• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.1
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• pp.12-20
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• 2010

Metamictization and color change in zircons from Cambodia and Tanzania were investigated. Elements analysis to detect radioactivity of elements such as U and Th, and spectroscopic analysis using UV-VIS and Fourier transform infrared spectroscopy were performed. According to the UV-VIS spectroscopic analysis, it was perceived that many and high intense absorption peaks appeared in blue and colorless zircons, while less and low intense absorption peaks appeared in uranium contained green and yellow zircons. It was found that those stones have made progress to the metamictization. After heat treatment, we could detect opposite results. As the results of FTIR spectroscopy analysis, in the metamict green and yellow zircon, it is showed that 3-phonon combination mode bands of $[SiO_4]^{4-}$ internal vibration in the region of 3100~3400 $cm^{-1}$ are broad and some of them disappear. However, the disappeared bands are observed again due to restored crystal lattice by the heat treatment. Also, $U^{4+}$ peaks that can detect the uranium content in zircon appears at near 4800 $cm^{-1}$ in the green and yellow samples. From this investigation, we could observe the metamictization effect and color change in uranium-bearing zircon by heat treatment using spectroscopic analysis.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.147-154
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• 2003

In this study, the fluorinated carbon blacks(CB) were used to reduce the negative temperature coefficient (NTC) phenomenon of the CB-filled high density polyethylene(HDPE) compounds in the fluorination pressure of 0.1-0.4 MPa. The changes in surface properties of the CB were investigated by using FT-IR, XPS and contact angle measurements. From the FT-IR results, the fluorinated CB showed the C-F absorption peak at 1400-1000 cm$^{-1}$ and the peak intensity was increased with increasing the fluorination pressure. Also, the analysis of XPS spectra of the fluorinated CB indicated that fluorine content was increased with increasing the fluorination pressure. Meanwhile, the surface free energy of the fluorinated CB was decreased with increasing the fluorination pressure. Consequently, the increase of fluorine contents on CB made a disappearance of NTC behaviors of CB/HDPE compounds, which was probably due to the reduction of CB reaggregation after melting point of the HDPE, resulting from decreasing the surface free energy of CB particles.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.253-266
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• 2001

Background: The causes of ADHD(attention deficit hyperactivity disorder) are various, so it is impossible to understand the whole characteristics of ADHD, only with simple intelligence testing scales. We compared cognitive characteristics of ADHD group with normal controls with Korean Kaufman Assessment Battery for Children(K-ABC). It is well known to evaluate neuropsychological and cognitive aspects of the children. Materials and Methods: Age and sex matched 40 ADHD patients and 40 normal controls tested with the K-ABC. Each subscales compared between pre-treatment patients and controls, pre-treatment and post-treatment in patient group, post-treatment patients and controls. Results: Significant differences are observed in sequential processing, simultaneous processing, cognitive processing and achievement between pre-treatment patients and controls, and in gestalt closure between pre-treatment and post-treatment patients group. But there are no significant differences between pre-treatment patients and controls in gestalt closure and reading/decoding. Conclusions: Methylphenidate improved the scores of simultaneous scale, which means improvement of executive functions such as divided attention, analysis and organization. Methylphenidate also reduced distractibility.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.282-290
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• 2020

Background: Ginseng is a commonly used herbal medicine in treating various medical conditions. Chronic gut inflammation is a recognized factor for the development of colorectal cancer (CRC). In this project, Asian ginseng berry polysaccharide preparations were used to assess their effects on CRC and related immune regulation mechanisms. Methods: Ginseng berry polysaccharide extract (GBPE) and purified ginseng berry polysaccharide portion (GBPP) were used to evaluate their activities on human HCT-116 and HT-29 CRC cell proliferation. Interleukin-8 secretion analysis was performed on HT-29 cells. Naive CD4 cell isolation and T-helper cell differentiation were performed and determined using flow cytometry for Th1 and Treg in addition to cell cycle and apoptotic investigation. Results: GBPE and GBPP significantly inhibited interleukin-8 secretion and cancer cell proliferation, inhibited CD4⁺IFN-γ⁺ cell (Th1) differentiation, and decreased CD4⁺FoxP3⁺ cell (Treg) differentiation. Compared to the GBPE, GBPP showed more potent antiinflammatory activities on the malignant cells. This is consistent with the observation that GBPP can also inhibit Th1-cell differentiation better, suggesting that it has an important role in antiinflammation, whereas Treg cells hinder the body's immune response against malignancies. Supported by cell cycle and apoptosis data, GBPE and GBPP, at various degrees, remarkably enhanced the anticancer activities of 5-fluorouracil. Conclusion: Data from this project suggested that Asian ginseng berry potentially has clinical utility in managing enteric inflammation and suppressing CRC through immunomodulation mechanisms.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1080-1086
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• 2006

본 연구에서는 해조류의 항돌연변이 및 항암 생리활성물질을 검색하여 발암물질 생성 방지 및 생체 방어 물질로서의 이용 가능성을 검토하고자 Ames test를 이용하여 직접돌연변이원인 MNNG와 간접돌연변이원인 $AFB_1$에 대한 항돌연변이 효과 및 암세포 증식 억제 효과를 알아보고자 하였다. $AFB_1$에 대해서 괭생이모자반(S. horneri)이 실험에 사용된 다른 해조류들 중에서 가장 높은 돌연변이 억제 효과를 보였다. 첨가농도 1.25mg/plate일 때, 괭생이모자반의 acetone+methylene chloride 추출물과 methanol 추출물은 각각 96%, 91%로 실험에 사용된 다른 해조류들의 추출물들 중에서 가장 높았으며 양성 대조군인 다시마의 용매 추출물보다도 높은 돌연변이 억제 효과를 보였다. $AFB_1$과 같은 농도인 0.6mg/plate의 농도의 MNNG를 사용하여 S. typhimurium TA100 균주에 대한 해조류의 항돌연변이성 실험을 한 결과, 간접 돌연변이원인 $AFB_1$에 비해 직접 돌연변이원인 MNNG에 대해서는 다소 항돌연변이 효과가 떨어지지만, 여기서도 실험에 사용된 해조류들의 돌연변이 억제 효과를 살펴볼 수 있었으며 acetone+methylene chloride 추출물의 경우가 methanol 추출물보다 다소 높은 활성을 나타내었다. 항돌연변이 실험에서 효과가 뛰어난 괭생이모자반과 짝잎모자반을 중심으로 인체 암세포(위암세포, AGS 및 결장암 세포, HT-29) 증식억제효과를 살펴본 결과, 용매 추출물을 0.5%, 1% 및 2%의 농도별로 암세포에 처리했을 때 acetone+methylene chloride 추출물과 methanol 추출물은 둘 다 가장 낮은 농도인 0.5%에서부터 농도 의존적으로 암세포 증식 억제 효과가 증가하였다. 이상의 7종의 갈조류 추출물들은 Ames test에서 높은 항돌연변이 효과를 나타냈을 뿐만 아니라 괭생이모자반 및 짝잎모자반은 인체 암세포에 대해서도 높은 증식 억제 효과를 나타냄을 살펴 볼 수가 있었다.

• Molecules and Cells
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• v.40 no.7
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• pp.466-475
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• 2017

Dietary supplements have exhibited myriads of positive health effects on human health conditions and with the advent of new technological advances, including in the fields of proteomics, genomics, and metabolomics, biological and pharmacological activities of dietary supplements are being evaluated for their ameliorative effects in human ailments. Recent interests in understanding and discovering the molecular targets of phytochemical-gene-protein-metabolite dynamics resulted in discovery of a few protein signature candidates that could potentially be used to assess the effects of dietary supplements on human health. Persimmon (Diospyros kaki) is a folk medicine, commonly used as dietary supplement in China, Japan, and South Korea, owing to its different beneficial health effects including anti-diabetic implications. However, neither mechanism of action nor molecular biomarkers have been discovered that could either validate or be used to evaluate effects of persimmon on human health. In present study, Mass Spectrometry (MS)-based proteomic studies were accomplished to discover proteomic molecular signatures that could be used to understand therapeutic potentials of persimmon leaf extract (PLE) in diabetes amelioration. Saliva, serum, and urine samples were analyzed and we propose that salivary proteins can be used for evaluating treatment effectiveness and in improving patient compliance. The present discovery proteomics study demonstrates that salivary proteomic profile changes were found as a result of PLE treatment in prediabetic subjects that could specifically be used as potential protein signature candidates.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.385-393
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• 2009

The spectroscopic characteristics of Madagascar tourmaline were investigated by UV-Vis and FTIR spectroscopy. Physical features were similar to other region's tourmalines. The green and blue samples showed strong absorption band in the 714~743 nm due to $Fe^{3+}$, pink samples showed strong absorption band in the 510~530 nm due to $Mn^{3+}$, brown samples showed strong absorption at 324 nm due to $Mn^{2+}-Ti^{4+}$ IVCT and the colorless samples only revealed weak absorption at 406~413 nm or no absorptions due to low quantity of Mn. Combination of the stretching and bending mode cationic hydroxyl units (metal-OH) are observed in the 4300~4500 $cm^{-1}$. The parallel tube-shaped inclusions which contain hematite were detected generally. This investigation revealed that Cu was not detected but Fe and Mn were detected in the Madagascar tourmalines, and the various colors appear according to the amount of those impurity elements.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.178-184
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• 2001

Transparent and highly oriented KLN thin films have been grown by an rf- magnetron sputtering deposition method. A homogeneous and stable KLN target was prepared by calcine and sintering process. For KLN target, stoichiometry and composition excess with K of 30% and 60%, and Li of 15% and 30% respectively, was prepared. The targets were sintered at low temperature to prevent vaporization of K and Li. KLN thin films were fabricated by rf-magnetron sputtering method using those targets. In this experiment, using the target of composition excessed with K of 60% and Li of 30%, single phase KLN thin film was produced. KLN thin film has excellent crystallinity and highly c-axis oriented on Corning 1737 substrate. Transmittance of thin film in visible range was 90%, absorption edge is 333 nm and refractive index at 632.8 nm was 1.93.

• Journal of the Korea Institute of Building Construction
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• v.15 no.3
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• pp.265-271
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• 2015

This study is intended to produce a PC (Precast Concrete) member without a steam curing process in developing the high early strength concrete satisfying the condition of 10MPa in compressive strength at the age of 6 hours, and is intended to ensure economic feasibility by increasing the turnover rate of concrete form. Hence, high early strength cement with high $C_3S$ content and the hardening accelerator of powder type accelerating the hydration of $C_3S$ was used. And the properties of concrete were evaluated according to the hardening accelerator mixing ratio (0, 1.2, 1.6, 2.0). No big difference was found from the tests of both slump and air content. When 1.6 % or higher amounts of the hardening accelerator were mixed, the compressive strength of 10MPa was achieved at the age of 6 hours. From the test results of autogenous (drying) shrinkage and plastic shrinkage, it can be seen that there was a difference according to hydration reaction rate due to the addition of the hardening accelerator. However, it was shown that no problem arose with crack and durability. And it was shown that resistance to freezing-thawing, carbonation, and penetration were excellent.

• Journal of the Korea Institute of Building Construction
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• v.13 no.4
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• pp.391-399
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• 2013

For high strength concrete of 40~60 MPa, the effects on the early strength and concrete dry shrinkage properties replacing 60~80% of Ordinary Portland Cement with Blast Furnace Slag Powder and using the Alkali Activator (Modified Alkali Sulfate type) are considered in this study. 1% Alkali Activator to the binder, cumulative heat of hydration for 72 hours was increased approximately 45%, indicating that heat of hydration contributes to the early strength of concrete, and the slump flow of concrete decreased slightly by 3.7~6.6%, and the 3- and 7- strength was increased by 8~12%, which that the Alkali Activator (Modified Alkali Sulfate type) is effective for ensuring the early strength when manufacturing High Strength Concrete (60%) of Blast Furnace Slag Powder. Furthermore, the dry shrinkage test, both 40 MPa and 60 MPa specimens had level of length changes in order of BS40 > BS60 > BS60A > BS80A, and the use of the Alkali Activator somewhat improved resistance to dry shrinkage.