• Journal of Plant Biotechnology
• /
• v.7 no.3
• /
• pp.183-186
• /
• 2005

Cryopreservation has been recognized as a practical and efficient tool for the long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of slow-freezing techniques on the cryopreservation of potato. In vitro plantlets of the potato genotypes of 'Atlantic', 'Superior’, 'Namseo', 'J138', and 'CTO5-5' were cold acclimated, and the excised axillary buds were precultured, osmoprotected, exposed to plant vitrification solution, frozen slowly to $-40^{\circ}C$ and then rapidly plunged into liquid nitrogen, thawed and finally plated on the regeneration medium. It was found that the higher the sucrose concentrations in the subculture medium of donor plantlets, the higher the survival rates of shoot tips after cryopreservation, and the highest survival (20%) was observed in the medium added with 0.25 M sucrose. As for the effect of cooling, $0.3^{\circ}C/min$ cooling speed showed the highest survival (25%). Different varieties showed different responses over different cryopreservation treatments. Survival rate was increased by slow-freezing technique method as compared with that of the basic cryopreservation method of vitrification alone in the diverse potato genotypes. Leaf and tuber morphologies of potatoes regenerated after cryopreservation using slow freezing technique were similar to those derived from the in vitro stock plantlets.

• Korean Journal of Veterinary Research
• /
• v.33 no.3
• /
• pp.547-554
• /
• 1993

This study was carried out to investigate the best condition for in vitro and in vivo culture after freezing and thawing of nuclear transplant 2 cell embryos. When nuclear transplant embryos were submitted to electrofusion, the significantly higher fusion rates of 2 cell donor nuclei were achieved at the electric field strength of DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The significantly higher fusion rates of 4 cell donor nuclei were achievecl at DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The fusion rates in 8 cell donor nuclei were 94.2~99.3%. The developmental potency to blastocyst in 2 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $150{\mu}sec$ treated group(p<0.01). The significantly higher developmental potency to blastocyst in 4 cell donor nuclei were achieved at the electric field strength of DC 2.0 kV/cm for $150{\mu}sec$ than DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The develop mental potency to blastocyst in 8 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2 cell donor nuclei than in 8 cell donor nuclei(p<0.01). When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant(p<0.01). The production rates of offspring after transfer of nuclear transplant embryos to recipient mouse were no significant difference in 2, 4 and 8 cell donor nuclei.

• Journal of Chest Surgery
• /
• v.40 no.8
• /
• pp.574-577
• /
• 2007

Primary malignant neoplasm of the pericardium is very rare, Neoplastic involvement of the pericardium may result in rapidly developing hemorrhagic effusion. A 30-year-old male who occasionally suffered from chest tightness was referred to our hospital under the diagnosis of unstable angina. He presented with acute chest pain and severe dyspnea that had developed one day previously. The diagnostic investigations such as echocardiography, chest CT and magnetic resonance image suggested cardiac tamponade that was caused by rupture of the pericardial teratoma. An operation to remove the tumor and effusion was performed. The pericardial mass was completely excised, and the result of the frozen biopsy favored malignancy. The final pathologic report was malignant fibrosarcoma of the pericardium and no malignant cells were found on the cytology of the pericardial effusion. The patient had a smooth postoperative course and was referred to another hospital for additional radiation therapy. We report here on this case of cardiac tamponade that was caused by primary pericardial fibrosarcoma, and this required urgent diagnosis and surgical management.

• Korean Journal of Animal Reproduction
• /
• v.17 no.4
• /
• pp.339-346
• /
• 1994

An understanding of the structure and function of mammalian spermatozoa requires the iso-lation of these components. In this study, frozen-thawed bovine spermatozoa were treated by physical treatments (vortexing, 26 gauge needle, strained 26 gauge needles and freezing-thawing) or chemical treatments (trypsin, dithiothreitol, sodium dodecylsulfate and $\beta$-mercaptoethanoJ) to yield free heads and tails. The most effective treatment was repeated pumping of sperm suspension through a strained 26 gauge needle conneted to a syringe. Spermatozoa by this treatment were mainly broken at the junction of the head and the tail, resulting in 90-100% yields. Also, sperm head surface did not modify during strained 26 gauge needle treatment when either spermatozoa or sperm heads were incubated in 250${\mu}\textrm{g}$/ml of FITC-UEA 1 for 1 h at room temperature to detect the modification of sperm surface components. Other physical treatments were less efficient for the breakdown of spermatozoa. The effects of chemical treatments on bovine spermatozoa are not noticeable. Dissected sperm heads and tails should be fractional leading to nearly pure components by sucrose gradient centrifugation at 1,000 rpm for 15 min. The result suggest that the established method may be useful for the biochemical study of spermatozoal components, and the understanding of oocyte activation mechanism either by spermatozoal components during fertilization or microinjection of isolated components.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.32 no.2
• /
• pp.137-143
• /
• 1987

To find out the optimum storage temperature and duration, changes in the content of sugars and soluble solids and flavor rate of two sweet corn hybrids (Great Bell and Golden Cross Bantam) and a super sweet corn (Crisp Super Sweet 720) were observed after storing at -20, 0, 5, 10, 15, 20, and 25$^{\circ}C$ for 1,3,5, and 7 days. At the temperatures below 10$^{\circ}C$, contents of soluble solids and total sugars and flavor rate were not changed significantly, but at the temperatures higher than 15$^{\circ}C$ they decreased as storage temperatures increased and duration extended. Storage duration conserving flavor seems to be 7 days at temperatures below 10$^{\circ}C$, 3 days at 15$^{\circ}C$, and 1-2 days at 25$^{\circ}C$. When corn was frozen, flavor rate was a little low compared with corn stored at 0$^{\circ}C$ although sugar content was higher. Both soluble solids and total sugar contents were positively correlated with flavor rate of cooked corn.

• Economic and Environmental Geology
• /
• v.35 no.5
• /
• pp.407-420
• /
• 2002

The Buddhist Triad Cave in Gunwi (National treasure No. 109) consists of porphyritic biotite granite, and it has been deteriorated into microorganic smears, white films, brown rusts, granular decay, color changes, and joints by the same weathering factors as rain, moisture, temperature variation and microorganic living. Main origin is probably the rain that leaks into the cave along joints in Palgongsan granite, and then its moisture grows many microorganism and is frozen over during winter. The granites around the cave regularly develop two NEE and NWW joint sets that are conjugate to be a joint system. The NEE set extends far away with narrow joint spacings and affects the leakage of the rains, and is divided into 4 joint zones, among which J$_{m}$ and J$_{3}$ immediately affect the leaking water into the cave. An extensional Joint, in northern wall of the cave, was formed by toppling of the block between J$_{m}$and J$_{3}$joint zones from widening the Jm aperture by roots of a big pine tree, and passes through the J$_{m}$joint zone. This bypass allows no circulation of small rain, but a good circulation of heavy rain from influx to the cave for a long pathway. Many Joints and cracks, in the ceiling near the cave entrance, immediately get through the J$_3$ joint zone, and have a good circulation of small rain 10 mm. Both J$_{m}$and J$_{3}$ joint zones are, therefore, chief influxes that cause leakage of the rains.

• Applied Microscopy
• /
• v.39 no.1
• /
• pp.65-72
• /
• 2009

Cryo-SEM which enables specimens to be observed in frozen form has been used to study liquid specimens in their native states. Cryo-methods, sample preparation for cryo-SEM, are quite complex and involve several discrete but vitally interconnected steps which are rapid cooling, fracturing, sectioning, etching and coating. It is important to select practical techniques and to optimize conditions of each steps considering analytic purpose and specimen characters, viz., sample dimension, water contents. In this study, etching methods and sample preparation before freezing had been studied for observation of cyanobacteria, Synechocystis sp. PCC 6803 using cryo-SEM and their cryo-SEM images were compared to Conventional SEM (CSEM) images treated by chemical fixation. We could observe the improved morphological images of the pili of the surface and membranes of Synechocystis sp. PCC 6803 and the three-dimensional architectures of their biofilm, which were difficult to observe using chemical fixation and CSEM. These results suggest that cryo-methods/cryo-SEM are useful techniques for morphological study of biological specimen.

• Journal of the Korean Society of Food Culture
• /
• v.10 no.2
• /
• pp.101-106
• /
• 1995

The effects of ${\alpha}-rice$ flour on the physicochemical properties of Korean rice cake were investigated. Before cooking, the degree of gelatinization of rice cake without ${\alpha}-rice$ flour was 5.75%, but 16% for adding ${\alpha}-rice$ flour. After cooking, the degree of gelatinization of rice cake were increased from 52% to 85% by adding ${\alpha}-rice$ flour. The L value of rice cake with ${\alpha}-rice$ flour increased, but there was no significant difference in L value between samples. The hardness of rice cake before and after cooking were increased by adding ${\alpha}-rice$ flour whereas after frozen stoarge there was no apparent effect on the color values of rice cake. The water absorption ratio of rice cakes during cooking were increased by addition of ${\alpha}-rice$ flour. Scanning electron photomicrographs revealed that the rice cake with ${\alpha}-rice$ flour has more porous structure with rapid rehydration.

• Journal of Food Hygiene and Safety
• /
• v.32 no.5
• /
• pp.363-370
• /
• 2017

In this study, we stored frozen shrimp (Litopenaeus vannamei) at $4^{\circ}C$ during 12 days and investigated the effect of chitosan coating with natural preservatives (0.05% carvacrol, 0.05% thymol) on the growth of microorganism (mesophilic bacteria, psychrophilic bacteria, Pseudomonas spp., $H_2S$ producing bacteria) and physiological characteristics (total volatile basic nitrogen and pH) and sensory evaluation (appearance, odor and general acceptance). Chitosan coating with natural antimicrobial compounds (0.05% carvacrol and 0.05% thymol) had inhibited the growth of all the target microorganism and showed the significant antimicrobial activity (p < 0.05) to mesophilic bacteria, psychrophilic bacteria and $H_2S$ producing bacteria until 12 day (the last day of this study). These treated groups had showed the significant difference (p < 0.05) in total volatile basic nitrogen and all the sensory characteristics but not in pH. Therefore, chitosan coating combined with natural antimicrobial compounds (0.05% carvacrol and 0.05% thymol) showed the effective antimicrobial activity on major spoilage microorganism on shrimp and could be used to elongate the shelf life of refrigerated shrimp.

• Korean Journal of Food Science and Technology
• /
• v.13 no.3
• /
• pp.176-180
• /
• 1981

Chicken patties and frankfurters were manufactured by varying the relative proportion of MDM to HDM as raw materials, and their palatability, shelf-life and textural properties were evaluated. The obtained results were as follows: 1. Chicken patty containing MDM slowed gradual increase in TBA value during frozen storage, but its storage up to g weeks presented no problems in flavor stability. 2. Color score and total palatability of chicken patty were best for the product containing 30% MDM. It was also concluded that MDM can be included in the patties up to 50% of total meat with good results, but more than 70% was not recommended. 3. The formulation of MDM up to 50% in frankfurter gave a quite satisfactory acceptability and textural properties compararable to frankfurter made of 100% HDM, but the inclusion of more than 70% MDM was not recommended. 4. The TBA value of frankfurter containg MDM did not increase to any great extent until 4 weeks of storage at $4^{\circ}C$, indicating no unique problems in flavor instability compared to regular frankfurter. 5. It was concluded that processed meat products such as patties and frankfurters containing MDM up to $30{\sim}35%$ of total meat ingredients gave satisfactory results in color, texture and palatability, comparable to regular products.