• 한국토양비료학회지
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• 제49권3호
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• pp.265-270
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• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• 폴리머
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• 제39권3호
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• pp.418-425
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• 2015

Polycaprolactone(PCL)과 biphasic calcium phosphate(BCP)는 생체적합성 및 골 형성 촉진 등으로 인해 정형외과 소재로 사용되고 있다. 하지만, PCL은 표면이 소수성으로 인해 세포의 부착 및 증식에 제한적이기 때문에 이를 극복하기 위해 본 연구에서는 감마선을 이용하여 골 재생을 위한 친수성이 향상된 PCL/BCP 나노섬유를 제조하였다. 나노섬유는 전기방사를 통해 제작했으며, 감마선을 이용하여 acrylic acid(AAc)를 도입하였다. SEM을 통해 나노섬유 표면을 확인하였고, AAc가 도입된 나노섬유 위에서 MG63의 초기 생존율이 현저히 증가한 것을 확인하였다. 알칼리성 포스파테이즈 활성은 $1.239{\pm}0.226nmole/{\mu}g/min$으로 개질되지 않은 나노섬유($0.590{\pm}0.286nmole/{\mu}g/min$) 보다 증가하였다. 따라서, AAc가 도입된 PCL/BCP 나노섬유는 골조직 재생에 활용될 수 있을 것으로 기대된다.

• 한국세라믹학회지
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• 제39권5호
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• pp.460-466
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• 2002

티타늄 임플란트의 표면을 열산화법을 이용하여 티타늄의 표면 위에 생체활성을 갖는 $TiO_2$ 박막을 생성시켜 다양한 의료분야의 응용 가능성을 검토하였다. 시판되고 있는 순수한 티타늄 디스크를 세척 공정을 거친 후, 공기와 아르곤 분위기에서 500, 550, 600, 650, 700${\circ}C$의 온도로 10분간 각각 열산화 처리를 실시하였다. 열처리된 시편의 인산칼슘 결정의 형성 능력을 시험하기 위하여 36.5${\circ}C$의 Eagle's minimum essential medium 용액에서 15일 동안 침적시험을 행하였다. 침적하기 전과 후의 시편의 표면 형상과 표면 조성을 Field Emission-Scanning Electron Microscopy(FE-SEM)와 Energy Dispersive X-ray Spectrometry(EDS)로 각각 분석하였다. In vitro 시험에서 미세한 $TiO_2$ 결정이 생성된 박막의 표면에는 탄소가 함유된 인산칼슘 결정이 생성됨을 확인하였다.

• Membrane and Water Treatment
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• 제14권1호
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• pp.1-10
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• 2023

This study explored the feasibility of calcium-rich food waste, Mactra veneriformis shells (MVS), as an adsorbent for phosphate removal, and its removal efficiency was enhanced by the thermal activation process. The CaCO3 in MVS was converted to CaO by thermal activation (>800 ℃), which is more favorable for adsorbing phosphate. Thermal activation did not noticeably influence the specific surface area of MVS. The MVS thermally activated at 800 ℃ (MVS-800), showed the highest phosphate adsorption capacity, was used for further adsorption experiments, including kinetics, equilibrium isotherms, and thermodynamic adsorption. The effects of environmental factors, including pH, competing anions, and adsorbent dosage, were also studied. Phosphate adsorption by MVS-800 reached equilibrium within 48h, and the kinetic adsorption data were well explained by the pseudo-first-order model. The Langmuir model was a better fit for phosphate adsorption by MVS-800 than the Freundlich model, and the maximum adsorption capacity of MVS-800 obtained via the Langmuir model was 188.86 mg/g. Phosphate adsorption is an endothermic and involuntary process. As the pH increased, the phosphate adsorption decreased, and a sharp decrease was observed between pH 7 and 9. The presence of anions had a negative impact on phosphate removal, and their impact followed the decreasing order CO₃^2- > SO₄²- > NO₃^- > Cl^-. The increase in adsorbent dosage increased phosphate removal percentage, and 6.67 g/L of MVS-800 dose achieved 99.9% of phosphate removal. It can be concluded that the thermally treated MVS-800 can be used as an effective adsorbent for removing phosphate.

• 대한정형외과학회지
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• 제55권2호
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• pp.169-177
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• 2020

목적: 요추부 후측방 유합술 시 자가골과 혼합 이식하는 골대체재의 종류에 따른 골유합률을 비교하여 효과적인 혼합 이식 재료를 제시하고자 한다. 대상 및 방법: 본 연구는 후측방 유합술 시행 후 최소 2년 추시한 환자들을 대상으로 후향적으로 시행하였으며 유합술 시 국소 자가골에 혼합하여 사용한 이식 재료에 따라 네 군으로 분류하였다. I군은 대퇴 골두 동종골을 사용한 48예, II군은 β-tricalcium phosphate를 사용한 38예, III군은 이상인산칼슘을 사용한 92예, IV군은 이상인산칼슘 및 자가 골수를 사용한 38예를 대상으로 하였다. 술 후 2년째 단순 방사선 검사를 추시하여 유합 여부와 임상결과로 판단하였으며, 단순 방사선 소견상 양측 상하 횡돌기간에 뚜렷하게 형성된 골괴와 함께 굴신 방사선 소견상 각 운동 범위가 2도 미만이면서 전위 소견이 보이지 않을 때 유합으로 정의하였다. 결과: 술 후 2년째 단순 방사선을 추시한 결과 이상인산칼슘 및 자가골수를 국소 자가골과 혼합 이식한 IV군에서 가장 높은 유합률을 나타냈다. 결론: 생체흡수성이 높아지고 기계적 강도가 보완된 골전도성 대체재인 이상인산칼슘과 골유도 및 골형성이 가능한 자가 골수의 물질적 특성이 골유합률을 높일 수 있을 것이다. 따라서 요추부 후측방 유합술 시 이상인산칼슘, 자가 골수 및 국소 자가골의 혼합 이식이 자가골 이식을 효과적으로 대체할 수 있는 방법으로 사용될 수 있으리라 생각된다.

• 한국임상약학회지
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• 제24권3호
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• pp.199-205
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• 2014

Objectives: Current studies are debating on the association of vascular calcification and the benefit of treatment to lower serum phosphorus level in patients with chronic kidney disease. The aim of this study was to evaluate the association of mortality and risk of vascular calcification in patients with CKD who were taking phosphate binders. Methods: This study was conducted through retrospective medical chart review for 420 patients aged 18 years and older who were admitted for chronic kidney disease. Results: Vascular calcification was not statistically significantly associated with increased mortality in patients with CKD [16.7% vs. 19.2%; 95% CI; 0.388 to 1.818 (p=0.656)]. Intervention of calcium-based phosphate binders was not significantly associated with vascular calcification in patients with CKD [9.1% vs. 12.5%; 95% CI; 0.364 to 1.358 (p=0.292)]. Ca x P product ${\geq}55mg^2/dL^2$ was not significantly associated with increased 1 year mortality in patients with CKD [25.4% vs. 17.5%; 95% CI; 0.851 to 3.013 (p=0.142)]. Intervention of sevelamer was significantly associated with reduced 1 year mortality in patients with CKD than that of patients who did not take sevelamer [6.3% vs. 25.3%; 95% CI; 0.044 to 0.880 (p=0.020)]. Conclusion: There was not a statistically significant association between vascular calcification and phosphate binder's use. But phosphate binder use was significantly associated with decreased mortality in patients with CKD.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2008년도 추계학술발표대회 및 제15회 신소재 심포지엄
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• pp.44.2-44.2
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• 2008

• Journal of Nutrition and Health
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• 제32권2호
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• pp.150-157
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• 1999

This study explored the effects of dietary calcium levels and/or ovariectomy on bone formation, bone composition and calcium metabolism using female Sprague-Dawley weanling rats(mean body weight$\pm$SEM : 232.3$\pm$6.7g) as a model. Rats received high(1.5%) calcium diets for eight weeks during the growth period and were randomly assigned to ovariectomy and sham groups. The two groups were than each randomly divided into three sub-groups and fed 0.1%, 0.5% and 1.5% calcium diets for eight weeks after operation. The results indicate that body weight gain was higher in ovariectomy groups than sham groups regardless of dietary calcium levels and food intakes. Serum Ca concentration was decreased in low Ca groups after operation and serum P concentration increased in ovariectomy groups. Serum Ca concentration was decreased in low Ca groups after operation and serum P concentration increased in ovariectomy groups. Serum alkaline phosphatase activity was increased in ovariectomy groups and was not influenced by dietary calcium levels after operation. Urinary hydroxyproline decreased in high Ca intake groups regardless of whether rats had received an ovariectomy or not. The weight, length and breaking force of the femur were not significantly different in all groups. Ash, calcium, phosphate and magnesium contents in the femur and lumbar were not significantly different regardless of ovariectomy operation and dietary calcium levels. But high/normal calcium intake after ovariectomy and sham operation increased the weight and calcium content in bone. Therefore, high calcium intake influenced the formation of peak bone mass during the growth period and calcium levels and calcium levels and calcium levels continued to influence bone growth and composition after ovariectomy.

• Applied Biological Chemistry
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• 제7권
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• pp.39-43
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• 1966

This experiment was carried out to determine how the water soluble, the available phosphoric acid and the urea-N would change as time went by, when mixtures of calcium superphosphate and urea were made. Two kinds of materials, i. e., calcium superphosphate and urea were engaged in this experiment. Two kinds of mixed fertilizer, i. e., A and B were made up by mixing these materials to satisfy the following ratio. 1) Urea 1+ calcium superphosphate 1${\cdots}\;{\cdots}$A 2) Urea 1+ calcium superphosphate 2${\cdots}\;{\cdots}$B A and B pIaced placed in desiccators respectively a six-month period. During the time of storage, the water soluble, the available $P_2O_5$ and the urea-N were measured once a month, seven times with the control measurement. The results may be summarized as follows. 1. The urea-N in both A and B showed no change by the passage of time. This fact suggested that the mixing of calcium superphosphate with urea was not unfavourable. 2. A and B showed no diminishing in the water soluble and the available $P_2O_5$ in the process of time. This fact indicated that the combination of calcium superphosphate with urea was not unfeasible.

• 대한치과교정학회지
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• 제40권4호
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• pp.212-226
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• 2010

치간 삭제 후 재광화 및 치아우식 예방법을 찾기 위한 노력의 일환으로 1.23% 인산화불소 젤 또는 5%, 10% 수산화인회석함유 페이스트를 치간 삭제된 법랑질 표면에 도포하였고, 그 후 젖산탈회용액으로 처리하였다. 법랑질 표면의 재광화 및 탈회 후 결정구조 변화를 주사전자현미경으로 관찰하고 칼슘, 인, 불소 함량 등의 변화를 energy dispersive X-ray spectroscopy로 분석해서 비교하였다. 치간 삭제 후 5%, 10% 수산화인회석함유 페이스트를 도포한 군에서 칼슘과 인 함량이 증가하였고, 1.23% 인산화불소 젤 도포 군에서는 불소 함량이 증가하였다. 또한 모든 재광화 제제에서 법랑질 표면이 매끄럽고 부드러워졌으며 결정구조가 작고 치밀해짐을 관찰할 수 있었다. 10% 수산화인회석함유 페이스트로 재광화한 군은 탈회 후에도 칼슘과 인 함량이 증가된 채로 유지되었고, 5% 수산화인회석함유 페이스트로 재광화한 군은 탈회 후 인 함량이 증가된 채로 유지되었다. 치간 삭제 후 탈회 처리 시 대조군의 법랑질은 파괴양상이 심해 거친 굴곡으로 이루어진 불규칙한 표면 상태를 나타내었으나 불소 및 수산화인회석으로 재광화한 군에서는 법랑질의 파괴양상이 적어 작은 결정입자들과 미세공극이 유지되었다.