• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.341-349
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• 2000

CsI(Br) single crystals doped with 1, 3, 5 or 10 mole% $Br^-$ ions, as an activator, were grown by Czochralski method. The lattice structure of grown CsI(Br) single crystal was bcc and its lattice constant was $4.568\;{\AA}$. The absorption edge of the CsI(Br) single crystals was observed at 243 nm. The spectral range of the luminescence excited by 243 nm of wavelength was $300{\sim}600\;nm$, and its peak emission appeared at 440 nm. The luminescence intensity was maximum when CsI(Br) was doped with 3 mole % $Br^-$ ions. The energy resolutions of the CsI(Br) scintillator doped with 3 mole % $Br^-$ ions were 15.0% for $^{137}Cs$(662 keV), 13.1% for $^{54}Mn$(835 keV), and 18.0% and 6.3% for $^{22}Na$(511 keV and 1275 keV), respectively. The decay curves had fast and slow components, and the fast component was about 41 ns independent on the concentration of the $Br^-$ ions. The time resolution of CsI(Br) scintillators decreased with increasing of the concentration of $Br^-$ ions.

• Journal of Embryo Transfer
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• v.25 no.2
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• pp.103-110
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• 2010

The first morphogenetic event of preimplantation development, compaction, was required efficient production of porcine embryos in vitro. Compaction of the porcine embryo, which takes place at post 4-cell stage, is dependent upon the adhesion molecule E-cadherin. The E-cadherin through ${\beta}$-catenin contributes to stable cell-cell adhesion. Rho-associated kinase (ROCK) signaling was found to support the integrity of E-cadherin based cell contacts. In this study, we traced the effects of ROCK-1 on early embryonic development and structural integrity of blastocysts in pigs. Then, in order to gain new insights into the process of compaction, we also examined whether ROCK-1 signaling is involved in the regulation of the compaction mediated by E-cadherin of cellular adhesion molecules. As a result, real-time RT-PCR analysis showed that the expression of ROCK-1 mRNA was presented throughout porcine preimplantation stages, but not expressed as consistent levels. Thus, we investigated the blastocyst formation of porcine embryos treated with LPA and Y27632. Blastocysts formation and their qualities in LPA treated group increased significantly compared to those in the Y27632-treated group (p < 0.05). Then, to determine whether ROCK-1 associates embryonic compaction, we explored the effect of activator and/or inhibitor of ROCK-1 on compaction of embryos in pigs. The rate of compacted morula in LPA treated group was increased compared to that in the Y27632-treated group (39.7 vs 12.0%). Furthermore, we investigated the localization and expression pattern of E-cadherin at 4-cell stage porcine embryos in both LPA- and Y27632-treated groups by immunocytochemical analysis and Western blot analysis. The expression of E-cadherin was increased in LPA-treated group compared to that in the Y27632-treated group. The localization of E-cadherin in LPA-treated group was enriched in part of blastomere contacts compared to that Y27632-treated group. ROCK-1 as a crucial mediator of embryo compaction may plays an important role in regulating compaction through E-cadherin of the cell adhesion during the porcine preimplantation embryo. We concluded that ROCK-1 gene may affect the developmental potential of porcine blastocysts through regulating embryonic compaction.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.137-142
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• 1994

Myrosinase in leaf mustard was purified and characterized to furnish a grounding information for utilizing the pungent taste and the potential antimicrobial capability of Dolsan leaf mustard to enhance the taste and storage life of kimchi. When myrosinase was purified from leaf mustard through a series of DEAE Sephadex, chromatofocusing and Con A Sepharose column chromatography, specific activity of the enzyme increased 7107-fold compared with that of crude enzyme preparation, and 18.8% yield was obtained. The purified myrosinase showed the optimum pH of 5.9, isoelectric point of 4.6, molecular weight of 129 kD, Km of 0.206 mM, and Vmax of $2.039\;{\mu}M{\cdot}min^{-1}{\cdot}mg\;protein^{-1}$, respectively. The optimum concentration of L-ascorbic for the maximum activity of the enzyme was 0.6 mM, and the enzyme activity decreased at a higher concentration of L-ascorbic acid than 0.6 mM, showing almost no enzyme activity at a L-ascorbic acid concentration of higher than 2.0 mM. Myrosinase activity in leaf mustard kimchi immediately after the kimchi was formulated was shown to be about 70 nmol/min/mg protein which decreased rapidly after 3 days of storage at $20^{\circ}C$, showing that less than half and almost none of the enzyme activity was retained in 4 and 10 days of storage, respectively.

• Journal of Life Science
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• v.14 no.4
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• pp.636-643
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• 2004

D-Xylose isomerase produced by Lactococcus sp. JK-8, isolated from kimchi, was purified 17-fold of homogeneity, and its physicochemical properties were determined. Although the N-terminal amino acid sequence of D-xylose isomerase was analysed to Ala-Tyr-Phe-Asn-Asp-Ile-Ala-Pro-Ile-Lys, it was not similar to that of Lactobacillus enzyme. The molecular weight of the purified enzyme was estimated to be 180 kDa by gel filtration, 45 kDa by SDS-PAGE and the enzyme was homotetramer. The optimum pH of the enzyme was around 7 and stable between pH 6 and 8. The optimum reaction temperature was 7$0^{\circ}C$ and stable up to 7$0^{\circ}C$ in the presence of 1 mM $Mn^{2+}$. Like other D-xylose isomerases, this enzyme required divalent cation, such as $Mg^{2+}$, $Co^{2+}$, or $Mn^{2+}$ for the activity and thermostability. $Mn^{2+}$was the best activator. Substrate specificity studies showed that this enzyme was highly active on D-xylose. The enzyme had an isoelectric point of 4.8, and fm values for D-xylose was 5.9 mM.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.5
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• pp.75-84
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• 2016

This paper presents an investigation of the mechanical properties on non-sintered cement pastes immersed in sea waters at three different temperatures. The non-sintered cement pastes were synthesized using blended binder(Class F fly ash; FA and ground granulated blast furnace slag; GGBFS) and alkali activator(sodium hydroxide and sodium silicate). Binders were prepared by mixing the FA and GGBFS in different blend weight ratios of 6:4, 7:3 and 8:2. The alkali activators were used 5wt% of blended binder, respectively. Calcium carbonate was used as an chemical additive. The compressive strength, bulk density and absorption of alkali-activated FA-GGBFS blends pastes were measured at 3 and 28 days after immersed in sea waters at three different temperatures($5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$). The XRD and SEM tests of the pastes were conducted at 28 days. Water-soluble chloride(free chloride) and acid-soluble chloride(total chloride) contents in the pastes were also measured after 28 days immersion in sea water. The experimental results showed that increasing the content of FA in alkali-activated FA-GGBFS blends pastes immersed in sea water increases the absorption, water-soluble chloride content and acid-soluble chloride content, and reduces the compressive strength and bulk density. And it was found that there was a variation of strength change for the alkali-activated FA-GGBFS blends pastes immersed in sea waters at three different temperatures that depends on the blending ratio of FA and GGBFS.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.117-125
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• 2014

This paper examines the fundamental properties of alkali-activated slag cement (AASC) activated by sodium hydroxide (NaOH). The water to binder (W/B) ratio was 0.4 and 0.5. And concentration of activator were 2M and 4M. Five mix design of each W/B ratios was considered. The N0 mixture was KS L 5109 method and N1~N4 were varied in different mixing time, mix step and entering points of fine aggregate. Test results clearly showed that the flow value, strength and drying shrinkage development of AASC were significantly dependent on the entering point of fine aggregate. The flow value tended to decreases with delaying entering point of fine aggregate. The compressive strength and flexural strength increases with delaying entering point. Moreover, the XRD analysis confirmed that there were sustain these results. The drying shrinkage increases with delaying entering point of fine aggregate. Futhermore, a modified mixing method incorporating all hereby experimentally derived parameters, is proposed to improvement the physical properties of AASC.

• Development and Reproduction
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• v.6 no.1
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• pp.17-23
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• 2002

In oocyte retrieval, a vein anesthetic drug is commonly used for induction and maintenance of general anesthesia. Propofol and Thiopental sodium are frequently used for ultrasound-guided transvaginal oocyte retrieval. The present study aimed to assess the effects of Propofol and Thiopental on in vitro fertilization(IVF). Immature porcine oocytes were exposed to various concentrations ot Propofo1 and Thiopental sodium. The rates of oocyte maturation, fertilization and development were observed. The parthenogenetic effects of the anesthetics were also evaluated. The rate of oocyte maturation after exposure to high concentrations of the anesthetics for long time was significantly higher than that of the control. But the rate of fertilization after long-time exposure to the high concentration of the anesthetic drugs was significantly lower than that of the control. The results support that Propofo1 serves like other anesthetics described, as a parthenogenetic activator. Oocytes exposed to Thiopental sodium showed decreased rates of maturation and fertilization. These results suggest that usage of optimum concentration of anesthetic drug is important in increasing the rates of oocyte maturation, fertilization and development in IVF.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.189-199
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• 1996

Myocardial ${\alpha}_1-adrenoceptors$ have been shown to mediate a biphaslc inotropic response that was characterized by a transient decline followed by a sustained increasing phase in guinea pig ventricular muscle. Recently one group reported that an ${\alpha}_1-adrenoceptors-induced$ intracellular $Na^+$ decrease is linked to fast $Na^+$ channel inhibition and another group reported that it is linked to $Na^+$-$K^+$ pump activation by ${\alpha}_{1b}-adrenoceptors$. But until now, its mechanism is not clear. Therefore, to see whether the $Na^+$channel or $Na^+-K^+$ pump is related to a decrease in intracellular $Na^+$ activity and/or the negative inotropic response, and which ${\alpha}_1-adrenoceptor$ subtype was involved in the decrease in intracellular $Na^+$activity by phenylephrine, we used conventional and sodium selective microelectrodes, and tension transducer to determine the effects of ${\alpha}_1-adrenergic$ stimulation on membrane potential, intracellular $Na^+$ activity, and twitch force in guinea pig ventricular muscles. $10^{-5}$ M Phenylephrine produced a slight hyperpolarization of the diastolic membrane potential, a decrease or increase in $a_N^i_a$, and a biphasic inotropic response. The negative inotropic response accompanied by a decrease in intracellular $Na^+$activity, whereas in muscles showing a remarkable positive inotropic response without initial negative inotropic effect was accompanied by an increase in intracellular $Na^+$ activity. The decrease in intracellular $Na^+$ activity was apparently inhibited by WB4101, an antagonist of the ${\alpha}_{1a}-adrenoceptors$. The decrease in intracellular $Na^+$ activity caused by phenylephrine was not abolished or reduced by a block of the fast $Na^+$ channels. $V_{max}$ also was not affected by phenylephrine. Phenylephrine produced an increase in intracellular $Na^+$ activity in the presence of a high concentration of extracellular $Ca^{2+}$ (in quiescent muscle) or phorbol dibutyrate, a protein kinase C activator(in beating muscle). These suggest that the ${\alpha}_{1a}-adrenoceptors-mediated$ decrease in intracellular $Na^+$ activity may be related to the protein kinase C.

• Journal of Life Science
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• v.20 no.6
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• pp.853-860
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• 2010

The DevSR two-component system is a major regulatory system involved in redox sensing in Mycobacterium smegmatis. The DevSR system consists of the DevS histidine kinase and its cognate DevR response regulator. When exposed to hypoxic conditions, the DevS histidine kinase is activated to phosphorylate the DevR response regulator, leading to the transcriptional activation of the DevR regulation. The ligand-binding state of the heme embedded in the N-terminal GAF domain of DevS determines the kinase activity of DevS. In this study, we demonstrated that the redox-responsive cysteine (C547) in the C-terminal kinase domain is involved in the redox-dependent control of DevS kinase activity. The formation of an intersubunit disulfide bond between the C547 residues in the presence of $O_2$ led to inactivation of DevS kinase activity. The reduction of the oxidized DevS with reductants such as $\beta$-mercaptoethanol and dithiothreitol resulted in the restoration of DevS kinase activity. It was demonstrated in vivo by complementation test that the substitution of C547 to alanine partially impaired the sensory function of DevS in M. smegmatis.

• Journal of Life Science
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• v.24 no.1
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• pp.54-60
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• 2014

Aromatic hydrocarbons are toxic environmental pollutants that are detrimental to the ecosystem and human health. Among them, chlorotoluene and nitrotoluene are toxic to hydrobios and irritate the skin, eyes, and respiratory organs of humans. We herein report the development of recombinant microbial biosensors for cheap and rapid monitoring of chlorotoluene and nitrotoluene compounds. Plasmids were constructed by inserting the xylR regulatory gene for BTEX (benzene, toluene, ethylbenzene, and xylene) degradation into upstream of Po' (the DmpR activator promoter Po with the deletion of its own upstream activating sequences) or Pu (the cognate promoter of XylR)::lacZ (the ${\beta}$-galactosidase gene) and transformed into Escherichia coli $DH5{\alpha}$. In the presence of inducers, the biosensor cells immobilized in agarose developed a red color in 1-2 h due to the hydrolysis of chlorophenol red ${\beta}$-D-galactopyranoside (CPRG), a substrate of ${\beta}$-galactosidase that was expressed by the inducers. Among BTEX, high responses were specifically observed with o-, m-, p-chlorotoluene ($0.1{\mu}M-100 mM$) and o-, m-, p-nitrotoluene (0.1 mM-100 mM). Po' demonstrated higher responses than those with Pu. The biosensors immobilized in agarose showed good stability after 21 days' storage at $4^{\circ}C$, and responses in untreated wastewater spiked with chlorotoluene and nitrotoluene, suggesting they can be used to detect compounds in wastewater.