• Journal of Powder Materials
• /
• v.1 no.2
• /
• pp.181-189
• /
• 1994

The compacts of pure and phosphorus-coated iron powder with 0~0.8%C were sintered at $1100^{\circ}C$ for 40 min. in cracked ammonia gas atmosphere. The tensile and impact strengths were measured and the relationship of the results with carbon content, phosphorus, quenching and tempering was investigated. The results obtained can be summarized as follows : (1) The tensile strength of sintered compacts increased slowly with carbon content. Increase in tensile strength by heat treatment was evident especially in the low carbon specimen. The specimen with phosphorus showed higher strength compared to pure iron compacts value. (2) No inflection point of elasticplastic deformation on stress-strain curve was observed in sintered steel. The elastic modulus of sintered steel had the same tendency as tensile strength. But the elongation showed the opposite tendency. (3) The impact absorption energy of sintered steel without addition of phosphorus decreased successively with carbon content and by quenching and tempering. On the contrary, addition of phosphorus resulted in an increase of the impact absorption energy. Quenching and tempering did not affect the impact energy especially in high carbon content. (4) The main fracture source was pore in specimen and the propagation of crack occured mostly along the grain boundaries. But the intragranular fracture was also observed in high carbon, quenched and tempered specimen, and especially in the specimen with phosphorus.

• Nutritional Sciences
• /
• v.7 no.4
• /
• pp.218-222
• /
• 2004

Iron deficiency anemia (IDA) is the world's most common nutritional problem. It is characterized by a low hemoglobin (Hb) level and low iron status. A study was conducted to investigate the incidence of iron deficiency anemia in day scholar girls belonging to different socioeconomic strata at Punjab University, Lahore. Iron status of the subjects was estimated by measuring Hb, hematocrit (Hct), red blood cell (RBC) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCR), serum iron, serum ferritin, total protein and albumin. Results indicated that females belonging to low socioeconomic strata had lower values for Hb, Hct, RBC count, total protein and albumin. Serum iron, serum ferritin, MCV and MCH values fell within the normal range for all of the socioeconomic groups. However, serum iron and ferritin varied with socioeconomic status and higher-income groups had significantly higher serum iron and ferritin. It was concluded that anemia may develop due to poor intake and absorption of iron and that those in the low-income bracket are the most affected group.

• The Korean Journal of Community Living Science
• /
• v.19 no.1
• /
• pp.75-85
• /
• 2008

This study investigated the effects of chitosan on mineral metabolism in rats exposed to cadmium by oral administration. Six week-old Sprague-Dawley rats were divided into eight groups. Four groups were fed AIN-93G based 3% ${\alpha}$-cellulose diets and the other four groups were fed 3% chitosan diets for four weeks with the oral administration of 0, 0.5, 1.0, 2.0 mg Cd/2ml distilled water three times per week, respectively. The essential mineral contents of serum, liver, kidney and bone (femur and lumbar), and the excretion of calcium in feces and urine were determined. There was no significant difference in weight gain and food intake among groups. The cadmium administration significantly decreased calcium in serum, iron in blood, calcium and iron in liver and iron contents in kidney. In contrast, calcium and zinc contents in kidney increased by the administration of cadmium. The weight, length and breaking forces of the femur and lumbar were not significantly different due to cadmium administration and chitosan among the groups. The fecal excretion of calcium was increased by the administration of cadmium. On the other hand, calcium absorption and the absorption rate were decreased by Cd administration. In the groups without Cd administered (N, N-Chi groups), chitosan significantly decreased the absorption rate of calcium by increasing the excretion in feces (p<0.05). These results suggest that cadmium administration may facilitate the decline of essential minerals in rats and also, chitosan may have a conflicting effect between cadmium and the essential minerals of tissues.

• Korean Journal of Community Nutrition
• /
• v.9 no.2
• /
• pp.142-150
• /
• 2004

To increase both iron and enhancers for iron absorption through diets should be a basic strategy to sufficiently provide increased iron for pregnancy. Previous studies reported that iron intakes of Korean pregnant women were short and their iron status deteriorated as pregnancy progressed. However, there is little data about the bioavailability of dietary iron during pregnancy. Therefore, this study was conducted to determine the changes of dietary iron intakes, its bioavailability and iron status during pregnancy longitudinally in Korean women. A total of 151 pregnant women in their first trimester of pregnancy voluntarily participated. Among them, 72 women finished the research protocol during the second trimester and 55 did it during the third trimester. Dietary intakes of total iron, both non-heme and heme iron, as well as enhancers, both MPF (meat, poulty, and fish) and vitamin C, increased significantly as pregnancy progressed. As the results, bioavailability of dietary iron and iron absorbed increased significantly as pregnancy progressed. However, the amount of iron absorbed at each trimester did not meet considerably the iron needed during pregnancy. All five indices examined in the study, Hb level, Hct, serum concentrations of ferritin and sTfR (soluble transferrin receptor), and sTfR: ferritin ratio, showed that iron status of the subjects deteriorated as pregnancy progressed. The rate of anemia of the subjects increased as pregnancy progressed although more than 80% of the subjects took iron supplements after the 20th week of pregnancy. These results imply that it is needed to provide more iron especially, heme iron and dietary enhancers to prevent the deterioration of iron status during pregnancy. Future research on bioavailability of supplemental iron should be performed to determine the iron balance precisely.

• Safety and Health at Work
• /
• v.5 no.3
• /
• pp.113-117
• /
• 2014

The mechanisms by which iron is absorbed are similar to those of divalent metals, particularly manganese, lead, and cadmium. These metals, however, show different toxicokinetics in relation to menarche or menopause, although their interaction with iron is the same. This review focuses on the kinetics of these three toxic metals (manganese, lead, and cadmium) in relation to menarche, pregnancy, and menopause. The iron-manganese interaction is the major factor determining sex-specific differences in blood manganese levels throughout the whole life cycle. The effects of estrogen overshadow the association between iron deficiency and increased blood lead concentrations, explaining why women, despite having lower ferritin concentrations, have lower blood lead concentrations than men. Iron deficiency is associated with elevated cadmium levels in premenopausal women, but not in postmenopausal women or men; these findings indicate that sex-specific differences in cadmium levels at older ages are not due to iron-cadmium interactions, and that further studies are required to identify the source of these differences. In summary, the potential causes of sex-specific differences in the blood levels of manganese, lead, and cadmium differ from each other, although all these three metals are associated with iron deficiency. Therefore, other factors such as estrogen effects, or absorption rate as well as iron deficiency, should be considered when addressing environmental exposure to toxic metals and sex-specific differences in the blood levels of these metals.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.1
• /
• pp.191-199
• /
• 1998

This paper has studied the nutritional iron status of adults in the city of Taegu. The subjects of the experiment were twenty six men and women living in the city of Taegu. The iron intake was 26.1mg for men and 17.1mg for women, which were respectively 217.5% and 95% of RDA. For men heme iron was 5% and nonheme iron, 95% for women heme iron was 5.8% and nonheme iron, 94.2%. The absorption rate of dietary iron was 6.2% for men and 9.1% for women. The hemoglobin was 14.5g/dl for men and 11.9g/dl for women, and the rate of developing anemia was 8.3% in men and 57.1% in women. The serum ferritin was 57.8ng/ml with men, which was found to be normal, and 14.7ng/ml with women, which showed that 57.1% of women were in the condition of iron depletion or iron deficiency anemia. The rate of developing anemia resulting from the deficiency of serum ferritin was as high as that from the deficiency of hemoglobin. The correlation between iron intake based on the dietary record, and energy intake, vegetable protein intake and dietary fiber intake was found to be positive. So was the correlation between the iron intake, and hemoglobin, serum ferritin and urinary iron excretion. There was also a positive correlation between hemoglobin, and hematocrit and serum ferritin. The correlation between fecal iron excretion and serum ferritin was positive. Fecal iron excretion and urinary iron excretion can be complemented by iron intake but the fact should be considered that 95% of iron intake is nonheme iron, which is difficult to absorb. Based on the above-mentioned things, serum ferritin and hemoglobin can be used as the standards of measuring anemia. As women in their child bearing years show the high rate of 57.1% of developing anemia, the more thorough nutritional education of iron is required.

• The Korean Journal of Nuclear Medicine
• /
• v.1 no.2
• /
• pp.61-74
• /
• 1967

In order to confirm whether acquired immunity or resistance can be developed by the repeated hookworm infections, the 150 mature actively moving filariform ancylostoma duodenale larvae obtained from the severe hookworm anemia patients were orally given to 8 healthy volunteers in three divided doses, 50 in each, at 5 day interval. Also the hematological changes as well as several ferrokinetics using $^{59}Fe$ were done and were compared with 10 controls. The clinical symptoms and signs were checked every day for the first 3 weeks and then twice weekly until the end of the experiment. The appearance of the ova in the stool was examined by the formalin ether method and the ova was counted by the Stoll's method. The following laboratory tests were done: 1) Red blood cell count, venous blood hematocrit(micromethod), hemoglobin count (cyanomethemoglobin method) were checked every 5 to 7 day interval. 2) Plasma iron concentration (Barkan's modified method) was determined every 2 to 3 week interval. 3) Radioisotope studies: a) Ferrokinetics: Huff et al and Bothwell's method were applied. Erythropoietic Index (% of normal)=$\frac{Subject's\;turnover/100ml\;whole\;blood{\times}100}{Average\;normal\;turnover/100ml\;whole\;blood}$ of the gastrointestinal absorption of iron: Radioiron($^{59}Fe$) balance b) Quantitative measurement method was applied. c) Determination of the plasma erythropoietin activity: Fried's method was applied. Following were the results: 1) The serum iron level was lower. The red cell volume was decreased, but with relative increase of plasma volume. 2) The plasma iron disappearance time was accelerated and the plasma iron turnover rate was decreased. The red cell iron turnover rate was markedly increased, while all of the red cell iron concentration, circulating red cell iron. plasma iron pool were decreased. The daily iron pool turnover and red cell renewal rate were increased. 3) The erythropoietic index, erythropoietin activity and intestinal absorption of iron($^{59}Fe$) were markedly increased. 4) The infectivity was $9.8{\pm}1.31%$ which was lower than that observed in the single infection. 5) From these observations, it is concluded that the hookworm anemia is essentially iron deficieny in its origin and some immunity acquisition is possible with repeated infections.

• The Journal of Internal Korean Medicine
• /
• v.25 no.4
• /
• pp.356-363
• /
• 2004

Iron Deficiency Anemia is defined as deficiency Fe in blood. The causal relationships between this and gastrointestinal bleeding, impaired absorption, excessive menstrual flow and other maladies are not well understood. In oriental medicine Iron Deficiency Anemia is generally characterized as deficiency of ki(氣)and blood(血) defined in terms of hypofunction of the spleen and stomach, and insufficiency of the spleen and kindneys. Two Iron Deficiency Anemia patients were treated with Ickibohyoul-tang, Samchulgunbi-tang, Ickibohyoul-tang ga antler, and Sachulgunbi-tang ga antler. Symptoms improved and Blood exams (RBC, Hb, Hct) yielded higher counts. Further research concerning this is necessary.

• Journal of Nutrition and Health
• /
• v.36 no.6
• /
• pp.646-652
• /
• 2003

This study was performed to determine the iron status of the adolescent Korean girls before and after menarche. The 101 subjects aged 11-13 years who attending in an elementary school in Mokpo were recruited. They were divided into pre-menarche (A) group or post-menarche (B) group based on their menstruation status. The latter subjects were sub-divided into one of the four groups according to the times of their menstruation B-I( $\geq$ 3 times), B-II (4-6 times), B-III (7-9 times) or B-W ( $\geq$ 10 times). In the total subjects, dietary iron intake, 11.3 mg/day, was below the Korean RDA for iron, the percentage of heme iron to total iron intake, 15%, and the bioavailability of dietary iron, 12.3%, seemed to be low. And their body iron storage, 140.8 mg, seemed to be insufficient. However, they tended to meet body's iron requirement in the cell level. Red blood cell number (RBC), hematocrit (Hct), and hemoglobin (Hb) level in the total subjects were 4.5 1012/I, 39.3%, and 13.0 g/㎗, respectively. The subjects in B group had lower (p<0.05) RBC and Hct compared to those in A group and the prevalence of iron-deficiency anemia tended to be high. Serum iron, ferritin, and soluble transferrin receptor (sTfR) and sTfR:ferritin ratio were 86.7 $\mu\textrm{g}$/d, 17.6 $\mu\textrm{g}$/l, 3.58 mg/1, and 230, respectively. Those four indices were not significantly different among the groups. The results of this study imply that, although there a tendency to affect negatively iron status, menstrual blood loss in adolescent females does not deteriorate obviously their iron status during the relatively short period up to 1 you. However, it should be better to improve their iron status after starting menarche by increasing iron intake, especially heme-iron, and enhancing factors for iron absorption.