• 한국세라믹학회지
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• 제41권1호
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• pp.45-50
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• 2004

Ca/P 비가 각각 1.62, 1.67, 1.72인 수산화아파타이트(Hydroxyapatite, HA) 세라믹스를 제조하고, HA 표면에서 수용액에 의하여 일어나는 용해현상을 고찰하였다. 수용액에서 3일간 침적시킨 경우 입계에서부터 용해가 시작되었으며, 침적시간이 10일로 증가하면서 이러한 입계용해에 의한 HA 세라믹스의 미세구조적 분해 현상은 비화학양론적 조성, 즉 Ca/P 비가 1.62 또는 1.72인 시편에서 두드러지게 나타났다. 주목할만한 것은, 용해가 진행되는 동안 세라믹스의 표면에는 골식세포의 흡수 과정에서 흔히 볼 수 있는 표면 결함(lacunae)과 매우 유사한 모양을 갖는 원형의 빈 공간(cavity)이 형성되었다.

• 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.

• Journal of Nutrition and Health
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• 제32권6호
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• pp.671-680
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• 1999

In order to investigate the relationship between plasma renin activity and metabolism of Ca and Na in blood pressure, the habitual dietary intakes of Na and Ca urinary excretion of Ca, Na and K, and plasma level of renin activity, aldosterone, and indices of Ca metabolism were measured in 27 untreated hypertensive women and 30 age-matched normal women on a free diet. Hypertensive subjects were classified into high renin hypertensive (HH), medium renin hypertensive(HM) and low renin showed no significant difference among normotensive, LH, MH and HM groups. It appeared that 25-(OH) Vit D3 level of HH group was significantly higher than LH group(p<0.05). There was significant difference in habitual intake of Ca between normotensive and LH groups. However, habitual intake of Na showed no significant difference among normotensive, LH, MH and HH group. Positive correlation of systolic and diastolic blood pressure with PTH(r=0.324, r=0.375) and urinary Ca(r=0.496, r=0.278) and a negative correlation of systolic blood pressure with habitual Ca intake(r=-0.371) existed(p<0.05). A relative magnitude of factors affecting hypertension was analyzed by multiple regression analysis. Overall results about relative influence of independent variables to dependent variable (systolic blood pressure) indicated that urinary Ca was the higher correlation in all subjects(p<0.0001), followed by age and aldosterone. PTH showed a significant correlation for relative influence on diastolic blood pressure in all subjects. The above results indicated that renin-aldosterone system and Ca regulating hormone had a mutual relationship in hypertension.

• 한국토양비료학회지
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• 제23권1호
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• pp.15-20
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• 1990

다량(多量)의 비료(肥料)가 인용(連用)되어온 원예작물(園藝作物) 재배지(栽培地) 13개지역(個地域)에서 149개 토양(土壤)을 채취분석(採取取析分)하여 토양의 화학적(化學的) 특성(特性)에 따른 무기태인(無機態燐)의 형태별(形態別) 조성(組成)을 검토(檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 토양(土壤) pH의 상승에 따라 총인(總燐)에 대한 Ca-P와 Saloid-P의 분포비율(分布比率)은 높아지고 상대적으로 Al-P와 Fe-P의 분포비율(分布比率)은 낮아졌으나, Fe-P 분포비율(分布比率)은 pH5.0~6.0 범위에 이를때까지 증가되다가 그 이상의 pH에서는 급격히 감소되는 경향이었다. 2. pH에 따른 A-P와 Fe-P 분포비(分布比)의 감소경향은 유효인산함량(有效燐酸含量)이 500ppm 이하로 낮은 토양에서는 완만하였으나 그 이상인 토양(土壤)에서는 더욱 뚜렷하였다. 3. 유효인산(有效燐酸) 500ppm 이하의 토양(土壤)에서는 분획인(分劃燐)의 분포비율(分布比率)이 Fe-P>Al-P>Ca-P>Saloid-P의 순이었으나 이보다 인산함량(燐酸含量)이 높아짐에 따라서 점차 Fe-P와 Al-P의 분포비율(分布比率)이 바뀌어 유효인산(有效燐酸) 1,000 ppm 이상의 토양(土壤)에서는 Al-P>Fe-P>Ca-P>Saloid-P 순으로 전환되었다. 4. Al-P와 Fe-P의 분포비(分布比)는 토양중(土壤中) 활성(活性) Al 함량(含量)이 증가함에 따라서 증가되었고, Fe-P의 분포비(分布比)는 토양중(土壤中) 활성(活性) Fe와 PS의 증가로 증가되나 Saloid-P, Al-P, Ca-P의 분포비(分布比)는 감소되었다.

• 한국세라믹학회지
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• 제50권4호
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• pp.275-279
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• 2013

The purpose of this study was to prepare calcium phosphate cement [CPC] for use in artificial bone. Nano-crystalline calcium phosphate [CaP] was precipitated at $37^{\circ}C$ using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. From the XRD measurements, the nano-CaP powder was close to apatitic TCP phase and the powders fired at $800^{\circ}C$ showed a critical ${\beta}$-TCP phase. A mixture of one mole $CaCO_3$ and two moles di-calcium phosphate was calcined at $1100^{\circ}C$ to make a reference ${\beta}$-TCP material. The nano-CaP powders were added to the normal ${\beta}$-TCP matrix and fired at $900^{\circ}C$ to make a ${\beta}$-TCP block. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between nano-CaP and normal ${\beta}$-TCP.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.231-237
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• 1994

Three concentrations of P (0.33, 0.43 and 0.54%) and two concentrations of Ca (0.60 and 0.97%) in ration dry matter were evaluated for effects on dry matter intake and on milk yield and composition using 24 Holstein cows. Cows were arranged in a $3{\times}2$ factorial experiment as an incomplete randomized block design with three 28-day periods. Each cow consumed at least one ration with each concentration of Ca. Dry matter intake, yield of 3.5% Fat Corrected Milk, and milk composition were not affected by concentration of P, but milk yield was greater when lowest concentration of P was fed (22.8 vs. 22.1 kg/day; p<0.07). Cows fed rations containing 0.60% Ca had greater milk (22.7 vs. 21.9 kg/day; p<0.02) and 3.5% Fat Corrected Milk yields (p<0.03) and slightly greater protein content than when fed 0.97% Ca. Dietary Ca:P ratios between 1.1:1 and 2.9:1 had no effect on dry matter intake, milk yield, or composition. Concentrations of P in plasma were within the normal range for all rations. Because cows had high dry matter intake, mean daily intakes of both P and Ca were greater than required for their level of milk yield.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.552-558
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• 2012

A $2{\times}2$ factorial experiment was conducted to study the effect of dietary calcium and non-phytate phosphorus (nPP) imbalance on calbindin and NaPi-IIb mRNA levels in the small intestine and tibia parameters of broiler chicks. One hundred and forty four 1-d-old Arbor Acres male broiler chicks were divided into four treatments consisted of six replicates with six chicks each. The two dietary calcium levels were 1.10% and 0.60%, and two dietary nPP levels were 0.50% and 0.27%. Results showed that a high Ca/nPP ratio diet (4.07:1) significantly depressed feed intake and weight gain of broilers (p<0.05), but a lower Ca:nPP ratio (1.2:1) had no influence (p>0.05). Low-Ca with low-P diet resulted in low tibia minerals and tibia breaking strength of broilers, and all the tibia parameters were further decreased when the dietary ratio of Ca to P was relative higher. Low dietary Ca or P up-regulated the calbindin and NaPi-IIb mRNA expression levels. Low Ca with normal P diet up-regulated duodenal calbindin mRNA expression level to the greatest extent. Low P with a normal Ca diet significantly enhanced NaPi-IIb mRNA expression level to the highest extent. These results suggest that the calbindin and NaPi-IIb mRNA expression were enhanced by the imbalance between dietary Ca and nPP, and their expression were not only influenced by Ca or nPP level, but also the ratio of Ca:nPP.

• 한국세라믹학회지
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• 제38권4호
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• pp.343-350
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• 2001

본 연구에서는 탄산화법으로 침강성 CaCO$_3$분말을 제조하고 제조된 CaCO$_3$현탁액의 분산안정성을 연구하였다. CaCO$_3$현탁액의 pH 변화와 고분자전해질 PMAA와 PAA의 첨가에 따른 입자크기, 유동학적 특성(점도), zeta potential 및 현탁액의 침강속도 등을 측정하였다. 탄산화법에 의해 약 0.1$\mu\textrm{m}$ 크기와 비표면적이 23.57$m^2$/g인 단분단 calcite형 CaCO$_3$분말을 제조하였다. pH가 11인 CaCO$_3$현탁액에 0.01 wt% PMAA가 첨가된 경우에 우수한 분산안정성을 나타내었는데 이는 CaCO$_3$입자표면에 PMAA의 흡착에 의한 electrosteric 안정화기구와 CaCO$_3$입자들 사이의 정전기적 반발력에 의한 것으로 판단된다. PMAA와 PAA 첨가량 변화에 따른 pH 6, 9, 11의 CaCO$_3$현탁액의 침전높이를 측정한 결과 PMAA와 PAA의 농도가 0.15 wt% 부근에서 분산안정성을 보였는데 이는 CaCO$_3$입자들 사이간의 분산제에 의한 뚜렷한 경계를 갖는 흡착층이 형성되었기 때문으로 생각되며 따라서 CaCO$_3$현탁액의 최적 분산안정성을 위해서는 적절한 pH 조절과 PMAA 및 PAA의 첨가가 필요함을 알 수 있다.

• 자원리싸이클링
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• 제10권4호
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• pp.24-33
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• 2001

For making a high degree of efficiency, this study attempts to gather each arisen-sludge from experiments and examine into its characteristics, in order to compare the biological reason of removing phosphorus with sintered body using calcite and the artificial reason of removing with a chemical reagent. First, it can be seen that sludge, which is identified CaCO$_3$, of 0.1∼0.2$\mu$m is regularly formed when using sintered body, calcite. And it is one of the results of the chemical methods in order to remove phosphorus that can be seen that sludges of 100∼50 $\mu$m are formed and that the forms of Ca$_2$P$_2$O$\_$7/, Ca$_3$(PO$_4$)$_2$$.$nH$_2$O, $\beta$-Ca$_2$P$_2$O$\_$7/ are shown when using a reagent, CaO dissolved water. The other of the results of the chemical methods can be seen that a lumpof sludge is formed when using wastewater and a reagent Ca$^2$$\^$+/ are used, and that the lump consists of Ca$_3$(PO$_4$)$_2$$.$nH$_2$O와 Ca$_2$H$_2$P$_4$O$\_$14/.

• 대한바이러스학회지
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• 제26권1호
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• pp.1-8
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• 1996

Human cytomegalovirus (HCMV) replication and $Ca^{2+}$ response in human cell lines of neuronal origin were investigated. SK-N-SH (neuroblastoma cells) and A172 cells (glioblastoma cells) were used. SK-N-SH cells were permissive for HCMV multiplication with a delay of one day compared to virus multiplication in human embryo lung (HEL) cells. The delay of HCMV multiplication in SK-N-SH cells appeared to be correlated with a delay in the $Ca^{2+}$ response. The cytoplasmic free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) began to increase at 12 h p.i. in HCMV-infected SK-N-SH cells, while $[Ca^{2+}]_i$ increase in HCMV-infected HEL cells was observed as early as 3 h p.i. On the whole, the level of the increase in $[Ca^{2+}]_i$ in SK-N-SH cells was about 30% of that in HEL cells. On the other hand, in A172 cells infected with HCMV, neither production of infectious virus nor detectable increase in $[Ca^{2+}]_i$ was observed. Treatment with TPA of HCMV-infected SK-N-SH cells resulted in $[Ca^{2+}]_i$ increase at 6 h p.i. The stimulatory effect of TPA on HCMV- induced $[Ca^{2+}]_i$ increase continued until 12 h p.i., but TPA failed to stimulate the $Ca^{2+}$ response in SK-N-SH cells at 24 h p.i., suggesting that the effect of TPA had disappeared in SK-N-SH cells at that time point. In conclusion, SK-N-SH cells are permissive for HCMV replication and the delay in $Ca^{2+}$ response may be a consequence of the lower responsiveness of SK-N-SH cells than HEL cells to HCMV infection.