• 한국약용작물학회지
• /
• 제10권3호
• /
• pp.222-229
• /
• 2002

씀바귀 뿌리 추출물 및 분획물에 대한 DPPH free radical 소거법에 의한 항산화활성을 검색한 결과 에칠아세테이트 분획물$(RC_{50}=12{\mu}g/ml)$이 대조구인 BHA$(RC_{50}=14{\mu}g/ml)$나 ${\alpha}-tocopherol(RC_{50}=12{\mu}g/ml)$과 유사한 활성을 나타내었다. 항미생물 활성을 측정한 결과 곰팡이 균주에 대해서는 물 분획물이 대체적으로 우수한 활성을 나타내었다. Hypocrea nigricans에서는 대조구인 Cyclohexamide$(13{\mu}g/ml)$보다 우수한 활성$(8{\mu}g/ml)$을 나타냈으며, Cladosporium herbarum에서는 부탄올 분획물$(8{\mu}g/ml)$과 메탄올 추출물$(16{\mu}g/ml)$에서 대조구$(25{\mu}g/ml)$보다 우수한 활성을 나타내었다. 반면에 세균 균주중 Bacillus subtilis 균주에 대해서는 물층 분획물$(32{\mu}g/ml)$과 에칠아세테이트 분획물$(125{\mu}g/ml)$이 우수하였으며, Candida lypolytica 균주에 대해서는 핵산 분획물 $(32{\mu}g/ml)$과 물충 분획물$(63{\mu}g/ml)$이 우수하였고, Escherichia coli 균주에 대해서는 에칠아세테이트 분획물$(125{\mu}g/ml)$과 메탄올 추출물$(250{\mu}g/ml)$이 우수한 활성을 나타내었다. 돌연변이원성 억제작용을 검토하기 위하여 Ames test 에서 양성반응을 나타내며, 물질 그 자체로서 돌연변이를 유발하는 직접 변이원물질로 MNNG와 4NQO 그리고 대사활성을 필요로 하는 간접 변이원 물질인 B(a)P을 사용하여 각각의 농도에 따른 돌연변이원성 억제활성 결과 MNNG$(0.4{\mu}g/plate)$의 경우 S. typhimurium TA100 균주에서 시료농도 $(100{\mu}g/plate)$에서 메탄올 추출물이 79.94%로 가장 높은 억제효과가 나타났다 4NQO$(0.15{\mu}g/plate)$에 대한 S. typhimurium TA98 균주에서 메탄올 추출물이 89.99%로 가장 높은 억제효과를 나타냈으며, TA100 균주의 경우에서도 메탄올 추출물에서 84.56% 로 가장 높은 억제 효과를 나타내었다. B(a)P$(10{\mu}g/plate)$에서는 TA98 균주에서 $(100{\mu}g/plate)$의 시료농도에서는 부탄올 분획물이 89.92%로 가장 높은 억제효과를 보였으며 TA100 균주에서는 메탄올 추출물이 77.47%로 가장 높은 억제효과를 나타내었다. 암세포주(A549, Hep3B, MCF-7)에 대한 씀바귀 뿌리추출물의 세포독성을 알아보기 위하여 실험한 결과, 페암세포주인 A549세포에서는 에칠아세테이트 분획물$(250{\mu}g/ml)$이 91.67%로 가장 높은 억제효과를 나타내었고, 간암세포주인 Hep3B에서는 에칠아세테이트 분획물 $(500{\mu}g/ml)$이 75.01%로 가장 높은 억제효과를 나타냈으며, 유방암 세포주인 MCF-7에서도 에칠아세테이트 분획물$(500{\mu}g/ml)$이 84%로 가장 높은 억제효과를 보였다. 정상 간세포주인 293에 대하여 시료농도에 따른 세포독성 효과를 나타낸 것으로 $(500{\mu}g/ml)$ 시료 첨가시 암세포에 대하여 대부분 50% 전후(물 분획물 제외)의 억제율을 보이는데 반해 293세포에 대해서는 29% 이하의 생육억제율을 보였다. 이는 암세포주에 대한 높은 억제효과에 비해 정상세포에 대해서는 비교적 낮은 독성효과를 나타냄을 알 수 있었다.

• 한국식품저장유통학회지
• /
• 제11권4호
• /
• pp.550-556
• /
• 2004

신나무(Acer ginnala Max.) 껍질의 메탄올 추출물 및 분획물들의 Ames test를 이용한 항돌연변이원성 및 SRB assay에 의한 세포독성 효과를 규명하였다. 시료자체는 돌연변이원성이 없는 것으로 나타났다. MNNG ($0.4\;{\mu}g/plate$)에 대한 항돌연변이 효과에서 S. typhimurium TA100 균주에 대해 신나무 껍질 메탄올 추출물에서 시료농도 $200\;{\mu}L/plate$ 첨가시 $83.3\%$로 가장 높게 나타났다. 동일시료 농도에서 4NQO에 대하여서는 S. typhimurium TA98과 TA100 두 균주 모두에서 메탄올 추출물이 $80\%$이상의 높은 항돌연변이원성을 나타내었다. B(a)P에 대한 S. typhimurium TA98 균주에 대해 시료 $200\;{\mu}L/plate$ 첨가시 메탄올 추출물과 에틸아세테이트 분획물에서 각각 $88.3\%$와 $78.6\%$의 억제활성을 나타내었으며 Trp-P-1 ($0.15{\mu}g/plate$)에서는 S. typhimurium TA98과 TA100 두 균주 모두에서 메탄올 추출물이 $80\%$이상의 높은 억제활성을 나타냈다. 폐암 세포주 A549에 대한 암세포 성장 억제활성을 검토한 결과 메탄올 추출물과 에틸아세테이트 분획물에서 0.25 mg/mL의 낮은 시료 농도에서도 $54.9\%$와 $55.3\%$의 억제효과를 보여주었다. 위암 세포 AGS의 경우 시료농도 1 mg/mL 첨가시 대부분의 시료에서 $90\%$이상의 매우 강한 활성을 나타내었다. 유방암세포 MCF-7와 간암세포 Hep3B에서는 메탄올 추출물이 시료농도 1 mg/mL 첨가시 $80\%$ 이상의 높은 암세포 성장 억제 효과를 나타내었다.

• Journal of Preventive Medicine and Public Health
• /
• 제31권3호
• /
• pp.372-383
• /
• 1998

For the purpose to analysis the characteristics of traffic accidents(TA) and investigate the relationship between traffic accidents and children attention problem rating scale(CAP) and, family environment scale(FES), this questionnaire survey was conducted to the 16 primary school students in Taejon from July 14 to August 26, 1997. The number of study subjects who had an experience of traffic accidents from July 1, 1996 to June 30, 1997 were 195, and the number of control sujects were 512. The main results were as follows; 1. The traffic accident rates was 0.9% as a whole, but those were 1.4% in boys, 0.7% in girls, 1.3% in low (1st-3rd) grade, and 0.8% in high (4th-6th) grade. 2. The rates of traffic accidents were high in spring, friday, afternoon and a drive-way around home. TA occurred during walking with friends most frequently. 3. In CAP the score of inattention was lower in TA group than control group, and hyperactivity was higher in TA group but they didn't showed significantly different. In FES, cohesion score was higher in TA group than control group, but Conflict score and Expressiveness score were in control group, but they didn't showed significantly different. 4. In CAP the odds ratio of inattention score for TA group was 0.84, but that of hyperactivity score was 1.15. In FES, the odds ratio of cohesion score was 1.06, but that of expression score and conflict score was 0.94 and 0.96, respectively. In conclusion, the relationships between TA and CAP, TA and FES in this study were not clear to explain personal characteristics and environmental conditions.

• 한국산학기술학회논문지
• /
• 제21권1호
• /
• pp.739-744
• /
• 2020

이번 연구의 목적은 pH, 적정산도, 형광소실도(△F)를 이용하여 혼합주의 부식위험성과 부식능에 대해 평가하고자 하였다. 실험군은 다음과 같이 분류하였다: 소주, 깔라만시+소주, 요구르트+소주, 콜라+소주, 에너지드링크+소주. 혼합주는 소주와 음료수를 7:3의 비율로 혼합하였다. pH와 적정산도(TA5.5, TA7.0; 음료의 pH를 5.5와 7.0까지 끌어 올리는데 필요한 1M NaOH의 양)는 교반하면서 pH미터기를 이용하여 측정하였다. 혼합주의 부식능은 우치를 1, 2, 4, 6시간 동안 침적하였다가 각 시간마다 꺼내어 quantitative light-induced fluorescence (QLF-D)를 이용하여 촬영, 분석하였다. 연구 결과, 혼합주는 평균 pH는 3.17 ± 0.50, 소주의 pH는 8.6 ± 0.01를 나타내었다. TA5.5와 TA7.0는 각각 0.5~18, 0.5~23.5의 분포를 나타내었다. 요구르트 혼합주를 제외한 나머지 혼합주의 △F는 시간이 지남에 따라 증가하였으며, 요구르트 혼합주에서는 부식이 나타나지 않았다. 결론적으로, 깔라만시 혼합주가 가장 강한 산성과 부식능을 보였으며, 요구르트가 가장 약한 부식능을 나타냈다. 혼합주는 치아 법랑질에 강한 부식위험성을 가지고 있으므로, 이에 대한 주의와 교육이 필요할 것으로 사료된다.

• 한국재료학회지
• /
• 제20권4호
• /
• pp.217-222
• /
• 2010

Zirconium diboride (ZrB2) and mixed diboride of (Zr0.7Ta0.3)B2 containing 30 vol.% silicon carbide (SiC) composites were prepared by hot-pressing at $1800^{\circ}C$. XRD analysis identified the high crystalline metal diboride-SiC composites at $1800^{\circ}C$. The TaB2 addition to ZrB2-SiC showed a slight peak shift to a higher angle of 2-theta of ZrB2, which confirmed the presence of a homogeneous solid solution. Elastic modulus, hardness and fracture toughness were slightly increased by addition of TaB2. A volatility diagram was calculated to understand the oxidation behavior. Oxidation behavior was investigated at $1500^{\circ}C$ under ambient and low oxygen partial pressure (pO2~10-8 Pa). In an ambient environment, the TaB2 addition to the ZrB2-SiC improved the oxidation resistance over entire range of evaluated temperatures by formation of a less porous oxide layer beneath the surface SiO2. Exposure of metal boride-SiC at low pO2 resulted in active oxidation of SiC due to the high vapor pressure of SiO (g), and, as a result, it produced a porous surface layer. The depth variations of the oxidized layer were measured by SEM. In the ZrB2-SiC composite, the thickness of the reaction layer linearly increased as a function of time and showed active oxidation kinetics. The TaB2 addition to the ZrB2-SiC composite showed improved oxidation resistance with slight deviation from the linearity in depth variation.

• 마이크로전자및패키징학회지
• /
• 제10권2호
• /
• pp.55-59
• /
• 2003

본 연구에서는 RF-Magnetron 스퍼터링 장치를 이용하여 $Al_xTa_{1-x}$(x=0.0∼1.0) 합금박막을 성장하였고, 4탐침법, XRD, AFM, micro-Vickers 미소경도계를 사용하여 시료의 구조적, 기계적, 전기적 특성을 분석하였다. Al조성 x=0.245(Al 24.5 at.%)에서 전기저항이 가장 높게 나타났고, 결정질이 가장 우수하였다. 표면 hillock에 있어서는 낮은 Al 조성영 역에서는 x가 증가할수록 hillock이 감소하다가, x=0.245에서 hillock이 완전히 배제되었고, 이후 x 증가에 따라 hillock 밀도가 다시 급격히 증가하였다. 미소경도의 경우, Al조성 x=0.2∼0.45의 영역에서 가장 높은 경도값이 측정되었다. 본 연구의 모든 결과를 종합적으로 고려할 때, $Al_xTa_{1-x}$ 합금박막의 결정질, 전기저항, 표면형상, 미소경도는 상호 밀접한 관계를 가지고 있었으며, Al 조성 x=0.245에서 가장 우수한 물리적 특성이 나타났다.

• Physical Therapy Rehabilitation Science
• /
• 제4권1호
• /
• pp.38-43
• /
• 2015

Objective: To investigate and compare the size of the rectus femoris (RF), tibialis anterior (TA), and medial gastrocnemius (GMM) using ultrasound (US) imaging in young, elderly, and very elderly groups. Design: Cross sectional study. Methods: This study consisted of 25 young (age 20 years), 24 elderly (age 65-74 years), and 25 very elderly (age 75-90 years) people with no physical dysfunctions. The cross sectional area (CSAs) of the RF and muscle thickness of the TA and GMM were measured at rest and during contraction using an US system. Results: The CSA of the RF and thickness of the TA and GMM were significantly smaller in the elderly and very elderly groups than in the young group (p<0.05). There was a significant difference of the CSA of the RF at rest and during contraction between elderly and very elderly group (p<0.05). In the comparison of the TA and GMM thickness between elderly and very elderly groups, there were no significant differences except for the TA thickness during contraction. There was a significant difference in the percentage change in RF CSA among the three groups (p<0.05). Conclusions: Our results revealed loss of muscle mass in the RF, TA, and GMM in elderly and very elderly people (${\geq}65$ years old). In particular, the greatest age-related decline in muscle mass was observed for the RF. Furthermore, the CSA of the RF declined with aging in the very elderly groups (${\geq}75$ years old).

• Applied Science and Convergence Technology
• /
• 제25권5호
• /
• pp.88-91
• /
• 2016

The $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+xwt%PbO systems at temperature of $1250^{\circ}C$ for 4 hours was successful synthesized. In this study, PbO-doped $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$ systems with non-linear behaviors showed ordering-degree dependence at the low temperature range were prepared using the columbite precursor method. And the characteristic of remnant polarization vs. electric field were analyzed. The pyroelectric, dielectric and piezoelectric properties of partially disordered $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+xwt%PbO solid solutions were studied as a function of temperature, frequency, and electric field. It showed distinct features of temperature dependent of pyroelectric coefficient, spontaneous polarization and dielectric constant at about $50^{\circ}C$. The figure of merit was calculated as pyroelectric coefficient, dielectric constant and dissipation factor. It was found that the high voltage responsivity FV, high detectivity FD were $0.0373m^2/C$ and $0.6735{\times}10^{-4}Pa{-1/2}$, respectively, in the $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+3.0 wt%PbO system.

• ALGAE
• /
• 제34권2호
• /
• pp.163-175
• /
• 2019

To compare the nutritional quality of TPG (Teleaulax / Plagioselmis / Geminigera) clade species of cryptomonads with that of RHO (Rhodomonas / Rhinomonas / Storeatula) clade species 6 Teleaulax amphioxeia (TA) and 1 Rhinomonas sp. strains were mass-cultured in newly designed 500-L photobioreactors to the end of exponential growth phase. Intraspecific variations (IVs) in terms of one standard deviation among the 6 TA strains in the compositions of the three macronutrients were 41.5 (protein), 89.8 (lipid), and 15.6% (carbohydrate) of the mean. When harvested from stationary growth phase mean compositions of essential amino acids (EAAs, 47.3%) and non-EAAs (52.7%) of the 2 TA strains, CR-MAL07 and CR-MAL08-2, were similar to those of a Chroomonas strain. The IVs between the 2 TA strains in the composition of EAAs (10.3 and 2.4) and non-EAAs (8.5 and 2.1% of the mean) were rather smaller than those of saturated fatty acids (30.3 and 26.1) and unsaturated fatty acids (UFAs, 12.0 and 12.5% of the mean) in f/2-Si and urea-based compound fertilizer (UCF) culture media, respectively. Mean compositions of eicosapentaenoic acid (EPA, 17.9%) and docosahexaenoic acid (DHA, 12.7%) of total fatty acids of the 2 TA strains were higher than those that of a Chroomonas strain. EPA and DHA compositions exhibited similar level of IVs between the 2 TA strains in f/2-Si (14.6 and 11.0) and UCF media (12.6 and 13.5% of the mean). Thus, the nutritional quality in terms of amino acids, UFAs, EPA, and DHA in a TPG clade species, T. amphioxeia was comparable to those of RHO clade species with notable IVs. Practically, biotechnological targets for TPG clade cryptomonad strains might be subspecies or clone level.

• 한국표면공학회지
• /
• 제54권4호
• /
• pp.178-183
• /
• 2021

The temperature and frequency dependence of the dielectric constant of the BaTiO₃ substituted with two types of donor dopants, Nb⁵⁺ and Ta⁵⁺, respectively, were compared and analyzed. Dielectric specimens of four specific compositions, Ba_0.95Nb_0.05TiO₃, Ba_0.90Nb_0.10TiO₃, Ba_0.95Ta_0.05TiO₃, and Ba_0.90Ta_0.010TiO₃ were prepared by calcining at 1100 ℃ and sintering at 1300 ℃ to have a perovskite structure to measure capacitance. XRD and SEM analysis were used to observe the structure, with particular focus on the integration into the Nb⁵⁺ and Ta⁵⁺ substituted BaTiO₃ crystal lattice. X-ray diffraction peaks in the (200) and (002) planes were observed between 45.10° and 45.45° of the BaTiO₃ solid solution substituted with different fractions of Nb⁵⁺ and Ta⁵⁺. The dielectric properties were analyzed and the relationship between the properties and structure of the substituted BaTiO₃ was established. The fine particles and high density of the substituted BaTiO₃ were maintained like pure BaTiO₃, and in particular, a shift toward the low temperature side of the phase transition temperature range was clearly found, unlike pure BaTiO₃. In addition, the phase transition at a temperature higher than the Curie temperature relatively satisfies the modified Curie-Weiss law.