• 환경생물
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• 제17권1호
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• pp.1-9
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• 1999

산업활동의 부산물인 chlorofluorocarbons(CFCs)와 같은 물질들의 대기권 유입으로 오존층의 파괴가 극심해짐에 따라 자외선의 지표유입량이 증가되는 추세를 보이는데, 특히 중파자외선의 증가는 DNA, 단백질, 지질 등에 의한 흡수를 통하여 생물학적 폐해를 야기할 수 있다는 점에서 주목된다. 최근 측정 결과 우리나라 동해안에서 해수표면에 도달되는 중파자외선 광량의 1%가 수심 l0 m까지 침투하는 것으로 나타났는데, 이는 해양생태계 생산성의 대부분이 해양 수심의 상위 2.5%에 해당되는 투광대에 의존한다는 점을 감안할 때 자외선에 의한 막대한 생태학적 폐해를 예견하게 해준다. 실내배양실험 연구에서 중파자외선은 대형해조류의 생장 및 광합성을 억제하고 광합성 색소를 파괴하는 등의 생물독성학적 효과를 보였다. 반면, 자외선의 피해로부터 해조류를 보호해 주는 몇 가지 기작이 밝혀진 바 있는데, 어린시기의 갈조류 다시마는 청색광에 의한 광재활성화 능력을 함유한 것으로 보이고, 한국산 녹조 구멍갈파래와 홍조 도박류에서는 자외선을 강하게 차단하는 흡수물질이 형성됨을 알 수 있었다. 그러나 이러한 적응기능들이 해조류에서 보편적으로 나타나는 것인지에 대해서는 좀 더 연구가 필요하다. 해양생태계는 대기 중 CO$x_2$를 이용하여 1년에 약 100 Gt의 유기물질을 생산해내고, 인류가 소비하는 식품의 30%를 제공한다는 점에서 자외선에 의한 생물량의 감소는 해조류 뿐만 아니라 먹이망에 의해서 복잡한 연결구조를 지닌 생태계 전체의 붕괴를 야기할 수 있는 심각한 사안이라고 할 수 있다. 따라서, 자외선에 대한 피해를 연구 평가하여 전략을 세우고 이를 예측하는 예보시스템을 개발할 필요성이 절실히 부각된다.

• Journal of Ginseng Research
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• 제45권1호
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• pp.48-57
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• 2021

Background: Ginsenoside Rh2 is well known for many pharmacological activities, such as anticancer, antidiabetes, antiinflammatory, and antiobesity properties. Glycosyltransferases (GTs) are ubiquitous enzymes present in nature and are widely used for the synthesis of oligosaccharides, polysaccharides, glycoconjugates, and novel derivatives. We aimed to synthesize new ginsenosides from Rh2 using the recombinant GT enzyme and investigate its cytotoxicity with diverse cell lines. Methods: We have used a GT gene with 1,224-bp gene sequence cloned from Lactobacillus rhamnosus (LRGT) and then expressed in Escherichia coli BL21 (DE3). The recombinant GT protein was purified and demonstrated to transform Rh2 into two novel ginsenosides, and they were characterized by nuclear magnetic resonance (NMR) techniques and evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Results: Two novel ginsenosides with an additional glucopyranosyl (6→1) and two additional glucopyranosyl (6→1) linked with the C-3 position of the substrate Rh2 were synthesized, respectively. Cell viability assay in the lung cancer (A549) cell line showed that glucosyl ginsenoside Rh2 inhibited cell viability more potently than ginsenoside Rg3 and Rh2 at a concentration of 10 μM. Furthermore, glucosyl ginsenoside Rh2 did not exhibit any cytotoxic effect in murine macrophage cells (RAW264.7), mouse embryo fibroblasts cells (3T3-L1), and skin cells (B16BL6) at a concentration of 10 μM compared with ginsenoside Rh2 and Rg3. Conclusion: This is the first report on the synthesis of two novel ginsenosides, namely, glucosyl ginsenoside Rh2 and diglucosyl ginsenoside Rh2 from Rh2 by using recombinant GT isolated from L. rhamnosus. Moreover, diglucosyl ginsenoside Rh2 might be a new candidate for treatment of inflammation, obesity, and skin whiting, and especially for anticancer.

• 대한수학회보
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• 제51권3호
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• pp.659-666
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• 2014

Let $\mathcal{A}$ be the class of analytic functions f in the open unit disk $\mathbb{U}$={z : ${\mid}z{\mid}$ < 1} with the normalization conditions $f(0)=f^{\prime}(0)-1=0$. If $f(z)=z+\sum_{n=2}^{\infty}a_nz^n$ and ${\delta}$ > 0 are given, then the $T_{\delta}$-neighborhood of the function f is defined as $$TN_{\delta}(f)\{g(z)=z+\sum_{n=2}^{\infty}b_nz^n{\in}\mathcal{A}:\sum_{n=2}^{\infty}T_n{\mid}a_n-b_n{\mid}{\leq}{\delta}\}$$, where $T=\{T_n\}_{n=2}^{\infty}$ is a sequence of positive numbers. In the present paper we investigate some problems concerning $T_{\delta}$-neighborhoods of function in various classes of analytic functions with $T=\{2^{-n}/n^2\}_{n=2}^{\infty}$. We also find bounds for $^{\delta}^*_T(A,B)$ defined by $$^{\delta}^*_T(A,B)=jnf\{{\delta}&gt;0:B{\subset}TN_{\delta}(f)\;for\;all\;f{\in}A\}$$ where A, B are given subsets of $\mathcal{A}$.

• 상하수도학회지
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• 제23권4호
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• pp.459-469
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• 2009

It is well known that coagulation pretreatment can reduce foulants prior to membrane filtration. The purpose of this research was to investigate the effects of coagulation on fouling of ceramic microfiltration membrane($0.1 {\mu}m$) using pilot plant of $150m^3/day/train$ capacity. Train A membrane system has pretreatment process of ozonation and coagulation while train B has only coagulation. Two types of coagulation operation were investigated: back mixer(rapid mixing with or without slow mixing) which is a conventional mechanically stirred mixer and an inline static mixer. Ozone dose rate for train A was 1 mg/L and ozone contact time was 12 min. The coagulation dose(PACl 10% as $Al_2O_3$) rate was changed 20~40 mg/L according to experimental schedule. In this experimental conditions, the coagulation of back mixer type with rapid mixing(GT=72,000) and slow mixing(GT=45,000) was the best effective in reduction of ceramic membrane fouling regardless preozonation. Especially, the effect of inline static mixer was sensitive to change in water quality. Ozonation mainly affected irreversible fouling rather than reversible fouling in accordance with less adsorption of NOM on the membrane surface. Thus, the increase rate of the nomalized TMP(trans membrane pressure) at $25^{\circ}C$ for train A was relatively lower than that of train B under same coagulation process with same coagulant dosage. The best performance of ceramic membrane appeared in case of combined process with ozonation, therefore this integrated process is able to archive less coagulant dosing and secure a stability of ceramic membrane system.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.3015-3020
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• 2016

Background: Numerous studies have investigated associations of DNA methyltransferase (DNMT) -149 C>T and -579 G>T polymorphisms with gastric cancer (GC) and colorectal cancer (CRC) susceptibility; however, the findings are inconsistent prompting the present meta-analysis. Materials and Methods: Related studies were identified from PubMed, Google scholar, and SID until 10 October 2015. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. Results: Eleven studies were included based on the search criteria for CRC and GC related to the DNMT3B 149 C>T (3,353 cases and 4,936 controls) and DNMT3B 579 G>T (1,387 cases and 2,064 controls) polymorphisms. There was no significant association overall between DNMT3B -149 and 579 polymorphisms and the risk of cancer. In the stratified analysis by cancer type, DNMT3B 579G>T polymorphism was associated with the risk of CRC and GC. While the DNMT3B -149C/T polymorphism was related with a significantly increased risk of CRC in two tested models, dominant (GG+GT vs. TT: OR 0.51, 95 % CI 0.38-0.69; P = 0.00, Pheterogeneity=0.69, $I^2=0%$) and heterozygote (GT vs. TT: OR 0.50, 95 % CI 0.37-0.69; P=0.00, Pheterogeneity=0.41, $I^2=0%$), no evidence of any association with GC risk was observed as in the pooled analyses. Conclusions: More studies are needed to assess associations of DNMT3B -149C/T and DNMT3B 579G>T polymorphisms with cancer in different ethnicities with large population sizes to generate comprehensive conclusions.

• 한국식품과학회지
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• 제36권2호
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• pp.349-354
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• 2004

수산식품에서 문제가 되는 식중독 균인 V. parahaemolyticus를 대상으로 온도, pH 및 초기균수에 따른 균의 성장 실험 결과를 데이터베이스화하여 이를 바탕으로 균의 성장을 정량적으로 평가할 수 있는 수학적 모델을 개발하였다. $1.0{\times}10^{2},\;1.0{\times}10^{3},\;1.0{\times}10^{4}\;CFU/mL$의 각 초기균수 조건에서 실험치와 예측치의 상관계수는 각각 0.966, 0.979, 0.965으로 나타났다. 또한, 초기균수를 고려하지 않은 모델식은 상관계수가 0.966으로 다음과 같이 나타났다. Polynomial model: $$k=1.10{\cdot}\exp(-0.5(((T-34.14)/9.09)^{2}+((pH-6.59)/4.68)^{2}))$$ 균의 증식 지표치인 최대증식속도상수 k는 온도에 지배적인 영향을 받았으며, pH 및 초기균수에 따른 유의적인 차이는 없었으므로 (P>0.05), k와 온도와의 관계식인 square root model로 나타내었다. Square root model: $${\sqrt{k}\;0.06(T-9.55)[1-\exp(0.07(T-49.98))]$$ V. parahaemolyticus의 경우, square root model에 의한 실험치와 예측치의 상관계수는 0.977로 polynomial model보다 높은 적용성을 나타내었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5317-5324
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• 2014

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene may influence the risk of cancer, but the results are still debatable. Therefore, we performed a systematic review to provide a more complete picture and conducted a meta-analysis to derive a precise estimation. We searched PubMed, EMBASE, EBSCO, Google Scholar and China National Knowledge Infrastructure (CNKI) databases until April 2014 to identify eligible studies. Thirty-one studies with cancer patients and controls were included in the meta-analysis. Overall, the polled analysis revealed that the T-786C polymorphism was significantly associated with increased cancer risk under multiple genetic models (C vs T: OR=1.135, 95%CI=1.048-1.228; CC vs TT: OR=1.278, 95%CI=1.045-1.562; TC vsTT: OR=1.136, 95%CI=1.023-1.261; CC+TC vs TT: OR=1.159, 95%CI=1.047-1.281; CC vs TC+TT: OR=1.204, 95%CI= 1.003-1.447). G894T was associated with significant risk for females (TT vs GG: OR=1.414, 95%CI=1.056-1.892; TT vs GT+GG: OR=1.356, 95%CI=1.108-1.661) and for breast cancer (T vs G: OR=1.097, 95%CI=1.001-1.203; TT vs GG: OR=1.346, 95%CI=1.012-1.789; TT vs GT+GG: OR=1.269, 95%CI=1.028-1.566). Increased susceptibility was revealed for prostate cancer with 4a/b (ba vs bb: OR=1.338, 95%CI=1.013-1.768; aa+ba vs bb: OR=1.474, 95%CI=1.002-2.170). This meta-analysis indicated that the eNOS T-786C polymorphism is associated with elevated cancer risk; the G894T polymorphism contributes to susceptibility to breast cancer and cancer generally in females; and the 4a/b polymorphism may be associated with prostate cancer risk.

• 천문학회지
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• 제40권4호
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• pp.99-106
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• 2007

Statistical analyses were performed to investigate the relative success and accuracy of daily maximum X-ray flux (MXF) predictions, using both multilinear regression and autoregressive time-series prediction methods. As input data for this work, we used 14 solar activity parameters recorded over the prior 2 year period (1989-1990) during the solar maximum of cycle 22. We applied the multilinear regression method to the following three groups: all 14 variables (G1), the 2 so-called 'cause' variables (sunspot complexity and sunspot group area) showing the highest correlations with MXF (G2), and the 2 'effect' variables (previous day MXF and the number of flares stronger than C4 class) showing the highest correlations with MXF (G3). For the advanced three days forecast, we applied the autoregressive timeseries method to the MXF data (GT). We compared the statistical results of these groups for 1991 data, using several statistical measures obtained from a $2{\times}2$ contingency table for forecasted versus observed events. As a result, we found that the statistical results of G1 and G3 are nearly the same each other and the 'effect' variables (G3) are more reliable predictors than the 'cause' variables. It is also found that while the statistical results of GT are a little worse than those of G1 for relatively weak flares, they are comparable to each other for strong flares. In general, all statistical measures show good predictions from all groups, provided that the flares are weaker than about M5 class; stronger flares rapidly become difficult to predict well, which is probably due to statistical inaccuracies arising from their rarity. Our statistical results of all flares except for the X-class flares were confirmed by Yates' $X^2$ statistical significance tests, at the 99% confidence level. Based on our model testing, we recommend a practical strategy for solar X-ray flare predictions.

• 수산해양교육연구
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• 제22권2호
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• pp.218-230
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• 2010

This study was conducted to determine the effect of the noise level on the boarding environment in a stern trawl ship, KAYA(GT: 1,737 tons, Pukyong National University). We measured the noise level at a working, an accommodation and a teaching area, and an engine space on January 9, 2010 while the KAYA was sailing on a liner sea route. At the working area, the ranges of the noise rating number(NRN) and the NRN determination frequency(FNRN) were from 44 to 73 and from 1000 to 2000Hz, respectively. The results were generally satisfied the criteria of the International Maritime Organization(IMO). The noise level at the area, except the radio room(w2), was exceeded the criteria(50dB(A)) for the efficient studying and working. The noise level at the engine control room and the machine workshop was respectively exceeded 1.2dB and 9.5dB than the criteria caused the conversation disturbance (70dB(A)). At the accommodation, NRN and FNRN were from 49 to 54 and from 1000 to 4000Hz, respectively. The noise level was below the criteria of IMO, but above 40dB(A) caused the sleep disturbance. At the teaching area, NRN and FNRN were from 44 to 63 and from 500 to 2000Hz, respectively. The noise level was exceeded than the criteria(50dB(A)) for the efficient studying. At the engine space, NRN and FNRN were from 95 to 100 and from 2000 to 4000Hz, respectively. The noise level was above the criteria of IMO(90dB(A)) for the residence, while it was not exceeded 110dB(A) for the transient.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.443-450
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• 2017

Dawley 계 숫컷 흰쥐(200~210g)를 정상군, $CCl_4$-대조군, $CCl_4$-실험군으로 나누어 실험군은 갈근 에탄올 추출물을 1,000mg/kg,b.w의 용량으로 1일1회7일간 경구 투여 후 사염화탄소를 0.6mg/kg,b.w의 용량으로 복강내 주사 후 다음날 개복하여 혈청내의 Alanine aminotransferase(ALT), Aspartate aminotransferase(AST), Alkaline phosphatase(ALP), Glutamyltranspeptidase(${\gamma}$-GT), Lactate dehydro-genase(LDH)의 활성도와 중성지방, 콜레스테롤 함량을 측정한 결과 갈근 추출물 투여군에서 $CCl_4$-대조군과 비교하여 유의적인 감소(p<0.05)를 나타내었으며, HDL-콜레스테롤은 유의적인 증가(P0.05)를 나타내었다. 간조직중의 지질과산화 함량과 Catalase(CAT), Glutathione peroxiddase(GSH-Px)의 항산화 효소 활성은 유의적인 감소를 나타내었다. 반면에 간 조직중의 glutathione 함량은 유의적인 증가를 나타내었다. 이 실험 결과 갈근 에탄올 추출물은 사염화탄소 투여에 의한 간 손상을 억제하는 보호물질과 항산화 물질을 함유하고 있음을 알 수 있었다.