期刊文献+
共找到2,572篇文章
< 1 2 129 >
每页显示 20 50 100
Tissue Carcinoembryonic Antigen,Calcium,Copper and Iron Levels in Cancerous Lung Patients
1
作者 Nasar YousufALWAHAIBI Jokha Sultan ALGHARIBI +1 位作者 Amna Salirn ALSHUKAILI Ahmed Khalifa ALSHUKAILI 《中国肺癌杂志》 CAS 2011年第1期28-32,共5页
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 a... 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. 展开更多
关键词 肺癌 免疫学 临床分析 患者
下载PDF
Simon Labbé's work on iron and copper homeostasis
2
作者 Simon Labbé 《World Journal of Biological Chemistry》 CAS 2010年第5期196-200,共5页
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... 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. 展开更多
关键词 iron and copper transport SYSTEMS Metalloregulatory sensors iron-and copper-responsivegenes Metal TRAFFICKING pathways METALLOENZYMES Fungi as model SYSTEMS
下载PDF
Recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation: process optimization and mineralogical study 被引量:2
3
作者 Rui-min Jiao Peng Xing +2 位作者 Cheng-yan Wang Bao-zhong Ma Yong-Qiang Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第9期974-982,共9页
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. ... 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%. 展开更多
关键词 copper tailings iron direct reduction magnetic separation RECOVERY process optimization
下载PDF
Modification of ash flow properties of coal rich in calcium and iron by coal gangue addition 被引量:4
4
作者 Huaizhu Li Lingxue Kong +3 位作者 Jin Bai Zongqing Bai Zhenxing Guo Wen Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第7期239-246,共8页
Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of whic... Flow property of coal ash and slag is an important parameter for slag tapping of entrained flow gasifier.The viscosity of slag with high contents of calcium and iron exhibits the behavior of a crystalline slag,of which viscosity sharply increases when temperature is lowered than temperature of critical viscosity(TCV).The fluctuation in temperature near the TCVcan cause an accumulation of slag inside the gasifier.In order to prevent slag blockage,it is necessary to adjust the ash composition by additive to modify the flow property of coal rich in calcium and iron.Main components of coal gangue are Al_(2)O_(3) and SiO_(2),which is a potential additive to modify the ash flow properties of these coals.In this work,we investigated the ash flow properties of a typical coal rich in calcium and iron by adding coal gangue with different SiO_(2)/Al_(2)O_(3)ratio.The results showed that the ash fusion temperatures(AFTs)firstly decreased,and then increased with increasing amount of coal gangue addition.Chemical composition of coal ash rich in calcium and iron moved from gehlenite primary phase to anorthite,quartz and corundum primary phases.The slags with coal gangue addition behaved as a glassy slag,of which the viscosity gradually increased as temperature decreased.Besides,a high SiO_(2)/Al_(2)O_(3)ratio of coal gangue was beneficial to modify the slag viscosity behavior.Addition of coal gangue with a high SiO_(2)/Al_(2)O_(3)ratio impeded formation of crystalline phases during cooling.This work demonstrated that coal gangue addition was an effective way to improve the ash flow properties of the coal rich in calcium and iron for the entrained flow gasifier. 展开更多
关键词 Coal gangue Coal rich in calcium and iron Ash fusion temperatures Viscosity-temperature characteristic Phase transformation
下载PDF
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 被引量:2
5
作者 Sajid H. Guzar JIN Qin-han 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第2期143-147,共5页
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 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. 展开更多
关键词 copper(Ⅱ) Nickel(Ⅱ) Cobalt(Ⅱ) iron(Ⅲ) 2-Pyridine carboxaldehyde isonicotinyl hydrazone(2-PYAINH) SPECTROPHOTOMETRY
下载PDF
Microstructure and properties of pure iron/copper composite cladding layers on carbon steel 被引量:3
6
作者 Long Wan Yong-xian Huang +2 位作者 Shi-xiong Lü Ti-fang Huang Zong-liang Lü 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第8期920-927,共8页
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 o... 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. 展开更多
关键词 tungsten inert gas welding metal cladding pure iron copper carbon steel interfacial properties
下载PDF
Effect of Copper and Iron on Acidogenic Biomass in an Anaerobic Packed Bed Reactor 被引量:1
7
作者 Gonzalo M. Figueroa-Torres Maria T. Certucha-Barragán +5 位作者 Francisco J. Almendariz-Tapia Onofre Monge-Amaya Evelia Acedo-Félix Martín I. Pech-Canul Ana L. Leal-Cruz Carlos I. VillaVelázquez-Mendoza 《Advances in Bioscience and Biotechnology》 2014年第6期564-571,共8页
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 ... 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. 展开更多
关键词 ACIDOGENESIS ANAEROBIC Digestion BIOMASS copper iron CLINOPTILOLITE
下载PDF
Distribution and Form of Iron and Calcium Compounds Before and After Residue Hydrogenation Under Different Space Velocities 被引量:1
8
作者 Wang Xianyuan Zhang Tao +3 位作者 Zhang Longli Zhao Yusheng Yang Chaohe Cui Ruili 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2022年第3期86-94,共9页
The distribution and form of iron and calcium compounds were studied using hydrogenation feedstock and hydrogenation products with different space velocities as the research object.The content of metallic elements,suc... The distribution and form of iron and calcium compounds were studied using hydrogenation feedstock and hydrogenation products with different space velocities as the research object.The content of metallic elements,such as calcium and iron in hydrogenation feedstock,and extract samples were determined via flame atomic absorption spectrometry.The water-soluble iron and calcium species in oil samples were determined by an IC2010 high-throughput ion chromatograph.Nearly 60%-80%of the iron or calcium compounds were mainly concentrated in resins and asphaltenes.Iron and calcium compounds mainly exist in the form of oil-soluble metal species in hydrogenation feedstock and hydrogenation products.Under certain conditions of reaction temperature,pressure,and volume ratio of hydrogen to oil,when the reaction space velocity was 0.6 h^(−1),about 30%of the iron or calcium compounds were converted from oil-soluble to water-soluble species after hydrogenation.When the reaction space velocity was decreased from 1.70 to 0.60 h^(−1),the proportion of iron compounds converted from oil-soluble to water-soluble increased from 8.4%to 28%.Moreover,the proportion of calcium compounds converted from oil-soluble to water-soluble increased from 10%to 37%.This denotes that with decreasing reaction space velocity,the ratio of oil-soluble to water-soluble species increases.Water-soluble iron and calcium compounds are present in the form of inorganic salts,such as chlorate and sulfate.This study helps in understanding the removal mechanism of iron and calcium compounds and optimizing the operating conditions of residue hydrogenation. 展开更多
关键词 residue hydrogenation space velocity iron compounds calcium compounds SPECIES
下载PDF
Influence of Ferric and Ferrous Iron on Chemical and Bacterial Leaching of Copper Flotation Concentrates 被引量:1
9
作者 Ali Ahmadi 《International Journal of Nonferrous Metallurgy》 2012年第3期42-48,共7页
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 examination... 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. 展开更多
关键词 Ferric iron FERROUS iron copper CONCENTRATE LEACHING Redox Potential
下载PDF
THE STUDY ON THE CHANGES OF ZINC, COPPER, CALCIUM AND MAGNESIUM IN PLASMA AND ERYTHROCYTES DURING CARDIOPULMONARY BYPASS
10
作者 耿希刚 李兆志 +1 位作者 李明 师桃 《Journal of Pharmaceutical Analysis》 SCIE CAS 2004年第1期71-74,共4页
Objective To study the changes and their influence factors involved of zinc, copper, calcium and magnesium in plasma and erythrocytes during cardiopulmonary bypass(CPB). Methods Zinc, copper, calcium and magnesium v... Objective To study the changes and their influence factors involved of zinc, copper, calcium and magnesium in plasma and erythrocytes during cardiopulmonary bypass(CPB). Methods Zinc, copper, calcium and magnesium values in plasma and erythrocytes were measured by atomic absorption spectrophotometer during CPB. Results Zinc and copper levels in plasma were significantly elevated above preinduction level before perfusion, but calcium and magnesium levels did not change significantly; zinc, copper and calcium levels in plasma were significantly below preoperation level during CPB, but magnesium level in plasma was significantly increased above preoperation; zinc level in plasma was increased to preoperation level after CPB and began to decrease again at 8 hours after CPB, copper level in plasma was increased to preoperation level at 20 hours after CPB, calcium in plasma was increased significantly from beginning to 8 hours after CPB, magnesium level in plasma was decreased to preoperation level at 8 hours afterCPB. Concentration of zinc , copper, calcium and magnesium in erythrocytes did not change significantly. Conclusion During CPB, the changes of zinc, copper, calcium and magnesium had relation to hemodilution, operative wound, carrier protein, stress and component of priming solution and cardioplegic solution, but no relation to transfer from plasma erythrocytes. The results indicate that it is beneficial to patient's recovery to supplement zinc, copper, calcium and magnesium properly by different ways during cardiac perioperation. 展开更多
关键词 cardiopulmonary bypass cardiac surgery ZINC copper calcium MAGNESIUM
下载PDF
Calcium channels and iron uptake into the heart
11
作者 Nipon Chattipakorn Sirinart Kumfu +1 位作者 Suthat Fucharoen Siriporn Chattipakorn 《World Journal of Cardiology》 CAS 2011年第7期215-218,共4页
Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overl... Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overload cardiomyopathy,a condition which provokes mortality due to heart failure in iron-overloaded patients.Currently,the mechanism of iron uptake into cardiomyocytes is still not clearly understood.Growing evidence suggests L-type Ca2+channels(LTCCs)as a possible pathway for ferrous iron(Fe2+)uptake into cardiomyocytes under iron overload conditions.Nevertheless,controversy still exists since some findings on pharmacological interventions and those using different cell types do not support LTCC’s role as a portal for iron uptake in cardiac cells.Recently,T-type Ca2+channels (TTCC)have been shown to play an important role in the diseased heart.Although TTCC and iron uptake in cardiomyocytes has not been investigated greatly,a recent finding indicated that TTCC could be an important portal in thalassemic hearts.In this review,comprehensive findings collected from previous studies as well as a discussion of the controversy regarding iron uptake mechanisms into cardiomyocytes via calcium channels are presented with the hope that understanding the cellular iron uptake mechanism in cardiomyocytes will lead to improved treatment and prevention strategies,particularly in iron-overloaded patients. 展开更多
关键词 CARDIOMYOCYTES L-TYPE calcium channel T-TYPE calcium channels iron OVERLOAD THALASSEMIA
下载PDF
Dissolution Equilibrium of Calcium Vapor in Liquid Iron
12
作者 Song Bo Han Qiyong Zhang Xiaodong 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 1996年第1期11-13,共3页
The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace by using vapor pressure method.A sealed Mo reaction chamber and a self-made CaO crucible were use... The dissolution equilibrium of calcium vapor in liquid iron was carried out at 1873 K in a two-temperature zone furnace by using vapor pressure method.A sealed Mo reaction chamber and a self-made CaO crucible were used in this experiment.The thermodynamic parameters obtained are as follows for reaction Ca(g) =[Ca]\nK = 4.27-15040/T△G^0 = 125000-35.5T J/mol The relation between dissolved amount of calcium in liquid iron(1873K) and calcium vapor pressure is expressed as[%Ca]= 0.028 pc. 展开更多
关键词 calcium liquid iron dissolution equilibrium thermodynamic parameter
下载PDF
Effects of Copper-Zinc Alloy Doped with Rare Earth Elements on Crystal of Calcium Carbonate 被引量:1
13
作者 丁燕 聂磊 +2 位作者 梁金生 汤庆国 陈蔓蔓 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S1期448-451,共4页
A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiti... A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiting ability of the alloy was tested by a corrosion measurement system and a scale inhibition evaluation system, respectively. Scale samples were characterized with SEM and XRD. It is found that the transfer of cations could be promoted by doping with proper rare earth elements, and the corrosion potentials descend by 25~126 mV. The results indicated that the copper-zinc alloy doped with rare earth elements has higher scale inhibiting ability of CaCO3. The growth of calcite was affected by zinc ions dissolved because of primary battery reaction, and the transition of calcium carbonate from aragonite to calcite was hampered resulting in the proportion of aragonite to calcite is changed from 1.7∶1 to 2.7∶1. 展开更多
关键词 rare earth elements copper-zinc alloy calcium carbonate CALCITE ARAGONITE scale inhibit CRYSTAL
下载PDF
Iron, Zinc, and Copper Malnutrition among Primary School Children in Lagos, Niagara
14
作者 Ifeoma A. Akeredolu Babatunde E. Oguntona +1 位作者 Chinwe Okafor Olufemi J. Osisanya 《Food and Nutrition Sciences》 2011年第10期1063-1070,共8页
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 techni... 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. 展开更多
关键词 MICRONUTRIENT Status iron ZINC copper Primary School Children Nigeria
下载PDF
Effect of routine iron supplementation on copper level and oxidative stress status in pregnant women
15
作者 Derouiche Samir Doudi Dalal Atia Noura 《Asian pacific Journal of Reproduction》 2020年第2期64-69,共6页
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 pregn... 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. 展开更多
关键词 PREGNANCY iron copper OXIDATIVE stress WOMEN
下载PDF
Copper Recovery from Barren Cyanide Solution by Using Electrocoagulation Iron Process
16
作者 José R. Parga Guillermo Tiburcio Munive +2 位作者 Jesús L. Valenzuela Víctor V. Vazquez Gregorio González Zamarripa 《Advances in Chemical Engineering and Science》 2013年第2期150-156,共7页
This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plan... This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to cyanide solution employed in gold processing, effluents generated have high contents of free cyanide as well as copper cyanide complexes, which lend them a high degree of toxicity. In this regard, two options for the treatment of cyanide barren solutions has been used;in two ways;first for cyanide destruction by oxidation with the use of the EC process, in theory, has the advantage of decomposing cyanide at the anode and collecting copper simultaneously by a sludge of copper magnetic iron. In both cases excellent performance can be achieved using the high capacity of the bipolar iron EC technology. We found that it is possible to reduce the copper cyanide complex from 720 mg·l-1 to below 10 mg·l-1 within 20 minutes. 展开更多
关键词 copper Recovery ELECTROCOAGULATION PROCESS BIPOLAR iron ELECTRODES CYANIDE
下载PDF
Study of diclofenac removal by the application of combined zero-valent iron and calcium peroxide nanoparticles in groundwater
17
作者 Wen Liang Nian-qing Zhou +3 位作者 Chao-meng Dai Yan-ping Duan Lang Zhou Yao-jen Tu 《Journal of Groundwater Science and Engineering》 2021年第3期171-180,共10页
Diclofenac(DCF)is one of the most frequently detected pharmaceuticals in groundwater,posing a great threat to the environment and human health due to its toxicity.To mitigate the DCF contamination,experiments on DCF d... Diclofenac(DCF)is one of the most frequently detected pharmaceuticals in groundwater,posing a great threat to the environment and human health due to its toxicity.To mitigate the DCF contamination,experiments on DCF degradation by the combined process of zero-valent iron nanoparticles(nZVI)and nano calcium peroxide(nCaO_(2))were performed.A batch experiment was conducted to examine the influence of the adding dosages of both nZVI and nCaO_(2)nanoparticles and pH value on the DCF removal.In the meantime,the continuous-flow experiment was done to explore the sustainability of the DCF degradation by jointly adding nZVI/nCaO_(2)nanoparticles in the reaction system.The results show that the nZVI/nCaO_(2)can effectively remove the DCF in the batch test with only 0.05 g/L nZVI and 0.2 g/L nCaO_(2)added,resulting in a removal rate of greater than 90%in a 2-hour reaction with an initial pH of 5.The degradation rate of DCF was positively correlated with the dosage of nCaO_(2),and negatively correlated with both nZVI dosage and the initial pH value.The order of significance of the three factors is identified as pH value>nZVI dosage>nCaO_(2)dosage.In the continuous-flow reaction system,the DCF removal rates remained above 75%within 150 minutes at the pH of 5,with the applied dosages of 0.5 g/L for nZVI and 1.0 g/L for nCaO_(2).These results provide a theoretical basis for the nZVI/nCaO_(2)application to remove DCF in groundwater. 展开更多
关键词 Nanoscale zero-valent iron(nZVI) Nano calcium peroxide(nCaO_(2)) DICLOFENAC Fenton-like reaction Groundwater pollution
下载PDF
Effect of Ceria on Structure and Thermostability of Copper-Iron-Oxide Catalyst
18
作者 卢冠忠 王幸宜 +1 位作者 王筠松 汪仁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2000年第3期190-195,共6页
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... 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. 展开更多
关键词 rare earths CERIA copper-iron-oxide catalyst thermostability
下载PDF
Experiment Research on the Enrichment of Precious Metals from Nickel-copper-iron Matte
19
作者 FAN Xingxiang LIU Yang +4 位作者 DONG Haigang FU Guangqiang WU Yuedong ZHAO Jiachun WU Xiaofeng 《贵金属》 CAS CSCD 北大核心 2012年第A01期5-10,共6页
According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals... According to the chemical and phase composition of the nickel-copper-iron matte containing precious metals and the progress in enrichment of precious metals from the nickel-copper-iron matte containing precious metals at home and abroad, this paper put forward the process route of enrichment of precious metals and selectively leaching of base metals from the nickel-copper-iron matte by sulfuric acid and sodium hypochlorite. The effects of particle size, leaching temperature, leaching time, amount of sulfuric acid and sodium hypochlorite on the leaching rate of nickel, cobalt, copper and iron are mainly discussed. The results show that raw material particle size has significantly effects on the leaching rate of base metals, high leaching rate of base metals and enrichment of precious metals are obtained with the suitable particle size. Through the experiments, the reasonable experiment parameters and conditions were determined as fellows: particle size of-200 to +250 mesh, leaching temperature 95℃ , leaching time 5 h, sulfuric acid concentration 30%, adding amount of sodium hypochlorite 3 times of matte weight. Under these experiment parameters and conditions, the leaching rate of nickel, cobalt, copper and iron were 97.39%, 96.24%, 98.30% and 99.01%, respectively. The content of nickel, cobalt, copper, iron in the leaching residues was 8.15%, 0.23%, 1.40% and 0.24%, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching residues was 247 g/t, 521 g/t, 112 g/t, 494 g/t and 24 g/t, respectively. The content of Pt, Pd, Au, Ag and Rh in the leaching solution was <0.0005 g/L, 0.0023 g/L, 0.0007 g/L, <0.0005 g/L and 0.00017 g/L, respectively. This process has advantages as follows: a small investment, simple technology, high enrichment efficiency. 展开更多
关键词 nickel-copper-iron matte sulfuric sodium hypochlorite LEACHING ENRICHMENT
下载PDF
Geological - Geophysical - Geochemical Exploration Models of Copper - Iron Deposits in Southeastern Hubei
20
作者 Guo XuequanSoutheast Hubei Geological Party, Hubei Bureau of Geology and Mineral Resources, Daye, Hubei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1994年第3期299-309,共11页
This paper discusses geological-geophysical-geochemical models of such typical deposits as the Tieshan-type Fe-Cu deposit, the Tonglushan-type Cu-Fe deposit, the Yehuaxiang-type Cu deposit, the Jiguanzui-type Cu-Au de... This paper discusses geological-geophysical-geochemical models of such typical deposits as the Tieshan-type Fe-Cu deposit, the Tonglushan-type Cu-Fe deposit, the Yehuaxiang-type Cu deposit, the Jiguanzui-type Cu-Au deposit, and the Tongshankou-type Cu (Mo) deposit. The models were established based on practical data of the polymetallic deposits dominated by copper ore in southeastern Hubei. These models, which are graphically illustrated in the paper, systematically summarize the metallogenic geological conditions and the geophysical-geochemical characteristics of copper deposits in this area. The models are of practical significance for studying copper deposits, predicting mineral resources, choosing exploration methods, and searching for ore deposits based on existing ones in the study area. 展开更多
关键词 southeastern Hubei copper-iron deposits composite exploration model
下载PDF
上一页 1 2 129 下一页 到第
使用帮助 返回顶部