• Atmosphere
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• v.22 no.1
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• pp.87-96
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• 2012

Aerosol number concentration ($N_{CN}$), size distribution and cloud condensation nuclei (CCN) concentration ($N_{CCN}$) were measured during 16-21 August 2008 at Daegwallyeong (DG) located in the eastern rural region of the Korean Peninsula. In the very next week (22-29 August 2008) the same aerosol properties were measured at Yeongjong Island (YJ) in the Yellow Sea. $N_{CN}$ for all 3 size cuts (above 3, 6 and 10 nm) was significantly higher at DG than YJ, but $N_{CCN}$ was significantly lower at the former and resulted in the $N_{CCN}/N_{CN}$ ratio more than twice higher at YJ ($0.94{\pm}0.09$ vs. $0.35{\pm}0.15$ at 0.53% supersaturation). The geometric mean diameter at DG, $53{\pm}15nm$, was much smaller than that at YJ, $91{\pm}6nm$, due to the particle formation events that were likely to have occurred continuously at DG. For given mean diameter, aerosols were more likely to act as CCN at YG compared to those at DG.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.66-73
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• 1995

Putative gamma aminobu%sic acid (GABA)-ersic elements in the basilar pontine nuclei were examined in the dos using an antiserum against GABA-glutaraldehvde-protein conjusBtes and the peroxidase-antiperoxidase method. GABA-immunoreactive neuronal somata in the basilar Pons exhibited various morphology with the majority being spindle-shaped or multipolar, while some were spheroidal. The size of GABA-orgic neuronal somata was relatively small (approximately $10-20\mum)$ in diameter. GABA-immunoreactive neurons were scattered throughout the pontine nuclei, but the midline region of the medial nucleus at the rostral pons, the lateral nucleus at mid-pontine levels, and the ventral nucleus at the caudal pons exhibited a relatively greater concentration of cell bodies. A sparse number of GABA-ergic neurons were observed within the cerebral peduncle and along the ventral borders of the basilar pons adjacent to the middle cerebellar peduncle at the rostrocaudal levels of the pontine nuclei. These obsenrations provide anatomic evidence of how this inhibitory neural element performs its function in the cortico-prontocerbellar circuitry.

• Journal of Microbiology
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• v.39 no.1
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• pp.42-48
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• 2001

The regulation of actin gene expression during the differentiation of Naegleria gruberi was examined. Actin mRNA concentration was maximal in amoebae and decreased rapidly after the initiation of differentiation. At 20 min after initiation, the concentration of actin mRNA decreased to 55% of the maximal value. The actin mRNA concentration decreased to the minimum at 80 min (15% of the maximum), and then began to increase slightly at the end of differentiation. This decrease of actin mRNA concentration was regulated by the repression of actin gene transcription based on nuclear run-on transcription experiments. The rates of transcription of actin gene in nuclei prepared at 40 and 80 min after the initiation of differentiation were 50 and 28% of that of nuclei prepared at the beginning of differentiation, respectively. The addition of cycloheximide at the initiation of differentiation inhibited both the rapid decrease in the concentration of actin mRNA and the repression of actin gene transcription. These results suggest that the rapid decrease in the concentration of actin mRNA during the differentiation of N. gruberi is accomplished by the repression of actin gene transcription and this transcriptional regulation requires continuous protein synthesis during the differentiation.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.276-280
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• 1994

To obtain hybrids producing antagonisms and plant growth promoting effects by intergeneric nuclei transfer, the nuclei were isolated from the protoplasts of Trichoderma harzianum T95 and treated with colchicine. The nuclei were tranferred into protoplast of multi-auxotrophic Gliocladium virens G88 which cannot grow in minimal medium. The nuclei tranferred into protoplasts of G. virens G88 were selected on the regeneration minimal medium containing chloroneb as a haploid inducer. Low transfer frequency of 0.08% was observed with three chemical treatment, however no segregants were found in the intergeneric nuclei transfer. The various types of hybrids with different morphology were detected when different concentration of chloroneb were treated. These morphologies were classified as parental, recombinant and petite type.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.3
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• pp.295-301
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• 2005

The fine particles in the range of $30\~500nm$ are monitored at Hanyang University campus in Ansan using house made DMA (differential mobility analyzer) and commercial CPC (condensation particle counter, TSI inc.) in SMPS mode. The monitoring period is March 16th 2004 through May 7th, 2004. During the monitoring period, Aitken nuclei mode $(30\~100nm)$ particle concentration has a tendency of increase in the morning and evening hours. However, the accumulation mode $(100\~500nm)$ particle concentration stays rather stable than that of Aitken mode.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.151-169
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• 1993

The present study was carried out to investigate the best condition for nuclear-cytoplasm fusion and in vitro culture of nuclear transplanted embryos and to investigate the production of nuclear transplanted offsprings. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulses at output voltage of 1.0, 1.5 and 2.0 kV/cm for 100, 150 and $200{\mu}$ sec to induce cell fusion. 1. The culture of intact or zona cut 2-cell embryos in the medium supplemented with cytochalasin B($5{\mu}g/m{\ell}$) and colcemide($0.1{\mu}g/m{\ell}$)for 30 and 60 minutes did not affect the development to later stage. 2. The in vitro developmental rates of group A(a nucleus from one of the blastomeres was removed) and B(electrofusion of group A) were significantly lower than that of control group(p<0.01). 3. When nuclear transplanted embryos were submitted to electrofusion, the significantly higher fusion rates of 2-cell donor nuclei were achieved at the electric field strength of DC 1.5kV/cm for 100 and $150{\mu}$ sec, DC 2.0 kV/cm for $100{\sim}200{\mu}$ sec than DC 1.0 kV/cm for 100 and $150{\mu}$ sec(p<0.01). The significantly higher fusion rates of 4-cell donor nuclei were achieved at DC 2.0 kV/cm for 100 and $150{\mu}$ sec than DC 1.0kV/cm for $100{\sim}200{\mu}$ sec(p<0.01). These fusion rates in 8-cell donor nuclei were 88.7~99.3%. 4. The developmental potency to blastocyst in 2- and 4-cell donor nuclei was significantly higher in DC 1.0 and 2.0 kV/cm for $100{\sim}200{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group (p<0.01). The developmental potency to blastocyst in 8-cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}$ sec treated group than in DC 1.0 kV/cm for $100{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group(p<001). 5. The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 6. The success rate of nuclear injection into enucleated 2-cell embryos was significantly higher in 2-cell donor nuclei than in 4- or 8-cell donor nuclei(p<0.01). 7. The culture time taken for the nuclear transplanted 2-cell embryos to blastocyst stage was significantly longer in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 8. There was no significant difference in the developmental potency of nuclear transplanted embryos within the concentration of EGF at 0 to 15 ng per $m{\ell}$ of BMOC-3 solution. 9. The production rates of offspring after transfer of nuclear transplanted embryos to recipient mouse were significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01).

• Journal of the Korean Ceramic Society
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• v.52 no.1
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• pp.28-32
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• 2015

In this article, the influence of a hydrolyzed wheat protein retarder on the hydration process, ion concentration in liquid phase, degree of supersaturation, and crystal morphology of plaster was investigated. Furthermore, the retarding mechanism and the strength loss of gypsum were also studied by scanning electron microscopy (SEM). The results indicate that the use of the hydrolyzed wheat protein retarder for plaster achieved a better retarding effect and lower strength loss. The combination of gypsum plaster with the retarder not only decreased the plaster's early hydration rate and prolonged its setting time efficiently, but also militated against the crystal morphology of dihydrate gypsum. For example, the crystal dimensions changed little, but the proportion of needle-shaped crystals decreased. Combination with calcium ions on the surface of dihydrate gypsum crystal nuclei may form a chemisorbed layer, reduce the surface energy of the crystal nuclei, and inhibit the growth of the crystal nuclei of dihydrate gypsum. Consequently, the hydration process of building gypsum becomes greatly extended and is slowed down significantly.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.6
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• pp.49-56
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• 2005

An electron microbeam system has been developed to investigate the biological effect of cells by irradiating cell-nuclei with low-energy and low-flux electrons. It is essential to discern the cell nucleus from its cytoplasm and the culture medium and to locateit exactly onto the beam exit. The irradiation speed at more than 10,000 cells per hour is another requisite for the observations on cellular response to have good statistics. Long-time labor with patience and high concentration is needed since the frames of $320{\times}240{\mu}m^2$ should be moved more than 500 times for irradiating more than 10,000 cells per an hour. This paper describes the electron microbeam system with a focus on the user interfaces concerning the process of automatically recognizing the cell nuclei and injecting electron beam into the target cell nuclei at the irradiation speed of more than 10,000 cell nuclei per hour.

• Atmosphere
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• v.26 no.2
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• pp.243-256
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• 2016

Total number concentration of aerosols larger than 10 nm ($N_{CN10}$), 3 nm ($N_{CN3}$), and cloud condensation nuclei ($N_{CCN}$) were measured during four different ship cruises over the Yellow Sea. Average values of $N_{CN10}$ and $N_{CCN}$ at 0.6% supersaturation were 6914 and $3353cm^{-3}$, respectively, and the minimum value of $N_{CN10}$ was $2000cm^{-3}$, suggesting significant anthropogenic influence even at relatively clean marine environment. Although $N_{CN10}$ and $N_{CN3}$ increased near the coast due to anthropogenic influence, $N_{CCN}$ was relatively constant and therefore $N_{CCN}/N_{CN10}$ ratio tended to decrease, suggesting that coastal aerosols were relatively less hygroscopic. In general $N_{CN10}$, $N_{CN3}$, and $N_{CCN}$ during the cruises seemed to be significantly influenced by wet scavenging effects (e.g. fog) and boundary layer height variation. Only one new particle formation (NPF) event was observed during the measurement period. Interestingly, the NPF event occurred during a dust storm event and spatial scale of the NPF event was estimated to be larger than 100 km. These results demonstrate that aerosol and CCN concentration over the Yellow Sea can vary due to various different factors.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.381-385
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• 2000

Objective: To verify the effect of two forms (growth factor and growthfactor-reduced) of solubilized Matrigel on the development in mouse preimplantation embryos. Methods: Late 2-cell stage eggs were cultured through the blastocyst stage in the presence of GF- or GFR-Matrigel (0.5%, v/v). Morphological development, cell number and % apoptotic nuclei of blastocyst were measured by Roecst staining and TUNEL of nuclei. Results: Morphological development, number of cells per embryo was significantly increased in the presence of GF- or GFR-Matrigel. Culture of the embryos in the GF-Matrigel gave the best result. Conclusion: Low concentration of solubilized Matrigel improved development of mouse embryos regardless of growth factor content of the Matrigel. Growth factors and extracellular matrix protein included in the Matrigel synergistically potentiated the development of mouse embryos.