• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.276-283
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• 2011

Recently, undifferentiated stem cells which exist in dental papillae of immature permanent teeth were newly discovered and these stem cells appear to be the origin of ameloblasts associated with the formation of root dentin. When treating immature permanent teeth, the preservation of these stem cells induce the continuous formation of the root. Therefore, it is reported that minimal invasion to periapical region in immature permanent teeth with periapical inflammation resulted in good-healing pattern in clinical and radiographic examination. In this case, a 10 year-old boy(mandibular right premolar) and a 8 year-old girl(maxillary left premolar) who visited the department of pediatric dentistry at Chosun University Dental Hospital were diagnosed with pulp necrosis and periapical abscess in clinical and radiographic examination. Endodontic instrumentation to the periapical region was limited and MTA(Mineral Trioxide Aggregate) was applied into the pulp canal. The periodic checks showed healing of periapical abscess and the development and growth pattern of roots. In permanent teeth with pulp necrosis and periapical abscess, preservation of pulp and dental papillae in the periapical region showed good prognosis during the periodic examinations. Therefore, a lot of clinical examination and long-term evaluation of conservative pulp treatment in immature permanent teeth are expected to be necessary.

• Journal of Mushroom
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• v.16 no.3
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• pp.131-139
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• 2018

The king oyster mushroom (Pleurotus eryngii) is widely consumed because of its flavor, texture, and its functional properties such as antioxidant activity and prebiotic effects. However, long-term product storage and transportation (e.g., export) are difficult because of its limited durability. The shelf-life of king oyster mushroom is affected by environmental factors such as temperature, humidity, gas composition, and ventilation, which may affect sensory characteristics including respiration rate, texture, moisture, flavor, color, and pH. The major problems regarding storage of mushrooms are browning, flavor changes, and softening. To address these problems, novel preservation techniques were developed, and more durable variants were bred. Different drying methods, gamma irradiation, chitosan coating, modified atmosphere (MA) packaging, and controlled atmosphere (CA) storage were evaluated in order to extend the shelf-life of king oyster mushrooms. Freeze drying showed better results for the preservation of mushrooms than other drying methods. Irradiation with 1 kGy was more effective for extending mushroom shelf-life than higher doses. The preservative performance of chitosan-based films was improved by combining the compound with other hydrocolloids, such as oil, protocatechuic acid, and wax. The CA storage conditions recommended for king oyster mushrooms are 5kPa $O_2$ and 10 to 15kPa $CO_2$ at temperatures below $10^{\circ}C$. Active MA packaging with microperforated PP film was also effective for maintaining quality during storage.

• Journal of Embryo Transfer
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• v.33 no.1
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• pp.23-30
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• 2018

The purpose of this study was to investigate the effects of the concentration of seminal plasma in aerobic and anaerobic conditions on the total motility(TM) and the progressive motility(PM) of spermatozoa in long term preservation of cooled equine semen. We also examine the pregnancy rates after artificial insemination using fresh, cooled or frozen semen, and different durations of cooled-preserved equine semen. In the aerobic state of cooled-preserved semen, As the increase of preserved duration to 24h, 48h, 72h, and 96h, TM tended to decrease in each of different concentrations of formalin-containing experimental group, TM tended to decrease regardless of the concentrations of SP. In different concentrations of SP, TM of without seminal plasma(SP W/O) group tended to be higher than that of SP 20%, SP 33% and SP 50%, especially TM of SP W/O group was significantly higher than other groups at 96 h (p<0.05). PM was higher in the groups of SP W/O and SP 20% than in the groups of SP 33% and SP 50% from 24 h to 72 h in cooled-preservation, especially PM of SP W/O group was significantly higher than other groups at 96 h (p<0.05). In the anaerobic condition of cooled-preserved semen, the results of TM and PM at different concentrations of SP were similar to the results in the aerobic condition although there was a difference in the ratio. The pregnancy rates of fresh-cooled, cooled-preserved and frozen semen were 66.3%, 60.7% and 34.5%, respectively, and the pregnancy rate of frozen semen was the lowest. We also found that it is possible to pregnancy after artificial insemination using 72 h cooled-preserved equine semen. There was similar of the pregnancy rates in the different month from April to August.

• Food Science and Preservation
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• v.8 no.4
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• pp.351-355
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• 2001

This study was carried out to examine the of quality on the dried Omija according to its package materials and storage plates. The changes of moisture contents, anthocyanin content, molds damage rates, and color values were measured during storage. In the sealing up by the P.E file, the moisture contents of the dried Omija had just a little differences among the storage places, but in the gauze bag remarkably as the storage period goes on, especially in this case, 8 months later since the storage in the cool chamber, the damage rates of the dried Omija by the mold was 9.0%, twice as much as in the indoor bag packaging it was increasand after 10 months, that was lather high in the indoor and warehouse. The anthocyanin content of the dried Omija after the storage of 10 months was the highest at 0.05mm black P.E film package in the cool chamber, which was 55.7 mg/100g, but in the indoor and warehouse 39.7, 45.0mg/100g, respectively. These results show thats the storage conditions had an important effect on the quality of the dried Omija during the long-term storage.

• Food Science and Preservation
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• v.23 no.6
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• pp.788-796
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• 2016

This study presented the change of quality characteristics of Doenjang with various salt concentrations (4, 8, 15, and 20%) during 12 months. The pHs of Doenjang during fermentation were gradually increased for 12 months, whereas the pHs of Doenjang with 4 and 8% salt increased rapidly. Titratable acidity of Doenjang with 4 and 8% salt was high at initial time, while Doenjang with 15 and 20% salt was high at the 9 and 12 months. The amino-type nitrogen content of Doenjang with 4 and 8% salt was increased and ${\alpha}-amylase$ activity of all Doenjang was decreased during whole fermentation period. The protease activity of Doenjang with 4 and 8% salt was higher than Doenjang with 15 and 20% salt until 7 months. Total aerobic bacteria number 8.0~9.1 log CFU/g for 12 months, which was steady during fermentation period. Doenjang with 8% salt showed the highest score in umami taste whereas the lowest score in bitterness, astringency, and sourness tastes between 5 and 12 months. In conclusion, Doenjang with 8% salt was a suitable concentration for low-salt fermented foods.

• Food Science and Preservation
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• v.5 no.4
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• pp.326-330
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• 1998

Freeze storage technique is widely used for food processing to keep freshness and quality of the product. This technique was applied to fresh, unshelled groundnut to develop a new type of product which could maintain fresh taste and nutritive values even after several months of storage. The groundnut varieties, Daepungtangkong, Daekwangtangkong and Sindaekwangtangkong were grown at the experimental field of NCES in 1996. Immatured pods or groundnut were harvested around 20 to 3o days before full maturity, washed, and steamed at 100$^{\circ}C$ for 5 min. to stop enzyme activity. After vacuum packing (at -760mmHg for 10 min.) with 0.08mm polyvinyldichloride film, the pods were immediately frozen at -70$^{\circ}C$ for 24h and transfered at -20$^{\circ}C$ for long-term storage. Physico-chemical properties of frozen vegetable groundnut were investigated at 2 months after storage and compared to those of conventionally dried groundnut. After 2 months storage, the thawed kernels were very palatable with softness and fresh taste. Acid value and hardness (measured as the compression force on the probe of a texture analyzer) were much lower in frozen vegetable groundnut than those in the air-dried ones. Presence of free sugars is one of the important factors affecting groundnut taste, and the free sugar contents were considerably decreased in the frozen vegetable groundnut compared to freshly harvested groundnut. But in dried groundnut no free sugar was detected.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.98-103
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• 2004

Recently, a New Great Harbour Bridge between Mokpo City and Koha Island is planned to be built across Mokpo Inner Harbour, and Namak New Town is under construction adjacent to Mokpo. Citizels' concorn of and participation in 「Campaign for Shaping Mokpo into Beautiful Seaport」 are necessary to match the view of Mokpo harbour with natural scenery beautifully and with marine environment harmoniously. Citizens'ㄹ levels of consciousness of coastal and marine environment were ascertained through questionnaire surveys of local citizenry attitudes and opinions, and citizenry action plans for the conservation of coastal and marine environments around Mokpo harbour are suggested on the basis of the results of questionnaire surveys. Citizens' voluntary participations in local policy for the control of marine wastes production and in a campaign for the collections of marine debris and wastes around beaches and coastal areas are required. The operation of municipal sewage treatment plants is to be performed effectively and efficiently, and to be monitored and evaluated periodically by the general public, the local federation for environmental movement or NGO. The development and performance of marine environmental education programs and an enlightenment campaign for environment preservation are to be incessantly done in cooperation with local residents. Only when local government of Mokpo collects the public opinions and continues to shape Mokpo into international beautiful seaport in the direction of a reflex of public opinion, coastal and marine environment around Mokpo harbour can be kept in good condition with citizens' positive participation in citizenry long-term practical action plans for environment conservation.

• Food Science and Preservation
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• v.6 no.4
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• pp.351-356
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• 1999

To develop and extend the shelf-life of vitamin C enriched fresh-cut apples using CA stored Fuji apples, dipping in 10% L-ascorbic acid and packaging with 0.03 mm LDPE, 0.04 mm PP and 0.08 mm Nylon/PE film(N$_2$displacement) were carried out. The changes of gas concentrations in the packaging and quality attributes of fresh-cut apples were examined during storage at 10$^{\circ}C$. The concentrations of O$_2$was maintained lower in Nylon/PE film than the other film, the level of O$_2$was in the range of 1∼3%. The increase of C$_2$H$_4$ concentrations in Nylon/PE film bag was more suppressed than the others. The vitamin C content of fresh-cut apples was enriched by dipping in L-ascorbic acid solution up to 241 mg$.$100 g-1 f.w., and the loss or that content was retarded differently by the package conditions of lower O$_2$level during storage. Browning in fresh-cut apples was shown after 6 days of storage in LDPE and PP film. but it was not shown by 14 days of storage in Nylon/PE film. Spoilage and off odor in fresh-cut apples were not detected up to 14 days of storage in Nylon/PE film. The results indicated that the vitamin C enriched fresh-cut apples can be processed from the long-term CA stored apples, and maintaining high quality of the products ill be possible in cases of the application of sealing packaging after O$_2$removal with film having low O$_2$permeability.

• Journal of Conservation Science
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• v.37 no.5
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• pp.464-476
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• 2021

Various materials, depending on the personality of the artist, are required for contemporary art. Thus, it is necessary to decipher the expressive intentions of the artist and characteristics of the materials required for the conservation of such art. The purpose of this study is to analyze the causes underlying the deterioration of sculptures made from soap and to determine the ideal hygrothermal environment required to stably exhibit and store these artworks. Furthermore, we aim to maintain the long-term structures of the artworks in accordance with the changing expressions and intentions of the artist. Our analysis confirmed that the extracts of the soap sculptures were composed of glycerin and that the sculptures were sensitive to humidity. Moreover, we determined that a relative humidity (RH.) of approximately 60~65% made for an appropriate hygrothermal environment required to preserve the sculptures. We also preserved each work in various ways by applying appropriate preservation treatment, and found that the optimum preservation environment for soap sculptures was a temperature of 20±2℃ and a RH. of 60±5%.

• Journal of Korean Library and Information Science Society
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• v.55 no.2
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• pp.1-28
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• 2024

This study aimed to present practical strategies for libraries in South Korea, including the National Central Library, to effectively respond to the new challenges of the digital era by systematically comparing and analyzing the status of online material collection and services of libraries both domestically and abroad. To achieve this, we sought to understand the cases and service status of online material collection in major foreign libraries and to derive directions and usage plans for our libraries based on the analysis of these foreign libraries' online material collection status. As a result of this research, it was found that the National Central Library needs to explore various strategies for expanding online material collection, including the proper collection and preservation of web resources that are being created and deleted, as well as expanding openness and utilizing archives. Secondly, as a central institution for future national information resources, it is necessary to establish a strategy for smoothly collecting, preserving, and servicing vast and complex web resources. Thirdly, there is a need to explore ways to implement a national-level web archive that can systematically collect, preserve, and utilize all web resources in our country. In the long term, it should be improved into a national platform capable of systematically collecting, preserving, and utilizing various types of web resources.