• Journal of Embryo Transfer
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• v.21 no.3
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• pp.191-198
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• 2006

The objectives of this study was to produce valuable offsprings of Hanwoo and Jeju black cattle using in vivo embryo production and embryo transfer techniques during 5 years ($2001{\sim}2005$) in Jeju. Two hundred and eighty six Hanwoo and sixty nine Jeju black cattles, at random stages of the estrous cycle, received a CIDR. Seven days later, the animals were superovulated with a total of 400 mg pFSH ($Folltropin^{(R)}-V$) administered twice daily in constant doses (each 50 mg) over 4 days. On the 6th administration of FSH, CIDR was withdrawn and 25 mg $PGF_{2{\alpha}}$ was administered. Cows were artificially inseminated thrice after estrous detection at 12 hr intervals. The cows received $250{\mu}g$ GnRH at the time of 2nd insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Recipients were synchronized with donors by insertion of a CIDR for 7 days and administration of 25 mg $PGF_{2{\alpha}}$ at the time of CIDR removal. The collected embryos were transferred to 1,219 recipients by 6 transfer persons. The mean numbers of total ova and transferable embryos from Hanwoo and Jeju black cattle donors were 7.4 and 4.7, respectively The number of transferable embryos differed between Hanwoo (5.0) and Jeju black cattle (3.5, p<0.05), while that of total ova did not differ. Repeated superovulation treatments decreased (p<0.05) the ratio of numbers of the flushed animals vs. superovulated animals in Jeju black cattle, and the numbers of total ova and transferable embryos in Hanwoo. More transferable embryos were collected at summer (5.6) than winter (2.9, p<0.01). The mean pregnancy rate was 40%. The pregnancy.ate was affected by transfer year (2001<2004, p<0.05) and transfer person ($33.0{\sim}41.9%$, p<0.01), while not by donor (embryo) breed. These results showed that in vivo embryo preduction and embryo transfer techniques using CIDR for Hanwoo and Jeju black cattle donors as well as recipient, regardless of their estrous cycle, may enable a stable embryo production and recipient preparation.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.608-615
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• 2015

Garlic (Allium sativum L.) has been used as both food and medicine in many cultures for thousands of years. Garlic cultivars are completely sterile and propagated through vegetative method. Collection of a large number of fertile accessions of these genus is needed to explore genetic variability. In order to investigate genetic variation among Allium species and its possibilities for direct cultivation in Korea, we characterized 12 accessions of A. longicuspis, flowering wild garlic which had collected from Central Asia, the main center of garlic diversity. Most of A. longicuspis accessions showed higher over-wintering and bolting rate, longer scape length and more number of bulbils than Korean landraces cultivar, Danyang and Euiseong, but A. longicuspis accessions exhibited smaller size of bulbs and bulbils. Most accessions of A. longicuspis had more number of cloves per bulb, except K229596 and K248824 than Korean landraces. All the accessions of A. longicuspis from Central Asia had complete bolters having many flowers and topsets in umbel. Further studies of A. longicuspis should focus on securing true seeds through removal of topsets and crosses among accessions to create the genetic variability.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.746-752
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• 2005

In this study, the effect of reaction parameters including reaction temperature, time, and pressure on sludge degradation and conversion to intermediates such as organic acids were investigated at low critical wet air oxidation(LC-WAO) conditions. Degradation pathways and a modified kinetic model in LC-WAO were proposed and the kinetics model predictions were compared with experimental data under various conditions. Results in the batch experiments showed that reaction temperature directly affected the thermal hydrolysis reaction rather than oxidation reaction. The efficiencies of sludge degradation and organic acid formation increased with the increase of the reaction temperature and time. The removal of SS at $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 10 min of reaction time were 52.6%, 68.3%, 72.6%, and 74.4%, respectively, indicating that most organic suspended solids were liquified at early stage of reaction. At $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 40 min of reaction time, the amounts of organic acids formed from 1 g of sludge were 93.5 mg/g SS, 116.4 mg/g SS, 113.6 mg/g SS, and 123.8 mg/g SS, respectively, and the amounts of acetic acid from 1 g of sludge were 24.5 mg/g SS, 65.5 mg/g SS, 88.1 mg/g SS, and 121.5 mg/g SS, respectively. This suggested that the formation of sludge to organic acids as well as the conversion of organic acids to acetic acid increased with reaction temperature. Based on the experimental results, a modified kinetic model was suggested for the liquefaction reaction of sludge and the formation of organic acids. The kinetic model predicted an increase in kinetic parameters $k_1$ (liquefaction of organic compounds), $k_2$ (formation of organic acids to intermediate), $k_3$ (final degradation of intermediate), and $k_4$ (final degradation of organic acids) with reaction temperature. This indicated that the liquefaction of organic solid materials and the formation of organic acids increase according to reaction temperature. The calculated activation energy for reaction kinetic constants were 20.7 kJ/mol, 12.3 kJ/mol, 28.4 kJ/mol, and 54.4 kJ/mol, respectively, leading to a conclusion that not thermal hydrolysis but oxidation reaction is the rate-limiting step.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.61-66
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• 2012

Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.10-10
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• 1981

The thyroglossal duct cyst is relatively rare disease that derived congenitally from the remnant of thyroglossal duct and that was found anywhere from the foramen cecum to pyramidal lobe of thyroid. We studied the 62 cases of above disease who admitted and operated at E.N.T. dept. of N.M.C. for 20 years since 1961 to 1980 on the clinical and histopathological aspect, and we concluded following results. 1. In the age distribution, 45 cases(72.6%) were under 20 years, and in the age distribution of the known on-set of symptoms, 26 cases(58.0%) were under 10 years. In the duration, 23 cases(37.0%) were under 1 year. The sex ratio of male to female revealed 1.2:1. 2. The palpable mass were complained at 48 cases(77.4%) and 14 cases(22.6%) complained of the discharge from sinus tracts and the other complaints were dysphagia and odynophagia, etc. 3. In location 55 cases (88.7%) were at midline, 1 case(1.6%) was at right and 6 cases(9.7%) were left sided. And 47 cases(75.8%) were situated at infrahyoid region, 11 cases(17.7%) at suprahyoid, 3 cases(4.8%) at suprasternal, only 1 case(1.6%) at intralingual region. 4. In 27 cases formed fistulae, spontaneous occurrance were 7 cases and artificial occurrance were 20 cases. 5. In histopathologically among 41 cases preserving available slides, 5 cases(12.2%) had single duct and 20 cases(48.8%) had multiple accessory ducts, but 16 cases were impossible to detect the ducts. The lining epithelium composed of chiefly respiratory and squamous epithelium. 15 cases had inflammatory reaction at periductal area and 7 cases had around the cysts. The ectopic thyroid tissue was found on 6 cases(14.6%) and 1 case had the follicular adenoma. 6. In the recurrance rate among 43 cases performed sistrunk type operation, 2 cases (4.6%) recurred, and among 19 cases performed simple removal of cysts, 4 cases (21.1%) recurred.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.100-114
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• 2018

Nationally designated Cultural Properties 'Scenic site No.12 Maisan Mountain, Jinan' designated areas and some protected areas, and taking into account the dynamics of naturalized plants causing problems, we will restore the original vegetation scenery of Mt. Maisan. The results of this study are as follows. A total of 76 families, 192 genera, 286 taxa, and inland and inhabited areas, 76 and 138 genera and 163 taxa were identified in the areas of Ammaibong. The total number of naturalized plants identified in this study area is 28 taxa total, which corresponds to 7.1% naturalization rate(NR) among the vascular plants of all 395 taxa, and the urbanization index(UI) corresponds to 8.4% of the 333 taxa of Korean naturalized plants. Ecosystem disturbance plants identified in the survey area were Ambrosia artemisiifolia 1 taxa. The naturalized plants controlled and managed by separate anthropogenic vegetation management within the designation and protection area of Maisan scenic place are three species of herbaceous Rumex acetosella, A. artemisiifolia and Festuca arundinacea. It was identified as a breed. Indigofera bungeana and F. arundinacea communities around the stairway and Amorpha fruticosa, I. bungeana, A. artemisiifolia and Amaranthus patulus of the top of Am-Maibong were selected as the first priority sites for exclusion of exotic species in Maisan area and target naturalized plants species to the Ammaibong peak. In addition, R. acetosella community around the temple was suggested to be removed first to preserve endemic species. For the restoration of vegetation, we suggest that Stephanandra incisa, Spiraea blumei, Weigela subsessilis, etc. should be planted after removal of I. bungeana, and F. arundinacea, C. lanceolata, Carex callitrichos var. nana.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.58-67
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• 2014

The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.353-361
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• 1998

Hypothermia is widely acknowledged as fundamental component of myocardial protection during cardiac operations. Although it prolongs the period of ischemic arrest by reducing oxygen demands, hypothermia is associated with a number of major disadvantages, including its detrimental effects on enzymatic function, energy generation, and cellular integrity. The ideal way to rotect the heart is to electromechanically arrest it and perfus it with blood that is aerobic arrest. However alternative technique has been developed, based on the principles of electromechanical arrest and normothermic aerobic perfusion using continuous warm blood cardioplegia. To determine if continuous warm blood cardioplegia was beneficial in clinical practice during valvular surgery, we studied two groups of patients matched by numbers and clinical characteristics. Group included is 31 patients undergoing valvular surgery who received intermittent cold crystalloid cardioplegia. Group II included 30 patients undergoing valvular surgery who received continuous warm blood cardioplegia. Our results suggest that the heartbeat in 100% of patients treated with continuous warm blood cardioplegia converted to normal sinus rhythm spontaneously after the removal of the aortic cross-clamp, compared to only 31% of the cold cardioplegia group. After operation, pericardial closure rate was 90% area in the warm group, compared to 35% area in the cold group. 12 hours after the operation, the total amount of urine output in the warm group was greater than that in the cold group(2863${\pm}$127 ml versus 2257${\pm}$127 ml; p<0.05). After the operation, left diaphragmatic elevation developed in 55% of the cold group but in 0% of the warm group. CK-MB level in the warm group was significantly lower than cold group(2.28${\pm}$0.62 versus 9.96${\pm}$2.12; p<0.01) 1 hour after operation and CK-MB level in the warm group was significantly lower than cold group(1.80${\pm}$1.01 versus 6.00${\pm}$1.74; p<0.05) 12hours after operation. Continuous warm blood cardioplegia is at least as safe and effective as hypothermic technique in patients undergoing cardiac valvular surgery. Conceptually, this represents a new approach to the problem of maintaining myocardial preservation during cardiac operations.

• Radiation Oncology Journal
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• v.23 no.2
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• pp.85-91
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• 2005

Purpose : This study was conducted to analyze treatment outcome and prognostic significance of World Health Organization (WHO)-defined thymic epithelial tumor (TET) subtype and to assess optimal radiation target volume in patients receiving surgery and adjuvant radiation therapy with TET. Materials and Methods: The record of 160 patients with TET, who received surgical resection at the Samsung medical Center, from December 1994 to June 2004, were reviewed. 99 patients were treated with postoperative radiation therapy (PORT). PORT was recommended when patients had more than one findings among suspicious Incomplete resection or positive resection margin or Wasaoka stage $II\~IV$ or WHO type $B2\~C$. PORT peformed to primary tumor bed only with a mean dose of 54 Gy. The prognostic factor and pattern of failure were analyzed retrospectively. Results : The overall survival rate at 5 years was $87.3\%$. Age (more than 60 years $77.8\%$, less than 60 years $91.1\%$; p=0.03), Wasaoka stage (I $92.2\%$, II $95.4\%$, III $82.1\%$, IV $57.5\%$; p=0.001), WHO tumor type (A-Bl $96.0\%$, B2-C $82.3\%$; p=0.001), Extent of resection (R0 resection $92.3\%$, R1 or 2 resection $72.6\%$, p=0.001) were the prognostic factors according to univariate analysis. But WHO tumor type was the only significant prognostic factor according to multivariate analysis. Recurrence was observed in 5 patients of 71 Masoka stage I-III patients who received grossly complete tumor removal (R0, R1 resection) and PORT to primary tumor bed. Mediastinal recurrence was observed In only one patients. There were no recurrence within irradiation field. Conclusion : WHO tumor type was the important prognostic factor to predict survival of patients with TET. This study suggest that PORT to only primary tumor bed was optimal. To avoid pleura- or pericardium-based recurrence, further study of effective chemotherapy should be investigated.

• Journal of Life Science
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• v.23 no.2
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• pp.197-206
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• 2013

The present study investigated whether leukemia-maintaining cells reside in a differentiation-resistant fraction using a megakaryocytic differentiation model of K562 cells. Treatment with phorbol-12-myristate-13-acetate (PMA) significantly inhibited the colony-forming efficiency of the K562 cells. At a PMA concentration of 1 nM or higher, colony was not formed, but approximately 40% of K562 cells still survived in soft agar. Approximately 70% of colony-forming cells that were isolated following the removal of PMA after exposure to the agent were differentiated after treatment with 10 nM PMA for 3 days. The differentiation rate of the colony-forming cells was gradually increased and reached about 90% 6 weeks after colony isolation, which was comparable to the level of a PMA-treated K562 control. Meanwhile, imatinib-resistant variants from the K562 cells, including K562/R1, K562/R2, and K562/R3 cells, did not show any colony-forming activity, and most imatinib-resistant variants were CD44 positive. After 4 months of culture in drug-free medium, the surface level of CD44 was decreased in comparison with primary imatinib-resistant variants, and a few colonies were formed from K562/R3 cells. In these cells, Bcr-Abl, which was lost in the imatinib-resistant variants, was re-expressed, and the original phenotypes of the K562 cells were partially recovered. These results suggest that leukemia-maintaining cells might reside in a differentiation-resistant population. Differentiation therapy to eliminate leukemia-maintaining cells could be a successful treatment for leukemia if the leukemia-maintaining cells were exposed to a differentiation inducer for a long time and at a high dose.