• Journal of Nutrition and Health
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• 제22권6호
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• pp.516-530
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• 1989

A 44-day metabolic study was conducted to compare the effects of soy protein and meat protein on N, Ca, P, and Mg metabolism in young Korean males. Meat protein diet(MPD) and soy protin diet(SPD) were provided for 3 weeks each. For MPD, meat protein Supplied 50.3% of total protein and mean daily suplies of Ca, P, and Mg were 33.28mg, 1013.01mg, 226.81mg respectively. For SPD, soy protein supplied 51.8% of total protein and mean contents of Ca, P and Mg were 737.86mg, 1261.76mg, and 451.3mg. Mean daily fecal and urinary excretions of Ca were 350.6mg and 113.3mg for MPD and 515.0mg and 118.3mg for SPD. Apparent absorption rates in MPD and SPD were 4.2mg in MPD and 700.4mg and 475.1mg SPD. Apparent absorption rates were 65.6% in MPD and 44.5% in SPD(p<0.01). For Mg, fecal and urinary excretions were 144.8mg and 81.2mg in MPD and 292.4mg and 65.5mg in SPD. Apparent absorption rates were 37.5% in MPD and 35.2% in SPD. The correlations between urinary Ca, P, and their balance were significant (p<0.001) in MPD, but not in SPD. Urinary Ca was significantly correlated with urinary N, P, Mg(p<0.001) in MPD, but not in SPD. From these results, meat protein seems to increase the excretions of major minerals compared to soy protein.

• Journal of Nutrition and Health
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• 제30권4호
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• pp.406-414
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• 1997

It has been known that dietary phytate decreases the absorption of body zinc pool which is composed of the dietary and endogenous zinc in the body. The purpose of this study was to examine the effect of phytate on the absorption of total bodyzinc in Zn-depleted rats. Rats were Zn-depleted with either low(0.8%) or high(1.6%) Ca diet containing sodium phytate for 4 weeks. After zinc depletion, rats were assigned into phytate or non-phytate dietary groups within each low-or high-Ca dietary group. ant feces were collected for 2 weeks of the initial collection and 1 week after dietary crossover, during which the phytate and the non-phytate diet was switched over within the same Ca group. The content of Zn and Ca measured by atomic absorption spectrophotometer and phytate content was analyzed. food intake was higher in the high Ca group than in the low Ca group(p <0.0001), and was also higher in the non-phytate group than in the phytate group(p <0.0001). Food intake and phytate level affected body weight gain in rats(p <0.0001). Zinc excretion in the total feces was higher in the phytate group than in the non-phytate group at both low and high Ca level(p <0.0001), except during the crossover collection period in high Ca group. Calcium, however, didn't show any synergistic effect on phytate effect(p <0.05). This study showed that phytate decreased the absorption of total body zinc at both low and high Ca levels in Zn-depleted rats. A large portion of total body zinc originated from the endogenous zinc pool in these rats. The results of the present study showed the same effect of phytate on the endogenous zinc in Zn-depleted rats as in a previous study, confirming that phytate adversely affects zinc bioavailability, especially under marginal and poor zinc nutrition.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.814-822
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• 2016

This study was conducted to determine and compare the effects of yeast yeast culture (YC) and vitamin E (VE) supplementation on endotoxin absorption and antioxidant status in lactating dairy goats suffering from heat stress (HS). Three first lactation Saanen dairy goats (body weight $30{\pm}1.5kg$) were surgically fitted with indwelling catheters in the portal vein, mesenteric vein and carotid artery, and were randomly assigned to a $3{\times}3$ Latin square design. Dietary treatments were the basal diet, and the basal diet supplemented with either 100 IU VE or 30 g YC. Goats were kept in temperature and humidity-controlled room at $35^{\circ}C$ from 8:00 to 20:00 and at $24^{\circ}C$ from 20:00 till the next morning at 8:00. The relative humidity was kept at 55%. HS increased dairy goats' rectum temperature and respiration frequency (p<0.01). HS reduced plasma flux rate of milk goats (p<0.01), but the plasma flux rate increased when the animal was under the conditions of the thermo-neutral period (p<0.01). The VE supplementation lowered dairy goats' rectum temperature during thermo-neutral period (p<0.01). Meanwhile, no significant differences were observed between the control and YC treatment in rectum temperature and respiration frequency (p>0.05). Dietary supplementation of VE and YC reduced heat stressed dairy goats' endotoxin concentration of the carotid artery and portal vein (p<0.01). However, the endotoxin concentration of the YC treatment was higher than that of the VE treatment (p<0.01). Both VE and YC supplementation decreased heat stressed dairy goats' absorption of endotoxin in portal vein (p<0.01). The endotoxin absorption of YC treatment was higher than the VE treatment (p<0.01). The addition of VE and YC decreased dairy goats' superoxide dismutase (SOD) concentration during HS and the whole experiment period (p<0.01). The addition of VE lowered SOD concentration during thermo-neutral period (p<0.01). Likewise, the addition of VE and YC lowered dairy goats' malonaldehyde (MDA) concentration during HS and the whole experimental period, and the MDA concentration in the VE treatment was lower than the YC treatment (p<0.05). The addition of VE decreased MDA concentration during thermo-neutral period. On the contrast, the addition of VE increased dairy goats total antioxidant potential (TAP) concentration during HS, thermo-neutral and the whole experimental period (p<0.01). The addition of YC increased TAP concentration only during HS period (p<0.01). It is concluded that both VE and YC are useful in alleviating HS of dairy goats by weakening endotoxin absorption and promoting antioxidant capacity. Compared with YC, VE is much more powerful in easing dairy goats HS.

• 전자공학회논문지D
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• 제34D권3호
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• pp.34-40
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• 1997

Intervalence subband absroption of normally incident infrared radiation in p-type InGaAs-InAlAs coupled quantum well (CQW) is theoretically investigated by the multiband effective mass formalism. By solving a 4*4 luttinger-kohn hamitonian, we calculate valence subband structures, intervalence subband transition matrix elements, and absorption coefficient spectrum in the CQW which consists of a wider well, a thinner well and a barreir between them. Using the flexible design parameters given to the valence band CQW structure, we show that the absorption coefficient profile can be tailored. For a carefully designed CQW, theabsorption coefficient cn be made to maintain a large value over a wider wavelength range of incident infrared radiation compared with that shown in intersubband absorption in usual single quantum well.

• Archives of Pharmacal Research
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• 제17권3호
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• pp.182-189
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• 1994

The effect of lipophilicity on the mechanisms of drug absorption through biomembranes was investigated empolying HPLC system and the fluorescence technique. Human erythrocyte ghost membranes were used as a model biomembrane. A series of four parabens (methyl, ethyl, rpopyl, and butyl) and p-hydroxybenzoic acid were used as the model drugs for lipophilicities and their partition coefficients were measured in Sorensen's phosphate buffer solution (pH 5)/octanol system. Absorption amount of parabens through erythrocyte ghost membranes increased with an increase of lipophilicity resulted from the addition of methylene group to the n-alkyl chain of parabens. And the effect of parabens on the fluidity of ghost membrane also increased with an increase of their lipophilicities.

• 한국광학회지
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• 제10권3호
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• pp.254-258
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• 1999

전계흡수형 반도체 광도파로에서 흡수된 빛에 의해 발생된 광전류는 전파되는 파장에 따라 Fabry-Perot 모드의 간섭패턴을 나타냄을 보이고, 이로부터 인가전압에 따른 흡수계수의 변화를 측정할 수 있는 방법을 제시하였다. 광전류 신호는 파장에 따라 공명 반공명을 반복해서 나타내며 그 진폭은 흡수계수의 크기에 의존하므로 전계에 따른 흡수계수의 변화량을 측정 할 수 있었고, 1.55 $\mu\textrm{m}$ 파장에서 역전압 1.5V 인가시 bulk in GaAsP의 흡수계수 변화는 대략 157cm-1임을 알 수 있었다.

• 약학회지
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• 제29권4호
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• pp.220-222
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• 1985

Rifampicin reacts with cupric ion to produce rifampicin-Cu(II) chelate (2:1) at pH 6.5, which can be extracted with methylisobutylketone (MIBK). Therefore, rifampicin can be quantitatively, determined by measuring the quantity of Cu(II) in the organic phase by atomic absorption spectrophotometry. Because higher absorbance ratio was obtained in pH 6.0~7.0, buffer solution at pH 6.5 was used in this measurement. Linear relationship was found between absorbance and concentration in the range of 1.0~4.0${\times}10^{-4}M$. This method might be applicable to the determination of rifampicin in the preparations.

• Preventive Nutrition and Food Science
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• 제22권2호
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• pp.67-80
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• 2017

Cholesterol is a vital component of the human body. It stabilizes cell membranes and is the precursor of bile acids, vitamin D and steroid hormones. However, cholesterol accumulation in the bloodstream (hypercholesterolemia) can cause atherosclerotic plaques within artery walls, leading to heart attacks and strokes. The efficiency of cholesterol absorption in the small intestine is of great interest because human and animal studies have linked cholesterol absorption with plasma concentration of total and low density lipoprotein cholesterol. Cholesterol absorption is highly regulated and influenced by particular compounds in the food supply. Therefore, it is desirable to learn more about natural food components that inhibit cholesterol absorption so that food ingredients and dietary supplements can be developed for consumers who wish to manage their plasma cholesterol levels by non-pharmacological means. Food components thus far identified as inhibitors of cholesterol absorption include phytosterols, soluble fibers, phospholipids, and stearic acid.

• 대한수의학회지
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• 제25권1호
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• pp.41-48
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• 1985

In the present studies, the effects of dietary high-potassium and high-urea on the metabolism of magnesium, calcium and potassium were checked as an aid to clarify the pathogenesis of hypomagnesaemia(so-called grass tetany) in ruminant. A total of 5 Korean native female goats kept in metabolic cage were received high-potassium(Mg: 0.25%, Ca: 0.94%, K: 5.41%), high-urea(Mg: 0.25%, Ca: 0.94%, K: 0.72%) or control(Mg: 0.25%, Ca: 0.94, K: 0.72%) ration for 15 or 21 days. Daily intakes, fecal and urinary excretions and serum concentrations of magnesium, calcium and potassium were measured with an atomic absorption spectrophotometer. The results obtained were summarized as follows: In high-potassium group, absorption, urinary excretion and serum concentration of magnesium were significantly (p<0.01, p<0.01 and p<0.05 respectively) decreased compared with the control group. On the other hand, the body retention was significantly (p<0.01) increased. However, no clinical symptom of hypomagnesaemic tetany was observable throughout the experimental period. No significant effects on the metabolism and seurm content of calcium were detected in the high-potassium group. In the high-potassium group, significant increase in absorption (p<0.01), urinary excretion (p<0.05) and body retention (p<0.01) of potassium were recognized. However, no significant difference in the concentration of serum was observable between the two groups. In high-urea group, no significant difference in the metabolism of magnesium and potassium or in the serum content were recognized compared with the control group. In high-urea group, tthe absorption, urinary excretion, body retention and serum content of calcium were decreased compared with the control group.

• Bulletin of the Korean Chemical Society
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• 제9권1호
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• pp.40-44
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• 1988

The pH dependence studies of Raman spectra are reported for water-soluble free-base, Zn, Co and Cu tetrakis (4-sulfonatophenyl) porphine in pH 4, pH 7 and pH 13.9 aqueous solution. For free base porphine, the substantial differences are found in absorption and Raman spectra between pH 4 and pH 7 or pH 10 aqueous solutions due to the protonation at low pH. For Zn and Co porphyrins, the hydrolysis equilibrium constants are obtained by spectrophotometric titration experiments. The consistent shifts in Raman frequencies are found at high pH due to the hydrolysis. For Cu porphyrins, instead of hydrolysis the aggregation effect is detected at high pH through the absorption and Raman studies.