Simon Labbé's work on iron and copper homeostasis

Iron and copper have a wealth of functions in biological systems,which makes them essential micronutrients for all living organisms.Defects in iron and copper homeostasis are directly responsible for diseases,and have been linked to impaired development,metabolic syndromes and fungal virulence.Consequently,it is crucial to gain a comprehensive understanding of the molecular bases of iron-and copper-dependent proteins in living systems.Simon Labbémaintains parallel programs on iron and copper homeostasis using the fission yeast Schizosaccharomyces pombe(Schiz.pombe) as a model system.The study of fission yeast transition-metal metabolism has been successful,not only in discerning the genes and pathways functioning in Schiz.pombe,but also the genes and pathways that are active in mammalian systems and for other fungi.

Recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation: process optimization and mineralogical study

Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150A degrees C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.

Simple, Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel(Ⅱ), Copper (Ⅱ), Cobalt (Ⅱ), and Iron (Ⅲ) with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.

Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation（LPS） prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.

Effect of Copper and Iron on Acidogenic Biomass in an Anaerobic Packed Bed Reactor

The aim of this study was to evaluate the effect of copper and iron on acidogenic biomass immobilized on clinoptilolite in an anaerobic packed bed reactor. Copper and iron were fed to the reactor at concentrations of 100 and 300 mg&middotL-1, respectively. Both metal ions had insignificant inhibitory effect over the metabolism of the biomass, specifically, on substrate consumption and production of volatile fatty acids (VFAs). The microstructural characterization of the biofilm by Scanning Electron Microscopy showed no effect on the morphology of the microorganisms after the metals treatment. Copper and iron removal was also measured in the reactor, achieving a breakthrough time of 3 days, during which removal efficiencies were higher than 90%. It was also observed that the biomass had a greater affinity for copper. The results indicate that acidogenic biomass can be used effectively as a sorbent agent. The pollution of river-streams with heavy metals—mainly copper and iron—was one of the most compelling motivations for conducting this investigation. The San Pedro River Basin, a trans-boundary river that originates near the mining town of Cananea, Sonora, México, and flows to Arizona, USA, exemplifies this environmental issue.

Influence of Ferric and Ferrous Iron on Chemical and Bacterial Leaching of Copper Flotation Concentrates

The effects of ferrous and ferric iron as well as redox potential on copper and iron extraction from the copper flotation concentrate of Sarcheshmeh, Kerman, Iran, were evaluated using shake flask leaching examinations. Experiments were carried out in the presence and absence of a mixed culture of moderately thermophile microorganisms at 50?C. Chemical leaching experiments were performed in the absence and presence of 0.15 M iron (ferric added medium, ferrous added medium and a mixture medium regulated at 420 mV, Pt. vs. Ag/AgCl). In addition, bioleaching experiments were carried out in the presence and absence of 0.1 M iron (ferric and ferrous added mediua) at pulp density 10% (w/v), inoculated bacteria 20% (v/v), initial pH 1.6, nutrient medium Norris and yeast extract addition 0.02% (w/w). Abiotic leaching tests showed that the addition of iron at low solution redox potentials significantly increased the rate and extent of copper dissolution but when ferric iron was added, despite a higher initial rate of copper dissolution, leaching process stopped. Addition of both ferrous and ferric iron to the bioleaching medium levelled off the copper extraction and had an inhibitory effect which decreased the final redox potential. The monitoring of ferrous iron, ferric iron and copper extraction in leach solutions gave helpful results to understand the behaviour of iron cations during chemical and bacterial leaching processes.

Copper slag assisted coke reduction of phosphogypsum for sulphur dioxide preparation

The reduction of phosphogypsum(PG)to lime slag and SO_(2)using coke can effectively alleviate the environmental problems caused by PG.However,the PG decomposition temperature remains high and the product yield remains poor.By adding additives,the decomposition temperature can be further reduced and PG decomposition rate and product yield can be improved.However,the use of current additives such as Fe_(2)O_(3)and SiO_(2)brings the problem of increasing economic cost.Therefore,it is proposed to use solid waste copper slag(CS)as a new additive to reduce PG to prepare SO2,which can reduce the cost and meet the environmental benefits at the same time.The effects of proportion,temperature and thermostatic time on PG decomposition are investigated by experimental and kinetic analysis combined with FactSage thermodynamic calculations to optimize the roasting conditions.Finally,the reaction mechanism is proposed.It is found that adding CS to the coke and PG system can increase the rate of PG decomposition and SO_(2)yield while lowering the PG decomposition temperature.For example,when the CS/PG mass ratio increases from 0 to 1,PG decomposition rate increases from 83.38%to 99.35%,SO_(2)yield increases from 78.62%to 96.81%,and PG decomposition temperature decreases from 992.4℃to 949.6℃.The optimal reaction parameters are CS/PG mass ratio of 1,Coke/PG mass ratio of 0.06 at 1100℃for 20 min with 99.35%PG decomposition rate and 96.81%SO_(2) yield.The process proceeds according to the following reactions:2CaSO_(4)+ 0.7C + 0.8Fe_(2)SiO_(4)→0.8Ca_(2)SiO_(4)+ 0.2Ca_(2)Fe_(2)O_(5)+ 0.4Fe_(3)O_(4)+2SO_(2)+ 0.7CO_(2)Finally,a process for decomposing PG with coke and CS is proposed.

Iron, Zinc, and Copper Malnutrition among Primary School Children in Lagos, Niagara

This study assessed the iron, zinc and copper status of primary school-attending children in Lagos. A sample of 200 primary School-attending children was randomly selected using a stratified 2 – stage sampling technique. Data was collected in the 2 major seasons in Nigeria;Dry and Rainy seasons using dietary intake (24 hr dietary recall protocol) venipuncture blood samples, and a self-administered questionnaire. The data were analyzed using descriptive and inferential statistics. Among ages 5 - 8 years, the main dietary intake for iron was 10.66 ± 12.44 mg/d (106% of DRI), for zinc, 7.30 ± 7.39 mg/d (92% of DRI) and for copper, 1.55 ± 1.31 mg/d (390% of DRI). For ages 9 - 13 yrs, the mean intake of micronutrients showed that iron was 11.03 ± 12.72 mg/d (138% of DRI), 3inc was 8.44 ± 7.7 mg/d (105% of DRI) and copper was 3.75 ± 15.17 mg/d (536% of DRI). Biochemical results indicated that 19.8% of the subjects had inadequate serum iron, 21% and 32.1% were zinc and copper deficient respectively prevalence of anemia was 38.1% while iron deficiency anemia was 13.06% and iron deficiency was 34.6%. Dietary intakes did not provide right amounts of micronutrients to meet body requirements. There is the need to formulate and implement nutrition education programs to correct micronutrient deficiency among primary school-attending children in Lagos, Nigeria.

Effect of routine iron supplementation on copper level and oxidative stress status in pregnant women

Objective:To determine the effects of routine iron supplementation on oxidative stress markers in pregnant women.Methods:This study enrolled 122 pregnant women aged between 20-38 years throughout three stages of pregnancy:beginning with pregnancy,until the twentieth week and up to the thirtieth week.They were divided into two groups:61 pregnant women not supplemented with iron(the control group),and 61 pregnant women supplemented with iron(the iron group).Blood samples were collected and protein,iron,uric acid,total bilirubin level and oxidative stress status were estimated using molecular spectrophotometric method.Copper levels were estimated by using atomic absorption spectroscopy method.Results:Iron,protein and copper concentrations were significantly increased(P<0.05)at 20 and 30 weeks of pregnancy and hemoglobin level was significantly increased(P<0.05)at the beginning of pregnancy and until 20 weeks in the iron group compared to the control group.In addition,levels of serum uric acid,serum total bilirubin and malondialdehyde in serum and erythrocytes were significantly increased at 20 and 30 weeks of pregnancy whereas the reduced glutathione level was significantly decreased in serum(30 weeks of pregnancy)and erythrocytes(20 and 30 weeks of pregnancy)in the iron group as compared to the control group.Serum oxygen radical absorbance capacity was not significantly changed.There was a significant positive correlation between serum iron level and serum copper,malondialdehyde level in serum and erythrocytes in pregnant women supplemented with iron.Conclusions:Iron supplement at 20 and 30 weeks of pregnancy plays a role in the development of oxidative stress which is the origin of several maternal-fetal complications.

Effect of Ceria on Structure and Thermostability of Copper-Iron-Oxide Catalyst

The solid structures and thermostabilities of Cu-Fe-O and Cu-Fe-Ce-O supported on alumina were studied by XRD, ESR, Mossbauer and TPR techniques. The studies indicate that there are Fe2CuO4, CuO and alpha-Fe2O3 phases in Cu-Fe-O with the granula of less than 13 nm. With the catalyst pretreatment temperature rising, the crystallite of Fe2CuO4 in the catalysts grows up and that of CuO disappears gradually. The presence of Ce leads to the increase of Cu2+ concentration, inhibits the crystal growth of CuO and Fe2CuO4 in the catalyst except that of Fe2O3, and eliminates the difference for reductive reaction of oxygen in Fe-O and Cu-O. At 800 degrees C, the crystal growth of Fe2O3 in Cu-Fe-Ce-O is slower than that in Cu-Fe-O, i.e., CeO2 in Cu-Fe-Ce-O inhibits the growth of Fe2O3 phase effectively, and enhances the thermostability of catalysts so as to avoid the sintering of active elements in catalysts. CeO2 promotes the reducibility of catalysts at lower temperature.

Petrology, Structural and Geochemistry of the Copper-Nickle-Iron Bearing Rocks in Korr-Marsabit Area, Northern Kenya

The main objective of this study was to investigate copper-Nickle-Iron bearing rocks of the northern Kenya, and understand their mode of formation. The area of study is bounded by latitudes 2&#186;52'00"N and 1&#186;52'00"N and longitudes 37&#186;19'00"E and 37&#186;36'00"E, South West of Marsabit town. The methods involved geological field mapping between September, 2020 and December 2020. Elemental analyses of the samples were done using an XRF. Pearsonian correlation on the analyzed elements was done using Oasis Montaj 8.4. Fabric8 software was used to analyze structural data. The area comprises metamorphic, igneous and sedimentary rocks. Metamorphic rocks include biotite hornblende gneisses, biotite gneisses, biotite muscovite gneisses and marbles. Basalts of different mineralogy were also found in the area. Colluvium and alluvium sediments were found covering some of the metamorphic rocks in some areas. Malachite occurs in gneisses in the central part of the area. The area has undergone deformation, which includes jointing and folding. The fold axis trend in the North-South direction and plunges to the southern part of the area. Correlation of the elements shows that there is a positive correlation of Copper-Nickel-Iron. This indicates similar mode of delivery within the host rocks. Kriging indicates spatial distribution of these elements within the study area. The average size of distribution can easily be computed from the maps produced by kriging.

Separation of copper and iron from chloride media using Cyanex 921 in kerosene

The extraction and separation of Cu(Ⅱ)and Fe(Ⅲ)from HCl media using Cyanex 921 in kerosene were investigated.The effect of shaking time,aqueous phase acid concentration,Fe(Ⅲ)/Cu(Ⅱ)concentration,Cyanex 921 concentration,temperature and aqueous to organic phase ratio on the separation of Cu(Ⅱ)and Fe(Ⅲ)was studied using 0.1 mol/L Cyanex 921 in kerosene.Maximum separation was achieved from 2 mol/L HCl containing 0.001 mol/L Cu(Ⅱ)and 0.005 mol/L Fe(Ⅲ)with 0.1 mol/L Cyanex 921 in kerosene.Feasible separation of copper and iron was also possible from 5 mol/L HCl using 0.02 mol/L Cyanex 921.

Studies of Sulphur- and Iron-induced Copper Deficiency in Tibetan Sheep

The clinical signs of Tibetan sheep with sulphur- and iron-induced copper deficiency in Maqu County of Gansu Province were defined as thin, decreased appetite, neonatal ataxia, pica, emaciation, and loss of hair color and anemia. The mineral composition of soil and forage, and samples of liver, blood and hair from Tibetan sheep in affected ranches in this region were compared with those from unaffected areas. The mean concentration of iron in soil and forage in affected pasture was 19 675 ±791 and 1 763 ±197 μg/g, respectively, compared with 8 761 ±871 and 357 ±39 μg/g in unaffected pasture. The mean concentration of sulphur in soil and forage in affected pasture was 1.98% ±0.79% and 0.88% ±0.16%, respectively, compared with 1.16%±0.26% and 0.47%±0.16%in unaffected pasture. The mean copper concentrations in soil and forage from the affected pastures were 15.9±1.8 and 6.7±1.6 μg/g, respectively, compared with 16.7±1.9 and 8.9±2.7 μg/g in unaffected pasture.The mean concentration of Cu in blood, liver, and hair from the affected Tibetan sheep were 0.32±0.12, 51.2±3.1 and 2.16±0.65μg/g, respectively, compared with 0.76±0.21, 191±11 and 3.27±0.96 μg/g for healthy animals. Oral administration of CuClO(OH)3prevented and cured anemia. We conclude that wool eating of Tibetan sheep in this region is probably caused by secondary Cu deficiency, mainly due to the high iron and sulphur contents in soils and forage.

Tissue Carcinoembryonic Antigen,Calcium,Copper and Iron Levels in Cancerous Lung Patients

Background and objective The expression of various trace elements and markers in lung cancer is controversial.The aim of this study is to evaluate the presence of calcium(Ca),copper(Cu),iron(Fe) and carcinoembryonic antigen(CEA) in cancerous untreated lung tissues and to determine a possible association between these markers and lung cancer.Methods Fourty-eight cancerous lung tissue blocks,from Sultan Qaboos University Hospital,Sultanate of Oman,were studied.Fe,Ca,Cu,and CEA were demonstrated in the tissue blocks using Perl's Prussian blue,Von Kossa's,modified rhodanine and immunohistochemical staining methods,respectively.Results Twenty-three of 48 specimens showed positive Fe staining,2 showed positive Ca staining and Cu was absent in all specimens.93.7% expressed CEA in varying degree of positivity.81.25% of these sections showed high expression of CEA.Conclusion Tissue concentrations of trace elements were not elevated in lung cancer and therefore cannot be considered as a potential marker.Despite the low sensitivity and specificity of CEA as previously reported,tissue CEA should be considered as a potential marker in the evaluation of lung cancer.

Influences of copper on solidification structure and hardening behavior of high chromium cast irons

The influences of copper on microstructure and the hardening behavior of high chromium cast irons subjected to sub-critical treatment were investigated. The results show that the microstructure of the as-cast high chromium cast irons consists of retained austenite, martensite and M7C3 type eutectic carbide. When copper is added into high chromium cast irons, austenite and carbide contents are increased. The increased addition of copper content from 0% to 1.84% leads to the increase of austenite and carbide from 15.9% and 20.0% to 61.0% and 35.5%, respectively. In the process of sub-critical treatment, the retained austenite in the matrix can be precipitated into secondary carbides and then transforms into martensite in cooling process, which causes the secondary hardening of the alloy under sub-critical treatment. High chromium cast irons containing copper in sub-critical treatment appear the second hardening curve peak due to the precipitation of copper from supersaturated matrix.

Ultra fast microwave-assisted leaching for the recovery of copper and tellurium from copper anode slime

The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. Leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology（RSM）. Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ± 0.16% and 98.68% ± 0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.

Agglomeration and leaching behaviors of copper oxides with different chemical binders

The chemical binder is one of the critical factors affecting ore agglomeration behavior and leaching efficiency.In this study,we in-vestigated the effect of the type of binder and mass fraction of the H_(2)SO_(4)solution used on the curing,soaking,and leaching behavior of ag-glomerations.The results revealed that Portland cement(3CaO·SiO_(2),2CaO·SiO_(2),and 3CaO·Al_(2)O_(3))was the optimal binder for obtaining a well-shaped,stable agglomeration structure.A higher extraction rate was achieved when using Portland cement than that obtained using sodi-um silicate,gypsum,or acid-proof cement.An excessive geometric mean size is not conducive to obtaining well-shaped agglomerations and desirable porosity.Using computed tomography(CT)and MATLAB,the porosity of two-dimensional CT images in sample concentrations L1-L3 was observed to increase at least 4.5vol%after acid leaching.Ore agglomerations began to be heavily destroyed and even to disinteg-rate when the sulfuric acid solution concentration was higher than 30 g/L,which was caused by the excessive accumulation of reaction products and residuals.

Sulfur-Induced Copper Deficiency in the Yaks

Since the 1990s, yak in the Haizi area in China has been affected by an ailment characterized by pica, emaciation, dyskinesia, and anemia. To determine the cause of disease, the mineral composition of soil and forages, and samples of blood, hair, and liver of yaks from the Haizi area in China were determined. The concentrations of copper in soil and forage from affected ranches and unaffected areas are within the normal ranges. The mean concentration of copper in blood and liver from the affected yaks was （0.31±0.03） and （13.7±3.1）μg·g^-1 respectively, compared with （0.98±0.16） and （95.6±11.2）μg·g^-1 for unaffected yaks. The concentrations of sulfur in soil and forage from affected ranches were （1.91±0.26） and （1.37±0.17）%, respectively, compared with （1.11±0.31） and （0.52±0.18）% （dry matter） for normal areas. The contents of sulfur in blood and liver affected animals were （7.32±1.8） and （2.54±3.1）%, respectively, compared with （4.22±0.73） and （1.31±0.33）% （in fresh and soft tissues） for healthy animals, respectively. Oral administration of tribasic copper chloride prevented and cured the disease. Thus it is reasonable to conclude that ailments of yaks in the Haizi area are probably caused by a secondary copper deficiency, mainly due to high sulfur content in soil and forage.

Ore Minerals and Genesis of Lala Copper Deposit,Sichuan Province

The Lala Cu deposit in Sichuan Province is one of the most important large deposits in SW China,both in terms of Cu and associated Au-Mo-Co-REE-Fe. Systematic ore petrology study shows that ore minerals are mainly composed of hydrothermal magnetite,chalcopyrite and molybdenite.The wall-rock alterations include biotitization,silicification, carbonatation,albitization,potash feldspathization, apatitation,actinolitation and fluoritation,et al. The Pyrite and magnetite have euhedral-subhedral crystalline grained texture and the chalcopyrite