• The Korean Journal of Ecology
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• 제21권1호
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• pp.47-63
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• 1998

In order to compare species-specific calcium metabolism, we collected 127 species belonging to 40 different families grown on various habitats including saline, limestone, wetland during the 1996 vegetation period, and analyzed their inorganic ion contents. Plants investigated were divided into 5 groups according to their physiological properties: 1) Chenopodiaceae, Aizoaceae, Caryophyllaceae, Portulacaceae and Phytolaccaceae of Centrospermales and Polygonaceae (Polygonales had a little water-soluble $Ca^{2+}$ but contained high contents of insoluble $Ca^{2+}$ particularly as Ca-oxalate (Chenopodiaceae type), 2) Some plant species such as Rosaceae produced oxalate in amounts insufficient to precipitate all incoming $Ca^{2+}$ and thus contained a surplus of dissolved $Ca^{2+}$ (Rosaceae type), 3) The contents of water-soluble $Ca^{2+}$ in plant species of Crassulaceae. Plantaginaceae, Asclepiadaceae, and Zygophyllaceae were equal to or greater than those of K ($K/Ca{\leq}1$; Crassulaceae type), and 4) K/Ca ratios of Compositae were significantly fluctuated depending on species and soil $Ca^{2+}$ level of their habitats (Compositae type). 5) Certain monocots (Gramineae, Cyperaceae, Juncaceae), in contrast to the dicotyledonous plant families mentioned above, showed a very distinct type of calcium metabolism, that is, the K/Ca ratios of 8~10 were maintained indifferently in the species and their habitat types (Graminae type). These results plants within the same taxon have similar physiological aspects as weel as morphological attributes. To understand calcium metabolism of certain plant species, therefore, it is desirable to approach on the basis of physiological concept (calciotroph or calciophobe) rather than the ecological one (calcicole or calcifuge).

• 식품산업과 영양
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• 제10권2호
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• pp.40-45
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• 2005

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.140-145
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• 2006

The behaviour of alginate immobilized and soluble watermelon (Citrullus vulgaris) urease in water miscible organic solvents like, acetonitrile, dimethylformamide (DMF), ethanol, methanol, and propanol is described. The organic solvents exhibited a concentration dependent inhibitory effect on both the immobilized and the soluble urease in the presence of urea. Pretreatment of soluble enzyme preparations with organic solvents in the absence of substrate for 10 min at $30^{\circ}C$ led to rapid loss in the activity, while similar pretreatment of immobilized urease with 50% (v/v) of ethanol, propanol, and acetonitrile was ineffective. Time-dependent inactivation of immobilized urease, both in the presence and in the absence of urea, revealed stability for longer duration of time even at very high concentration of organic solvents. The soluble enzyme, on the other hand, was rapidly inactivated even at fairly lower concentrations. The results suggest that the immobilization of watermelon urease in calcium alginate make it suitable for its application in organic media. The observations are discussed.

• Journal of Pharmaceutical Investigation
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• 제38권2호
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• pp.111-117
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• 2008

To overcome the solubility of poorly water-soluble drug, the formation of solid dispersion using a spray-dryer with polymeric material, that can potentially enhance the dissolution rate extend of drug absorption was considered in this study. $Eudragit^{(R)}$ E100 as carrier for solid dispersion is acrylate copolymer that soluble in acidic buffer solutions (below pH 5.0). It was used to increase dissolution of atorvastatin calcium as a water-insoluble drug in acidic environments. In this study, a spray-dryer was used to prepare solid dispersion of atorvastatin calcium and $Eudragit^{(R)}$ E100 for purpose of improving the solubility of drug. Atorvastatin calcium and $Eudragit^{(R)}$ E100 were dissolved in ethanol and spray-dryed. DSC and XRD were used to analyze the crystallinity of the sample. It was found that atorvastatin calcium is amorphous in the $Eudragit^{(R)}$ E100 solid dispersion. FT-IR was used to analyze the salt formation by interaction between atorvastatin calcium and $Eudragit^{(R)}$ E100. Comparative dissolution study exhibited better dissolution characteristics than the commercial drug ($Lipitor^{(R)}$) as control. The dissolution rate of atorvastatin calcium was markedly increased in solid dispersion system in simulated gastric juice (pH 1.2). This study proposed that this solid dispersion system improved the bioavailability of poorly water-soluble atorvastatin calcium.

• 한국연초학회지
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• 제10권2호
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• pp.99-107
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• 1988

Pot experiment was conducted to find out the effect of lime application on yield and chemical composition of burley tobacco in 1986, Lime increased exchangeable calcium and pH of soil, but decreased Al, Fe and Mn concentrations. Yield was increased by lime application, however lime could not be caused to yield increasing in the soil with high calcium contents. Cored leaves of limed Plot contained higher Mg. K, total nitrogen, NO3-nitrogen, water soluble and insoluble ash, alkalinity number of water soluble and insoluble ash, citric and malic acid, but lower Fe, Mn, protein-nitrogen, NH3-nitrogen, nicotine petroleum ether extract, palmitic and linolenic acid concentrations than those of unlined plot. The linoleic acid and volatile neutral constituents of cured leaves were not affected by liming. Lime increased yield, however it did not affect leaf duality in respect to chemical characteristics, suggesting that liming should be necessary for tobacco cultivation.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1436-1439
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• 2010

Many studies have clarified that poly(${\gamma}$-glutamic acid) (PGA) increases the solubility of $Ca^{2+}$, suggesting that PGA enhances calcium absorption in the small intestine. However, there has been no report on the specific interaction between PGA and $Ca^{2+}$ in water. We studied the aqueous solution properties of PGA calcium salt (PGA-Ca complex). The chelating ability and binding strength of PGA for $Ca^{2+}$ were evaluated. The PGA-Ca complex was soluble in water, in contrast to the insolubility of poly(acrylic acid) (PAA) calcium salt, and the chelating ability of PGA for $Ca^{2+}$ was almost the same as that of PAA. The globular conformation of the PGA-Ca complex in water was estimated by SEC and viscosity measurements. The chelation ability of PGA for $Ca^{2+}$ was examined by $^1H$ NMR. The present study showing the characteristics of the PGA-Ca complex will provide useful information about the calcium absorption by PGA in vivo.

• 한국환경농학회지
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• 제24권1호
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• pp.12-16
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• 2005

As a silicate source to rice, a coal ash was selected and mixed with phosphor-gypsum (50:50, wt $wt^{-1}$) to reduce the potential of boron toxicity and to supply calcium element. We expected that high con tent of calcium in this mixture might convert water-soluble phosphorus to less soluble forms and then reduce the release of soil phosphorus to surface runoff. The mixture was applied with the rate of 0, 20, 40, and 60 Mg $ha^{-1}$ in paddy soil (Nagdong series, a somewhat excessively drained loamy fine sand) in Daegok, Jinju, Korea The mixture reduced significantly water-soluble phosphorus (W-P) in the surface soils by shifting from W-P and Fe-P to Ca-P and Al-P during whole rice cultivation. In contrast with W-P, plant available phosphorus increased significantly with the mixture application due to high content of phosphorus and silicate in the mixture. The mixture of coal ash and phosphor-gypsum (50:50, wt $wt^{-l}$) would be a good alternative to reduce a phosphorus export in rice paddy soil together with increasing rice yields.

• 한국토양비료학회지
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• 제19권3호
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• pp.217-221
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• 1986

토양중(土壤中)에서 납(Pb)의 용출경감효과(溶出輕減效果)를 구명(究明)하기 위(爲)하여 토양(土壤)에 납을 $PbCl_2$로 310.8ppm 처리(處理)하고 경감제(輕減劑)로서 소석회(消石灰), 석고(石膏), 과석(過石), 인산(燐酸)을 처리(處理)하여 담수후(湛水後) 실온(室溫)에 보관(保管)하면서 납 용출량(溶出量) 및 Ca, $PO_4$, $SO_4$와 pH, Eh를 측정(測定)한 결과(結果)는 다음과 같다. 1. 납 용출량(溶出量)은 경감제시용량(輕減劑施用量)이 증가(增加)할수록 감소(減少)되었으며 $H_3PO_4$ 및 과석(過石)이 용출억제효과(溶出抑制效果)가 좋았다. 2. 토양(土壤)의 pH는 소석회(消石灰)가 높고 인산구(燐酸區)가 낮으며 토양(土壤)의 Eh는 반대(反對)의 경향(傾向)이었다. 3. 토양중(土壤中)의 수용성(水溶性) Ca, $PO_4$ 및 $SO_4$ 함량(含量)은 경감제(輕減劑) 시용량(施用量)이 증가(增加)할수록 증가(增加)되었다. 4. 시험후(試驗後) 토양(土壤)의 가용성(可溶性) 납함량(含量)은 과석(過石), 인산(燐酸), 소석회(消石灰), 석고(石膏), 대조(對照)의 순(順)으로 낮은 경향(傾向)이었다.

• BMB Reports
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• 제36권3호
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• pp.319-325
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• 2003

Changes in the concentrations of $\gamma$-aminobutyric acid (GABA), soluble calcium ions, glutamic acid, and the activity of glutamate decarboxylase (GAD) were investigated in non-germinated vs. germinated brown rice. Brown rice was germinated for 72 h by applying each of the following solutions: (1) distilled water, (2) 5 mM lactic acid, (3) 50 ppm chitosan in 5 mM lactic acid, (4) 5 mM glutamic acid, and (5) 50 ppm chitosan in 5 mM glutamic acid. GABA concentrations were enhanced in all of the germinated brown rice when compared to the non-germinated brown rice. The GABA concentration was highest in the chitosan/glutamic acid that germinated brown rice at 2,011 nmol/g fresh weight, which was 13 times higher than the GABA concentration in the non-germinated brown rice at 154 nmol/g fresh weight. The concentrations of glutamic acid were significantly decreased in all of the germinated rice, regardless of the germination solution. Soluble calcium and GAD were higher in the germinated brown rice with the chitosan/glutamic acid solution when compared to the rice that was germinated in the other solutions. GAD that was partially purified from germinated brown rice was stimulated about 3.6-fold by the addition of calmodulin in the presence of calcium. These data show that the germination of brown rice in a chitosan/glutamic acid solution can significantly increase GABA synthesis activity and the concentration of GABA.

• Environmental Engineering Research
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• 제24권4호
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• pp.654-661
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• 2019

This study assessed the stabilization of fluorine (F)-contaminated soil using calcium hydroxide (Ca(OH)₂) and the consequent changes in human health risk. The bioavailable F decreased to 3.5%, (i.e., 57.9 ± 1.27 mg/kg in 6% Ca(OH)₂-treated soil sample) from 43.0%, (i.e., 711 ± 23.4 mg/kg in control soil sample). This resulted from the conversion of water-soluble F to stable calcium fluoride, which was confirmed by XRD spectrometry. Soil ingestion, inhalation of fugitive dust from soil, and water ingestion were selected as exposure pathways for human health risk assessment. Non-carcinogenic risks of F in soils reduced to less than 1.0 after stabilization, ranging from 4.2 to 0.34 for child and from 3.0 to 0.25 for adult. Contaminated water ingestion owing to the leaching of F from soil to groundwater was considered as a major exposure pathway. The risks through soil ingestion and inhalation of fugitive dust from soil were insignificant both before and after stabilization, although F concentration exceeded the Korean soil regulatory level before stabilization. Our data suggested that substantial risk to human health owing to various potential exposure pathways could be addressed by managing F present in soil.