• KSBB Journal
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• v.18 no.5
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• pp.377-384
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• 2003

On-line monitoring techniques for fumaric acid and succinic acid were developed by flow injection analysis (FIA). For the determination of fumaric acid, two enzymes, fumarase and malic dehydrogenase were immobilized on VA-epoxy Biosynth E3-carrier and integrated into a FIA-system with a fluorescence detector. For the analysis of succinic acid, isocitrate lyase and isocitrate dehydrogenase were also immobilized on VA-epoxy polymer support and used in a FIA system. The immobilized enzymes in two FIA systems were characterized systematically, e.g. optimum pH and temperature, inhibitory effects etc. Two FIA systems were also used to on-line monitor the concentrations of fumaric acid and succinic acid in biotechnological processes. Good agreement between on-line monitored data and off-line data measured by HPLC showed extensive application of the FIA systems in bioprocesses.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.361-368
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• 2000

In other to examine the compressibility characteristics of cohesive soils in the mouth of the Nakdong river, the oedometer tests were peformed on undisturbed and reconstituted samples obtained by continuous boring typically at 3 different sites. It is meaningful to compare the consolidation behavior of natural clays with a reference state because the natural clays are depending on the stress history, sedimentary environment and geological history. In this study, the insitu state of the Pusan clays was investigated using the concepts of ISL(Nagaraj, 2000) and ICL and SCL(Burland, 1990). And for the purpose of confirming the existence of the underconsolidated clays, a standpipe type piezometer test and a dissipation test by piezocone were performed at their sites. Consequently, the Pusan clays were evaluated as normally consolidated clays.

• Molecules and Cells
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• v.37 no.8
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• pp.569-574
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• 2014

As a scaffold, SLX4/FANCP interacts with multiple proteins involved in genome integrity. Although not having recognizable catalytic domains, SLX4 participates in diverse genome maintenance pathways by delivering nucleases where they are needed, and promoting their cooperative execution to prevent genomic instabilities. Physiological importance of SLX4 is emphasized by the identification of causative mutations of SLX4 genes in patients diagnosed with Fanconi anemia (FA), a rare recessive genetic disorder characterized by genomic instability and predisposition to cancers. Recent progress in understanding functional roles of SLX4 has greatly expanded our knowledge in the repair of DNA interstrand crosslinks (ICLs), Holliday junction (HJ) resolution, telomere homeostasis and regulation of DNA damage response induced by replication stress. Here, these diverse functions of SLX4 are reviewed in detail.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.126-131
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• 1967

Various amines (Triethylamine, Diethylamine, Dimethylaniline, Pyridine and Diphenylamine) and electron acceptors (Carbontetrachloride, iodine monochloride and iodine) were reacted in the hexane solvent system to form a charge transfer complex in each case. The tendency of forming a charge transfer complex by these electron acceptors was proportional to the basicity of amines and the different type of complex was formed as the polarity of electron donor had markedly changed, which were identified by ultraviolet spectrophotometry. A correlation between the formation of complex and the basicity of amine and the polarity of electron acceptor was discussed.

• Molecules and Cells
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• v.38 no.8
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• pp.669-676
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• 2015

Genome instability, primarily caused by faulty DNA repair mechanisms, drives tumorigenesis. Therapeutic interventions that exploit deregulated DNA repair in cancer have made considerable progress by targeting tumor-specific alterations of DNA repair factors, which either induces synthetic lethality or augments the efficacy of conventional chemotherapy and radiotherapy. The study of Fanconianemia (FA), a rare inherited blood disorder and cancer predisposition syndrome, has been instrumental in understanding the extent to which DNA repair defects contribute to tumorigenesis. The FA pathway functions to resolve blocked replication forks in response to DNA interstrand cross-links (ICLs), and accumulating knowledge of its activation by the ubiquitin-mediated signaling pathway has provided promising therapeutic opportunities for cancer treatment. Here, we discuss recent advances in our understanding of FA pathway regulation and its potential application for designing tailored therapeutics that take advantage of deregulated DNA ICL repair in cancer.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1563-1570
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• 2010

To construct a highly sensitive detection system for endocrine disruptors (EDs), we have compared the activity of promoters with the n-alkane-inducible cytochrome P450 gene (ALK1), isocitrate lyase gene (ICL1), ribosomal protein S7 gene (RPS7), and the translation elongation factor-1${\alpha}$ gene (TEF1) for the heterologous gene in Yarrowia lipolytica. The promoters were introduced into the upstream of the lacZ or hERa reporter genes, respectively, and the activity was evaluated by ${\beta}$-galactosidase assay for lacZ and Western blot analysis for hER${\alpha}$. The expression analysis revealed that the ALK1 and ICL1 promoters were induced by n-decane and by EtOH, respectively. The constitutive promoter of RPS7 and TEF1 showed mostly a high level of expression in the presence of glucose and glycerol, respectively. In particular, the TEF1 promoter showed the highest ${\beta}$-galactosidase activity and a significant signal by Western blotting with the anti-estrogen receptor, compared with the other promoters. Moreover, the detection system was constructed with promoters linked to the upstream of the expression vector for the hER${\alpha}$ gene transformed into the Y. lipolytica with a chromosome-integrated lacZ reporter gene under the control of estrogen response elements (EREs). It was indicated that a combination of pTEF1p-hER${\alpha}$ and CXAU1-2XERE was the most effective system for the $E_2$-dependent induction of the ${\beta}$-galactosidase activity. This system showed the highest ${\beta}$-galactosidase activity at $10^{-6}\;M\;E_2$, and the activity could be detected at even the concentration of $10^{-10}\;M\;E_2$. As a result, we have constructed a strongly sensitive detection system with Y. lipolitica to evaluate recognized/suspected ED chemicals, such as natural/synthetic hormones, pesticides, and commercial chemicals. The results demonstrate the utility, sensitivity, and reproducibility of the system for identifying and characterizing environmental estrogens.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.80-85
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• 1989

The structural properties of covered and naked barley starches and those components were investigated. ${\beta}-amylosis\;limit(%)$ of covered and naked barley starches were 58.6 and 56.3%, respectively and those of their amyloses and amylopectins were 87.0, 77.7, 57.6 and 52.0%, respectively. The ratios of outer chain length ${\overline{OCL}}$ and inner chain length${\overline{ICL}}$ for amylopectins of covered and naked barley were about 2.2:1 and 2.0:1, respectively. The elution curves by Sephadex G-75 after debranching starches with pullulanase were similar patterns for two starches and yielded two peaks consisting of amylose component${\overline{dp}}>55$ and bimodal amylopectin components of ${\overline{dp}_(35-45)$ and ${\overline{dp}}(10-20)$ hydrolysates. Also, hydrolysis products by sequential hydrolysis with pullulanase and ${\beta}-amylase$ contained 0.03-0.5% non-hydrolyzed peak components of ${\overline{dp}}>55$. The elution profiles of ${\beta}-amylase$ hydrolysates yielded two peaks consisting of the inner components${\overline{dp}}>55$ and the outer chain components of amylopectin${\overline{dp}}>10$ regardless of samples. However, ${\overline{dp}}$ distributions of ${\overline{dp}>55}$ hydrolysates exhibited the significant differences due to the varieties.

• Journal of the Korean Chemical Society
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• v.25 no.6
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• pp.351-360
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• 1981

Ultraviolet spectrophotometric investigations have been carried out on the system of durene with iodine, bromine, iodine monochloride and iodine monobromide in carbon tetrachloride. The results reveal the formation of the charge transfer complexes of the type, $C_6H_2(CH_3)_4{\cdot}X_2$ or $C_6H_2(CH_3)_4{\cdot}IX$(X denotes halogen atoms). The equilibrium constant were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with the increasing temperatures. The thermodynamic parameters, ${\Delta}H,\;{\Delta}G\;and\;{\Delta}S$ for the formation of the charge transfer complexes were calculated from these values. These results indicate that the relative stabilities of the durene complexes at each temperature decrease in the order, $ICl>IBr>I_2>Br_2$. This order may be a measure of their relative acidities toward durene, which is explained in terms of the relative polarizabilities of halogen molecules and the relative electronegativities of halogen atoms. These results combined with previous study of this series indicated that the relative stabilities of the polymethylbenzene complexes with iodine increase in the order; Benzene

• Journal of the Korean Chemical Society
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• v.25 no.2
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• pp.75-84
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• 1981

Ultraviolet spectrophotometric investigations have been carried out on the systems of mesitylene with iodine, bromine, iodine monochloride and iodine monobromide in carbon tetrachloride. The results reveal the formation of the charge transfer complexes of the type, $C_6H_3(CH_3)_3{\cdot}X_2$ or $C_6H_3(CH_3)_3{\cdot}IX$ (X denotes halogen atoms). The equilibrium constants were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with the increasing temperatures. Thermodynamic parameters, ${\Delta}H$, ${\Delta}G$ and ${\Delta}S$ for the formation of the charge transfer complexes were calculated from these values. These results indicate that the relative stabilities of the mesitylene complexes at each temperature decrease in the order, ICl > IBr > $I_2$ > $Br_2$. This order may be a measure of their relative acidities toward mesitylene, which is explaned in terms of the relative polarizabilities of halogen molecules and the relative electronegativities of halogen atoms. These results combined with previous study of this series indicated that the relative stabilities of the polymethylbenzene complexes with iodine increase in the order Benzene < Toluene < Xylene < Mesitylene Thus, analysis of these findings is discussed.

• Journal of Life Science
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• v.26 no.8
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• pp.895-903
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• 2016

This study was carried out to discover the response of cucumber (Cucumis sativus L.) senescence- associated genes (SAGs) to several plant hormones in detached and developing cotyledon. Accordingly, a collection of cucumber SAGs were examined to characterize their gene expression response through semi-quantitative RT-PCR. Cotyledons were excised at day 14 after seed sowing from plantlets, then incubated in 100 μM each of IAA or zeatin solution for up to 4 days in light and darkness. They were collected at 2-day intervals and used for total RNA extraction and subjected to RT-PCR. Gene expression levels of several cucumber SAGs were significantly changed during the incubation period. More than five cucumber SAGs involving SAG 60 responded to the IAA and zeatin treatment. In the ethylene response study, cotyledons were exposed up to 10 days by ethylene gas. Most of the cucumber SAGs did not show immediate response to ethylene in green cotyledon. The exceptions were PCK, SAG 158, and SAG 288 genes, which responded after 1 day of exposure to green cotyledon, while ICL and SAG 281 revealed strong responses after 10 days of being exposed to yellowing cotyledon. These results suggest that several cucumber SAGs react actively in response to starvation or senescence against exogenously applied stimulus. This induced senescence response is able to understand the SAGs role in lipids and amino acids metabolism partly and function in organ senescence during development.