• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.339-339
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• 1994

It has been reported that Indole-3-carbinol (I3C), a naturally occurring compound In cruclferous vegetables, exerts anticarcinogenic activity In several organs In rodents. The modifying effects of I3C were therefore assessed uging a rat multi-organ carcinogenesis model. A total of 100 male Sprague-Dawley rats were divided Into 3 groups. Animals of groups 1 and 2 were sequentially treated with diethylnitrosamine (DEN; 100 mg/kg b.w., i.p.), N-methylnitrosourea (NNU; 20 mg/kg b.w., 4 times for 2 weeks, i.p), and dihydroxy-di-N-propylnitrosauine (DHPN; 0.1% In d.w. for 2 weeks) for 4 weeks (DMD treatment). Animals of groups 1 and 3 were given the diet of 0.25% I3C for 20 weeks after DMD initiation and then were given basal diet for 28 weeks. All animals were sacrificed at week 24 and 52, respectively. I3C has been clearly demonstrated promoting effects on the development of glutathione S-transferase placental form (GST-P) positive hepatic foci at 24 weeks of the experiment. And I3C also exerted promoting potential In the hepatocellular adenoma (4/14; 29%) and the adenoma (7/14; 50%) of the thyroid gland at 52 weeks of the experiment. Therefore, I3C may promote hepatocarcinogenesis and thyroid tumorigenesis in the rat multi-organ carcinogenesis model.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.908-913
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• 2000

CoSi$_2$/p+/n diodes(bilayer diodes) were fabricated by using epitaxial CoSi$_2$grown from Co/Ti bilayer as a diffusion source. The I-V characteristics of p+/n diodes were measured and compared with those of diode made from Co monolayer (monolayer diode). Monolayer diodes showed typical p+n junction characteristics with the leakage current of as low as 10$^{-12}$ A and forward current 6-orders higher than the leakage current, when drive-in annealed at 90$0^{\circ}C$ for 20 sec.. On the other hand, bilayer diodes showed the Schottky-like behaviors with forward currents rather higher than those of monolyer diodes, but with too high leakage currents, when drive-in annealed at $700^{\circ}C$ or higher. However, when the annealing temperature was lowered to $700^{\circ}C$ and annealing time was increased to 60 sec., the leakage current was reduced to 10$^{-11}$ A and thus sho3wed typical diode characteristics. The high leakage currents for diodes annealed at $700^{\circ}C$ or higher was attributed to Shannon contacts formed due to unremoved Co-Ti-Si precipitates. But when annealed at 50$0^{\circ}C$, B ions diffused in the direction of the surface layer, and thus the leakage currents were reduced by removing Shannon contacts.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.68-68
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• 2003

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.25 no.11
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• pp.89-96
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• 2007

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.35-41
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• 2015

In order to investigate the live food value of microalgae for efficacious rearing of larvae and spats of bivalve, we studied growth rates of four microalgal species (Isochrysis galbana, Pavlova lutheri, Chaetoceros simplex, Tetraselmis tetrathele) cultured in different environmental conditions. These include changes in temperatures (20, 25, 30 and $35^{\circ}C$), salinities (20, 25, 30 and 33 psu) and light intensities (60, 100 and $140{\mu}mol\;m^{-2}s^{-1}$). The growth rate of I. galbana was faster at $25^{\circ}C$ than that of $20^{\circ}C$. At $25^{\circ}C$ the highest growth rate of I. galbana was observed at 33 psu (0.413) and the lowest at 20 psu (0.368) in 10 days of culture (P < 0.05). The growth rate of I. galbana was lower at 25 psu (0.383) than that of 30 psu and higher than that of 20 psu (P < 0.05). Similar temperature and salinity-dependent changes were also found in P. lutheri and T. tetrathele. C. simplex showed faster growth rate at $30^{\circ}C$ than that of $25^{\circ}C$. The highest growth rate of C. simplex was observed at 33 psu (0.428) and the lowest at 20 psu (0.389) in 10 days of culture (P < 0.05). Upon exposure to the light with different intensities, all four microalgal species showed a significantly faster growth rate at $140{\mu}mol\;m^{-2}s^{-1}$ than at $100{\mu}mol\;m^{-2}s^{-1}$ (P < 0.05).

• Archives of Pharmacal Research
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• v.12 no.2
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• pp.88-93
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• 1989

In order to obtain some informations about the effect of molecular weight on the release rate of drug from drug carrier, two types of poly-L-glutamic acid (PLGA)-cytarabine (ara-C) conjugates, PLGA-ara-C:I and PLGA-ara-C:II, were synthesized using two types of PLGA having different average molecular weight, 43,000 and 77,800, respectively. The PLGA-ara-C conjugates were synthesized by mixed anhydride method and found to be covalently linked. Both types of conjugates charged negatively at biological pH. The pH-dependent release rate of ara-C was observed in both cases, and the release rate was accelerated in basic, acidic conditions (the k values were 0.015 $day^{-1}$ at pH 7.0, 0.024 $day^{-1}$ at pH 5.0, and 0.059 $day^{-1}$ at pH 9.0 in the case of PLGA-ara-C:I) and in the presence of pretense. The time required for the release of 16.5% of ara-C from PLGA-ara-C:I were 8 hr and 144 hr in the presence and absence of protease, respectively. Although both types of conjugates showed similar drug substitution ratio, they showed different release rates. Between the two types of conjugates, PLGA-ara-C:II showed the faster release rate (0.030 vs 0.042 $day^{-1}$ in pH 7.4 phosphate buffer solution at $37^{\circ}C$) and the smaller activation energy for the release of drug (12.5 vs 7.7 Kcal/mol) than PLGA-ara-C:I. The characteristic effect of molecular weight on the release rates of PLGA-ara-C conjugates suggests that the drug release rate might be effectively controlled over a prolonged period of time by the combined use of the different types of PLGA-ara-C conjugates having different molecular weights.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.433-438
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• 1991

The plasmid pSY130-14 for the high production of phenylalanine is a temperaturecontrollable expression vector composed of the $P_R$ and the $P_L$ promoter and a temperature sensitive repressor, $cI_{857}$ of bacteriophage lambda. Strain AT2471 harbouring plasmid pSY13O- 14 is induced the phenylalanine production by shifting up the incubation temperaure to $38.5^{\circ}C$. Plasmid stability of E. coli AT2471 harbouring pSY130-14 was very low, it was about 30% after 48 h cultivation at $38.5^{\circ}C$ without kanamycin. The plasmid disappeared immediately at $40^{\circ}C$ without kanamycin, and at $40^{\circ}C$ adding kanamycin, the plasmid stability decreased at the beginning, but rose with the extension of the culture time. For the improvement of plasmid stability, the plasmid obtaind was designated as pSY15O-1 by changing origin region (ori) pACYC 177 of pSY130-14 for ori pSC101. E. coli AT2471 harbouring pSY150-1 was stable at $38.5^{\circ}C$ without tetracycline, and the plasrnid stability was about 40% after 48 h cultivation at $40^{\circ}C$.

• Journal of Plant Biology
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• v.37 no.3
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• pp.349-355
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• 1994

Viral RNA was extracted from a purified orchid strain of tobacco mosaic virus (TMV-O) from Cymbidium "Grace Kelly". Polyadenylated viral RNAs were primed with Not I-oligo (dT) primer-adapter. First-strand cDNAs were reversely transcribed by Moloney murine leukaemia virus reverse transcriptase (RNAse H-), and then second-strand cDNAs were synthesized by RNase H and DNA polymerase I. The resulting double-stranded cDNAs were ligated into pSPORT1 vector and transformed into competent E. coli strain JM109 cells. The size of cDNAs within the recombinant plasmids was ranging from 0.9 to 3.9 kb. Among the selected clones, pTMO-0205 and -0210 covered the 3' half and the 5' half of the viral genomic RNA, respectively, which were covering more than 99% of the viral genemo size based on sequencing analysis. Two cDNA fragments which were 3.1 kb BamHI and NotI fragement released from pTMO-0.205 and 3.3 kb SalI and BamHI fragment released from pTMO-0210 were ligated with T4 DNA ligase. The clone was almost entire length, lacking only 31 nucleotides from the 5' terminus based on the sequencing result. This method was shown to be efficiently applicable to other plant viral gnomic RNA for the construction of cDNA.n of cDNA.

• Korean Journal of Microbiology
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• v.5 no.1
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• pp.20-23
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• 1967

I studied about temperature and pH concentration having influence upon chlorophyll decrease on the Glucose culture of Chlorella variegata Beijerinck(211/10a). I cultured under $25^{\circ}C$(standard), $15^{\circ}C$ and $35^{\circ}C$ and compared with each other. The culture of $15^{\circ}C$ didn't have any large difference with the standard culture($25^{\circ}C$) but the culture of $35^{\circ}C$ had a large amount of chlorophyll decrease without carbohydrate accumulation, stimulation of cell division and nitrogen-deficiency. Chlorella variegata had optimum pH 6.5-7 and was a little weak in all phenomenon under pH 8 rather than under pH 6.5-7. Under pH 5 they had deep chlorophyll decrease without phephytin.

• Journal of the Korean Chemical Society
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• v.14 no.4
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• pp.321-326
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• 1970

The relation between the heating temperature and the V.C.P(Vacuum Condensing Point) at different degree of vacuum through the sublimatographic separation was studied where by ; (1) Anthracene and Anthraquinone, ${\alpha}$-Naphtol and ${\beta}$-Naphthol, o-Aminobenzoicacid and p-Aminobeenzoicacid were easily separated from each of its mixtures as shown in Figure9, 10 and 11, while tailings appeared appreciably. The results were in good agreement with those expected from the $t_k$-V.C.P curves in Figures 3,4,5,6,7 and 8. (2) The relation between the degree of vacuum and the V.C.P. of ${\alpha}$-Naphthol and Anthracene at different heating temperatures appeared as follows and are shown in Figures 12 and 13.