTA complex which had negative charge could not adsorbed on the cation exchange resin because the complexation reaction between $NH_4^+$ and EDTA was impossible. So the elution time was much shorter than in $Zn^{2+}\;or\;Al^{3+}$ resin form. When the rare earths solution was loaded on the $Zn^{2+},\;Al^{3+}$ resin form bed, rare earths was adsorbed in the resin and the retaining ion was liberated. Adsorbed rare earths in resin bed was exchanged by EDTA eluent forming rare earths-EDTA complex, and eluted through these processes. On $NH_4^+$ resin form, rare earths loaded was adsorbed by exchange reaction with $NH_4^+$. As the EDTA eluent was added, rare earths was liberated from resin forming negatively charged rare earth-EDTA complex and eluted without any exchange reaction. So the elution time was greatly shortened and there was no metallic ion except rare earths in effluent. When the $Zn^{2+}\;and\;Al^{3+}$ was used as retaining ion, the pH of efflent was decreased seriousely because the $H^+$ liberated from EDTA molecule.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2941-2948
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• 2011

A nanogap formed by a metal nanoparticle and a flat metal substrate is one kind of "hot site" for surface-enhanced Raman scattering (SERS). The characteristics of a typical nanogap formed by a planar Au and either an Au and Ag nanoparticle have been well studied using 4-aminobenzenethiol (4-ABT) as a probe. 4-ABT is, however, an unusual molecule in the sense that its SERS spectral feature is dependent not only on the kinds of SERS substrates but also on the measurement conditions; thus further characterization is required using other adsorbate molecules such as 1,4-phenylenediisocyanide (1,4-PDI). In fact, no Raman signal was observable when 1,4-PDI was selfassembled on a flat Au substrate, but a distinct spectrum was obtained when 60 nm-sized Au or Ag nanoparticles were adsorbed on the pendent -NC groups of 1,4-PDI. This is definitely due to the electromagnetic coupling between the localized surface plasmon of Au or Ag nanoparticle with the surface plasmon polariton of the planar Au substrate, allowing an intense electric field to be induced in the gap between them. A higher Raman signal was observed when Ag nanoparticles were attached to 1,4-PDI, irrespective of the excitation wavelength, and especially the highest Raman signal was measured at the 632.8 nm excitation (with the enhancement factor on the order of ${\sim}10^3$), followed by the excitation at 568 and 514.5 nm, in agreement with the finite-difference timedomain calculation. From a separate potential-dependent SERS study, the voltage applied to the planar Au appeared to be transmitted without loss to the Au or Ag nanoparticles, and from the study of the effect of volatile organics, the voltage transmission from Au or Ag nanoparticles to the planar Au also appeared as equally probable to that from the planar Au to the Au or Ag nanoparticles in a nanogap electrode. The response of the Au-Ag nanogap to the external stimuli was, however, not the same as that of the Au-Au nanogap.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.507-519
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• 1999

The ultimate objective of periodontal treatment is to stop disease progression and to regenerate destroyed periodontal tissues and thereby regain normal function. Growth factors are naturally found polypetides which stimulate many cellular activities pertaining to wound healing by acting as signal molecule in controlling cell movement, proliferation, and matrix production. Platelet derived growth factor (PDGF) is 28,000-35,000 Da molecular weight dimeric protein with 2 long positively charged polypeptide chains connected by sulfide bonds. The purpose of this study is to evaluate histologically the initial guided tissue regeneration in a periodontal defect f a beagle dog treated with a biodegradable membrane formed with polylactic acid (poly-L-lactic acid) and polyglycolic acid loaded with 200ng/$cm^2$ platelet derived growth factor. 2 beagle dogs were used in he experiment. $5mm{\times}6mm$ alveolar bone defect was formed in upper and lower canines and third premolars and a reference notch was placed. PDGF-BB non-containing membrane was used as control. Each defect was randomly assigned to the test roup or the control group. The dogs were sacrificed 3 weeks after membrane placement. Toluidine blue and multiple staining was done for histological analysis. In the 3 week specimen in the control group, no new one formation could be seen. Small amount f bone resorption below the notch could be seen. In the notch, loose connective tissue with infiltration of inflammatory cells could be seen. Also thin discontinuous new cementum could be seen and the membrane still retained its structure. Where PDGF-BB containing membrane was used, new bone formation could be seen in the notch at weeks and also continuous thin cementum could be seen. PDL cells were observed between new bone and new cementum and some were attached to bone and cementum. These results suggest that new bone and cementum formation seen when PDGF-BB loaded membrane was used was due to inhibition of downgrowth of epithelial cells and also due to continuous release of the growth factor. Further study on the resorption characteristics of the membrane nd the release characteristics of the PDGF-BB is necessary. Also, development of a membrane easier to use clinically is necessary.

• Applied Chemistry for Engineering
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• v.2 no.3
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• pp.270-278
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• 1991

Carboxymethyl chitin(CM-chitin) was prepared by the reaction of alkali chitin with monochloroacetic acid in isopropyl alcohol. According to the pH variation, the adsorptivity of this chelating polymer to the alkali-earth metal ions such as $Ca^{2+},\;Mg^{2+}$, $Sr^{2+}$, $Ba^{2+}$ ions was determined by batch method. The adsorption tendency of this chelating polymer to most metal ions was increased with the increase of pH. The highest degree of adsorption was observed toward $Ca^{2+}$ ion among the alkali-earth metal ions. The selectivity adsorption property toward $Ca^{2+}$ ion was examined in the solution of $Ca^{2+}$ and $Mg^{2+}$ ions, and it was observed that CM-chitin showed excellent selectivity to $Ca^{2+}$ ion than $Mg^{2+}$ ion. $Mg^{2+}$ ion bound to CM-chitin molecule in the presence of $Ca^{2+}$ ion owing to low equilibrium constant. In the adsorption experiment of $Ca^{2+}$ and $Mg^{2+}$ ions to the CM-chitin under coexistence of $Na^+$ and $K^+$ ions, it observed that adsorptivity of only $Ca^{2+}$ ions was not affected by these monovalent cations.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.533-542
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• 1999

H. pylori produces urease abundantly amounting to 6% of total protein of bacterial mass. Urease genes are composed of a cluster of 9 genes of ureC, ureD, ureA, ureB, ureI, ureE, ureF, ureG, ureH. Production of H. pylori urease in E. coli was studied with genetic cotransformation. Structural genes ureA and ureB produce urease apoprotein in E. coli but the apoprotein has no enzymatic activity. ureC and ureD do not affect urease production nor enzyme activity ureF, ureG, and ureH are essential to produce the catalytically active H. pylori urease of structural genes (ureA and ureB) in E.coli. The kinetics of activation of H. pylori urease apoprotein were examined to understand the production of active H. pylori urease. Activation of H. pylori urease apoprotein, pH dependency, reversibility of $CO_2$ binding, irreversibility of $CO_2$ and $Ni^{2+}$ incorporation, and $CO_2$ dependency of initial rate of urease activity have been observed in vitro. The intrinsic reactivity (ko) for carbamylation of urease apoprotein co expressed with accessory genes was 17-fold greater than that of urease apoprotein expressed without accessory genes. It is concluded that accessory genes function in maximizing the carbamylating deprotonated ${\varepsilon}$-amino group of Lys 219 of urease B subunit and metallocenter of urease apoprotein is supposed to be assembled by reaction of a deprotonated protein side chain with an activating $CO_2$ molecule to generate ligands that facilitate productive nickel binding.

• Polymer(Korea)
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• v.30 no.4
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• pp.362-366
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• 2006

It was found by polarized FTIR spectroscopic studies that pentacene molecules are arranged with their molecular axes perpendicular to the substrate surface when pentacene films are deposited on a polyimide alignment layer. The ring plane in a pentacene molecule is arranged parallel to the rubbing direction of the polyimide alignment film while no specific arrangement of vertically deposited pentacene molecules was found for the film without rubbing. The pentacene band at $1296cm^{-1}$ which has a transition dipole moment parallel to the ring plane is much stronger in a polarized IR spectrum of parallel to the rubbing direction, whereas the band at $908cm^{-1}$ whose transition dipole align normal to the ring plane shows much stronger intensity in a spectrum of perpendicular to the rubbing direction. These findings indicate that orientation of polyimide chains affects the arrangement of pentacene molecules when they are deposited on a polyimide alignment film.

• Journal of Pharmaceutical Investigation
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• v.31 no.2
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• pp.89-94
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• 2001

The pharmacokinetics of recombinant human granulocyte colony stimulating factor (rhG-CSF) following intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) administration of HM1041l-lyo and HM10411-liq (lyophilized and liquid formulations of rhG-CSF, recently under development by Hanmi Pharmaceutical Company) were studied in rats, and compared with that of Filgrastim (conventional formulation of rhG-CSF on market). The plasma concentration of rhG-CSF was quantified using a specific ELISA. The pharmacokinetic parameters of rhG-CSF, after i.v., i.m. and s.c. administration of Filgrastim, HM1041l-lyo and HM1041l-liq to rats at a rhG-CSF dose of $10\;{\mu}g/kg$, were almost identical among the three formulations. No dose-dependency was observed in the pharmacokinetic parameters of rhG-CSF following i.v. administration in the dose range of $5{\sim}100\;{\mu}g/kg$. rhG-CSF, after i.v. administration of the three preparations at a dose of $10\;{\mu}g/kg$ to rats, was detected at low levels in all of the body tissues with highest tissue/plasma ratio of $0.46{\sim}0.51$ for the kidney at 30 min after the administration. The pharmacokinetics of rhG-CSF, after i.v. administration to mice at a dose of $10\;{\mu}g/kg$, were comparable among the three formulations. In conclusion, HM10411-lyo and HM10411-liq exhibited similar pharmacokinetics for rhG-CSF with Filgrastim regandless of animal species. Considering the fact that HM10411 series, contrary to Filgrastim, are proteins lacking a methionine residue, the methionine moiety in rhG-CSF molecule does not appear to influence the pharmacokinetics of the protein significantly.

• Herbal Formula Science
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• v.12 no.2
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• pp.175-202
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• 2004

Nitric oxide(NO) play an important role in normal and pathophysiological cells including as a messenger molecule, neurotransmitter, microbiocidal agent, or dilator of blood vessels and artheriosclerosis, hypertension, myocardial infarction, respectively. To investigate that Ondamtang in the potential contribution of the levels of nitric oxide generated by endothelial nitric oxide synthase (eNOS) and the mechanisms of protection against L-NAME, human ECV304 cells, which normally do not express eNOS, were expressed by L-NAME. L-NAME stimulated rat or cells were found to be resistant to injury and delayed death following the Ondam-tang. Inhibition of nitric oxide synthesis abolished the protective effect against L-NAME, thrombin and collagen exposure. Interestingly, such effects have bee observed during stimulation with agents such as KCl on L-NAME mediate rats, were damaged by the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Cardiovascular diseases is one of the blood vessels and renin-angiotensin system dynfunction. So we studied on herbal medicine that have a relation of vessels endothelium necrosis. In Oriental Medicine, Ondam-tang has been used for disease in relation to cardiovascular system. We studied on the protection and inhibitory effects of cardiovascular diseases in L-NAME induced rat or ECV304 cell lines through the Cell morphological pattern, Tunel assay, LDH activity, heart rate, blood pressure and immunohistochemistric analysis by Ondam-tang. As the result of this study, In group, the anti-apoptosis and necrosis in the cardiovascular system have a potential capacity for prevented, protected and treating the diseases of cardiovascular system, against the necrosis of rat and ECV304 cells with eNOS and calpain expression by L-NAME is promoted.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.531-536
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• 2011

The precise measurement of human emotion is of pivotal importance in the field of emotion science. Based on the perspective of psychoneuroimmunoendocrinology, human emotion is now considered to be measurable by body fluid. The biological molecule cortisol, which is known for the stress hormone, has been widely investigated to help researchers to estimate the stress loaded on human body. Until now, several measurement techniques such as High Performance Liquid Chromatography (HPLC), fluorometric assay, and reverse phase chromatography have been developed. However, since these measurements are expensive, take relatively long time for an operation, and they are not portable, they are not appropriate for POCT (point of care testing). In this paper we demonstrate the performance of a miniaturized-microwave resonant device in the measurement of cortisol. Our method has many advantages in that it requires a small volume of sample, has fast response time, is easy to operate and needs no labeling process. Besides, it will shed a light on the measurement techniques for emotion science.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.187-193
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• 2009

Purpose : Adiponectin is a molecule that plays an important role in the metabolic syndrome. In addition, its concentration is known to be decreased in obesity, type 2 diabetes, and coronary artery disease. Although a relationship between hypertension and serum adiponectin concentrations has been reported by several authors, such findings continue to be debated. We investigated whether hypoadiponectinemia is related to hypertension in adolescents and studied the associated genetic polymorphism. Methods : Forty hypertensive adolescents (Age 16-17 years old) and twenty normotensive matched subjects were included. Serum adipo-nectin, insulin, renin, aldosterone and angiotensin converting enzyme (ACE) levels were compared. Their carotid intima-media thickness (cIMT) and pulse wave velocity (PWV) were measured. Polymorphisms of the adiponectin I164T gene were investigated using polymerase chain reaction (PCR). Results : The hypertensive adolescents had significantly greater cIMT and PWV. In addition, the serum aldosterone, renin and insulin levels were significantly higher in the hypertensive group. The plasma concentrations of adiponectin did not differ significantly between the two groups. TC genotype was not found in our study subjects; they all had the TT genotype of the adiponectine gene. Conclusion : The results of our study showed that adiponectin levels were not significantly different in adolescents with hypertension. There was no distinctive genetic polymorphism observed in this group of patients. Further large scale studies are needed to clarify the association between genetic variations and adiponectin in hypertensive adolescents.