• Journal of Ecology and Environment
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• 제45권3호
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• pp.97-104
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• 2021

Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m²) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (G_st = 0.548, N_m = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

• 식물분류학회지
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• 제41권3호
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• pp.182-193
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• 2011

As a part of the on-going effort to conserve endangered Scrophularia takesimensis Nakai in Korea, its genetic structure and diversity from 3 population, consisted of 14 subpopulations in Ulleung Island were analyzed using RAPD band patterns. Out of 60 primers tested, 33 generated amplified bands with its genome, including 149 polymorphic and 67 monomorphic bands. The highest number (146) was found in northern population, especially, 64 in HY subpopulation; the smallest (40) in eastern population. An examination of its genetic structure with AMOVA revealed that about 60% of all variations could be assigned to among subpopulations within populations. Population differentiation among populations and subpopulations is seriously going now because of habitat fragmentation due to human activities, such as road and small port construction. Although the habitats of S. takesimensis in Ulleung Island, Korea are disappeared at an alarming rate, significant levels of genetic variation still exist at species level, and population level, especially northern population. Therefore, three conservation strategies should be needed urgently; 1) preservation of populations as it stands, 2) establishment of recovery plan to connect population and subpopulations genetically, and 3) long-term monitoring.

• Journal of Microbiology and Biotechnology
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• 제5권1호
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• pp.36-40
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• 1995

Valistatin, a new inhibitor of aminopeptidase M(AP-M) was discovered in the culture broth of Streptomyces sp. SL20209 isolated from a soil sample. The inhibitor was purified by extraction with n-butanol and the various column chromatographies, and then isolated as whitish powder. The $^1 H-and ^1 H, ^1 H-COSY$ NMR studies, amino acid analysis, and fragmentation patterns by FAB-MS suggested the presence of one 3-amino-2-hydroxy-4-phenylbutanoic acid and two valine residues in the inhibitor. Thus, the structure of valistatin was determined as 3-amino-2-hydroxy-4-phenylbutanoyl-valyl-valine. Valistatin has the molecular formular $C_20H_31N_3 O_5$ (MW 394), and its $IC_50$ value against hog kidney AP-M was determined to be 3.12 $mu g/ml$.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.41-41
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• 2003

To elucidate the apoptosis mechanism of Trichoplusia ni cell, fundamental studies for apoptosis induction and suppression were performed. Hygromycin B, a known inducer of apoptosis, started the inhibition of T ni cell growth at 200 ug/$m\ell$ concentration. Furthermore, at 400 $\mu\textrm{g}$/$m\ell$ concentration, DNA fragmentation was detected on day 2 of incubation. (omitted)

• Clinical and Experimental Reproductive Medicine
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• 제50권1호
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• pp.53-62
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• 2023

Objective: The aim of this study was to investigate the relationships of serum folate (vitamin B9), cobalamin (vitamin B12) levels and diet with semen parameters (semen standard parameters [SSP] and DNA fragmentation index [DFI]) in infertile men. Methods: Sperm samples were assessed for SSP and DFI (using the sperm chromatin dispersion test). Serum vitamin concentrations were measured with an immuno-electrochemiluminescence assay, and men completed a semi-quantitative food frequency questionnaire (FFQ). Results: Serum folate levels were positively correlated with sperm progressive motility and DFI. A comparison of SSP between two groups of patients according to serum folate concentration (B9 <4.840 ng/mL and B9 ≥4.840 ng/mL) showed significantly higher sperm concentration and sperm progressive motility in the latter group. However, there was no difference between these groups regarding DFI. Interestingly, serum folate levels were significantly higher in patients with a high DFI (using the cut-offs of 30% or 18%). FFQ data showed that the consumption of fruits and egg yolk correlated positively with sperm concentration and sperm motility, respectively. Conclusion: Serum folate levels showed significant associations with sperm concentration and sperm progressive motility. However, the positive association of serum folate with DFI raises the need for careful prescription of folate supplements.

• 한국인터넷방송통신학회논문지
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• 제17권5호
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• pp.131-136
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• 2017

최근 인터넷 미디어의 발달로 웹상에 수많은 문서자료들이 기하급수적으로 늘어나게 되었다. 이러한 자료들은 대부분 텍스트에 의해 그 내용이 무엇인지를 설명하고 있고 이에 따라 분류된다. 그러나 텍스트가 가지는 의미는 모호하게 해석되어질 여지가 많고 이를 정확히 해석하기 위해서는 다각도로 이를 살펴봐야 한다. 기존의 분류 방법에서는 단순히 텍스트의 출현만을 가지고 분류를 하였다. 따라서, 본 논문에서는 이를 유전자 알고리즘과 토픽추출을 기반으로 하여 용어 중의성을 분석하고 이를 단편화한 클러스터링 시스템을 구현하였다. 마지막으로 구현된 결과물을 토대로 기존의 방법과 비교하여 본 논문의 성능을 평가하였다.

• BMB Reports
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• 제44권3호
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• pp.211-216
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• 2011

Vitamin C (VC) is an important antioxidant and enzyme co-factor that works by stimulating the immune system and protecting against infections. It is well known that melanoma cells are more susceptible to VC than any other tumor cells. However, the role of VC in the treatment of colon cancer has not been studied. Cisplatin (CDDP) is a DNA damaging agent and is widely used for treating cancer, while the role of p53 in CDDP-induced cell death has been stressed. Using cell growth assays, morphological methods, Western blotting, flow cytometry, and DNA fragmentation analysis, we measured the expression of p53 level involved in the effect of VC on CDDP-induced apoptosis of HCT116, a human colon cancer cell line. CDDP plus VC treatment resulted in significantly increased apoptosis along with upregulation of p53 compared to untreated cells and/or CDDP-treated cells. These results suggest that VC enhanced CDDP sensitivity and apoptosis via upregulation of p53.

• Animal cells and systems
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• 제16권4호
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• pp.321-328
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• 2012

The oily bittering Acheilognathus koreensis is a freshwater species that is endemic to Korea and is experiencing severe declines in natural populations as a result of habitat fragmentation and water pollution. For the conservation and restoration of this species, it is necessary to assess its genetic diversity at the population level. We developed 13 polymorphic microsatellite loci that were used to analyze the genetic diversity of two populations collected from the Kum River and the Tamjin River in Korea. All loci exhibited Mendelian inheritance patterns when examined in controlled crosses. Both populations revealed high levels of variability, with the number of alleles ranging from 3 to 20 and observed and expected heterozygosities ranging from 0.500 to 0.969 and from 0.529 to 0.938, respectively. None of the loci showed significant deviation from Hardy-Weinberg equilibrium, and one pair of loci showed significant linkage disequilibrium after Bonferroni correction. Pairwise $F_{ST}$ and genetic distance estimation showed significant differences between two populations. These results suggest that the microsatellites developed herein can be used to study the genetic diversity, population structure and conservation measure of A. koreensis.

• Applied Microscopy
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• 제40권4호
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• pp.229-235
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• 2010

암은 전 세계적으로 사망률이 높은 질병으로 현재 자궁암 치료는 cisplatin, 5-fluorouracil (5FU) 등의 항암화학요법과 방사선 요법 등을 복합적으로 병행하고 있다. 최근 항암효과를 가지고 있는 자연식품의 섭취에 관심이 커지면서 커리의 주성분인 curcumin (CMN), 녹차의 주성분인 카테킨, 토마토의 주성분인 리코펜 등의 약리효과에 대한 연구가 활성화되고 있다. CMN은 동물실험 결과 항염증의 활성이 있고, 피부, 대장, 유방, 전립선 등에서 암으로의 진행을 억제한다는 보고가 있으나 인체 자궁암에서는 그 효과가 밝혀져 있지않다. 본 연구는 항암제 5FU와 CMN이 인체 자궁암세포 HeLa에 미치는 영향을 apoptosis의 유도로 평가하고, p53유전자 발현율과의 상관관계로 확인하고자 시행하였다. CMN은 HeLa 세포의 성장을 억제하였으며, 5FU로 유도된 apoptosis의 발생률과 p53유전자의 발현률을 현저하게 증가시키는 것으로 나타났다(p<0.05). 이러한 연구결과는 CMN이 자궁암 치료제의 가능성이 있으며, 또한 5FU와 복합적으로 사용하면 항암제를 단독으로 투여하는 경우보다 자궁암 치료에 보다 효과적임을 강력히 시사하는 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.163-168
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• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.