• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.310-310
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• 2007

Mg-Si-O계 세라믹스에 glass frit 조성을 첨가하여 저온에서의 소결 특성 및 마이크로파 유전 특성을 연구하였다. 기존의 Mg-Si-O계 세라믹스는 우수한 유전특성을 가지고 있으나 높은 소결온도로 인하여 LTCC용 기판 소재로 적용이 어려웠다. 본 연구에서는 MgO, $SiO_2$를 이용하여 $Mg_2SiO_4$을 합성한 후, $B_2O_3-ZnO-Na_2O-SiO_2-Al_2O_3$계 glass 조성을 20~40wt%로 첨가하여 소결온도를 감소시켜 LTCC 기판 소재로서의 적용성을 고찰하였다. glass frit 함량이 증가함에 따라 밀도($g/cm^3$) 및 유전율(${\varepsilon}_r$)은 증가하였고 품질계수($Qxf_0$)값은 감소하였다. glass frit 함량이 40wt%일때 $900^{\circ}C$에서 1시간 소결한 소결체의 유전톡성은 유전율 (${\varepsilon}_4$) = 6.5. 품질계수 ($Qxf_0$) = 4,000(GHz), 온도계수 $(\tau_t)\;=\;{\pm}\;10ppm/^{\circ}C$로 우수한 특성을 확인하였다.

• 자원환경지질
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• 제22권2호
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• pp.129-139
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• 1989

The anthracite coalfields of Korea are confined to the areas where sedimentary rocks of Permian and Jurassic are preserved. The Chungnam coalfield lies in the sedimentary rocks of Jurassic which belongs to the Daedong Supergroup (the Nampo group). For the property analysis of each coal seam interbeded in Daedong Supergroup, Seongju area is chosen and twelve coalseams are taken. Many standard tests have been established for optical analysis (maceral analysis, coalification degree measurement), chemical analysis (proximate, ultimate analysis) and physical analysis (ignition temperature, ash fusion temperature, hardgrove grindability index and X-ray diffraction). The Jurassic anthracite mainly consist of vitrinite and macrinite and the range of the reflectance is $R_{max}$ 5.0-6.5 which means metaanthracite rank. By the chemical composition analysis, it shows low H/C and high O/C value compare with international average value. By the physical analysis, it has very high ignition temperature ($531-584^{\circ}C$) and ash fusion temperature ($1510-1700^{\circ}C$) and very low combustion velocity (0.2-1.9 mg/min). The very wide range of the hardgrove grindability index (46-132) means that the grindability controlled mainly by the structural conditions of coal bearing strata.

• 한국미생물·생명공학회지
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• 제17권1호
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• pp.1-7
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• 1989

Transformant TSD-14의 starch 발효능을 향상시키기 위해, 52$^{\circ}C$에서 60분간의 열처리로써 regeneration능을 제거한 TSD-14의 protoplast와 C, tropicalis RCT-40 (lys-)의 protoplast를 20 mM CaC1$_2$를 함유한 30% PEG를 fusogenlc agent로 하여 융합시키고 최소배지상에서 fusant를 선별한 결과 4.4$\times$$10^{-5}$ 빈도로 fusant를 얻었다. Fusant들의 탄소원 자화능을 조사한 결과 parental strains의 성질이 동시에 존재함을 알 수 있었으며 cell volume은 Parental Strains에 비해 약 1.5배정도 크게 나타났다. 또한 fusant는 유전적으로 매우 안정하였으며, parent인 TSD-14와는 달리 $\alpha$-1, 6-glucosidic linkage를 가수분해할 수 있었다. Fusant중 가장 우수 한 FSC-14-75 균주는 15%의 liquefied potato starch로부터 8.7%(v/v)의 ethanol을 생성하였고 또한 이때의 fermentation broth에 0.3%의 peptone을 첨가한 경우, ethanol 생성은 9.3%(v/v) 수준으로 증가하여 총당에 대해 86.0%의 발효율을 나타냈으며 산업적 이용가능성을 시사하였다.

• 대한한의학방제학회지
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• 제25권4호
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• pp.449-456
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• 2017

Objective : Coptis rhizoma is traditional herb in Korean medicine, and Pelargonium sidoides extract has been used for relief of acute bronchitis in Western medicine. The present study examined the antibacterial effect of fusion formulation of Coptis rhizoma extract and Pelargonium sidoides extract against bronchial diseases bacteria. Methods : Test sample, fusion formulation of Korean and Western medicine, was prepared by mixing Coptis rhizoma extract and Pelargonium sidoides extract at a ratio of 1:2 (w/w). Antimicrobial properties of test sample were determined by agar diffusion assay and minimum inhibitory concentration (MIC) against bronchus diseases bacteria. Results : In agar diffusion assay, the highest amount of test sample (4 mg/disk) exhibited antibacterial activity against all microorganisms tested. Test sample showed the high activity for S. aureus (19.5 mm), C. diptheriae (16.5 mm), A. fumigatus (19.3 mm), F. nucleatum (22.7 mm) and Mycobactrium sp. (17.3 mm), whereas it showed a low activity for K. pneumonia (9.7 mm). The MIC value was determined as $250{\mu}g/m{\ell}$ against C. diptheriae. Test sample showed better growth inhibitory effects against S. aureus and A. fumigatus with the MIC valus of $125{\mu}g/m{\ell}$. Conclusion : These results suggest the possibility of application to chronic respiratory diseases of fusion formulation of Korean and Western medicine, which was prepared with Coptis rhizoma extract and Pelargonium sidoides extract.

• Journal of Korean Neurosurgical Society
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• 제60권6호
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• pp.691-700
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• 2017

Objective : The authors prospectively analyzed the effect of one-level or two-level anterior cervical discectomy and fusion (ACDF), comparing stand-alone cages and cage-with-plate fixation constructs with respect to clinical outcomes and radiologic changes. Methods : A total of 84 patients who underwent one-level (n=52) or two-level ACDF (n=32) for cervical disc disease and who completed 2 years of follow-up were included in this study. The patients were divided by cervical level and grouped into ACDF-Cage-only and ACDF-Cage-with-plate groups. The following parameters were assessed using radiographs : subsidence, C2-C7 lordosis angle, fusion segment angle, adjacent disc space narrowing, and fusion status. Clinical outcomes were assessed using the neck disability index (NDI) and visual analog scale scores for arm pain. Results : In the comparison of one-level ACDF-cage-only and ACDF-cage-with-plate groups, the NDI score was better in the cage-only group at the 3-, 12-, and 24-month follow-ups : however, no significant difference in clinical outcomes was observed. In the comparison of two-level ACDF-cage-only and ACDF-cage-with-plate groups, no difference in any clinical outcome was observed between the two groups. At the 24-month follow-up, subsidence was observed in 45.8% of patients in the one-level cage-only group and 32.1% of patients in the one-level cage-with-plate fixation group. There was no statistically significant difference in the incidence rate between the two groups (p=0.312). Subsidence in the two-level cage-only group (66.6%) was significantly more frequent than in the two-level cage-with-plate fixation group (30%; p=0.049). The fusion rate for patients in the one-level cage-only group was not significantly different from that in the one-level cage-with-plate fixation group (cage-only, 87.5%; cage-with-plate fixation, 92.9%; p=0.425) ; fusion rate in the two-level patients were also similar between groups (cage-only, 83.3%; cage-with-plate fixation, 95%; p=0.31). Conclusion : Our clinical results showed that for single-level cases, plate fixation had no additional benefit versus cage-only; for two-level ACDF cases, the fusion rate and clinical outcomes were similar, although the cage-with-plate fixation group had a lower incidence of cage subsidence than did the cage-only group. We conclude that physicians should be aware of this possible disadvantage associated with using cervical plates in one-level ACDF. However, in two-level ACDF, subsidence is more likely to occur without plate fixation, and thus the addition of plate fixation should be considered.

• 생명과학회지
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• 제14권2호
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• pp.315-319
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• 2004

사람의 serine palmitoyltransferase(SPT, EC 2.3.1.50)에 대한 항체를 제작하기 위하여 E. coli발현 vector인 pRset vector에 SPTLC1 및 SPTLC2 유전자를 subcloning하고 BL21 (DE3)pLys cell에 발현시켰다. 포유동물의 SPT는 원핵세포의 SPT homodimer와는 달리 SPTLC1 및 SPTLC2 2개의 sub-unit로 된 heterodimer이다. Human embryo kidney cell인 HEK293 cell의 total RNA로부터 RT-PCR을 행하여 cDNA library를 얻은 다음 SPTLC1 및 SPTLC2의 특이적인 primer 들을 이용하여 PCR을 행하였다. SPTLC1 및 SPTLC2 DNA를 hexahistidine fusion 단백질을 발현시킬 수 있는 pRset vector에 cloning하여 pRsetB/SPTLC1 및 pRsetA/SPTLC2를 얻고 염기서열을 확인하였다. 재조합 plasmid를 발현세포인 BL21 cell에 형질전환시킨 다음 ampicillin 및 chroramphenicol 배지에서 선별하여 재조합세포를 얻었다. 1 mM IPTG로서 발현을 유도하였으며 세포 단백질을 SDS-PAGE로 분리한 다음 His-tag antibody로 western blotting을 행하여 SPTLC 및 SPTLC2가 발현되었음을 확인하였다.

• 한국작물학회지
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• 제27권2호
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• pp.147-154
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• 1982

식물원형질체를 이용하여 체세포잡종을 육성하기 기초자료를 얻고자 식물의 엽육부위, Callus에서 효과적인 원형질체의 분리, 적합한 배양조건 및 세포융합에 관한 조건을 조사한 결과를 요약하면 다음과 같다. 1. 배양 융합조건에 적합한 식물원형질체의 분리 방법은 여러 종류의 효소농도에 따라 다르지만 담배 및 완두엽육 원형질체분리에는 Macerozyme 0.5%, Cellulase 2.0%, KDS 0.5%, Mannitol 0.7M의 효소용액에 처리시 활성 있는 원형질체를 얻을 수 있었다. 2. 배양중인 담배 및 대두의 Callus로부터 원형질체분리는 배양기간에 따라 세포활성도가 떨어지거나 쉽게 파괴되는 현상을 보여 양호한 원형질체를 얻을 수가 없었다. 3. 원형질체의 배양은 배양배지에 Plating할 경우 세포농도에 따라 차이가 있었으며 1.0$\times$$10^4$/ml이상이어야 분열이 가능하였고 배양조건은 150Lux 12시간 광암처리후가 세포분열 및 증식이 가장 왕성하였다. 4. 세포융합은 PEG농도가 중요하며 PEG 1500 0.33M에서 CaCl_2농도가 높을수록 융합율이 증가되는 경향이었다.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.296-300
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• 1990

자외선 조사와 NTG를 처리하여 Brevibacterium flavum 10AHR(arg his $Rif^r$)과 Corynebacterium glutamicum 11TS(trp $Sm^r$의 돌연변이주를 분리하였다. B.flavum 10AHR과 C.glutamicum 11TS를 300$\mu g$/ml의 lysozyme으로 18시간 처리하여 원형질체를 형성하고, 융합시 30의 PEG 6,000으로 처리하였을 때 가장 높은$3.7\times 10^{-6}$의 융합빈도를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.84-91
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• 2006

A Saccharomyces cerevisiae pgs1 nulI mutant, which is deficient with phosphatidyl glycerol (PG) and cardiolipin (CL) biosynthesis, grows well on most fermentable carbon sources, but fails to grow on non-fermentable carbon sources such as glycerol, ethanol, and lactate. This mutant also cannot grow on galactose medium as the sole carbon source. We found that the incorporation of $[^{14}C]-galactose$, which is the first step of the galactose metabolic pathway (Leloir pathway), into the pgs 1 null mutant cell was extremely repressed. Exogenously expressed PGS1 (YCpPGS1) under indigenous promoter could completely restore the pgs1 growth defect on non-fermentable carbon sources, and dramatically recovered $[^{14}C]-galactose$ incorporation into the pgs1 mutant cell. However, PGS1 expression under the GALl promoter $(YEpP_{GAL1}-PGS1myc)$ could not complement pgs1 mutation, and the GAL2-lacZ fusion gene $(YEpP_{GAL2}-lacZ)$ also did not exhibit its $\beta-galactosidase$ activity in the pgs1 mutant. In wild-type yeast, antimycin $A(1\;{\mu}g/ml)$, which inhibits mitochondrial complex III, severely repressed not only the expression of the GAL2-lacZ fusion gene, but also uptake of $[^{14}C]-galactose$. However, exogenously expressed PGS1 partially relieved these inhibitory effects of antimycin A in both the pgs1 mutant and wild-type yeast, although it could not basically restore the growth defect on galactose by antimycin A. These results suggest that the PGSI gene product has an important role in utilization of galactose by Gal genes, and that intact mitochondrial function with PGS1 should be required for galactose incorporation into the Leloir pathway. The PGS1 gene might provide a clue to resolve the historic issue about the incapability of galactose with deteriorated mitochondrial function.

• Molecules and Cells
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• 제40권10호
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• pp.752-760
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• 2017

A2B adenosine receptor (A2BAR) is known to be the regulator of bone homeostasis, but its regulatory mechanisms in osteoclast formation are less well-defined. Here, we demonstrate the effect of A2BAR stimulation on osteoclast differentiation and activity by RANKL. A2BAR was expressed in bone marrow-derived monocyte/macrophage (BMM) and RANKL increased A2BAR expression during osteoclastogenesis. A2BAR stimulation with its specific agonist BAY 60-6583 was sufficient to inhibit the activation of ERK1/2, p38 MAP kinases and $NF-{\kappa}B$ by RANKL as well as it abrogated cell-cell fusion in the late stage of osteoclast differentiation. Stimulation of A2BAR suppressed the expression of osteoclast marker genes, such as c-Fos, TRAP, Cathepsin-K and NFATc1, induced by RANKL, and transcriptional activity of NFATc1 was also inhibited by stimulation of A2BAR. A2BAR stimulation caused a notable reduction in the expression of Atp6v0d2 and DC-STAMP related to cell-cell fusion of osteoclasts. Especially, a decrease in bone resorption activity through suppression of actin ring formation by A2BAR stimulation was observed. Taken together, these results suggest that A2BAR stimulation inhibits the activation of ERK1/2, p38 and $NF-{\kappa}B$ by RANKL, which suppresses the induction of osteoclast marker genes, thus contributing to the decrease in osteoclast cell-cell fusion and bone resorption activity.