• Journal of Nutrition and Health
• /
• v.38 no.5
• /
• pp.380-385
• /
• 2005

This study was designed to investigate the effects of mulberry leaf powder supplementation on lead (Pb) status and mineral (Ca, Fe, Cu and Zn) content in Pb-administered rats for 4 weeks. Thirty two male rats were divided into 4 groups: a control, Pb, Pb5M (500 ppm $Pb + 5\%$ mulberry leaf powder), and Pb10M (500 ppm $Pb + 10\%$ mulberry leaf powder). There were no significant differences in food intake and initial body weight among groups. Mulberry leaf powder treatments showed significant decreases in food efficiency ratio and body weight gain. But FER of $Pb5M\%$ and Pb10M were significantly increases than that of Pb group. The levels of serum aspartate transaminase (AST) and creatinine were decreased by mulberry leaf powder treatment. Minerals content of liver and kidney were significantly decreased in the Pb groups than that of control group. Whereas, fecal minerals content were significantly increased in the Pb5M and Pb10M than those of control group. Pb content of serum, liver and kidney was significantly increased in the Pb group than those of control group. However, by mulberry leaf powder administration (Pb5M and Pb10M), Pb level of serum, liver and kidney were lowered than that of Pb group. And fecal Pb excretion was significantly increased in the Pb5M and Pb10M than that of Pb group. These results showed mulberry leaves were effective for lowing Pb accumulation in serum, organs, which may have potential to prevent Pb toxicity.

• Journal of the Korean Ceramic Society
• /
• v.30 no.10
• /
• pp.803-810
• /
• 1993

PbxZr0.4Ti0.6O3 thin films were prepared by reactive co-sputtering and annealed by RTA(Rapid Thermal Annealing) process. Effect of Pb content in PbxZr0.4Ti0.6O3 films on the phase transformation was intensively studied. It has been found out that depending on the Pb content as well as RTA temperature, crystal structure of PbxZr0.4Ti0.6O3 films change greatly. It turned out that transformation temperature for perovskite can be lowered and the width of transition temperature region was reduced by increasing Pb content in the film. And the lattice was expanded with increasing Pb content. With increasing RTA temperature, as-deposited phase was transformed into perovskite through three different transformation paths depending on Pb content. It was confirmed that activation energies for nucleation of perovskite structure are much larger than those of its growth.

• Corrosion Science and Technology
• /
• v.5 no.3
• /
• pp.94-98
• /
• 2006

The next generation nuclear power reactor will use Pb-Bi as the cooling material. The steel structure materials such as HT-9 used in the reactor suffer from corrosion when they are exposed to high temperature Pb-Bi. Therefore corrosion should be prevented to use Pb-Bi as the coolant material without any safety problem. One method is to control the oxygen content in Pb-Bi. An appropriate amount of oxygen in Pb-Bi can produce a thin oxide layer on steel, and this layer protects the steel from corrosion attack. Since the required oxygen content in Pb-Bi is in the range of $10^{-5}$ to $10^{-7}$ wt%, this small oxygen content can be controlled by flowing a mixture of hydrogen gas and water vapor. The stagnant corrosion test of HT-9 samples was performed by controlling the oxygen content up to 2,000 hours. The corrosion behavior of HT-9 was analyzed at the temperatures of $500^{\circ}C$ and $650^{\circ}C$ with a reduced condition and a oxygen content of $10^{-6}$ wt%.

• Journal of Nutrition and Health
• /
• v.23 no.7
• /
• pp.492-503
• /
• 1990

This study was performed to investigate nutritional effect of various dietary fibers on lead absorption, and protein and lipid metabolisms in growing rats. Sixty male rats of Sprague-Dawley strain weighing 140$\pm$1.1g were blocked into 10 groups according to body weight and fed 10 kinds of diet different with fiber sources [non-fiber, cellulose, pectin, guar gum or carboxymethylcellulose(CMC)] and lead levels (0 or 1%) for 4 weeks. Results were summerized as follows : 1) Food intake, weight gain, FER and PER were remarkably decreased in lead(Pb)-added groups. Weight gain, FER and PER in Pb-added pectin group were significantly lower than those in Pb-added non-fiber group. 2) Liver and kidney weights, femur weight and length, hematocrit and hemoglobin content were decreased in Pb-added groups. Especially femur and liver weights in pectin groups were the lowest among groups. 3) Total protein content in serum was significantly decreased in Pb-added groups but was not different with dietary fiber sources. Total lipid content in serum was not different with dietary Pb levels and fiber sources, but cholesterol content in serum of guar gum group was significantly decreased by Pb addition. 4) Nitrogen, lipid and cholesteol contents in liver were significantly decreased in Pb-added groups, and lipid content in liver of pectin and CMC groups was lower than other groups. 5) Daily urinary and fecal excretions of nitrogen, kipid and cholesterol were decreased in Pb-added groups, and fecal nitrogen was significantly increased in Pb-added groups, and fecal nitrogen of cellulose and guar gum groups was significantly higher than other groups. Fecal excretions of lipid and cholesterol were increased by dietary fibers, and especially fecal lipid was remarkably increased in pectin and guar hum group. 6) Pb contents in liver and femur were decreased by dietary fibers. Especially Pb contents in liver, kidney and femur were significantly decreased in guar gum group. 7) Daily urinary and fecal excretions of Pb were significantly increased in cellulose and guar gum groups, and fecla excretion of Pb in guar gum group was twice of non-fiber group. Pb absorption ratio was significantly decreased in guar gum group. In conclusion, dietary fibers have effect on protein and lipid metabolisms, and decreased intestinal absorption of Pb by increasing fecal excretion. But the degree of effect was different with dietary fiber sources.

• Journal of Environmental Science International
• /
• v.1 no.2
• /
• pp.145-155
• /
• 1992

The effect of various supplies of lead singly and in combination with aluminium on growth and chlorophyll biosynthesis was investigated in 7-day-old Vigna anguluris seedlings. Expose to 50 $\mu$N Pb or more drastically reduced root elongation rate. Significant depressions in root growth was observed within 1 day and no recovery of growth was seen over the duration of treatment period. Root elongation decreased depending on the Pb concentrations. Root growth inhibition was stronger than shoot growth inhibition. The initiation of lateral roots appeared to be more sensitive to Pb than the growth of main roots. Inhibition of root and shoot elongation by Pb was lessened by combined exposure of Pb and Al, suggesting that the presence of AA reverse the inhibitory effect of Pb alone. With the histochemical sodium rhodizonate method the rate of Pb uptake was dependent on the Pb concentration and exposure time of the roots to Pb salts. Pb was first deposited on the root surface and then translocated radially in the root cap cells. During a longer Pb administration (up to 72 h) Pb penetration was nonuniform, with accumulation within the cortex or endodermis. There was drastic reduction in chlorophyll content by Pb. The Pb inhibition of chlorophyll synthesis was concentration dependent. 5-Aminolevulinic acid dehydratase (ALAD) activity exhibited distinct inhibition from control. Reduction in chlorophyll content was accompanied by proportional changes in ALAD activity. Chlorophyll content and ALAD activity were less affected by combined exposure of Pb and Al, suggesting that Al has a protective effect against the inhibiting action of Pb on photosynthetic activity.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.1 no.2
• /
• pp.145-155
• /
• 1997

The effect of various supplies of lead singly and in combination with aluminium on growth and chlorophyll biosynthesis was investigated in 7-day-old Vigna angularis seedlings. Expose to 50 uM Pb or more drastically reduced root elongation rate. Significant depressions in root growth was observed within 1 day and no recovery of growth was seen over the duration of treatment period. Root elongation decreased depending on the Pb concentrations. Root growth inhibition was stronger than shoot growth inhibition. The initiation of lateral roots appeared to be more sensitive to Pb than the growth of main roots. Inhibition of root and shoot elongation by Pb was lessened by combined exposure of Pb and Al, suggesting that the presence of Al reverse the inhibitory effect of Pb alone. With the histochemical sodium rhodizonate method the rate of Pb uptake was dependent on the Pb concentration and exposure time of the roots to Pb salts. Pb was first deposited on the root surface and then translocated radially in the root cap cells. During a longer Pb administration (up to 72 h) Pb penetration was nonuniform, with accumulation within the cortex or endodermis. There was drastic reduction in chlorophyll content by Pb. The Pb inhibition of chlorophyll synthesis was concentration dependent. $\delta-Aminolevulinic$ acid dehydratase (ALAD) activity exhibited distinct inhibition from control. Reduction in chlorophyll content was accompanied by proportional changes in ALAD activity. Chlorophyll content and ALAD activity were less affected by combined exposure of Pb and Al, suggesting that Al has a protective effect against the inhibiting action of Pb on photosynthetic activity.

• Journal of Nutrition and Health
• /
• v.22 no.6
• /
• pp.485-496
• /
• 1989

This study was performed to investigate nutritional effect of various dietary fibers on lead absorption and metabolism of protein and lipid in growing rats. Forty eight male rats of Sprague-Dawley strain weighing 75.7$\pm$0.7g were blocked into six groups according to body weight and fed six kinds of diet different with fiber source(non-fiber, cellulose, pectin) and lead level(0%, 1% ) for 4 weeks. Results are summerized as follows: 1) Food intake, weight gain, FER and PER were remarkably decreased in lead(Pb) added groups, and FER and PER in Pb-added pectin group were significantly lower than those in Pb-added non-fiber group. 2) Weight of liver, kidney and epididymal fat pad, bone weight and length, hematocrit, and hemoglobin content were decreased in Pb-added groups. 3) Total protein content in serum was tended to be decreased in Pb-added groups, but total lipid and cholesterol contents in serum were not different with dietary Pb level and fiber source. 4) Nitrogen, lipid and cholesterol content in liver were tended to be deceased in Pb-added groups, and especially those of the Pb-added pectin group were the lowest among groups. 5) Daily urinary and fecal excretions of nitrogen, lipid and cholesterol were decreased in Pb-added groups. Especially fecal excretions of nitrogen, lipid and cholesterol in Pb-free groups were significantly increased by dietary cellulose and pectin. 6) Pb content in blood was significantly increased in Pb-added pectin group. There was no significant decrease in Pb contents of liver, kidney and tibia, and increase in excretion of Pb by feeding dietary fibers. In conculsion, dietary fibers had no effect on the absorption of Pb, and dietary pectin seemed to increase Pb poisoning by decreasing bioavailibility of protein, lipid and other nutrients in the diet.

• Journal of Plant Biology
• /
• v.23 no.2
• /
• pp.37-44
• /
• 1980

Kidneybean(Phaseolus vulgaris L.) and buckwheat(Fagopyrum esculentum M nch) seedlings grown with Hoagland solution to a height of 7 to 10 cm in the earthen pot containing sand were used for experimental plants. One group of the experimental plants was irrigated with Hoagland solution composed of various Pb-concentratons of 0 to 1000ppm containing 30ppm, and the other group was irrigated with Hoagland solution composed of various P-concentrations of 0 to 1,000ppm containing 30ppm Pb for a month during June and July in 1979. By Pb-surplus over 100ppm, the margins of buckwheat were curled down and turned into yellow-brown chlorosis, but the leaves of kidneybean were become dark-green at an early stage, and then developed chlorosis, finally shedded earlier than the control. Pb-toxicity was similar to the symptoms of P-deficiency. The ratio, 3/1 of chlorophyll a/b at an early stage, was unaffected by Pb-surplus or P-deficiency, but at the later stage it was altered. ATP content with Pb-surplus of 100ppm was decreased by 69% in kidneybean leaves and by 38% in buckwheat leaves, and it with P-deficiency was decreased by 75% in kidneybean leaves and by 43% in buckwheat leaves. In the assay of ATP content of the leaves at intervals of three hours for one day of July in the year, the rhythms of ATP level were unaffected by light or temperature although the amplitude of the level was modified. The rhythms of Pb-surplus and P-deficiency plants were observed at the lower range of ATP content than that of control.

• The Korean Journal of Food And Nutrition
• /
• v.14 no.2
• /
• pp.138-144
• /
• 2001

This study was performed to investigate the influence of Chlorella which effected the change of Pb contents, enzyme activity and lipid compounds on the rats fed the beverage involved Pb and the different contented Chlorella added-diets for 18weeks. The rat's weight of 200ppm Pb group was decreased 6.04% and the cause of that was Pb intake. But the rat's weight of Chlorella added-diets +200ppm Pb group was increased 4.02% (p<0.01). When feeding the different(0%, 2%, 5%, 10% ) Chlorella added-diets with the Pb contented beverage to the rats, we could know that the Pb contents accumulated on tissue were decreased to 20.70(0%), 12.88(2%), 14.83 (5%) and 19.56(10%), compared with the quantity of Pb taken in. Total-cholesterol, triglyceride, glucose content and AST, ALT, ALP, LDH enzyme activity in serum were the highest on 200ppm Pb group and those were decreased by the order of different(2%∼5% >10%) Chlorella contents + 200ppmPb group. A significance was recognized on the level of 1%. Therefore, when rats were exposed to Pb, it was thought that the amount of Chlorella intake was adequate on content 2∼5% for reducing the lead toxicity.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.3
• /
• pp.185-193
• /
• 1992

To investigate differences in lead content in soils and paddy rices, affected by air pollutants from the Janghang Smelter, soil samples at the different directions, distances, and depths, surface(0-15cm depth) and subsurface(15-30cm depth) in 1982 and 1990, and rice plants at soil sampling sites in 1990 were separately collected at the Janghang Smelter area affected by combustible waste gas from the smelter chimney. Soil samples were extracted with $4M-HNO_3$ and plant samples were digested with mixture of $HNO_3$ and $HCIO_4$ for analyzing by atomic absorption spectrophotometry. The Pb contents in soils ranged from 10.3 to 644.8mg $kg^{-1}$. The average content in 1990 was higher than that in 1982. The Pb content in soils at sites nearer the center of the smelter was higher than that at sites farther from the center. The highest lead content was found at the east direction, and was low in order of east>north-north east>north east > north. The variation of Pb level in soils at east sites was more considerable than other directions. The Pb level in surface soils was higher than that in subsurface soils. The contaminated radius of Pb was until 3km all at east, north-north east and north east. A significant correlation was found between Pb content in surface soils of 1982 and that in surface soils of 1990, between Pb content in soils and contents of Cd and Zn in soils, and between Pb content in soils and soil properties as organic matter, available silicate, cation exchange capacity, exchangeable $Ca^{++}$, $Mg^{++}$ and $Na^+$. Pb content in brown rice was low in the panicle axis, and brown rice, and Pb content in stem was 3.26 times of that in brown rice. Pb content in brown rice ranged from 2.2 to 9.0 mg $kg^{-1}$.