• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.289-296
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• 2001

The main objective of this topic is to establish strategies and to plan biotechnology researches which are related to the agricultural improvements especially focusing on the crop breeding in Korea. From 1960's to 1980's government policy had been emphasized to develope high yielding cultivars for the self sufficient supply of the staple food crops. As a result, considerable increase of rice production has been made with accumulating technology and man's powers. Recently genetically modified crops harboring useful characteristics have been developed using biotechnology and released in the developed countries. National research institutes and private companies have been developed biotechnology researches to establish competitive capabilities, however they have not been successfully used in commercialization. Therefore it is necessary to promote the practical. application by connecting molecular technology with conventional breeding. Proposed research projects are; (1) basic researches including plant genome studies, (2) developing new cultivars through gene transformation, (3) screening and producing antioxidants, secondary metabolite substances and edible vaccines. To set a government policy, both domestic and international research trends were reviewed and possibility of success based on the economic view point were discussed. The intellectual property and preservation of environment play a key role to decide the research priority. It is also necessary for us to make one step system for the distribution of research resources such as microorganisms, genes cloned, plant seeds and research informations for promoting research activities.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.201-210
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• 2000

Purpose : We observed response to PPD skin test and local side reactions among subjects who received inoculation with Tokyo 172 BCG strain by percutaneous method using multiple puncture device. Methods : 138 infants and young children were enrolled at Yongdong Severance Hospital and 7 private clinics. 5TU PPD skin test were performed at 4 months after inoculation. The local reactions at multiple puncture site were observed in 3 days, 4~6 weeks, 36 weeks, and 48 weeks after inoculations and physical check up was done for evaluation of lymphadenopathy. Results : During 48 weeks of observation period, 96 subjects among 138 who were enrolled were followed up completely with records of PPD skin test and observation of local side reactions, presenting with the photos. The size of the induration after 48 hours of PPD skin test, was less than 5mm in six subjects(6.3%), greater than 10mm in sixty seven subjects(70.0%) and greater than 12mm in forty six subjects(47.9%). All subjects showed inflammatory reaction and pustules at multiple puncture sites and only just small papules, ulcer and pustules remained 4-6 weeks later. Eight to twelve weeks later, all local inflammatory skin reactions disappeared with remaining crust. After 48 weeks, 4(4.2%) subjects showed no scar with only faint stain on the puncture site. More than 70% of subjects showed more than 10 faint pin-point scars on the sites. However, the size of scar was clearly smaller compared to that of intradermal inoculation. There were no cases of lymphadenopathy. Conclusion : We observed good immune response to 5TU PPD skin test among the infant and young children who were immunized with percutanous inoculation of Tokyo 172 BCG strain. We could not find any severe local scar at inoculation sites. A degree of satisfaction of the parents whose children received the percutaneous injection was very high.

• Pediatric Infection and Vaccine
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• v.12 no.1
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• pp.52-60
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• 2005

Purpose : The aim of this study is to know seasonal distribution of group A streptococci obtained from one center using emm genotyping and T serotyping in Masan from 2003 through 2004. Methods : Among children who visited the Changwon Fatima Hospital at Masan, Korea from June 2003 through February 2004, 100 patients who had clinical findings of acute pharyngitis, scarlet fever, and cellulitis were confirmed as GAS by culture, and were enrolled in our study. All obtained GAS were sent to the WHO Collaborative Center for Reference and Research on Streptococci, University of Minnesota, Minneapolis for T serotyping and emm genotyping. We classified these results again according to seasonal and disease's entities. Results : 19 different T serotypes was typed. T4(27.5%), T1(17.6%), T6(13.7%), and T12(13.7%) serotypes were relatively common in summer, while T4(28.3%), T12(15.2%), and T12/B3264(8.7%) were common in winter. T4 and T12 were persistent all year around. Distribution of T serotypes in 89 patients with pharyngotonsillitis were T4(26.7%), T12(14.0%), T1(12.8%), and T6(11.6%) in order of frequency. 15 different emm genotypes was typed. The number of emm 1, emm 6, emm 9, and emm 44 genotypes decreased or disappeared in winter, and the number of emm 3, emm 12, and emm 89 genotypes increased or reappeared in winter. Conclusion : Because T serotyping and emm genotyping are useful tools for evaluating epidemiology and pathogenesis of group A streptococci, we should monitor these strains every year, and should serotype and genotype GAS obtained from the invasive streptococcal infections.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Research in Plant Disease
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• v.17 no.1
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• pp.66-74
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• 2011

In 2005, a survey was conducted to identify virus diseases on victory onion, Allium victorialis var. platyphyllum grown in Ulleung island located in the East Sea. A total of 61 samples were collected from victory onion in the neighborhood of Seonginbong. The identification of viruses from the samples were carried out by electron microscopy and RT-PCR using primers species specific to GCLV, LYSV, SLV, OYDV and genus specific to Allexivirus, respectively. From sixty-one samples, filamentous rod particles (600-900 nm) were detected from four victory onion samples in EM, three samples containing SLV and one sample containing both SLV and Allexivirus in RT-PCR analysis, respectively. Victory onions naturally infected by the viruses were asymptomatic apparently. The viruses detected by RT-PCR were further characterized by the nucleotide sequence analysis of the coat protein region. Three isolates of SLV showed approximately 99% identities in the nucleotide and amino acid sequences, suggesting that they were likely to be the same strain. On the other hand, they showed approximately 75.7~83.7% identities in the nucleotide and 89.2~97.0% in amino acid sequences compared with the previously reported SLV isolates in Allium. The CP gene of the Allexivirus showed approximately 99.2% nucleotide identities and 98.8% amino acid identities with Garlic virus A. However, there was relatively low homology ranging from 60.6% to 81.5% compared with other Allexiviruses (GarV-C, GarV-E, GarV-X, GMbMV, and Shal-X). These data suggested that two viruses, SLV and GarV-A identified from victory onion, are named SLV-Ulleungdo and GarV-A-Ulleungdo, respectively. This is the first report of viruses infecting victory onion.

• Research in Plant Disease
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• v.17 no.1
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• pp.38-43
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• 2011

Almost 10~30% of vegetables were discarded by the spoilage from farms to tables. After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. This investigation was conducted to extent the knowledge of relationship the spoilage of vegetables and the diversity of microbes. The total aerobic bacterial numbers in fresh lettuce, perilla leaf, and chicory were $2.6{\sim}2.7{\times}10^6$, $4.6{\times}10^5$, $1.2{\times}10^6\;CFU/g$ of fresh weight, respectively. The most common bacterial species were Pseudomonas spp., Alysiella spp., and Burkholderia spp., and other 18 more genera were involved in. After one week of incubation of those vegetables at $28^{\circ}C$, the microbial diversity had been changed. The total aerobic bacterial numbers increased to $1.1{\sim}4.6{\times}10^8$, $4.9{\times}10^7$, and $7.6{\times}10^8\;CFU/g$ of fresh weight for lettuce, perilla leaf, and chicory that is about $10^2$ times increased bacterial numbers than that before spoilage. However, the diversity of microbes isolated had been simplified and fewer bacterial species had been isolated. The most bacterial population (~48%) was taken up by Pseudomonas spp., and followed by Arthrobacter spp. and Bacillus spp. The spoilage activity of individual bacterial isolates had been tested using axenic lettuce plants. Among tested isolates, Pseudomonas fluorescence and Pantoea agglomerans caused severe spoilage on lettuce.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.461-467
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• 2005

Pleura, diaphragm, pericardial fat pad, intercostal muscles and omentum can be used to protect and revascularize the bronchial suture line of tracheal transplantation, lung transplantation and pulmonary resection. The purpose of the present study is to compare the influence of the pleura, diaphragm and omentum in survival of isolated tracheal segments in the experimental animals. Material and Method: Sprague-Dawley rats weighing 250- 350g were used. The animals were divided in three groups; the pleura, omentum and diaphragm. Following intraperitoneal anesthesia, endotracheal intubation was performed. Then the trachea was exposed. A three-ring sec- tion of cervical trachea was excised. The resected trachea was implanted at each sites. After 2 weeks, rats were sacrificed. Histopathological examination of the tracheal segments was performed. For comparison of each groups, histopathological viability of resected tracheal segment was scored by three tissue layers; epithelium, submucosa, and cartilage. The results were presented as average score. Result: In histopathological examination, submucosa and cartilage using tracheal segment necrosis scoring system. The pleural group showed well preserved tissue. There was minimal necrosis and inflammation compared with other groups. In the pleural group, tracheal necrosis scores were $2.17\pm0.983$at epithelium, $1.67\pm0.516$ at submucosa and $2.17\pm0.753$ at cartilage. At the omental group, scores were $1.00\pm0.00,\;1.60\pm0.548\;and\;1.80\m0.447$. In the diaphragmatic group, scores were $1.40:\pm0.894,\;2.40\pm0.547\;and\;2.20\pm0.447$. Total necrosis score were $6.00\pm1.789$ in the pleural group, $4.40\pm0.894$ in the omental group and $6.00\pm1.414$ in the diaphragmatic group. Conclusion: There were no significant viability differences in terms of total necrosis score for the viability of resected tracheal segment. But the best result was achieved in the omental group. Therefore, omental wrapping on tracheal graft site will be beneficial for the prevention of graft necrosis.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.1-10
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• 2004

Background: Currently, the cardiopulmonary machine with non-pulsatile pumps, which are low in internal circuit pressure and cause little damage to blood cells, is widely used. However, a great number of experimental studies shows that pulsatile perfusions are more useful than non-pulsatile counterparts in many areas, such as homodynamic, metabolism, organ functions, and micro-circulation. Yet, many concerns relating to pulsatile cardiopulmonary machines, such as high internal circuit pressure and blood cell damage, have long hindered the development of pulsatile cardiopulmonary machines. Against this backdrop, this study focuses on the safety and effectiveness of the pulsatile cardiopulmonary machines developed by a domestic research lab. Material and Method: The dual-pulsatile cardiopulmonary bypass experiment with total extracorporeal circulation was conducted on six calves, Extracorporeal circulation was provided between superior/inferior vena cava and aorta. The membrane oxygenator, which was placed between the left and right pumps, was used for blood oxygenation. Circulation took four hours. Arterial blood gas analysis and blood tests were also conducted. Plasma hemoglobin levels were calculated, while pulse pressure and internal circuit pressure were carefully observed. Measurement was taken five times; once before the operation of the cardiopulmonary bypass, and after its operation it was taken every hour for four hours. Result: Through the arterial blood gas analysis, PCO2 and pH remained within normal levels. PO2 in arterial blood showed enough oxygenation of over 100 mmHg. The level of plasma hemoglobin, which had total cardiopulmonary circulation, steadily increased to 15.87 $\pm$ 5.63 after four hours passed, but remained below 20 mg/㎗. There was no obvious abnormal findings in blood test. Systolic blood pressure which was at 97.5$\pm$5.7 mmHg during the pre-circulation contraction period, was maintained over 100 mmHg as time passed. Moreover, diastolic blood pressure was 72.2 $\pm$ 7.7 mmHg during the expansion period and well kept at the appropriate level with time passing by. Average blood pressure which was 83$\pm$9.2 mmHg before circulation, increased as time passed, while pump flow was maintained over 3.3 L/min. Blood pressure fluctuation during total extracorporeal circulation showed a similar level of arterial blood pressure of pre-circulation heart. Conclusion: In the experiment mentioned above, pulsatile cardiopulmonary machines using the doual-pulsatile structure provided effective pulsatile blood flow with little damage in blood cells, showing excellence in the aspects of hematology and hemodynamic. Therefore, it is expected that the pulsatile cardiopulmonary machine, if it becomes a standard cardiopulmonary machine in all heart operations, will provide stable blood flow to end-organs.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.233-242
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• 2010

This study was conducted to know that if ionic liquids can be applicable as control agents of harmful algae in water-ecosystem and to find out problems caused by ionic liquid application. Firstly, the differential selectivity of various fresh-water algal species to several 1-alkyl-3-methylimidazolium chloride ionic liquids was investigated. There was a distinct differential response between alkyl chain lengths from butyl to dodecyl and towards the algal organisms : Generally algicidal activity was increased with increase of chain length and among the algae used in this study, Stephanodiscus hantzschii f. tenuis, Oscillatoria tenuis and Spirulina pratensis were most sensitive to 1-dodecyl-3-methylimidazolium chloride (MAIC12), next was Microcystis aeruginosa, and the others were relatively less sensitive to the chemical. The selectivity degree was about ten to twenty times based on the $EC_{80}$ (Effective concentration required for 80% growth inhibition). Secondly, an activity persistence of ionic liquids was investigated in natural mimic condition (using water bottle containing soil-sediments under the greenhouse condition). At the application of $1.0{\mu}g\;mL^{-1}$ of 1-octyl-3-methylimidazolium chloride (MAIC8), the algal growth did not occur at all until 6 days after treatment(DAT) and observed a only little growth at 9 DAT. But the algae grew rapidly after 9 DAT. So at 20 DAT, total chlorophylls was $264.4{\mu}g\;L^{-1}$ and the growth was inhibited by 58.2% compared to untreatment. On the other hand, MAIC12 also had a similar persistence pattern to MAIC8, showing nearly 5 times more activity than MAIC8. At 20 days after $0.2{\mu}g\;mL^{-1}$ application of MAIC12, that is, total chlorophylls was $251.2{\mu}g\;L^{-1}$ and the growth was inhibited by 55.2% compared to untreatment. In summary, 1-alkyl-3-methylimidazolium chloride ionic liquids is likely to be applicable for selective control of harmful algae as potent compounds having long lasting activity. However, the difficulty of degradation seems to be a limiting factor in an eco-friendly application of the compounds.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.242-247
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• 2013

Currently, methods for controlling weeds in organically produced crops have not been as effective as conventional methods. This research was carried out to determine the herbicidal effects of leaf, stem, fruit, root extracts of Trichosanthes kirilowii. The extraction methods used were water, boiling water and ethanol. The characteristics of potential herbicidal components among extraction methods were investigated by using the following solvent fractions: hexane, chloroform, ethyl acetate, butanol, and water. Generally, water extracts provided the best on inhibition of germination rate, plant height, and root length in cucumber and barley. Specifically, extractions made from fruit parts of T. kirilowii provided the greatest inhibition effect on plant growth in cucumber and barely. Inhibition of germination rate, plant height, and root length in cucumber and barley in solvent fractions was the best in water fractions, but there were no significant differences among the other fractions. Digitaria siliaris and Solanum nigrum were controlled 80-100% by 5% extractions of water fraction. However, there were no herbicidal effects from foliar treatment in cucumber, barley, black nightshade, and henry crabgrass by 5% extractions of the water fraction. These results show that extractions of T. kirilowii can be used for controlling some weeds in organically produced crops.