• Macromolecular Research
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• v.15 no.5
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• pp.396-402
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• 2007

The dielectric properties and various pattern-forming states of dual-frequency material in a nematic phase, as well as its mixture containing low concentrations of reactive monomers, are reported. The dielectric relaxation behaviors of nematic MLC 2048 are presented and compared to its mixture containing both mesogenic and nonmesogenic reactive monomers. The sign-inversion frequency of the dielectric anisotropy was significantly shifted on the addition of small amounts of the reactive monomers. However, all three mixtures used in this study essentially exhibited the same field-induced instabilities at different frequencies and voltage domains of the applied electric field. A broad band of modulated states were found to exist above a critical voltage and within a voltage dependent frequency band in the vicinity of the sign-inversion frequency, $f_I$, of the dielectric anisotropy. As the $f_I$ of the mixtures shifted, so did the bands of the modulated state of the different mixtures and the temperatures, which were well matched with the measured $f_I$ value.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.91-98
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• 1987

This study was designed to investigate the changing depositional pattern of inorganic enamel substances during enamel formation and maturation. For this purpose, white rat incisors which continuously grow and develop during the life, were chosen as specimens. And after treated with 20% KOH solution, outer surface of forming inorganic enamel were observed with the scanning electron microscope, dividing into 6 types according to the forming pattern from apical to cuspal direction. The observations lead to the following conclusions: 1. During the initial enamel forming stage, inorganic enamel substances were deposited with very irregular pyramidal shape on the root dentin surface. 2. During the enamel forming stage, inorganic enamel substances were deposited with relatively regular hexagonal, honey-comb appearance. 3. During the later enamel forming stage, inorganic enamel substances were deposited with very irregular and roughly amorphous appearance. 4. During the later enamel maturating stage, very small and round inorganic enamel substances were deposited densely, and made a flat enamel surface.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.23-28
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• 2012

In order to cloning of PPO gene as a melanin formation related genes involved in hardening and pigmentation of insect integument or wing, we cloned cDNA and analyzed the sequence of PPO gene of H. axyridis. PPO2 primer were designed based on the sequences of PPO genes of Tribolium castaneum and Drosophila melanogaster, and then plasmid DNA were cloned from PCR products obtained from different two color patterns. When the plasmid DNA band pattern were digested by restriction enzymes, BamH1, Xba1, and EcoR1, we found same size band pattern. However, this sequence was not homologous to sequence of T. castaneum PPO gene. Using the primer designed based on the sequence of D. melanogaster, 209 bp PCR product was observed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.862-872
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• 1997

Ice formation in a horizontal circular cylinder has been studied numerically. From the numerical analysis results, it was found that there were three types of freezing pattern and that freezing phenomenon was affected largely by density inversion and cooling rate. The type of freezing pattern largely depends on the secondary flow which is generated by density inversion. When supercooling energy is released before the development of the secondary flow, the annular ice layer grows. If the energy is released when the secondary flow is considerably developed and the supercooled region is removed to the upper half part of the cylinder, an asymmetric ice layer grows. And if the energy is released after perfect development of the secondary flow, instantaneous dendritic ice formation over the full region occurs. Furthermore, this secondary flow was found to have an effect on heat transfer characteristics. The heat transfer rate becomes small at the instant when the secondary flow is generated, but becomes large with the development of the flow. It's concluded that for the facilitation of heat transfer it is desirable to keep water in liquid phase until the secondary flow is perfectly developed. This study gave an instruction of performance improvement of capsule type ice storage tank.

• Journal of computational fluids engineering
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• v.16 no.4
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• pp.64-71
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured, a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• Journal of Korean Academy of Nursing Administration
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• v.3 no.1
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• pp.17-35
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• 1997

The purpose of this study was to identify the formation and changing pattern of nursing perspectives of nursing students. 176 subjects were composed of 118 nusing students and 58 non-nursing students. The data were collected through openended question and structured questionair. The result were as follows : 1. Nursing perspectives were classified six categories(nature of nursing, image of nursing, component of nursing, meaning of nursing, range of nursing, function of nursing) 2. As increased major lecture period, the item of ${\lceil}$Nursing is helping${\rfloor}$ was changing positively. 3. As incresed clinical practice, the student's perception about items of ${\lceil}$Nursing has gap between theory and practice${\rfloor}$, ${\lceil}$Nursing is helping${\rfloor}$ was increased. 4. As increased self-concept, the students were considered the item of ${\lceil}$Nursing is action that giving knowledge and helping to effective coping for individual and group${\rfloor}$ significantly. 5. 1) The students having religion were considered the item of ${\lceil}$Nursing must doing politely${\rfloor}$ significantly relatively to the students don't have religion. 2) The students having experience of admission to hospital in their or their family had negative nursing perspectives. 3) Against the students who select nursing major for his high school perfoermonce and advice of their significant others, the students who select nursing major for service had positive nursing perspectives.

• Journal of Plant Biology
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• v.34 no.4
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• pp.261-266
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• 1991

The hairy root was induced form potato tuber disc by infection of a. rhizogenes. The detection of the agropine and mannopine by paper electrophoresis confirmed that induced hairy root was transformed by A. rhizogenes. The activity of peroxidase was the highest at 5 weeks and isozyme pattern of peroxidase revealed 3 cathodic bands and 2 anodic bands and new C4 band(pI 4.6) was observed at 7 weeks after cultivation in hairy root was isoelectric focusing. To study the effect of Ca2+ on cell wall formation in hairy root, channel blocker of Ca2+ was treated. The activity of $\beta$-glucan synthetase II(GS II) related to cell wall synthesis was inhibited by about 50% in diltiazem and flunarizine treatment than that of control, but stimulated in CaCl2 treatment. Therefore these results showed that Ca2+ might be an effective factor in the cell wall formation. The activity of GS II by NaF treatment was increased by about 30%. This result suggested that the activity GS II is changed through phosphorylation process.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.161-168
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• KSBB Journal
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• v.6 no.1
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• pp.27-33
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• 1991

Hairy root induced by A. rhizogenes from potato tuber (Solanm tuberosum L.) synthesized the agropine and mannopine which were demonstrated with paper electrophoresis. And the starch contents in hairy root were increased gradually following the developmental stage. But protein contents were decreased. The activity of ${\beta}-glucan$ synthetase II(GSII) which is related to the cell wall biosynthesis was stimulated in hairy root on the developmental stage. And chloropromazine did not influence the activity of GS II while verapamil inhibited about 60% of the activity GS II. Therefore, these results showed $Ca^{2+}$ to be effective factor in the cell wall formation. Isozyme pattern of peroxidase was investigated in the callus and hairy root induced from potato tuber.

• Molecules and Cells
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• v.21 no.3
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• pp.436-442
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• 2006

Different proliferation of neuroblast 6-4 (NB6-4) in the thorax and abdomen produces segmental specific expression pattern of several neuroblast marker genes. NB6-4 is divided to form four medialmost cell body glia (MM-CBG) per segment in thorax and two MM-CBG per segment in abdomen. As homeotic genes determine the identities of embryonic segments along the A/P axis, we investigated if temporal and specific expression of homeotic genes affects MM-CBG patterns in thorax and abdomen. A Ubx loss-of-function mutation was found to hardly affect MM-CBG formation, whereas abd-A and Abd-B caused the transformation of abdominal MM-CBG to their thoracic counterparts. On the other hand, gain-of-function mutants of Ubx, abd-A and Abd-B genes reduced the number of thoracic MM-CBG, indicating that thoracic MM-CBG resembled abdominal MM-CBG. However, mutations in Polycomb group (PcG) genes, which are negative transregulators of homeotic genes, did not cause the thoracic to abdominal MM-CBG pattern transformation although the number of MM-CBG in a few percent of embryos were partially reduced or abnormally patterned. Our results indicate that temporal and spatial expression of the homeotic genes is important to determine segmental-specificity of NB6-4 daughter cells along the anterior-posterior (A/P) axis.