• Journal of Veterinary Science
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• 제24권2호
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• pp.22.1-22.12
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• 2023

Background: Citric acid (CA) and sodium hypochlorite (NaOCl) have been used to disinfect animals to protect them against avian influenza and foot-and-mouth disease. Objectives: We performed a good laboratory practice (GLP)-compliant animal toxicity study to assess the acute toxic effects of CA and NaOCl aerosol exposure in Sprague-Dawley rats. Methods: Groups of five rats per sex were exposed for 4 h to four concentrations of the two chemicals, i.e., 0.00, 0.22, 0.67, and 2.00 mg/L, using a nose-only exposure. After a single exposure to the chemicals, clinical signs, body weight, and mortality was observed during the observation period. On day 15, an autopsy, and then gross findings, and histopathological analysis were performed. Results: After exposure to CA and NaOCl, body weight loss was observed but recovered. Two males died in the CA 2.00 mg/L group and, two males and one female died in the 2.00 mg/L NaOCl group. In the gross findings and histopathological analysis, discoloration of the lungs was observed in the CA exposed group and inflammatory lesions with discoloration of the lungs were observed in the NaOCl exposed group. These results suggest that the lethal concentration 50 (LC50) of CA is 1.73390 mg/L for males and > 1.70 mg/L for females. For NaOCl, the LC50 was 2.22222 mg/L for males and 2.39456 mg/L for females. Conclusions: The Globally Harmonized System is category 4 for both CA and NaOCl. In this study, the LC50 results were obtained through a GLP-based acute inhalation toxicity assessment. These results provide useful data to reset safety standards for CA and NaOCl use.

• The Korean Journal of Physiology
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• 제22권1호
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• pp.13-29
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• 1988

In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.

• 대한지하수환경학회지
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• 제7권2호
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• pp.73-88
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• 2000

강원도 북동부지역에서 산출되는 탄산약수에 대한 지구화학적 연구를 수행하였다. 탄산약수는 화학적으로 Na-$HCO_3$형, Na-Ca-$HCO_3$형, Ca-$HCO_3$형으로 구분된다. 탄산수의 지화학적 특성은 심부기원으로부터 이산화탄소의 공급을 받은 지하수가 주변암석과의 반응을 통하여 탄산수를 형성하였고, 탄산수들의 상이한 유형은 탄산수를 형성하는 심부환경이 다른 조건에 기인하는 것으로 사료된다. 특히, 물-암석반응에서 온도환경에 따른 사장석의 용해도 차이는 탄산수의 지화학적 특성을 결정짓는데 중요한 역할을 하였을 것으로 판단된다. 온도조건이 높을수록 알바이트와 아노사이트간의 용해도차이는 감소하므로, 높은 Na/Ca비를 갖고 있는 화강암내 사장석의 화학조성을 고려할 때, 높은 온도환경에서의 물 -암석반응은 상대적으로 낮은 온도환경에 비해 높은 Na/Ca비를 갖는 탄산수를 형성한다. 지질온도계의 적용결과는 Na-$HCO_3$형의 경우 약15$0^{\circ}C$의 심부저장지의 온도를 보이는 반면, Ca-$HCO_3$형은 상대적으로 낮은 온도를 보여주고 있다. 일반적인 지열구배를 고려한다면, Na-$HCO_3$형의 탄산수는 Ca-$HCO_3$형에 비해 깊은 심도에서 형성되었을 것으로 해석할 수 있다.

• 대한약리학회지
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• 제24권2호
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• pp.179-187
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• 1988

소듐에 의한 칼슘의 유리는 verapamil, TTX, TEA의 영향을 받지 않았다. $100\;{\mu}M\;Cd6{++}$과 $Zn^{++}$은 소듐에 의한 칼슘 유출을 유의하게 억제하였다. $Cd^{++}$은 $Ki\;100\;{\mu}M\;Cd6{++}$로써 비상경적으로 소듐-칼슘 교환이동을 억제하였다. $Cd^{++}$은 SH기의 산화를 초래하였으나, $Zn^{++}$은 거의 영향을 나타내지 않았다. $Cd^{++}$과 $Zn^{++}$은 $Na^+-Ca^{++}$ ATPase를 효과적으로 억제하였으나 $Ca^{++}-Mg^{++}$ ATPase를 약간 억제시켰다. Carbonyl cyanide chlorophenylhydrazone, 2,4-dinitrophenol과 sodium arsenate는 소듐에 의한 칼슘 유리를 촉진하였다. Dibucaine과 oligomycin은 소듐에 의한 칼슘의 유리를 약간 억제하였으나, 이에 반하여 ouabain은 약간 촉진하였다. 이상의 실험 결과로부터 신경 세포막에서의 소듐-칼슘 교환은 이온 통로를 통하여 이루어지지 않을 것으로 시사되었다. 소듐-칼슘 교환이동은 $Cd^{++}$에 민감하게 억제되고 이 이동기전에 synaptosome막의 SH기가 관여할 것으로 사료되었다. 또한 소듐-칼슘 교환은 세포막 단백질 성분의 인산화 반응 동안에 억압될 것으로 추정되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제26권3호
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• pp.219-225
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• 2022

Glucagon like peptide-1 (GLP-1) released from enteroendocine L-cells in the intestine has incretin effects due to its ability to amplify glucose-dependent insulin secretion. Promotion of an endogenous release of GLP-1 is one of therapeutic targets for type 2 diabetes mellitus. Although the secretion of GLP-1 in response to nutrient or neural stimuli can be triggered by cytosolic Ca²⁺ elevation, the stimulus-secretion pathway is not completely understood yet. Therefore, the aim of this study was to investigate the role of reverse Na⁺/Ca²⁺ exchanger (rNCX) in Ca²⁺ entry induced by muscarinic stimulation in NCI-H716 cells, a human enteroendocrine GLP-1 secreting cell line. Intracellular Ca²⁺ was repetitively oscillated by the perfusion of carbamylcholine (CCh), a muscarinic agonist. The oscillation of cytosolic Ca²⁺ was ceased by substituting extracellular Na⁺ with Li⁺ or NMG⁺. KB-R7943, a specific rNCX blocker, completely diminished CCh-induced cytosolic Ca²⁺ oscillation. Type 1 Na⁺/Ca²⁺ exchanger (NCX₁) proteins were expressed in NCI-H716 cells. These results suggest that rNCX might play a crucial role in Ca²⁺ entry induced by cholinergic stimulation in NCI-H716 cells, a GLP-1 secreting cell line.

• 아시안잔디학회지
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• 제10권2호
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• pp.105-115
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• 1996

To find out the mineral cycles of calcium, magnesium and sodium in dynamic grassland cosystems in a steady state condition, this investigation was conducted along the northwest side on Mt. Kwanak. The experimental results may he suromarized on the communities of a Zoysia japonica and a Miscanthus sinesis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, cal- cium (Ca) was greater quantity in a Zoysia japonica, whereas, in a Miscanthus sicensis, sodium (Na)and magnesium (Mg) were greater in Mt. Kwanak. For the case of steady production and release, the ratio of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants of Ca, Mg and Na of the litter were 0.42, 0.25 and 0.29 in the Zoysia japonica grassland, and were 0.41, 0.54 arid 0.62 in the Miscanthus sinensis grassland, respect- ively. The half times of Ca, Mg and Na required for the release or accumulation of the litter on the grassland were 1.65, 2.77 and 2.39 in the Zoysia japonica, and were 1.69, 1.28 and 1.12 in the Miscauthus sinensis, respectively. The increasing order of the turnover parameters of the elements was Ca, Na and Mg in the Zoysia japonica grassland, and was Na, Mg and Ca in the Miscanthus Si nens is grassland. The amounts of annual cycles for Ca, Mg, Na in the grassland ecosystem under the steady-state conditions were 1.29, 0.20 and 0.12 g /m$^2$ in the Zoysia japonica grassland and 3.91, 1.04 and 0.61 g /m$^2$ in the Miscanthus sinensis grassland.

• 한국결정성장학회지
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• 제14권3호
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• pp.110-114
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• 2004

반응온도 $75^{\circ}C$에서 $Ca(OH)_2$ slurry 및 NaOH의 혼합용액에 $Na_2CO_3$ 수용액의 농도 및 첨가방법을 변화시키면서 아라고나이트 침강성 탄산칼슘의 생성거동을 관찰하였다. 이 반응에서 $Na^+$ 이온은 탄산칼슘 격자내의 $Ca^{2+}$ 이온 자리에 치환되어 칼사이트의 성장을 지연시키고, 특정방향으로의 결정성장이 진행되어 침상형 아라고나이트의 생성을 유리하게 하는 것을 알 수 있었다. 또한, $CO_3^{2-}$ 이온농도 조절에 의한 반응속도의 감소는 균일침전반응을 유도하고, $Na^+$ 이온의 치환능력을 증대시켜 아라고나이트의 생성 및 성장을 촉진하는 것으로 판단되었다.

• Journal of Nutrition and Health
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• 제33권4호
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• pp.403-410
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• 2000

The effects of dietary Ca and Na levels on lipid metabolism in hyper lipidemic/hypercholesterolemic rats were examined. In Expt. 1, normal rats were divided into six groups and fed high fat(15%, w/w)/cholesterol(1%, w/w) diet containing two levels of Na, low (0.05) or high(1.5%) and three levels of Ca, low(0.1%), normal (0.5%), or high(1.5%) for 8 weeks. In Expt. 2, hyperlipidemia / hypercholesterolemia rats were induced by feeding high fat / cholesterol diet for 4 weeks. They were divided into four groups and fed the high fat / cholesterol diet, containing two levels of Na, low or high and two levels of Ca, low or high for 4 weeks. In Expt. 1, total lipid and total cholesterol contents in serum and liver were significantly lower in rats fed high Ca diet than in rats fed normal or low Ca diet regardless of dietary Na levels. Serum TG was the highest in rats fed low Ca and low Na diet. In Expt. 2, Serum total lipid, TG, and total cholesterol levels decreased by 24, 35, 26% respectively in rats fed high Ca diet regardless of dietary Na levels. Serum total lipid level tended to increased in rats fed low Na diet. The total lipid and TG contents in liver slightly decreased in rats fed high Ca diet. Another observation was that high Ca intake significantly faciliated the fecal lipid and cholesterol excretion regardless of dietary Na levels. There results suggest that the hypolipidemidc/hypocholesterolemic effects of high Ca diet could be partly due to increase in lipid and cholesterol excretion and these effects may be independent of dietary Na levels.

• 한국세라믹학회지
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• 제31권12호
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• pp.1521-1528
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• 1994

To improve mechanical strength of bioglass, it is considered to use the glass as a coating material to alumina, but the difference in thermal expansion coefficient between two materials is too high to make a good coating. The aim of the present study, therefore, is to find out proper glass composition matching its thermal expansion coefficient to that of alumina without losing biocompatibility. In the present work, various glasses were prepared by substituting B2O3 and CaO for Na2O in the glass system of 55.1%SiO2-2.6%P2O5-20.1%Na2O-13.3%CaO-8.9%CaF2 (in mole%), and the thermal expansion property and reaction property in tris-buffer solution for the resulting glasses were measured. The thermal expansion coefficient of the glass was decreased with the substitution of B2O3 for Na2O, and it became close to that of alumina in the glass in which 8 mole% of CaO was substituted for Na2O. Hydroxyapatite formation was enhanced and silica rich layer thickness was decreased with B2O3 substitution for Na2O. CaO substitution for Na2O didn't deteriorated the hydroxyapatite development.

• 한국대기환경학회지
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• 제14권1호
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• pp.11-23
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• 1998

The purpose of this study was to survey chemical distribution of inorganic elements and ions in the submicron particles, to characterize qualitatively emitting sources by factor analysis, and finally to reveal existing patterns in terms of chemical compounds by a stepwise multiple regression analysis. Total of 141 samples were collected by a cascade impactor from 1989 to1996. Fifteen chemical species (Al, Ba, Cd, K, Pb, Cu, Fe, Ni, $Cl^-, NO_3^-, SO_4^{2-}, K^+, Mg^{2+}, Ca^{2+}, and Na^+$) were characterized by AAS and IC. The study showed that average seasonal levels of submicron particulate matters $(d_p<0.43 \mum)$ were 18.7 $\mug/m^3$ in spring, 15.5 $\mug/m^3$ in summer, 15.7 $\mug/m^3$ in fall, and 24.5 $\mug/m^3$ in winter, respectively. All of the anion concentrations in the particle were highest in the winter season. By applying a factor analysis, 5 source patterns were qualitatively obtained, such as sulfate related source, nitrate related source, oil burning source, calcium related source, and coal combustion source. Finally, when applying a stepwise multiple regression analysis, the results clearly showed that $Na^+ and Ca^{2+}, K^+ and Ca^{2+}, NO_3^-$ and relative humidity, $Cl^-$ and ambient temperature, $Ca^{2+} and Cl^-, Mg^{2+} and SO_4^{2-}, Na^+ and NO_3^-, and Ca^{2+} and NO_3^-$, respectively, are negatively contributed to each other. As a result of those statistical analysis, we could suggest that some chemical compounds in the submicron particles such as$NaNO_3, MgSO_4, Ca(NO_3)_2, and CaCl_2$ may not exist on the filter as final composing products; however, other compounds may possibly exist in the form of $Mg(NO_3)_2, CaSO_4, Na_2SO_4, K_2SO_4, MgCl_2, NaCl, and KCl$. Thus, it must be necessary to identify differences between the results of above statistical analysis and of the real world by laboratory experiments.