• 생물환경조절학회지
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• 제14권2호
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• pp.128-136
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• 2005

본 연구는 칼슘의 시비농도를 인위적으로 조절한 후 국화를 재배하면서 각 원소의 시비수준이 생육과 절화 품질에 미치는 영향을 구명하고 생육을 우수하게 유지할 수 있는 식물체 및 토양의 한계농도를 밝히기 위하여 수행하였다. Ca결핍 증상은 신엽에서 발생하였고, 신엽이 cup 형태로 구부러지는 기형증상이 나타났다. 정식 109일 후에 조사한 절화장은 무시비구, 3.0mM 그리고 4.5mM Ca처리에서 각각 105.8cm, 106.5cm, 107.3cm로 조사되었다. Ca시비농도가 증가할수록 절화중이 무거워져 무처리구가 51.6g이었고 6.0mM 시비구에서 59.4g으로 측정되었다. 건물중이 가장 무거웠던 6.0mM Ca시비구에서 $3.09\%$의 식물체내 Ca함량을 갖는 것으로 분석되어 국화 'Biarritz'의 정상 생육을 위해서는 $2.8\%$ 이상의 식물체내 Ca 함량을 갖도록 시비하여야 할 것으로 판단되었다. Ca 시비농도가 증가할수록 토양 농도도 뚜렷하게 높아져 무처리구, 1.5, 3.0, 4.5 및 6.0mM 시비구가 각각 5.0, 7.3, 12.1, 16.5 및 $28.2mg{\cdot}L^{-1}$로 분석되었다. 건물 생산량을 고려하여 정상 생육을 위한 최저한계점은 $25.4mg{\cdot}L^{-1}$이라고 판단되었다.

• Food Science and Biotechnology
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• 제17권1호
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• pp.8-14
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• 2008

The influence of salt concentration on the stability of sodium caseinate (CAS)-stabilized emulsions (20 wt% corn oil, 3.2 wt% CAS, 5 mM imidazole/acetate buffer, pH 7) was examined. In the absence of salt, laser diffraction measurements and optical microscopy measurements indicated there were some large oil droplets ($d>10\;{\mu}m$) in the emulsions stabilized by 0.8 to 3.2 wt% of CAS. The droplet aggregation (mostly droplet coalescence) observed in the emulsions containing ${\leq}2.8\;wt%$ CAS tended to decrease as the CAS concentration increased, however, after which concentration (at 3.2 wt% CAS) depletion flocculation occurred. The addition of $CaCl_2$ (5-20 mM) into the emulsions stabilized by 3.2 wt% CAS prevented the depletion flocculation although there was a small fraction of relatively large individual droplets in the emulsions, which was attributed to electrostatic screening effect and bridging effect of calcium ion. This study has shown that calcium ion that has been reputed to promote droplet aggregation could improve emulsion stability against droplet aggregation in CAS-stabilized emulsions.

• 한국대기환경학회지
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• 제9권2호
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• pp.147-153
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• 1993

From March 1990 to August 1991, every each 5mm bulk precipitation samples were collected at one residental area in Taejon City to investigate chemical characteristics of acid rain. Major ion concentrations of rain samples $(pH, SO_4^{2-}, NO_3^-, CL^-, NH_4^+, Na^+, K^+, Ca^{2+}, Mg^{2+})$ were analysed and compared with the concentration of air pollutants (T. S. P, $SO_2, NO_x$) that were measured by Ministry of Environment. The results of statistical analysis are as followings. Rain pH was relatively high on October and January and relatively low on August, November and February. Major anion is sulfate, and it's concentration is 2.36 times higher than nitrate's, and major cations are ammonium, sodium and calcium ion. Monthly variation of sulfate and calcium concentrations are higher than the others. Ion concentration and rain pH were correlated negatively with rainfall amount. Major ions in rain samples were $SO_4^{2-}, NO_3^-, NH_4^+, Ca^{2+}$ and regression equations are proposed by multiple regression of measured data. Also, regression equation between air pollutants(T. S. P, $SO_2$) and $SO_4^{2-}, Na^+, K^+, Ca^{2+}, Mg^{2+} ions in rain samples were made. From this wer can predict rain pH.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.231-237
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• 1994

Three concentrations of P (0.33, 0.43 and 0.54%) and two concentrations of Ca (0.60 and 0.97%) in ration dry matter were evaluated for effects on dry matter intake and on milk yield and composition using 24 Holstein cows. Cows were arranged in a $3{\times}2$ factorial experiment as an incomplete randomized block design with three 28-day periods. Each cow consumed at least one ration with each concentration of Ca. Dry matter intake, yield of 3.5% Fat Corrected Milk, and milk composition were not affected by concentration of P, but milk yield was greater when lowest concentration of P was fed (22.8 vs. 22.1 kg/day; p<0.07). Cows fed rations containing 0.60% Ca had greater milk (22.7 vs. 21.9 kg/day; p<0.02) and 3.5% Fat Corrected Milk yields (p<0.03) and slightly greater protein content than when fed 0.97% Ca. Dietary Ca:P ratios between 1.1:1 and 2.9:1 had no effect on dry matter intake, milk yield, or composition. Concentrations of P in plasma were within the normal range for all rations. Because cows had high dry matter intake, mean daily intakes of both P and Ca were greater than required for their level of milk yield.

• Environmental Analysis Health and Toxicology
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• 제11권1_2호
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• pp.41-47
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• 1996

1, 2, 4-Trichlorobenzene (1, 2, 4-TCB) is used as a dye carrier, as an intermediate in the synthesis of herbicides, as a flame retardant, and for other purpose. After a single oral administration of 1, 2, 4-TCB (200 mg/kg, 400 mg/kg) in rats, toxic effects were studied by means of serum biochemical and heatological analysis, and liver calcium concentration. Administration of 1, 2, 4-TCB resulted in dose-dependent liver and kidney damage as estimated by increased serum alanine aminotransferase (ALT) activities, liver calcium concentration and blood urea nitrogen (BUN). Pretreatment with DL-buthionine sulfoximine (BSO, 2 mmol/kg, i.p. ) considerably decreased liver glutathione concentration, which was accompanied by markedly elevated serum ALT activites. It is well-known that toxicity of halogenated benzene such as bromobenzene, 1, 4-dichlorobenzene is increased by pretreatment of henobarbital (PB), and protected by pretreatment of cytochrome P450 inhibitor including metyrapone (MP). However, there was no obvious alterations in toxicity of 1, 2, 4-TCB by pretreatment of phenobarbital or metyrapone. In comparison with control group, treatment groups exhibited significant changes in some parameters of hematological analysis but all hematological values remined within normal ranges.

• Journal of Pharmaceutical Investigation
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• 제30권4호
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• pp.253-258
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• 2000

In order to design the oral vaccine delivery system, we prepared the alginate micro spheres containing GFP (green fluorescent protein) as a model drug by spray method. To optimize the preparation conditions of microspheres, we investigated the effects of various parameters including nozzle pressure, nozzle opening angle, and concentrations of sodium alginate and calcium chloride. The prepared microspheres were evaluated by measuring their sizes, loading efficiency, and morphology. The particle size of microspheres was affected by the concentration of sodium alginate and calcium chloride, nozzle pressure, and nozzle opening angle. As the concentration of sodium alginate increased, GFP loading efficiency and particles size of microsphere also increased. However, it was observed to be difficult to spray the sodium alginate solution with concentration greater than 1.5% (w/v), due to high viscosity. The pressure over $3\;kgf/cm^2$ didn't affect the size of particles. As a result, the spraying method enabled us to prepare microspheres for oral vaccine delivery system. In this study, microspheres prepared with 1% (w/v) sodium alginate had greater loading efficiency and better spherical shape.

• Toxicological Research
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• 제12권1호
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• pp.29-34
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• 1996

1,2,4-trichlorobenzene (1,2,4-TCB) is used as a dye carrier, an intermediate in the syn[hesis of herbicides, aflame retardant, and for other purpose. After a single oral administration of 1,2,4-TCB (200 mg/kg, 400 mg/kg) in rats, toxic effects were studied by means of serum biochemical and hematological analysis, and liver calcium concentration. Administration of 1,2,4-TCB resulted in dose-dependent manner liver and kidney damage being suggested by increased serum alanine aminbtransferase (ALT) activities, liver calcium concentration and blood urea nitrogen (BUN). Pretreatment with DL-buthionine sulfoximine (BSO, 2 mmol/kg, i.p.) considerably decreased liver glatathione concentration, which was accompanied by markedly elevated serum ALT activites. It is well-known that toxicity of halogenated benzene such as bromobenzene, 1,4-dichlorobenzene is increased by pretreatment of phenobarbital, and protected by pretreatment of cytochrorn P450 inhibitor including metyrapone. However, there were no obvious alterations in toxicity of 1,2,4-TCB by pretreatment of phenobarbital or metyrapone. In comparison with control group, treatment groups exhibited significant changes in some parameters of hematological analysis but all hematological values remained within normal ranges.

• 한국어병학회지
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• 제36권2호
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• pp.349-360
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• 2023

Common carp (Cyprinus carpio) (Weight 23.05 ± 6.98 g, Length 12.65 ± 1.38 cm) were exposed to waterborne nitrite at 0, 50, 100, 200, 400 and 800 mg NO₂ ^-/L for 96 hours. The lethal concentration 50 (LC₅₀) of C. carpio exposed to waterborne nitrite was 398.6 mg NO₂ ^-/L. Hemoglobin, hematocrit and RBC count were significantly decreased by waterborne nitrite exposure. The MCV (mean mean corpuscular volume) (µl), MCH (mean corpuscular hemoglobin) (pg) and MCHC (mean corpuscular hemoglobin concentration) (%) were significantly increased. The inorganic component, plasma calcium, was significantly increased, and the organic components such as plasma cholesterol and total protein were significantly increased showing a similar tendency with calcium. In enzymatic components, the AST and ALT were also significantly increased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of C. carpio.

• 한국어병학회지
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• 제9권1호
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• pp.53-63
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• 1996

경골어류의 혈관평활근에 대한 choline 작동성 조절기작을 규명하기 위한 목적의 일환으로 틸라피아의 배대동맥(dorsal aorta)에 대한 acetylcholine 효과와 이들 효과의 매개에 관여하는 수용체의 subtype에 대한 연구를 수행하였으며 그 결과는 다음과 같다. 1. Acetylcholine은 틸라피아의 배대동맥에 대하여 농도의존적인 혈관수축반응만을 나타내었으며, 이와 같은 반응은 혈관내피세포와 methylene blue에 의해 영향을 받지 않았다. 2. Acetylcholine에 의한 농도의존적인 혈관수축반응곡선은 비선택적인 muscarine 수용체 길항제인 atropine과 선택적인 $M_2$-수용체 길항제인 gallamine의 경우 그 농도가 증가함에 따라 현저하게 오른쪽으로 평행이동되었으나, 선택적인 $M_1$-수용체 길항제인 pirenzepine에 의해서는 고농도($1{\times}10^{-5}$M)에서만 약간 이동되었다. 3. Acetylcholine의 수축효과는 cyclooxygenase 억제제인 indomethacin에 의해 거의 영향을 받지 않았다. 4. Acetylcholine의 혈관수축반응은 calcium제거 생리적 완충용액에서는 거의 소실되었으나, calcium 유입차단제인 verapamil에 의해서는 거의 영향을 받지 않았다. 이상의 실험결과에서 acetylcholine은 틸라피아 배대동맥에 대하여 내피세포와는 무관하게 혈관수축효과를 나타내었다. Acetylcholine에 의한 이 수축은 주로 $M_2$-subtype의 수용체를 매개하며 receptor-linked $Ca^{2+}$ channel을 통하여 유입된 세포질내의 $Ca^{2+}$에 의해 일어난다고 사료된다.

• 한국식품과학회지
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• 제9권1호
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• pp.13-18
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• 1977

Spur Red Delicious의 저장성(貯藏性)을 높이기 위하여 재배(栽培) 관리기간(管理其間)중 calcium물질(物質)을 시용(施用)하고 수확후 그 저장성(貯藏性)을 조사(調査)하였던 바 결과(結果)는 다음과 같다. 1. 사과의 저장성(貯藏性)은 calcium을 시용(施用)하지 않은 표준구(標準區)와 질소다비구(窒素多肥區)는 저장말기(貯藏末期)에 68%정도의 건전과율(健全果率)을 보였으나 calcium처리구(處理區)는 $73{\sim}78%$의 건전과율(健全果率)을 나타냈다. 2. 질소다비구(窒素多肥區)는 표준구(標準區)에 비하여 호흡(呼吸)이 증가되었으나 calcium처리구(處理區)는 저장중 계속 호흡억제효과(呼吸抑制?果)를 나타내었다. 3. 수확후 사과를 calcium용액(溶液)에 침지(浸漬)한 것보다 직접 과실(果實)에 엽면살포(葉面撒布)한 것이 더 좋은 결과(結果)를 보였다. 4. calcium처리구(處理區)는 무처리구(無處理區)보다 경도(硬度)가 높아 연화현상(軟化現象)이 적었다.