Structural and magnetic characterization of the lithiated iron oxide LixFe3O4

The Rietveld profile‐analysis method is used to investigate the x‐ray diffraction pattern of lithiated Fe3O4. It is shown that, after exposure to air, pure magnetite coexists with a lithium‐inserted LixFe3O4 phase. The Mössbauer spectra at 300 and 4.2 K have been used to estimate the lithium content of the sample, the pure magnetite concentration, and the iron distribution over the available 16c and 16d sites of the spinel structure. Magnetization measurements from 4.2 to 120 K with an external magnetic field up to 150 kOe have been used to obtain the saturation magnetic moment, the magnetic anisotropy constants, and the susceptibility. It is concluded that a noncollinear spin structure should be present in Li0.5Fe3O4. These results indicate that there is no room‐temperature extrusion of iron even for x→2.0, but that on exposure to air LixFe3O4 samples with x>0.5 are oxidized at room temperature by delithiation.

Networks of people in specialty production: family firms in the iron and steel Wire industries in Spain (1870-2000)

Capital intensive industries in specialized niches of production have constituted solid ground for family firms in Spain , as evidenced by the experience of the iron and steel wire industries between 1870 and 2000. The embeddedness of these firms in their local and regional environments have allowed the creation of networks that, together with favourable institutional conditions, significantly explain the dominance of family entrepreneurship in iron and steel wire manufacturing in Spain, until the end of the 20 th century. Dominance of family firms at the regional level has not been not an obstacle for innovation in wire manufacturing in Spain, which has taken place even when institutional conditions blocked innovation and traditional networking. Therefore, economic theories about the difficulties dynastic family firms may have to perform appropriately in science-based industries must be questioned

Iron deficiency in infancy: is an immigrant more at risk?

QUESTIONS UNDER STUDY: Iron deficiency with or without anaemia is the most common deficiency in the world. Its prevalence is higher in developing countries and in low socioeconomic populations. We aimed at determining and comparing the prevalence of iron deficiency in an immigrant and non-immigrant population. METHODS: Every child scheduled for a routine check-up at 12 months of age was allowed to participate in the study. Haemoglobin, ferritin, anthropometric data, familial and nutritional status were measured. RESULTS: 586 infants were eligible and 463 were included in the study as they had assessment data at 12 months. Children were divided into two groups: immigrants' children and non-immigrants' children. The global prevalence of iron deficiency was 5.7% at 12 months. A significant difference for iron deficiency was noticed between the groups at 12 months (p = 0.01). Among risk factors, immigration (odds ratio 2.91; 95% CI 1.05-8.04) and unemployment (odds ratio 6.08; 95% CI 1.18-31.30) had the higher odds in the multivariable analysis. CONCLUSION: The prevalence of iron deficiency in the immigrant population is higher than in non-immigrants. Immigration and the category of employment are risk factors for iron deficiency, as starting baby cereals before 9 months is a protective factor. Good socioeconomic conditions in Switzerland, the quality of food for pregnant women and young infants may be the explanation. A study up to five years of age is necessary before drawing general conclusions on infancy.

Evaluation of uptake and transport of ultrasmall superparamagnetic iron oxide nanoparticles by human brain-derived endothelial cells.

Aim: Ultrasmall superparamagnetic iron oxide nanoparticles (USPIO-NPs) are under development for imaging and drug delivery; however, their interaction with human blood-brain barrier models is not known. Materials & Methods: The uptake, reactive oxygen species production and transport of USPIO-NPs across human brain-derived endothelial cells as models of the blood-brain tumor barrier were evaluated for either uncoated, oleic acid-coated or polyvinylamine-coated USPIO-NPs. Results: Reactive oxygen species production was observed for oleic acid-coated and polyvinylamine-coated USPIO-NPs. The uptake and intracellular localization of the iron oxide core of the USPIO-NPs was confirmed by transmission electron microscopy. However, while the uptake of these USPIO-NPs by cells was observed, they were neither released by nor transported across these cells even in the presence of an external dynamic magnetic field. Conclusion: USPIO-NP-loaded filopodia were observed to invade the polyester membrane, suggesting that they can be transported by migrating angiogenic brain-derived endothelial cells.

Carence en fer sans anémie: où en est-on en 2012 [Iron deficiency without anemia: where are we in 2012?].

Should we treat iron deficiency without anemia? The simple fact that the question can be formulated already leads to controversies. During the past years, the development of a new formulation of intravenous iron has helped fuel the controversy. What is the situation in 2012? This article gives a practical point of view on the actual situation and provides indications on the use of new intravenous medications.

Iron Supplementation Therapy in a Large Swiss Cohort of Inflammatory Bowel Disease Patients: Shift from Oral to Intravenous Therapy over Time

Background a nd A ims: T he 2 007 ECCO g uidelines o nanemia in inflammatory bowel disease (IBD) favour intravenous(iv) over oral (po) i ron supplementation due to bettereffectiveness and tolerance. Application of guidelines in clinicalpractice m ay r equire time. We a imed to determine thepercentage of IBD patients under iron supplementation therapyand its application mode over time in a large IBD cohort.Methods: Helsana, a leading Swiss health insurance companyprovides c overage f or approximately 18% of t he Swisspopulation, corresponding to about 1.2 million enrollees.Patients with Crohn's disease (CD) and ulcerative colitis (UC)were identified b y keyword search from t he a nonymisedHelsana database.Results: I n total, 6 29 CD ( 61% female) a nd 4 03 UC ( 56%female) patients w ere identified, mean retrospectiveobservation time w as 2 0.4 m onths f or CD and 13 m onths f orUC patients. Of t he entire study population, 29.3% wereprescribed iron. O ccurrence of iron prescription was 21.3% inmales a nd 31.2% in f emales ( odds r atio [OR] 1 .69, 95%-confidence interval [CI] 1.26-2.28). The prescription of iv i ronincreased from 2006/2007 ( 48.8% w ith iv i ron) to 2 008/2009(65.2% with iv iron) by a factor of 1.89.Conclusions: One third of the IBD population was treated withiron supplementation. A gradual s hift from oral t o iv iron wasobserved over time in a large Swiss IBD cohort. This switch inprescription habits g oes a long with the implementation of theECCO consensus guidelines on anemia in IBD.

Iron supplementation in a large Swiss Cohort of Inflammatory Bowel Disease patients demonstrates a shift form oral to intravenous therapy over time

Background and Aims: The 2007 European Crohn's and Colitis Organization guidelines on anemia in inflammatory bowel disease (IBD) favour intravenous (iv) over oral (po) iron supplementation due to better effectiveness and tolerance. We aimed to determine the percentage of IBD patients under iron supplementation therapy and the dynamics of prescription habits (iv versus po) over time. Methods: Helsana, a leading Swiss health insurance company provides coverage for approximately 18% of the Swiss population, corresponding to about 1.2 million enrollees. Patients with Crohn's disease (CD) and ulcerative colitis (UC) were analyzed from the anonymised Helsana database. Results: In total, 629 CD (61% female) and 398 UC (57% female) patients were identified, mean observation time was 31.8 months for CD and 31.0 months for UC patients. Of the entire study population, 27.1% were prescribed iron (21.1% in males and 31.1% in females). Patients treated with IBD-specific drugs (steroids, immunomodulators, anti-TNF agents) were more frequently treated with iron compared to patients without any medication (35.0% vs. 20.9%, OR 1.91, 95%-CI 1.41-2.61). The prescription of iv iron increased from 2006/2007 (48.8% of all patients receiving any iron priscription) to 65.2% in 2008/2009 by a factor of 1.89. Conclusions: One third of the IBD population was treated with iron supplementation. A gradual shift from oral to iv iron was observed over time. This switch in prescription habits goes along with the implementation of the ECCO consensus guidelines on anemia in IBD.

On the dual contrast enhancement mechanism in frequency-selective inversion-recovery magnetic resonance angiography (IRON-MRA)

The susceptibility of blood changes after administration of a paramagnetic contrast agent that shortens T(1). Concomitantly, the resonance frequency of the blood vessels shifts in a geometry-dependent way. This frequency change may be exploited for incremental contrast generation by applying a frequency-selective saturation prepulse prior to the imaging sequence. The dual origin of vascular enhancement depending first on off-resonance and second on T(1) lowering was investigated in vitro, together with the geometry dependence of the signal at 3T. First results obtained in an in vivo rabbit model are presented.