• Archives of Pharmacal Research
• /
• v.19 no.4
• /
• pp.317-320
• /
• 1996

The time-kill curves of LB20304, a novel fluoroquinolone that has potent antibacterial activity against gram-positve and gram-negative bacteria, were calculated at the concentrations of 1/4-, 1/2-, 1-, 2- and 4-times the MIC against Staphylococcus aureus 77, Escherichia coli 3739E, Pseudomonas aeruginosa 1912E. The bactericidal activity of LB20304 for these strains was very rapid and comparable to that of ciprofloxacin. LB20304 produced a decrease in the $log_10$ CFU per milliliter of${\geq}$3 within 2 h at 4-times the MIC for all strains and consitently prevented regrowth of bacteria after 24 h of incubation. The MBCs (Minimal Bactericidal Concentration) of LB20304 against test organisms were equal to or at most four-times higher than the MICs.

• Journal of Microbiology
• /
• v.45 no.2
• /
• pp.168-170
• /
• 2007

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.735-738
• /
• 2001

Metabolically engineered Escherichia coli strains harboring a plasmid containing a novel artificial polyhydroxyalkanoate (PHA) operon consisting of the Aeromonas PHA biosynthesis related genes and Ralstonia eutropha reductase gene were developed for the production of poly(3-hydroxybutyrate-co-hydroxyhexanoate) [P(3HB-co-3HHx)] from dodecanoic acid. By applying stepwise reduction of dissolved oxygen concentration (DOC) during the fermentation, the final dry cell weight, PHA concentration, and PHA content of 79 g/L, 21.5 g/L, and 27.2 wt%, respectively, were obtained in 40.8 h, which resulted in the PHA productivity of 0.53 g/L/h. The 3HHx fraction slowly increased during the fed-batch culture to reach a final value of 10.8 mol%. The 3HHx fraction in the copolymer could be increased by three fold when the Aeromonas hydrophila orfl gene was co-expressed with the PHA biosynthesis genes.

• The Korean Journal of Mycology
• /
• v.45 no.3
• /
• pp.229-233
• /
• 2017

We isolated endophytic fungal strains from roots of Rhododendron schlippenbachii growing in Minjujisan mountain, Korea. The two strains were identified as Engyodontium album and Phaeosphaeria microscopica based on their morphological characteristics and sequence analysis of the internal transcribed spacer (ITS) and large subunit regions of the ribosomal DNA. These two species, E. album and P. microscopica, have not been previously reported in Korea.

• Structural Engineering and Mechanics
• /
• v.46 no.1
• /
• pp.91-110
• /
• 2013

This paper proposes a novel iterative procedure for the design of planar reinforced concrete structures in which the reinforcement is designed for stresses calculated in a nonlinear finite element analysis. The procedure is intended as an alternative to strut and tie modeling for the design of complex structures like deep beams with openings. Practical reinforcement arrangements are achieved by grouping the reinforcement into user defined horizontal and vertical bands. Two alternative strategies are proposed for designing the reinforcement which are designated A and B. Design constraints are specified in terms of permissible stresses and strains in the reinforcement and strains in the concrete. A case study of a deep beam with an opening is presented to illustrate the method. Comparisons are made between design strategies A and B of which B is shown to be most efficient. The resulting reinforcement weights are also shown to compare favorably with those previously reported in the literature.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.438-441
• /
• 2003

The present study reports the novel physiological function of dissimilatory perchlorate reduction by two strains JB101 and JB109 isolated from a sewage treatment facility in Incheon, South Korea. The physiological data of the isolates showed good correspondence with the members of the family Enterobacteriaceae. The partial 16S rRNA and 16S rDNA sequence of strains JB101 and JB109 showed similarity of 99.8% to Citrobacter amalonaticus and 98% to Citrobacter farmari, respectively. The study infers toward possibility of Citrobacter spp. to form an important group of dissimilatory perchlorate reducers within the (equation omitted) subclass of Proteobacteria because the majority of the known. members belong to two monophyletic groups namely Dechloromonas and Dechlorosoma in $\beta$ subclass of Proteobacteria.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.1
• /
• pp.15-22
• /
• 2015

In the present paper we report the results of a study into Friction Stir Welds (FSWs) made in 13 mm-thick 12%-Cr steel plates. Based on residual strains obtained by diffraction techniques, eigenstrain analysis was performed using the Eigenstrain Reconstruction Method (ERM), which is a novel methodology for the reconstruction of full-field residual strain and stress distributions within engineering components. Significant eigenstrain distributions were found at around Thermo-Mechanically Affected Zone (TMAZ) where the most severe plastic deformation was occurred. Microstructure analysis was used to elucidate this phenomenon showing that the grain structure in TMAZ was bent and not successfully recrystallised, resulting in severe deformation behaviour. The reconstructed residual strain distributions by the ERM agree well with the experimental results. It was found that the approach based on theory of eigenstrain is a powerful basis for reconstructing the full-field residual strain/stress distributions in engineering components and structures.

• The Korean Journal of Mycology
• /
• v.47 no.1
• /
• pp.35-42
• /
• 2019

We isolated endophytic fungi from the conifer leaves of Pinus densiflora inhabiting Buan-gun, Jeollabuk-do, Korea. We identified the isolated fungal strains based on phylogenetic analysis performed using the nucleotide sequences of the internal transcribed spacer, large subunit, and beta-tubulin. We confirmed the presence of three novel endophytic fungi in Korea, namely Paracamarosporium hawaiiense, Tubakia dryina, and Zasmidium fructigenum. In this report, we described the morphological characteristics of these fungal strains and the results of their phylogenetic analysis.

• The Korean Journal of Mycology
• /
• v.49 no.3
• /
• pp.259-283
• /
• 2021

We isolated nine fungal strains from different environmental materials collected from different locations during a survey of fungal diversity in Korea. Using molecular phylogenetic analyses and morphological characteristics, nine previously undescribed strains were identified and assigned to the species Collariella robusta, Fusicolla acetilerea, Hongkongmyces pedis, Hongkongmyces snookiorum, Mariannaea fusiformis, Metarhizium pemphigi, Pallidocercospora crystallina, Scopulariopsis candida, and Volutella citrinella. Diverse environmental samples may thus be a promising source for isolating and investigating novel fungal species, thus sampling efforts should be increased in future studies. This study also reports identification of some rare fungal species belonging to the genera Hongkongmyces and Pallidocercospora from Korea.

• Mycobiology
• /
• v.49 no.1
• /
• pp.15-23
• /
• 2021

Two fungal strains (KNU-JJ-1827 and KNU-JJ-1829) belonging to the class Dothideomycetes were discovered from Jeju Island, Korea during this investigation of soil microfungi. Strain KNU-JJ-1827 showed fewer conidial septations, larger conidiogenous cells, and smaller conidia compared to the previously identified closest species of Didymocyrtis. Strain KNU-JJ-1829 revealed the similar characteristics of the nearest certain species of the genus Parathyridaria with the production of conidiogenous cells and conidia, because no asexual morphs were detected from the closest type strain Parathyridaria rosae. The novelty of the strains was also confirmed by analyzing molecular data using internal transcribed spacer regions and 28S rDNA. The molecular phylogeny also strongly support the detailed description and illustration for each proposed species as Didymocyrtis septata sp. nov. (KNU-JJ-1827) and Parathyridaria ellipsoidea sp. nov. (KNU-JJ-1829) isolated from soil in Korea.