• Journal of Nutrition and Health
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• 제24권4호
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• pp.314-325
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• 1991

식이지방의 수준에 따라 n6 와 n3 불포화지방산이 혈장 지질조성에 미치는 영향과 또 그 기전이 다른지를 연구하고자 Sprague Dawley 종 수컷쥐에게 저지방(LF, 10% Cal)식이와 고지방식이(HF, 40% Cal)를 각각 6주동안 투여하였으며, 사용된 기름은 포화지방산 급원으로는 쇠기름, n6 linoleic acid(LA) 급원으로 corn oil, n3 ${\alpha}-linolenic$ acid(LL) 급원으로 perilla oil, n3 eicosapentaenoic acid(EPA)와 docosahexaenoic acid(DHA) 급원으로 fish oil이었다. Ultracentrifugation 방법으로 VLDL fraction을 분리하여 thin layer chromatography에 의해서 화학적조성을 구하였다. Plasma cholestere 수준은 LF 와 HF 모두 n6 LA에 의해서는 오히려 증가되었고 n3 LL과 n3 EPA에 의해서는 감소되었으며, HF 에서 n3 EPA가 가장 cholesterol 저하효과가 있었다. HDL-Chol 농도는 n6 LA에 의해서 증가되었으나, HF 경우 n3 EPA에 의해서 유의성있게 감소되었다. Plasma TG 농도는 n3 EPA에 의해서 가장 감소되었고 간의 lipogenic enzyme 활성을 억제하였으며 VLDL fraction의 TG상대적양(%)이 유의성 있게 낮아졌다. 이때 LF 군에서는VLDL fraction의 apo-B의 상대적양(%)이 감소되지 않았으나 HF군에서 n3 EPA에 의해서 유의성 있게 낮았다. 그러므로 n3 EPA의 hvpotriglyceridemic effect는 간에서 lipogenesis를 억제하여 plasma VLDL로 TG 분비가 억제되었을 것이며, HF일 경우는 간에서 apo-B 생성도 억제되었다. 관상동맥성심장질환의 예방적 차원에서 평상시에도 쇠기름과 corn oil 보다는 n3 PUFA가 풍부한 들기름이나 생선을 더욱 이용하는 것이 바람직하다.

• 대한화학회지
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• 제31권4호
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• pp.328-333
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• 1987

$C_18$ 역상 충전제에 1-eicosylsulfate($C_{20}H_{41}SO_4^-$)를 흡착하는 조건을 조사하였으며 $1.46{\times}10^{-4}M$의 흡착용액(25% 아세토니트릴 수용액) 1.2l를 통과시켰을 때 흡착평형이 일어났다. 이 분리관은 0.05 M ${\alpha}$-HiBA 용리액 10l까지 안정하였으며 Eu, Nd, Ce , La에 대한 분리관효율은 0.15M ${\alpha}$-HiBA 용리액 1.0ml/min에서 약 0.04 mm의 HETP를 나타내었다. 이 흡착분리관으로 희토류 원소 및 전이원소들을 개별 분리하였다.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3784-3789
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• 2021

We report a simple technique for direct neutron spectroscopy using pure LaCl₃ crystals. Pure LaCl₃ crystals exhibit considerably better pulse shape discrimination (PSD) capabilities with relatively good energy resolution as compared with Ce-doped LaCl₃ crystals. Single crystals of pure and Ce-doped LaCl₃ were grown using an inhouse-developed Bridgman furnace. PSD capabilities of these crystals were investigated using ²⁴¹Am and ¹³⁷Cs sources. Fast neutron detection was tested using a²⁵²Cf source and three separate bands corresponding to electron, proton, and alpha were observed. The proton band induced by the ³⁵Cl(n,p)³⁵S reaction can be used for direct neutron spectroscopy because proton energy is proportional to incident neutron energy. Owing to good scintillation performance and excellent PSD capabilities, pure LaCl₃ is a promising candidate for space detectors and other applications that necessitate gamma/fast neutron discrimination capability.

• 대한의생명과학회지
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• 제15권2호
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• pp.153-160
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• 2009

Photodynamic therapy(PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species(ROS), which selectively accumulate in target cells. The aim of present work is to investigate the photodynamic therapy mechanism of 9-HpbD-a-mediated PDT in HeLa cell lines. We studied the general reactive oxygen species(G-ROS) activation after 9-HpbD-a PDT using fluorescence stain with $H_2DCF-DA$. G-ROS activation observed after 9-HpbD-a PDT and higher activation condition was 1 hour after PDT at 0.5 ${\mu}g/ml$ 9-HpbD-a concentration. Sodium azide and reduced glutathione(the singlet oxygen quencher) could protect HeLa cells from cell death induced by 9-HpbD-a PDT. But D-mannitol(the hydroxyl radical scavenger) could not protect cell death. Singlet oxygen played a decisive role in 9-HpbD-a PDT induced HeLa cell death. Type II reaction was the main type of ROS formation at 9-HpbD-a PDT.

• 한국재료학회지
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• 제16권7호
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• pp.416-421
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• 2006

The varistor properties of ZPCCL-based ceramics were investigated at different $La_2O_3$ contents in the range of $0{\sim}2.0$ mol%. As $La_2O_3$ content increased, the ceramic density greatly increased in the range of $4.71{\sim}5.77\;g/cm^3$ and the varistor voltage greatly decreased in the range of $503.5{\sim}9.4$ V. The varistor with 0.5 mol% $La_2O_3$ exhibited good nonlinearity, in which the nonlinear exponent is 81.6 and the leakage current is 0.2 ${\mu}A$. Furthermore, the varistors exhibited the high electrical stability, with $%{\Delta}V_{1mA}=-1.1%,%{\Delta}{\alpha}=-3.7%$, and $%{\Delta}I_L=+100%$ for DC accelerated aging stress condition of 0.95 $V_{1mA}/150^{\circ}C/24$ h.

• Environmental Analysis Health and Toxicology
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• 제18권4호
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• pp.271-276
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• 2003

The purpose of the present study was to perform experiments of cytotoxicity using HeLa cell and to evaluate the possibility that QSAR is applicable to the cytotoxicity of alkylphenols. Higher toxicities were found in four alkylphenols in the following order: 4-n-Nonylphenol) 4-tert-Octylphenol) 4-n-Octylphenol > 4-n Heptylpheonl. Whereas other alkylphenols were apparently less toxic. By using Percent Hydrophilic Surface Area (PHSA) quantitative structure-activity relationships (QSARs) models were developed: Cytotoxicity (%) = 90.14089-4.72224 PHSA ($R^2$=0.2046, $\alpha$=0.0265). It is concluded that some of the obtained data are useful to determine whether QSAR methods can be of general use in predicting that until further work is undertaken to develop QSARs for a much wider range of homologous series of alkylphenol compounds.

• Korean Chemical Engineering Research
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• 제43권4호
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• pp.503-510
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• 2005

본 연구는 졸-겔법을 이용하여 복합 알루미나를 제조하였고, 다양한 첨가제의 첨가에 의한 복합 알루미나의 열적 안정성을 고찰하였다. $1,200^{\circ}C$에서 소성시킨 복합 알루미나의 열적 안정성은 사용된 첨가제에 따라서 $Si{\fallingdotseq}La$ > Ti > $Ba{\fallingdotseq}Ce$ > Y > $Zr{\fallingdotseq}Mg$ 순으로 나타났다. 특히 실리카 첨가시 ${\alpha}$-알루미나로의 상전이 온도를 $150^{\circ}C$이상 높여 $1,200^{\circ}C$에서 소성 후에도 ${\gamma}$-형에서 ${\delta}$-형의 알루미나 상을 유지함을 알 수 있었고, 비표면적이 $3m^2/g$인 ${\alpha}$-알루미나에 비해 $71m^2/g$(비표면적) 범위까지 증가됨을 보였다. 이러한 알루미나 입자의 특성변화는 실리카 첨가 알루미나의 경우 고온으로 소성시 Si-O-Al의 결합의 증가로 인하여 알루미나의 상전이를 지연시키는 결과로 나타나고, 란타늄 첨가 알루미나의 경우 $LaAlO_3$ 구조의 존재로 인해 알루미나의 입자간 소결을 지연시킴을 알 수 있었다. 또한 란타늄 첨가시 $1,000^{\circ}C$ 이하에서 소성시킨 경우 란타늄이 알루미나 표면에 $La_2O_3$ 구조로 존재하나 $1,000^{\circ}C$ 이상에서는 $LaAlO_3$의 perovskite 구조로 존재하고, $1,300^{\circ}C$ 이상에서는 $LaAl_{11}O_{18}$의 magneto-plumbite 구조로 존재함을 XRD와 XPS 분석 결과에 의해 확인할 수 있었다.

• 대한한방부인과학회지
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• 제27권2호
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• pp.1-11
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• 2014

Objectives: The purpose of this study was to investigate the effects of Longanae Arillus water extract (LA) on the production of inflammatory mediators in RAW 264.7 cell. LA is used for forgetfulness, insomnia, palpitation symptoms in korean medicine. Methods: In order to evaluate cytotoxicity of LA, cell viability was measured. To investigate anti-inflammatory effects of LA in the lipopolysacharide (LPS)-induced RAW 264.7 cell, the concentration of nitric oxide (NO) and cytokines were measured. And when p-value is below 0.05, it is judged to have the significant difference statistically. Results: 1. LA showed no cytotoxicity. 2. LA inhibited significantly the production on NO at the concentration of 50 and $200{\mu}g/ml$. 3. LA inhibited significantly the production on interleukin (IL)-$1{\beta}$ at the concentration of 25, 50, 100 and $200{\mu}g/ml$. 4. LA inhibited significantly the production on tumor necrosis factor (TNF)-${\alpha}$ at the concentration of 50, 100 and $200{\mu}g/ml$. 5. LA inhibited significantly the production on lipopolysaccharide-induced chemokine (LIX) at the concentration of 25, 100 and $200{\mu}g/ml$. 6. LA inhibited significantly the production on regulated on activation normal T cell expressed and secreted (RANTES) at the concentration of $200{\mu}g/ml$. Conclusions: These results suggest that LA has anti-inflammatory effect.

• 한국응용과학기술학회지
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• 제4권2호
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• pp.25-30
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• 1987

In order to investigate the effect to antioxygenic substances in Pine Needles on the photooxidation of linoleic acid (linoleic acid 100mg/10ml ethanol) added antioxidants and antioxygenic substances in Pine Needles was irradiated by the tungsten lamp attached with red fitter. The Photo oxidation of linoleic acid (LA) was conformed with Lea method and rhodan method. The following results were obtained: 1. Photooxidation of LA was greatly increased the presence of photosensitizer. However the Photo oxidation of LA without photosensitizer was smoothly increased by the irradiation. 2. The Photo oxidation of LA without irradiation occured quite lately whether photosensitizer was present or absent. 3. Photooxidation of LA under the presence of photosensitizer was inhibited by the addition of $dl-{\alpha}-tocopherol$ and the acetone fraction of methanol extract of Pine Needles but inhibited by BHT. Photooxidation of LA increased gradually as the addition of BHT increased but decreased gradually as that of acetone fraction increased.

• 공학논문집
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• 제3권1호
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• pp.215-222
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• 1998

촉매 연소용 촉매 담체인 $\gamma-Al_2O_3$ 분말의 열안정화에 미치는 La과 Si의 첨가 효과에 대하여 연구하였다. 첨가제의 첨가는 습식 impregnation방법으로 행하였고, 출발 물질은 $La(NO_3)_3{\cdot}6H_2O$와 $Si(OC_2H_5)_4$를 사용하였다. 열안정화 효과는 혼합분말을 고온에서 열처리 한 후 비표면적을 측정하여 고찰하였다. 첨가제로 첨가한 La과Si는 모두 순수한 $\gamma-Al_2O_3$분말에 비하여 소결을 억제함으로써 열 안정화 효과가 있음이 확인되었으며, 특히 Si 첨가한 경우에는 $\alpha-Al_2O_3$의 생성을 현저히 억제한다는 것을 확인하였다. 이들 첨가제에 의한 열안정화 효과는 첨가제에 의한 새로운 상의 생성과 표면 확산의 억제등이 주된 요인으로 판단되었다.