• 한국표면공학회지
• /
• 제43권2호
• /
• pp.51-56
• /
• 2010

The zinc electroplating with respect to the chloride concentration was investigated by X-ray diffraction(XRD), scanning electron microscope (SEM), and cathodic polarization measurement. The cathodic overpotential during electroplating was first decreased and then increased with increase of chloride concentration in electrolyte. The decreased cathodic overpotential leads to preferred orientation of (002) plane, high current efficiency and satisfactory zinc deposits. The increased cathodic overpotential causes random orientation, low current efficiency and edge burning. The cathodic overpotential was affected by chloride concentration in electrolyte, not by the kind of chloride, such as NaCl and KCl. An optimized chloride concentration was 3 M for zinc electroplating. Also, it is considered that NaCl can be a alternation for KCl as a main salt of zinc electroplating bath.

• Molecular & Cellular Toxicology
• /
• 제3권2호
• /
• pp.132-136
• /
• 2007

Zinc is essential metal and plays a role in a wide variety of physiological and biochemical processes. Prostate gland contains high level of zinc, generally 3-10 folds higher than other organs. Prostatic zinc uptake is resulted from the existence of zinc transporter (ZnT) protein families in membrane. In this study, we investigated the difference of zinc uptake efficiency of zinc-aspartate complex (Zn-Asp) into various organs compared with $ZnSO_4$. We observed that Plasma zinc concentration in both $ZnSO_4$ and Zn-Asp administrated group was increased progressively following administration, and reached a peak level at 2 hr. The increasing pattern of zinc concentration was similar to each groups, however the zinc concentration of Zn-Asp administrated group was higher than that of $ZnSO_4$ administrated group. We found that prostatic zinc level of Zn-Asp administrated group was higher than $ZnSO_4$ administrated group, and was increased approximately $\sim$2.7 fold and $\sim$4.2 fold at 4 and 8 hr after administration. From these observations, we suggest than Zn-Asp has high uptake efficiency of zinc into the prostate gland. Therefore, Zn-Asp is potentially useful treatment of many prostatic diseases.

• Korean Chemical Engineering Research
• /
• 제49권6호
• /
• pp.752-757
• /
• 2011

암모니아수와 zinc acetate로부터 액상 수열합성법에 의한 ZnO의 제조에 있어 반응온도, 반응물의 농도와 혼합방법, 용액의 pH 등 반응조건에 따른 ZnO 입자의 형상과 입자분포 등 제조특성을 고찰하고, UV 조사하에 tartrazine의 광분해를 측정하여 합성된 ZnO의 광촉매로서의 성능을 확인하였다. 반응용액의 pH가 높을수록 ZnO 입자의 평균 크기는 증가하였고, zinc acetate의 농도가 증가할수록 그리고 반응온도가 증가할수록 입자의 크기는 감소하였다. 반응용액의 혼합시 암모니아수 주입 후에 zinc acetate를 첨가하였을 경우 더 작은 입자를 얻을 수 있었다. 최소 크기의 ZnO 입자의 생성을 위한 최적 조건은 용액의 pH 11.2, zinc acetate의 농도 0.6 M, 반응온도 $90^{\circ}C$였으며, 입자 평균크기는 3.133 ${\mu}$m이었다. 합성온도 $80^{\circ}C$, zinc acetate 농도 1.0M 및 반응용액의 pH 11.2의 조건에서 합성된 ZnO에 의한 tartrazine의 광촉매 분해는 분해시간 60분에서 약 97%의 분해율을 보였다.

• Journal of Microbiology and Biotechnology
• /
• 제21권6호
• /
• pp.646-651
• /
• 2011

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 ${\mu}s$ pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 ${\mu}g$/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

• 한국임상약학회지
• /
• 제7권2호
• /
• pp.64-66
• /
• 1997

Zinc is employed in body cell growth and immune function. Zinc deficiency causes growth retardation, night blindness, delay of wound healing, skin disorders, alopecia, et al. Pharmacokinetic study of zinc in Korean has not yet been proceeded to apply to patient. In this study, we investigated to adjust zinc dosage for maintaining constant zinc optimum serum level. Five NPO inpatients (3 males, 2 females) in Seoul National University of Hospital were evaluated, retrospectively. Zinc was mixed with parenteral nutrition solution and administrated intravenously in 24 hour-continuous infusion, and zinc dosage range was 0.17-0.45 mg/kg/day. AUC to zinc dose (AUC/Dose) was $2.421\pm1.007\;kg{\cdot}min/ml.$ 0.5 mg/kg/day zinc administration may achieve the plasma zinc concentration of $120\;{\mu}g/dl.$(Kor. J. Clin. Pharm. 1997; 7: 64-66)

• 자원리싸이클링
• /
• 제12권4호
• /
• pp.30-37
• /
• 2003

황산 용액에서 Zinc-ferrite의 용해에 대한 반응속도론을 황산 용액의 반응온도와 농도 변화에 대해 조사하였다. 반응율(R)과 겉보기 반응 속도상수(K)는 황산 용액의 온도와 농도가 클수록 증가한다. Zinc-ferrite의 반응속도는 반응초기에서 $1-(1-K)^{1/3}=Kt$와 같은 속도식을 적용할 수 있다. 용해에 대한 활성화 에너지는 황산 용액의 농도에 관계없이 약 16.3kcal/mole 이다. Zinc-ferrite가 황산 용액에서 용해할 때는 Zinc-ferrite의 화학 양론적 조성으로 용해되며, Fe 또는 Zn의 단독으로는 용해되지 않는다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권7호
• /
• pp.1048-1052
• /
• 2008

The objective of this study was to determine the effect of sodium selenite and zinc-L-selenomethionine on performance and egg Se concentration in laying hens. Two hundred and twenty-four CP Browns aged 71 weeks were divided according to a $2{\times}3$ factorial in a completely randomized design. One more group without additional Se supplementation was used as a negative control. Each treatment consisted of four replicates and each replicate contained eight laying hens. The dietary treatments were T1: basal diet; T2, T3 and T4: basal diets plus 0.3, 1.0 and 3.0 mg Se from sodium selenite/kg, respectively; T5, T6 and T7: basal diets plus 0.3, 1.0 and 3.0 mg Se from zinc-L-selenomethionine/kg, respectively. The findings revealed that feed conversion rate/kg eggs, egg production, egg weight, Haugh units and eggshell thickness were not affected by source and level of Se (p>0.05). Increasing level of dietary Se significantly increased (p<0.05 the Se content of eggs. Zinc-L-selenomethionine markedly increased p<0.05 egg Se concentration as compared with sodium selenite. The results indicated that Se source did not influence performance of laying hens. However, zinc-L-selenomethionine increased p<0.05 egg Se concentration more than sodium selenite.

• Journal of Preventive Medicine and Public Health
• /
• 제16권1호
• /
• pp.19-24
• /
• 1983

In order to study the effects of iron and zinc on the lead poisoning of rats, lead with iron and zinc, or lead alone were administered orally to a total of 98 adult rats of Sprague-Dawley Species. The concentrations of lead, zinc, and iron were measured by atomic absorption spectrophotometer at every 20 days intervals of 20th, 40th, 60th, 80th and 120th day as a final measurement. Those datas were analysed and compared with those of control groups. The results were summarized as follows; 1. The concentration of lead in blood, bone. and liver tissues kept increasing in case of lead exposure group whereas it started decreasing at 60-80th day when concentration of zinc started increasing in case of combined exposure group. However, in kidney tissue, the concentration of lead in combined exposure group kept increasing up to the end of observation showing special high concentration at the final measurement at 120th day. 2. Concentration of zinc in blood and liver tissues had increased from 60-80th day in case of combined exposure group. 3. Concentration of iron in blood showed decreasing from $44.15{\pm}9.67\;to\;32.44{\pm}2.69{\mu}g/ml$ in case of lead exposure group, whereas it showed constant level of $47.50{\sim}45.65{\mu}g/ml$. However, in liver tissue it kept constant as control did from 40th to 60th days, but from 100th day on it started increasing to show much higher concentration than control.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권7호
• /
• pp.1022-1025
• /
• 2002

Effect of chemical stress of daily administration of glucocorticoid (dexamethasone @0.125 mg./calf/day) injections on plasma zinc levels, Zn status of body tissues and its distribution in sub cellular fractions, was studied in neonatal buffalo calves. Daily i/m injections of dexamethasone, starting at the completion of 1 week of age and continued till 8th week, led to a significant decline in plasma Zn concentration from 3rd week onwards, which then persisted throughout the rest of the experimental period. In control group, liver had the highest concentration of zinc, followed by heart, muscle, spleen, kidney and testis. In all these tissues, cytosolic fractions had the highest (>60%) zinc levels followed by nuclear, mitochondrial and microsomal fractions. In dexamethasone treated calves, there was a significant increase in the Zn uptake by the tissues of liver and muscle. This increase in zinc concentration was observed in all the sub cellular fractions of liver and muscle, however about 80% of this increase was in cytosolic fraction. It was concluded that glucocorticoid-induced stress caused increase in Zn levels of liver/muscles and decrease in blood plasma zinc, thus indicating a redistribution of Zn in body.

• Journal of Nutrition and Health
• /
• 제43권2호
• /
• pp.132-140
• /
• 2010

High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.