• 대한약리학회지
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• 제31권3호
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• pp.279-284
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• 1995

본 연구의 목적은 외부에서 nitric oxide (NO)를 투여 하였을때 심근 수축력, 심박동수의 변화 및 혈관 평활근에 대한 효과를 비교함으로서 NO에 대한 이들 장기의 민감도가 서로 같은지 또는 상이한지를 알아보고자 하였다. 본 실험에서는 PIANO 방법에 의한 근장력의 변화와 아울러 심근에서의 $Ca^{2+}$ current를 측정하였다. 랫트의 심방근에 대한 PIANO $(STZ,\;100\;{\mu}M)$는 심근수축력 및 심박동수에 전혀 변화를 주지 않았지만 혈관 평활근에서는 강한 이완 작용을 나타내었다. 한편, 8-Br-cGMP도 고농도 $(100\;{\mu}M)$에서만 심근 수축력을 억제하였다. 토끼의 심방근세포에서 Whole cell voltage patch clamp를 사용시 bradykinin, SNP, 8-Br-cGMP 및 PIANO는 $Ca^{2+}$ current를 억제하였다. 이러한 사실은 외부에서 공급되는 NO에 대한 심근과 혈관 평활근의 반응에는 민감도의 차이가 있음을 암시하며 더 나아가 심근의 경우에도 NO 반응에는 종 (species)간의 차이와 동일 종이라 하더라도 세포(cell)와 장기(tissue)에 차이가 있을 가능성을 제시하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제8권3호
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• pp.161-165
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• 2004

Exogenous carbon monoxide (0.2%) increases L-type calcium $(Ca^{2+})$ current in human jejunal circular smooth muscle cells. The stimulatory effect of carbon monoxide (CO) on L-type $Ca^{2+}$ current is inhibited by pre-application of L-NNA, a classical competitive inhibitor of nitric oxide synthase (NOS) with no significant isoform selectivity (Lim, 2003). In the present study, we investigated which isoform of NOS affected CO induced stimulation of L-type $Ca^{2+}$ current in human jejunal circular smooth muscle cells. Cells were voltage clamped by whole-cell mode patch clamp technique, and membrane currents were recorded with 10 mM barium as the charge carrier. Before the addition of CO, cells were pretreated with each inhibitor of three NOS isoforms for 15 minutes. CO-stimulating effect on L-type $Ca^{2+}$ current was partially blocked by N-(3-(Amino-methyl) benzyl) acetamidine 2HCl (1400W, an iNOS inhibitor). On the other hand, 3-bromo-7-nitroindazole (BNI, a nNOS inhibitor) or $N^5-(1-Iminoethyl)-L-ornithine$ dihydrochloride (L-NIO, an eNOS inhibitor) completely blocked the CO effect. These data suggest that low dose of exogenous CO may stimulate all NOS isoforms to increase L-type $Ca^{2+}$ channel through nitric oxide (NO) pathway in human jejunal circular smooth muscle cells.

• 대한영양사협회학술지
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• 제4권2호
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• pp.160-167
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• 1998

Current status of nutrient fortification in processed food in Korea were presented by analyzing the information shown on food labels. The obtained information was assessed by the regulations on food fortification in both Korea and other countries including Codex. The most current regulations were gathered from internet. The results are summarized as follows. 1. Major nutrients fortified were calcium, Vit C, Vit B complex, iron and fiber. The forfified foods were not limitted to certain food group with more frequent fortification in snackfoods, cereal, ramyun, retort pouch foods, milk, and youguart. The descriptive terms of nutrition label for the fortification were various including high, supplemented, added, source, fortified, and abundance though the difference among these terms were not distinct. 2. Current regulation on nutrition label requires to give the content of the fortified nutrient and % RDA. However not all of food items carry above information. Also some ingredients such as chitosan, DHA, taurine, $\omega$-3 fatty acid, chondrichin, bifidus were supplemented mainly to the snack foods which FDA(USA) does not allow to be fortified. 3. The nutrient most frequently fortified was calcium and general practice of fortification appears to follow the regulation in Korea. Presently the regulation itself is not well described, this nutient fortification can cause toxic effect. Since calcium was supplemented to wide range of food group consumers who are not conscious of the safe upper limit may intake the fortified food up to the level of 2g/day. 4. For the effective fortification in Korea, the regulation on fortification should be reformed in accordance with the international guideline Codex and the regulations in other countries especially in America and Japan.

• The Korean Journal of Physiology
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• 제24권2호
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• pp.377-388
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• 1990

Ca movements during the late plateau phase in rabbit atrium implicate Na-Ca exchange. In single atrial cells isolated from the rabbit the properties of the inward current of Na-Ca exchange were investigated using the whole cell voltage clamp technique. The inward currents were recorded during repolarization following brief 2 ms depolarizing pulse to +40 mV from a holding potential of -70 mV. Followings are the results obtained: 1) When stimulated every 30 sec, the inward currents were activated and reached peak values $6{\sim}12\;ms$ after the beginning of depolarizing pulse. The mean current amplitude was 342 pA/cell. 2) The current decayed spontaneously from the peak activation and the timecourse of the relaxation showed two different phases: fast and slow phase. 3) The recovery of the inward current was tested by paired pulse of various interval. The peak current recovered exponentialy with a time course similar to that of Ca current recovery. 4) Relaxation timecourse was also affected by pulse interval and time constant was reduced almost linearly according to the decrease of pulse interval between 30 sec and 1 sec. 5) The peak inward current was increased by long prepulse stimulation, Bay K, isoprenaline or c-AMP. 6) The relaxation time constant of the inward current was prolonged by Bay K or c-AMP, and shortened by isoprenaline. From the above results, it could be concluded that increase of the calcium current potentiates and prolongs intracellular calcium transients, while shortening of the timecourse by isoprenaline or short interval stimulations might be due to the facilitation of Ca uptake by SR.

• 한국식품영양과학회지
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• 제31권1호
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• pp.170-176
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• 2002

서울시내 백화점과 대형 마트에서 판매되는 칼슘강화식품을 조사하여 이들을 곡류가공품, 우유 및 유제품, 식.어육가공품, 라면류, 레토르트식품, 쥬스 및 음료류, 기타로 분류하고 각 제품에 표기된 영양표시를 중심으로 현재 우리나라 칼슘강화 현황과 영양표시 실태를 살펴보았다. 그러나 본 조사에서는 특정인을 위한 건강보조식품이나 특수영양식품 및 유아용 조제유와 이유식은 대상에서 제외하였다. 조사된 캄슘강화식품은 총 81건이었으며 곡류가공품, 라면류를 중심으로 광범위한 식품군에 강화되었다. 특히 칼슘이 기호식품에 첨가됨으로서 소비자의 식사 패턴과 기호도에 따라 개인별로 칼슘 섭취량의 차이가 클 가능성이 있었다. 그리고 칼슘강화식품은 대부분 칼슘이 단독으로 강화되었고 그 다음으로 칼슘 이외에 1종의 영양소가 추가로 강화된 제품들이 많았고 식품군에 따라서는 약간의 차이를 보였다. 특히 우유 및 유제품 식품군은 다중 강화식품군으로 한 제품과 칼슘과 1~8종의 영양소가 동시에 강화되었다. 또한 같이 첨가되는 영양소의 종류는 DHA가 가장 많았으며 그 외에 비타민류, 무기질류 등이 있었다. 제품의 칼슘함량을 표시하는 기준단위는 주로 '100g/100mL', '포장중량'이었으며 각 제품에 대한 소비자들의 실제 섭취량을 비교하기 위해 칼슘함량을 '1인 분량'당 % RDA로 환산해보면 2.5~27.6% RDA 범위였다. 특히 칼슘이 강화된 제품의 칼슘함량이 '1인 분량'당 10% RDA에도 미달되는 제품들이 많아 강화함량에 대한 전반적인 평가가 필요했다. 영양표시는 표시기준에 규정되지 않은 용어가 사용되고 규정된 용어를 사용하더라도 함량기준에 미달되는 경우가 있는 등 몇 가지 문제점을 드러냈다. 그러므로 영양강화가 제 역할을 다하기 위해서는 시대적인 요구에 능동적으로 대처하는 관련 정부기관의 노력과 식품업계의 강화에 따르는 기술력 향상 및 사후 품질관리가 필요했다. 또한 학술기관에서는 이에 대한 기초연구가 소비자들 대상으로 영양교육을 실시하고 소비자 스스로도 자신에 맞는 식품을 선택할 수 있는 능력을 갖추도록 꾸준한 노력과 관심을 가져야 할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제6권5호
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• pp.241-246
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• 2002

We studied the excitatory action of morphine on the responses of dorsal horn neuron to iontophoretic application of excitatory amino acid and C-fiber stimulation by using the in vivo electrophysiological technique in the rat. In 137 of the 232 wide dynamic range (WDR) neurons tested, iontophoretic application of morphine enhanced the WDR neuron responses to N-methyl-D-aspartate (NMDA), kainate, and graded electrical stimulation of C-fibers. Morphine did not have any excitatory effects on the responses of low threshold cells. Morphine-induced excitatory effect at low ejection current was naloxone-reversible and reversed to an inhibitory action at high ejection current. NMDA receptor, calcium channel and intracellular $Ca^{2+}$ antagonists strongly antagonized the morphine-induced excitatory effect. These results suggest that changes in intracellular ionic concentration, especially $Ca^{2+},$ play an important role in the induction of excitatory effect of morphine in the rat dorsal horn neurons.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1477-1482
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• 2016

This study was conducted to investigate the effects of diets with varying levels of calcium on egg production, shell quality and overall calcium status in aged laying hens. A total of five hundred 70-wk-old Hy-Line Brown layers were divided five groups and fed one of the five experimental diets with 3.5%, 3.8%, 4.1%, 4.4%, or 4.7% Ca, for 10 weeks. There were no significant differences in feed intake, egg production and egg weight among groups. The cracked eggs were linearly reduced as dietary Ca levels increased to 4.7% (p<0.01). A significant linear improvement for eggshell strength and thickness were determined with increasing dietary Ca levels (p<0.01). The contents of serum Ca and phosphorus were not affected by dietary Ca levels. With increase in dietary Ca levels, the tibial breaking strength slightly increased. There were no significant differences in the tibial contents of ash, Ca and phosphorus among groups. In conclusion, eggshell quality, as measured by appearance, strength and thickness of eggshell, were influenced by dietary Ca content as expected (p<0.05). These results suggested that aged laying hens require relatively higher level of Ca than required levels from current Korean feeding standards for poultry.

• 대한지역사회영양학회지
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• 제11권4호
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• pp.534-540
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• 2006

Recent studies have shown that environmental, biochemical, nutritional or genetic factors affect bone mineral density (BMD). The purpose of the present study was to investigate the effect of vitamin D receptor (VDR) gentotype and nutritional status on BMD of elderly women living in a rural area. Three hundred thirty five elderly women over 65 years in Asan participated the study. Data for demographic and nutrient intakes were obtained by survey with a two day 24 hr recall method. BMD was measured by broadband ultrasound attenuation (BUA) using quantitative ultrasound (QUS). VDR genotypes of the subjects analyzed with Bsm I restriction enzyme were bb (92%), Bb (7%) and BB (1%). No differences were found between genotypes bb and Bb/BB in age, menopausal age, body mass index and body fat. BUA of bb genotype was higher (62.5 $\pm$ 15.6 dB/MHz) than Bb/BB genotype (56.1 $\pm$ 17.6 dB/MHz) by Student's t-tests. Correlation analyses showed strong negative correlation of BMD and age, but positive correlation with BMI, energy and calcium intake. When subgroup analyses were conducted after stratification by the median calcium intake level (412.9 mg/d), the above median calcium intake group showed significant difference in BUA by VDR genotype while the lower median calcium intake group did not show significant difference. The current study confirmed interaction of calcium intake and VDR genotype in association with BMD. Further nutritional intervention will be needed to improve calcium status of the elderly women living in rural areas.

• The Korean Journal of Ceramics
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• 제5권4호
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• pp.357-362
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• 1999

ZnO varistors containing cobalt, praseodymium and calcium oxides were prepared. The current-voltage charcteristics and microstructures of the specimens were investigated with respect to calcium addition and sintering temperature. The potential barrier heights and the carrier densities were estimated from C-V relations. The compatibility of Ag-Pd as an internal electrode for multilayer chip varistor was also examined.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.475-476
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• 2010

Hydration products formed on the steel surface may impose the resistance to corrosion of steel when a concrete is exposed to a salt environment. In the present study, ordinary Portland cement (OPC), calcium aluminate cement (CAC) and calcium hydroxide are applied as coating materials on the steel surface to consider the hydrations of each binder at corrosion. Corrosion is measured in terms of the corrosion potential and galvanic current to detect the effects in mitigating the corrosion behavior.