• Mycobiology
• /
• 제51권6호
• /
• pp.379-387
• /
• 2023

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1^T could highly tolerate Cu²⁺ up to 10 mM, and the isolates could also grow in a wide range of pH (3-7), and temperature (10-40 ℃). Dried biomass of GL1 was able to remove Cu²⁺ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 ℃, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권10호
• /
• pp.495-499
• /
• 2004

Characteristics of ohmic Ni/Si/Ni contacts to n-type 4H-SiC are investigated systematically. The ohmic contacts were formed by annealing Ni/Si/Ni sputtered sequentially The annealings were performed at 950℃ using RTP in vacuum ambient and N₂ ambient, respectively. The specific contact resistivity(p/sub c/), sheet resistance(R/sub s/), contact resistance (R/sub c/) transfer length(L/sub T/) were calculated from resistance(R/sub T/) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. While the resulting measurement values of sample annealed at vacuum ambient were p/sub c/ = 3.8×10/sup -5/Ω㎠, R/sub c/ = 4.9 Ω and R/sub T/ = 9.8 Ω, those of sample annealed at N₂ ambient were p/sub c/ = 2.29×10/sup -4/Ω㎠, R/sub c/ = 12.9 Ω and R/sub T/ = 25.8 Ω. The physical properties of contacts were examined using XRD 3nd AES. The results showed that nickel silicide was formed on SiC and Ni was migrated into SiC. This result indicates that Ni/Si/Ni ohmic contact would be useful in high performance electronic devices.

• 인간식물환경학회지
• /
• 제23권2호
• /
• pp.211-220
• /
• 2020

The purpose of this study was to analyze the frequency and contents of horticultural activities in 696 individual activities listed in 11 teacher's guidebooks of Nuri Curriculum for 5-year-olds, and to find out the perceptions of horticultural activities in the formal curriculum. The target horticultural activities that were selected were those using natural objects like potted plants, water, wind, soil, stones, etc. as the topic or subject of activities, and those with different topics but are mentioning plants or natural objects as an example at least twice. The 150 selected horticultural activities were classified by life-based theme, activity type, activity domain, and medium. As a result of examining horticultural activities by life-based theme, there were 150 horticultural activities (21.55%): 40 in Spring, Summer, Autumn and Winter (5.75%), 34 in Animals, Plants, and Nature (4.89%), 22 in Environment and Life (3.16%), 19 in Our Country (2.73%), and nine in Our Neighborhood (1.29%), nine in Various Countries of the World (1.29%), four in Health and Safety (0.57%), four in Living tools (0.57%), four in Transportation (0.57%), three in Kindergarten and Friends (0.43%), two in Me and My Family (0.29%; χ²=130.427, p < .001). As a result of examining horticultural activities by activity type, there were 61 free choice activities (40.67%), 80 large and small group activities (53.33%), and nine outdoor play activities (6.00%), indicating that outdoor play was the fewest activity type (χ²=54.040, p < .001). The results of analyzing horticultural activities by activity domain showed that there were 25 in conversation (16.67%), 19 in science (12.50%), 14 in art (9.33%), 14 in cooking (9.33%), 10 in fairy tales (6.00%), nine in music (6.00%), eight in language (5.33%), eight in number operation (5.33%), eight in others (5.33%), six in children's plays (4.0%), six in games (4.0%), four in body and movement (2.67%), three in stacking (2.00%), three in roles (2.00%), three in rhythm (2.00%), two in children's poems (1.33%), two in field experience (1.33%) and one in outside play (0.67%; χ²=87.600, p < .001). As a result of examining the mediums used in the horticultural activities, 46 activities (30.67%) directly used plants as the mediums, 11 activities (7.33%) used soil such as stones, gravel, and earth as the mediums instead of plants, four activities (2.67%) used dry plants such as branches and dry leaves as the mediums, and 89 activities (59.33%) used videos, photos of plants, and pictures of plants as the mediums (χ²=121.307, p < .001).

• 한국식품과학회지
• /
• 제53권4호
• /
• pp.446-453
• /
• 2021

본 연구에서는 에탄올 농도에 따른 노니주스 추출물의 총 페놀 및 총 플라보노이드 함량을 측정하고, DPPH radical 소거능, ABTS⁺ radical 소거능 및 환원력을 측정하여 노니주스의 항산화 활성을 확인하였다. 또한 노니주스를 물에 대하여 각각 0, 25, 50, 75, 100%로 대체한 곤약젤리를 제조하여 품질특성 및 관능평가를 실시하였다. 노니주스 추출물의 총 페놀 함량은 0% EtOH 추출물이 6.76 mg GAE/100 g으로 가장 높게 나타났고, 총 플라보노이드는 100% EtOH 추출물이 2.40 mg NE/100 g으로 가장 높은 함량을 나타냈다. DPPH radical 소거능은 50% EtOH 추출물이 72.27%로 가장 높았고, ABTS⁺ radical 소거능은 100% EtOH 추출물이 42.20%로 높게 나타났다. 환원력은 추출용매에 따른 유의적인 차이가 없었다. 노니 곤약젤리의 pH와 수분함량은 시료 첨가량이 증가함에 따라 유의적으로 감소하였고, 당도는 시료 첨가량이 증가할수록 높아지는 경향을 보였다. 조직감 측정 결과, 노니주스의 첨가량이 증가할수록 곤약젤리의 경도와 검성은 증가하였고, 탄력성과 응집성은 감소하는 경향을 나타냈다. 노니 곤약젤리의 색도 측정결과에서 시료 첨가량이 증가할수록 L값과 b값은 감소하고, a값은 시료 50% 첨가량까지 증가하다가 이후에는 감소하는 경향을 보였다. 관능검사 결과에서 색(color)과 향(flavor)의 기호도는 0%와 25% 첨가군이 높은 점수를 받았고, 나머지 평가항목에서는 시료 간의 유의적인 차이가 없었다. 노니 곤약젤리 제조 시 노니주스 25%의 첨가량이 곤약젤리의 항산화 활성을 증가시킬 수 있고 색과 향의 기호도도 높아 가장 적당할 것으로 판단된다.

• 천문학회지
• /
• 제53권2호
• /
• pp.49-57
• /
• 2020

We present numerical simulations of decaying hydrodynamic turbulence initially driven by solenoidal (divergence-free) and compressive (curl-free) drivings. Most previous numerical studies for decaying turbulence assume an isothermal equation of state (EOS). Here we use a polytropic EOS, P ∝ ρ^γ, with polytropic exponent γ ranging from 0.7 to 5/3. We mainly aim at determining the effects of γ and driving schemes on the decay law of turbulence energy, E ∝ t^-α. We additionally study probability density function (PDF) of gas density and skewness of the distribution in polytropic turbulence driven by compressive driving. Our findings are as follows. First of all, we find that even if γ does not strongly change the decay law, the driving schemes weakly change the relation; in our all simulations, turbulence decays with α ≈ 1, but compressive driving yields smaller α than solenoidal driving at the same sonic Mach number. Second, we calculate compressive and solenoidal velocity components separately and compare their decay rates in turbulence initially driven by compressive driving. We find that the former decays much faster so that it ends up having a smaller fraction than the latter. Third, the density PDF of compressively driven turbulence with γ > 1 deviates from log-normal distribution: it has a power-law tail at low density as in the case of solenoidally driven turbulence. However, as it decays, the density PDF becomes approximately log-normal. We discuss why decay rates of compressive and solenoidal velocity components are different in compressively driven turbulence and astrophysical implication of our findings.

• 식물분류학회지
• /
• 제53권1호
• /
• pp.1-8
• /
• 2023

Sustainable habitats play a significant role in determining the survival and habitat preservation of endangered species. To conserve the endangered species Iris dichotoma Pall. and its habitat in Taeanhaean National Park, we collected seeds from a natural population and germinated and propagated them in a greenhouse. In 2019, the propagated individuals of I. dichotoma were transplanted at two study sites in Taeanhaean National Park. After conservation translocation, annual monitoring was conducted from 2020 to 2022, and factors related to the survival and growth of I. dichotoma (clonal propagation rate [%], the flowering rate [%], the population density [individual/m²], the maximum leaf bundle length [height; cm], the maximum leaf bundle width [cm], and the pedicel length [cm]) were measured. According to the results of the monitoring of the flowering and fruiting periods for three years after transplantation, 82.4% of individuals in total were found to have survived. During 2020 to 2022, the mean population density (individual/m²) increased from 0.36 to 0.42 and the size of the leaf bundle length and the width both decreased compared to the corresponding figures in 2019 (p < 0.05). According to the findings here, the transplanted population of I. dichotoma is considered to have adapted successfully to its new site in Taeanhaean National Park.

• 대한간호학회지
• /
• 제53권4호
• /
• pp.453-467
• /
• 2023

Purpose: This study investigated the cumulative effects of depressive symptoms on cognitive function over time in community-dwelling older adults. Methods: Data were investigated from 2,533 community-dwelling older adults who participated in the Korean Longitudinal Study of Aging (KLoSA) from the 5th (2014) to the 8th wave (2020). The association between cumulative depressive symptoms and cognitive function was identified through multiple regression analysis. Results: When the multiple regression analysis was conducted from each wave, the current depressive symptoms scores and cognitive function scores were negatively associated, regardless of the waves (B5th = - 0.26, B6th = - 0.26, B7th = - 0.26, and B8th = - 0.27; all p < .001). Further, when all the previous depressive symptoms scores were added as explanatory variables in the 8th wave, the current one (B8th = - 0.09, p < .001) and the previous ones (B5th = - 0.11, B6th = - 0.09, and B7th = - 0.13; all p < .001) were also negatively associated with the cognitive function score. The delta R², which indicates the difference between the model's R² with and without the depressive symptoms scores, was greater in the model with all the previous and current depressive symptoms scores (6.4%) than in the model with only the current depressive symptoms score (3.6%). Conclusion: Depressive symptoms in older adults have a long-term impact. This results in an accumulated adverse effect on the cognitive function. Therefore, to prevent cognitive decline in older adults, we suggest detecting their depressive symptoms early and providing continuous intervention to reduce exposure to long-term depressive symptoms.

• Animal Bioscience
• /
• 제35권10호
• /
• pp.1556-1565
• /
• 2022

Objective: Tan lambs (n = 36, 3 mo old, 19.1±0.53 kg) were used to assess effects of dietary guanidinoacetic acid (GAA) and rumen-protected methionine (RPM) on growth performance, carcass traits, meat quality, and serum parameters. Methods: Lambs were randomly assigned to three treatment groups, with 6 pens per group and 2 lambs per pen. Dietary treatments were: basal diet alone (I); basal diet supplemented with 0.08% GAA+0.06% RPM (II); and basal diet supplemented with 0.08% GAA+0.08% RPM (III). Diets were provided three times a day for 90 d. Intake per pen was recorded daily and individual lamb body weight (BW) was measured monthly. Carcass traits were measured after slaughter and meat quality at the end of the experiment, blood samples were taken on a subgroup of lambs for analysis of indicators mostly related to protein metabolism. Results: Final BW and average daily gain for the first and second month, and for the entire experiment were greater in Treatment II compared to Treatment I (p<0.05), whereas feed to gain ratio was lower (p<0.05). Treatment II had the optimal dressing percentage and net meat weight proportion, as well as crude protein and intramuscular fat concentrations in muscles. Treatment II improved meat quality, as indicated by the greater water holding capacity, pH after 45 min and 48 h, and lower shear force and cooking loss. Dietary supplementation of GAA and RPM also increased the meat color a^* and b^* values at 24 h. Finally, Treatment II increased total protein, and serum concentrations of albumin and creatinine, but decreased serum urea nitrogen concentrations, indicating improved protein efficiency. Conclusion: In this study, 0.08% GAA+0.06% RPM supplementation improved growth performance and meat quality of Tan lambs.

• 한국식품영양과학회지
• /
• 제33권1호
• /
• pp.1-6
• /
• 2004

$\beta$-Sitosterol은 과일과 야채 등을 포함한 대부분의 고등식물에 존재하는 중요한 phytosterol의 하나로서, 인체 암의 예방과 치료에 매우 유효한 것으로 보고되어져 오고 있다. 본 연구에서는 $\beta$-sitosterol의 암세포 증식억제 기전의 해석을 시도하기 위하여 인체 대장암세포 HCT116의 증식에 미치는 $\beta$-sitosterol의 영향을 조사하였다. $\beta$-Sitosterol의 처리로 HCT116 암세포의 증식은 처리 농도 의존적으로 감소되었으며, 특히 7.5 $\mu$M 이상 처리에서는 급격한 성장억제 효과가 있었다. 또한 5.0 $\mu$M 처리군에서부터 apoptotic body의 형성이 관찰되었고, $\beta$-catenin 단백질의 분해 현상과 연관성이 있었다. 그리고 $\beta$-sitosterol이 처리된 암세포에서는 종양억제유전자 p53 및 Cdk inhibitor p21의 발현이 전사 및 번역 수준에서 모두 증가되었다. 본 결과는 그동안 연구가 거의 진행되어져 있지 않았던 $\beta$-sitosterol에 의한 암세포주기 조절 해석을 위한 주요한 자료로 활용될 것이다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제27권5호
• /
• pp.438-445
• /
• 2005

Cyclosporine A(CsA) is a powerful immunossuppresive agent used to prevent graft rejection of organ and treat autoimmune disease. One of the major side effects associated with CsA treatment is the development of gingival overgrowth. The purpose of this study was to evaluate the expression and association of the several growth factors in gingival overgrowth induced CsA using by immunohistochemical technique. Normal tissues as control were obtained from healthy normal gingivae and overgrowth gingival tissues as experiments were obtained from the patients taken the CsA. The expressions of the MMP-1, TIMP-1, TGF$\beta$-1, p21, p53, PCNA were evaluated by immunohistochemical technique. The more overgrowth was detected at the epithelial and connective tissue area in experimental group. The MMP-1, TGF$\beta$-1, p21, p53, PCNA expressions were significantly increased in experimental group. The TIMP-1 expressions was not significantly increased in experimental group. We could conclude that the gingival overgrowth induced CsA was related with the collagen matabolism in connective tissue and also the production of the growth factor from epithelial tissue.