• 산업기술연구
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• 제21권B호
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• pp.27-30
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• 2001

For the development of a large-scale dialysis process for silk fibroin solution, a batch and continuous dialysis chamber was designed and built, which are to be used as a unit module for the process. A series of dialysis experiments were carried out to estimate the kinetic parameters for dialysis using the solutions of salt-solubilized silk fibroin. The solution was dialyzed by distilled water either batch-wise or continuously. Dialysis kinetics was monitored by measuring refractometery at high salt concentration and conductivity at lower salt concentration. The apparent dialysis coefficients were $5.4g/m^2-hr$ and $1.8g/m^2-hr$, for well mixed batch and continuous dialysis, respectively. The alteration of molecular weight distribution of dialyzed silk fibroin solution was monitored.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.761-763
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• 2001

Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Dendrimer can be made with high regularity and controlled molecular weight. Peculiar features of the dendritic geometry are the large number of end groups as well as the shape persistence in higher generations, approaching spherical geometry. One of the most peculiar characteristics of dendritic macromolecules is their controlled molecular structure and orientation, which means that they have a practical application in achieving a highly organized molecular arrangement. We attempted to fabricate a G4-48PyA dendrimer LB films containing 48 pyridinealdoxime functional end group that could form a complex structure with metal ions. Also, we investigated the surface activity of dendrimer films at air-water interface. And we have studied the electrical properties of the ultra-thin dendrimer LB films. The electrical properties of the ultra-thin dendrimer LB films were investigated by studying the current-voltage(I-V) characteristics of metal/dendrimer LB films/metal (MIM) structure. And rectifying behavior of the devices was occurred in applied field.

• 한국어병학회지
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• 제31권1호
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• pp.1-8
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• 2018

Causative agent of infectious hematopoietic necrosis (IHN) belonging to genus Novirhabdovirus (Rhabdoviridae). Economic losses caused by IHNV are serious in mainly Oncorhynchus spp. including rainbow trout O. mykiss and Atrantic salmon Salmo salar. IHNV was initially found by endemic presence in U.S. West Coast for sockeye salmon fry O. nerka and chinook salmon fry O. tshawytscha in the 1950s, and it has spread to Japan, Korea and Taiwan in the 1970s, and also to Italy and France in the 1990s. Currently, IHNV is detectable in many parts of the world, including Russia and South America. Mortality due to IHNV infection in fish with ${\leq}0.5g$ of body weight reaches 60% to 100%, while the mortality reduces by fish growing. In recent years, onset of IHNV infection has increased also in fish with large sizes. Here, we introduce molecular epidemiology and virulence changes of IHNV in East Asia, furthermore, we discuss on future prospects in IHNV researches.

• BMB Reports
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• 제30권1호
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• pp.46-54
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• 1997

Alkaliphilic Bacillus sp. S-1 secretes a large amount (approximately 80% of total pullulanase activity) of an extracellular pullulanase (PUL-E). The pullulanase exists in two forms: a precursor form (PUL-I: $M_r$ 180,000), and a processed form (PUL-E: $M_r$ 140,000). Two forms were purified to homogeneity and their properties were compared. PUL-I was different in molecular weight, isoelectric point, $NH_2$-terminal amino acid sequence, and stabilities over pH and temperature ranges. The catalytic activities of PUL-I were also distinguishable in the $K_m$ and $V_{max}$ values for various substrates, and in the specific activity for pullulan hydrolysis. PUL-E showed 10-fold higher specific activities than PUL-I. However. PUL-I is immunologically identical to PUL-E, suggesting that PUL-I is initially synthesized and proteolytically processed to the mature form of PUL-E. Processing was inhibited by PMSF, but not by pepstatin, suggesting that some intracellular serine proteases could be responsible for processing of the PUL-I. PUL-I has a different conformational structure for antibody recognition from that of PUL-E. It is also postulated that the translocation of alkaline pullulanase(AP) in the bacterium possibly requires processing of the $NH_2$-terminal region of the AP protein. Processing of the precursor involves a conformational shift. resulting in a mature form. Therefore. precursor processing not only cleaves the signal peptide, but also induces conformational shift. allowing development of active form of the enzyme.

• Journal of Pharmaceutical Investigation
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• 제35권6호
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• pp.403-409
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• 2005

For transdermal delivery of large molecular drugs such as vaccine and protein drugs, novel microneedle treatment device with roll was designed. The roll dimension is 1.43 cm diameter and 2.8 cm perimeter. Total number of microneedle on the roll is 3,360 with $230\;{\mu}m$ height and $740\;{\mu}m$ distance. The pore with $150\;{\mu}m$ depth and $35\;{\mu}m$ diameter on the skin was made by the designed microneedle device. This system could be achieved without pain. The permeation rates of FITC labelled ovalbumin (FITC-OVA, molecular weight: 45,000 g/mol) as a model protein were determined by modified Franz diffusion cells using skins of hairless mice or SD rats which were treated by using microneedle device two or four times. The average penetration fluxes of model protein increased from 674 to $872\;{\mu}g/cm^{2}{\cdot}hr$ as the number of treatment to make pore increased from two to four times. In conclusion, we confirmed the possibility of using the designed microneedle treatment device for transdermal delivery of the large molecular drugs.

• 한국잠사곤충학회지
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• 제31권2호
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• pp.82-90
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• 1989

분리.정제한 전잠 vitellin의 분자량추정, 당 및 지질성분의 존재유무, 전기현미경적인 형태 및 크기, 아미노산 조성, 내열성 및 여러 가지 특성을 조사하였다. 1. 분리.정제된 천잠의 vitellin은 전기영동상의 이동도가 다른 large 및 small subunit로 되어 있다. 2. 천잠 vitellin의 분자량은 약 450,000d로 추정되었고, large subunit와 small subunit는 각각 174,000d와 44,000d로 추정되었다. 3. Coomassie brilliant blue, sudan black B 및 PAS 염색에 의해서 천잠의 vitellin은 glycolipoprotein으로 동정되었으며, 2개의 subunit도 당과 지질성분을 가지고 있었다. 4. 천잠 vitellin의 지질성분 중에는 가잠이나 Eri-참에 비하여 매우 다양한 종류들이 검출되며 특히 포화지방이라고 추정되는 물질도 있었다. 5. 천잠 vitellin의 단백질과 당성분은 7$0^{\circ}C$에 60분까지는 안전성을 보였으나, 같은 조건에서 지질성분은 검출되지 않았다. 6. 천잠 vitellin의 아미노산 성분 중 다른 곤충에서는 함량이 적은 glycine이 현격히 많았고 기타 성분의 함량은 가잠이나 Eri-잠과 같은 경향이었다. 7. 천잠의 vitellin은 직경이 14$\pm$0.8nm의 균일한 구형이었다.

• The Korean Journal of Ceramics
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• 제6권3호
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• pp.318-321
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• 2000

Most compressive strengths commonly used in the construction field are in a range of 240 to 300 kgf/$\textrm{cm}^2$ at 28 days. To get this rage of strengths, however, high-flowing concrete requires cementitious binders more than 400 to 450 kg/$\textrm{cm}^2$ for preventing segregation and sedimentation of aggregates. This amount of cementitious binder generates a large emission of excessive hydration heat, which may consequently induce harmful cracks in concrete structure. In order to reduce excessive hydration heat, thus, this paper aims at fabricating a high-flowing concrete under the condition that cement content is kept as low as 350kg/$\textrm{cm}^3$ by using viscose agents. In a parametric study, effects of cement types such as a ternary blended cement and Type V on he physical characteristics of high-flowing concrete were evaluated. In addition, the influence of viscosity was also investigated by applying two different viscose agents, one in a range of 6,000 to 10,000 cps and the others of 10,000 to 14,000 cps. In terms of chemical admixtures used in concrete mixture, the superplasticizer was Sulfonated Melamine-Formaldehyde Condensate with about 30,000 of molecular weight, and main component of viscose agent was HPMC (Hydroxy Propyl Methyl Cellulose). Slump flow was fixed at 50cm with different dosages of superplasticizer in weight.

• Macromolecular Research
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• 제11권6호
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• pp.444-450
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• 2003

Hydrophobically End-capped polyethylene oxide Urethane Resin(HEUR)-associating polymers, HEUR 35(8), HEUR 35(12), and HEUR 35(18), comprise a polyethylene oxide (PEO) having a molecular weight of 35,000 that is end capped with two C$\_$8/H$\_$17/, C$\_$12/H$\_$25/, and C$\_$18/H$\_$37/ alkyl chains, respectively. These associating polymers were synthesized by condensation reactions with polyethylene oxides and alkyl isocyanates. The self-diffusion coefficients of HEUR-associating polymers were measured in aqueous solution by pulsed-gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) spectroscopy. All polymers underwent a decrease in their mean diffusion coefficients as the concentration was increased. However, the dispersion of the diffusion coefficients, ${\beta}$, about the mean fluctuated with changes in concentration. The large dispersion at low concentrations of HEUR 35(8) and HEUR 35(12) is related to the interaction between hydrophobic end groups, and the large dispersion at high concentrations of HEUR 35(18) is correlated with transient network formation. These results are valuable for predicting the associating mechanism of the large aggregates before and after their critical micelle concentration.

• Animal cells and systems
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• 제3권1호
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• pp.73-78
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• 1999

Although there are several methods for the preparation of mitochondrial DNA (mtDNA) from mammalian tissues, most are relatively long ultracentrifugation or manipulations by a small-scale method. We escribed a rapid method for large-scale extraction of mtDNA from human placental and horse liver tissues. The method is based on the preparation and homogenization of tissues, urification of crude mitochondria by differential centrifugations and isolation of mtDNA by alkaline Iysis. It was improved from Pre-existing methods by replacing some steps with simpler ones and discarding many others. This method gives a high yield of pure mtDNA(approximately 1-5mg from one placenta; ca. 400-600 g wet weight), depending on its sources (fresh tissue gave better results than frozen one). The resulting mtDNA indicated that this method can yield mtDNA in sufficient purity and quantity to identify the direct restriction analysis on agarose gel, random-primed labeling as a probe, and end labeling. Therefore, the method is ideal for obtaining good mtDNA samples to conduct routine restriction fragment length polymorphism (RFLP) analyses of natural populations for genetic studies.

• Animal Bioscience
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• 제37권5호
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• pp.832-838
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• 2024

Objective: The use of molecular genetic methods in pig breeding can significantly increase the efficiency of breeding and breeding work. We applied the F_st (fixsacion index) method, the main focus of the work was on the search for common options related to the number of born piglets and the weight of born piglets, since today the urgent task is to prevent a decrease in the weight of piglets at birth while maintaining high fertility of sows. Methods: One approach is to scan the genome, followed by an assessment of Fst and identification of selectively selected regions. We chose Large White sows (n = 237) with the same conditions of keeping and feeding. The data were collected from the sows across three farrowing. For genotyping, we used GeneSeek GGP Porcine HD Genomic Profiler v1, which included 68,516 single nucleotide polymorphisms evenly distributed with an average spacing of 25 kb (Illumina Inc, San Diego, CA, USA). Results: Based on the results of the Fst analysis, 724 variants representing selection signals for the signs BALWT, BALWT1, NBA, and TNB (weight of piglets born alive, average weight of the 1st piglets born alive, total number born alive, total number born). At the same time, 18 common variants have been identified that are potential markers for both the number of piglets at birth and the weight of piglets at birth, which is extremely important for breeding work to improve reproductive characteristics in sows. Conclusion: Our work resulted in identification of variants associated with the reproductive characteristics of pigs. Moreover, we identified, variants which are potential markers for both the number of piglets at birth and the weight of piglets at birth, which is extremely important for breeding work to improve reproductive performance in sows.