Fe Saturation Research Articles

Depth dependent Mössbauer spectroscopy of quenched slags

57Fe Mössbauer spectra were recorded at room temperature of six quenched slags in the system FeOFe 2O 3-CaOAl 2O 3-SiO 2 at depths of 10 μm, 250 μm and 1000 μm from the surface. The Fe 3+ composition decreases as a function of depth in CaO-containing slags, while it increases with depth when no CaO is present. The mean isomer shift of Fe 2+ is essentially constant with both bulk composition and depth, while the mean Fe 2+ quadrupole splitting increases substantially with bulk iron content and shows large depth dependence in slags synthesized at Fe saturation.

Laboratory mesocosm studies of Fe, Al, Mn, Ca, and Mg dynamics in wetlands exposed to synthetic acid coal mine drainage

To evaluate the potential for constructed wetlands to treat acid coal mine drainage, six model wetland mesocosms (each 2.4 m × 15 cm) were filled with Sphagnum peat (15 cm deep), planted either with cattails (Typha latifolia) and living Sphagnum, living Sphagnum only, or left as bare peat (2 mesocosms per treatment). The model wetlands were exposed to synthetic acid coal mine drainage (pH 3.5, concentrations of Fe2+, Al3+, Mn2*, Ca2+, and Mg2+ of 78.8, 10.0, 5.2, 12.0, and 4.5 mg L−1, respectively) at a rate of 90 mL min−1, 6 hr d−1, 5 d wk−1, over a 16 week period. Chemical analysis of peat at periodic intervals indicated that the model wetlands were net sources of Al3+, Mn2+ Ca2+ and Mg2+, but net sinks for Fe2+. Type of vegetation had no significant effect on Fe2+ retention; of the 204 g of Fe2+ added to the model wetland systems, 162 g were retained. Formation of Fe oxides accounted for 73 to 86% of the Fee' retention, with exchangeable Fe contributing 0.2 to 1.2%, organically bound Fe contributing 4 to 19%, and residual Fe contributing 7 to 15% of total Fee' retention. Fe retention was greatest at the inflow ends of the model wetlands where Fe retention appeared to reach saturation at a final Fe concentration in the peat of 235 mg g−1. At the rate of application of the synthetic acid mine drainage, we estimated that the model wetland systems would have reached complete Fe saturation after 157 days. We suggest that the mesocosm approach could be useful in generating site-specific data that can be applied to the formulation of cost-benefit analyses that can compare a proposed wetland treatment system with alternative conventional chemical methods for treating acid mine drainage.

Binding of Cu (II), Tb (III) and Fe (III) to chicken ovotransferrin

The kinetics of binding of Cu(II), Tb(III) and Fe(III) to ovotransferrin have been investigated using the stopped-flow technique. Rate constants for the second-order reaction, k+, were determined by monitoring the absorbance change upon formation of the metal-transferrin complex in time range of milliseconds to seconds. The N and C sites appeared to bind a particular metal ion with the same rate; thus, average formation rate constants k+ (average) were 2.4 x 10(4) M-1 s-1 and 8.3 x 10(4) M-1 s-1 for Cu(II) and Tb(III) respectively. Site preference (N site for Cu(II) and C site for Tb(III] is then mainly due to the difference in dissociation rate constant for the metals. Fe(III) binding from Fe-nitrilotriacetate complex to apo-ovotransferrin was found to be more rapid, giving an average formation rate constant k+ (average) of 5 x 10(5) M-1 s-1, which was followed by a slow increase in absorbance at 465 nm. This slow process has an apparent rate constant in the range 3 s-1 to 0.5 s-1, depending upon the degree of Fe(III) saturation. The variation in the rate of the second phase is thought to reflect the difference in the rate of a conformational change for monoferric and diferric ovotransferrins. Monoferric ovotransferrin changes its conformation more rapidly (3.4 s-1) than diferric ovotransferrin (0.52 s-1). A further absorbance decrease was observed over a period of several minutes; this could be assigned to release of NTA from the complex, as suggested by Honda et al. (1980).

Hematological effect of supplementing anemic children with vitamin A alone and in combination with iron

Ninety-nine anemic children aged 1-8 y were divided into four groups. Each group was supplemented for 2 mo with vitamin A, iron, vitamin A plus Fe, or a placebo. Clinical, hematological, and Fe biochemical evaluations were performed at the beginning and end of the study. Vitamin A supplementation produced significant elevations in the serum levels of retinol, blood hemoglobin, hematocrit, erythrocytes, serum Fe, and percent transferrin saturation (%TS) and had no effect on total Fe binding capacity (TIBC) or serum ferritin. Fe supplementation did not affect serum retinol. However, it improved hematological and Fe nutrition indicators, including TIBC and serum ferritin. The simultaneous administration of vitamin A and Fe resulted in a better response of serum Fe and %TS than when the supplement consisted only of vitamin A or Fe alone. Vitamin A benefits hematological condition and Fe metabolism.

Microstructure and Magnetic Behavior of Fe/Ti Multilayered Films

ABSTRACTFe/Ti multilayered films composed of Fe and Ti layers with various thickness ( dFe of 10 ∼ 1000 A and dTi of 10 ∼ 200 A ) have been prepared at Ar gas pressure of 2 mTorr by two pairs of Facing Targets Sputtering apparatus which can deposit very thin and continuous films on plasma-free substrates. The total thickness of Fe layers was 1000 A in all of the specimen films.The periodic microstructure due to compositional modulation was clearly observed not only in the low angle region of X-ray diffraction diagrams but also in the Auger electron spectroscopic depth profile.With decreasing dFe from 1000 to 20 A, the diffraction intensity of (110) plane in the Fe bcc phase lowered for dTi of 10∼200 A and its interplanar spacing ( d-spacing ) increased for dTi above 50A. This diffraction peak disappeared with further decreasing d below 15 A. At dFe around 25 A, a different peak appeared at the angle slightly lower than that of Fe(110) peak. The diffraction intensity of (002) plane in the Ti hcp phase increased with decreasing dFe. However, its d-spacing depended little on the dFe and took the same value as that of bulk Ti except for very small dTi.The net saturation magnetization of Fe layers in all of the specimen films decreased gradually with decreasing dFe from 1000 to 50 A, decreased abruptly with further decreasing dFe and became nearly zero at dFe below 15A.The films annealed at 200 and 400 °C showed obscure periodic microstructure and had larger d-spacing of ∝ −Fe(110) and smaller saturation magnetization than those of the as-deposited ones.

Masked vitamin B12 and folate deficiency in the elderly.

1. A high incidence of vitamin B12 or folate deficiency, or both, may be found in the elderly, particularly those in hospital. This report concerns fifty cases detected in an inner-city-area geriatric unit during the course of routine clinical investigation. The majority had none of the classical haematological signs of vitamin B12 or folate deficiency, and all the patients reported had a mean corpuscular volume (MCV) of less than 100 fl. 2. There was a significant negative correlation between the MCV and the erythrocyte folate (P less than 0.01), supporting earlier published work using a low serum folate as an index of folate deficiency. 3. There was no correlation between the MCV and the serum vitamin B12. Published work differs on this point. 4. Serum iron, total Fe-binding capacity and percentage Fe saturation results were available in forty patients in this series. There was a significant positive correlation between the serum Fe and the MCV (P less than 0.01) and 34% of patients had haematological evidence of Fe deficiency. In the majority, however, there was no evidence that associated Fe deficiency had masked the haematological signs of vitamin B12 or folate deficiency. 5. More attention should be paid to the problem of 'masked' vitamin B12 and folate deficiency in the elderly. There is a case for routine screening of the elderly for vitamin B12 and folate deficiency irrespective of the MCV.

Mössbauer spectroscopy study of amorphous Fe87B11Au2 ribbon and its crystallization products

Substantial increases in Fe saturation magnetization have been obtained in amorphous Fe–B containing small concentrations of gold. This material is also stable above 300 K, and thus has considerable practical significance. We report the results of an investigation of amorphous Fe87B11Au2 ribbon and its crystallization products based on 57Fe Mössbauer spectroscopy. The amorphous ribbon exhibits a broad magnetic hyperfine splitting pattern typical of a metallic glass with an effective hyperfine field, Heff=257 kOe, and an isomer shift of 0.058 mm/s relative to metallic Fe at 300 K. The spectra of samples annealed for 25 min between TA=618 and 708 K arise from a metastable amorphous phase of Fe–Au–B and a crystalline α-Fe phase. Heff of the metastable amorphous phase decreases with respect to increased annealing temperature. However, Heff of the α-Fe phase increases from 331 kOe for samples annealed at 618 K to 334 kOe for those annealed at 708 K. This increase can be attributed to an increased content of Au in the α-Fe phase. Annealing the samples at temperatures above 753 K for 25 min yields crystalline α-Fe and the intermetallic compound Fe2B.

Bioavailability of iron- and copper-supplemented milk for Mexican school children

Fortification of dairy products with trace metals requires use of assimilable compounds that do not catalyze off-flavors due to lipid peroxidation but show good biological availability. The Fe(III) and Cu(II) chelates of the promising chelator, lactobionic acid, have been compared to Fe(II) and Cu(II) salts for their ability to improve hematological status in a mildly anemic population. Fe- and Cu-fortified cow milk was administered to children (aged 6 to 15) in the Durango, Mexico, "school lunch" program. Children drank milk providing 20 mg Fe and 3 mg Cu as ferric/cupric lactobionate ("chelate") or ferrous/cupric chloride ("salt") for 5 of 7 days/wk for 3 months. Supplementation with "salt" and "chelate" raised Hb significantly by 1 and 0.3 g/dl, respectively, above the control (unsupplemented) group. No significant change was observed in incremental serum ferritin, serum Fe, or transferrin saturation, or in final serum Cu. Ferric lactobionate shows poorer bioavailability than ferrous ion in the presence of Cu, but milk can be an excellent vehicle for Fe or Cu supplementation.

BJN volume 48 issue 3 Cover and Front matter

1. An unsupplemented 4200 kJ (1000 kcal) diet emphasizing large quantities of relatively unrefined complex carbohydrates was evaluated among sixty obese adults for its effectiveness and nutritional adequacy in a long-term weight-control programme. Patients were followed individually as outpatients by a physician and dietician–an average of thirteen visits over 26 weeks. Assessment of health indices included anthropometric measurements, blood pressure, lipid levels and assays for seven vitamins, β–carotene and iron.2. Weight loss averaged 8.2 kg or 24% of excess weight during the 6 months of active treatment. Over an average of 17 months of post-treatment follow-up, 44% of patients continued to lose weight and 92% remained below pretreatment levels.3. Average skinfold thickness fell 7mm (p < 0·001) whereas muscle mass was maintained (arm muscle circumference+10mm, not significant; creatinine-height index + 3% of standard (Bistrian et al. 1975; not significant). Systolic and diastolic bleed pressure fell 7 and 5 mmHg respectively (P < 0·01). Total serum cholesterol and triglyceridesfell 200 and 660 mg/1 respectively (P < 0·01), while high-density-lipoprotein-cholesterol remained statistically unchanged. Mean serum levels of retinol, β-carotene, folate, vitamin B12, ascorbic acid, Fe and transferrin saturation, and activity coefficients for thiamin, riboflavin and pyridoxine were within normal limits after periods of treatment ranging from 5 to 84 weeks.4. An earlier age of onset of obesity tended to be associated with greater weight lossduring treatment and lesser weight rebound during follow-up.5. The results indicate that the experimental diet, without supplementation, was nutritionally adequate as well as effective for long-term weight control.

Dietary management of obesity: evaluation of the time-energy displacement diet in terms of its efficacy and nutritional adequacy for long-term weight control.

1. An unsupplemented 4200 kJ (1000 kcal) diet emphasizing large quantities of relatively unrefined complex carbohydrates was evaluated among sixty obese adults for its effectiveness and nutritional adequacy in a long-term weight-control programme. Patients were followed individually as outpatients by a physician and dietician-an average of thirteen visits over 26 weeks. Assessment of health indices included anthropometric measurements, blood pressure, lipid levels and assays for seven vitamins, beta-carotene and iron. 2. Weight loss averaged 8.2 kg or 24% of excess weight during the 6 months of active treatment. Over an average of 17 months of post-treatment follow-up, 44% of patients continued to lose weight and 92% remained below pretreatment levels. 3. Average skinfold thickness fell 7 mm (P less than 0.001) whereas muscle mass was maintained (arm muscle circumference + 10 mm, not significant; creatinine-height index + 3% of standard (Bistrian et al. 1975; not significant). Systolic and diastolic blood pressure fell 7 and 5 mmHg respectively (P less than 0.01). Total serum cholesterol and triglycerides fell 200 and 660 mg/1 respectively (P less than 0.01), while high-density-lipoprotein-cholesterol remained statistically unchanged. Mean serum levels of retinol, beta-carotene, folate, vitamin B12, ascorbic acid, Fe and transferrin saturation, and activity coefficients for thiamin, riboflavin and pyridoxine were within normal limits after periods of treatment ranging from 5 to 84 weeks. 4. An earlier age of onset of obesity tended to be associated with greater weight loss during treatment and lesser weight rebound during follow-up. 5. The results indicate that the experimental diet, without supplementation, was nutritionally adequate as well as effective for long-term weight control.

The effect of iron-deficiency anaemia on two indices of nutritional status, prealbumin and transferrin.

1. Serum prealbumin, transferrin and iron concentrations were measured in ninety-two north Cameroonian children under 5 years of age. The results were grouped according to the blood haemoglobin concentration range in order to show the interactions of anaemia with prealbumin and transferrin concentrations. 2. Transferrin concentration showed a significant negative correlation with serum Fe and percentage saturation of transferrin values. Prealbumin concentration showed a significant direct correlation with haemoglobin but did not correlate with either serum Fe or percentage saturation of transferrin. 3. It is concluded that in regions where Fe-deficiency anaemia is endemic transferrin concentration may be of little value in determining nutritional status. On the contrary, prealbumin seems to be more useful.

Serum ferritin as an index of iron nutrition in rural and urban South African children.

1. Serum ferritin concentrations were measured in 378 Zulu children aged 1–4 years living in Nqutu, KwaZulu and in 342 children of mixed race (Cape coloureds) aged between 1 and 16 years living near Johannesburg.2. The pattern of serum ferritin concentrations encountered in the children at different ages tended to parallel the changes in iron stores which are known to occur during development.3. Serum ferritin concentrations showed a significant direct correlation with age, haemoglobin, serum Fe and percentage saturation of transferrin values.4. Anaemia was most prevalent in the younger children. Of the rural and urban children aged 13–24 months 60 and 53% respectively were anaemic while only 11% of those over 24 months had haemoglobin concentrations that were below normal.5. The prevalence of anaemia among children who had serum ferritin values below 12 μg/l was only slightly higher than that for the groups as a whole (38.8 %v.24.3%), while the prevalence in those with values of 12 μg/l or more was only slightly less (18.2%). However, when a ferritin concentration of less than 12μg/l was associated with a percentage saturation of transferrin of less than 16%, the prevalence of anaemia was 70.0%, and only 10.2% of children in whom both values were within the normal range were anaemic.6. Since 67% of children had either a normal serum ferritin and a normal percentage saturation of transferrin or both values below the normal range, the two measurements taken together provided a useful means of separating the children who had significant Fe deficiency from those whose Fe stores were sufficient to make the appearance of anaemia unlikely.

Hyperfine interactions at Fe57and Sn119nuclei in MnSb

The ferromagnetic compound MnSb was studied using Mossbauer spectroscopy of the isotopes Fe57 and Sn119. The saturation values for the hyperfine magnetic fields at the nuclei of Fe57 and Sn119 impurities in MnSb are -110 kOe and -45 kOe respectively. The value of the field for Fe is similar to that observed in the related system FeSb. A spin-flop transition is observed depending on temperature and sample composition. The Fe saturation magnetic field scales with the saturation magnetisation of the host material. The difference between room temperature and liquid nitrogen temperature results suggests a relatively weak coupling between the Fe moment and the host magnetisation. The value of the Sn field is in agreement with trends observed for non-magnetic 5sp impurities in magnetic hosts.

Iron Uptake and Translocation by Tomato Plants as Influenced by Root Temperature and Manganese Nutrition

The uptake of iron (Fe) by VF-36 tomato plants as influenced by root temperature and manganese (Mn) nutrition was studied. Following a 1-week pretreatment period of various levels of Fe and Mn in the nutrient solution in a controlled temperature room, the uptake of (59)Fe from ferric ethylenediamine di(O-hydroxyphenylacetate) (FeEDDHA) at 1 mumole per liter was studied for periods of 1 to 5 days.Both Fe uptake and translocation were enhanced by increases in root temperature. Varied levels of Fe in the pretreatment period led to increased levels of Fe in the plant, which subsequently depressed further accumulation of (59)Fe. The effect of increased root temperature on (59)Fe uptake and translocation was decreased by increases in the level of Fe in the pretreatment cultures. As Mn in the nutrient solution was increased, (59)Fe uptake and translocation were increased to a point and then decreased.The degree of Fe saturation of the plant appeared to be a primary factor in regulating Fe uptake and translocation in the plant. As the Fe saturation of the plant decreased, the uptake of Fe in response to metabolic processes of the plant increased, as evidenced by increased response of absorption to root temperature.