• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.406-410
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• 2005

This study was conducted to establish the efficient protocols of the germination and cryopreservation of dehisced Korean ginseng seeds for long-term germ­plasm conservation. $GA_3$ and BA treated on seed for 24 hr facilitated germination at 5 and $10^{\circ}C$. Germination percentage of desiccated seeds was decreased under moisture content (MC) of below $7.2\%$. Dehisced ginseng seeds were dried under airflow of laminar floor cabinet and seed drying room. The high levels (more than $90\%$) of germination after cryogenic exposure were obtained after drying under vertical airflow of laminar floor for 12-30 hours (MC $10.6{\~}7.2\%$). Decrease in germination percentage of ginseng seeds due to desiccation damage and freezing injury was observed at MC of below $7.2\%$ and of above $12.1\%$, respectively. Therefore, MC of ginseng seeds need to be controlled with a range of $8{\~}10\%$ to avoid damages from both desiccation and freezing.

• Journal of fish pathology
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• v.18 no.1
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• pp.19-28
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• 2005

Scuticociliatosis has badly settled one of most damaging diseases during the seedling production process of olive flounder. Paralichthys olivaceus in Korea. We isolated a new type of Scuticociliate from flounder. The parasite metamorphoses to ciliate and cyst phases with each other by environmental changes and survive for a relatively long span. The ciliate was measured average 41.8 ${\mu}m$ in length and 21.0 ${\mu}m$ in width, and cyst was 17.0 ${\mu}m$ and 13.5 ${\mu}m$, respectively. Nutritional condition was determined as a major parameter of metamorphosing between ciliate and cyst stages. The ciliate transforms to a cyst stage because of food shortage, and the cyst returns to a ciliate stage with a favorite environmental condition and shows active growth and reproduction. The ciliate multiplied at the maximal density of $2.9 {\times} 10^5 {m\ell}^{-1}$cells in vitro cultivation at $15 ^{\circ}C$temperature using MS BHI medium and bacterial food sources. The ciliate could be proliferated at a 2.5 to $30 ^ \circ}C$ temperature range, pH 6 to 9, and 1 to 55 ppt salinity. Particularly, it survived over one week at $0 ^{\circ}C$temperature showing a high resistance against unfavorable environmental conditions. And the cyst survived for 320 days in the condition of $5 ^{\circ}C$with no feeding, but its survival period was markedly shortened in higher temperature conditions. The chemotherapeutants (formalin and hydrogen peroxide) were clarified as effective chemicals against the ciliate during in vitro trials, but the effect of therapeutants differed in proportion, depending upon the density and the bathing time of chemical compounds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.655-661
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• 1995

This study was conducted to get basic information of dry matter production and agronomic characteristics for increasing grain ripening in rice cultivar with large grains. Three cultivars which have different grain size were used. Of the two large grain cultivars, SR7796-3-1-5-1-l(SR7796F$_{7}$) had long culm and SR11269-13-3-4-2(SR11269F$_{6}$) had short culm. On the other hand, Tamjinbyeo was recommended cultivar had medium size of grain and culm. LAI was highest in Tamjinbyeo, followed by the SR11269F$_{6}$ and SR7796F$_{7}$, LAI decrement was higher in large grain cultivars than that of Tamjinbyeo after 20days after heading. Total dry weight(TDW) of areal part was highest in SR11269F$_{6}$, followed by the Tamjinbyeo and SR7796F$_{7}$. Dry weight (DW) of stem (leaf sheath+culm) at harvesting stage was decreased 15%, 12% in Tamjinbyeo, SR11269F$_{6}$, respectively, but was increased 5% in SR7796F$_{7}$ compared to heading stage. In distribution rate of each organ to TDW, distribution rate of leaf blade was low in large grain cultivar, but that of stem in Tamjinbyeo, SR7796F$_{7}$ and SR11269F$_{6}$ was 36%, 38% and 42%, respectively. In canopy architecture leaf blade weight was the highest 30~40cm, 40~50cm and 70~8Ocm above the ground in SR11269F$_{6}$, Tamjinbyeo and SR7796F$_{7}$, respectively. Range of panicle distribution in the canopy was 40cm in Tamjinbyeo, and was 70cm in large-grain cultivars. The results suggest that it has to take a growing interest in developing culture method for increasing LAI during growth stage, especially, around heading, in keeping green leaf till ripening stage and also in growing unformly plant within rice hill in large grain cultivars.cultivars.ltivars.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.198-208
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• 2006

This research was to apply a multi-metric approach, so called the Index of Biological Integrity (IBI) as a tool for biological evaluations of water environments, to a wadable stream. For the study, we surveyed 5 sampling locations in Kap Stream during August 2004 ${\sim}$ September 2005. We also compared the biological data with long-term water quality data, obtained from the Ministry of Environment, Korea and physical habitat conditions based on the Quantitative Habitat Evaluation Index (QHEI). We used ten metric systems for the IBI model to evaluate biological stream health. Overall IBI values in Kap Stream averaged 24 (range: 20${\sim}$30, n=5), indicating a "fair ${\sim}$ poor" conditions according to the modified criteria of Karr (1981) and US EPA(1993). Exclusive of 4th survey, average IBI values at the upstream reach (S1 ${\sim}$ S3)and downstream reach (S4 ${\sim}$ S5) were 20 and 24, respectively. However, in 4th survey the averages were 21 and 20 in the upstream and downstream reaches, respectively. This difference was larger in the upstream than in the downstream because of physical condition disturbed during summer monsoon. Values of the QHEI varied from 75(fair condition) to 148 (good condition) and values of QHEI in the S3 were significantly (P=0.001, n=5) lower than other sites. Biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were greater by 3 ${\sim}$ 8 fold in the downstream than in the upstream reach. We believe that present IBI approach applied in this study may be used as a key tool to set up specific goals for restoration of Kap Stream.

• Geophysics and Geophysical Exploration
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• v.1 no.2
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• pp.127-135
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• 1998

The Born approximation is widely used for solving the complex scattering problems in electromagnetics. Approximating total internal electric field by the background field is reasonable for small material contrasts as long as scatterer is not too large and the frequency is not too high. However in many geophysical applications, moderate and high conductivity contrasts cause both real and imaginary part of internal electric field to differ greatly from background. In the extended Born approximation, which can improve the accuracy of Born approximation dramatically, the total electric field in the integral over the scattering volume is approximated by the background electric field projected to a depolarization tensor. The finite difference and elements methods are usually used in EM scattering problems with a 2D model and a 3D source, due to their capability for simulating complex subsurface conductivity distributions. The price paid for a 3D source is that many wavenumber domain solutions and their inverse Fourier transform must be computed. In these differential equation methods, all the area including homogeneous region should be discretized, which increases the number of nodes and matrix size. Therefore, the differential equation methods need a lot of computing time and large memory. In this study, EM modeling program for a 2D model and a 3D source is developed, which is based on the extended Born approximation. The solution is very fast and stable. Using the program, crosshole EM responses with a vertical magnetic dipole source are obtained and the results are compared with those of 3D integral equation solutions. The agreement between the integral equation solution and extended Born approximation is remarkable within the entire frequency range, but degrades with the increase of conductivity contrast between anomalous body and background medium. The extended Born approximation is accurate in the case conductivity contrast is lower than 1:10. Therefore, the location and conductivity of the anomalous body can be estimated effectively by the extended Born approximation although the quantitative estimate of conductivity is difficult for the case conductivity contrast is too high.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.165-175
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• 2018

The purpose of this study is to provide the basic data such as distribution status, growth characteristics, and the structural characteristics of forest stands for the systematic conservation and management of relict forest trees (stem girth of 300cm or larger) established naturally in Gangwon Province, Korea. The survey showed that 434 individuals of 19 species (conifers: 228 individuals of 4 species, broad-leaved trees: 206 individuals of 15 species) were distributed in Gangwon Province, and Taxus cuspidata was the most abundant among them with 203 individuals or about 46.7 % of the total. The stem girth was average of 404cm (conifers: 373cm, broad-leaves: 421cm), and Tilia amurensis with multi-stemmed growing on Sorak mountain range had the largest stem girth at 1,113cm. The average height and the crown width of relict forest trees were 15.4m and 10.0m, respectively. Although the environments of relict forest trees showed a slight difference by species, the relative appearance frequencies of most trees were high in the environments where the altitude was higher than 1,000 m, slope degree was greater than $25^{\circ}$, the slope faced north, and microtopography was at the upper of slopes. Regarding the stand characteristics of relict forest trees per unit area ($/100m^2$), the average total coverage was 294% (max. 475%), the total average number of species was 36 species (max. 60 species), the average species diversity index (H') was 2.560 (max. 3.593), the average canopy closure was 84.8% (max. 94.6%), and the average basal area (/ha) was $52.7m^2$ (max. $116.4m^2$, relict trees $30.0m^2$, and other trees $22.7m^2$). The analysis of the dynamics of the forest stands where relict forest trees were growing showed four types of the maintenance mechanisms of relict forest trees depending on the supply pattern of succeeding trees: "Low-density but persistent type (Quercus mongolica, Abies holophylla, Tilia amurensis, and Pyrus ussuriensis)," "Long ago stopped type (Pinus densiflora)," "Recently stopped type (Abies nephrolepis, Quercus variabilis, and Betula schmidtii)," and "Periodically repeated types of supply and stop (Salix caprea and Quercus serrata).".

• Journal of Chest Surgery
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• v.36 no.11
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• pp.812-819
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• 2003

Background: Left ventricular dysfunction is one of the important prognostic factors of early mortality and long-term survival after valve operation. We studied the intermediate term results of mitral valve reconstruction in patients with moderate to severe left ventricular dysfunction. Material and Method: Forty four patients who underwent mitral valve reconstruction with a left ventricular ejection fraction (EF) of <45% or less (20∼45%) from April 1995 through July 2001 were reviewed retrospectively. Ages ranged from 10 to 67 years (46∼14 years) and 32 patients were in NYHA class III-IV. The mitral valve diseases were regurgitation (MR) in 28 patients, stenosis(MS) in 10, and mixed lesion in 5. The etiologies of mitral valve disease were rheumatic in 20 patients, degenerative in 14, ischemic in 5, annular dilatation in 2, congenital in 2, and endocarditis in 1. Operatively, all patients had annuloplasty and/or various valvuloplasty techniques, and a total of 52 procedures were concomitantly performed. Total cardiopulmonary bypass and aortic crossclamp time were 160$\pm$57 minutes and 112$\pm$45 minutes respectively. Result: Two operative deaths occurred as a result of left ventricular failure (4.5%). After the mean follow-up of 39 months (range, 10∼83 months), there was no late death. Transthoracic echocardiography revealed no or grade I of MR in 29 patients (72.5%) and no or mild MS in 35 patients (87.5%). The actuarial survival at 5 years was 100%. Four patients required mitral valve replacement due to progressive mitral valvular disease. The actuarial freedom from valve-related reoperation at 5 years was 84$\pm$9%. Conclusion: This study suggests that mitral valve reconstruction in patients with moderate to severe left ventricular dysfunction offers good early and intermediate survival and acceptable freedom from valve-related reoperation, and it is the strategy for effective management for these patients.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.229-236
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• 2008

Purpose: The purpose of this study was to evaluate the impact of the use of external radiation therapy (ERT) in terms of survival and compliance in patients with anaplastic thyroid carcinoma. Materials and Methods: The medical records of 17 patients with anaplastic thyroid carcinoma treated with ERT between 1993 and 2002 were retrospectively reviewed. ERT was administered after surgery in 14 patients and after a biopsy in three patients. Among the 14 patients who had undergone surgery, nine underwent a curative resection and five underwent a palliative resection. Six patients had associated well-differentiated thyroid carcinomas and 14 patients were diagnosed with a tumor size exceeding 5 cm. The radiation dose ranged from $6{\sim}70\;Gy$ (median dose, 37.5 Gy). Eleven patients completed the planned course of ERT, whereas six patients did not. The follow-up period ranged from $1{\sim}104$ months (median, 5 months; mean, 20 months). Results: Five patients started the ERT without the presence of a gross mass and all of the patients competed ERT without a re-growth of tumor. Twelve patients (four patients after a curative resection, five patients after a palliative resection and three patients after a biopsy) started ERT with a gross mass present and only six patients were able to complete the planned course of ERT. Among the six patients who completed ERT, two patients showed a marked regression of the tumor mass, whereas two patients showed slight regression and two patients showed no response. The median survival was five months (range, $1{\sim}104$ months) and the mean survival was 21 months. The overall survival was 41% at 1-year, 24% at 2-years and 12% at 5-years. Significant prognostic factors included the number of primary tumors present, tumor size, whether surgery was performed and completion of ERT as planned. Long-term survivors showed a tendency of having smaller sized initial tumors and smaller sized pre-ERT tumors than the short-term survivors. Conclusion: This study suggests that patients with a small initial tumor (${\leq}5\;cm$), which was treated by surgery (curative resection or palliative resection) before ERT, and without rapid re-growth of the mass seen at the surgical site at the beginning of the ERT course, would be the best candidates for postoperative ERT. In contrast, patients with a large initial tumor (>5 cm) and did not undergo surgery before ERT or that rapid re-growth of the mass was observed at the surgical site are likely to have a short survival time, along with the interruption of ERT. In these cases, the role of ERT is very limited and the omission of ERT could be considered.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.163-171
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• 1995

Purpose: Primary radiation therapy following breast-conserving surgery has been an accepted alternative to mastectomy during the past 2 decades. In this country, however, the practice of conservative therapy for early invasive breast cancer has not been generalized yet. The purpose of this report was to evaluate the results and complications of breast conservation therapy in Korean Cancer Center Hospital(KCCH). Materials and Methods: From January 1987 to December 1989. 45 Patients with early breast cancer treated with conservative treatment in KCCH were studied retrospectively Median follow up was 54 months(range, 4 to 82 months) . All patients received partial mastectomy (biopsy, tumorectomy. or quadrantectomy) and radiation therapy. Twenty eight patients received axillary dissection The breast was treated with two opposing tangential fields (total 50 Gy or 50.4 Gy in 5 weeks with daily target dose of 2 Gy or 1.8 Gy) Thirty patients received chemotherapy before and after radio-therapy Eleven patients received hormonal therapy. Results: Five-year survival rate, 5-rear disease free survival rate and 5-year local control rate were 87.2%, 86.5% and 97.6%,$ respectively. Administration of systemic Therapy (chemotherapy or hormonal therapy) correlated with good prognosis but statistically not significant (0.05 < p < 0.1). The severe late complication rate was 8.9% Conclusion: Primary radiation therapy following breast-conserving surgery for early breast cancer is an alternative treatment comparing to radical treatment. Long term follow-up and more patients collection is needed to evaluate the Prognostic factor and cosmetic outcome.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.364-372
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• 2010

Purpose : Good adherence of caregivers is essential for successful health outcomes in the treatment of childhood asthma. The purpose of this study was to identify the factors contributing to good adherence of maintenance treatment in children with well-controlled asthma. Methods : Children with well-controlled asthma being treated with a daily controller for at least 3 months in Korea University Anam Hospital were selected. Their caregivers who had good adherence to maintenance treatment were recruited. Qualitative study through in-depth interviews was conducted with 18 caregivers who agreed to the study. Results : The 18 caregivers (mean age, 40.0 years) consisted of 15 mothers, 2 grandmothers, and 1 father. The resulting consensus were identified and grouped into 2 domains: the caregiver/patient aspect with 8 theme factors and the treatment aspect with 4 theme factors. The main theme factors in the caregiver/patient aspect were enabling participation in physical activities and exercise (77.8%), perceptions regarding asthma and the need for long-term treatment (50.0%), and perceived value of the medications outweighing the risk of side effects (38.9%). The main theme factors in the treatment aspect were trust in the physician (77.8%), general satisfaction with the manner and attitude of the physician (77.8%) and verification of the necessity of further treatment by performing tests (38.9%). Conclusion : Efforts to improve caregivers' adherence to the treatment of childhood asthma must include a range of factors related to both caregiver/patient aspects and treatment aspects. Among all of these factors, it may be most important to establish a physician-caregiver partnership.