• Journal of Embryo Transfer
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• v.24 no.2
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• pp.105-108
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• 2009

This study was designed to investigate the effect of kinetin on in vitro development of parthenogenetic porcine oocytes exposed to demecolcine prior to activation. In vitro matured metaphase II stage oocytes were incubated in 0 or 2 ${\mu}$g/ml demecolcine supplemented defined culture medium for 3 h and the oocytes were activated electrically. The parthenogenetic porcine embryos were then cultured in 0 or 200 ${\mu}$M kinetin supplemented defined culture medium for 7 days. Regardless of demecolcine treatment, kinetin supplementation increased blastocyst rates significantly (7.0% versus 12.1% and 4.9% versus 8.5%; Control versus Kinetin and Demecolcine versus Kinetin + Demecolcine, respectively, p<0.05). Demecolcine treatment before activation tended to decrease blastocyst rates regardless of kinetin supplementation although it is not statistically significant. Total cell numbers in the blastocysts also tended to be elevated in embryos when supplemented with kinetin, however only the result between Kinetin and Demecolcine groups is statistically significant (37.6 ${\times}$ 7.2 versus 28.1 ${\times}$ 9.5, respectively, p<0.05). In conclusion, the present report shows that kinetin enhances developmental competence of parthenogenetic porcine embryo regardless of demecolcine pre-treatment before parthenogenetic activation when they were developed in defined culture condition.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.209-214
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• 2010

Cells that have endogenous multipotent properties can be used as a starting source for the generation of induced pluripotent cells (iPSC). In addition, small molecules associated with epigenetic reprogramming are also widely used to enhance the multi- or pluripotency of such cells. Skinderived precursor cells (SKPs) are multipotent, sphereforming and embryonic neural crest-related precursor cells. These cells can be isolated from a juvenile or adult mammalian dermis. SKPs are also an efficient starting cell source for reprogramming and the generation of iPSCs because of the high expression levels of Sox2 and Klf4 in these cells as well as their endogenous multipotency. In this study, valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, was tested in the generation of iPSCs as a potential enhancer of the reprogramming potential of SKPs. SKPs were isolated from the back skins of 5-6 week old C57BL/6 X DBA/2 F1 mice. After passage 3, the SKPs was treated with 2 mM of VPA and the quantitative real time RT-PCR was performed to quantify the expression of Oct4 and Klf4 (pluripotency specific genes), and Snai2 and Ngfr (neural crest specific genes). The results show that Oct4 and Klf4 expression was decreased by VPA treatment. However, there were no significant changes in neural crest specific gene expression following VPA treatment. Hence, although VPA is one of the most potent of the HDAC inhibitors, it does not enhance the reprogramming of multipotent skin precursor cells in mice.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1108-1113
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• 2012

The changes of soil organic carbon (SOC) content in paddy soils (sandy loam) were assessed from data of the 59 years fertilization plots in which the continuous rice cropping experiment started in 1954. The treatments were no fertilization(no fert.), NPK fertilization (N, NPK), NPK plus rice straw compost (NPK+C), and NPK plus rice straw compost, silicate fertilizer and lime (NPK+CLS). After 41 years, SOC content in NPK+C and NPK+CLS treatment in surface soils (0~15 cm) reached at the highest, followed by maintaining a plateau level for 8 years. After 51 years, they showed a tendency to decrease. Peak concentrations of soil organic carbon were $20.1g\;kg^{-1}$ in NPK+CLS, $19.1g\;kg^{-1}$ in NPK+C, $13.3g\;kg^{-1}$ in NPK, $11.9g\;kg^{-1}$ in N, and $11.6g\;kg^{-1}$ in control. Dissolved organic carbon(DOC) contents in surface soil solution were about 2.3 times higher in NPK+C than that in NPK+CLS. Therefore, SOC in subsurface soil(15~30 cm) was greater in NPK+C than the other treatments. These results indicate that continuous application of rice straw compost and silicate fertilizer affected significantly on the level of SOC in surface soils, subsurface soils, and soil solutions. Thus, the combined applications of NPK fertilizers with organic compost and silicate as a soil amendment are recommended as the best fertilization practice for soil carbon accumulation, environment conservation, and enhancement of soil fertility status in the continuous rice cropping system.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.33-37
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• 2012

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of $Tuj1$ increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous $Igf2$ may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

• Polymer(Korea)
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• v.32 no.3
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• pp.263-269
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• 2008

To develop carriers of hydrophobic anticancer agents based on chitosan, chitosan oligosaccharide lactate (COS) was chemically modified with lithocholic acid (LA) which is one of the bile acids as a hydrophobic group. The physicochemical properties of the lithocholic acid conjugated chitosan nanoparticles (COS-LA) were investigated using $^1H$-NMR spectroscopy, dynamic light scattering (DLS) and spectrofluorophotometer. COS-LA-paclitaxel (CLs-Tx) nanoparticles loading paclitaxel as an anticancer agent were prepared by a dialysis method and its loading efficiency was measured through HPLC. On the basis of DLS results, the estimated particle sizes of CLs-Tx were around 300 nm. Also, the critical micelle concentration (CMC) was proven to be dependent on the degree of substitution of lithocholic acid. It showed that the CLs-Tx has the superior potential for the application as a paclitaxel carrier.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.457-461
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• 2018

Corpus luteum (CL) is a transient endocrinal tissue that undergoes repeated formation and regression during the estrous cycle. In this study, we hypothesized that the functional and structural mechanism of angiogenesis is similar between CL and tumor formation. First, we measured mRNA and protein expression of angiogenic receptors (vascular endothelial growth factor receptor-2, VEGFR2; Tie 2) in the early, middle, and late phase CL tissues during the estrous cycle. Ral-interacting protein of 76 kDa (RLIP76) and H-ras mRNA and protein were also expressed in the CL tissues. VEGFR2 and Tie 2 mRNA and protein were expressed in the early and middle phase CLs and decreased in the late phase. H-ras mRNA and protein were expressed in the early and middle phase CLs, but not in the late phase. RLIP76 mRNA was expressed in all phase CLs, and the protein expression was highest in early phase CLs. We suggest that RLIP76 and H-ras, an oncogenic gene, regulate the function of the CL during the estrous cycle, and the proteins will play an important role in the angiogenic mechanism of the CL.

• Structural Engineering and Mechanics
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• v.24 no.2
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• pp.269-273
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• 2006

• Venture DIGEST
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• s.58
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• pp.10-11
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• 2004

금융은 해를 따라 움직인다는 말이 있다. 국가간의 시차로 인해 결제시간의 공백이 생기기 때문에 나온 말이다. 외환동시결제시스템 ‘CLS’를 구축하며 이 말을 정면으로 거스르는 기업이 있으니 바로 금융솔루션 전문기업 코마스이다. 1993년 SWIFT의 한국 비즈니스 파트너로서 첫발을 내딛고, 이후 12년 간 금융솔루션분야에 주력해온 코마스. 그 해가 지지 않는 쟁기질 소리를 들어보자.

• Journal of Genetic Medicine
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• v.4 no.2
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• pp.196-199
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• 2007

Coffin-Lowry syndrome (CLS) is a rare X-linked hereditary disorder characterized by moderate to severe mental retardation, facial dysmorphism, tapering fingers, and skeletal deformity. A 12-month-old boy was referred to our pediatric clinic for his developmental delay and seizure with fever. The boy exhibited a coarse facial appearance characterized by prominent, high-arched eyebrow, broad nose, downward palpebral fissure, high arched palate, hypodontia. The boy also showed finger tapering and puffy hand. Hypotonia, hyperextensible fingers and hypermobility of the joint were seen. Based on these findings, he was diagnosed as having Coffin-Lowry syndrome. We report a case of Coffin-Lowry syndrome with reference.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.955-965
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• 2014

Transport phenomena of reactant and product are directly linked to intrinsic inhomogeneous random configurations of catalyst layer (CL) that consist of ionomer, carbon-supported catalyst (Pt/C), and pores. Hence, electrochemically active surface area (ECSA) of Pt/C is dominated by geometrical morphology of mass transport path. Undoubtedly these ECSAs are key factor of total fuel cell efficiency. In this study, non-deterministic micro-scale CLs were randomly generated by Monte Carlo method and implemented with the percolation process. To ensure valid inference about Pt/C catalyst utilization, 600 samples were chosen as the number of necessary samples with 95% confidence level. Statistic results of 600 samples generated under particular condition (20vol% Pt/C, 30vol% ionomer, 50vol% pore, and 20nm particle diameter) reveal only 18.2%~81.0% of Pt/C can construct ECSAs with mean value of 53.8%. This study indicates that the catalyst utilization in fuel cell CLs cannot be identical notwithstanding the same design condition.