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Sample records for seed iron loading

  1. Iron in seedsloading pathways and subcellular localization

    PubMed Central

    Grillet, Louis; Mari, Stéphane; Schmidt, Wolfgang

    2014-01-01

    Iron (Fe) is one of the most abundant elements on earth, but its limited bioavailability poses a major constraint for agriculture and constitutes a serious problem in human health. Due to an improved understanding of the mechanisms that control Fe homeostasis in plants, major advances toward engineering biofortified crops have been made during the past decade. Examples of successful biofortification strategies are, however, still scarce and the process of Fe loading into seeds is far from being well understood in most crop species. In particular in grains where the embryo represents the main storage compartment such as legumes, increasing the seed Fe content remains a challenging task. This review aims at placing the recently identified actors in Fe transport into the unsolved puzzle of grain filling, taking the differences of Fe distribution between various species into consideration. We summarize the current knowledge on Fe transport between symplasmic and apoplasmic compartments, and provide models for Fe trafficking and localization in different seed types that may help to develop high seed Fe germplasms. PMID:24427161

  2. A loss-of-function mutation in AtYSL1 reveals its role in iron and nicotianamine seed loading.

    PubMed

    Le Jean, Marie; Schikora, Adam; Mari, Stéphane; Briat, Jean-François; Curie, Catherine

    2005-12-01

    The Arabidopsis Yellow Stripe 1-Like (YSL) proteins have been identified by homology with the maize (Zea mays) Yellow Stripe 1 (YS1) transporter which is responsible for iron-phytosiderophore (PS) uptake by roots in response to iron shortage. Although dicotyledonous plants do not synthesize PS, they do synthesize the PS precursor nicotianamine, a strong metal chelator essential for maintenance of iron homeostasis and copper translocation. Furthermore, ZmYS1 and the rice (Oryza sativa) protein OsYSL2 have metal-nicotianamine transport activities in heterologous expression systems. In this work, we have characterized the function of AtYSL1 in planta. Two insertional loss-of-function ysl1 mutants of Arabidopsis were found to exhibit increased nicotianamine accumulation in shoots. More importantly, seeds of both ysl1 knockouts contained less iron and nicotianamine than wild-type seeds, even when produced by plants grown in the presence of an excess of iron. This phenotype could be reverted by expressing the wild-type AtYSL1 gene in ysl1 plants. ysl1 seeds germinated slowly, but this defect was rescued by an iron supply. AtYSL1 was expressed in the xylem parenchyma of leaves, where it was upregulated in response to iron excess, as well as in pollen and in young silique parts. This pattern is consistent with long-distance circulation of iron and nicotianamine and their delivery to the seed. Taken together, our work provides strong physiological evidence that iron and nicotianamine levels in seeds rely in part on AtYSL1 function.

  3. Iron Transport to Developing Ovules of Pisum sativum (I. Seed Import Characteristics and Phloem Iron-Loading Capacity of Source Regions).

    PubMed Central

    Grusak, M. A.

    1994-01-01

    To understand the processes that control Fe transport to developing seeds, we have characterized seed growth and Fe accretion and have developed a radiotracer technique for quantifying phloem Fe loading in vegetative source regions of Pisum sativum. In hydroponically grown plants of cv Sparkle, developing ovules exhibited a seed-growth period of 22 d, with Fe import occurring throughout the 22-d period. Average Fe content of mature seeds was 19 [mu]g. Source tissues of intact plants were abraded and pulse labeled for 4 h with 100 [mu]M 59Fe(III)-citrate. Fe was successfully phloem loaded and transported to seeds from leaflets, stipules, and pod walls. Total export of 59Fe from labeled source regions was used to calculate tissue-loading rates of 36, 40, and 51 pmol of Fe cm-2 h-1 for the leaflet, stipule, and pod wall surfaces, respectively. By comparison, surface area measurements, along with seed-growth results, allowed us to calculate average theoretical influx values of 42 or 68 pmol of Fe cm-2 h-1 for vegetative tissues at nodes with one or two pods, respectively. Additional studies with the regulatory pea mutant, E107 (a single-gene mutant of cv Sparkle that can overaccumulate Fe), enabled us to increase Fe delivery endogenously to the vegetative tissues. A 36-fold increase in Fe content of E107 leaves, relative to Sparkle, resulted in no increase in Fe content of E107 seeds. Based on these findings, we hypothesized that Fe is phloem loaded in a chelated form, and the expression/synthesis of the endogenous chelator is an important factor in the control of Fe transport to the seeds. PMID:12232115

  4. Preparation of iron nanoparticles-loaded Spondias purpurea seed waste as an excellent adsorbent for removal of phosphate from synthetic and natural waters.

    PubMed

    Arshadi, M; Foroughifard, S; Etemad Gholtash, J; Abbaspourrad, A

    2015-08-15

    The synthesis and characterization of nanoscale zerovalent iron particles (NZVI) supported on Spondias purpurea seed waste (S-NaOH-NZVI) was performed for the adsorption of phosphate (P) ions from waste waters. The effects of various parameters, such as contact time, pH, concentration, reusability and temperature were studied. The adsorption of phosphate ions has been studied in terms of pseudo-first- and -second-order kinetics, and the Freundlich, and Langmuir isotherms models have also been used to the equilibrium adsorption data. The adsorption kinetics followed the mechanism of the pseudo-second-order equation. The thermodynamic parameters (ΔG, ΔH and ΔS) indicated that the adsorption of phosphate ions were feasible, spontaneous and endothermic at 25-80 °C. No significant loss of activity was observed; confirming that the S-NaOH-NZVI has high stability during the adsorption process even after 12th runs. The suggested adsorbent in this paper was also implemented to remove P from the Persian Gulf water. XRD, FTIR and EDX analysis indicated the presence of Fe3 (PO4)2⋅8H2O (vivianite) on the S-NaOH-NZVI@P surface. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. The hazards of iron loading.

    PubMed

    Weinberg, Eugene D

    2010-11-01

    Excessive or misplaced tissue iron now is recognized to pose a substantial health risk for an extensive array of endocrinological, gastrointestinal, infectious, neoplasmic, neurodegenerative, obstetric, ophthalmic, orthopedic, pulmonary and vascular diseases. Ingested, injected, inhaled and decompartmentalized iron contributes not only to disease, but also to aging and mortality. Iron is dangerous by catalyzing free radical formation and by serving as an essential nutrient for microbial and neoplasmic cell invaders. Our body cells exhibit wide variation in sensitivity to iron toxicity. Efficacy of our iron withholding defense system is modulated by numerous environmental, behavioral and genetic factors. A notable variety of methods for prevention and therapy of iron toxicity are now becoming available.

  6. Hepatic iron deposition does not predict extrahepatic iron loading in mouse models of hereditary hemochromatosis.

    PubMed

    Subramaniam, V Nathan; McDonald, Cameron J; Ostini, Lesa; Lusby, Patricia E; Wockner, Leesa F; Ramm, Grant A; Wallace, Daniel F

    2012-10-01

    Hereditary hemochromatosis is characterized by tissue iron loading and associated organ damage. However, the phenotype can be highly variable. The relationship between iron loading of different organs and the temporal nature of its deposition is still not well understood. We examined the progression of tissue iron loading in three mouse models to advance our understanding of the natural history of iron deposition in hereditary hemochromatosis. Wild-type, Hfe(-/-), Tfr2(-/-), and Hfe(-/-)/Tfr2(-/-) mice were analyzed at 3, 5, 10, 26, and 52 weeks, respectively. Hepatic, splenic, cardiac, and pancreatic iron concentrations were determined. Expression of both iron-regulatory and fibrosis genes was determined by quantitative real-time PCR in livers and hearts of 52-week-old mice. In all models, hepatic iron increased rapidly, plateauing before 10 weeks at different levels, depending on the genotype. Iron deposition in the pancreas and heart occurred after maximal iron loading of the liver was reached and was most marked in the Hfe(-/-)/Tfr2(-/-) mice. Although a significant positive correlation was identified between pancreatic and cardiac iron in all models at 52 weeks, there was no correlation between hepatic and either pancreatic or cardiac iron. There is variability in the timing and extent of tissue iron loading within a genotype, suggesting that hepatic iron levels in hereditary hemochromatosis may not accurately predict the iron content of other organs. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  7. Ineffective erythropoiesis and regulation of iron status in iron loading anaemias.

    PubMed

    Camaschella, Clara; Nai, Antonella

    2016-02-01

    The definition 'iron loading anaemias' encompasses a group of inherited and acquired anaemias characterized by ineffective erythropoiesis, low hepcidin levels, excessive iron absorption and secondary iron overload. Non-transfusion-dependent β-thalassaemia is the paradigmatic example of these conditions that include dyserythropoietic and sideroblastic anaemias and some forms of myelodysplasia. Interrupting the vicious cycle between ineffective erythropoiesis and iron overload may be of therapeutic benefit in all these diseases. Induction of iron restriction by means of transferrin infusions, minihepcidins or manipulation of the hepcidin pathway prevents iron overload, redistributes iron from parenchymal cells to macrophage stores and partially controls anaemia in β-thalassaemic mice. Inhibition of ineffective erythropoiesis by activin ligand traps improves anaemia and iron overload in the same models. Targeting iron loading or ineffective erythropoiesis shows promise in preclinical studies; activin ligand traps are in clinical trials with promising results and may be useful in patients with ineffective erythropoiesis.

  8. Iron loading: a risk factor for Whipple's disease?

    PubMed

    Weinberg, E D

    2001-07-01

    Because of impairment of microbial iron acquisition ability, some potential pathogens can cause disease only in iron loaded hosts. Tropheryma whippelii, the etiologic agent of Whipple's disease, is a possible example. Whipple's disease is non-contagious, occurs mainly in middle-aged white males, and displays many, but not all, of the complications of hereditary haemochromatosis. Tropheryma whippelii is a gastrointestinal commensal that causes disease in persons who have a Th1-Th2 imbalance. Host susceptibility may be exacerbated by iron loading. Consideration should be given to have patients evaluated for levels of interferon-gamma and interleukin-4 as well as for serum ferritin and transferrin iron saturation.

  9. Use of carbonyl iron to induce iron loading in the mussel Mytilus edulis

    SciTech Connect

    Bootsma, N.; Macey, D.J.; Webb, J.; Talbot, V. )

    1990-02-01

    It is now recognized that in organisms such as marine mussels, the prior presence of one metal can be important in determining the ultimate toxicological response to a second challenge by a different metal species. Thus, for example, the presence of iron in the mussel Mytilus edulis profoundly affects the subsequent accumulation of zinc. To determine these synergistic (or indeed antagonistic) effects in an organism such as the mussel, it is important to be able to both load the animal rapidly, and ensure that the metal ends up in a form which is ultimately the same as that found in the animal in the natural environment. Unfortunately, considerable problems have arisen with the form in which iron has been loaded into mussels. Recently, carbonyl iron has been used to induce iron loading in rats. This form of iron is prepared by reacting elemental iron at high temperatures with carbon monoxide to form iron pentacarbonyl. This study was thus undertaken to determine whether carbonyl iron could be used for the rapid non-toxic iron loading of the mussel Mytilus edulis. Such loading could subsequently be used for the investigation of synergistic metal accumulation in mussels, a topic of considerable interest due to their use as marine pollution indicator organisms. Biochemical aspects of this tissue iron loading, including the isolation and characterization of the major metal-binding protein ferritin, have been reported previously.

  10. Iron loading into ferritin by an intracellular ferroxidase.

    PubMed

    Reilly, C A; Aust, S D

    1998-11-01

    An intracellular, membrane-bound enzyme exhibiting both p-phenylenediamine oxidase activity and ferrous iron oxidase activity was isolated with the plasma membrane fraction of horse heart and studied for its ability to load iron into ferritin. The ferroxidase activity of the tissue oxidase was stimulated approximately twofold by horse spleen apoferritin, and the iron was loaded into ferritin. The loading of iron into ferritin by the tissue oxidase was inhibited by anti-horse serum ceruloplasmin antibody. The stoichiometry of iron oxidation and oxygen consumption during iron loading into ferritin by the tissue-derived oxidase and serum ceruloplasmin were 3.6 +/- 0.2 and 3.9 +/- 0.2, respectively. These data provide evidence that an enzyme analogous to ceruloplasmin is present on the plasma membrane of horse heart and that this ferroxidase is capable of catalyzing the loading of iron into ferritin. The implications of these data on the present models for the uptake and storage of iron by cells are discussed.

  11. Localization of Iron in Arabidopsis Seed Requires the Vacuolar Membrane Transporter VIT1

    SciTech Connect

    Kim,S.; Punshon, T.; Lanzirotti, A.; Li, L.; Alonso, J.; Ecker, J.; Kaplan, J.; Guerinot, M.

    2006-01-01

    Iron deficiency is a major human nutritional problem wherever plant-based diets are common. Using synchrotron x-ray fluorescence microtomography to directly visualize iron in Arabidopsis seeds, we show that iron is localized primarily to the provascular strands of the embryo. This localization is completely abolished when the vacuolar iron uptake transporter VIT1 is disrupted. Vacuolar iron storage is also critical for seedling development because vit1-1 seedlings grow poorly when iron is limiting. We have uncovered a fundamental aspect of seed biology that will ultimately aid the development of nutrient-rich seed, benefiting both human health and agricultural productivity.

  12. Physical properties and compression loading behaviour of corn seed

    NASA Astrophysics Data System (ADS)

    Babić, Lj.; Radojèin, M.; Pavkov, I.; Babić, M.; Turan, J.; Zoranović, M.; Stanišić, S.

    2013-03-01

    The aim of this study was to acquire data on the physical properties and compression loading behaviour of seed of six corn hybrid varieties. The mean values of length, width, thickness, geometric diameter, surface area, porosity, single kernel mass, sphericity, bulk and true density, 1 000 kernelmass and coefficient of friction were studied at single level of corn seed moisture content. The calculated secant modulus of elasticity during compressive loading for dent corn was 0.995 times that of the semi-flint type; there were no significant differences in the value of this mechanical property between semi-flint and dent corn varieties. The linear model showed a decreasing tendency of secant modulus of elasticity for all hybrids as the moisture content of seeds increased.

  13. Compression loading behaviour of sunflower seeds and kernels

    NASA Astrophysics Data System (ADS)

    Selvam, Thasaiya A.; Manikantan, Musuvadi R.; Chand, Tarsem; Sharma, Rajiv; Seerangurayar, Thirupathi

    2014-10-01

    The present study was carried out to investigate the compression loading behaviour of five Indian sunflower varieties (NIRMAL-196, NIRMAL-303, CO-2, KBSH-41, and PSH- 996) under four different moisture levels (6-18% d.b). The initial cracking force, mean rupture force, and rupture energy were measured as a function of moisture content. The observed results showed that the initial cracking force decreased linearly with an increase in moisture content for all varieties. The mean rupture force also decreased linearly with an increase in moisture content. However, the rupture energy was found to be increasing linearly for seed and kernel with moisture content. NIRMAL-196 and PSH-996 had maximum and minimum values of all the attributes studied for both seed and kernel, respectively. The values of all the studied attributes were higher for seed than kernel of all the varieties at all moisture levels. There was a significant effect of moisture and variety on compression loading behaviour.

  14. Proanthocyanidins inhibit iron absorption from soybean (Glycine max) seed ferritin in rats with iron deficiency anemia.

    PubMed

    Yun, Shaojun; Zhang, Tuo; Li, Meiliang; Chen, Bin; Zhao, Guanghua

    2011-09-01

    The objective of this study was to evaluate the effect of proanthocyanidins (PAs) on iron uptake from soybean seed ferritin (SSF) crude by rats with iron deficiency anemia (IDA) for the first time. Six groups of Sprague-Dawley (SD) rats (n = 10) were used, which contain (1) SSF crude group; (2) SSF crude + PAs group; (3) PAs group; (4) FeSO(4) group; (5) iron deficiency control group; and (6) control group. The bioavailability of iron was examined by measuring hemoglobin (Hb) concentration value, red blood cell (RBC) numbers, and serum iron stores. After 8 weeks, Hb concentration was almost recovered to the normal level upon feeding SSF crude or FeSO(4) to rats. In contrast, Hb concentration was recovered to less extent when SSF crude plus PAs was used instead of SSF crude alone (P < 0.05). A similar profile was observed with these three sample groups when serum iron and RBC were used as parameters. All rats in PAs group died at the 8th week. Taken together, all these results demonstrated that PAs inhibited iron uptake of rats from SSF, and are toxic for rats with IDA.

  15. Stability and iron oxidation properties of a novel homopolymeric plant ferritin from adzuki bean seeds: a comparative analysis with recombinant soybean seed H-1 chain ferritin.

    PubMed

    Li, Meiliang; Yun, Shaojun; Yang, Xiuli; Zhao, Guanghua

    2013-04-01

    All reported plant ferritins are heteropolymers comprising two different H-type subunits. Whether or not homopolymeric plant ferritin occurs in nature is an open question. A homopolymeric phytoferritin from adzuki bean seeds (ASF) was obtained by various protein purification techniques for the first time, which shares the highest identity (89.6%) with soybean seed H-1 ferritin (rH-1). Therefore, we compared iron oxidation activity and protein stability of ASF with those of rH-1 by stopped-flow combined with light scattering or UV/Vis spectrophotography, SDS- and native- PAGE analyses. Additionally, a new rH-1 variant (S68E) was prepared by site-directed mutagenesis approach to elucidate their difference in protein stability. At high iron loading of protein, the extension peptide (EP) of plant ferritin was involved in iron oxidation, and the EP of ASF exhibited a much stronger iron oxidative activity than that of rH-1. Besides, ASF is more stable than rH-1 during storage, which is ascribed to one amino acid residue, Ser68. ASF exhibits a different mechanism in iron oxidation from rH-1 at high iron loading of protein, and a higher stability than rH-1. These differences are mainly stemmed from their different EP sequences. This work demonstrates that plant cells have evolved the EP of phytoferritin to control iron chemistry and protein stability by exerting a fine tuning of its amino acid sequence. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Tissue Iron Distribution Assessed by MRI in Patients with Iron Loading Anemias

    PubMed Central

    Gutiérrez, Lucía; House, Michael J.; Vasavda, Nisha; Drašar, Emma; Gonzalez-Gascon y Marin, Isabel; Kulasekararaj, Austin G.; St Pierre, Tim G.; Thein, Swee L.

    2015-01-01

    Bone marrow, spleen, liver and kidney proton transverse relaxation rates (R2), together with cardiac R2* from patients with sickle cell disease (SCD), paroxysmal nocturnal hemoglobinuria (PNH) and non-transfusion dependent thalassemia (NTDT) have been compared with a control group. Increased liver and bone marrow R2 values for the three groups of patients in comparison with the controls have been found. SCD and PNH patients also present an increased spleen R2 in comparison with the controls. The simultaneous measurement of R2 values for several tissue types by magnetic resonance imaging (MRI) has allowed the identification of iron distribution patterns in diseases associated with iron imbalance. Preferential liver iron loading is found in the highly transfused SCD patients, while the low transfused ones present a preferential iron loading of the spleen. Similar to the highly transfused SCD group, PNH patients preferentially accumulate iron in the liver. A reduced spleen iron accumulation in comparison with the liver and bone marrow loading has been found in NTDT patients, presumably related to the differential increased intestinal iron absorption. The correlation between serum ferritin and tissue R2 is moderate to good for the liver, spleen and bone marrow in SCD and PNH patients. However, serum ferritin does not correlate with NTDT liver R2, spleen R2 or heart R2*. As opposed to serum ferritin measurements, tissue R2 values are a more direct measurement of each tissue’s iron loading. This kind of determination will allow a better understanding of the different patterns of tissue iron biodistribution in diseases predisposed to tissue iron accumulation. PMID:26406992

  17. Iron overload diseases: the chemical speciation of non-heme iron deposits in iron loaded mammalian tissues

    NASA Astrophysics Data System (ADS)

    St. Pierre, T. G.; Chua-Anusorn, W.; Webb, J.; Macey, D. J.

    2000-07-01

    57Fe Mössbauer spectra of iron overloaded human spleen, rat spleen and rat liver tissue samples at 78 K were found to consist of a quadrupole doublet (major component) with magnetic sextet (minor component with fractional spectral area F s). The distributions of F s for spleen tissue from two different clinically identifiable groups (n = 7 and n = 12) of thalassemic patients were found to be significantly different. The value of F s for dietary-iron loaded rat liver was found to rise significantly with age/duration (up to 24 months) of iron loading.

  18. Structure and Function of Iron-Loaded Synthetic Melanin

    SciTech Connect

    Li, Yiwen; Xie, Yijun; Wang, Zhao; Zang, Nanzhi; Carniato, Fabio; Huang, Yuran; Andolina, Christopher M.; Parent, Lucas R.; Ditri, Treffly B.; Walter, Eric D.; Botta, Mauro; Rinehart, Jeffrey D.; Gianneschi, Nathan C.

    2016-11-22

    We describe a synthetic method for increasing and controlling the iron loading of synthetic melanin nanoparticles and use the resulting materials to perform a systematic quantitative investigation on their structure- property relationship. A comprehensive analysis by magnetometry, electron paramagnetic resonance, and nuclear magnetic relaxation dispersion reveals the complexities of their magnetic behavior and how these intraparticle magnetic interactions manifest in useful material properties such as their performance as MRI contrast agents. This analysis allows predictions of the optimal iron loading through a quantitative modeling of antiferromagnetic coupling that arises from proximal iron ions. This study provides a detailed understanding of this complex class of synthetic biomaterials and gives insight into interactions and structures prevalent in naturally occurring melanins.

  19. Hepcidin response to acute iron intake and chronic iron loading in dysmetabolic iron overload syndrome

    PubMed Central

    Trombini, Paola; Paolini, Valentina; Pelucchi, Sara; Mariani, Raffaella; Nemeth, Elizabeta; Ganz, Tomas; Piperno, Alberto

    2014-01-01

    Background The pathogenesis of dysmetabolic iron overload syndrome (DIOS) is still unclear. Hepcidin is the key regulator of iron homeostasis controlling iron absorption and macrophage release. Aim To investigate hepcidin regulation by iron in DIOS. Methods We analysed urinary hepcidin at baseline and 24 h after a 65 mg oral iron dose in 24 patients at diagnosis and after iron depletion (n=13) and compared data with those previously observed in 23 healthy controls. Serum iron indices, liver histology and metabolic data were available for all patients. Results At diagnosis, hepcidin values were significantly higher than in controls (P<0.001). After iron depletion, hepcidin levels decreased to normal values in all patients. At baseline, a significant response of hepcidin to iron challenge was observed only in the subgroup with lower basal hepcidin concentration (P=0.007). In iron-depleted patients, urinary hepcidin significantly increased after oral iron test (P=0.006). Conclusions Ours findings suggest that in DIOS, the progression of iron accumulation is counteracted by the increase in hepcidin production and progressive reduction of iron absorption, explaining why these patients develop a mild–moderate iron overload that tends to a plateau. PMID:21733088

  20. Omega 3 Chia seed loading as a means of carbohydrate loading.

    PubMed

    Illian, Travis G; Casey, Jason C; Bishop, Phillip A

    2011-01-01

    The purpose of this study was to determine if Omega 3 Chia seed loading is a viable option for enhancing sports performance in events lasting >90 minutes and allow athletes to decrease their dietary intake of sugar while increasing their intake of Omega 3 fatty acids. It has been well documented that a high dietary carbohydrate (CHO) intake for several days before competition is known to increase muscle glycogen stores resulting in performance improvements in events lasting >90 minutes. This study compared performance testing results between 2 different CHO-loading treatments. The traditional CHO-loading treatment served as the control (100% cals from Gatorade). The Omega 3 Chia drink (50% of calories from Greens Plus Omega 3 Chia seeds, 50% Gatorade) served as the Omega 3 Chia loading drink. Both CHO-loading treatments were based on the subject's body weight and were thus isocaloric. Six highly trained male subjects V(O2)max 47.8-84.2 ml · kg(-1); mean (SD) of V(O2)max 70.3 ml · kg(-1) (13.3) performed a 1-hour run at ∼65% of their V(O2)max on a treadmill, followed by a 10k time trial on a track. There were 2 trials in a crossover counterbalanced repeated-measures design with a 2-week washout between testing sessions to allow the participants to recover from the intense exercise and any effects of the treatment. There was no statistical difference (p = 0.83) between Omega 3 Chia loading (mean 10k time = 37 minutes 49 seconds) and CHO loading (mean = 37 minutes 43 seconds). Under our conditions, Omega 3 Chia loading appears a viable option for enhancing performance for endurance events lasting >90 minutes and allows athletes to decrease their dietary intake of sugar while increasing their intake of Omega 3 fatty acids but offered no performance advantages.

  1. QTL for seed iron and zinc concentration and content in a Mesoamerican common bean (Phaseolus vulgaris L.) population.

    PubMed

    Blair, Matthew W; Medina, Juliana I; Astudillo, Carolina; Rengifo, Judith; Beebe, Steve E; Machado, Gloria; Graham, Robin

    2010-10-01

    Iron and zinc deficiencies are human health problems found throughout the world and biofortification is a plant breeding-based strategy to improve the staple crops that could address these dietary constraints. Common bean is an important legume crop with two major genepools that has been the focus of genetic improvement for seed micronutrient levels. The objective of this study was to evaluate the inheritance of seed iron and zinc concentrations and contents in an intra-genepool Mesoamerican × Mesoamerican recombinant inbred line population grown over three sites in Colombia and to identify quantitative trait loci (QTL) for each mineral. The population had 110 lines and was derived from a high-seed iron and zinc climbing bean genotype (G14519) crossed with a low-mineral Carioca-type, prostrate bush bean genotype (G4825). The genetic map for QTL analysis was created from SSR and RAPD markers covering all 11 chromosomes of the common bean genome. A set of across-site, overlapping iron and zinc QTL was discovered on linkage group b06 suggesting a possibly pleiotropic locus and common physiology for mineral uptake or loading. Other QTL for mineral concentration or content were found on linkage groups b02, b03, b04, b07, b08 and b11 and together with the b06 cluster were mostly novel compared to loci found in previous studies of the Andean genepool or inter-genepool crosses. The discovery of an important new locus for seed iron and zinc concentrations may facilitate crop improvement and biofortification using the high-mineral genotype especially within the Mesoamerican genepool.

  2. Persistence of iron limitation in the western subarctic Pacific SEEDS II mesoscale fertilization experiment

    NASA Astrophysics Data System (ADS)

    Wells, Mark L.; Trick, Charles G.; Cochlan, William P.; Beall, Ben

    2009-12-01

    The cumulative evidence from more than a dozen mesoscale iron-enrichment studies in high nitrate low chlorophyll (HNLC) waters demonstrates that iron limitation is widespread and very likely affects atmospheric carbon dioxide and thus global climate. However, the responses of microphytoplankton (>20 μm), predominantly diatoms, vary greatly among these mesoscale experiments even though similar amounts of iron were added, making it difficult to quantitatively incorporate iron effects into global climate models. Nowhere is this difference more dramatic than between the massive bloom observed during Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study (SEEDS) I and the order of magnitude smaller ecosystem response in SEEDS II; two mesocale experiments performed in the same HNLC region of the western subarctic Pacific in different years. Deckboard incubation experiments initiated during the early, middle, and late stages of the 32-day SEEDS II experiment show that while the two iron infusions increased phytoplankton growth, diatoms remained significantly limited by iron availability, despite total dissolved Fe concentrations in the patch being well above the diffusion-limited threshold for rapid diatom growth. This iron limitation was apparent <6 days after the initial iron infusion and was not alleviated by the second, smaller iron infusion. In contrast, smaller phytoplankton (<20 μm) showed a more restricted response to further iron amendments, indicating that their iron nutrition was near optimal. Iron complexed to desferrioximine B, a commonly available siderophore produced by at least one marine bacterium, was poorly available to diatoms throughout the patch evolution, indicating that these diatoms lacked the ability to induce high-affinity iron uptake systems. These results suggest that the strong organic complexation of Fe(III) observed in the SEEDS II-fertilized patch was not compatible with rapid diatom growth. In contrast, iron associated with

  3. Effect of green tea on iron status and oxidative stress in iron-loaded rats.

    PubMed

    Ounjaijean, S; Thephinlap, C; Khansuwan, U; Phisalapong, C; Fucharoen, S; Porter, J B; Srichairatanakool, S

    2008-07-01

    Plasma non-transferrin bound iron (NTBI) is potentially toxic and contributes to the generation of reactive oxygen species (ROS), consequently leading to tissue damage and organ dysfunction. Iron chelators and antioxidants are used for treatment of thalassemia patients. Green tea (GT) contains catechins derivatives that have many biological activities. The purpose of this study was to investigate the iron-chelating and free-radical scavenging capacities of green tea extract in vivo. Rats were injected ip with ferric citrate together with orally administered GT extract (GTE) for 4 months. Blood was collected monthly for measurement of iron overload and oxidative stress indicators. Plasma iron (PI) and total iron-binding capacity (TIBC) were quantified using bathophenanthroline method. Plasma NTBI was assayed with NTA chelation/HPLC. Plasma malonyldialdehyde (MDA) was determined by using the TBARS method. Erythrocyte oxidative stress was assessed using flow cytometry. Levels of PI, TIBC, NTBI and MDA, and erythrocyte ROS increased in the iron-loaded rats. Intervention with GT extract markedly decreased the PI and TIBC concentrations. It also lowered the transferrin saturation and effectively inhibited formation of NTBI. It also decreased the levels of erythrocyte ROS in week 4, 12 and 16. Therefore, green tea extract can decrease iron in plasma as well as eliminate lipid peroxidation in plasma, and destroy formation of erythrocyte ROS in the rats challenged with iron. The bifunctional effects could be beneficial in alleviating the iron and oxidative stress toxicity. In prospective, these GTE activities should be further examined in thalassemic animals or humans.

  4. Iron and ferritin accumulate in separate cellular locations in Phaseolus seeds

    PubMed Central

    2010-01-01

    Background Iron is an important micronutrient for all living organisms. Almost 25% of the world population is affected by iron deficiency, a leading cause of anemia. In plants, iron deficiency leads to chlorosis and reduced yield. Both animals and plants may suffer from iron deficiency when their diet or environment lacks bioavailable iron. A sustainable way to reduce iron malnutrition in humans is to develop staple crops with increased content of bioavailable iron. Knowledge of where and how iron accumulates in seeds of crop plants will increase the understanding of plant iron metabolism and will assist in the production of staples with increased bioavailable iron. Results Here we reveal the distribution of iron in seeds of three Phaseolus species including thirteen genotypes of P. vulgaris, P. coccineus, and P. lunatus. We showed that high concentrations of iron accumulate in cells surrounding the provascular tissue of P. vulgaris and P. coccineus seeds. Using the Perls' Prussian blue method, we were able to detect iron in the cytoplasm of epidermal cells, cells near the epidermis, and cells surrounding the provascular tissue. In contrast, the protein ferritin that has been suggested as the major iron storage protein in legumes was only detected in the amyloplasts of the seed embryo. Using the non-destructive micro-PIXE (Particle Induced X-ray Emission) technique we show that the tissue in the proximity of the provascular bundles holds up to 500 μg g-1 of iron, depending on the genotype. In contrast to P. vulgaris and P. coccineus, we did not observe iron accumulation in the cells surrounding the provascular tissues of P. lunatus cotyledons. A novel iron-rich genotype, NUA35, with a high concentration of iron both in the seed coat and cotyledons was bred from a cross between an Andean and a Mesoamerican genotype. Conclusions The presented results emphasize the importance of complementing research in model organisms with analysis in crop plants and they suggest

  5. Behavior of particulate materials during iron fertilization experiments in the Western Subarctic Pacific (SEEDS and SEEDS II)

    NASA Astrophysics Data System (ADS)

    Aramaki, Takafumi; Nojiri, Yukihiro; Imai, Keiri

    2009-12-01

    During two mesoscale iron-enrichment studies in the northwestern subarctic Pacific (SEEDS in 2001 summer and SEEDS II in 2004 summer), particulate materials from the iron-induced phytoplankton bloom in the upper water column were monitored to analyze the export processes beneath the upper mixed layer, mainly with drifting sediment traps. We could not observe the total downward export process of the high accumulation of particulate organic carbon from the mixed layer induced by the large diatom bloom of SEEDS [e.g., Tsuda, A., Takeda, S., Saito, H., Nishioka, J., Nojiri, Y., Kudo, I., Kiyosawa, H., Shiomoto, A., Imai, K., Ono, T., Shimamoto, A., Tsumune, D., Yoshimura, T., Aono, T., Hinuma, A., Kinugasa, M., Suzuki, K., Sohrin, Y., Noiri, Y., Tani, H., Deguchi, Y., Tsurushima, N., Ogawa, H., Fukami, K., Kuma, K., Saino, T., 2003. A mesoscale iron enrichment in the western subarctic Pacific induces large centric diatom bloom. Science 300, 958-961] because the 2-week observation period was too short to examine the decline phase of the bloom. In contrast, in SEEDS II, the particulate organic carbon and particulate organic nitrogen were accumulated 123 and 23 mmol m -2, respectively, in the mixed layer until day-15 (days from iron-enrichment), and then ca. 90% were removed from the mixed layer by day-25. The sediment traps at 40 m depth between day-15 and day-25 accounted for at least more than 35% of these particles. There was no large variation in chemical composition in settling particles above 100 m depth throughout the experimental periods both in SEEDS and SEEDS II. The content of biogenic opal remained more than 50% of all settling particles during SEEDS, while the content of biogenic calcium carbonate was relatively high, with a low biogenic opal content of consistently less than 30% during SEEDS II. These results suggest that high standing stock of seed population of diatoms before the iron fertilization, indicated by low C/Si ratio of particulate matter, is an

  6. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    DOE PAGES

    Yang, Haibing; Wei, Hui; Ma, Guojie; ...

    2016-04-07

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusionmore » polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. In conclusion, CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.« less

  7. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice.

    PubMed

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S Charlotte; Carpita, Nicholas C; Makowski, Lee; Himmel, Michael E; Tucker, Melvin P; McCann, Maureen C; Murphy, Angus S; Peer, Wendy A

    2016-10-01

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Zinc and selenium accumulation and their effect on iron bioavailability in common bean seeds.

    PubMed

    de Figueiredo, Marislaine A; Boldrin, Paulo F; Hart, Jonathan J; de Andrade, Messias J B; Guilherme, Luiz R G; Glahn, Raymond P; Li, Li

    2017-02-01

    Common beans (Phaseolus vulgaris) are the most important legume crops. They represent a major source of micronutrients and a target for essential trace mineral enhancement (i.e. biofortification). To investigate mineral accumulation during seed maturation and to examine whether it is possible to biofortify seeds with multi-micronutrients without affecting mineral bioavailability, three common bean cultivars were treated independently with zinc (Zn) and selenium (Se), the two critical micronutrients that can be effectively enhanced via fertilization. The seed mineral concentrations during seed maturation and the seed Fe bioavailability were analyzed. Common bean seeds were found to respond positively to Zn and Se treatments in accumulating these micronutrients. While the seed pods showed a decrease in Zn and Se along with Fe content during pod development, the seeds maintained relatively constant mineral concentrations during seed maturation. Selenium treatment had minimal effect on the seed accumulation of phytic acid and polyphenols, the compounds affecting Fe bioavailability. Zinc treatment reduced phytic acid level, but did not dramatically affect the concentrations of total polyphenols. Iron bioavailability was found not to be greatly affected in seeds biofortified with Se and Zn. In contrast, the inhibitory polyphenol compounds in the black bean profoundly reduced Fe bioavailability. These results provide valuable information for Se and Zn enhancement in common bean seeds and suggest the possibility to biofortify with these essential nutrients without greatly affecting mineral bioavailability to increase the food quality of common bean seeds. Published by Elsevier Masson SAS.

  9. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L.) and association with seed iron accumulation QTL

    PubMed Central

    2010-01-01

    Background Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L.) take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 × G19833), to identify quantitative trait loci (QTL) for this trait, and to assess possible associations with seed iron levels. Results The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III)-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient) were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe) on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe) on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Conclusions Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO) homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity under iron limited

  10. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L.) and association with seed iron accumulation QTL.

    PubMed

    Blair, Matthew W; Knewtson, Sharon Jb; Astudillo, Carolina; Li, Chee-Ming; Fernandez, Andrea C; Grusak, Michael A

    2010-10-05

    Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L.) take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 x G19833), to identify quantitative trait loci (QTL) for this trait, and to assess possible associations with seed iron levels. The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III)-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient) were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe) on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe) on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO) homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity under iron limited conditions may be useful in

  11. Effect of Dietary Iron Loading on Recognition Memory in Growing Rats

    PubMed Central

    Han, Murui; Kim, Jonghan

    2015-01-01

    While nutritional and neurobehavioral problems are associated with both iron deficiency during growth and overload in the elderly, the effect of iron loading in growing ages on neurobehavioral performance has not been fully explored. To characterize the role of dietary iron loading in memory function in the young, weanling rats were fed iron-loading diet (10,000 mg iron/kg diet) or iron-adequate control diet (50 mg/kg) for one month, during which a battery of behavioral tests were conducted. Iron-loaded rats displayed elevated non-heme iron levels in serum and liver, indicating a condition of systemic iron overload. In the brain, non-heme iron was elevated in the prefrontal cortex of iron-loaded rats compared with controls, whereas there was no difference in iron content in other brain regions between the two diet groups. While iron loading did not alter motor coordination or anxiety-like behavior, iron-loaded rats exhibited a better recognition memory, as represented by an increased novel object recognition index (22% increase from the reference value) than control rats (12% increase; P=0.047). Western blot analysis showed an up-regulation of dopamine receptor 1 in the prefrontal cortex from iron-loaded rats (142% increase; P=0.002). Furthermore, levels of glutamate receptors (both NMDA and AMPA) and nicotinic acetylcholine receptor (nAChR) were significantly elevated in the prefrontal cortex of iron-loaded rats (62% increase in NR1; 70% increase in Glu1A; 115% increase in nAChR). Dietary iron loading also increased the expression of NMDA receptors and nAChR in the hippocampus. These results support the idea that iron is essential for learning and memory and further reveal that iron supplementation during developmental and rapidly growing periods of life improves memory performance. Our investigation also demonstrates that both cholinergic and glutamatergic neurotransmission pathways are regulated by dietary iron and provides a molecular basis for the role of iron

  12. Microstructural fingerprints of phase transitions in shock-loaded iron

    NASA Astrophysics Data System (ADS)

    Wang, S. J.; Sui, M. L.; Chen, Y. T.; Lu, Q. H.; Ma, E.; Pei, X. Y.; Li, Q. Z.; Hu, H. B.

    2013-01-01

    The complex structural transformation in crystals under static pressure or shock loading has been a subject of long-standing interest to materials scientists and physicists. The polymorphic transformation is of particular importance for iron (Fe), due to its technological and sociological significance in the development of human civilization, as well as its prominent presence in the earth's core. The martensitic transformation α-->ɛ (bcc-->hcp) in iron under shock-loading, due to its reversible and transient nature, requires non-trivial detective work to uncover its occurrence. Here we reveal refined microstructural fingerprints, needle-like colonies and three sets of {112}<111> twins with a threefold symmetry, with tell-tale features that are indicative of two sequential martensitic transformations in the reversible α-->ɛ phase transition, even though no ɛ is retained in the post-shock samples. The signature orientation relationships are consistent with previously-proposed transformation mechanisms, and the unique microstructural fingerprints enable a quantitative assessment of the volume fraction transformed.

  13. Physical behaviors of the iron-fertilized patch in SEEDS II

    NASA Astrophysics Data System (ADS)

    Tsumune, Daisuke; Nishioka, Jun; Shimamoto, Akifumi; Watanabe, Yutaka W.; Aramaki, Takafumi; Nojiri, Yukihiro; Takeda, Shigenobu; Tsuda, Atsushi; Tsubono, Takaki

    2009-12-01

    Sulfur hexafluoride (SF 6) tracer release experiments were carried out to trace the iron-fertilized water mass during the iron-fertilization experiments in the western North Pacific of Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study II (SEEDS II) in 2004. A solution of Fe and SF 6 tracer was released into the surface mixed layer over an 8×8 km area, and the fertilized patch was traced by onboard SF 6 analysis for 12 days during each experiment. A Lagrangian frame of reference was maintained by the use of a drogued GPS buoy released at the center of the patch to reduce the advection effect on observations. The patch moved along the contour of sea-surface height (SSH) of a clockwise mesoscale eddy for 4 days after release. Then strong easterly winds dragged the patch across the contour of SSH. The patch behavior was affected by both the mesoscale eddy and surface winds. Apparent horizontal diffusivities were determined by the change of the distribution of SF 6 concentrations. The averaged apparent horizontal diffusivity was about 49 m 2 s -1 during SEEDS II. It was larger than the one in SEEDS. Mixed-layer depth (MLD) was 8.5-18 m during SEEDS, and 12-33 m during SEEDS II. The larger horizontal diffusivity and deeper MLD in SEEDS II were disadvantages to maintain a high iron concentration in the surface layer compared to SEEDS. Temporal change of the MLD corresponded to the temporal change of chlorophyll- a concentration. Temporal change in the surface MLD was also important for the response of phytoplankton by iron fertilization.

  14. Can an increase in leaf iron reductase activity enhance seed iron accumulation in soybean?

    USDA-ARS?s Scientific Manuscript database

    Iron is an important micronutrient for human nutrition, with plant foods providing a significant amount of dietary iron in certain population groups, and in some cases, providing the sole source of dietary iron. Because iron deficiency is unfortunately common in many human populations, we have been...

  15. Synthesis of iron nanoparticles via chemical reduction with palladium ion seeds.

    PubMed

    Huang, Kuo-Cheng; Ehrman, Sheryl H

    2007-01-30

    We report on the synthesis of highly monodisperse iron nanoparticles, using a chemical reduction method. Iron nanoparticles with an average diameter of 6 nm and a geometric standard deviation of 1.3 were synthesized at a pH of 9.50 from ferric chloride precursor with sodium borohydride as the reducing agent, polyacrylic acid as the dispersing agent, and palladium ions as seeds for iron nanoparticle nucleation. The resulting nanoparticles were ferromagnetic at 5 K and superparamagnetic at 350 K. The dispersing agent polyacrylic acid (PAA) was shown to prevent iron nanoparticles and possibly palladium clusters from aggregating; in the absence of PAA, only aggregated iron nanoparticles were obtained. The addition of palladium ions decreased the diameter of iron nanoparticles presumably by providing sites for heterogeneous nucleation onto palladium clusters. In the absence of palladium ions, the mean diameter of iron nanoparticles was approximately 110 nm and the standard deviation increased to 2.0. The pH of the solution also was found to have a significant effect on the particle diameter, likely by affecting PAA ionization and altering the conformation of the polymer chains. At lower pH (8.75), the PAA is less ionized and its ability to disperse palladium clusters is reduced, so the number of palladium seeds decreases. Therefore, the resulting iron nanoparticles were larger, 59 nm in diameter, versus 6 nm for nanoparticles formed at a pH of 9.50.

  16. Significant glial alterations in response to iron loading in a novel organotypic hippocampal slice culture model

    PubMed Central

    Healy, Sinead; McMahon, Jill; Owens, Peter; FitzGerald, Una

    2016-01-01

    Aberrant iron deposition in the brain is associated with neurodegenerative disorders including Multiple Sclerosis, Alzheimer’s disease and Parkinson’s disease. To study the collective response to iron loading, we have used hippocampal organotypic slices as a platform to develop a novel ex vivo model of iron accumulation. We demonstrated differential uptake and toxicity of iron after 12 h exposure to 10 μM ferrous ammonium sulphate, ferric citrate or ferrocene. Having established the supremacy of ferrocene in this model, the cultures were then loaded with 0.1–100 μM ferrocene for 12 h. One μM ferrocene exposure produced the maximal 1.6-fold increase in iron compared with vehicle. This was accompanied by a 1.4-fold increase in ferritin transcripts and mild toxicity. Using dual-immunohistochemistry, we detected ferritin in oligodendrocytes, microglia, but rarely in astrocytes and never in neurons in iron-loaded slice cultures. Moreover, iron loading led to a 15% loss of olig2-positive cells and a 16% increase in number and greater activation of microglia compared with vehicle. However, there was no appreciable effect of iron loading on astrocytes. In what we believe is a significant advance on traditional mono- or dual-cultures, our novel ex vivo slice-culture model allows characterization of the collective response of brain cells to iron-loading. PMID:27808258

  17. Does multiple seed loading in Blue Jays result in selective dispersal of smaller acorns?

    PubMed

    Bartlow, Andrew W; Kachmar, Michael; Lichti, Nathanael; Swihart, Robert K; Stratford, Jeffrey A; Steele, Michael A

    2011-09-01

    Studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds, potentially increasing seedling establishment in larger-seeded plants. Size-biased dispersal is evident in many oaks (Quercus) and is true both across and within species. Here, we predict that intraspecifc variation in seed size also influences acorn dispersal by the Blue Jay (Cyanocitta cristata Linnaeus), but in an opposite manner. Blue Jays are gape-limited and selectively disperse smaller acorn species (e.g. pin oaks [Quercus palustris Münchh]), but often carry several acorns in their crop during a single dispersal event. We predict that jays foraging on smaller acorns will load more seeds per trip and disperse seeds to greater distances than when single acorns are carried in the bill. To test this, we presented free-ranging Blue Jays with pin oak acorns of different sizes over a 2-year period. In each of 16 experimental trials, we monitored the birds at a feeding station with remote cameras and determined the number of acorns removed and the distance acorns were dispersed when cached. Jays were significantly more likely to engage in multiple seed loading with smaller seeds in both years of the study. During the second year, these smaller acorns were dispersed farther than larger acorns, and during the first year, larger acorns were dispersed farther, revealing an inconsistent response to seed size during our study. We suggest that in some circumstances, multiple seed loading by Blue Jays may favor dispersal in some plant species. © 2011 ISZS, Blackwell Publishing and IOZ/CAS.

  18. Changes in the characteristics and distribution of ferritin in iron-loaded cell cultures.

    PubMed Central

    Hoy, T G; Jacobs, A

    1981-01-01

    When Chang liver cells are grown in an iron-rich medium for up to 20 weeks, iron loading up to 50 times the normal cellular iron content may be obtained, although ferritin increases only to about 10 times normal. Ferritin has been isolated from such cells, and the isoferritin pattern found on elution from DEAE-Sephadex A-50 by increasing chloride concentrations has been used as a basis for studying changes in the properties of ferritin under conditions of cellular loading. A consistent shift of peak ferritin-elution position to higher chloride concentrations (lower pI) occurs when cells are loaded with ferric nitrilotriacetate for increasing lengths of time. A change in immunoreactivity also takes place on loading, the ratio of ferritin reacting with heart and spleen ferritin antibodies increasing at any particular value of pI. Cells were pulse-labelled with [59Fe]ferric nitrilotriacetate and [3H]leucine followed by non-radioactive iron in the same form. During the 72 h after the synthesis of new protein and its incorporation of iron, there is a slight acid shift in its isoelectric point. This effect is seen in both normal and loaded cells, with the whole spectrum being shifted towards lower pI in the loaded state. These findings suggest that the shift to more acidic ferritins on iron loading and the associated changes in antigenicity may be unrelated to subunit composition. PMID:7305937

  19. The effect of shock loading on the survival of plant seeds

    NASA Astrophysics Data System (ADS)

    Leighs, J. A.; Hazell, P. J.; Appleby-Thomas, G. J.

    2012-07-01

    Meteorite and asteroid impacts into planet Earth seem rare but over the lifetime of our planet have been relatively frequent. Such collisions (involving very large impactors) have been blamed for mass extinctions during Earth’s history. It has also been postulated that impactors could carry life with them throughout the universe and seed our planet. This is the basis of the theory of panspermia (‘life everywhere’) and suggests that life could be spread throughout the universe by ‘piggy-backing’ on inter-planetary bodies, e.g. asteroids, which then collide with other planets, thus seeding them with life. The shock behaviour of organic matter has an important role to play in helping to inform the feasibility of such theories. An example of a model carrier for life in seeding mechanisms is the plant seed. Here we present the development of an experimental technique in which plant seed samples are shock-loaded and their viability subsequently assessed post-shock. This technique was tested on Lepidium sativum (cress) seed samples. Experimentally, shocked seeds showed positive viability in all tests performed until shocked with a maximum peak shock pressure of ca. 0.8 GPa. These results suggest it is unlikely that the plant seeds tested would be able to survive the extreme conditions on an asteroid during impact, but may be able to survive shock waves that would be generated from such collisions when existing on a planetary body.

  20. Biosynthesis, Characterization, and Biological Activities of Iron Nanoparticles using Sesamum indicum Seeds Extract

    PubMed Central

    Bano, Farah; Baber, Muhammad; Ali, Amjad; Shah, Ziaullah; Muhammad, Syed Aun

    2017-01-01

    Background: Iron nanoparticles (FeNPs) have got many biomedical and health applications because of biocompatible and nontoxic nature to humans. Objective: To synthesize the FeNPs using natural sources. Materials and Methods: In this study, simple and economical procedure was adopted for FeNPs synthesis. Sesame seeds were processed to obtain seed extract as a biological material for FeNPs production. FeNPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopic. Results: The average diameter of these FeNPs was 99 nm. These nanoparticles showed significant anti-typhoid activity (30 mm zone of inhibition) as compared to ciprofloxacin (32 mm) as standard. Furthermore, in vitro alpha-amylase inhibitory assay also showed moderate antidiabetic activity with more than 50% inhibition. Conclusion: This study would be helpful in understanding of nanoparticles synthesis from natural sources and ultimately will be used as potential alternative therapeutic agents. SUMMARY Iron nanoparticles (FeNPs) were synthesized by Sesamum indicum seedsFeNPs were characterized by scanning electron microscope with average diameter of 99 nmThese FeNPs are effective against Salmonella typhi, a causative agent of typhoidThese FeNPs can be used as antidiabetic agent. Abbreviations used: FeNPs: Iron Nano Particles; SEM: Scanning Electron Microscopy; MIC: Minimum Inhibitory Concentration; S. indicum: Sesamum Indicum. PMID:28479723

  1. Impact of daily consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels (Cucurbita pepo) on serum iron in adult women.

    PubMed

    Naghii, Mohammad Reza; Mofid, Mahmood

    2007-01-01

    Iron deficiency, anemia, is the most prevalent nutritional problem in the world today. The objective of this study was to consider the effectiveness of consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels as two sources of dietary iron on status of iron nutrition and response of hematological characteristics of women at reproductive ages. Eight healthy female, single or non pregnant subjects, aged 20-37 y consumed 30 g of iron fortified ready-to-eat cereal (providing 7.1 mg iron/day) plus 30 g of pumpkin seed kernels (providing 4.0 mg iron/day) for four weeks. Blood samples collected on the day 20 of menstrual cycles before and after consumption and indices of iron status such as reticulocyte count, hemoglobin (Hb), hematocrit (Ht), serum ferritin, iron, total iron-binding capacity (TIBC), transferrin and transferrin saturation percent were determined. Better response for iron status was observed after consumption period. The statistical analysis showed a significant difference between the pre and post consumption phase for higher serum iron (60 +/- 22 vs. 85 +/- 23 ug/dl), higher transferrin saturation percent (16.8 +/- 8.0 vs. 25.6 +/- 9.0%), and lower TIBC (367 +/- 31 vs. 339 +/- 31 ug/dl). All individuals had higher serum iron after consumption. A significant positive correlation (r=0.981, p=0.000) between the differences in serum iron levels and differences in transferrin saturation percentages and a significant negative correlation (r=-0.916, p<0.001) between the differences in serum iron levels and differences in TIBC was found, as well. Fortified foods contribute to maintaining optimal nutritional status and minimizing the likelihood of iron insufficiencies and use of fortified ready-to-eat cereals is a common strategy. The results showed that adding another food source of iron such as pumpkin seed kernels improves the iron status. Additional and longer studies using these two food products are recommended to further determine the

  2. Curcumin reduces the toxic effects of iron loading in rat liver epithelial cells

    PubMed Central

    Messner, Donald J.; Sivam, Gowsala; Kowdley, Kris V.

    2008-01-01

    Background/aims Iron overload can cause liver toxicity and increase the risk of liver failure or hepatocellular carcinoma in humans. Curcumin (diferuloylmethane), a component of the food spice turmeric, has antioxidant, iron binding, and hepatoprotective properties. The aim of this study was to quantify its effects on iron overload and resulting downstream toxic effects in cultured T51B rat liver epithelial cells. Methods T51B cells were loaded with ferric ammonium citrate (FAC) with or without the iron delivery agent 8-hydroxyquinoline. Cytotoxicity was measured by MTT assay. Iron uptake and iron bioavailability were documented by chemical assay, quench of calcein fluorescence, and ferritin induction. Reactive oxygen species (ROS) were measured by fluorescence assay using 2′,7′-dichlorodihydrofluorescein diacetate. Oxidative stress signaling to jnk, c-jun, and p38 was measured by western blot with phospho-specific antibodies. Results Curcumin bound iron, but did not block iron uptake or bioavailability in T51B cells given FAC. However, it reduced cytotoxicity, blocked generation of ROS, and eliminated signaling to cellular stress pathways caused by iron. Inhibition was observed over a wide range of FAC concentrations (50 – 500 μM), with an apparent IC50 in all cases between 5 and 10 μM curcumin. In contrast, desferoxamine blocked both iron uptake and toxic effects of iron at concentrations that depended on the FAC concentration. Effects of curcumin also differed from those of α-tocopherol, which did not bind iron and was less effective at blocking iron-stimulated ROS generation. Conclusions Curcumin reduced iron-dependent oxidative stress and iron toxicity in T51B cells without blocking iron uptake. PMID:18492020

  3. Migration load in plants: role of pollen and seed dispersal in heterogeneous landscapes.

    PubMed

    Lopez, S; Rousset, F; Shaw, F H; Shaw, R G; Ronce, O

    2008-01-01

    Evolution of local adaptation depends critically on the level of gene flow, which, in plants, can be due to either pollen or seed dispersal. Using analytical predictions and individual-centred simulations, we investigate the specific influence of seed and pollen dispersal on local adaptation in plant populations growing in patchy heterogeneous landscapes. We study the evolution of a polygenic trait subject to stabilizing selection within populations, but divergent selection between populations. Deviations from linkage equilibrium and Hardy-Weinberg equilibrium make different contributions to genotypic variance depending on the dispersal mode. Local genotypic variance, differentiation between populations and genetic load vary with the rate of gene flow but are similar for seed and pollen dispersal, unless the landscape is very heterogeneous. In this case, genetic load is higher in the case of pollen dispersal, which appears to be due to differences in the distribution of genotypic values before selection.

  4. The behavior of iron under ultrafast shock loading driven by a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Ashitkov, S. I.; Zhakhovsky, V. V.; Inogamov, N. A.; Komarov, P. S.; Agranat, M. B.; Kanel, G. I.

    2017-01-01

    The results of experimental and theoretical investigations of shock-wave propagation in bcc iron under ultra-short loads driven by femtosecond laser pulses are presented. Chirped pulse interferometry was used for continuous diagnostics of movement in a picosecond range of the rear-side surface of thin iron films. The evolution of ultra-short elastic-plastic shock waves in samples with different thicknesses and purity has been studied. The obtained HEL and spall strength are close to ultimate values of shear and tensile stresses. Response of single-crystal iron to ultra-short shock loading/unloading was also explored in micron-sized films by molecular dynamics simulations. The experimental and simulation results on shock-induced elastic-plastic transformation and phase transition from bcc to hcp iron in a picosecond range of loading are discussed.

  5. The behavior of iron under ultrafast shock loading driven by a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Ashitkov, Sergey; Zhakhovsky, Vasily; Komarov, Pavel; Inogamov, Nail; Agranat, Mikhail; Kanel, Gennady

    2015-06-01

    The results of experimental and theoretical investigations of shock-wave propagation in bcc iron under ultra-short loads driven by femtosecond laser pulses are presented. Chirped pulse interferometry was used for continuous diagnostics of movement in a picosecond range of the rear-side surface of thin iron films. The evolution of ultra-short elastic-plastic shock waves in samples with different thicknesses and purity has been studied. The obtained HEL and spall strength are close to ultimate values of shear and tensile stresses. Response of single-crystal iron to ultra-short shock loading/unloading was also explored in micron-sized films by molecular dynamics simulations. The experimental and simulation results on shock-induced elastic-plastic transformation and phase transition from bcc to hcp iron in a picosecond range of loading are discussed.

  6. The knockdown of OsVIT2 and MIT affects iron localization in rice seed.

    PubMed

    Bashir, Khurram; Takahashi, Ryuichi; Akhtar, Shamim; Ishimaru, Yasuhiro; Nakanishi, Hiromi; Nishizawa, Naoko K

    2013-11-20

    The mechanism of iron (Fe) uptake in plants has been extensively characterized, but little is known about how Fe transport to different subcellular compartments affects Fe localization in rice seed. Here, we discuss the characterization of a rice vacuolar Fe transporter 2 (OsVIT2) T-DNA insertion line (osvit2) and report that the knockdown of OsVIT2 and mitochondrial Fe transporter (MIT) expression affects seed Fe localization. osvit2 plants accumulated less Fe in their shoots when grown under normal or excess Fe conditions, while the accumulation of Fe was comparable to that in wild-type (WT) plants under Fe-deficient conditions. The accumulation of zinc, copper, and manganese also changed significantly in the shoots of osvit2 plants. The growth of osvit2 plants was also slow compared to that of WT plants. The concentration of Fe increased in osvit2 polished seeds. Previously, we reported that the expression of OsVIT2 was higher in MIT knockdown (mit-2) plants, and in this study, the accumulation of Fe in mit-2 seeds decreased significantly. These results suggest that vacuolar Fe trafficking is important for plant Fe homeostasis and distribution, especially in plants grown in the presence of excess Fe. Moreover, changes in the expression of OsVIT2 and MIT affect the concentration and localization of metals in brown rice as well as in polished rice seeds.

  7. CHOP-mediated hepcidin suppression modulates hepatic iron load.

    PubMed

    Mueller, Katrin; Sunami, Yoshiaki; Stuetzle, Michael; Guldiken, Nurdan; Kucukoglu, Ozlem; Mueller, Sebastian; Kulaksiz, Hasan; Schwarz, Peggy; Strnad, Pavel

    2013-12-01

    The liver is the central regulator of iron metabolism and accordingly, chronic liver diseases often lead to systemic iron overload due to diminished expression of the iron-regulatory hormone hepcidin. To study the largely unknown regulation of iron metabolism in the context of hepatic disease, we used two established models of chronic liver injury, ie repeated carbon tetrachloride (CCl(4)) or thioacetamide (TAA) injections. To determine the impact of CCAAT/enhancer-binding protein (C/EBP)-homologous protein (CHOP) on hepcidin production, the effect of a single TAA injection was determined in wild-type and CHOP knockout mice. Furthermore, CHOP and hepcidin expression was assessed in control subjects and patients with alcoholic liver disease. Both chronic injury models developed a distinct iron overload in macrophages. TAA-, but not CCl(4) - injected mice displayed additional iron accumulation in hepatocytes, resulting in a significant hepatic and systemic iron overload which was due to suppressed hepcidin levels. C/EBPα signalling, a known hepcidin inducer, was markedly inhibited in TAA mice, due to lower C/EBPα levels and overexpression of CHOP, a C/EBPα inhibitor. A single TAA injection resulted in a long-lasting (> 6 days) suppression of hepcidin levels and CHOP knockouts (compared to wild-types) displayed significantly attenuated hepcidin down-regulation in response to acute TAA administration. CHOP mRNA levels increased 5-fold in alcoholic liver disease patients versus controls (p < 0.005) and negatively correlated with hepcidin expression. Our results establish CHOP as an important regulator of hepatic hepcidin expression in chronic liver disease. The differences in iron metabolism between the two widely used fibrosis models likely reflect the differential regulation of hepcidin expression in human liver disease.

  8. Iron, lactoferrin and iron regulatory protein activity in the synovium; relative importance of iron loading and the inflammatory response

    PubMed Central

    Guillen, C; McInnes, I; Kruger, H; Brock, J

    1998-01-01

    OBJECTIVES—To determine the ability of lactoferrin in rheumatoid arthritis (RA) synovial fluid to bind "free" iron, and to study the regulatory mechanisms therein that control iron homeostasis.
METHODS—"Free" iron was determined by the bleomycin assay and lactoferrin concentrations by enzyme linked immunosorbent assay. The activities of iron regulatory protein (IRP) and NF-κB in synovial fluid cells were assayed by mobility shift assay.
RESULTS—30% of synovial fluids contained "free" iron and in these, lactoferrin concentrations were significantly lower than in those with no "free" iron (p<0.01). Addition of exogenous lactoferrin consistently reduced the amount of "free" iron in positive synovial fluids. IRP activity in synovial cells did not correlate with synovial fluid iron concentrations but did correlate with NF-κB activation and with serum C reactive protein.
CONCLUSION—Lactoferrin may prevent iron mediated tissue damage in RA by reducing "free" synovial iron concentration when inflammatory stimuli have disregulated IRP mediated iron homeostasis.

 Keywords: lactoferrin; rheumatoid arthritis; inflammation PMID:9741316

  9. Glucose metabolism in the Belgrade rat, a model of iron-loading anemia.

    PubMed

    Jia, Xuming; Kim, Jonghan; Veuthey, Tania; Lee, Chih-Hao; Wessling-Resnick, Marianne

    2013-06-15

    The iron-diabetes hypothesis proposes an association between iron overload and glucose metabolism that is supported by a number of epidemiological studies. The prevalence of type 2 diabetes in patients with hereditary hemochromatosis and iron-loading thalassemia supports this hypothesis. The Belgrade rat carries a mutation in the iron transporter divalent metal transporter 1 (DMT1) resulting in iron-loading anemia. In this study, we characterized the glycometabolic status of the Belgrade rat. Belgrade rats displayed normal glycemic control. Insulin signaling and secretion were not impaired, and pancreatic tissue did not incur damage despite high levels of nonheme iron. These findings suggest that loss of DMT1 protects against oxidative damage to the pancreas and helps to maintain insulin sensitivity despite iron overload. Belgrade rats had lower body weight but increased food consumption compared with heterozygous littermates. The unexpected energy balance was associated with increased urinary glucose output. Increased urinary excretion of electrolytes, including iron, was also observed. Histopathological evidence suggests that altered renal function is secondary to changes in kidney morphology, including glomerulosclerosis. Thus, loss of DMT1 appears to protect the pancreas from injury but damages the integrity of kidney structure and function.

  10. Stimulation of the ferroxidase activity of ceruloplasmin during iron loading into ferritin.

    PubMed

    Reilly, C A; Aust, S D

    1997-11-15

    Ceruloplasmin purified from horse serum was rapidly reduced upon addition of increasing equivalents of ferrous iron, generating an electronically and conformationally distinct form. This form of ceruloplasmin was characterized by significant (80%) loss of EPR detectable type I and type II copper(II), complete loss of visible absorbance at 610 nm, as well as decreased hydrophobic surface area. The reduced form of ceruloplasmin slowly reduced molecular oxygen to complete its catalytic cycle. The presence of varied concentrations of apoferritin, but not apotransferrin, significantly enhanced the rate of ceruloplasmin oxidation. The magnitude of this stimulatory effect increased as the molar ratio of ceruloplasmin to apoferritin approached 1.0, shown previously to be the optimum ratio for loading iron into ferritin. The rate of ferrous iron oxidation by ceruloplasmin was significantly stimulated by the presence of apoferritin; however, apotransferrin had no effect. The length of time required for ceruloplasmin to oxidize all the iron and return to the native form of the enzyme was also affected by the concentration of iron. In addition, the rate of iron loading into ferritin was dependent upon ferrous iron concentration. These results provide evidence for the formation of a specific complex between the reduced form of ceruloplasmin and apoferritin and that reduction of ceruloplasmin by ferrous iron may be the signal for complex formation.

  11. Glucose metabolism in the Belgrade rat, a model of iron-loading anemia

    PubMed Central

    Jia, Xuming; Kim, Jonghan; Veuthey, Tania; Lee, Chih-Hao

    2013-01-01

    The iron-diabetes hypothesis proposes an association between iron overload and glucose metabolism that is supported by a number of epidemiological studies. The prevalence of type 2 diabetes in patients with hereditary hemochromatosis and iron-loading thalassemia supports this hypothesis. The Belgrade rat carries a mutation in the iron transporter divalent metal transporter 1 (DMT1) resulting in iron-loading anemia. In this study, we characterized the glycometabolic status of the Belgrade rat. Belgrade rats displayed normal glycemic control. Insulin signaling and secretion were not impaired, and pancreatic tissue did not incur damage despite high levels of nonheme iron. These findings suggest that loss of DMT1 protects against oxidative damage to the pancreas and helps to maintain insulin sensitivity despite iron overload. Belgrade rats had lower body weight but increased food consumption compared with heterozygous littermates. The unexpected energy balance was associated with increased urinary glucose output. Increased urinary excretion of electrolytes, including iron, was also observed. Histopathological evidence suggests that altered renal function is secondary to changes in kidney morphology, including glomerulosclerosis. Thus, loss of DMT1 appears to protect the pancreas from injury but damages the integrity of kidney structure and function. PMID:23599042

  12. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    SciTech Connect

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S.; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S. Charlotte; Carpita, Nicholas C.; Makowski, Lee; Himmel, Michael E.; Tucker, Melvin P.; McCann, Maureen C.; Murphy, Angus S.; Peer, Wendy A.

    2016-04-07

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  13. [Evaluation of the iron bioavailability from meals prepared with lentil (Lens esculenta) or with white kidney bean seeds (Phaseolus vulgaris) in anemic rats].

    PubMed

    Hamdaoui, Mohamed Hédi; Chabchoub Ellouze, Soufia; Doghri, Taïeb

    2005-04-01

    The aim of our study was to evaluate the iron bioavailability from lentil seeds and white kidney bean seeds. The iron bioavailability from diets was measured in rat by the depletion-repletion hemoglobin method and the reserve of iron stored in the liver. Our results showed that the iron bioavailability from meal based on cooked lentil seeds was significantly low (3.9 +/- 0.9%) as compared to the reference group fed with ferrous sulfate (20.4 +/- 4.9%) (p < 0.01) or to the group fed with cooked white kidney bean seeds (14.3 +/- 2.4%) (p < 0.01). Moreover, the reserve of iron stored in the liver was significantly low in rats fed with cooked lentil seeds (80.4 microg) compared to the reference group or to the group fed with cooked white kidney bean seeds (99 microg in the two groups, p < 0.01).

  14. Loading of iron into recombinant rat liver ferritin heteropolymers by ceruloplasmin.

    PubMed

    Juan, S H; Guo, J H; Aust, S D

    1997-05-15

    We have reported previously that the heavy chain of ferritin is required for iron incorporation by ceruloplasmin (J.-H. Guo, M. Abedi, and S. D. Aust (1996) Arch. Biochem. Biophys. 335(1)). The purpose of this study was to determine how many heavy chains were required for ceruloplasmin to interact with ferritin such that iron loading occurred. The cDNA sequences encoding the heavy and light chains of rat liver ferritin were cloned into the baculovirus transfer vector pA-cUW51 under the control of polyhedrin and p10 promoters, respectively, which was then incorporated by homologous recombination into the infections Autographa californica nuclear polyhedrosis virus genome. Both ferritin chains were expressed and assembled into two heteropolymers following the infection of insect cells by recombinant virus, which were separated by DEAE-Sepharose chromatography. The percentage of heavy (H) and light (L) chains making up the two heteropolymers, determined by gel scanning following the resolution of chains on SDS-PAGE, were equivalent to 1 H and 23 L chains and 2 H and 22 L chains. The maximal extent of iron loading was observed using 1 mol of rat ceruloplasmin per mole of H chain in the two heteropolymers. The extent of iron incorporation decreased with additional ceruloplasmin. Iron incorporation into rat liver ferritin, found to contain 10 H chains, increased as the molar ratio of ceruloplasmin to ferritin increased to 4:1 and remained the same up to 8:1. Iron loading into horse spleen ferritin, found to have one H chain, appeared similar to that for recombinant ferritin, having only one H chain. Therefore, we propose that the optimal molar ratio of ceruloplasmin to ferritin depends upon the numbers of H chain making up the ferritin molecule for the maximal incorporation of iron into ferritin. These results also suggest that the iron loading channel is contained within a single H chain subunit.

  15. The role of iron and chelators on infections in iron overload and non iron loaded conditions: prospects for the design of new antimicrobial therapies.

    PubMed

    Kontoghiorghes, George J; Kolnagou, Annita; Skiada, Anna; Petrikkos, George

    2010-06-01

    Iron overload is known to exacerbate many infectious diseases. Infectious complications are considered to be the second main cause of morbidity and mortality in iron loaded thalassemia patients. Effective chelation therapy leading to the normalization of the iron stores could reduce the incidence of related infections. Microbial pathogens could obtain growth-essential iron from healthy hosts. Conversely, iron withholding and/or removal is an important defense strategy for mammalian hosts, which is primarily accomplished by the iron chelating proteins transferrin and lactoferrin. Chelating drugs could prevent microbial growth and play an essential role in antimicrobial therapeutic strategies. Specific mechanisms and interactions apply in the transfer or withholding of iron between the chelating drugs deferoxamine (DFO), deferiprone (L1) and deferasirox (DFRA) with microbial pathogens such as bacteria, fungi and protozoa. In some cases, chelators and in particular DFO, could act as a siderophore for the microbe and exacerbate infections such as yersiniasis and mucormycosis. Deferiprone appears to have the highest therapeutic index for long-term antimicrobial activity and the highest tissue penetration, including access to the brain. Selection of specific chelation therapy protocols could be considered in conditions where other antimicrobial therapies have failed or where resistance has developed to existing therapies.

  16. A novel approach to oral iron delivery using ferrous sulphate loaded solid lipid nanoparticles.

    PubMed

    Zariwala, M Gulrez; Elsaid, Naba; Jackson, Timothy L; Corral López, Francisco; Farnaud, Sebastien; Somavarapu, Satyanarayana; Renshaw, Derek

    2013-11-18

    Iron (Fe) loaded solid lipid nanoparticles (SLN's) were formulated using stearic acid and iron absorption was evaluated in vitro using the cell line Caco-2 with intracellular ferritin formation as a marker of iron absorption. Iron loading was optimised at 1% Fe (w/w) lipid since an inverse relation was observed between initial iron concentration and SLN iron incorporation efficiency. Chitosan (Chi) was included to prepare chitosan coated SLN's. Particle size analysis revealed a sub-micron size range (300.3±31.75 nm to 495.1±80.42 nm), with chitosan containing particles having the largest dimensions. As expected, chitosan (0.1%, 0.2% and 0.4% w/v) conferred a net positive charge on the particle surface in a concentration dependent manner. For iron absorption experiments equal doses of Fe (20 μM) from selected formulations (SLN-FeA and SLN-Fe-ChiB) were added to Caco-2 cells and intracellular ferritin protein concentrations determined. Caco-2 iron absorption from SLN-FeA (583.98±40.83 ng/mg cell protein) and chitosan containing SLN-Fe-ChiB (642.77±29.37 ng/mg cell protein) were 13.42% and 24.9% greater than that from ferrous sulphate (FeSO4) reference (514.66±20.43 ng/mg cell protein) (p≤0.05). We demonstrate for the first time preparation, characterisation and superior iron absorption in vitro from SLN's, suggesting the potential of these formulations as a novel system for oral iron delivery.

  17. Tissue-specific accumulation of hepatic zinc metallothionein following parenteral iron loading

    SciTech Connect

    McCormick, C.C.

    1984-05-01

    The synthesis in various tissues of the unique metal-binding protein, metallothionein, can be influenced by the administration of certain trace elements. Zinc and cadmium, both of which bind to metallothionein, are most widely recognized as potent inducers. Preliminary results in our laboratory suggested that iron loading causes a marked accumulation of hepatic zinc metallothionein. In this report the effects of parenteral iron administration on metallothionein concentration in various tissues are presented. Male chicks (300-350 g) received (ip) either a single injection (+1 Fe) of iron (10 mg Fe/kg, as FeCl/sub 3/), two injections (+2 Fe) given 24-hr apart, three injections (+3 Fe) each given 24-hr apart, or an equivalent volume of 0.9% saline (control). Twenty-four hours following the final injection, chicks were killed and tissues analyzed for cytoplasmic zinc and metallothionein (Zn-MT). The parenteral administration of ferric iron, FeCl/sub 3/, resulted in a marked tissue-specific accumulation of zinc as metallothionein. In chicks given +2 Fe, hepatic Zn-MT increased more than 10-fold with a third injection (+3 Fe) causing no further change. The concentration of Zn-MT in renal and pancreatic tissue was unaffected by iron loading. An increase in hepatic Zn-MT was evident prior to detectable changes in total hepatic iron. The administration of other ferrous iron compounds at a similar rate produced comparable changes in hepatic Zn-MT. Feeding excess dietary iron, however, had no effect on liver Zn-MT levels even though similar hepatic iron concentrations were attained. Results indicated that parenteral administration, but not feeding, of various iron compounds causes a marked increase in zinc metallothionein, specifically in liver tissue.

  18. Genetic dissection of seed-iron and zinc concentrations in chickpea

    PubMed Central

    Upadhyaya, Hari D.; Bajaj, Deepak; Das, Shouvik; Kumar, Vinod; Gowda, C. L. L.; Sharma, Shivali; Tyagi, Akhilesh K.; Parida, Swarup K.

    2016-01-01

    The SNP-based high-resolution QTL mapping mapped eight major genomic regions harbouring robust QTLs governing seed-Fe and Zn concentrations (39.4% combined phenotypic variation explained/PVE) on six chromosomes of an intra-specific high-density genetic linkage map (1.56 cM map-density). 24620 SNPs discovered from genome-wide GBS (genotyping-by-sequencing) and 13 known cloned Fe and Zn contents-related chickpea gene-orthologs were genotyped in a structured population of 92 sequenced desi and kabuli accessions. The large-scale 16591 SNP genotyping- and phenotyping-based GWAS (genome-wide association study) identified 16 genomic loci/genes associated (29% combined PVE) with seed-Fe and Zn concentrations. Of these, 11 trait-associated SNPs in the genes linked tightly with eight QTLs were validated by QTL mapping. The seed-specific expression, including pronounced differential-regulation of 16 trait-associated genes particularly in accessions/mapping individuals with contrasting level of seed-Fe and Zn contents was apparent. Collectively, the aforementioned rapid integrated genomic strategy led to delineate novel functional non-synonymous and regulatory SNP allelic-variants from 16 known/candidate genes, including three strong trait-associated genes (encoding late embryogenesis abundant and yellow stripe-like 1 protein, and vacuolar protein sorting-associated protein) and eight major QTLs regulating seed-Fe and Zn concentrations in chickpea. These essential inputs thus have potential to be deployed in marker-assisted genetic enhancement for developing nutritionally-rich iron/zinc-biofortified chickpea cultivars. PMID:27063651

  19. Cardiac iron load and function in transfused patients treated with deferasirox (the MILE study).

    PubMed

    Ho, P Joy; Tay, Lay; Teo, Juliana; Marlton, Paula; Grigg, Andrew; St Pierre, Tim; Brown, Greg; Badcock, Caro-Anne; Traficante, Robert; Gervasio, Othon L; Bowden, Donald K

    2017-02-01

    To assess the effect of iron chelation therapy with deferasirox on cardiac iron and function in patients with transfusion-dependent thalassemia major, sickle cell disease (SCD), and myelodysplastic syndromes (MDS). This phase IV, single-arm, open-label study over 53 wk evaluated the change in cardiac and liver iron load with deferasirox (up to 40 mg/kg/d), measured by magnetic resonance imaging (MRI). Cardiac iron load (myocardial T2*) significantly improved (P = 0.002) overall (n = 46; n = 36 thalassemia major, n = 4 SCD, n = 6 MDS). Results were significant for patients with normal and moderate baseline cardiac iron (P = 0.017 and P = 0.015, respectively), but not in the five patients with severe cardiac iron load. Liver iron concentration (LIC) significantly decreased overall [mean LIC 10.4 to 8.2 mg Fe/g dry tissue (dw); P = 0.024], particularly in those with baseline LIC >7 mg Fe/g dw (19.9 to 15.6 mg Fe/g dw; P = 0.002). Furthermore, myocardial T2* significantly increased in patients with LIC <7 mg Fe/g dw, but not in those with a higher LIC. Safety was consistent with previous reports. Once-daily deferasirox over 1 yr significantly increased myocardial T2* and reduced LIC. This confirms that single-agent deferasirox is effective in the management of cardiac iron, especially for patients with myocardial T2* >10 ms (Clinicaltrials.gov identifier: NCT00673608). © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Frataxin and the molecular mechanism of mitochondrial iron-loading in Friedreich's ataxia.

    PubMed

    Chiang, Shannon; Kovacevic, Zaklina; Sahni, Sumit; Lane, Darius J R; Merlot, Angelica M; Kalinowski, Danuta S; Huang, Michael L-H; Richardson, Des R

    2016-06-01

    The mitochondrion is a major site for the metabolism of the transition metal, iron, which is necessary for metabolic processes critical for cell vitality. The enigmatic mitochondrial protein, frataxin, is known to play a significant role in both cellular and mitochondrial iron metabolism due to its iron-binding properties and its involvement in iron-sulfur cluster (ISC) and heme synthesis. The inherited neuro- and cardio-degenerative disease, Friedreich's ataxia (FA), is caused by the deficient expression of frataxin that leads to deleterious alterations in iron metabolism. These changes lead to the accumulation of inorganic iron aggregates in the mitochondrial matrix that are presumed to play a key role in the oxidative damage and subsequent degenerative features of this disease. Furthermore, the concurrent dys-regulation of cellular antioxidant defense, which coincides with frataxin deficiency, exacerbates oxidative stress. Hence, the pathogenesis of FA underscores the importance of the integrated homeostasis of cellular iron metabolism and the cytoplasmic and mitochondrial redox environments. This review focuses on describing the pathogenesis of the disease, the molecular mechanisms involved in mitochondrial iron-loading and the dys-regulation of cellular antioxidant defense due to frataxin deficiency. In turn, current and emerging therapeutic strategies are also discussed.

  1. Solid lipid nanoparticles loaded with iron to overcome barriers for treatment of iron deficiency anemia

    PubMed Central

    Hosny, Khaled Mohamed; Banjar, Zainy Mohammed; Hariri, Amani H; Hassan, Ali Habiballah

    2015-01-01

    According to the World Health Organization, 46% of the world’s children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability. PMID:25609917

  2. Solid lipid nanoparticles loaded with iron to overcome barriers for treatment of iron deficiency anemia.

    PubMed

    Hosny, Khaled Mohamed; Banjar, Zainy Mohammed; Hariri, Amani H; Hassan, Ali Habiballah

    2015-01-01

    According to the World Health Organization, 46% of the world's children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability.

  3. Inactivation effect of electron beam irradiation on fungal load of naturally contaminated maize seeds.

    PubMed

    Nemţanu, Monica R; Braşoveanu, Mirela; Karaca, Gürsel; Erper, İsmail

    2014-10-01

    This work focuses on the effect of accelerated electrons (0.1-6.2 kGy) on naturally attached fungi on maize seeds. The fungal viability and corresponding inactivation kinetics were determined. The inactivation and radiosensitivity of the most abundant species in the contaminant fungi detected on maize seeds (Aspergillus spp., Penicillium spp. and Fusarium spp.) are discussed. Fungal contamination of maize seeds decreased significantly with increasing irradiation dose. The survival curve of total fungi determined by the blotter test showed a sigmoidal pattern that can be attributed to the mixture of fungal subpopulations with different radiation sensitivities. This behaviour could be modelled well (R²  = 0.995) with a modified Gompertz equation. The predicted values for shoulder length and inactivation rate were 0.63 ± 0.10 kGy and 0.44 ± 0.04 kGy⁻¹ respectively. The sensitivity of the most common fungi to electron beam treatment followed the order Penicillium spp. > Fusarium spp. > Aspergillus spp., with total inactivation at irradiation doses of 1.7, 2.5 and 4.8 kGy respectively. The effect of electron beam treatment against fungi on naturally contaminated maize seeds depended on irradiation dose, allowing the control of maize fungal load. © 2014 Society of Chemical Industry.

  4. Exacerbation of Alcohol-Induced Oxidative Stress in Rats by Polyunsaturated Fatty Acids and Iron Load

    PubMed Central

    Patere, S. N.; Majumdar, A. S.; Saraf, M. N.

    2011-01-01

    The hypothesis that excessive intake of vegetable oil containing polyunsaturated fatty acids and iron load precipitate alcohol-induced liver damage was investigated in a rat model. In order to elucidate the mechanism underlying this synergism, the serum levels of iron, total protein, serum glutamate pyruvate transaminase, liver thiobarbituric acid reactive substances, and activities of antioxidant enzymes superoxide dismutase, catalase in liver of rats treated with alcohol, polyunsaturated fatty acids and iron per se and in combination were examined. Alcohol was fed to the rats at a level of 10-30% (blood alcohol was maintained between 150-350 mg/dl by using head space gas chromatography), polyunsaturated fatty acids at a level of 15% of diet and carbonyl iron 1.5-2% of diet per se and in combination to different groups for 30 days. Hepatotoxicity was assessed by measuring serum glutamate pyruvate transaminase, which was elevated and serum total protein, which was decreased significantly in rats fed with a combination of alcohol, polyunsaturated fatty acids and iron. It was also associated with increased lipid peroxidation and disruption of antioxidant defense in combination fed rats as compared to rats fed with alcohol or polyunsaturated fatty acids or iron. The present study revealed significant exacerbation of the alcohol-induced oxidative stress in presence of polyunsaturated fatty acids and iron. PMID:22303057

  5. Efficacy and safety of iron-chelation therapy with deferoxamine, deferiprone, and deferasirox for the treatment of iron-loaded patients with non-transfusion-dependent thalassemia syndromes

    PubMed Central

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-01-01

    The prevalence rate of thalassemia, which is endemic in Southeast Asia, the Middle East, and the Mediterranean, exceeds 100,000 live births per year. There are many genetic variants in thalassemia with different pathological severity, ranging from a mild and asymptomatic anemia to life-threatening clinical effects, requiring lifelong treatment, such as regular transfusions in thalassemia major (TM). Some of the thalassemias are non-transfusion-dependent, including many thalassemia intermedia (TI) variants, where iron overload is caused by chronic increase in iron absorption due to ineffective erythropoiesis. Many TI patients receive occasional transfusions. The rate of iron overloading in TI is much slower in comparison to TM patients. Iron toxicity in TI is usually manifested by the age of 30–40 years, and in TM by the age of 10 years. Subcutaneous deferoxamine (DFO), oral deferiprone (L1), and DFO–L1 combinations have been effectively used for more than 20 years for the treatment of iron overload in TM and TI patients, causing a significant reduction in morbidity and mortality. Selected protocols using DFO, L1, and their combination can be designed for personalized chelation therapy in TI, which can effectively and safely remove all the excess toxic iron and prevent cardiac, liver, and other organ damage. Both L1 and DF could also prevent iron absorption. The new oral chelator deferasirox (DFX) increases iron excretion and decreases liver iron in TM and TI. There are drawbacks in the use of DFX in TI, such as limitations related to dose, toxicity, and cost, iron load of the patients, and ineffective removal of excess iron from the heart. Furthermore, DFX appears to increase iron and other toxic metal absorption. Future treatments of TI and related iron-loading conditions could involve the use of the iron-chelating drugs and other drug combinations not only for increasing iron excretion but also for preventing iron absorption. PMID:26893541

  6. Efficacy and safety of iron-chelation therapy with deferoxamine, deferiprone, and deferasirox for the treatment of iron-loaded patients with non-transfusion-dependent thalassemia syndromes.

    PubMed

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-01-01

    The prevalence rate of thalassemia, which is endemic in Southeast Asia, the Middle East, and the Mediterranean, exceeds 100,000 live births per year. There are many genetic variants in thalassemia with different pathological severity, ranging from a mild and asymptomatic anemia to life-threatening clinical effects, requiring lifelong treatment, such as regular transfusions in thalassemia major (TM). Some of the thalassemias are non-transfusion-dependent, including many thalassemia intermedia (TI) variants, where iron overload is caused by chronic increase in iron absorption due to ineffective erythropoiesis. Many TI patients receive occasional transfusions. The rate of iron overloading in TI is much slower in comparison to TM patients. Iron toxicity in TI is usually manifested by the age of 30-40 years, and in TM by the age of 10 years. Subcutaneous deferoxamine (DFO), oral deferiprone (L1), and DFO-L1 combinations have been effectively used for more than 20 years for the treatment of iron overload in TM and TI patients, causing a significant reduction in morbidity and mortality. Selected protocols using DFO, L1, and their combination can be designed for personalized chelation therapy in TI, which can effectively and safely remove all the excess toxic iron and prevent cardiac, liver, and other organ damage. Both L1 and DF could also prevent iron absorption. The new oral chelator deferasirox (DFX) increases iron excretion and decreases liver iron in TM and TI. There are drawbacks in the use of DFX in TI, such as limitations related to dose, toxicity, and cost, iron load of the patients, and ineffective removal of excess iron from the heart. Furthermore, DFX appears to increase iron and other toxic metal absorption. Future treatments of TI and related iron-loading conditions could involve the use of the iron-chelating drugs and other drug combinations not only for increasing iron excretion but also for preventing iron absorption.

  7. Magnetic Properties of Polyvinyl Alcohol and Doxorubicine Loaded Iron Oxide Nanoparticles for Anticancer Drug Delivery Applications

    PubMed Central

    Nadeem, Muhammad; Ahmad, Munir; Akhtar, Muhammad Saeed; Shaari, Amiruddin; Riaz, Saira; Naseem, Shahzad; Masood, Misbah; Saeed, M. A.

    2016-01-01

    The current study emphasizes the synthesis of iron oxide nanoparticles (IONPs) and impact of hydrophilic polymer polyvinyl alcohol (PVA) coating concentration as well as anticancer drug doxorubicin (DOX) loading on saturation magnetization for target drug delivery applications. Iron oxide nanoparticles particles were synthesized by a reformed version of the co-precipitation method. The coating of polyvinyl alcohol along with doxorubicin loading was carried out by the physical immobilization method. X-ray diffraction confirmed the magnetite (Fe3O4) structure of particles that remained unchanged before and after polyvinyl alcohol coating and drug loading. Microstructure and morphological analysis was carried out by transmission electron microscopy revealing the formation of nanoparticles with an average size of 10 nm with slight variation after coating and drug loading. Transmission electron microscopy, energy dispersive, and Fourier transform infrared spectra further confirmed the conjugation of polymer and doxorubicin with iron oxide nanoparticles. The room temperature superparamagnetic behavior of polymer-coated and drug-loaded magnetite nanoparticles were studied by vibrating sample magnetometer. The variation in saturation magnetization after coating evaluated that a sufficient amount of polyvinyl alcohol would be 3 wt. % regarding the externally controlled movement of IONPs in blood under the influence of applied magnetic field for in-vivo target drug delivery. PMID:27348436

  8. Effect of iron oxide loading on the phase transformation and physicochemical properties of nanosized mesoporous ZrO{sub 2}

    SciTech Connect

    Basahel, S.N.; Ali, Tarek T.; Narasimharao, K.; Bagabas, A.A.; Mokhtar, M.

    2012-11-15

    Highlights: ► Modified preparation method for nanosized iron oxide supported ZrO{sub 2} catalysts. ► Systematic study of effect of high iron oxide loading over ZrO{sub 2}. ► Influence of iron oxide on the stabilization of tetragonal ZrO{sub 2} phase. ► A mesoporous nature of zirconia changed upon changing iron oxide loading. ► Surface to bulk migration of iron oxide evidenced by XPS technique. -- Abstract: Mesoporous ZrO{sub 2}-supported iron oxide materials were prepared with nominal loadings of iron oxide of 5, 10, 15 and 20 wt.% using a modified co-precipitation method. The physicochemical properties of the catalysts were characterized by thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, Raman spectroscopy, high resolution transmission electron microscopy, N{sub 2} adsorption, X-ray photoelectron spectroscopy and infrared spectroscopy methods. A delay in the ZrO{sub 2} phase transformation as a result of the incorporation of iron was determined using TG/DSC measurements. XRD, Raman spectroscopy and HRTEM results revealed that an increase of iron oxide loading from 5 to 15 wt.% enhanced the transformation of the monoclinic to tetragonal phase. Unexpectedly, 20 wt.% iron oxide loading was required for complete tetragonal structure stabilization due to the mesoporosity of the ZrO{sub 2} support. Iron oxide loadings from 5 to 15 wt.% showed an increase in the BET-surface area due to the presence of amorphous iron oxide on the surface. XPS and FTIR results indicated that increasing the iron oxide content to 20 wt.% resulted in stabilization of the tetragonal zirconia phase as a result of surface-to-bulk migration and incorporation of Fe{sup 3+} ions in the ZrO{sub 2} lattice.

  9. Evidence for a protein-protein complex during iron loading into ferritin by ceruloplasmin.

    PubMed

    Reilly, C A; Sorlie, M; Aust, S D

    1998-06-01

    The formation of a protein-protein complex for the loading of iron into ferritin by ceruloplasmin was investigated. Ferritin stimulated the ferroxidase activity of ceruloplasmin unless the ferritin was fully loaded, in which case it inhibited the ferroxidase activity of ceruloplasmin. The apparent association constant for the interaction of ferritin and ceruloplasmin was 24 nM. Isothermal titration calorimetry indicated that the interaction of ceruloplasmin and ferritin was endothermic, driven by positive changes in entropy. The association constants for complex formation between ferritin and ceruloplasmin were 4.5 +/- 0.7 x 10(5) and 9.5 +/- 0.3 x 10(4) M-1 for the reduced and oxidized forms of ceruloplasmin, respectively. The oxidized form of ceruloplasmin was retained on an affinity column with ferritin immobilized as the ligand and remained bound to the column with mobile phases of increased hydrophobicity, but was eluted with increased ionic strength. The ability of ceruloplasmin to remain bound to the affinity resin was affected by the species from which ceruloplasmin was isolated. Gradient ultracentrifugation also provided evidence that the two proteins were associated, since ferritin promoted migration of ceruloplasmin through the gradient. Including ferrous iron in the gradient resulted in reduction of ceruloplasmin and increased the mobility of ceruloplasmin with ferritin. These data provide evidence that ferritin and ceruloplasmin form a protein-protein complex during iron loading into ferritin, which may limit redox cycling of iron in vivo.

  10. Single Particle Analysis of Oceanic Suspended Matters During the SEEDS II Iron Fertilization Experiment

    NASA Astrophysics Data System (ADS)

    Iwamoto, Y.; Narita, Y.; Uematsu, M.

    2006-12-01

    Oceanic suspended particles play an important role regulating the chemical composition of seawater through the removal of trace elements from surface water to deep water and their lateral transport. Therefore, physical and chemical properties of these particles reflect the characteristics of water mass and marine ecosystem under the perturbation of marine environment such as iron fertilization. To consider the physical and/or chemical variation of these particles in the water column, it is necessary to analyze size, number and chemical composition of individual particles. Suspended particles in the surface seawater were collected during the SEEDS II (Subarctic Iron Experiment for Ecosystem and Dynamics Study II) iron fertilization experiment in the summer of 2004. The particulate samples were analyzed by Electron probe X-ray micro analyzer (EPMA) and characterized by size and major and minor elements ranged from 0.4 to 10 μ m in diameter. These particles were classified into five groups based on their chemical compositions: Al-Si, Si-rich, Ca-rich, Organic and Others. Most of particles were Si-rich, Ca-rich and Organic. Si-rich and Ca-rich particles were mainly consist of detritus of phytoplankton.In the iron-fertilized patch area, Chl-a concentration covaried with dry weight, number and volume concentrations of the suspended particles. At 20 m depth, the number concentration of Organic particles having two peaks at 1.1 and 0.65 μ m in diameter increased within 2 days after the iron fertilization, and then gradually increased. It is suggested that the increase in suspended particles, mostly detritus of planktonic shells, corresponded to that in primary production. The contents by weight of Si in Si-rich particle and the content by weight of Ca in Ca-rich particle tended to decrease in size. In fine mode particle, Si-rich and Ca-rich particles contained more P and S as biolimiting elements and less Al, Ti, Mn, and Fe as crustal elements. The smaller Organic

  11. Improvement of pea biomass and seed productivity by simultaneous increase of phloem and embryo loading with amino acids.

    PubMed

    Zhang, Lizhi; Garneau, Matthew G; Majumdar, Rajtilak; Grant, Jan; Tegeder, Mechthild

    2015-01-01

    The development of sink organs such as fruits and seeds strongly depends on the amount of nitrogen that is moved within the phloem from photosynthetic-active source leaves to the reproductive sinks. In many plant species nitrogen is transported as amino acids. In pea (Pisum sativum L.), source to sink partitioning of amino acids requires at least two active transport events mediated by plasma membrane-localized proteins, and these are: (i) amino acid phloem loading; and (ii) import of amino acids into the seed cotyledons via epidermal transfer cells. As each of these transport steps might potentially be limiting to efficient nitrogen delivery to the pea embryo, we manipulated both simultaneously. Additional copies of the pea amino acid permease PsAAP1 were introduced into the pea genome and expression of the transporter was targeted to the sieve element-companion cell complexes of the leaf phloem and to the epidermis of the seed cotyledons. The transgenic pea plants showed increased phloem loading and embryo loading of amino acids resulting in improved long distance transport of nitrogen, sink development and seed protein accumulation. Analyses of root and leaf tissues further revealed that genetic manipulation positively affected root nitrogen uptake, as well as primary source and sink metabolism. Overall, the results suggest that amino acid phloem loading exerts regulatory control over pea biomass production and seed yield, and that import of amino acids into the cotyledons limits seed protein levels. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  12. Synthesis of glycosaminoglycans in differently loaded regions of collagen gels seeded with valvular interstitial cells.

    PubMed

    Gupta, Vishal; Werdenberg, Jennifer A; Blevins, Tracy L; Grande-Allen, K Jane

    2007-01-01

    Cells respond to changes in mechanical strains by varying their production of extracellular matrix macromolecules. Because differences in strain patterns between mitral valve leaflets and chordae tendineae have been linked to different quantities and types of glycosaminoglycans (GAGs), we investigated the effects of various strain conditions on GAG synthesis by valvular interstitial cells (VICs) using an in vitro 3-dimensional tissue-engineering model. VICs from leaflets or chordae were seeded within collagen gels and subjected to uniaxial or biaxial static tension for 1 week. GAGs synthesized within the collagen gels and secreted into the surrounding medium were analyzed using fluorophore-assisted carbohydrate electrophoresis. In constrained conditions, more 4-sulfated GAGs were retained within the collagen gel, whereas more hyaluronan was secreted into the surrounding medium. Selected GAG classes were found in significantly different proportions in collagen gels seeded with leaflet cells versus chordal cells. The only significant difference between uniaxial and biaxial regions was found for 6-sulfated GAGs in the gels seeded with chordal cells (p<0.05). This study suggests how mechanical loading may influence GAG production and localization in the remodeling of the mitral valve and has design implications for engineered tissues.

  13. Transfer of useful variability of high grain iron and zinc from Aegilops kotschyi into wheat through seed irradiation approach.

    PubMed

    Verma, Shailender Kumar; Kumar, Satish; Sheikh, Imran; Malik, Sachin; Mathpal, Priyanka; Chugh, Vishal; Kumar, Sundip; Prasad, Ramasare; Dhaliwal, Harcharan Singh

    2016-01-01

    To transfer the 2S chromosomal fragment(s) of Aegilops kotschyi (2S(k)) into the bread wheat genome which could lead to the biofortification of wheat with high grain iron and zinc content. Wheat-Ae. kotschyi 2A/2S(k) substitution lines with high grain iron and zinc content were used to transfer the gene/loci for high grain Fe and Zn content into wheat using seed irradiation approach. Bread wheat plants derived from 40 krad-irradiated seeds showed the presence of univalents and multivalents during meiotic metaphase-I. Genomic in situ hybridization analysis of seed irradiation hybrid F2 seedlings showed several terminal and interstitial signals indicated the introgression of Ae. kotschyi chromosome segments. This proves the efficacy of seed radiation hybrid approach in gene transfer experiments. All the radiation-treated hybrid plants with high grain Fe and Zn content were analyzed with wheat group 2 chromosome-specific polymorphic simple sequence repeat markers to identify the introgression of small alien chromosome fragment(s). Radiation-induced hybrids showed more than 65% increase in grain iron and 54% increase in Zn contents with better harvest index than the elite wheat cultivar WL711 indicating effective and compensating translocations of 2S(k) fragments into wheat genome.

  14. Brain transcriptome perturbations in the Hfe(-/-) mouse model of genetic iron loading.

    PubMed

    Johnstone, Daniel; Graham, Ross M; Trinder, Debbie; Delima, Roheeth D; Riveros, Carlos; Olynyk, John K; Scott, Rodney J; Moscato, Pablo; Milward, Elizabeth A

    2012-04-11

    Severe disruption of brain iron homeostasis can cause fatal neurodegenerative disease, however debate surrounds the neurologic effects of milder, more common iron loading disorders such as hereditary hemochromatosis, which is usually caused by loss-of-function polymorphisms in the HFE gene. There is evidence from both human and animal studies that HFE gene variants may affect brain function and modify risks of brain disease. To investigate how disruption of HFE influences brain transcript levels, we used microarray and real-time reverse transcription polymerase chain reaction to assess the brain transcriptome in Hfe(-/-) mice relative to wildtype AKR controls (age 10 weeks, n≥4/group). The Hfe(-/-) mouse brain showed numerous significant changes in transcript levels (p<0.05) although few of these related to proteins directly involved in iron homeostasis. There were robust changes of at least 2-fold in levels of transcripts for prominent genes relating to transcriptional regulation (FBJ osteosarcoma oncogene Fos, early growth response genes), neurotransmission (glutamate NMDA receptor Grin1, GABA receptor Gabbr1) and synaptic plasticity and memory (calcium/calmodulin-dependent protein kinase IIα Camk2a). As previously reported for dietary iron-supplemented mice, there were altered levels of transcripts for genes linked to neuronal ceroid lipofuscinosis, a disease characterized by excessive lipofuscin deposition. Labile iron is known to enhance lipofuscin generation which may accelerate brain aging. The findings provide evidence that iron loading disorders can considerably perturb levels of transcripts for genes essential for normal brain function and may help explain some of the neurologic signs and symptoms reported in hemochromatosis patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. The expression of heterologous Fe (III) phytosiderophore transporter HvYS1 in rice increases Fe uptake, translocation and seed loading and excludes heavy metals by selective Fe transport.

    PubMed

    Banakar, Raviraj; Alvarez Fernández, Ána; Abadía, Javier; Capell, Teresa; Christou, Paul

    2017-04-01

    Many metal transporters in plants are promiscuous, accommodating multiple divalent cations including some which are toxic to humans. Previous attempts to increase the iron (Fe) and zinc (Zn) content of rice endosperm by overexpressing different metal transporters have therefore led unintentionally to the accumulation of copper (Cu), manganese (Mn) and cadmium (Cd). Unlike other metal transporters, barley Yellow Stripe 1 (HvYS1) is specific for Fe. We investigated the mechanistic basis of this preference by constitutively expressing HvYS1 in rice under the control of the maize ubiquitin1 promoter and comparing the mobilization and loading of different metals. Plants expressing HvYS1 showed modest increases in Fe uptake, root-to-shoot translocation, seed accumulation and endosperm loading, but without any change in the uptake and root-to-shoot translocation of Zn, Mn or Cu, confirming the selective transport of Fe. The concentrations of Zn and Mn in the endosperm did not differ significantly between the wild-type and HvYS1 lines, but the transgenic endosperm contained significantly lower concentrations of Cu. Furthermore, the transgenic lines showed a significantly reduced Cd uptake, root-to-shoot translocation and accumulation in the seeds. The underlying mechanism of metal uptake and translocation reflects the down-regulation of promiscuous endogenous metal transporters revealing an internal feedback mechanism that limits seed loading with Fe. This promotes the preferential mobilization and loading of Fe, therefore displacing Cu and Cd in the seed.

  16. The Rehbinder effect in iron during giga-cycle fatigue loading

    SciTech Connect

    Bannikov, M. V. Naimark, O. B.

    2015-10-27

    The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. The mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.

  17. Positive Contrast MRI Techniques for Visualization of Iron-Loaded Hernia Mesh Implants in Patients

    PubMed Central

    Ciritsis, Alexander; Truhn, Daniel; Hansen, Nienke L.; Otto, Jens; Kuhl, Christiane K.; Kraemer, Nils A.

    2016-01-01

    Object In MRI, implants and devices can be delineated via susceptibility artefacts. To discriminate susceptibility voids from proton-free structures, different positive contrast techniques were implemented. The purpose of this study was to evaluate a pulse sequence-based positive contrast technique (PCSI) and a post-processing susceptibility gradient mapping algorithm (SGM) for visualization of iron loaded mesh implants in patients. Material and Methods Five patients with iron-loaded MR-visible inguinal hernia mesh implants were examined at 1.5 Tesla. A gradient echo sequence (GRE; parameters: TR: 8.3ms; TE: 4.3ms; NSA:2; FA:20°; FOV:350mm²) and a PCSI sequence (parameters: TR: 25ms; TE: 4.6ms; NSA:4; FA:20°; FOV:350mm²) with on-resonant proton suppression were performed. SGM maps were calculated using two algorithms. Image quality and mesh delineation were independently evaluated by three radiologists. Results On GRE, the iron-loaded meshes generated distinct susceptibility-induced signal voids. PCSI exhibited susceptibility differences including the meshes as hyperintense signals. SGM exhibited susceptibility differences with positive contrast. Visually, the different algorithms presented no significant differences. Overall, the diagnostic value was rated best in GRE whereas PCSI and SGM were barely “sufficient”. Conclusion Both “positive contrast” techniques depicted implanted meshes with hyperintense signal. SGM comes without additional acquisition time and can therefore be utilized in every patient. PMID:27192201

  18. Effects of dust deposition on iron cycle in the surface Mediterranean Sea: results from a mesocosm seeding experiment

    NASA Astrophysics Data System (ADS)

    Wagener, T.; Guieu, C.; Leblond, N.

    2010-04-01

    Soil dust deposition is recognized as a major source of iron to the open ocean at global and regional scales. However, the processes that control the speciation and cycle of iron in the surface ocean after dust deposition are poorly documented mainly due to the logistical difficulties to investigate in-situ, natural dust events. The development of clean mesocosms in the frame of the DUNE project (a DUst experiment in a low Nutrient low chlorophyll Ecosystem) was a unique opportunity to investigate these processes at the unexplored scale of one dust deposition event. During the DUNE1 mesocosm seeding experiment, iron stocks (dissolved and particulate concentrations in the water column) and fluxes (export of particulate iron in sediment traps) were followed during 8 days after an artificial dust seeding mimicking a wet deposition of 10 g m-2. The addition of dust at the surface of the mesocosms was immediately followed by a decrease of dissolved iron [dFe] concentration in the 0-10 m water column. This decrease was likely due to dFe scavenging on settling dust particles and mineral organic aggregates. The scavenging ratio of dissolved iron on dust particles averaged 0.37 ± 0.12 nmol mg-1. Batch dissolution experiments conducted in parallel to the mesocosm experiment showed a increase (up to 600%) in dust iron dissolution capacity in dust-fertilized waters compared to control conditions. This study gives evidences of complex and unexpected effects of dust deposition on surface ocean biogeochemistry: (1) large dust deposition events may be a sink for surface ocean dissolved iron and (2) successive dust deposition events may induce different biogeochemical responses in the surface ocean.

  19. Effects of dust deposition on iron cycle in the surface Mediterranean Sea: results from a mesocosm seeding experiment

    NASA Astrophysics Data System (ADS)

    Wagener, T.; Guieu, C.; Leblond, N.

    2010-11-01

    Soil dust deposition is recognized as a major source of iron to the open ocean at global and regional scales. However, the processes that control the speciation and cycle of iron in the surface ocean after dust deposition are poorly documented mainly due to the logistical difficulties to investigate in-situ, natural dust events. The development of clean mesocosms in the frame of the DUNE project (a DUst experiment in a low Nutrient low chlorophyll Ecosystem) was a unique opportunity to investigate these processes at the unexplored scale of one dust deposition event. During the DUNE-1-P mesocosm seeding experiment, iron stocks (dissolved and particulate concentrations in the water column) and fluxes (export of particulate iron in sediment traps) were followed during 8 days after an artificial dust seeding mimicking a wet deposition of 10 g m-2. The addition of dust at the surface of the mesocosms was immediately followed by a decrease of dissolved iron [dFe] concentration in the 0-10 m water column. This decrease was likely due to dFe scavenging on settling dust particles and mineral organic aggregates. The scavenging ratio of dissolved iron on dust particles averaged 0.37 ± 0.12 nmol mg-1. Batch dissolution experiments conducted in parallel to the mesocosm experiment showed a increase (up to 600%) in dust iron dissolution capacity in dust-fertilized waters compared to control conditions. This study gives evidences of complex and unexpected effects of dust deposition on surface ocean biogeochemistry: (1) large dust deposition events may be a sink for surface ocean dissolved iron and (2) successive dust deposition events may induce different biogeochemical responses in the surface ocean.

  20. Physio-biochemical basis of iron-sulfide nanoparticle induced growth and seed yield enhancement in B. juncea.

    PubMed

    Rawat, Madhu; Nayan, Rajeev; Negi, Bhawana; Zaidi, M G H; Arora, Sandeep

    2017-09-01

    Metal nanoparticles have been reported to influence plant growth and productivity. However, the molecular mechanisms underlying the effects have not been completely understood yet. Current work describes the physio-biochemical basis of iron sulfide nanoparticle induced growth and yield enhancement in Brassica juncea. Iron sulfide nanoparticles (0, 2, 4, 6, 8 and 10 ppm) were used for foliar treatment of B. juncea at 30, 45 and 60 days after sowing, under field conditions. Foliar treatment of 4 ppm iron sulfide nanoparticle solution at 30 days after sowing brought maximal enhancement in agronomic attributes of the treated plants. Results of assays i.e. total chlorophyll, electrolyte leakage, Malondialdehyde (MDA), proline, H2O2 and antioxidant enzyme activities indicated the benign effect of iron sulfide nanoparticles on plants. Consequently, improved redox status of the treated plants, enabled them to assimilate higher photosynthate. The augmentation in growth and seed yield in iron sulfide nanoparticle treated plants was amply supported by activation of RUBISCO small subunit (rubisco S), RUBISCO large subunit (rubisco L), glutamine synthetase (gs) and glutamate synthase (gogat) genes. Thus, iron sulfide nanoparticle induced growth and yield enhancement is proposed to be mediated through activation of carbon and nitrogen assimilatory pathways at specific growth stage. The iron content in the leaves and root tissues of the treated plants was also significantly improved. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values

    EPA Science Inventory

    Small-scale continuous flow wetland mesocosms (~0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed ...

  2. Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values

    EPA Science Inventory

    Small-scale continuous flow wetland mesocosms (~0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed ...

  3. The effect of iron loading and iron chelation on the innate immune response and subclinical organ injury during human endotoxemia: a randomized trial

    PubMed Central

    van Eijk, Lucas T.; Heemskerk, Suzanne; van der Pluijm, Rob W.; van Wijk, Susanne M.; Peters, Wilbert H.M.; van der Hoeven, Johannes G.; Kox, Matthijs; Swinkels, Dorine W; Pickkers, Peter

    2014-01-01

    In this double-blind randomized placebo-controlled trial involving 30 healthy male volunteers we investigated the acute effects of iron loading (single dose of 1.25 mg/kg iron sucrose) and iron chelation therapy (single dose of 30 mg/kg deferasirox) on iron parameters, oxidative stress, the innate immune response, and subclinical organ injury during experimental human endotoxemia. The administration of iron sucrose induced a profound increase in plasma malondialdehyde 1 h after administration (433±37% of baseline; P<0.0001), but did not potentiate the endotoxemia-induced increase in malondialdehyde, as was seen 3 h after endotoxin administration in the placebo group (P=0.34) and the iron chelation group (P=0.008). Endotoxemia resulted in an initial increase in serum iron levels and transferrin saturation that was accompanied by an increase in labile plasma iron, especially when transferrin saturation reached levels above 90%. Thereafter, serum iron decreased to 51.6±9.7% of baseline at T=8 h in the placebo group versus 84±15% and 60.4±8.9% of baseline at 24 h in the groups treated with iron sucrose and deferasirox, respectively. No significant differences in the endotoxemia-induced cytokine response (TNF-α, IL-6, IL-10 and IL-1RA), subclinical vascular injury and kidney injury were observed between groups. However, vascular reactivity to noradrenalin was impaired in the 6 subjects in whom labile plasma iron was elevated during endotoxemia as opposed to those in whom no labile plasma iron was detected (P=0.029). In conclusion, a single dose of iron sucrose does not affect the innate immune response in a model of experimental human endotoxemia, but may impair vascular reactivity when labile plasma iron is formed. (Clinicaltrials.gov identifier:01349699) PMID:24241495

  4. OPT3 is a component of the iron-signaling network between leaves and roots and misregulation of OPT3 leads to an over-accumulation of cadmium in seeds.

    PubMed

    Mendoza-Cózatl, David G; Xie, Qingqing; Akmakjian, Garo Z; Jobe, Timothy O; Patel, Ami; Stacey, Minviluz G; Song, Lihui; Demoin, Dustin Wayne; Jurisson, Silvia S; Stacey, Gary; Schroeder, Julian I

    2014-09-01

    Plants and seeds are the main dietary sources of zinc, iron, manganese, and copper, but are also the main entry point for toxic elements such as cadmium into the food chain. We report here that an Arabidopsis oligopeptide transporter mutant, opt3-2, over-accumulates cadmium (Cd) in seeds and roots but, unexpectedly, under-accumulates Cd in leaves. The cadmium distribution in opt3-2 differs from iron, zinc, and manganese, suggesting a metal-specific mechanism for metal partitioning within the plant. The opt3-2 mutant constitutively up-regulates the Fe/Zn/Cd transporter IRT1 and FRO2 in roots, indicative of an iron-deficiency response. No genetic mutants that impair the shoot-to-root signaling of iron status in leaves have been identified. Interestingly, shoot-specific expression of OPT3 rescues the Cd sensitivity and complements the aberrant expression of IRT1 in opt3-2 roots, suggesting that OPT3 is required to relay the iron status from leaves to roots. OPT3 expression was found in the vasculature with preferential expression in the phloem at the plasma membrane. Using radioisotope experiments, we found that mobilization of Fe from leaves is severely affected in opt3-2, suggesting that Fe mobilization out of leaves is required for proper trace-metal homeostasis. When expressed in yeast, OPT3 does not localize to the plasma membrane, precluding the identification of the OPT3 substrate. Our in planta results show that OPT3 is important for leaf phloem-loading of iron and plays a key role regulating Fe, Zn, and Cd distribution within the plant. Furthermore, ferric chelate reductase activity analyses provide evidence that iron is not the sole signal transferred from leaves to roots in leaf iron status signaling.

  5. OPT3 Is a Component of the Iron-Signaling Network between Leaves and Roots and Misregulation of OPT3 Leads to an Over-Accumulation of Cadmium in Seeds

    PubMed Central

    Mendoza-Cózatl, David G.; Xie, Qingqing; Akmakjian, Garo Z.; Jobe, Timothy O.; Patel, Ami; Stacey, Minviluz G.; Song, Lihui; Demoin, Dustin Wayne; Jurisson, Silvia S.; Stacey, Gary; Schroeder, Julian I.

    2014-01-01

    Plants and seeds are the main dietary sources of zinc, iron, manganese, and copper, but are also the main entry point for toxic elements such as cadmium into the food chain. We report here that an Arabidopsis oligopeptide transporter mutant, opt3-2, over-accumulates cadmium (Cd) in seeds and roots but, unexpectedly, under-accumulates Cd in leaves. The cadmium distribution in opt3-2 differs from iron, zinc, and manganese, suggesting a metal-specific mechanism for metal partitioning within the plant. The opt3-2 mutant constitutively up-regulates the Fe/Zn/Cd transporter IRT1 and FRO2 in roots, indicative of an iron-deficiency response. No genetic mutants that impair the shoot-to-root signaling of iron status in leaves have been identified. Interestingly, shoot-specific expression of OPT3 rescues the Cd sensitivity and complements the aberrant expression of IRT1 in opt3-2 roots, suggesting that OPT3 is required to relay the iron status from leaves to roots. OPT3 expression was found in the vasculature with preferential expression in the phloem at the plasma membrane. Using radioisotope experiments, we found that mobilization of Fe from leaves is severely affected in opt3-2, suggesting that Fe mobilization out of leaves is required for proper trace-metal homeostasis. When expressed in yeast, OPT3 does not localize to the plasma membrane, precluding the identification of the OPT3 substrate. Our in planta results show that OPT3 is important for leaf phloem-loading of iron and plays a key role regulating Fe, Zn, and Cd distribution within the plant. Furthermore, ferric chelate reductase activity analyses provide evidence that iron is not the sole signal transferred from leaves to roots in leaf iron status signaling. PMID:24880337

  6. The Arabidopsis AtOPT3 Protein Functions in Metal Homeostasis and Movement of Iron to Developing Seeds1[W][OA

    PubMed Central

    Stacey, Minviluz G.; Patel, Ami; McClain, William E.; Mathieu, Melanie; Remley, Melissa; Rogers, Elizabeth E.; Gassmann, Walter; Blevins, Dale G.; Stacey, Gary

    2008-01-01

    The Arabidopsis thaliana AtOPT3 belongs to the oligopeptide transporter (OPT) family, a relatively poorly characterized family of peptide/modified peptide transporters found in archebacteria, bacteria, fungi, and plants. A null mutation in AtOPT3 resulted in embryo lethality, indicating an essential role for AtOPT3 in embryo development. In this article, we report on the isolation and phenotypic characterization of a second AtOPT3 mutant line, opt3-2, harboring a T-DNA insertion in the 5′ untranslated region of AtOPT3. The T-DNA insertion in the AtOPT3 promoter resulted in reduced but sufficient AtOPT3 expression to allow embryo formation in opt3-2 homozygous seeds. Phenotypic analyses of opt3-2 plants revealed three interesting loss-of-function phenotypes associated with iron metabolism. First, reduced AtOPT3 expression in opt3-2 plants resulted in the constitutive expression of root iron deficiency responses regardless of exogenous iron supply. Second, deregulation of root iron uptake processes in opt3-2 roots resulted in the accumulation of very high levels of iron in opt3-2 tissues. Hyperaccumulation of iron in opt3-2 resulted in the formation of brown necrotic areas in opt3-2 leaves and was more pronounced during the seed-filling stage. Third, reduced AtOPT3 expression resulted in decreased accumulation of iron in opt3-2 seeds. The reduced accumulation of iron in opt3-2 seeds is especially noteworthy considering the excessively high levels of accumulated iron in other opt3-2 tissues. AtOPT3, therefore, plays a critical role in two important aspects of iron metabolism, namely, maintenance of whole-plant iron homeostasis and iron nutrition of developing seeds. PMID:18083798

  7. Excess iron undermined bone load-bearing capacity through tumor necrosis factor-α-dependent osteoclastic activation in mice.

    PubMed

    Li, Junping; Hou, Yanli; Zhang, Shuping; Ji, Hong; Rong, Haiqin; Qu, Guangbo; Liu, Sijin

    2013-01-01

    Iron overload has been associated with bone mass loss. To elucidate the effects of excess iron on bone metabolism, an iron-overloading mouse model was established by administering iron-dextran at 250 mg/kg to female BALB/c mice. After 4 weeks, the mice were sacrificed and the biomechanical properties of the femurs were examined. The results suggested a notable decrease of the maximal bending stress and the modulus of bending elasticity in the femurs obtained from the excess iron-treated mice compared to the control mice. The levels of the serum osteocalcin, C-telopeptide of type I collagen (CTX-1) and tumor necrosis factor-α (TNF-α) were measured in order to investigate the underlying mechanism responsible for the excess iron-induced bone strength reduction. Overall, the results suggested that iron overload resulted in a marked reduction of bone load-bearing capacity through a TNF-triggered osteoclast differentiation and resorption mechanism.

  8. Effect of intracellular iron loading on lipid peroxidation of brain slices.

    PubMed

    Oubidar, M; Boquillon, M; Marie, C; Bouvier, C; Beley, A; Bralet, J

    1996-01-01

    The effect of artificially elevated cell iron content on oxygen-derived free radical production was assessed in brain slices by use of an iron ligand, 8-hydroxyquinoline (HQ). The iron complex Fe(3+)-HQ exhibited a high lipid solubility evidenced by n-octanol/water partition coefficient and was avidely taken up by brain slices. The catalytically active form of Fe3+ within the complex was evidenced by measuring the rate of ascorbate oxidation. Lipid peroxidation was assessed by measuring the thiobarbituric acid-reactive substances (TBARS) in brain homogenates or slices exposed to two doses of Fe(3+)-HQ (10 microM/20 microM, 100 microM/200 microM) or Fe(3+)-citrate (10 microM, 100 microM). Addition of the iron complexes to homogenates or slices resulted in a dose-dependent increase in lipid peroxidation. In homogenates, the effects were grossly similar with both complexes, whereas in slices the effects of Fe-HQ were significantly higher than those of Fe-citrate. Lipid peroxidation persisted in washed slices preexposed to Fe-HQ, but not in slices preexposed to the hydrophilic iron complex Fe-citrate. Fe-HQ-induced lipid peroxidation in slices was enhanced in the presence of H2O2, an effect that was not seen using Fe-citrate. Addition of Fe-HQ to brain homogenates in the presence of salicylic acid resulted in the production of 2,3-dihydroxybenzoic acid and the effect was potentiated in the presence of H2O2. This model of iron cell loading may be useful for evaluating the efficacy of antioxidant drugs.

  9. Effect of iron oxide loading on magnetoferritin structure in solution as revealed by SAXS and SANS.

    PubMed

    Melníková, L; Petrenko, V I; Avdeev, M V; Garamus, V M; Almásy, L; Ivankov, O I; Bulavin, L A; Mitróová, Z; Kopčanský, P

    2014-11-01

    Synthetic biological macromolecule of magnetoferritin containing an iron oxide core inside a protein shell (apoferritin) is prepared with different content of iron. Its structure in aqueous solution is analysed by small-angle synchrotron X-ray (SAXS) and neutron (SANS) scattering. The loading factor (LF) defined as the average number of iron atoms per protein is varied up to LF=800. With an increase of the LF, the scattering curves exhibit a relative increase in the total scattered intensity, a partial smearing and a shift of the match point in the SANS contrast variation data. The analysis shows an increase in the polydispersity of the proteins and a corresponding effective increase in the relative content of magnetic material against the protein moiety of the shell with the LF growth. At LFs above ∼150, the apoferritin shell undergoes structural changes, which is strongly indicative of the fact that the shell stability is affected by iron oxide presence. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Shear stress measurements in copper, iron, and mild steel under shock loading conditions

    SciTech Connect

    Millett, J.C.; Bourne, N.K.; Rosenberg, Z.

    1997-03-01

    A series of experiments have been conducted on metals subjected to planar impact loading in which a biaxial stress state and a uniaxial strain state is induced. Longitudinal and transverse stresses have been measured in copper, iron, and mild steel, using manganin stress gauges. The results have been used to calculate shear stress from the difference between the stress components. Results indicate that copper displays an increase in shear stress with pressure, showing similar trends to other work. An increase in dislocation density has been suggested as a possible mechanism. Iron shows a constant shear stress with increasing pressure, again in accordance with other workers. Finally, mild steel has been observed to have a significant increase in shear stress with increasing pressure. The inclusion of a hard second phase in the microstructure is thought to produce a large amount of dislocation debris, again explaining the observed hardening. {copyright} {ital 1997 American Institute of Physics.}

  11. Preparation and Characterization of Nanoscale Zero-Valent Iron-Loaded Porous Sepiolite for Decolorizing Methylene Blue in Aqueous Solutions

    NASA Astrophysics Data System (ADS)

    Wang, Qingmiao; Ren, Gaofeng; Jia, Feifei; Song, Shaoxian

    2017-04-01

    The preparation and characterization of nanoscale zero-valent iron-loaded porous sepiolite, as well as its application in the decolorization of methylene blue in aqueous solution, have been studied in this work through the measurements of field emission scanning electron microscope with energy dispersive spectrometry, x-ray photoelectron spectrometry, Fourier transform infrared spectroscopy and specific surface area. The results showed that nanoscale zero-valent iron particles were successfully loaded on the surface and interior pores of sepiolite through physical adsorption. It was revealed that the decoloration capacity of methylene blue on nanoscale zero-valent iron-loaded porous sepiolite in water was comparable to that of nanoscale zero-valent iron, and nine times higher than that of natural sepiolite. This indicates that porous sepiolite was a good supporter for the loading of nanoscale zero-valent iron and nanoscale zero-valent iron-loaded sepiolite was a good decolorant because of its high decoloration efficiency and easy separation.

  12. Preparation and Characterization of Nanoscale Zero-Valent Iron-Loaded Porous Sepiolite for Decolorizing Methylene Blue in Aqueous Solutions

    NASA Astrophysics Data System (ADS)

    Wang, Qingmiao; Ren, Gaofeng; Jia, Feifei; Song, Shaoxian

    2017-02-01

    The preparation and characterization of nanoscale zero-valent iron-loaded porous sepiolite, as well as its application in the decolorization of methylene blue in aqueous solution, have been studied in this work through the measurements of field emission scanning electron microscope with energy dispersive spectrometry, x-ray photoelectron spectrometry, Fourier transform infrared spectroscopy and specific surface area. The results showed that nanoscale zero-valent iron particles were successfully loaded on the surface and interior pores of sepiolite through physical adsorption. It was revealed that the decoloration capacity of methylene blue on nanoscale zero-valent iron-loaded porous sepiolite in water was comparable to that of nanoscale zero-valent iron, and nine times higher than that of natural sepiolite. This indicates that porous sepiolite was a good supporter for the loading of nanoscale zero-valent iron and nanoscale zero-valent iron-loaded sepiolite was a good decolorant because of its high decoloration efficiency and easy separation.

  13. Temporal changes in community composition of heterotrophic bacteria during in situ iron enrichment in the western subarctic Pacific (SEEDS-II)

    NASA Astrophysics Data System (ADS)

    Kataoka, Takafumi; Suzuki, Koji; Hayakawa, Maki; Kudo, Isao; Higashi, Seigo; Tsuda, Atsushi

    2009-12-01

    Little is known about the effects of iron enrichment in high-nitrate low-chlorophyll (HNLC) waters on the community composition of heterotrophic bacteria, which are crucial to nutrient recycling and microbial food webs. Using denaturing gradient gel electrophoresis (DGGE) of 16S rDNA fragments, we investigated the heterotrophic eubacterial community composition in surface waters during an in situ iron-enrichment experiment (SEEDS-II) in the western subarctic Pacific in the summer of 2004. DGGE fingerprints representing the community composition of eubacteria differed inside and outside the iron-enriched patch. Sequencing of DGGE bands revealed that at least five phylotypes of α-proteobacteria including Roseobacter, Cytophaga-Flavobacteria- Bacteroides (CFB), γ-proteobacteria, and Actinobacteria occurred in almost all samples from the iron-enriched patch. Diatoms did not bloom during SEEDS-II, but the eubacterial composition in the iron-enriched patch was similar to that in diatom blooms observed previously. Although dissolved organic carbon (DOC) accumulation was not detected in surface waters during SEEDS-II, growth of the Roseobacter clade might have been particularly stimulated after iron additions. Two identified phylotypes of CFB were closely related to the genus Saprospira, whose algicidal activity might degrade the phytoplankton assemblages increased by iron enrichment. These results suggest that the responses of heterotrophic bacteria to iron enrichment could differ among phylotypes during SEEDS-II.

  14. Acute acetaminophen intoxication leads to hepatic iron loading by decreased hepcidin synthesis.

    PubMed

    van Swelm, Rachel P L; Laarakkers, Coby M M; Blous, Linda; Peters, Janny G P; Blaney Davidson, Esmeralda N; van der Kraan, Peter M; Swinkels, Dorine W; Masereeuw, Rosalinde; Russel, Frans G M

    2012-09-01

    Acetaminophen (APAP), a major cause of acute liver injury in the Western world, is mediated by metabolism and oxidative stress. Recent studies have suggested a role for iron in potentiating APAP-induced liver injury although its regulatory mechanism is not completely understood. The current study was designed to unravel the iron-regulating pathways in mice after APAP-induced hepatotoxicity. Mice with severe injury showed a significant increase in liver iron concentration and oxidative stress. Concurrently, the plasma concentration of hepcidin, the key regulator in iron metabolism, and hepatic hepcidin antimicrobial peptide (Hamp) mRNA expression levels were significantly reduced. We showed that hepcidin transcription was inhibited via several hepcidin-regulating factors, including the bone morphogenetic protein/small mother against decapentaplegic (BMP/SMAD) pathway, CCAAT/enhancer-binding protein α (C/EBPα), and possibly also via erythropoietin (EPO). Downregulation of the BMP/SMAD signaling pathway was most likely caused by hypoxia-inducible factor 1α (HIF-1α), which was increased in mice with severe APAP-induced liver injury. HIF-1α stimulates cleaving of hemojuvelin, the cofactor of the BMP receptor, thereby blocking BMP-induced signaling. In addition, gene expression levels of C/ebpα were significantly reduced, and Epo mRNA expression levels were significantly increased after APAP intoxication. These factors are regulated through HIF-1α during oxidative stress and suggest that HIF-1α is a key modulator in reduced hepcidin transcription after APAP-induced hepatotoxicity. In conclusion, acute APAP-induced liver injury leads to activation of HIF-1α, which results in a downregulation in hepcidin expression through a BMP/SMAD signaling pathway and through C/EBPα inhibition. Eventually, this leads to hepatic iron loading associated with APAP cytotoxicity.

  15. Dynamics of trace metals during the subarctic Pacific iron experiment for ecosystem dynamics study (SEEDS2001)

    NASA Astrophysics Data System (ADS)

    Kinugasa, Masatoshi; Ishita, Tsunemi; Sohrin, Yoshiki; Okamura, Kei; Takeda, Shigenobu; Nishioka, Jun; Tsuda, Atsushi

    2005-02-01

    During the first iron-enrichment experiment in the northwest subarctic Pacific (SEEDS2001), the dynamics of dissolved and acid dissolvable trace metals were studied. Seawater samples were collected from the upper water column (5-70 m) of In- and Out-patch stations. Immediately after the collection, an aliquot of seawater for dissolved species was filtered through an 0.2 μm filter and acidified to pH 2.2. An aliquot for acid dissolvable species was acidified without filtration and stored for 3 years at an ambient temperature. Before the Fe enrichment, the dissolved Fe concentration in the surface mixed layer was <0.13 nM (the detection limit) and the acid dissolvable Fe concentration was 4.7 nM. The difference was a particulate fraction. Since the photochemical quantum efficiency of algal photosystem II was low, Fe in this fraction was not easily available to phytoplankton. After the Fe enrichment, acid dissolvable Fe in the patch decreased from 9.6 nM on day 2 to 4.6 nM on day 13, which was still ∼3 nM higher than that at the Out-patch station. Dissolved Fe was 1.4 nM on day 2 and decreased exponentially to <0.13 nM on day 11. The concentration ratio of the acid dissolvable fraction to the dissolved fraction for the other trace metals was lower than that for Fe. The acid dissolvable concentrations for Mn, Co, Ni, Cu, Zn and Cd did not show significant change during the observation. The dissolved concentrations for Co, Ni, Cu, Zn and Cd in the surface layer on day 2 were 0.039, 5.0, 1.7, 2.2 and 0.27 nM, respectively. They decreased exponentially to 0.013, 4.3, 1.2, 0.87 and 0.21 nM on day 13, respectively. The mole ratio of the concentration difference between days 2 and 13 was similar to the elemental ratio reported for phytoplankton. These are the first data showing that mesoscale iron fertilization alters the dynamics of dissolved Co, Ni, Cu and Zn.

  16. Effects of pollen load, parasitoids and the environment on pre-dispersal seed predation in the cleistogamous Ruellia nudiflora.

    PubMed

    Munguía-Rosas, Miguel A; Abdala-Roberts, Luis; Parra-Tabla, Víctor

    2013-11-01

    Few studies have simultaneously addressed the effects of biotic and abiotic factors on pre-dispersal seed predation (PSP). Plant-seed predator interactions may be influenced by natural enemies and pollinators (the latter through changes in fruit or seed traits), and the activity of pre-dispersal seed predators and their natural enemies may both be affected by the abiotic environment. Additionally, in the case of cleistogamous plants with fruit dimorphism, PSP may be biased towards larger and more seeded chasmogamous (CH) fruits [relative to the smaller cleistogamous (CL) fruits], and the effects of biotic and abiotic factors may be contingent upon this fruit dimorphism. We studied PSP in the cleistogamous Ruellia nudiflora using a split-plot experimental design and asked the following: (1) is PSP biased towards CH fruits and is there an effect of pollen load on PSP? (2) Do parasitoids influence PSP and is their effect influenced by pollen load or fruit type? And (3) do light and water availability modify PSP and parasitoid effects? PSP was higher for CH relative to CL fruits, and under low water availability it was lower for pollen-supplemented CH fruits relative to open-pollinated CH fruits. Parasitoids were not influenced by abiotic conditions, but their negative effect on PSP was stronger for pollen-supplemented CH fruits. Overall, we show that fruit dimorphism, abiotic factors and natural enemies affect PSP, and that these effects can be non-additive.

  17. Physical behavior of the SEEDS iron-fertilized patch by sulphur hexafluoride tracer release

    NASA Astrophysics Data System (ADS)

    Tsumune, Daisuke; Nishioka, Jun; Shimamoto, Akifumi; Takeda, Shigenobu; Tsuda, Atsushi

    2005-02-01

    The first iron (Fe) - fertilization experiment in the western North Pacific was carried out using SF 6 to trace the Fe-fertilized water mass. A solution in 10,800 liters of seawater of 350 kg of Fe and 0.48 M of SF 6 tracer was released into the mixed layer over a 8 × 10 km area. On the first underway transects through the patch after the Fe release, we observed a significant increase of dissolved Fe (ave. 2.89 nM). The fertilized patch was traced for 14 days by on-board SF 6 analysis. A Lagrangian frame of reference was maintained by the use of a drogued GPS buoy released at the center of the patch. The patch moved westward at a rate of 6.8 km d -1. Mixed layer depth increased from 8.5 to 15 m during the experiment. Horizontal diffusivity was determined by the change of SF 6 concentration in the patch. The horizontal diffusivity increased during the experiment. We evaluate here the fate of Fe in a Fe-fertilized patch using the dilution rate determined from sulphur hexafluoride (SF 6) concentration. Dissolved Fe concentrations subsequently decreased rapidly to ∼0.15 nM on Day 13. However, the dissolved Fe half-life of ∼43 h was relatively longer than in previous Fe-enrichment studies, and we observed a larger increase of the centric diatom standing stock and corresponding drawdown of macro-nutrients and carbon dioxide than in the previous studies. The most important reason for the larger response was the phytoplankton species in the western North Pacific. In addition, the smaller diffusivity and shallower mixed layer were effective to sustain the higher dissolved Fe concentration compared to previous experiments. This might be one reason for the larger response of diatoms in SEEDS.

  18. Myocardial Iron Loading Assessment by Automatic Left Ventricle Segmentation with Morphological Operations and Geodesic Active Contour on T2* images.

    PubMed

    Luo, Yun-gang; Ko, Jacky K L; Shi, Lin; Guan, Yuefeng; Li, Linong; Qin, Jing; Heng, Pheng-Ann; Chu, Winnie C W; Wang, Defeng

    2015-07-28

    Myocardial iron loading thalassemia patients could be identified using T2* magnetic resonance images (MRI). To quantitatively assess cardiac iron loading, we proposed an effective algorithm to segment aligned free induction decay sequential myocardium images based on morphological operations and geodesic active contour (GAC). Nine patients with thalassemia major were recruited (10 male and 16 female) to undergo a thoracic MRI scan in the short axis view. Free induction decay images were registered for T2* mapping. The GAC were utilized to segment aligned MR images with a robust initialization. Segmented myocardium regions were divided into sectors for a region-based quantification of cardiac iron loading. Our proposed automatic segmentation approach achieve a true positive rate at 84.6% and false positive rate at 53.8%. The area difference between manual and automatic segmentation was 25.5% after 1000 iterations. Results from T2* analysis indicated that regions with intensity lower than 20 ms were suffered from heavy iron loading in thalassemia major patients. The proposed method benefited from abundant edge information of the free induction decay sequential MRI. Experiment results demonstrated that the proposed method is feasible in myocardium segmentation and was clinically applicable to measure myocardium iron loading.

  19. Myocardial Iron Loading Assessment by Automatic Left Ventricle Segmentation with Morphological Operations and Geodesic Active Contour on T2* images

    NASA Astrophysics Data System (ADS)

    Luo, Yun-Gang; Ko, Jacky Kl; Shi, Lin; Guan, Yuefeng; Li, Linong; Qin, Jing; Heng, Pheng-Ann; Chu, Winnie Cw; Wang, Defeng

    2015-07-01

    Myocardial iron loading thalassemia patients could be identified using T2* magnetic resonance images (MRI). To quantitatively assess cardiac iron loading, we proposed an effective algorithm to segment aligned free induction decay sequential myocardium images based on morphological operations and geodesic active contour (GAC). Nine patients with thalassemia major were recruited (10 male and 16 female) to undergo a thoracic MRI scan in the short axis view. Free induction decay images were registered for T2* mapping. The GAC were utilized to segment aligned MR images with a robust initialization. Segmented myocardium regions were divided into sectors for a region-based quantification of cardiac iron loading. Our proposed automatic segmentation approach achieve a true positive rate at 84.6% and false positive rate at 53.8%. The area difference between manual and automatic segmentation was 25.5% after 1000 iterations. Results from T2* analysis indicated that regions with intensity lower than 20 ms were suffered from heavy iron loading in thalassemia major patients. The proposed method benefited from abundant edge information of the free induction decay sequential MRI. Experiment results demonstrated that the proposed method is feasible in myocardium segmentation and was clinically applicable to measure myocardium iron loading.

  20. Myocardial Iron Loading Assessment by Automatic Left Ventricle Segmentation with Morphological Operations and Geodesic Active Contour on T2* images

    PubMed Central

    Luo, Yun-gang; Ko, Jacky KL; Shi, Lin; Guan, Yuefeng; Li, Linong; Qin, Jing; Heng, Pheng-Ann; Chu, Winnie CW; Wang, Defeng

    2015-01-01

    Myocardial iron loading thalassemia patients could be identified using T2* magnetic resonance images (MRI). To quantitatively assess cardiac iron loading, we proposed an effective algorithm to segment aligned free induction decay sequential myocardium images based on morphological operations and geodesic active contour (GAC). Nine patients with thalassemia major were recruited (10 male and 16 female) to undergo a thoracic MRI scan in the short axis view. Free induction decay images were registered for T2* mapping. The GAC were utilized to segment aligned MR images with a robust initialization. Segmented myocardium regions were divided into sectors for a region-based quantification of cardiac iron loading. Our proposed automatic segmentation approach achieve a true positive rate at 84.6% and false positive rate at 53.8%. The area difference between manual and automatic segmentation was 25.5% after 1000 iterations. Results from T2* analysis indicated that regions with intensity lower than 20 ms were suffered from heavy iron loading in thalassemia major patients. The proposed method benefited from abundant edge information of the free induction decay sequential MRI. Experiment results demonstrated that the proposed method is feasible in myocardium segmentation and was clinically applicable to measure myocardium iron loading. PMID:26215336

  1. Iron-Loaded Magnetic Nanocapsules for pH-Triggered Drug Release and MRI Imaging

    PubMed Central

    2014-01-01

    Magnetic nanocapsules were synthesized for controlled drug release, magnetically assisted delivery, and MRI imaging. These magnetic nanocapsules, consisting of a stable iron nanocore and a mesoporous silica shell, were synthesized by controlled encapsulation of ellipsoidal hematite in silica, partial etching of the hematite core in acid, and reduction of the core by hydrogen. The iron core provided a high saturation magnetization and was stable against oxidation for at least 6 months in air and 1 month in aqueous solution. The hollow space between the iron core and mesoporous silica shell was used to load anticancer drug and a T1-weighted MRI contrast agent (Gd-DTPA). These multifunctional monodispersed magnetic “nanoeyes” were coated by multiple polyelectrolyte layers of biocompatible poly-l-lysine and sodium alginate to control the drug release as a function of pH. We studied pH-controlled release, magnetic hysteresis curves, and T1/T2 MRI contrast of the magnetic nanoeyes. They also served as MRI contrast agents with relaxivities of 8.6 mM–1 s–1 (r1) and 285 mM–1 s–1 (r2). PMID:24748722

  2. Development of iron/ethylcellulose (core/shell) nanoparticles loaded with diclofenac sodium for arthritis treatment.

    PubMed

    Arias, José L; López-Viota, Margarita; López-Viota, Julián; Delgado, Angel V

    2009-12-01

    Diclofenac sodium is a non-steroidal anti-inflammatory drug of choice to treat arthritis because of its potential anti-inflammatory and analgesic activity. Because of its shorter biological half-life, it is needed to be given frequently and at high doses to elicit the required therapeutic activity, simultaneously leading to severe side effects. We hypothesized that the efficient delivery of diclofenac sodium to inflammation using a magnetic colloid could reduce the dose required to bring out sufficient therapeutic response. Hence, we have developed a diclofenac sodium-loaded magnetic nanomedicine, consisting of a magnetic core (iron) and a biocompatible polymeric shell (ethylcellulose) for parenteral administration. These core/shell nanoparticles were synthesized by an emulsion solvent evaporation process. Two drug loading methods were analyzed: the first one being drug addition prior to the emulsion solvent evaporation process (leading to drug entrapment into the polymeric network), and the second method based on diclofenac sodium surface adsorption onto the preformed nanoparticles. Compared to drug adsorption, the entrapment of this active agent into the polymeric matrix yielded a higher drug loading and a slower drug release profile. Such nanocomposites possessed very important characteristics such as unusually high drug loading, enhanced magnetic susceptibility and prolonged drug release, indicating their potential use as nanocarriers for efficient delivery of diclofenac sodium to inflammation sites.

  3. [An experimental study on the protective effect of hepatocyte growth factor (HGF) for the primary cultured hepatocytes obtained from iron-loaded rats].

    PubMed

    Yoshida, J

    1995-01-01

    Pathological iron deposition in liver is often found in various liver diseases. The deposited iron is thought to be one of the most important factor of liver cell injury, not only in hemochromotosis but also in cirrhosis following hepatitis virus B or C infection. To investigate the influence of the deposited iron on damage and regeneration of hepatocyte, primary cultured hepatocytes obtained from carbonyl iron-loaded rats were treated with carbon tetrachloride (CCl4) in the presence or absence of hepatocyte growth factor (HGF). Although the section of liver from carbonyl iron-loaded rats showed no necrosis and fibrosis, iron-loaded hepatocytes contained about twofold more iron than control. The damage of iron-loaded hepatocytes induced by CCl4 was more serious than that of control, and HGF decreased this injury only in iron-loaded hepatocytes but not in control. There is no difference in DNA synthesis stimulated by HGF between iron-loaded hepatocytes and control. These findings suggest that the pathological iron deposition induces the fragility of hepatocyte and that cytoprotective effect of HGF is induced by this pathological iron.

  4. Inheritance of seed iron and zinc concentrations in common bean (Phaseolus vulgaris L.)

    USDA-ARS?s Scientific Manuscript database

    Micronutrients are essential elements needed in small amounts for adequate human nutrition and include the elements iron and zinc. Both of these minerals are essential to human well-being, and an adequate supply of iron and zinc helps to prevent iron deficiency anemia and zinc deficiency, two preva...

  5. Strong sexual selection in males against a mutation load that reduces offspring production in seed beetles.

    PubMed

    Grieshop, K; Stångberg, J; Martinossi-Allibert, I; Arnqvist, G; Berger, D

    2016-06-01

    Theory predicts that sexual reproduction can increase population viability relative to asexual reproduction by allowing sexual selection in males to remove deleterious mutations from the population without large demographic costs. This requires that selection acts more strongly in males than females and that mutations affecting male reproductive success have pleiotropic effects on population productivity, but empirical support for these assumptions is mixed. We used the seed beetle Callosobruchus maculatus to implement a three-generation breeding design where we induced mutations via ionizing radiation (IR) in the F0 generation and measured mutational effects (relative to nonirradiated controls) on an estimate of population productivity in the F1 and effects on sex-specific competitive lifetime reproductive success (LRS) in the F2 . Regardless of whether mutations were induced via F0 males or females, they had strong negative effects on male LRS, but a nonsignificant influence on female LRS, suggesting that selection is more efficient in removing deleterious alleles in males. Moreover, mutations had seemingly shared effects on population productivity and competitive LRS in both sexes. Thus, our results lend support to the hypothesis that strong sexual selection on males can act to remove the mutation load on population viability, thereby offering a benefit to sexual reproduction.

  6. Effect of ferrous sulfate fortification in germinated brown rice on seed iron concentration and bioavailability.

    PubMed

    Wei, Yanyan; Shohag, M J I; Ying, Feng; Yang, Xiaoe; Wu, Chunyong; Wang, Yuyan

    2013-06-01

    The present study evaluated the effectiveness of germination and iron fortification on iron concentration and bioavailability of brown rice. Iron fortification during germination process with 0.05-2 g/L ferrous sulfate increased the iron concentration in germinated brown rice from 1.1 to 15.6 times than those in raw brown rice. Based on the recommended dietary allowance of iron, maximum germination rate and γ-aminobutyric acid, we recommend the brown rice fortified with 0.25 g/L FeSO(4) as a suitable fortification level to use in germination process. Iron fortification during the germination process has a positive effect on iron concentration and bioavailability. A significant difference was observed among the cultivars in respect to the capacity for iron accumulation and bioavailability. Germination alone could improve in vitro iron solubility, but had no effect on iron bioavailability in Caco-2 cell, the additional fortification process should be combined to get high amount of bioavailable iron from the brown rice.

  7. Iron

    MedlinePlus

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  8. Chronic Opisthorchis viverrini infection and associated hepatobiliary disease is associated with iron loaded M2-like macrophages.

    PubMed

    Bility, Moses T; Sripa, Banchob

    2014-12-01

    Chronic Opisthorchis viverrini-induced hepatobiliary disease is associated with significant leukocyte infiltration, including activated macrophages; however, the polarization of infiltrating macrophages remains to be fully characterized. In this study, we characterized macrophage polarization and phenotype in chronic O. viverrini-induced hepatobiliary disease in humans and hamsters using gene expression and histochemical analysis. Chronic O. viverrini infection and associated hepatobiliary diseases were associated with iron loaded M2-like macrophages in both humans and hamsters. This study provides suggestive evidence that iron loaded M2-like macrophages promote hepatobiliary disease in chronic O. viverrini infection.

  9. Fabrication of Tamarindus indica seeds extract loaded-cream for photo-aged skin: Visioscan® studies

    PubMed Central

    Waqas, Muhammad Khurram; Akhtar, Naveed; Chowdhry, Farzana; Khan, Haroon; Bakhsh, Sattar; Khan, Shahzeb; Rasul, Akhtar

    2017-01-01

    Introduction Intracellular and extracellular oxidative stress triggered by free radicals promotes skin aging, which is designated by atypical pigmentation and wrinkles. The consumption of antioxidants is an efficacious measure to avert symptoms involved in skin aging. Aim The current research was commenced to explore the anti-aging potential of antioxidants present in Tamarindus indica seeds extract. Material and methods Tamarindus indica seeds extract was obtained by concentrating the ethanolic extract of seeds. The antioxidant activities of the extract were measured by nitric oxide radical scavenging assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, hydroxyl radical scavenging assay and superoxide radical scavenging assay. Formulation comprising 4% of the concentrated extract of seeds was formulated by loading it in the internal aqueous phase of water-in-oil (W/O) cosmetic emulsion. The base, used as control, consisted of the same emulsion but without loading Tamarindus indica seeds extract. The cosmetic emulsions were applied to the cheeks of 11 healthy male volunteers for duration of 12 weeks. Both base and formulation were assessed for their antioxidant effects on different skin parameters i.e. skin moisture contents, elasticity and surface evaluation of living skin (SELS). Results The formulation showed statistically significant (p ≤ 0.05) and the base showed insignificant (p > 0.05) effects on skin elasticity and skin moisture contents. There is a significant decline in SELS, skin scaliness (SEsc), skin wrinkles (SEw), skin smoothness (SEsm), and skin roughness (SEr) parameters after application of the formulation. Conclusions Topical application of the cosmetic emulsion entrapped with Tamarindus indica seeds extract containing various antioxidants exerts potential skin antiaging effects. PMID:28951709

  10. An Enhanced Drought-Tolerant Method Using SA-Loaded PAMPS Polymer Materials Applied on Tobacco Pelleted Seeds

    PubMed Central

    Guan, Yajing; Cui, Huawei; Ma, Wenguang; Zheng, Yunye; Tian, Yixin; Hu, Jin

    2014-01-01

    Drought is one of the most important stress factors limiting the seed industry and crop production. Present study was undertaken to create novel drought-resistant pelleted seeds using the combined materials with superabsorbent polymer, poly(2-acrylamide-2-methyl propane sulfonic acid) (PAMPS) hydrogel, and drought resistance agent, salicylic acid (SA). The optimized PAMPS hydrogel was obtained as the molar ratio of 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) to potassium peroxydisulfate (KPS) and N, N′-methylene-bis-acrylamide (MBA) was 1 : 0.00046 : 0.00134. The hydrogel weight after swelling in deionized water for 24 h reached 4306 times its own dry weight. The water retention ratio (RR) of PAMPS was significantly higher as compared with the control. It could keep as high as 85.3% of original weight after 30 min at 110°C; even at 25°C for 40 d, the PAMPS still kept RR at 33.67%. PAMPS disintegration ratio increased gradually and reached around 30% after embedding in soil or activated sludge for 60 d. In addition, there were better seed germination performance and seedling growth in the pelleted treatments with SA-loaded PAMPS hydrogel under drought stress than control. It suggested that SA-loaded PAMPS hydrogel, a nontoxic superabsorbent polymer, could be used as an effective drought resistance material applied to tobacco pelleted seeds. PMID:25250387

  11. An enhanced drought-tolerant method using SA-loaded PAMPS polymer materials applied on tobacco pelleted seeds.

    PubMed

    Guan, Yajing; Cui, Huawei; Ma, Wenguang; Zheng, Yunye; Tian, Yixin; Hu, Jin

    2014-01-01

    Drought is one of the most important stress factors limiting the seed industry and crop production. Present study was undertaken to create novel drought-resistant pelleted seeds using the combined materials with superabsorbent polymer, poly(2-acrylamide-2-methyl propane sulfonic acid) (PAMPS) hydrogel, and drought resistance agent, salicylic acid (SA). The optimized PAMPS hydrogel was obtained as the molar ratio of 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) to potassium peroxydisulfate (KPS) and N, N'-methylene-bis-acrylamide (MBA) was 1 : 0.00046 : 0.00134. The hydrogel weight after swelling in deionized water for 24 h reached 4306 times its own dry weight. The water retention ratio (RR) of PAMPS was significantly higher as compared with the control. It could keep as high as 85.3% of original weight after 30 min at 110 °C; even at 25 °C for 40 d, the PAMPS still kept RR at 33.67%. PAMPS disintegration ratio increased gradually and reached around 30% after embedding in soil or activated sludge for 60 d. In addition, there were better seed germination performance and seedling growth in the pelleted treatments with SA-loaded PAMPS hydrogel under drought stress than control. It suggested that SA-loaded PAMPS hydrogel, a nontoxic superabsorbent polymer, could be used as an effective drought resistance material applied to tobacco pelleted seeds.

  12. Effects of sediment load on emergence of aquatic invertebrates and plants from wetland soil egg and seed banks

    USGS Publications Warehouse

    Gleason, R.A.; Euliss, N.H.; Hubbard, D.E.; Duffy, W.G.

    2003-01-01

    Intensive agricultural activities near prairie wetlands may result in excessive sediment loads, which may bury seed and invertebrate egg banks that are important for maintenance and cycling of biotic communities during wet/dry cycles. Sediment-load experiments indicated that burial depths of 0.5 cm caused a 91.7% reduction in total seedling emergence and a 99.7% reduction in total invertebrate emergence. These results suggest sediment entering wetlands from agricultural erosion may hamper successional changes throughout interannual climate cycles.

  13. Moving toward a precise nutrition: preferential loading of seeds with essential nutrients over non-essential toxic elements

    PubMed Central

    Khan, Mather A.; Castro-Guerrero, Norma; Mendoza-Cozatl, David G.

    2014-01-01

    Plants and seeds are the main source of essential nutrients for humans and livestock. Many advances have recently been made in understanding the molecular mechanisms by which plants take up and accumulate micronutrients such as iron, zinc, copper and manganese. Some of these mechanisms, however, also facilitate the accumulation of non-essential toxic elements such as cadmium (Cd) and arsenic (As). In humans, Cd and As intake has been associated with multiple disorders including kidney failure, diabetes, cancer and mental health issues. Recent studies have shown that some transporters can discriminate between essential metals and non-essential elements. Furthermore, sequestration of non-essential elements in roots has been described in several plant species as a key process limiting the translocation of non-essential elements to aboveground edible tissues, including seeds. Increasing the concentration of bioavailable micronutrients (biofortification) in grains while lowering the accumulation of non-essential elements will likely require the concerted action of several transporters. This review discusses the most recent advances on mineral nutrition that could be used to preferentially enrich seeds with micronutrients and also illustrates how precision breeding and transport engineering could be used to enhance the nutritional value of crops by re-routing essential and non-essential elements to separate sink tissues (roots and seeds). PMID:24600463

  14. Low prevalence of cardiac siderosis in heavily iron loaded Egyptian thalassemia major patients.

    PubMed

    El Beshlawy, Amal; El Tagui, Mona; Hamdy, Mona; El Ghamrawy, Mona; Azim, Khaled Abdel; Salem, Doria; Said, Fadwa; Samir, Ahmed; St Pierre, Timothy; Pennell, Dudley J

    2014-03-01

    Myocardial siderosis in thalassemia major remains the leading cause of death in developing countries. Once heart failure develops, the outlook is usually poor with precipitous deterioration and death. Cardiovascular magnetic resonance (CMR) can measure cardiac iron deposition directly using the magnetic relaxation time T2*. This allows earlier diagnosis and treatment and helps to reduce mortality from this cardiac affection. This study aims to determine the prevalence of cardiac siderosis in Egyptian patients who are heavily iron loaded and its relation to liver iron concentration, serum ferritin, and left ventricular ejection fraction. Eighty-nine β-thalassemia patients receiving chelation therapy (mean age of 20.8 ± 6.4 years) were recruited in this study. Tissue iron levels were determined by CMR with cardiac T2* and liver R2*. The mean ± standard deviation (range) of cardiac T2* was 28.5 ± 11.7 ms (4.3 to 53.8 ms), the left ventricular ejection fraction (LVEF) was 67.7 ± 4.7 % (55 to 78 %), and the liver iron concentration (LIC) was 26.1 ± 13.4 mg Fe/g dry weight (dw) (1.5 to 56 mg Fe/g dw). The mean serum ferritin was 4,510 ± 2,847 ng/ml (533 to 22,360 ng/ml), and in 83.2 %, the serum ferritin was >2,500 ng/ml. The prevalence of myocardial siderosis (T2* of <20 ms) was 24.7 % (mean age 20.9 ± 7.5 years), with mean T2* of 12.7 ± 4.4 ms, mean LVEF of 68.6 ±5.8 %, mean LIC of 30.9 ± 13 mg Fe/g dw, and median serum ferritin of 4,996 ng/ml. There was no correlation between T2* and age, LVEF, LIC, and serum ferritin (P = 0.65, P = 0.085, P = 0.99, and P = 0.63, respectively). Severe cardiac siderosis (T2* of <10 ms) was present in 7.9 %, with a mean age of 18.4 ± 4.4 years. Although these patients had a mean T2* of 7.8 ± 1.7 ms, the LVEF was 65.1 ± 6.2 %, and only one patient had heart failure (T2* of 4.3 ms and LVEF of 55 %). LIC and serum ferritin results were 29.8 ± 17.0 mg/g and 7

  15. Albumin and Hyaluronic Acid-Coated Superparamagnetic Iron Oxide Nanoparticles Loaded with Paclitaxel for Biomedical Applications.

    PubMed

    Vismara, Elena; Bongio, Chiara; Coletti, Alessia; Edelman, Ravit; Serafini, Andrea; Mauri, Michele; Simonutti, Roberto; Bertini, Sabrina; Urso, Elena; Assaraf, Yehuda G; Livney, Yoav D

    2017-06-22

    Super paramagnetic iron oxide nanoparticles (SPION) were augmented by both hyaluronic acid (HA) and bovine serum albumin (BSA), each covalently conjugated to dopamine (DA) enabling their anchoring to the SPION. HA and BSA were found to simultaneously serve as stabilizing polymers of Fe₃O₄·DA-BSA/HA in water. Fe₃O₄·DA-BSA/HA efficiently entrapped and released the hydrophobic cytotoxic drug paclitaxel (PTX). The relative amount of HA and BSA modulates not only the total solubility but also the paramagnetic relaxation properties of the preparation. The entrapping of PTX did not influence the paramagnetic relaxation properties of Fe₃O₄·DA-BSA. Thus, by tuning the surface structure and loading, we can tune the theranostic properties of the system.

  16. Lasing and magnetic microbeads loaded with colloidal quantum dots and iron oxide nanocrystals.

    PubMed

    Li, Minxu; You, Guanjun; Wang, Andrew Y; Hu, Wenjia; Wang, Jingkang; Sun, Fengqing; Zhu, Yiming; Henderson, Ron; Xu, Jian

    2013-10-21

    This study investigates the feasibility of loading nanostructured lasing medium and magnetic nanocrystals in the same microbead for potential applications in bio- and chemical sensing. A sequential infiltration process is proposed and tested for the preparation of magnetic and lasing microbeads by incorporating, respectively, iron oxide nanocrystals in the inner cores and colloidal quantum dots (CQDs) in the periphery regions of mesoporous silica microbeads. The co-doped bead structure was confirmed by electron microscopy and energy dispersive spectroscopy. The lasing action of the CQD gain medium in the mesoporous beads was characterized with micro-photoluminescence, revealing sharp whispering gallery mode lasing signatures, whereas the distinguishing superparamagnetic property was measured from the co-doped microbeads with vibrating sample magnetometry.

  17. Effects of Radiation and a High Iron Load on Bone Mineral Density

    NASA Technical Reports Server (NTRS)

    Yuen, E.; Morgan, J. L. L.; Zwart, S. R.; Gonzales, E.; Camp, K.; Smith, S. M.; Bloomfield, S. A.

    2012-01-01

    Astronauts on long duration space flight missions to the moon or mars are exposed to radiation and have increase iron (Fe) stores, both of which can independently induce oxidative stress and may exacerbate bone mass loss and strength. We hypothesize a high Fe diet and a fractionated gamma radiation exposure would increase oxidative stress and lower bone mass. Three mo-old, SD rats (n=32) were randomized to receive an adequate Fe diet (45 mg Fe/kg diet) or a high Fe diet (650 mg Fe/kg diet) for 4 wks and either a cumulative 3 Gy dose (fractionated 8 x 0.375 Gy) of gamma radiation (Cs-137) or sham exposure starting on day 14. Elisa kit assessed serum catalase, clinical analyzer assessed serum Fe status and ex vivo pQCT scans measured bone parameters in the proximal/midshaft tibia and femoral neck. Mechanical strength was assessed by 3-pt bending and femoral neck test. There is a significant decrease in trabecular bone mineral density (BMD) from radiation (p less than 0.05) and a trend in diet (p=0.05) at the proximal tibia. There is a significant interaction in cortical BMD from the combined treatments at the midshaft tibia (p less than 0.05). There is a trending decrease in total BMD from diet (p=0.07) at the femoral neck. In addition, high serum Fe was correlated to low trabecular BMD (p less than 0.05) and high serum catalase was correlated to low BMD at all 3 bone sites (p less than 0.05). There was no difference in the max load of the tibia or femoral neck. Radiation and a high iron diet increases iron status and catalase in the serum and decreases BMD.

  18. Doxorubicin loaded iron oxide nanoparticles overcome multidrug resistance in cancer in vitro.

    PubMed

    Kievit, Forrest M; Wang, Freddy Y; Fang, Chen; Mok, Hyejung; Wang, Kui; Silber, John R; Ellenbogen, Richard G; Zhang, Miqin

    2011-05-30

    Multidrug resistance (MDR) is characterized by the overexpression of ATP-binding cassette (ABC) transporters that actively pump a broad class of hydrophobic chemotherapeutic drugs out of cancer cells. MDR is a major mechanism of treatment resistance in a variety of human tumors, and clinically applicable strategies to circumvent MDR remain to be characterized. Here we describe the fabrication and characterization of a drug-loaded iron oxide nanoparticle designed to circumvent MDR. Doxorubicin (DOX), an anthracycline antibiotic commonly used in cancer chemotherapy and substrate for ABC-mediated drug efflux, was covalently bound to polyethylenimine via a pH sensitive hydrazone linkage and conjugated to an iron oxide nanoparticle coated with amine terminated polyethylene glycol. Drug loading, physiochemical properties and pH lability of the DOX-hydrazone linkage were evaluated in vitro. Nanoparticle uptake, retention, and dose-dependent effects on viability were compared in wild-type and DOX-resistant ABC transporter over-expressing rat glioma C6 cells. We found that DOX release from nanoparticles was greatest at acidic pH, indicative of cleavage of the hydrazone linkage. DOX-conjugated nanoparticles were readily taken up by wild-type and drug-resistant cells. In contrast to free drug, DOX-conjugated nanoparticles persisted in drug-resistant cells, indicating that they were not subject to drug efflux. Greater retention of DOX-conjugated nanoparticles was accompanied by reduction of viability relative to cells treated with free drug. Our results suggest that DOX-conjugated nanoparticles could improve the efficacy of chemotherapy by circumventing MDR. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Fibrosis in Chronic Hepatitis C: Correlation between Immunohistochemically-Assessed Virus Load with Steatosis and Cellular Iron Content

    PubMed Central

    Akl, Maha; Hindawi, Ali EL; Mosaad, Maha; Montasser, Ahmed; Ray, Ahmed El; Khalil, Heba; Anas, Amgad; Atta, Raffat; Paradis, Valerie; Hadi, Ahmed Abdel; Hammam, Olfat

    2016-01-01

    AIM: We aimed study impact of hepatocytic viral load, steatosis, and iron load on fibrosis in chronic hepatitis C and role of VEGF and VEGFR overexpression in cirrhotic cases in evolving HCC. MATERIAL AND METHODS: Total of 120 cases were included from TBRI and Beaujon Hospital as chronic hepatitis C (CHC), post-hepatitis C cirrhosis, and HCC. Cases of CHC were stained for Sirius red, Prussian blue and immunohistochemically (IHC) for HCV-NS3/NS4. HCC were stained IHC for VEGF and by FISH. RESULTS: Stage of fibrosis was significantly correlated with inflammation in CHC (P < 0.01). Noticed iron load did not correlate with fibrosis. Steatosis was associated with higher inflammation and fibrosis. The cellular viral load did not correlate with inflammation, steatosis or fibrosis. VEGF by IHC was significantly higher in cases of HCC when compared to cirrhotic group (P < 0.001). Amplification of VEGFR2 was confirmed in 40% of cases of HCC. Scoring of VEGF by IHC was the good indicator of VEGFR2 amplification by FISH (P < 0.005). CONCLUSION: Grade of inflammation is the factor affecting fibrosis in CHC. The degree of liver damage is not related to cellular viral load or iron load. Steatosis is associated with higher inflammation and fibrosis. VEGF by IHC is correlated with overexpression of VEGFR2 by FISH. PMID:28028394

  20. NADH induces iron release from pea seed ferritin: a model for interaction between coenzyme and protein components in foodstuffs.

    PubMed

    Lv, Chenyan; Bai, Yufei; Yang, Senpei; Zhao, Guanghua; Chen, Bin

    2013-12-15

    Plant ferritin from legume seeds co-exists with coenzyme NADH (a reduced form of nicotinamide-adenine dinucleotide) in many foodstuffs. In the present study, the interaction of NADH with apo pea seed ferritin (PSF) was investigated by fluorescence resonance energy transfer (FRET), fluorescence titration, transmission electron microscope (TEM), and isothermal titration calorimetry (ITC). We found that NADH molecules bound on the outer surface of PSF close to the 4-fold channels, which was 1.58 nm from tryptophan residue (Trp). Consequently, such binding facilitates iron release from holo PSF, which might have a negative effect on PSF as an iron supplement, while NADH was oxidised into NAD(+). However, the binding of NADH to the protein does not affect the entry of toxic ferrous ions into the apo protein shell, where these ferrous ions were oxidised into less toxic ferric ions. Moreover, NADH binding markedly affects the tertiary structure around Trp residues of PSF. These findings advanced our understanding of the interactions between different naturally occurring components in a complex food system.

  1. Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values.

    PubMed

    Koster van Groos, Paul G; Kaplan, Daniel I; Chang, Hyun-Shik; Seaman, John C; Li, Dien; Peacock, Aaron D; Scheckel, Kirk G; Jaffé, Peter R

    2016-11-01

    Small-scale continuous flow wetland mesocosms (∼0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed sediments were an order of magnitude greater than concentrations in root excluded sediments. Micro X-ray absorption near-edge structure (μ-XANES) spectroscopy indicated that U was associated with the plant roots primarily as U(VI) or U(V), with limited evidence of U(IV). Micro X-ray fluorescence (μ-XRF) of plant roots suggested that for high iron loading at circumneutral pH, U was co-located with Fe, perhaps co-precipitated with root Fe plaques, while for low iron loading at a pH of ∼4 the correlation between U and Fe was not significant, consistent with previous observations of U associated with organic matter. Quantitative PCR analyses indicated that the root exposed sediments also contained elevated numbers of Geobacter spp., which are likely associated with enhanced iron cycling, but may also reduce mobile U(VI) to less mobile U(IV) species.

  2. Differential iron distribution in seeds of two closely related legume species

    USDA-ARS?s Scientific Manuscript database

    The World Health Organization states that the lack of micronutrients such as zinc and iron represents a major threat to the health and development of populations around the world. Iron deficiency affects over 2 billion people, in particular children and pregnant women in developing countries. A comm...

  3. Heterogeneous catalytic ozonation of dibutyl phthalate in aqueous solution in the presence of iron-loaded activated carbon.

    PubMed

    Huang, Yuanxing; Cui, Chenchen; Zhang, Daofang; Li, Liang; Pan, Ding

    2015-01-01

    Iron-loaded activated carbon was prepared and used as catalyst in heterogeneous catalytic ozonation of dibutyl phthalate (DBP). The catalytic activity of iron-loaded activated carbon was investigated under various conditions and the mechanisms of DBP removal were deduced. Characterization of catalyst indicated that the iron loaded on activated carbon was mainly in the form of goethite, which reduced its surface area, pore volume and pore diameter. The presence of metals on activated carbon positively contributed to its catalytic activity in ozonation of DBP. Iron loading content of 15% and initial water pH of 8 achieved highest DBP removal among all the tried conditions. Catalyst dosage of 10 mg L(-1) led to approximately 25% of increase in DBP (initial concentration 2 mg L(-1)) removal in 60 min as compared with ozone alone, and when catalyst dosage increased to 100 mg L(-1), the DBP removal was further improved by 46%. Based on a comparison of reaction rates for direct and indirect transformation of DBP, the increased removal of DBP in this study likely occurred via transformation of ozone into hydroxyl radicals on the catalyst surface.

  4. Dual drug loaded superparamagnetic iron oxide nanoparticles for targeted cancer therapy.

    PubMed

    Dilnawaz, Fahima; Singh, Abhalaxmi; Mohanty, Chandana; Sahoo, Sanjeeb K

    2010-05-01

    The primary inadequacy of chemotherapeutic drugs is their relative non-specificity and potential side effects to the healthy tissues. To overcome this, drug loaded multifunctional magnetic nanoparticles are conceptualized. We report here an aqueous based formulation of glycerol monooleate coated magnetic nanoparticles (GMO-MNPs) devoid of any surfactant capable of carrying high payload hydrophobic anticancer drugs. The biocompatibility was confirmed by tumor necrosis factor alpha assay, confocal microscopy. High entrapment efficiency approximately 95% and sustained release of encapsulated drugs for more than two weeks under in vitro conditions was achieved for different anticancer drugs (paclitaxel, rapamycin, alone or combination). Drug loaded GMO-MNPs did not affect the magnetization properties of the iron oxide core as confirmed by magnetization study. Additionally the MNPs were functionalized with carboxylic groups by coating with DMSA (Dimercaptosuccinic acid) for the supplementary conjugation of amines. For targeted therapy, HER2 antibody was conjugated to GMO-MNPs and showed enhanced uptake in human breast carcinoma cell line (MCF-7). The IC(50) doses revealed potential antiproliferative effect in MCF-7. Therefore, antibody conjugated GMO-MNPs could be used as potential drug carrier for the active therapeutic aspects in cancer therapy.

  5. Sonochemical synthesis of iron oxide nanoparticles loaded with folate and cisplatin: effect of ultrasonic frequency.

    PubMed

    Dolores, Reyman; Raquel, Serrano; Adianez, Garcia-Leis

    2015-03-01

    Simple preparative methods were used to sonosynthesize different magnetic iron oxide nanoparticles (FeNPs) via co-precipitation of aqueous solutions of ferrous salts in a basic aqueous solution of ethylene glycol (EG). Sonosynthesis was achieved using different frequencies of ultrasound: 581, 861, and 1141 kHz under the same acoustic power. The hydroxyl radicals generated by cavitational collapse, induced by the ultrasonic field, led to the oxidation of Fe(2+) to Fe(3+). The rate of sonochemical Fe(3+) production decreased linearly with the frequency. Three different systems of FeNPs were synthesized, all with the same core but a different shell: FeNPs capped with EG (EG/FeNPs), FeNPs capped with EG and folate (Fol/EG/FeNPs), and FeNPs capped with EG, folate and cisplatin (Pt/EG/FeNPs). The nanoparticles were characterized by transmission electron microscopy, fluorescence and Raman microspectroscopy, total-reflection X-ray fluorescence, and elemental analysis (C, N, and H). The magnetization hysteresis loops of these samples were also measured. The obtained values of saturation magnetization were within the interval between 60 and 93 Am(2)kg(-1). From the analysis of these results, it was found that the ultrasonic frequency did not affect the nanoparticle size (diameter of 21-31 nm). In contrast, the frequency affected the amount of drug loaded, as cisplatin loading increased proportionately with ultrasound frequency. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Bioremediation of Wastewater by Iron Oxide-Biochar Nanocomposites Loaded with Photosynthetic Bacteria

    PubMed Central

    He, Shiying; Zhong, Linghao; Duan, Jingjing; Feng, Yanfang; Yang, Bei; Yang, Linzhang

    2017-01-01

    It has been reported that bacteria-mediated degradation of contaminants is a practical and innocuous wastewater treatment. In addition, iron oxide nanoparticles (NP) are wastewater remediation agents with great potentials due to their strong adsorption capacity, chemical inertness and superparamagnetism. Therefore, a combination of NPs and microbes could produce a very desirable alternative to conventional wastewater treatment. For this purpose, we first prepared Fe3O4/biochar nano-composites, followed by loading photosynthetic bacteria (PSB) onto them. It was found that Fe3O4/biochar nano-composites exhibited a high adsorption capacity for PSB (5.45 × 109 cells/g). The efficiency of wastewater pollutants removal by this PSB/Fe3O4/biochar agent was then analyzed. Our results indicated that when loaded onto Fe3O4/biochar nano-composites, PSB’s nutrient removal capability was significantly enhanced (P < 0.05). This agent removed 83.1% of chemical oxygen demand, 87.5% of NH4+, and 92.1% of PO43- from the wastewater in our study. Our experiments also demonstrated that such composites are outstanding recyclable agents. Their nutrient removal capability remained effective even after five cycles. In conclusion, we found the PSB/Fe3O4/biochar composites as a very promising material for bioremediation in the wastewater treatment. PMID:28588556

  7. Excess iron undermined bone load-bearing capacity through tumor necrosis factor-α-dependent osteoclastic activation in mice

    PubMed Central

    LI, JUNPING; HOU, YANLI; ZHANG, SHUPING; JI, HONG; RONG, HAIQIN; QU, GUANGBO; LIU, SIJIN

    2013-01-01

    Iron overload has been associated with bone mass loss. To elucidate the effects of excess iron on bone metabolism, an iron-overloading mouse model was established by administering iron-dextran at 250 mg/kg to female BALB/c mice. After 4 weeks, the mice were sacrificed and the biomechanical properties of the femurs were examined. The results suggested a notable decrease of the maximal bending stress and the modulus of bending elasticity in the femurs obtained from the excess iron-treated mice compared to the control mice. The levels of the serum osteocalcin, C-telopeptide of type I collagen (CTX-1) and tumor necrosis factor-α (TNF-α) were measured in order to investigate the underlying mechanism responsible for the excess iron-induced bone strength reduction. Overall, the results suggested that iron overload resulted in a marked reduction of bone load-bearing capacity through a TNF-triggered osteoclast differentiation and resorption mechanism. PMID:24648899

  8. Folic acid-conjugated iron oxide porous nanorods loaded with doxorubicin for targeted drug delivery.

    PubMed

    Yu, Ping; Xia, Xi-Ming; Wu, Ming; Cui, Can; Zhang, Yang; Liu, Lei; Wu, Bo; Wang, Cai-Xia; Zhang, Liu-Jie; Zhou, Xiang; Zhuo, Ren-Xi; Huang, Shi-Wen

    2014-08-01

    Iron oxide porous nanorods (IOPNR) with lengths ranging from 40nm to 60nm and pore diameters ranging from 5nm to 10nm were prepared, and further modified with NH2-PEG-FA (FA-PEG-IOPNR) for ligand targeting and modified with NH2-PEG-OCH3 (PEG-IOPNR) as a control. Instead of chemical bonding, doxorubicin (DOX), a low water solubility anticancer drug, was loaded in the pores of the modified IOPNR because of their porous structure and high porosity. The release of DOX in acidic PBS solution (pH 5.3) was faster than that in neutral (pH 7.4) solution. The analysis results from TEM, inductively coupled plasma emission spectroscopy, confocal laser scanning microscopy, and flow cytometry analyses indicated that the presence of FA on the surface of the nanorods increase the cellular uptake of nanorods in the case of HeLa cells, a folate receptor (FR)-positive cell line. In contrast, for COS 7 cells, a FR-negative cell line, FA ligand on the surface of the nanorods showed no effect on the cellular uptake. MTT assay indicated that the cytotoxicity of DOX loaded in FA-PEG-IOPNR to HeLa cells was higher than that of DOX in PEG-IOPNR. In the case of COS 7 cells, no significant difference between the cytotoxicity of DOX loaded in FA-PEG-IOPNR and PEG-IOPNR was found. These results suggested that FA-PEG-IOPNR had the potential for target delivery of chemotherapeutic into cancer cells.

  9. Influence of nitrogen loading and flooding on seedling emergence and recruitment from a seed bank in Chaohu Lake Basin, China.

    PubMed

    Cui, Naxin; Wu, Juan; Dai, Yanran; Li, Zhu; Cheng, Shuiping

    2017-08-16

    Vegetation severely degraded and even disappeared in the water bodies of Chaohu Lake basin, which is the fifth largest freshwater lake in the Yangtze flood plain in China, because of water pollution and eutrophication. Vegetation restoration projects have been carried out. However, the influences of water quality and hydrology on vegetation restoration from seed banks have been rarely investigated. This experiment aimed to identify the effect of water level and nitrogen loading (ammonium and nitrate) on seedling emergence and recruitment from the riparian seed bank of the river in this basin. Most of the species in the seed bank germinated under moist conditions. Under flooding conditions, however, the growth of aquatic species, especially Vallisneria natans (Lour.) Hara, was inhibited when the nitrogen concentration increased. At 0.37 mg/L NH4(+)-N in the water column, the growth of V. natans was inhibited. The results suggested that flooding was a primary limiting factor of seedling emergence. The inhibitory effect of high nitrogen loading on the growth of aquatic species was one of the main driving mechanisms of macrophyte degradation under flooding conditions; nevertheless, competitive advantage might determine the community pattern in moist habitats. Therefore, water level control and water quality improvement should be the key aspects of vegetation restoration in degraded rivers or lakes.

  10. Genetic control and transgressive segregation of zinc, iron, potassium, phosphorus, calcium, and sodium accumulation in cowpea (Vigna unguiculata) seeds.

    PubMed

    Fernandes Santos, C A; Boiteux, L S

    2015-01-16

    Cowpea crop, through combining a range of essential minerals with high quality proteins, plays an important role in providing nutritional security to human population living in semi-arid regions. Studies on genetics of biofortification with essential minerals are still quite scarce, and the major objective of the present study was to provide genetic information on development of cowpea cultivars with high seed mineral contents. Genetic parameters heritability and minimum number of genes were estimated for seed accumulation of zinc (Zn), iron (Fe), calcium (Ca), phosphorus (P), potassium (K), and sodium (Na). Generation mean and variance analyses were conducted using contrasting parental lines, F₁, F₂, and backcross populations derived from IT97K-1042-3 x BRS Tapaihum and IT97K-1042-3 x Canapu crosses. High narrow-sense heritability (h²) values were found for accumulation of Fe (65-86%), P (74-77%), and K (77-88%), whereas moderate h(2) values were observed for accumulation of Ca (41-56%), Zn (51-83%), and Na (50-55%) in seeds. Significant additive genetic effects as well as parental mean effects were detected in both crosses for all minerals, whereas epistasis was important genetic component in Zn content. The minimum number of genes controlling the accumulation of minerals ranged from two (K) to 11 (P). Transgressive segregation was observed in F2 populations of both crosses for all minerals analyzed. The results suggest that, although under either oligogenic or polygenic control, the seed content of these six minerals in cowpea can be improved via standard breeding methods largely used for self-pollinated crops.

  11. QTL analyses for seed iron and zinc concentrations in an intra-genepool population of Andean common beans (Phaseolus vulgaris L.).

    PubMed

    Blair, Matthew W; Astudillo, Carohna; Rengifo, Judith; Beebe, Steve E; Graham, Robin

    2011-02-01

    Legumes provide essential micronutrients that are found only in low amounts in the cereals or root crops. An ongoing project at CIAT has shown that the legume common bean is variable in the amount of seed minerals (iron, zinc, and other elements), vitamins, and sulfur amino acids that they contain and that these traits are likely to be inherited quantitatively. In this study we analyzed iron and zinc concentrations in an Andean recombinant inbred line (RIL) population of 100 lines derived from a cross between G21242, a Colombian cream-mottled climbing bean with high seed iron/zinc and G21078, an Argentinean cream seeded climbing bean with low seed iron/zinc. The population was planted across three environments; seed from each genotype was analyzed with two analytical methods, and quantitative trait loci (QTL) were detected using composite interval mapping and single-point analyses. A complete genetic map was created for the cross using a total of 74 microsatellite markers to anchor the map to previously published reference maps and 42 RAPD markers. In total, nine seed mineral QTL were identified on five linkage groups (LGs) with the most important being new loci on b02 and other QTL on b06, b08, and b07 near phaseolin. Seed weight QTL were associated with these on b02 and b08. These Andean-derived QTL are candidates for marker-assisted selection either in combination with QTL from the Mesoamerican genepool or with other QTL found in inter and intra-genepool crosses, and the genetic map can be used to anchor other intra-genepool studies.

  12. Synthesis and neuroprotective effects of the complex nanoparticles of iron and sapogenin isolated from the defatted seeds of Camellia oleifera.

    PubMed

    Yang, Qian; Zhao, Chuang; Zhao, Jun; Ye, Yong

    2017-12-01

    The defatted seeds of Camellia oleifera var. monosperma Hung T. Chang (Theaceae) are currently discarded without effective utilization. However, sapogenin has been isolated and shows antioxidative, anti-inflammatory and analgesic activities suggestive of its neuroprotective function. In order to improve the activities of sapogenin, the nanoparticles of iron-sapogenin have been synthesized, and the neuroprotective effects are evaluated. Structural characters of the nanoparticles were analyzed, and the antioxidant effect was assessed by DPPH method, and the neuroprotective effect was evaluated by rotenone-induced neurodegeneration in Kunming mice injected subcutaneously into the back of neck with rotenone (50 mg/kg/day) for 6 weeks and then treated by tail intravenous injection with the iron-sapogenin at the dose of 25, 50 and 100 mg/kg for 7 days. Mice behaviour and neurotransmitters were tested. The product had an average size of 162 nm with spherical shape, and scavenged more than 90% DPPH radicals at 0.8 mg/mL concentration. It decreased behavioural disorder and malondialdehyde content in mice brain, and increased superoxide dismutase activity, tyrosine hydroxylase expression, dopamine and acetylcholine levels in brain in dose dependence, and their maximum changes were respectively up to 60.83%, 25.17%, 22.13%, 105.26%, 42.17% and 22.89% as compared to vehicle group. Iron-sapogenin nanoparticle shows significantly better effects than the sapogenin. Iron-sapogenin alleviates neurodegeneration of mice injured by neurotoxicity of rotenone, it is a superior candidate of drugs for neuroprotection.

  13. Browse diversity and iron loading in captive sumatran rhinoceroses (Dicerorhinus sumatrensis): a comparison of sanctuary and zoological populations.

    PubMed

    Candra, Dedi; Radcliffe, Robin W; Andriansyah; Khan, Mohammad; Tsu, I-Hsien; Paglia, Donald E

    2012-09-01

    Iron storage disease (ISD) is now recognized as a serious clinical disorder acquired by two species of browsing rhinoceroses, the African black (Diceros bicornis) and the Asian Sumatran (Dicerorhinus sumatrensis) rhinoceroses, when displaced from their natural habitats. The most complete knowledge of ISD comes from studies of the black rhinoceros, but the Asian species is also at risk. Sumatran rhinoceroses housed in traditional zoological settings outside of range countries have suffered significant morbidity and mortality potentially related to ISD induced by diet and/or other confinement conditions. With so few animals in captivity, very little information exists on iron loading in the Sumatran rhinoceros. To better characterize the problem, we retrospectively compared captive management conditions of Sumatran rhinoceroses housed under traditional zoological care with those in two native sanctuary environments. In general, zoo rhinoceroses are offered a paucity of plants and browse species compared with their sanctuary and wild counterparts managed in native rainforest habitats. Iron analyte levels and limited histopathologic observations in these populations suggest variable tendencies to overload iron, dependent upon differences in managed diet and individual food preferences. More detailed investigation of these markedly dissimilar ex situ populations is warranted to better understand the role of nutrition and other conditions affecting iron loading in browser rhinoceroses.

  14. Normalisation of total body iron load with very intensive combined chelation reverses cardiac and endocrine complications of thalassaemia major.

    PubMed

    Farmaki, Kallistheni; Tzoumari, Ioanna; Pappa, Christina; Chouliaras, Giorgos; Berdoukas, Vasilios

    2010-02-01

    Cardiac and endocrine disorders are common sequelae of iron overload in transfused thalassaemia patients. Combined chelation with desferrioxamine (DFO) and deferiprone (DFP) is well tolerated and produces an additive/synergistic effect superior to either drug alone. 52 thalassaemia major patients were transitioned from DFO to combined chelation with DFO and DFP. Serum ferritin, cardiac and hepatic iron levels were monitored regularly for up to 7 years, as were cardiac and endocrine function. Patients' iron load normalized, as judged by ferritin and cardiac and hepatic magnetic resonance imaging findings. In all 12 patients receiving treatment for cardiac dysfunction, symptoms reversed following combined chelation, enabling nine patients to discontinue heart medications. In the 39 patients with abnormal glucose metabolism, 44% normalized. In 18 requiring thyroxine supplementation for hypothyroidism, 10 were able to discontinue, and four reduced their thyroxine dose. In 14 hypogonadal males on testosterone therapy, seven stopped treatment. Of the 19 females, who were hypogonadal on DFO monotherapy, six were able to conceive. Moreover, no patients developed de novo cardiac or endocrine complications. These results suggest that intensive combined chelation normalized patients' iron load and thereby prevented and reversed cardiac and multiple endocrine complications associated with transfusion iron overload.

  15. Environmental effects on sex differences in the genetic load for adult lifespan in a seed-feeding beetle.

    PubMed

    Fox, C W; Stillwell, R C

    2009-07-01

    We have little understanding of how environmental conditions affect the expression of the genetic load for lifespan and adult mortality rates, or how this environmental dependence affect tests of models for the evolution of senescence. We use the seed-feeding beetle, Callosobruchus maculatus, as a model to explore how the inbreeding load (L) affecting adult lifespan varies with rearing conditions (diet and temperature), and how rearing conditions affect tests of the mutation accumulation model of senescence. When reared under benign conditions, there was a large sex difference in inbreeding depression (delta) and the inbreeding load (L=0.51-0.86 lethal equivalents per gamete for females L= approximately 0 for males). This sex difference in L was dependent on temperature, but not on rearing host or heat shock. At both high and low temperatures (relative to intermediate temperature) L increased for males, and L converged for the sexes at low temperature (L=0.26-0.53 for both sexes). Correlations were small for L between pairs of temperatures, indicating that the genes responsible for the inbreeding load differed between temperatures. In contrast to predictions of the mutation accumulation model of senescence, the age-specific inbreeding load for the adult mortality rate (L(u(t))) did not increase with age in any rearing environment. The genetic load underlying lifespan and adult mortality rates, and large sex differences in the genetic load, is highly dependent on environmental conditions. Estimating the genetic load in benign laboratory environments may be insufficient to predict the genetics underlying lifespan variation in nature where environmental variation is the norm.

  16. The effect of mechanical properties of iron oxide nanoparticle-loaded functional nano-carrier on tumor targeting and imaging.

    PubMed

    Choi, Won Il; Kim, Ja-Young; Heo, Seon U; Jeong, Yong Yeon; Kim, Young Ha; Tae, Giyoong

    2012-09-10

    To achieve a sufficient targeting efficiency and prolonged half-life in-vivo, the physicochemical parameters including size and surface chemistry of therapeutic and imaging agents should be controlled. In this study, we prepared an iron oxide nanoparticle (IONP)-loaded, functional nano-carrier with different loading contents to modulate the mechanical properties of the system, and compared the characteristics of tumor targeting and imaging in terms of loading contents of IONP. As a functional nano-carrier, chitosan-conjugated, Pluronic-based nano-carrier with useful properties such as long blood circulation, good tumor targeting, and easy loading of macromolecules was used. IONPs were efficiently encapsulated into the nano-carrier (high loading efficiency over 95%) and the mechanical properties of the IONP-loaded nano-carrier were controlled by varying the loading amount of IONP. The IONP-loaded nano-carrier with the higher loading content of IONP (40 wt.%) was significantly more rigid (over 2×) than those with lower loading contents of IONP (5 and 15 wt.%). Although the nano-carrier with the higher loading content of IONP showed more enhanced MR contrast effect with higher T(2) relaxivity and higher intracellular uptake in vitro, characteristics of in-vivo tumor targeting and MR cancer imaging were not good compared to that of the nano-carrrier with the lower loading contents of IONP. Since different loading contents did not affect other characteristics of the system (size, surface chemistry, and surface charge), the present result suggests that the mechanical properties (strength/flexibility) of nano-systems are also important factors to be controlled for targeted delivery and imaging.

  17. Protein Association and Dissociation Regulated by Extension Peptide: A Mode for Iron Control by Phytoferritin in Seeds1[C][W][OA

    PubMed Central

    Yang, Haixia; Fu, Xiaoping; Li, Meiliang; Leng, Xiaojing; Chen, Bin; Zhao, Guanghua

    2010-01-01

    Most of the iron in legume seeds is stored in ferritin located in the amyloplast, which is used during seed germination. However, there is a lack of information on the regulation of iron by phytoferritin. In this study, soluble and insoluble forms of pea (Pisum sativum) seed ferritin (PSF) isolated from dried seeds were found to be identical 24-mer ferritins comprising H-1 and H-2 subunits. The insoluble form is favored at low pH, whereas the two forms reversibly interconvert in the pH range of 6.0 to 7.8, with an apparent pKa of 6.7. This phenomenon was not observed in animal ferritins, indicating that PSF is unique. The pH of the amyloplast was found to be approximately 6.0, thus facilitating PSF association, which is consistent with the role of PSF in long-term iron storage. Similar to previous studies, the results of this work showed that protein degradation occurs in purified PSF during storage, thus proving that phytoferritin also undergoes degradation during seedling germination. In contrast, no degradation was observed in animal ferritins, suggesting that this degradation of phytoferritin may be due to the extension peptide (EP), a specific domain found only in phytoferritin. Indeed, removal of EP from PSF significantly increased protein stability and prevented degradation under identical conditions while promoting protein dissociation. Correlated with such dissociation was a considerable increase in the rate of ascorbate-induced iron release from PSF at pH 6.0. Thus, phytoferritin may have facilitated the evolution of EP to enable it to regulate iron for storage or complement in seeds. PMID:20841455

  18. Iron Loading-Induced Aggregation and Reduction of Iron Incorporation in Heteropolymeric Ferritin Containing a Mutant Light Chain that Causes Neurodegeneration

    PubMed Central

    Muhoberac, Barry B.; Baraibar, Martin A.; Vidal, Ruben

    2010-01-01

    Hereditary Ferritinopathy (HF) is a neurodegenerative disease characterized by intracellular ferritin inclusion bodies (IBs) and iron accumulation throughout the central nervous system. Ferritin IBs are composed of mutant ferritin light chain as well as wild type light (Wt-FTL) and heavy chain (FTH1) polypeptides. In vitro studies have shown that the mutant light chain polypeptide p.Phe167SerfsX26 (Mt-FTL) forms soluble ferritin 24-mer homopolymers having a specific structural disruption that explains its functional problems of reduced ability to incorporate iron and aggregation during iron loading. However, because ferritins are usually 24-mer heteropolymers and all three polypeptides are found in IBs, we investigated the properties of Mt-FTL/FTH1 and Mt-FTL/Wt-FTL heteropolymeric ferritins. We show here the facile assembly of Mt-FTL and FTH1 subunits into soluble ferritin heteropolymers, but their ability to incorporate iron was significantly reduced relative to Wt-FTL/FTH1 heteropolymers. In addition, Mt-FTL/FTH1 heteropolymers formed aggregates during iron loading, contrasting Wt-FTL/FTH1 heteropolymers and similar to what was seen for Mt-FTL homopolymers. The resulting precipitate contained both Mt-FTL and FTH1 polypeptides as do ferritin IBs in patients with HF. The presence of Mt-FTL subunits in Mt-FTL/Wt-FTL heteropolymers also caused iron loading-induced aggregation relative to Wt-FTL homopolymers, with the precipitate containing Mt- and Wt-FTL polypeptides again paralleling HF. Our data demonstrate that co-assembly with wild type subunits does not circumvent the functional problems caused by mutant subunits. Furthermore, the functional problems characterized here in heteropolymers that contain mutant subunits parallel those problems previously reported in homopolymers composed exclusively of mutant subunits, which strongly suggests that the structural disruption characterized previously in Mt-FTL homopolymers occurs in a similar manner and to a

  19. Iron loading-induced aggregation and reduction of iron incorporation in heteropolymeric ferritin containing a mutant light chain that causes neurodegeneration.

    PubMed

    Muhoberac, Barry B; Baraibar, Martin A; Vidal, Ruben

    2011-04-01

    Hereditary ferritinopathy (HF) is a neurodegenerative disease characterized by intracellular ferritin inclusion bodies (IBs) and iron accumulation throughout the central nervous system. Ferritin IBs are composed of mutant ferritin light chain as well as wild-type light (Wt-FTL) and heavy chain (FTH1) polypeptides. In vitro studies have shown that the mutant light chain polypeptide p.Phe167SerfsX26 (Mt-FTL) forms soluble ferritin 24-mer homopolymers having a specific structural disruption that explains its functional problems of reduced ability to incorporate iron and aggregation during iron loading. However, because ferritins are usually 24-mer heteropolymers and all three polypeptides are found in IBs, we investigated the properties of Mt-FTL/FTH1 and Mt-FTL/Wt-FTL heteropolymeric ferritins. We show here the facile assembly of Mt-FTL and FTH1 subunits into soluble ferritin heteropolymers, but their ability to incorporate iron was significantly reduced relative to Wt-FTL/FTH1 heteropolymers. In addition, Mt-FTL/FTH1 heteropolymers formed aggregates during iron loading, contrasting Wt-FTL/FTH1 heteropolymers and similar to what was seen for Mt-FTL homopolymers. The resulting precipitate contained both Mt-FTL and FTH1 polypeptides as do ferritin IBs in patients with HF. The presence of Mt-FTL subunits in Mt-FTL/Wt-FTL heteropolymers also caused iron loading-induced aggregation relative to Wt-FTL homopolymers, with the precipitate containing Mt- and Wt-FTL polypeptides again paralleling HF. Our data demonstrate that co-assembly with wild-type subunits does not circumvent the functional problems caused by mutant subunits. Furthermore, the functional problems characterized here in heteropolymers that contain mutant subunits parallel those problems previously reported in homopolymers composed exclusively of mutant subunits, which strongly suggests that the structural disruption characterized previously in Mt-FTL homopolymers occurs in a similar manner and to a

  20. Zinc and selenium accumulation and their effect on iron bioavailability in common bean seeds

    USDA-ARS?s Scientific Manuscript database

    Common bean (Phaseolus vulgaris) is the most important legume crop. It represents a major source of micronutrients and has been targeted for essential trace mineral enhancement (i.e. biofortification). The aim of the study was to investigate whether it is possible to biofortify seeds with multi-micr...

  1. The Arabidopsis MTP8 transporter determines the localization of manganese and iron in seeds.

    PubMed

    Chu, Heng-Hsuan; Car, Suzana; Socha, Amanda L; Hindt, Maria N; Punshon, Tracy; Guerinot, Mary Lou

    2017-09-08

    Understanding how seeds obtain and store nutrients is key to developing crops with higher agronomic and nutritional value. We have uncovered unique patterns of micronutrient localization in seeds using synchrotron X-ray fluorescence (SXRF). Although all four members of the Arabidopsis thaliana Mn-CDF family can transport Mn, here we show that only mtp8-2 has an altered Mn distribution pattern in seeds. In an mtp8-2 mutant, Mn no longer accumulates in hypocotyl cortex cells and sub-epidermal cells of the embryonic cotyledons, but rather accumulates with Fe in the cells surrounding the vasculature, a pattern previously shown to be determined by the vacuolar transporter VIT1. We also show that MTP8, unlike the other three Mn-CDF family members, can transport Fe and is responsible for localization of Fe to the same cells that store Mn. When both the VIT1 and MTP8 transporters are non-functional, there is no accumulation of Fe or Mn in specific cell types; rather these elements are distributed amongst all cell types in the seed. Disruption of the putative Fe binding sites in MTP8 resulted in loss of ability to transport Fe but did not affect the ability to transport Mn.

  2. Liposomes Loaded with Hydrophobic Iron Oxide Nanoparticles: Suitable T2 Contrast Agents for MRI

    PubMed Central

    Martínez-González, Raquel; Estelrich, Joan; Busquets, Maria Antònia

    2016-01-01

    There has been a recent surge of interest in the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents (CAs) for magnetic resonance imaging (MRI), due to their tunable properties and their low toxicity compared with other CAs such as gadolinium. SPIONs exert a strong influence on spin-spin T2 relaxation times by decreasing the MR signal in the regions to which they are delivered, consequently yielding darker images or negative contrast. Given the potential of these nanoparticles to enhance detection of alterations in soft tissues, we studied the MRI response of hydrophobic or hydrophilic SPIONs loaded into liposomes (magnetoliposomes) of different lipid composition obtained by sonication. These hybrid nanostructures were characterized by measuring several parameters such as size and polydispersity, and number of SPIONs encapsulated or embedded into the lipid systems. We then studied the influence of acyl chain length as well as its unsaturation, charge, and presence of cholesterol in the lipid bilayer at high field strength (7 T) to mimic the conditions used in preclinical assays. Our results showed a high variability depending on the nature of the magnetic particles. Focusing on the hydrophobic SPIONs, the cholesterol-containing samples showed a slight reduction in r2, while unsaturation of the lipid acyl chain and inclusion of a negatively charged lipid into the bilayer appeared to yield a marked increase in negative contrast, thus rendering these magnetoliposomes suitable candidates as CAs, especially as a liver CA. PMID:27472319

  3. Iron-loaded mangosteen as a heterogeneous Fenton catalyst for the treatment of landfill leachate.

    PubMed

    Laiju, A R; Sivasankar, T; Nidheesh, P V

    2014-09-01

    Iron-loaded mangosteen shell powder (Fe-MSP) was found as an effective heterogeneous Fenton catalyst for the treatment of stabilized landfill leachate. Sonolytically produced catalyst has higher efficiency than other catalysts. At the optimal conditions (pH 3, catalyst concentration of 1,750 mg/L and hydrogen peroxide concentration of 0.26 M), 81 % of the chemical oxygen demand (COD) was removed effectively from the landfill leachate. But, the efficiency of Fe-MSP was reduced in the first recycling due to the poisoning of active sites. A metal leaching study indicated that the degradation of the pollutant is mainly due to solid Fe ions present in Fe-MSP rather than the leached ferrous and ferric ions. Hydroxyl radical production in the system was confirmed by the Fenton oxidation of benzoic acid. Compared to the homogeneous Fenton process, the heterogeneous Fenton process using Fe-MSP had higher COD removal efficiency, indicating the practical applicability of the prepared catalyst.

  4. Liposomes Loaded with Hydrophobic Iron Oxide Nanoparticles: Suitable T₂ Contrast Agents for MRI.

    PubMed

    Martínez-González, Raquel; Estelrich, Joan; Busquets, Maria Antònia

    2016-07-27

    There has been a recent surge of interest in the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents (CAs) for magnetic resonance imaging (MRI), due to their tunable properties and their low toxicity compared with other CAs such as gadolinium. SPIONs exert a strong influence on spin-spin T₂ relaxation times by decreasing the MR signal in the regions to which they are delivered, consequently yielding darker images or negative contrast. Given the potential of these nanoparticles to enhance detection of alterations in soft tissues, we studied the MRI response of hydrophobic or hydrophilic SPIONs loaded into liposomes (magnetoliposomes) of different lipid composition obtained by sonication. These hybrid nanostructures were characterized by measuring several parameters such as size and polydispersity, and number of SPIONs encapsulated or embedded into the lipid systems. We then studied the influence of acyl chain length as well as its unsaturation, charge, and presence of cholesterol in the lipid bilayer at high field strength (7 T) to mimic the conditions used in preclinical assays. Our results showed a high variability depending on the nature of the magnetic particles. Focusing on the hydrophobic SPIONs, the cholesterol-containing samples showed a slight reduction in r₂, while unsaturation of the lipid acyl chain and inclusion of a negatively charged lipid into the bilayer appeared to yield a marked increase in negative contrast, thus rendering these magnetoliposomes suitable candidates as CAs, especially as a liver CA.

  5. Hydrogen production from steam reforming of ethylene glycol over iron loaded on MgO

    NASA Astrophysics Data System (ADS)

    Chen, Mingqiang; Wang, Yishuang; Liang, Tian; Yang, Jie; Yang, Zhonglian

    2017-01-01

    In this study, a series of Fe-based catalysts loaded on MgO were prepared by a precipitation technique. And they were tested in hydrogen production from steam reforming of ethylene glycol (SRE), which was a representative model compound of fast bio-oil. The catalysts were characterized by XRD, SEM and H2-TPR analysis. The results showed that the crystalline phases of catalysts contained Fe2O3 (Hematite), Fe3O4 (Magnetite), Fe2MgO4 (iron magnesium oxide) and MgO, and morphology of MgO was changed from the rugby-ball like particles to spherical particles with the addition of Fe. In addition, the catalytic test results indicated that the 18%Fe/MgO catalyst exhibited the highest ethylene glycol conversion (˜99.8%) and H2 molar percent (˜77%) during at the following conditions: H2O/C molar ratio is 5˜7, the feeding rate is 14 mL/h and the reaction temperature at 600˜650°C. Furthermore, the 18%Fe/MgO catalyst can keep outstanding stability during SRE for 12 h.

  6. Binding of iron, zinc, and lead ions from aqueous solution by shea butter (Butyrospermun Parkii) seed husks

    SciTech Connect

    Eromosele, I.C.; Otitolaye, O.O. )

    1994-08-01

    Several workers have reported on the potential use of agricultural products as substrates for the removal of metal ions from aqueous solutions. These studies demonstrated that considerable amounts of metal ions can be removed from aqueous solutions by cellulosic materials. The merit in the use of the latter is their relative abundance and cheapness compared to conventional materials for the removal of toxic metal ions from waste-waters. In some of the studies, chemical modification of cellulosic materials significantly enhanced their ion-binding properties, providing greater flexibility in their applications to a wide range of heavy metal ions. Shea butter plant (Butyrospermun Parkii) normally grows in the wild within the guinea-savana zone of Nigeria. The seeds are a rich source of edible oils and the husks are usually discarded. The husk is thus available in abundance and, hence, there is reason to examine its ion-binding properties for its possible application in the removal of toxic metal ions from industrial waste-waters. This paper reports on preliminary studies of the sorption of iron, zinc and lead ions from aqueous solution by modified and unmodified shea butter seed husks. 8 refs., 5 figs., 1 tab.

  7. Joint mimicking mechanical load activates TGFβ1 in fibrin-poly(ester-urethane) scaffolds seeded with mesenchymal stem cells.

    PubMed

    Gardner, Oliver F W; Fahy, Niamh; Alini, Mauro; Stoddart, Martin J

    2016-07-22

    Transforming growth factor-β1 (TGF-β1) is widely used in an active recombinant form to stimulate the chondrogenic differentiation of mesenchymal stem cells (MSCs). Recently, it has been shown that the application of multiaxial load, that mimics the loading within diarthrodial joints, to MSCs seeded in to fibrin-poly(ester-urethane) scaffolds leads to the endogenous production and secretion of TGF-β1 by the mechanically stimulated cells, which in turn drives the chondrogenic differentiation of the cells within the scaffold. The work presented in this short communication provides further evidence that the application of joint mimicking multiaxial load induces the secretion of TGF-β1 by mechanically stimulated MSCs. The results of this work also show that joint-like multiaxial mechanical load activates latent TGF-β1 in response to loading in the presence or absence of cells; this activation was not seen in non-loaded control scaffolds. Despite the application of mechanical load to scaffolds with different distributions/numbers of cells no significant differences were seen in the percentage of active TGF-β1 quantified in the culture medium of scaffolds from different groups. The similar level of activation in scaffolds containing different numbers of cells, cells at different stages of differentiation or with different distributions of cells suggests that this activation results from the mechanical forces applied to the culture system rather than differences in cellular behaviour. These results are relevant when considering rehabilitation protocols after cell therapy or microfracture, for articular cartilage repair, where increased TGF-β1 activation in response to joint mobilization may improve the quality of developing cartilaginous repair material. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Biodegradable Magnetic Silica@Iron Oxide Nanovectors with Ultra-Large Mesopores for High Protein Loading, Magnetothermal Release, and Delivery.

    PubMed

    Omar, Haneen; Croissant, Jonas G; Alamoudi, Kholod; Alsaiari, Shahad; Alradwan, Ibrahim; Majrashi, Majed A; Anjum, Dalaver H; Martins, Patricia; Moosa, Basem; Almalik, Abdulaziz; Khashab, Niveen M

    2016-11-29

    The delivery of large cargos of diameter above 15nm for biomedical applications has proved challenging since it requires biocompatible, stably-loaded, and biodegradable nanomaterials. In this study, we describe the design of biodegradable silica-iron oxide hybrid nanovectors with large mesopores for large protein delivery in cancer cells. The mesopores of the nanomaterials spanned from 20 to 60nm in diameter and post-functionalization allowed the electrostatic immobilization of large proteins (e.g. mTFP-Ferritin, ~534kDa). Half of the content of the nanovectors was based with iron oxide nanophases which allowed the rapid biodegradation of the carrier in fetal bovine serum and a magnetic responsiveness. The nanovectors released large protein cargos in aqueous solution under acidic pH or magnetic stimuli. The delivery of large proteins was then autonomously achieved in cancer cells via the silica-iron oxide nanovectors, which is thus a promising for biomedical applications.

  9. Left ventricular torsional mechanics and myocardial iron load in beta-thalassaemia major: a potential role of titin degradation.

    PubMed

    Chen, Mei-Pian; Li, Shu-Na; Lam, Wendy W M; Ho, Yuen-Chi; Ha, Shau-Yin; Chan, Godfrey C F; Cheung, Yiu-Fai

    2014-04-12

    Iron may damage sarcomeric proteins through oxidative stress. We explored the left ventricular (LV) torsional mechanics in patients with beta-thalassaemia major and its relationship to myocardial iron load. Using HL-1 cell and B6D2F1 mouse models, we further determined the impact of iron load on proteolysis of the giant sarcomeric protein titin. In 44 thalassaemia patients aged 25 ± 7 years and 38 healthy subjects, LV torsion and twisting velocities were determined at rest using speckle tracking echocardiography. Changes in LV torsional parameters during submaximal exercise testing were further assessed in 32 patients and 17 controls. Compared with controls, patients had significantly reduced LV apical rotation, torsion, systolic twisting velocity, and diastolic untwisting velocity. T2* cardiac magnetic resonance findings correlated with resting diastolic untwisting velocity. The increments from baseline and resultant LV torsion and systolic and diastolic untwisting velocities during exercise were significantly lower in patients than controls. Significant correlations existed between LV systolic torsion and diastolic untwisting velocities in patients and controls, both at rest and during exercise. In HL-1 cells and ventricular myocardium of B6D2F1 mice overloaded with iron, the titin-stained pattern of sarcomeric structure became disrupted. Gel electrophoresis of iron-overloaded mouse myocardial tissue further showed significant decrease in the amount of titin isoforms and increase in titin degradation products. Resting and dynamic LV torsional mechanics is impaired in patients with beta-thalassaemia major. Cell and animal models suggest a potential role of titin degradation in iron overload-induced alteration of LV torsional mechanics.

  10. Effects of pore topology and iron oxide core on doxorubicin loading and release from mesoporous silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Ronhovde, Cicily J.; Baer, John; Larsen, Sarah C.

    2017-06-01

    Mesoporous silica nanoparticles (MSNs) have a network of pores that give rise to extremely high specific surface areas, making them attractive materials for applications such as adsorption and drug delivery. The pore topology can be readily tuned to achieve a variety of structures such as the hexagonally ordered Mobil Crystalline Material 41 (MCM-41) and the disordered "wormhole" (WO) mesoporous silica (MS) structure. In this work, the effects of pore topology and iron oxide core on doxorubicin loading and release were investigated using MSNs with pore diameters of approximately 3 nm and sub-100 nm particle diameters. The nanoparticles were loaded with doxorubicin, and the drug release into phosphate-buffered saline (PBS, 10 mM, pH 7.4) at 37 °C was monitored by fluorescence spectroscopy. The release profiles were fit using the Peppas model. The results indicated diffusion-controlled release for all samples. Statistically significant differences were observed in the kinetic host-guest parameters for each sample due to the different pore topologies and the inclusion of an iron oxide core. Applying a static magnetic field to the iron oxide core WO-MS shell materials did not have a significant impact on the doxorubicin release. This is the first time that the effects of pore topology and iron oxide core have been isolated from pore diameter and particle size for these materials.

  11. Evaluation of seeding depth and guage-wheel load effects on maize emergence and yield

    USDA-ARS?s Scientific Manuscript database

    Planting represents perhaps the most important field operation with errors likely to negatively affect crop yield and thereby farm profitability. Performance of row-crop planters are evaluated by their ability to accurately place seeds into the soil at an adequate and pre-determined depth, the goal ...

  12. Green electrospun grape seed extract-loaded silk fibroin nanofibrous mats with excellent cytocompatibility and antioxidant effect.

    PubMed

    Lin, Si; Chen, Mengxia; Jiang, Huayue; Fan, Linpeng; Sun, Binbin; Yu, Fan; Yang, Xingxing; Lou, Xiangxin; He, Chuanglong; Wang, Hongsheng

    2016-03-01

    Silk fibroin (SF) from Bombyx mori has an excellent biocompatibility and thus be widely applied in the biomedical field. Recently, various SF-based composite nanofibers have been developed for more demanding applications. Additionally, grape seed extract (GSE) has been demonstrated to be powerful on antioxidation. In the present study, we dedicate to fabricate a GSE-loaded SF/polyethylene oxide (PEO) composite nanofiber by green electrospinning. Our results indicated the successful loading of GSE into the SF/PEO composite nanofibers. The introduction of GSE did not affect the morphology of the SF/PEO nanofibers and GSE can be released from the nanofibers with a sustained manner. Furthermore, comparing with the raw SF/PEO nanofibrous mats, the GSE-loaded SF/PEO nanofibrous mats significantly enhanced the proliferation of the skin fibroblasts and also protected them against the damage from tert-butyl hydroperoxide-induced oxidative stress. All these findings suggest a promising potential of this novel GSE-loaded SF/PEO composite nanofibrous mats applied in skin care, tissue regeneration and wound healing. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. On the accessibility of surface-bound drugs on magnetic nanoparticles. Encapsulation of drugs loaded on modified dextran-coated superparamagnetic iron oxide by β-cyclodextrin.

    PubMed

    Sudha, Natesan; Yousuf, Sameena; Israel, Enoch V M V; Paulraj, Mosae Selvakumar; Dhanaraj, Premnath

    2016-05-01

    We report the loading of drugs on aminoethylaminodextran-coated iron oxide nanoparticles, their superparamagnetic behavior, loading of drugs on them, and the β-cyclodextrin-complex formation of the drugs on the surface of the nanoparticles. The magnetic behavior is studied using vibrating sample magnetometry and X-ray photoelectron spectroscopy is used to analyze the elemental composition of drug-loaded nanoparticles. Scanning electron microscopy shows ordered structures of drug-loaded nanoparticles. UV-visible absorption and fluorescence spectroscopy are used to study the binding of the surface-loaded drugs to β-cyclodextrin. All of the drugs form 1:1 host-guest complexes. The iodide ion quenching of fluorescence of free- and iron oxide-attached drugs are compared. The binding strengths of the iron oxide surface-loaded drugs-β-cyclodextrin binding are smaller than those of the free drugs.

  14. The Effect of the Hemochromatosis (HFE) Genotype on Lead Load and Iron Metabolism among Lead Smelter Workers

    PubMed Central

    Fan, Guangqin; Du, Guihua; Li, Huijun; Lin, Fen; Sun, Ziyong; Yang, Wei; Feng, Chang; Zhu, Gaochun; Li, Yanshu; Chen, Ying; Jiao, Huan; Zhou, Fankun

    2014-01-01

    Background Both an excess of toxic lead (Pb) and an essential iron disorder have been implicated in many diseases and public health problems. Iron metabolism genes, such as the hemochromatosis (HFE) gene, have been reported to be modifiers for lead absorption and storage. However, the HFE gene studies among the Asian population with occupationally high lead exposure are lacking. Objectives To explore the modifying effects of the HFE genotype (wild-type, H63D variant and C282Y variant) on the Pb load and iron metabolism among Asian Pb-workers with high occupational exposure. Methods Seven hundred and seventy-one employees from a lead smelter manufacturing company were tested to determine their Pb intoxication parameters, iron metabolic indexes and identify the HFE genotype. Descriptive and multivariate analyses were conducted. Results Forty-five H63D variant carriers and no C282Y variant carrier were found among the 771 subjects. Compared with subjects with the wild-type genotype, H63D variant carriers had higher blood lead levels, even after controlling for factors such as age, sex, marriage, education, smoking and lead exposure levels. Multivariate analyses also showed that the H63D genotype modifies the associations between the blood lead levels and the body iron burden/transferrin. Conclusions No C282Y variant was found in this Asian population. The H63D genotype modified the association between the lead and iron metabolism such that increased blood lead is associated with a higher body iron content or a lower transferrin in the H63D variant. It is indicated that H63D variant carriers may be a potentially highly vulnerable sub-population if they are exposed to high lead levels occupationally. PMID:24988074

  15. MR quantitative susceptibility imaging for the evaluation of iron loading in the brains of patients with β-thalassemia major.

    PubMed

    Qiu, D; Chan, G C-F; Chu, J; Chan, Q; Ha, S-Y; Moseley, M E; Khong, P-L

    2014-06-01

    Patients with β-thalassemia require blood transfusion to prolong their survival, which could cause iron overload in multiple organs, including the heart, liver, and brain. In this study, we aimed to quantify iron loading in the brains of patients with β-thalassemia major through the use of MR quantitative susceptibility imaging. Thirty-one patients with thalassemia with a mean (± standard deviation) age of 25.3 (±5.9) years and 33 age-matched healthy volunteers were recruited and underwent MR imaging at 3T. Quantitative susceptibility images were reconstructed from a 3D gradient-echo sequence. Susceptibility values were measured in the caudate nucleus, putamen, globus pallidus, red nucleus, substantia nigra, dentate nucleus, and choroid plexus. General linear model analyses were performed to compare susceptibility values of different ROIs between the patients with thalassemia and healthy volunteers. Of the 31 patients, 27 (87.1%) had abnormal iron deposition in one of the ROIs examined. Significant positive age effect on susceptibility value was found in the putamen, dentate nucleus, substantia nigra, and red nucleus (P = .002, P = .017, P = .044, and P = .014, respectively) in the control subjects. Compared with healthy control subjects, patients with thalassemia showed significantly lower susceptibility value in the globus pallidus (P < .001) and substantia nigra (P = .003) and significantly higher susceptibility value in the red nucleus (P = .021) and choroid plexus (P < .001). A wide range of abnormal susceptibility values, indicating iron overloading or low iron content, was found in patients with thalassemia. MR susceptibility imaging is a sensitive method for quantifying iron concentration in the brain and can be used as a potentially valuable tool for brain iron assessment. © 2014 by American Journal of Neuroradiology.

  16. Influence of iron and temperature on growth, nutrient utilization ratios and phytoplankton species composition in the western subarctic Pacific Ocean during the SEEDS experiment

    NASA Astrophysics Data System (ADS)

    Noiri, Yoshifumi; Kudo, Isao; Kiyosawa, Hiroshi; Nishioka, Jun; Tsuda, Atsushi

    2005-02-01

    On-board bottle incubation experiments were carried out by adding different amounts of iron as part of the SEEDS (Subarctic Pacific Iron Experiment for Ecosystem Dynamics Study) experiment to elucidate the phytoplankton community response to various iron concentrations. A temperature gradient from 5 to 18 °C was also applied to the incubation experiment because temperature also affects growth rate and metabolic functions such as enzyme reactions. Chlorophyll- a increased with increasing iron concentration, while the increase in chlorophyll- a in the control bottles (no iron addition) was nominal. Size-fractionated chlorophyll- a indicated that micro-phytoplankton (>10 μm) became dominant in the iron-enriched bottles below 13 °C, which was consistent with the results from in situ observations in the simultaneous mesoscale iron-enrichment experiment and similar experiments for the other high nitrate and low chlorophyll (HNLC) waters. Macronutrients (silicate, nitrate and phosphate) were consumed in the bottles below 13 °C. The consumption ratio of silicate to nitrate was around 1:1 for iron-enriched bottles, but this ratio was slightly higher for control bottles, indicating a physiological stress due to low iron concentration on the diatoms. In contrast, nanophytoplankton (<10 μm) were dominant in the iron-enriched bottles at 18 °C. There was no silicate utilization, but nitrate and phosphate were consumed in these bottles. Bacillariophyceae were dominant in the bottles below 13 °C, but Prymnesiophyceae became dominant at 18 °C. This is the first report demonstrating that temperature influences phytoplankton composition after iron addition in HNLC waters. The Chlorophyll- a specific increase rate for micro-plankton (>10 μm) doubled from 5 to 8 °C and was the highest between 8 and 13 °C at the same iron concentration. The surface mixed layer temperature was 8 °C at the beginning of iron fertilization, but it had been 5 °C just 2 weeks before the

  17. Effects of Particle Size and Particle Loading on the Tensile Properties of Iron-Ore-Tailing-Filled Epoxy and Polypropylene Composites

    NASA Astrophysics Data System (ADS)

    Onitiri, M. A.; Akinlabi, E. T.

    2017-01-01

    The effect of particle size and particle loading on the stiffness and tensile strength of iron-ore-tailing-filled epoxy and polypropylene composites was investigated experimentally, and the results obtained are compared with calculations by various theoretical models. It was found that the stiffness of the materials increased with content of iron ore tailings.

  18. Mitigation of the divertor heat load in DEMO reactor by impurity seeding

    NASA Astrophysics Data System (ADS)

    Ivanova-Stanik, I.; Zagórski, R.

    2015-08-01

    This paper describes integrated numerical modeling applied to DEMO discharges with tungsten wall in slab geometry, rather than the full X-point geometry of the DEMO design, using the COREDIV code. Calculations are performed for inductive DEMO scenario with Ne, Ar and Ni seeding for different radial diffusion coefficients in the SOL region, and different pinch velocities for impurities in the core. Simulations show only for Ar and Ni, with high enough radial diffusion in the SOL, it is possible to achieve H-mode plasma operation (power to the SOL > L-H transition threshold power) with acceptable level of the power to the target plates. For neon seeding such regime of operation seems not to be possible.

  19. Changes in iron concentrations and bio-availability during an open-ocean mesoscale iron enrichment in the western subarctic Pacific, SEEDS II

    NASA Astrophysics Data System (ADS)

    Nishioka, Jun; Takeda, Shigenobu; Kondo, Yoshiko; Obata, Hajime; Doi, Takashi; Tsumune, Daisuke; Wong, C. S.; Keith Johnson, W.; Sutherland, N.; Tsuda, Atsushi

    2009-12-01

    A patch of water in the western subarctic gyre (low iron concentration, <0.02 nM) was fertilized twice with 322 and 159 kg of iron to induce a phytoplankton bloom. In order to understand the changes in iron distribution and bio-availability throughout the evolution and termination phase of the iron-induced bloom, iron concentrations were measured at stations inside and outside of the iron-fertilized patch, and shipboard culture experiments using iron and desferrioxamine B (DFB) inoculation to regulate iron availability were conducted 5 times with water collected from the center of the iron-fertilized patch on D2, D7, D11, D17 and D23. After the iron fertilization, we observed a significant increase in dissolved iron (1.38 nM at 5 m depth) at the center of the patch (D1). Dissolved iron concentrations subsequently decreased to an ambient level (~0.08 nM) on D16-D17, despite the second iron fertilization made on D6. During the 4-day incubations of the shipboard culture experiments, excess DFB-inoculated treatment inhibited the phytoplankton growth compared to the controls for D2, D7 and D11 patch water. This indicated that available iron existed in the iron-fertilized patch at least until D11. Moreover, iron-inoculated treatments induced growth of large-sized phytoplankton with an accompanying silicate decrease for D7, D11 and D17 patch water, but not for D23 patch water. These results indicated that large diatoms, which can respond to additional iron inoculation, existed in the iron-fertilized patch in evolution and early termination phase of the iron-induced bloom (at least until D17); however, there was no significant amount of large diatoms, which could rapidly respond to iron, in late termination phase (D23) of the iron-induced phytoplankton bloom.

  20. Effects of climate change and seed dispersal on airborne ragweed pollen loads in Europe

    NASA Astrophysics Data System (ADS)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Liu, Li; Solmon, Fabien; Viovy, Nicolas; Khvorostyanov, Dmitry; Essl, Franz; Chuine, Isabelle; Colette, Augustin; Semenov, Mikhail A.; Schaffhauser, Alice; Storkey, Jonathan; Thibaudon, Michel; Epstein, Michelle M.

    2015-08-01

    Common ragweed (Ambrosia artemisiifolia) is an invasive alien species in Europe producing pollen that causes severe allergic disease in susceptible individuals. Ragweed plants could further invade European land with climate and land-use changes. However, airborne pollen evolution depends not only on plant invasion, but also on pollen production, release and atmospheric dispersion changes. To predict the effect of climate and land-use changes on airborne pollen concentrations, we used two comprehensive modelling frameworks accounting for all these factors under high-end and moderate climate and land-use change scenarios. We estimate that by 2050 airborne ragweed pollen concentrations will be about 4 times higher than they are now, with a range of uncertainty from 2 to 12 largely depending on the seed dispersal rate assumptions. About a third of the airborne pollen increase is due to on-going seed dispersal, irrespective of climate change. The remaining two-thirds are related to climate and land-use changes that will extend ragweed habitat suitability in northern and eastern Europe and increase pollen production in established ragweed areas owing to increasing CO2. Therefore, climate change and ragweed seed dispersal in current and future suitable areas will increase airborne pollen concentrations, which may consequently heighten the incidence and prevalence of ragweed allergy.

  1. Variation and inheritance of iron reductase activity in the roots of common vean (Phaseolus vulgaris L.) and association with seed iron accumulation QTL

    USDA-ARS?s Scientific Manuscript database

    Iron deficiency anemia is a global problem, which often affects women and children of developing countries and is based on diets that are low in iron. Strategy I plants, such as common bean (Phaseolus vulgaris L.) take up iron through a process that involves an iron reduction mechanism in their root...

  2. Iron loading site on the Fe-S cluster assembly scaffold protein is distinct from the active site.

    PubMed

    Rodrigues, Andria V; Kandegedara, Ashoka; Rotondo, John A; Dancis, Andrew; Stemmler, Timothy L

    2015-06-01

    Iron-sulfur (Fe-S) cluster containing proteins are utilized in almost every biochemical pathway. The unique redox and coordination chemistry associated with the cofactor allows these proteins to participate in a diverse set of reactions, including electron transfer, enzyme catalysis, DNA synthesis and signaling within several pathways. Due to the high reactivity of the metal, it is not surprising that biological Fe-S cluster assembly is tightly regulated within cells. In yeast, the major assembly pathway for Fe-S clusters is the mitochondrial ISC pathway. Yeast Fe-S cluster assembly is accomplished using the scaffold protein (Isu1) as the molecular foundation, with assistance from the cysteine desulfurase (Nfs1) to provide sulfur, the accessory protein (Isd11) to regulate Nfs1 activity, the yeast frataxin homologue (Yfh1) to regulate Nfs1 activity and participate in Isu1 Fe loading possibly as a chaperone, and the ferredoxin (Yah1) to provide reducing equivalents for assembly. In this report, we utilize calorimetric and spectroscopic methods to provide molecular insight into how wt-Isu1 from S. cerevisiae becomes loaded with iron. Isothermal titration calorimetry and an iron competition binding assay were developed to characterize the energetics of protein Fe(II) binding. Differential scanning calorimetry was used to identify thermodynamic characteristics of the protein in the apo state or under iron loaded conditions. Finally, X-ray absorption spectroscopy was used to characterize the electronic and structural properties of Fe(II) bound to Isu1. Current data are compared to our previous characterization of the D37A Isu1 mutant, and these suggest that when Isu1 binds Fe(II) in a manner not perturbed by the D37A substitution, and that metal binding occurs at a site distinct from the cysteine rich active site in the protein.

  3. Study of the Effect of Iron Loaded with B4C on the Total Gamma Doses Emitted from Laminated Shield

    NASA Astrophysics Data System (ADS)

    Makarious, A. S.; Maayouf, R. M. A.; Megahid, R. M.; El-Sayed Abdo, A.

    In this work a comparative study of the effect of iron loaded with B4C on the suppression of gamma-rays in a laminated shield of water, iron and either ordinary or limenite concrete have been carried out. It was found that B4C loaded with iron has a remarkable effect on the suppression of gamma doses all through the laminated shield. The suppression is more pronounced in the concrete layer. It was also found that the decrease of gamma doses in ilmenite concrete is 1.7 that one for ordinary concrete.Translated AbstractUntersuchung des Einflusses von mit B4C angereichertem Eisen auf die Gesamt-Gamma-Dosis aus einem laminierten SchildDer Effekt von mit B4C angereichertem Eisen auf die Abschirmung von Gamma-Strahlen durch einen laminierten Schild aus Wasser, Eisen und entweder gewöhnlichem oder Ilmenitebeton wird vergleichend untersucht. Es erweist sich ein bemerkenswerter Effekt des angereicherten Eisens auf die Abschwächung der Gamma-Dosis im gesamten Schild. Sie ist in der Betonschicht am ausgeprägtesten. Die Abnahme der Gamma-Dosis in Ilmenitebeton ist etwa 1,7fach der in gewöhnlichem Beton.

  4. Electromagnetic and microwave absorbing properties of carbonyl iron/BaTiO3 composite absorber for matched load of isolator

    NASA Astrophysics Data System (ADS)

    Ren, Xiaohu; Cheng, Yankui

    2015-11-01

    Composite absorbers made from carbonyl iron powder and BaTiO3 were prepared by blending technique with the matrix of epoxy resin. The structure and microtopography of the carbonyl iron and BaTiO3 particles were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and electromagnetic properties of the as-prepared composites were investigated by SEM and vector network analyzer (VNA). The effect of the mass ratio of BaTiO3/carbonyl iron on the electromagnetic properties of the composites is investigated. The bandwidth with an absorption loss exceeding 30 dB is obtained in the whole measured frequency range for all composites, and an optimal reflection loss drop below 1.5 dB with 24 wt% BaTiO3. It is found that the carbonyl iron/BaTiO3 composite absorber can be a promising candidate as a matched load for the isolator.

  5. Production and air-sea flux of halomethanes in the western subarctic Pacific in relation to phytoplankton pigment concentrations during the iron fertilization experiment (SEEDS II)

    NASA Astrophysics Data System (ADS)

    Hashimoto, Shinya; Toda, Shuji; Suzuki, Koji; Kato, Shungo; Narita, Yasusi; Kurihara, Michiko K.; Akatsuka, Yoko; Oda, Hiroshi; Nagai, Takahiro; Nagao, Ippei; Kudo, Isao; Uematsu, Mitsuo

    2009-12-01

    Iron could play a key role in controlling phytoplankton biomass and productivity in high-nutrient, low-chlorophyll regions. As a part of the iron fertilization experiment carried out in the western subarctic Pacific from July to August 2004 (Subarctic Pacific iron Experiment for Ecosystem Dynamics Study II—SEEDS II), we analysed the concentrations of trace gases in the seawater for 12 d following iron fertilization. The mean concentrations of chlorophyll a in the mixed layer (5-30 m depth) increased from 0.94 to 2.81 μg L -1 for 8 d in the iron patch. The mean concentrations of methyl bromide (CH 3Br; 5-30 m depth) increased from 6.4 to 13.4 pmol L -1 for 11 d; the in-patch concentration increased relative to the out-patch concentration. A linear correlation was observed between the concentrations of 19'-hexanoyloxyfucoxanthin, which is a biomarker of several prymnesiophytes, and CH 3Br in the seawater. After fertilization, the air-sea flux of CH 3Br inside the patch changed from influx to efflux from the ocean. There was no clear evidence for the increase in saturation anomaly of methyl chloride (CH 3Cl) due to iron fertilization. Furthermore, CH 3Cl fluxes did not show a tendency to increase after fertilization of the patch. In contrast to CH 3Br, no change was observed in the concentrations of bromoform (in-patch day 11 and out-patch day 11: 1.7 and 1.7 pmol L -1), dibromomethane (2.1 and 2.2 pmol L -1), and dibromochloromethane (1.0 and 1.2 pmol L -1, respectively). The concentration of isoprene, which is known to have a relationship with chlorophyll a, did not change in this study. The responses of trace gases during SEEDS II differed from the previous findings ( in situ iron enrichment experiment—EisenEx, Southern Ocean iron experiment—SOFeX, and Subarctic Ecosystem Response to Iron Enrichment Study—SERIES). Thus, in order to estimate the concomitant effect of iron fertilization on the climate, it is important to assess the induction of biological

  6. Extramedullary hematopoiesis is associated with lower cardiac iron loading in chronically transfused thalassemia patients.

    PubMed

    Ricchi, Paolo; Meloni, Antonella; Spasiano, Anna; Neri, Maria Giovanna; Gamberini, Maria Rita; Cuccia, Liana; Caruso, Vincenzo; Gerardi, Calogera; D'Ascola, Domenico Giuseppe; Rosso, Rosamaria; Campisi, Saveria; Rizzo, Michele; Terrazzino, Fabrizia; Vangosa, Alessandra Briatico; Chiodi, Elisabetta; Missere, Massimiliano; Mangione, Maurizio; Positano, Vincenzo; Pepe, Alessia

    2015-11-01

    The aim of this study was to evaluate, in a large cohort of chronically transfused patients, whether the presence of extramedullary hematopoiesis (EMH) accounts for the typical patterns of cardiac iron distribution and/or cardiac function parameters. We retrospectively selected 1,266 thalassemia major patients who had undergone regular transfusions (611 men and 655 women; mean age: 31.3 ± 8.9 years, range: 4.2-66.6 years) and were consecutively enrolled within the Myocardial Iron Overload in Thalassemia network. The presence of EMH was evaluated based on steady-state free precession sequences; cardiac and liver iron overloads were quantified using a multiecho T2* approach; cardiac function parameters and pulmonary diameter were quantified using the steady-state free precession sequences; and myocardial fibrosis was evaluated using the late gadolinium enhancement technique. EMH was detected in 167 (13.2%) patients. The EMH+ patients had significantly lower cardiac iron overload than that of the EMH- patients (P = 0.003). The patterns of cardiac iron distribution were significantly different in the EMH+ and EMH- patients (P < 0.0001), with a higher prevalence of patients with no myocardial iron overload and heterogeneous myocardial iron overload and no significant global heart iron in the EMH+ group EMH+ patients had a significantly higher left ventricle mass index (P = 0.001) and a significantly higher pulmonary artery diameter (P = 0.002). In conclusion, in regularly transfused thalassemia patients, EMH was common and was associated with a thalassemia intermedia-like pattern of cardiac iron deposition despite regular transfusion therapy.

  7. Functional Reconstruction of Tracheal Defects by Protein-Loaded, Cell-Seeded, Fibrous Constructs in Rabbits

    PubMed Central

    Ott, Lindsey M.; Vu, Cindy H.; Farris, Ashley L.; Fox, Katrina D.; Galbraith, Richard A.; Weiss, Mark L.; Weatherly, Robert A.

    2015-01-01

    Tracheal stenosis is a life-threatening disease and current treatments include surgical reconstruction with autologous rib cartilage and the highly complex slide tracheoplasty surgical technique. We propose using a sustainable implant, composed of a tunable, fibrous scaffold with encapsulated chondrogenic growth factor (transforming growth factor-beta3 [TGF-β3]) or seeded allogeneic rabbit bone marrow mesenchymal stromal cells (BMSCs). In vivo functionality of these constructs was determined by implanting them in induced tracheal defects in rabbits for 6 or 12 weeks. The scaffolds maintained functional airways in a majority of the cases, with the BMSC-seeded group having an improved survival rate and the Scaffold-only group having a higher occurrence of more patent airways as determined by microcomputed tomography. The BMSC group had a greater accumulation of inflammatory cells over the graft, while also exhibiting normal epithelium, subepithelium, and cartilage formation. Overall, it was concluded that a simple, acellular scaffold is a viable option for tracheal tissue engineering, with the intraoperative addition of cells being an optional variation to the scaffolds. PMID:26094554

  8. Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment.

    PubMed

    Su, Yiming; Adeleye, Adeyemi S; Huang, Yuxiong; Zhou, Xuefei; Keller, Arturo A; Zhang, Yalei

    2016-04-20

    Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe(2+) to Fe(0) by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe(0) crystals. Nano-SiO2 seeding brings down the size of single Fe(0) grain from 32.4 nm to 18.7 nm, enhances final Fe(0) content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

  9. Gallium loading of gold seed for high yield of patterned GaAs nanowires

    SciTech Connect

    Boulanger, J. P.; Chia, A. C. E.; LaPierre, R. R.

    2014-08-25

    A method is presented for maximizing the yield and crystal phase purity of vertically aligned Au-assisted GaAs nanowires grown with an SiO{sub x} selective area epitaxy mask on GaAs (111)B substrates. The nanowires were grown by the vapor-liquid-solid (VLS) method in a gas source molecular beam epitaxy system. During annealing, Au VLS seeds will alloy with the underlying GaAs substrate and collect beneath the SiO{sub x} mask layer. This behavior is detrimental to obtaining vertically aligned, epitaxial nanowire growth. To circumvent this issue, Au droplets were pre-filled with Ga assuring vertical yields in excess of 99%.

  10. Growth of salmonellae on sprouting alfalfa seeds as affected by the inoculum size, native microbial load, and Pseudomonas fluorescens 2-79

    USDA-ARS?s Scientific Manuscript database

    The incidence of human illness associated with the consumption of fresh sprouts has increased very sharply during the past decade. The objective of this study was to investigate the growth dynamics of salmonellae on sprouting alfalfa seeds as affected by the inoculum size, native microbial load, an...

  11. Development, optimization and in vitro-in vivo evaluation of pioglitazone- loaded jackfruit seed starch-alginate beads.

    PubMed

    Nayak, Amit Kumar; Pal, Dilipkumar; Hasnain, Saquib Md

    2013-10-01

    The present investigation describes development and optimization of pioglitazone-loaded jackfruit seed starch (JFSS)-alginate beads by ionotropic-gelation using 3(2) factorial design. The effect of polymer-blend ratio and CaCl2 concentration on the drug encapsulation efficiency (DEE, %), and cumulative drug release after 10 hours (R10h, %) was optimized. The DEE (%) of these beads were 64.80 ± 1.92 to 94.07 ± 3.82 % with sustained in vitro drug release of 64.± 1.83 to 92.66 ± 4.54 % over 10 hours. The in vitro drug release from these beads followed controlled-release pattern with super case-II transport. Particle size range of these beads was 0.77 ± 0.04 to 1.24 ± 0.09 mm. The beads were also characterized by SEM and FTIR. The swelling of these beads was influenced by pH of the test medium. The optimized pioglitazone-loaded JFSS-alginate beads showed significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration.

  12. Black soyabean seed coat extract regulates iron metabolism by inhibiting the expression of hepcidin.

    PubMed

    Mu, Mingdao; Wu, Aimin; An, Peng; Du, Xiaoli; Wu, Qian; Shen, Xiaoyun; Wang, Fudi

    2014-04-14

    Hepcidin, a key regulator of Fe homeostasis, is an ideal drug target for treating patients with Fe disorders such as haemochromatosis, anaemia of chronic inflammation and Fe-deficiency anaemia. However, whether (and how) traditional Chinese black foods (e.g., black soyabeans) target hepcidin and improve Fe-deficiency anaemia remains unclear. Herein, we report that black soyabean seed coat extract (BSSCE) can potently inhibit the in vitro and in vivo expression of hepcidin. In the present study, in cells treated with 200 μg/ml BSSCE, hepcidin expression was found to be reduced to only 6% of the control levels (P<0.01). An AIN-76A diet containing 2% BSSCE was fed to 8-week-old male C57BL/6 mice for 0, 1, 7, 15 or 30 d; importantly, compared with the day 0 group, the day 7 group exhibited nearly a 50% decrease in hepatic hepcidin expression (P<0.01), a 35% decrease in splenic Fe concentrations (P<0.05) and a 135% increase in serum Fe concentrations (P<0.05). Mechanistically, the effect of BSSCE on hepcidin expression was mediated via a reduction in the phosphorylation levels of mothers against decapentaplegic homolog proteins (Smad)1/5/8. Consequently, the mice in the day 30 group exhibited large increases in erythrocyte counts (111% v. day 0, P<0.01), Hb concentrations (109%, P<0.01) and haematocrit values (108%, P<0.01). In conclusion, these results indicate that black soyabean extract regulates Fe metabolism by inhibiting the expression of hepcidin. This finding can be used to optimise the intervention of patients with hepcidin-related diseases, including Fe-deficiency anaemia.

  13. The response of the virus community to the SEEDS II mesoscale iron fertilization

    NASA Astrophysics Data System (ADS)

    Higgins, Julie L.; Kudo, Isao; Nishioka, Jun; Tsuda, Atsushi; Wilhelm, Steven W.

    2009-12-01

    Although the important role of viruses in marine biogeochemical cycles has been established in recent years, virus activity (including changes in this activity) has been largely ignored during mesoscale iron (Fe)-fertilization experiments relative to other processes. This is of particular interest as viruses have been shown to be critical to the transformation of Fe from the particulate (i.e., biological) to the dissolved pools. The goal of the present study was to evaluate changes in the virus-mediated lysis of heterotrophic bacterial cells following a shift in ecosystem trophic status brought about by a mesoscale Fe addition in the subarctic Pacific Ocean. Virus production rates, estimated by a reduction and reoccurrence assay, were coupled with transmission electron microscopy estimates of burst size and direct counts of virus and bacterial abundance. Fe fertilization of the upper mixed layer resulted in significant yet weak increases in virus production rates during the 12 days of observation immediately after fertilization, although the burst size (viruses produced per lytic event) and the percentage of visibly infected cells remained constant. The results imply that increases in virus production rates were most likely tied to a decreased lytic cycle length or the stimulation of lysogenized cells following the stimulation of primary and secondary productivity by the addition of Fe. The results also indicate that virus-induced cell-lysis regenerated an estimated nearly 200 pmol L -1 Fe daily, providing a significant return of Fe back to the water column, which may be critical in the maintenance of this added Fe as resident.

  14. Using iron-loaded sepiolite obtained by adsorption as a catalyst in the electro-Fenton oxidation of Reactive Black 5.

    PubMed

    Iglesias, O; Fernández de Dios, M A; Pazos, M; Sanromán, M A

    2013-09-01

    This study explores the possibility of using iron-loaded sepiolite, obtained by recovering iron from polluted water, as a catalyst in the electro-Fenton oxidation of organic pollutants in textile effluents. The removal of iron ions from aqueous solution by adsorption on sepiolite was studied in batch tests at iron concentrations between 100 and 1,000 ppm. Electro-Fenton experiments were carried out in an electrochemical cell with a working volume of 0.15 L, an air flow of 1 L/min, and 3 g of iron-loaded sepiolite. An electric field was applied using a boron-doped diamond anode and a graphite sheet cathode connected to a direct current power supply with a constant potential drop. Reactive Black 5 (100 mg/L) was selected as the model dye. The adsorption isotherms proved the ability of the used adsorbent. The removal of the iron ion by adsorption on sepiolite was in the range of 80-100 % for the studied concentration range. The Langmuir and Freundlich isotherms were found to be applicable in terms of the relatively high regression values. Iron-loaded sepiolite could be used as an effective heterogeneous catalyst for the degradation of organic dyes in the electro-Fenton process. Successive batch processes were performed at optimal working conditions (5 V and pH 2). The results indicate the suitability of the proposed combined process, adsorption to iron remediation followed by the application of the obtained iron-loaded sepiolite to the electro-Fenton technique, to oxidize polluted effluents.

  15. Ketoprofen-loaded pomegranate seed oil nanoemulsion stabilized by pullulan: Selective antiglioma formulation for intravenous administration.

    PubMed

    Ferreira, Luana M; Cervi, Verônica F; Gehrcke, Mailine; da Silveira, Elita F; Azambuja, Juliana H; Braganhol, Elizandra; Sari, Marcel H M; Zborowski, Vanessa A; Nogueira, Cristina W; Cruz, Letícia

    2015-06-01

    This study aimed to prepare pomegranate seed oil nanoemulsions containing ketoprofen using pullulan as a polymeric stabilizer, and to evaluate antitumor activity against in vitro glioma cells. Formulations were prepared by the spontaneous emulsification method and different concentrations of pullulan were tested. Nanoemulsions presented adequate droplet size, polydispersity index, zeta potential, pH, ketoprofen content and encapsulation efficiency. Nanoemulsions were able to delay the photodegradation profile of ketoprofen under UVC radiation, regardless of the concentration of pullulan. In vitro release study indicates that nanoemulsions were able to release approximately 95.0% of ketoprofen in 5h. Free ketoprofen and formulations were considered hemocompatible at 1 μg/mL, in a hemolysis study, for intravenous administration. In addition, a formulation containing the highest concentration of pullulan was tested against C6 cell line and demonstrated significant activity, and did not reduce fibroblasts viability. Thus, pullulan can be considered an interesting excipient to prepare nanostructured systems and nanoemulsion formulations can be considered promising alternatives for the treatment of glioma.

  16. Magnetic hyperthermia efficiency and 1H-NMR relaxation properties of iron oxide/paclitaxel-loaded PLGA nanoparticles

    NASA Astrophysics Data System (ADS)

    Ruggiero, Maria R.; Geninatti Crich, Simonetta; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio

    2016-07-01

    Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar 1H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15-20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications.

  17. Hydrogen induced cracking tests of high strength steels and nickel-iron base alloys using the bolt-loaded specimen

    SciTech Connect

    Vigilante, G.N.; Underwood, J.H.; Crayon, D.; Tauscher, S.; Sage, T.; Troiano, E.

    1997-12-31

    Hydrogen induced cracking tests were conducted on high strength steels and nickel-iron base alloys using the constant displacement bolt-loaded compact specimen. The bolt-loaded specimen was subjected to both acid and electrochemical cell environments in order to produce hydrogen. The materials tested were A723, Maraging 200, PH 13-8 Mo, Alloy 718, Alloy 706, and A286, and ranged in yield strength from 760--1400 MPa. The effects of chemical composition, refinement, heat treatment, and strength on hydrogen induced crack growth rates and thresholds were examined. In general, all high strength steels tested exhibited similar crack growth rates and thresholds were examined. In general, all high strength steels tested exhibited similar crack growth rates and threshold levels. In comparison, the nickel-iron base alloys tested exhibited up to three orders of magnitude lower crack growth rates than the high strength steels tested. It is widely known that high strength steels and nickel base alloys exhibit different crack growth rates, in part, because of their different crystal cell structure. In the high strength steels tested, refinement and heat treatment had some effect on hydrogen induced cracking, though strength was the predominant factor influencing susceptibility to cracking. When the yield strength of one of the high strength steels tested was increased moderately, from 1130 MPa to 1275 MPa, the incubation times decreased by over two orders of magnitude, the crack growth rates increased by an order of magnitude, and the threshold stress intensity was slightly lower.

  18. Preparation and characterization of carbonyl iron/glass composite absorber as matched load for isolator

    NASA Astrophysics Data System (ADS)

    Feng, Yongbao; Li, Yujiao; Qiu, Tai

    2012-09-01

    Composite absorbers made from 66 wt% carbonyl iron and 34 wt% low melting point glass powder were prepared by a pressureless sintering technique in a nitrogen atmosphere. Apparent porosity and bending strength of the as-prepared composites were investigated. The microstructure, heat resisting properties and electromagnetic properties were characterized by scanning electron microscopy, thermal gravimetric analysis-differential scanning calorimetry and vector network analyzer. The results show that the carbonyl iron/glass composite absorbers were difficult to densify. As the sintering temperature and soaking time increased, the apparent porosity first decreased and then increased, whereas the bending strength showed the opposite change. The composite absorber sintered at 520 °C for 40 min achieved the minimum apparent porosity of 13.08% and the highest bending strength of 52 MPa. Compared to the carbonyl iron/silicone rubber absorber, the carbonyl iron/glass composite absorber exhibited better heat resisting properties, and the initial oxidation temperature was increased about 200 °C. The composite absorber with a thickness of 1.25 mm showed a good microwave absorbing property in 8-12 GHz.

  19. Responses of DMS in the seawater and atmosphere to iron enrichment in the subarctic western North Pacific (SEEDS-II)

    NASA Astrophysics Data System (ADS)

    Nagao, Ippei; Hashimoto, Shinya; Suzuki, Koji; Toda, Shuji; Narita, Yasushi; Tsuda, Atsushi; Saito, Hiroaki; Kudo, Isao; Kato, Shungo; Kajii, Yoshizumi; Uematsu, Mitsuo

    2009-12-01

    Simultaneous measurements of dimethylsulfide (DMS) in the seawater and atmosphere were conducted during SEEDS-II to investigate the responses of DMS to iron (Fe) fertilization in the subarctic North Pacific. No significant increases in the seawater DMS (DMSw) concentration were observed inside the fertilized patch compared to those outside the patch, while particulate dimethylsulfoniopropionate (DMSPp) concentration inside the patch increased 2-fold compared to those outside the patch in the phytoplankton bloom of major DMSP producers such as prasinophytes, cryptophytes, diatoms and prymnesiophytes. In the decline phase of the bloom, maximum DMSw was observed both inside the patch (ca. 6.2 nM) and outside the patch (ca. 9.3 nM). In this period, increases in mesozooplankton and decreases in the DMSP producers (prymnesiophytes and diatoms) were observed both sides of the patch, but larger inside the patch than outside the patch. Large decreases in the DMSPp inside the patch, which was probably related to the large increases in mesozooplankton inside the patch, did not result in increases in the DMSw concentration. Considering biological and nonbiological parameters, we discussed these results, although they could not be completely explained. Unfortunately, the impact of Fe fertilization on the atmospheric DMS (DMSa) concentration was not detected due to no significant changes in DMSw. However, it is noted that DMSa concentrations were dependent on the sea-air DMS flux in the air from higher latitudes and/or the Eurasian continent, though the DMS flux was a minor role to the budget of DMSw. Therefore if DMSw were significantly changed by Fe fertilization, DMSa might be affected through changes in the sea-air flux in this condition.

  20. Neuroprotective effect of the active components of three Chinese herbs on brain iron load in a mouse model of Alzheimer’s disease

    PubMed Central

    DONG, XIAN-HUI; GAO, WEI-JUAN; KONG, WEI-NA; XIE, HONG-LIN; PENG, YAN; SHAO, TIE-MEI; YU, WEN-GUO; CHAI, XI-QING

    2015-01-01

    Alzheimer’s disease (AD) is a neurodegenerative brain disorder and the most common cause of dementia. New treatments for AD are required due to its increasing prevalence in aging populations. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on learning and memory impairment, β-amyloid (Aβ) reduction and brain iron load in an APPswe/PS1ΔE9 transgenic mouse model of AD. Increasing evidence indicates that a disturbance of normal iron homeostasis may contribute to the pathology of AD. However, the underlying mechanisms resulting in abnormal iron load in the AD brain remain unclear. It has been hypothesized that the brain iron load is influenced by the deregulation of certain proteins associated with brain iron metabolism, including divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1). The present study investigated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on the expression levels of DMT1 and FPN1. The treatment with the active components reduced cognitive deficits, inhibited Aβ plaque accumulation, reversed Aβ burden and reduced the brain iron load in AD model mice. A significant increase was observed in the levels of DMT1-iron-responsive element (IRE) and DMT1-nonIRE in the hippocampus of the AD mouse brain, which was reduced by treatment with the active components. In addition, the levels of FPN1 were significantly reduced in the hippocampus of the AD mouse brain compared with those of control mice, and these levels were increased following treatment with the active components. Thus, the present study indicated that the active components of Epimedium, Astragalus and Radix Puerariae may exert a neuroprotective effect against AD by reducing iron overload in the AD brain and may provide a novel approach for the development of drugs for the treatment of AD. PMID:25780429

  1. Neuroprotective effect of the active components of three Chinese herbs on brain iron load in a mouse model of Alzheimer's disease.

    PubMed

    Dong, Xian-Hui; Gao, Wei-Juan; Kong, Wei-Na; Xie, Hong-Lin; Peng, Yan; Shao, Tie-Mei; Yu, Wen-Guo; Chai, Xi-Qing

    2015-04-01

    Alzheimer's disease (AD) is a neurodegenerative brain disorder and the most common cause of dementia. New treatments for AD are required due to its increasing prevalence in aging populations. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on learning and memory impairment, β-amyloid (Aβ) reduction and brain iron load in an APPswe/PS1ΔE9 transgenic mouse model of AD. Increasing evidence indicates that a disturbance of normal iron homeostasis may contribute to the pathology of AD. However, the underlying mechanisms resulting in abnormal iron load in the AD brain remain unclear. It has been hypothesized that the brain iron load is influenced by the deregulation of certain proteins associated with brain iron metabolism, including divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1). The present study investigated the effects of the active components of Epimedium, Astragalus and Radix Puerariae on the expression levels of DMT1 and FPN1. The treatment with the active components reduced cognitive deficits, inhibited Aβ plaque accumulation, reversed Aβ burden and reduced the brain iron load in AD model mice. A significant increase was observed in the levels of DMT1-iron-responsive element (IRE) and DMT1-nonIRE in the hippocampus of the AD mouse brain, which was reduced by treatment with the active components. In addition, the levels of FPN1 were significantly reduced in the hippocampus of the AD mouse brain compared with those of control mice, and these levels were increased following treatment with the active components. Thus, the present study indicated that the active components of Epimedium, Astragalus and Radix Puerariae may exert a neuroprotective effect against AD by reducing iron overload in the AD brain and may provide a novel approach for the development of drugs for the treatment of AD.

  2. Cold catalytic recovery of loaded activated carbon using iron oxide-based nanoparticles.

    PubMed

    Bach, Altai; Zelmanov, Grigory; Semiat, Raphael

    2008-01-01

    A novel approach for the recovery of spent activated carbon by an advanced oxidation process using iron oxide-based nanocatalysts was proposed and investigated. Model organic contaminants, such as ethylene glycol and phenol, were chosen for this study as water pollutants. It was shown that there are several advantages in using catalytic oxidation recovery of activated carbon with iron oxide-based nanocatalysts: low temperature reactivity of catalytic recovery without heating; and a relatively large number of adsorption-recovery cycles, without a reduction in the adsorptive properties of the virgin activated carbon or without a performance decrease from the first adsorption-recovery cycle of the new modified adsorptive properties of the activated carbon. The catalytic recovery takes place without ultraviolet light or any visible radiation sources. Results show a high efficiency of catalytic recovery of spent activated carbon using iron oxide-based nanocatalysts. A 97-99% efficiency of spent activated carbon catalytic regeneration was achieved under chosen conditions after 15-20 min of reaction. The process may be also considered as cold in situ recovery of active carbon.

  3. Sexual conflict and the gender load: correlated evolution between population fitness and sexual dimorphism in seed beetles.

    PubMed

    Arnqvist, Göran; Tuda, Midori

    2010-05-07

    Although males and females share much of the same genome, selection is often distinct in the two sexes. Sexually antagonistic loci will in theory cause a gender load in populations, because sex-specific selection on a given trait in one sex will compromise the adaptive evolution of the same trait in the other sex. However, it is currently not clear whether such intralocus sexual conflict (ISC) represents a transient evolutionary state, where conflict is rapidly resolved by the evolution of sexual dimorphism (SD), or whether it is a more chronic impediment to adaptation. All else being equal, ISC should manifest itself as correlated evolution between population fitness and SD in traits expressed in both sexes. However, comparative tests of this prediction are problematic and have been unfeasible. Here, we assess the effects of ISC by comparing fitness and SD across distinct laboratory populations of seed beetles that should be well adapted to a shared environment. We show that SD in juvenile development time, a key life-history trait with a history of sexually antagonistic selection in this model system, is positively related to fitness. This effect is due to a correlated evolution between population fitness and development time that is positive in females but negative in males. Loosening the genetic bind between the sexes has evidently allowed the sexes to approach their distinct adaptive peaks.

  4. Strontium folate loaded biohybrid scaffolds seeded with dental pulp stem cells induce in vivo bone regeneration in critical sized defects.

    PubMed

    Martin-Del-Campo, Marcela; Rosales-Ibañez, Raul; Alvarado, Keila; Sampedro, Jose G; Garcia-Sepulveda, Christian A; Deb, Sanjukta; San Román, Julio; Rojo, Luis

    2016-10-18

    Strontium folate (SrFO) is a recently developed bone promoting agent with interest in medical and pharmaceutical fields due to its improved features in comparison to current strontium based therapies for osteoporosis and other bone diseases. In this work SrFO derivative was synthesized and loaded into biohybrid scaffolds obtained through lyophilisation of semi-interpenetrating networks of chitosan polyethylene glycol dimethacrylate and beta tri-calcium phosphate (βTCP) fabricated using free radical polymerization. The scaffolds were seeded with pluripotent stem cells obtained from human dental pulp and their potential to regenerate bone tissues were assessed using a critical sized defect model of calvaria in rats and compared with those obtained without SrFO. The results obtained both in vitro and in vivo demonstrated excellent cyto-compatibility with resorption of scaffolds in 4-6 weeks and a total regeneration of the defect, with a more rapid and dense bone formation in the group with SrFO. Thus, the use of stem cells sourced from human dental pulp in combination with SrFO are very promising systems for their application in compromised osseous tissue regeneration.

  5. Sexual conflict and the gender load: correlated evolution between population fitness and sexual dimorphism in seed beetles

    PubMed Central

    Arnqvist, Göran; Tuda, Midori

    2010-01-01

    Although males and females share much of the same genome, selection is often distinct in the two sexes. Sexually antagonistic loci will in theory cause a gender load in populations, because sex-specific selection on a given trait in one sex will compromise the adaptive evolution of the same trait in the other sex. However, it is currently not clear whether such intralocus sexual conflict (ISC) represents a transient evolutionary state, where conflict is rapidly resolved by the evolution of sexual dimorphism (SD), or whether it is a more chronic impediment to adaptation. All else being equal, ISC should manifest itself as correlated evolution between population fitness and SD in traits expressed in both sexes. However, comparative tests of this prediction are problematic and have been unfeasible. Here, we assess the effects of ISC by comparing fitness and SD across distinct laboratory populations of seed beetles that should be well adapted to a shared environment. We show that SD in juvenile development time, a key life-history trait with a history of sexually antagonistic selection in this model system, is positively related to fitness. This effect is due to a correlated evolution between population fitness and development time that is positive in females but negative in males. Loosening the genetic bind between the sexes has evidently allowed the sexes to approach their distinct adaptive peaks. PMID:20031994

  6. Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy

    PubMed Central

    He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

    2014-01-01

    Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone–releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer. PMID:25187709

  7. Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy.

    PubMed

    He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

    2014-01-01

    Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone-releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer.

  8. The proceedings of the 17th International Conference on Chelation: application of effective chelation therapies in iron loading and non iron loading conditions, and the gap in the prevention and treatment policies on thalassemia between developed and developing countries.

    PubMed

    Kontoghiorghes, George J

    2009-01-01

    Substantial progress in the use of chelating drugs for the treatment of iron overload and of non iron loading conditions has been presented during the 17th International Conference on Chelation (ICOC) held in November 2007 at Shenzhen, China. Major challenges lie ahead for the prevention and treatment of thalassemia in China, India, Thailand, Indonesia and many other developing countries where millions of heterozygote thalassemia carriers live and thousands of homozygote thalassemia patients are born annually. The progressive improvement of the economic climate in developing countries will increase the demand and resources for more prenatal and antenatal diagnoses, transfusions and chelation therapy in forthcoming years. Despite the major advances in diagnosis and treatment in developed countries, the vast majority of thalassemia patients in developing countries die untreated because they cannot afford the cost of transfusions and chelation therapy. New approaches and infrastructures and more efforts are needed to overcome the difficulties of supplying new techniques and treatments to patients in developing countries. International and local organizations need to be persuaded to act collectively and effectively to improve chelation and related treatments for thalassemia and other conditions, especially at this time that universally effective and inexpensive chelation therapies can be applied.

  9. Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment

    PubMed Central

    Su, Yiming; Adeleye, Adeyemi S.; Huang, Yuxiong; Zhou, Xuefei; Keller, Arturo A.; Zhang, Yalei

    2016-01-01

    Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe2+ to Fe0 by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe0 crystals. Nano-SiO2 seeding brings down the size of single Fe0 grain from 32.4 nm to 18.7 nm, enhances final Fe0 content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water. PMID:27095387

  10. Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment

    NASA Astrophysics Data System (ADS)

    Su, Yiming; Adeleye, Adeyemi S.; Huang, Yuxiong; Zhou, Xuefei; Keller, Arturo A.; Zhang, Yalei

    2016-04-01

    Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) is of great technical and scientific interest because of its promising application in groundwater remediation, although its synthesis is still a challenge. We develop a new nanoparticle seeding method to obtain a novel and reactive nanohybrid, which contains an Fe(0) core covered by a highly sulfidized layer under high extent of sulfidation. Syntheses monitoring experiments show that seeding accelerates the reduction rate from Fe2+ to Fe0 by 19%. X-ray adsorption near edge structure (XANES) spectroscopy and extended X-ray absorption fine structure analyses demonstrate the hexahedral Fe-Fe bond (2.45 and 2.83 Å) formation through breaking down of the 1.99 Å Fe-O bond both in crystalline and amorphous iron oxide. The XANES analysis also shows 24.2% (wt%) of FeS with bond length of 2.4 Å in final nanohybrid. Both X-ray diffraction and Mössbauer analyses further confirm that increased nanoparticle seeding results in formation of more Fe0 crystals. Nano-SiO2 seeding brings down the size of single Fe0 grain from 32.4 nm to 18.7 nm, enhances final Fe0 content from 5.9% to 55.6%, and increases magnetization from 4.7 to 65.5 emu/g. The synthesized nanohybrid has high cadmium removal capacity and holds promising prospects for treatment of metal-contaminated water.

  11. Reference design of 100 MW-h lithium/iron sulfide battery system for utility load leveling

    SciTech Connect

    Zivi, S.M.; Kacinskas, H.; Pollack, I.; Chilenskas, A.A.; Barney, D.L.; Grieve, W.; McFarland, B.L.; Sudar, S.; Goldstein, E.; Adler, E.

    1980-03-01

    The first year in a two-year cooperative effort between Argonne National Laboratory and Rockwell International to develop a conceptual design of a lithium alloy/iron sulfide battery for utility load leveling is presented. A conceptual design was developed for a 100 MW-h battery system based upon a parallel-series arrangement of 2.5 kW-h capacity cells. The sales price of such a battery system was estimated to be very high, $80.25/kW-h, exclusive of the cost of the individual cells, the dc-to-ac converters, site preparation, or land acquisition costs. Consequently, the second year's efforts were directed towards developing modified designs with significantly lower potential costs.

  12. Constitutive model for flake graphite cast iron automotive brake discs: induced anisotropic damage model under complex loadings

    NASA Astrophysics Data System (ADS)

    Augustins, L.; Billardon, R.; Hild, F.

    2016-09-01

    The present paper details an elasto-viscoplastic constitutive model for automotive brake discs made of flake graphite cast iron. In a companion paper (Augustins et al. in Contin Mech Thermodyn, 2015), the authors proposed a one-dimensional setting appropriate for representing the complex behavior of the material (i.e., asymmetry between tensile and compressive loadings) under anisothermal conditions. The generalization of this 1D model to 3D cases on a volume element and the associated challenges are addressed. A direct transposition is not possible, and an alternative solution without unilateral conditions is first proposed. Induced anisotropic damage and associated constitutive laws are then introduced. The transition from the volume element to the real structure and the numerical implementation require a specific basis change. Brake disc simulations with this constitutive model show that unilateral conditions are needed for the friction bands. A damage deactivation procedure is therefore defined.

  13. Influences of nanoscale zero valent iron loadings and bicarbonate and calcium concentrations on hydrogen evolution in anaerobic column experiments.

    PubMed

    Paar, Hendrik; Ruhl, Aki Sebastian; Jekel, Martin

    2015-01-01

    The estimation of nanoscale zero-valent iron (nZVI) reactivity after its injection into the subsurface is essential for its application in groundwater remediation. In the present study H₂ generation of commercially available nZVI and novel milled nZVI flakes were investigated in column experiments with varying nZVI loads (ranging from 8 to 43 g nZVI per kg sand). H₂ evolution rates were determined for column experiments without and with hydrogen carbonate and/or calcium. On average 0.29 mmol H₂/L per g Fe⁰ evolved within the first 30 days in column experiments with spherical, commercial nZVI particles. The H₂ evolution developed almost independently of the water matrices applied. The application of nZVI flakes resulted in lower H₂ generation rates. In general corrosion rates accelerated linearly with increasing initial amounts of iron. This was evident in experiments with both particle types. Concentration profiles of carbonate and calcium in influent and effluent were used to estimate corrosion products and precipitates. Despite the presence of high concentrations of inorganic carbon, Fe²⁺ reacted preferably with hydroxide ions to form ferrous hydroxide which is the precursor of magnetite. As a result only minor passivation of the reactive nZVI was observed.

  14. Dihydroartemisinin induces autophagy and inhibits the growth of iron-loaded human myeloid leukemia K562 cells via ROS toxicity

    PubMed Central

    Wang, Zeng; Hu, Wei; Zhang, Jia-Li; Wu, Xiu-Hua; Zhou, Hui-Jun

    2012-01-01

    Dihydroartemisinin (DHA), an active metabolite of artemisinin derivatives, is the most remarkable anti-malarial drug and has little toxicity to humans. Recent studies have shown that DHA effectively inhibits the growth of cancer cells. In the present study, we intended to elucidate the mechanisms underlying the inhibition of growth of iron-loaded human myeloid leukemia K562 cells by DHA. Mitochondria are important regulators of both autophagy and apoptosis, and one of the triggers for mitochondrial dysfunction is the generation of reactive oxygen species (ROS). We found that the DHA-induced autophagy of leukemia K562 cells, whose intracellular organelles are primarily mitochondria, was ROS dependent. The autophagy of these cells was followed by LC3-II protein expression and caspase-3 activation. In addition, we demonstrated that inhibition of the proliferation of leukemia K562 cells by DHA is also dependent upon iron. This inhibition includes the down-regulation of TfR expression and the induction of K562 cell growth arrest in the G2/M phase. PMID:23650588

  15. Quantitative Susceptibility Mapping Reveals an Association between Brain Iron Load and Depression Severity.

    PubMed

    Yao, Shun; Zhong, Yi; Xu, Yuhao; Qin, Jiasheng; Zhang, Ningning; Zhu, Xiaolan; Li, Yuefeng

    2017-01-01

    Previous studies have detected abnormal serum ferritin levels in patients with depression; however, the results have been inconsistent. This study used quantitative susceptibility mapping (QSM) for the first time to examine brain iron concentration in depressed patients and evaluated whether it is related to severity. We included three groups of age- and gender-matched participants: 30 patients with mild-moderate depression (MD), 14 patients with major depression disorder (MDD) and 20 control subjects. All participants underwent MR scans with a 3D gradient-echo sequence reconstructing for QSM and performed the 17-item Hamilton Depression Rating Scale (HDRS) test. In MDD, the susceptibility value in the bilateral putamen was significantly increased compared with MD or control subjects. In addition, a significant difference was also observed in the left thalamus in MDD patients compared with controls. However, the susceptibility values did not differ between MD patients and controls. The susceptibility values positively correlated with the severity of depression as indicated by the HDRS scores. Our results provide evidence that brain iron deposition may be associated with depression and may even be a biomarker for investigating the pathophysiological mechanism of depression.

  16. Salinomycin kills cancer stem cells by sequestering iron in lysosomes

    NASA Astrophysics Data System (ADS)

    Mai, Trang Thi; Hamaï, Ahmed; Hienzsch, Antje; Cañeque, Tatiana; Müller, Sebastian; Wicinski, Julien; Cabaud, Olivier; Leroy, Christine; David, Amandine; Acevedo, Verónica; Ryo, Akihide; Ginestier, Christophe; Birnbaum, Daniel; Charafe-Jauffret, Emmanuelle; Codogno, Patrice; Mehrpour, Maryam; Rodriguez, Raphaël

    2017-10-01

    Cancer stem cells (CSCs) represent a subset of cells within tumours that exhibit self-renewal properties and the capacity to seed tumours. CSCs are typically refractory to conventional treatments and have been associated to metastasis and relapse. Salinomycin operates as a selective agent against CSCs through mechanisms that remain elusive. Here, we provide evidence that a synthetic derivative of salinomycin, which we named ironomycin (AM5), exhibits a more potent and selective activity against breast CSCs in vitro and in vivo, by accumulating and sequestering iron in lysosomes. In response to the ensuing cytoplasmic depletion of iron, cells triggered the degradation of ferritin in lysosomes, leading to further iron loading in this organelle. Iron-mediated production of reactive oxygen species promoted lysosomal membrane permeabilization, activating a cell death pathway consistent with ferroptosis. These findings reveal the prevalence of iron homeostasis in breast CSCs, pointing towards iron and iron-mediated processes as potential targets against these cells.

  17. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    SciTech Connect

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; Clausen, Bjorn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K.

    2016-03-16

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. Furthermore, the study contributes to further understanding of load-partitioning characteristics in multiphase materials.

  18. Enhanced Fenton-like Degradation of Trichloroethylene by Hydrogen Peroxide Activated with Nanoscale Zero Valent Iron Loaded on Biochar

    NASA Astrophysics Data System (ADS)

    Yan, Jingchun; Qian, Linbo; Gao, Weiguo; Chen, Yun; Ouyang, Da; Chen, Mengfang

    2017-02-01

    Composite of nanoscale Zero Valent Iron (nZVI) loaded on Biochar (BC) was prepared and characterized as hydrogen peroxide (H2O2) activator for the degradation of trichloroethylene (TCE). nZVI is homogeneously loaded on lamellarly structured BC surfaces to form nZVI/BC with specific surface area (SBET) of 184.91 m2 g‑1, which can efficiently activate H2O2 to achieve TCE degradation efficiency of 98.9% with TOC removal of 78.2% within 30 min under the conditions of 0.10 mmol L‑1 TCE, 1.13 g L‑1 nZVI/BC and 1.50 mmol L‑1 H2O2. Test results from the Electron Spin Resonance (ESR) measurement and coumarin based fluorescent probe technology indicated that •OH radicals were the dominant species responsible for the degradation of TCE within the nZVI/BC-H2O2 system. Activation mechanism of the redox action of Fe2+/Fe3+ generated under both aerobic and anaerobic conditions from nZVI and single electron transfer process from BC surface bound C–OH to H2O2 promoted decomposition of H2O2 into •OH radicals was proposed.

  19. Evaluation Of Glass Density To Support The Estimation Of Fissile Mass Loadings From Iron Concentrations In SB8 Glasses

    SciTech Connect

    Edwards, T. B.; Peeler, D. K.; Kot, W. K.; Gan, H.; Pegg, I. L.

    2013-04-30

    The Department of Energy – Savannah River (DOE-SR) has provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of that guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft® Excel® spreadsheet for the evaluation of fissile loading in Sludge Batch 5 (SB5), Sludge Batch 6 (SB6), Sludge Batch 7a (SB7a), and Sludge Batch 7b (SB7b) glass based on the iron (Fe) concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that the necessary density information be provided to allow SRR to update the Excel® spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 8 (SB8). One of the primary inputs into the fissile loading spreadsheet includes an upper bound for the density of SB8-based glasses. Thus, these bounding density values are to be used to assess the fissile concentration in this glass system. It should be noted that no changes are needed to the underlying structure of the Excel-based spreadsheet to support fissile assessments for SB8. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB8 Waste Acceptance Product Specification (WAPS) sample.

  20. Superparamagnetic iron oxide nanoparticles-loaded chitosan-linoleic acid nanoparticles as an effective hepatocyte-targeted gene delivery system.

    PubMed

    Cheong, Su-Jin; Lee, Chang-Moon; Kim, Se-Lim; Jeong, Hwan-Jeong; Kim, Eun-Mi; Park, Eun-Hye; Kim, Dong Wook; Lim, Seok Tae; Sohn, Myung-Hee

    2009-05-08

    The goal of this study was to develop a gene delivery imaging system that targets hepatocytes to help diagnose and treat various liver diseases. To this end, we prepared superparamagnetic iron oxide nanoparticles (SPIO)-loaded with water-soluble chitosan (WSC)-linoleic acid (LA) nanoparticles (SCLNs) that formed gene complexes capable of localizing specifically to hepatocytes. We confirmed that (99m)Tc-labeled SCLNs delivered into mice via intravenous injection accumulated mainly in the liver using nuclear and magnetic resonance imaging. SCLN/enhanced green fluorescence protein (pEGFP) complexes were also successfully formed and were characterized with a gel retardation assay. SCLN/pEGFP complexes were transfected into primary hepatocytes, where GFP expression was observed in the cytoplasm. In addition, the injection of the gene complexes into mice resulted in significantly increased expression of GFP in hepatocytes in vivo. Furthermore, gene silencing was effectively achieved by administration of gene complexes loaded with specific siRNAs. In conclusion, our results indicate that the SCLNs have the potential to be useful for hepatocyte-targeted imaging and effective gene delivery into hepatocytes.

  1. Enhanced Fenton-like Degradation of Trichloroethylene by Hydrogen Peroxide Activated with Nanoscale Zero Valent Iron Loaded on Biochar

    PubMed Central

    Yan, Jingchun; Qian, Linbo; Gao, Weiguo; Chen, Yun; Ouyang, Da; Chen, Mengfang

    2017-01-01

    Composite of nanoscale Zero Valent Iron (nZVI) loaded on Biochar (BC) was prepared and characterized as hydrogen peroxide (H2O2) activator for the degradation of trichloroethylene (TCE). nZVI is homogeneously loaded on lamellarly structured BC surfaces to form nZVI/BC with specific surface area (SBET) of 184.91 m2 g−1, which can efficiently activate H2O2 to achieve TCE degradation efficiency of 98.9% with TOC removal of 78.2% within 30 min under the conditions of 0.10 mmol L−1 TCE, 1.13 g L−1 nZVI/BC and 1.50 mmol L−1 H2O2. Test results from the Electron Spin Resonance (ESR) measurement and coumarin based fluorescent probe technology indicated that ∙OH radicals were the dominant species responsible for the degradation of TCE within the nZVI/BC-H2O2 system. Activation mechanism of the redox action of Fe2+/Fe3+ generated under both aerobic and anaerobic conditions from nZVI and single electron transfer process from BC surface bound C–OH to H2O2 promoted decomposition of H2O2 into ∙OH radicals was proposed. PMID:28230207

  2. Age-related changes of brain iron load changes in the frontal cortex in APPswe/PS1ΔE9 transgenic mouse model of Alzheimer's disease.

    PubMed

    Xian-hui, Dong; Wei-juan, Gao; Tie-mei, Shao; Hong-lin, Xie; Jiang-tao, Bai; Jing-yi, Zhao; Xi-qing, Chai

    2015-04-01

    Alzheimer's disease (AD) as a neurodegenerative brain disorder is a devastating pathology leading to disastrous cognitive impairments and dementia, associated with major social and economic costs to society. Iron can catalyze damaging free radical reactions. With age, iron accumulates in brain frontal cortex regions and may contribute to the risk of AD. In this communication, we investigated the age-related brain iron load changes in the frontal cortex of 6- and 12-month-old C57BL/6J (C57) and APPswe/PS1ΔE9 (APP/PS1) double transgenic mouse by using graphite furnace atomic absorption spectrometry (GFAAS) and Perls' reaction. In the present study, we also evaluated the age-related changes of DMT1 and FPN1 by using Western blot and qPCR. We found that compared with 6-month-old APP/PS1 mice and the 12-month-old C57 mice, the 12-month-old APP/PS1 mice had increased iron load in the frontal cortex. The levels of DMT1 were significantly increased and the FPN1 were significantly reduced in the frontal cortex of the 12-month-old APP/PS1 mice than that in the 6-month-old APP/PS1 mice and 12-month-old C57 mice. We conclude that in AD damage occurs in conjunction with iron accumulation, and the brain iron load associated with loss control of the brain iron metabolism related protein DMT1 and FPN1 expressions.

  3. Identification of quantitative trait loci associated with seed iron in the legumes Lotus japonicus and Medicago truncatula

    USDA-ARS?s Scientific Manuscript database

    Iron deficiency is one of the leading micronuntrient deficiencies in humans, and increasing the amount of bioavailable iron in commonly consumed plant foods has been proposed as a means to ameliorate this deficiency. This approach seems especially beneficial in developing countries where plant food...

  4. Evaluation of constitutive iron reductase (AtFRO2) expression on mineral accumulation and distribution in soybean (Glycine max. L)

    PubMed Central

    Vasconcelos, Marta W.; Clemente, Thomas E.; Grusak, Michael A.

    2014-01-01

    Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene’s expression on root, leaf, pod wall, and seed mineral concentrations. High Fe supply, in combination with the constitutive expression of AtFRO2, resulted in significantly higher concentrations of different minerals in roots (K, P, Zn, Ca, Ni, Mg, and Mo), pod walls (Fe, K, P, Cu, and Ni), leaves (Fe, P, Cu, Ca, Ni, and Mg) and seeds (Fe, Zn, Cu, and Ni). Leaf and pod wall iron concentrations increased as much as 500% in transgenic plants, while seed iron concentrations only increased by 10%, suggesting that factors other than leaf and pod wall reductase activity were limiting the translocation of iron to seeds. Protoplasts isolated from transgenic leaves had three-fold higher reductase activity than controls. Expression levels of the iron storage protein, ferritin, were higher in the transgenic leaves than in wild-type, suggesting that the excess iron may be stored as ferritin in the leaves and therefore unavailable for phloem loading and delivery to the seeds. Also, citrate and malate levels in the roots and leaves of transgenic plants were significantly higher than in wild-type, suggesting that organic acid production could be related to the increased accumulation of minerals in roots, leaves, and pod walls, but not in the seeds. All together, these results suggest a more ubiquitous role for the iron reductase in whole-plant mineral accumulation and

  5. Determination of total iron-reactive phenolics, anthocyanins and tannins in wine grapes of skins and seeds based on near-infrared hyperspectral imaging.

    PubMed

    Zhang, Ni; Liu, Xu; Jin, Xiaoduo; Li, Chen; Wu, Xuan; Yang, Shuqin; Ning, Jifeng; Yanne, Paul

    2017-12-15

    Phenolics contents in wine grapes are key indicators for assessing ripeness. Near-infrared hyperspectral images during ripening have been explored to achieve an effective method for predicting phenolics contents. Principal component regression (PCR), partial least squares regression (PLSR) and support vector regression (SVR) models were built, respectively. The results show that SVR behaves globally better than PLSR and PCR, except in predicting tannins content of seeds. For the best prediction results, the squared correlation coefficient and root mean square error reached 0.8960 and 0.1069g/L (+)-catechin equivalents (CE), respectively, for tannins in skins, 0.9065 and 0.1776 (g/L CE) for total iron-reactive phenolics (TIRP) in skins, 0.8789 and 0.1442 (g/L M3G) for anthocyanins in skins, 0.9243 and 0.2401 (g/L CE) for tannins in seeds, and 0.8790 and 0.5190 (g/L CE) for TIRP in seeds. Our results indicated that NIR hyperspectral imaging has good prospects for evaluation of phenolics in wine grapes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Genetic reduction of phytate in common bean (Phaseolus vulgaris L.) seeds increases iron absorption in young women.

    PubMed

    Petry, Nicolai; Egli, Ines; Campion, Bruno; Nielsen, Erik; Hurrell, Richard

    2013-08-01

    Iron bioavailability from common beans is negatively influenced by phytic acid (PA) and polyphenols (PPs). Newly developed low-PA (lpa) beans with 90% less PA and variable PPs might improve iron bioavailability. The aim of this study was to evaluate the influence of lpa beans on iron bioavailability in women (n = 20). We compared iron absorption from 4 different beans using a paired, double meal, crossover design. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes (Fe(57), Fe(58)) from 2 lpa bean lines, one high in PPs (means ± SDs; PA = 124 ± 10 mg/100 g; PPs = 462 ± 25 mg/100 g) and one low in PPs (PA = 70 ± 10 mg/100 g; PPs = 54 ± 2 mg/100 g). The other 2 beans used were their parents with a normal PA concentration, one high in PPs (PA = 1030 ± 30 mg/100 g; PPs = 676 ± 19 mg/100 g) and one low in PPs (PA = 1360 ± 10 mg/100 g; PPs = 58 ± 1 mg/100 g). Fractional iron absorption from the lpa bean high in PPs was 6.1% (95% CI: 2.6, 14.7), which was 60 and 130% higher compared with the parent high in PPs (P < 0.001) and low in PPs (P < 0.001), respectively. The total amount of iron absorbed per test meal from the lpa bean high in PPs (372 μg; 95% CI: 160, 890) was 60 and 163% higher compared with the parent high in PPs (P < 0.001) and low in PPs (P < 0.001), respectively. Fractional iron absorption from the lpa line low in PPs (4%; 95% CI: 1.8, 8.7) was 50% higher and the total amount of iron absorbed per test meal (261 μg; 95% CI: 120, 570) was 85% higher than iron from the parent low in PPs (P < 0.001). There was no difference between the lpa beans high or low in PPs or between the parents high or low in PPs. A 90% reduction in PA leads to an increase in bioavailable iron from beans, independent of the PP concentration. The lpa mutation could be a key tool for improving iron bioavailability from beans.

  7. The efficacy of tissue Doppler imaging in predicting myocardial iron load in patients with beta-thalassemia major: correlation with T2* cardiovascular magnetic resonance.

    PubMed

    Aypar, Ebru; Alehan, Dursun; Hazirolan, Tuncay; Gümrük, Fatma

    2010-04-01

    Tissue Doppler imaging (TDI) can detect myocardial dysfunction related to iron load in patients with beta-thalassemia major (TM). We aimed to assess the efficacy of pulsed-wave TDI (PW-TDI) in predicting myocardial iron load in patients with TM using T2* magnetic resonance (MR) as the gold-standard non-invasive diagnostic test. 33 asymptomatic TM patients, mean aged 18 +/- 6 years (6-31) with normal left ventricular (LV) global systolic function were evaluated by conventional echocardiography and PW-TDI. Results were compared with 20 age and sex-matched controls. TDI measures included myocardial systolic (Sm), early (Em) and late (Am) diastolic velocities at basal and middle segments of septal and lateral LV wall. Myocardial iron deposition were measured in 29/33 patients by T2* MR. TM patients were also subgrouped according to those with iron load (T2* 20 ms). Mean T2* was 12.3 +/- 7.8 ms (4-31.3). Abnormal myocardial iron load (T2* < 20 ms) was found in 25/29 (86%) patients. The following TDI measures were lower in patients than in controls: basal septal Em (P < 0.001) and Am (P < 0.05), mid-septal Am (P < 0.05), mid-lateral LV wall Sm (P < 0.05) and Am (P < 0.05). Regional myocardial dysfunction were more prominent in patients with T2* iron load were determined. PW-TDI technique was found both sensitive and specific in predicting presence of myocardial iron load in TM patients with normal LV global systolic function. Therefore, it can be used for screening of TM patients.

  8. Micro-electrolysis of Cr (VI) in the nanoscale zero-valent iron loaded activated carbon.

    PubMed

    Wu, Limei; Liao, Libing; Lv, Guocheng; Qin, Faxiang; He, Yujuan; Wang, Xiaoyu

    2013-06-15

    In this paper we prepared a novel material of activated carbon/nanoscale zero-valent iron (C-Fe(0)) composite. The C-Fe(0) was proved to possess large specific surface area and outstanding reducibility that result in the rapid and stable reaction with Cr (VI). The prepared composite has been examined in detail in terms of the influence of solution pH, concentration and reaction time in the Cr (VI) removal experiments. The results showed that the C-Fe(0) formed a micro-electrolysis which dominated the reaction rate. The Micro-electrolysis reaches equilibrium is ten minutes. Its reaction rate is ten times higher than that of traditional adsorption reaction, and the removal rate of Cr reaches up to 99.5%. By analyzing the obtained profiles from the cyclic voltammetry, PXRD and XPS, we demonstrate that the Cr (VI) is reduced to insoluble Cr (III) compound in the reaction. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Magnetic resonance and ultrasound contrast imaging of polymer-shelled microbubbles loaded with iron oxide nanoparticles

    PubMed Central

    Sciallero, Claudia; Balbi, Luca; Paradossi, Gaio; Trucco, Andrea

    2016-01-01

    Dual-mode contrast agents (CAs) have great potential for improving diagnostics. However, the effectiveness of CAs is strictly related to both the solution adopted to merge the two agents into a single probe unit, and the ratio between the two agents. In this study, two dual-mode CAs for simultaneous magnetic resonance imaging (MRI) and ultrasound imaging (UI) were assessed. For this purpose, different densities of superparamagnetic iron oxide nanoparticles (SPIONs) were anchored to the external surface of polymer-shelled microbubbles (MBs) or were physically entrapped into the shell. In vitro static and dynamic experiments were carried out with a limited concentration of modified MBs (106 bubbles ml−1) by avoiding destruction during UI (performed at a peak pressure lower than 320 kPa) and by using a low-field MRI system (with a magnetic flux density equal to 0.25 T). Under these conditions, different imaging techniques, set-up parameters and SPION densities were used to achieve satisfactory detection of the CAs by using both UI and MRI. However, when the SPION density was increased, the MRI contrast improved, whereas the UI contrast worsened due to the reduced elasticity of the MB shell. For both UI and MRI, MBs with externally anchored SPIONs provided better performance than MBs with SPIONs entrapped into the shell. In particular, a SPION density of 29% with respect to the mass of the MBs was successfully tested. PMID:27853587

  10. The binding mechanism of pyoverdin with the outer membrane receptor FpvA in Pseudomonas aeruginosa is dependent on its iron-loaded status.

    PubMed

    Clément, Emilie; Mesini, Philippe J; Pattus, Franc; Schalk, Isabelle J

    2004-06-22

    In iron-deficient conditions, Pseudomonas aeruginosa secretes a major fluorescent siderophore named pyoverdin (Pvd), which after chelating iron(III) is transported back into the cell via its outer membrane receptor FpvA. FpvA is a TonB-dependent transport protein and has the ability to bind Pvd in its apo- or iron-loaded form. The fluorescence properties of Pvd were used to determine the binding kinetics of metal-free and metal-loaded Pvd to FpvA and showed two major features. First, the kinetics of formation of the FpvA-Pvd complex, in vivo and in vitro, are markedly slower compared to those observed for FpvA-Pvd-metal. Second, apo-Pvd and Pvd-metal absorbed with biphasic kinetics to FpvA: the bimolecular step (association of the ligand with the receptor) is followed by a slower step (t(1/2) values of 5 and 34 min for Pvd-metal and Pvd, respectively) that presumably leads to a more stable complex. The most likely explanation for this second step is that the binding of the ligand to the receptor induces a conformational change on FpvA, which may be different, depending on the loading status of Pvd. Analysis of the dissociation of metal-free Pvd from FpvA revealed an energy and a TonB dependency. The dissociation of iron-free Pvd from FpvA in the absence of the TonB protein occurs with slow kinetics in the range of hours, but it can be highly activated by the protonmotive force and TonB to reach a kinetic with a t(1/2) of 1 min. Apparently, under iron-limited conditions, TonB activates the FpvA receptor, resulting in a fast release of iron-free Pvd and generating an unloaded FpvA receptor, competent for binding extracellular Pvd-Fe.

  11. Interactions between coherent twin boundaries and phase transition of iron under dynamic loading and unloading

    NASA Astrophysics Data System (ADS)

    Wang, Kun; Chen, Jun; Zhang, Xueyang; Zhu, Wenjun

    2017-09-01

    Phase transitions and deformation twins are constantly reported in many BCC metals under high pressure, whose interactions are of fundamental importance to understand the strengthening mechanism of these metals under extreme conditions. However, the interactions between twins and phase transition in BCC metals remain largely unexplored. In this work, interactions between coherent twin boundaries and α ↔ ɛ phase transition of iron are investigated using both non-equilibrium molecular dynamics simulations and the nudged elastic band method. Mechanisms of both twin-assisted phase transition and reverse phase transition are studied, and orientation relationships between BCC and HCP phases are found to be ⟨"separators="|11 1 ¯ ⟩ B C C||⟨"separators="|1 ¯2 1 ¯ 0 ⟩ H C P and ⟨"separators="|1 1 ¯ 0 ⟩ B C C||⟨"separators="|0001 ⟩ H C P for both cases. The twin boundary corresponds to {"separators="|10 1 ¯ 0 } H C P after the phase transition. It is amazing that the reverse transition seems to be able to "memorize" and recover the initial BCC twins. The memory would be partly lost when plastic slips take place in the HCP phase before the reverse transition. In the recovered initial BCC twins, three major twin spacings are observed, which are well explained in terms of energy barriers of transition from the HCP phase to the BCC twin. Besides, the variant selection rule of the twin assisted phase transition is also discussed. The results of present work could be expected to give some clues for producing ultra-fine grain structures in materials exhibiting martensitic phase transition.

  12. Evaluation of material heterogeneity dosimetric effects using radiochromic film for COMS eye plaques loaded with {sup 125}I seeds (model I25.S16)

    SciTech Connect

    Acar, Hilal; Chiu-Tsao, Sou-Tung; Oezbay, Ismail; Kemikler, Goenuel; Tuncer, Samuray

    2013-01-15

    Purpose: (1) To measure absolute dose distributions in eye phantom for COMS eye plaques with {sup 125}I seeds (model I25.S16) using radiochromic EBT film dosimetry. (2) To determine the dose correction function for calculations involving the TG-43 formalism to account for the presence of the COMS eye plaque using Monte Carlo (MC) method specific to this seed model. (3) To test the heterogeneous dose calculation accuracy of the new version of Plaque Simulator (v5.3.9) against the EBT film data for this seed model. Methods: Using EBT film, absolute doses were measured for {sup 125}I seeds (model I25.S16) in COMS eye plaques (1) along the plaque's central axis for (a) uniformly loaded plaques (14-20 mm in diameter) and (b) a 20 mm plaque with single seed, and (2) in off-axis direction at depths of 5 and 12 mm for all four plaque sizes. The EBT film calibration was performed at {sup 125}I photon energy. MC calculations using MCNP5 code for a single seed at the center of a 20 mm plaque in homogeneous water and polystyrene medium were performed. The heterogeneity dose correction function was determined from the MC calculations. These function values at various depths were entered into PS software (v5.3.9) to calculate the heterogeneous dose distributions for the uniformly loaded plaques (of all four sizes). The dose distributions with homogeneous water assumptions were also calculated using PS for comparison. The EBT film measured absolute dose rate values (film) were compared with those calculated using PS with homogeneous assumption (PS Homo) and heterogeneity correction (PS Hetero). The values of dose ratio (film/PS Homo) and (film/PS Hetero) were obtained. Results: The central axis depth dose rate values for a single seed in 20 mm plaque measured using EBT film and calculated with MCNP5 code (both in ploystyrene phantom) were compared, and agreement within 9% was found. The dose ratio (film/PS Homo) values were substantially lower than unity (mostly between 0.8 and 0

  13. A Young Adult with Unintended Acute Intravenous Iron Intoxication Treated with Oral Chelation: The Use of Liver Ferriscan for Diagnosing and Monitoring Tissue Iron Load

    PubMed Central

    Yassin, Mohamed; Soliman, Ashraf T; De Sanctis, Vincenzo; Moustafa, Abbas; Samaan, Sandra Abou; Nashwan, Abdulqadir

    2017-01-01

    Acute iron intoxication (FeI) in humans has not been adequately studied. The manifestation of FeI, defined as a serum iron concentration >300 μg/dL (55 μmol/L) within 12 hours of ingestion, include various symptoms appearing in progressive stages. Systemic toxicity is expected with an intake of 60 mg/kg. A 27-year-old female nurse presented with unintended acute intravenous iron intoxication (FeI) a week after self-injecting herself with 20 ampoules of IV iron (4,000 mg elemental iron, 60 mg/kg). She had stable vital signs and mild hepatic tenderness. Hepatic MRI (Ferriscan®) showed a moderate/severe liver iron content (LIC: 9 mg/g dry tissue). Her hemogram, electrolytes, hepatic and renal functions were normal. Based on the high dose of iron received and her elevated LIC, chelation therapy was advised. She accepted only oral therapy and was started on deferasirox at a dose of 30 mg/kg daily. This oral chelation proved to be effective in clearing her hepatic iron overload after six months (LIC: 2 mg/g dry tissue), without side effects. This case also proved the value of Ferriscan® in diagnosing the degree of hepatic FeI and monitoring therapy to achieve a safe level of LIC. PMID:28101313

  14. Study on the physicochemical properties of Fe/CeO2 catalysts as an effect from different iron loading

    NASA Astrophysics Data System (ADS)

    Mohamad, Mas Fatiha; Ramli, Anita; Yusup, Suzana

    2012-11-01

    The use of catalyst in the biomass gasification is effective to elevate hydrogen content and to reduce tar formation. This study presents the development of 2.5-10 wt% Fe/CeO2 catalysts for biomass gasification to hydrogen. The catalysts were prepared using incipient wetness impregnation method. Different characterization methods such as Powder XRay Diffraction (XRD), Temperature Programmed Reduction (TPR), N2 adsorption-desorption isotherm and Field Emission Scanning Electron Microscopy (FESEM) were used to characterize the prepared catalysts. BET analysis clearly indicates that Fe/CeO2 catalysts are mainly nonporous and the surface area of the catalysts increases with increasing of Fe loading. Characterization by XRD exhibited the formation of a solid solution of iron-cerium oxide, with the presence of cubic CeO2 structure which is in agreement with FESEM images. The TPR results show the emergence of two reduction peaks, corresponding to the surface and bulk reduction of CeO2 to Ce2O3. No distinct peak related to the reduction of Fe2O3 to Fe3O4, instead a shoulder evolved, related to the reduction of Fe3O4 to Fe.

  15. Iron and vegetarian diets.

    PubMed

    Saunders, Angela V; Craig, Winston J; Baines, Surinder K; Posen, Jennifer S

    2013-08-19

    Vegetarians who eat a varied and well balanced diet are not at any greater risk of iron deficiency anaemia than non-vegetarians. A diet rich in wholegrains, legumes, nuts, seeds, dried fruits, iron-fortified cereals and green leafy vegetables provides an adequate iron intake. Vitamin C and other organic acids enhance non-haem iron absorption, a process that is carefully regulated by the gut. People with low iron stores or higher physiological need for iron will tend to absorb more iron and excrete less. Research to date on iron absorption has not been designed to accurately measure absorption rates in typical Western vegetarians with low ferritin levels.

  16. The genetic architecture of life span and mortality rates: gender and species differences in inbreeding load of two seed-feeding beetles.

    PubMed

    Fox, Charles W; Scheibly, Kristy L; Wallin, William G; Hitchcock, Lisa J; Stillwell, R Craig; Smith, Benjamin P

    2006-10-01

    We examine the inbreeding load for adult life span and mortality rates of two seed beetle species, Callosobruchus maculatus and Stator limbatus. Inbreeding load differs substantially between males and females in both study populations of C. maculatus--life span of inbred females was 9-13% shorter than the life span of outbred females, whereas the life span of inbred males did not differ from the life span of outbred males. The effect of inbreeding on female life span was largely due to an increase in the slope of the mortality curve. In contrast, inbreeding had only a small effect on the life span of S. limbatus--life spans of inbred beetles were approximately 5% shorter than those of outbred beetles, and there was no difference in inbreeding load between the sexes. The inbreeding load for mean life span was approximately 0.4-0.6 lethal equivalents per haploid gamete for female C. maculatus and approximately 0.2-0.3 for both males and females of S. limbatus, all within the range of estimates commonly obtained for Drosophila. However, contrary to the predictions of mutation-accumulation models, inbreeding load for loci affecting mortality rates did not increase with age in either species, despite an effect of inbreeding on the initial rate of increase in mortality. This was because mortality rates decelerated with age and converged to a mortality plateau for both outbred and inbred beetles.

  17. Some pollinators are more equal than others: Factors influencing pollen loads and seed set capacity of two actively and passively pollinating fig wasps

    NASA Astrophysics Data System (ADS)

    Kjellberg, Finn; Suleman, Nazia; Raja, Shazia; Tayou, Abelouahad; Hossaert-McKey, Martine; Compton, Stephen G.

    2014-05-01

    The nursery pollination system of fig trees (Ficus) results in the plants providing resources for pollinator fig wasp larvae as part of their male reproductive investment, with selection determining relative investment into pollinating wasps and the pollen they carry. The small size of Ficus pollen suggests that the quantities of pollen transported by individual wasps often limits male reproductive success. We assessed variation in fig wasp pollen loads and its influence on seed production in actively pollinated (Ficus montana) and passively pollinated (Ficus carica) dioecious fig trees.

  18. New innovative electrocoagulation (EC) treatment technology for BWR colloidal iron utilizing the seeding and filtration electronically (SAFET{sup TM}) system

    SciTech Connect

    Denton, Mark S.; Bostick, William D.

    2007-07-01

    is 1) to break the colloid (i.e., break the outer radius repulsive charges of the similar charged colloidal particles), 2) allow these particles to now flocculate (floc), and 3) form a type of floc that is more readily filterable, and, thus, de-waterable. This task has been carried out with the innovative application of electronically seeding the feed stream with the metal of choice, and without the addition of chemicals common to ferri-flocking, or polymer addition. This patent-pending new system and technique is called Seeding And Filtration Electronically, or the SAFE{sup TM} System. Once the colloid has been broken and flocking has begun, removal of the resultant floc can be carried out by standard, back-washable (or, in simple cases, dead-end) filters; or simply in de-waterable HICs or liners. Such applications include low level radwaste (LLW) from both PWRs and BWRs, fuel pools, storage basins, salt water collection tanks, etc. For the removal of magnetic materials, such as some BWR irons, an Electro Magnetic Filter (EMF) was developed to couple with the Electro Coagulation (EC), (or metal-Flocking) Unit. In the advent that the waste stream primarily contains magnetic materials (e.g., boiler condensates and magnetite, and he-magnetite from BWRs), the material was simply filtered using the EMF. Bench-, pilot- and full-scale systems have been assembled and applied on actual plant waste samples quite successfully. The effects of initial feed pH and conductivity, as well as flocculation retention times was examined prior to applying the production equipment into the field. Since the initial studies (Denton, et al, EPRI, 2006), the ultimate success of field applications is now being demonstrated as the next development phase. For such portable field demonstrations and demand systems, a fully self enclosed (secondary containment) EC system was first developed and assembled in a modified B 25 Box (Floc-In-A-Box) and is being deployed to a number of NPP sites. Finally

  19. Iodinated oil-loaded, fluorescent mesoporous silica-coated iron oxide nanoparticles for magnetic resonance imaging/computed tomography/fluorescence trimodal imaging.

    PubMed

    Xue, Sihan; Wang, Yao; Wang, Mengxing; Zhang, Lu; Du, Xiaoxia; Gu, Hongchen; Zhang, Chunfu

    2014-01-01

    In this study, a novel magnetic resonance imaging (MRI)/computed tomography (CT)/fluorescence trifunctional probe was prepared by loading iodinated oil into fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (i-fmSiO4@SPIONs). Fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (fmSiO4@SPIONs) were prepared by growing fluorescent dye-doped silica onto superparamagnetic iron oxide nanoparticles (SPIONs) directed by a cetyltrimethylammonium bromide template. As prepared, fmSiO4@SPIONs had a uniform size, a large surface area, and a large pore volume, which demonstrated high efficiency for iodinated oil loading. Iodinated oil loading did not change the sizes of fmSiO4@SPIONs, but they reduced the MRI T2 relaxivity (r2) markedly. I-fmSiO4@SPIONs were stable in their physical condition and did not demonstrate cytotoxic effects under the conditions investigated. In vitro studies indicated that the contrast enhancement of MRI and CT, and the fluorescence signal intensity of i-fmSiO4@SPION aqueous suspensions and macrophages, were intensified with increased i-fmSiO4@SPION concentrations in suspension and cell culture media. Moreover, for the in vivo study, the accumulation of i-fmSiO4@SPIONs in the liver could also be detected by MRI, CT, and fluorescence imaging. Our study demonstrated that i-fmSiO4@SPIONs had great potential for MRI/CT/fluorescence trimodal imaging.

  20. Iodinated oil-loaded, fluorescent mesoporous silica-coated iron oxide nanoparticles for magnetic resonance imaging/computed tomography/fluorescence trimodal imaging

    PubMed Central

    Xue, Sihan; Wang, Yao; Wang, Mengxing; Zhang, Lu; Du, Xiaoxia; Gu, Hongchen; Zhang, Chunfu

    2014-01-01

    In this study, a novel magnetic resonance imaging (MRI)/computed tomography (CT)/fluorescence trifunctional probe was prepared by loading iodinated oil into fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (i-fmSiO4@SPIONs). Fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (fmSiO4@SPIONs) were prepared by growing fluorescent dye-doped silica onto superparamagnetic iron oxide nanoparticles (SPIONs) directed by a cetyltrimethylammonium bromide template. As prepared, fmSiO4@SPIONs had a uniform size, a large surface area, and a large pore volume, which demonstrated high efficiency for iodinated oil loading. Iodinated oil loading did not change the sizes of fmSiO4@SPIONs, but they reduced the MRI T2 relaxivity (r2) markedly. I-fmSiO4@SPIONs were stable in their physical condition and did not demonstrate cytotoxic effects under the conditions investigated. In vitro studies indicated that the contrast enhancement of MRI and CT, and the fluorescence signal intensity of i-fmSiO4@SPION aqueous suspensions and macrophages, were intensified with increased i-fmSiO4@SPION concentrations in suspension and cell culture media. Moreover, for the in vivo study, the accumulation of i-fmSiO4@SPIONs in the liver could also be detected by MRI, CT, and fluorescence imaging. Our study demonstrated that i-fmSiO4@SPIONs had great potential for MRI/CT/fluorescence trimodal imaging. PMID:24904212

  1. Serum ferritin level changes in children with sickle cell disease on chronic blood transfusion are nonlinear and are associated with iron load and liver injury

    PubMed Central

    Abboud, Miguel R.; Paley, Carole; Olivieri, Nancy; Kirby-Allen, Melanie; Vichinsky, Elliott; Casella, James F.; Alvarez, Ofelia A.; Barredo, Julio C.; Lee, Margaret T.; Iyer, Rathi V.; Kutlar, Abdullah; McKie, Kathleen M.; McKie, Virgil; Odo, Nadine; Gee, Beatrice; Kwiatkowski, Janet L.; Woods, Gerald M.; Coates, Thomas; Wang, Winfred; Adams, Robert J.

    2009-01-01

    Chronic blood transfusion is increasingly indicated in patients with sickle cell disease. Measuring resulting iron overload remains a challenge. Children without viral hepatitis enrolled in 2 trials for stroke prevention were examined for iron overload (STOP and STOP2; n = 271). Most received desferrioxamine chelation. Serum ferritin (SF) changes appeared nonlinear compared with prechelation estimated transfusion iron load (TIL) or with liver iron concentrations (LICs). Averaged correlation coefficient between SF and TIL (patients/observations, 26 of 164) was r = 0.70; between SF and LIC (patients/observations, 33 of 47) was r = 0.55. In mixed models, SF was associated with LIC (P = .006), alanine transaminase (P = .025), and weight (P = .026). Most patients with SF between 750 and 1500 ng/mL had a TIL between 25 and 100 mg/kg (72.8% ± 5.9%; patients/observations, 24 of 50) or an LIC between 2.5 and 10 mg/g dry liver weight (75% ± 0%; patients/observations, 8 of 9). Most patients with SF of 3000 ng/mL or greater had a TIL of 100 mg/kg or greater (95.3% ± 6.7%; patients/observations, 7 of 16) or an LIC of 10 mg/g dry liver weight or greater (87.7% ± 4.3%; patients/observations, 11 of 18). Although SF changes are nonlinear, levels less than 1500 ng/mL indicated mostly acceptable iron overload; levels of 3000 ng/mL or greater were specific for significant iron overload and were associated with liver injury. However, to determine accurately iron overload in patients with intermediately elevated SF levels, other methods are required. These trials are registered at www.clinicaltrials.gov as #NCT00000592 and #NCT00006182. PMID:19721013

  2. Type I collagen gel in seeding medium improves murine mesencymal stem cell loading onto the scaffold, increases their subsequent proliferation, and enhances culture mineralization.

    PubMed

    Eslaminejad, Mohamadreza Baghaban; Mirzadeh, Hamid; Nickmahzar, Aghbibi; Mohamadi, Yossef; Mivehchi, Houri

    2009-08-01

    Collagen I as a major organic component of bone matrix may be important for establishment and maintenance of mesenchymal stem cells (MSCs) in osteogenic 3D culture. To explore this subject, murine marrow-derived MSCs were seeded onto hybrid scaffolds of alginate/gelatin/beta-tricalcium phosphate in a medium either with or without collagen I gel. The cultures were then provided with osteogenic medium and incubated for three weeks during which loading efficiency, cell proliferation and the culture mineralization were quantified and statistically compared. According to the findings, in culture with collagen, although about 60% of the cells left the scaffolds, the remaining cells, however, proliferated extensively with a population doubling number (PDN) equivalent to 2.46 +/- 0.31 and organized as cell aggregations that were heavily mineralized (calcium concentration = 1.017 +/- 0.141 mM per scaffold), whereas in the culture without collagen, about 75% of the cells left the scaffolds, less cell proliferation occurred (PDN = 1.48 +/- 0.29) and no cell aggregation was observed. The calcium concentration in this culture was 0.185 +/- 0.029 mM per scaffold. All these differences were statistically significant (p < 0.001). Taken together, these data suggested that using the collagen I in seeding medium could help mMSCs loading into the scaffold, enhance their subsequent proliferation, and increase calcium deposition in 3D culture system.

  3. Triterpene-loaded microemulsion using Coix lacryma-jobi seed extract as oil phase for enhanced antitumor efficacy: preparation and in vivo evaluation.

    PubMed

    Qu, Ding; He, Junjie; Liu, Congyan; Zhou, Jing; Chen, Yan

    2014-01-01

    Ganoderma lucidum triterpene-loaded microemulsions (TMEs) using Coix lacryma-jobi (adlay) seed oil as oil phase were prepared, characterized, and evaluated for enhanced antitumor activity. Ternary phase diagrams for the TMEs were constructed and the optimal preparation was developed. Transmission electron microscopy and dynamic light scattering showed that this formulation had a well defined spherical shape, a homogeneous distribution, a small size, and a narrow polydispersity index. The drug-loading rate was determined to be 9.87% by ultraviolet spectrophotometry, and acceptable stability under various stimulations in vitro was confirmed. Importantly, the TME formulation showed a significantly greater antiproliferative effect towards human lung carcinoma (A549) cells and murine lung tumor (Lewis) cells in comparison with suspension formulations containing triterpene and adlay seed oil as a positive control. The half-maximal inhibitory concentration of the TMEs was about 0.62 mg crude drug per mL, being 2.5-fold improved relative to that of the corresponding suspension formulation, but no significant cytotoxicity was observed for the bare microemulsion in A549 cells and Lewis cells. In vivo, the TME formulation showed markedly enhanced antitumor efficacy in a xenograft model of Lewis lung cancer after intragastric administration. Compared with cyclophosphamide, the TME formulation showed similar antitumor activity but less general toxicity. These results indicate the feasibility of using a microemulsion to increase the solubility of triterpene and adlay. TMEs hold promise as an efficient drug delivery system for the treatment of lung cancer.

  4. Triterpene-loaded microemulsion using Coix lacryma-jobi seed extract as oil phase for enhanced antitumor efficacy: preparation and in vivo evaluation

    PubMed Central

    Qu, Ding; He, Junjie; Liu, Congyan; Zhou, Jing; Chen, Yan

    2014-01-01

    Ganoderma lucidum triterpene-loaded microemulsions (TMEs) using Coix lacryma-jobi (adlay) seed oil as oil phase were prepared, characterized, and evaluated for enhanced antitumor activity. Ternary phase diagrams for the TMEs were constructed and the optimal preparation was developed. Transmission electron microscopy and dynamic light scattering showed that this formulation had a well defined spherical shape, a homogeneous distribution, a small size, and a narrow polydispersity index. The drug-loading rate was determined to be 9.87% by ultraviolet spectrophotometry, and acceptable stability under various stimulations in vitro was confirmed. Importantly, the TME formulation showed a significantly greater antiproliferative effect towards human lung carcinoma (A549) cells and murine lung tumor (Lewis) cells in comparison with suspension formulations containing triterpene and adlay seed oil as a positive control. The half-maximal inhibitory concentration of the TMEs was about 0.62 mg crude drug per mL, being 2.5-fold improved relative to that of the corresponding suspension formulation, but no significant cytotoxicity was observed for the bare microemulsion in A549 cells and Lewis cells. In vivo, the TME formulation showed markedly enhanced antitumor efficacy in a xenograft model of Lewis lung cancer after intragastric administration. Compared with cyclophosphamide, the TME formulation showed similar antitumor activity but less general toxicity. These results indicate the feasibility of using a microemulsion to increase the solubility of triterpene and adlay. TMEs hold promise as an efficient drug delivery system for the treatment of lung cancer. PMID:24379669

  5. Biogeochemical cycling of N and Si during the mesoscale iron-enrichment experiment in the western subarctic Pacific (SEEDS-II)

    NASA Astrophysics Data System (ADS)

    Saito, Hiroaki; Tsuda, Atsushi; Nojiri, Yukihiro; Aramaki, Takafumi; Ogawa, Hiroshi; Yoshimura, Takeshi; Imai, Keiri; Kudo, Isao; Nishioka, Jun; Ono, Tsuneo; Suzuki, Koji; Takeda, Shigenobu

    2009-12-01

    Biogeochemical cycles of N and Si were examined in the surface mixed layer during the mesoscale iron-enrichment (IE) experiment in the high-nutrient low-chlorophyll (HNLC) western subarctic Pacific (SEEDS-II). Although the IEs increased nitrate uptake, silicic acid utilization was not stimulated. The nitrate drawdown in the iron-patch (IN-patch, 140.3 mmol m -2 in the surface mixed layer, 0-30 m) was only 25% of the initial inventory, which was 1/3-2/5 of the previous IE experiments in the subarctic Pacific. This relatively weak response of nutrient drawdown to IEs was due to the high biomass of mesozooplankton (MZ) dominated by copepod Neocalanus plumchrus. Feeding of MZ (247.2 mmol m -2 during Day 0-21 from the first IE) in the IN-patch was higher than the nitrate drawdown and prevented further development of the phytoplankton bloom. In the later period of the experiment (Day 14-21), the increase in the feeding activity and resultant decrease in phytoplankton biomass induced the accumulation of dissolved organic nitrogen (DON) and ammonium. Among total growth of MZ (81.6 mmol N m -2), 89% (72.8 mmol N m -2) was transported to the depth by the ontogenetic downward migration of N. plumchrus. Although silicic acid drawdown was not increased by the IEs, Si export flux increased by 2.7 times. The increase in Si export was also due to the increase in MZ, which egested faecal pellets with higher Si:N ratio and faster sinking speed than diatoms. The export efficiency (78% of new production) and total amount of export flux (143.8 mmol N m -2, 1392 mmol C m -2) were highest records within the IE experiments despite weak responses of nutrient drawdown to the IE. During SEEDS-II, the high biomass of MZ reduced the phytoplankton response and nutrient drawdown to the IEs but via grazing and ontogenetic vertical migration accelerated the export flux as well as accumulations of dissolved forms of N. Results of the present and previous IE experiments indicate that the ecosystem

  6. Folate-targeted polymeric micelles loaded with ultrasmall superparamagnetic iron oxide: combined small size and high MRI sensitivity

    PubMed Central

    Hong, Guo-bin; Zhou, Jing-xing; Yuan, Ren-xu

    2012-01-01

    Targeted delivery of contrast agents is a highly desirable strategy for enhancing diagnostic efficiency and reducing side effects and toxicity. Water-soluble and tumor-targeting superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by loading hydrophobic SPIONs into micelles assembled from an amphiphilic block copolymer poly(ethylene glycol)- poly(ɛ-caprolactone) (PEG-PCL) bearing folate in the distal ends of PEG chains. Compared to the water-soluble SPIONs obtained by small molecular surfactant coating, ultrasmall SPION encapsulation with PEG-PCL micelles (PEG-PCL-SPIONs) simultaneously increases transverse (r2) and decreases longitudinal (r1) magnetic resonance (MR) relaxivities of water proton in micelle solution, leading to a notably high r2/r1 ratio up to 78, which makes the PEG-PCL-SPIONs a highly sensitive MR imaging (MRI) T2 contrast agent. The mean size of folate-attached SPION micelles (Fa-PEG-PCL-SPIONs) is 44 ± 3 nm on average, ideal for in vivo MRI applications in which long circulation is greatly determined by small particle size and is highly desirable. Prussian blue staining of BEL-7402 cells over-expressing folate receptors, after incubation with micelle-containing medium, demonstrated that folate functionalization of the magnetic particles significantly enhanced their cell uptake. The potential of Fa-PEG-PCL-SPIONs as a potent MRI probe for in vivo tumor detection was assessed. At 3 hours after intravenous injection of the Fa-PEG-PCL-SPION solution into mice bearing subcutaneous xenografts of human BEL-7402 hepatoma, a 41.2% signal intensity decrease was detected in the T2-weighted MR images of the tumor, indicating the efficient accumulation of Fa-PEG-PCL-SPIONs in the tumor tissue. PMID:22745549

  7. Development and Evaluation of Amphotericin B Loaded Iron Oxide Nanoparticles for Targeted Drug Delivery to Systemic Fungal Infections

    NASA Astrophysics Data System (ADS)

    Balabathula, Pavan

    A targeted nanotheronostic drug delivery system to diagnose and treat life threatening invasive fungal infections (IFIs) such as cryptococcal meningitis was designed, developed, characterized, and evaluated. To address the development processes, first, iron oxide nanoparticles (IONP) (34-40 nm) coated with bovine serum albumin (BSA), loaded and targeted with amphotericin B (AMB) (AMB-IONP) was formulated by applying a layer by layer approach. Several designs (A, B, C, D, & E) of AMB-IONP were developed and their physicochemical properties such as drug loading with HPLC method, particle size, poly dispersity index (PDI), and zeta-potential using dynamic light scattering (DLS) technique, morphology with transmission electronic microscopy (TEM), and in vitro drug release profile with dialysis method were evaluated. Second, uptake (with fluorescence microscopy and flow cytometry) and killing efficacy (with susceptibility testing) of AMB-IONP in fungal clinical isolates of Candida species were evaluated and compared with standard drug AMB deoxycholate (AMB-D) data. Third, the cellular uptake mechanisms with endocytosis inhibitors and intracellular trafficking using TEM for design D were evaluated in selected isolates. Fourth, a stable lyophilized AMB-IONP formulation was developed and was suitable for clinical trials. A validated isocratic HPLC method was developed and validated for the quantitative determination of AMB. Design D was determined to be the lead formulation with drug loading of 13.6+/-6.9 of AMB/mg of IONP. The size, zeta-potential, and PDI for all formulation designs were found to be in an optimum range for a nanomedicine with ≤36 nm, ˜ -20 mV, and ≤0.2, respectively. The TEM images confirmed that the nanoparticles were monodispersed and spherical in shape. The drug release profile indicated a burst release up to 3 hours for designs A and B, followed by a sustained drug release profile up to 72 hours. Designs C and D (with and without glutaraldehyde

  8. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    PubMed Central

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; Clausen, Bjørn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K.

    2016-01-01

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 °C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 °C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. The study contributes to further understanding of load-partitioning characteristics in multiphase materials. PMID:26979660

  9. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales

    DOE PAGES

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A.; ...

    2016-03-16

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix andmore » elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. Furthermore, the study contributes to further understanding of load-partitioning characteristics in multiphase materials.« less

  10. Load partitioning between the bcc-iron matrix and NiAl-type precipitates in a ferritic alloy on multiple length scales.

    PubMed

    Sun, Zhiqian; Song, Gian; Sisneros, Thomas A; Clausen, Bjørn; Pu, Chao; Li, Lin; Gao, Yanfei; Liaw, Peter K

    2016-03-16

    An understanding of load sharing among constituent phases aids in designing mechanical properties of multiphase materials. Here we investigate load partitioning between the body-centered-cubic iron matrix and NiAl-type precipitates in a ferritic alloy during uniaxial tensile tests at 364 and 506 °C on multiple length scales by in situ neutron diffraction and crystal plasticity finite element modeling. Our findings show that the macroscopic load-transfer efficiency is not as high as that predicted by the Eshelby model; moreover, it depends on the matrix strain-hardening behavior. We explain the grain-level anisotropic load-partitioning behavior by considering the plastic anisotropy of the matrix and elastic anisotropy of precipitates. We further demonstrate that the partitioned load on NiAl-type precipitates relaxes at 506 °C, most likely through thermally-activated dislocation rearrangement on the microscopic scale. The study contributes to further understanding of load-partitioning characteristics in multiphase materials.

  11. Magnetic resonance cell-tracking studies: spectrophotometry-based method for the quantification of cellular iron content after loading with superparamagnetic iron oxide nanoparticles.

    PubMed

    Böhm, Ingrid

    2011-08-01

    The purpose of this article is to present a user-friendly tool for quantifying the iron content of superparamagnetic labeled cells before cell tracking by magnetic resonance imaging (MRI). Iron quantification was evaluated by using Prussian blue staining and spectrophotometry. White blood cells were labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Labeling was confirmed by light microscopy. Subsequently, the cells were embedded in a phantom and scanned on a 3 T magnetic resonance tomography (MRT) whole-body system. Mean peak wavelengths λ(peak) was determined at A(720 nm) (range 719-722 nm). Linearity was proven for the measuring range 0.5 to 10 μg Fe/mL (r  =  .9958; p  =  2.2 × 10(-12)). The limit of detection was 0.01 μg Fe/mL (0.1785 mM), and the limit of quantification was 0.04 μg Fe/mL (0.714 mM). Accuracy was demonstrated by comparison with atomic absorption spectrometry. Precision and robustness were also proven. On T(2)-weighted images, signal intensity varied according to the iron concentration of SPIO-labeled cells. Absorption spectrophotometry is both a highly sensitive and user-friendly technique that is feasible for quantifying the iron content of magnetically labeled cells. The presented data suggest that spectrophotometry is a promising tool for promoting the implementation of magnetic resonance-based cell tracking in routine clinical applications (from bench to bedside).

  12. Identification of nutrient and physical seed trait QTL in the model legume Lotus japonicus.

    PubMed

    Klein, Melinda A; Grusak, Michael A

    2009-08-01

    Legume seeds have the potential to provide a significant portion of essential micronutrients to the human diet. To identify the genetic basis for seed nutrient density, quantitative trait locus (QTL) analysis was conducted with the Miyakojima MG-20 x Gifu B-129 recombinant inbred population from the model legume Lotus japonicus. This population was grown to seed under greenhouse conditions in 2006 and 2007. Phenotypic data were collected for seed calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn) concentrations and content. Data for physical seed traits (average seed mass and seed-pod allocation values) were also collected. Based on these phenotypic data, QTL analyses identified 103 QTL linked to 55 different molecular markers. Transgressive segregation, identified within this recombinant inbred population for both seed nutrient and physical traits, suggests new allelic combinations are available for agronomic trait improvement. QTL co-localization was also seen, suggesting that common transport processes might contribute to seed nutrient loading. Identification of loci involved in seed mineral density can be an important first step in identifying the genetic factors and, consequently, the physiological processes involved in mineral distribution to developing seeds. Longer term research efforts will focus on facilitating agronomic breeding efforts through ortholog identification in related crop legumes.

  13. Ascorbate Efflux as a New Strategy for Iron Reduction and Transport in Plants*

    PubMed Central

    Grillet, Louis; Ouerdane, Laurent; Flis, Paulina; Hoang, Minh Thi Thanh; Isaure, Marie-Pierre; Lobinski, Ryszard; Curie, Catherine; Mari, Stéphane

    2014-01-01

    Iron (Fe) is essential for virtually all living organisms. The identification of the chemical forms of iron (the speciation) circulating in and between cells is crucial to further understand the mechanisms of iron delivery to its final targets. Here we analyzed how iron is transported to the seeds by the chemical identification of iron complexes that are delivered to embryos, followed by the biochemical characterization of the transport of these complexes by the embryo, using the pea (Pisum sativum) as a model species. We have found that iron circulates as ferric complexes with citrate and malate (Fe(III)3Cit2Mal2, Fe(III)3Cit3Mal1, Fe(III)Cit2). Because dicotyledonous plants only transport ferrous iron, we checked whether embryos were capable of reducing iron of these complexes. Indeed, embryos did express a constitutively high ferric reduction activity. Surprisingly, iron(III) reduction is not catalyzed by the expected membrane-bound ferric reductase. Instead, embryos efflux high amounts of ascorbate that chemically reduce iron(III) from citrate-malate complexes. In vitro transport experiments on isolated embryos using radiolabeled 55Fe demonstrated that this ascorbate-mediated reduction is an obligatory step for the uptake of iron(II). Moreover, the ascorbate efflux activity was also measured in Arabidopsis embryos, suggesting that this new iron transport system may be generic to dicotyledonous plants. Finally, in embryos of the ascorbate-deficient mutants vtc2-4, vtc5-1, and vtc5-2, the reducing activity and the iron concentration were reduced significantly. Taken together, our results identified a new iron transport mechanism in plants that could play a major role to control iron loading in seeds. PMID:24347170

  14. Ascorbate efflux as a new strategy for iron reduction and transport in plants.

    PubMed

    Grillet, Louis; Ouerdane, Laurent; Flis, Paulina; Hoang, Minh Thi Thanh; Isaure, Marie-Pierre; Lobinski, Ryszard; Curie, Catherine; Mari, Stéphane

    2014-01-31

    Iron (Fe) is essential for virtually all living organisms. The identification of the chemical forms of iron (the speciation) circulating in and between cells is crucial to further understand the mechanisms of iron delivery to its final targets. Here we analyzed how iron is transported to the seeds by the chemical identification of iron complexes that are delivered to embryos, followed by the biochemical characterization of the transport of these complexes by the embryo, using the pea (Pisum sativum) as a model species. We have found that iron circulates as ferric complexes with citrate and malate (Fe(III)3Cit2Mal2, Fe(III)3Cit3Mal1, Fe(III)Cit2). Because dicotyledonous plants only transport ferrous iron, we checked whether embryos were capable of reducing iron of these complexes. Indeed, embryos did express a constitutively high ferric reduction activity. Surprisingly, iron(III) reduction is not catalyzed by the expected membrane-bound ferric reductase. Instead, embryos efflux high amounts of ascorbate that chemically reduce iron(III) from citrate-malate complexes. In vitro transport experiments on isolated embryos using radiolabeled (55)Fe demonstrated that this ascorbate-mediated reduction is an obligatory step for the uptake of iron(II). Moreover, the ascorbate efflux activity was also measured in Arabidopsis embryos, suggesting that this new iron transport system may be generic to dicotyledonous plants. Finally, in embryos of the ascorbate-deficient mutants vtc2-4, vtc5-1, and vtc5-2, the reducing activity and the iron concentration were reduced significantly. Taken together, our results identified a new iron transport mechanism in plants that could play a major role to control iron loading in seeds.

  15. Effects of silicon, copper and iron on static and dynamic properties of alloy 206 (aluminum-copper) in semi-solids produced by the SEED process

    NASA Astrophysics Data System (ADS)

    Lemieux, Alain

    The advantages of producing metal parts by rheocasting are generally recognised for common foundry alloys of Al-Si. However, other more performing alloys in terms of mechanical properties could have a great interest in specialized applications in the automotive industry, while remaining competitive in the forming. Indeed, the growing demand for more competitive products requires the development of new alloys better suited to semi-solid processes. Among others, Al-Cu alloys of the 2XX series are known for their superior mechanical strength. However, in the past, 2XX alloys were never candidates for pressure die casting. The main reason is their propensity to hot tearing. Semi-solid processes provide better conditions for molding with the rheological behavior of dough and molding temperatures lower reducing this type of defect. In the initial phase, this research has studied factors that reduce hot tearing susceptibility of castings produced by semi-solid SEED of alloy 206. Subsequently, a comparative study on the tensile properties and fatigue was performed on four variants of the alloy 206. The results of tensile strength and fatigue were compared with the specifications for applications in the automotive industry and also to other competing processes and alloys. During this study, several metallurgical aspects were analyzed. The following main points have been validated: i) the main effects of compositional variations of silicon, iron and copper alloy Al-Cu (206) on the mechanical properties, and ii) certain relationships between the mechanism of hot cracking and the solidification rate in semi-solid. Parts produced from the semi-solid paste coming from the SEED process combined with modified 206 alloys have been successfully molded and achieved superior mechanical properties than the requirements of the automotive industry. The fatigue properties of the two best modified 206 alloys were higher than those of A357 alloy castings and are close to those of the

  16. Folate-bovine serum albumin functionalized polymeric micelles loaded with superparamagnetic iron oxide nanoparticles for tumor targeting and magnetic resonance imaging.

    PubMed

    Li, Huan; Yan, Kai; Shang, Yalei; Shrestha, Lochan; Liao, Rufang; Liu, Fang; Li, Penghui; Xu, Haibo; Xu, Zushun; Chu, Paul K

    2015-03-01

    Polymeric micelles functionalized with folate conjugated bovine serum albumin (FA-BSA) and loaded with superparamagnetic iron oxide nanoparticles (SPIONs) are investigated as a specific contrast agent for tumor targeting and magnetic resonance imaging (MRI) in vitro and in vivo. The SPIONs-loaded polymeric micelles are produced by self-assembly of amphiphilic poly(HFMA-co-MOTAC)-g-PEGMA copolymers and oleic acid modified Fe3O4 nanoparticles and functionalized with FA-BSA by electrostatic interaction. The FA-BSA modified magnetic micelles have a hydrodynamic diameter of 196.1 nm, saturation magnetization of 5.5 emu/g, and transverse relaxivity of 167.0 mM(-1) S(-1). In vitro MR imaging, Prussian blue staining, and intracellular iron determination studies demonstrate that the folate-functionalized magnetic micelles have larger cellular uptake against the folate-receptor positive hepatoma cells Bel-7402 than the unmodified magnetic micelles. In vivo MR imaging conducted on nude mice bearing the Bel-7402 xenografts after bolus intravenous administration reveals excellent tumor targeting and MR imaging capabilities, especially at 24h post-injection. These findings suggest the potential of FA-BSA modified magnetic micelles as targeting MRI probe in tumor detection.

  17. Analysis of high iron rice lines reveals new miRNAs that target iron transporters in roots

    PubMed Central

    Paul, Soumitra; Gayen, Dipak; Datta, Swapan K.; Datta, Karabi

    2016-01-01

    The present study highlights the molecular regulation of iron transport in soyFER1-overexpressing transgenic rice. Accumulation of iron in three different seed developmental stages, milk, dough, and mature, has been examined. The transgenic seeds of the milk stage showed significant augmentation of iron and zinc levels compared with wild-type seeds, and similar results were observed throughout the dough and mature stages. To investigate the regulation of iron transport, the role of miRNAs was studied in roots of transgenic rice. Sequencing of small RNA libraries revealed 153 known and 41 novel miRNAs in roots. Among them, 59 known and 14 novel miRNAs were found to be significantly expressed. miR166, miR399, and miR408 were identified as playing a vital role in iron uptake in roots of transgenic plants . Most importantly, four putative novel miRNAs, namely miR11, miR26, miR30, and miR31, were found to be down-regulated in roots of transgenic plants. For all these four novel miRNAs, natural resistance-associated macrophage protein 4 (NRAMP4), encoding a metal transporter, was predicted as a target gene. It is hypothesized that the NRAMP4 transporter is activated in roots of transgenic plants due to the lower abundance of its corresponding putative novel miRNAs. The relative transcript level of the NRAMP4 transcript was increased from 0.107 in the wild type to 65.24 and 55.39 in transgenic plants, which demonstrates the elevated amount of iron transport in transgenic plants. In addition, up-regulation of OsYSL15, OsFRO2, and OsIRT1 in roots also facilitates iron loading in transgenic seeds. PMID:27729476

  18. Applicability of iron phosphate glass medium for loading NaCl originated from seawater used for cooling the stricken power reactors

    SciTech Connect

    Amamoto, Ippei; Kobayashi, Hidekazu; Yokozawa, Takuma; Yamashita, Teruo; Nagai, Takayuki; Kitamura, Naoto; Takebe, Hiromichi; Mitamura, Naoki; Tsuzuki, Tatsuya

    2013-07-01

    As the part of investigation for immobilization of the sludge as one of the radioactive wastes arising from the treatment of contaminated water at Fukushima Dai-ichi nuclear power plant, applicability of vitrification method has been evaluated as a candidate technique. The aim of this study is to evaluate the influence of NaCl as one of the main constituents of sludge, on glass formation and glass properties. Two kinds of iron phosphate glass (IPG) media in the xFe{sub 2}O{sub 3}-(100-x)P{sub 2}O{sub 5}, with x=30 and 35 (mol%) were chosen and the glass formation, structure and properties including density, coefficient of thermal expansion, glass transition temperature, onset crystallization temperature and chemical durability of NaCl-loaded IPG were studied. The results are summarized as follows. Sodium chloride, NaCl could be loaded into IPG medium as Na{sub 2}O and Cl contents and their loading ratio could be up to 19 and 15 mol%, respectively. Majority of Cl content of raw material NaCl was thought to be volatilized during glass melting. Loading NaCl into IPG induces to de-polymerize glass network of phosphate chains, leads to decrease both glass transition and onset crystallization temperatures, and to increase coefficient of thermal expansion. NaCl-loaded IPG indicated good chemical durability in case of using 35Fe{sub 2}O{sub 3}- 65P{sub 2}O{sub 5} medium. (authors)

  19. The influence of premolding load on the electrical behavior in the initial stage of electric current activated sintering of carbonyl iron powders

    NASA Astrophysics Data System (ADS)

    Ye, Yongquan; Li, Xiaoqiang; Hu, Ke; Lai, Yangen; Li, Yuanyuan

    2013-06-01

    This paper reports the premolding load effect on the electrical behavior in the initial stage of electric current activated sintering of carbonyl iron powders. An electrical network model is put forward to estimate the uniformity of electric current in a powder compact subjected to different premolding loads in the initial stage. The improvement in current uniformity can be reflected from a simultaneous increase in the number N and the mass fraction θ of conductive particle chains in the compact. Both N and θ are found to follow a power law with the premolding load F for different exponent values. When θ is equal to 1, a critical load is reached, at which point the current flows through all particles during sintering. Using the results of the model and the electrical contact theory, it is also found that only an increased temperature of less than 20 K across the particle contacts. The distribution of temperature is uniform in particles. This is clearly different from the general acceptance that local high temperature is created at contact during electric current activated sintering. The neck formation and growth are thought to be mainly due to heat bonding and electromigration, of which effects on mass transport are pronouncedly enhanced by increasing the bulk temperature. Because of the poor current uniformity and relatively large power dissipation, a soft thermal breakdown is observed in the sample with high initial resistance. A reduction in premolding load may cause an increase in the initial electrical resistance of the compact. Owing to the unique voltage-current characteristic of electric current activated sintering, a higher initial resistance of compact means more thermal energy is involved, consequently producing a higher bulk temperature and getting a better quality of sintering. This also provides theoretical explanation for the experimental results from Inoue and Istomina.

  20. Doxorubicin loaded PEG-b-poly(4-vinylbenzylphosphonate) coated magnetic iron oxide nanoparticles for targeted drug delivery

    NASA Astrophysics Data System (ADS)

    Hałupka-Bryl, Magdalena; Bednarowicz, Magdalena; Dobosz, Bernadeta; Krzyminiewski, Ryszard; Zalewski, Tomasz; Wereszczyńska, Beata; Nowaczyk, Grzegorz; Jarek, Marcin; Nagasaki, Yukio

    2015-06-01

    Due to their unique physical properties, superparamagnetic iron oxide nanoparticles are increasingly used in medical applications. They are very useful carriers for delivering antitumor drugs in targeted cancer treatment. Magnetic nanoparticles with chemiotherapeutic were synthesized by coprecipitation method followed by coating with biocompatible polymer. The aim of this work is to characterize physical and magnetic properties of synthesized nanoparicles. Characterization was carried out using EPR, HRTEM, X-ray diffraction, SQUID and NMR methods. The present findings show that synthesized nanosystem is promising tool for potential magnetic drug delivery.

  1. Diamond Synthesis Employing Nanoparticle Seeds

    NASA Technical Reports Server (NTRS)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  2. Sorption behavior of Pb(II) and Cd(II) on iron ore slime and characterization of metal ion loaded sorbent.

    PubMed

    Mohapatra, M; Rout, K; Mohapatra, B K; Anand, S

    2009-07-30

    The present investigation evaluates the sorption effectiveness of Pb(II) and Cd(II) ions on iron ore slime (IOS) obtained from Jindal Steel Ltd., Vijayanagaram, India. The sorption followed pseudo-second-order kinetics for both the cations. Pb(II) and Cd(II) sorption increased with the increase in pH from 2 to 4.5. The sorption data fitted well to Freundlich model as compared to Langmuir model. Synergistic effect of Pb(II) and Cd(II) on their sorption on IOS sample showed that Pb(II) sorption increases in presence of Cd(II) whereas Cd(II) sorption decreases. Presence of chloride or sulphate resulted in increased Pb(II) sorption but adversely affected Cd(II) sorption. The XRD patterns of Pb(II) adsorbed on IOS sample showed disappearance of some silica peaks and shifting of hematite peaks corresponding to 104 and 110 plane. For Cd(II) sorbed IOS sample, only peak shift for hematite of 104 and 110 plane was observed. Shifting of IR bands indicated that the Pb(II) sorption occurred through an inner sphere mechanism where as Cd(II) sorption occurred through outer sphere mechanism. EPMA studies showed that Pb(II) form a uniform thin layer and Cd(II) concentrate only on iron oxide phase. Regeneration and stability data on metal ion loaded IOS sample has been included.

  3. Doxorubicin loaded superparamagnetic PLGA-iron oxide multifunctional microbubbles for dual-mode US/MR imaging and therapy of metastasis in lymph nodes.

    PubMed

    Niu, Chengcheng; Wang, Zhigang; Lu, Guangming; Krupka, Tianyi M; Sun, Yang; You, Yufang; Song, Weixiang; Ran, Haitao; Li, Pan; Zheng, Yuanyi

    2013-03-01

    Current strategies for tumor-induced sentinel lymph node detection and metastasis therapy have limitations. In this work, we co-encapsulated iron oxide nanoparticles and chemotherapeutic drug into poly(lactic-co-glycolic acid) (PLGA) microbubbles to form multifunctional polymer microbubbles (MPMBs) for both tumor lymph node imaging and therapy. Fe(3)O(4) nanoparticles and doxorubicin (DOX) co-encapsulated PLGA microbubbles were prepared and filled with perfluorocarbon gas. Enhancement of ultrasound (US)/magnetic resonance (MR) imaging and US triggered drug delivery were evaluated both in vitro and in vivo. The MPMBs exhibited characters like narrow size distribution and smooth surface with a mean diameter of 868.0 ± 68.73 nm. In addition, varying the concentration of Fe(3)O(4) nanoparticles in the bubbles did not significantly influence the DOX encapsulation efficiency or drug loading efficiency. Our in vitro results demonstrated that these MPMBs could enhance both US and MR imaging which was further validated in vivo showing that these MPMBs enhanced tumor lymph nodes signals. The anti-tumor effect of MPMBs mediated chemotherapy was assessed in vivo using end markers like tumor proliferation index, micro blood vessel density and micro lymphatic vessel density, which were shown consistently the lowest after the MPMBs plus sonication treatment compared to controls. In line with these findings, the tumor cell apoptotic index was found the largest after the MPMBs plus sonication treatment. In conclusion, we have successfully developed a doxorubicin loaded superparamagnetic PLGA-Iron Oxide multifunctional theranostic agent for dual-mode US/MR Imaging of lymph node, and for low frequency US triggered therapy of metastasis in lymph nodes, which might provide a strategy for the imaging and chemotherapy of primary tumor and their metastases.

  4. Polymeric nanocomposites loaded with fluoridated hydroxyapatite Ln3+ (Ln = Eu or Tb)/iron oxide for magnetic targeted cellular imaging

    PubMed Central

    Pan, Jie; Liu, Wei-Jiao; Hua, Chao; Wang, Li-Li; Wan, Dong; Gong, Jun-Bo

    2015-01-01

    Objective To fabricate polymeric nanocomposites with excellent photoluminescence, magnetic properties, and stability in aqueous solutions, in order to improve specificity and sensitivity of cellular imaging under a magnetic field. Methods Fluoridated Ln3+-doped HAP (Ln3+-HAP) NPs and iron oxides (IOs) can be encapsulated with biocompatible polymers via a modified solvent exaction/evaporation technique to prepare polymeric nanocomposites with fluoridated Ln3+-HAP/iron oxide. The nanocomposites were characterized for surface morphology, fluorescence spectra, magnetic properties and in vitro cytotoxicity. Magnetic targeted cellular imaging of such nanocomposites was also evaluated with confocal laser scanning microscope using A549 cells with or without magnetic field. Results The fabricated nanocomposites showed good stability and excellent luminescent properties, as well as low in vitro cytotoxicity, indicating that the nanocomposites are suitable for biological applications. Nanocomposites under magnetic field achieved much higher cellular uptake via an energy-dependent pathway than those without magnetic field. Conclusion The nanocomposites fabricated in this study will be a promising tool for magnetic targeted cellular imaging with improved specificity and enhanced selection. PMID:26487962

  5. An active Mitochondrial Complex II Present in Mature Seeds Contains an Embryo-Specific Iron-Sulfur Subunit Regulated by ABA and bZIP53 and Is Involved in Germination and Seedling Establishment.

    PubMed

    Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier

    2017-01-01

    Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana, its iron-sulfur subunit (SDH2) is encoded by three genes, one of them (SDH2.3) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis-elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5' untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron-sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy.

  6. BEHAVIOR OF MODEL ASPHALT PAVEMENT CONTAINING A HYDRAULIC, GRADED IRON AND STEEL SLAG BASE-COURSE UNDER REPEATED PLATE-LOADING

    NASA Astrophysics Data System (ADS)

    Yoshida, Nobuyuki; Sugisako, Yasunari

    In this paper, the dynamic response of asphalt pave ment containing a hydraulic, graded iron and steel slag (hereafter called HMS) base-course under repeated plate-loading was investigated using a model asphalt pavement and the influence of hydraulicity on th e pavement behavior was discussed. The model pavement constructed was a 4-layer system consis ting of a dense-graded asphalt mix surface layer, a dense-graded asphalt mix binder-course, a HMS base-course and a Masado (heavily-weathered granitic sand) subgrade. A repeated plate-loading test was carri ed out so as to achieve a resilient state. It is shown that surface resilient deflection decreases as curing progresses and after 90 days, the deflection becomes almost half of the initial. Large horizontal tensile strains develop at the bottoms of binder- and base-course, which decrease significantly with curing. It is indicative that HMS base-course behaves like a stiffer plate resulting in a hard-to-deflect state due to the development of hydraulicity.

  7. Seed size selection by olive baboons.

    PubMed

    Kunz, Britta Kerstin; Linsenmair, Karl Eduard

    2008-10-01

    Seed size is an important plant fitness trait that can influence several steps between fruiting and the establishment of a plant's offspring. Seed size varies considerably within many plant species, yet the relevance of the trait for intra-specific fruit choice by primates has received little attention. Primates may select certain seed sizes within a species for a number of reasons, e.g. to decrease indigestible seed load or increase pulp intake per fruit. Olive baboons (Papio anubis, Cercopithecidae) are known to select seed size in unripe and mature pods of Parkia biglobosa (Mimosaceae) differentially, so that pods with small seeds, and an intermediate seed number, contribute most to dispersal by baboons. We tested whether olive baboons likewise select for smaller ripe seeds within each of nine additional fruit species whose fruit pulp baboons commonly consume, and for larger seeds in one species in which baboons feed on the seeds. Species differed in fruit type and seed number per fruit. For five of these species, baboons dispersed seeds that were significantly smaller than seeds extracted manually from randomly collected fresh fruits. In contrast, for three species, baboons swallowed seeds that were significantly longer and/or wider than seeds from fresh fruits. In two species, sizes of ingested seeds and seeds from fresh fruits did not differ significantly. Baboons frequently spat out seeds of Drypetes floribunda (Euphorbiaceae) but not those of other plant species having seeds of equal size. Oral processing of D. floribunda seeds depended on seed size: seeds that were spat out were significantly larger and swallowed seeds smaller, than seeds from randomly collected fresh fruits. We argue that seed size selection in baboons is influenced, among other traits, by the amount of pulp rewarded per fruit relative to seed load, which is likely to vary with fruit and seed shape.

  8. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

  9. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

  10. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

  11. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

  12. 46 CFR 56.60-10 - Cast iron and malleable iron.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be recognized and the use of these metals where shock loading may occur should be...

  13. Inhibiting excessive acidification using zero-valent iron in anaerobic digestion of food waste at high organic load rates.

    PubMed

    Kong, Xin; Wei, Yonghong; Xu, Shuang; Liu, Jianguo; Li, Huan; Liu, Yili; Yu, Shuyao

    2016-07-01

    Excessive acidification occurs frequently in food waste (FW) anaerobic digestion (AD) due to the high carbon-to-nitrogen ratio of FW. In this study, zero-valent iron (ZVI) was applied to prevent the excessive acidification. All of the control groups, without ZVI addition (pH∼5.3), produced little methane (CH4) and had high volatile fatty acids/bicarbonate alkalinity (VFA/ALK). By contrast, at OLR of 42.32gVS/Lreactor, the pH of effluent from the reactors with 0.4g/gVSFWadded of ZVI increased to 7.8-8.2, VFA/ALK decreased to <0.1, and the final CH4 yield was ∼380mL/gVSFWadded, suggesting inhibition of excessive acidification. After adding powdered or scrap metal ZVI to the acidogenic reactors, the fractional content of butyric acid changed from 30-40% to 0%, while, that of acetic acid increased. These results indicate that adding ZVI to FW digestion at high OLRs could eliminate excessive acidification by promoting butyric acid conversion and enhancing methanogen activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Epirubicin-loaded superparamagnetic iron-oxide nanoparticles for transdermal delivery: cancer therapy by circumventing the skin barrier.

    PubMed

    Rao, Yue-feng; Chen, Wei; Liang, Xing-guang; Huang, Yong-zhuo; Miao, Jing; Liu, Lin; Lou, Yan; Zhang, Xing-guo; Wang, Ben; Tang, Rui-kang; Chen, Zhong; Lu, Xiao-yang

    2015-01-14

    The transdermal administration of chemotherapeutic agents is a persistent challenge for tumor treatments. A model anticancer agent, epirubicin (EPI), is attached to functionalized superparamagnetic iron-oxide nanoparticles (SPION). The covalent modification of the SPION results in EPI-SPION, a potential drug delivery vector that uses magnetism for the targeted transdermal chemotherapy of skin tumors. The spherical EPI-SPION composite exhibits excellent magnetic responsiveness with a saturation magnetization intensity of 77.8 emu g(-1) . They feature specific pH-sensitive drug release, targeting the acidic microenvironment typical in common tumor tissues or endosomes/lysosomes. Cellular uptake studies using human keratinocyte HaCaT cells and melanoma WM266 cells demonstrate that SPION have good biocompatibility. After conjugation with EPI, the nanoparticles can inhibit WM266 cell proliferation; its inhibitory effect on tumor proliferation is determined to be dose-dependent. In vitro transdermal studies demonstrate that the EPI-SPION composites can penetrate deep inside the skin driven by an external magnetic field. The magnetic-field-assisted SPION transdermal vector can circumvent the stratum corneum via follicular pathways. The study indicates the potential of a SPION-based vector for feasible transdermal therapy of skin cancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Inactivation performance and mechanism of Escherichia coli in aqueous system exposed to iron oxide loaded graphene nanocomposites.

    PubMed

    Deng, Can-Hui; Gong, Ji-Lai; Zeng, Guang-Ming; Niu, Cheng-Gang; Niu, Qiu-Ya; Zhang, Wei; Liu, Hong-Yu

    2014-07-15

    The challenge to achieve efficient disinfection and microbial control without harmful disinfection byproducts calls for developing new technologies. Magnetic-graphene oxide (M-GO) with magnetic iron oxide nanoparticles well dispersed on graphene oxide (GO) nanosheets exerted excellent antibacterial activity against Escherichia coli. The antibacterial performance of M-GO was dependent on the concentration and the component mass ratio of M/GO. The synergetic antibacterial effect of M-GO was observed with M/GO mass ratio of 9.09. TEM images illustrated the interaction between E. coli cells and M-GO nanocomposites. M-GO nanomaterials were possible to deposit on or penetrate into cells leading to leakage of intercellular contents and loss of cell integrity. The inactivation mechanism of E. coli by M-GO was supposed to result from both the membrane stress and oxidation stress during the incubation period. M-GO with excellent antibacterial efficiency against E. coli and separation-convenient property from water could be potent bactericidal nanomaterials for water disinfection. Copyright © 2014. Published by Elsevier B.V.

  16. Iron(III) hydroxide-loaded coral limestone as an adsorbent for arsenic(III) and arsenic (V)

    SciTech Connect

    Maeda, Shigeru; Ohki, Akira; Saikoji, Shunsuke; Naka, Kensuke )

    1992-04-01

    Trace levels of As(III) and As(V) in aqueous media were effectively adsorbed onto a coral limestone loaded by Fe(OH){sub 3}. The adsorption of As(III) was almost comparable to that of As(V). The adsorption of As(III) and As(V) was almost independent of the pH of the aqueous phase (pH range: 3-10) because of a self-buffering effect of the coral. The addition of such anions as chloride, nitrate, sulfate, and acetate in the aqueous phase did not significantly affect the adsorption of As(III), whereas the addition of phosphate brought about a great decrease in the adsorption. The arsenic adsorption was effectively applied to the column method. Unloaded coral itself was effective as an adsorbent for As(V) when Fe(III) coexisted in the aqueous solutions.

  17. Epirubicin loaded super paramagnetic iron oxide nanoparticle-aptamer bioconjugate for combined colon cancer therapy and imaging in vivo.

    PubMed

    Jalalian, Seyed Hamid; Taghdisi, Seyed Mohammad; Shahidi Hamedani, Nasim; Kalat, Seyedeh Alia Moosavian; Lavaee, Parirokh; Zandkarimi, Majid; Ghows, Narjes; Jaafari, Mahmoud Reza; Naghibi, Saeed; Danesh, Noor Mohammad; Ramezani, Mohammad; Abnous, Khalil

    2013-10-09

    Every year a large number of new cases of colorectal cancer are diagnosed in the world. Application of Epirubicin (Epi) in treatment of cancer has been limited due to its cardiotoxicity. Specific delivery of chemotherapy drugs is an important factor in reducing the side effects of drugs used in chemotherapy. Enhanced permeability, retention effect and magnetic resonance (MR) traceability of super paramagnetic iron oxide nanoparticles (SPION) make them a great candidate in cancer therapy and imaging. In this study, Epirubicin-5TR1 aptamer-SPION tertiary complex was evaluated for the imaging and treatment of murine colon carcinoma cells (C26 cells, target). For cytotoxic studies (MTT assay), C26 and CHO-K1 (Chinese hamster ovary cells, nontarget) cells were treated with either Epi or Epi-Apt-SPION tertiary complex. Internalization was evaluated by flow cytometry. Finally, Apt-SPION bioconjugate was used for imaging of cancer in vivo. Flow cytometric analysis showed that the tertiary complex was internalized effectively to C26 cells, but not to CHO-K1 cells. Cytotoxicity of Epi-Apt-SPION tertiary complex also confirmed internalization data. The complex was less cytotoxic in CHO-K1 cells when compared to Epi alone. No significant change in viability between Epi- and complex-treated C26 cells was observed. Magnetic resonance imaging (MRI) indicated a high level of accumulation of the nano-magnets within the tumor site. In conclusion Epi-Apt-SPION tertiary complex is introduced as an effective system for targeted delivery of Epi to C26 cells. Moreover this complex could efficiently detect tumors when analyzed by MRI and inhibit tumor growth in vivo.

  18. Spark Plasma Sintering of Load-Bearing Iron-Carbon Nanotube-Tricalcium Phosphate CerMets for Orthopaedic Applications

    NASA Astrophysics Data System (ADS)

    Montufar, Edgar B.; Horynová, Miroslava; Casas-Luna, Mariano; Diaz-de-la-Torre, Sebastián; Celko, Ladislav; Klakurková, Lenka; Spotz, Zdenek; Diéguez-Trejo, Guillermo; Fohlerová, Zdenka; Dvorak, Karel; Zikmund, Tomáš; Kaiser, Jozef

    2016-04-01

    Recently, ceramic-metallic composite materials (CerMets) have been investigated for orthopaedic applications with promising results. This first generation of bio-CerMets combine the bioactivity of hydroxyapatite with the mechanical stability of titanium to fabricate bioactive, tough and biomechanically more biocompatible osteosynthetic devices. Nonetheless, these first CerMets are not biodegradable materials and a second surgery is required to remove the implant after bone healing. The present work aims to develop the next generation bio-CerMets, which are potential biodegradable materials. The process to produce the new biodegradable CerMet consisted of mixing powder of soluble and osteoconductive alpha tricalcium phosphate with biocompatible and biodegradable iron with consolidation through spark plasma sintering (SPS). The microstructure, composition and mechanical strength of the new CerMet were studied by metallography, x-ray diffraction and diametral tensile strength tests, respectively. The results show that SPS produces CerMet with higher mechanical performance (120 MPa) than the ceramic component alone (29 MPa) and similar mechanical strength to the pure metallic component (129 MPa). Nonetheless, although a short sintering time (10 min) was used, partial transformation of the alpha tricalcium phosphate into its allotropic and slightly less soluble beta phase was observed. Cell adhesion tests show that osteoblasts are able to attach to the CerMet surface, presenting spread morphology regardless of the component of the material with which they are in contact. However, the degradation process restricted to the small volume of the cell culture well quickly reduces the osteoblast viability.

  19. The chloroplast permease PIC1 regulates plant growth and development by directing homeostasis and transport of iron.

    PubMed

    Duy, Daniela; Stübe, Roland; Wanner, Gerhard; Philippar, Katrin

    2011-04-01

    The membrane-spanning protein PIC1 (for permease in chloroplasts 1) in Arabidopsis (Arabidopsis thaliana) was previously described to mediate iron transport across the inner envelope membrane of chloroplasts. The albino phenotype of pic1 knockout mutants was reminiscent of iron-deficiency symptoms and characterized by severely impaired plastid development and plant growth. In addition, plants lacking PIC1 showed a striking increase in chloroplast ferritin clusters, which function in protection from oxidative stress by sequestering highly reactive free iron in their spherical protein shell. In contrast, PIC1-overexpressing lines (PIC1ox) in this study rather resembled ferritin loss-of-function plants. PIC1ox plants suffered from oxidative stress and leaf chlorosis, most likely originating from iron overload in chloroplasts. Later during growth, plants were characterized by reduced biomass as well as severely defective flower and seed development. As a result of PIC1 protein increase in the inner envelope membrane of plastids, flower tissue showed elevated levels of iron, while the content of other transition metals (copper, zinc, manganese) remained unchanged. Seeds, however, specifically revealed iron deficiency, suggesting that PIC1 overexpression sequestered iron in flower plastids, thereby becoming unavailable for seed iron loading. In addition, expression of genes associated with metal transport and homeostasis as well as photosynthesis was deregulated in PIC1ox plants. Thus, PIC1 function in plastid iron transport is closely linked to ferritin and plastid iron homeostasis. In consequence, PIC1 is crucial for balancing plant iron metabolism in general, thereby regulating plant growth and in particular fruit development.

  20. Evaluation of Glass Density to Support the Estimation of Fissile Mass Loadings from Iron Concentrations in SB6 Glasses

    SciTech Connect

    Edwards, T.; Peeler, D.

    2010-12-15

    The Department of Energy - Savannah River (DOE-SR) previously provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of the guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft{reg_sign} Excel{reg_sign} spreadsheet for the evaluation of fissile loading in Sludge Batch 5 glass based on the Fe concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that SRNL provide the necessary information to allow SRR to update the Excel spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 6 (SB6). One of the primary inputs into the fissile loading spreadsheet includes a bounding density for SB6-based glasses. Based on the measured density data of select SB6 variability study glasses, SRNL recommends that SRR utilize the 99/99 Upper Tolerance Limit (UTL) density value at 38% WL (2.823 g/cm{sup 3}) as a bounding density for SB6 glasses to assess the fissile concentration in this glass system. That is, the 2.823 g/cm{sup 3} is recommended as a key (and fixed) input into the fissile concentration spreadsheet for SB6 processing. It should be noted that no changes are needed to the underlying structure of the Excel based spreadsheet to support fissile assessments for SB6. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB6 Waste Acceptance Product Specification (WAPS) sample. The purpose of this technical report is to present the density measurements that were determined for the SB6 variability study glasses and to conduct a statistical evaluation of these measurements to provide a bounding density value that may be used as input to the Excel{reg_sign} spreadsheet to be employed by SRR to maintain the

  1. Superparamagnetic iron oxide--loaded poly(lactic acid)-D-alpha-tocopherol polyethylene glycol 1000 succinate copolymer nanoparticles as MRI contrast agent.

    PubMed

    Prashant, Chandrasekharan; Dipak, Maity; Yang, Chang-Tong; Chuang, Kai-Hsiang; Jun, Ding; Feng, Si-Shen

    2010-07-01

    We developed a strategy to formulate supraparamagnetic iron oxides (SPIOs) in nanoparticles (NPs) of biodegradable copolymer made up of poly(lactic acid) (PLA) and d-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS) for medical imaging by magnetic resonance imaging (MRI) of high contrast and low side effects. The IOs-loaded PLA-TPGS NPs (IOs-PNPs) were prepared by the single emulsion method and the nanoprecipitation method. Effects of the process parameters such as the emulsifier concentration, IOs loading in the nanoparticles, and the solvent to non-solvent ratio on the IOs distribution within the polymeric matrix were investigated and the formulation was then optimized. The transmission electron microscopy (TEM) showed direct visual evidence for the well dispersed distribution of the IOs within the NPs. We further investigated the biocompatibility and cellular uptake of the IOs-PNPs in vitro with MCF-7 breast cancer cells and NIH-3T3 mouse fibroblast in close comparison with the commercial IOs imaging agent Resovist. MRI imaging was further carried out to investigate the biodistribution of the IOs formulated in the IOs-PNPs, especially in the liver to understand the liver clearance process, which was also made in close comparison with Resovist. We found that the PLA-TPGS NPs formulation at the clinically approved dose of 0.8 mg Fe/kg could be cleared within 24 h in comparison with several weeks for Resovist. Xenograft tumor model MRI confirmed the advantages of the IOs-PNPs formulation versus Resovist through the enhanced permeation and retention (EPR) effect of the tumor vasculature. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Iron, lanthanum and manganese oxides loaded on gamma-AI2O3 for selective catalytic reduction of NO with NH3 at low temperature.

    PubMed

    Zhao, Weiwei; Li, Caiting; Lu, Pei; Wen, Qingbo; Zhao, Yapei; Zhang, Xing; Fan, Chunzhen; Tao, Shasha

    2013-01-01

    A series of Mn/Al2O3, La-Mn/Al2O3 and Fe-La-Mn/Al2O3 catalysts were prepared by an impregnation method and investigated for selective catalytic reduction of NO with NH3 at low temperature. The experimental results revealed that NO conversion over La-Mn/Al2O3 was obviously improved after La doping. Addition of Fe increased both NO conversion and the resistance to H2O and SO2. The catalyst Fe0.04La0.03Mn0.06/Al2O3 with a load mass of MnO2 = 6%, La2O3 = 3% and Fe2O3 = 4% exhibited relatively high catalytic activity and yielded 98% NO conversion at 260 degrees with a space velocity of 15,000 h(-1). Meanwhile, the catalytic activity was slightly decreased in the presence of H2O and SO2. Moreover, the catalysts were characterized by N2 adsorption measurement, X-ray diffraction and X-ray photoelectron spectroscopy. The results showed that the doping of La enhanced the dispersion and oxidation states of Mn on the surface of Al2O3. On the surface of the Fe0.04La0.03Mn0.06/Al2O3 catalyst, La was highly dispersed and a mixed oxidation state of Mn existed, while iron ions were only in the Fe3+ state. The mechanism of selective catalytic reduction over these catalysts is also discussed. In this experiment, metal oxides loaded on the support were catalytic centres which served as electron transfer during NO reduction. The electron transfer between Mn3+ and Fe3+ might also exist and the mixture oxidation states of Mn on the surface of the Fe0.04La0.03Mn0.06/Al2O3 catalyst contributed to the SCR activity.

  3. Molecular dynamics simulations of iron- and aluminum-loaded serum transferrin: protonation of Tyr188 is necessary to prompt metal release.

    PubMed

    Mujika, J I; Escribano, B; Akhmatskaya, E; Ugalde, J M; Lopez, X

    2012-09-04

    Serum transferrin (sTf) carries iron in blood serum and delivers it into cells by receptor-mediated endocytosis. The protein can also bind other metals, including aluminum. The crystal structures of the metal-free and metal-loaded protein indicate that the metal release process involves an opening of the protein. In this process, Lys206 and Lys296 lying in the proximity of each other form the dilysine pair or, so-called, dilysine trigger. It was suggested that the conformational change takes place due to variations of the protonation state of the dilysine trigger at the acidic endosomal pH. In 2003, Rinaldo and Field (Biophys. J. 85, 3485-3501) proposed that the dilysine trigger alone can not explain the opening and that the protonation of Tyr188 is required to prompt the conformational change. However, no evidence was supplied to support this hypothesis. Here, we present several 60 ns molecular dynamics simulations considering various protonation states to investigate the complexes formed by sTf with Fe(III) and Al(III). The calculations demonstrate that only in those systems where Tyr188 has been protonated does the protein undergo the conformational change and that the dilysine trigger alone does not lead to the opening. The simulations also indicate that the metal release process is a stepwise mechanism, where the hinge-bending motion is followed by the hinge-twisting step. Therefore, the study demonstrates for the first time that the protonation of Tyr188 is required for the release of metal from the metal loaded sTf and provides valuable information about the whole process.

  4. Application of iron and zinc isotopes to track the sources and mechanisms of metal loading in a mountain watershed

    USGS Publications Warehouse

    Borrok, D.M.; Wanty, R.B.; Ian, Ridley W.; Lamothe, P.J.; Kimball, B.A.; Verplanck, P.L.; Runkel, R.L.

    2009-01-01

    Here the hydrogeochemical constraints of a tracer dilution study are combined with Fe and Zn isotopic measurements to pinpoint metal loading sources and attenuation mechanisms in an alpine watershed impacted by acid mine drainage. In the tested mountain catchment, ??56Fe and ??66Zn isotopic signatures of filtered stream water samples varied by ???3.5??? and 0.4???, respectively. The inherent differences in the aqueous geochemistry of Fe and Zn provided complimentary isotopic information. For example, variations in ??56Fe were linked to redox and precipitation reactions occurring in the stream, while changes in ??66Zn were indicative of conservative mixing of different Zn sources. Fen environments contributed distinctively light dissolved Fe (<-2.0???) and isotopically heavy suspended Fe precipitates to the watershed, while Zn from the fen was isotopically heavy (>+0.4???). Acidic drainage from mine wastes contributed heavier dissolved Fe (???+0.5???) and lighter Zn (???+0.2???) isotopes relative to the fen. Upwelling of Fe-rich groundwater near the mouth of the catchment was the major source of Fe (??56Fe ??? 0???) leaving the watershed in surface flow, while runoff from mining wastes was the major source of Zn. The results suggest that given a strong framework for interpretation, Fe and Zn isotopes are useful tools for identifying and tracking metal sources and attenuation mechanisms in mountain watersheds. ?? 2009 Elsevier Ltd.

  5. The Role of Gap Junctions and Mechanical Loading on Mineral Formation in a Collagen-I Scaffold Seeded with Osteoprogenitor Cells

    PubMed Central

    Damaraju, Swathi; Matyas, John R.; Rancourt, Derrick E.

    2015-01-01

    Fracture nonunions represent one of many large bone defects where current treatment strategies fall short in restoring both form and function of the injured tissue. In this case, the use of a tissue-engineered scaffold for promoting bone healing offers an accessible and easy-to-manipulate environment for studying bone formation processes in vitro. We have previously shown that mechanical prestimulation using confined compression of differentiating osteoblasts results in an increase in mineralization formed in a 3D collagen-I scaffold. This study builds on this knowledge by evaluating the short and long-term effects of blocking gap junction-mediated intercellular communication among osteogenic cells on their effectiveness to mineralize collagen-I scaffolds in vitro, and in the presence and absence of mechanical stimulation. In this study, confined compression was applied in conjunction with octanol (a general communication blocker) or 18-α-glycerrhetinic acid (AGA, a specific gap junction blocker) using a modified FlexCell plate to collagen-I scaffolds seeded with murine embryonic stem cells stimulated toward osteoblast differentiation using beta-glycerol phosphate. The activity, presence, and expression of osteoblast cadherin, connexin-43, as well as various pluripotent and osteogenic markers were examined at 5–30 days of differentiation. Fluorescence recovery after photobleaching, immunofluorescence, viability, histology assessments, and reverse-transcriptase polymerase chain reaction assessments revealed that inhibiting communication in this scaffold altered the lineage and function of differentiating osteoblasts. In particular, treatment with communication inhibitors caused reduced mineralization in the matrix, and dissociation between connexin-43 and integrin α5β1. This dissociation was not restored even after long-term recovery. Thus, in order for this scaffold to be considered as an alternative strategy for the repair of large bone defects, cell

  6. Automated seed manipulation and planting

    NASA Technical Reports Server (NTRS)

    Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

    1988-01-01

    The Mechanical Division fabricated three seed separators utilizing pressure gradients to move and separate wheat seeds. These separators are called minnow buckets and use air, water, or a combination of both to generate the pressure gradient. Electrostatic fields were employed in the seed separator constructed by the Electrical Division. This separator operates by forcing a temporary electric dipole on the wheat seeds and using charged electrodes to attract and move the seeds. Seed delivery to the hydroponic growth tray is accomplished by the seed cassette. The cassette is compatible with all the seed separators, and it consists of a plastic tube threaded with millipore filter paper. During planting operations, the seeds are placed in an empty cassette. The loaded cassette is then placed in the growth tray and nutrient solution provided. The solution wets the filter paper and capillary action draws the nutrients up to feed the seeds. These seeding systems were tested and showed encouraging results. Seeds were effectively separated and the cassette can support the growth of wheat plants. Problems remaining to be investigated include improving the success of delivering the seeds to the cassette and providing adequate spacing between seeds for the electric separator.

  7. Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin.

    PubMed

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

    2007-01-09

    The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L(-1) HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 microg L(-1) for aqueous samples and in the range of 2.5-9.4 ng g(-1) for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results.

  8. Seed coat removal improves iron bioavailability in cooked lentils: studies using an in vitro digestion/Caco-2 cell culture model.

    PubMed

    DellaValle, Diane M; Vandenberg, Albert; Glahn, Raymond P

    2013-08-28

    In this study we examined the range of Fe concentration and relative Fe bioavailability of 24 varieties of cooked lentils, as well as the impact of seed coat removal on Fe nutritional as well as antinutrient properties. Relative Fe bioavailability was assessed by the in vitro/Caco-2 cell culture method. While the Fe concentration of the whole lentil was moderately high (72.8 ± 10.8 μg/g, n = 24), the relative Fe bioavailability was moderate (2.4 ± 1.0 ng of ferritin/mg of protein). Although removing the seed coat reduced the Fe concentration by an average of 16.4 ± 9.4 μg/g, the bioavailability was significantly improved (+5.3 ± 2.2 ng of ferritin/mg of protein; p < 0.001), and the phytic acid concentration was reduced by 7% (p = 0.04). Like most legume seeds, the lentil seed coat contains a range of polyphenols known to inhibit Fe bioavailability. Thus, along with breeding for high Fe concentration and bioavailability (i.e., biofortification), seed coat removal appears to be a practical way to improve Fe bioavailability of the lentil.

  9. 20 Gb/s WDM-OFDM-PON over 20-km single fiber uplink transmission using optical millimeter-wave signal seeding with rate adaptive bit-power loading

    NASA Astrophysics Data System (ADS)

    Kartiwa, Iwa; Jung, Sang-Min; Hong, Moon-Ki; Han, Sang-Kook

    2013-06-01

    We experimentally demonstrate the use of millimeter-wave signal generation by optical carrier suppression (OCS) method using single-drive Mach-Zehnder modulator as a light sources seed for 20 Gb/s WDM-OFDM-PON in 20-km single fiber loopback transmission based on cost-effective RSOA modulation. Practical discrete rate adaptive bit loading algorithm was employed in this colorless ONU system to maximize the achievable bit rate for an average bit error rate (BER) below 2 × 10-3.

  10. Grape seed extract inhibits lipid oxidation in muscle from different species during refrigerated and frozen storage and oxidation catalyzed by peroxynitrite and iron/ascorbate in a pyrogallol red model system.

    PubMed

    Brannan, Robert G; Mah, Eunice

    2007-12-01

    The antioxidant effect of grape seed extract (GSE) was determined by assessing the bleaching of pyrogallol red (PGR) by peroxynitrite or iron/ascorbate, and the formation of lipid hydroperoxides (LOOH) and thiobarbituric acid substances (TBARS) in raw or cooked ground muscle during refrigerated or frozen storage. In PGR models, GSE was more effective than gallic acid in inhibiting oxidation. The formation of LOOH and TBARS was inhibited by GSE (0.1% and 1.0%) compared to untreated controls and samples treated with sodium tripolyphosphate. Diethylenetriaminepentaacetic acid (DTPA), alone or in combination with GSE, had no effect on LOOH or TBARS, which provides clues about the possible mechanism of action of GSE. These results show that GSE at concentrations as low as 0.1% is a very effective inhibitor of primary and secondary oxidation products in various muscle systems and has potential as a natural antioxidant in raw and cooked meat systems.

  11. Iron bioavailability in low phytate pea

    USDA-ARS?s Scientific Manuscript database

    Field pea (Pisum sativum L.) seeds have high nutritional value but also contain potential anti-nutritional factors, such as phytate and polyphenols. Phytate can store up to 80% of the phosphorus in seeds. In the seed and during digestion it can complex minerals such as iron and zinc and make them un...

  12. A graphene loading heterogeneous hydrated forms iron based fluoride nanocomposite as novel and high-capacity cathode material for lithium/sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Shen, Yongqiang; Wang, Xianyou; Hu, Hai; Jiang, Miaoling; Yang, Xiukang; Shu, Hongbo

    2015-06-01

    A graphene loading heterogeneous hydrated forms iron based fluoride (abbreviated as FeF3·xH2O/G) nanocomposite is successfully designed and synthesized for the first time by a sol-gel method. It found that the FeF3·xH2O nanoparticles distribute randomly on the surface of the graphene, stacking together to form a nanocomposite with high specific surface and abundant mesporous structure. The FeF3·xH2O was consisted of FeF3·3H2O and FeF2.5·0.5H2O with pyrochlore phase structure and FeF3·0.33H2O with hexagonal-tungsten-bronze-type structure (HTB). The FeF3·xH2O/G was used as cathode materials of rechargeable lithium/sodium batteries, respectively. It has been found that it can deliver a large reversible capacity exceeding 200 mAh g-1 and excellent cyclic performance with a residual capacity of 183 mAh g-1 after 100 cycles at 0.2C and 149 mAh g-1 after 200 cycles at 1C, especially, an outstanding rate performance exceeding 130 mAh g-1 at 5C in the voltage range of 1.5-4.5 V for Li-ion batteries. Moreover, when FeF3·xH2O/G is used as cathode material of Na-ion batteries, it exhibits also a high reversible capacity of 101 mAh g-1 after 30 cycles in the voltage range of 1.0-4.0 V at 0.1C. Therefore, FeF3·xH2O/G will a promising cathode material for high-performance lithium/sodium ion batteries.

  13. Genetic reduction of antinutrients in common bean (Phaseolus vulgaris L.) seed, increases nutrients and in vitro iron bioavailability without depressing main agronomical traits

    USDA-ARS?s Scientific Manuscript database

    In common bean, lectins, phytic acid, polyphenols and tannins exert major antinutritional effects when grains are consumed as a staple food. Reduced iron and zinc absorption, low protein digestibility and high toxicity at the intestinal level are the causes of their antinutritional effect. To improv...

  14. Characterizing the gut (Gallus gallus) microbiota following the consumption of an iron biofortified Rwandan cream seeded carioca (Phaseolus Vulgaris L.) bean-based diet

    USDA-ARS?s Scientific Manuscript database

    Biofortification is a plant breeding method that introduces increased concentrations of minerals in staple food crops (e.g., legumes, cereal grains), and has shown success in alleviating insufficient iron (Fe) intake in various human populations. Unlike other strategies utilized to alleviate Fe defi...

  15. Seed Germination

    USDA-ARS?s Scientific Manuscript database

    Initiation of seed germination is a critical decision for plants. It is important for seed populations under natural conditions to spread the timing of germination of individual seeds to maximize the probability of species survival. Therefore, seeds have evolved the multiple layers of mechanisms tha...

  16. Evaluation of Cepstrum Algorithm with Impact Seeded Fault Data of Helicopter Oil Cooler Fan Bearings and Machine Fault Simulator Data

    DTIC Science & Technology

    2013-02-01

    seeded fault without gearbox and magnet load...Figure B-1. Ball seeded fault bearings with and without gearbox and magnet load for level 1. ..18 Figure B-2. Ball seeded fault bearings with and...without gearbox and magnet load for level 3. ..19 Figure B-3. Ball seeded fault bearings with and without gearbox and magnet load for level 5. ..20

  17. Water quality, hydrology, and simulated response to changes in phosphorus loading of Mercer Lake, Iron County, Wisconsin, with special emphasis on the effects of wastewater discharges

    USGS Publications Warehouse

    Robertson, Dale M.; Garn, Herbert S.; Rose, William J.; Juckem, Paul F.; Reneau, Paul C.

    2012-01-01

    phosphorus was 0.023 mg/L, indicating the lake is borderline mesotrophic-eutrophic, or has moderate to high concentrations of phosphorus, whereas the average summer chlorophyll a concentration was 3.3 mg/L and water clarity, as measured with a Secchi depth, was 10.4 ft, both indicating mesotrophic conditions or that the lake has a moderate amount of algae and water clarity. Although actions have been taken to eliminate the wastewater discharges, the bottom sediment still has slightly elevated concentrations of several pollutants from wastewater discharges, lumber operations, and roadway drainage, and a few naturally occurring metals (such as iron). None of the concentrations, however, were high enough above the defined thresholds to be of concern. Based on nitrogen to phosphorus ratios, the productivity (algal growth) in Mercer Lake should typically be limited by phosphorus; therefore, understanding the phosphorus input to the lake is important when management efforts to improve or prevent degradation of the lake water quality are considered. Total inputs of phosphorus to Mercer Lake were directly estimated for MY 2008-09 at about 340 lb/yr and for a recent year with more typical hydrology at about 475 lb/yr. During these years, the largest sources of phosphorus were from Little Turtle Inlet, which contributed about 45 percent, and the drainage area near the lake containing the adjacent urban and residential developments, which contributed about 24 percent. Prior to 1965, when there was no sewage treatment plant and septic systems and other untreated systems contributed nutrients to the watershed, phosphorus loadings were estimated to be about 71 percent higher than during around 2009. In 1965, a sewage treatment plant was built, but its effluent was released in the downstream end of the lake. Depending on various assumptions on how much effluent was retained in the lake, phosphorus inputs from wastewater may have ranged from 0 to 342 lb. Future highway and stormwater

  18. Mucosal iron in the control of iron absorption in a rat intestinal transplant model

    SciTech Connect

    Adams, P.C.; Zhong, R.; Haist, J.; Flanagan, P.R.; Grant, D.R. )

    1991-02-01

    Isogeneic intestinal transplantation of iron-loaded and iron-deficient intestine into iron-deficient rats was performed in 20 Lewis rats to isolate the effect of intestinal mucosal iron on iron absorption. Rats were iron loaded with three weekly IM injections of 50 mg of iron dextran and were rendered iron deficient with an iron-deficient diet for 3 weeks. Iron status was assessed by hepatic and gut mucosal iron determination. Uptake and transfer of 59Fe-ascorbate was measured in an isolated perfused segment of transplanted intestine 48 hours after transplantation. The mean rate of uptake of 59Fe from an iron-loaded intestine (mean mucosal iron concentration, 7.97 +/- 2.02 mumol/g) was 431 +/- 27 nmol/30 min, and from an iron-deficient intestine (mean mucosal iron concentration, 1.35 +/- .84 mumol/g), 743 +/- 222 nmol/30 min (P less than 0.001). The mean transfer of 59Fe from the mucosal cell to the body through an iron-loaded intestine was 63 +/- 22 nmol/30 min, and through an iron-deficient intestine was 86 +/- 32 nmol/30 min (P less than 0.05). These results suggest that the gut mucosal iron concentration regulates the uptake and transfer of iron in the intestine.

  19. Increased Iron Loading Induces Bmp6 Expression in the Non-Parenchymal Cells of the Liver Independent of the BMP-Signaling Pathway

    PubMed Central

    Enns, Caroline A.; Ahmed, Riffat; Wang, Jiaohong; Ueno, Akiko; Worthen, Christal; Tsukamoto, Hidekazu; Zhang, An-Sheng

    2013-01-01

    Bone morphogenetic protein 6 (BMP6) is an essential cytokine for the expression of hepcidin, an iron regulatory hormone secreted predominantly by hepatocytes. Bmp6 expression is upregulated by increased iron-levels in the liver. Both hepatocytes and non-parenchymal liver cells have detectable Bmp6 mRNA. Here we showed that induction of hepcidin expression in hepatocytes by dietary iron is associated with an elevation of Bmp6 mRNA in the non-parenchymal cells of the liver. Consistently, incubation with iron-saturated transferrin induces Bmp6 mRNA expression in isolated hepatic stellate cells, but not in hepatocytes. These observations suggest an important role of the non-parenchymal liver cells in regulating iron-homeostasis by acting as a source of Bmp6. PMID:23565256

  20. 10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR STOREFRONT, SHOWING MANUFACTURER'S STAMP: IOWA IRON WOKS CO. DUBUQUE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

  1. How iron controls iron.

    PubMed

    Kühn, Lukas C

    2009-12-01

    Cells regulate iron homeostasis by posttranscriptional regulation of proteins responsible for iron uptake and storage. This requires RNA-binding activity of iron-regulatory proteins, IRP1 and IRP2. Two studies recently published in Science by Vashisht et al. (2009) and Salahudeen et al. (2009) reveal how cells adjust IRP2 activity.

  2. Synergistic antimicrobial efficacy of mesoporous ZnO loaded with 4-(α-L-rhamnosyloxy)-benzyl isothiocyanate isolated from the Moringa oleifera seed.

    PubMed

    Rim Jeon, Se; Ha Lee, Keun; Ha Shin, Dong; Sang Kwon, Sun; Sung Hwang, Jae

    2014-01-01

    The antimicrobial activities of isolated compounds from seed extracts of Moringa oleifera and synergistic antimicrobial efficacy through hybridized complex of organic-inorganic composite materials were studied. The two main components of the Moringa oleifera seed were isolated and determined to be niazimicin and 4-(α-L-rhamnosyloxy)-benzyl isothiocyanate (RBI). The antimicrobial activity of the separated compounds of the Moringa oleifera seed were tested in vitro against 3 bacterial species and 2 fungal species by the paper disc diffusion assay and broth dilution methods. Both compounds showed antimicrobial activity against tested species and RBI was more effective than niazimicin. The MIC of RBI on S. aureus, E. coli, P. aeruginosa, C. albicans, and A. niger was 0.005%, 0.1%, 0.5%, 0.5%, and 0.5%, respectively, while the MIC of niazimicin on S. aureus was 0.1%. Next, we investigated the combined antimicrobial action of mesoporous ZnO and RBI by incorporating the compound within the pore of mesoporous ZnO. The MIC of mesoporous ZnO with RBI on S. aureus, E. coli, P. aeruginosa, C. albicans, and A. niger was 0.001%, 0.01%, 0.5%, 0.1%, and 0.1%, respectively. A synergistic effect of RBI with mesoporous ZnO was shown. From these results, the mesoporous ZnO could act as a reservoir for RBI and mesoporous ZnO with RBI could be used for cosmetic preservatives.

  3. Magnetic separation of antibiotics by electrochemical magnetic seeding

    NASA Astrophysics Data System (ADS)

    Ihara, I.; Toyoda, K.; Beneragama, N.; Umetsu, K.

    2009-03-01

    Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of antibiotics in wastewater.

  4. Direct seeding

    Treesearch

    Richard M. Godman; G. A. Mattson

    1992-01-01

    At present, direct seeding of hardwoods in the Lake States is more of a supplemental than a primary means of artificial regeneration. Direct seeding may be used to augment a poor seed crop or increase the proportion of a preferred species. In the future, it will no doubt play a bigger role-in anticipation of this we need to collect and store the amounts of seed needed...

  5. Iron Chelation

    MedlinePlus

    ... iron overload and need treatment. What is iron overload? Iron chelation therapy is used when you have ... may want to perform: How quickly does iron overload happen? This is different for each person. It ...

  6. [Iron deficiency and pica].

    PubMed

    Muñoz, J A; Marcos, J; Risueño, C E; de Cos, C; López, R; Capote, F J; Martín, M V; Gil, J L

    1998-02-01

    To study the relationship between pica and iron-lack anaemia in a series of iron-deficiency patients in order to establish the pathogenesis of such relationship. Four-hundred and thirty-three patients were analysed. Pica was studied by introducing certain diet queries into the clinical history. All patients received oral iron and were periodically controlled with the usual clinico-haematological procedures. Pica was present in 23 patients (5.3%). Eight nourishing (namely, coffee grains, almonds, chocolate, ice, lettuce, carrots, sunflower seeds and bread) and 2 non-nourishing (clay and paper) substances were involved. A second episode of pica appeared in 9 cases upon relapsing of iron deficiency. Both anaemia and pica were cured by etiologic and substitutive therapy in all instances. No clear correlation was found with either socio-economic status or pathogenetic causes of iron deficiency and pica, and no haematological differences were seen between patients with pica and those without this alteration. (1) The pathogenesis of pica is unclear, although it appears unrelated to the degree of iron deficiency. (2) According to the findings in this series, pica seems a consequence of iron deficiency rather than its cause. (3) Adequate therapy can cure both conditions, although pica may reappear upon relapse of iron deficiency.

  7. In vitro loading of apoferritin.

    PubMed

    de Silva, D; Miller, D M; Reif, D W; Aust, S D

    1992-03-01

    This study compared the effect of loading apoferritin either with ferrous ammonium sulfate in various buffers or with ceruloplasmin and chelated ferrous iron. It was shown that loading of apoferritin with ferrous ammonium sulfate was dependent on buffer and pH, and was directly related to the rate of iron autoxidation. The ceruloplasmin-dependent loading of apoferritin, however, was unaffected by these factors. Isoelectric focusing and amino acid analysis of the differently loaded ferritins showed that ferrous ammonium sulfate loading of apoferritin resulted in the depletion of the basic amino acids, lysine and histidine, probably as a result of protein oxidation. No significant differences in amino acid composition was noted for ceruloplasmin-loaded ferritin. Furthermore, ferritin loaded with ferrous ammonium sulfate released more iron than either native or ceruloplasmin-loaded ferritin when either paraquat or EDTA was used as an iron mobilizing agent. We suggest that the loading of apoferritin with ferrous ammonium sulfate occurred as a result of iron autoxidation and may result in oxidation of amino acids and loss of integrity of the protein, and that ceruloplasmin may act as a catalyst for the incorporation of iron into apoferritin in a manner more closely related to that occurring in vivo.

  8. Green synthesis of CuO nanoparticles loaded on the seashell surface using Rumex crispus seeds extract and its catalytic applications for reduction of dyes.

    PubMed

    Rostami-Vartooni, Akbar

    2017-06-01

    In this study, CuO nanoparticles supported on the seashell (CuO NPs/seashell) was prepared using Rumex crispus seeds extract as a chelating and capping agent. The prepared nanocomposite was characterised by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy. The particle size of CuO NPs on the seashell sheets was in the range of 8-60 nm. Catalytic ability of CuO NPs/seashell was investigated for the reduction of 4-nitrophenol (4-NP) and Congo red (CR). It was observed that catalyst can be easily recovered and reused several times without any significant loss of catalytic efficiency.

  9. Well-defined iron complexes as efficient catalysts for "green" atom-transfer radical polymerization of styrene, methyl methacrylate, and butyl acrylate with low catalyst loadings and catalyst recycling.

    PubMed

    Nakanishi, So-Ichiro; Kawamura, Mitsunobu; Kai, Hidetomo; Jin, Ren-Hua; Sunada, Yusuke; Nagashima, Hideo

    2014-05-05

    Environmentally friendly iron(II) catalysts for atom-transfer radical polymerization (ATRP) were synthesized by careful selection of the nitrogen substituents of N,N,N-trialkylated-1,4,9-triazacyclononane (R3 TACN) ligands. Two types of structures were confirmed by crystallography: "[(R3 TACN)FeX2 ]" complexes with relatively small R groups have ionic and dinuclear structures including a [(R3 TACN)Fe(μ-X)3 Fe(R3 TACN)](+) moiety, whereas those with more bulky R groups are neutral and mononuclear. The twelve [(R3 TACN)FeX2 ]n complexes that were synthesized were subjected to bulk ATRP of styrene, methyl methacrylate (MMA), and butyl acrylate (BA). Among the iron complexes examined, [{(cyclopentyl)3 TACN}FeBr2 ] (4 b) was the best catalyst for the well-controlled ATRP of all three monomers. This species allowed easy catalyst separation and recycling, a lowering of the catalyst concentration needed for the reaction, and the absence of additional reducing reagents. The lowest catalyst loading was accomplished in the ATRP of MMA with 4 b (59 ppm of Fe based on the charged monomer). Catalyst recycling in ATRP with low catalyst loadings was also successful. The ATRP of styrene with 4 b (117 ppm Fe atom) was followed by precipitation from methanol to give polystyrene that contained residual iron below the calculated detection limit (0.28 ppm). Mechanisms that involve equilibria between the multinuclear and mononuclear species were also examined. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Procyanidines from Vitis vinifera seeds protect rabbit heart from ischemia/reperfusion injury: antioxidant intervention and/or iron and copper sequestering ability.

    PubMed

    Maffei Facinó, R; Carini, M; Aldini, G; Berti, F; Rossoni, G; Bombardelli, E; Morazzoni, P

    1996-12-01

    An isolated rabbit heart Langendorff preparation paced electrically was used to evaluate the effects of a highly purified, high molecular weight fraction of oligomeric procyanidines isolated from Vitis vinifera seeds on myocardial reperfusion injury after 40 minutes of low flow (1 ml/min) ischemia. Infusion of the heart with 100 or 200 micrograms/ml procyanidines dose-dependently reduced ventricular contracture during ischemia (LVEDP values decreased by 28% and 51%), decreased coronary perfusion pressure (CPP), improved cardiac mechanical performance upon reperfusion, increased the release of 6-keto-PGF1 alpha into the perfusate in both the pre-ischemic and the reperfusion periods (by 68% at 200 micrograms/ml), and suppressed rhythm irregularity. This antiarrhythmogenic action was confirmed in a more severe model of ischemia (flow rate 0.2 ml/ min). The cardioprotective agent allopurinol infused at 20 micrograms/ml had effects on the contractility and on the release of 6-keto-PGF1 alpha comparable to those of 200 micrograms/ml procyanidines. The results of the second part of this study show that procyanidines are potent scavengers of several reactive oxygen species involved in the ischemia/reperfusion damage: the superoxide anion (IC50 = 5.64 microM: rate constant K = 7.55 x 10(5) M-1 s-1, determined by the phenazine methosulfate/NADH method); the hydroxyl radical (IC50 = 28 microM; rate constant K = 1.2 x 10(12) M-1 s-1, determined by the electron spin resonance spectroscopy); peroxyl radicals (IC50 = 0.025 microM and 0.35 microM, determined using two different lipid substrates, phosphatidylcholine liposomes and methyl linoleate micelles by UV spectroscopy at 233 nm). Finally, procyanidines interact with Fe2+ and Cu2+ ions (the catalysts of HO. radicals production) giving rise to strong complexes, with stability constants (log K) ranging from 9.35 to approximately 9.

  11. Magnetic-seeding filtration

    SciTech Connect

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  12. Characterizing the gut (Gallus gallus) microbiota following the consumption of an iron biofortified Rwandan cream seeded carioca (Phaseolus Vulgaris L.) bean-based diet.

    PubMed

    Reed, Spenser; Neuman, Hadar; Glahn, Raymond P; Koren, Omry; Tako, Elad

    2017-01-01

    Biofortification is a plant breeding method that introduces increased concentrations of minerals in staple food crops (e.g., legumes, cereal grains), and has shown success in alleviating insufficient Fe intake in various human populations. Unlike other strategies utilized to alleviate Fe deficiency, studies of the gut microbiota in the context of Fe biofortification have not yet been reported, although the consumption of Fe biofortified staple food crops has increased significantly over time. Hence, in this study, we performed a 6-week feeding trial in Gallus gallus (n = 14), aimed to investigate the alterations in the gut microbiome following administration of an Fe biofortified bean-based diet (biofortified, BFe) versus a bean based diet with poorly-bioavailable Fe (standard, SFe). Cream seeded carioca bean based diets were designed in an identical fashion to those used in a recent human clinical trial of Fe biofortified beans in Rwanda. We hypothesized that the different dietary Fe contents in the beans based diets will alter the composition and function of the intestinal microbiome. The primary outcomes were changes in the gut microbiome composition and function analyzed by 16S rRNA gene sequencing. We observed no significant changes in phylogenetic diversity between groups. There were significant differences in the composition of the microbiota between groups, with the BFe group harboring fewer taxa participating in bacterial Fe uptake, increased abundance of bacteria involved in phenolic catabolism, and increased abundance of beneficial butyrate-producing bacteria. Additionally, depletion of key bacterial pathways responsible for bacterial viability and Fe uptake suggest that improvements in Fe bioavailability, in addition to increases in Fe-polyphenol and Fe-phytate complexes due to biofortification, led to decreased concentrations of cecal Fe available for bacterial utilization. Our findings demonstrate that Fe biofortification may improve Fe status without

  13. Characterizing the gut (Gallus gallus) microbiota following the consumption of an iron biofortified Rwandan cream seeded carioca (Phaseolus Vulgaris L.) bean-based diet

    PubMed Central

    Reed, Spenser; Neuman, Hadar; Glahn, Raymond P.; Koren, Omry

    2017-01-01

    Biofortification is a plant breeding method that introduces increased concentrations of minerals in staple food crops (e.g., legumes, cereal grains), and has shown success in alleviating insufficient Fe intake in various human populations. Unlike other strategies utilized to alleviate Fe deficiency, studies of the gut microbiota in the context of Fe biofortification have not yet been reported, although the consumption of Fe biofortified staple food crops has increased significantly over time. Hence, in this study, we performed a 6-week feeding trial in Gallus gallus (n = 14), aimed to investigate the alterations in the gut microbiome following administration of an Fe biofortified bean-based diet (biofortified, BFe) versus a bean based diet with poorly-bioavailable Fe (standard, SFe). Cream seeded carioca bean based diets were designed in an identical fashion to those used in a recent human clinical trial of Fe biofortified beans in Rwanda. We hypothesized that the different dietary Fe contents in the beans based diets will alter the composition and function of the intestinal microbiome. The primary outcomes were changes in the gut microbiome composition and function analyzed by 16S rRNA gene sequencing. We observed no significant changes in phylogenetic diversity between groups. There were significant differences in the composition of the microbiota between groups, with the BFe group harboring fewer taxa participating in bacterial Fe uptake, increased abundance of bacteria involved in phenolic catabolism, and increased abundance of beneficial butyrate-producing bacteria. Additionally, depletion of key bacterial pathways responsible for bacterial viability and Fe uptake suggest that improvements in Fe bioavailability, in addition to increases in Fe-polyphenol and Fe-phytate complexes due to biofortification, led to decreased concentrations of cecal Fe available for bacterial utilization. Our findings demonstrate that Fe biofortification may improve Fe status without

  14. Granulation by roller compaction and enteric coated tablet formulation of the extract of the seeds of Glinus lotoides loaded on Aeroperl 300 Pharma.

    PubMed

    Endale, Abebe; Gebre-Mariam, Tsige; Schmidt, Peter C

    2008-01-01

    The purpose of this research was to improve the hygroscopicity and poor flow properties of the crude dry extract of the seeds of Glinus lotoides and improve the disintegration time of the core-tablets for enteric coated formulation thereof. The liquid crude extract of the plant was adsorbed on granulated colloidal silicon dioxide (Aeroperl 300 Pharma) at 30% w/w and the dry extract preparation (DEP) was dry-granulated with roller-compaction using Micro-Pactor. Hygroscopicity, flow property and disintegration time were improved significantly due to the adsorption and granulation processes. Moreover, the DEP does not become mucilaginous even at higher relative humidity levels (above 65%). Oblong tablets (20 x 8.25 mm) containing 947 mg of the granulated DEP (equivalent to the traditional dose), 363 mg of Avicel PH101 and 90 mg of Ac-di-Sol as disintegrant were formulated using an instrumented eccentric tablet machine at 20 kN. The tablets showed a crushing strength of 195 N, a friability of 0.4% and disintegrated within 9 min. The tablets were then enteric coated using polymethacrylate co-polymers (Eudragit L 100-55 and Kollicoat MAE 100P). The coated tablets resisted disintegration or softening in simulated gastric fluid for a minimum of 2 h and disintegrated within 15 min in intestine simulated fluid at pH 6.8. In addition to controlling the release of the active agents, the enteric coating improved the strength and decreased friability of the core-tablets.

  15. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations

    PubMed Central

    de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa

    2016-01-01

    ABSTRACT Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption. PMID:26969708

  16. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations.

    PubMed

    de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa; Puig, Sergi

    2016-05-15

    Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Iron Test

    MedlinePlus

    ... are used together to detect and help diagnose iron deficiency or iron overload. In people with anemia , these ... help determine whether the condition is due to iron deficiency or another cause, such as chronic blood loss ...

  18. Reusability of contaminated seed crystal for cast quasi-single crystalline silicon ingots

    NASA Astrophysics Data System (ADS)

    Li, Zaoyang; Liu, Lijun; Zhou, Genshu

    2015-04-01

    Reusing seed crystal is beneficial for reducing the production costs for cast quasi-single crystalline (QSC) silicon ingots. We numerically investigate the reusability of seed crystal in the casting processes with quartz crucible and silicon feedstock of different purities. The reused seed crystal is recycled from the standard QSC ingot and has been highly contaminated by iron impurity. Transient simulations of iron transport are carried out and special attention is paid to the diffusion and distribution characteristics of iron impurity at the ingot bottom. The heights of the bottom iron contaminated region are compared for silicon ingots grown from normal and recycled seed crystals. The results show that the purity of quartz crucible can influence the reusability of seed crystal more significantly than that of the feedstock. The recycled seed crystal with high iron concentration can be reused for casting processes with standard crucible, whereas it is not recommended for reusing for processes with pure crucible.

  19. Cerebral abscess associated with odontogenic bacteremias, hypoxemia, and iron loading in immunocompetent patients with right-to-left shunting through pulmonary arteriovenous malformations.

    PubMed

    Boother, E J; Brownlow, S; Tighe, H C; Bamford, K B; Jackson, J E; Shovlin, C L

    2017-04-19

    Cerebral abscess is a recognised complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with CT-scan confirmed PAVMs (including 403 (90.5%) with hereditary haemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression, and detailed peri-abscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier non-overlapping series. Thirty-seven (8.3%) of the 445 patients experienced a cerebral abscesses at median age 50 (range 19-76) years. The rate adjusted for ascertainment bias was 27/435 (6.2%). 29/37 (78.4%) abscess patients had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. 21/37 (56.7%) suffered residual neurological deficits, most commonly memory/cognition impairment; hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events emphasised potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio 5.4 [95% confidence intervals 1.4, 21.1]); male gender; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower SaO2 and intravenous iron may be modifiable risk factors.

  20. Mutations in Arabidopsis Yellow Stripe-Like1 and Yellow Stripe-Like3 Reveal Their Roles in Metal Ion Homeostasis and Loading of Metal Ions in Seeds1

    PubMed Central

    Waters, Brian M.; Chu, Heng-Hsuan; DiDonato, Raymond J.; Roberts, Louis A.; Eisley, Robynn B.; Lahner, Brett; Salt, David E.; Walker, Elsbeth L.

    2006-01-01

    Here, we describe two members of the Arabidopsis (Arabidopsis thaliana) Yellow Stripe-Like (YSL) family, AtYSL1 and AtYSL3. The YSL1 and YSL3 proteins are members of the oligopeptide transporter family and are predicted to be integral membrane proteins. YSL1 and YSL3 are similar to the maize (Zea mays) YS1 phytosiderophore transporter (ZmYS1) and the AtYSL2 iron (Fe)-nicotianamine transporter, and are predicted to transport metal-nicotianamine complexes into cells. YSL1 and YSL3 mRNAs are expressed in both root and shoot tissues, and both are regulated in response to the Fe status of the plant. β-Glucuronidase reporter expression, driven by YSL1 and YSL3 promoters, reveals expression patterns of the genes in roots, leaves, and flowers. Expression was highest in senescing rosette leaves and cauline leaves. Whereas the single mutants ysl1 and ysl3 had no visible phenotypes, the ysl1ysl3 double mutant exhibited Fe deficiency symptoms, such as interveinal chlorosis. Leaf Fe concentrations are decreased in the double mutant, whereas manganese, zinc, and especially copper concentrations are elevated. In seeds of double-mutant plants, the concentrations of Fe, zinc, and copper are low. Mobilization of metals from leaves during senescence is impaired in the double mutant. In addition, the double mutant has reduced fertility due to defective anther and embryo development. The proposed physiological roles for YSL1 and YSL3 are in delivery of metal micronutrients to and from vascular tissues. PMID:16815956

  1. Iron regulatory proteins and their role in controlling iron metabolism.

    PubMed

    Kühn, Lukas C

    2015-02-01

    Cellular iron homeostasis is regulated by post-transcriptional feedback mechanisms, which control the expression of proteins involved in iron uptake, release and storage. Two cytoplasmic proteins with mRNA-binding properties, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a central role in this regulation. Foremost, IRPs regulate ferritin H and ferritin L translation and thus iron storage, as well as transferrin receptor 1 (TfR1) mRNA stability, thereby adjusting receptor expression and iron uptake via receptor-mediated endocytosis of iron-loaded transferrin. In addition splice variants of iron transporters for import and export at the plasma-membrane, divalent metal transporter 1 (DMT1) and ferroportin are regulated by IRPs. These mechanisms have probably evolved to maintain the cytoplasmic labile iron pool (LIP) at an appropriate level. In certain tissues, the regulation exerted by IRPs influences iron homeostasis and utilization of the entire organism. In intestine, the control of ferritin expression limits intestinal iron absorption and, thus, whole body iron levels. In bone marrow, erythroid heme biosynthesis is coordinated with iron availability through IRP-mediated translational control of erythroid 5-aminolevulinate synthase mRNA. Moreover, the translational control of HIF2α mRNA in kidney by IRP1 coordinates erythropoietin synthesis with iron and oxygen supply. Besides IRPs, body iron absorption is negatively regulated by hepcidin. This peptide hormone, synthesized and secreted by the liver in response to high serum iron, downregulates ferroportin at the protein level and thereby limits iron absorption from the diet. Hepcidin will not be discussed in further detail here.

  2. Bi-exponential proton transverse relaxation rate (R2) image analysis using RF field intensity-weighted spin density projection: potential for R2 measurement of iron-loaded liver.

    PubMed

    Clark, Paul R; Chua-anusorn, Wanida; St Pierre, Timothy G

    2003-06-01

    A bi-exponential proton transverse relaxation rate (R(2)) image analysis technique has been developed that enables the discrimination of dual compartment transverse relaxation behavior in systems with rapid transverse relaxation enhancement. The technique is particularly well suited to single spin-echo imaging studies where a limited number of images are available for analysis. The bi-exponential R(2) image analysis is facilitated by estimation of the initial proton spin density signal within the region of interest weighted by the RF field intensities. The RF field intensity-weighted spin density map is computed by solving a boundary value problem presented by a high spin density, long T(2) material encompassing the region for analysis. The accuracy of the bi-exponential R(2) image analysis technique is demonstrated on a simulated dual compartment manganese chloride phantom system with relaxation rates and relative population densities between the two compartments similar to the bi-exponential transverse relaxation behavior expected of iron loaded liver. Results from analysis of the phantoms illustrate the potential of bi-exponential R(2) image analysis with RF field intensity-weighted spin density projection for quantifying transverse relaxation enhancement as it occurs in liver iron overload.

  3. Compression ignition performance using sunflower seed oil

    SciTech Connect

    Yarbrough, C.M.; LePori, W.A.; Engler, C.R.

    1981-01-01

    Sunflower seed oil subjected to various levels of processing and blends with diesel fuel were evaluated in a single cylinder diesel engine. Results from short duration performance tests and longer duration load tests are reported. 8 refs.

  4. Seed germination and seedling fitness in Mesua ferrea L. in relation to fruit size and seed number per fruit

    NASA Astrophysics Data System (ADS)

    Khan, M. Latif; Bhuyan, Putul; Shankar, Uma; Todaria, Nagendra P.

    1999-11-01

    Effect of fruit size and seediness (seed number per fruit) was examined on germination and early growth of seedlings in Mesua ferrea L. Fruiting incidence (number of fruited trees in a population) and fruit loading (number of fruits per tree) vary from one year to the other, and were greater in 1997 than in 1998. Seeds from large fruits (> 40 g) are preferred for forestry plantations and those from small fruits (< 40 g) are discarded, despite a greater proportion of small fruits (63.2 %) than large fruits (36.8 %). A fruit, large or small in size, may contain one, two, three or four seeds. The germination percentage of seeds increased from 1-seeded through 4-seeded fruits both in laboratory and greenhouse conditions, and both in case of large and small fruits. Conversely, the mean seed weight and germination time decreased along this gradient, i.e. seeds from 1-seeded fruits were the heaviest and required maximum time for germination, and the seeds from 4-seeded fruits were the lightest and required minimum time for germination. The seeds from small fruits were lighter in weight, achieved lower germination percentages and required greater germination time than the seeds from large fruits in all four seeded categories. Seedlings from seeds from 1-seeded fruits survived better and with stronger vigour after 1 year of growth than seedlings from 2-, 3- and 4-seeded fruits. Further, seedling survival and vigour were greater for seeds from large rather than small fruits.

  5. Dimensional specific physical properties of fan palm fruits, seeds and seed coats (Washingtonia robusta)

    NASA Astrophysics Data System (ADS)

    Coşkuner, Yalçın; Gökbudak, Ayşe

    2016-07-01

    In this study some physical properties of fan palm (Washingtonia robusta) fruits, seeds and seed coats were determined using dimensional, bulk and single kernel physical analysis. The moisture content of whole fruits, seeds and seed coats was 12.0, 9.86 and 13.87% (d.b.), respectively. The sphericity values showed that seed shape (0.86) is close to a sphere, similar as the fruit shape (0.83), both of which were close to a scalene ellipsoid shape. The surface area values of fruits and seeds were obtained as 163.27 and 80.25 mm2, and volume values were obtained as 190.96 and 66.32 mm3, respectively. Bulk densities of fruits, seeds and seed coats were 559, 783 and 272 kg m-3, and the corresponding true densities were 1143, 1147 and 864 kg m-3, whereas the corresponding porosities were 48.87, 54.12, and 31.52%, respectively. The values of the static coefficient of friction and the angle of repose of fruits, seeds and seed coats of palm fruits were studied on aluminium, canvas, galvanised iron, plywood, PP knitted bag, PVC and stainless steel surfaces. As expected, seed coat has higher values of coefficient of static friction on the all surfaces than fruit and seed.

  6. Seed proteomics.

    PubMed

    Miernyk, Ján A; Hajduch, Martin

    2011-04-01

    Seeds comprise a protective covering, a small embryonic plant, and a nutrient-storage organ. Seeds are protein-rich, and have been the subject of many mass spectrometry-based analyses. Seed storage proteins (SSP), which are transient depots for reduced nitrogen, have been studied for decades by cell biologists, and many of the complicated aspects of their processing, assembly, and compartmentation are now well understood. Unfortunately, the abundance and complexity of the SSP requires that they be avoided or removed prior to gel-based analysis of non-SSP. While much of the extant data from MS-based proteomic analysis of seeds is descriptive, it has nevertheless provided a preliminary metabolic picture explaining much of their biology. Contemporary studies are moving more toward analysis of protein interactions and posttranslational modifications, and functions of metabolic networks. Many aspects of the biology of seeds make then an attractive platform for heterologous protein expression. Herein we present a broad review of the results from the proteomic studies of seeds, and speculate on a potential future research directions. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Iron does not cause arrhythmias in the guinea pig model of transfusional iron overload.

    PubMed

    Kaiser, Lana; Davis, John; Patterson, Jon; Boyd, Ryan F; Olivier, N Bari; Bohart, George; Schwartz, Kenneth A

    2007-08-01

    Cardiac events, including heart failure and arrhythmias, are the leading cause of death in patients with beta thalassemia. Although cardiac arrhythmias in humans are believed to result from iron overload, excluding confounding factors in the human population is difficult. The goal of the current study was to determine whether cardiac arrhythmias occurred in the guinea pig model of secondary iron overload. Electrocardiograms were recorded by using surgically implanted telemetry devices in guinea pigs loaded intraperitoneally with iron dextran (test animals) or dextran alone (controls). Loading occurred over approximately 6 wk. Electrocardiograms were recorded for 1 wk prior to loading, throughout loading, and for approximately 4 wk after loading was complete. Cardiac and liver iron concentrations were significantly increased in the iron-loaded animals compared with controls and were in the range of those reported for humans with thalassemia. Arrhythmias were rare in both iron-loaded and control guinea pigs. No life-threatening arrhythmias were detected in either group. These data suggest that iron alone may be insufficient to cause cardiac arrhythmias in the iron-loaded guinea pig model and that arrhythmias detected in human patients with iron overload may be the result of a complex interplay of factors.

  8. Efficiencies and mechanisms of ZSM5 zeolites loaded with cerium, iron, or manganese oxides for catalytic ozonation of nitrobenzene in water.

    PubMed

    Chen, Chunmao; Yan, Xin; Yoza, Brandon A; Zhou, Tingting; Li, Yang; Zhan, Yali; Wang, Qinghong; Li, Qing X

    2017-09-08

    Discharge of industrial wastewater causes water pollution. It is therefore necessary to treat wastewater prior to discharge. Catalytic ozonation processes (COP) using ZSM5 zeolites loaded with metallic (Ce, Fe, or Mn) oxides to remove nitrobenzene from water were investigated. The total organic carbon (TOC) removal by the COP treatment with NaZSM5-38, HZSM5-38, and NaZSM5-100 were increased by 6.7%, 23.1%, and 19.8%, respectively, in comparison with single ozonation efficiency (39.2%). The loadings of Ce, Fe, or Mn oxides increased the catalytic activity relative to ZSM5 zeolites alone. The Ce loaded material (Ce/NaZSM5-38) had the highest TOC removal (86.3%). The different-metallic-oxides loaded zeolites exhibited different chemical processes during the removal of nitrobenzene from water. During COP treatment, NaZSM5-38 zeolites removed nitrobenzene mainly via OH mediated oxidation. HZSM5-38 and NaZSM5-100 zeolites showed powerful adsorption toward nitrobenzene. Both adsorption and direct ozonation contribute the TOC removal in their early uses. The OH mediated oxidation dominates the TOC removal process as the adsorption became saturated after multiple uses. Surface SiO bonds and/or SiO(H)Al structures are the active sites for ZSM5 zeolites. Efficient surface dispersion of the metallic oxides enhances the catalytic activity. This study shows the high potentials of ZSM5 zeolites as catalysts in COP to efficiently treat refractory wastewaters. Copyright © 2017. Published by Elsevier B.V.

  9. Iron withholding: a defense against disease.

    PubMed

    Weinberg, Eugene D; Miklossy, Judith

    2008-05-01

    Excessive and misplaced iron promotes an array of neurodegenerative and endocrine diseases as well as cardiomyopathy, arthropathy, neoplasia and infection. Vertebrates maintain an iron withholding defense system designed to prevent accumulation of redox-active (free) iron in sensitive sites and to sequester the metal in innocuous packages. Numerous genetic, behavioral and environmental factors counteract the defense system. Our increasing awareness of the pathologic roles of iron, as well as of the methods for prevention of iron loading coupled with intensified research and development of tissue specific iron chelator drugs, can be expected to yield marked improvements in human health.

  10. The Role of Hepcidin in Iron Metabolism

    PubMed Central

    Nemeth, Elizabeta; Ganz, Tomas

    2009-01-01

    Hepcidin is the central regulator of systemic iron homeostasis. Dysregulation of hepcidin production results in a variety of iron disorders. Hepcidin deficiency is the cause of iron overload in hereditary hemochromatosis, iron-loading anemias, and hepatitis C. Hepcidin excess is associated with anemia of inflammation, chronic kidney disease and iron-refractory iron deficiency anemia. Diagnostic and therapeutic applications of this new knowledge are beginning to emerge. Dr. Ernest Beutler played a significant role in advancing our understanding of the function of hepcidin. This review is dedicated to his memory. PMID:19907144

  11. Studies of Cream Seeded Carioca Beans (Phaseolus vulgaris L.) from a Rwandan Efficacy Trial: In Vitro and In Vivo Screening Tools Reflect Human Studies and Predict Beneficial Results from Iron Biofortified Beans.

    PubMed

    Tako, Elad; Reed, Spenser; Anandaraman, Amrutha; Beebe, Steve E; Hart, Jonathan J; Glahn, Raymond P

    2015-01-01

    Iron (Fe) deficiency is a highly prevalent micronutrient insufficiency predominantly caused by a lack of bioavailable Fe from the diet. The consumption of beans as a major food crop in some populations suffering from Fe deficiency is relatively high. Therefore, our objective was to determine whether a biofortified variety of cream seeded carioca bean (Phaseolus vulgaris L.) could provide more bioavailable-Fe than a standard variety using in-vivo (broiler chicken, Gallus gallus) and in-vitro (Caco-2 cell) models. Studies were conducted under conditions designed to mimic the actual human feeding protocol. Two carioca-beans, a standard (G4825; 58 μg Fe/g) and a biofortified (SMC; 106 μg Fe/g), were utilized. Diets were formulated to meet the nutrient requirements of Gallus gallus except for Fe (33.7 and 48.7 μg Fe/g, standard and biofortified diets, respectively). In-vitro observations indicated that more bioavailable-Fe was present in the biofortified beans and diet (P<0.05). In-vivo, improvements in Fe-status were observed in the biofortified bean treatment, as indicated by the increased total-body-Hemoglobin-Fe, and hepatic Fe-concentration (P<0.05). Also, DMT-1 mRNA-expression was increased in the standard bean treatment (P<0.05), indicating an upregulation of absorption to compensate for less bioavailable-Fe. These results demonstrate that the biofortified beans provided more bioavailable Fe; however, the in vitro results revealed that ferritin formation values were relatively low. Such observations are indicative of the presence of high levels of polyphenols and phytate that inhibit Fe absorption. Indeed, we identified higher levels of phytate and quercetin 3-glucoside in the Fe biofortified bean variety. Our results indicate that the biofortified bean line was able to moderately improve Fe-status, and that concurrent increase in the concentration of phytate and polyphenols in beans may limit the benefit of increased Fe-concentration. Therefore, specific

  12. Studies of Cream Seeded Carioca Beans (Phaseolus vulgaris L.) from a Rwandan Efficacy Trial: In Vitro and In Vivo Screening Tools Reflect Human Studies and Predict Beneficial Results from Iron Biofortified Beans

    PubMed Central

    Tako, Elad; Reed, Spenser; Anandaraman, Amrutha; Beebe, Steve E.; Hart, Jonathan J.; Glahn, Raymond P.

    2015-01-01

    Iron (Fe) deficiency is a highly prevalent micronutrient insufficiency predominantly caused by a lack of bioavailable Fe from the diet. The consumption of beans as a major food crop in some populations suffering from Fe deficiency is relatively high. Therefore, our objective was to determine whether a biofortified variety of cream seeded carioca bean (Phaseolus vulgaris L.) could provide more bioavailable-Fe than a standard variety using in-vivo (broiler chicken, Gallus gallus) and in-vitro (Caco-2 cell) models. Studies were conducted under conditions designed to mimic the actual human feeding protocol. Two carioca-beans, a standard (G4825; 58μg Fe/g) and a biofortified (SMC; 106μg Fe/g), were utilized. Diets were formulated to meet the nutrient requirements of Gallus gallus except for Fe (33.7 and 48.7μg Fe/g, standard and biofortified diets, respectively). In-vitro observations indicated that more bioavailable-Fe was present in the biofortified beans and diet (P<0.05). In-vivo, improvements in Fe-status were observed in the biofortified bean treatment, as indicated by the increased total-body-Hemoglobin-Fe, and hepatic Fe-concentration (P<0.05). Also, DMT-1 mRNA-expression was increased in the standard bean treatment (P<0.05), indicating an upregulation of absorption to compensate for less bioavailable-Fe. These results demonstrate that the biofortified beans provided more bioavailable Fe; however, the in vitro results revealed that ferritin formation values were relatively low. Such observations are indicative of the presence of high levels of polyphenols and phytate that inhibit Fe absorption. Indeed, we identified higher levels of phytate and quercetin 3–glucoside in the Fe biofortified bean variety. Our results indicate that the biofortified bean line was able to moderately improve Fe-status, and that concurrent increase in the concentration of phytate and polyphenols in beans may limit the benefit of increased Fe-concentration. Therefore, specific

  13. Bypassing Iron Storage in Endodermal Vacuoles Rescues the Iron Mobilization Defect in the natural resistance associated-macrophage protein3natural resistance associated-macrophage protein4 Double Mutant.

    PubMed

    Mary, Viviane; Schnell Ramos, Magali; Gillet, Cynthia; Socha, Amanda L; Giraudat, Jérôme; Agorio, Astrid; Merlot, Sylvain; Clairet, Colin; Kim, Sun A; Punshon, Tracy; Guerinot, Mary Lou; Thomine, Sébastien

    2015-09-01

    To improve seed iron (Fe) content and bioavailability, it is crucial to decipher the mechanisms that control Fe storage during seed development. In Arabidopsis (Arabidopsis thaliana) seeds, most Fe is concentrated in insoluble precipitates, with phytate in the vacuoles of cells surrounding the vasculature of the embryo. NATURAL RESISTANCE ASSOCIATED-MACROPHAGE PROTEIN3 (AtNRAMP3) and AtNRAMP4 function redundantly in Fe retrieval from vacuoles during germination. When germinated under Fe-deficient conditions, development of the nramp3nramp4 double mutant is arrested as a consequence of impaired Fe mobilization. To identify novel genes involved in seed Fe homeostasis, we screened an ethyl methanesulfonate-mutagenized population of nramp3nramp4 seedlings for mutations suppressing their phenotypes on low Fe. Here, we report that, among the suppressors, two independent mutations in the VACUOLAR IRON TRANSPORTER1 (AtVIT1) gene caused the suppressor phenotype. The AtVIT1 transporter is involved in Fe influx into vacuoles of endodermal and bundle sheath cells. This result establishes a functional link between Fe loading in vacuoles by AtVIT1 and its remobilization by AtNRAMP3 and AtNRAMP4. Moreover, analysis of subcellular Fe localization indicates that simultaneous disruption of AtVIT1, AtNRAMP3, and AtNRAMP4 limits Fe accumulation in vacuolar globoids.

  14. Bypassing Iron Storage in Endodermal Vacuoles Rescues the Iron Mobilization Defect in the natural resistance associated-macrophage protein3natural resistance associated-macrophage protein4 Double Mutant1[OPEN

    PubMed Central

    Mary, Viviane; Schnell Ramos, Magali; Gillet, Cynthia; Socha, Amanda L.; Giraudat, Jérôme; Agorio, Astrid; Merlot, Sylvain; Clairet, Colin; Kim, Sun A.; Punshon, Tracy; Guerinot, Mary Lou; Thomine, Sébastien

    2015-01-01

    To improve seed iron (Fe) content and bioavailability, it is crucial to decipher the mechanisms that control Fe storage during seed development. In Arabidopsis (Arabidopsis thaliana) seeds, most Fe is concentrated in insoluble precipitates, with phytate in the vacuoles of cells surrounding the vasculature of the embryo. NATURAL RESISTANCE ASSOCIATED-MACROPHAGE PROTEIN3 (AtNRAMP3) and AtNRAMP4 function redundantly in Fe retrieval from vacuoles during germination. When germinated under Fe-deficient conditions, development of the nramp3nramp4 double mutant is arrested as a consequence of impaired Fe mobilization. To identify novel genes involved in seed Fe homeostasis, we screened an ethyl methanesulfonate-mutagenized population of nramp3nramp4 seedlings for mutations suppressing their phenotypes on low Fe. Here, we report that, among the suppressors, two independent mutations in the VACUOLAR IRON TRANSPORTER1 (AtVIT1) gene caused the suppressor phenotype. The AtVIT1 transporter is involved in Fe influx into vacuoles of endodermal and bundle sheath cells. This result establishes a functional link between Fe loading in vacuoles by AtVIT1 and its remobilization by AtNRAMP3 and AtNRAMP4. Moreover, analysis of subcellular Fe localization indicates that simultaneous disruption of AtVIT1, AtNRAMP3, and AtNRAMP4 limits Fe accumulation in vacuolar globoids. PMID:26232490

  15. Iron loading effects in Fe/SSZ-13 NH3-SCR catalysts: nature of the Fe-ions and structure-function relationships

    SciTech Connect

    Gao, Feng; Zheng, Yang; Kukkadapu, Ravi K.; Wang, Yilin; Walter, Eric D.; Schwenzer, Birgit; Szanyi, Janos; Peden, Charles HF

    2016-05-06

    Using a traditional aqueous solution ion-exchange method under a protecting atmosphere of N2, a series of Fe/SSZ-13 catalysts with various Fe loadings were synthesized. UV-Vis, EPR and Mössbauer spectroscopies, coupled with temperature programmed reduction and desorption techniques, were used to probe the nature of the Fe sites. The major monomeric and dimeric Fe species are extra-framework [Fe(OH)2]+ and [HO-Fe-O-Fe-OH]2+. Larger oligomers with unknown nuclearity, poorly crystallized Fe2O3 particles, together with isolated Fe2+ ions, are minor Fe-containing moieties. Reaction rate and Fe loading correlations suggest that isolated Fe3+ ions are the active sites for standard SCR while the dimeric sites are the active centers for NO oxidation. NH3 oxidation, on the other hand, is catalyzed by sites with higher nuclearity. A low-temperature standard SCR reaction network is proposed that includes redox cycling of both monomeric and dimeric Fe species, for SCR and NO2 generation, respectively. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Program for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  16. Characterizing rapid capacity fade and impedance evolution in high rate pulsed discharged lithium iron phosphate cells for complex, high power loads

    NASA Astrophysics Data System (ADS)

    Wong, Derek N.; Wetz, David A.; Heinzel, John M.; Mansour, Azzam N.

    2016-10-01

    Three 26650 LiFePO4 (LFP) cells are cycled using a 40 A pulsed charge/discharge profile to study their performance in high rate pulsed applications. This profile is used to simulate naval pulsed power loads planned for deployment aboard future vessels. The LFP cells studied experienced an exponential drop in their usable high-rate recharge capacity within sixty cycles due to a rapid rise in their internal resistance. Differential capacitance shows that the voltage window for charge storage is pushed outside of the recommended voltage cutoff limits. Investigation into the state of health of the electrodes shows minimal loss of active material from the cathode to side reactions. Post-mortem examination of the anodic surface films reveals a large increase in the concentration of reduced salt compounds indicating that the pulsed profile creates highly favorable conditions for LiPF6 salt to break down into LiF. This film slows the ionic movement at the interface, affecting transfer kinetics, resulting in charge buildup in the bulk anode without successful energy storage. The results indicate that the use of these cells as a power supply for high pulsed power loads is hindered because of ionically resistant film development and not by an increasing rate of active material loss.

  17. Secondary dispersal of bigcone Douglas-fir ( Pseudotsuga macrocarpa ) seeds

    NASA Astrophysics Data System (ADS)

    Vander Wall, Stephen B.; Borchert, Mark I.; Gworek, Jennifer R.

    2006-07-01

    Large-seeded pines ( Pinus spp.) are known to be dispersed by seed-caching corvids (i.e. jays and nutcrackers) and rodents (e.g. chipmunks and mice), with a concomitant decrease in seed dispersability by wind. We tested the idea that seeds of bigcone Douglas-fir ( Pseudotsuga macrocarpa), which are winged but larger than the seeds of other members of Pseudotsuga, are dispersed by a combination of wind and seed-caching rodents. We compared characteristics of seeds from P. macrocarpa in southern California (mean seed mass 132.6 mg) to seeds of a population of Pseudotsuga menziesii (Douglas-fir) in northern California (24.8 mg). We also tested whether rodents would cache seeds of P. macrocarpa. Seeds of P. macrocarpa had greater wing loadings (1.37 mg/mm 2) and descent velocities (2.47 m/s) than those of P. menziesii (0.52 mg/mm 2 and 1.28 m/s, respectively). These data indicate that the wind dispersability of P. macrocarpa is likely to be less than that of P. menziesii, but this loss of wind dispersability is partially compensated for by secondary dispersal of seeds by rodents, which readily gathered and cached the larger seeds of P. macrocarpa up to 34 m from source trees. Large seed size confers several advantages to P. macrocarpa, most importantly attracting seed-caching animals that effectively bury seeds.

  18. Effect of different iron loads on serum and tissue biochemical parameters and liver hepcidin mRNA abundance of neonatal piglets.

    PubMed

    Lia, Mengyun; Yin, Qingqiang; Dang, Xiaowei; Chang, Juan; Zuo, Ruiyu; Zheng, Qiuhong

    2011-12-01

    Iron (Fe) is an essential and important trace element for animals. In order to study its metabolism and relationship with hepcidin, piglet models of Fe-deficiency and Fe-overload were established by intramuscular injection with different doses of Fe-dextran (150 mg Fe/ml) within 1 week of age. Twelve piglets were divided into three groups of four animals: deficiency, regular and overload group, receiving 0 ml, 1 ml and 6 ml Fe-dextran, respectively. The piglets were euthanised at the age of 7 days for analysis. The results showed that the Fe-concentrations in liver, spleen and serum of piglets in the overload group were higher than in the regular and deficiency groups (p < 0.05). In the overload group, several serum biochemical parameters, e.g. globulin, total bilirubin, total cholesterol, high density lipoprotein (HDL), malondialdehyde, glutathione peroxidase (GPx), peroxidase and xanthine oxidase were higher, while alkaline phosphatase (AKP) and triglycerides were lower, compared with the regular group (p < 0.05). The serum concentrations of AKP, total bilirubin and peroxidase in the deficiency group were lower, while HDL and GPx were higher, compared with the regular group (p < 0.05). Hepcidin mRNA abundance was 131 times lower in the liver of piglets with Fe-deficiency, and 7 times higher in the overloaded group than that in the regular group (p < 0.05). In conclusion, Fe-overload and deficiency would influence Fe-metabolism, serum biochemical indexes, oxidation state and hepcidin mRNA abundance in piglet liver.

  19. Drug/Dye-Loaded, Multifunctional PEG-Chitosan-Iron Oxide Nanocomposites for Methotraxate Synergistically Self-Targeted Cancer Therapy and Dual Model Imaging.

    PubMed

    Lin, Jinyan; Li, Yang; Li, Yanxiu; Wu, Hongjie; Yu, Fei; Zhou, Shuifan; Xie, Liya; Luo, Fanghong; Lin, Changjian; Hou, Zhenqing

    2015-06-10

    Multifunctional nanocomposites hold great potential to integrate therapeutic and diagnostic functions into a single nanoscale structure. In this paper, we prepared the MTX-PEG-CS-IONPs-Cy5.5 nanocomposites by functionalizing the surface of chitosan-decorated iron oxide nanoparticles (CS-IONPs) with polyethylene glycolated methotraxate (MTX-PEG) and near-infrared fluorescent cyanin dye (Cy5.5). A clinically useful PEGylated anticancer prodrug, MTX-PEG, was also developed as a tumor cell-specific targeting ligand for self-targeted cancer treatment. In such nanocomposites, the advantage was that the orthogonally functionalized, self-targeted MTX-PEG-CS-IONPs-Cy5.5 can synergistically combine an early phase selective tumor-targeting efficacy with a late-phase cancer-killing effect, which was also confirmed by dual model (magnetic resonance and fluorescence) imaging. Furthermore, with the aids of the folate (FA) receptor-mediated endocytosis (able to turn cellular uptake "off" in normal cells and "on" in cancer cells) and pH/intracellular protease-mediated hydrolyzing peptide bonds (able to turn drug release "off" in systemic circulation and "on" inside endo/lysosomes), the MTX-PEG-CS-IONPs-Cy5.5 could deliver MTX to FA receptors-overexpressed cancer cells, showing the improved anticancer activity with the reduced side effects. Together, the MTX-PEG-CS-IONPs-Cy5.5 could act as a highly convergent, flexible, and simplified system for dual model imaging and synergistically self-targeted cancer therapy, holding great promise for versatile biomedical applications in future.

  20. Project SEED.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1986

    1986-01-01

    Reports on Project SEED (Summer Educational Experience for the Disadvantaged) a project in which high school students from low-income families work in summer jobs in a variety of academic, industrial, and government research labs. The program introduces the students to career possibilities in chemistry and to the advantages of higher education.…

  1. A legume biofortification quandary: variability and genetic control of seed coat micronutrient accumulation in common beans

    PubMed Central

    Blair, Matthew W.; Izquierdo, Paulo; Astudillo, Carolina; Grusak, Michael A.

    2013-01-01

    Common beans (Phaseolus vulgaris L.), like many legumes, are rich in iron, zinc, and certain other microelements that are generally found to be in low concentrations in cereals, other seed crops, and root or tubers and therefore are good candidates for biofortification. But a quandary exists in common bean biofortification: namely that the distribution of iron has been found to be variable between the principal parts of seed; namely the cotyledonary tissue, embryo axis and seed coat. The seed coat represents ten or more percent of the seed weight and must be considered specifically as it accumulates much of the anti-nutrients such as tannins that effect mineral bioavailability. Meanwhile the cotyledons accumulate starch and phosphorus in the form of phytates. The goal of this study was to evaluate a population of progeny derived from an advanced backcross of a wild bean and a cultivated Andean bean for seed coat versus cotyledonary minerals to identify variability and predict inheritance of the minerals. We used wild common beans because of their higher seed mineral concentration compared to cultivars and greater proportion of seed coat to total seed weight. Results showed the most important gene for seed coat iron was on linkage group B04 but also identified other QTL for seed coat and cotyledonary iron and zinc on other linkage groups, including B11 which has been important in studies of whole seed. The importance of these results in terms of physiology, candidate genes and plant breeding are discussed. PMID:23908660

  2. A legume biofortification quandary: variability and genetic control of seed coat micronutrient accumulation in common beans.

    PubMed

    Blair, Matthew W; Izquierdo, Paulo; Astudillo, Carolina; Grusak, Michael A

    2013-01-01

    Common beans (Phaseolus vulgaris L.), like many legumes, are rich in iron, zinc, and certain other microelements that are generally found to be in low concentrations in cereals, other seed crops, and root or tubers and therefore are good candidates for biofortification. But a quandary exists in common bean biofortification: namely that the distribution of iron has been found to be variable between the principal parts of seed; namely the cotyledonary tissue, embryo axis and seed coat. The seed coat represents ten or more percent of the seed weight and must be considered specifically as it accumulates much of the anti-nutrients such as tannins that effect mineral bioavailability. Meanwhile the cotyledons accumulate starch and phosphorus in the form of phytates. The goal of this study was to evaluate a population of progeny derived from an advanced backcross of a wild bean and a cultivated Andean bean for seed coat versus cotyledonary minerals to identify variability and predict inheritance of the minerals. We used wild common beans because of their higher seed mineral concentration compared to cultivars and greater proportion of seed coat to total seed weight. Results showed the most important gene for seed coat iron was on linkage group B04 but also identified other QTL for seed coat and cotyledonary iron and zinc on other linkage groups, including B11 which has been important in studies of whole seed. The importance of these results in terms of physiology, candidate genes and plant breeding are discussed.

  3. Evaluation of an automated seed loader for seed calibration in prostate brachytherapy.

    PubMed

    Wan, Shuying; Joshi, Chandra P; Carnes, Greg; Schreiner, L John

    2006-01-01

    Automated seed loaders for permanent prostate implants are now commercially available. Besides improved radiation safety, these systems offer seed assay capability and ease of needle loading, making preplanned as well as intra-operative implant procedures more time-efficient. The Isoloader (Mentor Corp., CA) uses individual I125 seeds (SL-125 ProstaSeed) loaded in up to 199 chambers inside a shielded cartridge. The unit performs seed counting and calibration using a builtin solid-state detector. In order to evaluate the reproducibility and accuracy of the calibration process, two test cartridges were measured with the Isoloader itself and compared with a well-type ionization chamber (HDR-1000Plus, Standard Imaging). The air kerma strength measurements for all seeds using the Isoloader had a standard deviation of about 2.7%. For the eight seeds assayed more intensively using both the Isoloader and well chamber, the standard deviations of the measurements for each seed were in the range of 0.8% to 2.8% and 0.6% to 1.3%, respectively. The variation in the Isoloader calibration is attributed to small detector solid angle and bead geometry within seed capsules (verified by radiographs). The reproducibility of the air kerma strength measured by the Isoloader was comparable to that from the well chamber and was clinically acceptable. Seed strength measured with the Isoloader was on average 1% 2% larger than that measured with the well chamber, indicating that the accuracy of the Isoloader was clinically acceptable.

  4. Automatic T2* determination for quantification of iron load in heart and liver: a comparison between automatic inline Maximum Likelihood Estimate and the truncation and offset methods.

    PubMed

    Hedström, Erik; Voigt, Tobias; Greil, Gerald; Schaeffter, Tobias; Nagel, Eike

    2017-05-01

    To validate ironload T2* by automatic inline Maximum Likelihood Estimate (MLE) with k-space Rician noise correction, against the manual and automated truncation, as well as offset methods, in phantoms and in heart and liver in patients. Twenty-five patients and an iron-oxide phantom were scanned at 1.5T using 2 multi-echo gradient-echo sequences. All parameters were identical (voxel 2-3 × 2-3 × 10 mm(3) , 10 echoes, TR = 26 ms, FA = 20°, BW = 833 Hz, SENSE = 2) except for TE (cardiac: TE1  = 2·5 ms, ΔTE = 2·5 ms; liver: TE1  = 1·2 ms, ΔTE = 1·5 ms). Phantoms were scanned at 1 and 32 signal averages (NSA), with NSA32 representing low-noise reference. Phantoms: MLE showed low variability between NSA1 and NSA32 (0·02 ± 0·29 ms, CI ±0·21 ms). Between methods, no difference was shown (MLE versus all: <0·31 ms, CI < ±0·35 ms). No differences were found between methods in heart (MLE versus all: <-0·22 ms, CI < ±0·75 ms) or liver (MLE versus all: <0·12 ms, CI < ±0·26 ms). The automatic inline MLE method is comparable to the general reference standards for determining cardiac and liver T2* for ironload in man. An automatic inline method may simplify ironload assessment, particularly in centres seeing fewer cases. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  5. Laboratory and pilot-scale field experiments for application of iron oxide nanoparticle-loaded chitosan composites to phosphate removal from natural water.

    PubMed

    Kim, Jae-Hyun; Kim, Song-Bae; Lee, Sang-Hyup; Choi, Jae-Woo

    2017-04-09

    The aim of this study was to apply iron oxide nanoparticle-chitosan (ION-chitosan) composites to phosphate removal from natural water collected from the Seoho Stream in Suwon, Republic of Korea. Laboratory batch experiments showed that phosphate removal by the ION-chitosan composites was not sensitive to pH changes between pH values of 5.0 and 9.0. During six cycles of adsorption-desorption, the composites could be successfully regenerated with 5 mM NaOH solution and reused for phosphate removal. Laboratory fixed-bed column experiments (column height = 10 and 20 cm, inner diameter = 2.5 cm, flow rate = 8.18 and 16.36 mL/min) demonstrated that the composites could be successfully applied for phosphate removal under dynamic flow conditions. A pilot-scale field experiment was performed in a pilot plant, which was mainly composed of chemical reactor/dissolved air flotation and an adsorption tower, built nearby the Seoho Stream. The natural water was pumped from the Seoho Stream into the pilot plant, passed through the chemical reactor/dissolved air flotation process, and then introduced into the adsorption tower (height = 100 cm, inner diameter = 45 cm, flow rate = 7.05 ± 0.18 L/min) for phosphate removal via the composites (composite volume = 80 L, composite weight = 85.74 kg). During monitoring of the adsorption tower (33 days), the influent total phosphorus (T-P) concentration was in the range of 0.020-0.046 mgP/L, whereas the effluent T-P concentration was in the range of 0.010-0.028 mgP/L. The percent removal of T-P in the adsorption tower was 52.3% with a phosphate removal capacity of 0.059 mgP/g.

  6. Iron regulatory proteins control a mucosal block to intestinal iron absorption.

    PubMed

    Galy, Bruno; Ferring-Appel, Dunja; Becker, Christiane; Gretz, Norbert; Gröne, Hermann-Josef; Schümann, Klaus; Hentze, Matthias W

    2013-03-28

    Mammalian iron metabolism is regulated systemically by the hormone hepcidin and cellularly by iron regulatory proteins (IRPs) that orchestrate a posttranscriptional regulatory network. Through ligand-inducible genetic ablation of both IRPs in the gut epithelium of adult mice, we demonstrate that IRP deficiency impairs iron absorption and promotes mucosal iron retention via a ferritin-mediated "mucosal block." We show that IRP deficiency does not interfere with intestinal sensing of body iron loading and erythropoietic iron need, but rather alters the basal expression of the iron-absorption machinery. IRPs thus secure sufficient iron transport across absorptive enterocytes by restricting the ferritin "mucosal block" and define a basal set point for iron absorption upon which IRP-independent systemic regulatory inputs are overlaid.

  7. Modelling iron mismanagement in neurodegenerative disease in vitro: paradigms, pitfalls, possibilities & practical considerations.

    PubMed

    Healy, Sinead; McMahon, Jill M; FitzGerald, Una

    2017-09-25

    Although aberrant metabolism and deposition of iron has been associated with aging and neurodegeneration, the contribution of iron to neuropathology is unclear. Well-designed model systems that are suited to studying the putative pathological effect of iron are likely to be essential if such unresolved details are to be clarified. In this review, we have evaluated the utility and effectiveness of the reductionist in vitro platform to study the molecular mechanisms putatively underlying iron perturbations of neurodegenerative disease. The expression and function of iron metabolism proteins in glia and neurons and the extent to which this iron regulatory system is replicated in in vitro models has been comprehensively described, followed by an appraisal of the inherent suitability of different in vitro and ex vivo models that have been, or might be, used for iron loading. Next, we have identified and critiqued the relevant experimental parameters that have been used in in vitro iron loading experiments, including the choice of iron reagent, relevant iron loading concentrations and supplementation with serum or ascorbate, and propose optimal iron loading conditions. Finally, we have provided a synthesis of the differential iron accumulation and toxicity in glia and neurons from reported iron loading paradigms. In summary, this review has amalgamated the findings and paradigms of the published reports modelling iron loading in monocultures, discussed the limitations and discrepancies of such work to critically propose a robust, relevant and reliable model of iron loading to be used for future investigations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Hepcidin and iron disorders: new biology and clinical approaches.

    PubMed

    Arezes, J; Nemeth, E

    2015-05-01

    Hepatic hormone hepcidin is a principal regulator of iron homeostasis and a pathogenic factor in common iron disorders. Hepcidin deficiency causes iron overload in hereditary hemochromatosis and iron-loading anemias, whereas hepcidin excess causes or contributes to the development of iron-restricted anemia in inflammatory diseases, infections, some cancers, and chronic kidney disease. Because of this, hepcidin may become a useful tool for diagnosis and management of iron disorders. Furthermore, a number of strategies that target hepcidin, its receptor, and its regulators are under development as novel therapeutic approaches for diseases associated with iron dysregulation.

  9. Seed maturity differentially mediates metabolic responses in black soybean.

    PubMed

    Lee, Jinwook; Hwang, Young-Sun; Chang, Woo-Suk; Moon, Jung-Kyeong; Choung, Myoung-Gun

    2013-12-01

    The soybean seed is placed in the middle of the morphological and developmental alterations, such as changes in seed size, weight, and colour, and alteration of the composition and contents of metabolites during maturation. In this study, we used black soybean seeds to investigate the effect of maturity on metabolite levels at different maturity stages. Seeds were sorted into five maturity categories, from M1 to M5, based on seed size and external pigmentation. Maturity stages M1, M3, and M5 are equivalent to R6, R7, and R8 on the soybean reproductive growth stage scale, indicating full seed, beginning maturity, and full maturity, respectively. As seed maturation progressed, the seed size decreased and the water soluble extract changed, indicating that a change of seed pigmentation occurred. At the same time, numerous metabolites responded differentially to seed maturation. The partial least squares (PLS) scores plot indicated that the metabolic alteration during maturation was clearly visible. Furthermore, isoflavones were highly associated with seed maturity on the PLS loading plot while fatty acids, glucose, fructose, and sucrose were less linked with seed maturity, indicating that those metabolites responded less to seed maturation. Overall, the results indicate that each category of metabolites is mediated differentially during maturation in black soybean seeds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Seed Treatment. Manual 92.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

  11. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  12. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  13. Seed Treatment. Manual 92.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

  14. Distribution of ferric iron in larval lampreys, Petromyzon marinus L.

    PubMed

    Hall, S J; Youson, J H

    1988-01-01

    The distribution and abundance of ferric iron in larval lampreys (Petromyzon marinus L.) were investigated using light microscopy and the Prussian blue stain. Animals from various watersheds contained different concentrations of iron, although the sites of deposition were the same for all animals. A major portion of iron is within adipose tissue, while the liver, and cartilage contain predominantly low to trace amounts of iron, respectively. Iron is associated with fibrous connective tissue in several places in the body, and this association may have particular significance in the inner ear. Iron is also located in cells of the meninges. The presence of iron in the epithelial cells of the posterior intestine may reflect elimination of the metal through the extrusion of iron-loaded cells into the intestinal lumen. Iron within mucous cells of the epidermis, suggest elimination of iron during mucous secretion. Iron-loaded cells of bipolar shape are also present in the epidermis, but are particularly prominent around the branchiopore. Low concentrations of iron are observed within in melanin-containing macrophages (melano-macrophages) in regions of iron absorption, erythrophagocytosis, and haemopoiesis. High levels of iron in the epithelia and lumina of pronephric tubules are concomitant with degeneration of this organ. These data are evidence of the wide spread distribution of iron in lamprey tissues and additional evidence for the potential value of lampreys for the study of iron metabolism in vertebrates.

  15. A general strategy toward graphitized carbon coating on iron oxides as advanced anodes for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Ding, Chunyan; Zhou, Weiwei; Wang, Bin; Li, Xin; Wang, Dong; Zhang, Yong; Wen, Guangwu

    2017-08-01

    Integration of carbon materials with benign iron oxides is blazing a trail in constructing high-performance anodes for lithium-ion batteries (LIBs). In this paper, a unique general, simple, and controllable strategy is developed toward in situ uniform coating of iron oxide nanostructures with graphitized carbon (GrC) layers. The basic synthetic procedure only involves a simple dip-coating process for the loading of Ni-containing seeds and a subsequent Ni-catalyzed chemical vapor deposition (CVD) process for the growth of GrC layers. More importantly, the CVD treatment is conducted at a quite low temperature (450 °C) and with extremely facile liquid carbon sources consisting of ethylene glycol (EG) and ethanol (EA). The GrC content of the resulting hybrids can be controllably regulated by altering the amount of carbon sources. The electrochemical results reveal remarkable performance enhancements of iron oxide@GrC hybrids compared with pristine iron oxides in terms of high specific capacity, excellent rate and cycling performance. This can be attributed to the network-like GrC coating, which can improve not only the electronic conductivity but also the structural integrity of iron oxides. Moreover, the lithium storage performance of samples with different GrC contents is measured, manifesting that optimized electrochemical property can be achieved with appropriate carbon content. Additionally, the superiority of GrC coating is demonstrated by the advanced performance of iron oxide@GrC compared with its corresponding counterpart, i.e., iron oxides with amorphous carbon (AmC) coating. All these results indicate the as-proposed protocol of GrC coating may pave the way for iron oxides to be promising anodes for LIBs.

  16. A general strategy toward graphitized carbon coating on iron oxides as advanced anodes for lithium-ion batteries.

    PubMed

    Ding, Chunyan; Zhou, Weiwei; Wang, Bin; Li, Xin; Wang, Dong; Zhang, Yong; Wen, Guangwu

    2017-08-25

    Integration of carbon materials with benign iron oxides is blazing a trail in constructing high-performance anodes for lithium-ion batteries (LIBs). In this paper, a unique general, simple, and controllable strategy is developed toward in situ uniform coating of iron oxide nanostructures with graphitized carbon (GrC) layers. The basic synthetic procedure only involves a simple dip-coating process for the loading of Ni-containing seeds and a subsequent Ni-catalyzed chemical vapor deposition (CVD) process for the growth of GrC layers. More importantly, the CVD treatment is conducted at a quite low temperature (450 °C) and with extremely facile liquid carbon sources consisting of ethylene glycol (EG) and ethanol (EA). The GrC content of the resulting hybrids can be controllably regulated by altering the amount of carbon sources. The electrochemical results reveal remarkable performance enhancements of iron oxide@GrC hybrids compared with pristine iron oxides in terms of high specific capacity, excellent rate and cycling performance. This can be attributed to the network-like GrC coating, which can improve not only the electronic conductivity but also the structural integrity of iron oxides. Moreover, the lithium storage performance of samples with different GrC contents is measured, manifesting that optimized electrochemical property can be achieved with appropriate carbon content. Additionally, the superiority of GrC coating is demonstrated by the advanced performance of iron oxide@GrC compared with its corresponding counterpart, i.e., iron oxides with amorphous carbon (AmC) coating. All these results indicate the as-proposed protocol of GrC coating may pave the way for iron oxides to be promising anodes for LIBs.

  17. Physical and mechanical properties of hemp seed

    NASA Astrophysics Data System (ADS)

    Taheri-Garavand, A.; Nassiri, A.; Gharibzahedi, S.

    2012-04-01

    The current study was conducted to investigate the effect of moisture content on the post-harvest physical and mechanical properties of hemp seed in the range of 5.39 to 27.12% d.b. Results showed that the effect of moisture content on the most physical properties of the grain was significant (P<0.05). The results of mechanical tests demonstrated that the effect of loading rate on the mechanical properties of hemp seed was not significant. However, the moisture content effect on rupture force and energy was significant (P<0.01). The lowest value of rupture force was obtained at the highest loading rate (3mm min-1)and in the moisture content of 27.12% d.b. Moreover, the interaction effects of loading rate and moisture content on the rupture force and energy of hemp seed were significant (P<0.05).

  18. Evaluation of a load measurement system for cotton harvesters

    USDA-ARS?s Scientific Manuscript database

    The objective of this work is to develop and characterize the performance of a system used onboard a cotton harvester for obtaining seed cotton weight data. This system can be used to measure seed cotton weight on a load by load basis, thereby enhancing the ability for a producer to conduct on-farm ...

  19. Iron refractory iron deficiency anemia

    PubMed Central

    De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U.; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole

    2013-01-01

    Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in adulthood. The disease is refractory to oral iron treatment but shows a slow response to intravenous iron injections and partial correction of the anemia. To date, 40 different Matriptase-2 mutations have been reported, affecting all the functional domains of the large ectodomain of the protein. In vitro experiments on transfected cells suggest that Matriptase-2 cleaves Hemojuvelin, a major regulator of hepcidin expression and that this function is altered in this genetic form of anemia. In contrast to the low/undetectable hepcidin levels observed in acquired iron deficiency, in patients with Matriptase-2 deficiency, serum hepcidin is inappropriately high for the low iron status and accounts for the absent/delayed response to oral iron treatment. A challenge for the clinicians and pediatricians is the recognition of the disorder among iron deficiency and other microcytic anemias commonly found in pediatric patients. The current treatment of iron refractory iron deficiency anemia is based on parenteral iron administration; in the future, manipulation of the hepcidin pathway with the aim of suppressing it might become an alternative therapeutic approach. PMID:23729726

  20. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  1. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  2. Quercetin as a shuttle for labile iron.

    PubMed

    Baccan, Mayara Marinovic; Chiarelli-Neto, Orlando; Pereira, Regina Mara Silva; Espósito, Breno Pannia

    2012-02-01

    The antioxidant activity of flavonoids may involve their ability to complex body iron in non-redox-active forms. In this study, it was found that the catechol flavonoids rutin and quercetin are able to suppress redox-active labile plasma iron (LPI) in both buffered solution and in iron-overloaded sera. Both flavonoids are effective in loading the metal into the iron-transport protein transferrin. Iron derivatives of quercetin and rutin are able to permeate cell membranes, however, only free quercetin is able to gain access to the cytosol and decrease intracellular labile iron pools. These results suggest that the antioxidant activity of quercetin may be dependent on its ability to shuttle labile iron from cell compartments followed by its transfer to transferrin.

  3. Bean Seed Imbibition.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1998-01-01

    Enables students to examine the time course for seed imbibition and the pressure generated by imbibing seeds. Provides background information, detailed procedures, and ideas for further investigation. (DDR)

  4. Serum iron test

    MedlinePlus

    ... test if you have: Signs of low iron (iron deficiency) Signs of too much iron Anemia caused by ... Brittenham GM. Disorders of iron homeostasis: iron deficiency and ... Basic Principles and Practice . 6th ed. Philadelphia, PA: ...

  5. Mechanical damage to green and red lentil seeds.

    PubMed

    Shahbazi, Feizollah; Valizade, Saman; Dowlatshah, Ali

    2017-07-01

    In this research, the breakage susceptibility of two classes of lentil (green and red) was evaluated as affected by impact energy and seed moisture content. The experiments were conducted at impact energies of 0.1, 0.2 and 0.3 J, and moisture contents of 10, 12.5, 15, 17.5, 20 and 25% (wet basis). Results showed that red lentil seeds had more breakage than green seeds and the difference in breakage percentage between green and red lentil seeds was significant at 0.01% level according to analysis of variance (p < .01). Percentage breakage of both green and red lentil seeds increased as the energy of impact increased. With increasing the seed moisture content of the both green and red lentils, the breakage percentage of seeds decreased. The average values of seeds breakage green and red lentil seeds varied from 100 to 67.7% and from 100 to 93.1%, respectively, as the seeds moisture content increased from 10 to 25%. The optimum seed moisture at which minimum damage was observed was 17.5% for green lentil and 15% for red lentil. Mathematical relationships composed of lentil seeds moisture content and energy of impact were developed for accurate description of the breakage percentage of green and red lentil seeds under impact loading.

  6. Fate of blood meal iron in mosquitos

    PubMed Central

    Zhou, Guoli; Kohlhepp, Pete; Geiser, Dawn; Frasquillo, Maria del Carmen; Vazquez-Moreno, Luz; Winzerling, Joy J.

    2007-01-01

    Iron is an essential element of living cells and organisms as a component of numerous metabolic pathways. Hemoglobin and ferric-transferrin in vertebrate host blood are the two major iron sources for female mosquitoes. We used inductively coupled plasma mass spectrometry (ICP-MS) and radioisotope-labeling to quantify the fate of iron supplied from hemoglobin or as transferrin in Aedes aegypti. At the end of the first gonotrophic cycloe, ~87% of the ingested total meal heme iron was excreted, while 7% was distributed into the eggs and 6% was stored in different tissues. In contrast, ~8% of the iron provided as transferrin was excreted and of that absorbed, 77% was allocated to the eggs and 15% distributed in the tissues. Further analyses indicate that of the iron supplied in a blood meal, ~7% appears in the eggs and of this iron 98% is from hemoglobin and 2% from ferric-transferrin. Whereas of iron from a blood meal retained in body of the female, ~97% is from heme and <1 % is from transferrin. Evaluation of iron-binding proteins in hemolymph and egg following intake of 59Fe-transferrin revealed that ferritin is iron loaded in these animals, and indicate that this protein plays a critical role in meal iron transport and iron storage in eggs in A. aegypti. PMID:17689557

  7. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1978-01-01

    Attempts are made to provide a total design of a Microbial Load Monitor (MLM) system flight engineering model. Activities include assembly and testing of Sample Receiving and Card Loading Devices (SRCLDs), operator related software, and testing of biological samples in the MLM. Progress was made in assembling SRCLDs with minimal leaks and which operate reliably in the Sample Loading System. Seven operator commands are used to control various aspects of the MLM such as calibrating and reading the incubating reading head, setting the clock and reading time, and status of Card. Testing of the instrument, both in hardware and biologically, was performed. Hardware testing concentrated on SRCLDs. Biological testing covered 66 clinical and seeded samples. Tentative thresholds were set and media performance listed.

  8. Studies of cream seeded carioca beans (phaseolus vulgaris L.) from a Rwandan efficacy trial: in vitro and in vivo screening tools reflect human studies and predict beneficial results from iron biofortified beans

    USDA-ARS?s Scientific Manuscript database

    Iron (Fe) deficiency is a highly prevalent micronutrient insufficiency predominantly caused by a lack of bioavailable Fe from the diet. The consumption of beans as a major food crop in some populations suffering from Fe deficiency is relatively high. Therefore, our objective was to determine whether...

  9. Physiology and Pathophysiology of Iron in Hemoglobin-Associated Diseases

    PubMed Central

    Coates, Thomas D

    2016-01-01

    Iron overload and iron toxicity, whether because of increased absorption or iron loading from repeated transfusions, can be major causes of morbidity and mortality in a number of chronic anemias. Significant advances have been made in our understanding of iron homeostasis over the past decade. At the same time, advances in magnetic resonance imaging have allowed clinicians to monitor and quantify iron concentrations non-invasively in specific organs. Furthermore, effective iron chelators are now available, including preparations that can be taken orally. This has resulted in substantial improvement in mortality and morbidity for patients with severe chronic iron overload. This paper reviews the key points of iron homeostasis and attempts to place clinical observations in patients with transfusional iron overload in context with the current understanding of iron homeostasis in humans. PMID:24726864

  10. Organic iron (III) complexing ligands during an iron enrichment experiment in the western subarctic North Pacific

    NASA Astrophysics Data System (ADS)

    Kondo, Yoshiko; Takeda, Shigenobu; Nishioka, Jun; Obata, Hajime; Furuya, Ken; Johnson, William Keith; Wong, C. S.

    2008-06-01

    Complexation of iron (III) with natural organic ligands was investigated during a mesoscale iron enrichment experiment in the western subarctic North Pacific (SEEDS II). After the iron infusions, ligand concentrations increased rapidly with subsequent decreases. While the increases of ligands might have been partly influenced by amorphous iron colloids formation (12-29%), most in-situ increases were attributable to the <200 kDa fraction. Dilution of the fertilized patch may have contributed to the rapid decreases of the ligands. During the bloom decline, ligand concentration increased again, and the high concentrations persisted for 10 days. The conditional stability constant was not different between inside and outside of the fertilized patch. These results suggest that the chemical speciation of the released iron was strongly affected by formation of the ligands; the production of ligands observed during the bloom decline will strongly impact the iron cycle and bioavailability in the surface water.

  11. [SQUID-biosusceptometry in iron overloaded patients with hematologic diseases].

    PubMed

    Nielsen, P; Kordes, U; Fischer, R; Engelhardt, R; Janka, G E

    2002-01-01

    For the long-term survival of iron-loaded patients, early and well adjusted treatment with iron chelators is of crucial importance, especially in children. Basis of the adequate treatment are appropriate diagnostic parameters which are capable to monitor the range of the individual iron burden. In the time period between 1989 and 2001, the status of iron loading was investigated in 1112 patients with post transfusion siderosis. The iron concentration in liver and spleen was quantified by SQUID-biosusceptometry. Using these values, the whole body iron stores were calculated. Based on a large number of patients with secondary siderosis, the benefit of SQUID-biosusceptometry for non-invasive liver iron quantification was evaluated retrospectively. In patients under treatment with deferoxamin, a new therapeutic DFO-index was defined which respects liver iron concentration instead of serum ferritin. This results in a more reliable information about DFO overdosing in a given patient.

  12. Dynamic control of hepatic Plasmodium numbers by hepcidin despite elevated liver iron during iron supplementation.

    PubMed

    Ferrer, Patricia; Castillo-Neyra, Ricardo; Roy, Cindy N; Sullivan, David J

    2016-01-01

    Treatment of iron deficiency anemia in malaria endemic areas is complicated as iron supplementation increases malaria risk while malaria decreases iron absorption. Here we measured the influence of hepcidin expression and non-heme iron during iron supplementation on hepatic Plasmodium berghei numbers in anemic and non-anemic mice. Despite elevated hepatic non-heme iron on the high iron diet, elevated hepcidin expression is associated with less parasite bioavailable iron and lower hepatic parasite loads in anemic, iron deficient mice after both two and six weeks of supplementation. A marginal trend to lower parasite hepatic numbers was seen in non-anemic, iron replete mice. In a transgenic model of severe anemia, mice with a deletion in Sec15l1, which reportedly have normal liver iron and normal hepcidin expression, there were no changes in liver parasite numbers or blood stage numbers or outcome in the lethal Plasmodium yoelii model. In summary during iron supplementation the lower hepatic malaria numbers are regulated more by hepcidin than the absolute level of non-heme hepatic iron.

  13. Dynamic control of hepatic Plasmodium numbers by hepcidin despite elevated liver iron during iron supplementation

    PubMed Central

    Ferrer, Patricia; Castillo-Neyra, Ricardo; Roy, Cindy N.; Sullivan, David J.

    2015-01-01

    Treatment of iron deficiency anemia in malaria endemic areas is complicated as iron supplementation increases malaria risk while malaria decreases iron absorption. Here we measured the influence of hepcidin expression and nonheme iron during iron supplementation on hepatic Plasmodium berghei numbers in anemic and nonanemic mice. Despite elevated hepatic nonheme iron on the high iron diet, elevated hepcidin expression is associated with less parasite bioavailable iron and lower hepatic parasite loads in anemic, iron deficient mice after both two and six weeks of supplementation. A marginal trend to lower parasite hepatic numbers was seen in nonanemic, iron replete mice. In a transgenic model of severe anemia, mice with a deletion in Sec15l1, which reportedly have normal liver iron and normal hepcidin expression, there were no changes in liver parasite numbers or bloodstage numbers or outcome in the lethal P. yoelii model. In summary during iron supplementation the lower hepatic malaria numbers are regulated more by hepcidin than the absolute level of nonheme hepatic iron. PMID:26384816

  14. [The role of iron as a deficient element].

    PubMed

    Schümann, K

    1989-12-01

    Iron is an essential trace element. In its heme-form as well as in its non heme-form it is a part of enzymes and hemoproteins. For a safe and adequate dietary intake 10-18 mg of iron are recommended daily. Frequently, this quantity is not available: approximately 20% of the world population is iron-deficient. In this state the enteral transfer capacity for toxic metals, e.g., Cd and Pb, is increased and the adaptation to physical strain as well as the immunological responses are depressed. Alterations of body iron-stores are almost exclusively balanced by adequate adaptation of the enteral iron-transfer capacity. The mechanism of this adaptation process can neither be satisfactorily explained by the "mucosal block hypothesis", nor by the "mucosal transferrin hypothesis". When the time-course of iron storage and its relation to intestinal iron transfer was investigated after i.v. iron administration to iron-deficient rats, the results indicated that the process of adaptation is located in the intestinal mucosa. Intestinal iron loading is decreased in iron deficiency, whereas the iron transfer into the organism is increased. Further investigation is necessary to find out by which mechanism the iron manages to bypass existing mucosal storage capacity in this situation. The geographical distribution of iron deficiency is influenced by a variety of local factors. Still, the paramount causes of iron-deficiency are unbalanced iron losses and the lack of bioavailable iron in the diet. The bioavailability of non heme iron is influenced by the composition of the diet. The effect of promotors of iron absorption, such as meat, amino acids, polycarbonic acids and ascorbate is opposed by the influence of inhibitors, such as bran, soya products, vegetables and egg-dishes. Iron losses are mainly due to blood losses. Thus, the wide distribution of hookworm diseases in tropical areas contributes significantly to the endemic iron-deficiency in these regions. A more physiological loss

  15. Iron-biofortification in rice by the introduction of three barley genes participated in mugineic acid biosynthesis with soybean ferritin gene.

    PubMed

    Masuda, Hiroshi; Kobayashi, Takanori; Ishimaru, Yasuhiro; Takahashi, Michiko; Aung, May S; Nakanishi, Hiromi; Mori, Satoshi; Nishizawa, Naoko K

    2013-01-01

    Iron deficiency is a serious problem around the world, especially in developing countries. The production of iron-biofortified rice will help ameliorate this problem. Previously, expression of the iron storage protein, ferritin, in rice using an endosperm-specific promoter resulted in a two-fold increase in iron concentration in the resultant transgenic seeds. However, further over expression of ferritin did not produce an additional increase in the seed iron concentration, and symptoms of iron deficiency were noted in the leaves of the transgenic plants. In the present study, we aimed to further increase the iron concentration in rice seeds without increasing the sensitivity to iron deficiency by enhancing the uptake and transport of iron via a ferric iron chelator, mugineic acid. To this end, we introduced the soybean ferritin gene (SoyferH2) driven by two endosperm-specific promoters, along with the barley nicotianamine synthase gene (HvNAS1), two nicotianamine aminotransferase genes (HvNAAT-A and -B), and a mugineic acid synthase gene (IDS3) to enhance mugineic acid production in rice plants. A marker-free vector was utilized as a means of increasing public acceptance. Representative lines were selected from 102 transformants based on the iron concentration in polished seeds and ferritin accumulation in the seeds. These lines were grown in both commercially supplied soil (iron-sufficient conditions) and calcareous soil (iron-deficient conditions). Lines expressing both ferritin and mugineic acid biosynthetic genes showed signs of iron-deficiency tolerance in calcareous soil. The iron concentration in polished T3 seeds was increased by 4 and 2.5 times, as compared to that in non-transgenic lines grown in normal and calcareous soil, respectively. These results indicate that the concomitant introduction of the ferritin gene and mugineic acid biosynthetic genes effectively increased the seed iron level without causing iron sensitivity under iron-limited conditions.

  16. METABOLISM OF IRON STORES

    PubMed Central

    SAITO, HIROSHI

    2014-01-01

    ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since the pioneering research by Shoden in 1953. However, we recently developed a new method for determining ferritin iron and hemosiderin iron by computer-assisted serum ferritin kinetics. Serum ferritin increase or decrease curves were measured in patients with normal storage iron levels (chronic hepatitis C and iron deficiency anemia treated by intravenous iron injection), and iron overload (hereditary hemochromatosis and transfusion dependent anemia). We thereby confirmed the existence of two iron pathways where iron flows followed the numbered order (1) labile iron, (2) ferritin and (3) hemosiderin in iron deposition and mobilization among many previously proposed but mostly unproven routes. We also demonstrated the increasing and decreasing phases of ferritin iron and hemosiderin iron in iron deposition and mobilization. The author first demonstrated here the change in proportion between pre-existing ferritin iron and new ferritin iron synthesized by removing iron from hemosiderin in the course of iron removal. In addition, the author disclosed the cause of underestimation of storage iron turnover rate which had been reported by previous investigators in estimating storage iron turnover rate of normal subjects. PMID:25741033

  17. The tribological chemistry of the triazine derivative additives in rape seed oil and synthetic diester

    NASA Astrophysics Data System (ADS)

    Qiao, Rui; Li, Jing; Wu, Hua; Ren, Tianhui; Zhao, Yidong; Ma, Chenyan

    2011-02-01

    The additives, laurylamino-methylthio-1,3,5-triazine-2,4-dithiol (referred to as TRLA) and diisooctylamino-methylthio-1,3,5-triazine-2,4-dithiol (referred to as TREA), were prepared in our laboratory. The products were characterized by means of infrared spectroscopy (IR) and elemental analysis. Their tribological behaviors as additives in raped seed oil and diester were evaluated using four-ball friction and wear testers as well. The results suggest that all the synthesized compounds have excellent tribological behaviors and they were compared with sulfurized isobutene (referred to as SIB) which is a commercial additive. The results show that they have good tribological properties. The two additives were investigated on thermal films and tribofilms by using X-ray absorption near edge structure (XANES) spectroscopy. The results of surface analysis reveal that the thermal films formed from TREA and TRLA in rape seed oil (referred to as RSO) and diester (referred to as DE), all are consist of iron sulfate; under mild AW conditions, the tribofilms from TRLA and TREA in DE is mainly composed of FeS, while the tribochemcal film from TRLA in RSO is mainly composed of iron sulfite; under EP-1 (the maximum non-seizure load) conditions, the tribochemical films from TRLA and TREA in RSO and DE mainly consist of FeS and FeSO4; under EP-2 (nearly weld load) conditions, the tribochemical films from TRLA and TREA in RSO and DE mainly consist of FeS.

  18. Hepatic macrophage iron aggravates experimental alcoholic steatohepatitis

    PubMed Central

    Xiong, Shigang; She, Hongyun; Zhang, An-Sheng; Wang, Jiaohong; Mkrtchyan, Hasmik; Dynnyk, Alla; Gordeuk, Victor R.; French, Samuel W.; Enns, Caroline A.; Tsukamoto, Hidekazu

    2008-01-01

    One prime feature of alcoholic liver disease (ALD) is iron accumulation in hepatic macrophages/Kupffer cells (KC) associated with enhanced NF-κB activation. Our recent work demonstrates a peroxynitrite-mediated transient rise in intracellular labile iron (ILI) as novel signaling for endotoxin-induced IKK and NF-κB activation in rodent KC. The present study investigated the mechanism of KC iron accumulation and its effects on ILI response in experimental ALD. We also tested ILI response in human blood monocytes. Chronic alcohol feeding in rats results in increased expression of transferrin (Tf) receptor-1 and hemochromatosis gene (HFE), enhanced iron uptake, an increase in nonheme iron content, and accentuated ILI response for NF-κB activation in KC. Ex vivo treatment of these KC with an iron chelator abrogates the increment of iron content, ILI response, and NF-κB activation. The ILI response is evident in macrophages derived from human blood monocytes by PMA treatment but not in vehicle-treated monocytes, and this differentiation-associated phenomenon is essential for maximal TNF-α release. PMA-induced macrophages load iron dextran and enhance ILI response and TNF-α release. These effects are reproduced in KC selectively loaded in vivo with iron dextran in mice and more importantly aggravate experimental ALD. Our results suggest enhanced iron uptake as a mechanism of KC iron loading in ALD and demonstrate the ILI response as a function acquired by differentiated macrophages in humans and as a priming mechanism for ALD. PMID:18599584

  19. Tree Seed Technology Training Course

    Treesearch

    F.T. Bonner; James A. Vozzo; W.W. Elam; S.B. Land

    1994-01-01

    This manual is intended primarily to train seed collectors, seed-plant managers, seed analysts, and nursery managers, but it can serve as a resource for any training course in forest regeneration. It includes both temperate and tropical tree species of all intended uses. The manual covers the following topics: seed biology, seed collection, seed handling, seed-quality...

  20. Chemical composition and nutritive value of lantana and sweet pepper seeds and nabak seed kernels.

    PubMed

    Embaby, Hassan El-Sayed; Mokhtar, Sayed Mohamed

    2011-01-01

    Chemical analysis was carried out on lantana (Lantana camara) and sweet pepper (Capsicum annuum L.) seeds and nabak (Zizyphus spina-christi) seed kernels. The proximate analysis (on dry weight basis) of sweet pepper seeds, lantana seeds, and nabak seed kernels showed the following composition: moisture 70.95%, 17.27%, and 4.22%; ash 4.88%, 1.81%, and 3.51%; fat 19.57%, 11.0%, and 30.19%; crude protein 19.28%, 6.3%, and 38.2%; and carbohydrate 56.3%, 80.9%, and 28.1%, respectively. For minerals, potassium was the most abundant element, followed by phosphorus and sodium. Also, zinc, iron, copper, and manganese were detected. Analysis of amino acids revealed that the first limiting amino acid was valine, for both lantana and sweet pepper seeds, but it was threonine for nabak seed kernels. Antinutritional compounds, including, phytic acid, trypsin inhibitor, and tannins, were detected in all seeds. Results of fatty acid compositions showed that the major fatty acid was oleic acid in both lantana (48.73%) and nabak oils (53.25%), but it was linoleic acid in sweet pepper oil (71.55%). Moreover, the degree of unsaturation of these oils was close to that of common vegetable oils. In all oils, there was absorbance in the ultraviolet (UV)-B and UV-C ranges with potential for use as broad spectrum UV protectants. It can be inferred that the seeds investigated are good sources of crude fat, crude protein, ash, carbohydrate, and some minerals. Furthermore, the oil extracts could be useful as edible oils and for industrial applications. The nutritional composition of the investigated seeds suggested that they could be used to meet part of the nutritional requirements of animal feeds. Also, they could be regarded as good sources of food ingredients and as new sources of edible oils. © 2011 Institute of Food Technologists®

  1. Iron-oxo clusters biomineralizing on protein surfaces: Structural analysis of Halobacterium salinarum DpsA in its low- and high-iron states

    PubMed Central

    Zeth, Kornelius; Offermann, Stefanie; Essen, Lars-Oliver; Oesterhelt, Dieter

    2004-01-01

    The crystal structure of the Dps-like (Dps, DNA-protecting protein during starvation) ferritin protein DpsA from the halophile Halobacterium salinarum was determined with low endogenous iron content at 1.6-Å resolution. The mechanism of iron uptake and storage was analyzed in this noncanonical ferritin by three high-resolution structures at successively increasing iron contents. In the high-iron state of the DpsA protein, up to 110 iron atoms were localized in the dodecameric protein complex. For ultimate iron storage, the archaeal ferritin shell comprises iron-binding sites for iron translocation, oxidation, and nucleation. Initial iron–protein interactions occur through acidic residues exposed along the outer surface in proximity to the iron entry pore. This narrow pore permits translocation of ions toward the ferroxidase centers via two discrete steps. Iron oxidation proceeds by transient formation of tri-iron ferroxidase centers. Iron storage by biomineralization inside the ferritin shell occurs at two iron nucleation centers. Here, a single iron atom provides a structural seed for iron-oxide cluster formation. The clusters with up to five iron atoms adopt a geometry that is different from natural biominerals like magnetite but resembles iron clusters so far known only from bioinorganic model compounds. PMID:15365182

  2. Morphologic investigations of the guinea pig model of iron overload.

    PubMed

    Schwartz, K A; Fisher, J; Adams, E T

    1993-01-01

    We have developed a guinea pig model of iron overload toxicity. Animals were administered intraperitoneal iron dextran 3 times a week to achieve total body iron load of 0.25, 0.5, 1.0, 1.5, and 2.0 g Fe/kg body weight in less than 30 days. Quantitation of tissue iron levels with atomic absorption indicated increased iron deposition in liver and heart of the iron-loaded guinea pigs (p < 0.001). Additionally, the iron-loaded pigs demonstrated decreased nuclear magnetic resonance spectroscopy T1 relaxation times in both liver and heart (p < 0.001). Serum iron, total body iron capacity, and transferrin saturation values were also determined in guinea pigs treated with 0.25, 0.5, and 1.0 g Fe/kg body weight. Serum iron and total iron-binding capacity were significantly increased at 0.5 and 1.0 g Fe/kg; transferrin saturation was elevated at 0.25 and 1.0 g Fe/kg. kg. Histologic examination of liver, heart, and bone marrow as well as ultrastructural studies on liver and heart confirmed increased iron deposition in treated animals. At the low iron dose level of 0.5 g Fe/kg, liver iron particles were primarily confined to Kupffer cells with minimal hepatocellular localization. Increased hepatocellular iron deposition was observed with larger doses of loaded iron. Myocardial iron was most prominent in interstitial cells of the epicardium, endocardium, myocardium, and coronary adipose tissue. Ultrastructurally, the presence of iron particles in perinuclear, membrane-bound structures (consistent with lysosomes) was confirmed using x-ray microanalysis. These morphological studies suggest that in this animal model siderosis of hepatic mononuclear phagocyte and myocardial interstitial cells may be the initial lesions leading to further biochemical and functional abnormalities. Correlation between tissue iron measurements and both light and electron microscopic changes, presented in this report, serve to introduce the iron-loaded guinea pig as a model for the study of iron

  3. Biomonitorization of iron accumulation in the substantia nigra from Lewy body disease patients

    PubMed Central

    Fernández, Belén; Ferrer, Isidro; Gil, Fernando; Hilfiker, Sabine

    2017-01-01

    Iron levels in the healthy human brain are known to be high in certain areas such as the substantia nigra (SN), and increase further with age. In addition, there is some evidence for a further increase in iron load in the SN of Parkinson's disease (PD) patients as compared to controls, which correlates with motor disability. Here, we have analyzed total iron levels in cells as well as mouse and human brain samples by atomic absorption spectroscopy (AAS). Our data indicate that iron load is more pronounced in cells with dopaminergic features. Moreover, region-specific differences in iron load reflecting those in the human brain were detected in rodent brains as well. Whilst altered iron load was not observed in other regions also affected in PD patients, we report a significant increase in iron load in the SN of Lewy body disease patients as compared to Alzheimer's disease (AD) patients or controls, which correlates with neurodegeneration in this brain area. PMID:28529891

  4. Total iron binding capacity

    MedlinePlus

    ... iron supplies are low. This can occur with: Iron deficiency anemia Pregnancy (late) Lower-than-normal TIBC may ... Brittenham GM. Disorders of iron homeostasis: iron deficiency and ... Basic Principles and Practice . 6th ed. Philadelphia, PA: ...

  5. Monocyte transferrin-iron uptake in hereditary hemochromatosis

    SciTech Connect

    Sizemore, D.J.; Bassett, M.L.

    1984-05-01

    Transferrin-iron uptake by peripheral blood monocytes was studied in vitro to test the hypothesis that the relative paucity of mononuclear phagocyte iron loading in hereditary hemochromatosis results from a defect in uptake of iron from transferrin. Monocytes from nine control subjects and 17 patients with hemochromatosis were cultured in the presence of 59Fe-labelled human transferrin. There was no difference in 59Fe uptake between monocytes from control subjects and monocytes from patients with hemochromatosis who had been treated by phlebotomy and who had normal body iron stores. However, 59Fe uptake by monocytes from iron-loaded patients with hemochromatosis was significantly reduced compared with either control subjects or treated hemochromatosis patients. It is likely that this was a secondary effect of iron loading since iron uptake by monocytes from treated hemochromatosis patients was normal. Assuming that monocytes in culture reflect mononuclear phagocyte iron metabolism in vivo, this study suggests that the relative paucity of mononuclear phagocyte iron loading in hemochromatosis is not related to an abnormality in transferrin-iron uptake by these cells.

  6. Iron and alloys of iron. [lunar resources

    NASA Technical Reports Server (NTRS)

    Sastri, Sankar

    1992-01-01

    All lunar soil contains iron in the metallic form, mostly as an iron-nickel alloy in concentrations of a few tenths of 1 percent. Some of this free iron can be easily separated by magnetic means. It is estimated that the magnetic separation of 100,000 tons of lunar soil would yield 150-200 tons of iron. Agglutinates contain metallic iron which could be extracted by melting and made into powder metallurgy products. The characteristics and potential uses of the pure-iron and iron-alloy lunar products are discussed. Processes for working iron that might be used in a nonterrestrial facility are also addressed.

  7. Efficiency of seed production in southern pine seed orchards

    Treesearch

    David L. Bramlett

    1977-01-01

    Seed production in southern pine seed orchards can be evaluated by estimating the efficiency of four separate stages of cone, seed, and seedling development. Calculated values are: cone efficiency (CE), the ratio of mature cones to the initial flower crop; seed efficiency (SE), the ratio of filled seeds per cone to the seed potential; extraction efficiency (EE), the...

  8. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds (crop...

  9. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds (crop...

  10. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds (crop...

  11. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds (crop...

  12. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds (crop...

  13. Seed Treatment. Sale Publication 4076.

    ERIC Educational Resources Information Center

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide gives information about types of seeds that may require chemical protection against pests, seed treatment pesticide formulations, seed treatment methods, labeling treated seed, and safety and environmental precautions. (Author/BB)

  14. What Are Chia Seeds?

    MedlinePlus

    ... The seeds of a related plant, Salvia columbariae (golden chia), were used primarily by Native Americans in ... Sprinkle ground or whole chia seeds on cereal, rice, yogurt or vegetables. In Mexico, a dish called ...

  15. Diagnosis and management of transfusion iron overload: The role of imaging

    PubMed Central

    Wood, John C.

    2010-01-01

    The characterization of iron stores is important to prevent and treat iron overload. Serum markers such as ferritin, serum iron, iron binding capacity, transferrin saturation, and nontransferrin-bound iron can be used to follow trends in iron status; however, variability in these markers limits predictive power for any given individual. Liver iron represents the best single marker of total iron balance. Measures of liver iron include biopsy, superconducting quantum interference device, computer tomography, and magnetic resonance imaging (MRI). MRI is the most accurate and widely available noninvasive tool to assess liver iron. The main advantages of MRI include a low-rate of variability between measurements and the ability to assess iron loading in endocrine tissues, the heart and the liver. This manuscript describes the principles, validation, and clinical utility of MRI for tissue iron estimation. PMID:17963249

  16. Genetics Home Reference: iron-refractory iron deficiency anemia

    MedlinePlus

    ... Conditions iron-refractory iron deficiency anemia iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable ... view the expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , ...

  17. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  18. Modulation of iron metabolism by iron chelation regulates intracellular calcium and increases sensitivity to doxorubicin

    PubMed Central

    Yalcintepe, Leman; Halis, Emre

    2016-01-01

    Increased intracellular iron levels can both promote cell proliferation and death, as such; iron has a “two-sided effect” in the delicate balance of human health. Though the role of iron in the development of cancer remains unclear, investigations of iron chelators as anti-tumor agents have revealed promising results. Here, we investigated the influence of iron and desferrioxamine (DFO), the iron chelating agent on intracellular calcium in a human leukemia cell line, K562. Iron uptake is associated with increased reactive oxygen species (ROS) generation. Therefore, we showed that iron also caused dose-dependent ROS generation in K562 cells. The measurement of intracellular calcium was determined using Furo-2 with a fluorescence spectrophotometer. The iron delivery process to the cytoplasmic iron pool was examined by monitoring the fluorescence of cells loaded with calcein-acetoxymethyl. Our data showed that iron increased intracellular calcium, and this response was 8 times higher when cells were incubated with DFO. K562 cells with DFO caused a 3.5 times increase of intracellular calcium in the presence of doxorubicin (DOX). In conclusion, DFO induces intracellular calcium and increases their sensitivity to DOX, a chemotherapeutic agent. PMID:26773173

  19. Iron Treatment Strategies in Dialysis-Dependent CKD.

    PubMed

    Pandey, Richa; Daloul, Reem; Coyne, Daniel W

    2016-03-01

    Iron deficiency is common in patients on chronic dialysis, and most require iron-replacement therapy. In addition to absolute iron deficiency, many patients have functional iron deficiency as shown by a suboptimal response to the use of erythropoietin-stimulating agents. Both absolute and functional iron-deficiency anemia have been shown to respond to intravenous (IV) iron replacement. Although parenteral iron is an efficacious method and superior to standard doses of oral iron in patients on hemodialysis, there are ongoing safety concerns about repeated exposure potentially enhancing infection risk and cardiovascular disease. Each IV iron product is composed of an iron core with a carbohydrate shell. The avidity of iron binding and the type of carbohydrate shell play roles in the safe maximal dose and the frequency and severity of acute infusion reactions. All IV iron products are taken up into the reticuloendothelial system where the shell is metabolized and the iron is stored within tissue ferritin or exported to circulating transferrin. IV iron can be given as large intermittent doses (loading therapy) or in smaller doses at frequent intervals (maintenance dosing regimen). Limited trial data and observational data suggest that a maintenance dosing regimen is more efficacious and possibly safer than loading therapy. There is no consensus regarding the preferred method of iron repletion in patients on peritoneal dialysis, although small studies comparing oral and parenteral iron regimens in these patients have shown the latter to be more efficacious. Use of IV iron in virtually all hemodialysis and many peritoneal dialysis patients remains the standard of care.

  20. Genetic diversity and association mapping of iron and zinc concentrations in chickpea (Cicer arietinum L.).

    PubMed

    Diapari, Marwan; Sindhu, Anoop; Bett, Kirstin; Deokar, Amit; Warkentin, Thomas D; Tar'an, Bunyamin

    2014-08-01

    Chickpea (Cicer arietinum L.) is the world's second most important pulse crop after common bean. Chickpea has historically been an important daily staple in the diet of millions of people, especially in the developing countries. Current chickpea breeding programs have mainly been directed toward high yield, biotic and abiotic stress resilience that has increased global production, but less attention has been directed toward improving micronutrient concentrations in seeds. In an effort to develop micronutrient-dense chickpea lines, a study to examine the variability and to identify SNP alleles associated with seed iron and zinc concentrations was conducted using 94 diverse accessions of chickpea. The results indicated that there is substantial variability present in chickpea germplasm for seed iron and zinc concentrations. In the current set of germplasm, zinc is negatively correlated with grain yield across all locations and years; whereas the negative correlation between iron and grain yield was only significant at the Elrose locality. Eight SNP loci associated with iron and (or) zinc concentrations in chickpea seeds were identified. One SNP located on chromosome 1 (chr1) is associated with both iron and zinc concentrations. On chr4, three SNPs associated with zinc concentration and two SNPs for iron concentration were identified. Two additional SNP loci, one on chr6 and the other on chr7, were also found to be associated with iron and zinc concentrations, respectively. The results show potential opportunity for molecular breeding for improvement of seed iron and zinc concentrations in chickpea.

  1. Seed Development and Germination

    USDA-ARS?s Scientific Manuscript database

    Seed is the fertilized and matured ovule of angiosperms and gymnosperms and represents a crucial stage in the life cycle of plants. Seeds of diverse plant species may display differences in size, shape and color. Despite apparent morphological variations, most mature seeds consist of three major com...

  2. Needs of Seeds

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether students overgeneralize the needs of seeds by assuming they have the same needs as the adult plants…

  3. Pasture seed banks

    USDA-ARS?s Scientific Manuscript database

    In our surveys of northeastern pastures, we found the equivalent of more than 8 million seeds per acre in the surface soil (the top four inches) from the seed bank study. These seeds came from 58 species of plants. The annual forbs (all broadleaf plants with the exception of legumes and trees) domin...

  4. Preservation of recalcitrant seeds

    USDA-ARS?s Scientific Manuscript database

    Recalcitrant and intermediate seeds are not included in seed banks because of misperceptions that these efforts would be futile. Between 20 and 25% of the Earth’s angiosperm species are estimated to produce recalcitrant or intermediate seeds. These species are more prevalent in the tropics and sub...

  5. Going to Seed.

    ERIC Educational Resources Information Center

    Powell, Richard R.

    1984-01-01

    Describes a unit on seeds designed to introduce students to their scientific and nutritional uses. Unit activities are easily done, employ a variety of process skills, and can be used at various grade levels. Suggests field trips to gather seeds, seed sprouting, and making cookies out of various whole grains. (JM)

  6. Seed Proteomics"

    USDA-ARS?s Scientific Manuscript database

    Proteomic analysis of seeds encounters some specific problems that do not impinge on analyses of other plant cells, tissues, or organs. There are anatomic considerations. Seeds comprise the seed coat, the storage organ(s), and the embryonic axis. Are these to be studied individually or as a compo...

  7. Needs of Seeds

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether students overgeneralize the needs of seeds by assuming they have the same needs as the adult plants…

  8. H₂S abatement in a biotrickling filter using iron(III) foam media.

    PubMed

    Goncalves, Juan J; Govind, Rakesh

    2008-11-01

    Airstreams polluted with H(2)S at inlet loads ranging from 2.4 to 40.9 g H(2)Sm(-3)h(-1) were treated in a biotrickling reactor packed with hematite bearing, open pore foam units, at Empty Bed Residence Times (EBRT) ranging from 20 to 60s over a period of 80 d, with almost complete removal of the pollutant from the startup of the system. The media had been seeded with sludge from a local water works facility, and removal efficiencies in excess of 80% were consistently observed along the operation of the reactor, with an average of 98%. Based on section performance, being a section one third of the bed length, observed elimination capacities (EC) reached up to 88.7 g H(2)Sm(-3)h(-)(1) and 72.0 g H(2)Sm(-3)h(-1) at section EBRT of 10 and 7s, respectively. The observed EC values compared much better than data reported on other packed bed reactors using biological iron oxidization to treat H(2)S airstreams indirectly, and so did it when comparing the EC per unit of specific area in a similar study using polyurethane (PU) foams. Further, and unlike PU packed biofilters, no compaction occurred due to the iron foam rigidity, which translated in much better observed gas phase pressure drop as opposed to other conventional biofilters. Denaturing gel gradient electrophoresis was performed on the biomass collected in the packing after the biofilter service, and it was found that though a multi bacterial colony was seeded in the system via the sludge, the only surviving genus was the iron oxidizing Alicyclobacillus spp.

  9. Calcium, Iron, and Zinc Bioaccessibilities of Australian Sweet Lupin (Lupinus angustifolius L.) Cultivars.

    PubMed

    Karnpanit, Weeraya; Coorey, Ranil; Clements, Jon; Benjapong, Wenika; Jayasena, Vijay

    2017-06-14

    In this study, we aimed to determine the effect of the cultivar and dehulling on calcium, iron, and zinc bioaccessibilities of Australian sweet lupin (ASL). Ten ASL cultivars grown in 2011, 2012, and 2013 in Western Australia were used for the study. The bioaccessibilities of calcium, iron, and zinc in whole seed and dehulled lupin samples were determined using a dialysability method. The cultivar had significant effects on calcium, iron, and zinc contents and their bioaccessibilities. Average bioaccessibilities of 6% for calcium, 17% for iron, and 9% for zinc were found for whole seeds. Dehulled ASL had average calcium, iron, and zinc bioaccessibilities of 11%, 21%, and 12%, respectively. Compared to some other pulses, ASL had better iron bioaccessibility and poorer calcium and zinc bioaccessibilities. Dehulling increased calcium bioaccessibilities of almost all lupin cultivars. The effect of dehulling on iron and zinc bioaccessibilities depends on the ASL cultivar.

  10. Cryopreservation of Bletilla striata mature seeds, 3-day germinating seeds and protocorms by droplet-vitrification.

    PubMed

    Jitsopakul, N; Thammasiri, K; Ishikawa, K

    2008-01-01

    Droplet-vitrification was studied for the cryopreservation of Bletilla striata mature seeds (0 day after sowing), 3-day germinating seeds and protocorms (6, 9 and 12 days after sowing). Mature seeds, 3-day germinating seeds and 6-day old protocorms were precultured in liquid medium supplemented with 0.3 M sucrose for 3 h on a shaker (110 rpm) and then dehydrated with 2 M glycerol and 0.4 M sucrose in liquid medium (loading solution) for 15 min and exposed to PVS2 solution for 60 min at 25 degree C. The plant materials were then immersed in liquid nitrogen, rewarmed rapidly and cultured on solidified ND medium supplemented with 3% sucrose for recovery. After cryopreservation, the highest germination percentage of mature seeds, 3-day germinating seeds and survival of cryopreserved 6-day old protocorms was 93%, 91% and 84%, respectively. For 9-day old protocorms, highest survival (66%) after cryopreservation was achieved after preculture with 0.5 M sucrose for 3 h on a shaker, dehydration with loading solution for 15 min, exposure to PVS2 solution for 40 min at 25 degree C, and culture on solidified ND medium supplemented with 480 mg per liter ammonium nitrate and 3% sucrose. No survival was observed in cryopreserved 12-day old protocorms.

  11. DISTANT VIEW, BLM TACK SHED ON LEFT, BLM SEED SHED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DISTANT VIEW, BLM TACK SHED ON LEFT, BLM SEED SHED AT LEFT CENTER, FIRE DISPATCH OFFICES 1 AND 2 AT RIGHT CENTER, UTILITY BUILDING "B" ON RIGHT. VIEW TO SOUTHWEST. - Cedar City Automotive Repair Shop, 820 North Main Street, Cedar City, Iron County, UT

  12. INFLUENCE OF IRON CHELATION ON R1 AND R2 CALIBRATION CURVES IN GERBIL LIVER AND HEART

    PubMed Central

    Wood, John C.; Aguilar, Michelle; Otto-Duessel, Maya; Nick, Hanspeter; Nelson, Marvin D.; Moats, Rex

    2008-01-01

    MRI is gaining increasing importance for the noninvasive quantification of organ iron burden. Since transverse relaxation rates depend on iron distribution as well as iron concentration, physiologic and pharmacologic processes that alter iron distribution could change MRI calibration curves. This paper compares the effect of three iron chelators, deferoxamine, deferiprone, and deferasirox on R1 and R2 calibration curves according to two iron loading and chelation strategies. 33 Mongolian gerbils underwent iron loading (iron dextran 500 mg/kg/wk) for 3 weeks followed by 4 weeks of chelation. An additional 56 animals received less aggressive loading (200 mg/kg/week) for 10 weeks, followed by 12 weeks of chelation. R1 and R2 calibration curves were compared to results from 23 iron-loaded animals that had not received chelation. Acute iron loading and chelation biased R1 and R2 from the unchelated reference calibration curves but chelator-specific changes were not observed, suggesting physiologic rather than pharmacologic differences in iron distribution. Long term chelation deferiprone treatment increased liver R1 50% (p<0.01), while long term deferasirox lowered liver R2 30.9% (p<0.0001). The relationship between R1 and R2 and organ iron concentration may depend upon the acuity of iron loading and unloading as well as the iron chelator administered. PMID:18581418

  13. Seed Dispersal Anachronisms: Rethinking the Fruits Extinct Megafauna Ate

    PubMed Central

    Guimarães, Paulo R.; Galetti, Mauro; Jordano, Pedro

    2008-01-01

    Background Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals >103 kg), yet these dispersers were extinct in South America 10–15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. Methodology/Principal Findings We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4–10 cm in diameter with up to five large seeds, and fruits >10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size) with either a single or few (<3 seeds) extremely large seeds or many small seeds (usually >100 seeds). Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. Conclusions/Significance Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal by relying on frugivores able to disperse enormous seed loads over long-distances. Present-day seed dispersal by scatter-hoarding rodents, introduced livestock, runoff, flooding, gravity, and human-mediated dispersal allowed survival of megafauna-dependent fruit species after extinction of the major seed dispersers. Megafauna extinction had several potential consequences, such as a scale shift reducing the seed dispersal distances, increasingly clumped spatial patterns, reduced geographic ranges and limited genetic

  14. Hormone Replacement Therapy, Iron, and Breast Cancer

    DTIC Science & Technology

    2005-10-01

    culture models with different status of estrogen and progesterone receptors as well as an iron loaded transgenic mouse model. Our results have shown that...Hormone replacement therapy, iron, estrogen, cell proliferation, progesterone , breast cancer 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...release an egg every month. Estrogen and progesterone together help regulate this event. As a woman matures, the ovaries have fewer eggs to stimulate

  15. Iron-refractory iron deficiency anemia (IRIDA).

    PubMed

    Heeney, Matthew M; Finberg, Karin E

    2014-08-01

    Iron deficiency anemia is a common global problem whose etiology is typically attributed to acquired inadequate dietary intake and/or chronic blood loss. However, in several kindreds multiple family members are affected with iron deficiency anemia that is unresponsive to oral iron supplementation and only partially responsive to parenteral iron therapy. The discovery that many of these cases harbor mutations in the TMPRSS6 gene led to the recognition that they represent a single clinical entity: iron-refractory iron deficiency anemia (IRIDA). This article reviews clinical features of IRIDA, recent genetic studies, and insights this disorder provides into the regulation of systemic iron homeostasis.

  16. Deferiprone for the treatment of transfusional iron overload in thalassemia.

    PubMed

    Belmont, Ami; Kwiatkowski, Janet L

    2017-06-01

    Transfusional iron overload can lead to hepatic fibrosis, arrhythmias and congestive heart failure and a number of endocrinopathies. Deferiprone is an oral iron chelator approved for use in the United States as a second line agent for the treatment of transfusional iron overload in patients with thalassemia. Areas covered: This article will review the data regarding the efficacy of deferiprone for iron chelation and prevention and reversal of iron related complications, the drug's adverse effect profile, and the use of this drug in combination regimens. Expert commentary: Extensive data support that deferiprone is particularly efficacious at cardiac iron removal and therefore, a chelator regimen that contains deferiprone is generally recommended when there is significant cardiac iron loading and/or in the setting of iron-related cardiac disease. The most concerning side effects of deferiprone are agranulocytosis and milder forms of neutropenia, which require appropriate monitoring and patient/provider education.

  17. Modulation of hepcidin to treat iron deregulation: potential clinical applications

    PubMed Central

    Blanchette, Nicole L.; Manz, David H.; Torti, Frank M.

    2016-01-01

    The secreted peptide hormone hepcidin regulates systemic and local iron homeostasis through degradation of the iron exporter ferroportin. Dysregulation of hepcidin leads to altered iron homeostasis and development of pathological disorders including hemochromatosis, and iron loading and iron restrictive anemias. Therapeutic modulation of hepcidin is a promising method to ameliorate these conditions. Several approaches have been taken to enhance or reduce the effects of hepcidin in vitro and in vivo. Based on these approaches, hepcidin modulating drugs have been developed and are undergoing clinical evaluation. In this article we review the rationale for development of these drugs, the data concerning their safety and efficacy, their therapeutic uses, and potential future prospects. PMID:26669208

  18. Modulation of hepcidin to treat iron deregulation: potential clinical applications.

    PubMed

    Blanchette, Nicole L; Manz, David H; Torti, Frank M; Torti, Suzy V

    2016-01-01

    The secreted peptide hormone hepcidin regulates systemic and local iron homeostasis through degradation of the iron exporter ferroportin. Dysregulation of hepcidin leads to altered iron homeostasis and development of pathological disorders including hemochromatosis, and iron loading and iron restrictive anemias. Therapeutic modulation of hepcidin is a promising method to ameliorate these conditions. Several approaches have been taken to enhance or reduce the effects of hepcidin in vitro and in vivo. Based on these approaches, hepcidin modulating drugs have been developed and are undergoing clinical evaluation. In this article we review the rationale for development of these drugs, the data concerning their safety and efficacy, their therapeutic uses, and potential future prospects.

  19. Atomic simulation of cracks under mixed mode loading

    NASA Technical Reports Server (NTRS)

    Mullins, M.

    1984-01-01

    A discrete atomic model of a crack tip in iron under mixed mode loads is examined. The results indicate that the behavior of the crack at the atomic scale as a function of the ratio of mode I to mode II component of load is quite complex. In general, crack tip plasticity appears to increase as the mode II component of load increases.

  20. Atomic simulation of cracks under mixed mode loading

    NASA Technical Reports Server (NTRS)

    Mullins, M.

    1984-01-01

    A discrete atomic model of a crack tip in iron under mixed mode loads is examined. The results indicate that the behavior of the crack at the atomic scale as a function of the ratio of mode I to mode II component of load is quite complex. In general, crack tip plasticity appears to increase as the mode II component of load increases.

  1. The seed nuclear proteome.

    PubMed

    Repetto, Ombretta; Rogniaux, Hélène; Larré, Colette; Thompson, Richard; Gallardo, Karine

    2012-01-01

    Understanding the regulatory networks coordinating seed development will help to manipulate seed traits, such as protein content and seed weight, in order to increase yield and seed nutritional value of important food crops, such as legumes. Because of the cardinal role of the nucleus in gene expression, sub-proteome analyses of nuclei from developing seeds were conducted, taking advantage of the sequences available for model species. In this review, we discuss the strategies used to separate and identify the nuclear proteins at a stage when the seed is preparing for reserve accumulation. We present how these data provide an insight into the complexity and distinctive features of the seed nuclear proteome. We discuss the presence of chromatin-modifying enzymes and proteins that have roles in RNA-directed DNA methylation and which may be involved in modifying genome architecture in preparation for seed filling. Specific features of the seed nuclei at the transition between the stage of cell divisions and that of cell expansion and reserve deposition are described here which may help to manipulate seed quality traits, such as seed weight.

  2. Nitric oxide and plant iron homeostasis.

    PubMed

    Buet, Agustina; Simontacchi, Marcela

    2015-03-01

    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes.

  3. Quantitative analysis and modelling of hepatic iron stores using stereology and spatial statistics.

    PubMed

    Ghugre, N R; Gonzalez-Gomez, I; Shimada, H; Coates, T D; Wood, J C

    2010-06-01

    Hepatic iron overload is a common clinical problem resulting from hyperabsorption syndromes and from chronic transfusion therapy. Not only does iron loading vary between reticuloendothelial stores and hepatocytes, but iron is heterogeneously distributed within hepatocytes as well. Since the accessibility of iron particles to chelation may depend, in part, on their distribution, we sought to characterize the shape and scale of iron deposition in humans with transfusional iron overload. Toward this end, we performed a histological analysis of iron stores in liver biopsy specimens of 20 patients (1.3-57.8 mg iron/g dry tissue weight) with aid of electron and light microscopy. We estimated distributions related to variability in siderosomal size, proximity of iron centres and inter-cellular iron loading. These distributions could be well modelled by Gamma distribution functions over most of the pathologic range of iron concentrations. Thus, for a given liver iron burden, a virtual iron-overloaded liver could be created that served as a model for the true histologic appearance. Such a model may be helpful for understanding the mechanics of iron loading or in predicting response to iron removal therapy.

  4. Platinum Attachments on Iron Oxide Nanoparticle Surfaces

    SciTech Connect

    Palchoudhury, Soubantika; Xu, Yaolin; An, Wei; Turner, C. H.; Bao, Yuping

    2010-04-30

    Platinum nanoparticles supported on metal oxide surfaces have shown great potential as heterogeneous catalysts to accelerate electrochemical processes, such as the oxygen reduction reaction in fuel cells. Recently, the use of magnetic supports has become a promising research topic for easy separation and recovery of catalysts using magnets, such as Pt nanoparticles supported on iron oxide nanoparticles. The attachment of Pt on iron oxide nanoparticles is limited by the wetting ability of the Pt (metal) on ceramic surfaces. A study of Pt nanoparticle attachment on iron oxide nanoparticle surfaces in an organic solvent is reported, which addresses the factors that promote or inhibit such attachment. It was discovered that the Pt attachment strongly depends on the capping molecules of the iron oxide seeds and the reaction temperature. For example, the attachment of Pt nanoparticles on oleic acid coated iron oxide nanoparticles was very challenging, because of the strong binding between the carboxylic groups and iron oxide surfaces. In contrast, when nanoparticles are coated with oleic acid/tri-n-octylphosphine oxide or oleic acid/oleylamine, a significant increase in Pt attachment was observed. Electronic structure calculations were then applied to estimate the binding energies between the capping molecules and iron ions, and the modeling results strongly support the experimental observations.

  5. Duodenal Absorption and Tissue Utilization of Dietary Heme and Nonheme Iron Differ in Rats123

    PubMed Central

    Cao, Chang; Thomas, Carrie E.; Insogna, Karl L.; O'Brien, Kimberly O.

    2014-01-01

    Background: Dietary heme contributes to iron intake, yet regulation of heme absorption and tissue utilization of absorbed heme remains undefined. Objectives: In a rat model of iron overload, we used stable iron isotopes to examine heme- and nonheme-iron absorption in relation to liver hepcidin and to compare relative utilization of absorbed heme and nonheme iron by erythroid (RBC) and iron storage tissues (liver and spleen). Methods: Twelve male Sprague-Dawley rats were randomly assigned to groups for injections of either saline or iron dextran (16 or 48 mg Fe over 2 wk). After iron loading, rats were administered oral stable iron in the forms of 57Fe-ferrous sulfate and 58Fe-labeled hemoglobin. Expression of liver hepcidin and duodenal iron transporters and tissue stable iron enrichment was determined 10 d postdosing. Results: High iron loading increased hepatic hepcidin by 3-fold and reduced duodenal expression of divalent metal transporter 1 (DMT1) by 76%. Nonheme-iron absorption was 2.5 times higher than heme-iron absorption (P = 0.0008). Absorption of both forms of iron was inversely correlated with hepatic hepcidin expression (heme-iron absorption: r = −0.77, P = 0.003; nonheme-iron absorption: r = −0.80, P = 0.002), but hepcidin had a stronger impact on nonheme-iron absorption (P = 0.04). Significantly more 57Fe was recovered in RBCs (P = 0.02), and more 58Fe was recovered in the spleen (P = 0.01). Conclusions: Elevated hepcidin significantly decreased heme- and nonheme-iron absorption but had a greater impact on nonheme-iron absorption. Differential tissue utilization of heme vs. nonheme iron was evident between erythroid and iron storage tissues, suggesting that some heme may be exported into the circulation in a form different from that of nonheme iron. PMID:25332470

  6. The effect of hydrostatic vs. shock pressure treatment of plant seeds

    NASA Astrophysics Data System (ADS)

    Mustey, A.; Leighs, J. A.; Appleby-Thomas, G. J.; Wood, D. C.; Hazael, R.; McMillan, P. F.; Hazell, P. J.

    2014-05-01

    The hydrostatic pressure and shock response of plant seeds has been investigated antecedently, primarily driven by interest in reducing bacterial contamination of crops and the theory of panspermia, respectively. However, comparisons have not previously been made between these two methods ofapplying pressure to plant seeds. Here such a comparison has been undertaken based on the premise that any correlations in collected data may provide a route to inform understanding of damage mechanisms in the seeds under test. In this work two varieties of plant seeds were subjected to hydrostatic pressure via a non-end-loaded piston cylinder setup and shock compression via employment of a 50 mm bore, single stage gas gun using the flyer plate technique. Results from germination tests of recovered seed samples have been compared and contrasted, and initial conclusions made regarding causes of trends in the resultant data-set. Data collected has shown that cress seeds are extremely resilient to static loading, whereas the difference in the two forms of loading is negligible for lettuce seeds. Germination time has been seen to extend dramatically following static loading of cress seeds to greater than 0.4 GPa. In addition, the cut-off pressure previously seen to cause 0% germination in dynamic experiments performed on cress seeds has now also been seen in lettuce seeds.

  7. Transdermal iron replenishment therapy.

    PubMed

    Modepalli, Naresh; Shivakumar, H N; Kanni, K L Paranjothy; Murthy, S Narasimha

    2015-01-01

    Iron deficiency anemia is one of the major nutritional deficiency disorders. Iron deficiency anemia occurs due to decreased absorption of iron from diet, chronic blood loss and other associated diseases. The importance of iron and deleterious effects of iron deficiency anemia are discussed briefly in this review followed by the transdermal approaches to deliver iron. Transdermal delivery of iron would be able to overcome the side effects associated with conventional oral and parenteral iron therapy and improves the patient compliance. During preliminary investigations, ferric pyrophosphate and iron dextran were selected as iron sources for transdermal delivery. Different biophysical techniques were explored to assess their efficiency in delivering iron across the skin, and in vivo studies were carried out using anemic rat model. Transdermal iron delivery is a promising approach that could make a huge positive impact on patients suffering with iron deficiency.

  8. [Iron dysregulation and anemias].

    PubMed

    Ikuta, Katsuya

    2015-10-01

    Most iron in the body is utilized as a component of hemoglobin that delivers oxygen to the entire body. Under normal conditions, the iron balance is tightly regulated. However, iron dysregulation does occasionally occur; total iron content reductions cause iron deficiency anemia and overexpression of the iron regulatory peptide hepcidin disturbs iron utilization resulting in anemia of chronic disease. Conversely, the presence of anemia may ultimately lead to iron overload; for example, thalassemia, a common hereditary anemia worldwide, often requires transfusion, but long-term transfusions cause iron accumulation that leads to organ damage and other poor outcomes. On the other hand, there is a possibility that iron overload itself can cause anemia; iron chelation therapy for the post-transfusion iron overload observed in myelodysplastic syndrome or aplastic anemia improves dependency on transfusions in some cases. These observations reflect the extremely close relationship between anemias and iron metabolism.

  9. Gastrins, iron and colorectal cancer.

    PubMed

    Baldwin, Graham S

    2009-09-01

    This minireview explores the connections between circulating gastrins, iron status and colorectal cancer. The peptide hormone gastrin is a major regulator of acid secretion and a potent mitogen for normal and malignant gastrointestinal cells. Gastrins bind two ferric ions with μM affinity and, in the case of non-amidated forms of the hormone, iron binding is essential for biological activity. The ferric ion ligands have been identified as glutamates 7, 8 and 9 in the 18 amino acid peptide glycine-extended gastrin. An interaction between gastrin and transferrin was first demonstrated by covalent crosslinking techniques, and has been recently confirmed by surface plasmon resonance. We have therefore proposed that gastrins act as catalysts in the loading of transferrin with iron. Several recent lines of evidence, including the facts that the concentrations of circulating gastrins are increased in mice and humans with the iron overload disease haemochromatosis, and that transferrin saturation positively correlates with circulating gastrin concentrations, suggest that gastrins may be involved in iron homeostasis. In addition the recognition that ferric ions may play an unexpected role in the biological activity of non-amidated gastrins may assist in the development of new therapies for colorectal carcinoma.

  10. Pharmacology of Iron Transport

    PubMed Central

    Byrne, Shaina L.; Krishnamurthy, Divya; Wessling-Resnick, Marianne

    2013-01-01

    Elucidating the molecular basis for the regulation of iron uptake, storage, and distribution is necessary to understand iron homeostasis. Pharmacological tools are emerging to identify and distinguish among different iron transport pathways. Stimulatory or inhibitory small molecules with effects on iron uptake can help characterize the mechanistic elements of iron transport and the roles of the transporters involved in these processes. In particular, iron chelators can serve as potential pharmacological tools to alleviate diseases of iron overload. This review focuses on the pharmacology of iron transport, introducing iron transport membrane proteins and known inhibitors. PMID:23020294

  11. Pharmacology of iron transport.

    PubMed

    Byrne, Shaina L; Krishnamurthy, Divya; Wessling-Resnick, Marianne

    2013-01-01

    Elucidating the molecular basis for the regulation of iron uptake, storage, and distribution is necessary to understand iron homeostasis. Pharmacological tools are emerging to identify and distinguish among different iron transport pathways. Stimulatory or inhibitory small molecules with effects on iron uptake can help characterize the mechanistic elements of iron transport and the roles of the transporters involved in these processes. In particular, iron chelators can serve as potential pharmacological tools to alleviate diseases of iron overload. This review focuses on the pharmacology of iron transport, introducing iron transport membrane proteins and known inhibitors.

  12. Cobalt Excretion Test for the Assessment of Body Iron Stores

    PubMed Central

    Sorbie, Janet; Olatunbosun, David; Corbett, William E. N.; Valberg, Leslie S.

    1971-01-01

    Iron absorption is under delicate control and the level of absorption is adjusted to comply with the body's need for iron. To measure the intestinal setting for iron absorption, and thereby indirectly assess body iron requirements, cobaltous chloride labelled with 57Co or 60Co was given by mouth and the percentage of the test dose excreted in the urine in 24 hours was measured in a gamma counter. Seventeen control subjects with normal iron stores excreted 18% (9-23%) of the dose. Increased excretion, 31% (23-42%), was found in 10 patients with iron deficiency anemia and in 15 patients with depleted iron stores in the absence of anemia. In contrast, 12 patients with anemia due to causes other than iron deficiency excreted amounts of radiocobalt within the normal control range. In patients with iron deficiency, replenishment of iron stores by either oral or parenteral iron caused the previously high results to return to normal. Excretion of the test dose was normal in portal cirrhosis with normal iron stores but it was markedly increased in patients with cirrhosis complicated by either iron deficiency or endogenous iron overload. It was also raised in primary hemochromatosis. Excretion of the dose was reduced in gluten-sensitive enteropathy. Gastrointestinal surgery and inflammatory disease of the lower small intestine had no effect on the results except that some patients with steatorrhea had diminished excretion. The cobalt excretion test provides the clinician with a tool for the assessment of iron absorption, the detection of a reduction in body iron stores below the level that is normal for the subject in question, the differentiation of iron deficiency anemia from anemia due to other causes, and the investigation of patients with iron-loading disorders. PMID:5578125

  13. FRD3 Controls Iron Localization in Arabidopsis1

    PubMed Central

    Green, Laura S.; Rogers, Elizabeth E.

    2004-01-01

    The frd3 mutant of Arabidopsis exhibits constitutive expression of its iron uptake responses and is chlorotic. These phenotypes are consistent with defects either in iron deficiency signaling or in iron translocation and localization. Here we present several experiments demonstrating that a functional FRD3 gene is necessary for correct iron localization in both the root and shoot of Arabidopsis plants. Reciprocal grafting experiments with frd3 and wild-type Arabidopsis plants reveal that the phenotype of a grafted plant is determined by the genotype of the root, not by the genotype of the shoot. This indicates that FRD3 function is root-specific and points to a role for FRD3 in delivering iron to the shoot in a usable form. When grown under certain conditions, frd3 mutant plants overaccumulate iron in their shoot tissues. However, we demonstrate by direct measurement of iron levels in shoot protoplasts that intracellular iron levels in frd3 are only about one-half the levels in wild type. Histochemical staining for iron reveals that frd3 mutants accumulate high levels of ferric iron in their root vascular cylinder, the same tissues in which the FRD3 gene is expressed. Taken together, these results clearly indicate a role for FRD3 in iron localization in Arabidopsis. Specifically, FRD3 is likely to function in root xylem loading of an iron chelator or other factor necessary for efficient iron uptake out of the xylem or apoplastic space and into leaf cells. PMID:15310833

  14. Morphology of the ferritin iron core by aberration corrected scanning transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Jian, Nan; Dowle, Miriam; Horniblow, Richard D.; Tselepis, Chris; Palmer, Richard E.

    2016-11-01

    As the major iron storage protein, ferritin stores and releases iron for maintaining the balance of iron in fauna, flora, and bacteria. We present an investigation of the morphology and iron loading of ferritin (from equine spleen) using aberration-corrected high angle annular dark field scanning transmission electron microscopy. Atom counting method, with size selected Au clusters as mass standards, was employed to determine the number of iron atoms in the nanoparticle core of each ferritin protein. Quantitative analysis shows that the nuclearity of iron atoms in the mineral core varies from a few hundred iron atoms to around 5000 atoms. Moreover, a relationship between the iron loading and iron core morphology is established, in which mineral core nucleates from a single nanoparticle, then grows along the protein shell before finally forming either a solid or hollow core structure.

  15. Morphology of the ferritin iron core by aberration corrected scanning transmission electron microscopy.

    PubMed

    Jian, Nan; Dowle, Miriam; Horniblow, Richard D; Tselepis, Chris; Palmer, Richard E

    2016-11-18

    As the major iron storage protein, ferritin stores and releases iron for maintaining the balance of iron in fauna, flora, and bacteria. We present an investigation of the morphology and iron loading of ferritin (from equine spleen) using aberration-corrected high angle annular dark field scanning transmission electron microscopy. Atom counting method, with size selected Au clusters as mass standards, was employed to determine the number of iron atoms in the nanoparticle core of each ferritin protein. Quantitative analysis shows that the nuclearity of iron atoms in the mineral core varies from a few hundred iron atoms to around 5000 atoms. Moreover, a relationship between the iron loading and iron core morphology is established, in which mineral core nucleates from a single nanoparticle, then grows along the protein shell before finally forming either a solid or hollow core structure.

  16. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function

    PubMed Central

    Lakhal-Littleton, Samira; Wolna, Magda; Carr, Carolyn A.; Miller, Jack J. J.; Christian, Helen C.; Ball, Vicky; Santos, Ana; Diaz, Rebeca; Biggs, Daniel; Stillion, Richard; Holdship, Philip; Clarke, Kieran; Davies, Benjamin; Robbins, Peter A.

    2015-01-01

    Iron is essential to the cell. Both iron deficiency and overload impinge negatively on cardiac health. Thus, effective iron homeostasis is important for cardiac function. Ferroportin (FPN), the only known mammalian iron-exporting protein, plays an essential role in iron homeostasis at the systemic level. It increases systemic iron availability by releasing iron from the cells of the duodenum, spleen, and liver, the sites of iron absorption, recycling, and storage respectively. However, FPN is also found in tissues with no known role in systemic iron handling, such as the heart, where its function remains unknown. To explore this function, we generated mice with a cardiomyocyte-specific deletion of Fpn. We show that these animals have severely impaired cardiac function, with a median survival of 22 wk, despite otherwise unaltered systemic iron status. We then compared their phenotype with that of ubiquitous hepcidin knockouts, a recognized model of the iron-loading disease hemochromatosis. The phenotype of the hepcidin knockouts was far milder, with normal survival up to 12 mo, despite far greater iron loading in the hearts. Histological examination demonstrated that, although cardiac iron accumulates within the cardiomyocytes of Fpn knockouts, it accumulates predominantly in other cell types in the hepcidin knockouts. We conclude, first, that cardiomyocyte FPN is essential for intracellular iron homeostasis and, second, that the site of deposition of iron within the heart determines the severity with which it affects cardiac function. Both findings have significant implications for the assessment and treatment of cardiac complications of iron dysregulation. PMID:25713362

  17. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function.

    PubMed

    Lakhal-Littleton, Samira; Wolna, Magda; Carr, Carolyn A; Miller, Jack J J; Christian, Helen C; Ball, Vicky; Santos, Ana; Diaz, Rebeca; Biggs, Daniel; Stillion, Richard; Holdship, Philip; Larner, Fiona; Tyler, Damian J; Clarke, Kieran; Davies, Benjamin; Robbins, Peter A

    2015-03-10

    Iron is essential to the cell. Both iron deficiency and overload impinge negatively on cardiac health. Thus, effective iron homeostasis is important for cardiac function. Ferroportin (FPN), the only known mammalian iron-exporting protein, plays an essential role in iron homeostasis at the systemic level. It increases systemic iron availability by releasing iron from the cells of the duodenum, spleen, and liver, the sites of iron absorption, recycling, and storage respectively. However, FPN is also found in tissues with no known role in systemic iron handling, such as the heart, where its function remains unknown. To explore this function, we generated mice with a cardiomyocyte-specific deletion of Fpn. We show that these animals have severely impaired cardiac function, with a median survival of 22 wk, despite otherwise unaltered systemic iron status. We then compared their phenotype with that of ubiquitous hepcidin knockouts, a recognized model of the iron-loading disease hemochromatosis. The phenotype of the hepcidin knockouts was far milder, with normal survival up to 12 mo, despite far greater iron loading in the hearts. Histological examination demonstrated that, although cardiac iron accumulates within the cardiomyocytes of Fpn knockouts, it accumulates predominantly in other cell types in the hepcidin knockouts. We conclude, first, that cardiomyocyte FPN is essential for intracellular iron homeostasis and, second, that the site of deposition of iron within the heart determines the severity with which it affects cardiac function. Both findings have significant implications for the assessment and treatment of cardiac complications of iron dysregulation.

  18. Natural Genetic Variation of Seed Micronutrients of Arabidopsis thaliana Grown in Zinc-Deficient and Zinc-Amended Soil

    PubMed Central

    Chen, Xiaochao; Yuan, Lixing; Ludewig, Uwe

    2016-01-01

    The quality of edible seeds for human and animal nutrition is crucially dependent on high zinc (Zn) and iron (Fe) seed concentrations. The micronutrient bioavailability is strongly reduced by seed phytate that forms complexes with seed cations. Superior genotypes with increased seed Zn concentrations had been identified, but low micronutrient seed levels often prevail when the plants are grown in Zn-deficient soils, which are globally widespread and correlate with human Zn-deficiency. Here, seed Zn concentrations of Arabidopsis accessions grown in Zn-deficient and Zn-amended conditions were measured together with seed Fe and manganese (Mn), in a panel of 108 accessions. By applying genome-wide association, de novo candidate genes potentially involved in the seed micronutrient accumulation were identified. However, a candidate inositol 1,3,4-trisphosphate 5/6-kinase 3 gene (ITPK3), located close to a significant nucleotide polymorphism associated with relative Zn seed concentrations, was dispensable for seed micronutrients accumulation in Col-0. Loss of this gene in itpk3-1 did neither affect phytate seed levels, nor seed Zn, Fe, and Mn. It is concluded that large natural variance of micronutrient seed levels is identified in the population and several accessions maintain high seed Zn despite growth in Zn-deficient conditions. PMID:27507976

  19. Minihepcidins prevent iron overload in a hepcidin-deficient mouse model of severe hemochromatosis.

    PubMed

    Ramos, Emilio; Ruchala, Piotr; Goodnough, Julia B; Kautz, Léon; Preza, Gloria C; Nemeth, Elizabeta; Ganz, Tomas

    2012-11-01

    The deficiency of hepcidin, the hormone that controls iron absorption and its tissue distribution, is the cause of iron overload in nearly all forms of hereditary hemochromatosis and in untransfused iron-loading anemias. In a recent study, we reported the development of minihepcidins, small drug-like hepcidin agonists. Here we explore the feasibility of using minihepcidins for the prevention and treatment of iron overload in hepcidin-deficient mice. An optimized minihepcidin (PR65) was developed that had superior potency and duration of action compared with natural hepcidin or other minihepcidins, and favorable cost of synthesis. PR65 was administered by subcutaneous injection daily for 2 weeks to iron-depleted or iron-loaded hepcidin knockout mice. PR65 administration to iron-depleted mice prevented liver iron loading, decreased heart iron levels, and caused the expected iron retention in the spleen and duodenum. At high doses, PR65 treatment also caused anemia because of profound iron restriction. PR65 administration to hepcidin knockout mice with pre-existing iron overload had a more moderate effect and caused partial redistribution of iron from the liver to the spleen. Our study demonstrates that minihepcidins could be beneficial in iron overload disorders either used alone for prevention or possibly as adjunctive therapy with phlebotomy or chelation.

  20. Colloidal semiconductor/magnetic heterostructures based on iron-oxide-functionalized brookite TiO2 nanorods.

    PubMed

    Buonsanti, Raffaella; Snoeck, Etienne; Giannini, Cinzia; Gozzo, Fabia; Garcia-Hernandez, Mar; Angel Garcia, Miguel; Cingolani, Roberto; Cozzoli, Pantaleo Davide

    2009-05-21

    A flexible colloidal seeded-growth strategy has been developed to synthesize all-oxide semiconductor/magnetic hybrid nanocrystals (HNCs) in various topological arrangements, for which the dimensions of the constituent material domains can be controlled independently over a wide range. Our approach relies on driving preferential heterogeneous nucleation and growth of spinel cubic iron oxide (IO) domains onto brookite TiO2 nanorods (b-TiO2) with tailored geometric parameters, by means of time-programmed delivery of organometallic precursors into a suitable TiO2-loaded surfactant environment. The b-TiO2 seeds exhibit size-dependent accessibility towards IO under diffusion-controlled growth regime, which allows attainment of HNCs individually made of a single b-TiO2 section functionalized with either one or multiple nearly spherical IO domains. In spite of the dissimilarity of the respective crystal-phases, the two materials share large interfacial junctions without significant lattice strain being induced across the heterostructures. The synthetic achievements have been supported by a systematic morphological, compositional and structural characterization of the as-prepared HNCs, offering a mechanistic insight into the specific role of the seeds in the control of heterostructure formation in liquid media. In addition, the impact of the formed b-TiO2/IO heterojunctions on the magnetic properties of IO has also been assessed.

  1. Iron and Your Child

    MedlinePlus

    ... get iron by eating foods like meat and dark green leafy vegetables. Iron is also added to ... tofu dried beans and peas dried fruits leafy dark green vegetables iron-fortified breakfast cereals, breads, and ...

  2. Iron metabolism and toxicity

    SciTech Connect

    Papanikolaou, G.; Pantopoulos, K. . E-mail: kostas.pantopoulos@mcgill.ca

    2005-01-15

    Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer.

  3. Artificial Ripening of Sweetgum Seeds

    Treesearch

    F. T. Bonner

    1969-01-01

    Untrained collectors of hardwood seeds often start picking the seeds too early in the year. The immature seeds germinate poorly, if at all, and nursery production suffers. In the study reported here, sweetgum (Liquidambar styraciflua L.) seeds collected in central Mississippi in mid-August were ripe. Seeds collected as early as July 19 were artificially ripened by...

  4. A role for seed storage proteins in Arabidopsis seed longevity

    PubMed Central

    Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

    2015-01-01

    Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation. PMID:26184996

  5. Crystallization on prestructured seeds.

    PubMed

    Jungblut, Swetlana; Dellago, Christoph

    2013-01-01

    The crystallization transition of an undercooled monodisperse Lennard-Jones fluid in the presence of small prestructured seeds is studied with transition path sampling combined with molecular dynamics simulations. Compared to the homogeneous crystallization, clusters of a few particles arranged into a face- and body-centered cubic structure enhance the crystallization, while icosahedrally ordered seeds do not change the reaction rate. We identify two distinct nucleation regimes-close to the seed and in the bulk. Crystallites form close to the face- and body-centered structures and tend to stay away from the icosahedrally ordered seeds.

  6. The case for iron

    SciTech Connect

    Martin, J.H.; Gordon, R.M.; Fitzwater, S.E. )

    1991-12-01

    Excess major nutrients occur in offshore areas ranging from the tropical equatorial Pacific to the polar Antarctic. In spite of the great ecological differences in these environments, the authors believe they share a common trait: iron deficiency. Here they present the case of iron; they point out that all of these areas are far from Fe-rich terrestrial sources and that atmospheric dust loads in these regions are among the lowest in the world. The authors summarize experiments performed in three nutrient-rich areas: The Gulf of Alaska, the Ross Sea, and the equatorial Pacific. In general, populations without added Fe doubled at rates 11-40% of the expected maxima at various temperatures. The additions of nanomole quantities of Fe increased these doubling rates by factors of 2-3. In spite of the lack of Fe, tightly coupled phytoplankton/zooplankton communities seem to inhabit these major nutrient-rich areas. Since Fe is required for the synthesis of chlorophyll and nitrate reductase, little chlorophyll is found and NH{sub 3} is the favored N source. Normal rate values of specific productivity indicate that these populations are healthy, but limited by the insufficient Fe supply. When Fe becomes available either artificially in bottle experiments or in the environment as Fe-rich land masses are approached, diatoms quickly bloom, chlorophyll levels increase, and nutrient stocks are rapidly depleted. These combined results indicate that Fe availability is the primary factor controlling phytoplankton production in nutrient-rich areas of the open sea.

  7. Analysis of interspecies physicochemical variation of grain legume seeds

    NASA Astrophysics Data System (ADS)

    Rybiński, Wojciech; Rusinek, Robert; Szot, Bogusław; Bocianowski, Jan; Starzycki, Michał

    2014-10-01

    The paper presents an attempt to assess the reaction of seeds to mechanical loads taking into account their geometry expressed as seed thickness and 1000 seed weight. The initial material comprised 33 genotypes of grain legume plants and included cultivars registered in the country and breeding lines that are subject to pre-registration trials. The analysis of variance revealed significant diversity of the cultivars and lines of the species studied in terms of each of the analysed trait. The highest weight of 1000 seeds were obtained for white lupine seeds and peas, the lowest for andean lupine seeds. The maximum deformation and energy were obtained for white lupine seeds, the lowest for pea seeds, the maximum force and module the lowest values were determined for narrow-leafed lupine and pea. The highest values of protein were obtained for andean and yellow lupine, a fat content for andean and white lupine. The fatty acid profile as much as 70% or more were linoleic and oleic acids. Against the background of all the species are distinguished by white lupine seeds with a high content of oleic acid and the lowest of linoleic acid, for yellow lupine were obtained the inverse ratio of the two acids.

  8. Effects of green tea on iron accumulation and oxidative stress in livers of iron-challenged thalassemic mice.

    PubMed

    Saewong, T; Ounjaijean, S; Mundee, Y; Pattanapanyasat, K; Fucharoen, S; Porter, J B; Srichairatanakool, S

    2010-03-01

    Liver is affected by secondary iron overload in transfusions dependent b-thalassemia patients. The redox iron can generate reactive oxidants that damage biomolecules, leading to liver fibrosis and cirrhosis. Iron chelators are used to treat thalassemias to achieve negative iron balance and relieve oxidant-induced organ dysfunctions. Green tea (GT) (Camellia sinensis) catechins exhibit anti-oxidation, the inhibition of carcinogenesis, the detoxification of CYP2E1-catalyzed HepG2 cells and iron chelation. The purpose of this study was to investigate the effectiveness of GT in iron-challenged thalassemic mice. Heterozygous BKO type-thalassemia (BKO) mice (C57BL/6) experienced induced iron overload by being fed a ferrocene-supplemented diet (Fe diet) for 8 weeks, and by orally being given GT extract (300 mg/kg) and deferiprone (DFP) (50 mg/kg) for a further 8 weeks. Liver iron content (LIC) was analyzed by TPTZ colorimetric and Perl's staining techniques. Concentrations of liver reduced glutathione (GSH), collagen and malondialdehyde (MDA) were also measured. Dosages of the GT extract and DFP lowered LIC in the Fe diet-fed BKO mice effectively. The extract did not change any concentrations of liver glutathione, collagen and MDA in the BKO mice. Histochemical examination showed leukocyte infiltration in the near by hepatic portal vein and high iron accumulation in the livers of the iron-loaded BKO mice, however GT treatment lowered the elevated iron deposition. In conclusion, green tea inhibits or delays the deposition of hepatic iron in regularly iron-loaded thalassemic mice effectively. This will prevent the iron-induced generation of free radicals via Haber-Weiss and Fenton reactions, and consequently liver damage and fibrosis. Combined chelation with green tea would be investigated in beta-thalassemia patients with iron overload.

  9. Producing the target seed: Seed collection, treatment, and storage

    Treesearch

    Robert P. Karrfalt

    2011-01-01

    The role of high quality seeds in producing target seedlings is reviewed. Basic seed handling and upgrading techniques are summarized. Current advances in seed science and technology as well as those on the horizon are discussed.

  10. Parenteral iron therapy options.

    PubMed

    Silverstein, Scott B; Rodgers, George M

    2004-05-01

    Parenteral iron therapy is occasionally necessary for patients intolerant or unresponsive to oral iron therapy, for receiving recombinant erythropoietin therapy, or for use in treating functional iron deficiency. There are now three parenteral iron products available: iron dextran, ferric gluconate, and iron sucrose. We summarize the advantages and disadvantages of each product, including risk of anaphylaxis and hypersensitivity, dosage regimens, and costs. The increased availability of multiple parenteral iron preparations should decrease the need to use red cell transfusions in patients with iron-deficiency anemia.

  11. Soybean Ferritin Forms an Iron-Containing Oligomer in Tofu Even after Heat Treatment.

    PubMed

    Masuda, Taro

    2015-10-14

    Ferritin, a multimeric iron storage protein distributed in almost all living kingdoms, has been highlighted recently as a nutritional iron source in plant-derived foodstuffs, because ferritin iron is suggested to have high bioavailability. In soybean seeds, ferritin contributes largely to the net iron contents. Here, the oligomeric states and iron contents of soybean ferritin during food processing (especially tofu gel formation) were analyzed. Ferritin was purified from tofu gel as an iron-containing oligomer (approximately 1000 Fe atoms per oligomer), which was composed of two types of subunits similar to the native soybean seed ferritin. Circular dichroism spectra also showed no differences in α-helical structure between native soybean ferritin and tofu ferritin. The present data demonstrate that ferritin was stable during the heat treatment (boiling procedure) in food processing, although partial denaturation was observed at temperatures higher than 80 °C.

  12. Transferrins: iron release from lactoferrin.

    PubMed

    Abdallah, F B; El Hage Chahine, J M

    2000-10-20

    Iron loss in vitro by the iron scavenger bovine lactoferrin was investigated in acidic media in the presence of three different monoanions (NO(3)(-), Cl(-) and Br(-)) and one dianion (SO(4)(2-)). Holo and monoferric C-site lactoferrins lose iron in acidic media (pH< or =3.5) by a four-step mechanism. The first two steps describe modifications in the conformation affecting the whole protein, which occur also with apolactoferrin. These two processes are independent of iron load and are followed by a third step consisting of the gain of two protons. This third step is kinetically controlled by the interaction with two Cl(-), Br(-) and NO(3)(-) or one SO(4)(2-). In the fourth step, iron loss is under the kinetic control of a slow gain of two protons; third-order rate-constants k(2), 4.3(+/-0.2)x10(3), 3.4(+/-0.5)x10(3), 3.3(+/-0.5)x10(3) and 1.5(+/-0.5)x10(3) M(-2) s(-1) when the protein is in interaction with SO(4)(2-), NO(3)(-), Cl(-) or Br(-), respectively. This step is accompanied by the loss of the interaction with the anions; equilibrium constant K(2), 20+/-5 mM, 1.0(+/-0.2)x10(-1), 1.5(+/-0.5)x10(-1) and 1.0(+/-0.3)x10(-1) M(2), for SO(4)(-), NO(3)(-), Cl(-) and Br(-), respectively. This mechanism is very different from that determined in mildly acidic media at low ionic strength (micro<0.5) for the iron transport proteins, serum transferrin and ovotransferrin, with which no prior change in conformation or interaction with anions is required. These differences may result from the fact that in the transport proteins, the interdomain hydrogen bonds that consolidate the closed conformation of the iron-binding cleft occur between amino acid side-chain residues that can protonate in mildly acidic media. With bovine lactoferrin, most of the interdomain hydrogen bonds involved in the C-site and one of those involved in the N-site occur between amino acid side-chain residues that cannot protonate. The breaking of the interdomain H-bond upon protonation can trigger the

  13. High-rate behaviour of iron ore pellet

    NASA Astrophysics Data System (ADS)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  14. Photoacoustic molecular imaging for in vivo liver iron quantitation

    NASA Astrophysics Data System (ADS)

    Maccarinelli, Federica; Carmona, Fernando; Regoni, Maria; Arosio, Paolo

    2016-05-01

    A recent study showed that ferritin is a suitable endogenous contrast agent for photoacoustic molecular imaging in cultured mammalian cells. We have therefore tested whether this imaging technique can be used for in vivo quantification of iron in mouse livers. To verify this hypothesis, we used multispectral optoacoustic tomography (MSOT) to image albino CD1 mice before and after experimental iron loading. Postmortem assays showed that the iron treatment caused a 15-fold increase in liver iron and a 40-fold increase in liver ferritin levels, while in vivo longitudinal analysis using MSOT revealed just a 1.6-fold increase in the ferritin/iron photoacoustic signal in the same animals. We conclude that MSOT can monitor changes in ferritin/iron levels in vivo, but its sensitivity is much lower than that of ex vivo iron assays.

  15. A quick SEED tutorial

    USGS Publications Warehouse

    Ringler, Adam; Evans, John R.

    2015-01-01

    A number of different government-funded seismic data centers offer free open-access data (e.g., U.S. Geological Survey, National Earthquake Information Center, the Incorporated Research Institutions for Seismology (IRIS), and Data Management System), which can be freely downloaded and shared among different members of the community (Lay, 2009). To efficiently share data, it is important that different data providers follow a common format. The Standard for the Exchange of Earthquake Data (SEED) provides one such format for storing seismic and other geophysical data. The SEED format is widely used in earthquake seismology; however, SEED and its structure can be difficult for many first-time users (ourselves included). Below is a quick tutorial that outlines the basic structure of SEED format. This write-up is in no way intended to replace the comprehensive SEED manual (Ahern et al., 2009), and instead of going into the details of any specific part of the SEED format we refer the reader to the manual for additional details. The goal of this write-up is to succinctly explain the basic structure of SEED format as well as the associated jargon, as most commonly used now, in a colloquial way so that novice users of SEED can become more familiar with the format and its application quickly. Our goal is to give the reader the necessary background so that when problems or questions about SEED format arise they will have some understanding of where they should look for more details or from where the problem might be stemming. As a secondary goal, we hope to help the reader become familiar with the SEED manual (Ahern et al., 2009), which contains detailed information about all aspects of the SEED format.

  16. Seed dormancy and germination.

    PubMed

    Penfield, Steven

    2017-09-11

    Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  17. Iron-Refractory Iron Deficiency Anemia

    PubMed Central

    Yılmaz Keskin, Ebru; Yenicesu, İdil

    2015-01-01

    Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the “atypical” microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field. PMID:25805669

  18. Iron-refractory iron deficiency anemia.

    PubMed

    Yılmaz Keskin, Ebru; Yenicesu, İdil

    2015-03-05

    Iron is essential for life because it is indispensable for several biological reactions, such as oxygen transport, DNA synthesis, and cell proliferation. Over the past few years, our understanding of iron metabolism and its regulation has changed dramatically. New disorders of iron metabolism have emerged, and the role of iron as a cofactor in other disorders has begun to be recognized. The study of genetic conditions such as hemochromatosis and iron-refractory iron deficiency anemia (IRIDA) has provided crucial insights into the molecular mechanisms controlling iron homeostasis. In the future, these advances may be exploited to improve treatment of both genetic and acquired iron disorders. IRIDA is caused by mutations in TMPRSS6, the gene encoding matriptase-2, which downregulates hepcidin expression under conditions of iron deficiency. The typical features of this disorder are hypochromic, microcytic anemia with a very low mean corpuscular volume of erythrocytes, low transferrin saturation, no (or inadequate) response to oral iron, and only a partial response to parenteral iron. In contrast to classic iron deficiency anemia, serum ferritin levels are usually low-normal, and serum or urinary hepcidin levels are inappropriately high for the degree of anemia. Although the number of cases reported thus far in the literature does not exceed 100, this disorder is considered the most common of the "atypical" microcytic anemias. The aim of this review is to share the current knowledge on IRIDA and increase awareness in this field.

  19. Iron distribution and histopathological study of the effects of deferoxamine and deferiprone in the kidneys of iron overloaded β-thalassemic mice.

    PubMed

    Yatmark, Paranee; Morales, Noppawan Phumala; Chaisri, Urai; Wichaiyo, Surasak; Hemstapat, Warinkarn; Srichairatanakool, Somdet; Svasti, Saovaros; Fucharoen, Suthat

    2016-09-01

    Renal glomerular and tubular dysfunctions have been reported with high prevalence in β-thalassemia. Iron toxicity is implicated in the kidney damage, which may be reversed by iron chelation therapy. To mimic heavy iron overload and evaluate the efficacy of iron chelators in the patients, iron dextran (180mg iron/mouse) was intraperitoneally (i.p.) injected in heterozygous β-globin knockout mice ((muβth-3/+), BKO) and wild type mice (C57BL/6J, WT) over a period of 2 weeks, followed by daily i.p. injection of deferoxamine (DFO) or deferiprone (L1) for 1 week. In BKO mice, iron preferentially accumulated in the proximal tubule with a grading score of 0-1 and increased to grade 3 after iron loading. In contrast, iron mainly deposited in the glomerulus and interstitial space in iron overloaded WT mice. Increased levels of kidney lipid peroxidation, glomerular and medullar damage and fibrosis in iron overloaded mice were reversed by treatment with iron chelators. L1 showed higher efficacy than DFO in reduction of glomerular iron, which was supported by a significantly decreased the amount of glomerular damage. Notably, DFO and L1 demonstrated a distinct pattern of iron distribution in the proximal tubule of BKO mice. In conclusion, chelation therapy has beneficial effects in iron-overloaded kidneys. However, the defect of kidney iron metabolism in thalassemia may be a determining factor of the treatment outcome in individual patients.

  20. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  1. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  2. Constitutive expression of a barley Fe phytosiderophore transporter increases alkaline soil tolerance and results in iron partitioning between vegetative and storage tissues under stress.

    PubMed

    Gómez-Galera, Sonia; Sudhakar, Duraialagaraja; Pelacho, Ana M; Capell, Teresa; Christou, Paul

    2012-04-01

    Cereals have evolved chelation systems to mobilize insoluble iron in the soil, but in rice this process is rather inefficient, making the crop highly susceptible to alkaline soils. We therefore engineered rice to express the barley iron-phytosiderophore transporter (HvYS1), which enables barley plants to take up iron from alkaline soils. A representative transgenic rice line was grown in standard (pH 5.5) or alkaline soil (pH 8.5) to evaluate alkaline tolerance and iron mobilization. Transgenic plants developed secondary tillers and set seeds when grown in standard soil although iron concentration remained similar in leaves and seeds compared to wild type. However, when grown in alkaline soil transgenic plants exhibited enhanced growth, yield and iron concentration in leaves compared to the wild type plants which were severely stunted. Transgenic plants took up iron more efficiently from alkaline soil compared to wild type, indicating an enhanced capacity to increase iron mobility ex situ. Interestingly, all the additional iron accumulated in vegetative tissues, i.e. there was no difference in iron concentration in the seeds of wild type and transgenic plants. Our data suggest that iron uptake from the rhizosphere can be enhanced through expression of HvYS1 and confirm the operation of a partitioning mechanism that diverts iron to leaves rather than seeds, under stress.

  3. Expression and purification of intact and functional soybean (Glycine max) seed ferritin complex in Escherichia coli.

    PubMed

    Dong, Xiangbai; Tang, Bo; Li, Jie; Xu, Qian; Fang, Shentong; Hua, Zichun

    2008-02-01

    Soybean seed ferritin is essential for human iron supplementation and iron deficiency anemia prevention because it contains abundant bioavailable iron and is frequently consumed in the human diet. However, it is poorly understood in regards its several properties, such as iron mineralization, subunit assembly, and protein folding. To address these issues, we decided to prepare the soybean seed ferritin complex via a recombinant DNA approach. In this paper, we report a rapid and simple Escherichia coli expression system to produce the soybean seed ferritin complex. In this system, two subunits of soybean seed ferritin, H-2 and H-1, were encoded in a single plasmid, and optimal expression was achieved by additionally coexpressing a team of molecular chaperones, trigger factor and GroEL-GroES. The His-tagged ferritin complex was purified by Ni2+ affinity chromatography, and an intact ferritin complex was obtained following His-tagged enterokinase (His-EK) digestion. The purified ferritin complex synthesized in E. coli demonstrated some reported features of its native counterpart from soybean seed, including an apparent molecular weight, multimeric assembly, and iron uptake activity. We believe that the strategy described in this paper may be of general utility in producing other recombinant plant ferritins built up from two types of subunits.

  4. OPT3 Is a Phloem-Specific Iron Transporter That Is Essential for Systemic Iron Signaling and Redistribution of Iron and Cadmium in Arabidopsis[W][OPEN

    PubMed Central

    Zhai, Zhiyang; Gayomba, Sheena R.; Jung, Ha-il; Vimalakumari, Nanditha K.; Piñeros, Miguel; Craft, Eric; Rutzke, Michael A.; Danku, John; Lahner, Brett; Punshon, Tracy; Guerinot, Mary Lou; Salt, David E.; Kochian, Leon V.; Vatamaniuk, Olena K.

    2014-01-01

    Iron is essential for both plant growth and human health and nutrition. Knowledge of the signaling mechanisms that communicate iron demand from shoots to roots to regulate iron uptake as well as the transport systems mediating iron partitioning into edible plant tissues is critical for the development of crop biofortification strategies. Here, we report that OPT3, previously classified as an oligopeptide transporter, is a plasma membrane transporter capable of transporting transition ions in vitro. Studies in Arabidopsis thaliana show that OPT3 loads iron into the phloem, facilitates iron recirculation from the xylem to the phloem, and regulates both shoot-to-root iron signaling and iron redistribution from mature to developing tissues. We also uncovered an aspect of crosstalk between iron homeostasis and cadmium partitioning that is mediated by OPT3. Together, these discoveries provide promising avenues for targeted strategies directed at increasing iron while decreasing cadmium density in the edible portions of crops and improving agricultural productivity in iron deficient soils. PMID:24867923

  5. Prevention of iron deficiency.

    PubMed

    Hallberg, L

    1994-12-01

    This chapter discusses different methods to prevent iron deficiency--to reduce iron losses (e.g. reducing menstrual iron losses by using a contraceptive pill or combating of hookworm infestation) or to increase iron absorption. Iron absorption can be increased (1) by modifying the composition of meals--increasing the content of dietary factors enhancing iron absorption (e.g. meat and ascorbic acid) or reducing the content of factors inhibiting iron absorption such as phytate and iron-binding phenolic compounds, (2) by increasing the iron content of the diet by fortification with iron, or by (3) supplementation with iron tablets. Several factors to consider in the choice of strategy are discussed such as the importance of the bioavailability of the diet for the efficacy of iron fortification, the choice of vehicle for iron fortification that is compatible with the iron compound used, the feasibility to increase the bioavailability of the dietary iron by modification of the composition of the diet and the short time available in pregnancy to ensure a sufficient supply of the extra iron needed limiting the effective measures available to supplementation with iron tablets.

  6. [Quality classification criteria of Paeonia suffruticosa seeds].

    PubMed

    Cao, Ya-yue; Zhu, Zai-biao; Guo, Qiao-sheng; Liu, Li; Wang, Chang-lin

    2015-02-01

    In order to establish the quality classification criteria of Paeonia suffruticosa seeds, thirty-one batches of P. suffruticosa seeds from different provenances were selected. The seed rooting rate, seed germination rate, seed purity, seed viability, 1,000-seed weight and moisture content were determined and analyzed through SPSS 20.0 software. Seed rooting rate, seed germination rate and seed purity were selected as the main index for classification, while 1,000-seed weight, seed viability and moisture content could be used as important references. The seed quality grading of P. suffruticosa was set as three grades. The seed quality of each grade should meet following requirements: For the first grade seeds, seed rooting rate ≥ 80%, seed germination rate ≥ 80%, seed purity ≥ 90%, seed viability ≥ 80%, 1,000-seed weight ≥ 250 g, moisture content, ≤ 10. For the second grade seeds, seed rooting rate ≥ 50%, seed germination rate ≥ 60%, seed purity ≥ 70%, seed viability ≥ 75%, 1,000-seed weight ≥ 225 g, moisture content ≤ 10. For the third grade seeds, seed rooting rate ≥ 20%, seed germination rate ≥ 45%, seed purity ≥ 60%, seed viability ≥ 45%, 1,000-seed weight ≥ 205 g, moisture content ≤ 10. The quality classification criteria of P. suffruticosa seeds have been initially established.

  7. GROWING SEEDS, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT, "GROWING SEEDS," IN WHICH SUCH BASIC SCIENCE SKILLS AND PROCESSES AS MEASUREMENT, OBSERVATION, AND HYPOTHESIS FORMATION ARE INTRODUCED THROUGH STUDENT ACTIVITIES INVOLVING SEEDS, GERMINATION, AND SEEDLING GROWTH. THE MATERIALS WERE DEVELOPED FOR USE IN…

  8. Longleaf Pine Seed Dispersal

    Treesearch

    William D. Boyer

    1963-01-01

    Production and dispersal of longleaf pine (Pinus palustris Mill.) seeds were sampled in 1955, 1957, and 1958 on the Escambia Experimental Forest in southwest Alabama.Two transects of seed traps were established at right angles to each of four forest walls enclosing a rectangular 80-acre clearing. Walls were oriented in the cardinal...

  9. Chapter 26. Seed germination

    Treesearch

    Kent R. Jorgensen; G. Richard Wilson

    2004-01-01

    Seed germination represents the means for survival and spread of many plants (McDonough 1977). Germination consists of three overlapping processes: (1) absorption of water, mainly by imbibition, causing swelling of the seed; (2) concurrent enzymatic activity and increased respiration and assimilation rates; and (3) cell enlargement and divisions resulting in emergence...

  10. California tree seed zones

    Treesearch

    John M. Buck; Ronald S. Adams; Jerrold Cone; M. Thompson Conkle; William J. Libby; Cecil J. Eden; Michel J. Knight

    1970-01-01

    California forest tree seed zones were established originally by Fowells (1946), with revisions proposed by Roy (1963) and Schubert (1966). The Forest Tree Seed Committee of the Northern California Section, Society of American Foresters, has revised the original zones and updated the recording system described in the earlier reports. Fowells' (1946) Research Note...

  11. Southern Pine Seed Sources

    Treesearch

    Ronald C. Schmidtling

    2001-01-01

    The selection of an appropriate seed source is critical for successful southern pine plantations. Guidelines for selection of seed sources are presented for loblolly (Pinus taeda L.), slash (P. elliottii Engelm.), longleaf (P. palustris Mill.), Virginia (P. virginiana Mill.), shortleaf (P. echinata...

  12. GROWING SEEDS, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT, "GROWING SEEDS," IN WHICH SUCH BASIC SCIENCE SKILLS AND PROCESSES AS MEASUREMENT, OBSERVATION, AND HYPOTHESIS FORMATION ARE INTRODUCED THROUGH STUDENT ACTIVITIES INVOLVING SEEDS, GERMINATION, AND SEEDLING GROWTH. THE MATERIALS WERE DEVELOPED FOR USE IN…

  13. LOADING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1958-10-01

    A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

  14. Nutrient composition of rose (Rosa canina L.) seed and oils.

    PubMed

    Ozcan, Musa

    2002-01-01

    Rose seeds were evaluated for weight of 100 seeds, moisture, crude protein, ash, crude oil, energy, and mineral content. Also, fatty acid composition was determined in the seed oils. The weight of 100 seeds, moisture, crude oil, energy, and iron (Fe) content of Ermenek rose seeds were found to be higher than those of other regions. The major fatty acids identified by gas chromatography of rose seed oils growing wild in the Hadim, Taskent, and Ermenek regions in Turkey were, respectively, as follows: palmitic (3.17%, 1.71%, and 2.14%), stearic (2.47%, 2.14%, and 1.69%), oleic (16.73%, 18.42%, and 14.71%), linoleic (54.41%, 51.71%, and 48,64%), linolenic (17.14%, 16.42%, and 18.41%), and arachidic (2.11%, 1.87%, and 2.61%). The seeds were rich in oil and minerals. The oil may be valuable for food and other uses because of its high unsaturated content.

  15. The earliest seeds

    USGS Publications Warehouse

    Gillespie, W.H.; Rothwell, G.W.; Scheckler, S.E.

    1981-01-01

    Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

  16. Seed germination and vigor.

    PubMed

    Rajjou, Loïc; Duval, Manuel; Gallardo, Karine; Catusse, Julie; Bally, Julia; Job, Claudette; Job, Dominique

    2012-01-01

    Germination vigor is driven by the ability of the plant embryo, embedded within the seed, to resume its metabolic activity in a coordinated and sequential manner. Studies using "-omics" approaches support the finding that a main contributor of seed germination success is the quality of the messenger RNAs stored during embryo maturation on the mother plant. In addition, proteostasis and DNA integrity play a major role in the germination phenotype. Because of its pivotal role in cell metabolism and its close relationships with hormone signaling pathways regulating seed germination, the sulfur amino acid metabolism pathway represents a key biochemical determinant of the commitment of the seed to initiate its development toward germination. This review highlights that germination vigor depends on multiple biochemical and molecular variables. Their characterization is expected to deliver new markers of seed quality that can be used in breeding programs and/or in biotechnological approaches to improve crop yields.

  17. Iron importers Zip8 and Zip14 are expressed in retina and regulated by retinal iron levels.

    PubMed

    Sterling, Jacob; Guttha, Samyuktha; Song, Ying; Song, Delu; Hadziahmetovic, Majda; Dunaief, Joshua L

    2017-02-01

    Intracellular retinal iron accumulation has been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of irreversible blindness among individuals over the age of 50. Ceruloplasmin/hephaestin double knockout mice (Cp/Heph DKO) and hepcidin knockout mice (Hepc KO) accumulate retinal iron and model some features of AMD. Two canonical pathways govern cellular iron import - transferrin-bound iron import and non-transferrin bound iron import. In Cp/Heph DKO and Hepc KO iron-loaded retinas, transferrin-bound iron import is downregulated. Despite this effort to reduce cellular iron burden, iron continues to accumulate in these retinas in an age-dependent manner. Quantitative RT-PCR and Western analysis were used to quantify the expression of three ferrous iron importers, Dmt1, Zip8, and Zip14, in wild-type (Wt), Cp/Heph DKO, and Hepc KO retinas. Zip8 and Zip14 protein levels were analyzed using Western analysis in mice injected intravitreally with either apo- or holo-transferrin to elucidate one possible mechanism of Zip14 regulation in the retina. Both zip8 and zip14 were expressed in the mouse retina. Paradoxically, protein levels of non-transferrin bound iron importers were upregulated in both Cp/Heph DKO and Hepc KO retinas. Intravitreal holo-transferrin injection decreased Zip 14 protein levels. These data indicate that Zip8 and Zip14 may take up increasing amounts of non-transferrin bound iron in these two mouse models of retinal iron accumulation. Their upregulation in these already iron-loaded retinas suggests a vicious cycle leading to toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Physiology of Oil Seeds

    PubMed Central

    Ketring, D. L.; Morgan, P. W.

    1972-01-01

    To further elucidate the regulation of dormancy release, we followed the natural afterripening of Virginia-type peanut (Arachis hypogaea L.) seeds from about the 5th to 40th week after harvest. Seeds were kept at low temperature (3 ± 2 C) until just prior to testing for germination, ethylene production, and internal ethylene concentration. Germination tended to fluctuate but did not increase significantly during the first 30 weeks; internal ethylene concentrations and ethylene production remained comparatively low during this time. When the seeds were placed at room temperature during the 30th to 40th weeks after harvest, there was a large increase in germination, 49% and 47% for apical and basal seeds, respectively. The data confirm our previous suggestion that production rates of 2.0 to 3.0 nanoliters per gram fresh weight per hour are necessary to provide internal ethylene concentrations at activation levels which cause a substantial increase of germination. Activation levels internally must be more than 0.4 microliter per liter and 0.9 microliter per liter for some apical and basal seeds, respectively, since dormant-imbibed seeds containing these concentrations did not germinate. Abscisic acid inhibited germination and ethylene production of afterripened seeds. Kinetin reversed the effects of ABA and this was correlated with its ability to stimulate ethylene production by the seeds. Ethylene also reversed the effects of abscisic acid. Carbon dioxide did not compete with ethylene action in this system. The data indicate that ethylene and an inhibitor, possibly abscisic acid, interact to control dormant peanut seed germination. The inability of CO2 to inhibit competitively the action of ethylene on dormancy release, as it does other ethylene effects, suggests that the primary site of action of ethylene in peanut seeds is different from the site for other plant responses to ethylene. PMID:16658179

  19. Iron and Your Child

    MedlinePlus

    ... vegetarian diet might also need added iron. What's Iron Deficiency? Iron deficiency is when a person's body doesn't have ... fact, many teenage girls are at risk for iron deficiency — even if they have normal periods — if their ...

  20. Iron stress in plants.

    PubMed

    Connolly, Erin L; Guerinot, Mary

    2002-07-30

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches

  1. Germination, growth rates, and electron microscope analysis of tomato seeds flown on the LDEF.

    PubMed

    Hammond, E C; Bridgers, K; Berry, F D

    1996-11-01

    The purpose of the experiment was to determine cosmic rays long-term effects on living tissue. A batch of tomato seeds were flown in orbit aboard the Long Duration Exposure Facility (LDEF) for almost 6 y. During this time, the seeds received an abundant exposure to cosmic radiation. Upon the return of the LDEF to Earth, the seeds were distributed throughout the United States and 30 foreign countries for analysis. Our university analysis included germination and growth rates as well as scanning electron microscopy (SEM) and X-ray analysis of the control as well as space exposed tomato seeds. In analyzing the seeds under the electron microscope, usual observations were performed on the nutritional and epidermis layer of the seed. These layers appeared to be more porous in the space exposed seeds than on Earth-based control seeds. This unusual characteristic may explain the increases in the space seeds growth pattern. (Several test results showed that the space-exposed seeds germinated sooner than Earth-based seeds. Also, the space-exposed seeds grew at a faster rate.) The porous nutritional region may allow the seeds to receive necessary nutrients and liquids more readily, thus enabling the plant to grow at a faster rate. Roots, leaves and stems were cut into small sections and mounted. After sputter coating the specimens with argon/gold palladium plasma, they were viewed under the electron microscope. Many micrographs were taken. The X-ray analysis displayed possible identifications of calcium, potassium, chlorine, copper, aluminum, silicon, phosphate, carbon, and sometimes sulfur and iron. The highest concentrations were shown in potassium and calcium. As a result of the electron interaction and X-ray production within the open seeds, the traditional layers of the space-exposed seed gave peaks of Mg, P and S, while the Earth seed gave an iron peak, which was not detected in the space-exposed seed because of electron beam positioning difference. The space

  2. Parenteral iron dextran therapy.

    PubMed

    Kumpf, V J; Holland, E G

    1990-02-01

    Parenteral iron therapy is indicated in patients with iron-deficiency anemia associated with conditions that interfere with the ingestion or absorption of oral iron. Replacement doses of iron required to replenish iron stores are based on body weight and the observed hemoglobin value. Methods of administering iron dextran are reviewed, including intramuscular and intravenous injections of the undiluted drug, intravenous infusion of a diluted preparation, and as an addition to parenteral nutrition solutions. The overall incidence of adverse reactions associated with the parenteral administration of iron is low, but the potential for an anaphylactic reaction requires that an initial test dose be given followed by careful patient observation.

  3. Iron Deficiency Anemia.

    PubMed

    DeLoughery, Thomas G

    2017-03-01

    Iron deficiency is one of the most common causes of anemia. The 2 main etiologies of iron deficiency are blood loss due to menstrual periods and blood loss due to gastrointestinal bleeding. Beyond anemia, lack of iron has protean manifestations, including fatigue, hair loss, and restless legs. The most efficient test for the diagnosis of iron deficiency is the serum ferritin. Iron replacement can be done orally, or in patients in whom oral iron is not effective or contraindicated, with intravenous iron. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Iron status of vegetarians.

    PubMed

    Craig, W J

    1994-05-01

    An appropriately planned well-balanced vegetarian diet is compatible with an adequate iron status. Although the iron stores of vegetarians may be reduced, the incidence of iron-deficiency anemia in vegetarians is not significantly different from that in omnivores. Restrictive vegetarian diets (eg, macrobiotic) are associated with more widespread iron-deficiency anemia. Western vegetarians who consume a variety of foods have a better iron status than do those in developing countries who consume a limited diet based on unleavened, unrefined cereals. Whereas phytates, polyphenolics, and other plant constituents found in vegetarian diets inhibit nonheme-iron absorption, vitamin C, citric acid, and other organic acids facilitate nonheme-iron absorption.

  5. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  6. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  7. Parenteral iron supplementation.

    PubMed

    Kumpf, V J

    1996-08-01

    Indications for the use of parenteral iron are limited to conditions in which the oral supplementation of iron is not possible or fails. An overview of iron balance and iron requirements is presented to describe situations in which iron supplementation may be required. When parenteral iron supplementation is required, careful attention to proper dosing and administration is necessary to optimize efficacy and safety. The purpose of this article is to review the literature regarding the clinical use of parenteral iron therapy and provide guidelines on dosing and administration. Methods of iron dextran administration, including the IV and intramuscular injection of undiluted drug and total dose infusion, are compared. Complications associated with the use of parenteral iron are also be reviewed. Finally, the use of iron supplementation in patients receiving parenteral nutrition care explored.

  8. Magnetic stimulation of marigold seed

    NASA Astrophysics Data System (ADS)

    Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

    2012-10-01

    The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

  9. Iron active electrode and method of making same

    DOEpatents

    Jackovitz, John F.; Seidel, Joseph; Pantier, Earl A.

    1982-10-26

    An iron active electrode and method of preparing same in which iron sulfate is calcined in an oxidizing atmosphere at a temperature in the range of from about 600.degree. C. to about 850.degree. C. for a time sufficient to produce an iron oxide with a trace amount of sulfate. The calcined material is loaded into an electrically conductive support and then heated in a reducing atmosphere at an elevated temperature to produce activated iron having a trace amount of sulfide which is formed into an electrode plate.

  10. Iron production maintenance effectiveness system

    SciTech Connect

    Augstman, J.J.

    1996-12-31

    In 1989, an internal study in the Coke and Iron Maintenance Department identified the opportunities available to increase production, by decreasing unscheduled maintenance delays from 4.6%. A five year front loaded plan was developed, and presented to the company president. The plan required an initial investment of $1.4 million and a conservative break-even point was calculated to be 2.5 years. Due to budget restraints, it would have to be self-funded, i.e., generate additional production or savings, to pay for the program. The program began in 1991 at number 2 coke plant and the blast furnaces. This paper will describe the Iron Production Maintenance Effectiveness System (ME), which began with the mechanical and pipefitting trades.

  11. Gastrins, iron homeostasis and colorectal cancer.

    PubMed

    Kovac, Suzana; Anderson, Gregory J; Baldwin, Graham S

    2011-05-01

    The peptide hormone gastrin has been identified as a major regulator of acid secretion and a potent mitogen for normal and malignant gastrointestinal cells. The importance of gastric acid in the absorption of dietary iron first became evident 50 years ago when iron deficiency anemia was recognized as a long-term consequence of partial gastrectomy. This review summarizes the connections between circulating gastrins, iron status and colorectal cancer. Gastrins bind two ferric ions with micromolar affinity and, in the case of non-amidated forms of the hormone, iron binding is essential for biological activity in vitro and in vivo. The demonstration of an interaction between gastrin and transferrin by biochemical techniques led to the proposal that gastrins catalyze the loading of transferrin with iron. Several lines of evidence, including the facts that the concentrations of circulating gastrins are increased in mice and humans with the iron overload disease hemochromatosis and that transferrin saturation positively correlates with circulating gastrin concentration, suggest the potential involvement of gastrins in iron homeostasis. Conversely, recognition that ferric ions play an unexpected role in the biological activity of gastrins may assist in the development of useful therapies for colorectal carcinoma and other disorders of mucosal proliferation in the gastrointestinal tract. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.

  12. Gastrins, Iron Homeostasis and Colorectal Cancer

    PubMed Central

    Kovac, Suzana; Anderson, Gregory J.; Baldwin, Graham S.

    2011-01-01

    The peptide hormone gastrin has been identified as a major regulator of acid secretion and a potent mitogen for normal and malignant gastrointestinal cells. The importance of gastric acid in the absorption of dietary iron first became evident 50 years ago when iron-deficiency anemia was recognised as a long-term consequence of partial gastrectomy. This review summarises the connections between circulating gastrins, iron status and colorectal cancer. Gastrins bind two ferric ions with micromolar affinity and, in the case of non-amidated forms of the hormone, iron-binding is essential for biological activity in vitro and in vivo. The demonstration of an interaction between gastrin and transferrin by biochemical techniques led to the proposal that gastrins catalyse the loading of transferrin with iron. Several lines of evidence, including the facts that the concentrations of circulating gastrins are increased in mice and humans with the iron-overload disease hemochromatosis and that transferrin saturation positively correlates with circulating gastrin concentration, suggest the potential involvement of gastrins in iron homeostasis. Conversely, recognition that ferric ions play an unexpected role in the biological activity of gastrins may assist in the development of useful therapies for colorectal carcinoma and other disorders of mucosal proliferation in the gastrointestinal tract. PMID:21320535

  13. Genetic modification of low phytic acid 1-1 maize to enhance iron content and bioavailability.

    PubMed

    Aluru, Maneesha R; Rodermel, Steve R; Reddy, Manju B

    2011-12-28

    High phytate co