• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.67-75
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• 2012

This paper presents an environment-friendly sand cementation method by precipitating calcium carbonate using plant extracts. The plant extracts contain urease like $Sporosarcina$ $pasteurii$, which can decompose urea into carbonate ion and ammonium ion. It can cause cementation within sand particles where carbonate ions decomposed from urea combine with calcium ions dissolved from calcium chloride or calcium hydroxide to form calcium carbonate. Plant extracts, urea and calcium chloride or calcium hydroxide were blended and then mixed with Nakdong River sand. The mixed sand was compacted into a cylindrical specimen and cured for 3 days at room temperature ($18^{\circ}C$). Unconfined compression test, SEM and XRD analyses were carried out to evaluate three levels of urea concentration and two different calcium sources. As urea concentration increased, the unconfined compressive strength increased up to 10 times those without plant extracts because calcium carbonate precipitated more, regardless of calcium source. It was also found that the strength of specimen using calcium chloride was higher than that of specimen using calcium hydroxide.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.1072-1077
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• 2010

Plant diseases including gray mold caused by Botrytis cinerea are often reduced when calcium compounds are used as alternative materials in paprika. However, much less information is available about the effects of calcium compounds on controlling of $B.$ $cinerea$. Seven calcium compounds such as calcium sulfate dihydrate, calcium chloride, calcium nitrate, calcium oxide, calcium hydroxide, calcium carbonate, and calcium hydride were evaluated for their effectiveness against $B.$ $cinerea$ on potato dextrose agar medium. The pH of selected calcium compounds was higher (pH 8.2-10) than that of the control (pH 6.6). Calcium carbonate, calcium oxide, calcium hydride, and calcium hydroxide among seven calcium compounds were more effectively inhibited the growth of $B.$ $cinerea$ than other calcium compounds. In the case of spraying the spore suspension on paprika applied with the selected four calcium compounds and supplied with the selected calcium supplements in a hydroponic culture system, the paprika treated with calcium compounds showed less severity of disease than those untreated plants. On the basis of our results, we propose that the suppressive effects of calcium compounds on $B.$ $cinerea$ in paprika resulted from the supply of calcium and a certain degree of salt stress.

• Journal of Life Science
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• v.29 no.7
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• pp.769-773
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• 2019

In this study, the migration route and the absorption rate of calcium and magnesium in apple leaves were compared and analyzed using plant nutrients prepared by wet nano-grinding technology. The plant nutrients were sprayed onto the leaves to confirm the component content and the movement route of the nanoized calcium and magnesium. At 2, 4, and 8 weeks after the plant nutrient treatment, the apple leaves were divided into petiole, lamina, and side, and SEM and EDS were used to measure the calcium and magnesium contents. The calcium and magnesium contents of the petiole increased from the 4th week after plant nutrient application to 1,115% at the 8th week. The calcium and magnesium contents of the lamina decreased after spraying but increased after 4 weeks. The calcium and magnesium contents increased in the side of the leaves compared to the control, reaching 673% after 4 weeks. The calcium and magnesium contents increased with increasing duration in all plots when compared with the control unsprayed leaves, suggesting that the usually poorly soluble calcium and magnesium were transferred from the petioles to the lamina. The results of this study indicate that improved calcium and magnesium absorption could be obtained in crops other than apples using plant nutrients produced through wet nano-processing technology. This technology is also expected to be applicable to natural products and bioindustries.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.137-143
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• 2012

Chinese cabbage plant was grown hydroponically for 4 weeks in order to examine the temporal relationship of calcium concentration of the nutrient solution with calcium content in the leaf tissue and susceptibility of the tissue to soft rot disease by $Pectobacterium$ $carotovorum$ ssp. $carotovorum$ (Pcc). Calcium concentration from 0.5 to 32.0 mM was maintained for 1 week using Hoagland & Arnon solution. The calcium content of the leaf was proportionally increased to the concentration of the nutrient in the solution (r = 0.912). In contrast, the severity of soft rot symptom in the young leaves was inversely related with the amount of calcium supplied to the nutrient solution (r = 0.899). Water-soluble chitosan, prepared by hollow fiber filtration (> 100 kDa) was applied into the nutrient solution from 0.0 to 5,000 ppm. The chitosan of 10 ppm was the most effective to promote calcium uptake of the leaf, showing 155% of the control. The same chitosan solution prohibited most soft rot development of the leaf by Pcc, exhibiting only 53% of the control. Among different molecular weight fractions, chitosan fraction obtained from 30-100 kDa molecular weight cut-off promoted calcium uptake the most up to 163% of the control, and reduced the development of soft rot disease recording merely 36% of the control of the leaf tissue. The results obtained in the present study suggest that large scale production of water-soluble chitosan with an optimum molecular weight and its commercial application to Chinese cabbage production will be important to improve yield and quality of the crop.

• Journal of Nutrition and Health
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• v.24 no.2
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• pp.124-131
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• 1991

This study was to examine the effects of dietary protein levels and the sources of protein(animal and plant) on calcium and phosphorus metabo lism in 10 healthy Korean female adults. The 26­d day study consisted of a 6-day adaptation period and lO-day moderate protein(109 N, 550mg Ca) a and IO-day high protein( 14g N, 570mg Ca) pe­r riod. During the experimental period, the subjects w were divided into two groups, either consuming a animal protein diet(75 % animal protein) or plant protein diet(75 % plant protein). Calcium(300 mg) was supplemented to two subjects of each d dict group for the last 4 days. Feces, urine and diet were analyzed nitrogen. calcium and phos­p phorus. The apparent absorption of calcium was significantly increased as the protein intake was inc­r reased from 60g to 90g in animal protein diet. A Average calcium absorption rate was 30% and 46 % from high and moderate levels of animal p protein diet Urinary calcium excretion was not affected by t the amount of the protein intake in both animal and plant protein diet. There was significantly higher urinary calcium excretion(I34mg) in high I level of animal protein diet than that( 83mg) in h high level of plant protein diet. Calcium balance was improved as the protein intake increased and c calcium was supplemented. Phosphorus absorp­t tion was more efficient in the high animal diet(77.81 %) than in the high plant diet(55-65%). The overall results indicate that an increase of protein and calcium supplement in moderate pro­ttein intake can improve calcium balance due to the increase of calcium absorption.

• Journal of Plant Biology
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• v.32 no.4
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• pp.343-350
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• 1989

Calcium promoted ethylene production from mungbean hypocotyl segments incubated in the presence of either auxin or cytokinin (kinetin). Time course studies indicated that the calcium effect on ethylene production had a longer latent period (about 6 h) in combination with kinetin than with auxin. Studies on the effects of agents that are known to interfere with either action or transport (uptake) of calcium on ethylene biosynthesis indicated different patterns between auxin- and kinetin-treated tissues. Auxin-induced ethylene production was inhibited by the calmodulin inhibitor, trifluoperazine (TFP), and this inhibition was overcome by high concentrations of calcium applied, but TFP had no significant effect on kinetin-induced ethylene production regardless of calcium in the medium. The calcium channel blocker, verapamil, inhibited auxin-induced, but had little effect on kinetin-induced, ethylene producton. In vivo activity of "ethylene forming enzyme (EFE)" was found to be substantially promoted by calcium treatment. The enzyme activity was further increased by kinetin when segments were simultaneously treated with calcium, but auxin did not have such an effect.an effect.

• The Korean Journal of Ecology
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• v.21 no.1
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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).

• Research in Plant Disease
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• v.10 no.1
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• pp.82-85
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• 2004

Bacterial soft rot by Erwinia carotovora subsp. carotovora is one of the diseases causing the biggest damages in Chinese cabbage cultivation. This study was conducted to evaluate on suppressive effect of calcium fertilizer to bacterial soft rot of Chinese cabbage. Seven calcium fertilizers were selected for evaluation. And screening was conducted to select effective agents for controlling bacterial soft rot. When applied by the nursery test condition using mineral oil inoculation method with Chinese cabbage, calcium hydroxide had more suppressive efficacy than any other calcium fertilizer, While nitrogen fertilizer was induced the disease, calcium hydroxide was suppressed soft rot disease in field test as well as seedling test. Treatment of calcium+nitrogen fertilizer as well as calcium only showed a significant control effect in the field experiment with Chinese cabbage 'Sanchon' in 2003.

• Journal of Plant Biotechnology
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• v.39 no.1
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• pp.23-32
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• 2012

Calcium is an essential nutrient for living organisms, with key structural and signaling roles. Its deficiency in plants can result in poor biotic and abiotic stress tolerance as well as reduced crop quality and yield. Calcium deficiency in humans causes various diseases such as osteoporosis and rickets. Biofortification of calcium in various food crops has been suggested as an economic and environmentally advantageous method to enhance human intake of calcium. Recent efforts to increase the levels of calcium in food crops have used calcium/proton antiporters ($CAXs$) and modified one to increase calcium transport into vacuoles through genetic engineering. It has been reported that overall calcium content of transgenic plants has been increased in their edible portions with some adverse effects. In conclusion, biofortification of calcium will add more value in crops as well as will be beneficial for animal and human. Therefore, more fundamental studies on the mechanisms of calcium ion storage and transporting are essential for more effective calcium biofortification.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.128-134
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• 2010

Purpose: The aim of this study was to evaluate the changes in bone density and reduction of time consumed for osteogenesis by $PostPlant^{TM}$ Calcium and to find out efficacy of $PostPlant^{TM}$ Calcium by comparing the group prescribed with $PostPlant^{TM}$ Calcium with the group without $PostPlant^{TM}$ Calcium prescription. Material and methods: The experimental group of 18 patients with 25 dental implant placement and the control group of 7 patients with 9 dental implant placement were randomly selected from the patients who visited prosthetic department of Dankook University Dental Hospital since July, 2006 (IRB Number ; 20060710). The experimental group was instructed to take $PostPlant^{TM}$ Calcium for 6 months after the implant surgery while the control group was instructed not to. Both experimental and control group were assigned for measurement using $Osstell^{TM}$ Mentor and $Periotest^{(R)}$ and radiographic examination was performed using specifically manufactured Aluminum Step Wedge. The results were compared and analyzed. Results: 1. According to the $Osstell^{TM}$ Mentor measurement, both the experimental and control group showed increase in values as time elapses and the experimental group showed significantly higher rate of increase (P < .05). 2. According to the $Periotest^{(R)}$ measurement, both the experimental and control group showed decrease in values as time elapses. In addition, greater decrease can be seen in the experimental group but no statistical significance was found. 3. By examining the radiographic images, both the experimental and control group showed tendency of increase in bone density. In addition, greater increase can be seen in the experimental group but no statistical significance was found. Conclusion: Clinically, taking $PostPlant^{TM}$ Calcium medicine for a long period of time after implant placement is expected for a better prognosis.