• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 2002.05a
• /
• pp.138-138
• /
• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• Journal of the Korean institute of surface engineering
• /
• v.28 no.1
• /
• pp.14-22
• /
• 1995

The effects of iron content in coated layer, surface roughness and lubricants on the formability of commercial Zn-Fe alloy electroplated steel sheets used for automotive bodies were investigated. The higher the iron content in deposit, the lower the friction coefficient of Zn-Fe alloy electroplated steel sheets. The surface roughness of coated layer hardly influenced the frictional characteristics. The formability of Zn-Fe alloy electroplated steel sheets was found to be more affected by the lubricant than by iron content in Zn-Fe alloy electrodeposit.

• The Korean Journal of Pharmacology
• /
• v.27 no.1
• /
• pp.69-80
• /
• 1991

Inhibitory effects of quercetin and rutin on lipid peroxidation of microsomes caused by iron(II) were investigated with respect to the scavenging action for oxygen radicals produced during oxidation of iron and the chelating action for iron. Lipid peroxidation by $Fe^{2+}$ alone was markedly inhibited by quercetin or rutin in a dose dependent fashion. Lipid peroxidation by ascorbate or NADPH in the presence of $Fe^{2+}$ was almost completely inhibited by both quercetin and rutin. The peroxidative action of $Fe^{2+}$ was inhibited by SOD and DABCO and slightly inhibited by catalase, DMSO and mannitol. Quercetin and rutin inhibited oxidation of $Fe^{2+}$ which is responsible for DETAPAC and they showed a significant initial chelating effect. Quercetin and rutin effectively inhibited lipid peroxidation by $H_{2}O_{2}$ and decomposed $H_{2}O_{2}$. Both $OH{\cdot}$ production in the presence of $Fe^{2+}$ and $^1O_2$ production by U.V. irradiation were inhibited by quercetin and rutin. Lipid peroxidations by $Cd^{2+},\;Cu^{2+},\;Ni^{2+},\;Pb^{2+}$ and $Zn^{2+}$ were almost completely inhibited by quercetin. Quercetin and rutin significantly prevented the loss of sulfhydryl groups by $Fe^{2+}$. These results suggest that inhibitory effects of quercetin and rutin on the peroxidative action of $Fe^{2+}$ in the presence or absence of ascorbate and NADPH may be attributable to their scavenging action on reactive oxygen species and chelating action on iron.

• Journal of Nutrition and Health
• /
• v.26 no.7
• /
• pp.887-898
• /
• 1993

In order to determine the effect of iron depletion and subsequent supplementation on the muscle capacity for peroxisomal (PO) and mitochondrial(MO) $\beta$-oxidation during high fat feeding, weanling rats were fed a 44% (HF) or 2.5% (LF) fat diet with (+Fe) or without (-Fe) iron for 6 or 9 weeks. After 1 week rats fed HF+Fe or HF-Fe had 50-100% more PO and MO in heart, soleus, psoas and gastrocnemius than did rats fed low fat, but after 3 weeks rats fed HF-Fe had lower muscle PO and MO. In muscles of iron depleted rats PO and MO were not increased by supplementation with iron for 3 weeks. After 6 weeks MO and PO in skeletal muscles of rats fed HF+Fe were lower than after 3 weeks. It is concluded that adequate iron is necessary for miaximum response of muscle PO and MO to high fat feeding. However, after 6 weeks both PO and MO have returned to levels similar to those of rats fed low fat diets, hence, the elevated catalase activities seen at this time do not reflect peroxisomal $\beta$-oxidation.

• Journal of the Korean Chemical Society
• /
• v.24 no.3
• /
• pp.233-238
• /
• 1980

It was observed that the magnetic moment for iron in $[(DPGH)_2FeO_2Fe(DPGH)_2]$, the oxygenation product of a octahedral iron(Ⅱ) complex, $[Fe(DPGH)_2(NH_3_2]$, decreases with decreasing temperature from ${\mu}$ = 3.60 B.M (Bohr Magneton) per iron at $298^{\circ}$K down to ${\mu}$ = 1.65 B.M per iron at $4.2^{\circ}K$. This observation may be explained by a weak antiferromagnetic coupling between two iron(Ⅲ) atoms of intermediate spin state (S = 3/2) in the molecule with the coupling constant $J = -l cm^{-1}$.

• Journal of Nutrition and Health
• /
• v.37 no.8
• /
• pp.645-654
• /
• 2004

This study examined the effect of excess calcium (Ca) on the iron (Fe) bioavailability and bone growth of marginally Fe deficient animals. Two groups of weanling female SD rats were fed either normal Fe (35 ppm) or Fe deficient diet (8 ppm) for 3 weeks. Then each group of animals were assigned randomly to one of three groups and were fed one of six experimental diets additionally for 4 weeks, containing normal (35 ppm) or low (15 ppm) Fe and one of three levels of Ca as normal (0.5%), high (1.0%), or excess (1.5%). Feces and urine were collected during the last 3 days of treatment. After sacrifice blood, organs, and femur bone were collected for analysis. Final body weight and average food intake were not affected by either the levels of dietary Ca or Fe. Low Fe diet significantly reduced the level of serum ferritin, however, for Hb, Hct, and TIBC no difference was shown than those in the normal Fe group. TIBC increased slightly by high and excess Ca intake in low Fe groups. For both normal and low Fe groups, high and excess Ca intakes reduced the apparent absorption of Fe and Fe contents of liver significantly (p < 0.05). Calcium contents in kidney and Femur of rats that were fed high and excess levels of Ca were significantly greater than those of normal Ca groups. However, weight, length, and breaking force of the bone were not affected by increased Ca intakes. Both in control and low Fe groups, high and excess intakes of Ca decreased the apparent absorption of Ca. These results indicate that the excess intakes of calcium than the normal needs would be undesirable for Fe bioavailability and that the adverse effects be more serious in marginally iron deficient growing animals. In addition bone growth and strength would not be favorably affected by high Ca intakes, though, the long term effect of increased Ca contents in bone requires further examination.

• Economic and Environmental Geology
• /
• v.53 no.3
• /
• pp.297-306
• /
• 2020

The red mud generated from bauxite during the Bayer alumina production process has been regarded as an industrial waste due to the high alkaline property and high content of Na. Despite of its environmental problem, various studies for recovery of the valuable resources from red mud has been also carried out because of high content (25.7 wt.% as Fe₂O₃ in this study) of iron in red mud. In order to recover the iron resource in the red mud, microwave heating experiments were performed with adding of activated carbon and elemental sulfur to the red mud. Through the microwave heating the powdered red mud mixtures converted to porous and vitrified solid aggregates. The vitrified aggregates produced by microwave heating are composed of goethite, zero valent iron (Fe⁰), pyrrhotite and pyrite. And then, the microwave heating samples were dissolved in the aqua regia solution, and Fe precipitates were obtained as a Fe-chlorides by adding of NaCl salt in the aqua regia solution. The Fe recovery rates in the Fe-chloride precipitates showed differences depending on the experimental mixture conditions, and Fe grades of the end products are 49.0 wt.%, 58.0 wt.% and 59.5 wt.% under mixture conditions of red mud, red mud + activated carbon, and red mud + activated carbon + elemental S, respectively. The Fe content of 56.0 wt.% is generally known as the grade value of Fe in a iron ore for iron production, and the Fe grades of microwave heating samples with adding activated carbon and elemental S in this study are higher than the grade value of 56.0 wt.%.

• Journal of the Korean institute of surface engineering
• /
• v.20 no.4
• /
• pp.144-153
• /
• 1987

In the case of dipping the Ni-Resist cast iron into molten aluminum with iron content, the thickness of intermetallic compound was remarkably increased with increasing iron content. The thickness was shown by following equation in the range of 1-3% iron content; $x=22.5t^{1/2}+4.47{\cdot}t{\cdot}(Fe%)$. where, x is thickness(${\mu}m$), t the time (minute), Fe% the iron w/o. When the Ni-Resist cast iron was dipped into the molten aluminum containing zinc content, the intermetallic compound thickness was also increased with increasing zinc contents. And thickness was represented by the following equation in the range of 2-10% zinc content; $x=3.46t^{1/2}+0.27{\cdot}t{\cdot}(Zn%)$. However, in the case of dipping the Ni-resist cast iron into molten aluminum with silicon content, the thickness of intermetallic compound was decreased with increasing silicon content, as shown in the following equation; $x=7.17t^{1/2}-0.15{\cdot}t{\cdot}(Si%)$. The intermetallic compound formed onto Ni-Resist cast iron was identified to be $FeAl_3\;and\;Fe_3Al$. As the result of hardness measurement, the peak hardness appeared in the intermetallic compound at near interface of the cast iron and the compound.

• Korean Chemical Engineering Research
• /
• v.46 no.3
• /
• pp.512-515
• /
• 2008

The removal of iron from neodymium chloride solution was carried out by solvent extraction using Alamine 336 in kerosine. The effect of Alamine 336, hydrochloric acid and chloride ion concentrations on the extraction of Fe were studied. The results showed that Alamine 336 as an extractant for removal of iron was effective and the extraction percentage of iron was increased with increasing hydrochloric acid and chloride ion concentration in aqueous solution. The extraction of 99% of iron is attained at a ratio of A/O = 4 by distilled water. The stripping yield of iron from loaded Alamine 336 decreased with decreasing hydrochloric acid concentration in stripping solution.

• Journal of the East Asian Society of Dietary Life
• /
• v.4 no.2
• /
• pp.9-16
• /
• 1994

This study was undertaken to investigate the effects of dietary low (Fe) levels on Fe metabolism of cadmium(Cd) poisoned rats. 40 male Sprague weaning Dawley rats weighing 80-90g were divided into 4 groups(LFe:low Fe, LFeCd:low Fe and Cd, AFe: adequate Fe, AFeCd: adequate Fe and Cd) according to Cd administration(0, 50ppm in drinking water) and Fe levels(Fe:6ppm, 40ppm in diet)for 12 weeks. The food intake and body weight gain of Cd group with low Fe(LFeCd) were significantly lower than those of without Cd group with adequate Fe(AFe)(p<0.01, P<0.05). But there was no significantly difference between Cd groups and without Cd groups in water intake. The blood levels of hemoglobin, hematocrit, and serum levels of Fe of LFeCd were significantly lower than those of AFe(p<0.01, p<0.05, p<0.001). The urinary and fecal excretion of Fe of LFeCd was significantly lower than that of AFe(p<0.05, p0.05). The levels of Fe of liver, spleen in LFeCd were lower than those of AFeCd(p<0.05, p<0.05). These results indicates that adequate iron supplementation to Cd pretreated rats induce protective effects on the reduction of Fe status by Cd poisoning.