• Polymer(Korea)
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• v.33 no.1
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• pp.26-32
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• 2009

The aim of this research was to prepare microparticulate systems based on poly (lactide-co-glycolide)(PLGA) for the local release of ipriflavone in order to reduce bone loss. We developed the IP loaded PLGA microspheres using relatively simple oil-in-water(O/W) solvent evaporation method. HPLC was used to perform the in vitro release test of IP and morphology of cell attached on the micro-spheres was investigated using SEM. Cytotoxicity was assayed by cell counting kit-8 (CCK-8) test. Osteogenic differential cells were analyzed by ALP activity. Through RT-PCR analysis, we observed osteocalcin, ALP, and Type I collagen mRNA expression. The release of IP in vitro was more prolonged over 42 days and IP/PLGA microspheres showed the improvement on the cell proliferation, ALP activity and RT-PCR comparing with control (only PLGA). This initial research will be used to direct future work involved in developing this composite injectable bone tissue engineering system.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.135-144
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• 2009

The purpose of this study is to develop a simple and rational crack evaluation system using Marshall tester. Fracture energy were used as a parameter to evaluate the crack resistance of asphalt mixtures. Marshall tester basically measures the vertical deformation obtained from the linear variable differential transformer(LVDT) attached on the specimen's exterior, which can cause a measurement error due to the local deformation near the loading head. Therefore, the validity of the measurement system of Marshall tester should be tested to use it in calculation of fracture energy. Two types of indirect tensile strength tests were performed using four types of asphalt mixtures at two temperature conditions. From the tests, it was shown that local deformation near the loading head had not occurred before a specimen was fractured, so that it did not cause the measurement error of fracture energy. And also from the statistic analysis, the coefficient of variation of vertical deformation measurements obtained on specimen's exterior is less than 15%. Thus, vertical deformation measurements obtained on the specimen's exterior can be used in crack evaluation system using Marshall tester.

• Journal of Life Science
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• v.22 no.3
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• pp.417-427
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• 2012

We compared the transcriptome in response to propanol stress in wild-type and propanol-resistant mutant Escherichia coli using the DNA microarray technique. The correlation value of RNA expression between the propanol-treated wild type and the untreated-one was about 0.949, and 50 genes were differentially expressed by more than twofold in both samples. The correlation value of RNA expression between the propanol-treated mutant and the untreated one was about 0.951, and 71 genes in two samples showed differential expression patterns. However, the values between the wild type and mutant, regardless of propanol addition, were 0.974-0.992 and only 1-2 genes were differentially expressed in the two strains. The representative characteristics among differentially expressed genes in W3110 or P19 treated with propanol compared to untreated samples were up-regulation of hest shock response genes and down-regulation of genes relating to ribosome biosynthesis. In addition, many genes were regulated by transcription regulation factors such as ArcA, CRP, FNR, H-NS, GatR, or PurR and overexpressed by sigma factor RpoH. We confirmed that RpoH mediated an important host defense function in propanol stress in E. coli W3110 and P19 by comparison of cell growth rate among the wild type, rpoH disruptant mutant, and rpoH-complemented strain.

• Molecules and Cells
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• v.27 no.4
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• pp.467-473
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• 2009

Our previous study suggested that OsBWMK1, a gene which encodes a member of the rice MAP kinase family, generates transcript variants which show distinct expression patterns in response to environmental stresses. The transcript variants are generated by alternative splicing and by use of alternative promoters. To test whether the two alternative promoters, pOsBWMK1L (promoter for the OsBWMK1L splice variant) and pOsBWMK1S (promoter for the OsBWMK1S splice variant), are biologically functional, we analyzed transgenic plants expressing GUS fusion constructs for each promoter. Both pOsBWMK1L and pOsBWMK1S are biologically active, although the activity of pOsBWMK1S is lower than that of pOsBWMK1L. Histochemical analysis revealed that pOsBWMK1L is constitutively active in most tissues at various developmental stages in rice and Arabidopsis, whereas pOsBWMK1S activity is spatially and temporally restricted. Furthermore, the expression of pOsBWMK1S::GUS was upregulated in response to hydrogen peroxide, a plant defense signaling molecule, in both plant species. These results suggest that the differential expression of OsBWMK1 splice variants is the result of alternative promoter usage and, moreover, that the mechanisms controlling OsBWMK1 gene expression are conserved in both monocot and dicot plants.

• Journal of the Korean Institute of Gas
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• v.2 no.1
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• pp.59-65
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• 1998

Morphology and thermal properties of polyurethane synthesized from 4,4'-diphenylmethane diisocyanate (MDI), polyester polyol, and 1,4-butane diol are investigated using fourier transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), and dynamic mechanical thermal analysis (DMTA). From the FT-IR study, it is found that the stretching peaks of hydrogen bonded N-H and C=O are shifted to the low frequencies with the increase of hard segment content of the polyurethanes. The shift of the stretching peaks of hydrogen bonded N-H and C=O indicates that the degree of hydrogen bonding is increased. From the DSC study, it appears that the glass transition temperature ($T_g$) of the polyurethanes is increased with the increase of the hard segment content. Also, it is found that the polyurethanes investigated in this study have the homogeneous network structure due to the high functionality of the MDI. From the DMTA study, transition of the soft segment was not found. Therefore it is concluded that the polyurethanes investigated in this study have the one-phase morphology which is consistent with the DSC results.

• Journal of The Korean Society of Emergency Medicine
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• v.28 no.5
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• pp.457-466
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• 2017

Purpose: Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Severity of the initial insult is one of the most significant factors affecting outcome following TBI. In order to investigate the mechanisms of cellular injury and develop novel therapeutic strategies for TBI, we designed a standardized animal TBI model and evaluated histological and functional outcomes according to the degree of impact severity. Methods: Male adult C57Bl/6 mice underwent controlled cortical impact (CCI) at varying depths of deflection (1.0-2.0 mm). We performed hematoxylin and eosin staining at 7 days after recovery from TBI. Neurobehavioral characterization after TBI was analyzed by the Barnes maze test, passive avoidance test, open field test, rotarod test, tail suspension test, and light/dark test. Results: We observed a graded injury response according to the degree of deflection depths tested (diameter, 3 mm; velocity, 3 m/s; and duration, 500 ms) compared to sham controls. In the Barnes maze test, the severe TBI (2 mm depth) group showed reduced spatial memory as compared with the sham and mild TBI (1 mm depth) groups at 7 days after TBI. There was a significant difference in the results of the open field test and light/dark test among the three groups. Conclusion: Our findings demonstrate that the graded injury responses following TBI resulted in differential histopathological and behavioral outcomes in a mouse experimental CCI model. Thus, a model of CCI with histologic/behavioral outcome analysis may offer a reliable and convenient design for preclinical TBI research involving mice.

• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.287-302
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• 2005

Digital Elevation Models (DEMs) were generated by ERS-l/2 and JERS-1 SAR interferometry in Daejon area, Korea. The quality of the DEM's was evaluated by the Ground Control Points (GCPs) in city area where GCPs were determined by GPS surveys, while in the mountain area with no GCPs, a 1:25,000 digital map was used. In order to minimize errors due to the inaccurate satellite orbit information and the phase unwrapping procedure, a Differential InSAR (DInSAR) was implemented in addition to the traditional InSAR analysis for DEM generation. In addition, DEMs from GTOPO30, SRTM-3, and 1:25,000 digital map were used for assessment the resolution of the DEM generated from DInSAR. 5-6 meters of elevation errors were found in the flat area regardless of the usage and the resolution of DEM, as a result of InSAR analyzing with a pair of ERS tandem and 6 pairs of JERS-1 interferograms. In the mountain area, however, DInSAR with DEMs from SRTM-3 and the digital map was found to be very effective to reduce errors due to phase unwrapping procedure. Also errors due to low signal-to-noise ratio of radar images and atmospheric effect were attenuated in the DEMs generated from the stacking of 6 pairs of JERS-1. SAR interferometry with multiple pairs of SAR interferogram with low resolution DEM can be effectively used to enhance the resolution of DEM in terms of data processing time and cost.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.2
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• pp.121-132
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• 2005

연구목적: 본 연구에서는 비폐쇄성 무정자증 환자에서 나타나는 정자형성과정의 이상과 고환세포의 세포자연사와의 연관관계 여부를 확인하였다. 또한 SELDI-TOF MS 분석을 통하여 고환 내 단백질 발현 양상을 확인하고, 질환에 따른 효과적인 biomarker 개발 가능성 여부를 확인하였다. 재료 및 방법: RT-PCR 및 면역조직화학법을 사용하여 고환에서의 Fas, FasL, Bcl-2, Bax와 Caspase-3의 발현 양상을 확인하고, in situ DNA 3'-end-labelling 방법으로 고환세포의 세포자연사 양상을 확인하였다. SELDI-TOF MS 분석법에 의한 고환의 병리학적 소견에 따른 단백질 발현 변화는 소수성 칩 ($H_4$)을 사용하여 분자량 10~100 kDa 범위 내에서 분석하였다. 결 과: 정상적인 정자형성과정을 보이는 폐쇄성 무정자증 환자의 고환에 비해 지주세포 증후군 (Sertoli cell only syndrome)과 성숙정지 (maturation arrest)를 보이는 고환 내 생식세포와 지주세포에서 세포자연사가 현저하게 증가한 것을 확인할 수 있었다. 세포자연사 관련인자들의 발현 양상을 확인한 결과, 지주세포 증후군과 성숙정지 환자군에서 Fas와 FasL mRNA의 발현이 증가하였으나, bcl-2, bax와 caspase-3 mRNA 발현의 경우에는 두 질환 모두에서 유의한 차이를 확인할 수 없었다. FasL 단백질 발현의 경우, 세포자연사의 증가가 관찰되었던 지주세포 증후군과 성숙정지를 보이는 환자의 간질세포와 지주세포에서 증가하는 양상을 나타내었다. SELDI-TOF MS 분석 결과에서 폐쇄성 무정자증 환자군에 비해 전체적인 단백질 발현양이 지주세포 증후군과 성숙정지 환자의 고환에서 감소하는 양상을 보였으며, 특히, 16.730 kDa 단백질의 현저한 감소를 확인할 수 있었다. 결 론: 본 연구결과를 통해 비폐쇄성 무정자증 환자에서 나타나는 정자형성과정의 장애는 생식세포의 비정상적인 세포자연사와 연관되어 있으며, 고환 내 Fas와 FasL의 비정상적인 발현이 주된 원인인 것을 확인할 수 있었다. 또한, SELDI-TOF MS 분석법을 통한 단백질 발현 양상의 연구는 무정자증 환자에서의 다양한 병리학적 소견을 쉽게 파악할 수 있는 biomarker 발굴뿐만 아니라 질환의 원인규명을 위한 연구에도 유용하게 이용될 수 있을 것으로 사료된다.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.207-216
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• 2005

Objective: To understand the crucial requirement for the normal early folliculogenesis, we evaluated molecular as well as physiological differences during in vitro ovarian culture. Among the important regulators for follicle development, anti-Müllerian hormone (AMH) and FSH Receptor (FSHR) have been known to be expressed in the cuboidal granulosa cells. Meanwhile, it is known that c-kit is germ cell-specific and GDF-9 is also oocyte-specific regulator. To evaluate the functional requirement for the competence of normal follicular development, we investigated the differential mRNA expression of several factors secreted from granulosa cells and oocytes between in vivo and in vitro developed ovaries. Materials and Methods: Ovaries from ICR neonates (the day of birth) were cultured for 4 days (for primordial to primary transition) or 8 days (for secondary follicle formation) in ${\alpha}$-MEM glutamax supplemented with 3 mg/ml BSA without serum or growth factors. The mRNA levels of the several factors were investigated by quantitative real-time PCR analysis. Freshly isolated 0-, 4-, and 8-day-old ovaries were used as control. Results: The mRNA of AMH and FSHR as granulosa cell factors was highly increased according to the ovarian development in both of 4- and 8-day-old control. However, the mRNA expression was not induced in both of 4- and 8-day in vitro cultured ovaries. The mRNA expression of GDF-9 known to regulate follicle growth as an oocyte factor was different between in vivo and in vitro developed ovaries. In addition, the transcript of GDF-9 was expressed in the primordial follicles of mouse ovaries. The mRNA expression of c-kit was not significantly different during the early folliculogenesis in vitro. Conclusion: This is the first report regarding endogenous AMH and FSHR expression during the early folliculogenesis in vitro. In conclusion, it will be very valuable to evaluate cuboidal granulosa cell factors as functional marker(s) for normal early folliculogenesis in vitro.

• Journal of Adhesion and Interface
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• v.15 no.1
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• pp.22-30
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• 2014

Self-photoinitiating acrylate (SPIA) which can undergo self-initiation under UV irradiation was synthesized by a Michael addition in the presence of a base catalyst. The SPIA polymerizations were investigated by photo-differential scanning calorimeter (photo-DSC) and surface physical properties such as pendulum hardness and pencil hardness. The results showed that the SPIA can cure upon UV irradiation by itself without a photoinitiator. But we found out that both the curing rate and the conversion were too low for the self-curing reaction of SPIA. In order to improve the SPIA curing properties, we introduced the SPIA/cationic hybrid system and observed the effects of the addition of commercial free radical type monomer and photoinitiator on the curing behaviors. SPIA/cationic hybrid system was the best suitable to improve the SPIA curing properties. The kinetic analysis indicated that the cationic monomer and photoinitiator apparently accelerated the cure reaction and rate of the hybrid SPIA system, mostly due to the synergistic effect of cationic monomer and photoinitiator increasing the mobility of active species and the generation of reactive species (free radical, cation) during the photopolymerization process. The physical properties showed that, unlike typical free radical system, the hybrid systems did not show oxygen inhibition effect because of cationic reaction on the coating surface.