High Amounts Of Iron Research Articles

Determination of Uranium in Seawater Samples by Liquid Chromatography using Mandelic Acid as a Complexing Agent

The determination of uranium at different stages of the recovery process as well as in seawater is important in its recovery study. A previous study developed a high-performance liquid chromatography (HPLC) method for uranium determination in seawater using α-hydroxy isobutyric acid as a chelating agent. However, this method causes turbidity in process samples containing high amounts of iron, resulting in the clogging of the HPLC column. In the present work, use of mandelic acid as a chelating agent for uranium has been explored. Elution conditions were optimized for the separation of iron [Fe(III)] and uranium [U(VI)] by studying the effect of an ion interaction reagent, the concentration of mandelic acid, and methanol content in the mobile phase. Different parameters were optimized to develop off- line pre-concentration of uranyl-mandelate on the reversed stationary phase. The method offers quantitative recovery of uranium and linearity in the U(VI) concentration range of 0.5 ppb to 500 ppb and can be used for the determination of U(VI) in process samples with Fe/U amount ratios up to 3,000. The method has been successfully used for the determination of U(VI) in seawater samples and process samples. The developed methodology was validated by comparing the results with those of isotope dilution-thermal ionization mass spectrometry.

Pulmonary toxicity comparison of raw and super-purified single-wall carbon nanotubes after intra-tracheal instillation in rats

Single-wall carbon nanotubes (SWCNTs) possess many properties and have various potential applications. Nanotubes are very light and could become airborne and potentially reach lungs. In order to evaluate the relation between the respiratory toxicological effects of carbon nanotubes and their physicochemical characteristics, we compared raw and super-purified SWCNTs toxicity. Oxidative stress and inflammation involvements as possible mechanisms of the toxicological effects of these nanotubes were examined. Rats were intratracheally instilled with 200 micro g of raw or super-purified SWCNTs, and euthanized 1, 7, 30, 90 or 180 days after the single treatment for histo-pathological study of the lungs, broncho-alveolar fluids and mRNA expression measurements. SWCNTs were suspended at 1.4 mg/ml in 3% ethanol and 1.4 mg/ml of BSA. The suspension was sonicated for 10 min in an ultrasonic bath. These two types of SWCNTs can induce granulomas. The quantity and size of granulomas appear to be greater after treatment with raw SWCNTs than super-purified SWCNTs. Regarding inflammation, interleukin-1s and interleukin-6 expression increased 24 h after instillation, more with super-purified than with raw SWCNTs. Oxidative stress enzymes expression (Heme oxygenase 1 and iNOS) were induced with a maximum reached at 7 days with raw SWCNTs and 1 month with super purified SWCNTs. Overall, the biological response after treatment with raw SWCNTs containing a high amount of iron (20%) occurred earlier than after treatment with super-purified SWCNTs containing a small amount of iron (2%). Raw SWCNTs seem eliminated more rapidly than super-purified SWCNTs. Purity of SWCNT is an important factor in pulmonary toxicity.

Extracting natural dyes from wool—an evaluation of extraction methods

The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

زمین شناسی، کانی سازی، ژئوشیمی و مطالعات مغناطیس سنجی در کانی سازی آهن منطقه کلاته شاهین، استان خراسان رضوی

کانی‌سازی آهن کلاته‌شاهین در 107 کیلومتری جاده قوچان- نیشابور (استان خراسان رضوی) قرار دارد. توده‌های نیمه‌عمیق با ترکیب مونزونیت تا هورنبلند دیوریت پورفیری در آهکهای کرتاسه نفوذ کرده اند. واحدهای رسوبی منطقه از قدیم به جدید شامل آهکهای مربوط به کرتاسه زیرین و میکروکنگلومرا تا ماسه‌سنگهای مربوط به ائوسن و پلیوسن- کواترنر می باشد. کانی سازی در این منطقه طی دو مرحله هیپوژن و سوپرژن شکل گرفته است. در مرحله هیپوژن، پیریت، مگنتیت و اسپکیولاریت و در مرحله سوپرژن، گوتیت، لیمونیت و هماتیت تشکیل شده اند. بررسی شرایط دمایی و فوگاسیته اکسیژن، دمای تشکیل کانی‌های هیدروترمالی شرق منطقه را در محدوده کمتر از oC350 معرفی می نماید. در غرب منطقه، میزان هماتیت و گوتیت بسیار کمتر و اغلب به‌صورت رگه و رگچه ای همراه با دولومیت هیدروترمالی می باشند. محلولهای هیدروترمالی عامل کانی سازی در غرب منطقه نسبت به شرق با میزان سولفید کمتر، اکسیدان تر و دمای کمتر بوده‌اند. نتایج آنالیز ژئوشیمی به روش جذب اتمی برای عناصر Fe، Mn، Mg و Ca، نشان‌دهنده بیشترین میزان آهن (4/30 درصد) در محل ترانشه در شرق منطقه است. آهن و منگنز در محل ترانشه همبستگی مثبت نشان می دهند. همچنین رابطه‌ای بین میزان این عناصر و فاصله از توده ها وجود ندارد. بنابراین توده‌های نفوذی منطقه غیربارور بوده و نقشی در کانی‌سازی ندارند. شدت کل میدان مغناطیسی در 742 نقطه در دو شبکه 5×20 متر اندازه‌گیری شد. نقشه‌های شدت‌کل میدان مغناطیسی، انتقال به قطب و همچنین ادامه به‌سمت بالا با نرم‌افزار Mapper ER تهیه شد. بررسی نقشه‌های تهیه‌شده، وجود آنومالی‌های A، B، C، F، E، D1، D2 و D3 را در منطقه نشان می‌دهد. با توجه به این که در فاصله تقریبا 40 متری آنومالی‌های B وC ، توده هورنبلند دیوریت پورفیری رخنمون دارد، این احتمال وجود دارد که منبع آنومالی ها مربوط به توده نفوذی باشد. از طرفی به‌دلیل وجود کانی‌سازی هماتیت در آهک‌های منطبق بر آنومالی‌های B و C این احتمال نیز وجود دارد که منبع این آنومالی‌ها مربوط به کانی‌سازی مگنتیت در عمق باشد. بنابراین در محل این دو آنومالی، حفاری اکتشافی پیشنهاد می شود.

Effect of steel-making slag as a soil amendment on arsenic uptake by radish (Raphanus sativa L.) in an upland soil

The steel-making slag (SMS), a by-product of steel manufacturing process with an alkaline pH (11–12) and high amount of iron (Fe) and calcium (Ca) oxides, was used to reduce arsenic (As) phytoextractability. The by-product was selected as an alternative to commercial Fe oxides, which can decrease plant uptake, but they are expensive if used as amendments of contaminated arable soils. SMS was applied at rates 0, 2, 4, and 8 Mg ha−1 to an As (1 N HCl-extractable As 25 mg kg−1) contaminated soil prepared by mixing non-contaminated soil and mine tailings and cropped to radish (Raphanus sativa L.) seeding. Calcium hydroxide (Ca(OH)2), a common liming material in Korea, was applied at the same rates for comparison. Steel-making slag more effectively suppressed radish As uptake and increased yield than Ca(OH)2 due to stronger As immobilization because it significantly increased extractable Fe concentration and decreased extractable As. The SMS-treated soil showed an apparent increase in As chemisorbed by Fe and Al oxides and hydroxides of surface soil, As associated at the Fe and Al oxides and hydroxides of internal surfaces of soil aggregates, and Ca-associated As. The steel-making slag can be a good soil amendment to suppress As phytoextractability and improve nutrient balance in As-contaminated soil.

Variations in labeling protocol influence incorporation, distribution and retention of iron oxide nanoparticles into human umbilical vein endothelial cells

Various studies have shown that various cell types can be labeled with iron oxide particles and visualized by magnetic resonance imaging (MRI). However, reported protocols for cell labeling show a large variation in terms of labeling dose and incubation time. It is therefore not clear how different labeling protocols may influence labeling efficiency. Systematic assessment of the effects of various labeling protocols on labeling efficiency of human umbilical vein endothelial cells (HUVEC) using two different types of iron oxide nanoparticles, i.e. super paramagnetic iron oxide particles (SPIOs) and microparticles of iron oxide (MPIOs), demonstrated that probe concentration, incubation time and particle characteristics all influence the efficiency of label incorporation, label distribution, label retention and cell behavior. For SPIO the optimal labeling protocol consisted of a dose of 12.5 µg iron/2 ml/9.5 cm(2) and an incubation time of 24 h, resulting in an average iron load of 12.0 pg iron/per cell (uptake efficiency of 9.6%). At 4 h many SPIOs are seen sticking to the outside of the cell instead of being taken up by the cell. For MPIO optimal labeling was obtained with a dose of 50 µg iron/2 ml/9.5 cm(2). Incubation time was of less importance since most of the particles were already incorporated within 4 h with a 100% labeling efficiency, resulting in an intracellular iron load of 626 pg/cell. MPIO were taken up more efficiently than SPIO and were also better tolerated. HUVEC could be exposed to and contain higher amounts of iron without causing significant cell death, even though MPIO had a much more pronounced effect on cell appearance. Using optimal labeling conditions as found for HUVEC on other cell lines, we observed that different cell types react differently to identical labeling conditions. Consequently, for each cell type separately an optimal protocol has to be established.

Iron concentrations in selected groundwater samples from the lower Friulian Plain, northeast Italy: importance of salinity

High amounts of iron, up to 14 mg/L, were found in groundwater samples from Marano Lagoon in the Friuli Venezia Giulia Plain (northeast Italy). In order to characterize groundwater hydrochemistry in the area, an investigation has been conducted on 35 wells that were monitored since 2006. Leaching tests were performed (under anaerobic conditions with deionized and saline waters) on two core samples in the area to study the iron release from soils to groundwater. Collected data indicated the main role of salinity in metal leaching and highlighted spatial correspondence between high levels of chloride and iron. To understand the mechanism of groundwater salinization, sulphate/chloride ratio has been investigated and a statistical relation between salinity, pH and iron was found. These data do not show any relation between past activities and high iron groundwater contents. High iron concentrations are diffuse in the whole area and therefore comparable to background values. Consequently, the study states that no remediation plan should have been made for iron concentrations in this area.

Homozygous deletion of CDKN2A/2B is a hallmark of iron-induced high-grade rat mesothelioma

In humans, mesothelioma has been linked to asbestos exposure, especially crocidolite and amosite asbestos, which contain high amounts of iron. Previously, we established a rat model of iron-induced peritoneal mesothelioma with repeated intraperitoneal injections of iron saccharate and an iron chelator, nitrilotriacetate. Here, we analyze these mesotheliomas using array-based comparative genomic hybridization (aCGH) and gene expression profiling by microarray. Mesotheliomas were classified into two distinct types after pathologic evaluation by immunohistochemistry. The major type, epithelioid mesothelioma (EM), originated in the vicinity of tunica vaginalis testis, expanded into the upper peritoneal cavity and exhibited papillary growth and intense podoplanin immunopositivity. The minor type, sarcomatoid mesothelioma (SM), originated from intraperitoneal organs and exhibited prominent invasiveness and lethality. Both mesothelioma types showed male preponderance. SMs revealed massive genomic alterations after aCGH analysis, including homozygous deletion of CDKN2A/2B and amplification of ERBB2 containing region, whereas EMs showed less genomic alterations. Uromodulin was highly expressed in most of the cases. After 4-week treatment, iron deposition in the mesothelia was observed with 8-hydroxy-2′-deoxyguanosine formation. These results not only show two distinct molecular pathways for iron-induced peritoneal mesothelioma, but also support the hypothesis that oxidative stress by iron overload is a major cause of CDKN2A/2B homozygous deletion.

Segmental Heterogeneity of Vasa Vasorum Neovascularization in Human Coronary Atherosclerosis

Our aim was to investigate the role of coronary vasa vasorum (VV) neovascularization in the progression and complications of human coronary atherosclerotic plaques. Accumulating evidence supports an important role of VV neovascularization in atherogenesis and lesion location determination in coronary artery disease. VV neovascularization can lead to intraplaque hemorrhage, which has been identified as a promoter of plaque progression and complications like plaque rupture. We hypothesized that distinctive patterns of VV neovascularization and associated plaque complications can be found in different stages of human coronary atherosclerosis. Hearts from 15 patients (age 52+/-5 years, mean+/-SEM) were obtained at autopsy, perfused with Microfil (Flow Tech, Inc., Carver, Massachusetts), and subsequently scanned with micro-computed tomography (CT). The 2-cm segments (n=50) were histologically classified as either normal (n=12), nonstenotic plaque (<50% stenosis, n=18), calcified (n=10) or noncalcified (n=10) stenotic plaque. Micro-CT images were analyzed for VV density (number/mm2), VV vascular area fraction (mm2/mm2), and VV endothelial surface fraction (mm2/mm3). Histological sections were stained for Mallory's (iron), von Kossa (calcium), and glycophorin-A (erythrocyte fragments) as well as endothelial nitric oxide synthase, vascular endothelial growth factor, and tumor necrosis factor-alpha. VV density was higher in segments with nonstenotic and noncalcified stenotic plaques as compared with normal segments (3.36+/-0.45, 3.72+/-1.03 vs. 1.16+/-0.21, p<0.01). In calcified stenotic plaques, VV spatial density was lowest (0.95+/-0.21, p<0.05 vs. nonstenotic and noncalcified stenotic plaque). The amount of iron and glycophorin A was significantly higher in nonstenotic and stenotic plaques as compared with normal segments, and correlated with VV density (Kendall-Tau correlation coefficient 0.65 and 0.58, respectively, p<0.01). Moreover, relatively high amounts of iron and glycophorin A were found in calcified plaques. Further immunohistochemical characterization of VV revealed positive staining for endothelial nitric oxide synthase and tumor necrosis factor-alpha but not vascular endothelial growth factor. Our results support a possible role of VV neovascularization, VV rupture, and intraplaque hemorrhage in the progression and complications of human coronary atherosclerosis.

Effect of iron content of twin-roll cast Al–Mg–Si alloy strips on filiform corrosion resistance

The effect of iron content of Al–Mg–Si alloy strips fabricated by the twin roll cast (TRC) on filiform corrosion resistance after paint was investigated. The filiform corrosion resistance was maintained to 0.4 mass% iron content. However, the resistance was deteriorated on 0.8 mass% iron content. The deterioration of the filiform corrosion resistance of Al–Mg–Si alloy with 0.8 mass% iron was related to the intermetallic compounds included iron. Higher amount of iron in Al–Mg–Si alloy made the intermetallic compounds formed on cell boundary during twin roll casting. The intermetallic compounds are found to be the origin of corrosion, and corrosion progress along the compounds. As a result, the continuous intermetallic compounds are decreased of filiform corrosion resistances on TRC strips.

Phosphorus forms and behaviors in selected heavily fertilized soils

The objective of this study was to characterize the heavily fertilized soils of northern Iran for their phosphorus (P) fractions and sorption properties for assessing their P availability status in order to minimize P applications and to reduce the danger of P loss to water sources. Different P fractions, namely, total, organic, inorganic, water extractable, and NH4-lactate extractable P varied widely among the studied soils, indicating a wide variability of P supplying capacity of these soils. High values of degree of phosphorus saturation were observed in soils with low amounts of organic carbon (C) and may indicate high P susceptibility to surface runoff and leaching. The maximum P buffering capacity (MPBC) and adsorption isotherm of P were highest in the sandy clay soil from Jamaleddinkola, which also contained high amounts of iron (Fe), aluminium (Al) and clay particles, and lowest in sandy soil from Deseleh, which contained very high initial NH4-lactate extractable P and the lowest content of Fe, Al, silt and clay among all the studied soils. The results suggest the importance of accounting for soil properties (especially soil texture and organic matter) along with soil P adsorption capacity when assessing the efficiency of applied P, P accumulation in soils and subsequently P nutrient management.

Comparing phosphorus mobilization strategies using Aspergillus niger for the mineral dissolution of three phosphate rocks

Phosphorus deficiencies are limiting crop production in agricultural soils worldwide. Locally available sources of raw phosphate rock (PR) are being recognized for their potential role in soil fertility improvement. Phosphorus bioavailability is essential for the efficiency of PRs and can be increased by acid treatments. The utilization of organic acid producing micro-organisms, notably Aspergillus niger, presents a sustainable alternative to the use of strong inorganic acids, but acid production of A. niger strongly depends on the mineral content of the growth media. This study compared the phosphorus mobilization efficiency of two biological treatments, namely addition of acidic cell-free supernatants from A. niger cultivations to PRs and the direct cultivation of A. niger with PRs. The results show that addition of PR to cultivations leads to significant differences in the profile of organic acids produced by A. niger. Additions of PR, especially igneous rocks containing high amounts of iron and manganese, lead to reduced citric acid concentrations. In spite of these differences, phosphorus mobilization was similar between treatments, suggesting that the simpler direct cultivation method was not inferior. In addition to citric acid, it is suggested that oxalic acid contributes to PR solubilization in direct cultivations with A. niger, which would benefit farmers in developing countries where conventional fertilizers are not adequately accessible.

Processes that occur during firing of the argillaceous part of zircon-ilmenite ore gravitation tailings

The nature of iron compound conversion during oxidation-reduction that occurs at the surface and within the central part of zircon-ilmenite ore argillaceous waste material specimens containing a high amount of iron is provided.

Optimization of a phytase-containing micronutrient powder with low amounts of highly bioavailable iron for in-home fortification of complementary foods

Background:In-home fortification of complementary foods with micronutrient powders containing low amounts of iron may be potentially safer than powders containing high amounts of iron. However, low iron doses have little nutritional effect, unless iron absorption is high.Objective: The objective was to maximize iron absorption from a low-iron micronutrient powder for in-home fortification by testing combinations of iron as NaFeEDTA, ascorbic acid, and a microbial phytase active at gut pH. In addition, a recently proposed enhancer of iron absorption, l-α-glycerophosphocholine (GPC), was tested.Design: In 6 separate iron-absorption studies using a crossover design, women (n = 101) consumed whole-maize porridge fortified with 3 mg stable isotope–labeled FeSO4 or NaFeEDTA with different combinations of enhancers added to the meals at the time of consumption. Incorporation of iron isotopes into erythrocytes 14 d later was measured.Results: The addition of phytase when iron was present as either NaFeEDTA or FeSO4, with or without ascorbic acid, significantly increased iron absorption. The combined addition of phytase, ascorbic acid, and NaFeEDTA resulted in an absorption of 7.4%, compared with an absorption of 1.5% from FeSO4 without enhancers in the same meal (P < 0.001). The addition of ascorbic acid did not significantly increase iron absorption from NaFeEDTA, and the addition of calcium did not significantly inhibit iron absorption from NaFeEDTA in the presence of ascorbic acid. The addition of l-α-glycerophosphocholine did not significantly increase iron absorption.Conclusion: Optimization of the micronutrient powder increased iron absorption from a highly inhibitory meal ≈5-fold. This approach may allow for effective, untargeted in-home fortification of complementary foods with low amounts of highly bioavailable iron.

National survey of the health and nutrition of schoolchildren in Ethiopia

To estimate the prevalence of chronic health and nutritional conditions of schoolchildren in Ethiopia. Cross-sectional survey in schools in each region randomly selected in proportion to size, then a random sample of 50-68 children in grades 3 and 4 in each school. Children were examined for signs of micronutrient deficiencies and chronic infections; weighed and measured; provided a faecal sample to diagnose intestinal parasitic infections; and were interviewed about their recent diet and hygiene practices. A total of 7572 children were studied in 142 schools in all 11 regions of Ethiopia. Nearly 17% of children were orphans. The prevalence of stunting was 22.3% and 23.1% of children were thin for age, but these may be underestimates as there was evidence that age may have been estimated based on stature when children enroll in school. Just under 10% of children were anaemic when altitude was accounted for. The overall prevalence of trachoma was 13% and children who washed their face before school were at lower risk of trachoma than children who had not. Children who reported that they had eaten fruits or vegetables the day before also had a lower risk of xerophthalmia than children who had not. Only 30% of children were infected with intestinal worms. Trachoma is a problem but anaemia and intestinal worms are relatively uncommon in Ethiopian schoolchildren. These data provide a basis for developing a school health policy and programmes.

Characteristics and modifying factors of asbestos‐induced oxidative DNA damage

Respiratory exposure to asbestos has been linked with mesothelioma in humans. However, its carcinogenic mechanism is still unclear. Here we studied the ability of chrysotile, crocidolite and amosite fibers to induce oxidative DNA damage and the modifying factors using four distinct approaches. Electron spin resonance analyses revealed that crocidolite and amosite containing high amounts of iron, but not chrysotile, catalyzed hydroxyl radical generation in the presence of H(2)O(2), which was enhanced by an iron chelator, nitrilotriacetic acid, and suppressed by desferal. Natural iron chelators, such as citrate, adenosine 5'-triphosphate and guanosine 5'-triphosphate, did not inhibit this reaction. Second, we used time-lapse video microscopy to evaluate how cells cope with asbestos fibers. RAW264.7 cells, MeT-5 A and HeLa cells engulfed asbestos fibers, which reached not only cytoplasm but also the nucleus. Third, we utilized supercoiled plasmid DNA to evaluate the ability of each asbestos to induce DNA double strand breaks (DSB). Crocidolite and amosite, but not chrysotile, induced DNA DSB in the presence of iron chelators. We cloned the fragments to identify break sites. DSB occurred preferentially within repeat sequences and between two G:C sequences. Finally, i.p. administration of each asbestos to rats induced not only formation of nuclear 8-hydroxy-2'-deoxyguanosine in the mesothelia, spleen, liver and kidney but also significant iron deposits in the spleen. Together with the established carcinogenicity of i.p. chrysotile, our data suggest that asbestos-associated catalytic iron, whether constitutional or induced by other mechanisms, plays an important role in asbestos-induced carcinogenesis and that chemoprevention may be possible through targeting the catalytic iron.

The Effect of Level and Period of Fe-methionine Chelate Supplementation on the Iron Content of Boiler Meat

A broiler experiment was conducted to compare the effects of duration and level of iron-methionine chelate (Fe-Met) supplementation on the iron, copper (Cu) and zinc (Zn) content of broiler meat. Two hundred and fifty hatched Ross broiler chickens were randomly assigned to 5 dietary treatments. Each treatment had 5 replicates of 10 birds (5 males and 5 females) each. Birds were housed in raised floor batteries and fed traditional broiler diets ad libitum for 5 weeks. Dietary treatments were as follows: Control and two levels of Fe-Met (100 or 200 ppm in Fe) supplemented for either the whole period (0-5 wk) or grower period (4-5 wk). Production performance was not significantly affected by treatments. Iron content in the muscles (breast, leg and wing) and organs (liver and spleen) were significantly (p<0.05) increased as the level and duration of Fe-Met supplementation increased. The highest concentration of iron was shown in Fe-Met 200 fed for the whole period. Liver contained the highest amount of iron followed by spleen, leg muscle, wing muscle and breast muscle. Supplementation of Fe-Met 200 for the grower period resulted in higher iron concentration in liver and spleen than supplementation of Fe-Met 100 for the whole period. However, the same treatment resulted in lower iron concentration in muscles (breast, leg and wing) than the treatment of Fe-Met 100 for the whole period. In order to achieve the highest iron enrichment in the muscles, Fe-Met should be supplemented at 200 ppm in Fe for the whole period (5 wks). Fe-Met supplementation increased copper concentration in all muscles and organs except wing muscle. Zinc concentration decreased in breast and wing muscle but tended to increase in leg muscle, liver and spleen by Fe-Met 200 supplementation. Color of muscle was not significantly affected by Fe-Met treatments. However, redness of leg and breast muscle, and yellowness of leg and breast muscle tended to increase by supplementation of Fe-Met for the whole period. It was concluded that iron content of broiler meat can be effectively enriched by supplementation of 200

Leaching of petroleum refinery ash by acidophilic sulfur-oxidizing microbial cultures

Sulfur-oxidising acidophilic bacteria were obtained from weathered sulfur piles produced by a petroleum refinery. When grown on commercial sulfur the yield was 10 10 cell/g S. Sulfur conversion to sulfate was about 95% after 17 days. Cultures were also grown together with ash obtained from incinerated refinery sludge, which contained high amounts of iron. Cultures grown in ash plus sulfur gave somewhat higher values for the growth parameters ( Y = 1.6 × 10 10 cell/g S). The sulfur conversion was about 70% (after 17 days) and more than 90% of the iron present in the ash was also leached. The sulfur-reduced compound thiosulfate, determined using ion pair HPLC, was found in the presence and absence of ash although the profile was different in each case. Sulfite was only found in non-ash containing cultures, whereas tetrathionate was only formed in the presence of ash. These results are discussed with reference to the substrates used by the micro-organisms.

Effect of iron on the properties of sulfated zirconia

Abstract Sulfated zirconia has found several industrial applications, mainly for catalyzing reactions which require acidic sites. In order to control the properties of this solid, the effect of iron on the sulfated zirconia properties was studied in this work. Samples with different iron to zirconium molar ratios were prepared by the sol–gel method, followed by sulfation and characterization by several techniques. It was found that all iron ions go into zirconia when Fe/Zr ≤ 0.4. However, when higher amounts of iron (Fe/Zr ≥ 0.8) are added, hematite is segregated. Different phases can be obtained depending on the iron content and on the sulfur presence. Iron increases the specific surface areas of both sulfated and pure zirconia but does not affect the incorporation of sulfate groups as compared to pure zirconia. Iron also makes the solids thermally more stable and modifies the sulfated zirconia surface creating acidic sites with medium strength. Therefore, it is possible to control the acidity of the solid doping the sulfated zirconia with iron. All these changes are very useful for catalytic applications.

Synthesis and biomedical applications of functionalized fluorescent and magnetic dualreporter nanoparticles as obtained in the miniemulsion process

As superparamagnetic nanoparticles capture new applications and markets, the flexibility andmodifications of these nanoparticles are increasingly important aspects. Therefore a series ofmagnetic polystyrene particles encapsulating magnetite nanoparticles (10–12 nm) in a hydrophobicpoly(styrene-co-acrylic acid) shell was synthesized by a three-step miniemulsion process. A high amount ofiron oxide was incorporated by this process (typically 30–40% (w/w)). As a secondreporter, a fluorescent dye was also integrated in order to obtain ‘dual reporter particles’.Finally, polymerization of the monomer styrene yielded nanoparticles in the range45–70 nm. By copolymerization of styrene with the hydrophilic acrylic acid, the amount ofcarboxyl groups on the surface was varied. The characterization of the latexes includeddynamic light scattering, transmission electron microscopy, surface charge and magneticmeasurements. For biomedical evaluation, the nanoparticles were incubated with differentcell types. The introduction of carboxyl groups on the particle surfaces enabled the uptakeof nanoparticles as demonstrated by the detection of the fluorescent signal by fluorescentactivated cell sorter (FACS) and laser scanning microscopy. The quantity of ironin the cells that is required for most biomedical applications (like detection bymagnetic resonance imaging) has to be significantly higher, as can be achievedby the uptake of magnetite encapsulated nanoparticles functionalized only withcarboxyl groups. A further increase of uptake can be accomplished by transfectionagents like poly-L-lysine or other positively charged polymers. This functionalitywas also engrafted into the surface of the nanoparticles by covalently couplinglysine to the carboxyl groups. The amount of iron that can be transfected waseven higher than with the nanoparticles with a transfection agent added andthis only physically adsorbed. Furthermore, the subcellular localization of thesenanoparticles was demonstrated to be clustered in endosomal compartments.