• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.85-88
• /
• 2001

We scaled up a covalent immobilization system of urokinase to the activated Sepharose and used it repeatedly to cleave a fusion protein consisting of human growth hormone and GST fragment. After scale up from 6 ml to 250 ml, the column system still demonstrated basically the same performance in terms of urokinase immobilization and fusion protein cleavage. When the column was washed with 6M guanidine HCl after the cleavage reaction. the immobilized urokinase showed no activity probably because it was fully unfolded. However. as the denaturant was gradually removed from the column the immobilized urokinase fully regained its bioactivity. which indicated it was properly refolded into its native conformation as covalently attached to the solid matrix. After 20 cycles of this 'solid-phase unfolding/refolding', the immobilized urokinase maintained approx. 80% of the initial bioactivity. This method provides an efficient protocol to apply the solid-phase refolding technique to improve the longevity of immobilized enzyme columns.

• Phonetics and Speech Sciences
• /
• v.3 no.4
• /
• pp.63-70
• /
• 2011

Recent studies on English $L^*$ (low pitch accent) have revealed the difference of changes in acoustic manifestation between utterances produced by Koreans and those produced by native speakers of English. However, not much effort has been made to compare $L^*$ focused constituents and non-focused constituents. At the same time, most previous works on focus realization are lacking in terms of normalization of acoustic measurement. Therefore, this research is dedicated to comparing the $L^*$ focused items and non-focused items realized by Koreans and Americans and to examining the realization of English $L^*$ produced by the two language groups with improved normalization of the acoustic features (F0, intensity and duration). Within-group analysis comparing focused words and non-focused words showed both Americans and Koreans prolonged the $L^*$ focused syllables but the effect size of syllable lengthening made by Koreans was far less than that made by Americans. Furthermore, significant F0 lowering was found in Americans but not in Koreans. However, the effect of intensity change caused by $L^*$ focus was not significant within each group. The effect of focused words was tested between the two groups revealing that Koreans implemented English $L^*$ focus with higher F0, lower intensity and shorter duration than Americans. In the instances in which a significant Group x Focus Location (initial, middle and final of a sentence) interaction was found, further analysis testing the effect of Group on each Focus Location was conducted. The testing showed that the Koreans produced shorter syllables at initial and middle of a sentence and higher F0 at initial of a sentence than Americans. Implications for the intonation training were also discussed.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.7 no.3
• /
• pp.35-47
• /
• 2004

In order to study changes in vegetation pursuant to rooftop revegetation plantation methods, plantation methods for rooftop revegetation were divided into two types through an analysis of recent trends. Then, Planted plants and invasive plants on sites where the planting methods were introduced were monitored. Planting methods were divided into mono-layer meadow cover type and multi-layer planting cover type. They showed some differences in terms of the availability of wetland, the structure of vegetation layers, the planted species, and the material of mulching. According to the results of monitoring the two sample sites for different plantation methods, the number of invasive plants was higher in multi-layer planting cover type and the ratio of naturalized plants was higher by 30% in average in mono-layer meadow cover type. The main reason for such a result is that the natural soil used in the multi-layer planting cover type likely contained some seeds. Moreover, it's harder for invasive plant seeds to germinate in volcanic rocks than in natural soil. Also, it is attributable to wetlands available in multi-layer planting cover type and diverse living environments created by multi-layer planting. The reason of the ratio of naturalized plants being higher by at least 10% in mono-layer meadow cover type is the character of naturalized plants being stronger in unfavorable conditions than nature plants are. Accordingly, the germination rate in the volcanic rock mulching has likely contributed in raising the introduction and germination of naturalized plants. The results showed that multi-layer planting cover type using wetland creation and nature soil can increase the number of invasive plants and lower the ratio of naturalized plants. However, since seeds contained in the natural soil can affect the growth of planted plants, this needs to be clarified, It was judged that mono-layer meadow cover type may affect more greatly on the germination and growth of invasive plants than on those of planted plants, Its potential adoption in highly urbanized areas was examined. By complementing with the mutual benefits of each plantation method, it appeared possible to shift to a rooftop revegetation system suitable to the site.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.9 no.3
• /
• pp.26-38
• /
• 2006

For both a healthy environment and sustainable development, we frame a habitat assessment method, concerning biodiversity and physical characteristics. With the method, we set up and extract conservation areas from Peace Valley Resort Development Areas which can function as habitats. Absolute and relative assessment items which are the size of area, habitation of species with conservation value, distribution of communities, functions of habitats, ratio of non-native plants, connectivity of habitats, vegetation layers of forests and age of forests, and water systems are considered on newly extracted conservation areas, and the habitat value assessment was calculated on the items in a 3-point scale. By comparing and examining 3 existing proposals for extracted conservation areas, we assess existing proposals, make an alternative proposal, and try to verify the possibility of applicability to extracted conservation areas. Proposal A and C must not be adopted since almost all conservation areas would be developed in the proposals. Proposal B, consisting of 53% development areas and 47% non-development areas, does not have enough development areas, so high density building arrangements should be encouraged in order to preserve conservation areas. Therefore, proposal B would be the best in ecological terms among the 3 proposals, if 3 conditions are considered : 1) new extracted conservation areas should be conserved; 2) 10~15m wide green-zones on both sides of the water system, which can play a role as ecological corridors, should be considered in development areas; 3) building arrangement should not interrupt the ecological corridors.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.6
• /
• pp.560-567
• /
• 1998

We have found that Thermoactinomyces vulgaris KFB-Cl00 produces a chitinase. The optimum temperature and pH of the enzyme activity were $55^{\circ}C$ and 6.5. The enzyme was stable after heat treatment at $80^{\circ}C$ for 30 min and stable in acidic and basic conditions (PH 6.0~11.0). The thermostable endo-chitinase from Thermoactinomyces vulgaris KFB-C100 was cloned into the plasmid pBR322 by using E. coli DH5$\alpha$ as a host strain. The positive clone carrying a recombinant plasmid (PKCHI23) with a 4.1-kb fragment containing the chitinase gene was found. The recombinant plasmid was analyzed to determine the essential region for chitinase activity and obtained a 2.3-kb fragment, which was sub cloned into pTrc99A using the PstI and SalI sites to construct pTrc99A/pKCHI23-3. The resulting plasmid exerted high chitinase activity upon transformation of E. coli XL1-Blue cells. Chitinase was overproduced 14 times more in the clone cells than in the wild-type cells and the enzyme was purified to homogeneity. The purified enzyme showed the similar properties as the native chitinase from T. vulgaris in terms of molecular weight and substrate specificity. The catalytic action of the cloned enzyme was an endo type, producing chitobiose as a major reaction product.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.39
• /
• pp.13.1-13.8
• /
• 2017

Background: Oronasal/antral communication, loss of teeth and/or tooth-supporting bone, and facial contour deformity may occur as a consequence of maxillectomy for cancer. As a result, speaking, chewing, swallowing, and appearance are variably affected. The restoration is focused on rebuilding the oronasal wall, using either flaps (local or free) for primary closure, either prosthetic obturator. Postoperative radiotherapy surely postpones every dental procedure aimed to set fixed devices, often makes it difficult and risky, even unfeasible. Regular prosthesis, tooth-bearing obturator, and endosseous implants (in native and/or transplanted bone) are used in order to complete dental rehabilitation. Zygomatic implantology (ZI) is a valid, usually delayed, multi-staged procedure, either after having primarily closed the oronasal/antral communication or after left it untreated or amended with obturator. The present paper is an early report of a relatively new, one-stage approach for rehabilitation of patients after tumour resection, with palatal repair with loco-regional flaps and zygomatic implant insertion: supposed advantages are concentration of surgical procedures, reduced time of rehabilitation, and lowered patient discomfort. Cases presentation: We report three patients who underwent alveolo-maxillary resection for cancer and had the resulting oroantral communication directly closed with loco-regional flaps. Simultaneous zygomatic implant insertion was added, in view of granting the optimal dental rehabilitation. Conclusions: All surgical procedures were successful in terms of oroantral separation and implant survival. One patient had the fixed dental restoration just after 3 months, and the others had to receive postoperative radiotherapy; thus, rehabilitation timing was longer, as expected. We think this approach could improve the outcome in selected patients.

• Biomaterials Research
• /
• v.22 no.4
• /
• pp.235-248
• /
• 2018

Background: Injectable hydrogels have been extensively researched for the use as scaffolds or as carriers of therapeutic agents such as drugs, cells, proteins, and bioactive molecules in the treatment of diseases and cancers and the repair and regeneration of tissues. It is because they have the injectability with minimal invasiveness and usability for irregularly shaped sites, in addition to typical advantages of conventional hydrogels such as biocompatibility, permeability to oxygen and nutrient, properties similar to the characteristics of the native extracellular matrix, and porous structure allowing therapeutic agents to be loaded. Main body: In this article, recent studies of injectable hydrogel systems applicable for therapeutic agent delivery, disease/cancer therapy, and tissue engineering have reviewed in terms of the various factors physically and chemically contributing to sol-gel transition via which gels have been formed. The various factors are as follows: several different non-covalent interactions resulting in physical crosslinking (the electrostatic interactions (e.g., the ionic and hydrogen bonds), hydrophobic interactions, ${\pi}$-interactions, and van der Waals forces), in-situ chemical reactions inducing chemical crosslinking (the Diels Alder click reactions, Michael reactions, Schiff base reactions, or enzyme-or photo-mediated reactions), and external stimuli (temperatures, pHs, lights, electric/magnetic fields, ultrasounds, or biomolecular species (e.g., enzyme)). Finally, their applications with accompanying therapeutic agents and notable properties used were reviewed as well. Conclusion: Injectable hydrogels, of which network morphology and properties could be tuned, have shown to control the load and release of therapeutic agents, consequently producing significant therapeutic efficacy. Accordingly, they are believed to be successful and promising biomaterials as scaffolds and carriers of therapeutic agents for disease and cancer therapy and tissue engineering.

• Journal of Advanced Navigation Technology
• /
• v.23 no.1
• /
• pp.55-60
• /
• 2019

The web is one of the most intimate technologies in people's daily lives, and most of the time, people are sharing data on the web. Simple messenger, news, video, as well as various data are now spreading through the web. In addition, with the emergence of Web assembly technology, the programs that run in the existing native environment start to enter the domain of the Web, and the data shared by the Web is now getting wider and larger in terms of VR / AR contents and big data. Therefore, in this paper, we have studied how to effectively deliver web contentsto users who use Web service by using service worker that can operate independently without being dependent on browser and cache API that can effectively store data in web browser.

• The Journal of Asian Women
• /
• v.53 no.2
• /
• pp.75-110
• /
• 2014

This research examines marriage migrant women's interpreting and translation work as an ethnic labor, analyzing its creation and work experiences. Major findings about ethnic labor in the research are as follows: First, Korean gendered and discriminatory- exclusive immigration policy enables the creation of interpreting and translation job to marriage migrant women. While the policy limits settlement and employment fields of male immigrant workers, marriage migration women are allowed to settle and find any job. Second, job security and wage of marriage migrant women's interpreting and translation work are still low, although the job is considered a relatively decent one in foreign immigrant labor market. Finally, they experience conflicts between role as neutral interpreters and identity as migrant women, facing native Koreans' distrust and discrimination against them. In conclusion, this study suggests some issues on marriage migrant women's empowerment and their labor market prospect in terms of the sustainability of this job.

• Food Science of Animal Resources
• /
• v.44 no.3
• /
• pp.662-683
• /
• 2024

Thai-Native×Anglo-Nubian goat meat cooked by grilling (GR), sous vide (SV), and microwave (MW), was compared to fresh meat (Raw) in terms of flavor development. Non-volatile [i.e., free amino acids, nucleotide-related compounds, taste active values (TAVs) and umami equivalency, sugars, lipid oxidation, Maillard reaction products] and volatile compounds, were investigated. Notably, inosine monophosphate and Glu/Gln were the major compounds contributing to umami taste, as indicated by the highest TAVs in all samples. Raw had higher TAVs than cooked ones, indicating that heat-cooking removes these desirable flavor and taste compounds. This could be proportionally associated with the increase in aldehyde, ketone, and nitrogen-containing volatiles in all cooked samples. GR showed the highest thiobarbituric acid reactive substances (1.46 mg malonaldehyde/kg sample) and browning intensity (0.73), indicating the greatest lipid oxidation and Maillard reaction due to the higher temperature among all cooked samples (p<0.05). In contrast, SV and Raw exhibited similar profiles, indicating that low cooking temperatures preserved natural goat meat flavor, particularly the goaty odor. The principal component analysis biplot linked volatiles and non-volatiles dominant for each cooked sample to their unique flavor and taste. Therefore, these findings shed light on cooking method selection based on desirable flavor and preferences.