• 천문학회보
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• 제40권2호
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• pp.37.1-37.1
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• 2015

It is suggested that relativistic jets associated with active galactic nuclei (AGNs) can have great impacts on the evolution of the host galaxy. However, the physical properties of AGN jets including the formation mechanism are not well known to date, and hence the AGN feedback on the host galaxy is yet poorly understood. OVV 1633+382 as a highly variable AGN source (a.k.a. blazer) with a compact core and very well developed jet components is an excellent laboratory to study the jet formation mechanism of radio-loud AGN. Near 2002, a major flare was reported at mm wavelength with a dramatic increase of the flux, which is likely to be followed by a dense and bright outflow. In order to probe the evolution of the innermost region of this radio-loud AGN, we have monitored using the Very Large Baseline Array (VLBA) and the Effelsberg 100m single-dish radio telescope in 12 epochs from 2002 and 2005. The observations were conducted at 22, 43 and 86 GHz in full polarization mode. In this work, we present the intensity and spectral index maps at 22 and 43 GHz from our monitoring observations. We probe the kinematics and geometry of individual jet components to discuss the evolution of the jet.

• 한국발생생물학회지:발생과생식
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• 제19권1호
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• pp.1-10
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• 2015

The purpose of the present study was to examine the seminiferous epithelium cycle of Bombina orientalis using a light microscope. The cycle was divided into a total of 10 stages, according to the morphological characteristics of the cells. The spermatogenetic cells included primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes, spermatid and sperm. At stage I, the primary spermatogonia was located closer to basal lamina of the seminiferous tubule without spermatocyst formations. Especially at the stage II, the secondary spermatogonia were located in the spermatocyst. The primary and secondary spermatocytes were found from stages III to VI. The secondary spermatocytes were smaller in size than the primary spermatocytes, but they had thicker nucleoplasm and smaller nuclei. The round-shaped, early sperm cells were formed in stage VII, and further divided at stage VIII to have more concentrated nucleoplasm before division to matured sperm cells. At stage X, the matured sperm cells emerged from the spermatocyst. Considering the above results, this study presented the special characteristics in the generation and type of sperm formation. The germ cell formation occurred in various stages, like the perspectives of Franca et al (1999), ultimately, providing taxonomically useful information.

• 한국수정란이식학회지
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• 제25권3호
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• pp.179-187
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• 2010

Embryonic compaction is essential for normal preimplantation development in mammals. The present study was to investigate the effects of compaction patterns on developmental competence of pig embryos. The proportion of blastocyst formation derived from compacted morula was higher than those of compacting and pre-compacting morula (P<0.01). Nuclei numbers of inner cell mass (ICM), trophectoderm (TE), and total of blastocysts derived from compacted group were also superior to those of compacting and pre-compacting groups (P<0.05). Then, compaction patterns, developmental ability and structural integrity were compared between mono- and poly-spermic embryos. The rate of compacted morula in mono-spermic embryos was higher than that of poly-spermic embryos (P<0.05). Especially, the rate of blastocyst formation derived from compacted embryos in mono-spermic embryo group was higher than that of poly-spermic embryo group (P<0.05), although no difference was detected between the two groups in the structural integrity. Finally, we confirmed that beta-catenin was differentially expressed according to compaction patterns in morula and blastocyst stage embryos. In conclusion, our results suggest that the compaction patterns during preimplantation development play a direct role in developmetal competence and quality of pig embryos.

• Applied Microscopy
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• 제11권1호
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• pp.51-57
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• 1981

Autographa californica Nuclear Polyhedrosis Virus의 Nucleocapsids의 형성과 Polyhedra Occlusion Bodies의 형성을 Spodoptera frugiperda 세포에 감염된 후 3 일째 된 것을 관찰하였다. 1. A. californica NPV는 Spodoptera 세포의 핵내에서 분열복제되어 Nucleocapsid를 형성하여, 외투막을 얻은 후에 Polyhedra Occlusion Bodies 로 함입 되었다. 2. A. californica NPV가 감염된 세포의 핵은 팽창되어 핵막이 세포질까지 거의 신장되어 있었다. 3. Polyhedra Occlusion Bodies의 형성은 NPV로 감염된 세포에서 작은 엉성한 단백질 또는 Polypeptides가 점진적으로 커지면서 바이리스들이 함입되면서 더욱 덩치가 커지게 되고, 세포질내에 NPV 바이러스들이 없어지면 Polyhedra는 외부에 매끈한 막을 형성하는 것이 관찰되었다. 4. Polyhedra Occlusion Bodies의 형태는 바이러스 다발이 함입되어 있는 상태에 따라서 다양하였다. 5. Polyhedra 에 있는 바이러스 다발들은 외투막을 가지며 바이러스사이에도 기저물질이 존재하는 것을 볼 수 있었다.

• Biomolecules & Therapeutics
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• 제12권1호
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• pp.9-18
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• 2004

Opening of the mitochondrial permeability transition pore has been recognized to be involved in cell death. The present study investigated the effect of ${\beta}$-carbolines (harmaline and harmalol) and deprenyl on the dopamine-induced change in the mitochondrial membrane permeability and cell death in differentiated PC12 cells. Cell death due to 250 4{\mu}$M dopamine was inhibited by caspase inhibitors (z-IETD.fmk, z-LEHD.fmk and z-DQMD.fmk) and antioxidants (N-acetylcysteine, ascorbate, superoxide dismutase, catalase and carboxy-PTIO). ${\beta}$-Carbolines prevented the dopamine-induced cell death in PCl2 cells, while deprenyl did not inhibit cell death. ${\beta}$-Carbolines decreased the condensation and fragmentation of nuclei caused by dopamine in PC12 cells. ${\beta}$-Carbolines inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, formation of reactive oxygen species and depletion of GSH caused by dopamine in PC12 cells, whereas deprenyl did not decrease dopamine-induced mitochondrial damage. ${\beta}$-Carbolines, deprenyl and antioxidants depressed the formation of nitric oxide and melanin in dopamine-treated PC12 cells. The results suggest that cell death due to dopamine PC12 cells is mediated by caspase-8, -9 and -3. Unlike deprenyl, ${\beta}$-carbolines may attenuate the dopamineinduced cell death in PC12 cells by suppressing change in the mitochondrial membrane permeability through inhibition of the toxic action of reactive oxygen and nitrogen species.

• 한국재료학회지
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• 제17권11호
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• pp.622-627
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• 2007

Porous poly(e-caprolactone) (PCL) scaffolds were fabricated by salt leaching method. The PCL scaffolds were treated with aqueous NaOH for 0h, 2h, 4h, 8h, and 12h at $40^{\circ}C$. The NaOH-treated PCL scaffolds were dipped in $CaCl_2$ and $K_2HPO_4{\cdot}_3H_2O$ solution alternately three times to induce apatite nuclei onto the surface of the scaffolds. The NaOH-treated PCL scaffolds were immersed into SBF solution for 1day to grow the apatite. The apatite formation were investigated as a fuction of NaOH treatment time. The hydrophilicty and surface area of the PCL scaffolds were increased with NaOH-treatment time. The NaOH-treated PCL scaffolds were successfully formed a dense and uniform bone-like apatite layer after immersion for 1 day in SBF solution.

• 천문학회보
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• 제36권2호
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• pp.55.1-55.1
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• 2011

Luminous infrared galaxies (LIRGs; $L_{IR}$ > ${10^{11}}_{Lsun}$) are the most powerful objects in the local Universe. Previous work suggested that dust re-processing of starburst and/or active galactic nuclei (AGN) activity, triggered by galaxy interactions, is responsible for their enormous infrared emission. To understand the nature of LIRGs, it is essential to determine their spectral types. Optical spectral types of 115 ultraluminous infrared galaxies in the southern sky are presented using CTIO observations. The AGN fraction is on average 50% and increases with infrared luminosity. Near-infrared spectral types of 36 LIRGs are also presented based on AKARI observations. In the sample, 12 optically elusive buried AGNs are found. To investigate the evolutionary sequence of LIRGs, star formation histories of ~6000 LIRGs in the SDSS and IRAS/AKARI matched sample are derived by comparing observed optical spectra and stellar population models. AGN-dominated LIRGs are currently massive relative to starburst-dominated LIRGs, which originates from an enhancement of star formation at intermediate-ages. For ~1100 early-type LIRGs, optical and NIR fundamental planes (FPs) are constructed. The FP of LIRGs is significantly different from that of normal early-type galaxies, but the difference is minimized in low luminous and AGN-like LIRGs. These findings support that the importance of AGN is growing as infrared luminosity increases and that LIRGs follow at least in the high mass regime the standard evolutionary scenario: starburst LIRGs evolve into AGN LIRGs and finally into normal early-type galaxies.

• 미생물학회지
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• 제29권1호
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• pp.8-15
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• 1991

Interspecific hybrids between the ASpergillus spp., A. awamori, A. usamii and A. oryzae, were obtained by nuclear transfer technique. Nuclei isolated from an auxotrophic mutant strain were transferred into the protoplasts of a recipient strain of different species. The frequency of interspecific hybrid formation by nuclear transfer was $2*10^{-5}$ $-7*10^{-4}$ In contrast, no interspecific hybrid was isolated by protoplast fusion. Among the hybrids tested, 10 strains showed increased activity of some or all components of cellulases, xylanases and amylase up to more than two times. Isozyme pattern of the hybrids were analyzed by polyacrylamide gel electrophoresis and isoelectric focusing followed by activity staining, which showed that some of the hybrids have isozyme patterns unidentical to either of the two parents. By measuring the DNA contents and the sizes ofthe conidia, the karyotypes of the hybrids were estimated to be aneuploid near to haploid, diploid or triploid. It was concluded that the unclear transfer technique is much more efficient in the formation of interspecific hybrids than protoplast fusion and is very useful for the improvement of Aspergillus strains.

• 천문학회보
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• 제39권1호
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• pp.40.2-40.2
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• 2014

The connection between the active galactic nuclei (AGNs) and star formation activity is one of the most important issues in understanding the coevolution of supermassive black holes (SMBHs) and galaxies. In our recent study, by using SDSS quasar spectra we found that the emission-line flux rations involving a nitrogen line, i.e., $NV{\lambda}1240$, correlate with the Eddington ratio. This correlation suggests that the mass accretion into SMBH is associated with a post-starburst phase, when AGB stars enrich the interstellar medium with the nitrogen. Moreover, we focused on nitrogen-loud quasars, which have prominent emission lines of the nitrogen, to investigate whether this argument is correct or not. We will present our recent results described above and discuss the relation between the star formation and feeding to SMBHs.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.206-211
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• 1997

The optimal conditions for the production and regeneration of the protoplasts from Lentinula edodes were studied. Protoplast formation from the mycelia of L. edodes which were cultured in liquid medium showed a significantly high yield compared with that of the mycelia which were cultured on cellophane covered agar media. A mixture of Novozyme 234 (15 mg/ml) and Cellulase Onozuka R10 (10 mg/ml) in 0.6 M mannitol (pH 4) was optimal lytic enzyme for the protoplast release. The optimal incubation time and mycelia age were 3.5-4 hours at $30^{\circ}C$ and 6-8 days, respectively. Regeneration frequency was 0.18% plated onto a medium containing 0.6 M sucrose, and 0.08% plated onto a medium containing mannitol. But hardly any regeneration was observed in the media containing NaCl, KCl, or $MgSO_{4}$ More than 90% of the protoplasts contained nuclei and the nucleus number per protoplast was 1.1. The DNA content per nucleus was 5.1 pg. The diameter of the protoplast was $3-5{\mu}m$ and it had a well defined cell structure.