• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.66-69
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• 1998

Most segmented polyurethanes are prepared from a two-step method where the polyol is end-capped with an excess of diisocyanate, followed by chain extension with stoichiometric amount of chain extender, In the final polymer the hard and soft segments tend to segregate, due to thermodynamic immiscibility and the differences in chemical structure between hard and soft segments, and produce a phase separated morphology of hard segment-rich and soft segment-rich phase. (omitted)

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.82-95
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• 1995

These experiments were carried out to isolate SIgA from human and bovine milk. The immunochemical properties of SIgA from human and bovine milk were examined by Gel filtration, DEAE and SDS-PAGE. Double Immunodiffusion, and Immunoelectrophoresis. The results obtained are as follows: 1. Human SIgA was purified from colostrum of Korean women by repeated gel filtration on Sephadex G-200 and Sepharose 6B, but bovine SigA was not cleary purified from bovine colostrum of Holstein cows by anion exchange chromatography using DEAE-Sephadex A-50 and gel filtration on Sephadex G-200 and Sepharose 6B. 2. The immunochemical properties of fractions from gel filtration on the Sephadex G-200 and Sepharose 6B column as assessed by Immunoelectrophoresis and double Immunodiffusion to identify the presence of IgM in first peak fraction, and the presence of pure SIgA in second peak fraction. However, Bovine SigA rich fraction from bovine colostrum of Holstein cows contained a large amount of $IgG_1$-dimer in addition to SIgA. 3. The fragments of reduced bovine colostrum SIgA rich fraction were estimated to have molecular weights of secretory component, heavy chain and light chain (75,000-80,000, 50,000-60,000, 25,000-27,000 daltons) by SDS-PAGE, respectively. Those were similar to the molecular weight of reduced SIgA from human milk.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.452-457
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• 1994

The water soluble long-chain crosslinker, sulfo-succinimidyl-6-[3'-(2-pyridyldithio)-propion-amido]hexanoate (S-LC-SPDP) was used to prepare ricin A chain (RAT) immunotoxins constructed with whole igG and Fab fragments of the anti-common acute lymphoblastic leukemiz antigen (CALLA)monoclonal antibody. In this study, a) S-LC-SPDP modification efficiencies immunoreactivity and cytotoxicity of immunotoxins constructed were examined. IgG-RTA and Fab-RTA immunotoxins were prepared with 67.3% and 57.0% conjugation yields, respectively. These long spacer intemolecular linked immunotoxins were selectively immunoreactive and to antigen K562 cells. Both IgG-RAT and Fab-RAT immunotoxins were 210-and 45-fold more active than intavt RAT in vitro, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.31-41
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• 2018

Seaweeds are composed of a variety of bioactive substances, including polysaccharides, pigments, minerals, peptides, and polyphenols. Among these substances, the arsenic content of seaweeds has been a significant cause for concern. The present study evaluated the toxicity of arsenic from three species of seaweed using a zebrafish Danio rerio model. The arsenic-rich extracts were obtained from Ecklonia cava (ECAE), Undaria pinnatifida (UPAE) and Hizikia fusiformis (HFAE) using a solvent of 50% methanol and 1% $HNO_3$. We investigated the toxicity of the arsenic-rich extracts in zebrafish embryos through survival rate, heart rate, yolk sac edema size, cell death, reactive oxygen species (ROS) production and real-time polymerase chain reaction (PCR). The hepatotoxicity of arsenic-rich extracts was assessed in the liver of adult zebrafish through real-time PCR and histopathology. The survival rates of embryos and adult zebrafish showed no significant changes at any concentration. At 100 ppm, embryos did not exhibit significant differences in heart rate, yolk sac edema size, cell death or ROS production. In addition, apoptosis-related genes in larvae and liver tissue were unaffected by treatment with arsenic-rich extracts. These data will help clarify that developmental changes, hepatic oxidative stress, and apoptosis are not associated with toxicity from arsenic-rich seaweed extracts in a zebrafish model.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.9-15
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• 2020

Jilin province has a rich variety of agricultural and sideline products. The circulation of agricultural products needs the support of cold chain logistics. The development of cold chain logistics in Jilin province is lagging behind, which leads to waste of agricultural products and decrease of farmers' income. As a result, this article from the perspective of cold chain logistics development, extracted the influence factors of fresh agricultural products cold chain logistics development in Jilin province, using the analytic hierarchy process (AHP) on the degree of restriction factors, weight analysis found that agricultural products cold chain logistics costs, information technology application and market-based degree of cold chain logistics is the three main factors for the development of Jilin province agricultural cold chain logistics, and puts forward the development plan, in order to guide the development direction of Jilin agricultural cold chain logistics.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1426-1435
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• 2014

Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (p<0.05). There was a decrease in acetate proportion (linear pattern; p<0.001) and an increase in propionate proportion (linear pattern; p<0.001) with increasing levels of saponin. Log protozoal count decreased (p<0.05) at higher saponin levels. Comparing between different saponin-rich sources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (p<0.05). Although numerically the order of effectiveness of saponin-rich sources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.

• The Journal of Information Systems
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• v.23 no.1
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• pp.93-109
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• 2014

This study aims to develop a rich understanding of user goals in user-empowering information technologies which have been dominating part in the information systems environment. A particular focus is on users' goals in a social network site (SNS) which is a typical example of user-empowering technologies. Users conduct various activities in order to achieve diverse goals in SNS. Thus, investigating what goals users pursue in SNS will give insights into understanding the users. We employed the laddering interview technique and means-end chain approach. Interviews of 50 Facebook users were analyzed to produce a hierarchical goal map showing users' goal structure. The map contains 18 goals, including self-reflection, psychological stability, belongingness, improving productivity, and amusement as ultimate goals in SNS. In the map, there are varied routes from activities to ultimate goals in SNS; that is, a complex assembly consisting of activities and goals. The findings call the information systems research community to have more interests in diverse goals and values users seek with technologies.

• The Journal of Information Systems
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• v.30 no.2
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• pp.127-146
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• 2021

Research Purpose Advances in digital technology have facilitated the widespread adoption of online learning, which has become a substantial way of learning. Although digital immigrants have become a main group of users of learning online, there is a lack of understanding of their online learning. This study aims to explore digital immigrants' adoption of online learning from the goal-pursuit perspective to gain insight into how they use online learning. Research Method A laddering interview was conducted with 22 Korean adults to elicit their goals in online learning. Then, a means-end chain analysis was used to derive their hierarchical goal structure. Findings The results reveal digital immigrants' goal structure of online learning, consisting of four attributes of online learning (e.g., accessibility, diversity, up-to-dateness, and repeatability) and six goals (e.g., self-esteem, enjoyment, recognition, productivity, gaining insights, and positive relations). This study contributes to the literature by providing a rich picture of their use of online learning.

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.106-112
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• 2012

Background : Complicated diabetic patients show impaired, delayed wound healing caused by multiple factors. A study on wound healing showed that platelet-rich plasma (PRP) was effective in normal tissue regeneration. Nonetheless, there is no evidence that when platelet-rich plasma is applied to diabetic wounds, it normalizes the diabetic wound healing process. In this study, we have analyzed matrix metalloproteinase (MMP)-2, MMP-9 expression to investigate the effect of PRP on diabetic wounds. Methods : Twenty-four-week-old male Otsuka Long-Evans Tokushima Fatty rats were provided by the Tokushima Research Institute. At 50 weeks, wounds were arranged in two sites on the lateral paraspinal areas. Each wound was treated with PRP gel and physiologic saline gauze. To determine the expression of MMP-2, MMP-9, which was chosen as a marker of wound healing, reverse transcription polymerase chain reaction (RT-PCR) was performed and local distribution and expression of MMP-2, MMP-9 was also observed throughout the immunohistochemical staining. Results : RT-PCR and the immunohistochemical study showed that the levels of MMP-2, MMP-9 mRNA expression in PRP applied tissues were higher than MMP-2, MMP-9 mRNA expression in saline-applied tissues. MMP-9 mRNA expression in wounds of diabetic rats decreased after healing began to occur. But no statistical differences were detected on the basis of body weight or fasting blood glucose levels. Conclusions : This study could indicate the extracellular matrix-regulating effect observed with PRP. Our results of the acceleration of wound healing events by PRP under hyperglycemic conditions might be a useful clue for future clinical treatment for diabetic wounds.

• Journal of Life Science
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• v.10 no.1
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• pp.10-13
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• 2000

To develope the genetic source of oak wild silkworm, Antheraea yamamai, the cDNA library was constructed with poly A+ mRNA isolated from posterial silk gland of fifth instar larvae. Titer of the cDNA library was about 5.1$\times$105 pfu in total. We presumed that the titer covered almost all transcripts existed in Antherea yamamai. From cDNA library of Antheraea yamamai, fibroin heavy chain gene, which is specifically expressed from posterial silk gland of Antheraea yamamai, was screened using oligonuclotide probe specific to alanine rich motif of fibrin heavy chain gene of Antheraea pernyi. As a result, fibroin clones isolated from 5$\times$104 plaques showed the highest homolgy (95%) with that of Antherea pernyi in nucleotide of Anthereaea yamamai and Bombyx mori shows that there is no homologous sequence in the 3+ partial 채야후 region Genomic southern hybridization suggested that one copy is present. Northern hybridization showed that fibroin transcript was approximateely 9 kb in length.