• Title/Summary/Keyword: Chemical library

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An Investigation into the College Students' Awareness of 'Library and Information' in the Library and Information Science (문헌정보학의 '문헌정보'에 대한 대학생 인식 조사)

  • Kang, Mi-Hee
    • Journal of Korean Library and Information Science Society
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    • v.45 no.3
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    • pp.297-319
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    • 2014
  • This research started from bringing up a problem about special situation of the library and information science, which is not easy to investigate its academic characteristics, although it has settled down as a powerful science studying related phenomena as well as education required for the whole process from production of information to consumption of it. Therefore, the purpose of this research is to questingly investigate whether the personal specialty and the experience of taking courses affect recognition of the term 'library and information', and if so, through which channel it influences. In this background, data were collected from 328 students of Chonnam National University for this research, and the following are the analysis results: first, as for the personal characteristics, differences were not generated according to gender and age, but according to scholastic year the results were different; second, as for the experience of taking courses, there were not differences according to whether or not of the experience, but the results varied according to the number and type of the experience; and third, most of the respondents surveyed understood the meaning of a term 'library and information' as the conception of covering the information contained in literature and information of it, regardless of the personal characteristics and the experience of taking courses. Through these results, it can be identified that the term 'library and information' meant in the library and information science is generally understood as expansion of range, rather than chemical combination of literature and information, it is a terminology with various meanings sometimes understood differently according to the special personal experiences, and it also needs scientific investigation of it.

Excavation of 3-amino-2-benzylimino-1,3-thiazolines, Selective Fungicide against Phytophthora infestans and Magnaporthe grisea (토마토 역병균과 벼 도열병균에 선택적인 살균활성의 3-아미노-2-벤질이미노-1,3-티아졸린 유도체 발굴)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Shin, Dong-Yoon;Choi, Gyung-Ja;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.10 no.3
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    • pp.165-171
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    • 2006
  • A new 3-amino-1,3-thiazoline chemical library was synthesized through parallel synthetic technology and in vivo antifungal activity of the compounds were investigated against the typical 6 plant diseases (100 ppm). The characteristic feature of these derivatives was that both a benzyl moiety in C-2 imino and an amino group in C-3 of 2-imino-1,3-thiazoline scaffold were substituted in the molecule respectively. Some compounds showed antifungal activity with selectivity against tomato late blight and rice blast. The fungitoxicity would be attributed to 3,4-dichlorophenyl moiety of the benzyl group.

Physical Chemistry Research Articles Published in the Bulletin of the Korean Chemical Society: 2003-2007

  • Sun, Ho-Sung;Lee, Sun-Yeoul;Lee, Choon-Shil
    • Bulletin of the Korean Chemical Society
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    • v.29 no.2
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    • pp.450-462
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    • 2008
  • The physical chemistry (PC) articles published in the Bulletin of the Korean Chemical Society (BKCS) from 2003 to 2007 are surveyed, and in-depth content analysis was conducted to classify the PC articles into 12 topics used in The Journal of Physical Chemistry (JPC). The PC articles published in the Journal of the American Chemical Society (JACS) in 2007 are also surveyed. The extensive summary of all PC articles in BKCS for the last five years reveals the current trend of physical chemistry research in Korea. The comparison study with the JACS shows that the proportion of PC articles among all articles published in BKCS (16%) is slightly higher than that of JACS (11%), and the non-Korean authorship ratio of BKCS (12%) is very low compared with the non-US authorship of JACS (52%). From the comparison study with articles published in JPC in 2007, it is found that BKCS disseminates various topics of physical chemistry researches adequately. In particular, BKCS most frequently published PC articles in molecular structure and spectroscopy topics, whereas JPC published surface chemistry and nano-chemistry articles most frequently. It is concluded that BKCS should publish more articles to be a leading journal, and it is suggested that the SCI impact factor of BKCS must be increased by improving the electronic version of BKCS.

Isolation of Deletion Mutants by Reverse Genetics in Caenorhabditis elegans

  • Park, Byung-Jae;Lee, Jin ll;Lee, Jiyeon;Kim, Sunja;Choi, Kyu Yeong;Park, Chul-Seung;Ahn, Joohong
    • Animal cells and systems
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    • v.5 no.1
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    • pp.65-69
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    • 2001
  • Obtaining mutant animals is important for studying the function of a particular gene. A chemical mutagenesis was first carried out to generate mutations in C. elegans. In this study, we used ultraviolet-activated 4,5',8-trimethylpsoralen to induce small deletion mutations. A library of mutagenized worms was prepared for recovery of candidate animals and stored at $15^{\circ}C$ during screening instead of being made into a frozen stock library. In order to isolate deletion mutations in target genes, a polymerase chain reaction (PCR)-based screening method was used. As a result, two independent mutants with deletions of approximately 1.0 kb and 1.3 kb were isolated. This modified and improved reverse genetic approach was proven to be effective and practical for isolating mutant animals to study gene function at the organismal level.

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In Vitro Selection of High Affinity DNA-Binding Protein Based on Plasmid Display Technology

  • Choi, Yoo-Seong;Joo, Hyun;Yoo, Young-Je
    • Journal of Microbiology and Biotechnology
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    • v.15 no.5
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    • pp.1022-1027
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    • 2005
  • Based on plasmid display technology by the complexes of fusion protein and the encoding plasmid DNA, an in vitro selection method for high affinity DNA-binding protein was developed and experimentally demonstrated. The GAL4 DNA-binding domain (GAL4 DBD) was selected as a model DNA-binding protein, and enhanced green fluorescent protein (EGFP) was used as an expression reporter for the selection of target proteins. Error prone PCR was conducted to construct a mutant library of the model. Based on the affinity decrease with increased salt concentration, mutants of GAL4 DBD having high affinity were selected from the mutant protein library of protein-encoding plasmid complex by this method. Two mutants of (Lys33Glu, Arg123Lys, Ile127Lys) and (Ser47Pro, Ser85Pro) having high affinity were obtained from the first generation mutants. This method can be used for rapid in vitro selection of high affinity DNA-binding proteins, and has high potential for the screening of high affinity DNA-binding proteins in a sequence-specific manner.

Trace Analysis as TBDMS Derivatives of Organic Acids in Aqueous Samples (TBDMS 유도체로서 수용액 시료중의 유기산 미량분석 연구)

  • Kim, Gyeong Rye;Kim, Jeong Han;Park, Hyeong Guk
    • Journal of the Korean Chemical Society
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    • v.34 no.4
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    • pp.352-359
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    • 1990
  • An effecient gas chromatographic method is described to be used routinely for the rapid profiling and identification of biochemically important organic acids. It involves the solid-phase extraction of organic acids from aqueous samples using Chromosorb P as the solid sorbent and diethyl ether as the eluting solvent, with subsequent triethylamine treatment. The resulting triethylammonium salts of acids were directly converted to volatile tert-butyldimethylsiyl derivatives, which were simultaneously analyzed by two capillary columns of different polarity, DB-5 and DB-1701, under the identical temperature programming condition. The retention index (RI) and area ratio (AR) values of each peak measured on DB-5 and DB-1701 enabled rapid identification of acids by computer RI library search and AR comparison. The application of the present method to the organic acid profiling of various complex samples is demonstrated.

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Thermal and Organic Chemical Stress Responsive Genes in Soft Coral, Scleronephthya gracillimum

  • Woo, Seon-Ock;Yum, Seung-Shic;Kim, Yong-Tae;Suh, Seung-Jik;Kim, Hack-Cheul;Lee, Jong-Rak;Kim, Sa-Heung;Lee, Taek-Kyun
    • Molecular & Cellular Toxicology
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    • v.2 no.3
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    • pp.170-175
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    • 2006
  • The extensive isolation of genes responsive to stressful conditions from a soft coral Scleronephthya gracillimum was described. Soft coral colonies were exposed to thermal and chemical stressors to induce the expression of stress related genes. Differentially expressed genes by natural or anthropogenic stressors were identified by construction of standard and stress exposed-paired subtractive cDNA library. Thirty-two and thirty-seven kinds of candidate genes were identified from thermal or benzo[a]pyrene stress exposed group, respectively, which are associated with cell cycle, cell signaling, transcription, translation, protein metabolism, and other cellular functions. The expected function of each gene was described. The isolated and identified differentially expressed genes have a great potential to identify environmental stressors in global environmental changes and could act as molecular biomarkers for biological responses against environmental changes. Finally, it may open a new paradigm on soft coral health assessment.

Expression and purification of human mPGES-1 in E. coli and identification of inhibitory compounds from a drug-library

  • Kim, Woo-Il;Choi, Kyung-A;Do , Hyun-Soo;Yu, Yeon-Gyu
    • BMB Reports
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    • v.41 no.11
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    • pp.808-813
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    • 2008
  • Human microsomal prostaglandin E synthase-1 (mPGES-1) is a membrane associated protein that catalyzes the conversion of prostaglandin $H_2$ ($PGH_2$) into prostaglandin $E_2$ ($PGE_2$). In this study, the expression of human mPGES-1 in E. coli was significantly enhanced by modifying the utility of specific codons and the recombinant mPGES-1 was efficiently purified to homogeneity. The $K_m$ and $V_{max}$ of the purified enzyme were determined and the trimeric state characterized by chemical cross-linking with glutaraldehyde. The purified mPGES-1 was used for the screening of a chemical library of bioactive or drug compounds to identify novel inhibitors, and oxacillin and dyphylline were identified as moderately inhibiting mPGES-1 with $I_{C50}$ values of 100 and 200 ${\mu}M$, respectively. As these compounds competitively inhibited the catalysis of $PGH_2$, their binding sites appeared to be located near the $PGH_2$ binding pocket.

Efficient Target Site Selection for an RNA-cleaving DNAzyme through Combinatorial Library Screening

  • Kim, Ki-Sun;Choi, Woo-Hyung;Gong, Soo-Jeong;Oh, Sang-taek;Kim, Jae-Hyun;Kim, Dong-Eun
    • Bulletin of the Korean Chemical Society
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    • v.27 no.5
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    • pp.657-662
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    • 2006
  • Identification of accessible sites in targeted RNAs is a major limitation to the effectiveness of antisense oligonucleotides. A class of antisense oligodeoxynucleotides, known as the “10-23” DNA enzyme or DNAzyme, which is a small catalytic DNA, has been shown to efficiently cleave target RNA at purine-pyrimidine junctions in vitro. We have designed a strategy to identify accessible cleavage sites in the target RNA, which is hepatitis C virus nonstructural gene 3 (HCV NS3) RNA that encodes viral helicase and protease, from a pool of random DNAzyme library. A pool of DNAzymes of 58 nucleotides-length that possess randomized annealing arms, catalytic core sequence, and fixed 5'/3'-end flanking sequences was designed and screened for their ability to cleave the target RNA. The screening procedure, which includes binding of DNAzyme pool to the target RNA under inactive condition, selection and amplification of active DNAzymes, incubation of the selected DNAzymes with the target RNA, and target site identification on sequencing gels, identified 16 potential cleavage sites in the target RNA. Corresponding DNAzymes were constructed for the selected target sites and were tested for RNA-cleavage in terms of kinetics and accessibility. These selected DNAzymes were effective in cleaving the target RNA in the presence of $Mg^{2+}$. This strategy can be applicable to identify accessible sites in any target RNA for antisense oligonucleotides-based gene inactivation methods.

Isolation and Characterization of Human scFv Molecules Specific for Recombinant Human Heat Shock Protein (HSP) 70.1

  • Baek, Hyun-jung;Lee, Jae-seon;Seo, Jeong-sun;Cha, Sang-hoon
    • IMMUNE NETWORK
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    • v.4 no.1
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    • pp.7-15
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    • 2004
  • Background: The heat shock proteins (HSPs) play an important role in cellular protection mechanisms against physical or chemical stresses. In this study scFv antibodies specific for human HSP70.1 were isolated from a semi-synthetic human scFv library with the ultimate goal of developing anti-HSP70.1 intracellular antibody (intrabody) that may offer an attractive alternative to gene targeting to study the function of the protein in cells. Methods: A semi-synthetic human scFv display library ($5{\times}10^{8}$ size) was constructed using pCANTAB-5E vector and the selection of the library against bacterially expressed recombinant human HSP70.1 was attempted by panning. Results: Three positive clones specific for recombinant HSP70.1 were identified. All three clones used $V_{H}$ subgroup III. On the other hand, $V_{L}$ of two clones belonged to the kappa light chain subgroup I, but the other utilized $V_{k}$ subgroup IV Interestingly, these scFv molecules specifically reacted to the recombinant HSP70.1, yet failed to recognize native HSP70 induced in U937 human monocytic cells by heat treatment. Conclusion: Our results indicated that affinity selection of an scFv phage display library using recombinant antigens produced in E. coli might not guarantee the isolation of scFv antibody molecules specific for a native form of the antigen. Therefore, the source of target antigens needs to be chosen carefully in order to isolate biofunctional antibody molecules.