• BMB Reports
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• v.31 no.6
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• pp.525-535
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• 1998

A critical step in the faithful translation of genetic information is specific tRNA recognition by aminoacyl-tRNA synthetases. These enzymes catalyze the covalent attachment of particular amino acids to the terminal adenosine of cognate tRNA substrates. In general, there is one synthetase for each of the twenty amino acids and each enzyme must discriminate against all of the cellular tRNAs that are specific for the nineteen noncognate amino acids. Primary sequence information combined with structural data have resulted in the division of the twenty synthetases into two classes. In recent years, several high-resolution co-crystal structures along with biochemical data have led to an increased understanding of tRNA recognition by synthetases of both classes. The anticodon sequence and the amino acid acceptor stem are the most common locations for critical recognition elements. This review will focus on acceptor stem discrimination by class II synthetases. In particular, the results of in vitro aminoacylation assays and site-directed and atomic group mutagenesis studies will be discussed. These studies have revealed that even subtle atomic determinants can provide signals for specific tRNA aminoacylation.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.802-806
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• 2000

The transglycosylation reaction by dextansucrase from Leuconostoc mesenteroides B512FMC/6HG8 was investigate with cellobiose as an acceptor molecule and sucrose as a donor. he optimal conditions of transglycosylation on cellobiose were found that the ration of sucrose to cellobiose was 3:1, the amount of enzyme was 2U/mL, the ionic strength of buffer was 25 mM, pH was 5.0 and reaction temperature was $25^{\circ}C$. also, acceptor products of cellobiose by transglycosylation were a series of oligosaccharides showing the degree of plymenzation of 6.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.74-74
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• 2001

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.1047-1054
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• 2003

Molecular chaperones have a crucial role in the folding of nascent polypeptides in endoplasmic reticulum. Some of them are known to be sensitive to the modification by electrophilic metabolites of organic pro-toxicants. In order to identify chaperone proteins sensitive to alkyators, ER extract was subjected to alkylation by 4-acetamido-4 -maleimidyl-stilbene-2,2 -disulfonate (AMS), and subsequent SDS-PAGE analyses. Protein spots, with molecular mass of 160, 100, 57 and 36 kDa, were found to be sensitive to AMS alkylation, and one abundant chaperon protein was identified to be protein disulfide isomerase (PDI) in comparison with the purified PDI. To see the reactivity of PDI with cysteine alkylators, the reduced form ($PDI_{red}$) of PDI was incubated with various alkylators containing Michael acceptor structure for 30 min at $38^{\circ}C$ at pH 6.3, and the remaining activity was determined by the insulin reduction assay. Iodoacetamide or N-ethylmaleimide at 0.1 mM remarkably inactivated $PDI_{red}$ with N-ethylmaleimide being more potent than iodoacetamide. A partial inactivation of $PDI_{oxid}$ was expressed by iodoacetamide, but not N-ethylmaleimide (NEM) at pH 6.3. Of Michael acceptor compounds tested, 1,4-benzoquinone ($IC_{50}, 15 \mu$ M) was the most potent, followed by 4-hydroxy-2-nonenal and 1,4-naphthoquinone. In contrast, 1,2-naphthoquinone, devoid of a remarkable inactivation action, was effective to cause the oxidative conversion of $PDI_{red}$ to $PDI_{oxid}$. Thus, the action of Michael acceptor compounds differed greatly depending on their structure. Based on these, it is proposed that POI, one of chaperone proteins in ER, could be susceptible to endogenous or xenobiotic Michael acceptor compounds in vivo system.

• Korea journal of population studies
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• v.7 no.1
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• pp.39-77
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• 1984

It has been well known that the family pjanning programme has a great deal with declining fertility in Korea. The present study was aimed to measure the impact of family planning program me on fertility level. The specific objectives are to overview the demographic changes ncluding fertility declining and to calculate actual number of birth averted during the last 20 years. The data used for the present study was collected from various sources such as service statistics of the government, survey and research reports, and other related papers. The tool used for calculation of birth prevention was "Standard Couple Years of Protection (SCYP) Method" developed by M Gorosh. The major findings are summarized as follows ; Total of family planning acceptors from 1962 to 1982 was 9,556,153. On the basis of this data, total of averted births was calculated for eachcontraceptive Method ; 1.Oral pills, total number of acceptors from 1968 to 1982 was 2.347,259. Estimated number of birth averted was 272 ,303 .70 and the Coefficient of births prevention per acceptor turned out to be 0.114 2.Condoms, total number of birth acceptors from 1962 to 1982 was 2,874,216. Estimated number of birth averted was 220,495.30 and the coefficient of births prevention per acceptor turned out to be 0.077. 3.IUD, total number of acceptors from 1962 to 1982 was 5,101 .650. Estimated number of birth averted was 1,377,584.76 and the coefficient of births prevention per acceptor turned out to be 0.270. 4.Vasectomy, total number of acceptors from 1962 to 1982 was 556,508. Estimated number of birth averted was 626 ,128 .80 and the coefficient of births prevention per acceptor turned out to be 1.125. 5.Tubaligation total number of birth acceptors from 1972 to 1982 was 1 210,775. Estimated number of birth averted was 1 ,117 679.00 and thecoefficient of birtlts prevention per acceptor turned nut to be 0.923. 6.Abortion, total number of acceptors from 1973 to 1982 was 465,525. Estimated number of birth averted was 355 ,283 .60 and the coefficient of births prevention per acceptor turned out to be 0.763.

• Polymer(Korea)
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• v.31 no.2
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• pp.136-140
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• 2007

Charge transfer interaction as a hybridization mechanism of silsesquioxane/polymer was tested using carbazole (electron donor) group and dinitrobenzene (electron acceptor) group. Hybridization test was conducted using films made from mixing/casting of poly (carbazole-styrene) (PS/D) and dimtrobenzyl silsesquioxane (Cube/A), and transparent hybrid films were successfully obtained under some conditions. $^1H-NMR$ of PS/D and Cube/A, and W absorption test of hybrid films showed that one acceptor and one donor can form one charge transfer complex when no silsesquioxane molecule was included in films, but transparent hybrids with no phase separation were obtained only at acceptor/donor ratios less than 0.7 : 1. These results also suggested that on average 4 charge transfer complexes form per one silsesquioxane.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.241-241
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• 2007

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2787-2790
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• 2011

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.432.2-432.2
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• 2016

A new A-D-A type (Acceptor-Donor-Acceptor) conjugated based on pyridine-borane complex (Donor), non-boron fluorine (Donor) and 2,5-bis(alkyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) (Acceptor) were designed and synthesized via Pd-catalyzed Suzuki cross-coupling reaction. The synthesized boron based complex exhibited high electron affinity, which indicates deep HOMO energy levels and good visible absorption led to their use as donors in BHJ (bulk heterojunction) solar cells. Inverted devices were fabricated, reaching open-circuit voltage as high as 0.91eV. To probe structure-property relationship and search for design principle, we have synthesized pyridine-boron based electron donating small molecules. In this study, we report a new synthetic approach, molecular structure, charge carrier mobility and morphology of blended film and their correlation with the photovoltaic J-V characteristics in details.