• 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.

• Journal of Chest Surgery
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• v.37 no.11
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• pp.897-902
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• 2004

Background: Although great concerns have been raised regarding the suitability of the use of the radial artery as a bypass conduit after transradial catheterization, there has been no studies that examined this issue in Korea. The purpose of this study was to compare clinical and angiographic results of radial artery grafting between patients with and without previous transradial catheterization. Material and Method: From January 2000 to February 2004, a total of 93 patients underwent coronary artery bypass grafting using the radial artery: 49 patients received preoperative transradial catheterization for coronary angiography (group I) and 44 patients did not (group II). These patients were retrospectively reviewed. Result: There was no significant difference in sex ratio, age, clinical diagnosis, risk factors, ejection fraction and early clinical outcomes between two groups. The graft patency rates in groups I and II were both 100% in the internal thoracic artery and in the radial artery, and 85% and 86% in the saphenous vein. respectively. The stenosis-free graft patency in groups I and II were 93% and 81% in the radial artery respectively but no statistical significance was shown. Conclusion: There was no significant difference in graft patency at postoperative coronary angiography between two groups. Radial artery graft after transradial catherization seems to be suitable for bypass conduit in short-term analysis.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.660-664
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• 2004

Background: Dilution of blood cardioplegia is not needed in IAWBC as it is in cold blood cardioplegia because it does not aggregate red blood cells on normal body temperature and does not compromise micro coronary circulation. This study was designed to evaluate the safety and efficacy of undiluted potassium solution in IAWBC. Material and Method: Thirty patients who underwent CABG with IAWBC were grouped into dilutedplegia (n=14) and microplegia (n=16). Potassium was delivered conventionally with 4 : 1 delivery kit in the dilutedplegia group. The undiluted potassium was directly connected on the blood of oxygenator in the microplegia group. Result: There were no differences in sex, age, left ventricular ejection fraction, number of grafts, aortic cross clamping time, and the value of perioperative myocardial enzyme between the two groups. There were no perioperative myocardial infarction and hospital mortality. The amount of crystalloid cardioplegia was 1346$\pm$597 mL in dilutedplegia (mean$\pm$standard deviation, and 28$\pm$9 mL in microplegia (p<0.0001). The hematocrit during cardiopulmonary bypass was 21$\pm$4% in dilutedplegia and 24$\pm$3% in microplegia (p>0.05). 11 patients in dilultedplegia received blood transfusion, but 4 patients in microplegia received blood transfusion (p<0.05). The amount of urine and hemofiltration during the operation were more in dilutedplegia (1250$\pm$810 mL, 1689$\pm$548 mL) than in microplegia (959$\pm$410 mL, 1461$\pm$784 mL; p<0.05). Conclusion: The undiluted potassium of IAWBC in CABG operation is a safe, effective technique for myocardial protection to prevent fluid overload, and blood transfusion. There is no need to use the delivery kit.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.446-454
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• 2017

Human papillomaviruses (HPVs) are major causes of cervical cancer. Sixteen high risk HPVs, including HPV 16, HPV 18, HPV31, HPV 33, HPV 35, HPV 39, HPV 45, HPV 51, HPV 52, HPV 53, HPV 56, HPV 58, HPV 59, HPV 66, HPV 68, and HPV 69 are found in cervical cancer. HPVs 16 and 18 are mainly presented in 70% of cervical cancer. Therefore, identifying the presence of these high-risk HPVs is crucial. The objective of this study is to establish the HPV ViroCheck for detecting 16 HR-HPVs and genotypes of HPVs 16 and 18, as well as to analyze the analytical performance of HPV ViroCheck. We performed the analytical sensitivity of HPV E6 / E7 genes of 16 high risk HPVs to confirm the limit of detection. Then, a cross reactivity of HPV ViroCheck with microorganisms and viruses related to the cervix were analyzed for analytical specificity. Analytical sensitivity of high risk HPV genotypes ranged from 1 to 100 copies when using cloned DNAs. The limit of detection was 10 cells for both SiHa and HeLa cells. Cervical-related microorganisms and viruses did not show cross-reactivity to HPV DNA. Moreover, the intra- and inter-assay coefficient variations (CVs) were below 5%. In conclusion, HPV Virocheck will be useful for the detection of 16 HR HPVs, as well as HPV 16 and HPV 18 genotypes rapidly.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.5-10
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• 2012

There is a still unsettled issue about the comparison of long-term clinical effects between sirolimus-(SES) and paclitaxel-eluting stents (PES) for the patients with acute myocardial infarction (AMI). Therefore, we performed a retrospective analysis to evaluate the 4-year clinical outcome of SES as compared with PES after percutaneous coronary intervention (PCI) in patients with AMI. From January 2004 to August 2006, all consecutive patients with acute ST-segment elevation myocardial infarction (STEMI) underwent primary PCI and acute NSTEMI underwent PCI by implantation either SES or PES were enrolled. The occurrence of death, cardiac death, recurrent infarction, target vessel revascularization (TVR) and stent thrombosis were analyzed. The composite of major adverse cardiac events (MACE; death, recurrent infarction and TVR) were also analyzed. During the study period, total 668 AMI patients had visited. Of them, total 522 patients (299 with SES and 223 with PES) were enrolled. During 4-year clinical follow-up, there were similar occurrences of death ($18.3{\pm}3.0%$ vs. $14.6{\pm}2.2%$, p=0.26), cardiac death ($11.2{\pm}2.6%$ vs. $6.8{\pm}1.52%$, p=0.39), re-infarction ($6.4{\pm}1.8%$ vs. $3.3{\pm}1.1%$, p=0.31), and stent thrombosis ($5.4{\pm}1.7%$ vs. $3.2{\pm}1.1%$, p=0.53) between the two groups, consecutively. The occurrences of TVR ($10.0{\pm}3.0%$ vs. $4.0{\pm}1.2%$, p=0.008) and MACE ($29.4{\pm}3.5%$ vs. $19.4{\pm}2.5%$, p=0.003) were significantly higher in patients treated with PES than SES. In AMI patients treated with either SES or PES implantation, SES had a significantly lower risk of TVR and MACE during 4-year clinical follow-up. Rates of death, cardiac death or recurrent infarction, and stent thrombosis were similar.

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.209-214
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• 2007

Background: Failed percutaneous transluminal coronary angioplasty (PTCA) is occasionally required for emergency coronary artery bypass grafting (CABG). The aim of this study was to assess the outcome of patients receiving emergency CABG after failed PTCA. Material and Method: Between May 1988 and May 2005, 5712 patients underwent PTCA, where 84 (1.4%) failed. 27 patients underwent emergency CABG after failed PTCA. The mean age was $63.7{\pm}8.9\;(46{\sim}80)$ years, with 14 male patients (51.9%). Result: All patients underwent emergent surgical revascularization within 6 hours. 22 patients underwent conventional CABG and 5 underwent off-pump CABG. The causes of PTCA failure were coronary obstruction due to new thrombi formation during the procedure (n=4), coronary dissection (n=17), coronary artery rupture (n=3) and 3 due to other causes. The rate of in-hospital operative mortality after emergent operation was 18.5% (5/27). A univariate analysis revealed that patients who died more often had left anterior descending artery disease, a preprocedural shock status, postoperative use of multiple isotropics and postoperative use of intra-aortic balloon pump. The mean follow up duration was $53.6{\pm}63.4$ months. Conclusion: Although PTCA is known to be life saving, there is still a high risk for morbidity and mortality following emergency CABG after failed PTCA, despite the advancement in PTCA techniques. This result will help identify and more effectively treat patients selected for PTCA when emergency CABG is required.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.307-327
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• 2008

Geochemical study on the rocks and minerals of the Gyeongju low and intermediate level waste repository was carried out in order to provide geochemical data for the safety assessment and geochemical modeling. Polarized microscopy, X-ray diffraction method, chemical analysis for the major and trace elements, scanning electron microscopy(SEM), and stable isotope analysis were applied. Fracture zones are locally developed with various degrees of alteration in the study area. The study area is mainly composed of granodiorite and diorite and their relation is gradational in the field. However, they could be easily distinguished by their chemical property. The granodiorite showed higher $SiO_2$ content and lower MgO and $Fe_2O_3$ contents than the diorite. Variation trends of the major elements of the granodiorite and diorite were plotted on the same line according to the increase of $SiO_2$ content suggesting that they were differentiated from the same magma. Spatial distribution of the various elements showed that the diorite region had lower $SiO_2,\;Al_2O_3,\;Na_2O\;and\;K_2O$ contents, and higher CaO, $Fe_2O_3$ contents than the granodiorite region. Especially, because the differences in the CaO and $Na_2O$ distribution were most distinct and their trends were reciprocal, the chemical variation of the plagioclase of the granitic rocks was the main parameter of the chemical variation of the host rocks in the study area. Identified fracture-filling minerals from the drill core were montmorillonite, zeolite minerals, chlorite, illite, calcite and pyrite. Especially pyrite and laumontite, which are known as indicating minerals of hydrothermal alteration, were widely distributed in the study area indicating that the study area was affected by mineralization and/or hydrothermal alteration. Sulfur isotope analysis for the pyrite and oxygen-hydrogen stable isotope analysis for the clay minerals indicated that they were originated from the magma. Therefore, it is considered that the fracture-filling minerals from the study area were affected by the hydrothermal solution as well as the simply water-rock interaction.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.81-86
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• 2013

'Mogwoo', a new high yield and whole crop silage rice (Oryza sativa L.) cultivar, was developed by the rice breeding team of the National Institute of Crop Science, RDA, Suwon, Korea, from 1999 to 2009, and was released in 2010. It was derived in 1999 from a cross between Dasanbyeo, having a high yield, and Suweon431/IR71190-45-2-1. A promising line, SR25848-C99-1-2-1, selected by the pedigree breeding method, was designated the name of 'Suweon 519' in 2007. This cultivar has about 155 days of growth period from seeding to heading, and is tolerance to lodging, with erect pubescent leaves as well as a long and thick culm. This cultivar has the same number of tillers per hill and higher spikelet numbers per panicle compared to Nokyang. 'Mogwoo' has longer leaves compared with other Tongil-type varieties. This new variety is resistant to grain shattering, leaf blast, bacterial leaf blight, and small brown planthopper. The biomass yield of 'Mogwoo' was 1,956 kg/10a in a regional test over three years. The result shows that 'Mogwoo' is adaptable to central and south-east plain areas of Korea.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.359-363
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• 2015

This study was conducted to investigate the differences in the physicochemical properties of organic and conventional milk from Chungnam and Jeonbuk, Korea. The milk was collected from 10 organic and 10 conventional milk farms in February, March and August, and then analyzed for milk composition, minerals and fatty acids. Organic milk showed lower fat (p<0.01) and total solid (p<0.05), but higher phosphorous (p<0.01) content than conventional milk. However, there was no difference in the content of lactose or the somatic cell count. Organic milk showed lower (p<0.01) stearic acid and total saturated fatty acid content, but higher (p<0.01) total, mono-, and poly-unsaturated fatty acid content. These results showed that organic and conventional milks differ mainly in their fat and unsaturated fatty acid content. Due to increasing consumer interest in food safety and health, organic milk, which contains more beneficial fatty acids, might be preferred over conventional milk.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.247-254
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• 2011

The agronomic characteristics, nutritional contents, and insect response of the potato clones transformed with a glufosinate ammonium resistance gene were evaluated. Among the 4 transgenic potato clones, the Bar 3 clone was selected as a promising one for commercialization. The Bar 3 clone showed similar tuber yield capacity but higher herbicide resistance as compared with the non-transgenic potato cv. Dejima. The herbicide resistance of the Bar 3 clone was more than 5 times higher when tested with the herbicide concentration recommended by the producer. The major agronomic characteristics of the Bar 3 clone were not different from those of the non-transgenic Dejima. The annual variation in yields and agronomic characteristics showed similar tendency for 2 years from the third to fourth generation after transformation. The tubers of the Bar 3 clone also showed low occurrence in common scab and physiological disorders such as cracking and secondary growth. But the reasons for such results are yet to be studied. Also, it was considered that the Bar 3 clone have a potential of reducing not only common scab occurrence but also soil erosion during potato cultivation in field. The nutritional contents (mineral compound, vitamin C and amino acid) and response to Spodoptera exigua of the transgenic potato clones were not significantly different.