• The Korean Journal of Physiology and Pharmacology
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• 제2권1호
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• pp.55-62
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• 1998

${\alpha},\;{\beta}-Adrenergics$, and calcium channels were known to be related to inducing cardiac hypertrophy. Recently, it was reported that the cardiac renin-angiotensin system (RAS) was an important factor in ventricular hypertrophy. The present study was aimed to investigate the effects of ${\alpha},\;{\beta}-adrenergic$, and calcium channel blockers that might be involved in the regulation of cardiac RAS. The reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of renin gene in the perfused rat heart. Changes in angiotensin converting enzyme (ACE) activity and cyclic AMP (cAMP) content which were thought to play a role in inducing cardiac hypertrophy were measured in the perfused rat heart. The expression of renin gene was not only increased by isoproterenol with metoprolol-pretreatment but also increased by vasopressin treatment in the presence of calcium channel blocker, nifedipine or verapamil. Either prazosin alone or norepinephrine with prazosin-pretreatment significantly increased the ACE activity. However, isoproterenol with metoprolol-pretreatment significantly decreased the ACE activity. On the other hand, the ACE activity was not changed by vasopressin, nifedipine, or verapamil treatments. The content of cAMP was significantly increased by either isoproterenol or vasopressin treatment. According to these results, renin gene expression was associated with ${\beta}2$ - adrenoceptor and calcium channel. ACE activity was associated with ${\alpha}-\;and{\beta}2$ - adrenoceptor. In conclusion, ${\beta}2$ - adrenoceptor was important in cardiac renin gene expression and ACE activity and ${\alpha},\;{\beta}$ -adrenergic, and calcium channel blockers might be involved in the regulation of cardiac RAS in a complicated way.

• 자연과학논문집
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• 제10권1호
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• pp.57-61
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• 1998

장십랑 배를 수확한 후에 $CaCl_2$에 침지 또는 감압침지하므로 과실의 칼슘함량이 증가되었다. 특히 과피와 과피직하 과육의 칼슘증가량이 많았다. 단순침지의 경우 $CaCl_2$의 농도가 2%에서 8%까지 높아질수록 과실의 칼슘함량이 증가되어 효과적이었고, 감압침지의 경우 200-600mmHg의 감압범위에서는 차이가 없었으며, 단순 침지와 감압침지 간에도 차이를 인정할 수 없었다. 처리 4주 후의 과실경도의 저하는 $CaCl_2$ 처리로 칼슘함량이 증가된 과실에서 둔화되었다.

• 구강회복응용과학지
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• 제37권2호
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• pp.95-100
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• 2021

수산화칼슘제재는 근관치료 과정 동안 근관 내 첩약제로서 널리 사용되고 있다. 이번 증례 보고에서는 근관 세척제로 사용된 수산화칼슘제재가 치근단 병소로 의도치 않게 과충전된 치아에 대해 정확한 진단과 적절하게 행해진 비외과적인 재근관치료를 통해 성공적으로 치료한 증례를 보고하고자 한다. 과충전된 수산화칼슘제재가 치근단 병소의 치유 과정에 영향을 줄 수 있으므로 수산화칼슘제재의 과충전이 발생하지 않도록 주의를 기울여야 한다.

• 대한금속재료학회지
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• 제46권2호
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• pp.105-110
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• 2008

Process of the hydroxyapatite (HA) formation on bioactive titanium metal prepared by NaOH treatment in a modified-simulated body fluid (mSBF) containing bovine serum albumin (BSA) was investigated by high resolution transmission electron microscope attached with energy dispersive X-ray spectrometer (EDX). The amorphous titanate, which was formed on titanium surface by NaOH treatment, combined with the calcium ions in the liquid to form an amorphous calcium titanite. With increasing of soaking time in the liquid, an amorphous calcium titanite combined with the phosphate ions to form an amorphous calcium phosphate with low Ca/P atomic ratio, and it grows as aggregates of plate (or needle)-like substance on titanium surface. The crystalline apatite layers, which are needle-shaped with the c axis parallel to the long axis, are formed in an amorphous calcium phosphate with further increase in soaking time. The formation of needle-shaped apatite layers can be explained by electrostatic effects and difference of concentration between calcium, phosphate, and albumin ions.

• Journal of Ceramic Processing Research
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• 제20권6호
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• pp.655-659
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• 2019

Calcium phosphates such as HA (hydroxyapatite), β-TCP (tricalcium phosphate) and biphasic HA/β-TCP, were synthesized by wet chemical precipitation in aqueous solution combined with ball milling process. Nanosize powders of the calcium phosphates were synthesized using Ca(OH)2 and H3PO4. The effects of initial precursor Ca/P ratio (1.30, 1.50 and 1.67), ball milling process and post heat-treatment on the phase evolution behavior of the powders were investigated. The phase of resulting powder was controllable by adjusting the initial Ca/P ratio. HA was the only phase for as-prepared powders in both cases of Ca/P ratios of 1.50 and 1.67. The single HA phase without any noticeable second phase was obtained for the initial Ca/P ratio of 1.67 in the overall heat-treatment range. Pure β-TCP and biphasic calcium phosphate (HA/β-TCP) were synthesized from precursor solutions having Ca/P molar ratios of 1.30 and 1.50, respectively, after having been heat-treated above 700 ℃. The β-TCP phase has appeared on the pre-existing DCPD (dicalcium phosphate dihydrate) and/or HA phase. Dense ceramics having translucency were obtained at a considerably lower sintering temperature. The modified process offered a fast, convenient and economical route for the synthesis of calcium phosphates.

• 운동영양학회지
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• 제24권4호
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• pp.24-27
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• 2020

[Purpose] Dehydroepiandrosterone (DHEA) administration reportedly recovers osteoporosis, a bone disorder associated with bone deficiency in postmenopausal women. However, the physiological mechanism of DHEA in osteoporosis remains elusive, especially in terms of intestinal calcium absorption. Therefore, we investigated the effect of DHEA administration on calcium absorption in ovariectomized (OVX) female rats using an estrogen receptor antagonist. [Methods] Female Sprague-Dawley rats (n=23, 6 weeks old) were randomized into three groups: OVX control group (OC, n=7), OVX with DHEA treatment group (OD, n=8), and OVX with DHEA inhibitor group (ODI, n=8) for 8 weeks. [Results] Intestinal calcium accumulation, as well as the rate of absorption, demonstrated no significant differences during the experimental period among investigated groups. The bone mineral density (BMD) of the tibia at the proximal metaphysis was higher in the OD group than that in the OC group (p<0.05); however, BMD of the ODI group showed no significant difference from investigated groups. Furthermore, the BMD of the tibia at the diaphysis did not significantly differ among these groups. [Conclusion] We revealed that DHEA administration does not involve intestinal Ca absorption, although this treatment improves BMD levels in OVX rats. These observations indicate that the effect of DHEA on the bone in postmenopausal women is solely due to its influence on bone metabolism and not intestinal calcium absorption.

• Journal of Chest Surgery
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• 제37권4호
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• pp.307-312
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• 2004

With the development of cardiac surgical technique, we need more prosthetic materials for repairing the intra- and extracardiac defects. Although bovine pericardial bioprosthesis treated with glutaraldehyde (GA) solution is one of the most popular materials, it has a drawback of later calcific degeneration. The purpose of this study is to investigate the effectiveness of several materials and methods in reducing the calcific degeneration of bovine pericardium. Material and Method: Forty square-shaped pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L MgCl$_2$ㆍ6$H_2O$ as a control group (group 1). Other 40 pieces pre-treated with 1 % SDS(group 2) and 40 pieces post-treated with 8% glutamate (group 3) and 2% chitosan (group 4) were also fixed in the same GA solution. Other 40 pieces pre-treated with 1% SDS and post-treated with 8% glutamate and 40 pieces post-treated with 2% chitosan were also fixed in the same GA solution (group 5, 6). The pericardial pieces were implanted into the belly of 40 Fisher 344 rats subdermally and were extracted 1 month, 2 months, 3 months, and 6 months after the implantation. With an atomic absorption spectrophotometry, we measured the calcium amount deposited and examined the tissue with microscope. Result: The calcium deposition in 1 month was less in group 2, 5, 6 than that in group 1 (p＜0.05). It was most prominent in group 5 (p＜0.01). This finding continued in 2 month. In 3 month, the calcium deposition was less in group 3 and 4 as well as group 2, 5, and 6 than in group 1. In 6 month, the calcium deposition in group 2, 3, 4, 5, and 6 was less than that in group 1 and the difference was more than that of 1, 2, and 6 month. The microscopic calcium deposition was also less in group 2 and 5. Calcium deposition developed in the whole layer of pericardium, beginning with the surrounding the collagen fiber and progressing inwardly. Conclusion: Pre-treatment with SDS, post-treatment with glutamate or chitosan, and SDS pre-treatment and post-treatment with glutamate or chitosan were effective in reducing the calcium deposition in bovine pericardium. Moreover, the combined method of SDS pre-treatment and glutamate post-treatment was more effective than other methods.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.207-207
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• 2017

The proso millet is vulnerable to lodging due to high plant height and shallow root. A lodging results in a hard mechanical harvesting and yield loss. One of solutions on this problem is inhibition of internode elongation. The objective of this study was to set up use time and dose of prohexadium-calcium, is growth inhibitor. The experimental variety was Ibaekchal. The experiment design was a split-plot design with three replications. The treatments were as follow: Main-plots were 25 and 35 day after sowing(DAS) as use time and sub-plots were 0%, 50%, 100%(diluted solution of 1000 times, $1000{\ell}\;ha^{-1}$), 150% as dose. The amount of nitrogen, phosphate and potassium fertilization were 90, 70, $80kg\;ha^{-1}$, respectively. The size of high ridge and plant spacing were $90{\times}30cm$ and $60{\times}15cm$, respectively. Proso millet was sown on June 9, 2016 by hands and was adjusted at 2 plant per hill. The growth survey of vegetative growth stage was conducted at 1 day before treatment and with one week interval after treatment. Data were collected: (1) grain yield: weight of grain in $kg\;ha^{-1}$, (2) 1000 grain weight: average weight of 1000 grain, (3) plant height: distance from soil to top of panicle or leaf in cm, (4) ear length: distance from top of stem to top of ear in cm, (5) stem diameter: diameter of second internode (6) degree of lodging: percentage of lodging area, etc. Analyses of variance were performed using R version 3.3.1(https://www. r- project. org). The Duncan's multiple range test(DMR) was used to separate treatment means at P < 0.05. There was a significant difference in plant height and number of stem among the use time and dose of prohexadium-calcium during vegetative growth stage. At 25 DAS, the difference with no treatment increased until 25 day after treatment and decreased since then. The difference in number of stem increased until 18 day and decreased since 25 day. At 35 DAS, the difference with no treatment in plant height and number of stem increased until 22 day after treatment and decreased since then. We assumed that the effect of prohexadium-calcium was inhibition of internode elongation and promotion of tillering, continued untel 25day after treatment. At 25 DAS, the degree of lodging deceased to 100%, 30%, 10% and 0% as dose increased. At 35 DAS, the degree of lodging decreased to 100%, 20%, 0% and 0% as dose increased. At 25 DAS, the yield was 2910, 2710, 3190, $2310kg\;ha^{-1}$ among dose. At 35 DAS, the yield was 2750, 2630, 2220, $2050kg\;ha^{-1}$. We recommend that the optimum use time and dose of prohexadium-calcium for proso millet is 1000 times diluted solution of $1000{\ell}$ per ha at 25 day after sowing.

• 한국약용작물학회지
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• 제20권2호
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• pp.124-128
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• 2012

When ginseng seedlings are cultured in paddy fields, quality degradation and yield reduction are induced by severe plant loss with chlorosis on leaves occurred physiological disorder by excessive salt and poor drainage, rusty-root occurrence, and root rot etc. Accordingly, in order to solve these problems, this study was performed to investigate the treatment method, concentrations and time of activated ion calcium as environment-friendly agricultural materials. Activated ion calcium is an enriched and purified water-soluble mineral calcium component for absorbing quickly into plant as a highly functional calcium and it is an alkaline calcium of 37% (370 $m{\ell}$/1 ${\ell}$) concentration with pH 13. Treatment method was that ginseng seeds were sown after removing water in the shade after seed immersion for 1 minute with active ion calcium of 20-fold diluted solution, and then irrigated $4{\ell}$ per 3.3 $m^2$ with 200-fold, 400-fold, and 600-fold diluted solution before emergence on late March, and supplied 1 time on leaves with 500-fold diluted solution in June and July respectively. The disease rate by treatment of activated ion calcium was that on the treatment of soil irrigated with 200-fold diluted solution compared to non-treated soil, damping-off was 33%, anthracnose was 100% reduced and the occurrence rate of rusty-root was 30% reduced. In addition, when active ion calcium of 200-fold diluted solution were soil irrigated, first and second grade ginseng were respectively 26% and 22% produced more, compared with control.

• 환경위생공학
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• 제17권4호
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• pp.10-18
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• 2002

The changes of conventional clarification processe and an increase in treatment cost are required to meet increasingly stringent regulations related to the treated water quality. Although many enhanced coagulations have introduced to improve organic matter removal, the results to remove color, nitrogen and phosphorus as well as organic material have not been very efficient yet. In this context as new flocculation using calcium hydroxide and magnesum sulfate was carried out. The removal of waste matters such as SS, organic matter, COD, nitrogen and phosphorus contained in stock wastewater was carried out by using the combination of calcium hydroxide and magnesium sulfate. The flocculation was investigated as a function of coagulant dose, pH, mixing time, settling time and coagulant addition modes such as the sequential addition of the two coagulants and the simultaneous addition of them. The flocculation by the combination of calcium hydroxide and magnesium sulfate was compared with that by aluminum sulfate. The mechanism of flocculation was investigated as well. About 60% of COD in stock watewater was removed by flocculation with combination of calcium hydroxide and magnesium sulfate.