• Korean Journal of Microbiology
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• v.49 no.1
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• pp.99-104
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• 2013

Bacteriophage P2 sir mutants are inefficient helpers for their satellite bacteriophage P4. The term, "P2 sir-associated helper inefficiency" has been used to define this phenomenon and it has been suggested that the DNA sequence difference between the cos region of P2 and that of P4 is responsible. To test this hypothesis, P4 derivative phage, P4 sid71 cosP2, containing the cos region of P2 and sid71 allele was constructed through several in vitro DNA manipulation steps. Its burst size was determined using a one-step growth experiment. The results showed that the substitution of the cos region of P2 for the cos region of P4 in P4 sid71 cosP2 overcame "P2 sir-associated helper inefficiency". P4 sid71 cosP2 stock phages prepared with P2 wild type helper and P2 sir helper were analyzed using a CsCl buoyant equilibrium density gradient experiment. The results revealed that the phage particles containing three copies of the P4 genome were the predominant particles in both cases.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.75-82
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• 2007

As one of the main support systems, rock bolts play a crucial role in the reinforcement of tunnels. Numerical and experimental studies using a transmission method of ultrasonic guided waves are performed to evaluate the integrity of rock bolts encapsulated by grouting paste. Numerical simulations using "DISPERSE" are carried out for the selection of the optimal experimental setup, i.e. non-destructive testing (NDT) system of the rock bolt. Based on results of the numerical simulation, the calculated frequency range for NDT testing is between 20kHz and 70kHz with the first longitudinal L(1) mode. Laboratory transmission tests are performed by attaching the piezo electric sensor at the tip of the rock bolt before embedding. Both of analytical and experimental results show that the amplitude of signals as well as the wave velocity increases with increase in the defect ratio of grouting paste. The defect in grouting paste means that the space around the rock bolt is not fully filled with the grouting paste. Experimental results also show that the increase of the wave velocity is more sensitive to the defect ratio increase than that of the amplitude. This study demonstrates that the transmission technique of ultrasonic guided waves may be a valuable tool in the evaluation of the rock bolt integrity.

• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.303-310
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• 1997

소 난포란의 체외성숙시 성숙배지에 FSH 및 LH의 첨가가 체외성숙난자의 calcium 반응과 체외수정란의 발달에 미치는 영향을 조사하였다. 난포란의 체외성숙은 TCM199을 기초로 한 4가지의 배양조건 하에서 : 1) 0.5$\mu\textrm{g}$/ml FSH＋5$\mu\textrm{g}$/ml LH, 2) 0.5$\mu\textrm{g}$/ml FSH, 3) 5$\mu\textrm{g}$/ml LH 및 4) 무 호르몬 첨가구로서 5% CO2에 24시간 동안 체외성숙을 유도하였다. 체외성숙 24기간째에 난포란의 과립막세포는 1ml PB1＋에서 4분 동안 vortexing을 하여 완전히 제거하였다. 세포 내 calcium 반응을 측정하기 위하여 2mM Fura-2 AM ester 및 0.02% Pluronic F-127가 첨가된 PB1-용액에 39$^{\circ}C$ in cubator에서 40분 동안 배양하였다. 30${\mu}\ell$ M2 medium drop을 30mm plastic dish에 만들어 20$\times$ 형광대물렌즈가 장착된 Nikon Diaphot 현미경의 장착된 Nikon Diaphot 현미경의 warm stage에 설치하였다. 세포 내 calcium 방출을 자극하기 위하여 난자에 25mM inositol 1, 4, 5-trasphophate(IP3)로 1.21kV/cm의 전기자극 또는 20mM ryanodine으로 미세주입을 실시하였다. 이러한 처리를 하지 않은 난자는 체외수정 후 CR1aa와 BRL monolayers의 공배양조건 하에서 체외발달을 유도하였다. 분할율(Day 2)과 배반포기발달율(Day 9)을 조사하였다. FSH와 LH의 처리구에서 IP3 또는 ryanodine으로 자극된 난자(1.79$\pm$0.05, 1.66$\pm$0.06)는 FSH, LH 및 무 호르몬처리구에 비하여 유의적으로 높은 calcium 반응을 보였다(1.00$\pm$0.03, 1.28$\pm$0.04, and 0.53$\pm$0.02 in IP3 elctroporation; 0.68$\pm$0.05, 1.03$\pm$0.05, and 0.47$\pm$0.04 in ryanodine microinjection). FSH와 LH, FSH, LH처리구에서 분할율(87.9, 71.5 및 75.6%)은 무 호르몬처리구(60.7%)(P<0.05)에 비하여 유의적으로 높았으며, FSH와 LH처리구(29.3%)에서의 배반포기 발달율은 FSH, LH 처리구뿐만 아니라 무 호르몬처리구보다 유의적으로 높았다(16.5, 19.0 and 9.8%)(P<0.05). Bovine FSH 및 Ovine FSH의 처리구에서의 calcium 반응은 유의적인 차이가 없었다(1.72$\pm$0.05, 1.61$\pm$0.06). 또한 분할율(82.2 and 84.0%) 및 배반포기(27.8 and 27.1%) 발달율도 bovine 및 ovine FSH처리구간에는 유의적인 차이가 없었다. 이상의 결과에서 전기자극에 의한 세포 내 calcium 반응은 체외성숙배지에 첨가하는 호르몬의 처리에 따라서 유의적인 변화를 보였다. 비록 분할율은 처리구간에 유의적인 차이가 없었지만 배반포기 발달율은 FSH와 LH 공동처리구에서 FSH, LH 단독처리구 및 무 호르몬처리구에 비하여 유의적으로 높은 발달율을 보였다. 체외성숙기간에 FSH와 LH의 공동첨가는 체외성숙 및 체외발달의 생리적인 교정을 위하여 요구되는 것으로 사려된다.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.563-574
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• 2007

Laser induced breakdown spectroscopy (LIBS) is a recently developed analytical technique that is based upon the measurement of emission lines generated by atomic species close to the surface of the sample, thus allowing their chemical detection, identification and quantification. With powerful advantages of LIBS compared to the conventional analytical methodology, this technique can be applied in the detection of heavy metals in the field. LIBS allows the rapid analysis by avoiding laborious chemical steps. LES have already been applied for the determination of element concentration in a wide range of materials in the solid, liquid and gaseous phase with simplicity of the instrument and diversity of the analytical application. These feasibility of rapid multi elemental analysis are appealing proprieties for the in-situ analytical technique in geochemical investigation, exploration and environmental analysis. There remain still some limitations to be solved for LIBS to be applied in soil environment as an in-situ analytical technology. We would like to provide the basic principle related to the plasma formation and laser-induced breakdown of sample materials. In addition, the matrix effect, laser properties and the various factors affecting on the analytical signal of LIBS was dealt with to enhance understanding of LIBS through literature review. Ultimately, it was investigated the feasibility of LIBS application in soil environment monitoring by considering the basic idea to enhance the data quality of LIBS including the calibration method for the various effects on the analytical signal of LIBS.

• Journal of Life Science
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• v.24 no.7
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• pp.798-803
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• 2014

Cathepsin D (CtsD), an aspartyl peptidase, is involved in apoptosis, resulting in the release of cytochrome C from mitochondria in cells. Here, we investigated microRNA regulation of CtsD expression in 3T3-L1 cells First, we observed the expression of CtsD in cells in response to doxorubicin (Dox). As expected, the level of CtsD mRNA was increased in 3T3-L1 cells exposed to Dox in a dose-dependent manner. Cellular viability of ectopically expressed CtsD cells was also decreased. Next, we used the miRanda program to search for particular microRNA targeting CtsD. MiR-145 was selected as a putative controller for CtsD because miR-145 had a high mirSVR score. In a reporter assay, the luciferase activity of cells containing the CtsD 3'-UTR region was decreased in cells transfected with miR-145 mimic compared to that of a control. The level of CtsD expression was down-regulated in preadipocytes ectopically expressing miR-145 and up-regulated by an miR-145 inhibitor. Cells also suppressed miR-145 expression when exposed to Dox. The miR-145 inhibitor reduced the cellular viability of 3T3-L1 cells. Taken together, these data suggest that miR-145 regulates CtsD-mediated cell death in adipocytes. These findings may have valuable implications concerning the molecular mechanism of CtsD-mediated cell death in obesity, suggesting that CtaD could be a useful therapeutic tool for the prevention and treatment of obesity by regulating fat cell numbers.

• Journal of Life Science
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• v.27 no.5
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• pp.545-552
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• 2017

Julbernardia globiflora, a tropical African tree widespread in Miombo woodland, has been used in folk medicine for the treatment of depression and stomach problems. However, the antioxidative and anticancer activities of J. globiflora remain unclear. The objective of this study is to evaluate the antioxidative and anticancer effects of methanol extract of J. globiflora (MEJG) and the molecular mechanism of its anticancer activity in human colon carcinoma HT29 cells. MEJG exhibited significant antioxidative effect with an $IC_{50}$ (concentration at 50% inhibition) value of $1.23{\mu}g/ml$ measuring by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and inhibited cell proliferation in a dose-dependent manner in HT29 cells. We found that MEJG induced apoptosis of HT29 cells with the increase of apoptotic cells and apoptotic bodies using Annexin V staining and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. The MEJG treatment showed the increase of Fas, a death receptor, and Bax, a pro-apoptotic protein, and the decrease of Bcl-2, an anti-apoptotic protein, resulting in the release of cytochrome c from the mitochondria into the cytosol and activation of caspase-3, -8 and -9. The apoptotic effects of MEJG were confirmed by cleavage of poly (ADP-ribose) polymerase (PARP). Collectively, these results suggest that MEJG may exert the anticancer effect in HT29 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• KSBB Journal
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• v.17 no.6
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• pp.525-530
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• 2002

The optimum culture conditions for tropane alkaloid production in hairy root cultures of Korea native Scopolia paviflora Nak. were investigated. Hairy root was induced from the rhizome of the mother plant on B5 medium containing 1.0 mg/L IBA. Among the culture media examined, 1/2 B5 medium was the best for tropane alkaloid production, whereas the growth of hairy root increased in SH medium. The best result on the growth of hairy root was obtained in 1.0 mg/L NAA, and tropane alkaloid production was obtained in plant growth regulator-free medium. Of the carbone sources tested, 3% sucrose promoted the growth of hairy root, whereas 5% sucrose increased tropane alkaloid production. Optimum inoculum densities for root growth and tropane alkaloid production were 0.5 g and 1 g, respectively. The addition of XAD resins (1 % w/v) to hairy root cultures led to increases in tropans alkaloid production, and the release of alkaloid into the medium and its adsorption by the resin accounted for about 50 to 80％ of total production. It is concluded that optimized culture conditions and the addition of XAD resins could be used in the development of a bioprocess for tropane alkaloid production in hairy root cultures of S. paviflora Nak.

• Journal of Conservation Science
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• v.30 no.3
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• pp.249-261
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• 2014

This study aims to examine production technique of white wares from the Guyre-2ri 1st and 2nd kiln sites, Wonju, Gangwon Province and characteristics of the used materials, and to find a correlation among materials of the excavated white wares. X-ray fluorescence sequential spectroscopy(XRF), X-ray diffraction(XRD), Dilatometer and Inductively coupled plasma mass spectrometry(ICP-MS), Inductively coupled plasma automic emission spectrometer(ICP-AES) were applied to determine the chemical composition, crystalline phase of samples, firing temperatures, trace elements and rare earth elements. White wares from the Guyre-2ri kiln sites contained high contents of coloring oxides and fluxes. Though firing temperature of each sample was different, they were mostly fired at a temperature below $1200^{\circ}C$ and some of them experienced a low temperature of $1000^{\circ}C{\pm}20^{\circ}C$ and a high temperature above $1200^{\circ}C$. When analyzing body crystalline phases of the white wares using the XRD method, quartz and mullite were extracted from all the samples, and the proportions were similar to each other. When analyzing the excavated white wares using the Seger formula, also, all the samples showed similar clay sources and production techniques. Moreover, the white wares were made of host rocks of the same geological origin, according to the result of rare earth elements analysis.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.168-175
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• 2000

Relatively little is known about the signaling mechanism of ginseng saponins (ginsenosides), active ingredients of ginseng, in non-neuronal cells. Here, we describe that ginsenosides utilize a common pathway of receptor-mediated signaling pathway in Xenopus oocytes: increase in intracellular $Ca^{2+}$ concentration via phospholipase C (PLC) and $Ca^{2+}$ mobilization. Ginsenosides induced a marked and robust artivation of $Ca^{2+}$-activated Cl- channels in Xenopus oocytes. The effect of ginsenosides was completely reversible, in a dose-dependent manner with EC$_{50}$ of 4.4 $\mu\textrm{g}$/mi, and specifically blocked by niflumic acid, an inhibitor of $Ca^{2+}$-activated Cl- channel. Intracellular injection of BAPIA abolished the effect of ginsenosides. Intracellular injection of GTP${\gamma}$S also abolished the effect of ginsenosides. The effect of gin senosides on $Ca^{2+}$-activated Cl- currents was greatly reduced by the intracellular injection of heparin, an IP$_3$ receptorantagonist or the pretreatment of PLC inhibitor. These results indicate that ginsenosides activate endogenous $Ca^{2+}$-activated Cl- channels via the activation of PLC and the release of $Ca^{2+}$ from the IP$_3$-sensitive intracellular store following the initial interaction with membrane component(s) from extracellular side. This signaling pathway of ginsenosides may be one of the action mechanisms for the pharmacological effects of ginseng.ts of ginseng.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.3-27
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• 1996

분체의 입자 배열이 불규칙한 경우뿐만 아니라 입자 크기가 극미세하여 X선회절분석이 불가능한 경우에도 비정질물질이라 한다. 수용액 속에서 이런 비정질 물질을 합성하기 위해서는 합성용액의 과포화도를 높여 계속 유지시킴에 따라 극미세 1차핵 생성의 지속적인 유도에 따른 입자 성장을 최대한 억제시켜야만 한다. 본 연구에서는 흡습제, 칼슘제 및 식품 첨가제 등으로 이용되는 비정질 탄산칼슘을 계에서 합성하고, 이때 생성된 비정질 상태의 겔을 수용액 환경을 변화시켜가면서 따라 결정화를 유도하고 탄산칼슘의 동질이상을 관찰하였다. CO2의 유속을 11/min, 교반속도를 600rpm으로 고정시키고, Ca(OH)2의 양을 10g에서 50g까지 변화시켜가면서 겔 상태의 비정질 탄산칼슘을 합성하였다. 이때 전기전도도는 CO2의 용해와 더불어 Ca(OH)2의 용해도가 증가함에 따라 변화하였으며, 반응종반부에는 겔화가 시작될 때까지 거의 일정하였다. 따라서, 이러한 사실들로부터 현탁액 내에서의 전기전도도의 변화는 Ca이온의 영향을 받는 것으로 사료된다. 비정질 탄산칼슘은 수용액에서 불안정하여 CO2 가스를 방출하면서 급격히 결정화되는데, 본 연구에서는 Ca(OH)2의 양을 20g으로 하여 위의 방법에 의해 얻어진 겔을 수용액의 종류와 농도 및 결정화 온도, 교반속도를 달리하면서 결정화시켰다. 교반속도를 100rpm으로 하여 물의 온도변화에 다라 결정화시킨 경우 전 온도범위에서 칼사이트상이었으며, 물의 온도가 5$^{\circ}C$일 경우에는 미세한 입자들이 응집된 형태였으나, 그 외의 온도변화조건에서는 모두 평균입경 0.4$\mu\textrm{m}$정도의 비교적 균일하 능면체 형태였다. 또한 교반속도를 500rpm으로 증가시켰을 경우에는 8$0^{\circ}C$에서 침상의 아라코나이트가 소량생성되었음을 SEM사진으로 관찰할 수 있었으며, 소량의 바테라이트도 혼재되어 결정화되었음을 XRD결과로 알 수 있었다. 교반속도를 100rpm으로 한 NH4Cl 0.5mol/l 수용액에서는 입자의 형태와 크기가 불규칙한 칼사이트로 결정화되었으며, MgCl2 0.05mol/l 수용액의 경우에는 순수한 H2O의 경우에서와는 달리 2$0^{\circ}C$에서는 모서리가 무딘 매우 균일한 크기의 칼사이트 입자가 관찰되었으며, 6$0^{\circ}C$부터는 아라고나이트가 생성됨을 관찰할 수 있었다. 따라서, 고온(8$0^{\circ}C$)의 농도 MgCl2 수용액(0.1, 0.2 mol/l)에서 교반속도를 높여(800rpm) 겔을 결정화시킨 결과 아라고나이트의 생성수율이 증가되는 것을 확인할 수 있었다.