• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1999.11a
• /
• pp.11-16
• /
• 1999

Discharge characteristics research for high voltage and large current electric machinery design, the development of ozonizer with high yield and efficiency for environment improvement, generation of plasma & laser and EMI EMC are research fields of Enersy & Environment Electromagnetic Laboratory(EEEL) in the school of electrical & electronic engineering of Yeungnam University. On this paper, we would like to introduce the discharge and ozone generation characteristics of ozonizers designed and manufactured by EEEL. After starting research for fluid gas discharge characteristics early in the 1980's, high voltage nozzle(HVN) type ozonizer, neon lamp(Nelamp) type ozonizer, ozone lamp(Olamp) type ozonizer and multi-discharge type ozonizer(MDO) have been investigated since 1990.

• Development and Reproduction
• /
• v.10 no.2
• /
• pp.97-103
• /
• 2006

Vitellogenin(Vg) is a sex specific serum protein present in sexually maturing female blood of oviparous vertebrates. Estrogen($E_2$) is a main inducer of hepatic Vg synthesis. We investigated the effects of androgen and growth hormone(GH) on regulation of Vg and estrogen receptor(ER) genes in Japanese eel. Immature eels($200{\sim}250\;g$) were given a single injection of $E_2(5{\sim}5,000\;{\mu}g/kg\;bw)$ alone, or in combination with eel recombinant GH(eGH, $1{\sim}10\;{\mu}g/kg$) or methyltestosterone(MT, $1{\sim}5\;mg/kg$) and sacrificed 10 days after the hormone treatments. Expression levels of ER and Vg genes from the liver were determined by means of reverse transcription and polymerase chain reaction(RT-PCR). Administration of $E_2$ stimulated Vg gene expression in a dose dependent manner. Levels of Vg mRNA after the injection of $E_2(500\;{\mu}g/kg)$ with MT(5mg/kg) or eGH($10\;{\mu}g/kg$) were much higher than in that of $E_2$ alone($500\;{\mu}g/kg$). Whereas, injection of either vehicle, eGH ($10\;{\mu}g/kg$) or MT(5mg/kg) alone did not induce the expression of Vg gene in the liver. ER mRNA was detected from the fish treated with vehicle alone. $E_2$ injection($5{\sim}500\;{\mu}g/kg\;bw$) increased this ER expression but dose dependent response was not clear. Addition of MT(5mg/kg) or eGH($10\;{\mu}g/kg$) did not affect $E_2-stimulated$ ER mRNA expression. This study confirms the necessity of $E_2$ as the primary factor for Vg gene expression and requirement of additional hormones such as MT or GH for the full expression of Vg mRNA, and suggests that the additive effect of MT or GH on Vg gene expression would be mediated by some unknown factors other than ER.