• 한국의학물리학회지:의학물리
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• 제8권1호
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• pp.3-15
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• 1997

Adrenal chromaffin cells secrete catecholamine in response to acetylcholine. The secretory response has absolute requirement for extracellular calcium, indication that $Ca^{2+}$ influx through voltage dependent $Ca^{2+}$ channel (VDCC) is the primary trigger of the secretion cascade. Although the existence of various types of $Ca^{2+}$ channels has been explored using patch clamp technique in adrenal chromaffin cells, the contribution of different types of $Ca^{2+}$ channels to catecholamine secretion remains to be established. To investigate the quantative contribution of different types of $Ca^{2+}$ channels to cate-cholamine secretion, $Ca^{2+}$ current($I_{Ca}$) and the resultant membrane capacitance increment($\Delta{C}_{m}$) were simultaneoulsy measured. Software based phasor detector technique was used to monitor $\Delta{C}_{m}$. After blockade of L type VDCC with nicardipine (1$\mu$M), $I_{ca}$ was blocked to 43.85$\pm$6.72%(mean$\pm$SEM) of control and the resultant ㅿC$_{m}$ was reduced ot 30.10$\pm$16.44% of control. In the presence of nicardipine and $\omega$-conotoxin in GVIA(l$\mu$M), an N type VDCC antagonist, $I_{ca}$ was blocked to 11.62$\pm$2.96% of control and the resultant $\Delta{C}_{m}$ was reduced to 26.13$\pm$8.25% of control. Finally, in the presence of L, N, and P type $Ca^{2\pm}$ channel antagonists(nicardipine, $\omega$-Conotoxin GVIA, and $\omega$-agatoxin IVA, respectively), $I_{ca}$ and resultant $\Delta{C}_{m}$ were almost completely blocked. From the observation of parallel effects of $Ca^{2+}$ channel antagonists on $I_{ca}$ and $\Delta{C}_{m}$, it was concluded that L, N, and also P type $Ca^{2+}$ channels served and $Ca^{2+}$ source for exocytosis and no difference was observed in their efficiency to evoke exocytosis amost L, N, and P type $Ca^{2+}$ channels.

• 한국환경농학회지
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• 제27권3호
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• pp.253-259
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• 2008

과수의 생육기간동안 양분흡수는 과원토양의 환경에 영향을 받는다. 수확기에 신고 배에 Ca 결핍장해과로 보이는 과실의 발생 원인을 조사하기 위하여 과실에 생리장해가 발생한 4개 지역(울산,경주,평택,안성)의 과원 토양의 화학성 및 잎과 과실의 무기성분 함량을 조사하였다. 과실에 생리장해가 발생한 과원 토양의 치환성 Ca 함량은 정상관원에 비해 낮은 반면, 치환성K와 Mg 함량 및 T-N 함량은 높았다(P=0.05). 생리장해 과실의 과육과 과피의 Ca 함량은 건전한 과실에 비해 낮았으며, 과육과 과피의 Mg/Ca 비율은 건전 과실보다 높았다(P=0.05). 잎에 N/Ca 및 K/Ca 비율은 생리장해가 발생한 나무가 건전한 나무의 잎 보다 높았다. 따라서 신고 배의 생리장해는 Ca 함량의 부족에 의해 발생하는 유부과로 판단되며, 이는 토양에 치환성 K와 Mg 이온 및 T-N가 Ca 이온의 흡수에 장해요인으로 작용한 것으로 생각된다.

• Journal of Nutrition and Health
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• 제27권10호
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• pp.1025-1036
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• 1994

This study was designed to investigate the effects of Ca and/or vitamin D supplementation for 53 weeks on bone metabolism in postmenopausal women. The subjects were healthy 18 women aged from 59 to 69 years old. They were divided into three groups : placebo, Ca(1000mg/day) supplementation and Ca(1000mg/day) with vitamin D(12.5$\mu\textrm{g}$/day) supplementation. During the experimental periods except for metabolic studies, the subjects ate their usual diets and the use of drugs as well as excessive exercise was prohibited. Metabolic studies were conducted in the 1st week and in the 53rd week of the experimental periods. The subjects ate experimental diets which consisted of 1787.3kcal, 69.6g of protein, 561.5mg of Ca and 1078.6mg of P daily during both of the metabolic study periods. The results were summarized as follows; 1) Bone density of the second lumbar spine and trochanter measured after treatment decreased significantly in control group as compared with pre-experimental level(p<0.05). On the contrary, bone density of femoral neck and Ward's triangle in Ca group and the second lumbar spine in Ca.Vit D group increased significantly after treatment. 2) Serum PTH and calcitonin levels did not show any significant differences among groups before and after treatment. But serum PTH level increased significantly in all groups after treatment(P<0.05). 3) Serum Ca and P levels did not show any significant differences among groups before and after treatment. But serum Ca level increased significantly in all groups after treatment (P<0.05) and serum P level decreased significantly in Ca.Vit D group after treatment(P<0.05). 4) Mean 24-hours fecal Ca excretion of Ca group was the highest in the 1st week of treatment(P<0.01), and that of control group was the lowest in the 53rd week of treatment(P<0.01). Fecal Ca excretion increased significantly in control and Ca.Vit D group in the 53rd week of treatment(P<0.05). Urinary Ca excretion did not show any significant differences among groups in the 1st and 53rd week of treatment, but that of Ca.Vit D group was the highest the 1st week of treatment(P<0.01). In the 53rd week of treatment Ca and Ca.Vit D group showed positive Ca balance, but control group showed negative Ca balance. The above results showed that it will be difficult to prevent degenerative bone loss without Ca and/or vitamin D supplementation in postmenopausal women eating Korean usual diets.

• The Korean Journal of Physiology and Pharmacology
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• 제22권2호
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• pp.215-223
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• 2018

Intracellular $Ca^{2+}$ mobilization is closely linked with the initiation of salivary secretion in parotid acinar cells. Reactive oxygen species (ROS) are known to be related to a variety of oxidative stress-induced cellular disorders and believed to be involved in salivary impairments. In this study, we investigated the underlying mechanism of hydrogen peroxide ($H_2O_2$) on cytosolic $Ca^{2+}$ accumulation in mouse parotid acinar cells. Intracellular $Ca^{2+}$ levels were slowly elevated when $1mM\;H_2O_2$ was perfused in the presence of normal extracellular $Ca^{2+}$. In a $Ca^{2+}-free$ medium, $1mM\;H_2O_2$ still enhanced the intracellular $Ca^{2+}$ level. $Ca^{2+}$ entry tested using manganese quenching technique was not affected by perfusion of $1mM\;H_2O_2$. On the other hand, $10mM\;H_2O_2$ induced more rapid $Ca^{2+}$ accumulation and facilitated $Ca^{2+}$ entry from extracellular fluid. $Ca^{2+}$ refill into intracellular $Ca^{2+}$ store and inositol 1,4,5-trisphosphate ($1{\mu}M$)-induced $Ca^{2+}$ release from $Ca^{2+}$ store was not affected by $1mM\;H_2O_2$ in permeabilized cells. $Ca^{2+}$ efflux through plasma membrane $Ca^{2+}-ATPase$ (PMCA) was markedly blocked by $1mM\;H_2O_2$ in thapsigargin-treated intact acinar cells. Antioxidants, either catalase or dithiothreitol, completely protected $H_2O_2-induced$ $Ca^{2+}$ accumulation through PMCA inactivation. From the above results, we suggest that excessive production of $H_2O_2$ under pathological conditions may lead to cytosolic $Ca^{2+}$ accumulation and that the primary mechanism of $H_2O_2-induced$ $Ca^{2+}$ accumulation is likely to inhibit $Ca^{2+}$ efflux through PMCA rather than mobilize $Ca^{2+}$ ions from extracellular medium or intracellular stores in mouse parotid acinar cells.

• Journal of Nutrition and Health
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• 제36권5호
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• pp.459-469
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• 2003

We examined the effects of calcium intake levels on mineral metabolism during pregnancy using calcium-deficient young adult rats. Five week-old female Sprague-Dawley rats were fed normal Ca (NCa, 0.5%) and low Ca (LCa, 0.15%) diets for five weeks (pre-pregnancy). The low Ca intake group was then divided into three groups and fed low Ca (0.15%), normal Ca (0.5%) and high Ca (1.5%) diets for 3 weeks (pregnancy). All of the rats were mated with normal male rats. The control group was fed a consistently normal Ca (0.5%) diet during pre-pregnancy and pregnancy. On the day after delivery, dams and their pups were sacrificed. We measured total protein, albumin, alkaline phosphatase and mineral content in serum and weight, length, breaking force, ash and mineral content in the femur and lumbar (L2-L4) of the dams. Whole body mineral content was measured in the pups. There was no difference in weight gain and food intake among the groups. Serum total protein and albumin were in the normal range but a little lower during pregnancy. High Ca supplementation decreased serum Mg and Fe during pregnancy. Weight, ash and Ca of the femur and lumbar significantly decreased in rats fed a chronically low Ca diet during pre-pregnancy and pregnancy. Calcium supplementation levels were above normal during pregnancy and increased the bone weight and breaking force of rats fed the low Ca diet during pre-pregnancy. However, Ca supplementation did not increase the ash and Ca contents in the bones. High Ca supplementation during pregnancy significantly decreased Mg in the bones and increased Ca and P in the kidneys. Ash content of pups from dams fed the chronically low Ca diet decreased but there was no difference in whole body Ca among the groups. Mg and Fe in the whole body decreased in pups from dams fed the high Ca diet. Pregnancy performance was reduced in dams fed the low Ca diet. These results suggest that above normal Ca supplementation levels during pregnancy restored maternal bone status to some extent in rats fed the chronically low Ca diet. The same could not be said for mineral content. Also, high Ca supplementation during pregnancy may deteriorate mineral composition in bones and other tissues. Therefore, more detailed research is needed to facilitate sound recommendations on appropriate calcium intake during pregnancy. (Korean J Nutrition 36(5): 459∼469, 2003)

• 한국동물학회지
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• 제17권1호
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• pp.5-16
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• 1974

초파리(Drosophila melanogaster)의 발생에 미치는 염화칼륨(KCI)과 염화칼슘($CaCl_2$)의 단독 영향 및 상호 작용을 검토하기 위하여 6가지 농도의 KCI이나 $CaCl_2$ 처리 메디아에 5계통의 초파리를 사육하여 우화율은 검토한 결과는 다음과 같다. 1. 우화율은 초파리 계통간에는 유의적인 차이를 볼 수 없으나, KCI이나 $CaCl_2$의 농도간에는 매우 유의적인 차이가 있으며, 그 농도가 커짐에 따라 우화율이 낮아진다. 2. 우화율에 미치는 $CaCl_2$의 억제적 효과는 KCI에 비하여 현저하게 크며, 이것은 초파리의 KCI에 대한 저항성이 $CaCl_2$에 대한 것 보다 크다는 것을 뜻한다. 3. KCI 이나 $CaCl_2$ 메디아에 소량의 $CaCl_2$ 이나 KCI를 첨가하면 KCI이나 $CaCl_2$ 의 우화율에 대한 억제적 효과의 길항작용을 보이고 있으나, 좀더 다량을 가하면 억제적 효과가 더욱 촉진된다. 4. 따라서 초파리의 발생에 대한 $K^+$ 와 $Ca^++$의 억제적 효과에 있어서 상호 작용이 관여하고 있음을 알수 있다.

• 자원리싸이클링
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• 제15권5호
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• pp.47-51
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• 2006

국내 생활쓰레기 소각시설에서 발생되는 소각재의 양은 2005년 경우 약 420,000톤에 달하고 있으며, 그중 비산재 발생량은 약 68,000톤에 달하고 있다. 비산재는 지정폐기물로 분류되어 일반적으로 고형화 및 안정화 처리 후 매립되고 있으며, 단지 발생량의 약 20%만이 재활용되고 있다. 비산재의 경우 CaO의 함량이 50%까지 이르고 있으며, 그 이유는 배가스 처리시 CaO를 기본으로 하는 물질을 다량으로 사용하기 때문이다. 본 연구에서는 비산재에 함유되어 있는 CaO를 회수하여 $CaCO_3$ 분말을 제조하기 위한 기초실험을 수행하였다. CaO를 선택적으로 용해하기 위하여 설탕용액을 사용하였으며, 기초 실험결과에 의하면 CaO용해를 위한 최적조건은 비산재 농도 10%, 반응시간 15분, 설탕농도 $10{\sim}15%$ 및 적정 pH는 $10.5{\sim}11$로 나타났다. $CaCO_3$ 분말은 회수된 CaO 용해액에 $CO_2$가스를 주입시켜 제조하였으며 회수된 $CaCO_3$ 백색도는 매우 우수한 것으로 조사되었다.

• 한국재료학회지
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• 제13권9호
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• pp.572-580
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• 2003

Synthesizing behavior and microstructural evolution of $CaZrO_3$and $m-ZrO_2$in a thermal reaction process of $ZrSiO_4$-$xCaCO_3$mixtures, where x is 7 and 19, were investigated to determine the addition amount of CaO in CaO:$ZrO_2$:$SiO_2$ternary composition. CaZrO$_3$-Ca$_2$SiO$_4$precursor prepared by the mixture of $ZrSiO_4$and CaCO$_3$in aqueous suspending media was controlled to the acidic (pH=4.0) condition with HCI solution to enhance the thermal reaction. The addition amount of dispersant into the $ZrSiO_4$-$xCaCO_3$slip increased with increasing mole ratio of $CaCO_3$, which was associated with the viscosity of slip. Decarbonation reaction was activated with an increase of the addition amount of $CaCO_3$, showing different final temperatures in $ZrSiO_4$-$7CaCO_3$and $ZrSiO_4$-$19CaCO_3$mixtures as about 980 and 116$0^{\circ}C$, respectively, for finishing decarbonation reaction. The grain morphology was changed to spherical shape for all samples with an increase of sintering temperature. The grain size and phase composition of the synthesized composites depended on the mixture ratio of Zrsi04 and CacO3 powders, indicating that the main crystals were m-ZrO2 ($\leq$3 $\mu\textrm{m}$) and $CaZrO_3$ ($\leq$ 7 $\mu\textrm{m}$) in $ZrSiO_4$$>-7CaCO_3$and $ZrSiO_4$-$19CaCO_3$mixtures, respectively.

• 대한화학회지
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• 제10권1호
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• pp.32-42
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• 1966

$CaCl_2$, CaO 및 $WO_3$로 構成되는 熔融鹽을 黑鉛 陽極과 鐵 陰極으로 電解하여 순수한 金屬텅스텐을 얻는 方法에 관하여 실험하였다. 電氣分解에 적합한 熔融浴을 選定하기 위하여 $CaCl_2$-CaO系와 $CaCl_2-CaWO_4$系에 관한 二相 狀態圖를 작성하였으며 同時에 $CaCl_2$와 $WO_3$와의 高溫下에서의 化學反應을 검토하여 安定한 電解浴을 얻기 위해서는 一定量의 CaO가 添加되어야 할 것임을 알 수 있었다. 炭素陽極을 사용하여 $WO_3$를 W와 CO로 분해시킬 때의 分解電壓은 -0.1 volt이었으며 熱力學的 計算에 의한 것은 -0.3 volt이었다. 熔融鹽을 電氣分解한 結果 金屬텅스텐이 100%에 가까운 電流效率로 電極에 析出되나 이는 陽極에서 二次的으로 발생하는 CO가스에 의하여 쉽게 WC등으로 변화하므로 순수한 텅스텐을 얻기 위해서는 電解浴의 溫度를 $1100^{\circ}C$이상으로 유지하여야 된다는 것을 알게 되었다. 電解浴의 組成은 可及的 低融點과 $WO_3$의 分解, $CaCl_2$의 蒸發 등을 억제하기 위해서는 $CaCl_2$ 100分에 대하여 CaO와 $WO_3$가 각 10 乃至 20分이 適切하였으며 CaO와 $WO_3$의 몰比率은 1이상이 요구되었다. 陰極 電流密度를 1~5 $amp/cm^2$의 範圍에서 變化시켜도 電流效率에 큰 影響이 없었다.

• 생태와환경
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• 제35권3호통권99호
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• pp.213-219
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• 2002

녹조 제어를 위하여 수중의 인 제거에 관여하는 CellCaSi의 여러 가지 조건별 인 제거효과를 조사하였다. CellCaSi의 입도에 따른 인 제거효과는 직경 1, 2 그리고 4mm 이하의 3가지 중 1mm 이하의 작은 입자를 사용했을 때 가장 우수하였다. CellCaSi의 인 제거효과는 처리량의 증가에 비례하였다. 수중의 pH 5, 7, 9에서 초기 인 농도 0.20mg/l는 각각 0.09, 0.08및 0.08mg/l로 감소되어 상이한 pH조건에 따른 CellCaSi의 인 제거효과는 큰 차이를 보이지 않았다. CellCaSi에서 용출되는 양이온은 Ca이며, Al과 Fe양이온은 검출되지 않았다. 초기에 급격히 용출된 Ca양이온은 수중의 인과 반응하는 것으로 확인되었다. 초기 인 농도 0.10, 1.0mg/1는 CellCaSi와 Ca, Fe 화합물을 첨가한 처리구에서 8일 후 각각 0.03,0.47mg/l를 기록하며 가장 많이 감소하였다. 이에 따라 인 제거효과는 CellCaSi와 Ca, Fe 화합물을 동시에 처리하였을 때 가장 좋은 것으로 조사되었다. CellCaSi의 처리에 따라 pH가 약간 증가하였고, 전기전도도도 증가되지만 상수원수 기준 허용치 (500${\mu}$S/cm) 이내였다.