A study, by fire-assay and ICP-MS, of the distribution of rhodium, platinum, and gold in iron-age pottery

Forty-six archaeological specimens were treated by fire-assay and subsequently analysed by ICP-MS for selected precious metals: Ph, Pt and Au. The investigation was prompted by the possibility that archaeological samples could serve as "indicators" of the precious metal composition of the clays from the excavated sites. Therefore, the experimentally obtained concentrations were carefully studied to determine if there were anomalous levels of these precious metals in the deposits from which the specimens originated. Furthermore, the analytical data were used to establish if it was feasible to distinguish ancient potsherds based on precious metal concentrations, for employment as a basis in provenance studies.

PSMA-targeting iron oxide magnetic nanoparticles enhance MRI of preclinical prostate cancer

Aim Evaluate potential of newly-developed, biocompatible iron oxide magnetic nanoparticles (MNPs) conjugated with J591, an antibody to an extracellular epitope of prostate specific membrane antigen (PSMA), to enhance MRI of prostate cancer (PCa). Materials & Methods Specific binding to PSMA by J591-MNP was investigated in vitro. MRI studies were performed on orthotopic tumor-bearing NOD.SCID mice 2h and 24hr after intravenous injection of J591-MNPs, or non-targeting MNPs. Results and Conclusions In vitro, MNPs did not affect PCa cell viability, and conjugation to J591 did not compromise antibody specificity and enhanced cellular iron uptake. In vivo, PSMA-targeting MNPs increased MR contrast of tumors, but not by non-targeting MNPs. This provides proof-of-concept that PSMA-targeting MNPs have potential to enhance MR detection/localization of PCa.,

Enhancing MRI of prostate cancer using PSMA-targeting iron oxide magnetic nanoparticles

Introduction Novel imaging techniques for prostate cancer (PCa) are required to improve staging and real-time assessment of therapeutic response. We performed preclinical evaluation of newly-developed, biocompatible magnetic nanoparticles (MNPs) conjugated with J591, an antibody specific for prostate specific membrane antigen (PSMA), to enhance magnetic resonance imaging (MRI) of PCa. PSMA is expressed on ∼90% of PCa, including those that are castrate-resistant, rendering it as a rational target for PCa imaging. Materials and Methods The specificity of J591 for PSMA was confirmed by flow cytometric analysis of several PCa cell lines of known PSMA status. MNPs were prepared, engineered to the appropriate size, labeled with DiR fluorophore, and their toxicity to a panel of PC cells was assessed by in vitro Alamar Blue assay. Immunohistochemistry, fluorescence microscopy and Prussian Blue staining (iron uptake) were used to evaluate PSMA specificity of J591-MNP conjugates. In vivo MRI studies (16.4T MRI system) were performed using live immunodeficient mice bearing orthotopic LNCaP xenografts and injected intravenously with J591-MNPs or MNPs alone. Results MNPs were non-toxic to PCa cells. J591-MNP conjugates showed no compromise in specificity of binding to PSMA+ cells and showed enhanced iron uptake compared with MNPs alone. In vivo, tumour targeting (significant MR image contrast) was evident in mice injected with J591-MNPs, but not MNPs alone. Resected tumours from targeted mice had an accumulation of MNPs, not seen in normal control prostate. Conclusions Application of PSMA-targeting MNPs into conventional MRI has potential to enhance PCa detection and localization in real-time, improving patient management.

Equilibrium and column studies of iron exchange with strong acid cation resin

The exchange of iron species from iron (III) chloride solutions with a strong acid cation resin has been investigated in relation to a variety of water and wastewater applications. A detailed equilibrium isotherm analysis was conducted wherein models such as Langmuir Vageler, Competitive Langmuir, Freundlich, Temkin, Dubinin Astakhov, Sips and Brouers-Sotolongo were applied to the experimental data. An important conclusion was that both the bottle-point method and solution normality used to generate the ion exchange equilibrium information influenced which sorption model fitted the isotherm profiles optimally. Invariably, the calculated value for the maximum loading of iron on strong acid cation resin was substantially higher than the value of 47.1 g/kg of resin which would occur if one Fe3+ ion exchanged for three “H+” sites on the resin surface. Consequently, it was suggested that above pH 1, various iron complexes sorbed to the resin in a manner which required less than 3 sites per iron moiety. Column trials suggested that the iron loading was 86.6 g/kg of resin when 1342 mg/L Fe (III) ions in water were flowed at 31.7 bed volumes per hour. Regeneration with 5 to 10 % HCl solutions reclaimed approximately 90 % of exchange sites.

Characterization of the sulphate mineral coquimbite, a secondary iron sulphate from Javier Ortega mine, Lucanas Province, Peru – Using infrared, Raman spectroscopy and thermogravimetry

The mineral coquimbite has been analysed using a range of techniques including SEM with EDX, thermal analytical techniques and Raman and infrared spectroscopy. The mineral originated from the Javier Ortega mine, Lucanas Province, Peru. The chemical formula was determined as ðFe3þ 1:37; Al0:63ÞP2:00ðSO4Þ3 9H2O. Thermal analysis showed a total mass loss of 73.4% on heating to 1000 C. A mass loss of 30.43% at 641.4 C is attributed to the loss of SO3. Observed Raman and infrared bands were assigned to the stretching and bending vibrations of sulphate tetrahedra, aluminium oxide/hydroxide octahedra, water molecules and hydroxyl ions. The Raman spectrum shows well resolved bands at 2994, 3176, 3327, 3422 and 3580 cm 1 attributed to water stretching vibrations. Vibrational spectroscopy combined with thermal analysis provides insight into the structure of coquimbite.

Estimating the burden of disease attributable to iron deficiency anaemia in South Africa in 2000

OBJECTIVES To estimate the extent of iron deficiency anaemia (IDA) among children aged 0 - 4 years and pregnant women aged 15 - 49 years, and the burden of disease attributed to IDA in South Africa in 2000. DESIGN The comparative risk assessment (CRA) methodology of the World Health Organization (WHO) was followed using local prevalence and burden estimates. IDA prevalence came from re-analysis of the South African Vitamin A Consultative Group study in the case of the children, and from a pooled estimate from several studies in the case of the pregnant women (haemoglobin level < 11 g/dl and ferritin level < 12 microg/l). Monte Carlo simulation-modelling was used for the uncertainty analysis. SETTING South Africa. SUBJECTS Children under 5 years and pregnant women 15 - 49 years. OUTCOME MEASURES Direct sequelae of IDA, maternal and perinatal deaths and disability-adjusted life years (DALYs) from mild mental disability related to IDA. Results. It is estimated that 5.1% of children and 9 - 12% of pregnant women had IDA and that about 7.3% of perinatal deaths and 4.9% of maternal deaths were attributed to IDA in 2000. Overall, about 174,976 (95% uncertainty interval 150,344 - 203,961) healthy years of life lost (YLLs), or between 0.9% and 1.3% of all DALYs in South Africa in 2000, were attributable to IDA. CONCLUSIONS This first study in South Africa to quantify the burden from IDA suggests that it is a less serious public health problem in South Africa than in many other developing countries. Nevertheless, this burden is preventable, and the study highlights the need to disseminate the food-based dietary guidelines formulated by the National Department of Health to people who need them and to monitor the impact of the food fortification programme.

Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis

Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (P<5 × 10−8) loci, some including known iron-related genes (​HFE, ​SLC40A1, ​TF, ​TFR2, ​TFRC, ​TMPRSS6) and others novel (​ABO, ​ARNTL, ​FADS2, ​NAT2, ​TEX14). SNPs at ​ARNTL, ​TF, and ​TFR2 affect iron markers in ​HFE C282Y homozygotes at risk for hemochromatosis. There is substantial overlap between our iron loci and loci affecting erythrocyte and lipid phenotypes. These results will facilitate investigation of the roles of iron in disease.

A review of iron species for visible-light photocatalytic water purification

Iron species are one of the least toxic and least expensive substances that are photocatalytic in the visible region of the spectrum. Therefore, this article focuses on iron-based photocatalysts sensitive to visible light. Photo-Fenton reactions are considered with respect to those assisted by and involve the in situ production of H2O2. The possible role that photoactive iron species play by interacting with natural organic matter in water purification in the natural environment is considered. The review also considered photosensitization by phthalocyanines and the potential role that layered double hydroxides may have not only as catalyst supports but also as photosensitizers themselves. Finally, photocatalytic disinfection of water is discussed, and the desirability of standardized metrics and experimental conditions to assist in the comparative evaluation of photocatalysts is highlighted.

Field performance of in-service cast iron water reticulation pipe buried in reactive clay

Field monitoring is an important means for understanding soil behaviour and its interaction with buried structures such as pipeline. This paper details the successful instrumentation of a section of an in-service cast iron water main buried in an area of reactive clay where frequent water pipe breakage has been observed. The instrumentation included measurement of pipe strain; pipe water pressure and temperature; soil pressure, temperature, moisture content and matric suction, as well as the meteorological conditions on site. The data generally indicated that changes in soil temperature, suction and moisture content were directly related to the local climatic variations. The suction and moisture content data indicated that the soil profile at the site down to around 700 mm, and probably down to 1000 mm, is affected by changes in surface weather, while soil conditions below this depth appear to be more stable. Analysis of pipe strain indicated that the pipe behaves like a cantilever beam, with the top experiencing predominantly tensile strains during summer. Subsequently, these trends reduce to compressive strains as soil swelling occurs due to increase of moisture content with the onset of winter.

Cloning and gastrointestinal expression of rat hephaestin: Relationship to other iron transport proteins

The membrane-bound ceruloplasmin homolog hephaestin plays a critical role in intestinal iron absorption. The aims of this study were to clone the rat hephaestin gene and to examine its expression in the gastrointestinal tract in relation to other genes encoding iron transport proteins. The rat hephaestin gene was isolated from intestinal mRNA and was found to encode a protein 96% identical to mouse hephaestin. Analysis by ribonuclease protection assay and Western blotting showed that hephaestin was expressed at high levels throughout the small intestine and colon. Immunofluorescence localized the hephaestin protein to the mature villus enterocytes with little or no expression in the crypts. Variations in iron status had a small but nonsignificant effect on hephaestin expression in the duodenum. The high sequence conservation between rat and mouse hephaestin is consistent with this protein playing a central role in intestinal iron absorption, although its precise function remains to be determined.

Studies on interaction of Paenibacillus polymyxa with iron ore minerals in relation to beneficiation

Interaction between Paenibacillus polymyxa with minerals such as hematite, corundum, quartz and kaolinite brought about significant surface chemical changes on all the minerals. Quartz and kaolinite were rendered more hydrophobic, while hematite and corundum, became more hydrophilic after biotreatment. The predominance of bacterial polysaccharides on interacted hematite and corundum and of proteins on quartz and kaolinite was responsible for the above surface-chemical changes. Bio-pretreatment of the above iron ore mineral mixtures resulted in the selective separation of silica and alumina from iron oxide, through bioflotation and bioflocculation. The utility of bioprocessing in the beneficiation of iron ores is demonstrated.

The influence of trace impurities on the mechanical characteristics of a superplastic 2 mol% yttria stabilized zirconia

In contrast to metallic alloys, the mechanical characteristics of superplastic ceramics are very sensitive to minor changes in levels of trace impurities. In the present study, the mechanical behavior of a 2 mol% yttria stabilized tetragonal zirconia was studied in tension and compression in two batches of material, with small variations in levels of trace impurities, to examine the influence of stress axis and impurity content on the deformation behavior. The mechanical properties of the material were characterized in terms of the expression: (epsilon)over dot proportional to sigma(n) where (epsilon)over dot is the strain rate, sigma is the stress and n is termed the stress exponent. The mechanical behavior of the ceramic was identical in tension and compression, for a material with a given level of impurity. The high purity specimens exhibited a transition from a stress exponent of similar to 3 to similar to 2 with an increase in stress, whereas the low purity material displayed only n similar to 2 behavior over the entire stress range studied. Detailed high resolution and analytical electron microscopy studies revealed that there was no amorphous phase at interfaces in both batches of material; however, segregation of Al at interfaces was detected only in the low purity material. The observed transition in stress exponents can be rationalized in terms of two sequential mechanisms: grain boundary sliding with n similar to 2 and interface reaction controlled grain boundary sliding with n similar to 3. The transition from n similar to 3 to similar to 2 occurred at lower stresses with an increase in the grain size and a decrease in the purity level.

Thermal shock characteristics of plasma sprayed mullite coatings

Commercially available mullite (3Al(2)O(3). 2SiO(2)) powders containing oxides of calcium and iron as impurities, have been made suitable for plasma spraying by using an organic binder. Stainless steel substrates covered with Ni-22Cr-10Al-1.0Y bond coat were spray coated with mullite, The 425 mu m thick coatings were subjected to thermal shock cycling under burner rig conditions between 1000 and 1200 degrees C and less than 200 degrees C with holding times of 1, 5, and 30 min. While the coatings withstood as high as 1000 shock cycles without failure between 1000 and 200 degrees C, spallation occurred early at 120 cycles when shocked from 1200 degrees C, The coatings appeared to go through a process of self erosion at high temperatures resulting in loss of material. Also observed were changes attributable to melting of the silicate grains, which smooth down the surface. Oxidation of the bond coat did not appear to influence the failure, These observations were supported by detailed scanning electron microscopy and quantitative chemical composition analysis, differential thermal analysis, and surface roughness measurements.