• Geomechanics and Engineering
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• 제17권5호
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• pp.429-438
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• 2019

Microbially induced carbonate precipitation (MICP) is an innovative soil improvement approach utilizing metabolic activity of microbes to hydrolyze urea. In this paper, the shear response and the erodibility of MICP-treated sand under axial compression and submerged impinging jet were evaluated at a low confining stress range. Loose, poorly graded silica sand was used in testing. Specimens were cemented at low confining stresses until target shear wave velocities were achieved. Results indicated that the erodibility parameters of cemented specimens showed an increase in the critical shear stress by up to three orders of magnitude, while the erodibility coefficient decreased by up to four orders of magnitude. Such a trend was observed to be dependent on the level of cementation. The treated sand showed dilative behavior while the untreated sands showed contractive behavior. The shear modulus as a function of strain level, based on monitored shear wave velocity, indicated mineral debonding may commence at 0.05% axial strain. The peak strength was enhanced in terms of emerging cohesion parameter based on utilizing the Mohr-Coulomb failure criteria.

• 대한약리학회지
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• 제26권1호
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• pp.83-90
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• 1990

Cimetidine이 theophylline의 약동학적 특성과 대사과정에 미치는 효과를 검토코자 6마리의 개를 대상으로 일주일간 정맥내 cimetidine(30mg/kg/day)투여 전후에 단일 용량의 정맥투여에 따른 theophylline의 약동학적 parameter 및 뇨중 theophylline 대사물 배설의 변화를 교차 실험을 통하여 관찰하였다. 대조실험에 비해 cimetidine투여후 theophylline의 청소율은 평균 31%(P<0.05)감소하였고 혈장반감기는 29%(P<0.01)연장되었다. 그러나 steady-state의 분포용적 및 혈장 단백 결합의 변화는 관찰할 수 없었다. Theophylline의 주 대사물인 3-methylxanthine, 1-methyluric acid 및 1,3-dimethyluric acid의 24시간 뇨증 배설량은 cimetidine투여후 모두 감소 하였으나 통계적으로 유의한 변화는 아니었으며 개별대사물의 배설 분획은 변화가 없었다. 이상의 결과로 부터 cimetidine이 theophylline의 demethylation과 8-hydroxylation대사과정 모두를 비선택적으로 억제함으로써 청소율을 감소시키고 반감기를 증가시킬 것으로 추정되었다.

• 한국토양비료학회지
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• 제44권1호
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• pp.146-159
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• 2011

The continuous increase in the production of metals and their subsequent release into the environment has lead to increased concentration of these elements in agricultural soils. Because microbes are involved in almost every chemical transformations taking place in the soil, considerable attention has been given to assessing their responses to metal contaminants. Short-term and long-term exposures to toxic metals have been shown to reduce microbial diversity, biomass and activities in the soil. Several studies show that microbial parameters like basal respiration, metabolic quotient, and enzymatic activities, including those of oxidoreductases and those involved in the cycle of C, N, P and other elements, exhibit sensitivity to soil metal concentrations. These have been therefore, regarded as good indices for assessing the impact of metal contaminants to the soil. Metal contamination has also been extensively shown to decrease species diversity and cause shifts in microbial community structure. Biochemical and molecular techniques that are currently being employed to detect these changes are continuously challenged by several limiting factors, although showing some degree of sensitivity and efficiency. Variations and inconsistencies in the responses of bioindicators to metal stress in the soil can also be explained by differences in bioavailability of the metal to the microorganisms. This, in turn, is influenced by soil characteristics such as CEC, pH, soil particles and other factors. Therefore, aside from selecting the appropriate techniques to better understand microbial responses to metals, it is also important to understand the prevalent environmental conditions that interplay to bring about observed changes in any given soil parameter.

• Reproductive and Developmental Biology
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• 제35권2호
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• pp.167-174
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• 2011

Acute ischemic stroke results from sudden decrease or loss of blood supply to an area of the brain, resulting in a coinciding loss of neurological function. The antioxidant action of melatonin is an important mechanism among its known effects to protective activity during ischemic/reperfusion injury. The focus of this research, therapeutic efficacy of melatonin on recovery of neurological function following long term treatment in ischemic brain injured rats. Male Sprague-Dawley rats (n=40; 8 weeks old) were divided into the control group, and MCAo groups (Vehicle, MT7 : MCAo+ melatonin injection at 7:00, MT19 : MCAo+melatonin injection at 19:00, and MT7,19 : MCAo+melatonin injection at 7:00 and 19:00). Rat body weight and neurological function were measured every week for 8 weeks. After 8 weeks, the rats were anesthetized with a mixture of zoletil (40 mg/kg) and xylazine (10 mg/kg) and sacrificed for further analysis. Tissues were then collected for RNA isolation from brain tissue. Also, brain tissues were analyzed by histological procedures. We elucidated that melatonin was not toxic in vital organs. MT7,19 was the most rapidly got back to mild symptom on test of neurological parameter. Also, exogenous melatonin induces both the down-regulation of detrimental genes, such as NOSs and the up-regulation of beneficial gene, including BDNF during long term administration after focal cerebral ischemia. Melatonin treatment reduced the loss of primary motor cortex. Therefore, we suggest that melatonin could be act as prophylactic as well as therapeutic agent for neurorehabilitative intervention.

• Journal of Community Nutrition
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• 제4권1호
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• pp.12-21
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• 2002

This study was conducted to investigate the dietary intake, anthropometric data, and association between two factors and main food sources contributing macronutrients for overweight and obese females. Subjects were 85 adult females (overweight : 28, obese 57) where mean age was 38.7y. The results are summarized as follows. Mean fat percent, BMI, obesity rate were 29.3, 23.9 and 15.1%, respectively for overweight women and 32.7, 28.3, 36.4%, respectively for obese women. There were significant differences for most of the anthropometric data between groups. Fat percent for all subjects was significantly correlated with weight, waist circumference, hip circumference, mid arm circumference or skinfold thickness for the triceps, subscapular and suprailiac (p < 0.001). The parameter which showed the highest correlation coefficient (r=0.6156) with fat Percentage was the waist to hip ratio. Any significant differences were not found in dietary intake of nutrients or in diet composition between groups. The mean energy intake was 2090.1kcal (104% of RDA) for overweight women and 2113.0kcal (106% of RDA) for obese women. PFC ratio for overweight was 17 : 24 : 59 and 18 : 23 : 58 for obese subjects, which can be regarded as higher fat and lower carbohydrate percentages compared to recommended PFC ratio (15 20 65) .4) Fat intake was positively correlated (r : 0.2301, p < 0.05) with the triceps skinfold thickness, protein intake was also positively correlated with waist circumference (r=0.2668, p < 0.05) or fat weight(r: 0.2406, p < 0.05) .5) The main food items that contributed to energy intake for overweight or obese subjects were similar (rice, pork, bread, grapes, barley) except com oil in overweight or instant noodle for obese group. The subjects in this study were taking less energy from rice and more energy from pork and bread than women from 98 National Health and Nutrition Survey. Because there were no significant differences of dietary data between overweight and obese group, further investigation considering basal metabolic rate or activity would be needed.

• KSBB Journal
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• 제17권6호
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• pp.560-565
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• 2002

생태계에서 중요한 역할을 담당하는 단백세균(Proteobacteria)의 보존적유전자(conserved gene)를 파악하고 서로간의 유연 관계를 밝히고자 clusters of orthologous groups of proteins(COG) 알고리즘을 이용한 접근법을 시도하였다. 42종의 원핵생물과 33종의 진정세균, 16종의 단백세균으로 가면서 보존적유전자가 증가하는 것을 확인하였다. 분석대상 원핵생물 모두에서 75종의 COG 즉 보존적 유전자가 관찰되었다. COG0195, COG0358 그리고 COG0528은 원핵생물에서만 관찰되어 새로운 분류의 parameter로 이용될 가능성이 있는 것으로 추측되었다. 64종류의 보존적 유전자가 33종의 진정세균(eubacteria)에서 관찰되었다. 이는 각 분류단계를 특징짓는 새로운 COG의 추가에 의한 결과로 사료되었다. 각 단백세균 그룹은 독자적인 COG 레퍼토리를 소유하였으며 물질대사에 관련된 보존적 유전자는 beta 그룹이 다른 그룹에 비해 다양한 것을 확인하였다. 본 연구는 단백세균의 기원과 진화적 유연관계를 파악하는데 도움을 줄뿐만 아니라 향후 세균분류학과 생명공학에 필수적인 유용유전자 탐색 등에서도 충분한 연구가치가 있는 것으로 사료되었다.

• 센서학회지
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• 제21권2호
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• pp.135-143
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• 2012

Arterial stiffness is causing the serious problems for human who is suffered from hypertension and metabolic syndrome. So it is important that measure the arterial stiffness for early prevention. Many researches point out that pulse wave velocity(PWV) is the reliable and simple method to predict arterial stiffness. In this paper, we developed the sensing parts that detect the pulse wave and ECG by using piezoelectric film and conductive textile with elastic band. Our system could detect 3ch pulse wave and ECG. Simultaneously, our algorithm extracts the features for calculating the delays among pulse waves. The delays are the significant parameter to estimate PWV, thus we design the experiment for evaluating the performance of our sensing parts. The reference is PP-1000(HanByul Meditech, Korea) that is good for performance evaluation. As a result, the start point of the pulse wave was the most reliable feature for comparing with PP-1000(r=0.691, P=0.00). The results between two operators showed that there is only a slight difference in the reproducibility of the devices. In conclusion, we assume that the suggested sensor could be more comfortable and faithful method for arterial stiffness.

• 대한본초학회지
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• 제34권2호
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• pp.49-58
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• 2019

Objectives : Obesity is a public health concern associated with chronic diseases including hyperlipidemia, diabetes, fatty liver, atherosclerosis and cancer. As several anti-obesity drugs have been limited owing to their side effects, the development of new anti-obesity drugs through herbal medicines has been increasing. Cynanchum Wilfordii Radix (CW) traditionally is consumed for various health benefits including immune enhancing, anti-inflammation and anti-tumor activities. The aim of the present study is to evaluate the effects of CW on High fat diet (HFD)-induced obese mice. Methods : The mice were randomly divided into four groups (n=7). The mice were respectively fed a normal diet (ND), a high-fat diet (HFD), HFD plus CW (50 mg/kg/day), HFD plus CW (100 mg/kg/day). All groups were assayed for body weights, food efficiency ratio, blood biochemistry parameters, and organic tissue weights. Results : HFD-fed mice showed an increase in the body weight and serum biochemistry parameters levels (total cholesterol and triglycerides) as well as organic tissue weights. However, the administration of CW to obese mice induced a reduction in their body weight, food efficiency ratio, blood biochemistry parameters and weight of liver and fat compared with the HFD fed mice. Additionally, we observed that CW inhibited the lipid accumulation in liver and serum lipid parameter induced by HFD. Conclusions : Taken together, the findings of this study suggest that CW may be a potential agent for use in the treatment of obesity and obesity-related metabolic diseases.

• 대한핵의학회지
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• 제32권4호
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• pp.332-343
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• 1998

목적 : 폐 FDG PET 동적영상을 분석하는 다양한 분석 방법을 개발하고 표준섭취계수, 패트랙 도표 분석법, 3구획 추적자 역학 모형(5매개변수 모형, 6매개변수 2관심영역 모형)으로 얻은 매개변수 값을 서로 비교, 분석하여 각 분석 방법들의 종양 진단 정확성과 유용성에 대해 고찰하였다. 대상 및 방법 : 22명의 폐종양 환자(9명: 양성 종양 환자(과오종: 1, 활동성 염증: 8), 13명: 악성 종양 환자(기관지 세포암: 5 포함))에게 약 370 MBq (10 mCi)의 FDG를 정맥 주사한 후, GE Advance 양전자방출단층촬영장치를 이용하여 56분 동안 PET 동적영상을 얻은 후, 감쇠보정하여 횡단면 영상을 얻었다. 환자의 몸무게와 혈장 포도당 농도로 규격화된 SUVglu를 계산하였으며, 패트랙 도표 분석법과 3구획 5매개변수 모형과 3구획 6매개변수 2관심영역 모형을 이용하여 FDG 섭취상수($K_{pat},\;K_{5p},\;K_{6p}$)와 당대사율($MR_{pat},\;MR_{5p},\;MR_{6p}$)을 구하였다. 다양한 분석 방법들로 얻은 매개변수들을 수신자판단특성곡선으로 분석하였으며 곡선 아래 면적을 구하였다. 결과: 다양한 분석방법으로 측정한 악성과 양성 병변의 섭취상수와 당대사율은 통계적으로 유의한 차이가 없었다. 각 방법으로 구한 수신자판단특성곡선 아래 면적은 다음과 같다: $SUVglu:\;0.73,\;K_{pat}:\;0.66,\;MR_{pat}:\;0.77,\;K_{5p}:\;0.71,\;MR_{5p},\;0.73,\;K_{6p}:\;0.70,\;MR_{6p}:\;0.78.\;K_{pat} $와 $MR_{pat}$의 곡선 아래 면적은 통계적으로 유의한 차이를 보였다(p<0.05). 결론: FDG PET 동적영상을 이용한 다양한 추적자 역학 분석 방법을 사용자가 편리하게 사용할 수 있도록 개발하였다. 표준섭취계수, 패트랙 도표 분석법, 3 구획 모형 분석법 둥에 의한 정략적 매개변수의 정확성은 유사헌 것으로 관찰되었다. 추적자 역학 분석 방법으로 얻어진 정량적 매개변수는 객관적 수치정보를 제공하므로써 FDG PET의 유용성을 증가시킬것으로 기대되며, 정량적 매개변수의 임상적 유용성을 밝히기 위해서는 활동성 염증, 과오종이나 기관지 세포암 확률이 낮은 환자군을 대상으로 한 추가 연구가 필요한 것으로 판단된다.

• Childhood Kidney Diseases
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• 제8권1호
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• pp.33-42
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• 2004

목 적 : 소아 신증후군에서 스테로이드 장기투여에 따른 대사성 골질환은 흔한 합병증 중의 하나이다. 저자들은 성인에서의 스테로이드 유발성 골다공증 치료에 유효한 bisphosphonate(alendronate)를 투여하여 소아 신증후군에서 스테로이드 유발 대사성 골질환에 대한 치료효과에 대해 전향적으로 평가하고자 하였다. 방 법 : 신증후군 이환 기간이 2년된 5-8세의 환자 58명에게 DEXA로 골밀도를 측정하여 요추 골밀도가 Z-score -1 이하인 환아 30명(51.7%)을 대상으로 선정한 후 이들을 alendronate 주 1회 투여군, calcitriol 투여군, 약제 비투여군등의 세 군으로 분류하여 1년간 연구하였다. 치료 6개월, 1년에 요추 L1-L4 골밀도를 측정하였고 치료 전과 치료 1년 후 생화학적 검사를 측정하였다. 각 군간 평균 연령, 기저 요추 골밀도, 스테로이드 축적량, 골밀도% 변화율, 요추 골밀도 Z-score를 측정 분석하였다. 결 과 : 총 30명 환자에서 기본 요추 골밀도 측정시 환아의 나이는 $7.4{\pm}1.7$세였고 신증후군 이환기간은 $2.2{\pm}1.2$년이었다. Z-score로 진단된 골밀도 감소증은 23명(76.7%), 골다공증은 7명(23.3%)이었다. 각 생화학적 변수들은 치료 전후로 차이가 없었으며, 군 간에도 유의한 차이가 없었다(P>0.05). 빈번 재발형 신증후군과 스테로이드 의존형 신증후군은 22명(73.3%)으로 드문 재발형 신증후군 8명(26.6%)에 비해 대사성 골질환의 빈도가 높았다. 골밀도 변화율은 alendronate 군에서 치료 1년에 8.56%였고, calcitriol군은 5.79% 증가를 보였으며, 비투여군은 1.9%증가를 보였다. Z-socre 변화는 alendronate 군과 calcitriol 군에서만 호전되었고, 비투여군에서는 감소하였다. 골밀도 증가율은 각 군간 유의한 차이를 보였지만(P=0.0002), alendronate 군과 비투여군, calcitriol 군과 비투여군 간에 있었고(P<0.05), alendronate 군과 calcitriol 군간에는 유의한 차이가 없었다. Alendronate 투여시 약복용을 중단할 만큼의 심각한 부작용은 발현되지 않았다. 결 론 : 소아 신증후군 환자에서 고용량의 스테로이드를 투여해야 하는 경우 대사성 골질환의 발생 위험이 높기 때문에 정기적인 골밀도 측정이 필요하며, 그 평가 도구로는 요추 골밀도 Z-score가 유용함을 알 수 있었다. 또한 신증후군 환아의 스테로이드 유발 대사성 골질환에서 alendronate 주 1회 경구투여는 요추 골밀도를 증가시키는 효과적인 치료법이었다.