• 한국지반환경공학회 논문집
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• 제15권5호
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• pp.39-46
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• 2014

본 연구에서는 다양한 호기/혐기조건에서 유류오염물질인 및 MTBE의 생분해 특성을 비교하고, 특히 탈질 조건에서 질산염 영향을 조사하여 유류오염지역의 혐기적 자연정화방법의 적용 가능성을 평가하고자 한다. 단일기질 및 혼합기질 분해실험 결과, BTEX는 3가지 실험조건에서 차이는 있었으나 모두 분해가 일어났다. 그러나 benzene과 p-xylene은 호기성 조건에서 초기 공급된 용존 산소의 부족으로 인하여 분해가 지연되는 것으로 나타났다. 또한 혼합기질에서는 단일기질에 비해 BTEX 분해가 기질 경쟁관계로 인해 다소 지연되는 경향이 관찰되었다. MTBE는 탈질 조건에서만 생분해가 관찰되었으나, TBA 축적 없이 $CO_2$로 무기화되는 것으로 추정된다. 또한 BTEX 및 MTBE 분해에 대한 질산염 농도의 영향 실험 결과, 저농도(>50 mg/L)에서 BTEX 분해는 제한되었으며, 고농도 질산염(<200 mg/L) 조건하에서는 BTEX 분해가 억제되는 현상이 관찰되었다. 본 연구에서 도출된 결과는 유류오염지역의 경우 호기/혐기성 조건에서 자연 생분해를 유도할 수 있을 것으로 예상된다.

• 지질공학
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• 제12권4호
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• pp.471-484
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• 2002

금강 유역의 충적층(면적 $3,029\textrm{km}^2$)에는 총 81억톤에 이르는 지하수가 부존하는 것으로 알려져 있으나, 과도한 농업활동에 의해 질소계 비료의 사용량이 증가함(250 N kg/ha 이상)에 따라 질산염 오염이 증가하고 있다 본 연구에서는 금강 권역의 대표적인 충적층 분포 지역의 충적층 지하수를 대상으로 질산염의 오염 현황 및 거동 특성을 파악하고자 광역적인 수리지구화학 연구를 수행하였다. 채취된 지하수 시료(총 186개)는 대체적으로 높은 질산염 농도(평균 42.2 mg/L, 최대 295 mg/L)를 보여주어 심하게 오염되어 있음을 나타내었다. 특히, 채취된 시료의 약 29%는 먹는물 수질 기준(44 mg/L $NO_3$)을 초과하고 있다. 연구지역 내 지하수 중의 질산염의 분포는 충적 대수층의 지구화학적 환경에 따라 크게 좌우되고 있다. 특히, 충적층 지하수의 산화-환원 전위(Eh)의 감소는 질산염의 농도 및 철과 망간의 농도 감소와 뚜렷한 상관성을 나타내었다. 따라서, 충적 대수층 지질매체 자체의 퇴적 환경의 차이를 반영하는 것으로 판단되는 산화-환원 상태(redox state)의 변화는 충적층 지하수 내의 질소계 오염물질의 거동을 지배함은 물론 탈질(denitrification)에 의한 자연저감을 조절하고 있는 것으로 판단된다. 특히, 탄소가 풍부한 실트질 충적층의 존재는 혐기성 환경을 조성함으로써, 질산염 오염에 대하여 상당한 정도의 완충 능력을 지니게 하는 것으로 판단된다.

• Animal cells and systems
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• 제1권4호
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• pp.595-602
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• 1997

Treatment of newborn female rats with gonadal steroids induces permanent sterility in adulthood. We investigated the alteration in expression patterns of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) in neonatally estrogenized sterile rats (ESR). Newborn female rats received daily injections of 17${\beta}$-estradiol (E, 10 ${\mu}$g) from the day of birth (day 1) to postnatal day 5. Controls were subjected to vehicles over the same period. All animals were sacrificed on week 7 after birth. Hypothalamic GnRH mANA levels were markedly higher in all ESR than in controls, while hypothalamic GnRH contents in ESR increased in proportion to the frequency of daily administration of E. However, both pituitary LH6 mRNA and serum LH levels were inversely decreased by the same treatment. The data indicate that neonatal exposure of E equally elevates the expression of GnRH gene, but reduces the secretion of GnRH, accordingly leading to attenuation of LH6 gene expression and circulating LH levels. The temporal effect of E and/or progesterone (P) on GnRH and LH6 mRNA levels was also examined in ESR. Newborn female rats were daily injected with E (10 ${\mu}$g) or vehicle for five successive days from day 1 and ovariectomized at week 5. They were implanted with E (235 ${\mu}$g/ml) two days prior to week 7, injected with P (1 mg) 42 h later, and sacrificed 7 h after P administration. In ovariectomized controls, hypothalamic GnRH mRNA levels were dropped to half by treatment of E and restored by subsequent treatment of P. The negative feedback action of E on GnRH mRNA levels observed in ovariectomized rats was completely blocked by neonatal exposure of E. The change in pituitary LH mRNA levels was similar to that in hypothalamic GnRH mRNA levels. Taken together, the results suggest that neonatal treatment of E alters the synthesis and release of GnRH in adulthood and furthermore blocks the negative feedback regulation of E which occurs normally after ovariectomy.

• Earthquakes and Structures
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• 제18권2호
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• pp.223-231
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• 2020

Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It occurred since 1900, the seismicity of the region was obtained statistically by considering the earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study, magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may affect the peak ground acceleration according to various attenuation relationships are calculated and using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5, 7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03 g, 0.58 g and 0.24 g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is high and the importance of considering the earthquake effect during construction is emphasized for this region.

• Animal cells and systems
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• 제4권2호
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• pp.173-179
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• 2000

Evidence suggested that atypical antipsychotics (APs) such as clozapine show less side effects than those of typical APs such as haloperidol and sulpiride. However, little is known about chronic effects of these drugs on changes in gonadotropin releasing hormone (GnRH) mRNA expression and luteinizing hormone (LH) immunoreactivity. Male rats were divided into water-, haloperidol-, sulpiride-, and clozapine-treated groups, and these drugs were administered orally for 4 weeks. The changes in the expression of GnRH mRNA and the LH immunoreactivity were determined in the hypothalamus and pituitary, respectively, using in situ hybridization and immunohistochemistry. GnRH mRNAs were clearly expressed in the water-treated control vats. This was significantly reduced by the chronic treatments with the typical APs, especially with haloperidol, but not with atypical APs clozapine. Likewise, LH immunoreactivity was clearly stained in the control group. While its immunoreativity was significantly reduced by the chronic APs treatments, clozapine treatment showed only slight attenuation. The results show that the atypical APs clozapine has less side effects in the gonadal function than the typical APs haloperidol and the sulpiride. These results suggest that clozapine is a safer drug than the typical APs, at least in the reproductive system.

• 한국지진공학회논문집
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• 제28권3호
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• pp.121-128
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• 2024

There are growing concerns that the recently implemented Earthquake Early Warning service is overestimating the rapidly provided earthquake magnitudes (M). As a result, the predicted damages unnecessarily activate earthquake protection systems for critical facilities and lifeline infrastructures that are far away. This study is conducted to improve the estimation accuracy of M by incorporating the observed S-wave seismograms in the near source region after removing the site effects of the seismograms in real time by filtering in the time domain. The ensemble of horizontal S-wave spectra from at least five seismograms without site effects is calculated and normalized to a hypocentric target distance (21.54 km) by using the distance attenuation model of Q(f)=348f^0.52 and a cross-over distance of 50 km. The natural logarithmic mean of the S-wave ensemble spectra is then fitted to Brune's source spectrum to obtain the best estimates for M and stress drop (SD) with the fitting weight of 1/standard deviation. The proposed methodology was tested on the 18 recent inland earthquakes in South Korea, and the condition of at least five records for the near-source region is sufficiently fulfilled at an epicentral distance of 30 km. The natural logarithmic standard deviation of the observed S-wave spectra of the ensemble was calculated to be 0.53 using records near the source for 1~10 Hz, compared to 0.42 using whole records. The result shows that the root-mean-square error of M and ln(SD) is approximately 0.17 and 0.6, respectively. This accuracy can provide a confidence interval of 0.4~2.3 of Peak Ground Acceleration values in the distant range.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권4호
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• pp.27-35
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• 2003

연구대상부지는 주로 선캄브리아기의 변성암의 일종인 편마암으로 형성되어 있으며, 토양은 하천에 축적된 비교적 투수성이 높은 매질로 구성된 충적토를 모재로 형성되었다. 지하수위는 지표로부터 평균 3.5m 깊이에서 나타나며. 하류 방향으로 갈수록 깊어지는 경향을 나타내었다. 대상부지의 수리전도도는 자갈이 혼재된 조립질 모래층은 5.0${\times}$$10^{-2}$∼1.85${\times}$$10^{-1}$ cm/sec, 세립질 모래층은 $1.5{\times}$$10^{-3}$ to 7.6${\times}$$10^{-3}$ cm/sec, 복토층은 $10^{-4}$ cm/sec 이하로 나타났다. 연구대상부지의 주오염물질은 Toluene, Ethylbenzene, xylene(이하 TEX)이며, 오염토양층은 1.5 m내외로 깊이별 토양중 TEX의 농도는 추정오염원으로부터 70m떨어진 곳의 질이 2.4∼4.8m에서 가장 높았다. 지하수중 TEX의 농도는 추정오염원의 주변지역에서 가장 높았으며, 조사대상부지의 중앙지역과 남서쪽지역에서도 높게 나타났으며, 이러한 지하수중 TEX의 농도분포는 토양중의 TEX의 농도분포와 상당히 일치하는 경향을 보이고 있다. 연구대상부지에 서식하고 있는 톨루엔 분해 호기성세균의 주종은 Pseudomonas fluorescence, Burkholderia cepacia, Acinetobactor lwoffi로 확인되었다. 지하수 분석결과 전자수용체인 용존산소, 질산염, 황산염 등이 배경지역에 비해 오염지역에서 상당히 낮게 나타났다. 한편, 연구대상부지에서의 계산된 전체 자연저감속도는 0.0017da $y^{-1}$이며, 1차 생분해속도는 0.0008 da $y^{-1}$로 계산되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.732-737
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• 2008

This study developed a natural ingredient as a functional food possessing properties of attenuation of hypertension and cardiovascular hypertrophy. In a previous study hydrolysates obtained from chicken leg bone protein using Alcalase strongly inhibited angiotensin I converting enzyme (ACE) in vitro. In particular, hydrolysate (A4H) from four hours of incubation exhibited the highest ACE inhibitory activity (IC50 = 0.545 mg/ml). A4H was selected as a potent ACE inhibitor and orally administrated to spontaneously hypertensive rats (SHR) for eight weeks to investigate attenuating effects on age-related development of hypertension and cardiovascular hypertrophy. Results showed that treatment with A4H of SHRs attenuated the development of hypertension as effectively as the clinical antihypertensive drug captopril. Moreover, a significantly lower heart to body weight ratio and thinness of coronary arterial wall was observed in SHRs that had been treated with A4H or captopril. The results suggest that A4H can be utilized in developing an ACE inhibitor as a potential ingredient of functional foods to alleviate hypertension and cardiovascular hypertrophy.

• 자원환경지질
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• 제9권4호
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• pp.213-223
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• 1976

해저(海底) 지층(地層)에서의 탄성파(彈性波)의 전파(傳播)와 감쇠(減衰)에 관하여 현재까지 부분적(部分的)으로 알려져있는 연구 결과(決果)를 토대로, 기본이론(基本理論)으로 부터 실제(實際)문제까지 재정리(再整理)를 시도(試圖)하였다. 탄성파(彈性波)의 기본(基本) 관계식을 유도(誘導)하고 해수내(海水內)에서의 전파(傳播), 해저면(海底面)에 의한 탄성파(彈性波)의 반향(反響)과 퇴적물(堆積物)의 물리적성질(物理的性質)의 관계(關係)를 다루었다.

• 대한본초학회지
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• 제31권1호
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• pp.1-5
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• 2016

Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on insulin resistance in rat skeletal muscle cells, L6 cells.Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Activity of α-glucosidase in POE was measured for blood glucose regulation. MTT assay was examined for cell toxicity. Western blot analysis for measurement of adiponectine, peroxisome proliferator-activated receptorγ (PPARγ), insulin receptor substrate (IRS), glucose transporter 4 (Glut-4) and phosphorylation of serine/threonine-specific protein kinase (Akt) expressions were performed. Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor.Results : The results revealed that POE inhibited α-glucosidase activity. Treatment of POE in L6 cells inhibited the differentiation of L6 cells compared to those of vehicl control. Additionally, protein expressions of adiponectine, PPARγ, IRS and Glut-4 were significantly regulated compared to those of vehicle control (p < 0.05), respectively. Futhermore, phosphorylation of Akt was increased in L6 cells treated with POE compared to that of vehicle control (p < 0.05). pAkt expression was significantly accentuated with Akt inhibitor (LY294002).Conclusions : These results suggest that POE may have potential as a natural agent for prevention/improvement of diabetes, especially, regulation of blood glucose. Therefore, further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.