• 방사성폐기물학회지
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• 제8권3호
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• pp.201-205
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• 2010

고준위방사성폐기물에서 유출되어 나오는 아이오딘의 이동을 저지하기 위하여 은을 흡착시킨 벤토나이트 블록에 NaI 용액을 흘려주었을 때 대부분의 아이오딘이 흡착되었다. 이 은이온에 의한 아이오딘의 저지 메커니즘을 상세히 조사하기 위하여 아이오딘과 접촉하기 전후의 은이 흡착된 벤토나이트의 X-ray Absorption Near Edge Structure (XANES)와 Extended X-ray Absorption Fine Structure (EXAFS) 스펙트 럼과 표준물질로서 AgO, $Ag_2O$, AgI의 스펙트럼을 비교하였다. 그 결과, 벤토나이트에 흡착되었던 은이 떨어져 나와 AgI 침전 클러스터를 형성함으로서 아이오딘의 이동이 지연되는 것으로 생각된다.

• 한국식품과학회지
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• 제28권4호
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• pp.689-695
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• 1996

보리가루로부터 ${\beta}-Glucan$을 추출, 정제하여 그의 소화관내 생리적 기능성을 알아보기 위해 반투막을 이용한 in vitro실험을 수행하였다. 보리가루로부터 ${\beta}-Glucan$을 6.2%의 수율로 정제하였으며 그의 순도를 확인한 결과 총 식이섬유 81.6%, 수용성 식이섬유 72.9%, 불용성 식이섬유 8.7%, 수분 8.5%, 단백질 2.5%, 회분 7.4%였다. ${\beta}-Glucan$ 제품의 수분보유력은 1g의 건조물당 6g이었다. 투석막을 이용하여 ${\beta}-Glucan$ 제품의 glucose 흡수 지연효과를 살펴 본 결과 ${\beta}-Glucan$을 3% 첨가한 경우 투석 30분이 경과되었을 때 glucose retardation index가 13.5%였고 시간이 경과할수록 그 효과는 감소하여 투석 2시간 후에는 그 효과가 거의 없는 것으로 나타났다. Bile acid 흡수 지연 효과를 살펴 본 결과 투석 30분이 경과되었을 때 bile acid retardation index는 ${\beta}-Glucan$이 1, 3, 5% 첨가된 경우 각각 3, 12, 18% 수준으로 같은 시간이 경과되었을 때의 glucose 흡수 지연 효과보다 더 크게 나타났으며 시간이 경과할수록 그 효과가 감소하였다.

• Journal of Preventive Medicine and Public Health
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• 제22권4호
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• pp.518-527
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• 1989

The relationship between copper content in scalp hair and mental retardation was investigated. Samples of scalp hair were collected from 297 mentally retarded children who were students in one of two schools providing special educational services, one, consisted of children living in an orphan home, the other, children living with parents. For comparison, 117 scalp hair samples were collected from the children who had got average or above average academic achivement in a regular elementary school. Hair samples were taken from the nape of the neck and the copper content was determined by an atomic absorption spectrophotometer (IL 551). There was no statistically significant difference in scalp copper levels across different age groups except female orphan group, but no trend or correlation between copper conents and age was found. The hair copper contents of the mentally retarded children groups were significantly lower than that of control groups. But there was no dose-response relationship between degree of mental retardation and hair copper level. The hair copper contents of the group accompanied by Down's syndrome and unknown group were significantly lower than that of control group in both sex, and in the case of accompanied by epilepsy or autism, lower than control group in male. Although the results of this study show no evidence that mental retardation has owed to copper deficiency, the possibility of copper deficiciency in their fetal or infant age could not be ruled out. Thus further study is needed to determine whether mental retardation could be attributed to copper deficiency, through the examinations about their living environments, dietary pattern, eating habit and the impact of copper deficiency on brain development.

• Journal of Preventive Medicine and Public Health
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• 제22권2호
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• pp.215-222
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• 1989

정신지체와 인체내 카드뮴 함량과의 관련성을 보기 위해 정신지체아 297명(가정이 있는 아동이 다니는 특수학교 1개교의 132명과 고아로 구성된 특수학교 1개교의 165명)을 대상으로 두발중 카드뮴 및 아연함량을 측정하였으며 학업성적이 중위권 이상인 일반 국민학교 학생 117명을 대조군으로 하여 비교해 보았다. 시료의 분석은 원자흡광광도계를 이용하였다. 두발 중 카드뮴 함량의 연령에 따른 차이는 없었으며 아연은 대조군 남자의 경우 연령 증가에 비례하였다. 가정이 있는 정신지체아의 경우 카드뮴 함량이 남녀 각각 $0.64{\pm}0.24ppm,\;0.66{\pm}0.18ppm$, 가정이 없는 정신지체아(고아군)의 경우 남녀 각각 $0.71{\pm}0.19ppm,\;0.65{\pm}0.15ppm$ 으로써 대조군 (남;$0.45{\pm}0.15ppm$, 여:$0.49{\pm}0.16ppm$)에 비해 유의한 차이가 있었다. 그러나 아연의 경우 유의한 차이는 없었다. 정신지체의 정도별로 보았을때 고아인 경우 남녀 모두 카드뮴 함량이 지체정도가 심할수록 높았으나 가정이 있는 지체아의 경우는 그러한 차이가 없었다. 다만 선천성 질환인 Down증후군은 남녀 모두 대조군과 카드뮴함량의 차이가 없었다. 자폐증이 있는 경우 아연의 함량이 특이적으로 낮았다. 본 연구의 결과에서 카드뮴이 정신지체에 어느 정도의 영향을 끼칠 것으로 추측되나 더욱 연구를 계속해 보아야 하겠다.

• 한국식품과학회지
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• 제26권4호
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• pp.348-354
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• 1994

반응 조건을 달리하여 게껍질에서 chitin을 추출하고 이를 탈아세틸화하여 chitosan을 제조하였으며, 이들의 물리, 화학적 특성과 소화관내 기능성을 in vitro법으로 실시하였다. 이들 chitin질의 bulk density는 $127{\sim}208\;mg/ml$, 점도는 0.1% chitin의 경우 $80{\sim}581\;cP$, 0.5%, chitosan은 $80{\sim}3,670\;cP$로 다양한 수치를 나타냈으며, chitosan의 탈아세틸화도는 $81{\sim}93%$로 비교적 높았다. Chitosan 제조시의 알칼리 농도와 반응 온도가 일정할 때 반응 시간이 경과할수록 탈아세틸화도는 증가하였고, 점도는 감소하는 경향을 보였다. Chitin질의 보수력은 온도 상승에 따라 약간 상승하였고, $37^{\circ}C$에서 chitosan D가 가장 높았으며, bulk density가 낮을수록 높은 보수력을 나타냈다. Glucose 흡수 억제 효과는 bulk density가 낮고 보수력이 큰 chitin길이 더 컸고 chitosan D가 가장 높은 38%를 나타냈다. Chitin질의 bile acid 흡수 억제 효과는 투석 1시간 후에 $15{\sim}34%$를 나타냈고, pectin은 39%, cellulose는 9%를 나타냈으며 chitosan D는 3% 농도에서 34%의 가장 높은 억제 효과를 나타냈다.

• The Korean Journal of Physiology
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• 제7권1호
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• pp.23-31
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• 1973

Numerous factors concern with the absorption of substances through the membrane of the gastrointestinal tract. To simplify the experimental condition, present work has been restricted to observe the disappearance rate of substance from the intestinal loop which was made in the jejunum, 70 cm apart from the pylorus of the adult rabbit. The purpose of the study is to clarify the absorption of urea through the jejunal wall is solely attributable to the concentration difference between the luminal fluid and plasma, and to observe the effect of adding red pepper upon the rate of absorption. The rabbits were anesthetized with nembutal, 35mg/kg I.V. Jejunal loop was made by ligating at 2 spots, 70 cm and 80cm apart from the pylorus. After rinsing with normal saline solution through the polyethylene tubing inserted from the end of the loop, 8 ml of test solution was placed through the same tubing. The test solution contained 200 mg% of urea and 150mg% of polyethylene glycol(M.W. 4,000) in normal saline solution. Right after placing the test solution the first specimen was taken through the tubing, and successive samplings were performed at 5, 10, 20, and 30 minutes. Logarithm of the difference of urea concentration between the luminal fluid and plasma was plotted against time elapsed after the onset of the experiment. If straight line is revealed, it would verify the nature of transport mechanism as diffusion, obeying the Fick's principle. The concentration of polyethylene glycol (PEG) was also measured in order to examine the change in the volume. PEG was used as the marker substance because it is not absorbable in the intestinal tract. Consequently the concentration of PEG relates inversely to the volume of the loop. Instantaneous concentration of urea in the loop times the volume will give the amount of urea remaining in the luminal fluid. The change in the amount of any substance is directly relate to the volume of the compartment and differs from the change in the concentration which is independent of the volume. After completion of the experiment without red pepper, it was added in the test solution and was centrifuged after thorough mixing. Supernatant of the mixture was placed in the loop and similar sampling were performed with the same time intervals that of previous run in order to observe the effects of the red pepper on the passive transport of the water soluble small substance, urea. The results obtained were as follows: 1. Logarithm of the concentration difference of urea between the luminal fluid and plasma was diminished exponentially as time elapsed. The decay constant in the experiment without red pepper was 0.0563/min. By adding red pepper in the test solution as much as the concentration rose to 4,000 mg% and 8,000 mg%, the decay constants were lowered to 0.0493/min and to 0.0506/min, respectively. The time interval by which the concentration difference dropped to one half of the initial value was prolonged. Without red pepper the half concentration time was 13.30 minutes, and by adding extract of red pepper, 15.31 minutes and 15.71 minutes were revealed. 2. The profile of the diminishing rate of tile amount of urea was quite different from that of the concentration because of the change in the volume of the loop during the observed period. 3. By adding the extract of red pepper, it slowed down the rate of absorption of urea in the intestinal loop, suggesting an increase in the diffusional barrier. 4. Larger dosage of red pepper brought an increase in the secretion of intestinal fluid with concomitant expansion of the luminal volume, and the retardation of the absorption of urea was noticed. This effect was largely dependent on the sensitivity of the individual animal to the red pepper, extract. The amount of urea remained after 10 minutes interval was 55.5% of the initial amount in the experiment without red pepper. On the other hand it was not consistent after administration of red pepper, showing 50.6% and 66.5% of the initial figures by adding 400 mg and 800 mg of red pepper in the test solution, respectively. It was postulated that symptom of diarrhea often encountered by taking a hot (red pepper) food might be attributable to the increase of secretion and the retardation of absorption in the intestinal tract.

• Applied Biological Chemistry
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• 제44권3호
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• pp.137-142
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• 2001

미생물로부터 고분자 물질을 생산하여 기능성 식품보조제로 사용하기 위하여 Bacillus coagulans CE-74에 의해 생산된 biopolymer를 이용해 glucose, bile acid 흡수 지연 효과 및 ACE와 tyrosinase 저해 효과를 조사 검토하였다. 분리된 biopolymer의 소화관내 생리적 기능성을 알아보기 위해 반투막을 이용한 in vitro 실험을 수행하였다. 투석막을 이용하여 biopolymer의 glucose흡수 지연 효과를 살펴본 결과 biopolymer를 2% 첨가한 경우 투석 30분이 경과되었을 때 히ucose retardation index가 43.5%였고 시간이 경과 할수록 그 효과는 감소 하였으며 투석 5시간 이후에는 그 효과가 거의 없는 것으로 나타났다. Bile acid흡수 지연 효과를 살펴본 결과 투석 30 분이 경과 되었을 때 bile acid retardation index는 biopolymer가 1%, 2% 첨가된 경우 각각 34%, 44.2%였으며 시간이 경과할수록 그 효과가 감소하였다. 분리된 biopolymer의 ACE저해효과는 $10\;{\mu}g/{\mu}l$의 농도에서는 97%의 저해를 보였으며, tyrosinase 저해효과를 관찰한 결과 $20\;{\mu}g/{\mu}l$농도에서 48.5%의 저해효과를 나타내었다.

• 한국식품영양과학회지
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• 제27권4호
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• pp.705-711
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• 1998

The digestibility of xylooligosaccharide(XO) by juices of the digestive tract and retardation effect of XO on the adsorption of bile acids were compared with fructooligosaccharide(FO) and isomaltooligosaccharide(IO). In vitro digestion experiments showed that any hydrolyzed products of FO, IO and XO were not detected by HPLC after reaction with saliva, pancreatic, artifical intesteinal, and large intestinal luices, and artifical sera for 4 hours at 37$^{\circ}C$. However, IO were mostly digested by the small intestinal juice, and some quantity of FO were digested. XO were not digested at all by any enzyme of digestive tract. In order to investigate retardation effect of XO on the bile acid absorption. In vitro, permeability of bile acid against dialysis membrane was determined in the mixture which contained guar gum instead of XO was set 100%. The premeability of bile acid showed about 50% in the FO and IO mixture and 43% in the XO mixture. The activity of lactase in FO group and activity of sucrase and maltase in XO group in rat small intestinal mucosa were significantly decreased. Consequently, the present results indicate that XO is indigestible in digestive tract and has retarding effect of adsorption of bile acid compared with the other oligosaccharides. The disaccharidase activity of the XO dietary group was lower than that of the other oligosaccharides dietary group. Furthermore, it was suggested that hydrolysis of sugar may be retarded in digestive tract and glucose level in blood may be controlled effectively by the XO.

• 한국분말재료학회지
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• 제12권6호
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• pp.433-440
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• 2005

The hydrogen sorption speed of $Zr_{57}V_{36}Fe_7$ nanocrystalline and amorphous alloys was evaluated at room temperature. Nanocrystalline alloys of $Zr_{57}V_{36}Fe_7$ were prepared by planetary ball milling. The hydrogen sorption speed of nanocrystalline alloys was higher than that of the amorphous alloy. The enhanced sorption speed of nanocrystalline alloys was explained in terms of surface oxygen stability which has been known to retard the activation of amorphous alloys. The retardation can be reduced by formation of nanocrystals, which results in the observed increase in sorption properties.

• 한국재료학회지
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• 제15권12호
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• pp.802-808
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• 2005

The hydrogen sorption speeds of $Zr_{57}V_{36}Fe_7$ amorphous alloy and its crystallized alloys were evaluated at room temperature $Zr_{57}V_{36}Fe_7$ amorphous alloy was prepared by ball milling. The amorphous alloy was crystallized through two stages. Initially, $\alpha-Zr$ solid solution was appeared from the amorphous phase. Two cubic Laves compounds were precipitated afterwards from the remained amorphous and from excessively saturated solid solution at higher temperature. The hydrogen sorption speed of the partially crystallized alloy was higher than that of amorphous. The enhanced sorption speed of partially crystallized alloy was explained in terms of surface oxygen stability which has been known to retard the activation of amorphous alloys. The retardation could be reduce by crystallization process resulting in the observed increase in sorption property.