• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.18-30
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• 2012

Objectives: The purpose of this study was to estimate the exposure level to extremely low frequency-magnetic fields (ELF-MF) among a selected Korean population using 24-hour personal exposure measurement. Methods: Participants were randomly selected for the measurement of MF exposure under the assumption that the subjects are representative of the overall Korean population. Levels of personal exposure to MF were measured according to the subject's daily activities. Results: The 24-hour time-weighted average (TWA) of 250 participants was $1.56{\pm}4.56$ mG (GM, GSD: 0.79, 2.46 mG). Personal exposure levels for females were higher than for males. The highest personal exposure level was shown in the age group between 20-60 years old. Personal exposure levels according to job category were higher for the non-occupational group than for the occupational group. Conclusions: Our results showed MF exposure exceeding 2 mG per day among 11.3% of the Korean population, indicating a somewhat higher percentage compared to the EMF RAPID Program's results for the U.S population.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.13-21
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• 2008

Final regulatory steps for commercialization of transgenic crops are risk assessment and variety registration. The risk assessment of transgenic crops requires broad network of scientists, high cost and long term. Developers of transgenic crops, therefore, face to additional challenges to consider theoretical and strategic aspects on risk assessment. The general concept for risk assessment of genetically modified organisms was derived from chemical risk assessment. Due to the complexity of organisms, however, comparative approaches that are substantial equivalence and familarity have been developed. In practical view, the integration of risk assessment is more difficult than the evaluation of each risk factors involving gene flow, toxicity and allergenicity. Variety registration of transgenic crops requires the results of risk assessment compared with non-GM crops and agronomic data analyzed with standard varieties. For economic and fast commercialization, risk assessment process should combined with condition of cultivation test for variety registration.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4215-4220
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• 2011

This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-${\alpha}$, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-${\alpha}$, which were bound to the immunologically captured TNF-${\alpha}$ on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 $ngmL^{-1}$ and showed good linearity up to TNF-${\alpha}$ concentrations as high as 2.0 ${\mu}gmL^{-1}$. The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.

• Journal of Yeungnam Medical Science
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• v.27 no.1
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• pp.57-62
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• 2010

Pulmonary alveolar proteinosis (PAP) is a rare disorder that's characterized by accumulation of surfactant components in the alveolar space. Idiopathic PAP is recognized as an autoimmune disease that's due to impaired alveolar macrophage function and this caused by autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). We report here a case of pulmonary alveolar proteinosis that was deemed interstitial lung disease at the initial diagnosis. A 61-year-old man presented with intermittent blood tinged sputum and dyspnea on exertion. The man was a painter for 30 years and he had a 10 pack-years smoking history. Chest computerized tomography (CT) revealed multifocal ground-glass opacity with interstitial thickening at both lungs. His pulmonary function tests and methacholine test revealed non specific results. He was diagnosed with interstitial lung disease on the basis of the chest CT finding and occupational history. However, seven months later, his symptoms progressed. Follow-up chest CT was performed. Wedge resection via video-assisted thoracoscopic surgery (the anterior basal segment of the left lower lobe) was done. Microscopic examination showed large groups of alveoli with excessive amounts of surfactant and a complex mixture of protein and lipid (fat) molecules. Finally, he was diagnosed as having pulmonary alveolar proteinosis.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.519-522
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• 1997

Buffalo heifers weighing from 400 - 500 kg and having a history of reproductive problems like anestrus, irregular estrus or failure to conceive after repeated inseminations were administered subcutaneously with estradiol-$17{\beta}$ and progesterone in two dosage rate 0.1 mg and 0.25 mg, respectively, per kg body weight per day for 7 days in experiment-I and 0.1 mg and 0.125 mg, respectively, per kg body weight per day for 7 days in experiment II. In experiment-I, 9 out of 10 buffaloes responded positively to the hormonal treatment. Milk secretion started between 14-20 days after the start of the treatment. The total milk yield in the successfully induced animals varied from 471.98-625.40 kg. The average daily milk yield varied from 2.08-2.76 kg and peak yield from 3.6-5.3 kg. The time taken to reach peak yield varied from 12-14 weeks. In experiment - II, the established lactation response was absent, although milk secretion process was initiated, the yield could not reach more than 50 - 100 gm at each milking. In experiment - I, the first estrus occurred between days 87 - 231 following the hormonal treatment. Four animals in which lactation was established successfully got pregnant after one or two services. In experiment - II the first estrus occurred between 85 - 173 days following the treatment and only one animal got pregnant.

• Biomedical Science Letters
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• v.9 no.1
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• pp.9-13
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• 2003

Currently bone biochemical markers are considered to be the best indicators of present and the future state of bone turnover. A recent study has reported that chlorella increases the bone mineral density (BMD) on postmenopausal women, but presently there are no studies on bone biochemical markers treated with chlorella dietary supplementation. The purpose of the present study was to assess the bone biochemical markers for the short term and long term treatment groups, and non-treatment group as a control. Twenty two postmenopausal woman were treated for four months and eighteen for one year with 4 gm of chlorella dietary supplementation per day, and then assessed bone biochemical markers from serum and urine samples. Bone turnover rates calculated with Osteocalcin (OC), bone specific alkaline phosphatase (BAP) as a bone formation markers and deoxypyridinoline (DP), cross-linked N-telopeptides of type I collagen (NTx) as a bone resorption markers, showed 1131$\pm$87% for control group, 61$\pm$11% for short term treated group and 190$\pm$101% for long term treated group. We conclude that chlorella dietary supplementation enhances the bone formation, and NTx as a single markers, OC/Dp as a single markers of bone turnover rate were very useful tools for determine the effectiveness of chlorella dietary supplementation (or the postmenopausal women.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.287-287
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• 2011

ITRS(international technology roadmap for semiconductors)에 따르면 MOS (metal-oxide-semiconductor)의 CD(critical dimension)가 45 nm node이하로 줄어들면서 poly-Si/SiO2를 대체할 수 있는 poly-Si/metal gate/high-k dielectric이 대두되고 있다. 일반적으로 metal gate를 식각시 정확한 CD를 형성시키기 위해서 plasma를 이용한 RIE(reactive ion etching)를 사용하고 있지만 PIDs(plasma induced damages)의 하나인 PICD(plasma induced charging damage)의 발생이 문제가 되고 있다. PICD의 원인으로 plasma의 non-uniform으로 locally imbalanced한 ion과 electron이 PICC(plasma induced charging current)를 gate oxide에 발생시켜 gate oxide의 interface에 trap을 형성시키므로 그 결과 소자 특성 저하가 보고되고 있다. 그러므로 본 연구에서는 이에 차세대 MOS의 metal gate의 식각공정에 HDP(high density plasma)의 ICP(inductively coupled plasma) source를 이용한 중성빔 시스템을 사용하여 PICD를 줄일 수 있는 새로운 식각 공정에 대한 연구를 하였다. 식각공정조건으로 gas는 HBr 12 sccm (80%)와 Cl2 3 sccm (20%)와 power는 300 w를 사용하였고 200 eV의 에너지로 식각공정시 TEM(transmission electron microscopy)으로 TiN의 anisotropic한 형상을 볼 수 있었고 100 eV 이하의 에너지로 식각공정시 하부층인 HfO2와 높은 etch selectivity로 etch stop을 시킬 수 있었다. 실제 공정을 MOS의 metal gate에 적용시켜 metal gate/high-k dielectric CMOSFETs의 NCSU(North Carolina State University) CVC model로 effective electric field electron mobility를 구한 결과 electorn mobility의 증가를 볼 수 있었고 또한 mos parameter인 transconductance (Gm)의 증가를 볼 수 있었다. 그 원인으로 CP(Charge pumping) 1MHz로 gate oxide의 inteface의 분석 결과 이러한 결과가 gate oxide의 interface trap양의 감소로 개선으로 기인함을 확인할 수 있었다.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.19-22
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• 1995

A biomechanical study was made to demonstrate the superior mechanical performance of the newly designed Miniplate staple to the conventional Coventry staple in high tibial osteotomy(HTO). Using twenty fresh porcine tibiae, the fixational strengh of the two different types of staple in HTO was compared. To minimize the error due to the specimen-to-specimen individuality, the bone mineral density of the tibiae was measured with a bone densitometry (Dual photon absorptionometer, Luner, USA) and those with $0.8\;{\sim}\;1.2\;gm/cm^2$ at the proximal tibia was used in the biomechanical test. Testing was performed on a material testing system (Autogram ET-5, Shimatzu, Japan) with aid of a commercial data processor (IBM 80386/ ASYST). Using two differant loading modes, 'pull-out' and 'push-out', the maximum resistant force required to release the staple from the substrate bone was recorded. In the pull-out test, ten non-osteotomized specimens were used and the staple was pullout by subjecting an axial tension on the head of the staple inserted. While in the pull-out test where ten tibiae osteotomized in the usual way of HTO were used, the staple was not directly loaded. In this testing, as a mimic condition of the natural knee, the distal part of the specimen tibia was pushed horizontally in order for the staple to be pulled out while the proximal tibia was fixed. The pull-out strength of Coventry staple and miniplate staple were found to be $27.88\;{\pm}\;5.12\;kgf$ and $182.47\;{\pm}\;32.75\;kgf$, respectively. The push-out strength of Coventry staple and miniplate staple were $18.40\;{\pm}\;4.47\;kgf$ and $119.95\;{\pm}\;19.06\;kgf$, respectively. The result revealed that miniplate staple had the pull-out/ push-out strength at least fivetimes higher than Coventry staple. Based on the measured data, it was believed that the newly designed miniplate staple could provide much better postoperative fixation in HTO. The postoerative application of long leg casting may not be needed after HTO surgery.

• Genomics & Informatics
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• v.13 no.3
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• pp.81-85
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• 2015

Molecular characterization technology in genetically modified organisms, in addition to how transgenic biotechnologies are developed now require full transparency to assess the risk to living modified and non-modified organisms. Next generation sequencing (NGS) methodology is suggested as an effective means in genome characterization and detection of transgenic insertion locations. In the present study, we applied NGS to insert transgenic loci, specifically the epidermal growth factor (EGF) in genetically modified rice cells. A total of 29.3 Gb (${\sim}72{\times}coverage$) was sequenced with a $2{\times}150bp$ paired end method by Illumina HiSeq2500, which was consecutively mapped to the rice genome and T-vector sequence. The compatible pairs of reads were successfully mapped to 10 loci on the rice chromosome and vector sequences were validated to the insertion location by polymerase chain reaction (PCR) amplification. The EGF transgenic site was confirmed only on chromosome 4 by PCR. Results of this study demonstrated the success of NGS data to characterize the rice genome. Bioinformatics analyses must be developed in association with NGS data to identify highly accurate transgenic sites.

• The Korean Journal of Physiology
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• v.5 no.1
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• pp.43-49
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• 1971

In an attempt to better understand the effect of whole body X-irradiation on the spontaneous motility of the isolated mouse duodenum and to clarify the possible radioprotective notion of reduced glutathione (GSH), a whole body X-irradiation of 1,000r was given to albino mouse either singularly or immediately after injecting GSH intraperitoneally to mouse in the dose of 1mg per gm of body weight. The total length of contraction of the isolated duodenum was recorded on kymograph every five minutes for 60 minutes, and the comparison was made with the control (i.e., normal). The results thus obtained are summarized as follows: 1. The spontaneous motility of the isolated duodenum in the X·irradiated groups showed a significantly elevated pattern for the first 15 minutes comparing with the control. The motility, however, decreased after 15 minutes and remained so in the X-irradiated groups to the level of the non-irradiated control, but 12 hours post-irradiation group showed a significantly increased motility throughout the experiment comparing with the control. 2. When GSH was injected intraperitoneally Prior to the whole body X·irradiation with 1,000r, the spontaneous motility of the isolated duodenum of mouse showed a significantly decreased pattern for the first 10 and 15 minutes comparing with the X·irradiated group followed by the similar motility thereafter comparing with the control and X-irradiated groups. 3. The above results suggest that GSH is effective as a radioprotector in terms of the motility of the isolated mouse duodenum.