• International Journal of Oral Biology
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• v.32 no.4
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• pp.143-151
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• 2007

This study was conducted to investigate the preventing effects of OPB (Rehmannia glutinosa Libosch and Eleutherococcus senticosus Max extracts) and combined OPB/Calcium therapy on bone loss in ovariectomized rats. Sixty Sprague Dawley rats of 12-week-old were divided into eight groups: OVX (ovariectomized), OPBL (OPB 50 mg/kg), OPBM (OPB100 mg/kg), OPBH (OPB 200 mg/kg), OPBL/CAL(OPBL+CAL), OPBM/CAL (OPBM+CAL), OPBH/CAL (OPBH+CAL) and CAL (Calcium citrate 88.33 mg/kg+1$\alpha$, 25-dihydroxy-vitamin $D_3$ 33.33 IU/kg). Bone mineral density (BMD), bone mineral content (BMC), bone strength indices and cortical thickness were analyzed by peripheral quantitative computerized tomography (pQCT). pQCT scanning showed that OVX induced a significant decrease in trabecular bone mineral density and bone mineral content in the proximal tibia $(-36.4\pm2.4%,\;-21.8\pm12.7%)$. These decreases were significantly prevented by the administration of OPBM and OPBM/CAL. Cortical BMD and BMC of tibia were slightly enhanced by OPB and OPB/CAL. However there was no significant difference between OVX and OPB, OPB/CAL treated group. Bone strength indices and cortical thickness were not significantly different. Our results suggest that OPB and combined OPB/Calcium therapy are effective in preventing the development of bone loss induced by ovariectomy in rats.

• Food Science and Preservation
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• v.10 no.2
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• pp.147-153
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• 2003

Quality changes of citrus tangor(Citrus kiyomi) during storage by chitosan and calcium treatment and storage warehouse were investigated. Citrus fruits were treated with 2000-folds diluted iminoctadime-triacetate solution, and 1.5% chitosan with 0.5% CaC1$_2$solution, and were at 30$^{\circ}C$ for 24 hr before storage. The citrus fruits of about 12 kg/26 L plastic container were stored at 4$^{\circ}C$ with 87% relative humidity. Decay ratio of citrus with precise temperature and humidity control were lower than the others during storage. Weight loss, moisture content of peel and flesh were decreased slowly during storage. 15 ∼ 18% of acid content were decreased on 120 days' storage. Vitamin C content were decreased rapidly during storage. 23 free amino acids were detected. Isoleucine and leucine were not detected, but alanine was detected only on stored citrus. Citrus fruits was kept well on its commodity quality for 3 month at 4$^{\circ}C$ with 87% relative humidity.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1118-1128
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• 1993

This study was undertaken to investigate the acute effect of caffeine consumption on the change of mineral concentration in serum and urinary mineral excretion in healthy young females. On two separate mornings at one week intervals, each subject drank a coffee which contained no caffeine and 3mg/kg body weight caffeine. To obviate dietary effects on mineral concentration in serum and urine, each subject fasted at least ten hours before consuming the test beverage. At one, two, three and four hours, serum and urine production collected seperately for measurement of sodium, potassium, calcium, phosphorus and magnesium concentration. The results were as following : 1) Mean age of subjects was 20.6$\pm$0.32, Mean body mass index of subjects was 21.64$\pm$0.89, which was within $\pm$10% of ideal body weight. 2) Total urine volume of caffein groups for 4 hour after caffeine consumption was higher than that of decaffeine one, but urine pH was unchanged after caffeine consumption. Total urinary four hour excretion of creatinine was not affected by caffeine consumption and creatinine clearance also was not different from the control value. 3) In serum, mean three hour content of sodium(p<0.01) and phosphorus was higher in the subject given the caffeine. Mean serum magnesium and calcium contents were lower in caffeine group than that of decaffeine one. Mean serum magnesium content for three hour after caffeine ingestion was affected by caffeine consumption(p<0.001). Mean serum content of potassium was unaffected by caffeine consumption. 4) Total urinary four hour excretion of sodium, increased significantly after caffeine consumption(p<0.05), while total urinary four hour excretion of potassium, calcium, phosphorus and magnesium was unchanged after caffeine intake. Urinary excretion of Na, Ca, P and Mg was greatest at one hour after caffeine consumption, especially urinary sodium and potassium excretion was significantly high(p<0.05, p<0.01). The above results show that only 3mg caffeine per kg body weight increase the urinary macro mineral excretion in healthy young females.

• Geomechanics and Engineering
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• v.32 no.3
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• pp.347-359
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• 2023

With the development of infrastructure, there is a critical shortage of filling materials all over the word. However, a large amount of silt accumulated in the lower reaches of the Yellow River is treated as waste every year, which will cause environmental pollution and waste of resources. Microbial induced calcium carbonate precipitation (MICP) technology, with the advantage of efficient, economical and environmentally friendly protection, is selected to solidify the abandoned Yellow River silt with poor mechanical properties into high-quality filling material in this paper. Based on unconfined compressive strength (UCS) test, determination of calcium carbonate (CaCO₃) content and scanning electron microscope (SEM) test, the effects of cementation solution concentration, treatment times and relative density on the solidification effect were studied. The results show that the loose silt particles can be effectively solidified together into filling material with excellent mechanical properties through MICP technology. The concentration of cementation solution have a significant impact on the solidification effect, and the reasonable concentration of cementation solution is 1.5 mol/L. With the increase of treatment times, the pores in the soil are filled with CaCO₃, and the UCS of the specimens after 10 times of treatment can reach 2.5 MPa with a relatively high CaCO₃ content of 26%. With the improvement of treatment degree, the influence of relative density on the UCS increases gradually. Microscopic analysis revealed that after MICP reinforcement, CaCO₃ adhered to the surface of soil particles and cemented with each other to form a dense structure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.128-133
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• 2000

This study was carried out to investigate the effect of forms and levels of nitrogen fertilizer on plant growth and essential oil production of Agastache rugosa. Calcium nitrate had more influenced on length and width of leaves and lateral branch length than did urea. When nitrogen fertilizer level was increased from 12 kgN/I0a to 24kgN/I0a, plant growth was stimulated and dry matter of leaf and inflorescence were increased. Top dry matter of plant with calcium nitrate treatment (38.4 g) was heavier than that of urea treatment (32.8 g). Interactions among accession and nitrogen form and nitrogen rate were not significantly different for top dry matter. The forms and rate of nitrogen fertilizer did not affect estragole content. The estragole contents was higher in leaf (91.8%) than that of inflorescence (81.3%). While the essential oil content was not affected by different nitrogen forms, nitrogen level affected the essential oil contents positively by increasing dry matter. Essential oil yield was not affected by accession or nitrogen form, but by nitrogen rate. With increasing N application from 12kgN/I0a to 24 kgN/I0a, essential oil yield was increased by 95.8 %.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1122-1127
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• 2008

A high dietary oxalate intake may lead to calcium oxalate (CaOx) kidney stones in the gastrointestinal tract. Most soy foods contain high concentrations of oxalate and/or phytate. This study analyzed the changes in oxalate (Ox), phytate ($InsP_6$), and calcium (Ca) during soymilk processing from the seeds of Korean recommended soybean cultivars (cvs). The contents of Ox, $InsP_6$, and Ca in 21 cvs ranged from 14, 108, and 148 to 231, 279, and 246 mg/100 g of dry seed, respectively. Seven cultivars were selected from the 21 cvs by the distributions of Ox, $InsP_6$, and Ca. Then, each contents of soymilk prepared from the 7 cvs were determined. All contents were lower in soymilk than in seeds, but the Ox to $InsP_6$ ratios changed from varying ratios (0.1-0.8) to normal ratios (0.8-1.0) in all cvs except 'Paldalkong'. Consequently, during soymilk processing, the Ox content was decreased and the $InsP_6$ content was remained higher than the Ox content although the Ox was likely to be less reductive than the $InsP_6$. These results may provide better information for minimizing the risk of formation of Ox kidney stones due to consumption of soy products.

• Journal of Environmental Science International
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• v.29 no.6
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• pp.605-612
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• 2020

To improve the initial strength and stability of lightweight-foamed concrete, which shows suitable sound absorption and insulation characteristics, the effect of CO₂-reduced cement on the properties of the concrete was investigated. Various mixing ratios were applied by substituting a certain amount of slag and Calcium Sulfo Aluminate (CSA) in CO₂-reduced Ordinary Portland Cement (OPC) and the physical properties of the samples were examined using the Korean Standard. The kiln temperatures of the CSA were 100-200℃ ; these values are lower than those of OPC and can lead to energy saving. In addition, the low limestone content reduces greenhouse gas emissions by 20 %. Adding a small amount of CSA in OPC content activates Ca-Al-H₂-based hydrates, and the initial compressive strength of the concrete is improved. As the CSA content increased, the thermal conductivity of the concrete decreased by up to 8% compared to plain concrete, thus indicating an improvement in its insulation. Therefore, the settlement stability was improved as the addition of CSA shortened the setting time.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.453-460
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• 2005

This investigation was performed to study Cd toxicity and the influence of Ca on Cd toxicity in growth, and photosynthetic pigments and enzymes in tobacco. Cd inhibited both growth and level of chlorophyll, but the inhibition was compensated by the treatment of Ca. Especially, chlorophyll content was significantly increased by the combination of Cd and Ca treatment compared with Cd treatment alone. In addition, activity and content of rubisco by Cd treatment was also significantly lesser than the non-treated control. The highly reduced activity of rubisco was minimized by the combined treatment of Ca to Cd. Rubisco activase activity and content also showed a pattern of change similar to the rubisco level, suggesting that Cd- and Ca-induced changes of rubisco could be caused by rubisco activase.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• The Korean Journal of Mycology
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• v.49 no.1
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• pp.109-118
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• 2021

In this study, we analyzed the diversity of ectomycorrhizal (ECM) fungal communities of Quercus spp. roots in the limestone area. We identified 45 generd of ECM using next generation sequencing (NGS) analysis. Soil chemical composition analysis confirmed soil pH, substitution calcium concentration, total nitrogen content, organic phosphate, and organic matter content. Shannon's Index was calculated according to the changes in soil chemical composition. The results of cluster analysis showed that Sebacina, Tomentella, Tuber, Densospora, Inocybe, Suillus, and Piloderma were the main genera of symbiotic ECM fungi that thrived in soil with high pH and calcium content.