• 한국토양비료학회지
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• 제48권2호
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• pp.81-86
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• 2015

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard (5 sites for sandy loam, 7 sites for silt loam, and 13 sites for loam) in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average values for 25 orchard soil samples were $270nmol\;g^{-1}$ of total FAMEs, $72nmol\;g^{-1}$ of total bacteria, $34nmol\;g^{-1}$ of Gram-negative bacteria, $34nmol\;g^{-1}$ of Gram-positive bacteria, $6nmol\;g^{-1}$ of actinomycetes, $49nmol\;g^{-1}$ of fungi, and $7nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, silt loam soils had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ compared with those of loam soils (p < 0.05), indicating that microbial activity increased. The average soil microbial communities in the orchard soils were 26.7% of bacteria, 17.9% of fungi, 12.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.5% of arbuscular mycorrhizal fungi, and 2.2% of actinomycetes. The soil microbial community of Gram-negative bacteria in silt loam soils was significantly higher than those of sandy loam and loam soils (p < 0.05).

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1303-1309
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• 2012

A novel ligand N,N'-(2,6-pyridinedicarbonyl)bis[N-(carboxymethyl)] (L1) was designed and synthesized. Four co-luminescence groups of Sm-La-pyridyl carboxylic acids systems were researched, which are $K_4Sm_{(1-x)}-La_x(L_1)Cl_3{\cdot}y_1H_2O$, $K_4Sm_{(1-x)}La_x(L_2)Cl_3{\cdot}y_2H_2O$, $K_6Sm_{2(1-x)}La_{2x}(L_3)Cl_6{\cdot}y_3H_2O$, $K_4Sm_{(1-x)}La_x(L_4)Cl_3{\cdot}y_4H_2O$. The results indicated the addition of La(III) could sensitize the luminescence of Sm(III) obviously in a certain range, enhancing emission intensity of Sm-pyridyl carboxylic acids relative to the undoped ones. The optimal mole percentages of La(III) in the mixed ions for $L_1$, $L_2$, $L_3$, $L_4$ were confirmed to be 0.6, 0.5, 0.3, 0.6, respectively. The mechanism of the fluorescence enhancement effect was discussed in detail. Furthermore, the binding interaction of $K_4Sm_{0.4}La_{0.6}(L_4)Cl_3{\cdot}5H_2O$ with bovine serum albumin (BSA) have been investigated due to its potential biological activity. The binding site number n was equal to 1.0 and binding constant $K_a$ was about $2.5{\times}10^5\;L{\cdot}mol^{-1}$.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2156-2162
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• 2012

Many literatures focus on the biological relevance and the identification of biomarkers for disease activity assessment while less attention has been paid to the development of standard procedures for sample preparation and storage based on liquid chromatography technique. The influencing factors including protein precipitation, storage temperature, storage time, and reconstitution by ultra pure water were analyzed employing HPLC-DAD. The effects were investigated from five participants over three months by principal components analysis (PCA) and the values of percent changes (PC). The samples with protein precipitation might slow the rate of bacterial enzymatic conversion. After protein precipitation, the average PC of urine samples ($0.136{\pm}0.013$, n = 5) is relatively less than that of the serum samples ($0.173{\pm}0.026$, n = 5) for three months. Minimal effects on metabolic profiles of serum and urine (PC < 0.15) are reasonable for metabolomic studies after protein precipitation and storage at $-20^{\circ}C$ for two months.

• Mycobiology
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• 제38권2호
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• pp.102-107
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• 2010

We identified a gene for $\beta$-1,3-glucan synthesis (GBG1), a nonessential gene whose disruption alters cell wall synthesis enzyme activities and cell wall composition. This gene was cloned by functional complementation of defects in $\beta$-1,3-glucan synthase activity of the the previously isolated Saccharomyces cerevisiae mutant LP0353, which displays a number of cell wall defects at restrictive temperature. Disruption of the GBG1 gene did not affect cell viability or growth rate, but did cause alterations in cell wall synthesis enzyme activities: reduction of $\beta$-1,3-glucan synthase and chitin synthase III activities as well as increased chitin synthase I and II activities. GBG1 disruption also showed altered cell wall composition as well as susceptibility toward cell wall inhibitors such as Zymolyase, Calcofluor white, and Nikkomycin Z. These results indicate that GBG1 plays a role in cell wall biogenesis in S. cerevisiae.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2250-2261
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• 2020

Accurate localization of radioactive materials is crucial in homeland security and radiological emergencies. Coded-aperture gamma camera is an interesting solution for such applications and can be developed into portable real-time imaging devices. However, traditional reconstruction methods cannot effectively deal with signal-independent noise, thereby hindering low-noise real-time imaging. In this study, a novel reconstruction method with excellent noise-suppression capability based on a multi-layer perceptron (MLP) is proposed. A coded-aperture gamma camera based on pixel detector and coded-aperture mask was constructed, and the process of radioactive source imaging was simulated. Results showed that the MLP method performs better in noise suppression than the traditional correlation analysis method. When the Co-57 source with an activity of 1 MBq was at 289 different positions within the field of view which correspond to 289 different pixels in the reconstructed image, the average contrast-to-noise ratio (CNR) obtained by the MLP method was 21.82, whereas that obtained by the correlation analysis method was 5.85. The variance in CNR of the MLP method is larger than that of correlation analysis, which means the MLP method has some instability in certain conditions.

• 약학회지
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• 제47권6호
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• pp.410-416
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• 2003

Autotaxin(ATX) was originally purified from conditioned media of A2058 human melanoma cells and shown to be a potent cell motility-stimulating factor, possessing a type II nucleotide pyrophosphatase/phosphodiesterase (NPP2) activity. Recombinant ATX has recently demonstrated that human plasma lysophosholipase D is identical to ATX and uses lysophosphatidylcholine as a substrate to mediate various biological functions including tumor cell growth and motility through G-protein coupled receptor. However, despite pivotal roles of ATX on physiological or pathophysiological states, the production of ATX is solely depends on complicated purification method which employs multiple column steps, but resulted in very poor yield. This limited the use of ATX for extensive analysis. We, therefore, expressed six histidine-tagged recombinant human ATX(His-ATX) in High Five TM insect cells to improve the generation of ATX and to make simple the purification of ATX. The signal sequence of the human ATX gene was truncated and replaced with sequence of insect cell secretion signal within expression vector. In addition, codons for six histidines were added to the C-termini of 120kDa ATX cDNA construct. A simple purification scheme utilizing two-step affinity column chromatography was designed to purify His-ATX to homogeneity from the culture supernatant of transfected insect cells. Homogenous His-ATX was detected and isolated from the concentrated insect cell medium using concanavalin A agarose and nickel affinity chromatography. Purified His-ATX was in full length with ATX capacity. A combination of this expression system and purification scheme would be useful for production and purification of high-quality functional ATX for research and practical application of multiple functional motogen, ATX/NPP-2.

• 한국식품과학회지
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• 제11권4호
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• pp.249-257
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• 1979

전보에서 저자들을 물리적 견고성이 우수한 포도당 이성화 효소를 세포 고정화 시킨 제품을 얻었다.(한국 식품 과학 회지, 11(No. 3), 192(1979). 이 효소 제품을 사용하여 실험실 조건에서 회분식 반응조와 충진식 반응조를 운영하여 효소의 반응 특성과 생산성, 활성 감소 현상을 비교 하였다. 본 고정화 효소의 비활성 역가는 회분식 반응조와 충진식 반응조에서 1 g당 각각 48 및 114 units였으며 연속적인 공정에서 더 높은 생산성과 이성화율을 보였다. 효소의 생산성은 체장 시간, 기질의 농도, 효소 부하율(附荷率) 및 반응조의 외형에 영향을 받았으며 충진 밀도가 450 g/l일 때 실제 공간율은 0.36이었으며 비교적 좋은 충진 현상을 보였다. 연속 공정중 효소의 활성 감퇴 현상을 고찰하기 위하여 2.5 M 포도당 용액을 체장 시간이 5.3시간이 되도록 약 220시간 동안 반응시켜 본 결과, 효소 활성 감퇴 곡선은 일차 반응을 따르며 활성 반감기는 115일로 연속 공정에 이용 가능함을 알았다. 이 고정화 효소 제품은 물리적 안정성이 높은 반면 물질 전달 계수가 반응 속도에 큰 영향을 미치는 것으로 나타났다.

• 생명과학회지
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• 제23권12호
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• pp.1553-1556
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• 2013

본 연구는 재래감귤종의 하나인 진귤 과피 추출물이 산화적 스트레스에 의한 MMP-1의 발현 조절에 미치는 효과를 확인하기 위해 수행되었다. $H_2O_2$를 피부세포에 처리하여 산화적 스트레스를 유도한 결과 노화 유발에 중요한 역할을 하는 것으로 알려진 MMP-1의 발현량이 증가하였고 진귤과피 추출물의 처리는 산화적 스트레스에 의해 증가된 MMP-1의 활성을 현저히 감소시켰다. 이러한 활성 조절이 ERK signaling을 통해 조절되는지 확인한 결과 산화적 스트레스에 의해 증가된 ERK의 인산화는 진귤과피 추출물의 처리로 억제되었고 MEK 억제재인 U0216을 처리하였을 경우 MMP-1의 활성도 또한 저해시키는 것을 확인하였다. 이상의 결과로 보아 $H_2O_2$에 의해 유도된 산화적 스트레스는 MMP-1의 발현을 촉진시켰고 진귤과피 추출물은 ERK 신호전달 경로를 통해 MMP-1의 발현을 조절하는 것으로 보여진다.

• Molecules and Cells
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• 제21권2호
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• pp.229-236
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• 2006

Gaegurin 4 (GGN4), a novel peptide isolated from the skin of a Korean frog, Rana rugosa, has broad spectrum antimicrobial activity. A number of amphipathic peptides closely related to GGN4 undergo a coil to helix transition with concomitant oligomerization in lipid membranes or membrane-mimicking environments. Despite intensive study of their secondary structures, the oligomeric states of the peptides before and after the transition are not well understood. To clarify the structural basis of its antibiotic action, we used analytical ultracentrifugation to define the aggregation state of GGN4 in water, ethyl alcohol, and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The maximum size of GGN4 in 15% HFIP corresponded to a decamer, whereas it was monomeric in buffer. The oligomeric transition is accompanied by a cooperative 9 nm blue-shift of maximum fluorescence emission and a large secondary structure change from an almost random coil to an ${\alpha}$-helical structure. GGN4 induces pores in lipid membranes and, using electrophysiological methods, we estimated the diameter of the pores to be exceed $7.3{\AA}$, which suggests that the minimal oligomer structure responsible is a pentamer.

• Molecules and Cells
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• 제39권4호
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• pp.330-336
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• 2016

Long non-coding RNAs (lncRNAs) are involved in multiple cellular events, as well as in tumorigenesis. Colon cance-rassociated transcript-1 (CCAT1) gene encodes an lncRNA whose over-activation was observed in an expanding list of primary human solid tumors and tumor cell lines, however its biological roles in acute myeloid leukaemia (AML) has not been reported yet at present. In this study, the aberrant upregulation of CCAT1 was detected in French-American-British M4 and M5 subtypes of adult AML patients. By gain- and loss-of-function analysis, we determined that CCAT1 repressed monocytic differentiation and promoted cell growth of HL-60 by sequestering tumor suppressive miR-155. Accordingly, a significant decrease in miR-155 level was detected in AML patients. Reintroduction of miR-155 into HL-60 cells restored monocytic maturation and repressed cell proliferation. Furthermore, CCAT1 could up-regulated c-Myc via its competing endogenous RNA (ceRNA) activity on miR-155. In conclusion, these results revealed new mechanism of lncRNA CCAT1 in AML development, and suggested that the manipulation of CCAT1 expression could serve as a potential strategy in AML therapy.